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Secretion of the Bile ----- 265 e. Secretion of Urine ..... 281 f. Connexion between the Stomach and the Kidneys - 297 Glandiform Ganglions - - - - - - 300 a. The Spleen ------ 300 BOOK III. REPRODUCTIVE FUNCTIONS. Chap. I. Generation ....... 397 315 315 325 331 342 351 355 356 360 381 381 384 398 408 410 419 425 1. Generative Apparatus a. Genital Organs of the Male 1. Sperm b. Genital Organs of the Female 1. Menstruation c. Sexual Ambiguity 2. Physiology of Generation a. Copulation b. Fecundation ... c. Theories of Generation - 1. Epigenesis ... 2. Evolution - a. Conception - b. Superfoetation c. Pregnancy ... d. Signs of Pregnancy e. Duration of Pregnancy /. Parturition .,.._. "^a g. Lactation -,.._. .„. Chap. II. Foetal Existence. — Embryology .... ..„ 1. Special Anatomy and Histology of the Foetus - . 443 CONTENTS. 7 PAGE a. Dependencies of the Foetus . - - - 443 b. Development of the Ovum . - - - 458 c. Peculiarities of the Foetus . - - - 475 2. Physiology of the Foetus - 482 a. Animal Functions - - - - - 482 6. Functions of Nutrition ... - 484 c. Functions of Reproduction ... - 509 BOOK IV. Chap. I. Ages.......510 1. Infancy - - - - - - - 510 a. First period of Infancy ... - 510 b. Second period of Infancy or first Dentition - - 515 c. Third period of Infancy . - - - 520 2. Childhood.......520 3. Adolescence ------ 524 4. Virility or Manhood ------ 527 5. Old Age.......529 Chap. II. Sleep........534 1. Dreams ------ o6\) 2. Waking Dreams ------ 547 3. Revery ------ 554 Chap. HI. Correlation of Functions ----- 555 1. Mechanical Correlations - - - - 555 2. Functional Correlations ... - - 556 3. Sympathy' ------ 561 a. Sympathy of Continuity ... - 562 b. Sympathy of Contiguity ... - 562 c. Remote Sympathies ----- 564 d. Imagination ------ 564 e. Superstitions connected with Sympathy - - 566 /. Agents by which Sympathy is accomplished - 568 Chap. IV. Individual Differences amongst Mankind - - - 570 1. Temperaments ----- 570 a. Sanguine Temperament ----- 571 b. Bilious or Choleric Temperament - - - 572 c. Melancholic or Atrabilious Temperament - - 573 d. Phlegmatic, Lymphatic or Pituitous Temperament - 573 e. Nervous Temperament ... - 573 2. Idiosyncrasy ------ 575 3. Of Natural and Acquired Differences - - - 577 1. Natural Differences ... - 577 a. Peculiarities of the Female ... - 577 2. Acquired Differences .... 581 1. Habit - - - - " - 581 2. Association ----- 585 3. Imitation - ... - 586 4. Varieties of Mankind ... - 587 1. Division of the Races - - - - 590 a. Caucasian Race ... - 591 b. Ethiopian Race ----- 593 c. Mongolian Race ... - 594 d. American Race ----- 595 2. Oriorin of the Different Races - - - 597 8 CONTENTS. PAGE Chap. V. Of Life - - - - - - " J05 1. Instinct - - - - - ' \ 2. Vital Properties - - - - ' - 619 3. Life of the Blood ----- 624 Chap. VI. Of Death ------- 630 1. Death from Old Age ----- 630 2. Accidental Death ----- 633 a. Death beginning in the Heart ... 633 b. Death beginning in the Brain - 634 c. Death beginning in the Lungs ... 634 Index --------- 645 LIST OF ILLUSTRATIONS IN VOL. II. FIG. PAGE 145. The thorax ----.... 14 146. Anterior view of the thorax, after Wilson - - - - 14 147. Anatomy of the heart and lungs, after Wilson - - - - 16 148. Reflections of the Pleura ...... 20 149. Do. Do. ...... 21 150. Section of the thorax and abdomen ..... 27 151. Thoracic and abdominal viscera ..... 36 152. Do. Do. of the ostrich - - - - 65 153. Heart of the dugong .---.--66 154. The right and left hearts separated - - - - - 67 155. Pulmonic heart .......68 156. Section of the pulmonic heart ------ 68 157. Semicircular valves closed --.-.. 69 158. View of the heart in situ ------ 72 -159. Circulation in the web of the frog's foot, after Wagner - - 79 160. Portion of the web of the frog's foot, after Wagner - - - 79 161. Capillaries of the web of the frog's foot, after Wagner - - - 81 162. Bloodvessels of the lung of a live newt, after Wagner - - - 82 163. Ramifications of the splenic artery in the spleen - - - 84 164. Portal system, after Wilson ------ 88 165. Corpuscles of human blood from a vein, beaten so as to separate the fibrin, after Wagner ------- 93 166. Blood corpuscles of the edible frog, Rana esculenta, after Wagner - 93 167. Hydraulic apparatus, after Venturi ... - 121 168. Haemadynamometer of Poisseuille ..... 130 169. Section of a forcing pump ..---- 133 170. A small venous branch, from the web of a frog's foot, after Wagner - 140 171. Large vein of frog's foot, after Wagner .... 141 172. Diagram illustrating the circulation - - - - - 142 173. Diagram of vena contracta, from Venturi .... 149 174. Do. adjutage, Do. - - - - - 150 175. Circulation in the frog ------- 169 176. Circulation in fishes - - - - - - -169 177. Interior of the leech, after Sir E. Home ----- 170 10 LIST OF ILLUSTRATIONS. PAGE 176 177 177 178 180 18;") 222 FIG. 178. Globular structure of cellular tissue 179. Do. muscular Do. 180. Do. nervous Do. 181. Do. the brain 182. Primary organic cell, after Todd and Bowman 183. Tattooed head of a New Zealand chief - 184. Secreting arteries, and nerves of the intestines - 185. Portion of areolar tissue inflated and dried, after Todd and Bowman - 235 186. Fat vesicles, after Todd and Bowman - 187. Bloodvessels of fat vesicles, after Todd and Bowman - - - 236 188. Fat vesicles from an emaciated subject, after Todd and Bowman - 238 189. Diapnogenous apparatus from the palm of the hand, after Wagner - 245 190. Sebaceous and ceruminous glands, after Wagner - 260 191. A small portion of the parotid of a new-born infant, filled with mercury, after Wagner - - - - - - -261 192. Biliary and pancreatic ducts ------ 264 193. Abdominal and pelvic viscera ------ 266 194. Lobules of the liver, after Wagner ..... 268 195. Connection of lobules of liver with hepatic vein, after Wagner - - 268 196. Transverse section of the lobules of the liver, after Kiernan - - 269 197. Horizontal section of three superficial lobules, showing the two principal systems of bloodvessels, after Kiernan .... 269 198. Horizontal section of two superficial lobules, showing interlobular plexuses of biliary ducts, after Kiernan - 269 199. First stage of hepatic venous congestion, after Kiernan - - 270 200. Second Do Do. - - 270 201. Portal venous congestion, after Kiernan .... 270 202. Under surface of liver, after Wilson ..... 271 203. Section of a kidney. — Supra-renal capsule - - - . 282 204. Portion of kidneys of new-born infants, after Wagner ... 283 205. Small portion of kidney magnified 60 diameters, after Wagner - - 284 206. A side view of viscera of male pelvis in situ, after Wilson - - 286 207. Entrance of the ureter into the bladder - - . . 292 208. Section of the spleen ------. 302 209. Transverse section of testis, after Wilson - 317 210. Male organs, after Sir C. Bell ---.,_ ^If 211. Human testis injected with mercury, after Lauth ... 319 212. Plan of the structure of the testis and epididymis, after Lauth - . 31a 213. Posterior view of male bladder, after Wilson - - . 001 214. Section of the vesiculae seminales, &c. .... „_. 215. Section of bladder, prostate, and penis, after Wilson ... o22 216. Section of the penis ---.._ 217. Spermatozoa, after Wagner .... 218. Lateral view of pelvic viscera in the female 219. Anterior view of the female organs - . . 220. Female organs of generation, after Wilson 221. Section of the uterus - 222. Nerves of the uterus, after Dr. R. Lee - 324 329 333 334 335 336 338 LIST OF ILLUSTRATIONS. 11 PIG. PJGE 223. Fallopian tube....." " - 339 224. Section of ovary - - - - 225. Ripe ovum of rabbit, taken from the Graafian vesicle, after Wagner - 341 226. Longitudinal division of the ovary - - - - • S47 227. Ovary of a female dying during menstruation - 364 228. Tubal pregnancy - - - - 229, Corpus luteum in the third month, after Montgomery - - - 377 230. Corpus luteum at the end of the ninth month, after Montgomery - 377 379 231. Corpora lutea, after Sir E. Home - - - - 232. Do. Do. ------ 380 233. Villi of lining membrane of uterus, after Von Baer - - - 410 234. Section of the uterus about eight days after impregnation, after Wagner 412 235. Do. when the ovum is entering its cavity, Do. 412 236. Do. with the ovum somewhat advanced, Do. - 413 415 237. Extra-uterine pregnancy . - - - 238. Arteries of the impregnated uterus - 239. Cervix uteri at three months - - 422 240. Do. six months - - - - 422 241. Do. eight months - - - - - 423 242. Do. nine months . - - - 429 243. Natural labour ------- 244. Kotation of the head - - - - - 245. Breech presentation - - - - - 432 246. Arm presentation - - - • - 247. Milk ducts in human mamma, after Sir A. Cooper - - - 434 248. Commencement of milk ducts, after Sir A.Cooper - - - 435 249. Transverse section of the uterus and placenta, after Dr. J. Reid - - 449 250. Connection between the maternal and foetal vessels, after Dr. J. Reid - 450 251. Uterine surface of the placenta - 252. Fcetal Do. ----- 451 253. Knotted umbilical cord - - - - 254. Diagram of the foetus and membrane about the sixth week, after Carus - 4o5 255. Ovarium of the laying hen, after Sir E. Home - - - 459 256. New laid egg with its molecule, after Sir E. Home - - - 460 257. Section of a hen's egg within the ovary, after T. W. Jones - - 460 258. Egg, thirty-six hours after incubation, after Sir E. Home 259. Egg, opened three days after incubation, after Sir E. Home - - 463 260. Egg five Do. Do. - - - 464 261. Egg ten Do. Do. - - - 464 262. Embryo of the egg, after Sir E. Home - - - - - 465 263. Embryo eighteen days old, after Sir E. Home - - - - 465 264. Ovum, fourteen days old, after Velpeau ... - 466 265. Ovum and embryo, fifteen days old, after Maygrier - - - 467 266. Do. twenty-one days old, after Maygrier - - 467 267. Foetus at forty-five days 268. Foetus at two months - 269. Corpora Wolffiana, with kidney and testes, from embryo of birds - 468 270. Foetus at three months, in its membranes - 469 12 LIST OF ILLUSTRATIONS. PAGE 473 475 FIG. 271. Full period of utero-gestation - 272. Foetus at full term ------ 273. Section of the thymus gland at the eighth month, after Sir A. Cooper - 476 274. Circulatory organs of the foetus, after Wilson 275. Descent of the testicle - - - - - * - 481 276. Do. ------- 481 277. Decidual cotyledons, after Montgomery - - 8° 278. Front view of the temporary teeth - - - - - 518 279. The separate temporary teeth of each jaw - - - - 518 280. Permanent rudiment given off from the temporary in an incisor and in a molaris, after T. Bell - - - - - - 521 281. Temporary tooth and permanent rudiment, after T. Bell - - 521 282. Temporary teeth and permanent rudiments, after T. Bell - - 522 283. Do. Do. - - - 522 284. Upper and lower teeth of the left side of the jaws, after T. Bell - 523 285. Upper and lower teeth ------ 524 286. Skull of the aged, after Sir C. Bell - - - - 530 287. Physiognomy of the aged, after Sir C. Bell .... 530 288. Curves indicating the development of the heights and weight of man and woman at different ages, after Quetelet .... 532 289. Caucasian variety ....... 59] 290. Negro variety ------- 593 291. Mongolian variety ....... 594 292. American variety ..... . 595 293. Curve indicating the viability or existibility at different ages, after Quetelet 637 HUMAN PHYSIOLOGY. BOOK II. CHAPTER III. RESPIRATION. The consideration of the function of absorption has shown us how the different products of nutritive absorption reach the venous blood. By simple admixture with this fluid they do not become converted into a substance, capable of supplying the losses, sus- tained by the frame from the different excretions. Nothing is better' established than the fact, that no being, and no part of any being, can continue its functions unless supplied with blood, which has be- come arterial, by exposure to air. It is in the lungs, that the absorbed matters undergo their final conversion into that fluid, — by a function, which has been termed hsematosis, and which is the great object of that we have now to investigate — Respiration. This conversion is occasioned by the venous blood of the pulmo- nary vessels coming in contact with the air in the air-cells of the lungs, during which contact, the blood gives to the air some of its constituents, and, in return, the air parts with its elements to the blood. To comprehend this mysterious process, we must be acquainted with the pulmonary apparatus, as well as with the properties of atmospheric air, and the mode in which the contact between it and the blood is effected. 1. ANATOMY OP THE RESPIRATORY ORGANS. The thorax or chest contains the lungs, which are the great agents of respiration. It is of a conical shape, the apex of the cone being formed by the neck, and the .base by a muscle, which has already been referred to, more than once, — the diaphragm. The osseous framework, Figs. 145 and 146, is formed,posteriorly, of twelve dorsal vertebrae : anteriorly, of the sternum, originally composed of eight or nine pieces; and laterally, of twelve ribs on each side, passing from the vertebra3 to, or towards, the sternum. Of these, the seven uppermost extend the whole distance from the spine to the breast-bone, and are called the true or sternal ribs; sometimes, the vertebrosternal. They become larger as VOL. II. —2 14 RESPIRATION. Fig. 145. The Thorax. a. Sternum or breast-bone. 6. b. The spine. c. c. c. c. The ribs. Fig. 146. Anterior view of the Thorax. 1. Superior piece of sternum. 2. Middle piece. 3. Inferior piece, or ensiform cartilage. 4. First dorsal vertebra. 5. Last dorsal vertebra. G. First rib. 7. Its head. 8. Its neck, resting against transverse process of first dorsal verte- bra. 9. Its tuberosity. 10. Seventh or last true rib. 11. Costal cartilages of true ribs. 12. Two last false ribs —floating ribs. 13. The groove along lower border of rib for lodgment of inter- costal vessels and nerve.—{Wilson.) they descend, and are situate more obliquely in regard to the spine. Theotherfive,called/fl&e or asternal,do not proceed as far as the sternum; but thecartilages of three of them join that of the seventh true rib, whilst the two lowest have no union with those above them, and are therefore called floating ribs. These false ribs become shorter and shorter as they descend ; so that the se- venth true rib may be regarded as the common base of two cones, formed by the true and false ribs respectively. The different bones, constitut- ing the thorax, are so articu- lated as to admit of motion, and thus to allow of dilatation and contraction of the cavity. The motion of the vertebrae • on each otherhas been describ- ed under another head. It is not materially concerned in the respiratory movements. The articulation of the ribs with the spine and sternum demands at- tention. They are articulated with the spine in two places,— at the capitulum or head, and at the tubercle. In the former of these, the extremity of the ribs, encrusted with cartilage, is received into a depression, simi- larly encrusted, at the side of the spine. One half of this de- pression is in the body of the upper vertebra ; the other half in the one beneath it; and, con- sequently, partly in the interver- tebral fibro-cartilage between the two. The joint is rendered secure by various ligaments; but it can move readily up and down on the spine. In the first eleventh, and twelfth ribs, the articulations are with single'ver- tebrae respectively. ln the se- cond articulation, the tuber- RESPIRATORY ORGANS. 15 cle of the rib, also encrusted with cartilage, is received into a cavity in the transverse process of each corresponding vertebra; and the joint is rendered strong by three distinct ligaments. In the eleventh and twelfth ribs, this articulation is wanting. The articulation of the ribs with the sternum is effected by an inter- mediate cartilage, which becomes gradually longer, from the first to the tenth ribs, as seen in Figs. 145 and 146. The end of the cartilage is received into a cavity at the side of the sternum; and the junction is strengthened by an anterior and posterior ligament* This articu- lation does not admit of much motion ; butthe existence of a syno- vial membrane shows, that it is destined for some. The cavity of the thorax is completed by muscles. In the in- tervals between the ribs are two planes of muscles, whose fibres pass in inverse directions, and cross each other. These are the intercostal muscles. The diaphragm forms the septum between the thorax and abdomen Above, the cavity is open ; and through the opening numerous vessels and nerves enter. The muscles, concerned in the respiratory function, are numer- ous. The most important of these is the diaphragm. It is attached, by its circumference, around the base of the chest; but its centre rises into the thorax ; and, during its state of relaxa- tion, forms an arch, the middle of which is opposite the inferior extremity of the sternum. It is tendinous in its centre, and is attached by two fasciculi, called pillars, to the spine, — to the bodies of the two first lumbar vertebras. It has three apertures; one before for the passage of the vena cava inferior; and two behind, between the pillars, for the passage of the oesophagus and aorta. The other great muscles of respiration are the serratus posticus inferior, the serratus posticus superior, the levatores cos- tarum, the intercostal muscles, the infra-cost ales and the trian- gularis sterni or sterno-costalis; but, in an excited condition of respiration, all the muscles, that raise and depress the ribs, directly or indirectly, participate — as the scaleni, sterno-mastoidei, pecto- ralis, {major and minor,) serratus major anticus, abdominal muscles, &c. In the structure of the lungs, as Magendiea has remarked, nature has resolved a mechanical problem of extreme difficulty. The problem was, — to establish an immense surface of contact between the blood and the air, in the small space occupied by the lungs. The admirable arrangement adopted consists in this,— that each of the minute vessels, in which the pulmonary artery terminates, and the pulmonary veins originate, is surrounded on every side by the air. The lungs are two organs of considerable size, situate in the lateral parts of the chest, and subdivided into lobes and lobules, the shape and number of which cannot be readily determined. They are termed right and left, respectively, according to the side of the cavity of the chest which they occupy. The former consists of three lobes ; the latter of two. Each of » Precis, &c. ii. 307. • 16 RESPIRATION. these exactly fills the corresponding cavity of the P1®"™^ frc>€ veins, besides the organic elements, that appertain to every living structure, — arteries, veins, lymphatics, nerves and cellular tissue. The ramifications of the windpipe form the cavity of the organ of respiration. The trachea is continuous with the larynx, from which it receives the external air conveyed to it by the mouth and nose. It passes down to the thorax, at the anterior part of the neck, and bifurcates opposite the second dorsal vertebra, forming two large canals, called bronchi or bronchia. One of these goes to each lung ; and, after numerous subdivisions, becomes imperceptible : hence, the multitudinous speculations that have been indulged regard- ing the mode in which the bronchial ramifications terminate. Malpighi8 believed that they form vesicles, at the inner surface of which the pulmonary artery ramifies. Reisseisenb describes the * Epist. de Pulmon, i. p. 133. * Ueber den Bau der Lungen, u. s. w., Berlin, 1822 ; also, in Latin, Berl. 1822 See, likewise, Horner, Special Anatomy and Histology, 6th edit. ii. 161,Philad. 1843] RESPIRATORY ORGANS. 17 vesicles as of a cylindrical, and somewhat rounded figure ; and he states, that they do not communicate with each other. Helvetius,3 on the other hand, affirmed, that they end in cells, formed by the different constituent elements of the lungs, —the cells having no determinate shape, or regular connexion with each other; whilst Magendieb asserts, that the minute bronchial division, which arrives at a lobe, does not enter it, but terminates suddenly as soon as it has reached the parenchyma ; and, he remarks, that as the bronchus does not penetrate the spongy tissue of the lung, it is not probable that the surface of the cells, with which the air comes in contact, is lined by a prolongation of the mucous coat, which forms the inner membrane of the air-passages. Certain it is, that the most attentive examination has failed to detect its presence. The ramifications of the pulmonary artery are another consti- tuent element of the lung. This vessel arises from the right ven- tricle of the heart, and, at a short distance from that organ, divides into two branches; one passing to each lung. Each branch ac- companies the corresponding bronchus in all its divisions ; and, at length, becomes capillary and imperceptible. Its termination, also, has given rise to conjecture. Malpighi conceived it to end at the mucous surface of the bronchi, in an extremely delicate network, which he called rete mirabile. This was also the opinion of Reis- seisen. According to others, the pulmonary artery, in its ultimate ramifications, is continuous with two kinds of vessels, — the capil- lary extremities of the pulmonary veins, and the exhalants en- gaged in the secretion of the pulmonary transpiration. Bichatc admits, at the extremities of the pulmonary artery, and between that artery and the veins of the same name, vessels of a more de- licate character, which he conceives to be the agents of hsematosis, and which he calls the capillary system of the lungs. All that we know is, that the air gets a ready access to the blood in the pulmonary artery ; but, with regard to the precise arrangement of the means of such access, we are ignorant. The same may be said of the third'constituent of the lungs — the pulmonary veins. Their radicles manifestly communicate freely with those of the pulmonary artery; but they equally escape detection. When we observe them, they are found uniting, to constitute larger and larger veins, until they ultimately end in four large trunks, which open into the left auricle of the heart. In addition to these organic constituents, the lung, like other organs, receives arteries, veins, lymphatics, and nerves. It is not nourished by the blood of the pulmonary artery, which is not adapted for that purpose, seeing that it is venous. The bronchial arteries are its nutritive vessels. They arise from the aorta, and are distributed to the bronchi. Around the bronchi, and near where they dip into the tissue of the lung, lymphatic, glands exist, the colour of which is almost » Memoires de PAcadem. pour 1718, p. 18. b Precis, &c., ii. 309. e Anatomie Descriptive, vol. iv., Paris, 1801. 2* 18 RESPIRATION. black, and with which the few lymphatic vessels, that arise from the superficial and deep-seated parts of the lung, communicate. Hallera has traced the efferent vessels of these glands into the tho- racic duct. The nerves, distributed to the lungs, proceed chiefly from the eighth pair or pneumogastric. A few filaments of the great sym- pathetic are also sent to them. The eighth pair — after having given off the superior laryngeal nerves, and some twigs to the heart — interlaces with numerous branches of the great sympa- thetic, and forms an extensive nervous network, called the anterior pulmonary plexus. After this, the nerve gives off the recurrents, and interlaces a second time with branches of the great sympathetic, forming another network, called the posterior pulmonary plexus. It then proceeds to the stomach, where it terminates. (See Fig. 108, vol. i., p. 418.) From these two plexuses the nerves proceed, that are distributed to the lungs. These accompany the bronchi, and are spread chiefly on the mucous membrane of the air-tubes. The lung likewise receives some nerves directly from the three cervical ganglions of the great sympathetic, and from the first thoracic ganglion. In addition to these, a distinct system of nerves — the respiratory system, described in the first volume of this work — is supposed by Sir Charles Bell to be distributed to the multitude of muscles, which are associated in the respiratory function, in a voluntary or involuntary manner. This system includes one of the nerves just referred to — the eighth pair — and the phrenic nerves, which are distributed to the diaphragm. The various nerves composing it are intimately connected, so that, in forced or hurried respiration, in coughing, sneezing, &c, they are always associated in action.b Lastly, the lungs are constituted, also, of cellular tissue, which has been termed interlobular tissue ; but it does not differ from cellular tissue in other parts of the body. Such are the constituent elements of the pulmonary tissue; but, with regard to the mode, in which they are combined to form the intimate texture of the lung, we are uninstructed. We find, that the lobes are divided into lobules, and these,again, seem to be sub- divided almost indefinitely, forming an extremely delicate spongy tissue, the areolae of which can only be seen by the aid of the mi- croscope. It is generally thought, that the areolae communicate with each other, and that they are enveloped by the cellular tissue which separates the lobules, Magendie° inflated a portion of lung and dried and cut it in slices, in order that he might examine the deep-seated cells. These appeared to him to be irregular and to be formed by the final ramifications of the pulmonary arte'rv and the pnm.ary ramifications of the pulmonary veins ; the cells of one lobule communicating with each other, but not with those of an- * Elem. Physiologic, viii. 2. * . b Muller's Handbuch, u. s. w., Baly's translation, p. 318, Lond 1838 e Precis, &c. ii. 309. RESPIRATORY ORGANS. 19 other lobule. Professor Horner,3 of the University of Pennsylvania, has attempted to exhibit that this communication between the cells is lateral. After filling the pulmonary arteries and the pulmonary veins with minute injection, the ramifications of the bronchi, with the air-cells, were distended to their natural size by an injection of melted tallow. The latter, being permitted to cool, the lung was cut into slices and dried. The slices were subsequently immersed in spirit of turpentine, and digested, at a moderate heat, for seve- ral days. By this process, all the tallow was removed, and the parts, on being dried, appeared to exhibit the air-cells empty, and, seemingly, of their natural size and shape. Preparations, thus made, appear to show the air-cells to be generally about the twelfth of a line in diameter, and of a spherical shape, the cells of each lobule communicating freely, like the cells of fine sponge, by late- ral apertures. The lobules, however, only communicate by branches of the bronchi, and not by contiguous cells. This would seem to negative the presumption of some anatomists and physiologists,— as Blumenbach, Cuvier, &c, — that each air-cell is insulated, com- municating only with the minute bronchus, that opens into it; whilst it cortfirms the views of Haller, Monro (Secundus), Boyer, Sprengel, Magendie, and others ; but it is impossible to decide posi- tively, where all is so minute. Many anatomists, and perhaps with accuracy, by the term air-cell, mean simply the ultimate ter- mination of a bronchus.b The surface afforded by the air-cells is immense. Halesc sup- posed them to be polyhedral, and about one-hundredth part of an inch in diameter. The surface of the bronchi he estimated at 1035 square inches; and that of the air-cells at 20,000. Keilld estimated the number of cells to be 1,744,1S6,015 ; and the surface 21,906 square inches; and Lieberkiihn has valued it at the enormous amount of 1500 square feet !e All that we can derive from these mathematical conjectures is, that the extent of surface is surprising, when we consider the small size of the lungs themselves. Recently, Professor Hornerf has published an account of various experiments, which exhibit the ready communication between the pulmonary air-vessels and the pulmonary veins. By fixing a pipe into the human trachea, and permitting a column of water to pass gently, he found that the air-cells became dis- tended with water; and that the left side of the heart filled, and the aorta discharged water freely from its cut branches. a American Journal of the Medical Sciences, for Feb. 1832, p. 538, and Op. cit. •> See, on the Minute Anatomy of the Lungs, Wagner, Elements of Physiol., by R. Willis, Lond. 1842, and Bourgery, Gazette Med. Juill. 16, 1842, and Brit, and For. Med. Rev. Oct. 1842, p. 546 ; and W. Addison, Proceedings of Royal Society, March 17, 1812, and Brit, and For. Med. Rev. Oct. 1842, p. 574. <■ Statical Essays, vi. p. 241. d Tentam. Med. Phys. p. 80. • Blumenbach, in EUiotson's Physiology, p. 197, Lond. 1835. f Amer. Journ. of the Medical Sciences, April, 1843, p. 332 ; and Special Anatomy and Histology, 6th edit. ii. 163. 20 RESPIRATION. This experiment he repeated on human lungs on different occa- sions, and with like results. Very little water flowed from me pulmonary artery. In the sheep and the calf, however, wnen the experiment was practised upon them after they had been pretty thoroughly evacuated of blood, the water passed freely through both the pulmonary veins and the pulmonary arteries. Dr. Horner is disposed to infer, that his experiments exhibit a communication of the pulmonary air-vesicles by a direct route with the pulmonary bloodvessels, especially the veins; but this may well be questioned. It is possible, that such a communication may really have been made by the force of the column of water : and if not so, the pas- sage of the fluid from the air-cells to the bloodvessels might have been effected through the pores, as in ordinary imbibition, which, we have elsewhere seen, is readily accomplished in the lungs, but not more readily perhaps than in the case of serous and other tissues under favourable circumstances. Hemorrhage by transudation occurs we know most rapidly at times through the coats of vessels; and a thinner fluid would of course transude more easily. It can scarcely be doubted, from Dr. Horner's experiments, that a certain arrangement exists between the air-vesicles and the pul- monary veins in man, which admits of a more ready imbibition and transudation ; but what that arrangement is, admits of question. Each lung is covered by the pleura, — a serous membrane analogous to the peritoneum, — and, in birds, a prolongation of the latter. This membrane is reflected from the adjacent surface of the lung to the pericardium which covers the heart, and is then spread over the interior paries of the half of the thorax to which it belongs; lining the ribs and intercostal muscles, and covering the convex or upper surface of the diaphragm. There are, con- sequently, two pleura?, each of which is confined to its own half of the thorax, lining its cavity and cover- ing the lung. Behind the sternum, however, they are contiguous to each other, and form the partition, called mediastinum, which extends between the sternum and spine'. In Fig. 148, the dotted lines exhibit the boundaries of the two cavities of the pleura, and the middle space between is the me- diastinum. Within this septum, the heart, enveloped by the pericardium, is situate, and separates the pleura? considerably from each other. Ana- tomists generally subdivide the me- diastinum into two regions ; one pass- ing from the front of the pericardium to the sternum, called the anterior mediastinum ; the other, from the posterior surface of the pericardium to the dorsal vertebrae, — the posterior mediasli- Fig. 148. Reflections of the Pleura. RESPIRATORY ORGANS. 21 num ; and, by some, the part, which first ribs, is termed superior medias- tinum. The second of these contains the most important organs, — the lower end of the trachea, oesophagus, aorta, vena azygos, thoracic duct, and pneumogastric nerves. The portion of the pleura, covering each lung, is called pleura pulmonalis; that, which lines the thorax, pleura costa- lis. The mode, in which the two are connected to form one whole,is shown by the dotted line in Fig. 149, repre- senting a vertical section of the chest. It is obvious, that, as in the case of the abdomen, the viscera are not in the cavity of the pleura, but external to it; and that there is no commu- nication between the serous sac of one side and that of the other. The use of the pleura is to attach the lungs, by their roots, to their respective cavities, and to facilitate their movements. To aid this effect, the membrane is always lubricated by a fluid, exhaled from its surface. The other surface is attached to the lung in such v a manner, that air cannot get between it and the parietes of the thorax. Dr. Stokes,a of Dublin, has described a proper fibrous tunic of the lungs. In a healthy state, this capsule, although possessing great strength, is transparent, a circumstance in which it differs from the fibrous capsules of the pericardium, and which, Dr. Stokes thinks, has probably led to its having been overlooked. It invests the whole of both lungs; covers a portion of the great vessels; and the pericardium seems to be but its continuation, — endowed, in that particular situation, with a greater degree of strength, for purposes that are obvious. It covers the diaphragm where it is more opaque ; in connexion with the pleura, it lines the ribs ; and, turning, forms the mediastina, which are thus shown to consist of four layers,— two serous and two fibrous. It seems, that Dr. Hart, of Dublin, has, for years, demonstrated this tunic to his class. It was, at one time, the prevalent belief, that air always exists in the cavity of the chest. Galen supported the opinion by the fact, that, having applied a bladder, filled with air, to a wound, which had penetrated the chest, the air was drawn out of the blad- der at the time of inspiration. This was also maintained by Ham- berger, Hales,b and numerous others. The case, alluded to by Galen, is insufficient to establish the position, inasmuch as we have no evidence, that the wound did not also implicate the pul- monary tissue. Since the time of Haller, who opposed the pre- valent doctrine by observation and reasoning, the fact of the ab- » On Diseases of the Chest, Part i. p. 460, Dublin, 1837 ; or Dunglison's American Medical Library edition, p. 301, Philad. 1837, * Statical Essays, ii. 81. Reflections of the Pleura. 22 RESPIRATION. sence of air in the cavity of the pleura is generally considered to be entirely established. It is obvious, that its presence there would materially interfere with the dilatation of the lungs, and thus be productive of much inconvenience; besides, anatomy in- structs us, that the lungs lie in pretty close contact with the pleura costalis. When the intercostal muscles are dissected off, and the pleura costalis is exposed, the surface of the lungs is seen in con- tact with that transparent membrane; and, when the pleura is punctured, the air rushes in, and the lungs retire, in proportion as the air is admitted. This occurs in cases of injuries inflicted upon the chest of the living animal. Moreover, if a dead or living body be placed under water, and the pleura be punctured, so as not to implicate the lungs, it has been found by the experiments of Brimn, Sprogel, Caldani, Sir John Floyer, Haller,a and others, that not a bubble of air escapes, — which would necessarily be the case, if air were contained in the cavity of the pleura.b 2. ATMOSPHERIC AIR. The globe is surrounded every where, to the height of fifteen or sixteen leagues, by a rare and transparent fluid called air; the total mass of which constitutes the atmosphere. Atmospheric air, although invisible, can be proved to possess the ordinary properties of matter; and, amongst these, weight. It also partakes of the character of a fluid, adapting itself to the form of the vessel in which it is contained, and pressing equally in all directions. As air is possessed of weight, it results, that every body on the earth's surface must be subjected to its pressure ; and as it is elastic or capable of yielding to pressure, the part of the atmosphere near the earth's surface must be denser than that above it. Asa body, therefore, ascends, the pressure will be diminished ; and this ac- counts for the different feelings experienced by those who ascend lofty mountains, or voyage in balloons, into the higher strata of the atmosphere.0 Dr. Edwardsd ascribes part, at least, of the effect produced upon the breathing, at great elevations, to the increased evaporation which takes place from the skin and lungs; and in many aerial voyages great inconvenience has certainly been sus- tained from this cause. The pressure of the atmosphere at the level of the sea is the result of the whole weight of the atmosphere, and is capable of sustaining a column of water thirty-four feet high, or one of mer- cury of the height of thirty inches, —as in the common barometer. This is equal to about fifteen pounds avoirdupois on every square inch of surface ; so that the body of a man of ordinary stature the a Element. Physiol, via. 2 b Bostock's Physiology, 3d edit. p. 305, Lond. 1836; and Adelon, PhvsiolomP de I'Homme, edit. cit. iii. 144. * rnvsio»ogie ae e Bee the author's Elements of Hygiene, p. 39, Philad. 1835 ; and art Atmr> k by the author, in Amer. Cyclop, of Pract. Med. iii. 529, Philad. 1836. ' ^"nosPnere> d De l'lnfluence des Agens Physiques, &c. p. 493, Paris, 1824. ATMOSPHERIC AIR. 23 surface of which Haller estimates to be fifteen square feet, sustains a pressure of 32,400 pounds. Yet, as the elasticity of the air within the body exactly balances or counteracts the pressure from without, he is not sensible of it. The experiments of Davy, Dalton, Gay Lussac, Humboldt, Des- pretz, and others, have shown, that pure atmospheric air is com- posed essentially of two gases, oxygen and azote, which exist in it in the proportion of21 of the formerto 79 of the latter: Dr. T. Thom- son, whose analysis is one of the mostrecentandsatisfactory,says20 of oxygen to 80 of azote or nitrogen; and these proportions have been found to prevail in the air whencesoever taken; — whether from the summit of Mont Blanc, the top of Chimborazo, the sandy plains of Egypt, or from an altitude of 23,000 feet in the air.a Chemical analysis has not been able to detect the presence of any emanation from the soil of the most insalubrious regions, or from the bodies of those labouring under the most contagious diseases,— malignant and material as such emanations unquestionably must be. This uniformity in the proportion of the oxygen to the nitro- gen in the atmosphere has led to the conclusion, that as there are many processes, which consume the oxygen, there must be some natural agency, by which a quantity of oxygen is produced equal to that consumed. The only source, however, by which oxygen is known to be supplied, is the process of vegetation. A healthy plant absorbs carbonic acid during the day; appropriates the carbon to its own necessities, and gives off the oxygen with which it was combined. During the night an opposite effect is produced. The oxygen is then taken from the air, and carbonic acid given off; but the experiments of Davy and Priestley show, that plants, during the twenty-four hours, yield more oxygen than they consume. It is impossible to look to this as the great cause of equilibrium be- tween the oxygen and azote. Its influence can extend to a small distance only ; and yet the uniformity has been found to prevail, as we have seen, in the most elevated regions, and in countries whose arid sands never admit of vegetation. In addition to the oxygen and azote, — the principal constituents of atmospheric air, — another gas exists in very small proportion, but is always present. This is carbonic acid. It was found by De Saussure on Mont Blanc, and by Humboldt in air brought down, by Garnerin, the aeronaut, from the height of several thou- sand feet. The proportion is estimated by Dalton not to exceed the xoVoth or 74*0 otri of its bulk. In one of the wards of La Pitie, in Paris, which had been kept shut during the night, M. Felix Leblancb found a larger portion of carbonic acid, nearly T,TV0ths; and in one of the dormitories of La Salpetriere, the air yielded T-8ffT)ths; the largest proportion found by him in the air of hos- pitals. In the lecture room of the Sorbonne, which is capable of * Art. Atmosphere, (Physical and Chemical History,) by Dr. R. M. Patterson, in Amer. Cyclopedia of Practical Medicine and Surgery, vol. ii. p. 526, Philad. 1836. b Gazette Med. de Paris, 11 Juin, 1842. RESPIRATION 24 uning 1000 cubic inches of air, after » J^™,,»°0^™ JwJJ half long and at which 900 persons were present, the °*y8e" found ?oghave los, 1 iu ever/lOO, although two doors were op „ whilst the carbonic acid was ncreosed, in rather a greater rauo. fn award in an institution for children althoughi the door was; half open, and there was an open space in the roof, the an^ was found to contain T^ffths of carbonic acid, and there was a proportional diminution of oxygen. (B nf 9(mn These, then, may be looked upon as the constituents of atmo- spheric air. There are certain substances, however, which are ad- ventitiously present in variable proportions ; and which, witn tne constitution of the atmosphere as to density and temperature, are the causes of general or local salubrity, or the contrary. Water is one of these. The quantity, according to De Saussure, in a cubic foot of air, charged with moisture, at 65° Fahr., is 11 grains. Its amount in the atmosphere is very variable, owing to the continual change of temperature to which the air is subject; and even when the temperature is the same, the quantity of vapour is found to vary, as the air is very rarely in a state of saturation. The vary- ing condition as to moisture is indicated by the hygrometer. From a comparison of numerous observations, Gay Lussac affirms, that the mean hygrometric state of the atmosphere is such, that the air holds just one-half the moisture necessary for its saturation. In his celebrated aerial voyage, he found the air to contain but one- eighth of the moisture necessary for saturation. This is the greatest degree of dryness ever noticed. It has been presumed, that the hygrometric condition of the atmo- spheric air has more agency in the production of disease than either the barometric or thermometric. It is not easy to say which exerts the greatest influence : probably all are concerned, and when we have a union of particular barometric, thermometric, hygrometric, electric, and other conditions, we have certain epidemics existing, which do not prevail under any other combination. When the air is dry, we feel a degree of elasticity and buoyancy ; whilst, if it be saturated with moisture, — especially during the heat of sum- mer,— languor and lassitude, and indisposition to mental or cor- poreal exertion are excited. Inadditiontoaqueous vapour, numerous emanations from animal and vegetable substances must be generally present, especially in the lower strata of the atmosphere ; by which the salubrity of the air may be more or less affected. All living bodies, when crowded together, deteriorate the air so much as to render it unfit for the maintenance of the healthy function. If animals be kept crowded together in ill-ventilated apartments, they speedily sicken. The horse becomes attacked with glanders ; fowls with pep, and sheep with a disease peculiar to them if they be too closely folded. This is probably a principal cause of the insalubrity of cities com- pared with the country. In them, the air must necessarily be de- teriorated by the impracticability of due ventilation, and this with ATMOSPHERIC AIR. 25 the want of due exercise, is a fruitful cause of cachexia — and of tuberculous cachexia ; hence, also, it is, that in work-houses and manufactories, diseases dependent on this condition of constitu- tion are prevalent. One of the greatest evidences we possess of the positive insalubrity of (owns is the case of the young. In London, the proportion of those that die annually under five years of age to the whole number of deaths is as much as thirty-eight per cent., and. under two years, twenty-eight per cent.; in Paris, under two years of age, twenty-five per cent. ; and in Philadel- phia and Baltimore, rather less than a third. These estimates may be considered approximations; the proportions varying somewhat, according to the precise year in which they have been taken. Manifest, however.as is the existence of some deleterious principle, in these cases, it has always escaped the researches of the chemist. Lastly. Air is indispensable to organic existence. No being, — animal or vegetable, — can continue to live without a due supply of it; nor can any other gas be substituted for it. This is proved by the fact, that "all organized bodies cease to exist, if placed in vacuo. They require, likewise, renovation of the air, otherwise they die ; and if the residual air be examined, it is found to be diminished in quantity, and to have received a gas, which is totally unfit for life, — carbonic acid. The experiments of Hales prove this as regards vegetables.; whilst Spallanzani and Vauquelin have confirmed it in the case of the lower animals. The necessity for the presence of air, and its due renewal, — as regards man and the upper classes of animals, — is sufficiently obvious. Not less neces- sary is a due supply of air to aquatic animals. They can be readily drowned, when the air in the water is consumed, if prevented from coming to the surface : if the fluid be put under the receiver of an air-pump, and the air be withdrawn, or if the vessel be placed so that the air cannot be renewed, the same changes are found to have been produced in the air ; and hence the necessity for making holes through the ice, where small fish-ponds are frozen over, if we be desirous of preserving the fish alive. The necessity for the renewal of air is not, however, alike imperative in all animals. Whilst the mammalia, birds, fishes, &c, speedily expire, when placed under the receiver of an air-pump, if the receiver be exhausted; the frog is but slightly incommoded. It swells up almost to bursting, but retains its position, and when the air is admitted, seems to have sustained no injury. This exception, afforded by the amphibious animal to the ordinary effects of destructive agents, we have al- ready had occasion to refer to more than once ; and it is strikingly exemplified in the fact, now indisputable, that the toad has been found alive in the substance of trees and rocks, where no access of air appeared practicable. The influence of air an mankind is most interesting and import- ant in its hygienic relations, and has accordingly been a topic of vol. n. — 3 26 RESPIRATION. study since the days of Hippocrates. In other works, it has been investigated, at considerable length, by the author.3 3. PHYSIOLOGY OP RESPIRATION. a. Mechanical Phenomena of Respiration. — Within certain limits, the function of respiration is under the influence of volition. The'muscles, belonging to it, have consequently been termed mixed, as we can at pleasure increase or diminish their action, but cannot arrest it altogether, or for any great length of time. If, by a forced inspiration, we take air into the chest in large quantity, we find it impossible to keep the chest in this condition beyond a certain period. ' Expiration irresistibly succeeds, and the chest re- sumes its pristine situation. The same occurs if we expel the air as much as possible from the lungs. The expiratory effort cannot be prolonged indefinitely, and the chest expands in spite of the effort of the will. The most expert divers do not appear capable of suspending the respiratory movements longer than 95 or 100 seconds. Dr. Lefevreb found the average period of the Turkish divers to be 76 seconds for each man. These facts have given rise to two curious and deeply interesting topics of inquiry ; — the cause of the first inspiration in the new-born infant ? and of the regular alternation of inspiration and expiration during the remainder of existence ? The first of these questions will fall under considera- tion when we investigate the physiology of infancy ; .the latter will claim some attention at present. Hallerc attempted to account for the phenomenon by the passage of the blood through the lungs being impeded during expiration,— a reflux of blood into the veins, and a degree of pressure upon the brain being thus induced. Hence, a painful sense of suffocation arises, in consequence of which the muscles of inspiration are called into action by the will, for the purpose of enlarging the chest, and, in this way, removing the impediment. The same uneasy feelings, however, ensue from inspiration, if too long protracted: the muscles cease to act, and, by their relaxation, the opposite state of the chest is induced. Whyttd conceived, that the passage of the blood through the pul- monary vessels is impeded by expiration, and that a sense of anxiety is thus produced. The unpleasant sensation acts as a stimulus upon the nerves of the lungs and the parts connected with them, which arouses the enej-gy of the sentient principle ; and this, by acting in a reflex manner, causes contraction of the diaphragm, enlarges the chest, and removes the painful feeling The muscles then cease to act, in consequence of the stimulus no a Elements of Hygiene, pp. 33 to 305, Philad. 1835 ; a-nd American Cyclopedia of Practical Medicine and Surgery, art. Atmosphere, p. 527, Philad 1836 " Loudon's Magazine of Nat. Hist. p. 617, Dec. 1836; and Dumrlison's Amer Med. Intelligencer, p. 30, April 15, 1837. c Elementa PhyrioS °Hi 4 1? ^An Essay on the Vital and other Involuntary Motions of Animals, sect', viii.', Edino. MECHANICAL PHENOMENA — INSPIRATION. 27 Fig. 150. \V longer existing.8 These, and all other methods of accounting for the phenomena, are, however, too pathological. From the first moment of respiration the process appears to be accomplished without the slightest difficulty, and to be as much a part of the instinctive extra-uterine actions of the frame, as circulation, diges- tion, or absorption. It is obviously an internal sensation, after respiration has been once established ; and, like all internal sen- sations, is inexplicable in our existing state of knowledge. The part which developes the impression is proba- bly the lung, through its ganglionic nerves; the pneumogastric nerves convey the impression 16 the brain or spinal marrow, which calls into action the muscles of inspiration. We say, that the action of impression arises in the lungs, and this, from some inter- nal cause, connected with the office to be filled in the economy: but in so saying we sufficiently exhibit our total want of acquaintance with its nature. The movements of inspiration and expiration, which, together, constitute the function of respiration, are entire- ly accomplished by the dilatation and contraction of the thorax. The air enters the chest when the latter is expanded; and it is driven out when the chest is restored to its ordinary dimensions; — the thorax thus seem- ing to act like an ordinary pair of bellows with the valve stopped : when the sides are separated, the air enters at the nozzle, and it is forced out when they are brought together. 1. INSPIRATION. The augmentation of the capacity of the thorax, which consti- tutes inspiration, may be effected to a greater or less extent, accord- ing to the number of muscles which are thrown into action. The chest may, for example, be dilated by the diaphragm alone. This muscle, as we have seen, in its ordinary relaxed condition is convex towards the chest, as in Figures 150 and 151. When, however, it contracts, it becomes more horizontal; and assumes the position indicated by the dotted line d, Fig. 150, in this manner augmenting the cavity of the chest in a vertical direction. The sides or lateral portions of the diaphragm, which are fleshy and correspond to the » See, also, Dr. M. Hall's Lectures on the Nervous System, p. 55, Lond. 1836; or Amer. Edit. p. 36, Philad. 1836. Section of the Thorax and Abdomen. i. Thorax, b. Abdomen, e. Relaxed diaphragm. gg RESPIRATION. lungs, descend more, in this movement, than the central, tendinous portion, which is moreover kept immovable by itsattachment to the sternum, and its union with the pericardium. In the gentlest of all breathing, the diaphragm appears to be the sole agent of inspira- tion ; and in cases of inflammation of the pleura costalis, or of frac- tured rib, our endeavours are directed to the prevention of any ele- vation of the ribs by which the diseased part can be put upon the stretch. Generally, however.as the diaphragm descends, the viscera of the abdomen are compressed ; the abdominal muscles assume the position of the double dotted line/, and the ribs and the breast bone are raised so that the latter is protruded as far as the dotted line e. When the diaphragm acts,and, in addition, the ribs and ster- num are raised, the cavity of the chest is still farther augmented. The mechanism, by which the ribs are raised, has been produc- tive of more controversy than the subject merits. Hallera asserted, that the first rib is immovable, or at least admits of but trifling motion when compared with the others; and he denies that the thorax makes any movement, as a whole, of either elevation or depression ; affirming that the ribs are raised successively towards the top of the cavity ; and this to a greater extent as they are more distant from the first. Magendie,b on the other hand, denies that they are elevated in this manner; and endeavours to show that they are all raised at the same time ; that the first rib, instead of being the least movable, is the most so ; and that the disadvantage, which the lower ribs possess in the movement, by their admitting of less motion in their posterior articulations, is compensated by the greater length of these ribs. This compensation he considers to have its advantages ; for as the true ribs, with their cartilages and the sternum, usually move together, and the motion of oneof these parts almost always induces that of the rest, it would follow, that if the lower ribs were more movable, they could not execute a more extensive movement than they do ; whilst the solidity of the thorax would be diminished. By the elevation, then, of the ribs, and the depression of the diaphragm, the chest is augmented, and a deeper inspiration effected than when the diaphragm acts singly. In this elevation of the ribs, we see the advantage of their obliquity as regards the spine. Had they been horizontal,or inclined obliquely upwards, any elevation would necessarily have contracted the tho- racic cavity, and favoured expiration instead of inspiration. The muscles chiefly concerned in inspiration are the intercos- tals, and those muscles which arise, either directly or indirectly from the spine, head, or upper extremities, and which can in any manner, elevate the thorax. Amongst these, are the scaleni antici and postici, the levatorescostarum, the muscles of the neck which are attached to the sternum, &c. As no air exists in the cavity of the pleura, it necessarily happens that, when the capacity of the chest is augmented, the residuary air' contained in the air-cells of the lungs after expiraton, is rarefied' * Elementa Physiologic, viii. b Pr6cis> &c ^ .^ .. ^ ' MECHANICAL PHENOMENA — INSPIRATION. 29 and, in consequence, the denser air without enters the larynx by the mouth and nose, until the air within the lungs has attained the density, which the residuary air had, prior to inspiration,— not that of the external air, as has been affirmed.3 At the time of inspira- tion, the glottis opens by the relaxation of the arytenoidei muscles, as Legalloisb proved by experiments, performed at the Ecole de Mt- decine of Paris. On exposing the glottis of a living animal, the aper- ture is found to dilate very distinctly at each inspiration,and to con- tract at each expiration. If the eighth pair of nerves be divided low down in the neck, and the dilator muscles of the glottis, which receive their nerves from the recurrents— branches of the eighth pair — be thus paralysed, the aperture is no longer enlarged during inspiration, whilst the constrictors — the arytenoidei muscles — which receive their nerves from the superior laryngeal, — given off above the point of section —preserve their action, and close the glottis more or less completely. When the air is inspired through the mouth, the velum is raised, so as to allow the air to pass freely to the glottis ; and, in forced inspiration, it is so horizontal, as to completely expose the pharynx to view. The physician takes advantage of this, in examining mor- bid affections of those parts, and can often succeed much better in this way than by pressing down the tongue. On the other hand, when inspiration is effected entirely through the nose, the velum palati is depressed, until it becomes vertical, and no obsta- cles exist to the free entrance of the air into the larynx. In such case, where difficulty of breathing exists, the small muscles of the alas nasi are frequently thrown into violent action, alternately di- lating and contracting the apertures of the nostrils; and hence this is a common symptom in pulmonary affections. Mayowc conceived, that the air enters the lungs in inspiration as it would a bladder put into a pair of bellows, and communicating with the external air by the pipe of the instrument. The lungs, however, are not probably so passive as this view would indicate. In cases of hernia of the lungs, the extruded portion has been observed to dilate and contract in inspiration and expiration. Reisseisen believed this to be owing to muscular fibres, which Meckel and himself conceived to perform the whole circuit of the bronchial ramifications. These are not, however, generally ad- mitted by anatomists, and the phenomenon is usually ascribed to the bronchi having in their composition the highly elastic tissue, which is an important constituent of the arteries, Laennecd affirms, that he has endeavoured, without success, to verify the observations of Reisseisen; but that the manifest existence of a Animal Physiology, Library of Useful Knowledge, p. 100, Lond. 1829. b (Euvres, p. 177, Paris, 1824. e Tractatus Quinque, p. 271, Oxon. 1674. i On the Diseases of the Chest, &c, 4th edit., Lond. 1834: reprinted in this country, Philad. 1835. See, also, Dr. Watson, Lectures in Lond. Med. Gaz. Feb. 11, 1842 ; and the author's Practice of Medicine, 2d edit. vol. ii. art Asthma, Philad. 1844. 3* 3Q RESPIRATION. circular fibres in branches of a moderate size, and the pheno- mena, presented by many kinds of asthma, induce him to consider the temporary constriction and occlusion of the minute bronchial ramifications as a thing well established.3 In the trachea, an ob- vious muscular structure exists in the posterior third, where the cartilages are wanting. There it consists of a thin muscular plane, the fibres of which pass transversely between the interrupted ex- tremities of the cartilaginous rings of the trachea and bronchi, to which a layer of longitudinal fibres may at times be seen super- added^ The use of the transverse muscular tissue, as suggested by Dr. Physick,c and, since him, by Cruveilhier and Sir Charles Bell,d is to diminish the calibre of the air-tubes in expectoration ; so that the air having to pass through the contracted portion with greater velocity, its momentum may remove the secretions that are adherent to the mucous membrane. The explanation is in- genious and probably just. Magendiee asserts, that the lung has a constant tendency tore- turn upon itself, and to occupy a smaller space than that which it fills ; and, that it consequently exerts a degree of traction on every part of the parietes of the thorax. This traction has but little effect upon the ribs, which cannot yield : but upon the diaphragm it is considerable. It is, indeed, in his opinion, the cause, why that muscle is always tense, and drawn so as to be vaulted up- wards ; and when the muscle is depressed during contraction, it is compelled to draw down the lungs towards the base of the chest, so that they are stretched, and, by virtue of their elasticity, have a more powerful tendency to return upon themselves, and to draw the diaphragm upwards. If a puncture be made into the chest in one of the intercostal spaces, the air will enter the chest through the aperture, and the lung will shrink. By this experiment, the atmospheric pressure is equalized on both surfaces of the lung, and the organ assumes a bulk determined by its elas- ticity and weight. Owing to this resiliency of the lungs, and to their consequent tendency to recede from the pleura costalis/ there is less pressure upon all the parts against which the lungs are ap- plied ; and, accordingly, the heart is not exposed to the°same de- gree of pressure as the parts external to the chest; and the degree of pressure is still farther reduced, when the chest is fully dilated, the lungs farther expanded, and their elastic resi- liency increased. Many physiologists have pointed out three degrees of inspira- a See, on this subject Trousseau and Belloc on Laryngeal Phthisis, translated by Dr Warder, of Cincinnati, for Dunghson's Amer. Med. Library d 81 Phila.l 1839 • and Carpenter, Human Physiology, § 527, Lond 1842 -fhilad. 18J9 , Phila^'l^t^' ^ WilS°n'S Anat°miSt'S Vade-™cum, Amer. edit., p. 484, note. <= Horner's Lessons in Pract. Anat., p. 179, Philad 183R » nnj « • , Histology, 4th edit., Philad. 1843. 6 ' a"d &Pec,al Anal, and d Philos. Transact, for 1832, p. 301. e p ■ f J. Carson, on the Elasticity, of the Lungs, in Philos TransactieCI% 325' Inquiry into the Causes of Respiration, &c. 2d edit., Lond 1833 torl82°; an<1 MECHANICAL PHENOMENA — INSPIRATION. 31 tion,but it is manifest that there maybe innumerable shades be- tween them:— 1. Ordinary gentle inspiration, which is owing simply to the action of the diaphragm; or,in addition, to a slight elevation of the chest. 2. Deep inspiration, where, with the de- pression or contraction of the diaphragm, there is evident eleva- tion of the thorax, and, lastly,/?™?*/ inspiration, when the air is strongly drawn in, by the rapid dilatation, produced by the action of all the respiratory muscles that elevate the chest directly or in- directly. Trials have been instituted for determining the quantity of air taken into the lungs at an inspiration ; and considerable diversity, as might be expected, exists in the evaluations of different experi- menters.a We have just remarked, that, in the same individual, the inspiration may be gentle, deep,or forced; and, in each case, the quantity of air inspired will necessarily differ. There is, like- wise, considerable diversity in individuals, as regards the size of the chest; so that an approximation can alone be attained. The following table sufficiently exhibits the discordance of authors on this point. Many, however, of the estimates, which seem so extremely discrepant, may probably be referred to imperfection in the mode of conducting the experiment, as well as to the causes above mentioned : 1 Reil, Menzies, Sauvages, Hales, Haller, Ellis, | Sprengel, Sbmmering, Thomson, Bostock, J Jurin, - - - - >• Cubic inches at each Inspiration. 42 to 100 40 35 to 38 Fontana, .----.. Richerand, ------ Dalton, -------- Herholdt,....... Jurine and Coathupe, Allen and Pepys, - - - J. Borelli,...... Goodwin, ------- Sir H. Davy, ----- Abernethy and Mojon, Keutsch, -----.. Cubic inches at each Inspiration. 35 30 to 40 30 20 to 29 20 16£ 15 to 40 14 13 to 17 12 6 to 12*> In passing through the mouth, nasal fossae, pharynx, larynx, tra- chea, and bronchi, the inspired air acquires pretty nearly the tem- perature of the body ; and, if the air be cool, the same quantity by weight occupies a much larger space in the lungs, owing to its rarefaction in those organs. In its passage, too, it becomes mixed with the halitus, which is constantly exhaled from the mucous membrane of the air-passages ; and, in this condition, it enters the air-cells, and becomes mixed, by diffusion, with the residuary air in the lungs after expiration. a Dr. Marshall Hall has devised a pneumatometer for this purpose. See art. Irri- tability, in Cyclop, of Anat. and Physiol. July, 1840. b Bostoek's Essay on Respiration, Liverpool, 1804; and Elementary, System of Phvsiology, 3d edit. p. 314, Lond. 1836 ; and C. T. Coathupe, in Philos. Magaz. June, 1839. RESPIRATION. It is obvious, that if we knew the exact capacity of the longs in an individ^when in health, we might be able to determine the Stent'f solidification in pulmonary auctions y the diminu ion in their capacity. Owing, however, to our want of this requisite preliminary knowledge, the test is not of much avail. 2. EXPIRATION. An interval, scarcely appreciable, elapses after the accomplish- ment of inspiration, before the reverse movement of expiration sue- ceeds • and the air is expelled from the chest. The great cause of this expulsion is the restoration of the chest to its former dimen- sions; and the elasticity of the yellow tissue composing the bron- chial ramifications, which have been put upon the stretch by the air rushing into them during inspiration. The restoration of the chest to its dimensions may be effected simply by the cessation of the contraction of the muscles, that have raised it, and the elasti- city of the cartilages, which connect the bony portions of the ribs with the sternum or breast-bone. In active expiration, however, the ribs are depressed by the action of appropriate muscles, and the chest is thus still farther contracted. The chief expiratory muscles are the triangularis sterni, the broad muscles of the abdo- men, rectus abdominis, sacro-lumbalis, longissimus dorsi, serratus posticus inferior, &c. Haller3 conceived that the ribs, in expira- tion, are successively depressed towards the last rib ; which is first fixed by the abdominal muscles and quadratus lumborum. The intercostal muscles then act and draw the ribs successively down- wards. Magendieb contests the explanation of Haller; and the truth would seem to be, that the muscles, just mentioned, partici- pate with the intercostals in every expiratory movement. By this action, the capacity of the chest is diminished ; the lungs are cor- respondent^ pressed upon, and the air issues by the glottis. It has been already remarked, that, during expiration, the arytenoidei muscles contract, and the glottis appears to close. Still, space suffi- cient is left to permit the exit of the air. It has been asked — is the air expired precisely that which has been taken in by the previous inspiration? It is impossible to empty the lungs wholly by the most forced expiration. A portion still remains; and hence it has been assumed, that the use of inspi- ration is to constantly renew the air remaining in the air-cells. On this subject we are not well informed; but it is probable that the lighter and more rarefied air mixes, by diffusion, with the newly- arrived and denser medium. Many experiments have been made makes it about TJ5th ; Allen and Pepys a little more per cent. Berthollet from 0-69 to 3-70 per cent.; and"Bostock » Element. Physiol, viii. 4. b PrJciS) &c .. c Researches, Chemical and Philosophical, p. 431, Lond. 1800 * »• **• MECHANICAL PHRNOMENA — EXPIRATION. 33 Yflh, — as the average diminution. Assuming this last estimate to be correct; and forty cubic inches to be the quantity of air drawn into the lungs at each inspiration, it will follow, that half a cubic inch disappears each time we respire. This, in a day, would amount to 14,400 cubic inches, or to rather more than eight cubic feet. The experiments of MM. Dulong and Despretz make the diminution considerable. The latter gentleman placed six small rabbits in forty-nine quarts of air for two hours, at the expiration of which time the air had diminished one quart. A portion of the inspired air must consequently have been absorbed. Attempts have been made to estimate the quantity of air remain- ing in the lungs after respiration; but the sources of discrepancy are here as numerous as in the cases of inspiration or expiration. Goodwyna estimated it at 109 cubic inches; Menziesb at 179; Jurinc at 220; Fontanad at 40 ; and Cuvier, after a forced inspira- tion, at from 100 to 60. Davye concluded, that his lungs, after a forced expiration,still retained41 cubic inchesofair; after a natural expiration they contained 118 cubic inches ; after a natural inspi- ration, 135 ; after a forced inspiration, 254 ; by a full forced expi- ration after a forced inspiration, he threw out 190 cubic inches ; after a natural inspiration, 7S-5 ; after a natural expiration, 67-5. It is impossible, from such variable data, to deduce any thing like a satisfactory conclusion ; but if we assume with Bostock, (and Dr. Thomsonf is disposed to adopt the estimate,) 170 cubic inches as the quantity, that may be forcibly expelled, and that 120 cubic inches will be still left in the lungs, we shall have 290 cubic inches as the measure of the lungs in their natural or quiescent state ; to this quantity. 40 cubic inches are added by each ordinary inspira- tion, giving 330 cubic inches as the measure of the lungs in their distended state. Hence it would seem, that about one-eighth of the whole contents of the lungs is changed by each respiration ; and that rather more than two-thirds can be expelled by a forcible expiration. Supposing, that each act of respiration occupies three seconds, or that we respire twenty times in a minute, a quantity of air, rather more than 2| times the whole contents of the lungs, will be expelled in a minute, or about four thousand times their bulk in twenty-four hours. The quantity of air, respired during this period, will be 1,152,000 cubic inches, about 6664 cubic feet. Such is Bestock's estimate. It is the residuary air, that gives to the lungs the property of floating on the surface of water, after they have once received the breath of life, and no pressure, that can be employed, will force out the air, so as to make them sink.s Hence, the chief proofs, whether a child has been born alive or dead, are deduced from the lungs. These proofs constitute the docimasia * Op. citat. p. 36. ■> Op. citat. p. 31. c Philosoph. Trans, vol. xxx. p. 758. <• Philos. Trans, for 1799, p. 355. » Op. citat. p. 411. f System of Chemistry, vol. iv. & Mr. Jennings, Transactions of the Provincial Medical and Surgical Association, vol. 1. „. RESPIRATION. 34 pulmonum, Lungenprobe, or Athemprobe, ("Lung- Droof or Respiration-proof,") of the Germans. P Expiration, like inspiration, has been divided into three grades; ordinary, free, and forced; but it must necessarily admit of multi- tudinous shades of difference. In ordinary passive respiration, ex- piration is effected solely by the relaxation of the diaphragm. In free active respiration, the muscles that raise the ribs are likewise relaxed, and there is a slight action of the direct expiratory mus- cles. In forced expiration, all the respiratory muscles are thrown into action. In this manner, the air makes its way along the air- passages through the mouth or nostrils or both ; carrying with it a fresh portion of the halitus from the mucous membrane. This it deposits, when the atmosphere is colder than the temperature ac- quired by the respired air, and if the atmosphere be sufficiently cold, as in winter, the vapour becomes condensed as it passes out, and renders expiration visible. If the whole time occupied by a respiratory act — that is, from the beginning of one inspiration to the beginning of the next — be represented by 10, the time occupied by the inspiratory movement has been estimated approximately at 5 ; that of the expiratory at 4; and of the pause between the expiratory and succeeding inspi- ratory movement at l.a The number of respirations in a given time differs considerably in different individuals. Dr. Hales reckons them at twenty. A man, on whom Menzies made experiments, breathed only fourteen times in a minute. Sir Humphry Davy made between twenty- six and twenty-seven in a minute. Dr. Thomson about nineteen, and Magendie fifteen. Our own average, is sixteen. The aver- age, deduced from the few observers, that have recorded their statement, — or twenty per minute,— has generally been taken ; but we are satisfied it is above the truth ; eighteen would be nearer the general average ; and it has accordingly been admitted by many. Eighteen in a minute give twenty-five thousand nine hundred and twenty in the twenty-four hours. The number is influenced, however, by various circumstances. The child and the female, and perhaps also the aged, breathe more rapidly than the adult male. MM. Hourmann and Dechambreb examined two hundred and fifty-five women, between the ages of sixty and ninety-six, the average number of whose respirations was 21-79 per minute. We find as much variety in man as we do in the horse : whilst some men are short, others are long-winded; and this last condition may be improved by appropriate training; to which the pedestrian and the prize-fighter, equally with the horse, are submitted for some time before they are called upon to exhibit their powers. In sleep, the respiration is generally deeper, • Walshe, Physical Diagnosis and Diseases of the Lungs, Amer. Edit. p. 11, Philad. ApritT836,pf555.de M*decine'Nov" 18355 and B"tish and Foreign Med. Rev., MECHANICAL PHENOMENA — STRAINING. 35 less frequent, and appears to be effected greatly by the intercostals and diaphragm.* Motion has also a sensible effect in hurrying the respiration, as well as distension of the stomach by food, cer- tain mental emotions, &c. : its condition during disease becomes, also, a subject of interesting study to the physician, and one that has been much facilitated by the acoustic method, introduced by Laennec. To his instrument — the stethoscope — allusion has already been made. By it or by the ear applied to the chest, we are able to hear distinctly the respiratory murmur and its modifi- cations ; and thus to judge of the nature of the pulmonary affec- tion when existent. But this is a topic that appertains more espe- cially to pathology. 3. RESPIRATORY PHENOMENA CONCERNED IN CERTAIN FUNCTIONS. There are certain respiratory movements concerned in effecting other functions, which require consideration. Some of these have already been topics of discussion. Adelonb has classed them into : First. Those employed in the sense of smell, either for the purpose of conveying the odorous molecules into the nasal fossa?; or to repel them and prevent their ingress. Secondly. The inspiratory action employed in the digestive function, as in sucking. Thirdly. Those connected with muscular motion when forcibly exerted ; and particularly in straining or the employment of violent effort. Fourthly. Those concerned in the various excretions, either volun- tary,— as in defecation and spitting ; or involuntary, — as in coughing, sneezing, vomiting, accouchement, &c.; and lastly, such as constitute phenomena of expression—as sighing, yawning, laughing, crying, sobbing, &c. Some of these, that have already engaged attention, do not demand comment ; others are topics of considerable interest, and require investigation. 1. Straining. —The state of respiration is much affected during the more active voluntary movements. Muscular exertion, of whatever kind, when considerable, is preceded by a long and deep inspiration ; the glottis is then closed ; the diaphragm and respira- tory muscles of the chest are contracted, as well as the abdominal muscles which press upon the contents of the abdomen in all direc- tions. At the same time that the proper respiratory muscles are exerted, those of the face participate, owing to their association through the medium of particular nerves. By this series of actions, the chest is rendered capacious; and the force, that can be deve- loped is augmented, in consequence of the trunk being rendered immovable as regards its individual parts, — thus serving as a fixed point for the muscles that arise from it, so that they are enabled to employ their full effect.0 The physiological state of muscular action, as connected with the mechanical function of respiration, is happily described by 1 Adelon, Physiologie de l'Homme, iii. 185. b Ibid. p. 188. c Ibid. p. 190; and art. Effort, in Diet, de Med. vii. 319, Paris, 1823. 36 RESPIRATION. Fig. 151. Shakspeare, when he makes the 5th Harry encourage his soldiers at the siege of Harfieur.a . . In the effort required for effecting the various excretions, a simi- lar action of the respiratory muscles takes place. The organs, from which these excretions have to be removed, exist either in the thorax or abdomen ; and in all cases, they have to be com- pressed by the parietes of those cavities. See Fig. 151. A full in- spiration is first made ; the expiratory muscles, with those that close the glottis, are then forcibly and simultaneously contracted, and by this means the thoracic and abdominal viscera are com- pressed. Some difference, however, exists, according as the viscus to be emptied, is seated in the abdomen or thorax. In the evacuation of the faeces, the lungs are first filled with air; and, whilst the muscles of the larynx contract to close the glottis, those of the abdomen contract also; and as the lung, in conse- quence of the included air, resists the ascent of the diaphragm, the com- pression bears upon the large intestine. The same hagpens in the excretion of the urine, and in ac- couchement. 2. Coughing and SneeZ' ing. — When the organ, that has to be cleared, is in the thorax,— as in coughing to remove mu- cus from the air-passages — the same action of the muscles of the abdomen is invoked ; but the glot- tis is open to allow the exit of the mucus. In this case, the expiratory muscles contract convul- sively and forcibly, so that the air is driven vio- and. in its passage .weeps off the irrita^^dl^ Stirlen the sinews, summon up the blood • Now ^t the teeth, and stretch the nostrils wide • King Henry V. iii. 1. Thoracic and Abdominal Viscera. h^r^n^-T B>I1eft iung- C- Ri8ht ventricle of the heart. D. R.ght auricle ol the heart. £. Vena cava suue nor. F F Subclavian ve.ns. G. G. Internal ju'Xr veins H. Ascending aorta. 1. Pulmonary artery K Diaphragm. L. L. Eight and left lobes of the liver M Ligamentum rotundum. N. Fundus of gall-bladder o Stomach. ,P. Spleen a. a. Situation of the kidneys & hind the intestines. R. It. Small intestines. y ' MECHANICAL PHENOMENA — SPITTING. 37 out of the body. To aid this, the muscular fibres, at the posterior part of the trachea and larger bronchial tubes, contract, so as to diminish the calibre of these canals; and, in this way, expectora- tion is facilitated. The action differs, however, according as the expired air is sent through the nose or mouth ; in the former case, constituting sneezing; in the latter, coughing. The former is more violent than the latter, and is involuntary ; whilst the latter is not necessarily so. In both cases the movement is excited by some external irritant, applied directly to the mucous membrane of the windpipe or nose; or by some modified action in the very ' tissue of the part, which acts as an irritating cause. In both cases the air is driven forcibly forward, and both are accompanied by sounds that cannot be mistaken. In these actions, we have strik- ing exemplifications of the extensive association of muscles, through the medium of nerves, to which we have so often alluded. The pathologist, too, has repeated opportunities for observing the extensive sympathy between distant parts of the frame, as indicated by the actions of sneezing and coughing, especially of the former. If a person be exposed for a short period to the partial and irre- gular application of cold, so that the capillary action of a part of the body is modified, as where we get the feet wet, or sit in a draught of air, a few minutes will frequently be sufficient to ex- hibit sympathetic irritation in the Schneiderian membrane of the nose, and sneezing, Nor is it necessary, that the .capillary action of a distant part shall be modified by the application of cold. We have had the most positive evidence, that if the capillary circula- tion be irregularly excited, even by the application of heat, whilst the rest of the body is receiving none of its influence, inflamma- tion of the mucous membrane of the nasal fossae and fauces follows with no less certainty. 3. Blowing the Nose. — The substance that has to be excreted by this operation is composed of the nasal mucus, the tears sent down the ductus ad nasum, and the particles deposited on the membrane by the air, in its passage through the nasal fossa?. Commonly, these secretions are only present in quantity sufficient to keep the membrane moist, the remainder being evaporated or absorbed. Frequently, however, they exist in such quantity as to fall by their own gravity into the pharynx, where they are sent down into the stomach by deglutition, are thrown out at the mouth, or make their exit at the anterior nares. To prevent this last effect more especially, we have recourse to blowing the nose. This is accomplished by taking in air, and driving it out suddenly and forcibly, closing the mouth at the same time, so that the air may issue by the nasal fossa? and clear them; the nose being com- pressed so as to make the velocity of the air greater, as well as to express all the mucus that may be forced forwards. 4. Spitting differs somewhat according to the part in which the mucus or matter to be ejected is seated. At times, it is exclusively in the mouth ; at others in the back part of the nose, pharynx or VOL. II. — 4 38 RESPIRATION. larynx. When the mucus or saliva of the mouth has to be ex- creted, the muscular parietes of the cavity, as well as the tongue, contract so as to eject it from the mouth; the lips being at times approximated, so as to render the passage narrow, and impel tne sputa more strongly forward. The air of expiration may be, at the same time, driven forcibly through the mouth, so as to send the matter to a considerable distance. The practised spitter some- times astonishes us with the accuracy and power of propulsion of which he is capable. When the matter to be evacuated is in the ' nose, pharynx, or larynx, it requires to be brought, first of all, into the mouth. If in the posterior nares, the mouth is closed, and the air is drawn in forcibly through the nose, the pharynx being at the same time constricted so as to prevent the substances from passing down into the oesophagus. The pharynx now contracts, from below to above, in an inverse movement from that required in deglutition, and the farther excretion from the mouth is effected in the manner just described. Where the matters are situate in the air-passages, the action may consist in coughing ; or, if higher up, simply in hawking. A forcible expiration, unaccompanied by cough, is, indeed, in many cases, sufficient to detach the superfluous mucous secretion from even the bronchial tubes. In hawking, the expired air is forcibly sent forwards, and the parts about the fauces are suddenly con- tracted so as to diminish the capacity of the tube and propel the matters onwards. The noise is produced by their discordant vibra- tions. Both these modes bear the general name of expectoration. When these secretions are swallowed, they are subjected to the digestive process ; a part is taken up, and the remainder rejected; so that they belong to the division of recremento-excrementitial fluids of some physiologists. 4. RESPIRATORY PHENOMENA CONNECTED WITH EXPRESSION. It remains to speak of the expiratory phenomena that strictly form part of the function of expression, and depict the moral feeling of the individual who gives utterance to them. 1. Sighing consists of a deep inspiration, by which a large quan- tity of air is received slowly and gradually into the lungs, to com- pensate for the deficiency in the due aeration of the blood which precedes it. The most common cause of sighing is mental uneasi- ness ; it also occurs at the approach of sleep, or immediately after waking. In all these cases, the respiratory efforts are executed more imperfectly than undery ordinary circumstances: the blood consequently does not circulate through the lungs in due quantity, but accumulates more or less in these organs, and in the right side' of the heart; and it is to restore the due balance, that the deep inspiration is now and then established. 2. Yawning, oscitancy, oscitation or gaping, is likewise a full, deep, and protracted inspiration, accompanied by a wide separa- tion of the jaws, and followed by a prolonged and sometimes sono- STRETCHING — LAUGHING. 39 rous expiration. Yawning is excited by many of the same causes as sighing. It is not, however, the expression of any depressing passion, but is occasioned by any circumstance that impedes the necessary aeration of the blood ; whether this be retardation of the action of the respiratory muscles, or the air being less rich in oxy- gen. Hence we y,awn at the approach of sleep, and immediately after waking. The inspiratory muscles, fatigued from any cause, experience some difficulty in dilating the chest; the lungs are con- sequently not properly traversed by the blood from the right side of the heart: oxygenation is, therefore, not duly effected, and an uneasy sensation is induced, which is put an end to by the action of yawning, which allows the admission of a considerable quan- tity of air. We yawn at the approach of sleep, because the agents of respiration, becoming gradually more debilitated, require to be now and then excited to fresh activity, and the blood needs the necessary aeration. Yawning on waking seems to be partly for the purpose of stimulating the respiratory muscles to greater activity, the respiration being always slower and deeper during sleep. It is, of course, impossible to explain, why the respiratory nerves should be those that are chiefly concerned, under the guidance of the brain, in these respiratory movements of an expressive cha- racter. The fact, however, is certain ; and it is remarkably proved by the circumstance, that yawning can be excited by even looking at another affected in this manner; nay, by simply looking at a sketch, and by even thinking of the action. The same also applies to sighing and laughing, and especially to the latter. 3. Pandiculation or stretching is a frequent concomitant of yawning, and appears to be established instinctively to arouse the extensor muscles to a balance of power, when the action of the flexors has been predominant. In sleep, the flexor muscles exer- cise that preponderance which, in the waking state, is exerted by the extensors. This, in time, is productive of some uneasiness; and, hence, at times during sleep, but still more at the moment of waking, the extensor muscles are roused to action, to restore the equipoise; or, perhaps, as the muscles of the upper extremities, and those concerned directly or indirectly in respiration, are chiefly concerned in the action, it is exerted for the purpose of arousing the respiratory muscles to increased activity. By Dr. Good,* yawning and stretching have been regarded as morbid affections and amongst the signs of debility and lassitude: — " Every one," he remarks, " who resigns himself ingloriously to a life of lassitude and indolence will be sure to catch these motions as a part of that general idleness which he covets. And, in this manner, a natural and useful action is converted into a morbid habit; and there are loungers to be found in the world, who, though in the prime of life, spend their days as well as their nights in a perpetual routine of these convulsive movements, over which they have no power ; who cannot rise from the sofa without stretching 1 Study of Medicine, class 4, ord. 3, gen. 2, sp. 6. 40 ' RESPIRATION. their limbs, nor open their mouths to answer a plain question with- out gaping in one's face. The disease is here idiopathic and chro- nic ; it may perhaps be cured by a permanent exertion of the will, and ridicule or hard labour will generally be found the best reme- dies for calling the will into action." 4. Laughing is a convulsive action of the muscles of respiration and voice, accompanied by a facial expression* which has been explained elsewhere. It consists of a succession of short, sonorous expirations. The air is first inspired so as to fill the lungs. To this succeed short, interrupted expirations, with simultaneous con- tractions of the muscles of the glottis, so that this aperture is slightly contracted, and the lips assume the tension, necessary for the pro- duction of sound. The interrupted character of the expirations is caused by convulsive contractions of the diaphragm, which consti- tute the greater part of the action. In very violent laughter, the respiratory muscles are thrown into such forcible contractions, that the hands are applied to the sides to support them. The convul- sive action of the thorax likewise interferes with the circulation through the lungs; the blood, consequently, stagnates in the upper part of the body; the face becomes flushed; the sweat trickles down the forehead, and the eyes are suffused with tears ; but this is apparently owing to mechanical causes; not to the lachrymal gland being excited to unusual action, as in weeping. At times, however, we find the latter cause in operation, also. 5. Weeping. The action of weeping is very similar to that of laughing; although the causes are so dissimilar. It consists in an inspiration, followed by a succession of short, sonorous expirations. The facial expression, so diametrically opposite to that of laughter, has been depicted in another place. Laughter and weeping appear to be characteristic of humanity. Animals shed tears, but this does not seem to be accompanied with the mental emotion that characterizes crying in the sense in which we employ the term. It has, indeed, been affirmed by Steller,a that the phoca ursina or ursine seal; by Pallas,b that the camel • and by Von Humboldt,0 that a small American monkey, shed tears when labouring under distressingemotions. The last scientific travel- ler states, that " the countenance of the titi of the Orinoco __the simia sciurea of Linnaeus, — is that of a child ; the same expres- sion of innocence ; the same smile ; the same rapidity in the tran- sition from joy to sorrow. The Indians affirm, that it weeps like man, when it experiences chagrin; and the remark is accurate The large eyes of the ape are suffused with tears, when it expe- riences fear or any acute suffering." * Shakspeare's description of the weeping of the stag __ " That from the hunter's aim had ta'en a hurt" » Nov. Comm. Academ. Scient. Petropol. ii. 353. Th falD;71UnBen Historisch- Nachricht- *ber die Mongolischen Volkerschaften, ' Recueil d'Observations de Zoologie, &c. i. 333. SOBBING — PANTING. 41 is doubtless familiar to most of our readers.* We have less evi- dence in favour of the laughter of animals. Le Cat,b indeed, as- serts, that he saw the chimpanse both laugh and weep. The ourang-outang, carried to Great Britain from Batavia, by Dr. Clarke Abel, never laughed ; but he was seen occasionally to weep.c 6. Sobbing still more resembles laughing, except that, like weep- ing, it is usually indicative of the depressing passions; and gene- rally accompanies weeping. It consists of a convulsive action of the diaphragm; which is alternately raised and depressed, but to a greater extent than in laughing, and with less rapidity. It is susceptible of various degrees, and has the same physical effects upon the circulation as weeping. Dr. Wardropd considers laughter, crying, weeping,"sobbing, sighing, &c, as efforts made with a view to effect certain alterations in the quantity of blood in the lungs and heart, when the circulation has been disturbed by mental emotions. 7. Panting or anhelation consists in a succession of alternate, quick, and short inspirations and expirations. Their physiology, however, does not differ from that of ordinary respiration. The object is, to produce a frequent renewal of air in the lungs, in cases where the circulation is unusually rapid; or where, owing to dis- ease of the thoracic viscera, a more than ordinary supply of fresh air is demanded. We can, hence, understand, why dyspnoea should be one of the concomitants of most of the severe diseases of the chest; and why it should occur whenever the air we breathe does not contain a sufficient quantity of oxygen. The panting, pro- duced by running, is owing to the necessity for keeping the chest as immovable as possible, that the whole effort may be exerted on the muscles of locomotion ; and thus suspending, for a time, the respiration, or admitting only of its imperfect accomplishment. This induces an accumulation of blood in the lungs and right side * " The wretched animal heaved forth such groans, That their discharge did stretch his leathern coat Almost to bursting ; and the big round tears Coursed one another down his innocent nose* In piteous chase ; and thus the hairy fool, Much marked of the melancholy Jaques, Stood on th' extremest verge of the swift brook, Augmenting it with tears." As You Like It, ii. 1. b Traite de l'Existence du Fluide des Nerves, p. 35. c Lawrence, Lectures on Physiology, Zoology, and the Natural History of Man, p. 236, Lond. 1814. d On the Nature and Treatment of Diseases of the Heart, parti, p. 62, Lond. 1837. * " The alleged ' big round tears,' which ' course one another down the innocent nose' of the deer, the hare and other animals when hotly pursued, are in fact only sebaceous matter, which, under these circumstances, flows in profusion from a collection of fol- licles in the hollow of the cheek." — Fletcher's Rudiments of Physiology, part. ii. b. p. 50, Edinb. 1836. 4* 42 RESPIRATION. of the heart; and panting is the consequence of the augmented action necessary for transmitting it through the vessels. b. Chemical Phenomena of Respiration. Having studied the mode in which air is received into, and ex- pelled from, the lungs, we have now to inquire into the changes produced on the venous blood — containing the products of the various absorptions — in the lungs, as well as on the air itself. These changes are effected by the function of sanguification, hxmatosis, respiration, in the restricted sense in which it is em- ployed by some, arterialization of the blood, decarbonization, aeration, atmospherization, &c. With the ancients this process was but little understood. It was generally believed to act as the means of cooling the body; and, in modern times, Helvetius re- vived the notion, attributing to it the office of refrigerating the blood,— heated by its passage through the long and narrow channels of the circulation,— by the cool air constantly received into the lungs. The reasons, that led to this opinion, were : — that the air, which enters the lungs in a cool state, issues warm; and that the pulmonary veins, which convey the blood from the lungs, are of less dimension than the pulmonary artery, which conveys it to them. From this it was concluded, that the blood, during its progress through the lungs, must lose somewhat of its volume or be condensed by refrigeration. The warmth of the expired air can, however, be readily accounted for; and it is not true that the pulmonary veins are smaller than the pulmonary artery. The reverse is, indeed, the fact; and it is equally obvious, that the doctrine of Helvetius does not explain how we can exist in a temperature superior to our own: this ought, in his hypo- thesis, to be impracticable.a Another theory, which prevailed for some time, was: — that during inspiration the vessels of the lungs are unfolded, as it were, and that thus the passage of the blood from the right side of the heart to the left, through the lungs, is facilitated. Its progress was, indeed,conceived to be impossible during expiration, in con- sequence of the considerable flexures of the pulmonary vessels. The discovery of the circulation of the blood gave rise to this theory ; and Hallerb attaches considerable importance to it, when taken in connexion with the changes effected upon the blood in the vessels. It is inaccurate, however, to suppose, that the circu- lation of the blood through the lungs is mechanically interrupted, when respiration is arrested. The experiments of Williams' and Kayd would seem to show, that the interruption is owino- to the non-conversion of venous into arterial blood, and to the non- adaptation of the radicles of the pulmonary veins for any thing » Adelon, Physiologie de l'Homme, edit. cit. iii. 201. b Element Phv^i „;;; e Edinb. Med. and Surg. Journ. vol. lxxvii. 1823. ' "J"5101' vm> * Edinb. Med. and Surg. Journ. vol. xxix.; and Physiology and Patholotrv &r «f Asphyxia, Lond. 1834. 5> lu°">gy, &c, ot H.2EMAT0SIS. 43 but arterial blood, owing to which causes stagnation of blood su- pervenes in the pulmonary radicles.* Numerous other objections might be made to this view. In the first place, it supposes, that the lungs are emptied at each expiration, and, again, if a simple deploying or unfolding of the vessels were all that is required, any gas ought to be sufficient for respiration, — which is not the fact. In these different theories, the principal object of respiration is overlooked — the conversion of the venous blood and its various absorptions, conveyed to the lungs by the pulmonary artery, into arterial blood. This is effected by the contact of the inspired air with the venous blood ; in which they both lose certain elements, and gain others. Most physiologists have considered that the whole function of hasmatosis is effected in the lungs. Chaussier,b however, has presumed, that the air, in passing through the cavities of the nose and mouth, and the different bronchial ramifications, experiences some kind of elaboration, by being agitated with the bronchial mucus; similar to what he conceives to be effected by the mucus ou the aliment in its passage from the mouth to the stomach ; but his view is conjectural in both one case and the other. Legallois,c again, thought, that haematosis commences at the part, where the chyle and lymph are mixed with the vepous blood, or in the subclavian veins. This admixture, he conceives, occurs more or less immediately; is aided in the heart, and the conver- sion is completed in the lungs. To this belief he was led by the circumstance, that when the blood quits the lungs it is manifestly arterial, and he thought, that what the products of absorption lose or gain in the lungs is too inconsiderable to account for the im- portant and extensive change ; and that therefore it must have commenced previously. Facts, however, are not exactly in ac- cordance with the view of Legallois. They seem to show, that the blood of the pulmonary artery is analogous to that of the sub- clavian veins; and hence it is probable, that there is no other ac- tion exerted upon the fluid in this part of the venous system, than a more intimate admixture of the venous blood with the chyle and lymph in their passage through the heart. The changes, wrought on the air by respiration, are considera- ble. It is immediately deprived of a portion of both of its main constituents — oxygen and azote; and it always contains, when expired, a quantity of carbonic acid greater than it had when re- ceived into the lungs, along with an aqueous and albuminous ex- halation to-a considerable amount. a Sec the article "Asphyxia," by the author, in the " American Cyclopedia of Prac- tical M-edicine and Surgery," part, x., Philad. 1^36; and Practice of Medicine, 2d edit. vol. i., Philad. 1844 ; also, Dr. VV. P. Alison, in the Fourth Report of the British Asso- ciation, and in Edinb. Med. and ^urs>. Journ for Jan. 1836 ; and Dr. J. Reid, on the order of succession in which the vital actions are arrested in Asphyxia, Edinb. Med. and Surg. Journ., April, 1841, p 437. b Adelon, Physiologie, de I'Hommc, iii. 205. * Annales de Chimie, iv. 115. 44 RESPIRATION. Oxygen is consumed ;n the respiration of all animals, from the largest quadruped to the most insignificant insect; and, if we exa- mine the expired air, the deficiency is manifest. Many attempts have been made to estimate the precise quantity consumed during respiration ; but the results vary essentially from each other ; partly owing to the fact, that the amount consumed by the same animal in different circumstances is not identical. Menzies* was probably the first that attempted to ascertain the quantity consumed by a man in a day. According to him, 36 cubic inches are expended in a minute ; and, consequently, 51840 in the twenty-four hours, equal to 17496 grains. Lavoisierb makes it 46048 cubic inches, or 15541 grains. This was the result of his earlier experiments; and, in his last, which he was executing at the time when he fell a victim to the tyranny of Robespierre, he made it 15592-5 grains; corre- sponding largely with the results of his earlier observations. The experiments of Sir Humphry Davyc coincide greatly with those of Lavoisier. He found the quantity consumed in a minute to be 31-6 cubic inches; making 45504 cubic inches, or 15337 grains in twenty-four hours. The results obtained by Messrs. Allen and Pepysd make it much less. They consider the average consump- tion to be, in the twenty-four hours, under ordinary circumstances, 39534 cubic inches, equal to 13343 grains. Now, if we regard the experiments of Lavoisier and Davy, between which there is the greatest coincidence, to be an approximation to the truth, it will follow, that in a day, a man consumes rather more than 25 cubic feet of oxygen; and as the oxygen amounts to only about one-fifth of the respired air, he must render 125 cubic feet of air unfit for supporting combustion and respiration. The experiments of Crawford, Jurine, Lavoisier and Seguin, Prout, Fyfe, and Ed- wards,e have proved, that the quantity of oxygen consumed varies according to the condition of the functions aud of the system ge- nerally. Se.guinf found, that muscular exertion increases it nearly fourfold. Prout,s who gave much attention to the subject, was induced to conclude, from his experiments, that moderate exercise increases the consumption ; but if the exercise be continued so as to induce fatigue, a diminished consumption takes place. The exhilarating passions also appeared to increase the quantity; whilst the depressing passions and sleep, the use of alcohol and tea, diminished it. He discovered, also, that the quantity of oxy- gen consumed is not uniformly the same during the twenty-four hours. Its maximum occurred between 10 a.m. and 2 p.m., or generally between 11 a.m. and 1 p.m.; its minimum'com- menced about 8£ p.m., and it continued nearly uniform till about 3% a.m. Dr. Fyfeh found, that the quantity was likewise dimi- » Dissertation on Respiration, p. 21, Edinb. 1796. b Memoir, de l'Academ. des Sciences, 1789, 1790. <= Researches &o n A*^ i Philos. Transact, for 1808. ' c- p' ™1' e De Tlnfluence des Agens Physiques sur la Vie, p. 410, Paris, 1S24 • or Hodekin and Fisher's translation. f Mem. de l'Academ. des Sciences 1789 nn,l l i%n g Annals of Philos. ii. 330, iv. 331, and xiii. 269. ' woaanu 17au- b Annals of Philos. iv. 334, and Bostock's Physiol, i. 350. HjEMATOSIS. 45 nished by a course of nitric acid, by a vegetable diet, and by af- fecting the system with mercury. Temperature, also, has an in- fluence, Crawforda found, that a Guinea-pig, confined in air at the temperature of 55°, consumed double the quantity which it did in air at 104°. He also observed, in such cases, that the venous blood, when the body was exposed to a high temperature, had not its usual dark colour ; but, by its florid hue, indicated that the full change had not taken place in its constitution, in the course of cir- culation. We may thus understand the great lassitude and yawn- ing, induced by the hot weather of summer; and the languor and listlessness which are so characteristic of those who have long re- sided in torrid climes. Dr. Prout conceives, that the presence or absence of the sun alone regulates the variation in the consump- tion of oxygen which he has described ; but the deduction of Dr. Fleming1' appears to us more legitimate, — that it keeps pace with the degree of muscular action, and is dependent upon it. Consequently, a state of increased consumption is always followed by an equally great decrease, in the same manner as activity is followed by fatigue. The disagreement of experimenters, as respects the removal of nitrogen or azote from the air, during respiration, is still greater than in the case of oxygen. Priestley, Davy, Humboldt, Hender- son, Cuvier, Pfaff, and Thomson, found a less quantity exhaled than was inspired. Spallanzani,Lavoisier and Seguin, Vauquelin, Allen and Pepys, Ellis, and Dalton, inferred that neither absorp- tion nor exhalation takes place, — the quantity of that gas, in their opinion, undergoing no change during its passage through the air- cells of the lungs; whilst Jurine, Nysten, Berthollet, and Dulong and Despretz, on the contrary, found an increase in the bulk of the azote.c In this uncertainty, most physiologists have been of opinion that the azote is entirely passive in the function. The facts, ascer- tained by Dr. W. F. Edwards,d of Paris, shed considerable light on the causes of this discrepancy amongst observers. He has satis- factorily shown that, during the respiration of the same animal, the quantity of azote may, at one time, be augmented, at another, diminished, and, at a third, wholly unchanged. These phenomena he has traced to the influence of the seasons, and he suspects that other causes have a share in their production. In nearly all the lower animals that were the subjects of experiment, an augmenta- tion of azote was observable during summer. Sometimes, indeed, it was so slight that it might be disregarded; but, in numerous other instances, it was so great as to place the fact beyond the pos- sibility of doubt; and, on some occasions, it almost equalled the whole bulk of the animal. Such were the results of his observa- tions until the close of October, when he noticed a sensible dimi- nution in the nitrogen of the inspired air, and the same continued throughout the whole of winter and the beginning of spring. Dr. » Op. cit. p. 387. b Philosophy of Zoology, Edinburgh, 1822. c Bostock, op. citat. 3d edit. p. 356. d Op. citat. p. 462. 46 RESPIRATION. Edwards considers it probable, that, in all cases, both exhalation and absorption of azote are going on ; that they are frequently accurately balanced, so as to exhibit neither excess nor deficiency of azote in the expired air, whilst, in other cases, depending, as it would appear, chiefly upon temperature, either the absorption or the exhalation is in excess, producing a corresponding effect upon the composition of the air of" expiration. But not only has the respired air lost its oxygenous portion, it has gained, as we have remarked, an accession of carbonic acid, and, likewise, a quantity of serous vapour. If we breathe through a tube, one end of which is inserted into a vessel of lime-water, the fluid soon becomes milky, owing to the formation of carbonate of lime, which is insoluble in water. Carbonic acid must consequently have been given off from the lungs. In the case of this gas, again, the quantity, formed in the day, has been attempted to be computed. Jurine conceived, that the amount, in air once respired in natural respiration, is in the enormous proportion of Tyh or fyh. Menzies, that it is ^Lth ; and, from his estimate of the total quantity of air re- spired in the twenty-four hours, he deduced the amount of carbonic acid formed to be 51840 cubic inches, equal to 24105-6 grains. La- voisier and Seguin,3 in their first experiments, valued it at 17720-89 grains ; but in the very next year they reduced their estimate more than one-half; — to 8450-20 grains; and, in Lavoisier's last experi- ment, it was farther reduced to 7550-4 grains. Sir Humphry Davy's estimate nearly corresponds with that of the first experiment of Lavoisier and Seguin,— 17811-36 grains; and Messrs. Allen and Pepys accord pretty nearly with him. These gentlemen found, that atmospheric air, when inspired, issued on the succeeding expi- ration, charged with from 8 to 6 per cent, of carbonic acid gas; but this estimate exceeds considerably that of Dr. Apjohn,b of Dublin, who, in his experiments, found the expired air to contain only 3-6 per cent of this gas. The experiments and observations of Crawford, Prout, Edwards, and others, to which we have re- ferred— as regards the consumption of oxygen, under various cir- cumstances—apply equally to the quantity of carbonic acid formed, which always bears a pretty close proportion to the oxygen con- sumed. These experiments also account, in some degree, for the discrepancy in the statements of different individuals on this sub- ject. One fatal objection, however, to all these estimates is, that more carbon must be given off than is received in the daily food The experiments of Mr. Coathupe,0 which were carefully conducted make the amount of carbonic acid generated in the 24 hours about 17-856 cubic inches, that is, 2-616 grains or 5% ounces of solid car- bon. Liebig found the proportion of carbon expired by himself to » Memoir, de l'Academ. des Sciences, p. 609, Paris, 1790. b Edinb. Med. and Surg. Journal, Jan. 1831; Dublin Hospital Reports vol v a Select Medico-Chirurgical Transactions, p. 230, Philad. 1831. See also Mr thupe, Philos. Magaz. June, 1839. « Philos. Magazine, June' 1839 HJEMATOSIS. 47 be 8^ ounces daily ; by a soldier, 13^ ounces; by prisoners in close confinement, 7 ounces ; and by a boy who took considerable ex- ercise, 9 ounces.3 Recently, further experiments have been made on this subject by competent observers. Professor Scharling,b of Copenhagen, found, that, at the age 35, he exhaled 7-7 ounces avoirdupois of carbon in the twenty-four hours — seven of which were passed in sleep. A soldier, 28 years of age, exhaled 8-15 ounces ; a lad, of 16, 7-9 ounces-, a young woman, aged 19, 5-83 ounces; a boy, 9£ years old, 3-069 ounces; and a girl, 10 years old, 4-42 ounces. In the two last, the time spent in sleep was 9 hours. From all his experiments, Professor Scharling deduces, that males exhale more carbonic acid than females; and children comparatively more than adults. MM. Andral and Gavarret have been engaged in an interesting set of experiments on this subject. Their first object was to ascertain the modifying influence of age, sex, and constitution on the quantity of carbonic acid exhaled from the lungs. To determine this, their observations were made under circumstances as uniform as possible. Each experiment, too, was re- peated several times on the same subject. The apparatus employed was so devised as to enable the respirations to be freely perform- ed : no portion of the expired air was again inspired ; and the greatest care was taken to analyze the expired air with accuracy. The general results obtained by these observers were as follows : — 1. The quantity of carbonic acid exhaled by the lungs in a given time varies according to the age, sex, and constitution. 2. In both male 'and female, the quantity undergoes modification, according to the ages of the individuals experimented upon, quite inde- pendently of their weights. 3. In all periods of life, there is a difference between the male and female in the amount of carbonic acid exhaled from the lungs in a given time : cseteris paribus, man exhales a much larger quantity than woman. Between the ages of 16 and 40, the former exhales nearly twice as much as the latter. 4. In man, the quantity exhaled goes on regularly increas- ing from 8 to 30 years of age ; and a remarkable augmentation takes place at puberty. After 30, it begins to decrease ; and the decrease continues becoming more and more marked as the indi- vidual approaches nearer and nearer to extreme old age ; so that, at this last period, it returns to the standard at which it was about the age of 10. 5. In woman, the exhalation augments up to the period of puberty, according to the same law as in man : the in- crease then suddenly ceases, and the quantity continues at this low standard, with little variation so long as the catamenia regularly appear; but as soon as they cease, the exhalation of carbonic acid from the lungs undergoes a considerable augmentation, after which it decreases as in man, according as age advances. 6. During gestation, the amount of carbonic acid exhaled is raised tempora- * Graham's Elements of Chemistry, Amer. Edit. p. 686, Philad. 1843. b Annales des Sciences Naturelles, Fevrier, 1843 ; and Brit, and For. Med. Rev. for July, 1843, p. 285. • 48 RESPIRATION. rily to the standard which it attains after the cessation of the cata- menia. 7. In both sexes, and at all ages, the quantity ot carbonic acid exhaled by the lungs is greater in proportion to the strength of the constitution, and the development of the muscular system. The following table exhibits the quantity of solid carbon calcu- lated to be exhaled in one hour at different ages : the gramme is equal to about I5i grains. 8 years. 15 - 16 - 18-20 20-30 30-40 40-60 60-80 102 5 grammes. - 8-7 - 10-8 - 11-4 - 12-2 - 12-2 - 10-1 - 9-2 - 5-9 8 years. 12-38 38-50 50-60 60-80 82 5 grammes. - 6-4 - 8-4 - 7-3 - 6-8 - 6-0 The same standard con- tinues in women during the whole of the menstrual pe- riod : but if the catamenia be temporarily suppressed, or pregnancy occur, it rises to the standard it attains after their entire cessation, namely, 8-4 grammes. These numbers express the averages, the maximum amount being often considerably greater. In a young man of athletic sys- tem, and sound constitution, the quantity of carbonic acid exhaled in an hour was 14-1 grammes; a man of 60, equally vigorous for his age, exhaled 13-6 grammes ; and one of 63,12-4 grammes. An old man, of 92, who*preserved a remarkable degree of energy, and who had possessed unusual vigour in his youth, was found to ex- hale 8-S grammes per hour; whilst the same amount appeared to be the ordinary standard in a man of 45 ; who, unlike the last, had a feeble system, although he was in equally good health. How far these variations were connected with differences in the capa- city of the chest, and with the number of the respiratory movements, MM. Andral and Gavarret propose to investigate subsequently. It has been a question amongst physiologists, whether the quan- tity of carbonic acid gas given out its equal in bulk to the oxygen taken in. In Priestley's experiments,3 the latter had the prepon- derance. Menzies and Crawford found them to be equal. Lavoi- sier and Seguin supposed the oxygen, consumed in the twenty- four hours, to be 15661-66 grains ; whilst the oxygen, required for the formation of the carbonic acid given out, was no more than 12924 grains; and Sir Humphry Davy, in the same time, found the oxygen consumed to be 15337 grains, whilst the carbonic acid produced was 17811-36 grains; which would contain 12824-18 grains of oxygen. The experiments of Allen and Pepys seem, however, to show that the oxygen which disappears is replaced by an equal volume of carbonic acid ; and hence it was supoosed that the whole of it must have been employed in the formation of this acid. They, consequently, accord with Menzies and Crawford; and the view is embraced by Dalton, Prout, Ellis, Henry and other distinguished individuals.b On the other hand, the view of * Experiments, &c. on different kinds of Air, vol. iii. b Bostock's Physiology, 3d edit. p. 352, Lond. 1836. HiEUATOSIS. 49 those, who consider that the quantity of carbonic acid produced is less than that of the oxygen which has disappeared, is embraced by Thomson, and by Dulong and Despretz. In the carnivorous ani- mal, they found the difference as much as one-third; in the herbi- vorous, on the average, only one-tenth. The more recent experi- ments of Dr. Edwards have shown, that here, also, the discordance has not depended so much upon the different methods and skill of the operators, as upon a variation in the results arising from other causes ; and he concludes, that the proportion of oxygen consumed, to that employed in the production of carbonic acid, varies from more than one-third of the volume of carbonic acid to almost nothing; that the variation depends upon the particular animal species, subjected to experiment; upon its age, or upon some pecu- liarity of constitution, and that it differs considerably in the same individual at different times. It would appear, then, that the whole of the oxygen, which re- spiration abstracts from the air, is not accounted for, in all cases, by the quantity of carbonic acid formed ; and that, consequently, a portion of it disappears altogether. It has been supposed by some, that a part of the watery vapour, given off during expira- tion, is occasioned by the union of a portion of the oxygen of the air with hydrogen from the blood in the lungs; but this view is entirely conjectural. This subject, with the quantity of vapour combined with the expired air, will be the subject of inquiry under the head of Secretion. The air likewise loses, during inspiration, certain foreign mat- ters that may be diffused in it. In this way, medicines have been attempted to be conveyed into the system. If air, charged with odorous particles,— as with those of turpentine, — be breathed for a short time, their presence in the urine will be detected ; and it is probably in this manner, that miasmata produce their effects on the frame. All these substances pass immediately through the coats of the pulmonary veins by imbibition, and, in this way, speedily affect the system. These changes, produced in the air during respiration, are easily shown, by placing an animal under a bell-glass until it dies. On examining the air, it will be found to have lost a portion of its oxygen and azote and to contain carbonic acid and aqueous vapour. Let us now inquire whether the changes produced in the re- spired air be connected with those effected on the blood in the lungs. In its progress through the lungs, this fluid has been changed from venous into arterial. It has become of a florid red colour ; of a stronger odour ; of a higher temperature by nearly two degrees, according to some,3- but others have perceived no > Magendie, Precis de Physiologie, ii. 343; and Dr. J. Davy, in Philos. Transact. for 1814. VOL. II. — 5 50 RESPIRATION. difference, whilst others, again, have found it of lower tempera. ture ;a of less specific gravity, in the ratio'of 1053 to 1050 on the average, according to Dr. John Davy,b and it coagulates more speedily, according to most observers, but Thackrahc observed the contrary.** That this conversion is owing to the contact of air in the lungs we have many proofs. Lowere was one of the first, who clearly pointed out, that the change of colour occurs in the capillaries of the lungs. Prior to his time, the. most confused notions had prevailed on the subject, and the most visionary hypo- theses had been indulged. On opening the thorax of a livingani- mal, he observed the precise point of the circulation at which the change of colour takes place, and he showed, that it is not in the heart, since the blood continues to be purple, when it leaves the right ventricle. He then kept the lungs artificially distended,first with a regular supply of fresh air, and afterwards with the same portion of air without renewing it. In the former case, the blood experienced the usual change of colour. In the latter, it was returned to the left side of the heart unchanged. Experiments, more or less resembling those of Lower, have been performed by Good wyn,f Cigna, Bichat/ Wilson Philip, and numerous others, with similar results. The direct experiments of Priestleyh more clearly showed, that the change, effected on the blood, was to be ascribed to the air. He found, that the clot of venous blood, when confined in a small quantity of air, assumed a scarlet colour, and that the air expe- rienced the same change as from respiration. He afterwards exa- mined the effect produced on the blood by the gaseous elements of the atmosphere separately, as well as by the other gaseous fluids that had been discovered. The clot was reddened more rapidly by oxygen than by the air of the atmosphere, whilst it was reduced to a dark purple by nitrogen, hydrogen, and carbonic acid. Since Priestley's time, the effect of different gases on the colour of venous blood has been investigated by numerous individuals. The following is the result of their observations, as given by The- nard.1 It must be remarked, however, that all the experiments have been made on blood, when out of the body ; and it by no means follows, that precisely the same changes would be accom- plished if the fluid were circulating in the vessels. » Wagner's Elements of Physiology, by R. Willis, § 180, Lond. 1842. i> Physiological and Anatomical Researches, vol. ii. c Inquiry into the Nature and Properties of the Blood, p. 42, Lond. 1819 4 See, on this subject, J. Muller's Handbuch, u. s. w., Baly's translation p 323 • and Burdach's Physiologie als Erfahrungswissenschaft, Band. iv. s. 381 Leinz 1832 ' e Tractatus de Corde, &c. c. iii. Amstelod. 1761. ' P • f The Connexion of Life with Respiration, &c, Lond. 1788. g Recherches Physiol, sur la Vie et la Mort, Paris, 1800. i' Experiments, &c. on different kinds of Air, &c. Lond. 1781. > Traite de Chimie, &c. 5e edit. Paris, 1827. HJEMATOSIS. 51 Gas. Colour. Remarks. Atmospheric air - - -Gaseous oxide of carbon Deutoxide of azote - -Carburetted hydrogen -Carbonic acid - - - -Protoxide of azote - -Arsenuretted hydrogen -Sulphuretted hydrogen -Chlorohydric acid gas -Sulphurous acid gas Rose red. Do. Cherry Red. Slightly violet red. Do. Do. Brown red. Do.* Do. Do. TDeep violet, passing < gradually to a green-ish brown. Maroon brown. "N Black Brown. / f" B lackish B rown, > < passing by degrees V (_ to a yellowish white. J The blood employed had been b.eaten, and, consequently, deprived of its fibrin. These three gases coa-gulated the blood at the same time. It is sufficiently manifest, then, from the disappearance of a part of the oxygen from the inspired air, and from the effects of that gas on venous blood out of the body, that it forms an essential part in the function of sanguification. But we have seen, that the expired air contains an unusual proportion of carbonic acid . Hence carbon, either in its simple state or united with oxygen, must have been given off from the blood in the vessels of the lungs. To account for these changes on chemical principles has been a great object with chemical physiologists at all times. At an early period, the conversion of venous into arterial blood was supposed to be a kind of combustion; and, according to the notion of combustion then prevalent, it was presumed to consist in the disengagement of phlogiston; in other words, the abstraction or addition of a portion of phlogiston, made the blood, it was conceived, arterial or venous; and the removal of phlogiston was looked upon as the principal use of respiration. This view was modified by La- voisier, who proposed one of the chemical views to be now men- tioned. Two chief chemical theories have been framed to explain the mode in which the carbon is given off. The first is that of Black,h Priestley,0 Lavoisier,d and Crawford ;e —that the oxygen of the inspired air attracts carbon from the venous blood, and that the carbonic acid is generated by their union. The second, which has been supported by La Grange/ Hassenfratz,s Edwards,h Muller,1 * MUHer says he agitated blood with hydrogen, but could perceive no change of colour. Handbuch, u. s. w., Baly's translation, p. 322, Lond. 1838. b Lectures on the Elements of Chemistry, by Robison, ii. 87, Edinb. 1803. c Philosoph. Transact, for 1776, p. 147. d Mem. de l'Acad. des Sciences, pour 1777, p. 185. ' On Animal Heat, 2d edit. Lond. 1788. f Annales de Chimie, ix. 269. « Ibid. ix. 265. h De influence des Agens Physiques, &c. p. 411, Paris, 1823; and Hodgkin and Fisher's translation. ' Physiology, by Baly, p. 537. 52 RESPIRATION. Bischoff, Magnus, and others,—that the carbonic acid is gene- rated in the course of the circulation, and is given off from the venous blood in the lungs, whilst oxygen gas is absorbed. Ine former of these views is still maintained by many physiologists. It is conceived, that the oxygen, derived from the air, unites with certain parts of the venous blood, —the carbon and the hydro- gen, — owing to which union carbonic acid and water are found in the expired air; the venous blood, thus depurated of its carbon and hydrogen becomes arterialized ; and, in consequence of these various combinations, heat enough is disengaged to keep the body always at the due temperature. According to this theory, as we have seen in the views of Priestley, Lavoisier, &c, respiration is assimilated to combustion. The resemblance, indeed, between the two processes is striking. The presence of air is absolutely necessary for respiration; in every variety of respiration the air is robbed of a portion of its oxygen; and hence a fresh supply is continually needed; and respiration is always arrested before the whole of the oxygen of the air is exhausted, and this partly on account of the residuary azote, and the carbonic acid gas given off during expiration. Lastly, it can be continued much longer when an animal is confined in pure oxygen gas than in atmospheric air. All these circumstances likewise prevail in combustion. Every kind of combustion requires the presence of air. A part of the oxygen is consumed; and, unless the air is renewed, combustion is impossible. It is arrested, too, before the whole of the oxygen is consumed, owing to the residuary azote, and the carbonic acid formed ; and it can be longer maintained in pure oxygen than in atmospheric air. Moreover, when the air lias been respired, it becomes unfit for combustion, — and con- versely. Again, the oxygen of the air, in which combustion is taking place, combines with the carbon and hydrogen of the burn- ing body; hence the formation of carbonic acid and water; and as, in this combination, the oxygen passes from the state of a very rare gas, or one containing a considerable quantity of caloric between its molecules, to the condition of a much denser «as or even of a liquid, the whole of the caloric, which the oxyo-en con- tained in its former state, can no longer be held in the latter and it is accordingly disengaged; hence the heat, which is given off. In like manner, in respiration, the oxygen of the inspired air it is conceived, combines with the carbon and hydrogen of the venous blood, giving rise to the formation of carbonic acid and water • and, as in these combinations, the oxygen passes from the state of a very rare to that of a denser gas, or of a liquid, there is a con siderable disengagement of caloric, which becomes the source of the high temperature maintained by the human hody M Th narda admits a modification of this view, —sanguification 'beitf* owing, he conceives, to the combustion of the carbonaceous narK of the venous blood, and probably of its colouring matter bv th oxygen of the air. ' * me * Tuaite de Chimte, edit, eitat. HJEMATOSIS. 53 This chemical theory, which originated chiefly with Lavoisier, and La Place and Seguin, was adopted by many physiologists with but little modification. Mr. Ellis imagined, that the carbon is separated from the venous blood by a secretory process; and that, then, coming into direct contact with oxygen, it is converted into carbonic acid. The cir- cumstance that led him to this opinion was his disbelief in the possibility of oxygen being able to act upon the blood through the animal membrane or coat of the vessel in which it is confined. It is obvious, however, that to reach the blood circulating in the lungs, the oxygen must, in all cases, pass through the coats of the pul- monary vessels. These coats, indeed, offer little or no obstacle, and, consequently, there is no necessity for the vital or secretory action suggested by Mr. Ellis. Priestley and Hassenfratz exposed venous blood to atmospheric air and oxygen in a bladder. In all cases, the parts of the blood, in contact with the gases, became of a florid colour. The experiments of Faust, Mitchell,and others (vol.i., p. 44), are, in this aspect, pregnant with interest. They prove the great facility with which the tissues are penetrated by the gases, and confirm the facts developed by the experiments of Priestley, Hassenfratz and others. The second theory, — that the carbonic acid is generated in the course of the circulation, — was proposed by La Grange, inconse- quence of the objection he saw to the former hypothesis — that the lung ought to be consumed by the perpetual disengagement of caloric taking place within it; or, if not so, that its temperature ought, at least, to be superior to that of other parts. He accord- ingly suggested, that, in the lungs, the oxygen is simply absorbed, passes into the venous blood, circulates with it, and unites, in its course, with the carbon and hydrogen, so as to form carbonic acid and water, which circulate with the blood and are finally exhaled from the lungs. The ingenious and apparently accurate experiments of Dr. Ed- wards* prove convincingly, not only that oxygen is absorbed by the pulmonary vessels, but that carbonic acid is exhaled from them. When he confined a small animal in a large quantity of air, and continued the experiment sufficiently long, he found, that the rate of absorption was greater at the commencement than towards the termination of the experiment; whilst at the former period, there was an excess of oxygen present, and at the latter an excess of carbonic acid. This proved to him that the diminution was de- pendent upon the absorption of oxygen, not of carbonic acid. His experiments, in proof of the exhalation of carbonic acid, ready formed, by the lungs, are decisive. Spallanzani had asserted, that when certain of the lower animals are confined in gases, containing no oxygen, the production of carbonic acid is uninterrupted. Upon the strength of this assertion, Edwards confined frogs in pure hy- drogen, for a length of time. The result indicated, that carbonic 1 Op. citat. p. 437, and Messrs. Allen and Pepys, in Philos. Transactions for 1829, 5* 54 RESPIRATION. acid was produced, and, in such quantity as to show, that it could not have been derived from the residuary air in the lungs; as it was, in some cases, equal to the bulk of the animal. The same results, although to a less degree, were obtained with fishes and snails,—the animals on which Spallanzani's observations were made. The experiments of Edwards were extended to the mam- malia. Kittens, two or three days old, were immersed in hydro- gen : they remained in this situation for nearly twenty minutes, without dying, and on examining the air of the vessel after death, it was found, that they had given off a quantity of carbonic acid greater than could possibly have been contained in their lungs at the commencement of the experiment. The conclusion, deduced by Dr. Edwards, from his various experiments, is, " that the car- bonic acid expired is an exhalation proceeding wholly or in part from the carbonic acid contained in the mass of blood." Several experiments were subsequently made by M. Collard de Martigny,3 who substituted azote for hydrogen ; and, in all cases, carbonic acid gas was given out in considerable quantity. These and other experiments would seem, then, to show, that, in the lungs, carbonic acid is exhaled, and that oxygen and azote are absorbed. They would also seem to prove the existence of carbonic acid in venous blood, respecting which so much dissi- dence has existed amongst chemists. Allusion has already been made to the fact, that gelatin is not met with in the blood, and to the idea of Dr. Prout,b that its form- ation from albumen must be a reducing process. This process, he considers to be one great source of the carbonic acid, which exists ' in venous blood. Gelatin contains three or four per cent, less car- bon than albumen ; it enters into the structure of every part of the animal frame, and especially of the skin ; the skin, indeed, contains little else than gelatin. Dr. Prout considers it, therefore, most probable, that a large part of the carbonic acid of venous blood is formed in the skin, and analogous textures." " Indeed," he adds, " we know that the skin of many animals gives off carbonic acid| and absorbs oxygen ; — in other words, performs all the offices of the lungs; —a function of the skin perfectly intelligible, on the supposition, that near the surface of the body, the^lbuminous portions of the blood are always converted into gelatin." Gmelin Tiedemann, and Mitscherlich,c and Stromever/1 affirm however' on the strength of experiments, that the blood does not contain free carbonic acid gas, but that it holds a certain quantity in a state . of combination, which is set free in the lungs, and commin-les with the expired air. The views of Gmelin and Tiedemann, a=nd Mits- » Journal de Physiologic x 111. For an account of various experiments relative to the exha ation of carbonic acd, dunng respiration in gases which contain no oxygen' see Muller's Handbuch, u. s. w., Baly's translation, p. 338, Lond 1838 oxySen< b Bridgewatcr Treatise, Amer. Edit. p. 280, Philad. 1834. " Tiedemann und Trcviranus, Zeitschrilt fur Physiol. B v H ' i Schweigger's Journal fiir Chimie, u. s. w., lxiv. 105. H^MATOSIS. 55 cherlich on this subject are as follows. It may be laid down as a truth, that the greater part, if not all, of the properties of secreted fluids are not dependent upon any act of the secreting organs, but are derived from the blood, which again must either owe them to the food, or to changes effected on it within the body. These changes are probably accomplished in part, during the process of digestion, but are doubtless mainly effected on the lungs by the contact of the blood with the air. Now, most of the animal fluids, when exposed to the air, generate, by the absorption of oxygen, acetic or lactic acid, and this is aided by an elevated temperature like that of the lungs. In their theory of respiration, the azote of the inspired air is but sparingly absorbed ; by far the greater pro- portion remaining in the air-cells. The oxygen, on the other hand, penetrates the membranes freely, mingles with the blood, combines partly with the carbon and hydrogen of that fluid, and generates carbonic acid and water, which are thrown off with the expired air, whilst the remainder combines with the organic particles of the blood, forming new compounds, of which the acetic and lactic acids are some ; these unite with the carbonated alkaline salts of the blood, and set free the carbonic acid, so that it can be thrown off by the lungs. The acetate of soda, thus formed during the passage of the blood through the lungs, is deprived of its acetic acid by the several secretions, especially by those of the skin and kidneys, and the soda again combines with the carbonic acid, which, during the circulation of the blood through the body, is formed by the decomposition of its organic elements. Carbonate of soda is thus regenerated and conveyed to the lungs, to be again decomposed by the fresh formation of acids in those organs. Almost the same view is entertained by MM. Dumas and Bous- singault, and it is esteemed by Professor Graham3 to have a high degree of probability; and another view, in many respects simi- lar, is held by Professor Arnold.b As it is more than probable, he remarks, that the carbonic acid occurs in the venous blood, united with some substance from which it is separated, with greater or less, rapidity, by the contact of the atmospheric air; and as, further, the carbonate of the protoxide of iron greedily with- draws oxygen from the atmosphere, at the same time parting with its carbonic acid and becoming changed into a peroxide, it may reasonably be supposed, he thinks, that the carbonic acid of the venous blood is united with the iron of the red colouring mattes, and that it is set free during the act of respiration, by the reciprocal action of the blood and air. The protoxide, at the same time, by absorption of oxygen, becomes a peroxide, which, during the cir- culation of the blood through the capillaries, again parts with its oxygen. Carbon is at the same time eliminated from the blood, * Elements of Chemistry, Amer. Edit, by Dr. Bridges, p. 687, Philad. 1843. b Lchrhuch der Physiologie des Menschen, Zurich, 1836-7 ; and Brit, and For. Med. Rev. Oct. 1839, p. 481. See, on this subject, Dr. J. Davy, Researches, Physio- logical and Anatomical, in Dunglison's Amer. Med. Lib. Edit. p. 80, Philad. 1840, RESPIRATION. and unites with the liberated oxygen to form M'bo^d^h^ is thrown out by the lungs, whilst oxygen is again ^"hkl This is the view embraced by Liebig,* who has affirmed that the amount of iron present in the blood, if in the state of protoxide s sufficient to furnish the means of transporting twice as much car- bonic acid as can possibly be formed by the oxygen absorbed in the lungs. , . , , c u Chaussier and Adelon," again, regard the whole process of hsema- tosis as essentially organic and vital. They think, that an action of selection and elaboration is exerted both as regards the reception of the oxygen and the elimination of the carbonic acid. But their arguments on this point are unsatisfactory, and are negatived by the facility with which oxygen can be imbibed, and with which carbonic acid transudes through animal membranes. In their view, the whole process is effected in the lungs, as soon as the air comes in contact with the vessels containing the venous blood. The imbi- bition of oxygen they look upon as a case of ordinary absorption ; the transudation of carbonic acid as one of exhalation; both of which they conceive to be, in all cases, vital actions, and not to be likened to any physical or chemical operation. Admitting, then, that the oxygen and a portion of nitrogen abso- lutely enter the pulmonary vessels, of which we appear to have direct proof, are they, it has been asked, separated from the air in the air-cells, and then absorbed; or does the air enter undecom- posed into the vessels, and then furnish the proportion of each of its constituents necessary for the wants of the system, the excess being rejected ? Could it be shown that such a decomposition is actually effected at the point of contact between the pulmonary vessels and the air in the lungs, it would seem, at first, to prove the notion of Ellis,0 and of Chaussier and Adelon, that an action of selection, or of vitality is exerted ; but the knowledge we have attained of late, of the transmission of gases through animal mem- branes, would suggest another explanation. The rate of transmis- sion of carbonic acid is greater than that of oxygen ; and that of oxygen greater than that of azote (see vol. i., p. 46). We can hence understand, that more oxygen than azote may pass through the coats of the pulmonary bloodvessels, and can comprehend the facility with which the carbonic acid, formed in the course of the circulation, permeates the same vessels, and mixes with the air in the lungs. Sir Humphry Davy is of opinion, that the whole of the air is absorbed, and that the surplus quantity of each of the con- stituents is subsequently discharged. In favour of this view he remarks that air has the power of acting upon the blood through a stratum of serum, and he thinks that the undecomposed air must be absorbed before it can arrive at the blood in the vessels. It is * Animal Chemistry, Webster's Amer. Edit., p. 261, Cambridge 1843 b Physiologie de 1'Homme, edit. cit. iii. 254. c An Enquiry into the Changes induced on Atmospheric Air, &c. Edinb 1807 • and Further Enquiries, Edinb. 1816. , ' ' ' ' HJEMAT0S1S. 57 obvious, however, from the different penetrating powers of the gases — oxygen and azote — which compose it, that the propor- tion of those constituents cannot be the same in the interior as at the exterior of the pulmonary vessels. Muller,a however, accords with Davy, and supposes that the air, on entering the lungs, is decomposed in consequence of the affinity of the oxygen for the red particles of the blood ; carbonic acid being formed, which is exhaled in the gaseous form, along with the greater part of the azote. * It has been remarked, that when oxygen is applied to venous blood, the latter assumes a florid colour. On what part of the blood, then, does the oxygen act? The general belief is, upon the red globules. The facts, hereafter stated in the description of venous blood, have shown, that these globules appear to consist of a colourless nucleus, surrounded by a coloured envelope ; that both of these are devoid of colour, whilst the}'' exist as chyle and lymph ; but that, in the lungs, the contact of air changes the envelope to a florid red. Some, indeed, have believed, that both the envelope and its colour are added in the lungs. The coloration of the blood, consequently, seems to be effected in the lungs; but whether this change be of any importance in hsematosis is doubtful. Several tissues of the body are not supplied with red blood: in many ani- mals, the red colour does not exist; and, in all, it can perhaps only be esteemed an evidence, that the other important changes have been accomplished in the lungs. Recently, the opinion has been revived, that the oxygen of the air acts upon the iron, which Engelhart and Roseb have detected in the colouring matter, but how we know not. It is asserted, that if the iron be separated, the rest of the colouring matter, which is of a venous red colour, loses the property of becoming scarlet by the contact of oxygen. A different view of arterialization has been advanced by Dr. Stevens.0 According to him, the colouring matter of the blood is naturally very dark; is rendered still darker by acids, and acquires a florid hue from the addition of chloride of sodium, and from the neutral salts of the alkalies generally. The colour of arterial blood is ascribed by him to hematosin reddened by the salts contained in the serum ; the characters of venous blood to the presumed presence of carbonic acid, which, like other acids, darkens hema- tosin ; and the conversion of venous into arterial blood to the influence of the saline matter in the serum being restored by the separation of carbonic acid. If we take a firm clot of venous 1 Handbuch, u. s. w., Baly's translation, p. 334, Lond. 1838 ; see, also, Magnus, in Annales de Chimie et de Physique, Nov. 1837. b Edinb. Med. and Surg. Journal, for Jan. 1827. c Observations on the Healthy and Diseased Properties of the Blood, Lond. 1832 ; and Proceedings of the Royal Society, for 1834-5, p. 334. See, also, Dr. Robert E. Rogers, in Amer. Journ. of the Med. Sciences, p. 282, Aug. 1836; and Mr. Aneell, Lectures on the Physiology and Pathology of the Blood, Feb. 1, 1840, p. 686. 58 RESPIRATION. blood, cut off a thin slice, and soak it for an hour or two in re- peatedly renevVed portions of distilled water ; in proportion as the serum is washed away, the colour of the clot deepens, and, when scarcely any serum remains, the colour, by reflected light, is quite black. In this state, it may be exposed to the atmosphere, or a current of air may be blown upon it without any change of tint whatever; whence it would follow, that when a clot of venous blood, moistened with serum, is made florid by the air, the pre- sence of serum is essential to the phenomenon. The serum is believed, by Dr. Stevens, to. contribute to this change by means of its saline matter; for when a dark clot of blood, which oxygen fails to redden, is immersed in a pure solution of salt, it quickly acquires the crimson tint of arterial blood, and loses it agaiu when the salt is abstracted by soaking in distilled water. The facts, de- tailed by Stevens, are confirmed by Mr. Prater,a and by Dr, Tur- ner,15 of the London University. The latter gentleman, assisted by Professor Quain,of the same institution, performed the follow- ing satisfactory experiment. He collected some perfectly florid blood from the femoral artery of a dog ; and on the following day, when a firm coagulum had formed, several thin slices were cut from the clot with a sharp penknife, and the serum was removed from them by distilled water, which had just before been briskly boiled, and allowed to cool in a well-corked bottle. The water was gently poured on these slices, so that while the serum was dissolved, as little as possible of the colouring matter should be lost. After the water had been poured off, and renewed four or five times, occupying in all about an hour, the moist slices were placed in a saucer, at the side of the original clot, and both portions were shown to several medical friends, all of whom unhesitatingly pro- nounced the unwashed clot to have the perfect appearance of arterial blood, and the washed slices to be as perfectly venous. On restoring one of the slices to the serum, it shortly recovered its florid colour ; and another slice, placed in a solution of bicar- bonate of soda, instantly acquired a similar tint; — yet, as we have seen, the carbonate of soda is considered by Messrs Gmelin, Tiedemann, and Mitscherlich, to exist in venous or black blood ! In brightening, in this way, a dark clot by a solution of salt or a bicarbonate, Dr. Turner found the colour to be often still more florid than that of arterial blood; but the colours were exactly alike when the salt was duly diluted. Dr, Turner remarks that he is ?i ? l°v!S 1° d/aVny °?er infT??e fr°m this experiment, than that the florid colour of arterial blood is not due to oxveen but, as Dr. Stevens affirms, to the saline matter of the serum The arterial blood, which was used, had been duly oxygenized within the body of the animal, and should not in that state have lost its * Experim, Inquiries in Chemical Physioloev. Dart i on tb* pi,„i T > Elements of Chemistry, 5th edit. b/F. BaThe" p 609? P&S M™' '^ HJEMATOSIS. 59 tint by the mere removal of its serum; and he adds, the change from venous to arterial blood appears, contrary to the received doc- trine, to consist of two parts essentially distinct: one is a chemi- cal change, essential to life, accompanied by the absorption of oxygen, and the evolution of carbonic acid; the other depends on the saline matter of the blood, which gives a florid tint to the colouring matter after it has been modified by the action of oyx- gen. " Such," says Dr. Turner, " appears to be a fair inference from the facts above stated ; but being drawn from very limited observations, it is offered with diffidence, and requires to be con- firmed or modified by future researches." But we are perhaps scarcely justified in inferring from the experiments of Stevens, Turner, and others, more than the fact, that a florid tint is com- municated to blood by sea-salt, and by the neutral salts of the alka- lies in general, and indeed by admixture with sugars ; whilst acids render it still darker. The precise changes that occur during the arterialization of the blood in the lungs are still unknown ; and if we rely on the recent experiments of Gmelin, Tiedemann, and Mitscherlich, venous blood cannot owe its colour to free carbonic acid, because none is to be met with in it; whilst the presence of the carbonates of alkalies ought to communicate the florid hue to it. Since Dr. Stevens first published his opinions, the subject has been farther investigated by Dr. William Gregory, and by Mr. Irvine. They introduced portions of clot, freed by washing from serum, into vessels containing pure hydrogen, nitrogen, and car- bonic acid, placed over mercury. As soon as the strong saline solution came in contact with them, the colour of the clot, in all the true gases, changed from black to bright red, and the same change was found to take place in the Torricellian vacuum. On repeating these experiments with the serum of the blood, and a solution of salt in water of equal strength with the serum, no change took place until atmospheric air, or oxygen gas, was ad- mitted. It therefore appears — as properly inferred by the late Mr. Egerton A. Jennings, from whom we have an interesting " Report on the Chemistry of the Blood as Illustrative of Patho- logy ,"a — that though saline matter may be necessary to effect the change of colour from that of venous to that of arterial blood, still, with so dilute a saline solution, as that which exists in serum, the presence of oxygen is likewise necessary. Dr. Davyb dissents, however, from those conclusions, and is disposed to infer, from all the facts with which he is acquainted, that the colour of the blood, whether venous or arterial, that is, dark or florid, is independent of the saline matter in the serum, considered in relation to agency ; and that, according to the commonly received view, oxygen is the a Transactions of the Provincial Medical and Surgical Association, vol, iii., Wor- cester and London, 1835. b Researches, Physiological and Anatomical, Dunglison's Amer. Med. Lib. Edit. p. 96, Philad. 1840. 60 RESPIRATION. cause of the bright hue of the arterial fluid, and its consumption and conversion into carbonic acid, the cause of the dark hue of the venous —the saline matter being negative in regard to colour, and its chief use^ being, in his opinion, " to preserve the red glo- bules from injury, prevent the solution of their colouring matter, retain their forms unchanged, and to bear them in their course through the circulation." The slight diminution, if it exist, in the specific gravity of ar- terial blood is considered, but we know not on what grounds, to depend on the transpiratioq, which takes place into the air-cells, and which was formerly thought to be owing to the combustion of oxygen and hydrogen. This will engage us in another place, as well as the changes produced in its capacity for heat, on which several ingenious speculations have been founded, to account for animal temperature. The other changes are at present inex- plicable, and can only'be understood hereafter by minute chemical analysis, and by an accurate comparison of the two kinds of blood, — venous and arterial. It is manifest, from the preceding detail, that our knowledge re- garding the precise changes effected upon the air and the blood by respiration is by no means definite. We may, however, consider the following points established. In the first place : — the air loses a part of its oxygen, and of its azote ; but this loss varies accord- ing to numerous circumstances. 2dly. It is found to have ac- quired carbonic acid, the quantity of which is also variable. 3dly. The bulk of the air is diminished; but the extent of this likewise differs. 4thly. The blood when it attains the left, side of the heart, has a more florid colour. 5thly. This change appears to be caused by the contact of oxygen. 6thly. The blood in the lungs gets rid of a quantity of carbonic acid. 7thly. The oxygen taken in is more than necessary for the carbonic acid formed. Sthly. The constituents of the air pass directly through the coats of the pul- monary vessels, and certain portions of each are discharged or re- tained, according to circumstances. Lastly. A quantity of aqueous vapour, containing albumen, is discharged from the lungs.a c. Cutaneous Respiration, $c. A question, again has arisen, whether any absorption and exhalation of air, and conversion of blood from venous to arte- rial, take place in any other part of the body than the lunss The reasons, urged in favour of the affirmative of this question are • -that, in the lower classes of animals, the skin T manifesty the organ for the reception of air; that the mucous membrane of the lungs evidently absorbs air, and is simplv a Drolonffatinn of the skin, resembling it in texture; and lastly?that °K limited quantity of air has been placed in contact with the skin of a living animal, it has been absorbed, and found to have * Bostock's Physiology, 3d edit. p. 361 and 377, Lond. 1836 EFFECTS OF DIVIDING CEREBRAL NERVES. 61 experienced the same changes as are effected in the lungs. Mr. Cruikshanka and Mr. Abernethyb analyzed air, in which the hand or foot had been confined for a time, and detected in it a consider- able quantity of carbonic acid. Jurine, having placed his arm in a cylinder herrnetically closed, found, after it had remained there two hours, that oxygen had disappeared, and that 0-08 of carbonic acid had been formed. These results were confirmed by Gattoni.c On the other hand, Drs. Priestley,d Klapp,e and Gordon/ could never perceive the least change in the air under such circum- stances. Perhaps in these, as in all cases where the respectability of testimony is equal, the positive should be adopted rather than the negative. It is probable, however, that absorption is effected with difficulty; and that the cuticle, as we have elsewhere shown, is placed on the outer surface to obviate the bad effects which would be induced by heterogeneous gaseous, miasmatic, or other absorption. We have seen that some of the deleterious gases, as sulphuretted hydrogen, are most powerfully penetrant, and, if they could enter the surface of the body with readiness, unfortunate results might supervene. In those parts where the cuticle is ex- tremely delicate, as in the lips, some conversion of the venous blood into arterial may be effected, and this may be a great cause of their florid colour. According to this view, the arterialization of the blood occurs in the lungs chiefly, owing to their formation being so admirably adapted to the purpose, and it is not effected in other parts, because their arrangement is unfavourable for such results d. Effects of the Section of the Cerebral Nerves on Respiration. It remains for us to inquire into the effect produced on the lungs by the cerebral nerves distributed to them, — or rather, into what is the effect of depriving the respiratory organs of their ner- vous influence from the brain. The only cerebral or encephalic nerves, distributed to them, are the pneumogastric or eighth pair of Willis, which, we have seen, are sent, as their name imports,,to both the lungs and the stomach. The section of these nerves early sug- gested itself to physiologists, but it is only in recent times that the phenomena resulting from it have been clearly comprehended. The operation appears to have been performed as long ago as the time of Rufusof Ephesus, and was afterwards repeated by Chirac, * Experiments on the Insensible Perspiration, &c, Lond. 1795. See, also, Edwards, Sur l'Influence des Agens Physiques, p. 12 ; or Hodgkin and Fisher's translation. b Surgical and Physiological Essays, part ii. p. 115, Lond. 1793. c Diet, des Sciences Medicales, art. Peau. ' Experiments and Observations on different kinds of Air, ii. 193, and v. 100, Lond. 1774. e Inaugural Essay on Cuticular Absorption, p. 24, Philad. 1805. f Ellis's Inquiry into the Changes of Atmospheric Air, &c, p. 355, Edinb. 1837. See, also, Madden's Experimental Inquiry on Cutaneous Absorption, p. 130, Lond. 1838. s Muller's Handbuch, u. s. w., Baly's translation, p. 334, Lond. 1838. VOL. II.---6 62 RESPIRATION. Bohn, Duverney, Vieussens, Schrader, Valsalva, Morg agni, Haller, and numerous other distinguished physiologists." It is chiefly, however, in very recent times, and especially by the labours of Dupuytren, Dumas, De Blainville, Provencal, Legallois, Magen- die, Breschet, Hastings, Broughton, Brodie, Wilson Philip, and Dr. John Reid, that the precise effects upon the respiratory and digestive functions have been appreciated. When the nerves are divided in a living animal, on both sides at once, the animal dies more or less promptly ; at times, imme- diately after their division, but sometimes it lives for a few days; Magendie says never beyond three or four. The effects produced upon the voice, by their division above the origin of the recurrents, have been referred to under another head (vol. i., p. 421). Such division, however, does not simply implicate the larynx, but ne- cessarily affects the lungs, as well as the stomach. As regards the larynx, precisely the same results, according to Magendie,b are produced by dividing the trunk of the pneumogastric above the origin of the recurrents, as by the division of the recurrents them- selves : the muscles, whose function it is to dilate the glottis, are paralyzed; and, consequently, during inspiration, no dilatation takes place ; whilst the constrictors, which receive their nerves from the superior laryngeal, preserve all their action, and close the glottis, at times so completely, that the animal dies immediately from suffocation. But if the division of these nerves should not induce instant death in this manner, a series of symptoms follows, considerably alike in all cases, which go on until the death of the animal. These phenomena are the following: ■— respiration is, at first, difficult; the inspiratory movements are more extensive and rapid, and the animal's attention appears to be particularly directed to them; the locomotive movements are less frequent, and evi- dently fatigue ; frequently, the animal remains entirely at rest; the formation of arterial blood is not prevented at first, but soon, on the second day for instance, the difficulty of breathing augments, and the inspiratory efforts become gradually greater. The arterial blood has now no longer the vermilion hue which is proper to it. It is darker than it ought to be. Its temperature falls. Respira- tion requires the exertion of all the respiratory powers. At length, the arterial blood is almost like the venous, and the arteries con- tain but little of it; the body gradually becomes cold, and the animal dies. On opening the chest, the air-cells, the bronchi, and frequently even the trachea, are found filled by a frothy fluid, which is sometimes bloody ; the substance of the lung is tumid • the divisions and even the trunk of the pulmonary artery are greatly distended with dark, almost black, blood ; and extensive effusions of serum and even of blood are found in the parenchyma of the lungs. Experiments have, likewise, shown that, in propor- tion as these symptoms appeared, the animals consumed less and * Haller. Element. Physiologic. b pr£cis> &c 2de ^ .. ^ EFFECTS OF DIVIDING CEREBRAL NERVES. 63 less oxygen, and gave off a progressively diminishing amount of carbonic acid.a From the phenomena that occur after the section of these nerves on both sides, it would seem to follow, that the first effect is ex- erted upon the tissue of the lungs, which, being deprived of the nervous influence they receive from the brain, are no longer capa- ble of exerting their ordinary elasticity or muscularity, whichsoever it may be. Respiration, consequently, becomes difficult; the blood no longer circulates freely through the capillary vessels of the lungs ; the consequence of this is, that transudation of its serous portions, and occasionally effusion of blood, owing to rupture of small vessels, takes place, filling the air-cells more or less; until, ultimately, all communication is prevented between the inspired air and the bloodvessels of the lungs, and the conversion of the venous into arterial blood is completely precluded. Death is then the inevitable and immediate consequence. The division of the nerve on one side affects merely the lung of the corresponding side : life can be continued by the action of one lung only. It is, indeed, a matter of astonishment how long some individuals have lived when the lungs have been almost wholly obstructed. Every mor- bid anatomist has had repeated opportunities for observing, that, in cases of pulmonary consumption, for a length of time prior to dissolution, the process of respiration must have been wholly car- ried on by a very small portion of lung. From his experiments on this subject, Sir Astley Cooper infers, that the pneumogastric nerve is most important; — 1st, in assist- ing in the support of the function of the lungs, by contributing to the changing of the venous into arterial blood ; 2dly, in being ne- cessary to the act of swallowing; and 3dly, in being very essential to the digestive process; whilst Dr. John Reid is of opinion, that the pulmonary branches seem to be the nerves, chiefly concerned in transmitting to the medulla oblongata the impressions which excite respiratory movements, and are thus principally afferent nerves; but it is possible, he adds, that they contain motor fila- ments also.b The experiments of Dr. Wilson Philip0 and others moreover show, — what has been more than once inculcated, — the great similarity between the nervous and galvanic fluids. Wheu the state of dyspnoea was induced by the division of the pneumogas- tric nerves, the galvanic current was passed from one divided extremity to the other, and, in numerous cases, the dyspnoea entirely ceased. The results of these experiments induced him to try the effect of galvanism in cases of asthma. By transmitting 1 See Sir Astley Cooper, in Guy's Hospital Reports, part i. 468, Lond. 1836 ; also Dr. J. Reid, Edinb. Med. and Surg. Journ. p. 163, for Jan. 1838. b Edinb. Med. and Surg. Journ. April, 1839. c Experimental Inquiry into the Laws of the Vital Functions, &c. 2d edit. p. 223, Lond. 1818; also, Journal of Science and Arts, viii. 72 ; and art. Galvanism, in Ure's Diet, of Chemistry, 2d edit. Lond. 1823. 64 RESPIRATION. its influence from the nape of the neck to the pit of the stomach, he gave decided relief in every one of twenty-two cases, four of which occurred in private practice, and eighteen in the Worcester Infirmary. Sir A. Coopera instituted similar experiments on the phrenic nerves. As soon as these were tied, the most determined asthma was produced; breathing went on by means of the intercostal muscles; the chest was elevated to the utmost by them ; and in expiration the chest was as remarkably drawn in. The animals did not live an hour ; but they did not die suddenly, as they do from pressure on the carotid and vertebral arteries. The lungs appeared healthy, but the chest contained more than its natural exhalation. He also tied the great sympathetic; but little effect was produced : the animal's heart appeared to beat more quickly and feebly than usual. The animal was kept seven days, and one nerve was ulcerated through, and the other nearly so at the situa- tion of the ligatures. No particular alteration of any organ was observed, on examination. Lastly, Sir Astley tied all three nerves on each side, the pneumogastric,phrenic, and grand sympathetic: the animal lived little more than a quarter of an hour, and died of dyspnoea. From these experiments, he infers, that the sudden death, which he found in his experiments to take place from pressure on the sides of the neck, cannot be attributed to any injury of the nerves, but to an impediment to the due supply of blood to the great centre of nervous influence. The centre of the respiratory movements is now considered to be the upper part of the medulla oblongata. Into it the pneumo- gastric nerves, which appear to be the chief excitors of respiration, may be traced, and from it the different motor or efferent nerves, which Sir Charles Bell has grouped together in his respiratory system, proceed either directly or indirectly. Of these, the most important is the phrenic.b e. Respiration of Animals. In concluding the subject of respiration, we may briefly advert to the different modes in which the process is effected in the classes of animals, and especially in birds, the respiratory organs of which constitute one of the most singular structures of the ani- mal economy. The lungs themselves, — as in the marginal figure of the lungs, &c of the ostrich, (Fig. 152,)-are comparatively small, and are adherent to the chest,—where they seem to be placed in the intervals of the ribs. They are covered by the pleura only on their under surface, so that they are, in fact on the outside of the cavity of the chest. A great part of the thorax, as well as oi the abdomen, is occupied by membranous air-cells into which the lungs open by considerable apertures. Besides these a Op. cit. p. 475. * Dr. Carpenter, Human Physiology, p. 138 Lon(] lg42 OF ANIMALS. 65 Fig. 152. cells, a considerable portion of the skeleton forms receptacles for air, in many birds ; and if we break a long bone of a bird of flight, and blow into it, the body of the bird being im- mersed in water, bubbles of air will escape from the bill. The object, of course, of all this, is to render the body light, and thus to facilitate its motions. Hence the largest and most numerous bony cells are found in such birds as have the high- est and most rapid flight, as the eagle. The barrels of the quills are likewise hollow, and can be filled with air, or emp- tied at pleasure. In addition to the uses just mentioned, these receptacles of air dimi- nish the necessity of breathing so frequently, in the rapid and long-continued motions of se- veral birds, and in the great vocal exertions of singing birds. In fishes, in the place of lungs we find branchiae or gills, which are placed behind the head on each side, and have a moveable gill-cover. By the throat, which is connected with these organs the water is conveyed to the gills, and distributed through them : by this means, the air, contained in the water, which, ac- cording to Biot, Von Humboldt,3 and Provencal, Configliachi, and Thomson,11 is richer in oxygen than that of the atmosphere, having from 29 to 32 parts in the 100, instead of 20 or 21, comes in con- tact with the blood circulating through the gills. The water is afterwards discharged through the branchial openings, — aper- turas branchiales, — and consequently, they do not expire along the same channel as they inspire. Lastly, in the insect tribe, — in the white-blooded animal, — we find the function of respiration effected altogether by the sur- face of the body ; at least, so far as regards the reception of air, which passes into the body through apertures termed stigmata, 1 Memoir, de la Societe d'Arcueil, i. 252, and ii. 400 ; Annals of Philosophy, v. 40; and Richerand's Elemens de Physiologie, 18eme e"dit. par M. Berard, aine, p. 141, Bruxelles, 1837. b Dr. Thomson found that 100 cubic inches of the water of the river Clyde con- tained 3-113 inches of air; and that the air contained 29 per cent, of oxygen. Edinb, New Philosoph. Journal, xxi. 370, Edinb. 1836. 6* Thoraeic and Abdominal Viscera of the Ostrich. a. Heart, lodged in one great air-cell. b. The stomach, c. The intestines, surrounded by large air-cells, rf. The trachea dividing into bronchi. e, e. The lungs. 1, 2, 3./,/. Other great air-cells, communicating with other cells and with the lungs, g, g. The openings by which such com- munication is made. gg CIRCULATION. the external termination of tracheae or air-tubes, whose office it is to convey the air to different parts of the system. In all these cases, we find precisely the same changes erlected upon the inspired air, and especially, that oxygen and azote have disappeared, and that carbonic acid is contained in nearly equal bulk with the azote in the residuary air.a CHAPTER IV. CIRCULATION. The next function to be considered is that by which the products of the various absorptions, converted into arterial blood in the lungs, are distributed to every part of the body, — a function of the most important character to the physiologist, and the pathologist, and without a knowledge of which it is impossible for the latter to comprehend the doctrine of disease. Assuming the heart to be the great central organ of the function, the circulatory fluid must set out from it, be distributed.through the lungs, undergo aeration there, be sent to the opposite side of the heart, whence it is distributed to every part of the system by efferent vessels, and be thence returned by the veins or afferent vessels to the right side, from which it set out, — thus performing a complete circuit. The lower classes of animals differ essentially, as we shall find hereafter, in their organs of circulation : whilst in some, the appa- ratus appears to be confounded with the digestive ; in others, the blood is propelled without any great central organ; and in others, again, the heart is but a single organ. In man, and in the upper classes of animals, the heart is double ; — consisting of two sides, or really of two hearts, separated from each other by a septum. 153. In the dugong, the two ventricles are almost entirely detached from each other.b As all the blood of the body has to be emptied into this central organ, and to be subsequently sent from it, and as its flow is continuous, two cavities are required in each heart,— the one to receive the blood, the other to propel it. This last con- tracts and dilates alternately. The cavity or chamber of each heart, which receives the blood, is called Heart of the Dugong. ■ auricle, and the vessels that trans- d. Right auricle, e Right ventricle, port it thither are the w»)t . tViP L. Left auricle. L. Left ventricle. F. ;, l„ TO> • , t, , V^US; me Pulmonary artery. A. Aorta. Cavity by which the blood is prO- * Roget's Animal and Vegetable Physiology, ii. 221, Amer. Edit.; and T' 1 Traite Complet de Physiologie de l'Homme, par Jourdan, p. 302 plr;„ 1B!e,Uemann« " Roget,op. cit.,ii. 200, Philad. 1836. ' s' iM1- CIRCULATORY APPARATUS. 67 jected forwards is called ventricle, and the vessels, along which the blood is sent, are the arteries. One of these hearts is entirely ap- propriated to circulation of venous blood, and hence has been called the venous heart, — also the right or anterior heart, frorn its situation, — and [hepulmonary from the pulmonary artery arising from it. The other is for the circulation of arterial blood, and is hence called the arterial heart, also the left or posterior, from its situation, and the aortic heart, because the aorta arises from it. In Fig. 154, the two hearts are separated from each other, and shown to be distinct organs in the adult, although in the subject they seem to form but one. Between the two, after birth, there is not the slightest com- munication ; and con- sequently, all the blood, with the exception of that sent out by the co- ronary artery, and re- turned by the coro- nary vein, which has to attain the left side of the heart, must make the circuit through the lungs. The whole of the vessels communicating with the right heart, contain venous blood; those of the left side, arterial blood. If we consider the heart to be the centre, two circulations are ac- complished before the blood, setting out from one side of the heart, performs the whole cir- cuit. One of these consists in the transmission of the blood from the right side of the heart, through the lungs, to the left; the other in its transmission from the left side, along the arteries, and, by means of the veins, back to the right side. The former of these is called the lesser ox pulmonic, the latter the greater or systemic circulation. The organs, by which these are effected, will require a more detailed examination. 1. ANATOMY OF THE CIRCULATORY ORGANS. The circulatory apparatus is composed of the organs, by which the blood is put in motion, and along which it passes during its circuit. a. Heart. To simplify the consideration of the subject, we shall consider Fig. 154. The Right and Left Hearts, separated. a, a. Venee cavee ascendens, and descendens. b. Right auri - cle. c, c. Right ventricle, d. Pulmonary artery, e. Pulmo- nary veins. /. Left auricle, g. Left ventricle. A, A. Aorta. The arrows indicate the course of the blood. 68 CIKCULATION. the heart double; and that each ^^tem of circulation is compoaed of a Heartj of arteri*. ^"gh wh ch , e b,ood se.^from the The pulmonic, right,ox anterior heart, caneu a- »--»^yj black blood, is composed of an auricle and a ventricle Thea uncle. =ind" of veins, by which the blood is returned th minute termination of each of these is the capillary su^em We Thall first describe the central organ, as forming two distulct hearts; and afterwards the two united. anterior heart, called also the Aear/ of The auricle, d termed from some resemblance to an ear, is situate at the base of the organ, and receives the whole of the blood returning from various parts of the body by three veins; "3~?/% ls¥v^<^ the two vense cavae, and the coro- nary. The vena cava descendens terminates in the auricle in the di- rection of the aperture by which the auricle communicates with the ven- tricle. The vena cava ascendens, the termination of which is directed more backwards, has the remains of a valve which is much larger in the foetus, called the valve of Eusta- chius. The third vein is the cardiac or coronary; it returns the blood from the heart which has been car- ried thither by the coronary artery. In the septum between the right and left auricle, there is a superficial depression, about the size of the point of the finger, which is the vestige of the foramen ovale,— an important part of the circulatory apparatus of the foetus. The opening, through which the auricle projects its blood into the ven- tricle, is situate downwards and Pulmonic Heart. A. Right auricle with its venae cavae. Right ventricle. C Pulmonary artery. Fig. 156. Section of the Pulmonic Heart. A. Right auricle. B. Right ventricle. C. Pul- monary artery. forwards, as seen in Fig. 156. The inner surface of the proper auricle, or that which more par- ticularly resembles the ear of a quadruped, — the remainder be- ing sometimes called the sinus venosus or sinus venarum cava- rum, — is distinguished by hav- ing a number of fleshy pillars in it. which, from their supposed re- semblance to the teeth of a comb, are called musculi pectinatl They are mere varieties, how- ever, of the columnse earnest of the ventricles. The right ventricle ox pulmo- nary ventricle is situate in the an- CIRCULATORY APPARATUS. 69 terior part of the heart; the base and apex corresponding to those of the heart. Its cavity is generally greater than that of the left side, and its parietes not so thick, owing to their merely having to force the blood through the lungs. It communicates with the auricle by the auriculo-ventricular opening — the ostium venosum; and the only other opening into it is that which communicates with the interior of the pulmonary artery. The opening, between the auri- cle and ventricle, is furnished with a tripartite valve, called tri- cuspid ox triglochin ; and the pulmonary artery has three others, called sigmoid or semilunar. From the whole edge of the tricus- pid valve, next the apex of the heart, small, round, tendinous cords, called chordae tendineae, are sent off, which are fixed, as represented in Fig. 156,to the extremities of a few strong columnae carnex.' These tendinous cords are of such a length as to allow the valve to be laid against the sides of the ventricle, in the dilated state of that organ, and to admit of its being pushed back by the blood, until a nearly complete septum is formed, during the con- traction of the ventricle. The semilunar or sigmoid valves are three in number, situate around the artery. When these fall toge- ther, there must necessarily be a space left between them. To obviate the inconvenience, that would result from the existence of such a free space, a small granular body is attached to the middle of the margin of each valve ; and, these coming together, as at A, Fig. 157, when the valves are shut down, complete the diaphragm, and Fis- 157- prevent any blood from passing back to the heart. These small bodies are termed, from their reputed discoverer, corpuscula Arantii, and also corpus- cula Morg a gnii ; or, from their resem- blance to the seed of the sesamum, corpuscula sesamoidea. The valves, when shut, are concave towards the lungs, and convex towards the ventri- cle. Immediately above them the semilunar valves closed. artery bulges out, forming three sacculi or sinuses, called sinuses of Valsalva. These are often said to be partly formed by the pressure of the blood upon the sides of the vessels. The structure is doubtless ordained, and is admirably adapted for a specific purpose, namely, to allow the free edges of the valves to be readily caught by the refluent blood, and thus to facilitate their closure. Within the right ventricle, and especi- ally towards the apex of the heart, many strong eminences are seen, which are called columnae carnex (Fig. 156). These run in different directions, but the strongest of them longitudinally with respect to the ventricle. They are of various sizes, and form a beautifully reticulated texture. Their chief use probably is, to strengthen the ventricle and prevent it from being over-distended ; in addition to which they may tend to mix the different products of absorption. 70 CIRCULATION. The corporeal, left, aortic ox systemicheart,— called also the heart of red blood,-has likewise an auricle and a ventr e ine left auricle is considerably thicker and stronger but smaller than the right; and is likewise divided into sinusvenosus an ^properauri- cle, which form a common cavity. The columns in the latte • aie like those of the right auricle, but less distinct. From the under part of the auricle, a circular passage, termed ostium arteriosum or auricular orifice leads to the posterior part of the base ot tne cavity of the left ventricle. The left auricle receives the blood from the pulmonary veins. The left or aortic ventricle: is situate at the posterior and left part of the heart. Its sides are three times thicker and stronger than those of the right ventricle, to permit the much greater force which it has to exert; for, whilst the right ventricle merely sends its blood to the lungs, the left ventricle transmits it to every part of the body. It is narrower and rounder, but considerably longer, than the right ventricle, and forms the apex of the heart. The internal surface of this ventricle has the same general appearance as the other, but differs from it in having its columns carnese larger, more numerous, firmer, and stronger. In the aperture of communication with the corresponding auricle, there is here, as in the opposite side of the heart, a ring or zone, from which a valve, essentially like the tricuspid, goes off. It is stronger, however, and divided into two principal portions only.: the chorda? tendineoe are also stronger and more numerous. This valve has been termed mitral, from some supposed resemblance to a bishop's mitre. At the fore and right side of the mitral valve, and behind the commencement of the pulmonary artery, a round opening exists, which is the mouth of the aorta. Here are three semilunar valves, with their corpuscula Arantii, exactly like those of the pulmonary artery, but a little stronger ; and, on the outer side of the semilunar valves, are the sinuses of Valsalva, a little more prominent than those of the pulmonary artery. The structure of the two hearts is the same. A serous mem- brane covers both, which is an extension of the inner membrane of the pericardium. The substance of the heart is essentially muscular. The fibres run in different directions, longitudinally and transversely, but most of them obliquely. Many pass over the point, from one heart to the other, and all are so involved as to render it difficult to unravel them. The cavities are lined by a thin membrane, the endocardium, which differs somewhat in the two hearts; — being in one a prolongation of the inner coat of the aorta, and in the other of the venae cavae. On this account, the inner coat of the left heart is but slightly extensible, more easily ruptured, and con- siderably disposed to ossify ; that of the right heart, on the other hand, is very extensible, not readily ruptured, and but little liable to ossify. M. Deschampsa has described a membrane which is situate between the endocardium and the cellular tissue that lines a Gazette Medicale de Paris, No. 10, and Encyclographie des Sciences Medicates, Avril, 1840, p. 281. CIRCULATORY APPARATUS. 71 the musculat structure at its inner surface, and belongs essentially to the elastic fibrous tissue. The tissue of the heart is supplied with blood by the cardiac or coronary arteries—the first division of the aorta; and their blood is conveyed back to the right auricle by the coronary veins. The nerves, which follow the ramifica- tions of the coronary arteries, proceed chiefly from a plexus, formed by the pneumogastric nerves, and great sympathetic. In both hearts, the auricles are much thinner and more capa- cious than the ventricles ; but they are themselves much alike in structure and size. The observation, that the right ventricle is larger than the left, is as old as Hippocrates, and has been attempted to be accounted for in various ways. Some have ascribed it to original conformation ; others to the blood being cooled in its passage through the lung, and therefore occupying a smaller space when it reaches the left side of the heart. Haller3 and Meckelb assert that it is dependent upon the kind of death ;c that if the right ventricle be usually more capacious, it is owing to the lung being one of the organs that yields first, thus occasioning accumulation of blood in the right cavities of the heart; and they state that they succeeded, in their experiments, in rendering either one or the other of the ventricles more capacious, according as the cause of death arrested first the circulation in the lung or in the aorta ; but the experiments of Legallois,d and Seiler,e especially of the former, — with mercury poured into the cavities, on dogs, cats, Guinea- pigs, rabbits, in the adult, the child, and the still-born foetus, have shown, that, except in the foetus, the right ventricle is more capa- cious, whether death have been produced by suffocation, in which i the blood is accumulated in the right side of the heart, or by he- morrhage ;* and Legalloisf thinks that the difference is owing to the left ventricle being more muscular, and, therefore, returning more upon itself.s The capacity of each of the ventricles in the full sized heart, may be estimated at about two fluid ounces. The two hearts, united together by a median septum, form, then, one organ, which is situate in the middle of the chest, (see Fig. 147,) between the lungs, and consequently in the most fixed part of the thorax. Figure 158 is modified from one carefully ! made from nature by Dr. Pennock.h It represents the normal po- sition of the heart and great vessels. According to Carus,1 the weight of the heart compared with that of the body is as 1 to 160. M. J. WeberJ found the proportion, in one case, as 1 to 150 ; Dr. Clendinningk that of the male 1 to 160 ; a Element. Physiol., iv. 3. 3. b Handbuch der Menschlichen Anatomie, Halle, 1817, s. 46 ; or the translation from the French version, by Dr. Doane, Philad. 1832. c Clendinning, Report to the British Association, Lond. Med. Gaz. Nov. 13, 1840. d Diet, des Sciences Medicales, v. 440. e Art. Herz, in Anat. Physiol. Real Wbrterb. iv. 32, Leipz. 1821. ' 03uvrcs, Paris, 1824. g Burdach, Physiologie, u. s. w., iv. 214. "> Medical Examiner, April 4, 1840. ' Introduction to Comp. Anat. translated by R. T. Gore, Lond. 1827. j Hildebrandt's Handbuch der Anatomie, von E. H. Weber, Braunschweig, 1831. Band. iii. s. 125. k Journal of the Statistical Society of London, July, 1838. View of the Heart in situ. S. Outline of Sternum. C C. Clavicles. I, 2, 3, 4, 5,6, &c. The ribs. ]', 2\ 3', 4', 5', 6', *e. Cartilages of the ribs. 4". Eight and left nipples, a. Right ventricle. J. Left ventricle, c. Sep' turn between the ventricles, d. Right auricle, e. Left auricle. /. The aorta, f. Needle passing through aortic valves, g. Pulmonary artery, g'. Needle passing through valves of pulmonary artery, h. Vena cava descendens. i. Line of direction of mitral valve ; the dotted portion poste- rior to the right ventricle, t'. Needle passed into the mitral valve at its extreme left. ft. Line of tricuspid valve, o. Trachea. Dr. Clendinning carefully examined nearly four hundred hearts of persons of both sexes, and of all ages above puberty. The result was about nine ounces avoirdupois, much less than that obtained recently by Dr. John Reid,c who found the average weight of the male heart — of 89 weighed — to be 11 oz. and 1 dr. ; and of the female heart — of 53 weighed — to be 9 oz. and \ dr. * Traite Clinique des Maladies du Cceur, &c. Paris, 1835. b See, also, Dr. Gross, Elements of Pathological Anatomy, ii. 124, Boston 1839. c Lond. and Edinb. Monthly Journ. of Med. Science, April, 1843, p. 322. ' CIRCULATORY APPARATUS. 73 The dimensions of the heart, according to Lobstein and Bouil- laud. are as follows:—Weight of heart, 9 to lOounces; length from base to apex, 5 inches 6 lines; breadth at the base, 3 inches; thick- ness of walls of left ventricle, 7 lines ; do. at a finger's breadth above the apex, 4 lines ; thickness of walls of right ventricle, 2\ lines ; do. at apex, h a line ; thickness of right auricle, 1 line ; do. of left auricle, \ a line. M. Bizota has given the following measure- ments, taking the average of males from 16 to 89 years. Base. Middle. Apex. Left ventricle, 4£ lines b\ 3f Right ventricle, Iff If Vo In the female, the average thickness is something less. Recently, Dr. Rankingb has published the results of measure- ments, evidently made with accuracy, of upwards of 100 hearts,— care being taken to exclude all those that exhibited any trace of organic change. The following are the mean admeasurements. Of 15 male hearts, the mean circumference was 9||ths inches; of 17 female hearts, 8i|ths inches. The mean length of the male heart was 4i|ths inches ; of the female, 4-Jfths. The mean thick- ness of the left ventricle in the male was ffths of an inch; in the female, ffths ; of the right ventricle, in the male, /Fths ; in the female, ^g-t^s. The septum ventriculorum has, in the male, a mean thickness of ffths of an inch; in the female, ^f ths. The aortic orifice, in the male, had a mean circumference of 2^|ths inches; the right auriculo-ventricular orifice, 4|f ths inches ; the left auriculo-ventricular orifice, 3||ths inches. The corresponding parts of the female were relatively less. Dr. Ranking infers, that the heart of the male is larger than that of the female, — that the length of the healthy heart to its circumference is rather less than 1 to 2 —that the thickness of the parietes of the right ventricle to the left is as 1 to 3 nearly: — that the pulmonary artery is slightly wider than the aorta; and, lastly, that the right auriculo-ventri- cular opening is considerably larger than the left. It need scarcely be said, that the weight and dimensions of the organ must vary according to the age, sex, &c. of the indi- vidual. M. Bizotc found, that the influence of stature on its size was slight; and not such as might have been expected & priori; as in individuals of the male sex above sixty inches, and in females above fifty-five inches in height, the mean dimensions of the organ, especially its breadth, were less than in persons of lower stature. He found the width of the shoulders to furnish a better propor- tionate standard of its measures, — the distance between the acro- » For an account of the results of M. Bizot's researches, to ascertain the dimensions of the heart and arteries, see Memoires de la Societe Medicale d'Observation, Paris, 1837; and Hope on the Diseases of the Heart, Amer. Edit., by Dr. Pennock, p. 234, Philad. 1842. •> London Medical Gazette, No. xxiv. 1842. e Memoires de la Societe Medicale d'Observation de Paris, torn, lere, Paris, 1836. VOL. II. — 7 74 CIRCULATION. mial point of the clavicles, and the length and breadth of the heart increasing in tolerably regular ratio. The heart is surrounded by its proper capsule, called the peri- cardium— a fibro-serous membrane, which is composed of two layers. The outermost of these is fibrous, semitransparent, and inelastic; strongly resembling the dura mater in its texture. Its thickness is greater at the sides than below, where it rests upon the diaphragm ; or than above, where it passes along the great vessels which communicate with the heart. The inner layer is of a serous character, and lines the outer, giving the polish to its car- diac surface; it is then reflected over the heart, and adheres to it by cellular substance. Like other serous membranes, it secretes a fluid, which is termed liquor pericardii, to lubricate the surface of the heart. This fluid is always found in greater or less quan- tity after death; and a question has arisen regarding the amount that must be considered morbid. This must obviously vary ac- cording to circumstances. It seldom, however, in the healthy condition, is above a tea-spoonful. When its quantity is aug- mented, along with inflammation of the membrane, the disease hydropericarditis exists. The great use of the pericardium is probably to keep the heart constantly moist by the exhalation effected from it; and, also, to restrain the movements of the heart, which, under the influence of the emotions, sometimes leaps inor- dinately. If the pericardium be divided in a living animal, the heart is found to bound, as it were, from its ordinary position ; and hence the expression — " leaping of the heart," during emotion — is physiologically accurate. b. Arteries. The arteries are solid, elastic tubes, which arise, by a single trunk, from the ventricle of each heart, and gradually divide and subdivide, until they are lost in the capillary system. The large artery, which arises from the left ventricle, and conducts the blood to every part of the body, — even to the lungs, so far as regards their nutrition, — is, as we have seen, the aorta ; and that, which arises from the right ventricle and conveys the venous blood to the lungs, for aeration, is the pulmonary artery. Neither the one nor the other is a continuation of the proper tissue of the ventri- cles ; the inner membrane is alone continuous, the muscular struc- ture of the heart being united to the fibrous coat of the arteries, by means of an intermediate fibrous tissue. The aorta, as soon as it quits the left ventricle, passes beneath the pulmonary artery, is entirely concealed by it, and ascends to form a curvature with the convexity upwards, the summit of which rises to within three- quarters of an inch or an inch of the superior edge of the sternum. This great curvature is called the cross or arch of the aorta. The vessel then passes downwards, from the top of the thorax to nearly as far as the sacrum, where it divides into two trunk's, one of which proceeds to each lower extremity. In the whole of this CIRCULATORY APPARATUS. 75 course, it lies close to the spine, and gives off the various branches that convey arterial blood to the different parts of the body. Of the immense multitude of these ramifications, an idea may be formed, when we reflect, that the finest pointed needle cannot be run into any part of the surface of the body, without blood, — probably both arterial and venous, — flowing. The larger arte- ries are situate deeply, and are thus remote from external in- jury. They communicate freely with each other, and their anas- tomoses are more frequent as the arteries become smaller and far- ther from the heart. At their final terminations, they communi- cate with the veins and the lymphatics. It has been a common, but erroneous belief, that the branches of the aorta, when taken collectively, are of much greater capa- city than the parent trunk, and that this inequality goes on aug- menting ; so that the ultimate divisions of an artery are of much greater capacity than the trunk of the vessel. Hence, the arterial system has been considered to represent, in the aggregate, a cone, whose apex is at the heart, and the base in the organs; but as all the minute arterial ramifications are not visible, it is obviously impracticable to discover the ratio between their united capacity and that of the aorta at its origin; yet the problem has been attempted. Keil, by experiments made upon an injected subject, considered it to be as 44507 to 1. J. C. A. Helvetius and Sylva as 500 to 1. Senac estimated, not their capacities but their diame- ters, and he conceived the ratio of these to be as 118,490 to 90,000 ; and George Martine affirmed, that the calibre of a parent arterial trunk is equal to the cube root of the united diameters of the branches.3 It will be shown, however, hereafter, from the observations of M. Poiseuille and of Mr. Ferneley, that the notion of the much greater capacity of the branches than of the parent trunk is a fallacy. This subject will be referred to hereafter. The pulmonary artery strongly resembles the aorta. Its dis- tribution has been already described as a part of the respiratory organs (page 16). The arteries are composed of different coats in superposition, respecting the number of which anatomists have not been entirely of accord. Some have admitted six,b others five, others four, but at the present day, three only are perhaps generally received ; —first, an external or cellular, called also nervous, and cartilaginous by Vesalius, and tendinous by Heister, which is formed of condensed cellular substance, and has considerable strength and elasticity, so that if a ligature be applied tightly round the vessel, the middle and internal coats may be completely cut through, whilst the outer coat may remain entire. Scarpa is not disposed to admit this as one of the coats. He considers that it is only an exterior * Haller, Elementa Physiologise, torn. iv. b See, on the Histology of the Arteries, Henle, and Mr. Paget, Brit, and For. Med. Rev. July, 1842, p. 284; and Mandl, Manuel d'Anatomie gengrale, p. 187, Paris, 1843. 7g CIRCULATION. , i • '4* Thp next coat is the envelope, to retain the vessel ^^.f^aracter of which has been middle, muscular ox proper coat he character 01 the subject of much discussion. It is composed ot ye , lar fibres, which do not appear individually to PasSp^ 'eHeved the vessel. This coat was, at one time, almost umve«f »5^believe to be muscular. Such was the opinion of Hunter and r,enc the muscularity of the arteries was regarded as an age it in be circulation. Careful examination does not, however exhb^ he characters of ordinary muscular tissue. 1 he la tier is so t,ext ei si ble contractile and of a red colour : the arterial tunic is farm, not a little the muscular coat of the intestines. Henle* advances the opinion, that its structure is intermediate between cellular and muscular tissue; its microscopic elements being broad and very flat, slightly granulated fibres or bands, which he in rings around the internal membrane, and are about 0-003 lines m dia- meter These with a system or network of dark streaks con- stitute the middle coat of the artery. Nysten,c Magendie,d and Miillere applied the galvanic stimulus to it, but without effect; and it is known, that this is the most sensible test of irritability. The middle coat appears to be a tissue of a peculiar character, the base of which is formed by.the tissujaune, or yellow tissue of the later comparative anatomists; itself composed essentially of gela- tin/ It is proper to remark, that the heart also seems equally unsusceptible of the galvanic stimulus; or at least is not affected by it like the voluntary muscles. In the cases of two executed criminals, which the author had an opportunity of observing, al- though all degrees of galvanism were applied, half an hour after the drop fell, no motion whatever was perceptible ; yet the vo- luntary muscles contracted, and continued to do so for an hour and a half after execution. The same fact is recorded in the galvanic experiments of Dr. Ure, detailed in another part of this work, (vol. i., p. 368,) and is attested by Bichat, Treviranus and others. Humboldt, Pfaff, J. F. Meckel, Wedemeyer, and J. Mai- ler however, affirm the contrary. The last observer states,? that with a single pair of plates he excited contractions not only in a frog's heart, which had ceased to beat, but also in that of a dog, under similar circumstances. Into the subject of the cause of the heart's action, we shall, however, inquire presently. Miillerh sug- gests, that in the capability to contract under the influence of cold a On the Blood, p. 124, Lond. 1794. b Casper's Wochenschrift, May 23, 1840, and Brit, and For. Med. Rev. Oct. 1840, p, 551. c Recherches de Physiologie, &c. p. 325, Paris, 1811. d Precis, 2d edit. ii. 387, Paris, 1825. e Handbuch der Physiologie, Baly's translation, p. 205, Lond. 1838. f Eulenberg, De Tela Elastica Diss. Berol. 1836, cited by Mandl, Manuel d'Ana- tomie generate, p. 181, Paris, 1843. g Handbuch, u. s. w. translation, p. 205. h Archiv. fiir 1836, and Lond. Med. Gaz. May, 1837. CIRCULATORY APPARATUS. 77 as exhibited in the experiments of Schwann, referred to hereafter, the contractile tissue of the arteries resembles that of the dartos, and that which is found in many parts of the skin, as about the nipple and follicles, although the physical characters of the latter are so different from elastic tissue. The third or inner coat is smooth and polished,and is a continuation of the membrane which lines the ventricles. It has an epithelial lining, resembles the serous membranes, and is lubricated by a kind of serous exhalation.3 The arteries receive the constituents that belong to every living part, — arteries, veins, lymphatics, and nerves. These arteries pro- ceed not from the vessels themselves, which they nourish,but from adjacent trunks, as we have remarked of the vasa vasorum, to which class they really belong. The nerves proceed from the great sympathetic, form plexuses around the vessels, and accompany them through all their ramifications. By some anatomists, the arteries of the head, neck, thorax and abdomen, are conceived to be supplied from the great sympathetic, whilst those of the extre- mities are supplied from the nerves of the spinal marrow. It is probable, however, that more accurate discrimination might trace the dispersion of the twigs of the great nervous system of invo- luntary motion on all these vessels. The organization of the arte- ries renders them very tough and extremely elastic, both of which qualities are necessary to enable them to withstand the impulse of the blood sent from the heart, and to react upon the fluid so as to influence its course. It is, likewise, by virtue of this structure, that the parietes retain their form in the dead body, — one of the points that distinguish them from the veins. The vitality of the arteries is inconsiderable. Hence their dis- eases are by no means numerous or frequent; an important fact, seeing that their functions are eminent, and their activity in- cessant. c. Intermediate, Peripheral or Capillary System. The capillary or intermediate vessels are the vessels of extreme minuteness, by some considered to be formed by the termination of the arteries and the commencement of the veins ; by others to be a distinct set of vessels. This system forms a plexus, which is distributed over every part of the body, and constitutes, in the aggregate, what is meant by the capillary system. It admits of two great divisions, one of which is situate at the termination of the branches given off from the aorta, and is called the general capillary system ; the other at the termination of the branches of the pulmonary artery,— the pulmonic capillary system. Al- though the capillary system of man does not admit of detection by » For some speculations as to the agency of this secretion in the production of the buffy state of the blood, &c, see M. Komain Gerardin, in Journal des Connaisances Medico-Chirurgicales, Mars, 1836. 7* 78 CIRCULATION. the unaided sight, its existence is evidenced by the microscope by injections, which can develope it artificially in almps every organ ; by the application of excitants, and by inflammat 01. Ida parietes of the vessels frequently cannot be distinguished from the substance of the organs;-the colour of the blood, or the matter of the injection alone indicating their course. In some parts as in the white textures, these vessels do not seem to admit the red par- tides of the blood, whilst, in others, the red particles always cir- culate. This diversity has given rise to the distinction of the ca- pillaries into red and white ; but there are probably no white capillaries. It is difficult, indeed, to conceive of the red particles being arrested at the mouths of the white vessels — if such existed, without their preventing the entrance of fluid into them. The true cause of the whiteness appears to be the small quantity of blood, which they receive, and it is only when the network is very close, and the quantity of blood passing through them great, that a perceptible colour is produced by the red particles.b There are certain textures,again, which receive neither the one nor the other, — the corneous and epidermoid, for example, which are probably nourished by transudation of nutritive matter from the vessels0 through the cells of the tissue. The ancients were of opinion, that the arteries and veins are separated by an intermediate substance, consisting of some fluid effused from the blood, and which they called, in consequence, parenchymal The notion 'is, indeed, still entertained, and is con- sidered to be supported by microscopical observations. In the ex- amination of delicate and transparent tissues, currents of moving globules are seen with many spaces of apparently solid substances, resembling small islets, surrounded by an agitated fluid. If it be irritated, by thrusting a fine needle into it, the motion of the glo- bules becomes more rapid, new currents arise where none were previously perceptible, and the whole becomes a mass of moving particles, the general direction of which tends towards the points of irritation. But, although a part of the apparatus of intermediate circulation may be arranged, as we shall see presently, in this manner, there are reasons for the belief, that a more direct com- munication between the arteries and the veins exists also. The substance of an injection passes from one set of vessels into the other without any evidence of intermediate extravasation. The blood has been seen, too, passing in living animals, directly from the arteries into the veins. Leeuenhoeke and Malpighi/on ex- 1 See Berres, in Magendie on the Blood, Select Medical Library Edit., p. 170, Philad. 1839. b Carpenter, Human Physiology, § 479, Lond. 1842. See, also, Mandl, Manuel d'Anatomie generate, p. 194, Paris, 1843. c Mr. Toynbee, Proceedings of the Royal Society, No. 48. a Galen., Administrat. Anatom. vi. 2. e Select Works, containing his Microscopical Discoveries, by Samuel Hooke, p. 90, Lond. 1778. f Epist. de Pulmonibus, 1661, and Haller, Element. Physiol. 78 CIRCULATION. the unaided sight, its existence is evidenced by the microscope ;« by injections, which can develope it artificially in almpst every organ ; by the application of excitants, and by inflammation. The parietes of the vessels frequently cannot be distinguished from the substance of the organs ; — the" colour of the blood, or the matter of the injection alone indicating their course. In some parts, as in the white textures, these vessels do not seem to admit the red par- ticles of the blood, whilst, in others, the red particles always cir- culate. This diversity has given rise to the distinction of the ca- pillaries into red and white ; but there are probably no white capillaries. It is difficult, indeed, to conceive of the red particles being arrested at the mouths of the white vessels — if such existed, without their preventing the entrance of fluid into them. The true cause of the whiteness appears to be the small quantity of blood, which they receive, and it is only when the network is very close, and the quantity of blood passing through them great, that a perceptible colour is produced by the red particles.b There are certain textures,again, which receive neither the one nor the other, — the corneous and epidermous, for example, which are probably nourished by transudation of nutritive matter from the vessels' through the cells of the tissue. The ancients were of opinion, that the arteries and veins are separated by an intermediate substance, consisting of some fluid effused from the blood, and which they called, in consequence, parenchymal The notion 'is, indeed, still entertained, and is con- sidered to be supported by microscopical observations. In the ex- amination of delicate and transparent tissues, currents of moving globules are seen with many spaces of apparently solid substances, resembling small islets, surrounded by an agitated fluid. If it be irritated, by thrusting a fine needle into it, the motion of the glo- bules becomes more rapid, new currents arise where none were previously perceptible, and the whole becomes a mass of moving particles, the general direction of which tends towards the points of irritation. But, although a part of the apparatus of intermediate circulation may be arranged, as we shall see presently, in this manner, there are reasons for the belief, that a more direct com- munication between the arteries and the veins exists also. The substance of an injection passes from one set of vessels into the other without any evidence of intermediate extravasation. The blood has been seen, too, passing in living animals, directly from the arteries into the veins. Leeuenhoeke and Malpighi/on ex- » See Berres, in Magendie on the Blood, Select Medical Library Edit,, p. 170, Philad. 1839. b Carpenter, Human Physiology, § 479, Lond. 1842. See, also, Mandl, Manuel d'Anatomie generate, p. 194, Paris, 1843. c Mr. Toynbee, Proceedings of the Royal Society, No. 48. i Galen., Administrat. Anatom. vi. 2. e Select Works, containing his Microscopical Discoveries, by Samuel Hooke, p. 90, Lond. 1778. f Epist. de Pulmonibus, 1661, and Haller, Element. Physiol. 80 CIRCULATION. here figured, according to Wagner,8 are furnished with distinct parietes. The capillary vessels have been esteemed by some to belong chiefly to the arteries, the venous radicles not arising almost imper- ceptibly from the capillary system, as the arteries terminate in it, but having a marked size at the part where they quit this system, which strikingly contrasts with the excessive tenuity of the capil- lary arterial vessels; whilst between the capillary system and the arteries, there is no distinct line of demarcation. The opinion of Bichatb was, that this system is entirely independent of both arte- ries and veins; and Autenriethc imagined, that the minute arteries unite to form trunks, which again divide before communicating with the veins, so as to represent a system analogous to that of the vena portse. The experiments of Dr. Marshall Halld on the batra- chia, which were performed with signal care, led him to the fol- lowing conclusions, which agree with those of Bichat, so far as regards the independent existence of a capillary system. The minute vessels, he says, may be considered as arterial, so long as they continue to divide and subdivide into smaller and smaller branches. The minute veins are the vessels that gradually enlarge from the successive addition of small roots. The true capillary vessels are distinct from these. They do not become smaller by subdivision, or larger by conjunction, but they are characterized by continual and successive union and division, or anastomoses, whilst they retain a nearly uniform diameter. The last branches of the arterial system, and the first root of the venous, Dr. Hall remarks, may be denominated minute, but the term " capillary" must be reserved for, and appropriated to, vessels of a distinct character and order, and of an intermediate station, carrying red globules, and perfectly visible by means of the microscope. The capillary arteries are distinct in structure — as we shall see they are in office — from the larger arteries. All the coats of these minute vessels diminish in thickness and strength, as the tubes lessen in size, but more especially the middle coat, which, accord- ing to Wedemeyer, may still be distinguished by its colour in the transverse section of any vessels whose calibre is no less than the tenth of a line; but entirely disappears in vessels too small to re- ceive the wave of blood in a manifest jet. But while the coats diminish, the nervous filaments, distributed to them, increase ; the smaller and thinner the capillary, the greater the proportionate quantity of its nervous matter. The coats of the capillaries, becom- ing successively thinner and thinner, at length disappear alto- ■ gether, and the vessels — many of them at least — terminate in membraneless canals or interstitial passages, formed in the sub- stance of the tissues. The blood is contained — according to We- » Elements of Physiology, by R. Willis, Lond. 1842. b Anatomie Generate, torn. i. c Physiologie, ii. 138. a A Critical and Experimental Essay on the Circulation, &c, Lond. 1330 • Amer Edit. Philad. 1835. CIRCULATORY APPARATUS. 81 demeyer, Gruithuisen, Dollinger, Carus,a and others,b in the different tissues, in channels, which it forms in them ; even under the micro- scope, the stream is seen to work out for itself, easily and rapidly, a new passage in the tissues, which it penetrates, and it has been esteemed certain, that in the figura venosa of the egg, the blood is not surrounded by vascular parietes.c Most histologists of the day are disposed, however, to believe that the capillaries are provided with distinct coats. Such, as has been seen, appeared to Wagner to be the case in the frog's foot, when magnified 45 diameters; and it has even been announced, that these are composed of a fibrous structure, analogous to the mus- cular. Capillaries of the Web of the Frog's Foot. a. Deep venous trunk, composed of three principal branches, b, b, b ; and covered with a rete of smaller vessels.—(Warner.) Fig. 161, also from Wagner, exhibits the vascular rete and circu- lation of the web of the hind foot of a frog — Rama temporaria, magnified 110 times, in which the parietes are very distinct. In Fig. 162, from Wagner, which represents a portion of a live newt, magnified 150 diameters, the capillaries are exceedingly delicate, and their walls by no means so distinct. The arterial and venous a Tiedemann, loc. cit. b Burdach, op. cit. iv. 191. See, also, Dr. Marshall Hall and others, Lond. Lancet, Nov. 5,1842, p. 197. <= See J. Miiller's Handbuch, u. s. w., Baly's translation, p. 216 ; and Geddings, art. Arteries, in American Cyclopedia of Practical Medicine, ii. 305, Philad. 1836. 83 CIRCULATION. trunks and the capillaries that form the medium of communication between them are well seen, as well as the islets of the substance of the lung, on which a granular or cellular texture is indistinctly Bloodvessels of the Lung of a Live Newt. rf iniJ^lm°naT Vein receivinS Wood from another vein, c; itself made up of two branches ^iTr)aryarteryanaSt0m0Sing With the Penary veins by means of ^apiCy vessels - perceptible* Dr. Carpenter1- is of opinion, that the mode of origin of the capillaries, also refutes the supposition, that they are mere passages channelled out of the tissues through which they convey the blood. He thinks there can be no doubt, that they are pro- duced, in any newly forming tissue, not by the retirement of the ^ Wth ;°mtt 0t?ei''S° aS-t0 leave Phages between them, but by the formation of communications among certain cells, whose cavities become connected with each other, so as to constitute a plexus of tubes, of which the original cell-walls become the panetes. But farther observations are needed on this matter The whole affair of the arrangement of cells in the building ud of tissues has appeared to the author to have been adopted too hastilv • and opinions will doubtless experience vast modifications here- after. » See, on this subject, Mr. Paget, Brit, and For. Med. Rev., Julv lfua « o«« •> Human Physiology, § 477, Lond. 1842. 7' * "' P" 286, CIRCULATORY APPARATUS. 83 Of these fine capillaries, — the diameter of which, in parts finely injected, varies from the r^m t0 tlle 4oth, and the joVoth of an inch,a and even moreb — some, according to Wedemeyer, commu- nicate with veins. In the others, there are no visible openings or pores in the sides or ends, by which the blood can be extravasated preparatory to its being imbibed by the veins. There is nowhere apparent a sudden passage of the arterial into the venous stream; no abrupt boundary between the division of the two systems. The arterial streamlet winds through long routes before it assumes the nature, and takes the direction, of a venous streamlet. The ulti- mate capillary rarely passes from a large arterial into a large venous branch. Many speculations have, however, been indulged,regard- ing the mode in which the vascular extremities of the capillary system are arranged.6 Bichat regarded it as a vast reservoir, whence originate, besides veins, vessels of a particular order, whose office it is to pour out, by their free extremity, the materials of nu- trition,— vessels, which had been previously imagined by Boer- haave, and are commonly known under the appellation of exha- lants. Mascagnid supposed that the final arterial terminations are pierced, towards their point of junction with the veins, by lateral pores, through which the secreted matters transude ; — but these points will farther engage attention under the heads of Nutrition, and Secretion. d. Veins. The origin of the veins, like that of all capillary vessels, is im- perceptible. By some they are regarded as continuous with the capillary arteries; Malpighie and Leeuenhoekfstate this as the result of their microscopic observations on living animals ; and it has been inferred, from the facility with which an injection passes from the arteries into the veins. According to others, cells exist between the arterial and the venous capillaries, in which the former deposit their fluid and whence the latter obtain it. Others, again, substitute a spongy tissue for the cells. A question has also been asked, — whether the veins terminate by open mouths; or whether there may not be more delicate ves- sels, communicating with their radicles, similar to the exhalants, which are presumed to exist at the extremities of the arteries, and which are regarded as the agents of exhalation. All this is, how- ever, conjectural. It has already been observed, that the mesen- teric veins haye been considered by some to terminate by open mouths in the villi of the intestines; and the same arrangement has been conceived to prevail with regard to other veins. Ribes 1 Muller, op. cit. p. 211. b Krause, in Muller's Archiv. Heft. 1, 1837 ; and Brit, and For. Med. Rev., July, 1838, p. 218 ; also, Henle, Allgemeine Anatomie, S. 176, Leipz. 1841. c See, on this subject, Wilbrand, Physiologie des Menschen, s. Rap. xxviii. and xxix. Leipz. 1840. <» Vasor. Lymph. Corpor. Human. Histor., Sen. 1817 ; and Prodromo della Grande Anatomie, Firenz. 1819. • Opera., Lond. 1687. f Opera., Lugd. Bat. 1722. 84 CIRCULATION. concludes, from the results of injecting the veins, that some of the venous capillaries are immediately continuous with the minute arteries, whilst others open into the cells of the laminated tissue, and into the substance of the different organs. Fig. 163. Ramifications of the Splenic Artery in the Spleen. When the veins become visible,they appear as an infinite number of tubes, extremely small, and communicating very freely with each other; so as to form a very fine network. These vessels gradually become larger and less numerous, but still preserve their reticular arrangement; until, ultimately, all the veins of the body empty themselves into the heart, by three trunks — the vena cava inferior, the vena cava superior, and the coronary vein. The first of these receives the veins from the lower part of the body, and extends from the fourth lumbar vertebra to the right auricle; the second receives all the veins of the upper part of the body ; and into it the subclavian opens, into which the chyle and lymph • CIRCULATORY APPARATUS. 85 are discharged, It extends from the cartilage of the first rib to the right auricle. The coronary vein belongs to the heart exclu- sively. Between the superior and inferior cava a communication is formed by means of the vena azygos. Certain organs appear almost wholly composed of venous radi- cles. The spleen is one of these. Fig. 163 represents the ramifica- tions of the splenic artery, in the substance of that organ; and if we consider, that the splenic vein has corresponding ramifications, the viscus would seem to be almost wholly formed of bloodvessels. The same may be said of the corpus cavernosum of the penis and clitoris, the nipple, urethra, glans penis, &c. If an injection be thrown into one of the veins that issue from these different tissues, they are wholly filled by the injection ; which rarely occurs, if the injection be forced into the artery. Magendiea affirms, that the communication of the cavernous tissue of the penis with the veins occurs through apertures two or three millimetres — in. 0*117 — in diameter. In their course towards the heart, particularly in the extremities, the veins are divided into two planes; — one subcutaneous or super- ficial; the other deep-seated, and accompanying the deep-seated arteries. Numerous anastomoses occur between these, especially when the veins become small, or are more distant from the heart. We find, that their disposition differs according to the organ. In the brain, they constitute, in great part, the pia mater; and enter the ventricles, where they contribute to the formation of the plexus choroides and tela choroidea. Leaving the organ we find them situate between the lamina? of the dura mater; when they take the name of sinuses. In the spermatic cord, they are extremely tortuous, anastomose repeatedly, and form the corpus pampini- forme ; around the vagina, they constitute the corpus retiforme ; in the uterus, the uterine sinuses, &c. The veins have three coats iu superposition, according to most anatomists : but many modern anatomists are disposed to assign them six.b The outer coat is cellular, dense, and very difficult to rupture. The middle coat has been termed the proper membrane of the vei7is. The gene- rality of anatomists describe it as composed of longitudinal fibres, which are more distinct in the vena cava inferior than in the vena cava superior ; in the superficial veins than in the deep-seated; and in the branches than in the trunks. Magendiec states, that he has never been able to observe the fibres of the middle coat; but that he has always seen a multitude of filaments interlacing in all directions; and assuming the appearance of longitudinal fibres, when the vein is folded or wrinkled longitudinally, which is fre- quently the case in the large veins. It exhibits no signs of muscu- larity ; even when the galvanic stimulus is applied ; yet Magendie suspects its chemical nature to be fibrinous. It was remarked, in » Precis, &c. ii. 238. b See, on the researches of recent histologists, Mr. Paget, Brit, and For. Med. Rev. July, 1842, p. 285. c ibid. ii. 242. VOL. II. --- 8 36 CIRCULATION. an early part of this work, (vol. i., p. 38,) that the bases of the cel- lular and muscular tissue are, respectively, gelatin, and fibrin; and that the various resisting solids may all be brought to one or other of these tissues. The middle coat of the veins doubtless be- longs to the former, and is a variety of the tissu jaune of the French anatomists. Magendie merely states its fibrinous nature to be a suspicion ; and, like numerous suspicions, it may be devoid of foundation. Yet we have reason to believe, that it is contrac- tile. Broussaisa affirms, that this action is one of the principal causes of the return of the blood to the heart. He conceives, that the alternate movements of contraction and relaxation are alto- gether similar to those of the heart; but that they are so light as not to have been rendered perceptible by any process in the majo- rity of the veins, although very visible in the vena cava of frogs, where it joins the right auricle. In some experiments by Sarlan- diere on the circulatioii, he observed these movements to be inde- pendent of those of the heart. After the heart was removed, the contraction and relaxation of the vein continued for many minutes in the cut extremity, and even after the blood had ceased to flow.b The inner coat is extremely thin and smooth at its inner sur- face, and has an epithelial lining. It is very extensible, and yet pre- sents considerable resistance ; bearing a very tight ligature with- out being ruptured. In many of the veins, parabolic folds of the inner coat exist, like those in the lymphatics, and inservient to a similar purpose : the free edge of these valves is directed towards the centre of the circulation ; showing that their office is to per- mit the blood to flow in that direction, and to prevent its retro- gression. They do not seem, however, in many cases, well adapt- ed for the purpose ; inasmuch as their size is insufficient to obli- terate the cavity of the vein. By most anatomists, this arrange- ment is considered to depend upon primary organization; but Bichat conceives it to be wholly owing to the state of contraction, or dilatation of the veins at the moment of death. Magendie, however, affirms, that he has never seen the distension of the veins exert any influence on the size of the valves ; but that their shape is somewhat modified by the state of contraction or dilata- tion ; and this he thinks probably misled Bichat.c Moreover, they are covered by the epithelial coat and consist of tissue like that of fibrous membrane, which, as Hunterd observed, shows, that they are not duplicatures of the lining membranes Their number varies in different veins. As a general rule, they are more numerous, where the blood proceeds against its gravity, or where the veins are very extensible, and receive but a feeble sup- port from the circumambient parts, as in the extremities. They are entirely wanting in the veins of the deep-seated viscera • in 1 Op. citat., Amer. translation, p. 391. b See, on this subject, the remarks on the circulation in the veins. c Precis, &c. ii. 241. d Treatise on the Blood -&c * Henle; and Mr. Paget, Brit, and For. Med. Rev. July, 1842, p. 284. CIRCULATORY APPARATUS. 87 those of the brain and spinal marrow, and of the lungs ; in the vena portae, and in the veins of the kidneys, bladder and uterus. They exist, however, in the spermatic veins; and, sometimes, in the in- ternal mammary, and in the branches of the vena azygos. On the cardiac side of these valves, cavities or sinuses exist, which appear externally in the form of varices. These dilatations enable the refluent blood to catch the free edges of the valves, and thus to depress them, so as to close the cavity of the vessel; serving, in this respect, precisely the same functions as the sinuses of the pulmonary artery and aorta in regard to the semilunar valves. The valves exist in veins of less than a line in diameter.* The three coats united form a solid vessel, — according to Bichat devoid of elasticity, but in the opinion of Magendie,b elastic in an eminent degree. The elasticity is certainly much less than that of the arteries. The veins are nourished by vasa vasorum, or by small arteries, which have their accompanying veins. Every ves- sel, indeed, in the body, if we may judge from analogy, appears to draw its nutriment, not from the blood circulating in it, but from small arterial vessels, hence termed vasa vasorum. This applies not only to the veins, but to the arteries. The heart, for example, is not nourished by the fluid constantly passingthrough it; but by vessels, which arise from the aorta, and are distributed over its surface, and in its intimate texture. The coronary arteries and their corresponding veins are, consequently, the vasa vasorum of the heart. In like manner, the aorta and all its branches, as well as the veins, receive their vasa vasorum. There must, however, be a term to this ; and if our powers of observation were sufficient we ought to be able to discover a vessel, which must derive its support or nourishment exclusively from its own stores*. The nerves that have been detected on the veins, are branches of the great sympathetic. The capacity of the venous system is generally esteemed to be double that of the arterial. It is obvious, however, that we can only arrive at an approximation, and that not a very close one. The size and number of the veins is generally so much greater than that of the corresponding arteries, that when the vessels of a membranous part are injected, the veins are observed to form a plexus, and, in a great measure, to conceal the arteries: in the in- testines, the number is more nearly equal. The difficulty of arriv- ing at any exact conclusion, regarding the relative capacities of the two systems, is forcibly indicated by the fact, that, whilst Bo- relli conceived the preponderance in favour of the veins to be as four to one, Sauvages estimated it at nine to four, Haller at sixteen to nine, and Keill at twenty-five to nine.° There is one portion of the venous system, to which allusion has already been made, which is peculiar. We mean the abdomi- nal venous ox portal system. All the veins, that return from the digestive organs, situate in the abdomen, unite into a large trunk, » Henle, op. cit. b Precis, &c.,ii. 243. c Elementa Physiologiae, Lausan. 1757-1766. 88 CIRCULATION. Fig. 164. called the vena portx. This, instead of pass- ing into a larger vein — into the vena cava, for example — pro- ceeds to the liver, and ramifies, like an ar- tery in its substance. From the liver, other veins, called supra- hepatic, arise, which empty themselves into the vena cava; and which correspond to the branches of the hepatic artery as well as to those of the ve- na portse. The por- tal system is con- cerned only with the veins of the digestive organs situate in the abdomen; as, the spleen, pancreas, sto- mach, intestines and omenta. The veins of all the other abdo- minal organs, — of the kidney, supra- renal capsules, &c, are not connected with it. The first part of the vena portae is call- ed, by some authors, venaportx ahdominalis vel ventralis, to dis- tinguish it from the hepatic portion, which is of great size, and has been called the sinus of the venaportas. 2. BLOOD. It is not easy to ascertain the total quantity of blood, circulating in both arteries and veins. Many attempts have been instituted for this purpose, but the statements are most diversified, partly owing to the erroneous direction followed by the experimenters but, still more, to the variation that must be perpetually occurring in the amount of fluid, according to age, sex, temperament, acti- vity of secretion, &c. Harvey and the earlier experimenters formed their estimates, by opening the veins and arterieslreely on a living animal, collecting the blood that flowed, and comparing this with the weight of the body. The plan is, however, objectionable as the whole of the blood can never be obtained in this manner, and the proportion discharged varies in different animals and circum Portal System. 1.. Inferior mesenteric vein : it is traced hy means of dotted lines behind the pancreas (2) to terminate in splenic vein (3). 4. Spleen. 5. Oastric veins, opening into splenic vein. 6. Su- perior mesenteric vein. 7. Descending portion of the duodenum. 8. Its transverse portion which is crossed by superior mesenteric vein and by a part of trunk of superior mesenteric artery. 9. Portal vein. 10. Hepatic artery. 11. Ductus communis ehole- dochus. 12. Divisions of duct and vessels at transverse fissure of liver. 13. Cystic ductleading to gall-bladder. — {JVilson.) BLOOD. 89 stances. By this method, Moulins found the proportion in a sheep to be -^sd; King, in a lamb, ?yh ; in a duck, 7yh ; and in a rabbit, •sVh. From these and other observations, Harvey concluded, that the weight of the blood of an animal is to that of the whole ani- mal as 1 to 20. Drelincourt, however, found the proportion in a hog to be nearly -j^th ; and Moor, TVtrl«a An animal, according to Sir Astley Cooper,b generally expires, as soon as blood, equal to about -L.th of the weight of the body, is abstracted. Thus, if it weigh sixteen ounces, the loss of an ounce of blood will be sufficient to destroy it; ten pounds will destroy a man weighing one hundred and sixty pounds; and,on examining the body, blood will still be found — in the small vessels espe- cially — even although every facility may have been afforded for draining them. Experiments have, however, shown, that no fixed proportion of the circulating fluid can be indicated as necessary for the maintenance of life. In the experiments of Rosa, asphyxia oc- curred in young calves when from three to six pounds, or from ^d to J, th of their weight, had been abstracted, but in older ones not until they had lost from twelve to sixteen pounds, or from TVth to |th of their weight. In a lamb, asphyxia supervened on a loss of twenty-eight ounces, or ^Tth of its weight, and in a wether, on a loss of sixty-one ounces, or ^\d of its weight. Blundell0 found that some dogs died after losing nine ounces, or ^Bth of their weight; and others withstood the abstraction of a pound, or T^th of their weight; and Piorry affirms, that dogs can bear the loss of ^jth of their weight, but if a few ounces more be drawn, they succumb. From all the experiments and observations, Burdachd concludes, that, on the average, death occurs when gths or |ths, of the mass of blood is lost, although he has observed it in many cases, as in haemoptysis, to supervene on the loss of iih, and even of ath. The following table exhibits the computations of different phy- siologists, regarding the weight of the circulating fluid — arterial and venous. lbs. lbs. Harvey, -\ Wagner, - - 20 to 25 Lister, (. . . 8 Quesnai, - - - 27 Mou'ins> , ( F.Hoffmann, - - - 28 Abildguard, Blumenbach, Haller, - - - 28 to 30 Lobb, £ - 10 young, - 40 Lower, J Hambergcr, - 80 Sprengel, - - 10 to 15 ... MUller and Burdach, - 20 Kei11' - - - - IUU Although the absolute estimate of Hoffmann is perhaps below » Haller, ElementaPhysiologise, iv. 2, seq. b Principles and Practice of Surgery, p. 33, Lee s edition, Lond. 18-ib ' Researches, Physiological and Pathological, p. 66 and 94, Lond. 1825. d Die Physiologie als Erfahrungswissenschaft, iv. 101 and 334, Leipzig, 1832. ' Haller, op. citat.; and Herbst, Comment. Histarico-eritica, &c, de Sanguinis Quantitate, Gotting. 1822. 8* 90 CIRCULATION. the truth, his proportion is probably nearly accurate. He con- ceives, that the weight of the blood is to that of the whole body as l to 5. Accordingly, an individual, weighing one hundred and fifty pounds, will have about thirty pounds of blood ; one of two hundred pounds, forty; and so on. Of this, one-third is supposed to be contained in the arteries, and two-thirds in the veins. The estimate of Haller is, perhaps, near the truth; the arterial blood being, he conceives, to the venous, as 4 to 9. If we assume, there- fore, that the whole quantity of the blood is thirty pounds in a man weighing one hundred and fifty pounds, — which is perhaps allow- ing too much, — nine pounds, at least, may be contained in the arteries, and the remainder in the veins.a An ingenious plan, proposed by M. Valentin for estimating the quantity of blood in the body, affords an approximation to the truth, and confirmatory of the estimate made from other data. Having weighed an animal, and determined the proportion of solid matter in a portion of its blood, he injects into its vessels a given quantity of distilled water, which soon becomes mixed with the blood. He then takes away a fresh portion of blood, and ascer- tains the proportion of solid matter in it. The relation between the amount of solid matter in the blood first taken, and that in the blood diluted with the given quantity of water, enables him to calculate the quantity of blood in the body of the animal.b In this manner, M. Valentin found the ratio of blood to the weight of the body to be in the male dog as 1 to 4-36 in the male sex; and 1 to 4-93 for the female, and adapting these proportions to M. Quetelet's table of the weight of the human subject at different ages, he in- ferred, that the mean quantity of blood in the male adult, at the a Good's Study of Medicine, Physiological Proem to class Hasmatica ; Haller, Op. citat; Rudolphi, Grundriss der Physiol, i. 40; Brandt, in art. Blut, in Encyclopad. Wbrterb. der Medic. Wissenschaft. v. 598, Berlin, 1830 ; and Mr. Ancell, Lectures on the Physiol, and Pathology of the Blood, in Lond. Lancet, May 16, 1840, p. 257. b The following question and solution are given, in order to show, how the quantity of blood may be estimated in the manner proposed by Valentin. A portion of blood, (=1190 grains,) drawn from a dog, yielded 24-54 per cent, of solid matter. After injecting 10905 grains of water into the bloodvessels, a portion of blood drawn yielded 21-86, (or, by another trial, 21-89,) per cent, of solid matter. What was the amount of blood in the body at the commencement of the experiment 1 Let x be the amount of blood after the first experiment. Then, since it contained 24-54 per cent, of solid residue, the amount of solid matter in it was 2454 x. After injecting the water the whole amount of the diluted blood was x 4.10905; and, (by the experiment,) the solid matter which it contained was =-2186 (x-l-10905). But the solid matter was of the same amount in both cases. Therefore we have •2454 x = -2186 (x + 10905) or, (-2454 — -2186) x = -2186+10905 2373-8330 or, x = -Q268—■ = 88576 grs. Add for the blood first drawn, - 1190 And we get.......89766 grs. the weight of blood in the body, at the commencement of the experiment. The ratio 21-89 per cent, gives - 91269 grs. And the mean of the two is .... 90517 » BLOOD. 91 time when the weight of the body may be presumed to be greatest, namely, at 30 years, should be about 34£ pounds; and that of the female at 50, when the weight is generally greatest, at about 26 pounds.11 The blood strongly resembles the chyle in its properties;—the great difference consisting in the colour; and the venous blood, and the chyle, and the lymph become equally converted into the same fluid — arterial blood — in the lungs. Venous blood, which chiefly concerns us at present, is contained in all the veins, in the right side of the heart, and in the pulmonary artery ; — organs which constitute the apparatus of venous circu- lation. As drawn from the arm, its appearance is familiar to every one. At first, it seems to be entirely homogeneous; but, after resting for some time, it separates into different portions. The colour of venous blood is much darker than that of arterial; — so dark, indeed, as to have had the epithet black blood applied to it. Its smell is faint and peculiar; by some compared to a fra- grant garlic odour, but it is sui generis ; its taste is slightly saline, and also peculiar. It is viscid to the touch; coagulable, and its temperature has been estimated at 96° Fahrenheit; simply, we believe, on the authority of the inventor of that thermometric scale, who marked 96° as blood heat. This is too low by at least three or four degrees. Rudolphi,b and the German writers in general, estimate it at 29° of Reaumur, or " from 98° to 100° of Fahrenheit;" whilst, by the French writers in general, its mean temperature is stated at 31° of Reaumur, or 102° of Fahr- enheit ; Magendie,0 who is usually very accurate, fixes the tem- perature of venous blood at 31° of Reaumur, or 102° of Fahren- heit; and that of arterial blood at 32° of Reaumur, or 104° of Fahrenheit. 100° may perhaps be taken as the average. This was the natural temperature of the stomach in the case related by Dr. Beaumont,d which has been so often referred to in these pages. In many animals, the temperature is considerably higher. In the sheep it is 102° or 103°; but it is most elevated in birds. In the duck it is 107°. On this subject, however, further information will be given under the head of Calorification. The specific gravity of the blood is differently estimated by dif- ferent writers. Hence it is probable, that it varies in different individuals, and in the same individual at different periods. Com- pared with water its mean specific gravity has been estimated, by some, to be as 1-0527, by others, as 1-0800, to 1-0000. It is stated, however, to have been found as high as 1-126 ; and, in disease, as low as 1-022. It has, moreover, been conceived, that the effect of disease is, invariably, to make it lighter; and that the more healthy the individual, the greater is the specific gravity of the * Muller's Physiology, by Baly, Book ii. Sect. I. b Grundriss der Physiologie, i. 143, Berlin, 1821. « Precis, &c. ii. 229. •i Experiments, &c. on the Gastric Juice, &c. p. 274, Plattsburg, 1833. 92 CIRCULATION. blood ; but our information on this point is vague. That it is not always the same in health is proved by the discrepancy of ob- servers. Boyle estimated it at 1041 ; Martine, at 1-045; Jurin,at 1-054 ; Muschenbroek, at 1-056 ; Denis, at 1-059 ; Senac, at 1-082 ; and Berzelius at from 1-052 to 1-126 ;a J. Muller, at from 1-0527 to 1-057 ; and Mandl, at from 1-050 to 1-059. The average may'perhaps be stated at 1-050. A part of the discrepancy may be owing to the specific gravity not having been always taken at the same temperature. Dr. B. Babington found experimentally, that four degrees of temperature corresponded with a difference of •001 of specific weight: consequently, if one author states the spe- cific gravity of blood at about its circulating temperature — say 98° of Fahr. — while another states it at 60° Fahr. — the usual standard — the former will make it -0095 lighter than the latter.b When blood is examined with a microscope of high magnifying powers, it appears to be composed of numerous, minute, redparti- cles or corpuscles, commonly called red globules, blood corpuscles and blood disks, suspended in the serum. These red particles have a different shape and dimension, according to the nature of the animal. In Ihe mammalia, they are circular; and, in birds and cold-blooded animals, elliptical. In all animals, they are affirmed, by some observers, to be flattened, and marked in the centre with a luminous point, of a shape analogous to the general shape of the globule. Prof. Giacomonic of Padua, has, however, affirmed, that the red globules, swimming in serum, — which have been described by so many writers on the circulating fluid, — exist only in their imaginations. As in every case which rests on mi- croscopic observation, the greatest discrepancy prevails here, not only as regards the shape but the size of the globules. These were first noticed by Malpighi,d and were afterwards more mi- nutely examined by Leeuenhoek,e who at first described them, correctly enough, in general terms; but, subsequently, became hypothetical, and advanced the phantasy, that the red particles are composed of a series of globular bodies, descending in regu- lar gradations; each of the red particles being supposed to be composed of six particles of serum; a particle of serum of six particles of lymph, &c. Totally devoid of foundation, as the whole notion was, it was implicitly believed for a considerable period, even until the time when Haller wrote. Hewsonf de- scribed the globules as consisting of a solid centre, surrounded bv a vesicle, filled with a fluid ; and to be " as flat as a guinea." Hunter,^ on the other hand, did not regard them as solid bodies but as liquids, possessing a central attraction, which determines » Burdach, Die Physiologie als Erfahrungswissenschaft, iv. 15, Leipz. 1832. b Dr. Babington, in Cyclop. Anat. and Physiol, parts iv. and v. e Encyclogr. des Sciences Medicales, Avril, 1840, p. 529. <« Opera, Lond. 1687. e Martine, in Edinb. Med. Essays, ii. 74; and Phil. Transact, for 1694. f Experimental Inquiries, part iii. p. 16, Lond. 1777. e On the Blood, by Palmer, reprinted in Select Med. Lib. p. 63, Philad. 1840. BLOOD. 93 Fig. 165. "ti, D Corpuscles of Human C Blood from vein, beaten so as to separate the Fibrin, mag- nified 900 times. a. Blood corpuscles seen, a, on the flat face. b. On edge * a three quarter view. b. Congeries of blood corpuscles in columns. c. A blood corpuscle undergoing change as by exposure to air. d. A lymph corpuscle mingled with the proper blood corpuscle. — {Wagner.) their shape. Delia Torre8 supposed them to be a kind of disk or ring,pierced in the centre ; whilst Monro conceived them to be cir- cular, flattened bodies, like coins, with a dark spot in the centre, which he thought was not owing to a perforation, as Delia Torre had imagined, but to a depression. Cavallo,b again, conceived, that all these appearances are deceptive, depending upon the peculiar modi- fication of the rays of light, as affected by the form of the particle ; and he concluded, that they are simple spheres. Amici found them of two kinds, both with angular margins; but, in the one, the cen- tre was depressed on both sides ; whilst, in the other, it was elevated. The observations of Dr. Young,c of Sir Everard Home and Mr. Bauer,d and of MM. Prevost and Dumas,e accord chiefly with those of Hewson. All these gentle- men consider the red particles to be composed of a central Fis- 166- globule, which is transparent and whitish, and of a red en- velope, which is less transpa- rent. Still more recently, how- ever, Dr. Hodgkiu and Mr. Lister/ have denied that they are spherical, and that they consist of a central nucleus inclosed in a vesicle. They affirm, on the authority of a microscope, which, on com- parison, was found equal to a celebrated one, taken a few years ago to Great Britain by Profes- sor Amici.s that the particles of human blood appear to consist of circular, flattened, transparent cakes, their thickness being about ■J-th part of their diameter. These, when seen singly, appear to be nearly or quite colourless. Their edges are rounded, and being the thickest part, occasion a depression in the middle, which » Philos. Trans, for 1765, p. 252. •> An Essay on the Medicinal Properties of Factitious Air, &c. p. 237, Lond. 1798. c Introduct. to Med. Literature, p. 545. i Philosoph. Transact, for 1811-18; and Lectures on Comp. Anat. iii. 4, Lond. 1823. B Annates de Chimie, &c. xxiii. 50,90 ; and Journal of Science and Arts, xvi. 115. r Philosoph. Magazine and Annals of Philosophy, ii. 130, Lond. 1827; also, Hodg- kin, Catalogue of the Preparations in the Anatomical Museum of Guy's Hospital, introd. to sect. xi. P. i. Lond. 1829. s Edinb. Medical and Surgical Journal, xvi, 120. Blood Corpuscles of the edible frog, Rana esculenta- a, a a, b. Blood corpuscles, b. Seen edgewise. e. Lymph corpuscle, d. Altered by dilute acetic acid. —(.Wagner.) 94 CIRCULATION. exists on both surfaces. The view of these gentlemen, conse- quently, appears to resemble that of Monro. Amidst this discordance, it is difficult to know which view to adopt.a The belief in their consisting of circular, flattened, trans- parent bodies, with a depression in the centre, and that they con- sist .of an external envelope and of a central nucleus, the former of which is red and gives colour to the blood, appears to have the greatest weight of authority in its favour. The nucleus is devoid of colour, and appears to be independent of the envelope ; as, when the latter is destroyed, the central portion preserves its origi- nal shape. The nucleus is much smaller than the envelope, being, according to Dr. Young, only about one-third the length, and one-half the breadth of the entire particle. According to Sir Everard Home,b the globules, when enveloped in the colouring matter, are -^th part of an inch in diameter, requiring 2,890,000 to a square inch; but when deprived of their colouring matter, they appear to be ^i^th part of an inch in diameter, requiring 4,000,000 of globules to a square inch. According to these mea- surements, the globules, when deprived of their colouring matter, are not quite one-fifth smaller. The views of MM. Prevost and Dumas, who have investigated the subject with extreme care and signal ingenuity, are deserving of great attention. They conceive the blood to consist essentially of serum, in which a quantity of red particles is suspended ; that each of these particles consists of an external red vesicle, which incloses, in its centre, a colourless globule ; that, during the progress of coagulation, the vesicle bursts, and permits the central globule to escape ; that, on losing their envelope, the central globules are attracted together; that they are disposed to arrange themselves in lines and fibres; that these fibres form a network, in the meshes of which they me- chanically entangle a quantity of both the serum and the colour- ing matter; that these latter substances may be removed by draining, and by ablution in water; that, when this is done, there remains only pure fibrin ; and that, consequently, fibrin consists of an aggregation of the central globules of the red parti- cles, while the general mass, that constitutes the crassamentum or clot, is composed of the entire particle. So far this seems satisfac- tory ; but, we have seen, Dr. Hodgkin does not recognise the existence of external vesicle, or of central globule ; and he affirms, contrary to the notion of Sir Everard Home and others, that the particles are disposed to coalesce in their entire state. This is best seen, when the blood is viewed between two slips of glass. Under such circumstances, the following appearances, according to Dr. Hodgkin, are perceptible. When human blood, or that of any other animal having circular particles, is examined in this manner, considerable agitation is, at first, seen to take place among i See, on this subject, Paine, Medical and Physiological Commentaries, vol. i, Ap- pendix on the Microscope, p. 899, New York, 1840; Mr. Paget. British and'For. Med. Rev. July, 1842, p. 260 ; and Mr. T. Wharton Jones, Brit, and For. Med. Rev Oct. 1842, p. 585. b Lectures oft Comparative Anatomy, iii. 4, and v. 100, Lond. 1828. BLOOD. 95 the particles ; but, as this subsides, they apply themselves to each other by their broad surfaces, and form piles or rouleaux, which are sometimes of considerable length. These rouleaux often again combine amongst themselves. — the end of one being attached to the side of another, — producing at times, very curious ramifica- tions. (See Fig. 165, b.) The belief in the particles being flattened disks is now generally received; and the form of the disk is found to be altered by va- rious substances. Its external envelope admits readily the endos- mose of fluids, so that, if placed in water, they may assume a truly globular shape. In examining the blood, consequently, it is advisable to dilute it with a fluid of as nearly as possible the same character as the serum. In the particles of the blood of the frog — as represented in Fig. 166 — a nucleus is observed projecting some- what from the central portion : this is rendered extremely distinct by the action of acetic acid, which dissolves the rest of the parti- cle, and renders the nucleus more opaque. It then appears to consist of a granular substance.3 • Microscopical discordances are no less evidenced by the esti- mates, which have been made of the size of the red globules ; yet all are adduced on the faith of positive admeasurements. Leaving out of view the older, and, consequently, it might be presumed, less accurate observations, the following table will show their dia- meter in human blood, on the authority of some of the most emi- nent microscopic observers of more recent times. Sir E. Home and Bauer, with colouring? ^th f . { matter,.....} \ r ' Eller,......iTTo Sir E. Home and Bauer, without colour- ing matter, - Jurin,...... Miiller,......' Mandl,..... Hodgkin, Lister, and Rudolphi, Sprefigel,..... Cavallo, - Blumenbach and Senac, Tabor, ..... Milne Edwards,..... Wagner,..... Kater, _..._. Prevost and Dumas, - Haller, Wollaston, and Weber, - Youn^,......_!_b =>' 6060 » Carpenter, Human Physiology, § 570, Lond. 1842 ; see, also, Dr. G. O. Rees, and Mr. S. Lane, in Guy's Hospital Reports, No. xiii. Oct. 1841. b Butdach, Die Physiologie als Erfahrungswissenschaft, iv. 21, Leipz. 1832. See, also, Ancell, Lectures on the Physiology and Pathology of the Blood, in Lond. Lancet, Dec. 7, 1839, p. 380. 96 CIRCULATION. The blood of different animals is found to differ greatly in the relative quantity of the red globules it contains, the number seem- ing to bear a pretty exact ratio with the temperature of tne ani- mal. The higher the natural temperature, the greater the propor- tion of particles; and arterial always containing a much greater proportion than venous blood. The blood corpuscles of the greater part of the mammalia have the same shape as those of man ; but their size varies greatly in different families. It would appear, from the researches of Mandl,* that of the mammalia the elephant has the largest globules, (T^th of a millimetre,) and the ruminantia the smallest; that the family of camels is the only one, whose corpuscles are not round like those of the other mammalia, but elliptical like those of birds, reptiles, and fishes.b The chemical constitution of the blood corpuscles is not definitely settled. Two proximate principles have been discovered in them — hematosin and globulin. The former, as mentioned hereafter, has been supposed to be the colouring matter. The latter, which differs from the globulin of Laennec, — an impure hematosin mingled with some albumen,— is the main constituent of the glo- bules, and is the same as the blood-casein of Simon. It has not been separated, but is presumed to differ but little in its properties from protein.* They are supposed to be produced originally in the germinal membrane of the embryo ; but throughout the remainder of existence, they are formed in the blood from the chyle.d In addition to the red globules, colourless or white corpus- cles are observed in the blood. These were observed by Mul- ler in the blood of frogs ; and by Mandle in that of the mammalia. They are small, colourless corpuscles, finely granulated ; inso- luble in water, and strongly refracting light. According to Mandl, they maybe separated into two species,— some round, and containing two or three granules, which become more evi- dent when they are treated with acetic acid: these are the true lymph globules, described already (vol. i., p. 625) ;-the others, gene- rally also round ; sometimes oblong ; and at others irregular ; the edges slightly notched ; and the surface finely granulated. They appear to be composed of a multitude of small molecules, from TUL_th to t^th of a millimetre in diameter; some are also found single. These globules are seen forming under the microscope, when the blood, placed between two glasses, is attentively ex- amined. They are, in Mandl's opinion, produced by the coagu- lation of the fibrin, and hence they are called by him fibrinous globules. Recently, however, he has abandoned this name, " be- 1 Manuel d'Anatomie generate, p. 248, Paris, 1843. b Op. citat., and Annales des Sciences Naturelles, 1824 and 1825. See on the blood corpuscles of different animals, Burdach, Op. cit. p. 21 ; and Gulliver, Appendix to Gerber's Elements of the General and Minute Anatomy of Man and the Mammalia Lond. 1842. c Carpenter, Human Physiology, § 575, Lond. 1842. d Wagner, Elements of Physiology, by Willis, § 96, Lond. 1842. * Gazette Medicale, 1837 ; and Manuel d'Anatomie generale, p. 252 Paris 1843. BLOOD. 97 cause it rests on a chemical character, that, requires confirmation ; and because it is not drawn from anatomical characters, which ought chiefly to fix the attention of the microscopist." He now terms them white granulated corpuscles* Dr. Barry and Mr. Addison, however, think, that the colourless corpuscles,— which have gene- rally been regarded as lymph corpuscles—are formed from the central portion of the blood corpuscles: they consider them to hold an intermediate position between the true red corpuscles, and the greatly modified forms of corpuscles, which, in their view, are the bases of the tissues, as well as of pus and other globules. The subject, requires further investigation.b When blood is drawn from a vessel, and left to itself, it exhales, so long as it is warm, a fetid vapour consisting of water and animal matter, of a nature not known.0 This vapour is what has been called the halitus of the blood, — by Plenck, the gas animate sanguinis, which he conceives to be composed of carbon and hydrogen, and to be inservient to many supposititious uses in the economy. The odour exhaled by the blood would appear to preserve the same general characters under all circumstances. After a time, the blood coagulates, giving off, at the same time, it has been said, a quan- tity of carbonic acid gas. • This disengagement is not evident, when the blood is suffered to remain exposed to the air, except, perhaps, by the apertures or canals formed by its passage through the clot; but it can be collected by placing the blood under the receiver of an air-pump, and exhausting the air. On this fact, however, ob- servers do not all accord. The experiments of Vogel,d Brande,e Sir E. Home/and Sir C. Scudamore,s are in favour of such evo- lution ; and. the last gentleman conceives it even to be an essential part of the process; but other distinguished experimenters have not been able to detect it. Neither Dr. John Davy,h nor Dr. Dun- can, Jr., nor Dr. Christison, could procure it during the coagulation of the blood. Dr. Turner' suggests that the appearance of the carbonic acid, in the experiments of Vogel, Brande, and Scuda- more, might easily have been occasioned by casual exposure to the atmosphere, previous to the blood being placed under the receiver; but we have no reason for believing, that this source of fallacy was not guarded against as much by one set of experimenters as by the other. Our knowledge, on this point, is confined then to the fact, * Manuel d'Anatomie generate, p. 554, Paris, 1843. b See, on this point, Carpenter, Human Physiology, Amer. Edit., p. 419, Philad. 1843 ; and Andral, Hematologic Pathologique, p. 34, Paris, 1843. c Ancell, Lectures on the Blood, Lancet, Jan. 18, 1840, p. 608. d Annales de Chimie, t. xciii. e Philosophical Transactions for 1818, p. 181. f Lectures, &c. iii. 8. g Philosophical Transactions for 1820, p. 6; and an Essay on the Blood, p. 107, Lond. 1824. h Phil. Trans, for 1823, p. 506 ; and Edinb. Med. and Surg. Journ. xxix. 253 Since that time, however, Dr. Davy has succeeded in extricating it both from venous and arte- rial blood. See his Researches, Physiological and Anatomical, Dunglison's Amer. Med. Lib. Edit. p. 82, Philad. 1840. i Elements of Chemistry, 5th edit, by Dr. Bache, p. 607, Philad. 1835. VOL. II. — 9 98 CIRCULATION. that, by some, carbonic acid gas has been found exhaled during the process of coagulation ; — by others, not. More recent expe- riments, by Stromeyer,a and by Gmelin, Tiedemann, and Mits- cherlich,b would seem to decide, that the blood does not give off any free carbonic acid, but that it holds a certain quantity in a state of combination; and that this combination is intimate is shown by the fact, mentioned by Muller,c that blood, artificially impregnated with carbonic acid, yields no appreciable quantity of the gas, when subjected to the air-pump. M. Magnus,1' however, found, in his experiments, that not only venous, but arterial blood, contains carbonic acid, oxygen, and azote, and that, as regards carbonic acid, arterial blood contains more than venous ; and he accounts for the failure of those, who have attempted to elicit car- bonic acid from venous blood by the air-pump, to the air in the receiver not having been sufficiently rarefied. Prof. C. H Schultz, of Berlin — who believes that the vesicles of the blood, in a per- fect state, are composed of a membranous covering, whose interior is filled with an aeriform fluid in the midst of which is found the nucleuse—succeeded in so evident a manner by the following simple method in extracting air from the blood, " that it is impos- sible to doubt there exists a great quantity of air in the vesicles." He completely filled a bottle with warm blood, flowing imme- diately from the vein of a horse, and hermetically sealed the bottle so that the cork was plunged into the blood, thus absolutely pre- venting the contact of air. The blood, in cooling, diminished in volume, and thus produced a perfect vacuum in the upper part of the bottle ; and in proportion as this took place, bubbles of air arose from the blood and filled the vacuum. Chemical analysis of this air demonstrated that it was carbonic, acid. In arterial blood, he found oxygen mixed with more or less carbonic acid/ The expe- riments of Dr. Stevens,eand of Dr. Robert E. Rogers,h also exhibit, that carbonic acid is contained in the blood. The latter observer found, when a portion of venous blood was placed in a bag of some membrane, and the bag was immersed in an atmosphere of some gas — as oxygen, hydrogen, or nitrogen — that carbonic acid was pretty freely evolved. Whilst the blood is circulating in the vessels, it consists of liquor sanguinis and red corpuscles; but during coagulation, it separates into two distinct portions; a yellowish liquid, called the serum ; and a red solid, known by the name of the clot, cruor, crassamentum, coagulum,placenta, insula or hepar sanguinis. The proportion of the serum to the crassamentum varies greatly in * Schweigger's Journal fur Chemie, u. s. w. lxiv. 105. b Tiedemann und Treviranus, Zeitschrift fur Physiologie, B. v H i • Geddines's North Amer. Archives for July and August, 1835 ; and British and ForeiVn Med Re- view, No. 9, p. 590, April, 1836. ? Op eft p 329 a Annales de Chinne et de Physique, Nov. 1837. See, also, Carpenter, Human Physiology, § 541, Lond. 1842. r ' e Lond. Lancet, Aug. 10, 1839, p. 713. f jbid ?,. > Philos. Transact, for 1834-5, p. 334. See, also, Dr. M. Edwards in article "Blood," Cyclopaedia of Anat. and Phys. Part. iv. p. 404, Lond. 1836 ' Amer. Journ. of the Med. Sciences, Aug. 1836, p. 283. BLOOD. 99 different animals, and in the same animal at different times, ac- cording to the state of the system. . The latter is more abundant in healthy, vigorous animals, than in those that have been im- poverished by depletion, low living, or disease. Sir Charles / Scudamorea found, by taking the mean of twelve experiments, that the crassamentum amounted to 53-307 per cent, in healthy blood. The difference between living and coagulated blood may be ex- pressed in a tabular form as follows: — r bo Liquor Sanguinis, \Jfced Corpuscles, Water, Various Salts, Fatty matters, Extractive do. Albumen, Fibrin, 1 Serum, } Crassamentum,b H O The serum is viscods, transparent, of a slightly yellowish hue, and alkaline, owing to the presence of a little free soda. Its smell and taste resemble those of the blood. Its average specific gravity has been estimated at about l-027.c But on this point, also, observ- ers differ. Dr. John Davyd found it to vary from 1-020 to 1-031. Martine, Muschenbroek, Jurin, and Haller, from 1-022 to 1-037; Berzelius and Wagner,e from 1-027 to 1-029 ; Christison,f from 1-029 to 1-031; Lauer,sfrom 1-009 to 1-011; whilst Thackrahh found the extremes to be 1-004 and 1-080. At 158° of Fahrenheit, it coagulates; forming at the same time, numerous cells, containing a fluid, which oozes out from the coagulum of the serum, and is called the serosity. It contains, according to Bostock, about Tyh of its weight of animal matter, together with a little chloride of sodium. Of this animal matter, a portion is albumen, which may be readily coagulated by means of galvanism ; but a small quantity of some other principle is present, which differs from albumen and gelatin, and to which Marcet' gave the name muco-extractive matter, and Bostock,J uncoagulable matter of the blood—as a term expressive of its most characteristic property. Serum pre- serves its property of coagulating, even when largely diluted with water. According to Brande,k it is almost pure liquid albumen, a Roget's(Outlines of Physiology, American Edition, by the author, § 385, Philad. 1839. b B. Babington, art. Blood, in Cyclop, of Anat. and Physiol., Lond. 1836 ; T. W. Jones, Brit, and For. Med. Rev., Oct. 1842, p. 588 ; and Mandl, Manuel d'Anatomie generate, p. 255, Paris, 1843. c Bostock's Physiology, &c. edit. cit. p. 287; Marcet, in Medico-Chirurg. Trans. iii. 363; and Mandl, Manuel d'Anatom. generate, p. 230, Paris, 1843. d Researches, Physiological and Anatomical, Dunglison's Amer. Med. Lib. Edit. p. 11. Philad. 1840. e Elements of Physiology, by R. Willis, § 103, Lond. 1842. f On Granular Degeneration of the Kidneys, p. 61, London, 1839, or Dunglison's American Med. Library Edit., Philad. 1839. s Hecker's Annalen, xviii. 393 ; and Burdach, op. cit. iv. 29. h Inquiry into the Nature and Properties of the Blood, &c. Lond. 1819. i Medico-Chirurg. Transact, ii. 364. J Op. cit. p. 292. t Philosoph. Transact, for 1809, p. 373. 100 CIRCULATION. united with soda, which keeps it fluid. Consequently, he affirms, any reagent, which takes away the soda, will produce coagulation ; and by^the agency of caloric, "the soda may transform a part of the albumen into mucus. The action of the galvanic pile coagulates the serum, and forms globules in it analogous to those of the blood. * From the analysis of serum, by Berzelius,3 it appears to consist in 1000 parts; —of water, 903; albumen, 80; substances soluble in alcohol, —as lactate of soda and extractive matter, chlorides of sodium and potassium, 10; substances soluble in water,—as soda and animal matter, and phosphate of soda, 4 ; loss, 3. Marcet assigns it. the following composition: —water, 900 parts; albumen, 86-8; chlorides of potassium and sodium, 6-6 ; muco-extractive matter, 4; carbonate of soda, 1-65 ; sulphate of potassa, 0-35, and earthy phos- phates, 0-60; — a result, which closely corresponds with that of Berzelius, who states that the extractive matter of Marcet is lac- tate of soda, united with animal matter. One of the most recent analyses is by M. Lecanu.b According to him, 1000 parts contain, — water, 906 parts; albumen, 78 ; animal matter,soluble in water and alcohol, 1-G9; albumen combined with soda, 2-10; crystalliza- ble fatty matter, 1-20 ; oily matter, 1 ; chlorides of sodium and po- tassium, 6 ; subcarbonate and phosphate of soda, and sulphate of potassa, 2-10; phosphate of lime, magnesia and iron, with subcar- bonate of lime and magnesia, 0-91; loss, l.c Occasionally, the serum presents a whitish hue, which has given rise to the opinion that it contains chyle; but it would seem that this is fatty matter, and that it is always present. In the serum of the blood of .spirit drinkers, Dr. Traill found a considerable portion of this substance, which has been considered to favour the notion, that the human body may, by intemperance, become preternaturally combustible; and has been used to account for some of the strange cases of spon- taneous combustion, or rather of preternatural combustibility, • which are on record. Dr. Christison has likewise met with fat mechanically diffused through the serum, like oil in an emulsion. On one occasion, he procured five per cent, of fat from milky serum, and one per cent, from serum which had the aspect of whey.d The crassamentum or clot is a solid mass, of a reddish-brown colour, which, when gently washed for some time under a small stream of water, separates into two portions, — colouring matter and fibrin. As soon as the blood is drawn from a vessel, the colouring matter of the red globules leaves the central nucleus free; these then unite, as we have seen, and form a network, con- taining some of the colouring matter, and many whole globules. By washing the clot in cold water, the free colouring matter and the globules can be removed, and the fibrin will alone remain. When freed from the colouring matter, the fibrin is solid, whitish, insipid, inodorous, heavier than water, and without action on vege- l$m * Medico-Chirurg. Transactions, iii. 231. b Journal de Pharmacie, xvii.; and Annales de Chimie, &c, xlviii. 308. ' c See,jilso, Boudet, in Journal de Pharmacie, Juin, 1833 ; and Annales de Chimie, Jii^337. d Edinb. Med. and Surg. Journal, xvii. 235, and xxxiii. 274. BLOOD. 101 table colours ; elastic when moist, and becoming brittle by desicca- tion. It yields, on distillation, much carbonate of ammonia, and a bulky coal, the ashes of which contain a considerable quantity of phosphate of lime, a little phosphate of magnesia, carbonate of lime, and carbonate of soda. One hundred parts of fibrin, according to Berzelius, consist of carbon, 53-360; oxygen, 19-685; hydrogen, 7-021 ; azote, 19-934. Fibrin has been designated by various names. It is the gluten, coagulable lymph, ax\6\ fibre of the blood of different writers. Its specific gravity is said to be greater than that of the serum; but the difference has not been accurately esti- mated, and cannot be great. The red particles are manifestly, however, heavier than either, as we find them subsiding during coagulation to the lower surface of the clot, when the blood has flowed freely from the orifice in the vein. Fibrin appears to be the most important constituent of the blood. It exists in animals, in which the red particles are absent, and is the basis of the mus- cular tissue. The colouring matter of the blood, called,by some, cruorin,hema- tin, hematosin, zoo-hematin, hemachroin, globulin (of Lecanu,) and rubrin, has been the subject of anxious investigation with the analytical chemist. We have already remarked, that it resides in distinct particles or globules; and, in the opinion of the best observ- ers, in the envelope of those globules. The globules themselves are insoluble in serum, but their colouring principle is dissolved by pure water, acids, alkalies, and alcohol. Raspail" asserts, that the globules or nuclei are entirely soluble in pure water, but MM. Donne and Boudet, who repeated his experiments, declare that they are wholly insoluble, and Miillerb is of the same opinion. Great uncertainty has always existed regarding the cause of the colour of the globules. As soon as the blood was found to contain iron, the peroxide of which has a red hue, the colour of the red globules was ascribed to the presence of that metal. Fourcroy and Vauquelinc held this opinion, conceiving the iron to be in the state of subphosphate; and they affirmed, that if this salt be dissolved in serum by means of an alkali, the colour of the solution is exactly like that of the blood. Berzelius,d however, showed, that the sub- phosphate of iron cannot be dissolved in serum by means of an alkali, except in very minute quantity; a*nd that this salt, even when rendered soluble by phosphoric acid, communicates a tint quite different from that of the red globules. He found that the ashes of the colouring matter always yield oxide of iron in the proportion of ^r.th of the original mass; whence it was inferred, that iron is somehow or other concerned in the production of the colour; but the experiments of Berzelius did not indicate the state in which that metal exists in the blood. He could not detect its presence by any of the liquid tests. * Chimie Organique, p. 368, Paris, 1833. b Handbuch der Physiologie, Baly's translation, p. 105, Lond. 1S38. 1 System. Ohyra. ix. 207. Annales de Chimie, xii. 147. f A Treatise on the Blood, &c. p. 27, Lond. 1794. s Annals of Philosophy, vol. iv. 139. t An Essay on the Blood, p. 68, Lond. 1824. i Researches, Physiological and Anatomical, Dunglison's Amer. Med. Lib. Edit. p. 6, Philad. 1840. J Muller's Physiology, Baly's translation, p. 98, Lond. 1838. k Chimie Organique, p. 361. IQQ CIRCULATION. blood, prevent or retard its coagulation. Hewson found, that the sulphate of soda, the chloride of sodium, and the nitrate of potassa were amongst the most powerful salts in this respect. The muriate of ammonia and a solution of potassa have the same effect. On the contrary, coagulation is promoted by alum, and by the sulphates of zinc and copper." How these salts act on the fibrin, so as to prevent its particles from coming together, it is not easy to explain. But these are not the only inscrutable circumstances that affect the coagulation of the blood. Many causes of sudden death have been considered to have this result: — lightning and electricity ; a blow upon the stomach ; injury of the brain ; the bites of venomous ani- mals ; certain narcotico-acrid vegetable poisons; also, excessive exercise and violent mental emotions, when they suddenly destroy, &c. Many of these affirmations doubtless rest on insufficient proof. Sir C. Scudamore, for example, asserts that lightning has not this effect. Blood, through which electric discharges were transmitted, coagulated as quickly as that which was not electrified ; and, in animals, killed by the discharge of a powerful galvanic battery, the blood in the veins was always found in a solid state. M. Mandl has summed up the results of modern experiments on this subject as follows. First. The alkalies—potassa, soda, and ammonia—completelypreventcoagulation: limeretardsit. Second- ly. The soluble alkaline salts — combinations of soda, potassa, am- monia, magnesia, baryta and lime, with carbonic,acetic,nitric,phos- phoric, tartaric, citric, boracic, sulphuric and cyanohydric acid, also . thechlorides, in very small quantity,favourcoagulation. On the other hand, these substances in concentrated solution retard it, and even prevent it entirely. The most active salts are the carbonates ; the least so, the combinations of chlorine, and sulphates. 0-007 of carbonate of soda retards coagulation for several hours, whilst the sulphates do not act in the proportion of 14 per 1000. The action of a salt is more marked in proportion as it reddens more the blood; whilst the combinations of chrome, chlorine and iodine do not redden it, and do not prevent its coagulation. When water is added to blood thus liquefied by a salt it coagulates again — the fibrin being precipitated. Thirdly. Metallic salts decompose the blood; some causing coagulation; others preventing it. Fourthly. Very dilute vegetable acids favour coagulation ; when a little more concentrated, they prevent it; and when highly concentrated, they decompose it like the mineral acids. Fifthly. The action of the vegetable substances has not been sufficiently studied: some affirm, for instance,,that narcotics prevent coagulation ; others that they favour it. The same doubt exists in regard to the action of poisons ; it is generally believed, however, that they — as well as lightning, a violent discharge of electricity, the instantaneous destruction of the nervous system, &c. — prevent coagulation. Sixthly. Very dilute solutions of gum Arabic, sugar, albumen, milk, &c, appear to act a Magendie, Lectures on the Blood, in London Lancet, reprinted in Bell's Select Medical Library, Philad- 1839. BLOOD. 1Q7 only in a mechanical manner by preventing the approximation of the coagulated particles. We shall find, hereafter, that the presumed action of some of these agents has been considered evidence that the blood may be killed; and, consequently, that it is possessed of life. All the phenomena, indeed, of coagulation, inexplicable in the present state of our knowledge, have been invoked to prove this position. The preservation of the fluid state, whilst circulating in the vessels — although agitation, when it is out of the body, does not prevent its coagulation — has been regarded of itself, sufficient evidence in favour of the doctrine. Dr. Bostock,3 indeed, asserts, that perhaps the most obvious and consistent view of the subject is, that fibrin has a natural disposition to assume the solid form, when no cir- cumstance prevents it from exercising this inherent tendency. As it is gradually added to the blood, particle by particle, whilst that fluid is in a state of agitation in the vessels, it. has no opportunity, he conceives, of concreting; but when it is suffered to lie at rest, either within or without the vessels, it is then liable to exercise its natural tendency. It is not our intention, at present, to enter into the subject of the vitality of the blood. The general question will be considered in a subsequent part of this work. We may merely observe, that, by the generality of physiologists, the blood is pre- sumed, either to be endowed with a principle of vitality, or to receive from the organs, with which it comes in contact, a vital impression or influence, which, together with the constant motion, counteracts its tendency to coagulation.b Even Magendie,6 — who is unusually and properly chary in having recourse to this method of explaining the no turn per ignotius, — affirms, that instead of referring the coagulation of the blood to any physical influence, it should be considered as essentially a vital process; or, in other words, as affording a demonstrative proof, that the blood is endowed with life. Within a few years, Vauquelin has discovered in the blood a considerable quantity of fatty matter, of a soft consistence, which he, at first, considered to be fat; but Chevreul,d after careful in- vestigation, declared it to be identical with the matter of the brain and nerves, and to form the singular compound of an azoted fat. Cholesterin has been detected in it by Gmelin,e and by Boudet.f Prevost and Dumas, Segalas, and others have likewise demon- strated the existence of urea in the blood of animals, from which the kidneys had been removed. Chemical analysis is, indeed, adding daily to our stock of information on. this matter; and is exhibiting to us, that many of the substances, which compose the tissues, exist in the very state in the blood in which we meet with them in the tissues. This is signally shown in the analysis of the 1 Physiology, 3d edit. p. 271, Lond. 1836. b J. Muller's Handbuch, u. s. w. Baly's translation, p. 97, Lond. 1838. c Precis, &c, ii. 234. * Bostock's Physiology, p. 294. « Chimie, iv. 1163. f Journ. de Pharmacie, Paris, 1833, and Annales de Chimie, Hi. 337. 108 CIRCULATION. blood by M. Lecanu,3 who found it,in one analysis, to be composed — in 1000 parts — of water, 785-590; albumen, 69-415; fibrin, 3-565; colouring matter, 119626; crystallizable fatty matter, 4-300; oily matter, 2-270; extractive matter, soluble in alcohol and water, 1-920; albumen'combined with soda, 2010 ; chlorides of sodium and potassium, alkaline phosphate, sulphate, and sub- carbonates, 7-304 ; subcarbonate of lime and magnesia, phosphates of lime, magnesia, and iron, peroxide of iron, 1-414; loss, 2-586. On this analysis, Dr. Proutc has remarked, that gelatin is never found in the blood, or any product of glandular secretion, and he adds, that a given weight of gelatin contains at least three or four per cent, less carbon than an equal weight of albumen. Hence, the production of gelatin from albumen, he conceives, must be a reducing process. We have seen, under the head of Respiration, what application he makes of these considerations. Dutrochet believed that he had formed muscular fibres from al- bumen by the agency of galvanism; and he supposed that the red particles of the blood formed each a pair of plates, the nucleus being negative, the envelope positive :d but Mullere has shown, that all the appearances, which he attributed to different electric proper- ties of the blood are explicable by the precipitation of the albumen and fibrin, in consequence of the decomposition of the salts of the serum, and of the oxidation of the copper wire used in the expe- riments, — both the decomposition of the salts and the oxidation of the copper being the usual effects of galvanic action. With the galvanometer he was unable to discover any electric current in the blood: he perceived no variation in the needle of the multi- plicator,even when he inserted one wire into an artery of a living animal, and the other into a vein. Lastly,— some interesting experiments and considerations on the blood have been published by Dr. Benjamin G. Babington/ The principal experiment was the following. He drew blood, in a full stream, from the vein of a person labouring under acute rhematism, into a glass vessel filled to the brim. On close inspection, a colourless fluid was immediately perceived around the edge of the surface, and after a rest of four or five minutes, a bluish appearance was observed forming an upper a Annales de Chimie et de Physique, xlviii. 308, and Journal de Pharmacie, Sept. 1831. b For an analysis of the Blood by Boudet, see Journal de Pharmacie, Juin, 1833. c Bridgewater Treatise, Amer. Edit. p. 280, Philad. 1834; see, also, J. Miiller, op. citat. 133 ; Thomson, Animal Chemistry, p. 349, Edinb. 1843. d See, also, Bellingeri Experimenta in Etectricitatem Sanguinis, Urinae et Bilis Ani- maliuin, Aug. Taurin. 1826 — cited by J. Miiller, loc. cit.; and Burdach, Die Physio- logie als Erfahrungswissenschaft, iv. 15 und 103, Berlin, 1832. e Handbuch, u. s. w., Baly's translation, p. 133. f Med. Chirurg. Transact, vol. xvi. part 2, Lond. 1831 ; art. Blood (Morbid Con- ditions of the) in Cyclop. Anat. and Physiol., Lond. 1836 — reprinted in Dunglison's American Medical Library and Intelligencer, for April, 1837. See, also, on this sub- ject, the views of Dr. John Davy, in his Researches, Physiological and Anatomical, Dunglison's Amer. Medical Library edit., p. 13, Philad. 1840. BLOOD. 109 layer on the blood, which was owing to the subsidence of the red particles to a certain distance below the surface, and the con- sequent existence of a clear liquor between the plane of the red particles and the eye. A spoon, previously moistened with water, was now immersed into the upper layer of liquid, by a gentle de- pression of one border. The liquid was thus collected quite free from red particles, and was found to be an opalescent, and some- what viscid solution, perfectly homogeneous in appearance. By repeating the immersion, the fluid was collected in quantity, and transferred to another vessel. That, which Dr. Babington em- ployed, was a bottle, holding about 180 grains, of globular form, with a narrow neck and perforated glass stopper. The solution, with which the globular bottle was filled, though quite homoge- neous at the time it was thus collected, was found, after a time, to separate into two parts, viz., into a clot of fibrin, which had the precise form of the bottle into which it was received, and a clear serum, possessing all the usual characters of the fluid. From this experiment, Dr. Babington infers, that buffed blood, to which we shall have to refer under another head, consists of only two con- stituents, the red particles, and a liquid to which he gives the name, liquor sanguinis — the plasma of Schultz8 — so called by him, because he esteems it to be the true nutritive and plastic portion of the blood, from which all the organs of the body are formed and nourished. It has long been observed, that the blood of inflammation is longer in coagulating than the blood of health, and that the last portion of blood drawn from an animal, coagulates the quickest. The immediate cause of this buffy coat is thus explained by Dr. Babington. The blood, consisting of liquor sanguinis and inso- luble red particles, preserves its fluidity long enough to permit the red particles, which are of greater specific gravity, to subside through the liquor sanguinis. At length, the liquor sanguinis separates, by a general coagulation and contraction, into two parts, and this phenomenon takes place uniformly throughout the liquor. That part of it, through which the red particles had time to fall, furnishes a pure fibrin or buffed crust, whilst the portion, into which the red particles had descended, furnishes the coloured clot. This, in extreme cases, may be very loose at the bottom, from the great number of red particles collected there, each of which has supplanted its bulk of fibrin, and consequently diminished its firmness in that part. There is, however, with this limitation, no more fibrin in one part of the blood than another. It is a well known fact, that the shape of the vessel, into which the blood is received, influences the depth of the buff.b The space, left by the gravitation of the red particles, bears a proportion to the whole perpendicular depth of the blood, so that in a shallow vessel scarcely any buff may appear, whilst the same blood in a » See an analysis of Professor Schultz's Views, in Lond. Lancet, Aug. 1839, p. 712. b Dr. J. Davy, op. citat. p. 45. VOL. II. — 10 110 CIRCULATION. deep vessel would have furnished a crust of considerable thickness; but Dr. Babington asserts, that even the quantity of the crassa- mentum is dependent, within certain limits, on the form of the ves- sel. If this be shallow, the crassamentum will be abundant; if approaching the cube or sphere in form, it will be scanty. The difference is owing to the greater or less distance of the coagulating particles of fibrin from a common centre, which causes a more or less powerful adhesion and contraction of these particles. This is a matter of practical moment, inasmuch as blood is conceived to be thick or thin, rich or poor, in reference to the quantity of cras- samentum; and pathological views are entertained in consequence of conditions, which after all depend not perhaps on the blood itself, but on the vessel into which it is received. To remove an objection, that might be urged against a general conclusion deduced from the experiment cited, — that it was made upon blood in a diseased state, Dr. Babington received some healthy blood into a tall glass vessel, half filled with oil, which enabled the red particles to subside more quickly than would otherwise have been the case. This blood was found to have a layer of liquor sanguinis, which formed a buffy coat, whilst a portion of the same blood, received into a similar vessel, in which there was no oil, had no buff. Hence, it would appear, that healthy blood is similarly constituted as blood disposed to form a buffy coat, the only difference being, that the former coagulates more quickly than the latter. Dr. J. Davy,a however, has observed, that inflammatory blood, in some instances, does not coagulate more slowly than healthy blood, and as from the experiments of J. Miillerb it would appear that the presence of fibrin in the blood favours the subsidence of the red particles, Miiller was led to infer, that the formation of the buffy coat may arise from the blood containing a larger quantity of fibrin, which the blood of inflam- mation is known to do. So that the principal causes, he thinks, of the subsidence of the red particles and the formation of the buffy coat in inflammatory blood appear to be — the slow coagulation of the blood and the increased quantity of fibrin.c The most correct view is, perhaps, that of Andral,*1 that the essential condition of the huffy coat is an increase in the quantity of fibrin'in proportion to the red particles. Hence, if there be an absolute increase of fibrin, thered particles remaining the same, as in inflammation ; or, if there be a diminution in the proportion of the red particles, the fibrin remaining the same, the buffy coat may result. » Philosophical Transactions, for 1822. b Op. citat. p. 117; and Magendie, Legons sur le Sang, &c, or translation in Lond. Lancet, and in Bell's Med. Libr. edition, p. 77, Philad. 1839. c Dr. J. Davy, Researches, &c. p. 28 ; see, connected with the buffy coat and the life of the blood, the remarks in the latter part of this volume, under the head of Life. * Hematologic Pathologique, p. 75, Paris, 73. See, also, Carpenter, Human Physio- logy, § 589, Lond. 1842, or Amer. Edit. p. 430 ; and the author's Practice of Medi- cine, Book 3, 2d edit., Philad. 1844. BLOOD. Ill It need scarcely be said, that venous blood must differ somewhat in its character in the different veins. In its passage through the capillary or intermediate circulation, the arterial blood is deprived of several of its elements, but this deprivation is different in differ- ent parts of the body. The blood, for example, which returns from the salivary glands, must vary from that which returns from the kidneys. In the blood of the abdominal venous system, the greatest variation is observed. Professor Schultza has, of late, in- quired into the chemical and physiological differences between the blood of the vena portae and that of the arteries and other veins. He found, that it is not reddened by the neutral salts, or by expo- sure to the atmosphere, or to oxygen; that it does not generally coagulate; that it contains 5-23 per cent, less fibrin; proportion- ably more cruor, and less albumen; and has twice as much fat in its solid parts as that of the arteries and the other veins; the pro- portions being as follows: Blood of the vena portae - 1'66 per cent. ---- of the arteries ... 0-92 ---- of the other veins - - - 0-83 The character and quantity of the different constituents of the blood, as well as its coagulation, vary greatly in disease; and the investigation is one of the most important in the domain of patho- logy.11 It is one which has attracted the attention of modern patho- logists, and especially of MM. Andral and Gavarret, who have en- deavoured to detect the changes that occur in disease in the amount of the organic elements of the fluid. These the author has referred to in their appropriate places in another work.0 The usual propor- tions of each element, in 1000 parts of healthy blood, are as follows: Fibrin, 3; red particles, 127; solid matter of serum, 80; water, 790. The proportion of fibrin may perhaps vary, within the limits of health, from 2h to 31 parts in a thousand. The amount of red particles appears to be subject to greater variation, within the limits of health, than that of the fibrin. The maximum is about 140, but this is connected with a plethoric condition ; the minimum is about 110. Strength of constitution contributes most to raise the globules towards the maximum; whilst debility, con- genital or acquired, diminishes them towards the minimum pro- portion. The solid matter of the serum likewise varies, but » Rust, Magazin fiir die gesammt. Heilkund. Bde. 44, H. i. See, also, Ancell's Lec- tures on the Physiology, &c. of the Blood, Feb. 1, 1840, p. 682 ; and Prof. Schultz, in Lond. Lancet, Aug. 10, 1839, p. 7 17. b See, on this subject, Babington, op. citat.; G. O. Rees's Analysis of the Blood and Urine, in Health and Disease, Lond. 1836 ; Mr. E. A. Jennings's Report on the Che- mistry of the Blood, as illustrating its Pathology, in Transact, of the Provincial Medical and Surgical Association, vol. iii., Lond. 1835 ; Giacomini, De la Nature, de la Vie, et des Maladies du Sang, — Monograph, in Encyclographie des Sciences Medicales, Avril, 1840; L, Mandl, Manuel d'Anatomie generale, 271, Paris, 1843; MM. Andral and Gavarret, Archiv. General. Serie 3, torn. viii. p. 501 ; and Andral, Hematologic Pa- thologique, Paris, 1843. f Practice of Medicine, 2d edit. Philad. 1844. 112 CIRCULATION. there is a certain point of diminution below which they do not pass in health.* 3. PHYSIOLOGY OF THE CIRCULATION. The blood, contained in the circulatory apparatus, is in constant motion. The venous blood, brought from every part of the body, is emptied into the right auricle ; from the right auricle it passes into the corresponding ventricle ; the latter projects it into the pul- monary artery, by which it is conveyed to the lungs,passing through the capillary system into the pulmonary veins. These convey it to the left auricle ; from the left auricle it enters the corresponding ventricle ; and the left ventricle sends it into the aorta, along which it passes to the different organs and tissues of the body, through the general intermediate or capillary system, which communicates with the veins; these last vessels return the blood to the part whence it set out. This entire circuit includes both the lesser and the greater circulation. It was not until the commencement of the seventeenth century, that any precise ideas were entertained regarding the general cir- culation. In antiquity, the most erroneous notions prevailed; the arteries being generally looked upon as tubes for the conveyance of some aerial fluid to, and from, the heart, whilst the veins con- ducted the blood, but whither or for what precise purpose was not understood. The names, given to the principal arterial vessel — the aorta — and to the arteries, sufficiently show the functions originally ascribed to them, both being derived from the Greek, ««v, " air," and nftu, " to keep ;" and this is farther confirmed by the fact, that the trachea or windpipe was originally termed an artery, — the */>t*/>/* tfn^u* of the Greeks, — the aspera arteria of the Latin writers. In the time of Galen, however, the arteries were known to contain blood; and he seems to have had some notions of a circulation. He remarks, that the chyle, the product of digestion, is collected by the meseraic veins and carried to the liver, where it is converted into blood ; the supra-hepatic veins then convey it to the pulmonary heart; thence it proceeds in part to the lungs, and the remainder to the rest of the body, passing- through the median septum of the auricles and ventricles. This limited knowledge of the circulation continued through the whole of the middle ages; the functions of the veins being3 universally misapprehended ; and the general notion being, that they also con- vey blood from the heart to the organs ; from the centre to the circumference. It was not until after the middle of the sixteenth century, that the lesser circulation, or that through the lun»s was comprehended, by the labours of Michael Servetusb__who'fell a » Andral, Hematologic Pathologique, p. 29, Paris, 1843, b See the unnoticed theories of Servetus, by Geo. Sigmond, M.D., Lond 1828 • Hecker, Lehre vom Kreislauf von Harvey, Berlin, 1831 ; Haller, Element. Physiol' iv. 4, 17 ; Sprengel's Hist, de Me'decine, par Jourdan, torn. iv.; Dr. J. R Coxe In! quiry into the Claims of Dr. W. Harvey to the Discovery of the Circulation &c Philad. 1834 ; and Gerdy, in art. Circulation, Diction, de Medecine, 2de edit viii 68 Paris, 1834. * * ' PHYSIOLOGY OF THE CIRCULATION. 113 victim to the persecution and intolerance of Calvin, — and of An- drew Caesalpinus, and Realdus Columbus. It has, indeed, been imagined, that they possessed some notion of the greater circula- tion. However this may have been, all nations unite in awarding to Harvey the merit, if not of entire originality, of at least of hav- ing first clearly described it. The honour of the discovery is, there- fore, his; and by it his name has been rendered immortal, for its importance to the physiology and pathology of the animal fabric is overwhelming. How vague and inaccurate must have been the notions of the earlier pathologists regarding the doctrine of acute diseases, in which the circulation is always largely affected, — diseases, which, according to the estimate of some writers, consti- tute two-thirds of the morbid states to which mankind are liable. It was in the year 1619, that Harvey attained a full knowledge of the circulation ; but his discovery was not promulgated until the year 1628 ; in a tract, to which the merit of clearness, perspicuity and demonstration has been awarded by all.a Yet so strong is the force of prejudice, and so difficult is it to discard preconceived notions, that it was remarked, according to Hume,b that no physi- cian in Europe, who had reached forty years of age, ever, to the end of his existence, adopted Harvey's doctrine of the circulation ; and Harvey's practice in London diminished extremely for a time from the reproach drawn upon him by that great and signal dis- covery.0 Of the truth of the course of the blood, as established by Harvey, we have numerous and incontestable evidences, which it may now be almost a work of supererogation to adduce. Of these the fol- lowing are some of the most striking. First. If we open the chest of a living animal, we find the heart alternately dilating and con- tracting so as manifestly to receive and expel the blood in reciprocal succession. Secondly. The valves of the heart, and of the great arteries, which arise from the ventricles, are so arranged as to allow the blood to flow in one direction, and not in another; and the same may be said of those veins, which are directed towards the heart. The tricuspid valve permits the blood to flow only from the right auricle into the corresponding ventricle; the sigmoid valves admit it to enter the pulmonary artery, but not to return : and, as there is, in the adult, no immediate communication between the right and left sides of the heart, the blood must pass along the pulmonary artery and by the pulmonary veins to the left auricle. The mitral valve, again, is so situate, that the blood can only pass in one direction from auricle to ventricle ; and, at the mouth of the aorta, the same valvular arrangement exists, as at the mouth of the pulmonary artery, permitting the blood to proceed along the artery, but preventing its reflux. Thirdly. If an artery and a » Exercitat. Anatom. de Motu Cordis et Sanguinis, Francof, 1628, Glasguse, 1751. b History of England, chap. lxii. c See, also, Purkinje.in art. Circulatio Sanguinis, in Encyclop. Wb'rterb. der Medicin, Wissenschaft. vii. 695, Berlin, 1831. 10* 114 CIRCULATION. vein be wounded, the blood will be observed to flow from the part of the vessel nearest the heart in the case of the artery ; from the other extremity in that of a vein. The ordinary operation of bloodletting at the flexure of the arm affords us an elucidation of this. The bandage is applied above the elbow, for the purpose of compressing the superficial veins, but not so tightly as to compress, also, the deep-seated artery. The blood passes along the artery to the extremity of the fingers, and returns by the veins, but its progress back to the heart by the subcutaneous veins being pre- vented by the ligature, they become turgid; and, if a puncture be made, the blood flows freely. If, however, the ligature be applied so forcibly as to compress the main artery, the blood no longer flows to the extremity of the fingers; there is none, consequently, to be returned by the veins; they do not rise properly ; and if a puncture be made no blood flows. This is not an unfrequent cause of the failure of an inexperienced phlebotomist. If the ban- dage, under such circumstances, be slackened, the blood will re- sume its course along the artery, and a copious stream will issue from the orifice, which did not previously transmit a drop. This operation, then, exhibits the fact of the flow of blood along the arteries from the heart, and of its return by the veins. From what has been said, too, it will be obvious, that if a ligature be applied to both vessels, the artery will become turgid above the ligature, the vein below it. Fourthly. The microscopical experi- ments of Leeuenhoek, Malpighi, Spallanzani, and others, have ex- hibited to the eye the passage of the blood in successive waves by the arteries towards the veins, and its return by the latter. Lastly. The fact is farther demonstrated by the effects of transfusion of blood, and of the injection of substances into the vessels; both of which operations will be alluded to in another place.a In tracing the physiological action of the different parts of the circulatory apparatus, we shall follow the order observed in the anatomical sketch ; and describe, in succession, the circulation in the heart, in the arteries, in the capillary vessels, and in the veins ; on all of which points there has been much interesting diversity of opinion, and much room for ingenious speculation, and for farther improvement. a. Circulation in the Heart. It has been already observed, that when the heart of a living animal is exposed, it is remarked to undergo alternate contraction and dilatation. The mode, in which the circulation through the heart is accomplished, is generally considered to be as follows: —- the blood is received into the two auricles at the same time, and is transmitted into the two great arteries synchronously. In order that the heart shall receive blood, it is necessary that the auricle should be dilated. This movement is partly, perhaps, ef- fected by virtue of the elasticity which it possesses in its structure. » Bostock's Physiology, 3d edit. p. 213, Lond. 1836. IX THE HEART. 115 Let us suppose it to be once filled ; the stimulus of the blood ex- cites it to contraction, and the blood is thus sent into the corre- sponding ventricle. As soon, however, as it has emptied itself, the stimulus is withdrawn : and, by virtue of its elasticity, it re- turns to the state in which it was prior to contraction. An approach to a vacuum is thus formed in the cavity, and the blood is solicited towards it from the veins, until it is again filled and its contraction is renewed. When the right auricle contracts there are four chan- nels by which the blood might be presumed to pass from it, — the two terminations of the ve'nse cavae, the coronary vein, and the auriculo-ventricular communication. The constant flow of blood from every part of the body prevents it from readily returning by the venae cavse, whilst the small quantity, which, under other cir- cumstances, might have entered the coronary vein, is prevented by its valve. To the flow of the blood through the aperture into the ventricle, which is in a state of dilatation, there is no obstacle, and accordingly it takes this course, raising the tricuspid valves. It may be remarked, that physiologists are not entirely of ac- cord regarding the reflux of blood into the venas cavas. Some think that this always occurs to a slight extent; others, that it is never present in the physiological or healthy state. Its existence is unequivocal, where an obstacle occurs to the due discharge of the blood into the ventricle. For example, if any impediment exists to the flow of blood along the pulmonary artery, either owing to mechanical obstruction or to diminished force of the ven- tricle, the reflux will be manifested by a kind of pulsation in the veins, which Haller has called the venous pulse. The blood, having attained the right ventricle, by the effort exerted by the contraction of the auricle, and by the aspiration exerted by the dilatation of the cavity through the agency of its elastic structure,the ventricle contracts. Into it there are but two apertures, — the auriculo-ventricular, and the mouth of the pul- monary artery. By the former, much of the blood cannot escape, owing to the tricuspid valve, which acts like the sail of a ship,__ the blood distending it, as the wind does a sail, and the chorda) tendineas retaining it in position, so that the greater part of the blood is precluded from reflowing into the auricle. This auriculo- ventricular valve is not, however, as perfect as that of the left heart. The observations of Mr. Kinga show, that whilst the struc- ture of the mitral valve is adapted to close accurately all commu- nication between the left auricle and ventricle during the contrac- tion of the latter, that of the tricuspid valve is designedly calcu- lated to permit, when closed, the flow of a certain quantity of blood into the auricle. The comparatively imperfect valvular function of the tricuspid was shown by various experiments on recent hearts, in which it was found, that fluids, injected through the aorta into the left ventricle, were perfectly retained in that ■ Guy's Hospital Reports, No. iv. for April, 1837 ; see, also, P. Blakiston, Lond. Med. Gaz., Aug. 1841. 116 CIRCULATION. cavity, by the closing of the mitral valve, but that when the right ventricle was similarly injected through the pulmonary artery, the tricuspid valves generally allowed the escape of the fluid in streams, more or less copious, in consequence of the incomplete apposition of their margins. This peculiarity of structure in the tricuspid, Mr. King regards as an express provision against the mischiefs that might result from an excessive afflux of blood to the lungs, — the tricuspid thus acting as a safety valve, and being more especially advantageous in incipient diseased enlarge- ments of the right ventricle. The only other way the blood can escape from the right ventricle is by "the pulmonary artery, the sigmoid valves of which it raises. These had been closed like flood-gates, during the dilatation of the ventricle; but they are readily pushed outwards, by the column transmitted from the ventricle. Such is the circulation through one heart,— the pul- monic. The same explanation is applied to the other, — the sys- temic ; and hence it is, that the structure, as well as the functions of the heart, is so much better comprehended, by conceiving it to be constituted of two essentially similar organs. The above description is that which is usually given of the cir- culation through the heart. There is great reason, however, for the belief, that too much importance has been assigned to the distinct contraction of the auricles. If we examine their anato- mical arrangement we discover, that there are no valves at the mouths of the great veins which open into them, and that, although, in the proper auricular or dog's ear portion, muscular fibres, and columns, — somewhat analogous to those of the columnae cameae of the ventricles, and probably destined for similar uses — exist, the parietes of the main portions of the auricles — or those that constitute the venous sinuses — are but little adapted for anything like energetic contraction. In experiments on living animals ob- servation shows, that the rhythmic acts of dilatation and contrac- tion are more signally exhibited by the ventricle, whilst in some monsters the auricles are wanting, and in birds they are very small. M. d'Espine, too, considers the auricles, in receiving or transmitting blood, to have only a vermicular motion, not one of contraction ; and in an interesting case of monstrosity, described by Dr. T. Robinson,a of Petersburg, Virginia, no distinct systole and diastole of the auricles could be detected. Besides, if we admit both an active power of dilatation and of contraction in the ventricles, any similar action of the auricles would seem to be superfluous. In the state of active dilatation of the ventricles, the blood is drawn into their cavities; and as soon as they enter into contraction, the auriculo-ventricular valves prevent the farther entrance into them of the blood arriving in the auricles by the large veins, and give occasion to the distension of the auricles; in this way, the dilatation of the auricles, synchronous with the contraction of the ventricles, is accounted for. As soon as the ven- 1 American Journal of the Medical Sciences, No. xxii. for February, 1833. IN THE HEART. 117 tricle has emptied itself of its blood, it dilates actively ; the blood then passes suddenly from the auricle into its cavity through the auriculo-ventricular opening. From careful experiments instituted by Drs. Pennock and Moore,a they drew the following conclusion : —the ventricles con- tract and the auricles dilate at the same time, occupying about one-half the whole time required for contraction, diastole, and re- pose. Immediately at the termination of the systole of the ven- tricle, its diastole succeeds, occupying about one-fourth of the whole time, synchronously with which the auricle diminishes, by emptying a portion of its blood into the ventricle, but without muscular contraction. The remaining fourth is devoted to the repose of the ventricles, near the termination of which the auricle contracts actively, with a short, quick motion, thus distending the ventricles with an additional quantity of blood; this motion is pro- pagated immediately to the ventricles, and their systole takes place, thus rendering their contractions almost continuous. From the termination of their diastole to the commencement of their systole, the ventricles are in a state of perfect repose, their cavities remaining full, but not distended; whilst those of the auricles are partially so, during the whole time. It appears probable, that the great use of the auricles —in which we include the sinuses — is to act as true " sinuses" or gulfs for the reception of the blood proceeding from every part of the body ; — and that little effect is produced on the circulation by their varying condition.13 The state of the heart in which the ventricles are dilated is termed its Diastole ; that, in which they are contracted, its Systole. Since the valuable improvement, introduced by Laennec in the discrimination of diseases of the chest by audible evidences, it has been discovered, that the heart is not in a state of incessant activity, but that it has, like other muscles, its intervals of repose. If we apply the ear or the stethoscope, to the praecordial region, we hear, first, a dull,lengthened sound,c which according to Laennec is syn- chronous with the arterial pulse, and is produced by the contrac- tion of the ventricles. This is instantly succeeded by a sharp, quick sound like that of the valve of a bellows or the lapping of a dog. To convey a notion of these sounds, Dr. C. J. B. Williams employs the word lubb-dup. The first word of the compound expressing the protracted first sound — and the latter the short second sound. The latter sound corresponds to the interval between two pulsations, and is owing to the contraction of the auricles. The space of time, that elapses between this and the sound of the contraction of the ventricles, is the period of repose. The relative a Medical Examiner, Nov. 2, 1839, and Dunglison's American Medical Intelligencer, Dec. 16, 1839, p. 277. b See, on this subject, Elliotson's Human Physiology, p. 174, Lond. 1840. c A Treatise on the Diseases of the Chest, translated by Dr. Forbes, 4th edit. Lond. 1834. s 118 CIRCULATION. duration of these periods is as follows :— one half, or somewhat less, for the contraction of the ventricles; a quarter, or somewhat more, for the contraction of the auricles ; and the remaining quarter for the period of total cessation from labour. So that in the twenty- four hours the ventricles work twelve hours and rest twelve ; and the auricles work six and rest eighteen. Such is the view of Laen- nec ; but it is manifestly erroneous. Ocular observation on living animals, as Dr. Alison3 has remarked, shows that the emptying of the auricle precedes that of the ventricle, and that the interval of rest is between the contraction of the ventricle, and the next con- traction or emptying of the auricle : between the contraction of the auricle, and that of the ventricle, there is no appreciable interval. Pucheltb thinks it most probable that the first sound is caused by the impulse of the blood against the walls of the ventricle during the contraction of the auricles, and the second by the impulse of the blood against the commencement of the arteries during the contraction of the ventricles. M. d'Espine thinks that the first sound is produced by the contraction of tne ventricle, and that the second is owing to their dilatation.0 Our knowledge, indeed/^of the. cause of the sounds rendered by the heart, is sufficiently imprecise this is farther proved by the circumstance, that Magendie ascribed the first sound to the shock or impulsion of the apex of the heart during its diastole, and the second to the impulsion of the base of the heart during its systole; but the results of more recent expe- riments'1 lead him to infer, that the first sound is owing to the con- traction of the ventricles, and to the impulse of the apex of the heart against the ribs, and the second sound to a similar impulse produced by their dilatation. Rouanete ascribes the first or dull sound to the shock or impulse of the tricuspid and mitral valves against the auriculo-ventricular orifices, and the second or clear sound to the succussion of the blood in the distended aorta and pulmonary artery backwards against the semilunar valves, during the dilatation of the ventricles; and a similar opinion is entertained by Dr. Hopef and by Messrs. Mayos and Bouillaud.h Mr. Car- lisle' and Dr. WilliamsJ referred the first sound, with Laennec, to the systole of the ventricles, and the second to the obstacle pre- sented by the semilunar valves to the return of the blood from the * Outlines of Physiology, Lond. 1831. b System der Medicin. th. i. Auflage 2te, s. 149, Heidelb. 1835. c Revue Medicale, Oct. 1831. & Annales des Sciences Naturelles, 1834. e Ibid. No. xcvii. f For an elaborate account of the Experiments on the Action and Sounds of the Heart up to the period of the publication of the work, see Dr. Hope, Treatise on Dis- eases of the Heart, 3d edit. p. 9, Lond. 1839 ; or Amer. Edit, by Dr. Pennock Philad 1842. s Outlines of Human Pathology, p. 465, Lond. 1836. b Journal Hebdomad. No. ix., 1834. i Report of the Third Meeting of the British Association for the Advancement of Science ; and Amer. Journal of Med. Sciences, p. 477, for Feb. 1835. j A Rational Exposition of the Physical Signs of Diseases of the Lungs and Pleura Amer. Edit. Philad. 1830. 5 eun*' IN THE HEART. k 119 arteries into the heart, — and Messrs. Corrigan,a Pigeaux,b Stokes0 and Mackintosh*1 thought the first sound to be owing to the systole of the venous sinuses, and the second to the systole of the ventri- cles— an opinion, which Burdaclr5 thinks is best founded, but which, as we have seen, is manifestly erroneous/ In a case of ectopia cordis, recently described by Cruveilhier,* by applying the finger to the origin of the pulmonary artery, a distinct vibratory thrill was perceived, which corresponded with the ventricular diastole; but no such thrill could be felt by the fino-er when it was applied to any part of the base of the ven- tricles. He inferred, therefore, that the first sound cannot be de- pendent upon the action of the auriculo-ventricular valves. The greatest intensity of the first sound was, indeed, in the same situa- tion as the greatest intensity of the second, that is, at the origin of the large arteries. Dr. Carpenter* thinks the results of these observations of M. Cruveilhier, clearly establish, that the prin- cipal cause of the first sound exists at the entrances to the arte- rial trunks; and it does not seem to him, that any other reason can be assigned for it than the prolonged rush of blood through their orifices, and the throwing back of the semilunar valves, which, in suddenly flapping down again, produce the second sound. M. Cruveilhier states it, in his opinion, to be a uniform occurrence, that disease of the semilunar valves modifies both sounds; —a fact, which the author has long noticed. Without expressing an opinion as to the validity of M. Cruveilhier's conclusion regarding the two sounds of the heart, Dr. Forbes evidently regards it with favour, under the view long maintained by him, that although certainly characteristically different, the two sounds have so great a simi- larity and are so allied in time and place, that he could not readily brin-his mind to believe, that they do not both depend upon one and ^he same cause, slightly modified, or, at least, on the different play of the same parts.1 Drs. Pennock and Moore,J who agree in the main with Dr. Hope, found'the first sound, the impulse, and the systole of the ventricles to be synchronous ; and the second sound to be synchronous with the diastole of the ventricles. The first sound, they suggest, may be a combination of that caused by the contraction of the auricles the flaDpino- of the auriculo-ventricular valves, the rush of blood from the ventricles, and the sound of muscular contraction. In four of their experiments, when the heart was removed from the a Dublin Medical Trans., vol. i., New Series. b Bulletin des Sciences Medicates, par Ferussac, xxv. 272. c Edinb. Med. and Surg. Journal, vol. xxxiv. d Principles of Pathology, &c, 2d Amer. edit a. 6, Philad. 1837 « Die Physiologie als Erfahrungswissenschaft, iv. 219, Leipz. 183- f Muller's Handbuch, u. s. w., Baly's translation, p 176, Lond.1838. « Gazette Med. de Paris, 7 Aout, 1841, p .535; and Br..j. .n d 1 or Med. Rev., Oct. ,sdl _ =0= h Human Physiology, § 486, Lond. 1842. . Trandation of Laennec, 4th edit.; and Brit, and For. Med. Rev., loc. cit. i Op. citat. 120 CIRCULATION. body, the ventricles cut open and emptied of their contents, and the auriculo-ventricular valves elevated, a sound resembling the first was still heard, which they attribute chiefly to muscular con- traction. The second sound they refer exclusively to the closure of the semilunar valves by the refluent blood from the aorta and pulmonary artery. " This," they remark," is proved by the greater intensity of this sound over the aorta than elsewhere, the blood having a strong tendency to return through the valvular opening; by the greater feebleness of the sound over the pulmonary artery, which is short, and soon distributes its blood through the lungs, thus producing but slight impulse upon the valves in the attempt to regurgitate ; by the disappearance of the sound when the heart becomes congested and contracts feebly ; and, finally, on account of its entire extinction when the valve of the aorta was elevated." The main results of the experiments of Drs. Pennock and Moore accord closely with what the author has entertained and taught on this subject,3 but the views of M. Cruveilhier are well worthy of attention. The whole matter is still open for further inves- tigation. Whilst these sheets, indeed, are passing through the press, a case of thoracic ectopia is published by M. Monod,bin which it is stated, that the maximum of intensity of the first sound did not occur at the base of the ventricles, but at the middle of their fleshy walls; and M. Monod thinks, that it was caused by the shock of the walls of the ventricles against the internal fleshy columns at the moment of contraction. As to the second sound he is of opinion, that it was owing to the return of the wave of blood against the semilunar valves. It has been a question with physiologists, whether the cavities of the heart completely empty themselves at each contraction. Senac,c and Thomas Bartholine,d from their experiments, were long ago led to answer the question negatively. On the other hand, Haller,*5 entertained an opposite opinion, — suggested, he remarks, by his experiments; but, perhaps, notwithstanding all his candour/con- nected, in some manner, with his doctrine of irritability, which could not easily admit the presence of an irritant in a cavity which had ceased to contract. It has been remarked by Magendie/ that if we notice the heart of a living animal, whilst it is in a state of action, it is obvious, that the extent of the contractions cannot have » See Elliotson, Human Physiology, part i. p. 175, Lond. 1840; Hope, op. citat.; Gerhard, on the Diagnosis of Diseases of the Chest, Philad. 1836; Bouillaud Traite' Clinique des Maladies du Cceur, Paris, 1835 ; Raciborski, Manual of Auscultation, by Fitzherbert, p. 102, Lond. 1835; Piorry, Traite de Diagnostic, § 273,2de edit., Brux- elles, 1838; C. J. B. Williams, Lectures on the Chest, in Lond. Lancet, reprinted in Bell's Select Medical Library, Philad. 1839; Drs. Williams, Todd andClendinning in Lond. Med. Gaz. Dec. 10, 1836; and W. H. Walshe, Physical Diagnosis of Dis- eases of the Lungs, Amer. Edit. Philad. 1843. b Bullet, del. Academ. Royale de Med. 7, Fevrier, 1843; and Edinb Med and Surg. Journ., July, 1843. c Traite de la Structure du Cceur, &c. 2d edit. Paris, 1774. * Dissertat. de Corde, Hafn. 1648. c Element. Physiol, iv. f Precis, &c. torn. ii. IN THE HEART. 121 the effect of completely emptying the ventricles; but it must, at the same time, be admitted, that such experiments are inconclusive, inasmuch as they exhibit to us the action of the organ under power- fully deranging influences, and such as could be readily conceived to modify materially the extent of the contractions. They cer- tainly are insufficient to prove, that, whilst an animal is in a phy- siological condition, the auricles and ventricles are not emptied of their contents by their contraction. The quantity of blood con- sequently propelled at each ventricular contraction, must fall short of two fluid ounces. The objection that has been urged against the opposite view, that there would always be stagnant blood in the cavities of the heart, is not valid. The experiments of Venturi,a have shown, that even in an ordinary hy- draulic appara- Fig.167. tus, the motion us suppose a '^ ^ stream of water to enter the vessel D E F B, Fig 167, which is full of fluid, by the pipe A C, and that opposite to this pipe is the tube S M B R. The stream will pass up this tube higher than the vessel, and discharge itself at B V. At the same time, the fluid in the vessel will be observed to be in motion, and, in a few seconds, the level in the vessel will fall from D B to H M. During the systole of the heart, the organ is suddenly carried forward ; and although it appears to be rendered shorter, its point strikes the left side of the chest opposite the interval between the •fifth and seventh true ribs; producing what is called the " beating of the heart." The cause of this phenomenon was, at one period, a topic of warm controversy. Borelli,b Winslow, and others, affirmed, that it was owing to the organ being elongated during contraction ; but to this it was replied by Bassuel,0 that if such elongation took place, the tricuspid and mitral valves, kept down by the colnmnas carneae, could not possibly close the openings be- tween the corresponding auricles and ventricles. Experiments by » Sur la Communication Laterale du Mouvement dans les Fluides, Paris, 1798; ■ml Sir C Bell, in Animal Mechanics, p. 35, Library of Useful Knowledge, Lond. 1829. * De Motu Animalium, Lugd. Bat. 1710. c Magendie, Precis, &c. ii. 395. VOL. II. -- 11 122 CIRCULATION. Drs. Pennock and Moore,a exhibited to them, that the expulsion of the blood from the ventricles was effected by an approximation of the sides of the heart, and not by a contraction of the apex towards the base ; and that, during the systole, the heart performs a spiral movement and becomes elongated. Senacb ascribed the beating of the heart to three causes, and his views have been adopted by most physiologists: — 1, to the dilatation of the auricles, which occurs during the contraction of the ventricles ; 2, to the dilatation of the aorta and pulmonary artery by the introduction of the blood, sent into them by the ventricles ; and 3,to the straightening of the arch of the aorta, owing to the blood being forced against it by the contraction of the left ventricle. Dr. William Hunter,0 con- sidered the last cause quite sufficient to explain the phenomenon, and many physiologists have assented to his view. Sir David Barryd instituted some experiments upon this subject. He opened the thorax of a living animal, and by passing his hands into the cavity, endeavoured to ascertain the actual condition of the heart and great vessels, as to distension and relative position. He per- formed seven experiments, of this kind, from which he concluded, that the vena cava is considerably increased in size during inspira- tion, which he ascribes, as will be better understood hereafter, to the partial vacuum then formed in the chest. He supposes, that the force exerted by the venous blood on entering the heart, in conse- quence of the expansion of the chest and the great vessels behind the heart, pushes the organ forwards, and thus causes it to strike against the ribs. Drs. Pennock and Moore,e however, in their experiments, found the impulse to be synchronous with and caused by the contraction of the ventricles, and that, when felt externally, it arose from the striking of the apex of the heart against the thorax. This is probably the true explanation ; yet Miillerf thinks that great uncertainty rests as to whether the impulse be produced during the contraction or dilatation of the ventricles. The systole of the heart is admitted by all to be active. Some physiologists are disposed to think the diastole passive, — thsU is, the effect of relaxation of the fibres or of the cessation of con- traction. Pechlin, Perrault, Hamberger, d'Espine, Alison, and numerous others, have supported an opposite view ; — affirming that direct experiment on living animals shows, that positive effort is exerted at the time of the dilatation of the cavities ; — a view ■ strikingly confirmed by the case of monstrosity related by Dr. Robinson.& His opinion is, that the force of the diastole was in > Med. Examiner, Nov. 2, 1839. b Traite de la Structure du Cceur, &c, Paris, 1749. c John Hunter, Treatise on the Blood, &c. * Exper. Researches on the influence of atmospheric pressure upon the circulation, Lond. 1826. e 0p- citat> f Handbuch, u. s. w., Baly's translation, p. 175, Lond. 1838. s Amer. Journal of the Medical Sciences, No. xxii. Feb. 1833. See, also a case of partial Ectopia Cordis, by Dr. John O'Bryen, in Lond. Lancet, for July 7, 1838 n 520 • Cruveilhier, op. cit.; and Monod, Bullet de l'Acad. Royale de Med 7 Fev lsi^i a Edinb. Med. and Surg. Journ., July, 1843. '' *™; and IN THE HEART. 123 that case, equal to, if not greater than that of the systole. In the case obseryed by Cruveilhier, the diastole had the rapidity and energy of a very active movement, overcoming pressure exerted upon the heart, so that the hand closed upon it when contracted was opened with violence. It has been suggested, that if the course of all the fibres, composing the muscular parietes of the organ, were better known, this apparent anomaly might perhaps be as easily explained as in the ordinary case of antagonist mus- cles. It is probable, however, that the active force, exerted in the dilatation of these cavities, is that of elasticity; and that when the contraction of the muscular fibres has ceased, this is aroused to action, and promptly restores the organ to its previously dilated condition. According to this view, the natural state would be that of dilatation. We shall see, hereafter, that this elasticity is probably one of the agents of the circulation of the blood along the vessels. The cause of the heart's action has been a deeply interesting question to the physiologist, and, in the obscurity of the subject, has given rise to many and warm controversies. From the first moment of foetal existence, at which the heart becomes percepti- ble, till the cessation of vitality, it continues to move. By many of the ancients this was supposed to be owing to an inherent pulsific virtue? which enabled it to contract and dilate alternately, — a mode of expression, which, in the infancy of physical science, was frequently employed to cover ignorance, and which has been properly and severely castigated by Moliere.b It was in ridicule of the same failing that Swift represents the action of a smokejack as depending on a meat-roasting power.0 Descartes'1 imagined that an explosion took place in the ventri- cles as sudden as that of gunpowder. With equal nescience, the phenomenon was ascribed, by Van Helmonte to his imaginary archaeus ; and by Stahl,f and the rest of the animists, to the anima, soul or intelligent principle, which Is supposed to preside over all the mental and corporeal phenomena. Stahl was, however, one of the first that attempted any rational explanation of the heart's action. Its muscular tissue ; the similarity of its contractions to those of ordinary muscles, with the exception of their not being a Haller, Elementa Physiologise, ii. 6. b " Mihi a doctore Domandatur causam et rationem quare Opium facit dormire. A quoi respondeo; Quia est in eo Virtus dormitiva, Cujus est natura Sensus assoupire." Le Malade Imaginaire, Interraede iii. c Fletcher's Rudiments of Physiology, P. ii. a, p. 52, Edinb. 1836. a Tract, de Homine, p. 167, Amst. 1677. » Ortus Medicin, &c. Amstel. 1648. t Theoria vera Medica, Hal. 1737 ; Sprengel's Hist, de Medecine, par Jourdan, v. 195, Paris, 1815. 124 CIRCULATION. voluntary; the fact of its action being modified by the pas- sions, &c, led him to liken its movements to those of muscles. He admitted, that, generally, we possess neither perception of, nor power over, its motions; but he-affirmed, that habit alone had rendered them involuntary; in the same manner as certain muscular twitchings or tics, which are at first voluntary, may be- come irresistible by habit. A strong confirmation of this opinion was drawn from the celebrated case of the honourable Colonel Townshend, (called by Adelona and other French writers, Captain Towson,) who was able, (not all his life, as Adelon. asserts, but a short time before his death,) to suspend the movements of his heart at pleasure. This case is of so singular a character, in a physiological as well as pathological point of view, that we shall give it in the words of Dr. George Cheyne,b one of the physicians who attended him, and whose character for veracity is bejond sus- picion. " Colonel Townshend, a gentleman of excellent natural parts, and of great honour and integrity, had, for many years, been afflicted with constant vomitings, which had made his life painful and miserable. During the whole time of his illness he had observed the strictest regimen, living on the softest vegetables and lightest animal food ; drinking asses' milk daily, even in the camp; and for common drink, Bristol water, which, the summer before his death, he had drunk on the spot. But his illness increasing, and his strength decaying, he came from Bristol to Bath in a litter, in autumn, and lay at the Bell Inn. Dr. Baynard, who is since dead, and I were called to him, and attended twice a day for about the space of a week : but, his vomitings continuing still incessant, and obstinate against all remedies, we despaired of his recovery. While he was in this condition, he sent for us early one morning; we waited on him with Mr. Skrine, his apothecary (since dead also) ; we found his-senses clear, and his mind calm; his nurse and several servants were about him. He had made his will and settled his affairs. He told us he had sent for us to give him some account of an odd sensation he had for some time ob- served and felt in himself, which was that, composing himself, he could die or expire when he pleased, and yet by an effort, or some- how, he could come to life again ; which it seems he had some- times tried before he had sent for us. We heard this with sur- prise ; but as it was not to be accounted for from tried common principles, we could hardly believe the fact as he related it, much less give any account of it; unless he should please to make the experiment before us, which we were unwilling he should do, lest, in his weak condition, he might carry it too far. He continued to talk very distinctly and sensibly above a quarter of an hour, about this (to him) surprising sensation, and insisted so much on our seeing the trial made, that we were at last forced to comply. We all three felt his pulse first; it was distinct, though small and a Physiologie de l'Homme, edit. cit. iii. 302. b Treatise on Nervous Diseases, p. 307. IN THE HEART. 125 thready; and his heart had its usual beating. He composed him- self on his back, and lay in a still posture, some time. While I held his right hand, Dr. B. laid his hand on his heart, and Mr. S. held a clean looking-glass to his mouth. I found his pulse sink gradually, till at last I could not feel any, by the most exact and nice touch. Dr. Baynard could not feel the least motion in. his heart, nor Mr. Skrine the least soil of breath on the bright mirror he held to his mouth. Then each of us, by turn, examined his arm, heart and breath, but could not by the nicest scrutiny discover the least symptom of life in him. We reasoned a long time about this odd appearance as well as we could; and all of us judging it inexplicable and unaccountable ; and finding he still continued in that condition, we began to conclude indeed that he had carried the experiment too far, and at last were satisfied that he was actually dead, and were just ready to leave him. This continued about half an hour, by nine o'clock in the morning, in autumn. As we were going away, we observed some motion about the body, and upon examination found his pulse and the motion of his heart gradually returning ; he began to breathe gently, and speak softly ; we were all astonished, to the last degree, at this unexpected change, and after some further conversation with him, and among ourselves, went away fully satisfied as to all the particulars of this fact, but confounded and puzzled, and not able to form any rational scheme, that might account for it. He afterwards called for his attorney, added a codicil to his will, settled legacies on his servants, received the sacrament, and calmly and composedly expired about five or six o'clock that evening." It is manifest that this case — unaccountable as it is, in many respects — can add no weight to the views of the Stahlians. It is as strange, as it is inexplicable. The opinion, with them, that the heart's action is a muscular function, was accurate. The error lay in placing it amongst the voluntary functions. It belongs to the involuntary class, equally with many of the muscles concerned in deglutition, and with those of the stomach and intestines; and how well is it for us, as Sir Charles Bell has remarked, that the actions of this and other organs, directly instrumental to the organic functions, are placed out of our control! " A doubt — a moment's pause of irresolution — a forgetfulness of a single action at its ap- pointed time — would otherwise have terminated our existence."a In an oriental journal, Mr. H.'M. Twedelb has published a case, even more extraordinary than that of Col. Townshend, — of a Hindoo, thirty years of age, who " is said, by long practice, to have acquired the art of holding his breath, by shutting the mouth, and stopping the interior opening of the nostrils with the tongue." This man submitted to be buried for a month, and was dug out alive at the expiration of that period. " He was taken out in a perfectly * See Fletcher's Rudiments of Physiology, part ii. b, p. 71, Edinb. 1836. b India Journal of Medical and Physical Sciences; and Amer. Journ. of the Medical Sciences, p. 250, Nov. 1837. 11* 126 CIRCULATION. senseless state — his eyes closed, his hands cramped and powerless — his stomach shrunk very much, and his teeth jammed so fast together, that they were forced to open his mouth with an iron in- strument to pour a little water down his throat. He gradually re- covered his senses, and the use of his limbs, and was restored to perfect health ! The doctrine of Hallera on the heart's action rested upon the vis insita or irritability to which he referred all muscular contrac- tions, whether voluntary or involuntary. This property, as stated in another place, he conceived to be possessed by muscles as mus- cles, independently of all nervous influence. The heart, being a muscle, enjoyed it of necessity ; and the irritant, which developed it incessantly, was the blood. In evidence of this, he observes, that its contractions are always more forcible and rapid, when the blood is more abundant ; and that they occur successively in the cavities of the heart as the blood reaches them. So completely did Haller assign the heart's action to this irritability, that he denied the nerves any influence over it; resting his belief on the admitted facts, — that the. heart will continue to beat after decapitation; after the division of the spinal marrow in the neck; and of the nerves distributed to the organ ; and, even, after it has been en- tirely removed from the body. How far the opinions of this great man are correct, respecting the power of contraction residing in the heart, as he conceived it to do in other muscles, we shall inquire presently. The heart, however, is, doubtless, indirectly, under the nervous influence. We see it affected in the various emotions; sometimes augmenting its action violently, at others retarding it. These circumstances have led some individuals to adopt a kind of intermediate opinion, and to regard the nervous influence as one of the conditions necessary for all muscular contraction, just as the due circulation of blood is one of those conditions ; and to admit, at the same time, the separate existence of a vis insita. Sommer- ing,b and Behrendsc have, indeed, asserted that the cardiac nerves are not distributed to the tissue of the heart, but merely to the ramifications of the coronary arteries ; and hence, that these nerves are not concerned in the functions of the organ, but only in its nu- trition ; but this is denied by Scarpa,"1 and by the generality of anatomists.*5 Although the emotions manifestly affect the heart, direct experi- ments exhibit but little influence'over it on the part of the nerves. This, indeed, we have seen, is one of the grounds for the doctrine of Haller. Willis1" divided the eighth pair of nerves ; yet the action of the heart persisted for days. Similar results followed the sec- » Op. citat. b Corpor. Human. Fabric, iii. § 32. c Dissert, qua Demonstrat. Cor. Nervis Carere, Mogunt. 1792; and in Ludwigii Script. Neurol. Min. i. 1. d Tabulae Neurological, &c, Ticin. 1794. e Seiler, in art. Herz, in Anat. Phys. Real. Wbrterb. iv. 33, Leipz. 1821 • and MUI- ler's Handbuch, Baly's translation, p. 190, Lond. 1838. f Cerebri Anat. cap. xxiv. in Oper., Genev. 1776. IN THE HEART. 127 tion of the great sympathetic. Magendie* states, that he removed, on several occasions, the cervical ganglions, and the first thoracic; but was unable to determine any thing satisfactory from the ope- ration in consequence of the immediate death of the animal from such extensive injury as was inevitable. He observed, however, no direct influence on the heart. We have numerous examples of the comparative independence of the organ, as regards the encephalon. Decapitated reptiles have lived for months; and anencephalous infants or those born with part of the brain only have vegetated during the whole period of pregnancy, and for some days after birth. Legalloisb kept several decapitated mammiferous animals alive ; and maintained the heart in action, (having taken the precaution to tie the vessels of the neck for the purpose of preventing hemorrhage,) by employing artificial respiration, so as to keep up the conversion of venous into arterial blood, and thus to insure to the heart a supply of its appropriate fluid. We find, too, that in fracture of the skull in apoplexy, and in congenerous affections, the functions of the heart are the last to be arrested. The result of his own experiments led Legallois to infer, that the power of the heart is altogether derived from the spinal marrow; and he conceived, that through the cardiac nerves it is influenced by this portion of the cerebro-spinal axis, and is liable to be affected by the passions, because the spinal marrow is itself influenced by the brain. Dr. Wilson Philip0 has, however, shown, that the facts do not warrant the conclusions ; and he has exhibited, by direct experiment, that the brain has as much influ- ence as the spinal marrow over the motions of the heart, when the circumstances of the experiment are precisely the same. The re- moval of the spinal marrow, like that of the brain, if the experiment be performed cautiously and slowly, does not sensibly affect the motion of the heart, — the animal having been previously deprived of sensibility. In these experiments, the circulation ceased quite as soon without, as with, the destruction of the spinal marrow. Loss of blood appeared to be the chief cause of its cessation ; and pain would have contributed to the same effect, if the animal had been operated on, without having been previously rendered insensible. Mr. Clift,dthe ingenious conservator of the Museum of the Royal College of Surgeons of London, made a series of experiments to as- certain the influence of the spinal marrow on the action of the heart in fishes, and he found, that, whether the heart be exposed or not, its action continues long after the brain and spinal marrow are destroyed, and still longer when the brain is removed without injury to its substance. Similar results were obtained by Trevirauus on the frog, and by Saviole on the chick in ovo. Zinn and Ent too » Precis, &c. ii. 401. See, also, Sir A. Cooper, in Guy's Hospital Reports, i. 470, Lond. 1836 ; Miiller, op. citat. p. 198 ; and Burdach, op. citat. iv. 457. b Sur le Principe de la Vie, p. 138. c An Experimental Inquiry into the Laws of the Vital Functions, &c. p. 62, Lond. 1817. a Philosoph. Transact, for 1815. 128 CIRCULATION. found, that after the destruction of the cerebellum, to which Willis ascribed the heart's action, it continued to beat.a All these facts plainly exhibit, that, although the heart is indi- rectly influenced by the brain or spinal marrow, it is not directly acted upon by either one or the other, and that its action can be maintained for some time, after the destruction of one or both, provided artificial respiration be kept up; but this last agent is unnecessary : the heart will continue to beat, even after it has been removed from the body. In the case of the rattlesnake, Dr. Harlanb observed the heart, torn from the body, continue its contractions for ten or twelve hours ; and in the monstrous foetus, observed by Dr. T. Robinson,0 its motion continued for some time after the auri- cles and ventricles had been laid open ; the organ roughly handled, and thrown into a basin of cold water. We are compelled, then, if we do not admit the whole of the Hallerian doctrine of irritability, to presume, that there is something inherent in the structure of the heart, which enables it to contract and dilate, when appropriately stimulated ; and it is not even necessary, that this should be by the fluid, to which it is habituated. It is certain, that the organ, when separated from the body, may be stimulated to contraction, by being immersed in warm water, or pricked with a sharp-pointed instrument. In some experiments by Sir B. Brodie,d he emptied the heart of its blood, and found that it still contracted and relaxed alternately. Similar experiments were instituted by M. Mayo,e and with like results, from which he concludes that the alternations of contraction and relaxation in the heart depend upon something in its structure. The conclusion is, indeed, irrefutable, if we add to these evidences the results of some experiments by Prof. J. K. Mitchell/of Philadelphia. In 1823, being engaged in dissecting a sturgeon — Acipenser brevirostrum ? — its heart was taken out and laid on the ground, and, after a time, having ceased to beat, was inflated with the breath, for the purpose of drying it. Hung up in this state, it began again to move, and continued for ten hours to pulsate regularly, though more and more slowly ; and when last ob- served in motion, the auricles had become so dry as to rustle when they contracted and dilated. He subsequently repeated the experi- ment with the heart of a Testudo serpentaria or snapper, and found it to beat well under the influence of oxygen, hydrogen, carbonic acid, and nitrogen, thrown into it in succession. Water also sti- mulated it, — perhaps more strongly,—but made its substance look pale and hydropic, and, in one minute, destroyed action be- yond recovery. 1 Burdach, Physiologie als Erfahrungswissenschaft, &c. iv. 454, Leipz. 1832. See, also, Miiller, op. citat. p. 191. b Medical and Physical Researches, p. 103, Philad. 1835. e Amer. Journ. of the Med. Sciences, No. xxii. Feb. 1833. i Cooke's Treatise on Nervous Diseases, Introd. p. 61, Lond. 1820-23, Amer. Edit., Boston, 1824. <= Outlines of Human Physiology, 4th edit. p. 46, Lond. 1837. f American Journal of the Medical Sciences, vii. 58, Philad. 1830. IN THE HEART. 129 It has been supposed, that when the heart is empty of blood, the contact of air with its cavities is the stimulus by which its irritability is excited,a but Dr. John Reid,b found, when he placed a frog's heart in a state of activity under the receiver of an air-pump, that its action still continued after the receiver had been exhausted. The heart is the generator of one of the forces that move the blood. This force has been the subject of much calcula- tion, but the results have been so discordant as to throw dis- credit upon all mathematical investigations on living organs; a circumstance which renders it unnecessary to state the different plans that have been pursued in these estimations. They are all given in the elaborate work of Haller,c to which the reader, who may be desirous of examining them, is referred. Borellid conceived the force exerted by the left ventricle to be equivalent to 180,000 pounds; Senac6 to 40 pounds; Halesfto 51 pounds 5 ounces; Jurins to 15 pounds 4 ounces ; whilst Keillh conceived it not to exceed from 5 to 8 ounces! The mode adopted by Hales has always been regarded the most satisfactory. By inserting a glass tube into the carotid of various animals, he noticed how high the blood rose in the tube. This he found to be, in the dog, 6 feet 8 inches ; in the ram, 6 feet 5\ inches; in the horse, 9 feet 8 inches; and he estimated, that, in man, it would rise as high as 7i feet. Now, a tube, whose area is one inch square and two feet long, holds nearly a pound of water. We may therefore reckon the weight, pressing on each square inch of the ventricle, to be, on a rough estimate, three pounds and three-quarters, or four pounds ; and if we consider, with Michelotti, the surface of the left ventricle to be fifteen square inches, it will exert a force, during its contraction, capable of raising sixty pounds.1 Its ex- tent is more frequently, however, estimated at 10 square inches, and the force developed would therefore be forty pounds; but this is, of course, a rude approximation. In such a deranging experiment, the force of the heart cannot fail to be modified ; and it is so much affected by age, sex, temperament, idiosyncrasy, &c. that the attainment of accurate knowledge on the subject is im- practicable. The indefinite character of our information on this matter is sufficiently shown by the investigations of Poiseuille,J which led him to suppose, that the force with which the heart propels the blood in the human aorta is about 4 pounds, 3 ounces, and 43 grains. By means of an instrument, which, from its use, » Carpenter, Human Physiology, § 480, Lond. 1842. b Cyclop, of Anat. and Physiol, ii. 611. c Elementa Physiologies, torn. ii. Lausann. 1757-1766. d De Motu Animalium, part ii. Ludg. Bat. 1710. c Traite de la Structure du Cceur, Paris, 1749. f Statical Essays, &c, 4th edit. vol. ii. % Philosophical Transactions, for 1718 and 1719. b Tentamina Medico-Physica, &,c. Lond. 1718. > Martini, Lezioni di Fisiologia, tomo sesto, p. 420, Torino, 1828; and Arnott's Elements of Physics, Amer. Edit. vol. i. 2d edit. Philad. 1835. J Magendie's Journal de Physiologie, x. 241. 130 RESPIRATION. he terms hxmadynamometer, the same physiologist has endea- voured to show, that the blood is urged forward with as great a momentum in a small artery, far from the heart, as in any import- ant branch near it. In other words, that there is a uniform amount of pressure exerted by the blood upon the coats of the arteries in every part of the body;—those in the immediate vicinity of the heart being distended by an equal force with those the most remote from it. M. Poiseuillea made the experiment on the carotid, and on the muscular branch of the thigh of the horse, and notwithstanding the very great dissimilarity in the diame- ter, and distance from the heart, of the two tubes, the displace- ment of the mercury was exactly the same in both. This infer- ence, if correct, — and the experiments Fig. 168. have been repeated by Magendieb with corresponding effects, — are important in a therapeutical point of view, as they would lead to the belief, that if it be desirable to lessen the quantity of the circulating fluid, it is of little consequence what vessel is opened. The instrument, employed of M. Poi- seuille, consists of a bent glass tube, of the form represented in the marginal figure,filled with mercury in the lower bent part a, d, e. The horizontal part b, provided with a brass head, is fitted into the artery, and a small quantity of a solution of carbonate of soda is inter- posed between the mercury and the blood, which is allowed to enter the tube with the view of preventing the coagulation of the blood. WThen the blood is allowed to press upon the fluid in the horizontal limb, the rise of the mercury towards e, measured from the level to which it has fallen towards d, gives the pressure under which the Hxmadynamometer. b]()od moveg# b. Circulation in the Arteries. The blood, propelled from the heart by the series of actions we have described, enters the two great bloodvessels; — the pulmonary artery from the right ventricle, and the aorta from the left; the former of which sends it to the lungs, the latter to every part of the system ; and, in both vessels, it is prevented from re- turning into the corresponding ventricles by the depression of the » Magendie, Journal de Physiologie, ix. 46 ; and art. Circulation, Cyclop, of Anat. and Physiol. b Lecons sur le Sang, &c, or translation in Lond. Lancet, Sept. 1838 to March 1839 ; in Bell's Select Medical Library, p. 57, Philad. 1839. IN THE ARTERIES. 131 semilunar valves. We have now to inquire into the circum- stances, which act upon it in the arteries, or whether it be the contraction of the ventricle, which is alone concerned in its pro- gression. Harvey* and the whole of the mechanical physiologists regarded the arteries as entirely passive in the circulation, and as acting like so many lifeless tubes; the heart being, in their view, the sole agent in the circulation. We have, however, numerous reasons for believing that the arteries are concerned, to a certain degree, in the progression of the blood. If we open a large artery, in a living animal, the blood flows in distinct pulses; but this effect gradually diminishes as the artery recedes from the heart, and ultimately ceases in the smallest arterial ramifications ; —seeming to show, that the force, exerted by the heart, is not the only one concerned in propelling the blood through these vessels. It is mani- fest, too, that if the action of the heart were alone concerned, the blood ought to flow out of the aperture, when the artery is opened, at intervals coinciding with the contractions of the heart; and that during the diastole of the artery, no blood ought to issue. This, however, is not the case, notwithstanding the authority of Bichat, and some others is in its favour. The flow is uninter- rupted, but in jets or pulses, coinciding with the contractions of the ventricles.6 Again, if two ligatures be put around an arterial trunk, at some distance from each other, and a puncture be made between the ligatures, the blood flows with a jet, — indicating that compression is exerted upon it; and if the diameter of the artery be measured with a pair of compasses, before and after the puncture, it will be found manifestly smaller in the latter case ; — an experiment which shows the fallacy of a remark of Bichat,— that the force with which the arteries return upon themselves is in- sufficient to expel the blood they contain. An experiment of Magen- die0 exhibits this yet more clearly. He exposed the crural artery and vein in a dog, and passed a ligature behind the vessels, tying it strongly at the posterior part of the thigh, so that the blood could only pass to the limb by the artery, and return by the vein. He then measured, with a pair of compasses, the diameter of the artery ; and, on pressing the vessel between his fingers, to inter- cept the course of blood in it, the artery was observed to diminish perceptibly in size below the part compressed, and to empty itself of the blood it contained. On readmitting the blood, by re- moving the fingers, the artery became gradually distended at each contraction of the heart, and resumed its previous dimensions. These facts prove, that the arteries contract; but the kind of contraction has given occasion to much discussion., It has been imagined, by some physiologists, that their proper coat is muscu- lar, and that they exert a similar action on the blood to that of the 1 Exercitatio Anat. De Motu Cordis et Sanguinis, &c, Rotterd. 1648. b Magendie, Precis, &c. ii. 388. c Journal de Physiologie, i. Ill; and Precis, &c. ii. 386. 132 CIRCULATION. heart ; dilating to receive it from that organ, and contracting to propel it onwards; — their systole being synchronous with the sys- tole of the auricles and the diastole of the ventricles, and their diastole with that of the auricles and the systole of the ventricles. The principal reasons, urged in favour of this view, are ; — the fact of the circulation being effected solely by the arteries in acar- diac foetuses, and in animals which have no heart; — the assertion of MM. Lamure and Lafosse,that they noticed, in an experiment with the carotid artery, similar to that described above, that the vessel continued to beat between the ligatures ; — the affirmations of Verschnir,a Bikker, Giulio, and Rossi,b Thomson,0 Parry,d Hast- ings,6 Wedemeyer, and numerous others/ thai when they irritated arteries with the point of a scalpel or subjected them to the elec- trical and galvanic influences, th|y exhibited manifest contrac- tility; and lastly, the fact, that the pulse is not perfectly synchro- nous in different parts of the body, which ought to be the case, were the arteries not possessed of any distinct action. The chief objection to the views, founded on the muscularity of the middle coat, is the want of evidence of the fact. In the ana- tomical proem to the function of the circulation, it was stated, that this coat does not seem to consist of the fibrous or muscular tissue; and that the experiments of Magendie, Nysten, and others, had not been able to exhibit any contraction, on the application of the or- dinary excitants of muscular irritability. The chemical analyses of Berzelius^ and Youngh also show, that the transverse fibres differ essentially from those of proper muscles. Again, if an artery be exposed in a living animal, we observe none of that contraction and dilatation which is perceptible in the heart ; although a manifest pulsation is confmunicated to the fin- ger placed over it. The phenomena of the pulse will engage at- tention speedily. We may merely remark, at present, that the pulsations are manifestly more dependent upon the action of the heart than upon that of the arteries. In syncope, they entirely cease; and whilst they continue beneath an aneurismal tumour, because the continuity of the vessel is not destroyed, they com- pletely cease beneath a ligature, so applied around an artery as to cut off the flow of blood. Bichat attached an inert tube to the carotid artery of a living animal, so that the blood could flow through it : the same kind of pulsation was observed in it as in the artery. To this he adapted a bag of gummed taffeta, so as to simulate an aneurismal tumour: the pulsations were evidenced in the bag. If, again, arterial blood be passed into a vein, the » De Arteriar. et Venar. vi Irritabili, &c, Groning. 1766. b Elemens de Medec. Operat., Turin, 1806. c Lectures on Inflammation, p. 83, Edinh. 1813; also,2d Amer. Edit. Philad 1831. d On the Arterial Pulse, p. 52, Bath, 1816. « On Inflammation of the Mucous Membrane of the Lungs, p. 20 Lond. 1820. t See Henle, Allgemein. Anatom. u. s. w. S. 513, Leipz. 1841. e View of the Progress of Animal Chemistry, p. 25, Lond. 1813. t An Introduction to Medical Literature, p. 501, Lond. 1813. IN THE ARTERIES. 133 Fig. 169. latter vessel, which has ordinarily no pulsation, now begins to beat; whilst, if blood from a vein be directed into an artery, the latter ceases to beat.a Another class of physiologists have reduced the whole of the arterial action to simple elasticity; a property, which the yellow tissue that composes the proper membrane of the artery, seems to possess in an unusual degree. Such is the opinion of Magendie.b "Admitting it to be certain," he remarks, " that contraction and dilatation occur in the arteries, I am far from thinking, with some authors of the last century, that they dilate of themselves, and con- tract in the manner of muscular fibres. On the contrary, I am cer- tain, that they are passive in both cases, that is, that their dilata- tion, and contraction are the simple effect of the elasticity of their parietes, put in action by the blood, which the heart sends inces- santly into their cavity," —and he farther remarks, that there is no difference, in this respect, between the large and the small arteries. As regards the larger arteries, it is probable, that this elasticity is the principal but not the only action exerted; and that it is the cause, why the blood flows in a continuous, though pulsatory, stream, when an opening is made into them; thus acting like the reservoir of air in certain pumps. In the pump A B, represented in the marginal figure, were there no air-vessel C, the water would flow through the pipe E at each stroke of the piston, but the stream would be interrupted. By means of the air-vessel, this is remedied. The water, at each stroke, is sent into the vessel ; the air contained in the air-vessel is thuscompressed, and its elasticity thereby augment- ed ; so that it keeps up a constant pressure on the surface of the water, and forces it out of the ves- sel, through the pipe D, in a nearly uniform stream. Now, in the heart, the contraction of the ven- tricle acts like the depression of the piston ; the blood is propelled into the artery in an interrupted manner, but the elasticity of the bloodvessel presses upon the blood, in the same manner as the airin the air-vessel presses upon the water within it; and thus the blood flows along the vessel in an unin- terrupted, although pulsatory, stream. There are many difficulties, however, in the way of admitting the whole of the action of the arteries in the circulation to be de- » Adelon, Physiol, de l'Horome, edit. cit. iii. 380; and art. Circulation, in Diet, de Medecine, lere edit. v. 321, Paris, 1822. b Precis, &c. edit. cit. ii. 387. VOL. II. — 12 Section of a Forcing Pump. 134 CIRCULATION. pendent upon simple elasticity. The heart of a salamander was opened by Spallanzani.a yet the blood continued to flow through the vessels for twelve minutes after the operation. The heart of a tadpole was cut out, yet the circulation was maintained for some time in several of the vascular ramifications of the tail. The heart of the chick in ovo was destroyed immediately after contraction; the arterial blood took a retrograde direction, and the momentum of the venous blood was redoubled. The circulation continued in this manner for eighteen minutes. Dr. Wilson Philipb states, that he distinctly saw the circulation in the smaller vessels, for some time after the heart had been removed from the body, and a similar observation was made by Dr. Hastings.0 The latter gentleman states, that in the large arterial trunks, and even in the veins, he has no- ticed, in the clearest manner, their contraction on the application of varions stimulants, both chemical and mechanical. It is, more- over, well known, that if a small living artery be cut across, it will soon contract, so as to arrest hemorrhage ; and that, whilst an animal is bleeding to death, the arteries will accommodate them- selves to the decreasing quantity of blood in the vessels, and con- tract beyond the degree to which their elasticity could be presumed to carry them ; and that after death they will again relax. Dr. Parry found, that the artery of a living animal, if exposed to the air, will sometimes contract in a few minutes to a great extent; in such case, only a single fibre of the artery may be affected, nar- rowing the channel in the same way as if a thread were tied round it. The experiments, which have been instituted for the purpose of discovering the dependence of the arterial action on the nervous system, have likewise afforded evidences of their capability of assuming a contractile action, and have led to a better compre- hension of those cases of what have been called local determina- tions of blood. Dr. Philip found, that the motion of the blood in the capillaries is influenced by stimulants applied to the central parts of the nervous system, which must be owing to the capillaries possess- ing a power of contractility, capable of being aroused to action by the nervous influence. The experiments of Sir Everard Homed are, however, more applicable, as they were directed to the larger arteries, respecting which the greatest doubts have been entertained. The carotid artery of a dog was laid bare; the par vagum and great sympathetic, which, in that animal, form one bundle, were separated from it by a flattened probe, for one-tenth of an inch in length ; the head and neck of the dog were then placed in an easy position, and the pulsations of the carotid artery were attended to by all present for two minutes, in order that "the eye might be accustomed to their force in a natural state. The nerve, passin0- » Experiments on the Circulation, &c, translated by R. Hall, Lond. 1801. b An Experimental Inquiry into the Laws of the Vital Functions, Loud 1817- and Lond. Med. Gazette, for March 25th, 1837, p. 952. c Qp. citat. p. 51. d Lectures on Comparative Anatomy, iii. 57, Lond. 1823. IN THE ARTERIES. 135 over the probe, was then slightly touched with caustic potassa. In a minute and a half, the pulsations of the exposed artery be- came more distinct. In two minutes, the beats were stronger; in four minutes, their violence was lessened ; and in five minutes, the action was restored to its natural state. The experiment was re- peated, with analogous results, upon a rabbit. In this animal, the par vagum was separated from the intercostal nerve ; and it was found, that, when the former nerve alone was irritated, no increase took place in the force of the action of the artery. " The carotid artery," says Sir Everard, " was chosen as the only artery in the body of sufficient size, that can be readily exposed, to which the nervous branches, supplying it, can be traced from their trunk. This experiment was repeated three different times, so as to leave no doubts respecting the result." These experiments demonstrate, that, under the nervous influence, an increase or diminution may take place in the contraction of an artery; and they aid us in the explanation of those cases, in which the circulation has been ac- complished, where the heart has been altogether wanting or com- pletely defective in structure. Sir Everard instituted some farther experiments, with the view of determining whether heat or cold have the greatest agency in stimulating the nerves to produce this effect upon the artery. The wrist of one arm was surrounded by bladders filled with ice ; and after it had remained in that state for five minutes, the pulse of the two wrists was felt at the same time. The beats in that which had been cooled were found to be manifestly stronger. A similar experiment was now made with water, heated to 120° or 130° of Fahrenheit. The pulse was found to be softer and feebler in the heated arm. When one wrist was cooled and the other heated, the stroke of the pulse, in the cooled arm, had much greater farce than that of the heated one. These experiments were repeated upon the wrist of several young men and young women of different ages, with uniform results. Lastly, we have remarked, and shall have occasion to refer to the matter again, that certain animals, which have no heart,"-have circulating vessels in which contraction and dilatation are percep- tible. This is the case with the class vermes of Cuvier, and can be seen very distinctly in the lumbricus marinus or lug, the leech, &c. The fact has been invoked both by the believers in the mus- cular contractility of arteries, and by those who conceive the con- tractility to be peculiar; but our acquaintance with the intimate structure of the coats of the vessels, in those animals, is too minute for us to assert more than that they are manifestly contractile. In an interesting case of acardiac foetus examined by Dr. Houston, of Dublin, it seemed impossible that the heart of a twin foetus could have occasioned the movement of blood in the acardiac one; and » See a case of this kind in the human foetus, by Dr. J. S. B. Jackson, of Boston, in the American Journal of the Medical Sciences, for February, 1838, p. 362; and another by Dr. Houston, in the Dublin Journal of Med. Sciences, No. xxix. See, also, Prof. Graves, Lond. Med. Gaz, June 30, 1838, p. 562. 136 CIRCULATION. hence that there must have been some power in the vessels of the latter to effect the circulation through it. From these and other considerations, the majority of physiolo- gists have admitted a contractile action, not simply in the capillary vessels, but in the larger arterial trunks; and, at the present day, the most general and satisfactory opinion appears to be, that, in addition to the highly elastic property possessed by the middle coat, it is capable of being thrown into contraction ; that, in the larger vessels, this contraction is but little exerted, the action of the artery being mainly produced by its elasticity ; but that, in the smaller arterial ramifications, the contractility is more apparent; and, in the capillary vessels, is scarcely equivocal. To this action of con- tractility, necessarily connected with the life of the vessel, and dif- fering from both muscular contractility and simple elasticity, Dr. Parrya gave the name tonicity. c. Circulation through the Capillaries. The agency of the capillary vessels in the circulation has been a subject of contention. It was the opinion of Harvey, and it is embraced by J. Miiller,b that the action of the heart is alone sufficient to send the blood through the whole circuit; but we have seen, that, even when aided by the elasticity and con- tractility of the arterial trunks, the pulsations of the heart become imperceptible in the smaller arteries; and, hence, that there is some show of reason for the belief, that, in the capillary vessels, the force may be entirely spent. Were we, indeed, to admit that the force of the heart were sufficient to send the blood through a single capillary circulation, it would be difficult to admit that it could send it through two — as in the portal circulation. Bichat regarded the capillaries as organs of propulsion, and alone con- cerned in returning the blood to the heart through the veins. Dr. Marshall Hall,' on the other hand, denies that we have any proof of irritability in the true capillaries; and Magendie1'conceives the contraction of the heart to be the principal cause of the passage of the blood through these vessels. In support of this view he ad- duces the following experiment. Having passed a ligature round the thigh of a dog, so as not to compress the crural artery or vein, he tied the vein near the groin, and made a small opening into the vessel. The blood immediately issued with a considerable jet. He then pressed the artery between the fingers, so as to prevent the arterial blood from passing to the limb. The jet of venous blood did not, however, stop. It continued for some moments, but went on diminishing, and the flow was arrested, although the vein was filled throughout its whole extent. When the artery was examined during these events, it was observed to contract gradually, and at length became completely empty when the eourse of theblood in a On the Arterial Pulse, p. 52, Bath. 1810. b Handbuch, u. s. w., Baly's translation, p. 220, Lond. 1838. e A Critical and Experimental Essay on the Circulation, &c. p. 78, Lond. 1831. Reprinted in this country, Philad. 1835. d Pre*cis, &c, ii. 390. IN THE CAPILLARIES. 137 the vein ceased. At this stage of the experiment, the compression was removed from the artery ; the blood immediately passed into the artery, and, as soon as it had reached the final divisions, it began to flow again through the opening in the vein, and the jet was gradually restored. On compressing the artery again, until it was emptied, and afterwards allowing the arterial blood to pass slowly along the vessel, the discharge from the vein occurred, but without any jet; which was resumed, however, as soon as the artery was entirely free. This experiment is not so convincing to us as it appears to be to M. Magendie. The chief fact, which it exhibits, is the elastic, and probably contractile, power of the arteries. It might have been expected, h priori, under any hypothesis, that the quantity of blood discharged from the vein would hold a ratio with that sent by the artery ; and, consequently, the experiment appears to us to bear but little on the question regarding the separate contractile action of the capillaries. It is difficult, indeed, to believe, that such an action does not exist. In addition to the circumstance, already mentioned, of the absence of pulsation in the smaller arteries, almost every writer on the theory of inflammation considers the fact of a distinct action of the capillaries established, and leaves to the physiologist the by no means easy task of proving it. Dr. Wilson Philipa placed "the web of a frog's foot in the microscope, and distinctly saw the capillaries contract upon the application of those stimulants, which produce contraction of the muscular fibre. The result of Dr. Thomson's5 experiments, in investigating the subject of inflammation, were the same, as well as those of Dr. Hastings.0 The facts, which we have already referred to, regarding the continuance of the circulation in the minute vessels after the heart has been removed, are confirmatory of the same point; as well as the observation of Dr. Philip, that the blood in the capilla- ries is influenced by stimulants applied to the central parts of the nervous system. The experiments of Thomson, Philip, and Hast- ings, were repeated by Wedemeyer,d with great care. The circu- lation in the mesentery of the frog, and in the web of its foot, being observed through the microscope, it was evident, that no change oc- curred in the diameter of the small arteries, or in that of the capil- laries, so long as the circulation was allowed to go on in its natural state; but as soon as excitants were applied to them, an alteration of their calibre was perceptible. Alcohol arrested the flow of blood without inducing much apparent contraction of the vessels. Chloride of sodium, in the course of three or four minutes, caused the vessels to contract one-fifth of their calibre, which contraction was followed by dilatation of the vessels, and a gradual retardation and stoppage of the blood. In a space of time varying from ten » A Treatise on Febrile Diseases, 3d edit. ii. 17, Lond. 1813 ; and Medico-Chirur. Transact, vol. xii. p. 401. b Lectures on Inflammation, p. 83, Edinb. 1813. c Op. citat. <» Untersuch. iiber die Krieslauf, u. s. w., Hannover, 1828; and Edinb. Med. and Surg. Journ. vol. xxxii. 12* 138 CIRCULATION. to thirty seconds, and sometimes immediately after the application of the galvanic circle, the vessels contracted, some one-fourth, others one-half, and others three-fourths of their calibre. The contraction sometimes continued for a considerable time, occasion- ally several hours; in other instances, it ceased in ten minutes, and the vessels resumed their natural diameter. A second application of galvanism to the same capillaries seldom caused any material contraction.* Schwann" likewise found, that when cold water was poured on the vessels of a frog, which had been previously in a warm atmosphere, the capillaries immediately contracted, but after a time regained their diameter. Farther, Mr. Hunter found that on exposing arteries to the air, they contracted so much as to occasion obliteration of their tubes; and it is well known, that when arteries — as the temporal — are divided, hemorrhage may be arrested by the spontaneous contraction of the divided extremity, — a contraction, which, as remarked by Dr. Carpenter, is much greater than could be accounted for by simple elasticity of tissue, and is more marked in small than in large vessels.0 All these facts prove the existence of a vital power in the capil- laries, capable of modifying, to considerable extent, the flow of blood through them.d Again, of this independent action of the capillary vessels we have, every day, proofs in local inflammation ; in which there is increased redness of a part, without the general circulation ex- hibiting the slightest evidences of augmented action or excitement. In the natural state, the vessels of the tunica conjunctiva cover- ing the white of the eye, receive little blood; but if any cause of irritation exists, as a grain of sand entering between the eyelids, we find blood rapidly sent into them, giving the ap- pearance, which has been termed, not inappropriately, " blood- shot."6 In the experiments of Kaltenbrunner/ which were fully confirmed on repetition, the blood was at first observed,in inflam- mation, streaming to the irritated part, in consequence of which the capillary vessels became distended ; afterwards irregularity of circulation occurred in the gorged capillary system; and subse- quently complete arrestation of the circulation, and disorganiza- tion. These phenomena are of themselves sufficient to prove the existence of the separate action of the capillaries, and when taken in conjunction with other facts, are overwhelming. The blush of modesty, and the paleness of guilt, the hectic glow, and the trans- » Richerand's Elemens de Physiologie, 13eme edit., par Berard aine-, Edit. Beige, p. 125, Bruxelles, 1837. b Miiller's Archives, 1836, and Lond. M.ed. Gazette, May, 1837; and Miiller's Hand- buch, u. s. w., Baly's translation, p. 206. c Human Physiology, § 502, Lond. 1842. a Purkinje, in Encyclop. Wbrterb. der Medicin. Wissenschaft. vii. 660,.Berlin, 1831; Prof. Graves, Lond. Med. Gazette, June 30, 1838, p. 561 ; Gerdy, Diet, de Med. viii. p. 60; Dubois d'Amiens, L'Experience, No. clxxi. 1840 ; and Dr. Calvert Holland, Edinb. Med. and Surg. Journ., July, 1842. « Thomson's Lectures on Inflammation, Edinb. 1813. f Experimenta circa Statum Sanguinis et Vasorum in Inflammatione, p 23, Monach W26. IN THE CAPILLARIES. 139 lucency of congelation, are all circumstances, that go to establish the same point. The contractile power of the capillaries is doubtless modified by the condition of the ganglionic nerves distributed to them, which, as we have seen, are observed to increase as the size of the vessels and the thickness of their coats diminish. Their in- fluence is, indeed, strikingly evinced in actions, which are altoge- ther nervous, as in the flushed countenance occasioned by sudden mental emotions. By some, however, the whole capillary circula- tion has been ascribed to the motive faculty inherent in the globules of the blood ; whilst others, again, have asserted, that the " electro- galvanic power," — or in other words — the nervous power, ge- nerated in the nervous system, and acting on the blood globules through the parietes of the capillary system of vessels is the imme- diate agent directing the movements or circulation in the capil- laries : all this, however, enters into the inscrutable question of what is the cause of life in the fluids or tissues, — a question to be agitated, but not solved, in a subsequent part of this volnme.a But, not only has a vital power of contraction been conceded to the capillaries; it has been imagined, that they possess what the Germans call a Lebensturgor {turgor vitalis) or vital pro- perty of expansibility or turgescence. Such appears to be the opinion of Hebenstreit5 and of Prus ;c and it has been embraced, in this country, by Professor Smith of Yale College, by his son, Professor N. R. Smith of Baltimore, in his excellent work on the " Arteries,"*1 and by Professor Hodgee of Philadelphia. The idea has been esteemed to be confirmed by the fact of excitants having been seen under the microscope, by Hastings, Wedemeyer, and others, to occasion not only contraction but dilatation of the capillaries. The phenomena, observed in the erectile tissues, have likewise been considered to favour the hypothesis; but, in answer to these arguments, it maybe replied, that the irregular excitation, produced in the parts by the application of powerful stimulants, might readily give occasion to an appearance of expansibility - under the microscope, without our being justified in-inferring, that these vessels possess an innate vital property of expansibility; and, in many of the cases, in which ammonia and galvanism were applied by Thomson, Hastings, Wedemeyer and others, the action of contraction ought rather to be esteemed physical or chemical, than vital/ The results of the application of such exci- tants, as diluted alcohol, dilute solutions of ammonia and of chlo- ride of sodium, can alone be adduced as evidences of vital action * Alison's Outlines of Physiology, Supplement to 2d edit., Edinb. 1836; and A Short Inquiry into the Capillary Circulation, &c. by James Black, M.D., Lond. 1825. b Dissert.de Turgore Vitali, Lips. 1795; Hildebrandt's Physiologie, Auflag. 5, § 84 ; and Tiedemann's Physiologie, trad, par Jourdan, p. 625, Paris, 1831. e De I'lrritation, &c, Paris, 1825. d Surgical Anatomy of the Arteries, 2d edit., Baltimore, 1835. c North Amer. Med. and Surg. Journal, June, 1828. See, also, Prof. Graves, in Lond. Med. Gazette, for June 30, and July 7, 1838. f Burdach's Physiologie als Erfahrungswissenschaft, B. iv. Leipz 1832. 140 CIRCULATION. on the part of these vessels. The dilatation of the capillary system and of the smaller arteries, which has been remarked on the con- tact of these agents, is not, as Oesterreichera has remarked, the primary effect: it is the consequence of the afflux of blood to the irritated part, as is also demonstrated in the experiments of Kal- tenbrunner on inflammation, to which allusion has been made. Lastly, attentive observation of the phenomena presented by the erectile tissues must lead to the conclusion that the turgescence of the vessels is not the first link in the chain of phenomena; ex- citation is first induced in the nerves of the part — generally through the influence of the brain, and from thence, perhaps, through the sympathetic nerve,— and the afflux of fluid supervenes on this.5 The vital expansibility of the capillaries cannot then, we think, be regarded as proved, or probable. The circulation through the capillaries has long been an inter- esting topic of microscopic research. According to Wagner,0 a magnifying power of from two to three hundred diameters is re- quired to make out the particular details. According to him, the blood in mass, or in the larger channels, is seen to flow more rapidly than in the smaller. Here the blood corpuscles advance with great rapidity, especially in the arteries, and with a whirling motion, and form a closely crowded stream in the middle of .the vessel, without ever touching its parietes. With a little attention, a narrower and clearer, but always very distinct, space is seen to remain between the great middle current of blood corpuscles and the walls of the vessel, in which a few white corpuscles, or what Wagnerconsidersto be lymphcor- puscles (?) (see vol. i., p. 625) are moved onwards, but at a much slower rate. These white corpus- cles swim in smaller numbers in the transparent liquor sanguinis, and glide slowly, and in general smoothly, though they sometimes advance by fits and starts more rapidly, but with intervening pauses; and, as a general rule,at least ten or twelve times more slowly than the corpuscles of the a small venous Branch from the web of a Frogs central stream. The clear soace, Foot, magnified 350 diameters. „,, , . , " _ t ' b, b. Cells of pavement epithelium, contain- nhed With liquor Sanguinis and ingnuclei. In the space between the current of white COrDUScles i ODVIOUS 111 ail sei, the round transparent lymphgiobuies (?) are the larger capillaries, whether ar- seen.-(Wagner.) ^^j of venougj y^ ^ ceases tQ » Versuch einer Darstellung der Lehre vom Kreislaufe des Blutes, Nurnberg, 1826. «> Rullier, art. Expansibility in Diet, de Med. viii. 423, Paris, 1823 ; and Purkinje", in art. Circulatio Sanguinis, in.Encyclopad. Wb'rterb. derMedicin. Wissenschaft. b vii! s. 667, Berl. 1831. e Elements of Physiology, translated by R. Willis, § 122, Lond. 1842. IN THE CAPILLARIES. 141 be apparent on the smaller intermediate vessels which admit but one or two rows of blood corpuscles (Fig. 160). In these vessels, the two sets of globules proceed pari passu; but, according to Wagner, it is easy to see, that the blood corpuscles glide more readily on- wards— the white corpus- cles seeming often to be detained at the bendings of vessels, and at the an- gles, where anastomosing branches are given off; where they remain adhe- rent for an instant, and then suddenly proceed onwards. These phenomena are ob- served in every part of the peripheral systemic circu- lation ; but an exception appears to exist in the pulmonic circulation ; the capillaries there being fill- ed with both kinds of globules to their very walls. It is in this — the inter- mediate— part of the san- guiferous system, that most important functions take place. In the smallest ar- tery, we find arterial blood; and in the smallest vein, communi- cating with it, blood always possessing the venous properties. Be- tween those points, a change must have occurred, precisely the reverse of that which happens in the lungs. It is in this very part, too, that nutrition, secretion, and calorification are effected. In the explanation of these functions, we shall find it impossible not to suppose a distinct and elective agency in the tissues concerned; and as it is by such agency, that the varying activity of the differ- ent functions is regulated, we are constrained to believe, that the capillary vessels may be able to exert a controlling influence over the quantity and velocity of the blood circulating in them. In disease, the agency of this system of vessels is an object of attentive study with the pathologist. To its influence in inflam- mation, we have already alluded ; but it is no less exemplified in the more general diseases of the frame, — as in the cold, hot, and sweating stages of an intermittent. Local, irregular capil- lary action is, indeed, one of tKe most common causes of acute affections, and these generally occur in some organ, at a dis- tance from the seat of the deranging influence. It is a common and just observation, that getting the feet wet, and sitting in a draught of air, are more certain causes of catarrh than sudden at- mospheric vicissitudes, which apply to the whole body; and so Large Vein of Frog's Foot, magnified 600 diameters. b, c. Blood corpuscles, a, a. Lymph corpuscles (?) principally conspicuous on the clear space near the parietes of the vessel. — (Wagner.) 142 CIRCULATION. extensive is the sympathy between the various portions of this system of vessels, that the most diversified effects will be pro- ducedin different individuals exposed to the same common cause ; one may have inflammatory sore throat; another, ordinary ca- tarrh; another, inflammation of the bowels; — according to the precise predisposition, existing in the individual at the time, to have one structure morbidly affected rather than another;—but these are interesting topics, which belong more strictly to the pathologist. By the united action, then, of the heart, the arteries, and the capillary or intermediate system of vessels, the blood attains the veins. We have now to consider the circulation in those vessels. d. Circulation in the Veins. It has been already observed, that Harvey considered the force of the heart to be of itself sufficient to return the blood, sent from the left ventricle, to the heart; whilst Bichat conceived the whole propulsory effort to be lost Fig. 172. in the capillaries, and the transmission of the blood along the veins to be en- tirely effected by the agency of the capillary system. It is singular, that an indi- vidual of such distinguished powers of discrimination should have been led into an error of such magnitude. It is a well-known princi- ple in hydrostatics, that al- though water, when uncon- fined, can never rise above its level at any point, and can never move upwards ; yet, by being confined in pipes or close channels of any kind, it will rise to the height from which it came. Hence the water or blood in the vessel A, Fig. 172, which may be con- sidered to represent the right auricle, would stand at "the same height as that in the vessel B, which we may look upon as the left ventricle, were they inanimate tubes. We need be at no loss, therefore, in understanding how the blood might attain the right auricle, when the body is erect, by this hydrostatic principle alone; but we have seen, that the force exerted by the heart, by the arte- ties, and by the capillary system is superadded to this, so that the blood would rise much higher than the right auricle, and conse- quently exert a manifest effort to enter it. It may be remarked, also, that the left ventricle is not the true height of the source, but the top of the arch of the aorta, which is more elevated, by seve- ral inches, than the right auricle. A similar view is embraced by Br. Billing,3 but Dr. Carpenter,b — in commenting on the author's i First Principles of Medicine, Amer. Edit., p. 36, Philad. 1842. t» Human Physiology, § 516, Lond. 1842. IN THE VEINS. 143 observations on this subject—suggests, that the influence of this hy- drostatic force would scarcely be felt through the plexus of capil- lary vessels ; " for the interposition of a system of tubes even of much larger calibre would be, by the friction created between the fluid and their walls, an effectual obstacle to the rapid ascent of a current, which had so slight an impetus as that derived from its previous fall." The author did not mean, however, to say more than that the blood " might attain" the right auricle by the hy- drostatic force alone ; he did not wish to convey the idea, that the circulation could be carried on without 'the aid of an additional force ; but that a slight effort only on the part of the heart and arte- ries might be needed to enable the blood to perform its entire circuit. Are we then to regard the veins as simple elastic tubes ? This is the prevalent belief. Their elasticity is, however, much less than that of the arteries. Some physiologists have conceived them to possess also contractile properties. Such is the opinion of Brous- sais,a who founds it, in part, upon certain experiments by Sarlan- diere, already referred to, in which contraction and relaxation of the vense cavae of a frog were seen, for many minutes after the heart was removed from the body. These pulsations of the vense cavae and also of the pulmonary veins in their natural state have been seen by numerous observers — by Steno, Lower, Wepfer, Borrachius, Whytt, Haller, Lancisi, Miiller, Marshall Hall, FJou- rens, J. J. Allison, and others.b The experiments of Dr. Allison, in reference to the venae cavae and pulmonary veins, appeared to him, to prove,— that they pulsate near the heart in the four classes of the vertebrata, — that in dying animals they pulsate long after the auricle and ventricle have ceased to beat, — that they will also beat even in quadrupeds, for hours after they have been separated from the heart and from the body ; — and that they can be stimu- lated to contract either when in or out of the body, by mechanical and galvanic means, especially by the latter, after all motion has ceased for some time. It seems to be very doubtful, whether the veins generally possess any sensible contraction like that of the vense cavae and pulmonary veins near the heart, for although irritated by galvanic and mechanical stimuli by Haller, Nysten, Muller, J. J. Allison, and others, no motion whatever could be detected in them.c Gerber affirms, that the fibres of the middle coat of the veins bear a stronger resemblance to those of muscular tissue than do those of the corresponding part of the arteries, which resemble more the ordinary elastic fibres; but Dr. Carpenterd thinks it not improbable, that his observations were made on portions of the veins near the heart, which partake of its contractility. » Traite* de Physiol. &c, Drs. Bell and La Roche's translat. p. 391, Philad. 1832. See also, Miiller's Handbuch, u. s. w., Baly's translation, p. 171, Lond. 1838. b See the experiments of the last named gentleman proving the existence of a venous pulse independent of the Heart, and Nervous System, in Amer. Journal of the Medical Sciences, Feb. 1839, p. 306. c J. Muller, Elements of Physiology, p. 170, Lond. 1838, and J.J. Allison, op. cit, p. 320. d Human Physiology, § 514, Note. Lond. 1842. 144 CIRCULATION. In the experiments of Dr. Marshall Hall,a on the circulation in the web of the frog's foot, he was almost invariably able to detect, with a good microscope, a degree of pulsatory acceleration of the blood in the arteries at each contraction of the heart; and he is disposed to conclude, from his observations, that the natural cir- culation is rapid, and entirely pulsatory in the minute arteries, and slow and equable in the capillary and venous systems. But whenever the circulation was in the slightest degree impeded, the pulsatory movement became very manifest at each systole of the heart, and it was seen in all the three systems of vessels — arterial, capillary, and venous. He observed, that in the arteries there was generally an alternate, more or less rapid flow of the globules at each systole and diastole of the ventricle; and that in the capillaries and veins the blood was often completely arrested during the dias- tole, and again propelled by a pulsatory movement during the sys- tole ; all which he esteems conclusive proof, that the power and influence of the heart extend through the arteries to the capillaries, and through these to the veins, even in the extreme parts of the body. That the veins are possessed of elasticity is proved by the ope- ration of bloodletting, in which a part of the jet, on puncturing the vein, is owing to the over-distended vessel returning upon itself; but that this property exists to a trifling extent only is shown by the varicose state of the vessels, which is so frequently seen in the lower extremities. e. Forces that propel the Blood. From the inquiry into the agency of the different circulatory organs in propelling the blood, it is manifest, that the action of the heart, the elasticity of the arteries, and a certain degree of contrac- tile action, in the smaller vessels more especially, a distinct action of the capillary vessels, and a slight elastic and perhaps contractile action on the part of the veins, must be esteemed the chief agents. Of these, the action of the heart and capillaries, and the contraction of the arteries and veins, can alone be regarded as sources of mo- tion, the elasticity of the vessels being simple directors, not gene- rators of force. But there is another agency, which is probably more efficient than has been generally conceived. This is the suction power of the heart, or derivation, as it has been termed, to which attention has been chiefly directed by Haller b Wilson c Carson,d Zugenbiihler, Schubarth, Platner, Blumenbach,* and others; but which is not assented to by Oesterreicher/ Miiller sand * Essay on the Circulation, ch. i. Lond. 1831, and Philad. 1835. b Elem. Physiol, ii. lib. vi. <= Enquiry into the Moving Powers employed in the Circulation of the Blood Lond. 1784. i Inquiry into the Causes of the Motion of the Blood, 2d edit. Lond 1833 « Tiedemann's Traite de Physiol, par Jourdan, p. 347; and Burclach's Phvsioloeie als Erfahrungswissenschaft, iv. 270, Leipz. 1832. * Lehre vom Kreislauf des Blutes, Nurnberg, 1826, e Handbuch, u. s. w., Baly's translation, p. 173. FORCES THAT PROPEL THE BLOOD. 145 some others.8 It is presumed, that the muscular fibres of the heart are mixed up with a large quantity of cellular tissue ; and that, whilst the contraction of the cavities is effected by the action of the muscular fibres, dilatation is produced by the relaxation of the con- tracted fibres, and the elasticity of the cellular tissue ; so that when the heart has contracted, and sent its blood onwards, its elasticity instantly restores it to its dilated condition ; a vacuum is formed, and the blood rushes in to fill it. This action has been compared by Dr. Bostock,b and by Dr. Southwood Smith,0 Prof. Turner,d and others, to that of an elastic gum bottle, which, when filled with water, and compressed by the hand, allows the fluid to be driven from its mouth with a velocity proportionate to the compressing force. But the instant the pressure is removed, elasticity begins to operate, and if the mouth of the bottle be now immersed in water, a considerable quantity of that fluid will be drawn up into the bottle, in consequence of the vacuum formed within it. The existence of this force is confirmed by Dollinger,e — who, when examining the embryo of birds, saw the blood advance along the veins, whilst the venous trunks poured it into the auricles at the moment when they dilated to receive it; as well as by Dr. T. Robinson/ who was forcibly struck with the activity with which the diastole was effected, in the case of monstrosity more than once referred to. Dr. Carpenters thinks it very doubtful "how far the auricles have such a power of active dilatation as would be required for this purpose;" but the question need not regard the auricles. It is but necessary to suppose, that an action of power of dilatation exists in the ventricles; and this is now generally ad- mitted. He farther remarks, that it has been shown experiment- ally by Dr. Arnott and others, that no suction power exerted at the farther end of a long tube, whose walls are as deficient in firm- ness, as those of the veins are, can occasion any acceleration in a current of fluid transmitted through it; for the effect of the suc- tion is destroyed at no great distance from the point at which it is applied by the flapping together of the sides of the vessel; but in answer to this it may be observed, that it remains to be shown, that such flapping of the sides would necessarily occur in the veins, which are living vessels, and constantly receiving blood from the capillaries under the action of vital forces. Another accessory force, which has been invoked, is the suction power of the chest, or the inspiration of venous blood, as it has been termed. This is conceived to be effected by the same me- chanism as that which draws air into the chest. The chest is di- * Carpenter, Human Physiology, § 575, Lond. 1842. b Physiology, 3d edit. p. 251, Lond. 1836. ' Animal Physiology, (Library of Useful Knowledge,) p. 83, Lond. 1829. i Edinb. Medico-Chirurg. Transact iii. 225. « Denkschriften der Kbnigl. Akademie der Wissenschaft. zu Munchen, vii. 217; and Burdach, op. citat. p. 272. 1 American Journal of the Medical Sciences, No. xxii. t Human Physiology, § 515, Lond. 1842. VOL. II.-- 13 146 CIRCULATION. lated during inspiration; an approach to a vacuum occurs in the thorax; and the blood, as well as the air, is forcibly drawn towards that cavity. On the other hand, during expiration, all the thoracic viscera are compressed ; the venous blood is repelled from the chest, and the arterial blood reaches its destination with greater celerity, owing to the action of the expiratory muscles being added to that of the left ventricle. Haller,a Lamure,b and Lorryc had observed, that the blood, in the external jugular vein, moves under manifestly different influences, during inspiration and expiration. Generally, when the chest is dilated in inspiration, the vein empties itself briskly, becomes flat, and its sides are, occasionally, accurately applied against each other; — but, during expiration, the vein rises and becomes filled with blood ; — effects, which are more evident, when the respiratory movements are more extensive. The ex- planation of this phenomenon, by Haller and Lorry, is the one given above. To discover whether the same thing happens to the venas cavae, Magendie introduced a gum elastic catheter into the jugular vein, so as to penetrate the vena cava and even the right auricle ; — the blood was observed to flow from the extremity of the tube at the time of expiration only. During inspiration, air was rapidly drawn into the heart, giving, rise to the symptoms to be mentioned here- after, which attend the reception of air into that organ. Similar results were obtained, when the tube was introduced into the crural vein in the direction of the abdomen. So far as regards the larger venous trunks, therefore, the influence of respiration on the circu- lation is sufficiently evidenced.*1 It can be easily shown, by opening an artery of the limbs, that expiration manifestly,accelerates the motion of arterial blood; espe- cially in forced expiration, and during violent exertion. In animals, subjected to experiment, it is impracticable to excite either the forced expiration or the violent effort at pleasure ; but we can, as a substitute, compress the sides of the chest with the hands, ac- cording to the plan recommended by Lamure, when the blood will be found to flow more or less copiously in proportion to the pres- sure exerted. It occurred to Magendie, that this effect of respira- tion on the course of the blood in the arteries might influence the flow along the veins. To prove this, he passed a ligature around one of the jugular veins of a dog. The vessel emptied itself beneath the ligature, and became turgid above it. He then made a slight puncture, with a lancet, in the distended portion ; and in this way obtained a jet of blood, which was not sensibly modified by the ordinary respiratory movements, but became of triple or quadruple the size, when the animal struggled. As it might be objected to this experiment, that the effect of respiration was not transmitted by the arteries to the open vein, but rather by the veins that had remained free, which might have conveyed the blood, repelled * Elementa Physiologise, torn. ii. b Mem.de l'Acad.des Sciences, pour 1749. = Magendie, Pr6cis, &c. ii. 416. d See, also, Poiseuille, in Magendie's Journal de Physiologie, viii. 272. FORCES THAT PROPEL THE BLOOD. 147 from the vena cava, towards the tied vein, by means of anasto- moses, the experiment was varied. The dog has not, like man, large internal jugular veins, which receive the blood from the in- terior of the head. The circulation from the head and neck is, in it, almost wholly confined to the external jugular veins, which are extremely large; the internal jugulars being little more than ves- tiges. By tying both of these veins at once, Magendie made sure of obviating, in great part, the reflux in question ; but, instead of this double ligature diminishing the phenomenon under considera- tion, the jet became more closely connected with the respiratory movement; for it was manifestly modified even by ordinary respiration, which was not the case when a single ligature was employed. From these and other experiments, Magendie properly concludes, that the turgescence of the veins must not be ascribed, with Haller, Lamure, and Lorry, simply to the reflux of the blood of the venae cavae into the branches opening directly or indirectly into them; but that it is partly owing to the blood being sent in larger quan- tity into the veins from the arteries.a In the same manner are explained — the rising and sinking of the brain, which, as was observed in an early part of this work, (vol. i., p. 79,) are synchronous with expiration and inspiration. During expiration, the thoracic and abdominal viscera are com- pressed ; the blood is driven more into the branches of the ascend- ing aorta, and it is, at the same time, prevented from returning by the veins : owing to the combination of these causes, the brain is raised during expiration. In inspiration, all this pressure is re- moved ; the blood is free to pass equally by the descending, as by the ascending, aorta; the return by the veins is ready, and the brain therefore sinks.b We can thus, also, explain why the face is red and swollen during crying, running, straining, and the vio- lent emotions; and why pain is augmented in local inflammations of an extremity, — as in cases of whitlow, and when respiration is hurried or impeded by running, crying, &c. The blood accu- mulates in the part, owing to the compound effect of increased flow by the arteries, and impeded return by the veins. The same explanation applies to the production of hemorrhage by any vio- lent exertion ; and Bourdon0 affirms, that he has always seen he- morrhage from the nose largely augmented during expiration; diminished at the time of inspiration, and arrested by prolonged inspiration; —a therapeutical fact of some interest. It is manifest, then, that the circulation is modified by the move- ments of inspiration and expiration/1 — the former facilitating the 1 Precis, &c. ii. 421. b This motion of the brain must not be confounded with that which is synchronous with the contraction of the left ventricle; and which is owing to the pulsation of the arteries at the base of the brain. <= Recherches sur lc Mecanisme de la Respiration et sur la Circulation du Sang, Paris, 1820. <* Dr. Clendinning's Report to the Brit. Association, 1839-40, Lond. Med. Gazette, Nov. 13, 1840, p. 270. 148 CIRCULATION. flow of blood to the heart by the veins, and the latter encouraging the flow by the arteries ; and we shall see hereafter, that there is great reason for the belief, that the dilatation of the chest, — which constitutes the first inspiration of the new-born child, — is a great cause of the establishment of the new circulation ; the same dila- tation, which causes the entrance of air into the air-cells, soliciting the flow of blood, or the " inspiration of venous blood," as Ma- gendie3 has termed it. In a paper read before the Royal Society of London, in June, 1S35, Dr. Wardrop,b after remarking, that he considers inspiration as an auxiliary to the venous, and expiration to the arterial circulation, attempts, on this principle, to explain the influence exerted on the circulation, and on the action of the heart, by various modes of respiration, whether voluntary or in- voluntary, in different circumstances. Laughter, crying, weeping, sobbing, and sighing, he regards as efforts made with a view to effect certain alterations in the quantity of blood in the lungs and heart, when the circulation has been disturbed by mental emo- tions. The influence of ordinary respiration can, however, be but trifling; yet it has been brought forward by Sir David Barryc as the efficient cause of venous circulation. His reasons for this be- lief are,— the facts just mentioned, regarding the influence of in- spiration on the flow of blood towards the heart, and certain in- geniously modified experiments, tending to the elucidation of the same result. He introduced one end of a spirally convoluted tube into the jugular vein of an animal, and plunged the other into a vessel filled with a coloured fluid. During inspiration, the fluid passed from the vessel into the vein ; during expiration, it re- mained stationary in the tube, or was repelled into the vessel. Dr. Bostock*3 remarks, that he was present at some experiments, which were performed by Sir David, at the Veterinary College in Lon- don, and it appeared sufficiently obvious, that when one end of a glass tube was inserted either into the large veins, into the cavity of the thorax, or into the pericardium,— the other end being plunged into a vessel of coloured water, — the water was seen to rise up the tube during inspiration, and to descend during expira- tion. The conclusion of Sir David from these experiments is most comprehensive; — that "the circulation in the great veins depends upon atmospheric pressure in all animals possessing the power of contracting and dilating a cavity around that point, to •which the centripetal current of their circulation is directed ;" and he conceives, that as, during inspiration, a vacuum is formed around the heart, the equilibrium of pressure is destroyed, and the atmosphere acts upon the superficial veins, propelling their con- tents onwards to supply the vacuum. Independently of other objections, there are a few, which ap- » Precis, &c. ii. 416. b On the Nature and Treatment of the Diseases of the Heart; with some new views of the Physiology of the Circulation, Lond. 1837. c Experimental Researches on the Influence of Atmospheric Pressure upon the Cir- culation of the Blood, &c, Lond. 1826. d Physiology, 3d edit. p. 330, Note, Lond. 1836. FORCES THAT PROPEL THE BLOOD. 149 pear to us convincing against this sole agency of ordinary respi- ration in effecting venous circulation. According to Sir David's hypothesis, blood ought to arrive at the heart at the time of inspi- ration only ; and as there are, in the average, seventy-two con- tractions of the heart for every eighteen inspirations; or four con- tractions, or— what is the same thing — four dilatations of the auricle for each respiration ; one of these only ought to be con- cerned in the propulsion of blood, whilst the rest should be blood- less ; yet we feel no difference in the strength of tne four pulsa- tions. It is clear, too, if we adopt Sir David's reasoning, that, of the four pulsations, two,-and consequently two dilatations of the auricles; must occur during expiration, at which time the capacity of the chest is actually diminished : moreover, holding the breath ought to suspend the circulation ; and the respiratory influence cannot be invoked to explain the circulation in the foetus or in aquatic animals. At the most, therefore, respiration can only be regarded as a feeble auxiliary in the circulation. In favour of Dr. Barry's opinion of the efficiency of atmospheric pressure in causing the return of blood by the veins, he adduces the fact, — al- ready referred to,under the head of Absorption,— that the applica- tion of an exhausted vessel over a poisoned wound prevents the ab- sorption of the poison; but this, aswe have seen, appearsto bea phy- sical effect, which would apply equally to any view of the subject. In all these cases, the elastic resilience of the lungs, by contri- buting to diminish the atmospheric pressure from the outer surface of the auricles, may, likewise, as suggested by Dr. Carson,a have some agency in soliciting the blood into these cavities, but the agency cannot be great. There is another circumstance of a purely physical nature, which may exert some, influence upon the flow of the blood along the veins.; viz., the expanded termination of the vense cavae in the right auricle. To explain this, it is necessary to premise a detail of a few hydraulic facts. If an aperture A, Fig. 173, exist in a cis- tern X, the water will not issue at the aperture by a stream of uniform size ; but, at a short distance from the reservoir, it will be contracted as at B, constituting what has been termed the vena contractu. Now, it has been found, that if a tube, technically called an adjutage, be attached to this aperture, so as to accurately fit the stream, as at A B, Fig. 174, as much fluid will flow from the reservoir as if the aperture alone existed. Again, if the pipeB C be attached » Philosoph. Transact, for 1820, and An Inquiry into the Causes of Respiration, &c. 3d edit. Liverpool, 1833. 13* 150 CIRCULATION. to the adjutage A B, the expanded extremity at A will occasion the flow of Fig. 174. water, from and if to the tube B C, a truncated conical tube C D be attached, the length of which is nearly nine times the diameter of C ; and the diameter of C to that of D be as 1 to 8 ; the flow of water will be augmented in the proportion of 24 to 12-1 ; so that, by the two adjutages A B and C D, the expenditure through the pipe B C is increased in the ratio of 24 to 10. This fact, — the result of direct experiment, and so important to those who contract to supply water by means of pipes,— was known to the Romans. Private persons, according to Frontinus,* were in the habit of pur- chasing the right of delivering water in their houses from the public reservoirs, but the law prohibited them from making the conducting pipe larger than the opening allowed them in the re- servoir, within the distance of fifty feet. The Roman legislature must, therefore, have been aware of the fact, that an adjutage with an expanded orifice, would increase the flow of water ; but they were ignorant that the same effect would be induced beyond the fifty feet. Let us apply this law to the circulation. In the first place, at the origin of the pulmonary artery and aorta, there is a manifest narrowness, formed by the ring at the base of the semilunar valves (see Fig. 156) ; and this might be conceived unfavourable to the flow of the blood along those vessels during the systole of the ventricles ; but from the law, which has been laid down, the narrowness would occupy the natural situation of the vena con- tracta, and, therefore, little or no effect would be induced. The discharge would be the same as if no such narrowness existed. We have seen, again, that the vena cava becomes of larger calibre as it approaches the right auricle, and finally terminates in that cavity by an expanded aperture. This may have a similar effect with the expanded tube C D, Fig. 174, which doubles the ex- penditure.5 In making these conjectures,—some of which have been ad- duced by Sir Charles Bell, —it is proper to observe, that, in the 1 Lat. Oudendorp, Lugd. Bat. 1731. b Venturi, Sur la Communication Laterale du Mouvement dans les Fluides Paris, 1798 ; andPouillet, Elemensde Physiologie, i. 205, Paris, 1832. FORCES THAT PROPEL THE BLOOD. 151 opinion of some natural philosophers, the effect of the adjutage is entirely due to atmospheric pressure, and that no such acceleration occurs, provided the experiment be repeated in vacuo. Sir Charles Bella conceives, that " the weight of the descending column in the reservoir being the force, and this operating as a vis h tergo, it is like the water propelled from the jet d'eau, and the gradual ex- pansion of the tube permits the stream from behind to force itself between the filaments, and disperses them, without producing that pressure on the sides of the tube, which must take place, where it is of uniform calibre." It is on this latter view only, that these singular hydrostatic facts can be applied to the doctrine of the cir- culation. In addition to the movements, impressed on the blood by the" parietes of the cavities in which it moves, it has been considered by many physiologists, — as by Harvey, Glisson, Bohn, Albinus, Rosa, Tiedemann, G. R. Treviranus,b Rogerson,0 Alison,d and others,e — to possess a power of automatic or self-motion. Broussaisf asserts, that he has seen experiments, — originally performed by P. A. Fabre, which showed, that the blood, in the capillary system, fre- quently moves in an opposite direction to that given it by the heart, — repeated by M. Sarlandiere, on the mesentery of the frog. In these, the blood was seen to rush for some moments towards the point irritated, and, when a congestion had taken place there, they remarked, that the globules took a different direction, and traversed vessels which conveyed them in an opposite course, and, a few seconds afterwards, these were again observed to retnrn with equal rapidity to the point from which they had been repelled. Tiede- manng has collected the testimonies of various individuals on this point. Haller,h Spallanzani,1 Wilson Philip,-* G. R. Treviranus,k and others, have remarked, by the aid of the microscope, that the blood continued to move in the vessels of different animals, but chiefly of frogs, for some time after the great vessels had been tied, or the heart itself removed ; — a fact which Tiedemann, also, often witnessed. C. F. Wolff,1 Rolando,"1 Dollinger, and Pander," Pre- vost and Dumas,0 Von Baer,? and others, saw globules of blood in » * Animal Mechanics, p. 40, in Library of Useful Knowledge, Lond. 1829. t> Tiedemann, Traite Complet de Physiologie de l'Homme, traduit par Jourdan, i. 348, Paris, 1831. « A Treatise on Inflammation, &c, Lond. 1832. d Edinburgh Med. and Surg. Journal for Jan. 1836. Also, Prof. R. J. Graves, in Lond. Med. Gazette, June 30, 1838, p. 561. e Dr. S. Smith's Philosophy of Health, p. 398, Lond. 1835; and Messrs. Emmerson and Reader, in Edinb. Med. and Surg. Journal, April, 1836. f Traite" de Physiologie, &c, translated by Drs. Bell and La Roche, 3d edit. p. 374, Philad. 1832. s Op. citat. h Oper. Minor, i. 115, Sect. 8. ' Exper. on the Circulation, &c, in Eng. by R. Hall, Lond. 1801. J Philos. Transact. 1815; and Medico-Chirurg. Trans, vol. xii. k Vermischte Schriften, i. 102, ' Theoria Generations, Hal. 1759. mDizionario Periodico di Medicina, Torino, 1822-1823. n Dissert, sist. Hist. Metamorphoseos quam Ovum Incubatum prioribus quinque Diebus subit, Wirceb. 1817. 0 Annales des Sciences Naturelles, torn. xii. p. 415, Dec. 1827. P Ueber Entwickelungsgeschichte der Thiere, u. s. w. Th. i. Kb'nigsberg, 1828. See, 152 CIRCULATION. motion in the incubated egg, before the formation of either vessels or heart; and Hunter, Gruithuisen, and Kaltenbrunner observed — in the midst of the cellular tissue of inflamed parts, in tissues undergoing regeneration, and during the cicatrization of wounds,— bloody points placed successively in contact with each other, form- ing small currents, which represented new vessels, and united to those already existing. The fact, indeed, that the embryo forms its own vessels, and that blood in motion can be detected before ves- sels are in esse, is a sufficient proof, — were there no other, — that the globules of the blood possess the faculty of motion,a either in themselves, or by virtue of an attraction exerted upon them by the solid parietes in which they move. The idea of spontaneous motion in a fluid, independently of attraction or repulsion from the sides of another object, Miillerb thinks is inconceivable ; but as Tiede- mann0 has remarked, if we admit this faculty in animals provided with a heart, the progression of the blood must be mainly owing to that viscus; for, after the heart ceases to act, the circulation is soon arrested. The blood, too, only remains fluid, and possesses the faculty of motion, whilst it is in connexion with the living body. When taken from the vessel in which it circulates, it soon coagulates, and loses its motive power. This motion has, by some, — and, according to Brandt,'1 not without grounds, — been pre- sumed to be owing to electro-chemical agency. Burdache has properly observed, that the old but perfectly cor- rect saying, " ubi stimulus, ibi affluxus," means nothing more than that where the vital activity of an organ is augmented, more blood will be drawn to it; whence it naturally follows, that the progression of blood in the capillaries must be, in some measure, dependent on the activity of the vital manifestations in the tissue/ It has been already shown, that if the capillary action be excited by stimulants, a greater flow of blood takes place into that system of vessels; and, as the functions of nutrition and secretion are accomplished by that system, it is obvious, that any increase in the activity of these functions must attract a larger afflux of fluids, and, in this manner, modify the circulation independently of the heart and larger vessels. But this, again, can have but a subor- dinate influence on the general circulation. Lastly, Rapsails resolves the whole of the circulation, as he does also, Dr. Allen Thomson, on the Formation of New Bloodvessels, Edinb. 1832 ; and art. Circulation, in Cyclopaedia of Anat. and Physiology, p. 7, Lond. 1836 ; Alison's Outlines of Physiology, 2d edit., Supplement, Lond. 1836 ; and Purkinje, in art. Circu- latio Sanguinis, Encycl. Wbrterb. u. s. w. B. vii. s. 676, Berl. 1831. •Mr. Ancell, Lectures on the Physiology and Pathology of the Blood, &c, in Lond. Lancet, Oct. 26, 1839, p. 147. b Handbuch, u. s. w., Baly's translation, p. 224, Lond. 1838. See, also, Magendie on the Blood, Amer. Edit, in Bell's Select Medical Library, p. 150, Philad 1839 c Op. cit. p. 349. d Art. Blut, in Encyclopiid. Wbrterb. der Medicinisch. Wissenschaft v 596 Berlin, 1830. e Die Physiologie als Erfahrungswissenschaft, &c, Band, iv., Leipz. 1832. f C. D. Shultz, Der Lebensprocess im Blute, Berl. 1822. s Chimie Organique, p. 364, Paris, 1833. ACCELERATING AND RETARDING FORCES. 153 every other function, into a double action of aspiration and ex- piration by the tissues concerned. As the blood is the bearer of life to every part of the organism, and of nourishment and repara- tion to the organs,— to prevent its destination being annulled, a part of the fluid, he says, must be absorbed by the surfaces, which it bathes: these surfaces must attract nutritive juices from the blood, and they must return to the blood the refuse of their elaboration,— in other words, they must aspire and expire. Now, this double function cannot take place without the fluid being set in motion, and this motion must be the more constant and uniform as the double function is inherent in every molecule of the surface of the vessels. In this way he accounts for the mercury, placed in a tube communicating with an artery, being kept at the same height near to, or at a distance from, the heart; because, he says, it is not the action of the heart which supports it, but the action of the parietes of the vessels. Every surface, which aspires, provided it is flexible, must be, in its turn, he conceives, attracted by the sub- stance aspired, and, consequently, by the act of aspiration alone, the motions of systole and diastole of the heart and arteries may be explained. When their inner parietes aspire — or assimilate the fluid—the heart will contract; when, on the contrary, they expire, owing to the mutual repulsion between the heart and the fluid, the former will dilate ; and, as the movement of the heart is energetic on account of its size, its movements will add to the ve- locity of the circulation in the arteries, which will, therefore, be- sides their proper actions of aspiration and expiration, present movements isochronous with the pulsations of the heart. " Add to this accessory cause of arterial pulsations, the movements impress- ed by the aerial aspiration, which takes place in the lungs, and the circulation of the blood will no longer present insurmountable problems." All this, we need scarcely say, is ingenious, but nothing more. f. Accelerating and Retarding Forces. The above are the chief accelerating causes of the circulation. There are some others, which at times accelerate, and at others retard; and others, again, that must always be regarded as im- peding influences. All these are of a physical character, and apply as well to inert hydraulic machines, as to the pipes of the human body. 1. Friction always acts as a retarding force. That, which occurs between a solid and the surface on which it moves, can be subjected to calculation, but not so with a fluid; inasmuch as all its particles do not move equally : whilst one part is moving rapidly, another may be stationary, moving slowly, or even in a contrary direction, as is seen in rivers, where the middle of the stream always flows with much greater velocity than the sides. The same thing happens to water flowing through pipes; the water, which is in contact with the sides of the pipe, moves more slowly 154 CIRCULATION. than that at the centre. This retarding force is much diminished by the polished state of the inner surface of the blood vessels, as is proved by the circumstance, that if we introduce an inert tube into an artery, the blood will not flow through it for any length of time. Poiseuille3 infers, from his investigations, that a layer of serum lines the interior of the capillary vessels, which may have some effect in retarding the blood globules in their progress through the intermediate system. Yet the viscosity of the blood, within cer- tain limits, would seem to enable it to pass through the capillary system. Magendie, indeed, pronounces it to be an indispensable condition for its free circulation through the capillaries.1* 2. Gravity may either be an active or retarding force, and is always exerting itself, in both ways, on different sets of vessels. If, for example, the flow of blood to the lower extremity, by the arte- ries, be aided in the erect attitude by the force of gravity, its return by the veins is retarded by the same cause. Every observer must have noticed, that the pulse of an individual in health beats slower when he is in the recumbent, than in the erect, attitude. This is owing to there being no necessity for the heart to make use of un- usual exertions for the purpose of forcing the blood, against gra- vity, towards the upper part of the body. In therapeutics, the phy- sician finds great advantage from bearing this influence in mind; and, hence, in diseases of the head, — as in inflammation of the brain, in apoplectic tendency, ophthalmia, &c, — he directs the patient's head to be kept raised ; whilst, in uterine affections, the horizontal posture, or one in which the lower part of the body is raised even higher than the head, is inculcated ; and in ulcers or inflammatory diseases of the lower extremities, the leg is recom- mended to be kept elevated. Every one, who has had the mis- fortune to suffer from whitlow, must have experienced the essen- tial difference, as regards the degree of pain, produced by position. If the finger be held clown, gravity aids the flow of blood by the .arteries, and retards its return by the veins: the consequence is turgescence and painful distension ; but if it be held higher than the centre of the circulation, the flow by the arteries is impeded, whilst its return by the veins is accelerated, and hence the marked relief afforded.0 3. Curvatures. — Besides friction, the existence of curvatures has considerable effect on the velocity and quantity of the fluid passing through pipes. A jet will not rise as high from the pipe or adjutage of a reservoir, if there be an angular turn in it, as if the bend were a gradual curve or sweep. The expense of force, produced by such curvatures in arteries, is seen at each contrac- tion of the ventricle, — the tendency in the artery to become straight producing an evident movement, which has been called the locomotion of the artery, and has been looked upon, by some as the principal cause of the pulse. This motion is, of course' » Biblioth. Universelle, Novemb. 1835. b Magendie, Lectures on the Blood, edit. cit. p. 102, Philad. 1839 e Mr. Moseley, in Lond. Medical Gazette, April 15, 1837. ACCELERATING AND RETARDING FORCES. 155 more perceptible the nearer it is to the heart and the greater the vessel; hence it is more obvious at the arch of the aorta; and we can now understand why this arch should be so gradual. We have a striking example of the force, used in this effort at straight- ening the artery, in the case of the popliteal artery, when the legs are crossed, and a curvature is thus produced. The force is suffi- cient to raise a weight of upwards of fifty pounds at each contrac- tion of the ventricle, notwithstanding it acts at the extremity of so long a lever. This fact is sufficient to exhibit the inaccuracy of the notion of Bichat and Bricheteau,a that the curvatures in the arteries can have no effect in retarding the flow of blood. Such could only be the case, Bichat thinks, if the vessels were empty at each systole. 4. Anastomoses. — The anastomoses of vessels have, doubtless, also some influence on the course of the blood ; but it is impossi- ble to appreciate it. The superficial veins are especially liable to have the circulation impeded by compression in the different pos- tures of the body; but, by means of the numerous anastomoses that exist, if the blood cannot pass by one channel, it is diverted into others. Although, however, a forcible compression may arrest or retard the flow by these vessels, a slight degree of sup- port prevents dilatation of the vein by the force of the blood passing into it, and thus favours its motion. The constant pressure of the skin is hence serviceable to the circulation through the subcuta- neous veins; and if, by any means, the pressure is diminished, especially in those parts in which the blood has to make its way contrary to gravity — as in the lower extremities—varices or dilatations of the vessels arise, which are remedied by the mecha- nical compression of an appropriate bandage. Attempts have been made to calculate the velocity with which the blood proceeds in its course ; and how long it would take for a globule of blood, setting out from the left side of the heart, to attain the right side. It is clear, that the data are, in the first place, totally insufficient for any approximation. We know not the exact quantity of blood, contained in the vessels ; the quantity sent into the artery at each contraction of the ventricle; the rela- tive velocity of the arterial, venous, and capillary circulations ; and if we knew them at any one moment, they are liable to incessant fluctuations, which would preclude any accurate average from being deduced. Were these circumstances insufficient to exhibit the inanity of such researches, the varying estimates of different ob- servers would fully establish it. These assign the time occupied in the circulation from two minutes to fifteen or twenty hours ! Moreover, the distance the globules have to traverse must be very various. In the heart, the passage from one side to the other by the coronary vessels is very short, whilst if the blood have to pro- ceed to a remote part of the body, the distance must be considerable. » Clinique Medicale, p. 145, Paris, 1835 ; and the author's translation in his Ame- rican Medical Library, Philad. 1837. 156 CIRCULATION. Were we to regard the vascular system as forming a single tube__by knowing the weight of the blood and the quantity which the left ventricle is capable of sending forward at each con- traction, we could calculate with facility the period that must elapse before the whole mass is distributed. Thus, if we estimate the quantity propelled forward at each contraction of the ventricle to be two ounces; and the whole mass of blood to be 30 pounds, it will require, on an average, about 240 beats of the heart to send it onwards; which can be accomplished in little more than 3 minutes:» yet, notwithstanding the absence of the requisite data, a recent writer has gone so far as to affirm the average velocity of the blood in the aorta, to be about eight inches per second; whilst " the ve- locity in the extreme capillaries is found to be often less than one inch per minute." A similar estimate was made by Dr. Young ;b Hales,c too, estimated the velocity of the blood leaving the heart at 149*2 feet per minute, and the quantity of blood passing through the organ every hour at twenty times the weight of the blood in the body; but the judicious physiologist knows well, that in all operations, which are partly of a vital character, the results of every kind of calculation must be given with caution and humility. In the larger animals, as the whale, the quantity of the fluid cir- culating in the aorta must be prodigious. Dr. Hunter, in his ac- count of the dissection of a whale, states that the aorta was a foot in diameter, and that ten or fifteen gallons of blood were probably thrown out of the heart at each stroke ; so that this vessel is in the whale actually larger than the main pipe of the old water-works at London Bridge; and the water, rushing through the pipe, it has been conceived, had less impetus and velocity than that gush- ing from the heart of this leviathan.d These estimates, as to the velocity of the circulatory current, are probably far beneath the truth, inasmuch as experiments have shown, that snbstances introduced into the venous circulation may be detected in the remotest parts of the arterial circulation in ani- mals larger even than man in less than thirty seconds. Ten seconds after having injected a solution of nitrate of baryta into the jugular vein of a horse, Mr. Blakee drew blood from the carotid of the opposite side ; after allowing this to flow for five seconds, he re- ceived the blood that flowed during the next five seconds into an- other vessel; and that which flowed after the twentieth second, by which time the action of the heart had stopped, was received into a third vessel. No trace of baryta could be detected in the blood that flowed between the tenth and fifteenth second ; but it was discovered in that which flowed between the fifteenth and twen- a For various estimates, see Burdach, Die Physiologie als Erfahrungswissenschaft, iv. 253, Leipzig, 1832; Dr. Allen Thomson, Cyclop, of Anatomy and Physiol, art, Circulation ; and Miiller's Handbuch, u. s. w., Baly's translation, p. 186. b Med. Literature, Lond. 1813. « Statical Essays, vol. ii. Lond. 1829. i Paley's Natural Theology; and Animal Physiology, p. 75, Library of Useful Knowledge, Lond. 1829. « Edinb. Med. and Surg. Journal, Oct. 1841. VELOCITY OF THE CIRCULATION. 157 tieth. From the results of these and other experiments, Dr. Car- penter thinks it difficult to resist the conclusion, that some other force than its contractions must have a share in producing the movement of the blood through the vessels." The velocity of the circulating fluid in the minute vessels is gene- rally thought to be less than in the larger ;band their united calibres to be much greater than that of the trunk with which they commu- nicate.0 Were this the case, the diminution of velocity would be in accordance with a law of hydrodynamics; — that when a liquid flows through a full pipe, the quantity which traverses the differ- ent sections of the pipe, in a given time, must be every where the same ; so that where the pipe is wider the velocity diminishes; and, on the contrary, where it is narrower the velocity increases. This would not seem, however, to be consistent with the experiments of Poiseuille, already referred to, which appear to show, that the pressure exerted on the blood in different parts of the body — as measured by the column of mercury, which the blood in different arteries will sustain — is almost exactly the same. The cause of error in the common belief, that the capacity of the arterial tubes increases in proportion to their distance from the heart, has been explained by Mr. Ferneley.d It is true, he observes, that the sum of the diameters of the branches is con- siderably greater than that of the trunk. .Thus a trunk, 7 lines across, may divide into two branches of 5 lines each, or a trunk of 17 into three branches of 10, 10, and 9§ ; but when their areas are compared, which is the only mode of arriving at their calibres, the correspondence is as close, he thinks, as can be reasonably expected, when the nature of the measurement is taken into ac- count. In the first case, the area of the trunk is represented by the square of 7 — that is 49 ; whilst the area of each branch will be 25, and the sum of the two will be 50. In the second instance, the area of the trunk will be 17 squared, or 289; whilst that of the branches is the sum of 100, 100, and 90^, making 2905.e This will be more strikingly seen from the following table :f — Trunk. Branches. Diameter. Square of Diameter. r~ ................ Diameter. Sum of Squares Diameter. I. 9 81 7-5 + 5 81*25 II. 7-2 51-64 6 + 4 52 III. 3-5 12-25 3 + 2 13 IV. 7-0 49 5 + 5 50 V. 17 289 10+10 + 9-5 290-25 VI. 10 100 7 + 7 + 2 102 VII. 4-5 20-25 3-5+3 21-25 VIII. 8 64 4+7 65 » Human Physiology, § 491, Lond. 1842. " Dr. J. R. Graves , in Lond. Med. Gazette for June 30, 1838, p. 559. c Horner, Special Anatomy and Histology, ii. 172, Philad. 1843. * Lond. Med. Gaz. Dec. 7, 1839. e Lond. Med. Gazette, Dec. 7, 1839; and Brit, and For. Med. Rev., April, 1840, p. 422. f Carpenter, Human Physiology, § 476, Lond. 1843. VOL. II. — 14 158 CIRCULATION. It will be observed, that the sum of the squares of the dia- meters of the branches is in every case slightly more, than the square of the diameter of the trunk. This was found to be some- what greater in subsequent experiments made by Mr. Paget.8 The following table gives the ratio of the area of each arterial trunk to the joint area of its branches, as observed by him. Arch of the aorta - Innominata - Common carotid - External carotid - Subclavian - - Abdominal aorta to the last lumbar arteries -------------just before dividing - Common iliac .... External iliac .... Trunk. Branches. 1 1-055 1 1-147 1 : 1013 1 1-19 1 1055 1 1-183 1 •893 1 •982 1 1-15 It would appear, that where the aorta divides into the common iliacs, or at the division next lower down, the stream is always contracted ; an effect, which, Mr. Paget suggests, must be to acce- lerate the circulation not only in the iliacs themselves, but in the arteries given off from the trunk above them, — as the mesenteric and the renal. From what has been said, regarding the curvatures and angles of vessels, it will be understood, that the blood must proceed to dif- ferent organs with different velocities. The renal artery is extremely short, straight, and large, and must consequently transmit the blood very differently to the kidney, from what the tortuous carotid does to the brain; or the spermatic artery to the testicle. A different impulse must, consequently, be given to their corresponding organs by these different vessels. A great portion, however,of the impulse of the heart must fail to reach the kidney, short as the renal artery is, owing to its passing off from the aorta at a right angle; and, hence, the impulse of the blood on the kidney may not be as great as might be imagined at first sight. The tortuosity of the carotid arteries is such as to greatly destroy the impetus of the blood; so that but trifling hemorrhage takes place when the brain is sliced away on a livfng animal, although it is presumed, that one-eighth of the whole quantity of blood is sent to the encephalon. Dr. Rush supposed, that the use of the thyroid gland is to break the afflux of blood to the brain ; for which its situation between the heart and the head appeared to him to adapt it; and he adduced, as farther arguments, —first, the num- ber of arteries which it receives, although effecting no secretion; secondly, the effect on the brain, which he conceived to be caused by diseases, and by extirpation, of the thyroid; the operation hav- ing actually occasioned,in his opinion, in one case, inflammation of the brain, rapidly terminating fatally ; and, thirdly, the fact that goitre is often accompanied by idiotism. The opinion, however, is so entirely conjectural, and some of the facts, on which it rests so questionable, that it does not demand serious examination. » Lond. Med. Gaz., July 8, 1842. VELOCITY OF THE CIRCULATION. 159 This leads us to remark, that the thyroid gland, as well as other organs, with whose precise functions we are totally unacquainted — as the thymus, spleen, and supra-renal capsules, — have been con- ceived to serve as diverticula or temporary reservoirs to the blood, when, owing to particular circumstances, that fluid cannot, circu- late properly in other parts. Lieutaud having observed, that the spleen is always larger when the stomach is empty than when full, considered that the blood, when digestion is not going on, reflows into the spleen, and that thus this organ becomes a diverticulum to the stomach. The opinion has been indulged by many, with more or less modification. Dr. Rush's view was yet more com- prehensive. He regarded the'spleen as a diverticulum, not simply to the stomach, but to the whole system, when the circulation is violently excited, as in passion, or in violent muscular efforts, at which times there is danger of sanguineous congestion indifferent organs; and in support of his view, he invoked the spongy nature of the spleen ; the frequency of its distension ; the large quantity of blood distributed to it; its vicinity to the centre of the circula- tion ; and the sensation referred to it, in running, laughing, &c. Broussais3 has still farther extended the notion of diverticula. He affirms, that they always exist in the vicinity of organs, whose functions are manifestly intermittent. In the foetus, the blood does not circulate through the lungs as when respiration has been es- tablished : diverticula, he, therefore, considers to be necessary: these are the thymus and thyroid glands. The kidneys do not act in utero : hence the use of the supra-renal capsules as diverticula. At birth, these organs are either wholly obliterated, if the organs to which they previously acted as diverticula have continuous functions; or they are only partly obliterated, if the functions be intermittent. Thus, the spleen continues as a diverticulum to the stomach, because its functions are intermittent through life ; and the thymus disappears, when respiration is established : the liver and the portal system he regards as a reservoir, inservient to the reception of the blood in cases of impediment to the circulation in different parts of the body. These notions are entirely hypothetical. We shall see, here- after, that our ignorance of the offices of the spleen, thymus, &c, is extreme ; and we have already shown, that much more proba- ble uses can be assigned to the portal system. The insufficiency of Broussais's doctrine of diverticula is strikingly evidenced by the fact, that whilst the thymus gland disappears gradually in the progress of age, the thyroid remains, as well as the supra-renal capsules,0 The erectile tissues offer a variety in the circulation, which requires some comment. Examples of these occur in the corpora cavernosa of the penis and clitoris; and in the nipple. » Commentaries des Propositions de Pathologie, &c, Paris, 1829; or Drs. Hays and Griffith's translation, p. 214, Philad. 1832. i> Adelon, Physiologie de l'Homme, torn. iii. 328, 2de €dit Paris, 1829. 160 CIRCULATION. They appear, according to Gerber,3 to consist of a plexus or rete of varicose veins enclosed in a fibrous envelope, with relatively minute interspaces, which are occupied and traversed in all directions by arteries, nerves, contractile fibres, and by elastic, fibrous and cellular tissue. Of the particular arrangement of ves- sels in the corpora cavernosa, mention will be made hereafter: the mode of termination of the arteries in the erectile tissues has not been sufficiently studied,b nor are views uniform in regard to their mode of action ; some being of opinion, that they afford ex- amples of vital expansibility ; but, as before remarked (page 138), the excitation is first induced in the nerves of the part, generally through the influence of the brain, and the turgescence of vessels is a consequence. The arrangement of the portal system of the liver is also pecu- liar, and has been given already (p. 87). g. The Pulse. We have had occasion, more than once, to refer to the subject of the pulse, or to the beat felt by the finger when applied over any of the larger arteries. Opinions have varied essentially re- garding its cause. Whilst most physiologists have believed it to be owing to distension of the arteries, caused by each contraction of the left ventricle ; some have admitted a systole and diastole of the vessel itself; others, as Bichat and Weitbrecht,e have thought that it is owing to the locomotion of the artery; others, that the impulse of the heart's contraction is transmitted through the fluid blood, as through a solid body; and others, as Dr. Youngd and Dr. Parry,e that it is owing to the sudden rush forward of the blood in the artery without distension. Bichat was one of the first, who was disposed to doubt, whether the dilatation of the artery, which was almost universally admitted, really existed ; or if it did, whether it were sufficient to explain the phenomenon; and, since his time, numerous experiments have been made by Dr. Parry, the result of which satisfied him, that not the smallest dilatation can be detected in the larger arteries, when they are laid bare during life ; nor does he believe, that there is such a degree of locomotion of the vessel as ean account for the effect produced upon the finger. He ascribes the pulse to " impulse of distension from the systole of the left ventricle, given by the blood, as it passes through any part of an artery contracted within its natural diameter." Dr. Bostockf appears 'to coincide » Elements of General Anatomy, by Gulliver, p. 298, Lond. 1842. t> Mandl, Manuel d'Anatomie generale, p. 197, Paris, 1843. c Comment. Acad. Imper. Scient. Petropol. ad Ann. 1734 and 1735, Petrop* 1740. •i Croonian Lectures, in Philos. Transact, for 1809, Part i. e An Experimental Inquiry into the Nature, Causes, and Varieties of the Arterial Pulse, by Caleb Hillier Parry, Lond. 181 6 ; also, Additional Experiments on the arte ries of warm-blooded animals, &c, by Ch. Henry Parry, M.D., &c, Lond. 1819/ • Dr. Prichard, in Transact, of the Provincial Med. and Surg. Association, iv. 16, Land" 1836. f Physiology, 3d edit. p. 246, Loud. 1836. PULSE. 161 with Dr. Parry, if we understand him rightly, or at all. " According to this (Dr. Parry's) doctrine," he remarks, " we must regard the artery as an elastic and distensible tube, which is at all times filled although with the contained fluid not in an equally condensed state, and that the effect produced upon the finger depends upon the amount of this condensation, or upon the pressure which it exer- cises upon the vessel, as determined by the degree, in which it is ca- pable of being compressed. Where there is no resistance to the flow of the blood along the arteries, there is no variation, it is conceived, in their diameter, and it is only the pressure of the finger or some other substance against the side of an artery that produces its pulse.3 Most of the theories of the pulse take the contractility of the artery too little into account. In pathology, where we have an opportunity of observing the pulse in various phases, we meet with sensations communicated to the fingers, which it is difficult to explain upon any theory, except that of the compound action of the heart and arteries. The impulse is obviously that of the heart, and although the fact of distension escaped the observation of Bi- chat, Parry, Weitbrecht, Lamure, Dollinger, Rudolphi,b Jager,c and others, we ought not to conclude, that it does not occur. It is, indeed, difficult for us to believe, that such an impulse can be communicated to a fluid filling an elastic vessel without pulsatory distension supervening. In opposition, too, to the negative obser- vations of Bichat and Parry, we have the positive averment of Dr. Hastings,andofPoiseuille,dOesterreicher,Segalas, and Wedemeyer, that the alternate contraction and dilatation of the larger arteries was clearly seen.e The pulsations of the different arteries are pretty nearly syn- chronous with that of the left ventricle. Those of the vessels near the heart may be regarded as almost wholly so, but an appreciable interval exists in the pulsations of the more remote vessels/ We have remarked, that the arterial system is manifestly more or less affected by the nerves distributed to it; that it may be sti- mulated by irritants, applied to the great nervous centres, or to the nerves passing to it; and this is, doubtless, the cause of many of the modifications of arterial tension, that we notice in disease. No inflammation can affect any part of the system, for any length of time, without both heart and arteries participating, and affording us unequivocal signs of such inflammation. This, however, is a subject that belongs more especially to pathology. * Good's Study of Medicine, Physiological Proem to the class Hasmatica. b Grundriss der Physiologie, &c. Berlin, 1821. « Tractatus Atiatomico-physiologicus de Arteriarum Pulsu. Vircerb. 1830. * Repertoire generale d'Anatomie, &c. par Breschet, 1829, torn. vi. and vii. and Ma- gendie's Journal de Physiol, viii. and ix. e Burdach's Physiologie als Erfahrungswissenschaft, torn. iv. Leipz. 1832. For a mode of estimating the arterial distension, see Poiseuille, in Magendie's Journal de Physiologie, ix. 44, and Jules Herison's description of an instrument — the Sphygmo- meter— which makes the action of the arteries apparent to the eye. f Dr. Allen Thomson, art. Circulation, Cyclopaedia of Anatomy and Physiology, P. vii. p. 664, Lond. 1836 ; and Miiller's Handbuch, u. s. w., Baly's translation, p, 2.00, 14* 162 CIRCULATION. The ordinary number of pulsations, per minute, in the healthy adult male, is from seventy to seventy-five ; but this varies greatly according to temperament, habit of life, position, — whether lying, sitting, or standing,8 &c. Dr. Guy,b from numerous observations, found the pulse, in healthy males, of the mean age of 27 years, in a state of rest, 79 when standing ; 70, sitting, and 67, lying; the difference between standing and sitting being 9 beats; between sitting and lying, 3 beats; and between standing and lying, 12 beats. When all exceptions to the general rule were excluded, the numbers were: standing, 81; sitting, 71 ; and lying, 66; — the difference between standingand sitting being 10 beats; between sitting and lying, 5 beats; and between standing and lying, 15 beats. The effect produced upon the pulse by change of posture, Dr. Guy ascribes to muscular contraction, whether employed to change the position of the body, or to maintain it in the same position. In children, the difference between the pulse in the sit- ting and lying position is often very marked. In a boy, six years of age, now before the author, it amounts to fifteen beats; and Dr. Evansonc states, that he has often found the pulse, which at night (during sleep) was 80, full and steady, up to 100 or even 120 during the day, small and hurried, — and this in children six or seven years of age and in perfect health. In some individuals in health, the number of beats is singularly few. The pulse of a person, known to the author, was on the average thirty-six per minute; and Lizzarid affirms, that he knew a person in whom it was not more than ten. It is not impro- bable, however, that in these cases, obscure beats may have taken place intermediately, and yet not have been detected. In a case of pericarditis, in which the author felt great interest, the pulse ex- hibited a decided intermission every few beats, yet the heart beat its due number of times ; the intermission of the pulse at the wrist consisting in the loss of one of the beats of the heart. It was not improbable but that in this case the contractility of the aorta was unusually developed by the inflammatory condition of the heart; and that the flow of blood from the ventricle was thus occasionally diminished or entirely impeded. The quickest pulse, which Dr. Elliotsone ever felt, was 20S, counted easily, he says, at the heart, though not at the wrist. The pulse of the adult female is usually from ten to fourteen beats in a minute quicker than that of the male.f In infancy, it is generally irregular, intermitting, and always rapid, and it gradu- » Dr. M'Donnel, in Dublin Journal of Med. and Chemical Science, Sept. 1835. b Guy's Hospital Reports, No. vi. April, 1838, p. 92. See, also, Dr. John M. B. Harden, Amer. Journ. of the Med. Sciences, April, 1843, p. 340. e Practical Treatise on the Management and Diseases of Children, by Messrs. Evan- son and Maunsell: Amer. Edit, by Dr. Condie, p. 19, Philad., 1843. Quetelet, op. citat. p. 87. ' c Human Physiology, p. 215, Lond. 1835. See, also, Dr. Ch. Hooker, of New Haven, Conn., in Boston Medical and Surgical Journal, for May 16 23 &c 1838 a Edinburgh Medica! and Surgical Journal, April, 1837. See, also, Dr. Stratton in Edinb, Med. and Surg Journ. for Jan. 1843. USES. 165 spirituous liquors must be greatly aggravated in those who drink before dinner. 5. Sleep does not farther affect the heart's action than by a cessation of all voluntary motion, and by a recumbent position. 6. In weak persons, muscular action excites the action of the heart more powerfully than in strong and healthy indivi- duals ; but this does not apply to other stimulants, to wine, for ex- ample, or to spirituous liquors. 7. The effects of the position of the body, in increasing or diminishing the number of pulsations, is solely attributable to the muscular exertion required to maintain the body in the sitting or erect posture ; the debility may be mea- sured by altering the position of the person from a recumbent to a sitting or the erect position. 8. The most powerful stimulant to the heart's action is muscular exertion. The febrile pulse never equals this.a h. Uses of the Circulation. The chief uses of the circulation are, — to transmit to the lungs the products of absorption, in order that they may be converted into arterial blood; and to convey to the different organs this arterial blood, which is not only necessary for their vitality, but is the fluid by which the different processes of nutrition, calorification and se- cretion are effected. These functions will engage us next. We may remark, in conclusion, that the agency of the blood, as the cause of health or insalubrity,has had greater importance assigned to it than it merits ; and that although the blood may be the medium, by which the source of disease is conveyed to other organs, we can- not look to it as the seat of those taints that are commonly referred to it. " Upon the whole," says Dr. Good,b " we cannot but regard the blood as, in many respects, the most important fluid of the ani- mal machine ; from it all the solids are derived and nourished, and all the other fluids are secreted; and it is hence the basis or com- mon pabulum of every part. And as it is the source of general health, so is it also of general disease. In inflammation, it takes a considerable share, and evinces a peculiar appearance. The miasms of fevers and exanthema are harmless to every part of the system, and only become mischievous when they reach the blood ; and emetic tartar, when introduced into the jugular vein, will vomit in one or two minutes, although it might require, perhaps, half an hour if thrown into the stomach, and in fact it does not vomit till it has reached the circulation. And the same is true of opium, jalap, and most of the poisons, animal, mineral and vege- table. If imperfectly elaborated, or with a disproportion of some of its constituent principles to the rest, the whole system partakes of the evil, and a dysthesis or morbid habit is the certain conse- quence ; whence tabes, atrophy,' scurvy, and various species of gangrene. And if it becomes once impregnated with a peculiar taint, it is wonderful to remark the tenacity with which it retains a Dr. Guy, op. citat.; and in Edinb. Med. and Surg. Journal, p. 90, Jan. 1841. \> Loc citat. 166 CIRCULATION. it, though often in a state of dormancy and inactivity for years, or even entire generations. For as every germ and fibre of every other part is formed and regenerated from the blood, there is no other part of the system that we can so well look to as the seat of such taints, or the predisposing cause of the disorders lam now alluding to ; often corporeal, as gout, struma, phthisis : sometimes mental, as madness; and occasionally both, as cretinism." This picture is largely overdrawn. Setting aside the patholo- gical allusions, which are erroneous in assigning to the blood what properly belongs to the system of nutrition, how can we suppose a taint to continue for years, or even entire generations, in a fluid which is perpetually undergoing renovation, and, at any distinct interval, cannot be presumed to have one of its quondam particles remaining? Were all hereditary diseases derived from the mother, we could better comprehend this doctrine of taints; inasmuch as, during the whole of foetal existence, she transmits the pabulum for the support of her offspring: the child is, how- ever, equally liable to receive the taint from the father, who sup- plies no pabulum, but merely a secretion from the blood at a fecun- dating copulation, and from that moment cannot exert any influ- ence upon the character of his progeny. The impulse to this or that organization or conformation must be given from the moment of union of the particles, furnished by each parent at a fecundating intercourse; and it is probable, that no subsequent influence is exerted even by the mother. She affords the pabulum, but the embryo accomplishes its own construction, as independently of the parents as the chick in ova. (See, on the morbid influences of the blood, the author's Practice of Medicine, 2d edit., Philad. 1844.) i. Transfusion and Infusion. The operation of Transfusion, — as well as of Infusion of medi- cinal agents, — was adduced in an early part of this chapter, to prove the course of the circulation to be by the arteries into the veins. Both these operations were suggested by the discovery of Harvey. The former, more especially, was looked upon as a means of curing all diseases, and of renovating the aged ad libi- tum. The cause of every disease and decay was presumed to reside in the blood, and consequently, all that was conceived to be necessary was to remove the faulty fluid, and to substitute pure blood obtained from a healthy animal in its place. As a therapeutical agent, the history of this operation does not belong to physiology. The detail of the fluctuation of opinions regarding it, and its total disuse, are given at some length in the Histories of Medicine, to which we must refer the reader.a There are some interesting physiological facts, however, that cannot be passed over. MM. Prevost and Dumas found that the vivifying a Sprengel, Hist, de Med. par Jourdan, iv. 120, Paris, 1815; Dr. J. P. Kay, art. Transfusion, Cyclopaedia of Practical Medicine, P. xxi. 246, Lond. 1834; and E. Grafe, art Infusion und Transfusion, Encyclop. Wdrterb. der Medicin. Wissenschaft. xviii.S.434, Berlin, 1838. TRANSFUSION AND INFUSION. 167 power of the blood does not reside so much in the serum as in the red particles. An animal bled to syncope was not revived by the injection of water or of pure serum at a proper temperature ; but if blood of one of the same species was used, the animal seemed to acquire fresh life, at every stroke of the piston, and was at length restored. Transfusion has been revived by Dr. Blundell,3 of London, and by MM. Prevost and Dumas ;b the first of whom has employed it with safety, and he thinks with happy effects, in extensive uterine hemorrhage. All these gentlemen remark, that it can only be adopted with perfect safety, in animals of like kinds, or in those, the globules of whose blood are of similar configuration. MM. Prevost and Dumas, Dielfenbachc and Bischoff,d all agree as to the deadly influence of the blood of the mammalia when injected into the veins of birds. This influence, according to Miiller, is in some way connected with the fibrin of the blood. Experiments have certainly shown, that blood deprived of fibrin acts most injuriously when injected into the vessels.e The-introduction of the practice of infusing medicinal agents into the blood was coeval with that of transfusion. Both, indeed, are affirmed to have been commenced in 1657, at the suggestion of Sir Christopher Wren/ It is a singular fact, that in cases of infu- sion, medicinal substances are found to exert their specific actions upon certain parts of the body, precisely in the same manner as if they had been received into the stomach. Tartar emetic, for example, vomits, and castor oil purges, not only as certainly, but with much greater speed; for whilst the former, as before re- marked, requires to be in the stomach for fifteen or twenty minutes, before vomiting is excited, it produces its effect in one or two mi- nutes, when thrown into the veins. Dr. E. Hale, Junr. of Boston, has published an interesting pamphtet on this subject.^ In it he traces the history of the operation, and details several interesting experiments upon animals; and one upon himself, which con- sisted in the introduction of a quantity of castor oil into the veins. In this experiment, he did not experience much inconvenience immediately after the injection ; but very speedily he felt an oily taste in the mouth, which continued for a length of time, and the medicine acted powerfully as a cathartic. • Considerable difficulty was experienced in the introduction of » Medico-Chirurgical Transactions, ix. 56 ; and x. 296 ; and appendix to Ashwell's Practical Treatise on Parturition, London, 1828. b Biobliotheque Universelle, xvii. 215. " Die Transfuson dies Blutes Berlin, 1828. d Miiller's Archiv. 1835 ; cited in Baly's translation of J. Miiller's Handbuch, u. s. w. e Magendie on the Blood, in Lond. Lancet, and Bell's Select Medical Library Edit. p. 154, Philad. 1839. See, also, on the different effects of transfusion of arterial and venous blood on animals, Bischoff,in Miiller's Archiv. Heft iv. 1838, and Brit, and For. Med. Rev. April, 1839, p. 548. f Sprengel, op. citat. iv. 121. s Boylston Medical Prize Dissertations, for the years 1819 and 1821, p. 100, Bos- ton, 1821. 168 CIRCULATION. the oil, to which circumstance Magendiea ascribes Dr. Hale's safety; for it is found, by experiments on animals, that viscid fluids, such as oil, are unable to pass through the pulmonary capillaries, in consequence of which the circulation is arrested, and death follows. Such also appears to have been the result of the experiments of Dr. Hale with powdered substances. The injection of medicines into the veins has been largely prac- tised at the Veterinary School of Copenhagen, and with complete success, — the action of the medicine being incomparably more speedy, and the dose required much less. It is rarely employed by the physician, except in his experiments on animals ; but it is obvious that it might be had recourse to, with happy effects, where narcotic and other poisons have been taken, and where the mechanical means for their removal are not at hand.b 3. CIRCULATORY APPARATUS IN ANIMALS. In concluding this subject, a brief allusion to the circulatory ap- paratus of other parts of the animal kingdom may be interesting and instructive. In the mammalia in general, the inner structure of the heart is the same as in man, but its situation differs materially; and, in some of them, as in the stag and pig, two small flat bones, called bones of the heart, exist, where the aorta arises from the left ven- tricle. In the amphibious mammalia and the cetacea, it has been supposed that the foramen ovale, situate in the septum between the auricles, is open as in the human foetus, to allow those ani- mals to pass a considerable time under water without breathing ; but the observations of Blumenbach, Cuvier, and others seem to show, that it is almost always closed. Sir Everard Home found it open in the sea otter, in two instances; but these are regarded by naturalists as exceptions to the general rule. In several of the web-footed mammalia and cetacea, as in the common otter, the sea otter, and the dolphin, particular vessels are found to be always greatly enlarged and tortuous ; — a struc- ture which has been chiefly noticed in the vena cava inferior, and which is supposed to serve the purpose of a diverticulum, whilst the animal is under water, or to receive a part of the returning blood, and to retain it until respiration can be resumed. In birds, the structure of the heart universally possesses a sin- gular peculiarity. Instead of the right ventricle having a mem- branous valve, as in the left, and as in all the mammalia, it is provided with a strong, tense, and nearly triangular muscle, which aids in the propulsion of the blood from the right side of the heart into the lungs. This is presumed to be necessary, in consequence of thetr lungs not admitting of expansion like those of the mam- malia, and of their being connected with numerous air-cells. * Precis, &c. ii. 430. b See on the Infusion of different Medicinal Agents, Mr. Blake, Edinb. Med and Surg. Journal, April, 1839. IN ANIMALS. 169 Fig. 175. Circulation in the Frog. Fig. 176. The heart of reptiles or amphibia in gene- ral consists either of only one ventricle, or of two ventricles ; which freely communi- cate, so as essentially to constitute but one. The number of auricles always corresponds with that of the ventricles. That the cavi- ties — auricular or ventricular — are, how- ever, single, although apparently double, is confirmed by the fact, that, in all, there is only a single artery proceeding from the heart, which serves both for the pulmonic and systemic circulations. After this vessel has left the heart, it divides into two branches, by one of which a part only of the blood is conveyed to the lungs, whilst the other proceds to different parts of the body. These two portions are united in the heart, and after being mixed together are sent again through the great artery. In tbese animals, therefore, aeration is obviously less necessary than in the higher classes; and we can thus understand many of their peculiarities how the circulation may continue, when the animal is so situate as to be incapa- ble, for a time, of respiration; and the great resistance to ordinary deranging in- fluences, by which they are characterized. The marginal figure (Fig. 175) represents the circulatory apparatus of the frog ; in which E is the ventricle and D the auricle. From the former arises the aorta F, which soon divides into two trunks. These, after sending branches to the head and neck, turn downwards, (0 and P,) and unite in the single trunk A. This vessel sends ar- teries to the body and limbs, which ulti- mately terminate in veins, and unite to form the vena cava C. From each of the trunks into which the aorta bifurcates at its origin, arise the arteries F. These are distributed to the lungs, and communicate with the pulmonary veins, which return the blood to the auricle, D, where it becomes mixed with the blood of the systemic circulation. In the tadpole state, the circulation is branchial, as in fishes. The heart then sends the whole of its blood to the branchiae or gills, and it is returned by veins following the course of the dotted lines M and N, (Fig. 175,) which unite to form the descending VOL. II. — 15 Circulation in Fishes. 170 CIRCULATION. aorta. As the lungs undergo their development, small arterial branches arise from the aorta and are distri- buted to those organs, and in proportion as these arteries enlarge, the original branchial arteries diminish, until ultimately they are obli- terated, and the blood flows wholly through the enlarged lateral trunks, 0 and P, which, by their union, form the descending aorta. In fishes, the heart is extremely small, in pro- portion to the body; and its structure is simple; consisting of a single auricle and ventricle, D and E (Fig. 176). From the ventricle E an arterial trunk arises, which, in most fishes, is expanded, into a kind of bulb, F, as it leaves the heart, and proceeds straight forward to the branchix or gills, G and H. From these, the blood passes into a large artery, A, analogous to the aorta, which proceeds along the spine, and conveys the blood to the various parts of the system ; and, by the vena cava, C, the blood is returned to the auricle. This is, conse- quently, a case of single circulation. Insects appear to be devoid of bloodvessels. Cuvier examined all the organs in them, which, ,s> red-blooded animals, are most vascular, b. two large arteries, without discovering the least appearance ol a c. c. Mucous elands, d. d. , , -, , , , , 1 :„....*„ _„„.: Glands connected with the bloodvessel, although extremely minute rami- /f'peS /' uieraT-cS; ncations of the trachea were obvious in every E.Home.) part< Insects, however, both in their perfect and larva state, have a membranous tube running along the back, in which alternate dilatations and contractions are perceptible ; and which has been considered as their heart; but it is closed at both ends, and no vessels can be perceived to originate from it. To this the innumerable ramifications of the trachea convey the air, and thus, as Cuvier has remarked, " le sang ne pouvant aller chercher 1'air, e'est Fair qui va chercher le sang ;" (" the blood not being able to go in search of the air—the airseeksthe blood.") Carus has, however, discovered a continuous circulation through arteries and veins in a few of the perfect insects, and especially in some larvae. Lastly, in many genera of the class vermes, particularly amongst the molluscous and testaceous animals, there is a manifest heart, which is sometimes of a singular structure. Some of the bivalves are affirmed to have as many as four auricles ; whilst many ani- mals, as the leech and Lumbricus marinus, have no heart; but circulating vessels exist, in which contraction and dilatation are perceptible. The marginal figure, (Fig. 177,) of the interior of a leech, given by Sir Everard Home, will exhibit the mode of circulation and respiration in that animal. There is no heart, but a large vessel b. b Interior of the Leech. Respiratory cells. NUTRITION. 171 exists on each side of the animal. The water is received, through openings in the belly, into the cells or respiratory organs, and passes out through the same.3 CHAPTER V. NUTRITION. The investigation of the phenomena of the circulation has exhi- bited the mode in which arterial blood is distributed over the body in minute vessels, not appreciable by the naked eye, and often not even with the microscope, and so numerous, that it is impossible for the finest-pointed instrument to be forced through the skin without penetrating one, and perhaps several. We have seen, likewise, that, in the capillary system of vessels, this arterial blood is changed into venous; and it was observed, that in the same system, parts are deposited or separated from the blood, and cer- tain phenomena accomplished, into the nature of which we have now to inquire, beginning with those of nutrition, which com- prise the incessant changes that are taking place in the body, both of absorption and deposition, and which effect the decomposition and renovation of each organ. Nutrition is well defined by Ade- lonb as the action, by which every part of the body, on the one hand, appropriates or assimilates to itself a portion of the blood distributed to it; and, on the other, yields to the absorbing vessels a portion of the materials that previously composed it. The pre- cise character of the apparatus, by which this important function is accomplished, we have no means of knowing. All admit, how- ever, that the old matter must be taken up by absorbents, and the new be deposited by arteries, or by vessels, continuous with them. As the precise arrangement of these minute vessels is not percep- tible by the eye, even when aided by powerful instruments, their arrangement has given rise to much controversy. Whilst some have imagined lateral pores in the capillary system of vessels, for the transudation of nutritive deposits; others have presumed, that inconceivably small vessels are given off from the capillary system, which constitute a distinct order, and whose function is to exhale the nutritive substance. Hence, they have been termed exhalants or nutritive exhalants ; but the physiological student must bear in mind, that whenever the term is used by writers, they do not always pledge themselves to the existence of any distinct set of vessels, but merely mean the capillary vessel, whatever may be its nature, which is the agent of nutrition, and conveys the blood to the different tissues. * See, on all this subject, Roget's Animal and Vegetable Physiology, Amer. Edit. ii., 137, Philad. 1836; art. Circulation, by Dr. Allen Thomson, in Cyclopaedia of Anat. and Physiol., p. 641, Lond. 1836 ; and Carpenter, Principles of General and Compa- rative Physiology, 2d edit., Lond. 1841. d Physiologie de 1'Homme, torn, iii- p. 359, 2de edit., Paris, 1829. 172 NUTRITION. In investigating the physiology of nutrition, two topics neces- sarily divide our attention ; 1st. The action of decomposition, by which the organ yields to the absorbing vessels a portion of its constituents ; and 2dly. The action of composition, by which the organ assimilates a part of the arterial blood that enters it, and supplies the loss, which it has sustained by the previous action of decomposition. The .former of these actions obviously belongs to the function of absorption ; but its physiology was deferred, in consequence of its close application to the function we are now considering. It comprises what is meant by interstitial, organic or decomposing absorption, and does not require many comments, after the long investigation of the general phenomena of absorp- tion into which we entered. The conclusion, at which we then arrived, was, — that the chyliferons and lymphatic vessels form only chyle and lymph respectively, refusing the admission of all other substances; that the veins admit every liquid which pos- sesses the necessary tenuity ; and that, whilst all the absorptions, — which require the substance acted upon to be decomposed and transformed, — are effected by the chyliferous and lymphatic ves- sels, those that demand no alteration are accomplished through the coats of the veins by imbibition. It is easy, then, to deduce the agents to which we refer the absorption of decomposition. As it is exerted on solids, and as these cannot pass through the coats of the vessel in their solid condition, it follows, that other agents than the veins must accomplish the process ; and, again, as we never find in the lymphatic vessels any thing but lymph, and as we have every reason to believe that an action of selection is exerted at their extremities, similar to that of the chyliferous ves- sels on the heteiogeneous substances exposed to them, we naturally look to the lymphatics as the main, if not the sole, organs, concerned in the absorption of solids. It has been maintained, by some physiologists, that the different tissues are endowed with a vital attractive and elective force, which they exert upon the blood; — that each tissue attracts only those constituents of which it is itself composed ; and thus, that the whole function of nutrition is an affair of elective affinity ; but this, ob- viously, cannot be the force that presides over the original forma- tion of the tissues in the embryo. An attraction cannot be exerted by parts not yet in existence. To account for this, it has been imagined, that a peculiar force is destined to preside over forma- tion and nutrition, and.to this force various names have been as- signed. By most of the ancients it was termed facultas forma- trix, nutrix, auctrix ; by Van Helmont,a Bias alterativum ; and by Bacon,b motus assimilationis. It was the fucultas vegetativa of Harvey ;c the anima vegetativa of Stahl ;d the puissance du moule intirieur of Buffon ;e the vis essentialis of C. F. Wolff-f a Opera, pars i. i> Novum Organum, lib. ii. aphor.48. c De Generatione Animalium, Lond. 1651, p. 170. i Theoria Medica Vera. Hal. 1708. <= Histoire Naturelle, torn. ii. f De Generatione, Hal. 1759. NUTRITION. 173 . and the B i 1 d u n g s t r i e b or nisus formativus of Blumenbach and most of the German writers.8 This force is meant, when writers speak of the plastic force, force of nutrition, force of formation, and force of vegetation. Whatever difference there may be in the terms selected, all appear to regard it as charged with main- taining, for a certain length of time, living bodies and all their parts, in the possession of their due composition, organization, and vital properties, and of putting them in a condition, during a cer- tain period of their existence, to produce beings of the same kind as themselves. It is obvious, however, that none of these terms elucidate the intricate phenomena of nutrition, and that none ex- press more than — that living bodies possess a vital force under the action of which formation and nutrition are accomplished. Under the idea, that all the vessels of the intermediate system are possessed of coats, it is not easy to comprehend how either nutrition or secretion can be accomplished. Lateral pores, as we shall see under the head of Secretion, have been imagined, but this supposed arrangement, provided it existed, which has not been, and cannot easily be, demonstrated,11 would not materially elucidate the subject; but if we adopt the opinion, before referred to, that many of the vessels of the capillary system consist of mem- braneless or coatless vessels, we can comprehend, that by the elec- tive and attractive forces possessed by the tissues and exerted by them on the blood, materials may be obtained from that fluid as it passes through the intermediate system, which may be inservient to the nutrition of the various tissues that are bathed by it, — the mode in which the blood is distributed through the tissues resem- bling that in which the water of a river is distributed through a marsh, conveying to the vegetable bodies that flourish on its sur- face, the materials for their nutrition. To adopt the language of an intelligent and philosophical writer,0 " In every part of the body, in the brain, the heart, the lung, the muscle, the membrane, the bone, each tissue attracts only those constituents of which it is itself composed. Thus the common current, rich in all the proximate constituents of the tissues, flows out to each. As the current approaches the tissue, the particles appropriate to the tissue feel its attractive force, obey it, quit the stream, mingle with the substance of the tissue, become identified with it, and are changed into its own true and proper nature. Meantime, the particles which are not appropriate to that particular tissue, not being at- tracted by it, do not quit the current, but„passing on, are borne by other capillaries to other tissues, to which they are appropriate, and by which they are apprehended and assimilated. When it has given to the tissues the constituents with which it abounded, and received from them particles no longer useful, and which would become noxious, the blood flows into the veins, to be re- » Comment. Societ. Gbtting. torn. viii.; Elliotson's Blumenbach's Physiology, 4th edit., Lond. 1828, p. 490 ; and Tiedemann's Traite de Physiologie, par Jourdan, p. 405, Paris, 1831. >< Mandl, Manuel d'Anatomie generale, p. 188, Paris, 1843. e The Philosophy of Health, by Dr. Southwood Smith, vol. i., p. 405, London,1835. 15* • 174 NUTRITION. turned by the pulmonic heart to the lung, where, parting with the useless and noxious matter it has accumulated, and replenished with new proximate principles, it returns to the systemic heart, by which it is again sent back to the tissues." Particles of blood are seen to quifthe current and mingle with the tissues; particles are seen to quit the tissues, and mingle with the current; but all that we can see, as Dr. Smith has remarked, with the best aid we can get, does but bring us to the confines of the grand operations that go on, of which we are altogether ignorant. It would not seem, however, to be necessary for the nutrition of certain parts, that they should receive capillary vessels. There are tis- sues, commonly termed extra-vascular, in the substance of which, neither injection no$ the microscope has exhibited the existence of bloodvessels, which would seem to derive their nourishment from blood flowing in the vessels of adjacent tissues by imbibition. To these belong the crystalline, the epidermis and epithelium, hair, nails, enamel of the teeth, &c, &c.a We have said, that the main, if not the sole, agents of the ab- sorption of solids, are the lymphatics. Almost all admit, that they receive the product of absorption ; but all do not admit, that the action of taking up solid parts is accomplished immediately by the absorbents. They who think, that a kind of spongy tissue or " parenchyma" is situate at the radicles of the absorbent vessels, believe that this sponge possesses a vital action of absorption, when bodies, possessing the requisite constitution and consistence, are put in contact with it; but they maintain that the solid parts of the body are broken down by the same agents— the extreme arteries — which secreted them, and that, when reduced to the proper fluid condition, they are imbibed by the parenchyma, and conveyed into the lymphatics. If the existence of this sponge were demonstrated, the above explanation would be the only one, perhaps, that could be admitted ; for the sponge could scarcely be conceived to do more than imbibe ; it could not break down the solid textures, and reduce them to lymph —the only fluid, which, as we have seen, is ever met with in the lymphatic vessels. But its existence is altogether supposititious. Besides, the arrange- ment has not been invoked in favour of the chyliferous vessels, which are so analogous in their organization and functions to the lymphatics. It has not been contended, that the arteries of the intestinal canal form the chyle from the alimentary matters in the small intestine, and tlfat the office of the chyliferous vessels is re- stricted to the reception of this chyle, imbibed and brought in con- tact with their radicles by this ideal sponge or parenchyma. We have before shown, that there is every reason for the belief, that a vital action of selection and elaboration exists at the very radicles of the chyliferous vessels; and the same may be inferred of theradicles of the lymphatics. The great difficulty is in believ- ing how either exhaling artery or absorbing lymphatic can reduce * Mr. J. Toynbee, Philos. Transact. 1841; and Medico-Chirurg. Rev., April, 1842, p. 426; also, Carpenter, Human Physiology, Amer. Edit., p. 46irPhilad. 1843. NUTRITION. 175 the solid matter — of bone, for example — to the necessary con- stitution and consistence to enter the lymphatics ; but we can con- ceive, that the latter as readily as the former, by virtue of its vital properties — for the operation must be admitted by all to be vital — and by means of its contained fluid, may soften the solid so as to admit of its being received into the vessel. We leave, then, wholly unexplained, the mysterious operation by which these ab- sorbents are enabled to reduce to their elements, bone., muscle, tendon, &c, and to recompose them into the form of lymph. Dr. Bostocka fancifully suggests, that the first step in this series of ope- rations is the death of the part, by which expression he means, that it is no longer under the influence of arterial action. " It therefore ceases to receive the supply of matter which is essential to the support of all vital parts, and the process of decomposition necessarily commences." The whole of his remarks on this sub- ject are eminently gratuitous, and appear to be suggested by his extreme unwillingness to ascribe the process to any thing but phy- sical causes. If there be, however, anyone phenomenon of the ani- mal economy, which is more manifestly referable to vital action than another, it is the function of nutrition, both as regards the absorption of parts already deposited, and the exhalation of new ; and it is wise to confess our utter ignorance of the mode in which it is accomplished. We know that the blood contains most of the principles that are necessary for the nutrition of organs, and that it must contain the elements of all. Fibrin, albumen, fat, osma- zome, salts, &c, exist in it, and these are deposited, as the blood traverses the tissues ; but why one should be selected by one set of vessels, as by the exhalants of bone, and another by another set, and in what manner the elements of those, not already formed in the blood, are brought together, is totally unknown to us. Blood has been designated as "liquid flesh," —chair coul ante,— but something more than simple transudation through vessels is necessary to form it into flesh, and to give' it the compound organi- zation of fibrin, gelatin, osmazome, &c. — in the form of muscular fibre and cellular membrane — which we observe in the rrluscle. Nothing, perhaps, more clearly exhibits our want of knowledge on the subject than the following vague attempt at solving the mystery by one of the most distinguished physiologists of the age. " Some immediate principles, that enter into the composition of the organs or of the fluids, are not found in the blood, — such as gela- tin, uric acid, &c. They are consequently formed at the ex- pense of other principles, in the parenchyma of the organs, and by a chemical action, the nature of which is unknown to us, but which is not the less real, and must necessarily have the effect of developing heat and electricity." Histologists have not been content with endeavouring to re- duce the different organized textures to primary fibres and fila- ments, but, by the aid of the microscope, they have attempted to discover the particular arrangement and mode of formation of the » Physiol., edit. cit. p. 625. 176 NUTRITION. constituent corpuscles. The discovery of that valuable instrument gave the impulse, and very soon the scientific world was pre- sented with the results obtained by numerous observers. These observations have been, from time to time, continued until the present day. It is, however, to be regretted, that, until recently, our information, derived from this source, was not as accurate as was desirable. From different quarters the most discordant statements were presented, exhibiting clearly, either that the nar- rators employed instruments of very diffrent powers, or that they were blinded, or had the vision depraved, by preconceived theo- ries or hypotheses. One of the very first effects of the discovery of the microscope was the detection of a globular structure of the primitive tissue of the body, by Leeuenhoek,a an announcement that gave rise to much controversy, which has continued, indeed, till the present time, and has engaged the attention particularly of Prochaska,b Fontana,c Sir Everard Home, Mr. Bauer, the bro- thers Wenzel,d Dr. Milne Edwards, MM. Prevost and Dumas,e Dutrochet, Hodgkin/ Raspail, and others. The observations and experiments of Dr. Edwards especially occasioned at the time much interesting speculation and inquiry. They may perhaps be taken as the foundation on which the believers in the globular structure rest their opinions. His views were first published in 1823, in a communication, entitled " Mimoire sur la Structure (limentaire desprincipaux Tissues Organiques des Animaux;" and in a second article in the Annales des Sciences Nalurelles, for December, 1826, entitled " Recherches microscopiques sur la Structure inlime des Tissues Organiques des Animaux." He examined all the principal textures of the body, the cellular tissue, the membranes, tendons, muscular fibre,nervous tissue, the skin, the coats of the bloodvessels, &c. When the cellular tissue was viewed through a powerful lens, it seemed to consist of cylinders ; but, by using still higher magnifying powers, these cylinders were found to be, formed of rows of globules all of the same size, that is, about the TjVotn or •b-cW" °f an mcn m diameter (Fig. 178) ; separated from each other, and lying in various directions; crossing and interlacing; some of the rows straight, others bent, and some twisted, forming irregular layers, united by a kind of network. The membranes, which con- sist of cellular tissue, were found to pre- sent exactly the same kind of arrangement, The muscular fibre, when examined in the like manner, was found to be formed of globules also ^th part of an inch in » Opera Omnia, &c, Lugdun. Batav. 1722. b De Structura Nervorum, Vind. 1779. e Sur les Poisons, ii 18. 4 De Structura Cerebri, Tubing. 1812. « Bibliotheque Universelle des Sciences et Arts, t. xvii. f In Drs. Hodgkin and Fisher's translation of W. Edwards, Sur les Agens Physiques, Lond. 1832; and Hodgkin's Lectures on the Morbid Anatomy of the Serous and Mu- cous Membranes, p. 26, Lond. 1836 ; or Dunglison's Amer. Med. Lib. Edit. Phil. 1S38. NUTRITION. 177 diameter. Here, however, the rows of globules are always parallel. The fibres never intersect each other like those of cellular tissue,and this is the only discernible difference, — the form and size 'of the globules being alike. The size of the globules, and the linear arrangement they assume, seemed to be the same in all animals that possess a muscular structure. (Fig. 179.) The nervous structure has, by almost all observers, been es- teemed globular — and one of the recent observers1 has satisfied himself that this is certainly the most uniform ap- pearance. The examination of Dr. Edwards Fig. 179. yielded similar results. It seemed to be composed of lines of globules of the same size with those that form the cellular membrane and the mus- cles ; but holding an intermediate place as to the regularity of their arrangement, and having a fatty matter interposed between the rows. In regard to the size of the globules, Dr. Edwards, however, differed materially from an accurate and experienced microscopic observer, Mr. Bauer,b who asserted that the cerebral globules are of vari- ous sizes. (Fig. 180.) From the results of his own diversified observations, Dr. Edwards concluded, that " spherical corpuscles, of the diameter of 7Joth of a millimetre, constitute, by their aggregation, all the organic textures, whatever may be the properties, in other respects, of those parts, and the functions for which they are destined." Fig- 180. The harmony and simplicity, which would thus seem to reign through the struc- tures of the animal body, attracted great attention to the labours of Dr. Edwards. The vegetable kingdom was subjected to equal scrutiny ; and, what seemed still more astounding, it was affirmed, that the micro- scope proved it also to be constituted of globules exactly like those of the animal, and of the same magnitude, j-oV^th of an inch in diameter ; hence, it was assumed, that all organized bodies possess the same elementary structure, and of necessity, that the animal and the vegetable are readily convertible into each other under favourable circumstances, and that they differ only in the greater or less complexity of their organization. Independently of all other objections, however, the » Dr. Luigi Calori, in Bulletino dello Scienze Medich. di Bologna, Sett. 1836, p. 152. i> Philosoph. Transact, for 1818 ; and Sir E. Home's Lectures on Comparative Ana- tomy, vol. iii. lect. 3, Lond. 1823. 178 NUTRITION. animal differs, as we have seen, from the vegetable, in composi- tion ; and this difference must exist not only in the whole, but in its parts; so that, even were it demonstrated, that the globules of the beings of the two kingdoms are alike in size, it would by no means follow, that they should be identical in intimate compo- sition. The discordance which we have deplored, is strikingly applica- ble to the case before us. The appearance of the memoir of Dr. Edwards excited the attention of Dutrochet, and in the following year his " Researches" on the same subject were published, in which he asserts, that the globules, which compose the different structures of the invertebrated animals, are considerably larger than those of the vertebrated ; that the former appear to consist of cells, containing other globules still smaller; and hence he infers, that the globules of vertebrated animalsare likewise cellular,andcon- tain series of still smaller globules. Dr. Edwards, in his experiments, found, that the globules of the nervous tissue, whether examined in the brain, in the spinal cord, in the ganglia, or in the nerves, have the same shape and diameter, and that no difference can be dis- tinguished in them, from whatever animal the tissue is taken. Dutrochet, on the other hand, considers, with Sir Everard Home and the brothers Wenzel, that the globules of the brain are cellules of extreme minuteness, containing a medullary or nervous sub- stance, which is capable of becoming concrete by the action of heat and of acids. This structure, he remarks, is strikingly evi- denced in certain molluscous animals; and he instances Fig. 181. the small pulpy nucleus, forming the cerebral hemi- sphere of the Umax rufus, and the helix pornatia, composed of globular, agglomerated cellules, on the parietes of which a considerable number of globular or ovoid corpuscles are perceptible. (Fig. 181.) M. Dutrochet, again, did not find the structure of the nerves to correspond with that of the brain. He asserts, that the elementary fibres, which enter into their compo- sition, do not consist simply of rows of globules, according to the opinion of Edwards and others, but that they are cylinders of a diaphanous substance, the surface of which is studded with globu- lar corpuscles, and that, as these cover the whole surface of the cylinder, we are led to believe that they are situate internally. After detailing this difference of structure between the brain and the nerves, the former consisting chiefly of nervous corpuscles, the latter chiefly of cylinders or fibres, Dutrochet announces the hypo- thesis, which exhibits too many indications of having been formed prior to his microscopic investigations, —that these cerebral cor- puscles are destined for the production of the nervous power, and that the nervous fibres are tubes, filled with a peculiar fluid, by the agency of which nervimotion is effected. For further deve- lopments of the analysis of Dutrochet, the reader is referred to the NUTRITION. 179 work itself, which exhibits all the author's ingenuity and enthu- siasm, but can scarcely be considered historical. The beautiful superstructure of Dr. Edwards, and the ingenuity of Dutrochet, were, however, most fatally assailed by subsequent experiments, with a microscope of unusual power, by Dr. Hodgkin. The globular structure of the animal tissues, so often developed, and apparently so clearly and satisfactorily established by Dr. M. Edwards, is, we are told by Dr. Hodgkin,3 a mere deception; and the most minute parts of the cellular membrane, muscles, and nerves had again to be referred to the striated or fibrous arrange- ment. A part of the discrepancy between Messrs. Edwards and Dutrochet may be explained by the fact of the former using an in- strument of greater magnifying power than the latter; who employ- ed the simple microscope only. It has been observed, that when Dr Edwards used an ordinary lens, the arrangement of a tissue appeared cylindrical, which, with the compound microscope, was distinctly globular. The discordance between Messrs. Edwards and Hodgkin was reconcilable with more difficulty. On the whole subject, indeed, minds were kept in a state of doubt, and the ra- tional physiologist waited for ulterior developments. Messrs. Prevost and Dumas, and Dr. Edwards, farther affirmed, that all the proximate principles —albumen, fibrin, gelatin, &c — assume a globular form, whenever they pass from the fluid to the solid state, whatever may be the cause producing such conversion. M. Rasp'ailb ranged himself among those who considered, that the ultimate structure of all organic textures is vesicular, and that the organic molecule, in its simplest form, is an imperforate vesicle, en- dowed with the faculty of inspiring gaseous and liquid substances, and of expiring again such of their decomposed elements, as it can- not assimilate; —properties, which he conceived it to possess under the influence of vitality. His views contain, perhaps, the o-erm of those that follow, and that now occupy the minds of ob- is servers The microscopical researches of Schwann and Schleidenc led them to affirm, that the new-forming tissues of vegetables origi- nate from a liquid gum or vegetable mucus, and those of animals probably from the liquor sanguinis, which consists essentially of fibrin after transudation from the capillary vessels. This substance itself, in a state fully prepared for the formation of the tissue, is termed by them intercellular substance and Cytoblastema. In the * Op. citat. p. 466. See, also, Grainger's Elements of General Anatomy, London' 1829. b Op. citat. & 126. . . • , e. i . a e Mikroskopische Untersuchungen Uber die Uebereinstimmung in der Strukturund dem Wachstum der Thiere und Prlanzen, von Dr. Th. Schwann und Schleiden in Miiller's Archiv. p. 137, 1838 ; and an interesting notice of the same, in Brit, and for. Med. Review, p. 495, April, 1840. See, also, Muller, Henle, Carpenter, Wagner, and Mandl. lg0 NUTRITION. first instance, it exhibits minute granular points, Fig. 182. which grow and become more regular and defined from the agglomeration of the minuter granules around the larger, constituting nuclei or cytoblasts, having, when fully formed, and in fact formed before them, one or more well- defined bodies within them, called nucleoli. From the cytoblasts, cells—primordial cells — are formed. A transparent vesicle grows over each, and becomes filled with fluid ; this gradu- Primary organic cell, ' i i , 1 i i showing the ceii, mem- ally extends and becomes so large that the cy- nucleWsh-cZcJa"dCd toblast appears like a small body within its man-i walls. The form of the cells is at first irregular, then more regular, and they are alternately flattened by pressure against each other, assuming different forms in different tissues. Such is their description of the vegetable cells from which all the tissues of plants take their origin. In like manner, the tis- sues of animals are formed from a fluid, in which first nucleoli, then nuclei or cytoblasts, and then cells are developed. The globules of lymph, pus, and mucus, according to them, are cells with their walls distinct and isolated from each other; horny tis- sues are cells with distinct walls, but united into coherent tissues; bone, cartilage, &c, are formed of cells whose walls have coalesced; cellular tissues, tendon, &c, are cells which have split into fibres, and muscles, nerves and capillary vessels are cells of which both the walls and cavities have coalesced. According to the fashionable doctrine of the day, these cells pos- sess an independent life, and a limited duration, which has no immediate connection with that of the organism, and the continual decomposition, which is taking place in the living body, is con- nected with the death of the cells of which the several parts are constructed ; and for the reintroduction of .which into the circu- lating fluid, the lymphatic system appears to be specially destined.8 By virtue of this vital power, they not only attract but change the substance brought into contact with them, or in other words, have a power of self-nutrition. That this is probably independent of the nerves is shown by an experiment of Dr. Sharpey, in which the reproduction of a portion of the tail of a salamander took place, although it was cut off, after the organ had been completely paralysed by dissecting out at its root a portion of the spinal cord, together with the arches of the vertebrae.b The doctrine of the development of all the organic tissues from cells is embraced at the present day by almost all histological in- quirers; yet there are some who doubt it; and others, who by no means regard it as applicable to all the tissues. Thus, Mandl,c one a Carpenter, Human Physiology, § 645, Amer. Edit., Philad. 1843. i> Ancell, Lectures on the Physiology, &c. of the Blood, in Lond. Lancet, p. 157, April 25, 1840. c Manuel d'Anatomie generale, p. 549, Paris', 1843. NUTRITION. 181 of the latest histologists, objects to the term cytoblastema as applicable to the matrix or organizing material of the tissues, because it necessarily involves the supposition that it gives ori- gin to cells. According to him, the elements, which are deve- loped in the blastema — as he prefers to call it — do not generally deserve the name of cells, inasmuch as they may either liquify as in the glands; consolidate as in the amorphous membranes; or become transformed directly into fibres, as in the cellular tissue. Mr. Gulliver,a too, has inferred from his observations, that the mere extension of the parietes of the cells is not essential to the formation of all tissues, since fine fibres or fibrils are found in fibrin that has coagulated even out of the body. He has, also, given several figures to exhibit the analogy of structure between false membranes and fibrin coagulated after death, or after the removal of the blood from the body. Schwann, on the other hand, lays down the rule, which he considers of universal application, that all the organic tissues, however different they may be, have one common principle of development as their basis, viz., the for- mation of cells ; — that is to say, nature never unites molecules immediately into a fibre, a tube, &c.; but she always, in the first instance, forms a round cell, or changes, when it is requisite, the cells into the various primary tissues as they present themselves in the adult state ; but " how," says Mr. Gulliver,b " is the origin of the fibrils, which I have depicted in so many varieties of fibrin, to be reconciled with this doctriue ? and what is the proof that these fibrils may not be the primordial fibres of animal textures? I could never see any satisfactory evidence, that the fibrils of fibrin are changed cells; and indeed, in many cases, the fibrils are formed so quickly after coagulation, that their production, accord- ing to the views of the eminent physiologist just quoted [Schwann], would hardly seem possible. Nor have 1 been able to see, that these fibrils arise from the interior of the blood-disks, like certain fibres delineated in the last interesting researches of Dr. Barry." Mr. T. Wharton Jones,c also, in a paper read to the Royal Society, on the 8th of December, 1842, has considered the notion entertained by Dr. Barry,d that a fibre exists in the interior of the blood corpuscles, and that these fibres, after their escape from thence, constitute the fibres which are formed by the consolidation of the fibrin of the liquor sanguinis, to be wholly erroneous. He regards the appearance as altogether illusive. Dr. Carpenter,e in remarking on Mr. Gulliver's figures, all of which, as he properly observes, clearly show,that a small portion of coagulated fibrin contains a far larger number of fibres than we » Appendix to Gerber's Anatomy, Atlas, p. 60, and Figs. 244-6, Lond. 1842. •> Load, and Edinb. Philosoph. Magazine, Oct. 1842; see, also, Andral, Hemato- logic Pathologique, p. 77, Paris, 1843. c Proceedings of the Royal Society, No. 56. a Philosophical Transactions for 1842. e Sec his interesting report on the Origin and Functions of Cells, in Brit, and For, Med. Rev. for Jan. 1843, p. 277. VOL. II. — 16 182 NUTRITION. can imagine to be contained in the number of blood-disks that would fill the same space, states, that he has lately discovered a very interesting example of a membrane composed almost entirely of matted fibres, which so strongly resembles the delineations of fibrous coagula given by Mr. Gulliver, that he cannot but believe in the identity of the process by which they are produced. This is the membrane enclosing the white of the egg, and forming the animal basis of the shell. If the shell be treated with dilute acid, a tough membrane remains, exactly resembling that which lines it; and if the hen have not been supplied with lime, there is no dif- ference between the two membranes even without the action of acid on the outer one. Each of these membranes consists of nu- merous laminae of most beautifully matted fibres intermixed with round bodies exactly resembling exudation cells. It is in the in- terstices of these fibres that the calcareous particles are deposited, which give density to the shell. These membranes, according to Dr. Carpenter, are formed around the albumen, which is deposited upon the surface of the ovary during its passage along the oviduct, from the interior of which the fibrinous exudation must take place. It is clear, then, that this doctrine of the origin of all the tissues from cells, cannot be considered established. Nor can ideas be esteemed more fixed in regard to the character of the matrix or blastema. Mandla affirms, that we know not whether it is the albumen or fibrin of the blood. Others, and perhaps the majority of the present day, ascribe it to fibrin, between which, as we have elsewhere seen, and albumen, there is, ac- cording to Mulder, Liebig, and others, an almost identity of che- mical composition. Fibrin, however, is considered to possess much higher vital properties, and the change of albumen into fibrin has been esteemed the first important step in the process of assimila- tion.1' In the alimentary mass in the small intestines, albumen is found, but not fibrin : in the chyliferous vessels, however, the lat- ter is met with, and its proportion increases as the chyle and lymph proceed onwards in the vessels ; whilst that of the albumen di- minishes. Such, however, is not rigorously the fact, for on refer- ring to the table slightly modified from that of Gerber, which has been given elsewhere (vol. i., p. 609), it will be seen, that in the afferent lacteals between the intestines and mesenteric glands, the albumen has been found in minimum quantity; in the efferent or central lacteals, from the mesenteric glands to'the thoracic duct, in maximum quantity ; and in the thoracic duct in medium quan- tity ; whilst the fibrin goes on progressively increasing in the pro- gress of the chyle and lymph onwards. On the other hand, the fat was found to diminish progressively ; so that there appears to be more probability that the fibrin is formed from the fat, directly or indirectly, than from the albumen. It would seem not improbable, that some organized substance like pepsin, or diastase in plants, is secreted from the parietes of the chyliferous vessels, » Op. cit. p. 548. b Carpenter, Brit, and For. Med. Rev., Jan. 1843, p. 269. NUTRITION. 183 which occasions a change in the elements of those constituents of the chyle, and is the earliest step of animalization. That there is an essential difference, however, between fibrin and albumen, not- withstanding their affirmed similarity in chemical composition, is shown by the fact, that effused fibrin has a tendency to sponta- neous coagulation, whilst albumen requires the agency of heat; and that, as we have seen, there is an appearance of distinct orga- nization in coagulated fibrin. This difference in properties would necessarily induce the belief, that the two substances differ more perhaps in chemical composition than the results of the analyses of Mulder, Liebig, and others, would seem to indicate ; and such appears to be proved by the recent analysis of MM. Dumas and Cahours, which have been conducted on a very extensive scale, and show, that the proportion of carbon is seven per cent, less in fibrin than in albumen ; whilst that of azote is from eight to nine per cent. more. A correct idea, these gentlemen think, may be formed of the elementary composition of fibrin by considering it a compound of casein, albumen, and ammonia.a Such is the state of uncertainty in which we are compelled to rest in regard to this importantfunction. None of the views can be es- teemed established. They areinastateoftransition;andall,perhaps, that we are justified in deducing is, that the vital property, which exists in organizable matters— in the fibrinous portion of the blood, and in the blastema that is furnished by the parents at a fecundating union — gives occasion to the formation of cells, in some cases, of fibres in others; and that the tissues are farther developed through the agency of this cell-life ox fibre-life, so as to constitute all the tex- tures of which the body is composed.b It is the action of nutrition, that occasions the constant fluctua- tions in the weight and size .of the body, from the earliest embryo condition till advanced life. The cause of the development or growth of organs and of the body generally, as well as of the limit, accurately assigned to such development, according to the animal or vegetable species,is dependent upon vital laws that are unfathomable. Nor are we able to detect the precise mode in which the growth of parts is effected. It cannot be simple exten- sion, for the obvious reason that the body and its various com- partments augment in weight as well as in dimension. The ra- pidity with which certain growths are effected is astonishing. The Bovista giganteum has been known to increase, in a single night, . from a mere point to the size of a large gourd, estimated* to con- tain 48,000,000,000 cellules ; and supposing twelve hours to have been necessary for its growth, the cells in it must have been produced at the rate of 4,000,000,000 an hour, or more than 66,000,000 a minute, — the greater part of the elements necessary » Med. Examiner, Oct. 14, 1843, p. 232. ■» See, on all this subject, Carpenter, Brit, and For. Med. Rev., Jan. 1843, p. 259. 184 NUTRITION. for this astonishing formation being obtained from the air.a But these "rapid growths possess little vitality, and their decay is almost as rapid as their productions.1* Analogous growths — but not to the like extent — occur in the human body, and the same remark applies to them. In the large trees of our forests we find a fresh layer or ring added each year to the stem, until the full period of development; and it has been supposed that the growth of the animal body may be effected in a similar manner, both as regards its soft and harder materials, — that is, by layers deposited externally. That the long bones lengthen at their extremities is proved by an experi- ment of Mr. Hunter. Having exposed the tibia of a pig, he bored a hole into each extremity of the shaft, and inserted a shot. The distance between the shots was then accurately taken. Some months afterwards, the same bone was examined, and the shots were found at precisely their original distance from each other; but the extremities of the bone had extended much beyond their first distance from them. The flat bones also increase by a de- position at their margins, and the long bones by a similar deposi- tion at their periphery, — additional circumstances strongly ex- hibiting the analogy between the successive developmentof animals and vegetables. Exercise or rest, freedom from, or the existence of, pressure produce augmentation of the size of organs, or the con- trary ; and there are certain medicines, as iodine, which occasion the emaciation of particular organs only — as of the female mammae. The effects of disease is likewise, in this respect, familiar and striking.6 The ancients had noticed the changes effected upon the body by the function we are considering, and attempted to estimate the period at which a thorough conversion might be accomplished, so that not one of its quondam constituents should be preseut. By some, this was supposed to be seven years ; by others, three. It is hardly necessary to say, that in such a calculation we have nothing but conjecture to guide us. The nutrition of the body and of its parts varies, indeed, according to numerous circumstances. It is not the same during the period of growth as subsequently, when the absorption and deposition are balanced, so far at least as con- cerns the augmentation of the body in one direction. Particular organs have, likewise, their period of development, at which time the nutrition of such parts must necessarily be more active, — the organs ©f generation, for example, at the period of puberty; the enlargement of the mammas in the female ; the appearance of the beard and the amplification of the larynx in the male, &c. All these changes occur after a determinate plan. » M. Truman, Food and its influence on Health and Disease, &c.,p. 229, Lond. 1842. b Carpenter, Animal Physiology, pp. 118, 130, Lond. 184a; and Human Physio- logy, Amer. Edit., by Dr. Clymer, p. 411, Philad. 1843. • c See the author's General Therapeutics, p. 419, Philad. 1836 ; and his General Therapeutics, and Mat. Med. vol. ii. Philad. 1843. NUTRITION. 185 Fig. 183. Tattooed Head of a New Zealand Chief. The activity of nutrition ap- pears to be increased by ex- ercise, at least in the muscular organs; hence the well-marked muscles of thearminthe prize- fighter, of the legs in the dancer, &c. The muscles of the male are, in general, much more clearly defined ; but the dffference between those of the hard-working female and of the inactive male may not be very apparent. The most active organs in their nutrition are the glands, muscles, and skin, which alter their character — as to size, colour and consistence — with great rapidity; whilst the tendons, fibrous membranes, bones, &c, are much less so, and are altered more slowly by the effect of disease. A practice, which prevails amongst cer- tain professions and people, would seem at first sight to show that the nutrition of the skin cannot be energetic. Sailors are frequently in the habit of forcing gunpowder through the cuticle with a point- ed instrument, and of figuring the initials of their names upon the arm in this manner : the particles of the gunpowder are thus driven into the cutis vera and remain for life. The operation of tattooing, or of puncturing and staining the skin, prevails in many parts of the globe and especially in Polynesia, where it is looked upon as greatly ornamental. The art is said to be carried to its greatest perfection in the Washington or New Marquesas Islands ;a where the wealthy are often covered with various designs from head to foot; subjecting themselves to a most painful operation for this strange kind of personal decoration. The operation consists in puncturing the skin with some rude instrument, according to figures previously traced upon it, and then rubbing into the punctures a thick dye, frequently composed of the ashes of the plant that fur- nishes the colouring matter. The marks, thus made, are indelible. Magendiebasks: —" How can we reconcile this phenomenon with the renovation, which, according to authors," (and he might have added, according to himself,) " happens to the skin ?" It does not seem to us to be in any manner connected with the nutrition of the skin. The colouring matter is an extraneous substance, which takes no part in the changes constantly going on in the tissue in which it is imbedded; and the circumstance seems to afford a » Lawrence's Lectures on Physiology, &c, p. 411, Lond. 1819. b Precis, &c. edit. cit. ii. 483. * 16* 186 CALORIFICATION. negative argument in favour of venous absorption. Had the sub- stance possessed the necessary tenuity it would have entered the veins like other colouring matters: but the particles are too gross* for this, and hence they remain free from all absorbent influence. CHAPTER VI. CALORIFICATION. The function, which we have now to consider, is one of the most important to organic existence, and one of the most curious in its causes and results. It has, consequently, been an object of inter- esting examination with the physiologist, both in animals and plants, and as it has been presumed, by a large class of speculatists, to be greatly owing to respiration, it has been a favourite topic with the chemist also. Most of the hypotheses, devised for its expla- nation, have, indeed, been of a chemical character; and hence it will be advisable to premise a few observations regarding the physical relations of caloric or the matter of heat, — an imponder- able body, according to common belief, which is generally distri- buted throughout nature. It is this that constitutes the tempera- ture of bodies,— by which is meant, the sensation of heat or cold, which we experience, when bodies are touched by us; or the height at which the mercury is raised or depressed by them, in the instru- ment called the thermometer; — the elevation of the mercury being caused by the caloric entering between its particles, and thus adding to its bulk ; and the depression being produced by the ab- straction of caloric. Caloric exists in bodies in two states; — in the free, uncombined or sensible, and in the latent or combined. In the latter case, it is intimately united with the other elementary constituents of bodies, and is neither indicated by the feelings nor by the thermometer. It has, consequently, no agency in the temperature of bodies ; but, by its proportion to the force of cohesion, it determines their con- dition ; — whether they shall he solid, liquid or gaseous. In the former case, caloric is simply interposed between the molecules, and is incessantly disengaged, or abstracted from surrounding bodies; and, by impressing the surface of the body or by acting upon the thermometer, it indicates to us their temperature. Equal weights of the same body, at the same temperature, contain the same quantities of caloric ; but equal weights of different bodies, at the same temperature, have by no means the same quantities. The quantity, which ofie body contains, compared with that in another is called its specific caloric, or specific heat; and the power or properly, which enables bodies to retain different quan- tities of caloric, is called capacity for caloric. If a pound of water, TEMPERATURE OF ANIMALS. 187 heated to 156°, be mixed with a pound of quicksilver at 40°, the resulting temperature is 152°, — instead of 98°, the exact mean. The water, consequently, must have lost four degrees of tempera- ture, and the quicksilver gained 112°; from which we deduce, that the quantity of caloric, capable of raising one pound of mercury from 40° to 152° is the same as that required to raise one pound of water from 152° to 156° ; or, in other words, that the same quan- tity of heat, which raises the temperature of a pound of water four degrees, raises the same weight of mercury one hundred and twelve degrees. Accordingly, it is said, that the capacity of water for heat is to that of mercury, as 2S to 1; and that the specific heat is twenty-eight times greater. All bodies are capable of giving and taking free caloric, and consequently, all have a temperature. If the quantity given off be great, the temperature of the body is elevated. If it take heat from the thermometer, it is cooler than the instrument. In inor- ganic bodies, the disengagement of caloric is induced by various causes: such as electricity, friction, percussion, compression, the change of condition from a fluid to a solid state ; and by chemical changes, giving rise to new compounds, so that the caloric, which was previously latent, becomes free. If, for example, two sub- stances, each containing a certain amount of specific heat, unite, so as to form a compound, whose specific heat is less, a portion of caloric must be set free, and this will be indicated by a rise in the temperature. It is this principle, which is chiefly concerned in some of the theories of calorification. The subject of the equilibrium and conduction of caloric has already been treated of, under the sense of touch (vol. i., p. 103); where several other topics were discussed, that bear more or less upon the present inquiry. It was there stated, that inorganic bo- dies speedily attain the same temperature, either by radiation or conduction ; so that the different objects in an apartment will ex- hibit the same degree of heat by the thermometer ; but the temper- ature of animals, being the result of a vital operation, they retain the degree of heat peculiar to them, with but. little modification from external temperature. There is adifference,however,in this respect, sufficient to cause the partition of animals into two great divisions— the warm-blooded and the cold-blooded; the former comprising those whose temperature is high, and but little influenced by that of ex- ternal objects; — the latter those whose temperature is greatly modified by external influences. The range of the temperature of the warm-blooded — amongst which are all the higher animals — is limited ; but of the cold-blooded extensive.11 The following table exhibits the peculiar temperature of various animals in round numbers; — that of man being 98° or 100°, when taken under the tongue. The temperature in the axilla is something less. In the » Turner's Elements of Chemistry, 5th Amer. Edit., by Prof. F. Bache, from 5th London, p. 5, Philad. 1835. 188 CALORIFICATION. latter situation, Dr. Edwards" found it to vary, in twenty adults, from 96° to 99° Fahrenheit, the mean being 97°-5. Animals, Arctic fox,....... Arctic wolf, ------- Squirrel,....... Hare,........ Whale, -------- Arctomys citillus, zizil, — in summer, Do. when torpid, Goat,....... Bat, in summer, ------ Musk,........ Marmota bobac,— Bobac, - House mouse, ------ Arctomys marmota, marmot — in summer, Do. when torpid, Rabbit,........ Polar Bear,....... Dog,.......' Cat,....... Swine, ------- Sheep, -------- Ox,....... Guinea-pig,...... Arctomys glis, ...--• Shrew, ------ Young wolf, ------ Fringilla arctica, Arctic finch, Rubecola, redbreast, - - . - Fringilla linaria, lesser red poll, Falco palumbarius, goshawk, - - - Caprimulgus Europxus, European goat-sucker, Emberiza nivalis, snow-bunting, Falco lanarius, lanner, - - - . ■ Fringilla carduelis, goldfinch, Corvus corax, raven, - - - - - Turdus, thrush, (of Ceylon,) - - - - Telrao perdrix, partridge, .... Anas clypeata, shoveler, .... Tringa pugnax, ruffe, .... Scolopax limosa, lesser godwit, Tetrao tetrix, grouse, ----- Fringilla brumalis, winternnch, Loxia pyrrhula, ------ Falco nisus, sparrowhawk, - - - , Vultur barbatus, ...... « » De I'lnfluence des Agens Physiques, &c, Paris, 1824 ; or Hodgkin and Fisher's translation, Lond. 1832. b Parry's Second Voyage to the Arctic Regions. » Nov. Species Quadruped, de Glirium Ordine, Erlang. 1774. & An Account of the Arctic Regions, Edinb. 1820. « Bibliotheque Univers. xvfl. 294. Med and Philos. Essays, Lond. 1740; and De Similibus Animalibus et Animal. Calore, &c, Lond. 1740. e Nov. Comment. Acad. Petropol. xiii. 419. h Annales de Chimie, xxvi. 337, Amst. 1824. 1 Edinb. Philos. Journal, Jan. 1826. Observers. Temperature. Capt. Lyon.b 107 Do. Pallas.' 1 105 Do. Scoresby.d } 104 Pallas. 103 Pallas. 80 to 84 Prevost and Dumas." 103 Do. Do. \ 102 Do. 101 or 102 Do. 101 Do. 101 or 102 Do. 43 Delaroche. 100 to 104 Capt. Lyor i. 100 Martine.' Do. Do. 100 to 103 Do. Do. Delaroche. 100 to 102 Pallas. 99 Do. 98 Do. 96 Braun.s Pallas. 1 111 Do. 110 or 111 Do. Do. \ 110 Do. 109 to 110 Do. ^ Do. Despretz.h >. 109 J. Davy." Pallas. . Do. i Do. Do. Do. Do. >. 108 Do. Do. Do. TEMPERATURE OF ANIMALS. 189 Anser pulchricollis, - Colymbus auritus, dusky grebe, Tringa vanellus, lapwing, (wounded,) Tetrao lagopus, ptarmigan, Fringilla domestica, house-sparrow, Strix passenina, little owl, Hxmatopus estralagus, sea-pie, Anas penelope, wigeon, - - - Anas strepera, gadwall, - - - Pelecanus carbo, - - - - Falco ossifragus, sea-eagle, Fulica atra, coot, - Anas acuta, pintail-duck, Falco milvus, kite, (wounded,) - JMerops apiaster, bee-eater, Goose, ------ Hen,...... Dove, -----. Duck,...... Ardea stellaris, - Falco albicollis, - - - . Picus major, - Cossus ligniperda, - - - - Shark,...... Torpedo J\Iarmorata, According to the above table it will be observed, that the inha- bitants of the Arctic regions — whether belonging to the class of mammalia or birds—are among those whose temperature ishighest. That of the Arctic fox is, indeed, probably higher than the amount given in the table, being taken after death, when the temperature of the air was as low as— 14° of Fahrenheit, and when loss of heat may be supposed to have taken place rapidly. The temperature of the smaller insects it is, of course, impracti- cable to indicate ; but we can arrive at an approximation in those that congregate in masses, as the bee and the ant; for it is impos- sible to suppose, with Maraldi, that the augmented temperature is dependent upon the motion and friction of the wings and bodies of the busy multitudes. Juchb found, that when the temperature of the atmosphere was — 18° of Fahrenheit, that of a hive of bees was 44° : in an ant-hill, the thermometer stood at 68° or 70°, when the temperature of the air was 55°; and at 75°, when that of the air was 66°; and Hausmann0 and Renggerd saw the thermometer rise, when put into narrow glasses in which they had placed sca- rabaei and other insects.e Berthold detected the elevation of heat only when several insects were collected together, not in one iso- lated from the rest. This, Mr. Newport*- affirms, must have arisen » Grundriss der Physiol., &c, band i. 166 ; Tiedemann's Traite de Physiologie, par Jourdan, p. 498, Paris, 1831; and P. H. Berard, art. Chaleur Animale, in Diet, de Med. 2de £dit. vii. 177, Paris, 1834. t> Ideen zu einer Zoochemie, i. 90. "> De Animal. Exsanguium Respiratione, p. 65. * Physiologische Untersuchung. iiber die Insecten, p. 40, Tubing, 1817. e Tiedemann, op. citat. p. 511. f Philosoph. Transact, for 1837, part ii. p. 259. See Dr. W. B. Carpenter, Prin- ciples of General and Comparative Physiology, p. 372, Lond. 1839; and some experi- 107 107 to 111 106 105 104 103 to 107 103 89 to 91 83 74 190 CALORIFICATION. from his having ascertained the temperature only whilst the insect was in a state of rest: for Mr. Newport found,that although during such a state, the temperature of the insect was very nearly or ex- actly that of the surrounding medium, yet when the insect was excited or disturbed, or in a state of great activity from any cause, the thermometer rose in some instances, even to 20° Fahr. above the temperature of the atmosphere, — for instance, to 91°, when the heat of the air was 71°. The power of preserving their temperature within certain limits, is not, however, possessed exclusively by animals. The heat of a tree, examined by Mr. Hunter,3 was found to be always several degrees higher than that of the atmosphere, when the temperature of the air was below 56° of Fahr.; but it was always several de- grees below it when the weather was warmer. Some plants de- velope a considerable degree of heat, during the period of blooming. This was first noticed by De Lamarckbin the Arum italicum. In the Arum cordifolium, of the Isle of Bourbon, Hubert found, when the temperature of the air was 80°, that of the spathe or sheath was as high as 134°; and Bory De St. Vincent0 observed a similar elevation, although to a less degree, in the Arum esculentum, esculent arum or Indian kale.A The animal body is so far influenced by external heat as to rise or fall with it; but the range, as we have already remarked, is limited in the warm-blooded animal, — more extensive in the cold-blooded. Dr. Currie found the temperature of a man plunged into sea-water at 44° sink, in the course of a minute and a half after immersion, from 98° to 87°; and, in other experiments, it descended as low as 85°, and even to 83°.e It was always found, however, that, in a few minutes, the heat approached its previous elevation ; and in no instance, could it be depressed lower than 83°j or 15° below the temperature at the commencement of the operation. Similar experiments have been performed on other warm-blooded animals. Hunter found the temperature of a com- mon mouse to be 99°, when that of the atmosphere was 60°: when the same animal was exposed, for an hour, to an atmosphere of 15°, its heat had sunk to 83° ;f but the depression could be carried no farther. He found, also, that a dormouse, — whose heat in an atmosphere at 64°, was 81§°, —when put into air, at 20°, had its temperature raised, in the course of half an hour to 93°; an hour after, the air being at 30°, it was still 93°; another hour after, the air being at 19°, the heat of the pelvis was as low as 83°,— an experiment, which strongly proves the great counteracting in- fluence exerted, when animals are exposed to an unusually low ments proving the same point in Dr. M. Paine's Medical and Physiological Commenta- ries, ii. 76, New Vork, 1840. . a Philos. Transact. 1775 and 1778. b Encyclop. Method, iii. 9. » ' Voyage dans les Quatre Principales lies des Mers d'Afrique, ii. 66. d Sir J. E. Smith, Introduction to the Study of Botany, 7th edit, by Sir W. J. Hooker, p. 47, Lond. 1833; Tiedemann, p. 492 ; and Carpenter, op. citat. p. 368. e Philos. Transact, for 1792, p. 199. f ibid. 1778, p. 21. TEMPERATURE OF ANIMALS. 191 temperature. In this experiment, the dormouse had maftitained its temperature about 70° higher than that of the surrounding me- dium, and for the space of two hours and a half. In the hibernating torpid quadruped the reduction of temperature, during their tor- pidity, is considerable. Jennera found the temperature of a hedge- hog, in the cavity of the abdomen, towards the pelvis, to be 95°, and that of the diaphragm 97° of Fahrenheit, in summer, when the thermometer in the shade stood at 78°; whilst in the winter, the temperature of the air being 44°, and the animal torpid, the heat in the pelvis was 45°, and of the diaphragm 485°. When the temperature of the atmosphere was at 26°, the heat of the animal, in the cavity of the abdomen, where an incision was made, was reduced as low as 30°; but — what singularly exhibits the power, possessed by the system, of regulating its temperature, — when the same animal was exposed to a cold atmosphere of 26° for two days, its heat, in the rectum, was raised to 93°, or 67° above that of the atmosphere. At this time, however, it was lively and active, and the bed, on which it lay, felt warm. In the cold-blooded ani- mal, we have equal evidence of the generation of heat. Hunter found, that the heat of a viper, placed in a vessel at 10°, was reduced in ten minutes, to 37°; in the next ten minutes, the temperature of the vessel being 13°, it fell to 35°; and in the next ten minutes, the vessel being at 20°, to 31°.b In frogs, he was able to lower the temperature to 31°; but beyond this point it was not possible to lessen the heat, without destroying the animal. In the Arctic regions, the animal temperature appears to be steadily maintained, notwithstanding the intense cold that prevails ; and we have already seen, that the animals of those hyperborean latitudes possess a more elevated temperature than those of more genial climes. In the enterprising voyages, undertaken by the British government for the discovery of a northwest passage,,the crews of the ships were frequently exposed to the temperature of —40° or —50° of Fahrenheit's scale; and the same thing hap- pened during the disastrous campaign of Russia in 1812, in which so many of the French army perished from cold. The lowest temperature noticed by Captain Parryc was —55° of Fahrenheit. Captain Frank'lin,d on the northern part of this continent, observed the thermometer on one occasion — Feb. 7, 1827, — as low as —5S°of Fahrenheit; and M. Von Wrangele states that, in January, on the north coast of Siberia, the cold reaches —59° of Fahren- heit ; but the greatest observed natural cold was marked by Cap- » Hunter on the Animal Economy, p. 99, 2d edit., Lond. 1792, or Owen's edit, in Bell's Select Med. Lib. p. 165, Philad. 1840. See, also, Miiller's Handbuch, u. s. w., Baly's translation, p. 76, Lond. 1838. b Op. citat. c Journal of a Voyage for the Discovery of a Northwest Passage, Amer. Edit. p. 130, Philad. 1821. <* Narrative of a Second Expedition to the Shores of the Polar Sea, &c, Amer. Edit. p. 245, Philad. 1835. « Reise des Kaiserlich. Russischen Flotten, Lieutenants Ferdinand Von Wrangel, langs der JXordkiiste von Siberien, u. s. w., Berlin, 1839, translated in Harpers Family Library. 192 CALORIFICATION. tain Ba#ka in his expedition to the Arctic regions : on the 17th of January, 1834, the thermometer stood at —70° of Fahrenheit, or 102° below the freezing point! During the second voyage of Captain Parry,bthe following tem- peratures of animals, immediately after death, were taken princi- pally by Captain Lyon. Temperature of the ,------^—'-----* 1821. Animal. Atmosphere. Nov. 15. An Arctic fox - 106£° - —14° Dec. 3. Do......101£ - — 5 Do......100 — 3 11. Do......101| - — 21 15. Do......99f - — 15 17. Do......98 - '—10 19. Do......99f - — 14 1822 Jan. 3. Do......104^ - — 23 9. A white hare ... - 101 — 21 10. An Arctic fox 100 — 15 17. Do......106 — 32 24. Do......103 — 27 Do......103 — 27 Do......102 — 25 27. Do......101 — 32 Feb. 2. A wolf - - - - - 105 - — 27 These animals must, therefore, have to maintain a temperature at least 100° higher than that of the atmosphere, throughout the whole of winter; and it would appear as if the counteracting energy becomes proportionately greater as the temperature is more depressed. It is, however, a part of their nature to be constantly eliciting this unusual quantity of caloric, and therefore they do not suffer. Where animals, not so accustomed, are placed in an un- usuajly cold medium, the efforts of the system rapidly exhaust the nervous energy ; and when this becomes so far depressed as to in- terfere materially with the function of calorification, which we shall find is to a certain extent under the nervous influence, the tempera- ture sinks, and the individual dies lethargic — or, as if struck with apoplexy. The ship Endeavour, being on the coast of Terra del Fuego, on the 21st of December, 1769, Messrs. Banks, Solander, and others were desirous of making a botanical excursion upon the hills on the coast, which did not appear to be far distant. The party, consisting of eleven persons, were overtaken by night on the hills, during extreme cold. Dr. Solander, who had crossed the mountains which divide Sweden from Norway, knowing the al- most irresistible desire for sleep produced by exposure to great cold, more especially when united with fatigue, enjoined his com- panions to keep moving, whatever pains it might cost them, and whatever might be the relief promised by an indulgence in rest. " Whoever sits down," said he, " will sleep, and whoever sleeps will wake no more." Thus admonished, they set forward but a Narrative of the Arctic Land Expedition to the mouth of the Great Fish river &c, in the years 1833, 1834, and 1835, Lond. 1836. b Qp. citat. p. 157. ' EFFECTS OF DEPRESSED TEMPERATURE. 193 whilst still upon the bare rock, and before they had got among the bushes, the cold suddenly became so severe as to produce the effects that had been dreaded. Dr. Solander himself was the first who found the desire irresistible, and insisted on being suffered to lie down. Mr. Banks, (afterwards Sir Joseph,) entreated and remon- strated in vain. The doctor lay down upon the ground, although it was covered with snow; and it was with the greatest difficulty that his friend could keep him from sleeping. Richmond, one of the black servants, began to linger and to suffer from the cold, in the same manner as Dr. Solander. Mr. Banks, therefore, sent five of the company forward to get a fire ready at the first convenient place they came to ; and himself, with four others, remained with the doctor and Richmond, whom, partly by persuasion and partly by force, they carried forward ; but when they had got through the birch and swamp, they both declared they could go no farther. Mr. Banks had again recourse to entreaty and expostulation, but without effect. When Richmond was told, that if he did not go on, he would, in a short time, be frozen to death, he answered, that he desired nothing but to lie down and die. Dr. Solander was not so obstinate, but was willing to go on, if they would first allow him to take some sleep, although he had before observed, that to sleep was to perish. Mr. Banks and the rest of the party found it impossible to carry them, and they were consequently suffered to sit down, being partly supported by the bushes, and, in a few ♦ minutes they fell into a profound sleep. Soon after, some of the people, who had been sent forward, returned with the welcome intelligence, that a fire had been kindled about a quarter of a mile farther on the way. Mr. Banks then endeavoured to rouse Dr. Solander, and happily succeeded, but, although he had not slept five minutes, he had almost lost the use of his limbs, and the soft parts were so shrunk, that his shoes fell from his feet. He con- sented to go forward with such assistance as could be given him, but no attempts to relieve Richmond were successful. He, with another black left with him, died. Several others began to lose their sensibility, having been exposed to the cold near an hour and a half, but the fire recovered them.a The preceding history is interesting in another point of view be- sides the one for which it was more especially cited. Both the individuals, who perished, were blacks, and it has been a common observation, that they bear exposure to great heat with more im- punity, and suffer more from intense cold, than the white variety of the species. As regards inorganic bodies, it has been satisfac- torily shown, that the phenomena of the radiation of caloric are connected with the nature of the radiating surface ; and that those surfaces, which radiate most, possess, in the highest degree, the absorbing power ; in other words, bodies that have their temper- atures most readily raised by radiant heat are those that are most ■ See, on the effects of Cold, Sir H. Halford, in Lond. Med. Gazette, for March 11, 1837, p. 902. VOL. II. — 17 194 CALORIFICATION. easily cooled by their own radiation. In the experiments of Pro- fessor Leslie8 it was found, that a clean metallic surface produced an effect upon the thermometer equal to 12 ; but when covered with a thin coat of glue its radiating power was so far increased as to produce an effect equal to 80 ; and, on covering it with lamp- black, it became equal to 100. We can thus understand why, in the negro, there should be a greater expense of caloric than in the white, owing to the greater radiation ; not because as much calo- ric may not have been elicited as in the white. In the same man- ner we can understand that, owing to the greater absorbing power of his skin, he may suffer less from excessive heat than the white ; and this is perhaps the great use of the dark rete mucosum. To ascertain, whether such be the fact, the following experiments were instituted by Sir Everard Home.b He exposed the back of his hand to the sun at twelve o'clock, with a thermometer attached to it, another thermometer being placed upon a table with the same exposure. The temperature, indicated by that on his hand, was 90° ; by the other, 102°. In forty-five minutes, blisters arose, and coagulable lymph was thrown out. The pain was very se- vere. In a second experiment, he exposed his face, eyelids, and the back of his hand to water heated to 120°; in a few minutes they became painful; and, when the heat was farther increased, he was unable to bear it; but no blisters were produced. In a third experiment, he exposed the backs of both hands, with a thermometer upon each, to the sun's rays. The one hand was un- covered ; the other had a covering of black cloth, under which the ball of the thermometer was placed. After ten minutes, the degree of heat of each thermometer was marked, and the appearance of the skin examined. This was repeated at three different times. The first time, the thermometer under the cloth stood at 91°, the other thermometer at 85°; the second time, they indicated respec- tively 94° and 91° ; and the third time, 106° and 98°. In every one of these trials, the skin, that was uncovered, was scorched, whilst the other had not suffered in the slightest degree. From all his experiments, Sir Everard concludes, that the power of the sun's rays to scorch the skin of animals is destroyed, when applied to a black surface ; although the absolute heat, in consequence of the absorption of the rays, is greater. When cold is applied to particular parts of the body, the heat of those parts sinks lower than the minimum of depressed temperature. Although Hunter was unable to heat the urethra one degree above the maximum of elevated temperature of the body, he succeeded in cooling it 29° lower than the minimum of depressed tempera ture, or to 58°. He cooled down the ears of rabbits until they froze ; and when thawed, they recovered their natural heat and circulation. The same experiment was performed on the comb and wattles of a cock. Resuscitation was, however, in no instance * On Heat, Edinb. 1804 ; and Dr. Stark, in Philosoph. Transact, part ii. for 1833. b Lect. on Comp. Anat. iii. 217, Lond. 1823. EFFECTS OF DEPRESSED TEMPERATURE. 195 practicable where the whole body had been frozen.a The same observer found, that the power of generating heat, when exposed to a cooling influence, was possessed even by the egg. An egg, which had been frozen and thawed, was put into a cold mixture along with one newly laid. The latter was seven minutes and a half longer in freezing than the other. In another experiment, a fresh-laid egg, and one which had been frozen and thawed, were put into a cold mixture at 15°; the thawed one soon rose to 32°, and began to swell and congeal; the fresh one sank to 29|°, and in twenty-five minutes after the dead one, it rose to 32°, and be- gan to swell and freeze. All these facts prove, that when the living body is exposed to a lower temperature than usual, a counteract- ing power of calorification exists ; but that, in the human species, such exposure to cold is incapable of depressing the temperature of the system lower than about 15° beneath the natural standard. In fish, the vital principle can survive the action even of frost. Captain Franklin found, that those which they caught in Winter Lake, froze as they were taken out of the net; but if, in this com- pletely frozen state, they were thawed before the fire, they re- covered their animation. This was especially the case with a carp, which recovered so far as to leap about with some vigour after it had been frozen for thirty-six hours.5 On the other hand, when the living body is exposed to a tem- perature greatly above the natural standard, an action of refrigera- tion is exerted; so that the animal heat cannot rise beyond a cer- tain number of degrees ; — to a much smaller extent in fact than it is capable of being depressed by the opposite influence. Boer- haavec maintained the strange opinion, that no warm-blooded ani- mal could exist in a temperature higher than that of its own body. In some parts of Virginia, there are days in every summer, in which the thermometer reaches 98° of Fahrenheit; and in other parts of this country, it is occasionally much higher. The meteoro- logical registers show it to be at times as high as 10S° at Council Bluffs, in Missouri; at 104°in New York; and at 100°in Michigan ;d whilst in most of the states, on some days of summer, it reaches 96° or 98°. At Sierra Leone, Messrs. Watt and Winterbottom,e saw it frequently at 100°, and even as high as 102° and 103°, at some distance from the coast. Adamson saw it at Senegal as high as IOS50. Brydone affirms, that when the sirocco blows in Sicily the heat rises to 112°.f Dr. Chalmers observed a heat * Sir E. Home's Lect. &c. iii. 438. b See, also, Dr. W. B. Carpenter, art. Life, in Cyclop, of Anat. and Physiol. Sept. 1840. c " Observatio docet nullum animal quod pulmones habent, posse in aere vivere, cujus eadem est temperies cum suo sanguine." Element. Chemise, i. 275, Lug. Bat. 1732 ; and Haller, Element. Physiologiae, torn. ii. <• Meteorological Register, for the years 1822, 1823, 1824, and 1825, from observa- tions made by the surgeons at the military posts of the United States. See, also, a (similar register for the years 1826, 1827, 1828, 1829, and 1830, Philad. 1840. " Account of the Native Africans, vol. i., p. 32 and 33. f Lawrence's Lectures on Physiology, &c, p. 306, London, 1819. 196 CALORIFICATION. of 115°a in South Carolina; Humboldtb of 110° to 115° in the Llanos or Plains near the Orinoco; and Captain Tuckey asserts, that on the Red Sea he never observed the thermometer at mid- night under 94°; at sunrise under 104° ; or at mid-day under 112°. In British India it is asserted to have been seen as high as 130°.e So long ago as 1758, Governer Ellisd of Georgia had noticed how little the heat of the body is influenced by the external atmo- sphere. " I have frequently," he remarks, " walked an hundred yards under an umbrella with a thermometer suspended from it by a thread, to the height of my nostrils, when the mercury has rose to 105°, which is prodigious. At the same time I have confined this instrument close to the hottest part of my body, and have been astonished to observe, that it has subsided several degrees. Indeed I never could raise the mercury above 97° with the heat of my body." Two years after the date of this communication, the power of resisting a much higher atmospheric temperature, was discovered by accident. MM. Duhamel and Tillet,e in some experiments for destroying an insect,that infested the grain of the neighbourhood, — having occasion to use a large public oven, on the same day in which bread had been baked in it, were desirous of ascertaining its temperature. This they endeavoured to accom- plish by introducing a thermometer into the oven at the end of a shovel. On being withdrawn, the thermometer indicated a de- gree of heat considerably above that of boiling water; but M. Tillet, feeling satisfied that the thermometer had fallen several degrees in approaching the mouth of the oven, and seeming to be at a loss how to rectify the error, a girl, — one of the servants of the baker, and an attendant on the oven, — offered to enter and mark with a pencil the height at which the thermometer stood within the oven. The girl smiled at M. Tillet's hesitation at her proposition, entered the oven, and noted the temperature to be 260° of Fahrenheit. M. Tillet, anxious for her safety, called upon her to come out; but she assured him she felt no inconvenience from her situation, and remained ten minutes longer, when the thermometer had risen to 280° and upwards. She then came out of the oven, with her face considerably flushed, but her respira- tion by no means quick or laborious. These facts excited considerable interest, but no farther experi- ments appear to have been instituted, until, in the year 1774, Dr. Geo. Fordyce, and Sir Charles Blagdenf made their celebrated trials with heated air. The rooms, in which these were made, » Account of the Weather and Diseases of South Carolina, London, 1776. •> Tableau Physique des Regions Equatoriales. c Prof. Jameson, in British India, Amer. edit. iii. 170, New York, 1832. For an account of the highest temperature, observed in different climates, see the author's « Elements of Hygiene," p. 96 ; art. Atmosphere, by the author, in the Cyclopsedia of Practical Medicine, Philadelphia, 1836; Annuaire du Bureau des Longitudes, 1825; and Eleroens de Physique, par Pouillet, iv. 637, 2de £dit., Paris, 1832. i Philosophical Transactions, 1758, p. 755. e Memoir, de l'Academie des Sciences de Paris, 1762, p. 186. f Philosophical Transactions for 1775,p. 111. EFFECTS OF ELEVATED TEMPERATURE. 197 were heated by flues in the floor. Having taken off his coat, waistcoat, and shirt, and being provided with wooden shoes, tied on with list, Dr. Fordyce went into one of the rooms, as soon as the thermometer indicated a degree of heat above that of boiling water. The first impression of this heated air upon his body was exceedingly disagreeable ; but in a few minutes all uneasiness was removed by copious perspiration. At the end of twelve minutes he left the room very much fatigued, but not otherwise disordered. The thermometer had risen to 220°. In other ex- periments, it was found, that a heat even of 260° could be borne with tolerable ease. At this temperature, every piece of metal was intolerably hot; small quantities of water, in metallic ves- sels, quickly boiled; and streams of moisture poured down over the whole surface of his body. That this was merely the vapour of the room, condensed by the cooler skin, was proved by the fact, that when a Florence flask, filled with water of the same temperature as the body, was placed in the room, the vapour condensed in like manner upon its surface, and ran down in streams. Whenever the thermometer was breathed upon, the mer* cury sank several degrees. Every expiration — especially if made with any degree of violence—communicated a pleasant impres- sion of coolness to the nostrils, scorched immediately before by the hot air rushing against them when they inspired. In the same manner, their comparatively cool breath cooled their fingers, whenever it reached them. l< To prove," says Sir Charles Blag- den, " that there was no fallacy in the degree of heat shown by the thermometer, but that the air which we breathed, was capa- ble of producing all the well-known effects of such an heat on inanimate matter, we put some eggs and beef-steak upon a tin frame, placed near the standard thermometer, and farther distant from the cockle than from the wall of the room. In about twenty minutes, the eggs were taken out roasted quite hard; and in forty-seven minutes, the steak was not only dressed, but almost dry. Another beef-steak was rather overdone in thirty-three minutes. In the evening, when the heat was still greater, we laid a third beef-steak in the same place ; and as it had now ' been observed, that the effect of the heated air was much increased by putting it in motion, we blew upon the steak with a pair of bellows, which produced a visible change on its surface, and seemed to hasten the dressing: the greatest part of it was found pretty well done in thirteen minutes." In all these experiments, and similar ones were made in the following year, by Dobson,a of Liverpool, the heat of the body, in air of a high temperature, speedily reached 100° ; but exposure to 212°, and more, did not carry it higher. These results are not, however, exactly in ac- cordance with those of MM. Berger and Delaroche,b deduced » Philosophical Transactions for 1775, p. 463. b Exper. sur les Effects qu'une forte Chaleur produit sur l'Economie, Paris, 1805 j and Journal de Physique, lxiii. 207, Ixxi, 289, and lxxvii. 1. 17* 198 CALORIFICATION. from experiments performed in 1806. Having exposed them- selves, for some time, to a stove, — the temperature of which was 39° of Reaumur, or 120° of Fahrenheit, —their temperature was raised 3° of Reaumur, or 63° of Fahrenheit; and M. Delaroche found, that his rose to 4° of Reaumur, or 9° of Fahrenheit, when he had remained sixteen minutes in a stove heated to 176° of Fahr- enheit. According to Sir David Brewster,a —the distinguished sculptor, Chantry, exposed himself to a temperature yet higher. The furnace which he employs for drying his moulds, is about 14 feet long, 12 feet high, and 12 feet broad. When raised to its highest temperature, with the doors closed, the thermometer stands at 350°, and the iron floor is red-hot. The workmen often enter it at a temperature of 340°, walking over the iron floor with wooden clogs, which are, of course, charred on the surface. On one occasion, Mr. Chantry, accompanied by five or six of his friends, entered the furnace, and after remaining two minutes, they brought out a thermometer, which stood at 320°. Some of the party experienced sharp pains in the tips of their ears, and in the septum of the nose, whilst others felt a pain in the eyes. In some experiments of Chabert, who exhibited his powers as a " Fire King," in this country as well as in Europe, he is said to have entered an oven with impunity, the heat of which was from 400° to 600° of Fahrenheit. Experiments have shown, that the same power of resisting excessive heat is possessed by other ani- mals. Drs. Fordyce and Blagden shut up a dog in a room, the temperature of which was between 220° and 236°, for half an hour; at the end of this time a thermometer was applied between the thigh and flank of the animal; and in about a minute the mer- cury sank to 110°; but the real heat of the body was certainly less than this, as the ball of the thermometer could not be kept a sufficient time in proper contact ; and the hair, which felt sen- sibly hotter than the bare skin, could not be prevented from touch- ing the instrument. The temperature of this animal, in the natu- ral state, is 101°. We find in the case of aquatic animals, astonishing cases of adaptation to the medium in which they live. Although man is capable of breathing air, heated to above the boiling point of water with impunity, we have seen, that he cannot bear the contact of water much below that temperature. Yet we find certain of the lower animals— as fishes — living in water at a temperature, which would be entirely sufficient to boil them if dead. In the thermal springs of Bahia, in Brazil, many small fishes are seen swimming in a rivulet, which raises the thermometer to 88°, when the tem- perature of the air is only 77^°. Sonnerat, again, found fishes existing in a hot spring at the Manillas, at 158° Fah.; and MM. Humboldt and Bonpland, in travelling through the province of Quito in South America, perceived them thrown up alive, and appa- rently in health, from the bottom of a volcano, in the course of its * Letters on Natural Magic, p. 281, Amer. Edit., New York, 1832. EFFECTS OF ELEVATED TEMPERATURE. 199 explosions, along with water and heated vapour, which raised the thermometer to 210°, or only two degrees short of the boiling point.8 Dr. Reeve found living larvae in a spring, whose temperature was 208°; Lord Bute saw confervas and beetles in the boiling springs of Albano, which died when plunged into cold water; and Dr. Elliotson knew a gentleman, who boiled some honeycomb, two years old, and, after extracting all the sweet matter, threw the refuse into a stable, which was soon filled with bees.b When the heating influence is applied to a part of the body only, as to the urethra, the temperature of the part, it has been affirmed, is not increased beyond the degree to which the whole body may be raised. From all these facts, then, we may conclude, that when the body is exposed to a temperature, greatly above the ordinary standard of the animal, a frigorific influence is exerted ; but this is effected at a great expense of the vital energy ; and hence is followed by con- siderable exhaustion, if the effort be prolonged. In the cold-blooded animal, the power of resisting heat is not great; so that it expires in water not hotter than the human blood occasionally is. Dr. Ed- wards found that a frog, which can live eight hours in water at 32°, is destroyed in a few seconds in water at 105°: this appears to be the highest temperature that cold-blooded animals can bear. Observation has shown, that although the average temperature of an animal is such as we have stated in the table, particular circumstances may give occasion to some fluctuation. A slight difference exists, according to sex, temperament, idiosyncrasy, &c. MM. Edwards and Gentil found the temperature of a young female half a degree less than that of two boys of the same age. Edwards0 tried the temperature of twenty sexagenarians, thirty-seven septua- genarians, fifteen octogenarians, and five centenarians, at the large establishment of Bicetre, and he observed a slight difference in each class. John Davyd found, that the temperature of a lamb was a degree higher than that of its mother; in five new-born children, the heat was about half a degree higher than that of the mother, and it rose half a degree higher in the first twelve hours after birth. Dr. Holland,*5 too, found that the mean temperature of forty infants exceeded that of the same number of adults by 13°: twelve of thev children possessed a temperature of 100° to 103i°. Edwards, on the other hand, found, that, in the warm-blooded animal, the faculty • of producing heat is less, the nearer to birth ; and that in many cases, as soon as the young dropped from the mother, the tempera- ture fell to within a degree or two to that of the circumambient air ; 1 Animal Physiology, Library of Useful Knowledge, p. 3. i> Physiology, p. 247, Lond. 1840; also, Hodgkin and Fisher's Appendix to their translation of Edwards, Sur l'lnfluence des Agens Physiques, &c, p. 467 ; and Car- penter, Principles of General and Comparative Physiology, p. 154, Lond. 1839. <■ De l'lnfluence des Agens, &c, p. 436, Paris, 1826. a Philosoph. Transact, p. 602, for 1814. " An Inquiry into the Laws of Life, &c, Edinb. 1829 ; and Despretz, in Edinb. Journal of Science, &c, iv. 185. 200 CALORIFICATION. and he moreover affirms, that the faculty of producing heat is at its minimum at birth, and that it increases successively to the adult age. His trials on children, at the large Hopital des Enfans of Paris,and on the aged atBicetre, showed that the temperature of infants, one or two days old, was from 93° to 95° of Fahrenheit; of the sexagenarian from 95° to 97°; of the octogenarian 94° or 95°; and that, as a general rule, it varied according to the age. In his experiments connected with this subject, he discovered a striking analogy between warm-blooded animals in general. Some of these are born with the eyes closed ; others with them open : the former, until the eyes are opened, he found to resemble the cold-blooded animal; the latter — or those born with the eyes open — the warm- blooded. Thus, he remarks, the state of the eyes, although having no immediate connexion with the production of heat, may yet coin- cide with an internal structure influencing that function, and it cer- tainly furnishes signs, which indicate a remarkable change in this respect; for, at the period of the opening of their eyes, all young mammalia have nearly the same temperature as adults. Now,in accordance with analogy, a new-born infant, at the full period, having its eyes open, should have the power of maintaining a pretty uniform temperature during the warm seasons ; but, if birth should take place at the fifth or sixth month, the case is altered; the pupil isgenerally covered with.the membrana pupillaris, which places the young being in a condition similar to that of closure of the eyelids an animals. Analogy, then, would induce us to conclude, that, in such an infant, the power of producing heat should be inconsider- able, and observation confirms the conclusion ; although we ob- viously have not the same facilities, as in the case of animals, of exposing the infant to a depressed temperature. The temperature of a seven months' child, though well swathed, and near a good fire, was, within two or three hours after birth, no more than 89-6° Fahrenheit. Before the period at which this infant was born, the membrana pupillaris disappears ; and it is probable, as Dr. Ed- wards has suggested, if it had been born prior to the disappearance of the membrane, its power of producing heat might have been so feeble, that it would scarcely have differed from that of mammalia born with their eyes closed.8 The state of the system, as to health or disease, also influences the evolution of heat. Dr. Francis Home,b of Edinburgh, took the heat of various patients at different periods of their indispositions. He found that of two persons, labouring under the cold stage of an intermittent, to be 104°; whilst, during the sweat and after- wards, it fell to 101°, and to 99°. The highest degree, which he noticed m fever, was 107°.c We have often witnessed the ther- mometer at 106° in scarlatina and in typhus, but it probably rarely » Op. cit., and Analytical Review of Hodgkin and Fisher's translation, by the author ot this work, in Amer. Journ. of Medical Sciences, p. 150, for May, 1834 i> Medical Facts and Experim., Lond. 1759. c Currie's Medical Reports, Liverpool, 1798, and Philad. 1808, CIRCUMSTANCES INFLUENCING 201 exceeds this, although it is stated to have been seen as high as 112°," and this is the point designated as "fever heat," on Fahr- enheit's scale. M. Edwards alludes to a case of tetanus, in a child, the particulars of which were communicated to him by M. Prevost. of Geneva, in which the temperature rose to 110-75° Fahr- enheit.1' Hunter0 found the interior of a hydrocele, on the day of operation, to raise the mercury to 92°; on the following day, when inflammation had commenced, it rose to 99°. The fluid, obtained from the abdomen of an individual, tapped for the seventh time for dropsy of the lower belly, indicated a temperature of 101°. Twelve days thereafter, when the operation was repeated for the eighth time, the temperature was 104°. Dr. Granvilled has assert- ed that the temperature of the uterine system sometimes rises as high as 120° — the elevation seeming to bear some ratio to the degree of action in the organ. We have frequently been struck with the seemingly elevated temperature of the vagina under these circumstances, but cannot help suspecting some inaccuracy in the observations of Dr. Granville, the temperature, he indicates, being so much higher than has ever been noticed in any condition of the system. Under this feeling, several experiments were made, at the author's request, by Dr. Barnes,e one of the resident physi- cians of the Philadelphia Hospital, which exhibit only a slight dif- ference between the temperature of the vagina and that of the uterus during parturition. In two cases, the temperature of the labia was 100°, and in a third 105°; whilst that of the uterus was 100°, 102°, and 106° respectively. Dr. James Currie had himself bled ; and during the operation, the mercury of a thermometer, which he held in his hand, sank, at first slowly and afterwards rapidly, nearly 10°; and when he fainted, the assistant found, that it had sunk 8° farther. MM. Edwards and Gentil assert, that they have likewise ob-r served diurnal variations in the temperature of individuals, and these produced, apparently, by the particular succession in the exercise of the different organs; as where intellectual meditation was followed by digestion. These variations, they affirm, fre- quently amounted to two or three degrees, between morning and evening/ M. Chevalliers has investigated the temperature of the urine on issuing from the bladder. This he did not find to vary from ex- ternal temperature, but it was effected by rest, fatigue, change of regimen, remaining in bed, &c. The lowest temperature, which was observed on rising in the morning, was about 92°; the highest, * G. T. Morgan's First Principles of Surgery, p. 80, Lond. 1837. b Edwards, op. citat. p. 490. c On the Blood, &c. p. 296, Lond. 1794. a Philos. Transact, p. 262, for 1825 ; and Sir E. Home, in Lect. on Comp. Anat. v. 201, Lond. 1828. " Dunglison's American Medical Intelligencer, Feb. 15, 1839, p. 346. f See Purkinje, in art. Calor Animalis, in Encyclop. Wbrterbuch der Medicin. Wissenschaft. Band. vi. s. 530, Berlin, 1831. i Essai sur la Dissolution de la Gravelle, &c. p. 120, Paris, 1837. 202 CALORIFICATION. after dinner, and when fatigued, 99°. In the case of another per- son, the temperature of the urine was never lower than 101°, and occasionally upwards of 102°, when he was fatigued. Such are the prominent facts connected with the subject of ani- mal heat. It is obvious, that it is altogether disengaged by an action of the system, which enables it to counteract, within certain limits, the extremes of atmospheric heat and cold. The animal body, like all other substances, is subjected to the laws regarding the equilibrium, the conduction, and the radiation of caloric ; but, by virtue of the important function we are now considering, its own temperature is neither elevated nor depressed by those in- fluences to any great amount. Into the seat and nature of this mysterious process, and the various ingenious theories that have been indulged, we shall now inquire. Physiologists have been by no means agreed, regarding the organs or apparatus of calorification. Some, indeed, have affirm- ed that there is not, strictly speaking, any such apparatus; and that animal heat is a result of all the other vital operations. Amongst those, too, who admit the existence of such an apparatus, a difference of sentiment prevails; some thinking, that it is local, or effected in a particular part of the body; others, that it is gene- ral, or disseminated through the whole economy. Under the name caloricite, Chaussier admits a primary vital property, by virtue of which living beings disengage the caloric on which their proper temperature is dependent, in the same manner as they accomplish their other vital operations, by other vital properties; and in sup- port of this doctrine, he adduces the circumstance, that each living body has its own proper temperature ; which is coexistent only with the living state ; is common to every living part; ceases at death ; and augments by every cause, that excites the vital activity. It has been properly objected, however, to this view, that the same arguments would apply equally to many other vital operations, — and that it would be obviously improper to admit, for each of these functions, a special vital principle. The notion has not ex- perienced favour from the physiologist, and is, we believe, confined to the individual from whom it emanated.11 Amongst those who admit that calorification is a local action, some have believed, that the caloric is disengaged in a particular organ, whence it is distributed to every part of the body; whilst others conceive, that every part disengages its own caloric and has its special temperature. • So striking a phenomenon as animal temperature could not fail to attract early attention; and accordingly, we find amongst the ancients various speculations on the subject. The most prevalent was, — that its seat is in the heart; that the heat is communicated to the blood in that viscus, and is afterwards sent to every part of the system; and that the great use of respiration is to cool the i Art. Caloricite, by Coutanceau, in Diet, de Medecine, torn. iv. Paris 1822 • and Adelon's Physiologie de l'Homme, torn. iii. 407, 2de edit., Paris, 1829. SEAT OF 203 heart; butthishypothesisisliabletoall the objections, which apply to the notion of any organ of the body acting as a furnace, — that such organ ought to be calcined ; and it has the additional objec- tion, applicable to all speculations, regarding the ebullition and effervescence of the blood as a cause of heat, that it is purely con- jectural, without the slightest fact or argument in its favour. It was not, indeed, until the chemical doctrines prevailed, that any thing like argument was adduced in support of the local disen- gagement of heat: the opinions of physiologists then settled almost universally upon the lungs; and this, chiefly, in consequence of the-observation, that animals, which do not breathe, have a tem- perature but little superior to the medium in which they live ; whilst man and animals that breathe have a temperature con- siderably higher than the medium heat of the climate in which they exist, and one which is but little affected by changes in the thermal condition of that medium; and, moreover, that birds, which breathe, in proportion, a greater quantity of air than man, have a still higher temperature than he. Mayow,a whose theory of animal heat was, in other respects, sufficiently unmeaning, affirmed, that the effect of respiration is not to cool the blood, as had been previously maintained, but to generate heat, which it did by an operation analogous to combustion. It was not, however, until the promulgation of Dr. Black's doctrine of latent heat, that any plausible explanation of the phenomenon appeared.b Ac- cording to that distinguished philosopher, a part of the latent heat of the inspired air becomes sensible ; consequently, the tempera- ture of the lungs, and of the blood passing through them, must be elevated; and, as the blood is distributed to the whole system, it communicates its heat to the parts as it proceeds on its course. But this view was liable to an obvious objection, which was, in- deed, fatal to it, and so Black himself appears to have thought, from his silence on the subject. If the whole of the caloric were disengaged in the lungs, as in a furnace, and were distributed through the bloodvessels, as heated air is transmitted along con- ducting pipes, the temperature of the lungs ought to be much greater than that, of the parts more distant from the heart; so great indeed, as to consume that important organ in a short space of time. The doctrine, maintained by Lavoisier0 and Seguin, was; — that the oxygen of the inspired air combines with the carbon and hydrogen of the venous blood, and produces combustion. The caloric given off is then taken up by the bloodvessels, and is dis- tributed over the body. The arguments, which they adduced in favour of this view, were : — the great resemblance between respiration and combustion, so that if the latter gives off heat, the former ought to do so likewise ; — the fact that arterial blood is * * Tract, quinque, Oxon. 1674. b Bostock's Physiology, 3d edit. p. 440, Lond. 1836. < Mem.de l'Acad. des Sciences pour 1777, 1780, and 1790. 204 CALORIFICATION. somewhat warmer than venous ; — and certain experiments of La- voisier and La Place,* which consisted in placing animals in the calorimeter, and comparing the quantity of ice which they melted, and, consequently, the quantity of heat, which they gave off, with the quantity of carbonic acid produced; and finding, that the quan- tity of caloric, which would result from the carbonic acid formed, was exactly that disengaged by those animals. Independently, however, of other objections, this hypothesis is liable to those already urged against that of Black, which it closely resembles. The objection, that the lungs ought to be much hotter than they really are—both absolutely and relatively—was attempted to be obviated by Dr. Crawfordb in a most ingenious and apparently logical man- ner. The oxygen of the inspired air, according to him, combines with the carbon given out by the blood, so as to form carbonic acid. But the specific heat of this is less than that of oxygen : and ac- cordingly, a quantity of latent caloric is set free ; and this caloric is not only sufficient to support the temperature of the body, but also to carry off the water — which was supposed to be formed by the union of the hydrogen and the oxygen — in the state of vapour, and to raise the temperature of the inspired air consider- ably. So far the theory of Crawford was liable to the same ob- jections as those of Black, and Lavoisier and Seguin. He affirmed, however, that the same process by which the oxygen of the in- spired air is converted into carbonic acid, converts likewise the venous into arterial blood; and as he assumed from his experiments, that the capacity for caloric of arterial blood is greater than that of venous, in the proportion of 1-0300 to 0-892S ; he conceived, that the caloric, set free in the formation of the carbonic acid, in * place of raising the temperature of the arterial blood, is employed in saturating its increased capacity, and in maintaining its tem- perature at the same degree with the venous. According to this view, therefore, the heat is not absolutely set free in the lungs, although arterial blood contains a greater quantity of caloric than venous; but when, in the capillaries, the arterial becomes con- verted into venous blood, or into blood of a less capacity for caloric, the heat is disengaged, and occasions the temperature of the body. If the facts, which served as a foundation for this beautiful theory of animal heat, were not false, the deductions would be irresistible; and,accordingly,it was at one time almost universally received, especially by those who consider that all vital operations can be assimilated to chemical processes; and it is still favoured by many. " The animal heat," observes a recent writer,0 •• has been accounted for in different ways by several ingenious physio- logists; from the aggregate of their opinions and experiments, I deduce, that heat is extricated all over the frame, in the capillaries, a Memoir, tie l'Acad. des Sciences pour 1780. b Exp. &c. on Animal Heat, 2d edit. Lond. 1788 ; and Fleming's Philosophy of - Zoology, i. 387, Edinb. 1822. e Dr. Billing, First Principles of Medicine, 2d edit., p. 19, Lond. 1837. SEAT OF 205 by the action of the nerves, during the change of the blood, from scarlet arterial to purple venous ; and also whilst it is changing in the lungs from purple to scarlet. There is a perpetual deposition by the capillary system of new matter, and decomposition of the old all over the frame, influenced by the nerves ; in this decom- position there is a continual disengagement of carbon, which mixes with the blood returning to the heart, at the time it changes from scarlet to purple ; this decomposition, being effected by the electric agency of the nerves, produces constant extrication of caloric; again, in the lungs that carbon is thrown off and united with oxy- gen, during which caloric is again set free, so that we have in the lungs a charcoal fire constantly burning, and in the other parts a wood fire, the one producing carbonic acid gas, the other carbon, the food supplying through the circulation the vegetable (or what answers the same end, animal) fuel, from which the charcoal is prepared which is burned in the lung."a Numerous objections have, however, been made against the view of Crawford. In the first place, it was objected, that our knowledge is limited to the fact, that oxygen is taken into the pulmonary vessels, and carbonic acid given off, but that we had no means of knowing whether the one goes immediately to the formation of the other. Dr. Crawford had inferred from his experiments, that the specific heat of oxygen is 4-7490 ; of carbonic acid, 1-0454 ; of azote, 0-7936 ; and ofat- mospheric air, 1-7900 ; but the more recent experiments of Dela- roche and Berard make that of oxygen, 0-2361 ; of carbonic acid, 0-2210 ; of azote, 0-2754; and of atmospheric air, 0-2669 ; a dif- ference of such trifling amount, that it has been conceived the , quantity of caloric, given out by oxygen during its conversion into carbonic acid, would be insufficient to heat the residual air, which is expelled in breathing, to its ordinary elevation. Secondly. The elevation of temperature of one or two degrees, which appears to take place in the conversion of venous into arterial blood, although generally believed, is not assented to by all. The experiments in- stituted on this point have been few and imprecise ; and the most recent by MM. Becquerel and Breschet,b made by introducing de- licate thermometers into the auricles of the heart of dogs, invari- ably gave the temperature of arterial blood only a few fractions of a degree higher than that of venous blood. Thirdly. M. Du- long,c — on repeating the experiments of Lavoisier and La Place, for comparing the quantities of caloric, given off by animals, in the calorimeter, with that which would result from the carbonic acid, formed during the same time in their respiration — did not attain a like result. The quantity of caloric disengaged by the animal was always superior to that which would result from the carbonic acid formed. Fourthly. The estimate of Crawford, regarding the specific heat of venous and arterial blood, has been contested. He made that of the former, we have seen, 0*8928; of the latter, 1 See, also, Elliotson, Human Physiology, p. 238, Lond. 1840. b Comptes Rendus, Oct. 1841. ' Magendie's Journal de Physiologie, iii. 45. VOL. II. — 18 806 CALORIFICATION. 1*0300. The result of the experiments of Dr. John Davya give 0-903 to the former, and 0-913 to the latter ; and in another case, the result of which has been adopted by Magendie, the specific heat of the venous was greater than that of the arterial blood, in the proportion of -852 to -839. Granting, however, that the case is as stated by Crawford, it is insufficient to explain the phenomena. It has, indeed, been attempted to show, that if the whole of thecalo- ric, set free in the manner mentioned, were immediately absorbed, it would be insufficient for the constitution of the arterial blood ; and that, instead of the lung running the risk of being calcined, it would be threatened with congelation. Of late, the theory of combustion has received the powerful support of Liebig, and many able elucidations and expansions from that able chemist. According to him, the carbon and hydrogen of the food, in being converted, through the agency of oxygen, into carbonic acid and water, must give out as much heat as if these gases were burned in the open air. The temperature of the human body is essentially the same in the torrid as in the frigid zone ; but as the body may be regarded in the light of a heated vessel, which cools with the greater rapidity the colder the surrounding medium, the fuel, necessary to maintain its heat, must vary, he maintains, in different climates. How unequal must be the loss of heat at Palermo, where the external temperature is nearly equal to that of the body, and in the polar regions, where the external temper- ature is from 70° to 90° lower. In the animal body, the food is the fuel, and with a proper supply of oxygen we obtain the heat during its oxidation or combustion. In winter, when we take ex- ercise in a cold atmosphere, and when, consequently, the amount of inspired oxygen increases, the necessity for food containing carbon and hydrogen increases in the same ratio, and, by gratify- ing the appetite thus excited, we obtain the most efficient protec- tion against piercing cold. A starving man is soon frozen to death; and every one, according to Liebig, knows, that the animals of prey in the arctic regions far exceed, in voracity, those of the torrid zone. Our clothing is merely an equivalent for a certain amount of food. Were we to go naked, like certain savage tribes, or if, in hunting or fishing, we were exposed to the same degree of cold as the Samoyedes, we should be able with ease to consume sixteen pounds of flesh, and perhaps a dozen tallow candles into the bar- gain, as warmly clad travellers have related with astonishment of these people. We should then, also, be able to take the same quantity of brandy or train-oil without bad effects, because the carbon and hydrogen of these substances would only suffice to keep up the equilibrium between the external temperature and that of our bodies. The whole process of respiration is clearly exhibited when we view the condition of man or animals under abstinenceYrom all food. Oxygen is abstracted from the air, and carbonic acid and water expired, because the number of respira- » Philos. Transactions for 1814. THEORIES OF CALORIFICATION. 207 tions remains unaltered. With the continuance of the abstinence, the carbon and hydrogen of the body are seen diminishing. The first effect of abstinence is the disappearance of the fat, which canbe detected neither in the scanty faeces nor urine ; its carbon and hy- drogen are thrown off by the skin and lungs, in the form of a compound with oxygen. These constituents, then, have served for the purposes of respiration. Every day, 32^ ounces of oxygen are inspired; and these must remove their equivalents of carbon to form carbonic acid. When this combination ceases to go on, respiration terminates : death has taken place. The time required for starving an animal to death depends on its fatness, on the state of its activity, on the temperature of the air, and on the presence or absence of water. That the quantity of heat evolved by the combination of 13-9 ounces of carbon is amply sufficient to account for the temperature of the human body may be estimated by figures ; an ounce of carbon, according to the experiments of Des- pretz, burned, would evolve 14067 degrees of heat; and 13-9 oz. would therefore give out 195531-3 degrees of heat. This would suffice to boil 679 pounds of water at 32°, or to convert 11*4 pounds of water at 98-3° into vapour. If we consider, then, the quantity of water vaporized through the skin to be, in twenty- four hours, 48 ounces or 3 pounds, there will remain, after de- ducting the necessary amount of heat, 144137*7 degrees of heat, which are dissipated by radiation, by heating the expired air, and by the excrementitious matters.* These views of Liebig have necessarily attracted the attention of the chemical physiologist, and have met with unqualified sup- port from some, whilst they have been as much condemned by others, who appear to have a horror at the introduction of chemi- cal explanations to account for vital phenomenal Yet it cannot be contested, that the function of calorification is an act of vital chemistry, and, therefore, although the views of Liebig may fail to convince, they certainly have taken the proper direction, and, all must admit, have been plausibly and ably supported. It has been objected, that if even the theory of Liebig be allowed to be applicable to mammalia, birds and reptiles, it is by no means so to animals that respire by means of branchiae or gills, all of which consume but little oxygen, comparatively speaking, yet many of them devour very great quantities of food. Even the largest and most voracious of the reptiles, as the alligators, crocodiles, &c, which consume enormous quantities of food, under a burning climate too, breathe- feebly with their vesicular lungs, and con- sume but little oxygen. Fishes, too, whose blood is but imper- fectly oxygenized by their branchial apparatus, are perhaps amongst the most voracious of animals; yet, according to the above theory, they ought to eat little, because they consume little oxygen. These and other facts were early urged by M. Virey,c » Animal Chemistry, Amer. Edit, by Webster, p. 33, Cambridge, 1842. b See, on Liebig's views, Mr. Ancell, London Lancet, 1842-3. < Journal de Pharmacie, Mai, 1842. 208 CALORIFICATION. as objections to the views of the Professor of Giessen. It may be replied, however, that in such cases, a large portion of the carbon must pass off in the excrements. There is no country in the world, according to Madame Calderon de la Barco,a where so much animal animal food is consumed as in Mex*ico, " and there is no country in which so little is required." To this and to want of exercise she ascribes the early fading of beauty in the higher classes, the decay of teeth, and the over-corpulency so common amongst them ; and in regard to the last she is, doubtless, correct. To the statement of Liebig respecting the greater voraciousness of the animals of prey of the arctic regions, it has been urged,b that a Bengal tiger or cape hyaena requires, in proportion to its size, quite as much aliment as any of the arctic carnivora, and that the vultures of Hindostan and Persia exceed, perhaps, all other ani- mals in gluttony. The voraciousness of the shark, too, even within the tropics, is proverbial. " Those who ride over the Pampas in South America," says Dr. Graves, " at the rate of one hundred miles a day, exposed to a burning sun, subsist entirely on boiled beef and water, without a particle of vegetable food of any kind, and yet they attain to an extraordinary condition, and capability of enduring violent and long-continued exertion. Liebig's theory must be very ductile, if it can explain how it happens, that an exclusively animal diet agrees with man quite as well at the equator as within the arctic circle." Numerous facts, indeed, can be brought forward of an opposite tendency to those of Liebig, and which render it impracticable for us, in the present state of our knowledge, to embrace all his positions. Under Respiration, the theory, supported by him, that the blood corpuscles are the car- riers of oxygen from the lungs to the tissues; and the conveyers of carbonic acid back from the tissues to the lungs, was mentioned. It would seem probable, therefore, that if the amount of blood corpuscles should become diminished from any cause, the function of calorification ought to be impaired to the like extent. To dis- cover what effect was produced on the temperature of the living body by diminution in the quantity of blood corpuscles, Andral recently performed some experiments, which showed that the temperature remained normal, even in cases in which the corpus- cles had experienced the greatest diminution in number. In the axilla, the temperature was 98° or 99° of Fahrenheit in persons, the proportion of whose blood corpuscles was not higher than 50, 40, 30, and even 21 parts in the 1000; the healthy ratio being 127. Indeed, notwithstanding the great depression in anaemic patients, the heat rose as usual, when they were attacked with fever, to which they are as subject as other individuals.0 But the theories of combustion have been most seriously assailed • Life in Mexico, vol. i., p. 152, Boston, 1842. b Dr. R. .1. Graves, A System of Clinical Medicine, p. 57, Dublin 1843. • Andral, Hematologie Pathologique, p. 60, Paris, 1843. THEORTCS OF CALORIFICATION. 209 By other experiments, tending to show, that the function of calorifi- cation is derived from the great nervous centres. When an animal is decapitated, or when the spinal marrow, or the brain, or both, are destroyed, the action of the heart may still be kept up, provided the lungs be artificially inflated. In such case, it is found, that the usual change in the blood, from venous to arterial, is pro- duced ; and that oxygen is absorbed and carbonic acid exhaled as usual. Sir Benjamin Brodie,a in performing this experiment, di- rected his attention to the point, — whether animal heat, under such circumstances, be evolved, and the temperature maintained, as where the brain and spinal marrow are entire — and he found, that although the blood appeared to undergo its ordinary changes, the generation of animal heat seemed to be suspended; and con- sequently, if the inspired air happened to be colder than the body, the effect of respiration was to cool the animal; so that an animal, on which artificial respiration was kept up, became sooner cold than one killed at the same time and left undisturbed. The infer- ence, deduced from these experiments, was, that instead of circu- lation and respiration maintaining the heat, they dissipate it; and that as the heat is diminished by the destruction of the nervous centres, its disengagement must be ascribed to the action of those centres, and particularly to that of the encephalon. M. Chossatb endeavoured to discover the precise part of the ner- vous system engaged in calorification ; but the results of his expe- riments were not such as to induce him to refer it exclusively, with Sir B. Brodie, to the encephalon. He divided the brain, anterior to the pons varolii, in a living animal, so that the eighth pair of nerves were uninjured. Respiration, consequently, continued, and inflation of the lungs was unnecessary. Notwithstanding this serious mutilation, the circulation went on ; and Chossat observed distinctly, that arterial blood circulated in the arteries. Yet the temperature of the animal gradually sank, from 104° Fahr.,— its elevation at the commencement of the experiment, — to 76°, in twelve hours, when the animal died. It seemed manifest to M. Chossat, that, from the time the brain was divided, heat was no longer given off, and the body gradually cooled, as it would have done after death. He, moreover, noticed, that the time, at which the refrigeration occurred most rapidly, was that in which the cir- culation was most active, — at the commencement of the experi- ment. In other experiments, M. Chossat paralysed the action of the brain by a violent concussion, and by injecting a strong decoc- tion of opium into the jugular vein, — keeping up respiration at the same time artificially. The results were the same. From these experiments, he drew the conclusion, that the brain has a direct influence over the production of heat. His next experiments were » Philos. Trans, for 1811 and 1812. b Sur la Chaleur Animale, Paris, 1820 ; Adelon, op. cit. iii. 416 ; Coutanceau, in art. Chaleur Animale, Diet, de Med. iv. 17, Paris, 1822 ; and P. H. Berard, art. Cha- , leur Animale, Diet, de Med. 2de edit. vii. 206, Paris, 1834. 18* 21Q CALORIFICATION. directed to the discovery of the medium through which the brain acts, — the eighth pair of nerves, or spinal marrow. He divided the eighth pair of nerves in a dog, and kept up artificial respira- tion. The temperature sank gradually, and, at the expiration of sixty hours, when the animal died, it was reduced to 6S° of Fahr- enheit. Yet death did not occur from asphyxia or suspension of the phenomena of respiration, as the lungs crepitated, exhibited no signs of infiltration, and were partly filled with arterial blood. The animal appeared to M. Chossat to expire from cold. As, how- ever, the mean depression of heat was less than in the preceding experiments, he inferred that a slight degree of heat is still disen- gaged after the section of the eighth pair, whilst, after injury done to the brain directly, heat is no longer given off. Again, he di- vided the spinal marrow beneath the occiput, and although artifi- cial respiration was maintained, as in the experiments of Brodie, the temperature gradually fell, and the animal died ten hours af- terwards, its heat being 79°; and as death occurred in this case so much more speedily than in the last, he inferred, that the in- fluence of the brain over the production of heat is transmitted rather by the spinal marrow than by the eighth pair of nerves. In his farther experiments, Chossat found, that when the spinal mar- row was divided between each of the twelve dorsal vertebras, the depression of temperature occurred less and less rapidly, the lower the intervertebral section ; and at the lowest it was imperceptible; he, therefore, concluded, that the spinal marrow does not act di- rectly in the function, but indirectly through the trisplanchuic nerve. To satisfy himself on this point, he opened a living animal on the left side, beneath the twelfth rib, and removed the supra- renal capsule of that side, dividing the trisplanchuic where it joins the semilunar plexus. The animal gradually lost its heat, and died ten hours afterwards in the same state, as regarded temperature, as when the spinal marrow was divided beneath the occiput. Desiring to obtain more satisfactory results, — the last experi- ment applying to only one of the trisplanchuic nerves,— he tied the aorta, which supplies both with the materials on which they ope- rate, beneath the place where it passes through the arch of the diaphragm, at the same time preventing asphyxia by inflating the lungs. The animal lost its heat much more rapidly, and died in five hours. In all these cases, according to Chossat, death occur- red from cold ; the function, by which the caloric, constantly ab- stracted from the system by the surrounding medium, is generated, having been rendered impracticable. To obtain a medium of comparison, he killed several animals by protracted immersion in cold water, and found, that the lowest temperature, to which the warm-blooded could be reduced, and life persist was 79° of Fahr- enheit. M. Chossat also alludes to cases of natural death by con- gelation, which he conceives to destroy in the manner before sug- gested, by impairing the nervous energy, as indicated by progres- THEORIES OF CALORIFICATION. 211 sive stupor, and by debility of the chief functions of the economy. Lastly : — on killing animals suddenly, and attending to the pro- gress of refrigeration after death, he found it to be identical with that which follows direct injury of the brain, or division of the spinal marrow beneath the occiput. A view somewhat analogous to this of M. Chossat, has been embraced by Sir Everard Home.a He conceives, that the pheno- menon is restricted to the ganglionic part of the nervous system, and he rests the opinion chiefly upon the position, that there are certain animals, which have a brain, or some part equivalent to one, but whose temperature is not higher than that of the sur- rounding medium ; whilst, on the other hand, all the animals that evolve heat are provided with ganglia. The doctrines of Brodie, Chossat, and Home have been consi- dered by the generality of the chemists, — by Brande,b Thomson^ and Paris,d — to be completely subversive of the chemical doc- trines, which refer the production of animal heat to the respiratory function ; and their position, — that it is a nervous function, — has seemed to be confirmed by the facts attendant upon injury done to the nerves of parts, and by what is witnessed in paralytic limbs, the heat of which is generally and markedly inferior to that of the sound parts. But there are many difficulties in the way of ad- mitting, that the nervous system is the special organ for the pro- duction of animal temperature. Dr. Wilson Philip,e from a repe- tition of the experiments of Sir Benjamin Brodie, was led to con- clude, that the cause, why the temperature of the animal body diminished more rapidly, when "artificial inflation was practised, than when the animal was left undisturbed, was — too large a quantity of air having been sent into the lungs ; and he found, that when a less quantity was used, the cooling process was sen- sibly retarded by the inflation. The experiments of Legallois/ Hastings,e and Williams,h although differing from each other in certain particulars, corroborate the conclusion of Dr. Philip, and, what is singular, they would appear to show, that the tempera- ture occasionally rises during the experiment; facts, which would rather confirm the view that respiration is greatly concerned in the evolution of heat. Many of the facts, detailed by Chossat, are curious, and exhibit the indirect agency of the nervous system, but his conclusion, that the trisplanchnic is the great organ for its development, is liable to the objections already urged regarding the theory, which looks upon the heart, or the lungs as furnaces for the disengagement of 1 Philos. Trans, p. 257, for 1825 ; Journal of Science and Arts, xx. 307; and Lect. on Comparative Anat. v. 121 and 194, Lond. 1828. b Manual of Chemistry, vol. iii. c System of Chemistry, vol, iv. d Medical Chemistry, p. 327, Lond. 1825. e An Experimental Inquiry into the Laws of the Vital Functions, 3d edit. p. 180. ' Annales de Chimie, iv. 5, Paris, 1817. t Wilson Philip, op. cit.; and Journal of Science, &c. xiv. 96. k Edinb. Medico-Chirurgical Transact, ii. 192. 212 CALORIFICATION. caloric, that they ought to be consumed in a short space of time by the operation. All the facts, however, exhibit, that, in the upper classes of animals, the three great acts of innervation, respiration and circulation are indirectly concerned in the function; not that any one is the special apparatus. M. Edwards has attempted to show, that it is more connected with the second of these than with either of the others. Thus, animals, whose temperature is highest, bear privation of air the least; whilst cold-blooded animals suffer comparatively little from it; and young animals are less affected by it than the adult. Now, the greater the temperature of the animal, and the nearer to the adult age, the greater is the con- sumption of oxygen. He farther observed, that whilst the seasons modify calorification, they affect also respiration; and that if, in summer, less heat be elicited, and in winter more, respiration con- sumes less oxygen in the former season than in the latter. The experiments of Legallois, as well as those instituted by Edwards, led the latter to infer, that there is a certain ratio be- tween heat and respiration, in both cold-blooded and warm-blooded animals, and in hibernating animals, both in the periods of tor- pidity and of full activity. When the eighth pair of nerves is divided in the young of the mammalia, a considerable diminution is produced in the opening of the glottis ; so that, in puppies, re- cently born, or one or two days old, so little air enters the lungs, that when the experiment is made in ordinary circumstances, the animal perishes as quickly as if it were entirely deprived of air. It lives about half an hour. But, if the same operation be performed upon puppies of the same age, benumbed with cold, they will live a whole day. In the first case, M. Edwards thinks, and plausibly, the small quantity of air is insufficient to counteract the effect of the heat; whilst, in the other, it is sufficient to prolong life con- siderably, and he deduces the following practical inferences appli- cable to the adult age, and particularly to man. A person, he remarks, is asphyxied by an excessive quantity of carbonic acid in the air he breathes; the pulse is no longer perceptible ; the respiratory movements cannot be discerned, but his temperature is still elevated. How should we proceed to recall life. Although the action of the respiratory organs is no longer visible, all com- munication with the air is not cut off. The air is in contact with the skin, upon which it exerts a vivifying influence ; it is also in contact with the lungs, in which it is renewed by the agitation constantly taking place in the atmosphere, and by the heat of the body, which rarefies it. The heart continues to beat, and main- tains a certain degree of circulation, although not perceptible by the pulse. The temperature of the body is too high to allow the feeble respiration to produce upon the system all the effect of which it is capable. The temperature must then be reduced; the patient must be withdrawn from the deleterious atmo- sphere ; be stripped of his clothes, in order that the air may have a more extended action upon his skin; be exposed to THEORIES OF CALORIFICATION. 213 the cold, although it be winter, and cold water be thrown upon his face until the respiratory movements reappear. This is pre- cisely the treatment adopted in practice to revive an individual from a state of asphyxia. If, instead ofcold, continued warmth were to be applied, it would be one of the most effectual means of extin- guishing life. This consequence, like the former, is confirmed by experience. In sudden faintings, where the pulse is weak or im- perceptible, the action of the respiratory organs diminished, and sensation and voluntary motion suspended, persons, the most ignorant of medicine, are aware, that means of refrigeration must be employed,—such as exposure to air, ventilation, and sprink- ling with cold water. In violent attacks of asthma, also, when the extent of respiration is so limited that the patient experiences a sense of suffocation, he courts the cold air even in the severest weather; opens the windows; breathes a frosty air, and finds himself relieved. As a general rule, an elevated temperature accelerates the respi- ratory movements, but the degree of temperature, requisite to pro- duce this effect, is not the same in all. The object of this accelerated respiration is, that more air may come in contact with the lungs, in a given time, so as to reanimate what the heat depresses. It is proper to remark, however, that we meet with many ex- ceptions to the rule endeavoured to be laid down by M.Edwards, as regards the constant ratio between heat and respiration. Ex- periments on the lower animals, and pathological cases in man, have shown, that lesions of the upper part of the spinal marrow give occasion, at times, to an extraordinary development of heat. In the case of a man at St. George's Hospital, London, labouring under a lesion of the cervical vertebras, Sir B. Brodie observed the temperature to rise to 111°, at a time when the respirations were not more than five or six in a minute.a Drs. Graves and Stokesb give the case of a patient who laboured under a very extensive development of tubercles, had tubercular abscesses in the upper portions of both lungs, and general bronchitis. In this case, at a period when the skin was hotter than usual, and the pulse 126, the respirations were only 14 in the minute; besides,as Dr. Alison0 has remarked, the temperature of the body is not raised by volun- tarily increasing or quickening the acts of respiration ; but by voluntary exertions of other muscles, which accelerate the circu- lation, and thus necessitate an increased frequency of respiration ; a fact, which would seem to show that calorification is dependent not simply on the application of oxygen to the blood, but on the changes that take place during circulation, and to the maintenance of which the oxygenation of the blood is one essential condition. » Lond. Med. Gazette, for June, 1836, and G. T. Morgan's First Principles of Sur- gery, p. 85, Lond. 1837. b Dublin Hospital Reports, vol. v. See, also, Dr. Graves, Clinical Lectures, Dungli- son's Amer. Med. Lib. Edit. p. 126, Philad. 1838; and Dr. John Davy, Researches, Physiological and Anatomical, Amer. Med. Lib. Edit. p. 89, Philad. 1840. « Outlines of Physiol., Lond. 1831. 214 CALORIFICATION. Moreover, in the foetus in utero, there is, of course, no respiration; yet its temperature equals, and indeed is said to even exceed, that of the mother; and we know that its circulation is more rapid, and its nutrition more active.3 That innervation is indirectly con- cerned in the phenomenon is proved by the various facts which have been referred to ; and Legallois, although he does not accord with Sir B. Brodie, conceives, that the temperature is greatly under the influence of the nervous system, and that whatever weakens the nervous power, proportionally diminishes the capa- bility of producing heat. Dr. Philip, too, concluded from his ex- periments, that the nervous influence is so intimately connected with the power of evolving heat, that it must be looked upon as a necessary medium between the different steps of the operation. He found, that if the galvanic influence be applied to fresh drawn arterial blood, an evolution of heat, amounting to three or four degrees, takes place, whilst the blood assumes the venous hue and becomes partly coagulated. He regards the process of calorifica- tion as a secretion ; and explains it upon his general principle of the identity of the nervous and galvanic influences, and of the necessity for the exercise of such influence in the function of secretion.b Mr. H. Earlec found the temperature of paralysed limbs to be slightly lower than that of sound limbs, and the same effect upon calorification is observed to supervene on traumatic injuries of the nerves. In a case of hemiplegia, of five months' duration, under the author's care at the Blockley Hospital, the thermometer in the right — the sound — axilla of the man stood at 96^° ; in the axilla of the paralysed side at 96°. The difference in temperature of the hands was more signal. The right hand carried the mercury to 87°, whilst the left raised it no further than 795°. In another case — that of a female — of two weeks' duration, accompanied with signs of cerebral turgescence, the temperature in the axilla of the sound side, was 100Q; in that of the paralysed 98-25°; of the hand of the sound side, 94°; of the other 90°.d It is a general fact, that the temperature of the paralysed side in hemiplegia is less than that of the sound side ; yet the irregularity of nervous action is so great, and the power of resistance to excitant or depressing agents so much diminished, that the author has not unfrequently found the temperature to be more elevated.e Lastly, that the circulation is necessary to calorification, we have evidence in the circumstance that if the vessels, proceeding to a part be tied, animal heat is no longer disengaged from it. a See, also, on the connexion of respiration with calorification, P. H. Berard, art. Chaleur Animale, in Diet, de M6d. 2de edit. vii. 175, Paris, 1834; Dr. Southwood Smith's Philosophy of Health, vol. ii. Lond. 1838; and Mr. Newport on the Temper- ature of Insects, and its Connexion with the Functions of Respiration and Circulation in this class of invertebrated animals, Philos. Transact, part ii. 4to. p. 77, Lond. 1837. b Ley, in Appendix to Essay on Laryngismus Stridulus, &c. p. 374, Lond. 1836. c Medico-Chirurgical Transactions, vii. 173, Lond. 1819. d See Nasse, Untersuchungen zur Physiologie und Pathologie, Bonn. 1835-6. p See the author in his American Med. Intelligencer, Oct. 15, 1838, p. 225. THEORIES OF CALORIFICATION. 215 It is manifest, then, that in animals, and especially in the warm- blooded, the three great vital operations are necessary for the dis- engagement of the due temperature, but we have no sufficient evidence of the direct agency of any one, and we see heat elicited in the vegetable, in which these functions are at all events rudi- mental; and the existence of one of them—innervation — perhaps more than doubtful.a The view of those, who consider, that the disengagement of caloric occurs in the intermediate system or system of nutrition of the whole body, appears to us the most consistent with observed phenomena. These views have varied according to the physical circumstances, that have been looked upon as producing heat. By some, it has been regarded as the product of effervescence of the blood and humours; by others, as owing to the disengage- ment of an igneous matter, or spirit from the blood ; by others, to an agitation of the sulphureous parts of the blood; whilst Boerhaaveb and Douglas0 ascribe it to the friction of the blood against the parietes of the vessels, and of the globules against each other. In favour of the last hypothesis, it was urged, that animal heat is in a direct ratio with the velocity of the circulation, the circumfer- ence of the vessels, and the extent of their surface ; and that thus we are able to explain, why the heat of parts decreases in a direct ratio with their distance from the heart; and the greater heat of the arterial blood, in the lungs,,was accounted for, by the suppo- sition, that the pulmonary circulation is far more rapid. Most of these notions are entirely hypothetical. The data are generally incorrect, and the deductions characteristic of the faulty physics of the period in which they were indulged. The correct view, it appears to us, is, that caloric is disengaged in every part, by a special chemico-vital action, which, in animals, is greatly under the nervous influence. In this manner, calorification becomes a function executed in the whole system of nutrition, and there- fore appropriately considered in this place. It has been remarked by Tiedemann,d that the intussusception of alimentary matters, and their assimilation by digestion and respiration, the circulation of the humours, nutrition and secretion, the renewal of materials accompanying the exercise of life, and the constant changes of composition in the solid and liquid parts of the organism, — all of which are under the nervous influence, —participate in the evo- lution of heat, and we deceive ourselves when we look for the cause in one of those acts only. In some experiments by Dr. Robert E. Rogers,*5 he found that when recently drawn venous » Dr. W. B. Carpenter, Principles of General and Comparative Physiology,p. 379, Lond. 1839. b Gerard Van Swieten, Comment in Boerhaav. Aphorism., &c. § 382, 675, Ludg. Bat. 1742-1772. c On Animal Heat, p. 47, Lond. 1747. dTraite de Physiologie, &c. trad, par Jourdan, p. 514, Paris, 1831; Ley, op. cit. Appendix, p. 303; and Collard de Martigny.in Journal Comptementaire des Sciences M^dicales, xliii. 268, Paris, 1832. e Amer. Journ. of the Med. Sciences, p. 297, for Aug. 1836. 216 CALORIFICATION. blood contained in a freshly removed pig's bladder was im- mersed in oxygen gas, there was a remarkable elevation of temper- ature. Dr. Davya performed some experiments which led to the same results. In one of these, he took a very thin vial,.of the capacity of eight liquid ounces, and carefully enveloped it in badly conducting substances —namely, several folds of flannel, of fine oiled paper, and of oiled cloth. Thus prepared, and a perfo- rated cork being provided, holding a delicate thermometer, two cubic inches of mercury were introduced, and immediately after it was filled with venous blood kept liquid by agitation. The vial was then corked, and shaken. The thermometer included was stationary at 45°. After five minutes, during which it remained stationary, it was withdrawn ; the vial closed by another cork, was transferred inverted to a mercurial bath, and \h cubic inch of oxygen was introduced. The common cork was returned, and the vial was well agitated for about a minute: the thermometer was now introduced ; it rose immediately to 46°, and by continu- ing the agitation, it rose further to 46-5°, and very nearly to 47°. This experiment was made on the blood of the sheep. These and other experiments of a similar character, in Dr. Davy's opinion, appear to favour the idea, that animal heat is owing, first, to the fixation or condensation of oxygen in the blood in the lungs, in its conversion from venous to arterial; and secondly, to the com- binations into which it enters in the circulation in connexion with the different secretions and changes essential to animal life. It is by the theory of the general evolution of caloric in the capillary system, or in the system of nutrition, that we are capable of accounting for the increased heat that occurs in certain local affections, in which the temperature greatly exceeds that of the same parts in health. By some, it has been doubted, whether, in cases of local inflammation, any such augmentation of tempera- ture exists, but the error seems to have arisen from the temperature of the part, in health, having generally been ranked at blood heat; whereas, we shall find, that it differs essentially in differ- ent parts. Dr. Thomson found, that a small inflamed spot, in his right groin, gave out, in the course of four days, a quantity of heat, sufficient to have heated seven wine-pints of water from 40° to 212°; yet the temperature was not sensibly less than that of the rest of the body at the end of the experiment, when the inflammation had ceased.b Of the mode in which heat is evolved in the capillaries, it is im- possible for us to arrive at any satisfactory information. The result alone indicates, that the process has been accomplished. In the present slate of our knowledge, we are compelled to refer it to some vital action, of the nature of which we are ignorant; but which seems to be possessed by all organized bodies,__vegetable as well as animal. By supposing, that calorification is effected » Proceedings of the Royal Society for 1837-8, No. 34, and Researches, Physiolo- gical and Anatomical, Dunglison's American Med. Lib. Edit. p. 89, Philad. 1840. b Annals of Philosophy, ii. 27. THEORIES OF CALORIFICATION. 217 in every part of the body, we can understand why different por- tions should have different temperatures ; as the activity of the function may vary, in this respect, according to the organ.8 Cho- part and Dessault found the heat of the rectum to be 100°; of the axilla and groin, when covered with clothes, 96°; and of the chest, 92°. Dr. Davyb found the temperature of a naked man, just risen from bed, to be 90° in the middle of the sole of the foot; 93° between the inner ankle and tendo-achillis ; 91-5° in the mid- dle of the shin; 93° in the calf; 95° in the ham; 91° in the mid- dle of the thigh; 96-5° in the fold of the groin ; 95° at three lines beneath the umbilicus; 94° on the sixth rib of the left side; 93° on the same rib of the right side ; and 98° in the axilla. MM. Edwards and Gent.il found the temperature of a strong adult male, to be, in the rectum and mouth, 102°; in the hands, 100°; in the axilla and groins, 98°; on the cheeks, 97° ; in the prepuce and the feet,96° ; and on the chestandabdomen, 95°. All theseexperiments, it is obvious, concern only temperature of parts, which can be readily modified by the circumambient medium. To judge of the comparative temperature of the internal organs, Dr. Davy killed a calf, and noted the temperature of different parts, both external and internal. The blood of the jugular vein raised the thermo- meter to 105-5°; and that of the carotid artery to 107°. The heat of the rectum was 1055°; of the metatarsus, 97°; of the tarsus, 90°; of the knee, 102°; of the head of the femur, 103° ; of the groin, 104°; of the under part of the liver, 106° ; of the substance of that organ, 106°; of the lung, 106-5°; of the left ventricle, 107° ; of the right, 106°; and of the substance of the brain, 104°. In the case of fistulous opening into the stomach, observed by Dr, Beaumont,0 the thermometer indicated a difference of three- fourths of a degree between the splenic and pyloric orifices of the stomach ; the temperature of the latter being more elevated. It is not easy to account for these differences without supposing that each part has the power of disengaging its own heat, and that the communication of caloric is not sufficiently ready to prevent the difference from being perceptible. It was stated early in this section, that man possesses the power of resisting cold as well as heat within certain limits, and of pre- serving his temperature greatly unmodified. Let us inquire into the direct and indirect agents of these counteracting influences. As the mean temperature of the warmest regions does not exceed 85° of Fahrenheit, it is obvious that he must be constantly disen- gaging caloric to the surrounding medium: — still, his temperature remains the same. This is effected by the mysterious agency which we have been considering, materially aided, however, by several circumstances, both intrinsic and extrinsic. The external envelope of the body is a bad conductor of caloric, and therefore a J. Hunter, Observations on the Animal 03conomy, Lond. 1786. b Philosoph. Transact, for 1814. » Exp. and Observations on the Gastric Juice, p. 274, Plattsburg, 1833. VOL. II. — 19 218 CALORIFICATION. it protects the internal organs, to a certain extent, from the sudden influence of excessive heat or cold. But the cutaneous system of man is a much less efficient protection than that of animals. In the warm-blooded animals, in general, the bodies are covered with hair or feathers. The whale is destitute of hair; but, be- sides the protection which is afforded by the extraordinary thick- ness of its skin, and the stratum of fat — a bad conductor of caloric — with which the skin is lined, as the animal constantly resides in the water, it is not subjected to the same vicissitudes of temperature as land animals. The seals, bears, and walruses, which seek their food in the same seas, sleep on land. They have a coating of hair to protect them. In the cases of some of the birds of the genus Anas, of northern regions, we meet with a singular anomaly, — the whole of the circumference of the anus being devoid of fea- thers, but to make amends for this deficiency, the animal has the power of secreting an oleaginous substance, with which the sur- face is kept constantly smeared. It may be remarked, that we do not find the quantity of feathers on the bodies of birds to be pro- portionate to the cold of the climates in which they reside, as is pretty universally the case regarding the quantity of hair on the mammalia. Man is compelled to have recourse to clothing, for the purpose of preventing the sudden abstraction or reception of heat. This he does by covering himself with substances which are bad con- ductors of caloric, and retain an atmosphere next to the surface, which is warmed by the caloric of the body. He is compelled, also, in the colder seasons, to have recourse to artificial temperature, and it will be obvious, from what has already been said, that the greater the degree of activity of any organ or set of organs, the greater will be the heat developed; and in this way muscular exertion and digestion influence its production. By an attention to all these points, and by his acquaintance with the physical laws relative to the development and propaga- tion of caloric, man is enabled to live amongst the arctic snows, and to exist in climates, where the temperature is frequently for a length of time upwards of 150° lower than that of his own body. The contrivances adopted in the polar voyages, under the direc- tion of Captain Parry and others, are monuments of ingenuity directed to obviate one of the greatest obstacles to prolonged ex- istence in inhospitable regions, for which man is naturally incapa- citated, and for which he attains the capability solely by the exer- cise of that superior intellect with which he has been vested by the Author of his being. In periods of intense cold, the extreme parts of the body do not possess the necessary degree of vitality to resist congelation, unless they are carefully protected. In the disastrous expedition of Napoleon to Russia, the loss of the nose and ears was a common casualty ; and, in arctic voyages, frost-bites occur in spite of every care.a W'hen the temperature of the whole body ■ Larrey, Memoires de Chirurgie Militaire et Campagnes, torn. iv. p. 91, 106, and 123, Paris, 1817. THEORIES OF CALORIFICATION. 219 sinks to about 78° or 79°, death takes place, preceded by the symptoms of nervous depression, which have been previously depicted. The counteracting influence, which is exerted, when the body is exposed to a temperature greatly above the ordinary standard of the animal, is as difficult of appreciation as that by which calorifi- cation is effected. The probability is, that, in such case, the disen- gagement of animal heat is suspended ; and that the body receives heat from without, by direct, but not by rapid, communication, owing to its being an imperfect conductor of caloric. Through the agency of this extraneous heat, the temperature rises a limited number of degrees ; but its elevation is generally considered to be checked by the evaporation, constantly taking place through the cutaneous and pulmonary transpirations. For this last idea we are indebted to Franklin,3 and its correctness and truth have been maintained by most observers. MM. Berger and Delaroche put into an oven, heated to from 120° to 140°, a frog, one of those porous vessels, called alcarazas — which permit the transudation of the fluid, within them, through their sides — filled with water at the animal heat, and two sponges, imbibed with the same water. The temperature of the frog at the expiration of two hours, was 99°; and the other bodies continued at the same. Having substi- tuted a rabbit for the frog, the result was identical. On the other hand, having placed animals in a warm atmosphere, so saturated with humidity that no evaporation could occur, they received the caloric by communication, and their temperature rose ; whilst inert, evaporable bodies, put into a dry stove, became but slightly warm- ed ; — much less so, indeed, than the warm-blooded animals in the moist stove.b Hence they concluded, that evaporation is a great refrigerative agent when the body is exposed to excessive heat; and that such evaporation was considerable, was shown by the loss in weight, which animals sustain by the experiment. Recently, however, it has been contested, that the cutaneous evaporation has any effect in tempering the heat of the body ; whilst it is admitted that the elimination from the system of a certain quantity of aqueous matter is all important; — whatever arrests it being the source of morbid phenomena. MM. Becquerel and Breschet" found, when the hair of rabbits had been shaved off, and the skin covered with an impermeable coating of strong glue, suet, and resin, that the animals died very soon afterwards, and, they thought, by a process of asphyxia in consequence of the trans- piration from the skin being prevented. In these experiments, they found to their surprise, that the temperature of the animals, instead of rising, fell considerably. Thus, the temperature of the first rabbit, before it was shaved, and covered with the impermeable 1 Works, iii. 294, Philad. 1809 ; or Spark's edit. vi. 213, Boston, 1838. b Delaroche, in Journal de Physique, lxxi. 289, Paris, 1810 ; Coutanceau, Diet, de Med. v. 23 ; and Magendie's Precis, ii. 509. c Comptes Rendus, Oct. 1841. 220 CALORIFICATION. coating, was 3S° centigrade; but immediately after the coating was dry, the temperature of the muscles of the thigh and breast had fallen to 24-5 centigrade. In another rabbit, the coating on which was put on with more care, — as soon as the coating was dried, the temperature was found to have fallen so much that it was only three degrees above that of the surrounding atmosphere, which was on that day 17° centigrade. An hour after this, the ani- mal died. These experiments clearly exhibit the importance of the functions executed by the skin. Dr. Carpenter3 thinks they place in a very striking point of view the importance of the cuta- neous surface as a respiratory organ, and enable us to understand how, when the aerating power of the lungs is nearly destroyed by disease, the heat of the body is kept up to its natural standard by the action of the skin. " A valuable therapeutic indication, also," he adds, " is derivable from the knowledge which we thus gain of the importance of the cutaneous respiration; for it leads us to perceive the desirableness of keeping the skin moist in those febrile diseases in which there is great heat and dryness of the surface, since aeration cannot properly take place through a dry mem- brane. Dr. Edwards, in his experiments on the influence of physical agents on life, found, that warm-blooded animals have less power of producing heat, after they have been exposed for some time to an elevated temperature, as in summer,—whilst the opposite effect occurs in winter. He instituted a series of experiments, which consisted in exposing birds to the influence of a freezing mixture, first in February, and afterwards in July and August, and observing in what degree they were cooled by remaining in this situation for equal lengths of time ; the result of which was, that the same kind of animal was cooled six oreight times as much in the summer as in the winter months. This principle he pre- sumes to be of great importance in maintaining the regularity of the temperature at the different seasons; even more so than eva- poration, the effect of which, in this respect, he thinks, has been greatly exaggerated. From several experiments on yellow ham- mers made at different periods in the course of the year, it would result, that the averages of their temperature ranged progressively upwards from the depth of winter to the height of summer, within the limits of five or six degrees of Fahrenheit, and the contrary was observed in the fall of the year. Hence, Dr. Edwards infers, and with every probability, that the temperature of man expe- riences a similar fluctuation.11 When exposed to high atmospheric temperature, the ingenuity of man has to be as much exerted as in the opposite circumstances. The clothing must be duly regulated according to physical princi- » Human Physiology, § 726, Lond. 1842. See, also, Dr. R. Willis, Proceedings of the Royal Society of London, No. 56. b De l'lnfluence des Agens Physiques, p. 489 ; and Hodgkin and Fisher's transla* tion, Lond. 1832. SECRETION. 221 ples,a and perfect quietude be observed, so that undue activity of any of the organs that materially influence the disengagement of animal heat may be prevented. It is only within limits, that this refrigerating action is sufficient. At a certain degree, the transpi- ration is inadequate, the temperature of the animal rises, and death supervenes. CHAPTER VII. SECRETION. We have yet to describe an important and multiple function, which also takes place in the intermediate system — in the very tissue of our organs — and which separates from the blood the various humours of the body. This is the function of secretion, — a term literally signifying separa lion, and which has been applied both to the operation and the product. Thus, the liver is said to separate the bile from the blood by an action of secretion, and the bile is said to be a secretion. The organs that execute the various secretory operations differ greatly from each other. They have, however, been grouped by anatomists into three classes, each of which will require a general notice. 1. ANATOMY OF THE SECRETORY APPARATUS. The secretory organs have been divided into the exhalant, the follicular, and the glandular. The remarks made respecting the exhalant vessels, under the head of nutrition, will render it unnecessary to allude, in this place, to any of the apocryphal descriptions of them, especially as their very existence is supposititious. Many, indeed, imagine them to be nothing more than the minute radicles of ordinary arteries. The follicle or crypt has the form of an ampulla or vesicle, and is situate in the substance of the skin and mucous membranes; secreting a fluid for the purpose of lubricating those parts. In the exhalant vessel, the secreted fluid passes immediately from the bloodvessel, without being received into any excretory duct; and, in the follicle, there is essentially no duct specially destined for the excretion of the humour. The follicle is membranous and vascu- lar, having an internal cavity into which the secretion is poured ; and the product is excreted upon the surface beneath which it is situate, either by a central aperture, or by a very short duct — if duct it can be called — generally termed a lacuna. The gland is of a more complex structure than the last. It con- sists of an artery which conveys blood to it; of an intermediate » See the chapter on Clothing in the author's " Elements of Hygiene," p. 388, Philad. 1835. 19* 222 SECRETION. body, — the gland, properly so called, — and of an excretory duct to carry off the secreted fluid, and to pour it on the surface of the skin or mucous membrane. The bloodvessel, that conveys to the gland the material from which the secretion has to be effected, Fig. 184. Secreting Arteries, and Nerves of the Intestines. « a. A portion of the intestine. 6 6. Part of the aorta, ccc. Nerves following the branches of the aorta to supply the intestine. enters the organ, at times, by various branches ; at others, by a single trunk, and ramifies in the tissue of the gland ; communica- ting at its extremities with the origins of the veins and of the ex- cretory ducts. These ducts arise by fine radicles at the part where the arterial ramifications terminate ; and they unite to form larger and less numerous canals, until they terminate in one large duct, as in the pancreas; or in several, as in the lachrymal gland ; the duct generally leaving the gland at the part where the bloodvessel enters. Of this we have a good exemplification in the kidney. The pavement and the cylinder epithelium, as weU as all the intermediate forms, are met with in the different glands. These are not necessarily a continuation of that of the cutaneous system ; on the contrary, the epithelium of the latter is often seen changing its form at its entrance into the gland.a Besides the vessels above mentioned, veins exist, which com- municate with the vessels that convey blood to the gland, both for the formation of the humour and the nutrition of the organ, and which return the residuary blood to the heart. Lymphatic vessels are likewise there ; and nerves, — which proceed from the gan- » Mandl, Manuel d'Anatomie generale, p. 450, Paris, 1843. SECRETORY APPARATUS. 223 glionic system, — form a network around the secreting arteries, as in Fig. 184, accompany them into the interior of the organ, and terminate, like them, invisibly. Bordeua was of opinion, that the glands, judging from the parotid, are largely supplied with nerves. The nerves, however, do not all belong to it, some merely crossing it in their course to other parts. Bichat,b from the small number sent to the liver, was in- duced to draw opposite conclusions to those of Bordeu. These may be looked upon as the great components of the glan- dular structure. They are bound together by cellular membrane, and have generally an outer envelope. The intimate texture of * these organs has been a topic of much speculation. It is generally considered, that the final ramifications of the arterial vessels, with the radicles of the veins and excretory ducts, and the final ramifications of the lymphatic vessels and nerves, form so many small lobules, composed of minute, granular masses. Such, in- deed, is the appearance the texture presents, when examined by the naked eye. Each lobule is conceived to contain a final rami- fication of the vessel or vessels that convey blood to the organ, a nerve, a vein, a lymphatic, and an excretory duct,— with cellular tissue binding them together. When the organ has an external membrane, it usually forms a sheath to the various vessels. The lobated structure is not equally apparent in all the glands. It is well seen in the pancreas, and in the salivary and lachrymal. The precise mode in which the bloodvessel, from the blood of which the secretion is effected, communicates with the excretory duct, does not admit of detection. Some have supposed, that between the termination of the bloodvessel and the commencement of the duct, a secretory vessel, or a spongy tissue specially charged with the function, exists, which conveys the secreted humour into the excre- tory duct. Of this, however, we have no evidence. Professor Mullerc maintains, that the glandular structure consists essentially of a duct with a blind extremity, on whose parietes plexuses of bloodvessels ramify, from which the secretions are immediately produced, — a view which is confirmed by the pathological appear- ances, in a case of disease of the portal system, that fell under the author's observation, and is referred to under the Secretion of Bile. The opinion of Malpighid was similar. He affirmed that such glands as the liver are composed of very minute bodies, called acini, from their resemblance to the stones of grapes ; that these acini are hollow internally, and are covered externally by a net- work of bloodvessels; and that these minute bloodvessels pour into the cavities of the acini the secreted fluid, from which it is » Sur les Glandes in CEuvres Completes, par M. Richerand, Paris, 1818. b Anat. General, torn. ii. e De Glandular. Secernent. Structura Penitiori, &c, Lips. 1830; or the English Edit, by Mr. Solly, Lond. 1839. * Opera Omnia, &c, p. 300, Lugd. Batav. 1687. 224 SECRETION. subsequently taken up by the excretory ducts. Ruysch,8 however, held, that the acini of Malpighi are merely convoluted vessels, and that they are continuous with the excretory ducts. In Mal- pighi's view, the secretory organ is a mere collection of follicles; in Ruysch's, simply an exhalant membrane variously convoluted. " The chief, if not the only difference," says a popular writer,b "between the secreting structure of glands and that of simple sur- faces, appears to consist in the different number and the different arrangement of their capillary vessels. The actual secreting organ is in both cases the same,—capillary bloodvessel; and it is un- certain whether either its peculiar arrangement, or greater extent in glandular texture, be productive of any other effect than that of furnishing the largest quantity of bloodvessels within the smallest space. Thus convoluted and packed up, secreting organ may be procured to any amount that may be required, without the incon- venience of bulk and weight."0 It is manifest then, that the simplest form of the secretory appa- ratus is this simple capillary vessel; and that the follicles and glands are structures of a more complex organization. 2. PHYSIOLOGY OP SECRETION. The uncertainty which rests upon the intimate structure of se- creting organs, and upon the mode in which the different blood- vessels communicate with the commencement of the excretory duct, envelopes the function, executed by those parts, in obscurity. Wfe see the pancreatic artery pass to the pancreas, ramify in its tissue, become capillary, and escape detection ; and we see other vessels becoming larger and larger, and emptying themselves into vessels of greater magnitude, until, ultimately, all the secreted humour is contained in one large duct, which passes onwards and discharges its fluid into the small intestine. Yet if we follow the pancreatic artery as far back as the eye can carry us, even when aided by glasses of considerable magnifying power, or if we trace back the pancreatic duct as far as practicable, we find, in the former vessel, always arterial blood, and in the latter, always pan- creatic juice. It must, consequently, be between the part at which the artery ceases to be visible, and at which the pancreatic duct becomes so, that secretion is effected; and we cut the knot by asserting, that it occurs in the very tissue, parenchyma, or in the capillary system of the secretory organ. Conjecture, in the ab- sence of positive knowledge, has been busy, at all times, in at- tempting to explain the mysterious agency by which we find such various humours separated from the same fluid; and, ac- cording as chemical, or mechanical, or exclusively vital doctrines » Epist. Anatom. qua Respondet Viro Clarissimo Hermann. Boerhaav. p. 45. Lugd. Batav. 1722. y b Dr. Southwood Smith, in Animal Physiology, p. 115; Library of Useful Know- ledge, Lond. 1829. " See Beclard, in art. Glande, Diet, de Med, x. 256, Paris, 1824 ; and Carpenter, Human Physiology, § 649, London, 1842. PHYSIOLOGY OF SECRETION. 225 have prevailed in physiology, the function has been referred to one or other of those agencies. The general belief, amongst the phy- siologists of the sixteenth and seventeenth centuries, was, that each gland possesses a peculiar kind of fermentation, which assimi- lates to its own nature the blood passing through it. The notion of fermentation was, indeed, applied to most of the vital pheno- mena. It is now totally abandoned owing to its being purely ima- ginary, and inconsistent with all our ideas of the vital operations. When this notion passed away, and the fashion of accounting for physiological phenomena on mechanical principles usurped its place, the opinion prevailed, that the secretions are effected through the glands as through filters. To admit of this mechanical result, it was maintained, that all the secreted fluids exist ready formed in the blood, and that, when they respectively arrive at the differ- ent secretory organs, they pass through, and are received by the excretory ducts. Descartes3 and Leibnitzb were warm supporters of this mechanical doctrine, although their views differed mate- rially with regard to the precise nature of the operation. Descartes supposed, that the particles of the various humours are of different shapes, and that the pores of the glands have respectively a cor- responding figure ; so that each gland permits those particles only to pass through it which have the shape of its pores. Leibnitz, on the other hand, likened the glands to filters, which had their pores saturated with their own peculiar substance, so that they admitted this substance to pass through them, and excluded all others, — as paper, saturated with oil, will prevent the filtration of water. The mechanical doctrine of secretion was taught by Malpighi and by Boerhaave,c and it continued to prevail even till the time of Haller. All the secretions were conceived to be ready formed in the blood, and the glands were looked upon as the sieves or strainers to convey off the appropriate fluids or humours. In this view of the subject, all secretion was a transudation through the coats of the vessels, — particles of various sizes passing through pores "adapted to them.d The mechanical doctrine of transudation, in this shape, is found- ed upon supposititious data; and the whole facts and arguments are so manifestly defective, that no refutation is necessary. It is now, indeed, wholly abandoned. MM. Magendie and Fodera have, however, revived the mechanical doctrine of late years, but under an essentally different form ; and one applicable especially to the exhalations. The former gentleman,e believing that many of the exhalations exist ready formed in the blood, thinks, that the character of the exhaled fluid is dependent upon the physical arrangement of the small vessels, and his views repose upon the following experiments. If, in the dead body, we inject warm » Tractatus de Homine, p. 18, Amstel. 1677. b Haller, Element. Physiol, vii. 3. *• Praelectiones Academics, &c. edit. A. Haller, § 253, Gotting. 1740-1743. d Mascagni, Nova per Poros Inorganicos Secretionem Theoria. Rom. 1793, torn. ii. e Precis, &c. edit. cit. ii. 444. 226 SECRETION. water into an artery passing to a serous membrane, as soon as the current is established from the artery to the vein, a multitude of minute drops may be observed oozing through the membrane, which speedily evaporate. If, again, a solution of gelatin,coloured with vermilion, be injected into all the vessels, it will often hap- pen, that the gelatin is deposited around the cerebral convolu- tions, and in the anfractuosities, without the colouring matter escaping from the vessels, whilst the latter is spread over the exter- nal and internal surface of the choroid. If, again, linseed oil, also coloured with vermilion, form the matter of the injection, the oil, devoid of colouring matter, is deposited in the articulations, that are furnished with large synovial capsules, no transudation takes place at the surface of the brain, or in the interior of the eye. Magendie asks, if these be not instances of true secretion taking place post-mortem, and evidently dependent upon the physical arrangement of the small vessels ; and whether it be not extremely probable, that the same arrangement must, in part at least, preside over exhalation during life ? Fodera,a to whose experiments on the imbibition of tissues we had occasion to allude under the head of absorption, embraces the views of Magendie. If the vessels of a dead body, he remarks, be injected, the sub- stance of the injection is seen oozing through the vessels; and if an artery and a vein be exposed in a living animal, a similar oozing through the parietes is observable. This is more manifest if the trunk, whence the artery originates, be tied,— the fluid being occasionally bloody. If the jugular veins be tied, not only does oedema occur in the parts above the ligatures,.but there is an increase of the salivary secretion. It is not necessary to adduce the various experiments of Fodera, relating to this topic, or those of Harlan, Lawrence and Coates, or of Dutrochet, Faust, Mitchell, and others. They are of precisely the same character as those that we have previously described regarding the imbibition of tis- sues ; and transudation is only imbibition or soaking from within to without: Magendie and Fodera, indeed, conclude, that one pri- mary physical cause of exhalation is the same as that of absorp- tion, — namely, imbibition. Another physical cause, adduced by Magendie, is the pressure experienced by the blood in the circulatory system, which, he con- ceives, contributes powerfully to cause the more aqueous part to pass through the coats of the vessels. If water be forcibly injected, by means of a syringe, into an artery, all the surfaces, to which the vessel is distributed, as well as the larger branches and the trunk itself, exhibit the injected fluid* oozing in greater abundance ac- cording to the force exerted in the injection. He farther remarks, that if water be injected into the veins of an animal, in sufficient quantity to double or treble the natural amount of blood, a con- siderable distension of the circulatory organs is produced ; and, * Magendie's Journal de Physiologie, iii. 35; and Recherches, &c. sur l'Absorption et l'Exhalation, Paris, 1824. r PHYSIOLOGY OF SECRETION. 227 consequently, the pressure, experienced by the circulating fluid, is largely augmented. If any serous membrane be now exa- mined,— as the peritoneum,— a serous fluid is observed issuing rapidly from its surface, which accumulates in the cavity, and pro- duces a true dropsy under the eyes of the experimenter, and, occa- sionally, the colouring part of the blood transudes at the surface of certain organs, as the liver, spleen, &c. Hamberger, again, broached the untenable physical hypothesis, that each secreted humour is deposited in its proper secretory organ, by virtue of its specific gravity.* It is obvious, that all these speculations proceed upon the belief, that the exhalations exist ready formed in the blood; and that, consequently, the act of secretion, so far as concerns them, is one of separation or of secerning, — not of fresh formation. That this is the case with the more aqueous secretions is probable, and not impossible with regard to the rest. Organic chemistry is subject to more difficulties in the way of analysis than inorganic ; and it can be readily understood, that, in a fluid so heterogeneous as the blood, the discovery of any distinct humour may be imprac- ticable. Of course, the elements of every fluid, as well as solid, must be contained in it; and we have already seen, that not merely the inorganic elements, but the organic, or compounds of organization, have been detected by the labours of Chevreul and others. There are, indeed, some singular facts connected with this subject. MM, Prevost and Dumas,b having removed the kidneys in cats and dogs, and afterwards analyzed the blood, found urea in it — the characteristic element of urine. This prin- ciple was contained in greater quantity, the longer the period that had elapsed after the operation ; whilst it could not be detected in the blood, where the kidneys existed. The experiment was soon af- terwards repeated by Vauquelin and Segalasc with the same results. The latter introduced urea into the veins of an animal, whose kid- neys were untouched ; he was unable to detect the principle in the blood; but the urinary secretion was largely augmented after the in- jection. Whence he concludes that urea is an excellent diuretic. More recently, MM. Gmelin and Tiedemann,in association with M. Mitscherlich,d have arrived,experimentally, at the same conclusions as MM. Prevost and Dumas. The existence of urea in the fluid ejected from the stomach of the animal was rendered probable, but there were no traces of it in the faeces or the bile. The animal died the day after the extirpation of the second kidney. They were totally unable to detect either urea, or sugar of milk in the healthy blood of the cow. These circumstances would favour the idea, a See Adelon, Physiologie de 1'Homme, 2de edit. iii. 455, Paris, 1829 ; and Riche- rand, Elemens de Pyysiologie, 13eme edit, par M. Berard aine, p. 176, Bruxelles, 1837. b Annales de Chimie, torn. xxii. and xxxiii. 90. c Magendie, Precis, &c, ii. 478. a Tiedemann und Treviranus, Zeitschrift fur Physiol. B. v. Heft i.; and Brit, and Foreign .Med. Review, p. 592, for April, 1836, 228 SECRETION. that certain of the secretions may be formed in the blood, and may simply require the intervention of a secreting organ to sepa- rate them ;a but the mode in which such separation is effected is entirely inexplicable under the doctrine of simple mechanical filtration or transudation. It is unlike any physical process, which can be imagined. The doctrines of filtration and transuda- tion can apply only to those exhalations, in which the humour has undergone no apparent change ; and it is obviously impossible to specify these, in the imperfect state of our means of analysis. In the ordinary aqueous secretions, simple transudation may embrace the whole process; and, therefore, it is unnecessary to have re- course to any other explanation ; especially after the experiments instituted by Magendie, supported by pathological observations in which there has been partial oedema of the legs, accompanied by more or less complete obliteration of the veins of the infiltrated part, — the vessels being obstructed by fibrinous coagula, or com- pressed by circumjacent tumours. It is obvious, that ascites or dropsy of the lower belly may be frequently occasioned by ob- struction of the portal circulation in the liver, and that in this way, we may account for the frequency with which we find a union of hydropic and hepatic affections in the same individual. The same pathological doctrine, founded on direct observation, has been extended to phlegmatia dolens or swelled leg; an affection occurring in the puerperal state, and which has often been found connected with obstruction in the great veins that convey the blood back from the lower extremity. It may not, consequently, be wide of the truth — if not wholly accurate— to consider the secre- tions, with Dr. Billing,b to be " vital transudations from the capil- laries into the excretory ducts of the glands, by pores invisible to our senses, even when aided by the most perfect optical instru- ments." The generality of physiologists have regarded the more complex secretions — the follicular and the glandular—as the results of chemical action ; and under the view, that these secretions do not exist ready formed in the blood, and that the elements alone are contained in that fluid, it is impossible not to admit that chemical agency must be exerted. In support of the chemical hypothesis, which has appeared under various forms,—some, as Keill,c pre- suming that the secretions are formed in the blood, before they arrive at the place appointed for secretion ; others, that the change is effected in the glands themselves, —the fact of the formation of a number of substances from a very few elements, provided these be united in different proportions, has been adduced. For exam- ple : take the elementary bodies, oxygen and azote. These, in one proportion, form atmospheric air ; in another, nitrous oxide ; in another, nitric oxide ; in a fourth, hyponitrous acid; in a fifth, a Dr. W. Philip, in Lond. Med. Gazette for March 25th, 1837, p. 952. i> First Principles of Medicine, Amer. Edit. p. 55, Philad. 1842. « Tentamina Medico-Physica, iv,; and Haller, Element. Physiolog. &c. vii. 3. THEORIES. 229 nitrous acid ; in a sixth, nitric acid, &c, substances which differ as much as the various secretions differ from each other and from the blood. Many of the compounds of organization likewise ex- hibit by their elementary composition, that but a slight change is necessary, in order that they may be converted into each other. Dr. Prouta has exhibited this close alliance between three sub- stances— urea, lithic acid, and sugar—and has shown.how they may be converted into each other, by the addition or subtraction of single elements of their constituents. Urea is composed of two atoms of hydrogen, and one of carbon, oxygen, and azote re- spectively; by removing one of the atoms of hydrogen and the atom of nitrogen, it is converted into sugar; by adding to it an additional atom of carbon, into lithic acid. Dr. Bostock,b — who is disposed to push the application of chemistry to the explanation of the functions as far as possible,— to aid us in conceiving how a variety of substances may be produced from a single compound, by the intervention of physical causes alone, supposes the case of a quantity of the materials adapted for the vinous fermentation being allowed to flow from a reservoir, through tubes of various diameters, and with various degrees of velocity. " If we were to draw off portions of this, fluid in different parts of its course or from tubes, Which differed in their capacity, we should, in the first instance, obtain a portion of unfermented syrup ; in the next, we should have a fluid in a state of incipient fermentation ; in a third, the complete vinous liquor ; while, in a fourth, we might have acetous acid." Any explanation, however, founded upon this loose analogy, is mani- festly too physical: this Bostock admits, for he subsequently re- marks, that " if we adopt the chemical theory of secretion, we must conceive of it as originating in the vital action of the vessels, which enables them to transmit the blood, or certain parts of it, to the various organs or structures of the body, where it is sub- jected to the action of those reagents, which are necessary to the production of these changes." The admission of such vital agency, in some shape, seems to be indispensable. Attempts have been made to establish secretion as a nervous action ; and numerous arguments and experiments have been brought forward in support of the position. That many of the secretions are affected by the condition of the mind is known to all. The act of crying, in evidence of joy or sorrow ; the aug- mented action of the salivary glands at the sight of pleasant food ; the increased secretion of the kidney during fear or anxiety, and the experimental confirmation, by Mr. Hunter, of the truth of the common assertion — that the she-ass gives milk no longer than the impression of the foal is on her mind ; the skin of her foal, thrown over the back of another, and frequently brought near her, being sufficient to renew the secretion,— sufficiently indicate, that the a Medico-Chirurg. Transact, viii. 540. b Physiol. 3d edit. p. 519, Lond. 1836. VOL. II. — 20 230 SECRETION. organs of secretion can be influenced through the nervous system in the same manner as the functions of nutrition and calorification.11 The discovery of galvanism naturally suggested it as an im- portant agent in the process, — or rather suggested, that the ner- vous fluid strongly resembles it. This conjecture seems to have been first hazarded by Berzelius, and by Sir Everard Home ;b and, about the same time, an experiment was made by Dr. Wollaston,c which he conceived to throw light upon the process. He took a glass tube, two inches high, and three-quarters of an inch in dia- meter ; and closed it at one extremity with a piece of bladder. He then poured into the tube a little water, containing ^th of its weight of muriate of soda, moistened the bladder on the outside, and placed it upon a piece of silver. On curving a zinc wire so that one of its extremities touched the piece of metal, and the other dipped into the liquid to the depth of an inch, the outer sur- face of the bladder immediately indicated the presence of pure soda; so that, under this feeble electric influence, the muriate of soda was decomposed, and the soda, separated from the acid, passed through the bladder. M. Foderad performed a similar ex- periment, and found, that whilst ordinary transudation frequently required an hour before it was evidenced, it was instantaneously exhibited under the galvanic influence. On putting a solution of prussiate of potassa into the bladder of a rabbit, forming a com- munication with the solution by means of a copper wire; and placing on the outside, a cloth soaked in a solution of sulphate of iron, to which an iron wire was attached; he found, by bringing these wires into communication with the galvanic pile, that the bladder or the cloth was suddenly coloured blue, according as the galvanic current set from without to within, or from within to without; — that is, according as the iron wire was made to com- municate with the positive pole, and the copper wire with the ne- gative, or conversely. But it is not necessary that there should be any communication with the galvanic pile. If an animal mem- brane, as a bladder containing iron filings, be immersed in a solu- tion of sulphate of copper, the sulphuric acid will penetrate the membrane to reach the irqn, with which it forms a sulphate, and the metallic copper will be deposited on the lower surface of the membrane ;e the animal membrane in such case, offering no ob- stacle to the action of the ordinary chemical affinities. 1 For several examples of the same kind, see Fletcher's Rudiments of Physiology, part ii. 6, p. 10, Edinb. 1836 ; Burdach, Physiologie, u. s. w. § 522; Dr. A. Combe, on Infancy, Lond. and Philad. 1841 ; and Carpenter, Human Physiology, § 427,428, Lond.1842. b Lectures on Comp. Anat. iii. 16, Lond 1836 ; and v. 154, Lond. 1828. e Philosoph. Mag. xxxiii. 438. * Magendie's Journal de Physiologie, iii. 35 ; and Researches, &c, sur 1'Absorption et l'Exhalation, Paris, 1824. e Dr. Robert E. Rogers, in the American Journal of the Medical Sciences, p. 291, for August, 1836. See, also, the observations of Prof. Mitchell and Dr. Draper, else- where referred to. THEORIES. 231 With some of the chemical physiologists, there has been a dis- position to resolve secretion into a mere play of electric affinities. Thus, M. Donnea affirms, that from the whole cutaneous surface is secreted an acid humour, whilst the digestive tube, except in the stomach, secretes an alkaline mucus; and hence, he infers, that the external acid, and the internal alkaline membranes of the human body represent the two poles of a pile, the electrical effects of which are appreciable by the galvanometer. On placing one of the conductors of the instrument in contact with the mu- cous membrane of the mouth, and the other in contact with the skin, the magnetic needle, he affirms, deviated fifteen, twenty, and even thirty degrees, according to its sensibility ; and its direction indicated, that the mucous or alkaline membrane took negative, and the cutaneous membrane, positive electricity. He further asserts, that, between the acid stomach and the alkaline liver, ex- tremely powerful electrical currents are formed. These experi- ments do not, however, aid us materially in our solution of the phenomena of secretion. They exhibit merely electric pheno- mena dependent upon difference of chemical composition. This is, indeed, corroborated by the experiments of M. Donne himself on the secretions of vegetables. He observed electrical pheno- mena of the same kind in them, but, he says, electric currents in vegetables are not produced by the acid or alkaline conditions of the parts as in animals, the juice of fruits being always more or less acid. Experiments of M. Biot, however, show, that the juices, which arrive by the pedicle, are modified in some part of the fruit, and M. Donn6 thinks it is perhaps to this difference in the chemical composition of the juices of the two extremities, that the electrical phenomena are to be attributed. The effects of the section of the pneumogastric nerves on the functions of digestion and respiration have been given elsewhere, at some length. It was there stated, that when digestion was suspended by their division, Dr. Wilson Philipb was led to ascribe the suspension to the secretion of the gastric juice having been arrested; an opinion, which Sir B. Brodie had been induced to form previously, from the results of experiments, which showed, that the secretion of urine is suspended by the removal or destruction of the brain ; and that when an animal is destroyed by arsenic, after the division of the pneumogastric nerves, all the usual symptoms are produced, except the peculiar secietion from the stomach. Sir B. Brodie did not draw the conclusion, that the nervous influence is absolutely necessary to secretion, but that it is a step in the process, and the experiments of Magendie0 on the effect of the division of the nerve of the fifth pair on the nutritive secretion of the cornea, confirm the position. We have, indeed, numerous evidences, that the nervous system cannot be indispensable to secretion. In all ani- mals, this power must exist, yet there are some in which no ner- vous system is apparent. Dr. Bostockd has given references, in a * Annates de Chimie, &c. lvii. 400; and Journal Hebdomad., Fev. 1834. * Lond. Med. Gazette for March 18, and March 25, 1837. c Precis, &c. ii. 489. ' Physiology, edit. cit. p. 525, Lond. 1836. 232 SECRETION. note, to cases of monstrous or deformed fcetuses, born with many of their organs fully developed, yet where there was no nervous system. It may be said, however, that, in all these cases, an or- ganic nervous system must have existed ; but setting aside the cases of animals, we have the most indisputable testimony of the existence of secretion in the vegetable, in which there is no nervous system, or, at the most, a rudimental one ; yet the function is ac- complished as perfectly, and perhaps in as multiple a manner, as in man. It is manifest, therefore, that this is one of the vital ac- tions occurring in the very tissue of organs, of which we have no more knowledge than we have of the capillary actions in general. All that we know is, that in particular organs various humours are secreted from the blood, some of which can be detected in that fluid, others not, but we are ignorant of the precise agency, by which this mysterious process is effected. Recently, the fashionable doctrine of cells has been applied to secretion. We have elsewhere stated the mode in which cells are stated by Mr. Goodsir3 to effect absorption (vol. i., p. 605). Se- cretion, according to him, is accomplished in a similar manner. During the progress of the development and growth of cells formed by the secreting organs, they appropriate certain substances with which they may be in relation ; and when their term of existence is over— which is longer or shorter, in different cases— they dis- charge their contents into the excretory channels. An acinus, ac- cording to Mr. Goodsir, is at first a single nucleated cell. From the nucleus of this cell others are produced. From these, again, others arise in the same manner. The parent cell, however, does not dissolve away, but remains as a covering to the whole mass, and is appended to the extremity of the duct. Its cavity, there- fore, as a consequence of its mode of development, has no commu- nication with the duct. The original parent cell now begins to dissolve away, or to burst into the duct at a period when its con- tents have attained their full maturity, — this period varying in dif- ferent glands, according to a law or laws impressed upon each of them. Mr. Goodsir considers growth and secretion to be identical — the same process under different circumstances. His views are worthy of the attention of the histological inquirer. In cases of vicarious secretion, we have the singular phenomenon of organs assuming an action for which they were not destined. If the secretion from the kidney, for example, be arrested, urine is occasionally found in the ventricles of the brain, and, at other times, a urinous fluid has been discharged by vomiting or by cuta- neous transpiration :b the capillaries of these parts must, conse- quently, have assumed the functions of the kidney, and to this they must have been excited by the presence of urea, or of the elements of the urinary secretion in the blood — a fact, which exhibits the i Transactions of the Royal Society of Edinburgh, 1842. See, also, Brit, and For, Med. Rev. Oct. 1842, p. 566 ; Carpenter, ibid. Jan. 1843, p. 279; and Mandl, Manuei d'Anatomie generate, p. 507, Paris, 1843. <> Haller, Elementa Physiologiae, lib. vii. S. i. § 9. THEORIES. 233 important influence, that the condition of the blood must exert on the secretions,and, indeed,on nutrition in general. It istluis that many of our remedial agents, alkalies, the preparations of iodine, &c. — produce their effects. They first enter the mass of blood, and, by circulating in the capillary system, induce a modification of its functions. There are other cases, again, in which the condi- tion of the blood being natural, the vessels of nutrition may take on morbid action. Of this we have examples in the ossification of organs, which, in the healthy condition, have no osseous con- stituent ; in the deposition of fat in cases of diseased ovaria; and in the altered secretions produced by any source of irritation in a secreting organ. In describing the physiology of the different secretions, one of three arrangements has usually been adopted ; either according to the nature of the secreting organ, the function of the secreted fluid, or its chemical character. The first of these has been fol- lowed by Bichat and by Magendie,a who have adopted the divi- sion into exhaled, follicular and glandular secretions. It is the arrangement followed by Lepelletier, except that he substitutes the term perspiratory for exhaled. According to the second, embraced by Boyer,b Sabatier,c and Adelon,d they are divided into recrementitial secretions, or such as are taken up by internal absorption and re-enter the circulation, and into excrementitial, or such as are evacuated from the body, and constitute the ex- cretions. Some physiologists add a third division — the recre- mento-excrementitial,— in which a part of the humour is ab- sorbed and the remainder ejected. Lastly, the division accord- ing to chemical character, has been followed, with more or less modification, by Plenck,e Richerand/ Blumenbach,s Youngh and Bostock :' the last of whom, one of the most recent writers, has eight classes : — the aqueous, albuminous, mucous, gelatinous, fibrinous, oleaginous, resinous, and saline. To all of these classi- fications cogent objections might be made. The one we shall follow is the anatomical, not because it is the most perfect, but because it is the course that has been usually adopted throughout this work. EXHALATIONS. All the exhalations take place in the areolae and internal cavi- ties of the body, or from the skin and mucous membranes : — hence their division into internal and external. The former are recrementitial, the latter recremento-excrementitial. To the class of internal exhalations belong: 1. The serous exhalation. . Precis de Physiologie, 2de £dit. ii. 343, Paris, 1825. b Anatomie, 2de £dit. i. 8, Paris, 1803. « Traite Complet d'Anatomie, Paris, 1791. Philad. 1833; and Craigie, art. Adipose Tissue, in Cycl. Anat. and Physiol, part i. p. 56, Lond. 1835. t> Recherches Chimiques sur les Corps Gras, &c, Paris, 1823 ; W. T. Brande, art. Fat, Cyclopajd. Afiat, and Physiol. August, 1837, p. 231. c See page 32, vol. i.; and Thomson, Chemistry of Animal Bodies, p. 135, Edinb. 1843. 238 [ SECRETION. the marginal figure at b, b, b, the elain occupying the remainder of the vesicle, except where there is an Fig. 188. unusually small quantity of fat, when a ^^ little aqueous fluid is seen interposed be- /■jL)..................4 tween the elain and the cell-membrane. a.....v^Salifi^ I1 's Pr0Dap'e> tr)at chemical analysis /^^m^^Mj......^ would exhibit the fat to vary in different %__1L If&iJl^ parts of the body, as its sensible properties ^(P'/ are manifestly different. Sir Everard „ „ Home,a on loose analogies and inconclu- Fat vesicles from an emaciated . , j -i i • • subject. sive arguments, has advanced the opinion, ai f• ^uThe cfii-membrane. that it is more than probable, that fat is 6. b. b. The solid portion col- . . . . . r . ' lected as a star-iike mass, with formed in the lower portion of the intes- Kattotniimn?iK«H^S2 tines, and from thence is carried, through and Bowman.) me medium of the circulating blood, to be deposited in almost every part of the body. " When there is a great demand for it, as in youth, for carrying on growth, it is laid immediately under the skin, or-in the neighbourhood of the abdomen. When not likely to be wanted, as in old age, it is deposited in the interstices of muscular fibres, to make up in bulk for the wasting of these organs." M. de Blainvilleb is of opinion, that fat is derived from venous blood, and that it is exhaled through the coats of the vessels. This opinion he founds on the mode in which the fat is distributed in the omenta along the course of the vein; and he affirms, that he has seen it flow out of the jugular vein in a dead elephant. But this last fact, as Lepelletierc has judiciously remarked, proves nothing more than that the fat — taken up by the absorbents, from the vesicles, in which it had been deposited by the exhalants — had been conveyed into the venous blood with other absorbed matters. It in no wise shows, that the venous blood is the pabulum of the secretion, or that the veins accomplish it. The uses of the fat are both general and local. The great gene- ral use is, by some physiologists, conceived to be, — to serve as a provision in cases of wasting indisposition ; when the digestive- function is incapacitated for performing its due office, and emacia- tion is the consequence. In favour of this view, the rapidity with which fat disappears after slight abstinence has been urged, as well as the facts, connected with the torpidity of animals, which are always found To diminish in weight during this state. Professor Mangili, of Pavia, procured two marmots from the Alps, on the 1st of December. The larger weighed 25 Milanese ounces; the smaller only 22gth; on the 3d of January, the larger had lost |ths of an ounce, and the smaller f£ths. On the 5th of February, the larger weighed only 22|; the smaller 21. Dr. Monro kept a hedgehog from the month of November to the month of March » Lect, on Comp. Anat. i, 468, Lond. 1814, and vol. vi., Lond. 1828 ; and Philos. Transact. 1821, p. 34. *> De l'Organisation des Animaux, dec, Paris, 1825. « Physiologie Medicale et Philosophique, ii. 496, Paris, 1832. EXHALATIONS -ADIPOUS. 239 following, which lost, in the meanwhile, a considerable portion of its weight. On the 25th of December, it weighed 13 ounces and 3 drachms; on the 6th of February, 11 ounces and 7 drachms; and on the Sth of March, 11 ounces and 3 drachms. The loss was 13 grains daily." The local uses of fat are chiefly of a physi- cal character. On the sole of the foot it diminishes the effects of pressure, and its use is the same on the nates : in the orbit, it forms a kind of cushion, on which the eyeball moves with facility ; and when in certain limits it gives that rotundity to the frame, which we are accustomed to regard as symmetry. Dr. Fletcher,1* indeed, considers its principal use to be, to fill up interstices, and thus to give a pleasing contour to the body. In another place, it was ob- served, that fatty substances are bad conductors of caloric; and hence that it may tend to preserve the temperature of the body in cold seasons ; a view which is favoured by the fact, that many of the arctic animals are largely supplied with fat beneath the common integuments; and it has been affirmed, that fat people generally suffer less than lean from the cold of winter. It is obviously impracticable to estimate, accurately, the total quantity of fat in the body. It has been supposed that, in an adult male of moderate size, it forms syh of the whole weight; but it is doubtful whether we ought to regard this as even an approxima- tion ; the data being so inadequate. In some cases of polysarcia or obesity, the bulk of the body has been enormous. The case of a girl is detailed, who weighed 256 pounds, when only four years old.c A man of the name of Bright, at Maiden, England, weighed 728 pounds ; and the celebrated Daniel Lambert, of Leicester, England, weighed 739 pounds a little before his death, which oc- curred in the fortieth year of his age.d The circumference of his body was three yards and four inches ; of his leg one yard and one inch. His coffin was six feet four inches long; four feet four inches wide ; and two feet four inches deep. The public journals of this country* have recorded the death of a Mr. Cornelius, who weighed 720 pounds. Dr. Elliotsonf says he saw a female child, but a year old, who weighed sixty pounds. She had begun to grow fat at the end of the third month. In these cases, the spe- cific gravity of the body may be much less than that of water.s It is said, that some time ago there was a fat lighterman, on the river Thames, " who had fallen overboard repeatedly, without any farther inconvenience than that of a good ducking; since though » Fleming's Philosophy of Zoology, ii. 59, Edinb. 1822. b Rudiments of Physiology, part iii., by Dr. Lewins, p. 71, Edinb. 1837. c Philos. Transact. No. 185. d Good's Study of Medicine, Class vi. Ord. I. Gen. 1. Sp. 1. e Philadelphia Public Ledger, Oct. 4, 1841. f Human Physiology, Lond. 1841, P. i. 301 ; and Fletcher's Rudiments of Physio- logy, Edinburgh, 1835, P. i. p. 123. g For various cases of great obesity, see Choulant, in art. Fettbereitung, in Pierer, op. citat. B. 3. s. 53; A. L. Richter, in Encyclopadisches Wdrterbuch der Medicin- ischen Wissenschaften, Band. i. s. 733, art. Adiposis, Berlin, 1828; and Fletcher's Rudiments of Physiology. 240 SECRETION. he knew nothing whatever of the art of swimming, he always con- tinued to flounder about like a firkin of butter, till he was picked up."a In some of the varieties of the human family we meet with sin- gular adipous deposits. In the Bosjesman female vast masses of fat accumulate on the buttocks, which give them the most extravagant appearance. The projection of the posterior part of the body, in one subject, according to Barrow,b measured five inches and a half from a line touching the spine. " This protuberance," he remarks, "consisted of fat, and when the woman walked, had the most ridi- culous appearance imaginable, every step being accompanied with a quivering and tremulous motion, as if two masses of jelly were attached behind." The " Hottentot Venus," who had several pro- jections, measured more than nineteen inches around the haunches; and the projection of the hips exceeded 6§ inches. Dr. Somerville* found on dissection, that the size of the buttocks arose from a vast mass of fat, interposed between the integuments and muscles, which equalled four fingers'breadth in thickness. It is singular, that, according to the statement of this female, which is corrobo- rated by the testimony of Mr. Barrow, the deposition does not take place till the first pregnancy. Pallasd has described a variety of sheep — the ovissteatopyga or " fat-buttocked," — which is reared in immense flocks by the pastoral tribes of Asia. In it, a large mass of fat covers the nates and occupies the place of the tail. The protuberance is smooth beneath, and resembles a double hemisphere, when viewed behind ; the os coccygis or rump-bone being perceptible to the touch in the notch between the two. They consist merely of fat; and, when very large, shake in walking like the buttocks of the female Bosjesman. Mr. Lawrencee remarks, that there are herds of sheep in Persia, Syria, Palestine and some parts of Africa, in which the tail is not wanting as in the ovis steatopyga, but retains its usual length, and becomes loaded with fat. In the view of Liebig/ the abnormous condition, which causes the deposition of fat in the animal body, depends on a dispropor- tion between the quantity of carbon in the food, and that of the oxygen absorbed by the skin and lungs. In the normal condition, the quantity of carbon given out is exactly equal to that which is taken in the food, and the body experiences no increase of weight from the accumulation of substances containing much carbon and no azote ; but if the supply of highly carbonized food be increased, then the normal state can only be preserved, by exercise and labour, through which the waste of the body is increased, and the supply of oxygen accumulated in the same proportion. The pro- duction of fat, Liebig maintains, is always a consequence of a 1 Fletcher, op. citat. p. 71. b Travels, p. 281. c Medico-Chirurgical Transactions, vii. 157. d Spicilegia Zoologica, fasc. xi. p. 63. e Lectures on Physiology, Zoology, &c. p. 427, Lond. 1819. f Animal Chemistry, Webster's edit. p. 85, Cambridge, Mass., 1842. EXHALATIONS — MARROW. 241 deficient supply of oxygen, for oxygen is absolutely indispensable for the dissipation of the excess of carbon in the food. " This ex- cess of carbon, deposited in the form of fat, is never seen in the Bedouin or in the Arab of the desert, who exhibits with pride to the traveller his lean, muscular, sinewy limbs, altogether free from fat; but in prisons and jails it appears as a puffiness in the inmates, fed, as they are, on a poor and scanty diet: it appears in the se- dentary females of oriental countries; and finally it is produced under the well known conditions of the fattening of domestic ani- mals." In accordance, too, with his views of animal heat, already referred to, Liebig considers that in the formation of fat there is a new source of heat. The oxygen set free in the action is given out in combination with carbon and hydrogen ; and whether this carbon and hydrogen proceed from the substance that yields the oxygen, or from other compounds, still there must have been generated by this formation of carbonic acid or water, as much heat as if an equal weight of carbon or hydrogen had been burned in air or in oxygen gas. Whether the view of Liebig be admitted or not — it is certain that the circumstances, which favour obesity, are ab- sence of activity and of excitement of all kinds; hence, for the purpose of fattening animals in rural economy, they are kept in entire darkness, to deprive them of the stimulus of light, and to favour sleep and muscular inactivity. Castration — by abolishing one kind of excitability —and the time of life at which the gene- rative functions cease to be exerted, especially in the female, are favourable to the same result. d. Exhalation of the Marroiv. A fluid, essentially resembling fat, is found in the cavity of long bones,in the spongy tissue of short bones, and in the areolae of bones of every kind. This is the marrow. The secretory organ is the very delicate membrane which is perceptible in the interior of the long bones, lining the medullary cavity, and sending prolongations into the compact substance, and others internally, which form septa and spaces for the reception of the marrow. The cells, thus formed, are distinct from each other. From the observations of Howship,a it would seem probable, that the oil of bones is deposited in longitu- dinal canals, that pass through the solid substance of the bone, and through which its vessels are transmitted. This oil of bones is the marroiv of the compact structure, the latter term being generally restricted to this secretion when contained in the cavities of long bones ; that which exists in the spongy substance being termed, by some writers, the medullary juice. The medullary membrane, called also the internal periosteum, consists chiefly of bloodvessels ramifying on an extremely delicate cellular tissue, in which nerves may likewise be traced. Berzelius examined marrow obtained from the thigh-bone of an ox, and found it to consist of the following constituents : — pure • Medico-Chirurg. Trans, vii. 393. VOL. II. — 21 242 SECRETION. adipous matter, 96 ; skins and bloodvessels, 1; albumen, gelatin, extractive, peculiar matter, and water, 3.a The marrow is one of the corporeal components, of whose use we can scarcely offer a plausible conjecture. It has been supposed to render the bones less brittle ; but this is not correct, as those of the foetus, which contain little or no marrow, are less brittle than those of the adult; whilst the bones of old persons, in which the medullary cavity is extremely large, are more brittle than those of the adulL It is possible that it may be placed in the cavities of the bones, — which would otherwise be so many vacant spaces,— to serve the general purposes of the fat, when it is required by the system. The other hypotheses, that have been entertained on the subject, are not deserving of notice. e. Synovial Exhalation. Within the articular capsules, and the bursae mucosas, — which have been described under the head of muscular motion, — a fluid is secreted, which is spread over the articular surfaces of the bones, and facilitates their movements. Haversb considered this fluid to be secreted by synovial glands, — for such he conceived the red- dish cellular masses to be, that are found in certain articulations. Haller0 strangely regarded the synovia as the marrow, which had transuded through the spongy extremities of the bones ; but, since the time of Bichat, every anatomist and physiologist has ascribed' it to the exhalant action of the synovial membrane, which strongly resembles the serous membranes in form, structure, and functions, and whose folds constitute the projections, which Havers mistook for glands.d This membrane exists in all the movable articula- tions, and in the channels and sheaths in which the tendons play. The generality of anatomists regard the articular capsules as shut sacs i the membrane being reflected over the incrusting cartilages. Magendie, however, affirms, that he has several times satisfied himself, that the membranes do not pass beyond the circumference of the cartilages. From the inner surface of these membranes the synovia is exhaled, in the same manner as in other serous cavities. Marguerone analyzed the synovia, obtained from the posterior extremity of the ox, and found it to consist of fibrous matter, 11-S6 ; albumen, 4-52 ; chloride of sodium, 1-75 ; soda, 0-71 ; phos- phate of lime, 0-70; and water, 80-46. M. Donnef says it is always alkaline in health; but in certain diseases it sometimes be- comes acid. » Thomson, Chemistry of Animal Bodies, p. 256, Edinburgh, 1843. b De Ossibus, serm iv. c. 1; and Osteologia Nova, Lond. 1691. c Element. Physiol, iv. 11. Beclard, Elements of General Anat. by Togno, p. 140. e Annales de Chimie, xiv. 123; also, Thomson, Chemistry of Animal Bodies, p. 505, Edinburgh, 1843. f Journal Hebdomad. Fevricr, 1834. EXHALATIONS — SKIN. 243 f. Exhalation of the Colouring matter of the Skin and other parts. The nature of the exhalation, which constitutes the colouring matter of the rete mucosum, has already engaged our attention, when treating of the skin, under the Sense of Touch. It is pre- sumed to be exhaled by the vessels of the skin, and to be deposit- ed beneath the cuticle, so as to communicate the colours that cha- racterize the different races. Such are regarded as the secretory organs by most anatomists and physiologists; but Gaultier,3 whose researches into the intimate constitution of the skin have gained him much celebrity, is of opinion, that it is furnished by the bulbs of the hair; and he assigns, as reasons for this belief, that the negro, in whom it is abundant, has short hair; that the female, whose hair is more beautiful and abundant than that of the male, has the fairest skin ; and that when he applied blisters to the skin of the negro, he saw the colouring matter oozing from the bulbs of the hair, and deposited at the surface of the rete mucosum. Breschet, again, describes a particular chromatogenous apparatus, for producing the colouring matter, which is composed of a glan- dular or secreting parenchyma, situate a little below the papillae, and having excretory ducts, which pour the colouring principle on the surface of the true skin. This mingles with the soft and dif- • fluent mucous matter, the admixture producing the "pretended reticular body of Malpighi," and the epidermis or cuticle.b He describes particular organs, or a " blennogenous apparatus," for the secretion of this mucous matter. They consist of a glandular parenchyma, or organ of secretion, in the substance of the true skin; and of excretory ducts, which issue from the latter and de- posit the mucous matter between the papillae. The composition of this pigment cannot be determined with pre- cision, owing to its quantity being too Small to admit of examina- tion. Chlorine deprives it of its black hue, and renders it yellow. A negro, by keeping his foot for some time in water impregnated with this gas, deprived it of its colour, and rendered it nearly white; but, in a few days, the black colour returned with its former intensity. This experiment was made with similar results on the fingers of a negro. Blumenbach0 thought, that the mucous pig- ment was formed chiefly of carbon; and the notion has received favour with many.d The colour appears to be owing to pigment cells, of which the pigmentum nigrum of the eye is wholly composed. They are considered to exhibit, usually, the original form of the cell with little alteration. On the choroid coat of the eye they form a kind of pavement, and have somewhat of a polyhedral shape. In the human skin, they are scattered through the ordinary epidermic * Recherches sur l'Organisation de la Peau de I'Homme, &c, Paris, 1809, and 1811. - b Nouvelles Recherches sur la Structure de la Peau, Paris, 1835. c Instit. Physiol. § 274 ; and Elliotson's translation, 4th edit. Lond. 1828. J Carpenter, op. cit. § 616, 244 SECRETION. cells, and the colour of the skin is determined by that of their con- tents.11 Pigment granules are amongst the most minute structures of the body, being not more than jJSo-Bth part of an inch in their largest diameter, and about one-fourth as much in thick- ness.b The uses of the pigment of the skin — as well as of that which lines the choroid coat of the eye, the posterior surface of the iris, and of the ciliary processes — ase detailed in another place.0 g. Areolar- Exhalation. Under this term, Adelond has included different recrementitial secretions effected within the organs of sense, or in parenchymatous structures, — as the aqueous, crystalline, and vitreous humours of the eye, and the liquor of Cutugno, all of which have already en- gaged attention j the exhalation of a kind of albuminous, reddish, or whitish lymph into the interior of the lymphatic ganglions, and into the organs, called, by Chaussier, glandiform ganglions, and by Beclard, sanguineous ganglions; — namely, the thymus, thyroid, supra-renal capsules, and spleen. We know but little, however, of the fluids formed in these various parts. They have never been analyzed, and their uses are inappreciable. By some physiologists, a fluid is- supposed to be exhaled from the inner coat of the arterial, venous and lymphatic vessels. We are unaware, however, of the nature of this fluid. Its chief rase is presumed to be to lubricate the interior of the vessel, and to pre- vent adhesion between it and the fluid circulating within it. 2. EXTERNAL EXHALATIONS. a. Cutaneous: Exhalation or Transpiration. A transparent fluid is constantly exhaled from the skin, which is generally invisible in consequence of its being converted into* vapour as soon as it reaches the surface; but, at other times, owing to augmentation of the secretion, or to the air being loaded with humidity, it is apparent on the surface of the body. When invisible, it is called the insensible transpiration or perspiration ; when perceptible, sweat* In the state of health, according to Thenard,e this fluid reddens litmus paper; yet the taste is rather saline — resembling that of common salt — than acid. Wagner/ indeed, affirms that it generally shows alkaline reaction ; and at other times does not affect vegetable blues; but the sweat of many parts of the body,— the armpits for example, — is said always to react like an alkali. Allusion has already been made » Carpenter, Human Physiology, § 6.16, Lond. 1842. » Henle; and Paget, in Brit, and For. Med. Hev., July, 1842, p. 2&6. c See, on the subject of the Pigments, Burdach's Physiologie als Erfahrungswissen- achaft, v. 176, Leipz. 1835. & Physiologie de I'Homme, 2de edit. torn. iii. 483, Paris, 1829. e Traite- de Chimie, torn. iii. f Elements of Physiology, by R. Willis, § 204, Lond. 1842. EXHALATIONS — CUTANEOUS. 245 to the views of M. Donne,a who considers, that the external acid, and the internal alkaline membranes of the human body represent the two poles of a pile, the electrical effects of which are appreciable by the gal- vanometer. The smell of the perspi- ration is peculiar, and becomes almost insupportable when concentrated,and especially when subjected to distilla- tion. The fluid is composed, according to Thenard, of much water, a small quantity of acetic acid,chloride of so- dium,and perhapsof potassium, a very little earthy phosphate, a trace of oxide of iron, and an inappreciable quantity of animal matter. Berzeliusb regards it as water, holding in solution the chlorides of potassium and sodium, lactic acid, lactate of soda, and a little animal matter; and Anselmino,c as consisting of a solution of osmazome, chlorides of sodiu m and calcium, acetic acid and an alkaline acetate, salivary matter, sulphates of soda and po- tassa, and calcareous salts, with mu- cus, albumen, sebaceous humour, and gelatin in variable proportions. Raspaild regards the sweat as an acid product of the disorganization of the skin. After evaporation upon a clean glass plate, fragments of epi- dermic cells are generally observed in it, and crystals are left behind, which are those of its contained salts. In a memoir presented to the Acadimie Boy ale des Sciences, of Paris, MM. Breschet and Roussel de Vauzeme have shown, that there ex- ists in the skin an apparatus for the secretion of the sweat, consisting of a glandular parenchyma, which se- cretes the liquid, and of ducts, which pour it on the surface of the body. These ducts are said to be arranged spirally, and to ope?.: very obliquely under the scales of the epidermis. To this appara- • Journal Hebdomad., Fevrier, 1834. ■» Medico-Chir. Trans, iii. 256, and Bostock, ibid. xiv. 424. c Lepelletier, Physiologie Medicale et Philosophique, ii. 452, Paris, 1832. Also, Thomson, Chemistry of Animal Bodies, p. 523, Edinburgh, 1843. ' bladder, c, d. Body and neck of gallbladder, e. Cys- affirms, that he SUCCeeded, lie duct./. Ductus communis choledochus. g,g. Trunk , intrnrLinino- intn thp in. and branches of pancreatic duct. A. termination of by introducing 11110 me 111- ductus communis choledochus and ductus pancreaticus. testinal end of the excretory duct, a small quill, terminat- ing in a phial fixed under the belly of the animal. Magendie,d however, states, that he tried this plan several times, but without success; and he believes it to be impracticable. The plan he adopts is to expose the intestinal orifice of the duct; to wipe, with a fine cloth, the surrounding mucous membrane ; and as soon as a drop of the fluid oozes, to suck it up by means of a pipette or small glass tube. In this way, he collected a few drops, but never sufficient to undertake a satisfactory analysis. Messrs. Tiedemann and Gmeline make an incision into the abdomen; draw out the duodenum, and a part of the pancreas; and, opening the excretory duct, insert a tube into it; and a similar plan was adopted successfully on a horse by MM. Leuret and Lassaigne.f The difficulty, experienced in collecting a due quantity, is a pro- bable cause of some of the discrepancy amongst observers, regard- ■ Recherches sur le Pancreas, ses Fonctions et ses Alterations Organiques, These, Strasbourg, 1830, cited by Mondiere, Archives Generates de Medecine, Mai, 1836. b Precis Elementaire, i. 462 ; J. P. Mondiere, op. cit. e Tract, de Pancreat. Lugd. Bat. 1761; Haller, Elem. Physiol, lib. xxii. t Precis, &c, ii. 462. e Researches, &c, i. 41. * Researches, &c, p. 49. GLANDULAR — OF THE BILE. 265 ing its sensible and chemical properties. Some of the older phy- siologists affirm it to be acidulous and saline ; others assert that it is alkaline.* The majority of those of the present day compare it with the saliva, and affirm it to be inodorous, insipid, viscid, lim- pid, and of a bluish-white colour.b The latest experimenters by no means accord with each other. According to Magendie, it is of a slightly yellowish hue, saline taste, devoid of smell, occasion- ally alkaline, and partly coagulable by heat. MM. Leuret and Lassaigne found that of the horse, — of which they obtained three ounces,— to be alkaline, and composed of 991 parts of water in 1000; of an animal matter, soluble in alcohol; another, soluble in water; traces of albumen and mucus; free soda; chloride of sodium; chloride of potassium, and phosphate of lime. In their view, consequently, the pancreatic juice strongly resembles saliva. MM. Tiedemann and Gmelin succeeded in obtaining upwards of two drachms of the juice in four hours; and, in 100 parts, they found from five to eight of solid. These solid parts consisted of osmazome ; a matter which became red by chlorine ; another ana- logous-to casein, and probably associated with salivary matter; much albumen; a little free acid, probably the acetic ; the acetate, phosphate, and sulphate of soda, with a little potassa; chloride of potassium, and carbonate and phosphate of lime : — so that, ac- cording to these gentlemen, the pancreatic juice differs from the saliva in containing: — a little free acid, whilst the saliva is alka- line; much albumen, and matter resembling casein; but little mucus and salivary matter, and no sulpho-cyanate of potassa." The precise use of the pancreatic juice in digestion — as we have previously seen — is not determined. Brunner1' removed almost the whole pancreas from dogs, and tied and cut away portions of the duct; yet they lived apparently as well as ever. It is not pre- sumable, therefore, that the secretion can be possessed of very im- portant uses. d. Secretion of the Bile. The biliary secretion is, also, a digestive fluid, of which we have spoken in the appropriate place. The mode, however, in which the process is effected, has not yet been investigated. The appa- ratus consists of the liver, which accomplishes the formation of the fluid; the hepatic duct,— the excretory channel, by which the bile is discharged; the gall-bladder, in which a portion of the bile is retained for a time; the cystic duct, — the excretory channel of the gall-bladder ; and the ductus communis choledochus, or 1 Haller, Elem. Physiol, vi. 10 ; and Seiler,in art. Pancreas, Pierer's Anat. Physiol. Real Wbrterb., Band. vi. 100, Altenb. 1825. b Fourcroy and Thomson in their Systems of Chemistry. e Burdach's Physiologie, u. s. w., v. 257, Leipz. 1835; and Thomson, Chemistry of Animal Bodies, p. 403, Edinb. 1843. <• Experimenta nova circa Pancreas, Amstel. 1683 ; and J. T. Mondiere, op. cit., in a Memoire, crowned by the Societe Medicale d'Emulation, of Paris, and entitled " Re- cherches pour servir a I'Histoire Pathologique du Pancreas." VOL. II. — 23 266 SECRETION. Fig. 193. choledoch duct, formed by the union of the hepatic and cystic ducts, and which conveys the bile immediately into the duodenum. The liver, (A, A, Fig. 129, and A, A, Fig. 193,) is the largest gland in the body ; situate in the abdomen beneath the diaphragm, above the stomach, the arch of the colon, and the duodenum; filling the whole of the right hypochondrium, and more or less of the epigastrium, and fixed in its situation by duplicatures of the peritoneum, called ligaments of the liver. The weight of the human liver is generally, in the adult, about three or four pounds. Some make the average about five pounds ;a but this is a large estimate. Of 60 male livers weighed, Dr. John Reidb found the average weight to be 52 oz. \2\ dr.: and of 25 female, 45 oz. 3§ dr. In disease, however, it sometimes weighs twenty or twenty-five pounds; and, at other times, not as many ounces. Its shape is ir- regular, and it is divided into three chief lobes, the right, the left, and the lobulus Spigelii. Its upper con- vex surface touches every where the arch of the diaphragm. The lower concave surface corresponds to the stomach, colon, and right kidney. On the latter surface, two fissures are observable ; — the one passing from before to behind, and lodging the umbilical vein in the foetus — called the horizontal sul- cus or fissure, great fissure ox fossa umbilicalis; the other, cutting the last at right angles, and running from right to left, by which the dif- ferent nerves and vessels proceed to and from the liver, and called the principal fissure, or sulcus trans- versus. The liver itself is composed of the following anatomical elements : Abdominal and Pelvic Viscera. A, A. w.rd.,.n^,r^rii%d?,K™u%dsTL The hepatic artery, a branch of geiii. BetweenBandc.thepoitaofineiivtr.the coeliac, which ramifies minutely D. Ligamentum rotundum. E, F. Gall-Mad- , , ^, , . r ^. J der. G. The pancreas. H. The spleen. l.thrOUgtl the SUDStailCe Of the Orgail. The ribs. K, K. The kidneys. L, L. Renal rpup rnimiter hranrhpq nf thi R.Willis, Lond. and Edinb. Monthly Journ. of Med. Science, Sept. 1841, p. 628. c Adelon, art. Foie, (Physiol.) in Diet, de Med. ix. 193, Paris, 1824; and Physiol . de I'Homme, torn. iii. 505, Paris, 1829. d Encyclograph. des Sciences Medicales, Avril, 1840. 274 SECRETION. In the absence of accurate knowledge, derived from direct ex- periment, physiologists have usually embraced one or the other of these exclusive views. The generality, as we have remarked, assign the function to the vena porta?. Bichat, on the other hand, ascribes it to the hepatic artery. Broussais8 thinks it probable, that the blood of the vena porta? is not foreign to the formation of the bile, since it is confounded with that of the hepatic artery in the parenchyma of the liver; " but to say with the older writers, that the bile cannot be formed but by venous blood, is, in our opinion," he remarks, " to advance too bold a position, since the hepatic arteries send branches to each of the glandular acini, that compose the liver." Magendie likewise concludes, that nothing militates against the idea of both kinds of blood serving in the secretion ; and that it is supported by anatomy; as injections prove, that all the vessels of the liver, — arterial, venous, lympha- tic, and excretory,— communicate with each other. Mr. Kier- nan, as we have seen, considers that the blood of the hepatic artery, after having nourished the liver, is inservient to the secre- tion, but not until it has become venous, and entered the portal veins.b He, — with all those that coincide with him in the anatomi- cal arrangement of these parts — denies that there is any commu- nication between the ducts and the bloodvessels; and he asserts that if injections pass between them, it is owing to the rupture of the coats of the vessels. Experiments on pigeons, by M. Simon,c of Metz, showed, that when the hepatic artery was tied, the secre- tion of bile continued, but that if the veins of the porta and the hepatic veins were tied, no trace of bile was subsequently found in the liver. It would thence appear, that in these animals the secretion of bile takes place, from venous blood; but inferences from the ligature of those vessels have been very discordant. In two cases, in which Mr. Phillips tied the hepatic artery, the secre- tion of bile was uninterrupted: yet the same thing was observed in three other cases, in which the ligature was applied to the trunk of the vena porta?. The view, that ascribes the bile to the hepatic artery, has always appeared to the author the most probable. It has all analogy in its favour. We have no disputed origin as regards the other secretions, excepting recently in the case of the urinary secretion. They all proceed from arterial blood ; and function sufficient, we think, can be assigned to the portal system, without conceiving it to be concerned in the formation of bile. (See vol. i., p. 617.) We have, moreover, pathological cases, which would seem to show that bile can be formedfrom the blood of the hepatic artery. Mr. Abernethyd met with an instance, in which the trunk of the vena 1 Traite de Physiologie, &c, Drs. Bell and La Roche's translation, 3d edit. p. 456, Philad. 1832. See, also, Conwell's Treatise on the Liver, p. 54, London 1835. b Carpenter, Human Physiology, § 662, Lond. 1842. c Edinb. Med. and Surg. Journal, xc. 229 ; and Mayo's Outlines of Human Phvsio logy, 3d edit. p. 130, Lond. 1833. J d Philosoph. Transact, vol. lxxxiii. GLANDULAR —OF THE BILE. 275 portae terminated in the vena cava; yet bile was found in the biliary ducts. A similar case is given by Mr. Lawrence ;a and the present Professor Monrob details a case communicated to him by the late Mr. Wilson, of the Windmill Street School, in which there was reason to suppose, that the greater part of the bile had been derived from the hepatic artery. The patient, a female, thirteen years old, died from the effects of an injury of the head. On dissection, Mr. Wilson found a large swelling at the root of the mesentery, consisting of several absorbent glands in a scrofulous state. Upon cutting into the mass, he accidentally observed a large vein passing directly from it into the vena cava inferior, which, on dissection, proved to be the vena porta?; and on tracing the vessels entering into it, one proved to be the inferior me- senteric vein : and another, which came directly to meet it, from behind the stomach, proved to be a branch of the splenic vein, but somewhat larger, which ran upwards by the side of the vena cava inferior, and entered that vein immediately before it passes behind the liver. Mr. Wilson then traced the branches of the trunk of the vessel corresponding to the vena porta? sufficiently far in the mesentery and mesocolon, to be convinced, that it was the only vessel that returned the blood from the small intestines, and from the caecum and colon of the large intestines. He could trace no vein passing into the liver at the cavity of the porta ; but a small vein descended from the little epiploon, and soon joined one of the larger branches of the splenic vein. The hepatic artery came off in a distinct trunk from the aorta, and ran directly to the liver. It was much larger than usual. The greater size of the hepatic artery, in this case, would favour the idea, that the arterial blood had to execute some office, that ordinarily belongs to the vena portae. Was this the formation of bile ? The case seems, too, to show, that bile can be formed from the blood of the hepatic artery. In Professor Hall's patient, (p. 267,) the vena porta? and its bifurcation were completely filled with encephaloid matter, so that no blood could pass through it to the liver ; the secretion of the bile could not, consequently, be effected through its agency. It has been pre- sumed, however, that in such cases, portal blood might still enter the liver through the extensive anastomoses, which Professor Ret- zius,c of Stockholm, found to exist between the abdominal veins. That gentleman observed, when he tied the vena porta? near the liver, and threw a coloured injection into the portion below the ligature, that branches were filled, some of which, proceeding from the duodenum, terminated in the vena cava ; whilst others, arising from the colon, terminated in the left emnlgent vein. In subse- quent investigations, he observed an extensive plexus of minute veins ramifying in the cellular tissue on the outer surface of the 1 Medico-Chirurgical Transact, iv. 174. b Elements of Anatomy, Edinb. 1825. <-• Ars Berattelse af Setterblad, 1835, s. 9 ; cited in Zeitschrift fur die Gesammte Hetl- kunde, Feb. 1837, s. 251 ; also, Miiller's Handbuch, u. s. w., Baly's translation, p. 185, Lond. 1837. 276 SECRETION. peritoneum, part of which was connected with the vena porta?, whilst the other part terminated in the system of the vena cava. In a successful injection, these veins were seen anastomosing very freely, in the posterior part of the abdomen, with the colic veins, as well as those of the kidneys, pelvis, and even with the vena cava. The arrangement, pointed out by Retzius, accounts for the mode in which the blood of the abdominal venous system reaches ihe cava, when the vena porta? is obliterated from any cause ; and it shows the possibility of portal blood reaching the liver so as to be inservient to the biliary secretion, but does not, we think, ex- hibit its probability. It would seem, then, that the portal system is not absolutely ne- cessary to the formation of bile, inasmuch as it has occasionally been found absent; yet a recent writer" considers it "a most puerile question" to ask whether the secretion can be effected from •venous blood ! "Had not," he adds, " secretion been destined to take place from the blood of the vena portarum, nature would not have been at the pains to distribute it through the liver; the pecu- liar arrangement is already an answer to the question; the end of it is, as I have said, to economise arterial blood." Yet, as before remarked, a sufficient function can be assigned to the portal system without supposing that it has any agency in the secretion of bile. When bile is once secreted in the tissue of the liver, it is received into the minute excretory radicles, whence it proceeds along the ducts until it arrives, from all quarters, at the hepatic duct. A difference of sentiment exists regarding the flow of the bile from the liver and gall-bladder into the duodenum. According to some, it is constantly passing along the choledoch duct; but the quantity is not the same during digestion as at other times. In the inter- vals, a part only of the secreted bile attains the duodenum; the remainder ascends along the cystic duct, and is deposited in the gall-bladder. During digestion, however, not only the whole of the secretion arrives at the duodenum, but all that which had been collected in the interval is evacuated into the intestine. In sup- port of this view it is affirmed, that bile is always met with in the duodenum ; that the gall-bladder always contains more bile when abstinence is prolonged, whilst it is empty immediately after di- gestion. The great difficulties have been, to explain how the bile gets into the gall-bladder, and how it is expelled from that reservoir. In many birds, reptiles, and fishes, the hepatic duct and the cystic duct open separately into the duodenum ; whilst ducts, called hepa- lo-cystic, pass directly from the liver to the gall-bladder. In man, however, the only visible route, by which it can reach that reser- voir, is by the cystic duct, the direction of which is retrograde ; and, consequently, the bile has to ascend against gravity. The spiral » Dr. R. Willis, Lond. and Edinb. Monthly Journal of Med. Science, Sept. 1841, p. 628. See, also, Dr. Bostock, Ibid., May, 1842, p. 403. GLANDULAR —OF THE BILE. 277 « valve of Amussat has been presumed to act like the screw of Archi- medes, and to facilitate the entrance of the refluent bile, but this appears to be imaginary. It is, indeed, impossible to see any ana- logy between the corporeal and the hydraulic instrument. The arrangement of the termination of the choledoch duct in the duo- denum has probably a more positive influence. The embouchure is the narrowest part of the duct, the ratio of its calibre to that of the hepatic duct having been estimated at not more than one to six, and to the calibre of its own duct as one to fifteen. This might render it impracticable for the bile to flow into the duodenum as promptly as it arrives at the embouchure; and, in this way collect- ing in the duct, it might reflow into the gall-bladder. Amussat, indeed, affirms, that this can be demonstrated on the dead body. By injecting water or mercury into the upper part of the hepatic duct, the injected liquid was found to issue both by the aperture into the duodenum, and by the upper aperture of the cystic duct' into the gall-bladder. With regard to the mode in which the gall-bladder empties itself during digestion, it is probably by a contractile action. We have seen, that it has not usually been admitted to possess a muscular coat, but that it is manifestly contractile. The chyme, as it passes into the duodenum, excites the orifice of the choledoch duct; this excitement is propagated along the ducts to the gall-bladder, which contracts ; but according to Amussat, it does not evacuate its con- tents suddenly, for the different planes of the spiral valve are ap- plied against each other, and only permit the flow to take place slowly. This he found was the case, in the subject, when water was injected into the gall-bladder, and pressed out through the cystic duct.a Other physiologists have presumed, that although the bile is secreted in a continuous manner, it only flows into the duode- num at the time of chylification; at other times, the choledoch duct is contracted, so that the bile is compelled to reflow through the cystic duct into the gall-bladder; and it is only when the gall- bladder is filled, that it passes freely into the duodenum. Inde- pendently, however, of other objections to this view, vivisections have shown, that if the orifice of the choledoch duct be exposed, whatever may be the circumstances in which the animal is placed, the bile is seen issuing guttatim at the surface of the intestine. That the flow of bile from the gall-bladder, however, is depend- ent upon the presence of aliment in the intestines, is shown by the fact, that the reservoir is almost always found turgid in those who have died from starvation; the secretion formed at the ordi- nary slow rate having gradually accumulated for want of demand. This fact, it has been properly remarked, is important in juridi- cal inquiries.11 The biliary secretion, which proceeds immediately from the liver, —hence called hepatic bile, differs from that obtained from the gall- * Adelon, Physiol, de I'Homme, iii. 494 ; and art. Foie, op. citat. >> Carpenter, Human Physiology, 4 664, Lond. 1842. VOL. II. — 24 278 SECRETION. » bladder, which is termed cystic bile. The latter possesses greater bitterness, is thicker, of a deeper colour, and is that which has been usually analyzed. It is of a yellowish-green colour, viscid, and slightly bitter. Its chemical properties have been frequently exa- mined ; yet much is still needed, before we can consider the analysis satisfactory. It has been examined by Boerhaave, Verheyen, Bag- livi, Hartmann, Macbride, Ramsay, Gaubius, Cadet, Fourcroy, Maclurg, Thenard, Berzelius, Chevreul, Lenret and Lassaigne, Frommherz and Gugert, Schultz, Vogel, John, Treviranus, Tiede- mann and Gmelin, &c, &c. ThenardV analysis of 1100 parts of human bile is as follows : — water, 1000; albumen, 42 ; resinous matter, 41 ; yellow matter, 2 to 10; free soda, 5 or 6 ; phosphate, chloride of calcium, and sulphate of soda, phosphate of lime, and oxide of iron, 4 or 5. According to Chevallier, it contains also a quantity of picromel, now called bilin. Berzeliusb calls in question the correctness Of Thenard's analysis, and gives the following : — water, 90S-4 ; picromel, 80 ; albumen, 3-0 ; soda, 4-1; phosphate of lime,0-1; common salt, 3-4 ; phosphate of soda, with some lime, 1-0. The results of Dr. Davy's0 analysis of healthy bile were as follows: — water, 86-0; resin of bile, 12-5; albumen, 1-5. Lastly, the experiments of Gmelin, for which he is highly complimented by Berzelius,d although Berzelius considers, that some of the products may have been formed by the reaction of elements upon each other — yielded the following results : — an odorous material, like musk; cholesterin ; oleic acid; margaric acid; cholic acid ; resin of bile ; taurin (gallen-asparagin); picromel ; colouring matter, now called biliverdin; osmazome; a substance, which, when heated, had the odour of urine; a substance resembling birdlime, gleadin; albumen (?); mucus of the gall-bladder; casein, or a similar substance; ptyalin, or a similar matter; bicarbonate of soda; carbonate of ammonia ; acetate of soda ; oleate, margarate, cholate, and phosphate of potassa and soda ; chloride of sodium and phosphate of lime. Cadete considered bile as a soap with a base of soda, mixed with sugar of milk,— a view, which Raspail,f Demarcay,& and others think harmonizes with observed facts. Every other substance met with in the bile, Raspail looks upon as accessary. Lastly, it has been more recently analysed by Mura- * Mem. de la Societe d'Arcueil, i. 38, Paris, 1807. b Med. Chirurgical Transactions, iii. 241. c Monro's Elements of Anatomy, i. 579. d Henle, art. Galle, in Encyclop. Wbrterb. u. s. w., p. 126, and his Allgemein. Anat. u. s, w., or French translation by Jourdan, p. 80, Paris, 1843 ; art. Bile, by Mr. Brande, in Cyclop, of Anat. and Physiol, part iv. 374, Lond. 1835 ; Orfila, art. Bile, in Diet. de Medecine, i. 355, Paris, 1821 ; and Burdach's Physiologie als Erfahrungswissen- schaft, v. 260, Leipz. 1835. e Experiences sur la Bile des Hommes, &c. in Mem. de l'Academ. de Paris, 1767. f Chimie Organique, p. 45), Edinb. 1833. % Annal. der Pharmac. xxvii., cited by Liebig, Animal Chemistry, Webster's edit., p. 305, Cambridge, Mass. See, also, Prout, on Stomach and Renal Diseases, p. 510, 4th edit., Lond. 1843 ; and Thomson, Chemistry of Animal Bodies, p 412, Edinb. 1843. GLANDULAR —OF THE BILE. 279 tori,* who assigns it the following constituents;—water, 832 ; peculiar fatty matter, 5; colouring matter — biliverdin—11; cholesterin combined with soda, 4 ; picromel of Thenard, 94-86 ; extract of flesh (Estratto di came), 2-69 ; mucus, 37 ; soda, 5-14; phosphate of soda, 3-45; phosphate of lime, 3; and chloride of sodium, 1-86. The proportion of solid matter in the bile is usually from 9 to 12 per cent., nearly the whole of which consists of cholesterin and bilin. The cholesterin is almost altogether com- posed of carbon and hydrogen. Bilin contains nitrogen. The specific gravity of bile, at 6° centigrade, according to The- nard, is 1-026. Schultz found that of an ox, after feeding, at 15° to be 1-026 ; of a fasting animal, 1-030. Hepatic and cystic bile do not appear to differ materially from each other, except in the greater concentration of the different ele- ments in the latter. Leuret and Lassaigneb found them to be alike in the dog. Orfila,e however, affirms, that human hepatic bile does not contain picromel. When bile is examined with the microscope, it is seen to contain a few, and but a few, globules of mucus, proceeding, according to Mandl,d from the muciparous glands of the gall-bladder; lamella? of cylinder-epithelium swimming in an amorphous liquid, and small yellowish globules. At times, some crystals of cholesterin are also observed in it. The great uses of the bile have been detailed under the head of digestion. It has been conceived to be a necessary depurative ex- cretion ; separating from the blood matters that would be injurious if retained. This last idea is probable ; but our knowledge of the precise changes, produced in the mass of blood by it, are extremely limited. The view has been ingeniously contended for by MM. Tiedemann and Gmelin,e who regard the function of the liver to be supplementary to that of the lungs — in other words, to remove hydro-carbon from the system. The arguments, adduced in favour of their position, are highly specious, and ingenious. The resin of the bile, they say, abounds most in herbivorous animals, whose food contains a great disproportion of carbon and hydrogen. The pulmonary and biliary apparatuses are in different tribes of ani- mals, and even in different animals of the same species, in a state of antagonism to each other. The size of the liver, and the quan- tity of bile are not in proportion to the quantity of food and fre- quency of eating, but inversely proportionate to the size and perfection of the lungs. Thus, in warm-blooded animals, which have large lungs, and live always in the air, the liver, compared with the body, is proportionally less than in those that live partly » Bulletino Mediche di Bologna, p. 160, Agosto et Settembre, 1836. b Recherches, &c. sur la Digestion, Paris, 1825. « Elem. de Chimie, Paris, 1817. <» Mandl, Manuel d'Anatomie generate, p. 501, Paris, 1843. • Die Verdaung nach Versuch. &c. traduit par Jourdan, Paris, 1827. See, also, Lsfargue, Bullet. Medical du Midi, Fevrier, 1839. 280 SECRETION. in water. The liver is proportionally still larger in reptiles, which have lungs with large cells incapable of rapidly decarbonizing the blood, — and in fishes, which decarbonize the blood but slowly by the gills, and, above all, in molluscous animals, which effect the same change very slowly, either by gills, or by small imperfectly developed lungs. Again, — the quantity of venous blood, sent through the liver, increases as the pulmonary system becomes less perfect. In the mammalia, and in birds, the vena portae is formed by the veins of the stomach, intestines, spleen, and pancreas; in the tortoise, it receives also the veins of the hind legs, pelvis, tail,— and the vena azygos : in serpents, it receives the right renal, and all the intercostal veins; in fishes the renal veins, and those of the tail and genital organs. Moreover, during the hibernation of cer- tain of the mammalia, when respiration is suspended, and no food taken, the secretion of bile goes on. Another argument is deduced from the physiology of the foetus, in which the liver is proportion- ally larger than in the adult, and in which the bile is secreted copi- ously, as appears from the great increase of the meconium during the latter months of utero-gestation. Their last argument is drawn from pathological facts. In pneumonia and phthisis, the secretion of bile, according to their observations, is increased ; in diseases of the heart the liver is enlarged ; and in the morbus ca?ruleus, the liver retains its foetal proportion. In hot climates, too, where, in consequence of the greater rarefaction of the air, respiration is less perfectly effected than in colder, a vicarious decarbonization of the blood is established by an increased flow of bile. That the sepa- ration of the bile from the blood, however, is not an indispensable function, is shown by Dr. Blundell,a who gives the cases of two children that lived for four months, apparently well fed and healthy, and on opening their bodies, it was found that the biliary ducts terminated in a cul-de-sac, and that consequently not a drop of bile had been discharged into the intestines. It is proper to re- mark, however, that azote is given off likewise in the bile, — being one of the constituents of bilin. Admitting, then, that the bile is essentially a depurative secretion, it by no means follows, that this depuration must be effected upon the blood of the hepatic artery. It is more probably exerted upon that of the portal system. The veins of the stomach and small intestines necessarily absorb much heterogeneous matter; this may be separated by the liver, along with other products that might be injurious if they passed into the blood. The recent views of Liebigb on this function, as well as on that of the urinary secretion, are ingenious, and, if not true, are at least plausible. Venous blood, before reaching the heart, passes through the liver; arterial blood through the kidney ; and both these » Stokes, Theory and Practice of Medicine, Dunglison's American Medical Library Edition, p. 104, Philad. 1837. b Animal Chemistry, Webster's edit., p. 57, Cambridge, Mass. 1843, GLANDULAR —OF THE URINE. 281 organs separate from the blood the substances that are incapable of serving for the nutrition of the tissues. The compounds which contain the nitrogen or azote of the transformed tissues are col- lected in the urinary bladder, and, not being inservient to any further use, are expelled from the body. Those, again, which contain the carbon of the transformed tissues, are collected in the gall-bladder, in the form of a compound of soda, the bile, which is miscible with water in every proportion, and which, passing into the duodenum, mixes with the chyme. All those parts of the bile, which, during the digestive process, do not lose their solu- bility, return, during that process, into the circulation in a state of extreme division. The soda of the bile, and the highly carbonized portions, which are not precipitated by a weak acid,-retain the capability of being taken up by the absorbents of the small and large intestines, — a capability which has been directly proved by the administration of enemata containing bile — the whole of the bile having disappeared along with the fluid injected into the rec- tum. Liebig affirms, that the constituents of the bile cannot be recognized in the faeces of carnivorous animals; whence he infers that the whole of the bile has been reabsorbed ; and, he believes, in order that its hydro-carbon may pass off by the lungs. This can scarcely, however, apply to man ; and Liebig admits, that in the herbivora a certain portion of the elements of the bile can be dis- covered in the fa?ces. Certainly, a marked difference is observable in the faeces of a patient whose biliary ducts are obstructed. As to the precise change effected in the bile in order to fit it for being reabsorbed, Liebig leaves us wholly in the dark. His observa- tions on this matter afford room for interesting reflection ; but they can only at present be regarded in the light of suggestions. If the excretion of the bile be prevented from any cause, we know that derangement of health is induced ; but it is probable that its agency in the production of disease is much overrated; and that, as Broussais has suggested, the source of many of the affections termed bilious is in the mucous membrane lining the stomach and intestines; which, owing to the heterogeneous matters constantly brought into contact with it, must be peculiarly liable to be morbidly affected. When irritation exists there, we can easily understand how the secretion from the liver may be consecutively modified ; the excitement spreading directly along the biliary ducts to the secretory organ. e. Secretion of Urine. This is the most extensive secretion accomplished by any of the glandular structures of the body, and is essentially depurative ; its suppression gives rise to formidable evils. The apparatus consists of the kidneys, which secrete the fluid ; the ureters, which convey the urine to the bladder; the bladder itself, which serves as a re- 24* 282 SECRETION. servoir for the urine ; and the urethra, which conveys the urine externally. These will require a distinct consideration. The kidneys are two glands situate in the abdomen; one on each side of the spine, (Fig. 193, K, K,) in the posterior part of the lumbar region. They are without the cavity of the peritoneum, which covers them at the anterior part only, and are situate in the midst of a considerable mass of adipous cellular tissue. The right kidney is nearly an inch lower down than the left, owing to the thick posterior margin of the right lobe of the liver pressing it downwards. Occasionally, there is but one kidney; at other times, three have been met with. They have the form of the haricot or kidney-bean, which has, indeed, been called after them; and are situate vertically — the fissure being turned inwards. If we compare them with the liver, their size is by no means in propor- tion with the extensive secretion effected by them. Their united weight does not amount to more than six or eight ounces. Of 65 male kidneys, weighed by Dr. John Reid,a the average weight was found to be 5 oz. 7 dr. for the right kidney; 5 oz. 11} dr. for the left. Of 28 female kidneys, the right weighed 4 oz. 13 dr.; the left, 5 oz. 2 dr. The left kidney generally weighs more than the right at all ages. They are hard, solid bodies, of a brown colour. The sanguiferous vessels, which convey and return the blood to them, as well as the excretory duct, communicate with the kidney at the fissure. The anatomical constituents of these organs are ; — 1. The renal artery, which arises from the abdominal aorta at a right angle, and, after a short course, enters the kidney, ramifying in its substanee. 2. The excretory ducts, which arise from every part of the tissue, in which the ramifications of the renal artery terminate, and end in the pelvis of the kidney. (Fig. 203.) 3. The renal veins, which receive the superfluous blood, after the urine has been separated from it, and terminate in the renal ox emul- gent vein, which issues at the fissure and opens into the abdominal vena cava. 4. Of lymphatic vessels, ar- ranged in two planes — a super- ficial and a deep-seated, which ter- minate in the lumbar glands. 5. Of nerves, which proceed from the semilunar ganglion, solar plexus, &c, and which surround the renal artery as with a network, following Of cellular membrane, which, as in » Lond. and Edinb. Monthly Journ. of Med. Sciences, April, 1843, p. 323. Fig. 203. Section of a Kidney. Supra-renal Capsule. 1. Supra-renal capsule. 2. Cortical or vas- cular portion. 3,3. Tubular portion. 4,4. Oalices receiving the apices of cones. 5,5,5. Infundibula. 6. Pelvis. 7. Ureter. it in all its ramifications. 6. GLANDULAR —OF THE URINE. 283 Fig. 204. every other organ, binds the parts together. These anatomical elements, by their union, constitute the organ as we find it. When the kidney is divided longitudinally, it is seen to consist of two substances, which differ in their situation, colour, consist- ence, and texture. The one of these, and the more external, is called the cortical or glandular substance. It forms the whole circumference of the kidney; is about two lines in thickness; of less consistence than the other ; of a pale red colour; and receives almost entirely the ramifications of the renal artery. The other and innermost is the tubular, medullary, uriniferous, conoidal, or radiated substance. It is more dense than the other ; less red ; and seems to be formed of numerous minute tubes, which unite in conical bundles of unequal size, and the base of which is turned towards the cortical portion ; the apices forming the papillae or mam miliary processes, and facing the pelvis of the kidney. The papilla? vary in number, from five to eighteen; are of a florid colour; and upon their points or apices are the terminations of the uriniferous tubes large enough to be distinguished by the naked eye. Around the root of each papilla a membranous tube arises called calix or infundibulum : this receives the urine from the papilla, and conveys it into the pelvis of the kidney, which may be regarded as the commencement of the ureter. The cortical part of the kidney is the most vascular; and the plexus formed by the tubuli uriniferi appears to come there in closest relation with the plexus formed by the renal capilla- ries. In the marginal illustrations of the two portions as they appear in the new-born in- fant, A exhibits them of the natural size : a a, are the corpora Malpighiana or Malpighian bodies appearing as points in the cortical sub- stance ; b, is one of the papilla?. These Malpighian bodies are scattered through the plexus formed by the bloodvessels and uriniferous tubes. Each one of these, when examined by a high magnify- ing power, is found to consist of a convoluted mass of minute bloodvessels. In these — it was at one time supposed — the uriniferous tubes ori- ginate ; but the examinations of Muller and Huschke have seemed to show, that they are only capable of injection from the arteries or veins. They are found in the kidneys of most, if not all, of the vertebrata.a In the cortical substance, ac- cording to Wagner,b the tubuli can be traced, al- urinlferi.^wagner.j though with difficulty, winding among the vascular plexuses, or skeins, mostly looped towards the margin of the organ, and running • J. Miiller, Baly's edit, or Bell's Amer.abridgment, p. 435, Philad. 1843 ; Carpenter, Human Physiology, § 667, Lond. 1842. " Elements of Physiology, by R. Willis, § 193, Lond. 1842. Portion of Kidneys of New-born Infants. a. Natural size. b. A small portion of a. magnified, a a. Corpora Malpighiana. b Tubuli 284 SECRETION. into one another, or having blind or coecal extremities; more rarely enlarg- ed and club-shaped as in Fig. 12, and occasionally cleft (Fig. 205). The entire cortical sub- stance, according to Wagner, consists of convolutions of the uriniferous tubes; which present a nearly uniform dia- meter, and,on an average, may be from about the 60th to the 50th of a line. Mr. Goodsir,3 how- ever, without deny- ing the existence of occasional blind ex- tremities of the tu- buli uriniferi, the result probably, he thinks, of arrested development, states that he has never seen the ducts ter- minate in this way. He describes a fibro- cellular or frame- work, which, per- vading every part of the gland, and particularly its cor- tical portion, per- forms the same office in the kidney, which the capsule of Glisson does in the liver, forming a ba- sis of support to the Small Portion of Kidney magnified 60 Diameters. delicate StrUCtlire a. Ccecal extremity of a tubulus ; b b, loops of tubuli; c e, bifurcated °* the gland, COn- tubuli; d ef, tubuli converging towards the papillae; gg s, corpora Hnrtina thp hlnnrl Malpighiana ; h, arterial trunk. UUUtHlg Uie DIOOU- vessels through the organ, and constituting small chambers in the cortical portion in, » Lond. and Edinb. Monthly Journ. of Med. Science, May, 1842. GLANDULAR —OF THE URINE. 285 each of which a single ultimate coil or loop of the uriniferous ducts is lodged. Mr. Goodsir believes, that the urine is formed at first within the epithelium cells of the ducts, and that these burst, dissolve, and throw out their contents, and are succeeded by others, which perform the same functions. The urine of man has not been detected by Mr. Goodsir within the cells, which line the ducts, but he has submitted to the Royal Society of Edinburgh a memoir, already referred to (p. 232), in which he has endeavoured to show, that the urine, bile and milk, as well as the other more important secretions in the lower animals, are formed within the nucleated cells of the ducts themselves; and he is of opinion, that the urine of man is poured at first into the cavities of the nu- cleated cells of the human kidney. More recently, Mr. Bowman" has affirmed, that the kidney is furnished with a true portal sys- tem, and that the urine, like the bile, is secreted —in part at least — from blood, which is traversing at the time a second set of capil- laries. According to him, each of the exceedingly tortuous and convoluted urinary conduits terminates, at its final extremity, by a contracted neck, which leads into a little chamber or cyst, in which is contained the true glandule of Malpighi, which consists of a tuft or coil of capillary bloodvessels, totally naked, that originates in one of the ultimate branches of the renal artery, and terminates in an efferent vessel. Several of these latter form, by their anasto- mosing ramifications, the plexus that surrounds each urinary con- duit and tubule ; the urinary conduits being lined by thick epithe- lium, and their necks furnished with vibratile cilia. All the blood of the renal artery, according to him, — with the exception of a small quantity distributed to the capsule, surrounding fat, and the coats of the larger vessels — enters the capillary tufts of the corpora Malpighiana; thence it passes into the capillary plexus surround- ing the uriniferous tubes, and finally leaves the organ through the branches of the renal vein. Thus, there are in the kidney two perfectly distinct systems of capillary vessels; the first, that inserted into the dilated extremities of the uriniferous tubes, and in immediate connection with the arteries — the Malpighian bodies:—the second, that enveloping the convolutions of the tubes, and communicating directly with the veins. The efferent vessels of the Malpighian bodies,that carry the blood between these two systems, are termed by Mr. Bowman the portal system of the kidney. The views of Mr. Bowman have been embraced by some histologists ;b but they stand in need of further observation. In the quadruped, each kidney is made up of numerous lobes, which are more or less intimately united according to the species. In birds, the kidneys consists of a double row of distinct, but con- nected, glandular bodies, placed on both sides the lumbar vertebra?. The ureter is a membranous duct, which extends from the » Proceedings of the Royal Society, No. Iii. Feb. 3,1842 ; and Philo's. Transactions, ptl 1, p. 57, Lond. 1842. b Aldridge, Dublin Journal of Med. Science, cited in Amer. Journ. of the Medical Sciences, Oct. 1843, p. 445. 286 kidney to the bladder. SECRETION. It is about the size of a goosequill; de- scends through Fig. 206. the lumbar re- gion ; dips into the pelvis by crossing in front of the primitive iliac vessels and the internal iliac; crosses the vas deferens at the back of the blad- der, and, pene- trating that vis- cus obliquely, ter- minates by an orifice, ten or twelve lines be- hind that of the „ „ . . neck of the blad- A side view of Viscera of Male Pelvis tn situ. -, . - 1. Divided surface of os pubis. 2 Divided surface of sacrum. 3. der. At UTSt, it Body of bladder. 4. Its fundus; from apex is seen passing upwards npnotMtoc tnrr» nf the urachus. 5. Base of bladder. 6. Ureter. 7. Neck of bladder. 8, PalletIcUei I WO Ol 8. Pelvic fascia; fibres immediately above 7 are given off from pelvic the COatS Only of fascia and represent anterior ligaments of bladder. 9. Prostate gland. ,, , . 10. Membranous portion of urethra, between two layeft of deep peri- neal fascia. 11. Deep perineal fascia formed of two layers. 12. One of Cowper's glands between two layers of deep perineal fascia, and be- neath membranous portion of urethra. 13. Bulbof corpus spongiosum. 14. Body of corpus spongiosum. 15. Right cms penis. 16. Upper part of first portion of rectum. 17. Recto-vesical fold of peritoneum. 18. Second portion of rectum. 19. Right vesicular seminalis. 20. Vas deferens. 21. Rectum covered with descending layer of pelvic fascia, just as it is making its bend backwards to constitute third portion. 22. A part of levator ani muscle investing lower part of rectum. 23. Ex- ternal sphincter ani. 24. Interval between deep and superficial peri- neal fascia; they are seen to be continuous beneath the figure. — (Wilson.) ters have two coats. The outermost is a dense fibrous membrane ; the inner- most a thin mucous layer, continuous at its lower extremity with the inner coat of the bladder; and at the upper end supposed, by some, to be reflected, over the papillae, and even to pass for some distance into the tubuli uriniferi. The bladder is a musculo-membranoussac, situate in the pelvis ; anterior to the rectum, and behind the pubes. Its superior end is called the upper fundus ; and the lower end, the inferior fundus or bas-fond ; the body being situate between the two. The part where it joins the urethra is the neck. The shape and situation of the organ are influenced by age and by sex. In very young infants, it is cylindroid, and rises up almost wholly into the abdo- men. In the adult female, who has borne many children, it is nearly spherical; has its greatest diameter transverse, and is more capacious than in the male. Like the other hollow viscera, the bladder consists of several coats. 1. The peritoneal coat, which covers only the fundus and back part. Towards the lower por- that viscus; run- ning for the space of an inch be- tween the mu- cous and muscu- lar coats, and then entering the cavity. The ure- GLANDULAR —OF THE URINE. 287 tion the organ is invested by cellular membrane, which takes the place of the peritoneal coat of the fundus. This tissue is very loose, and permits the distension and contraction of the bladder. 2. The muscular coat is very strong ; so much so, that it has been classed amongst the distinct muscles, under the name detrusor urinae. The fibres are pale, and pass in various directions. To- wards the lower part of the bladder, they are particularly strong ; arranged in fasciculi, and form a kind of network of muscles in- closing the bladder. In cases of stricture of the urethra, where much effort is necessary to expel the urine, these fasciculi acquire considerable thickness and strength. 3. The mucous or villous coat is the lining membrane, which is continuous with that of the ureters and urethra, and is generally rugous, in consequence of its being more extensive than the muscular coat without. It is fur- nished with numerous follicles, which secrete a fluid to lubricate it. Towards the neck of the organ, it is thin and white, though reddish in the rest of its extent. A fourth coat, called the cellular, has been reckoned by most anatomists, but it is nothing more than cellular tissue uniting the mucous and muscular coats. The part of the internal surface of the bladder, situate immediately behind and below its neck, and occupying the space between it and the orifices of the ureters, is called the vesicle triangle, trigo- nus Lieutaudi or trigone vesical. The anterior angle of the tri- angle looks into the orifice of the urethra, and is generally so promi- nent, that it has obtained the name uvula vesicae. It is merely a projection of the mucous membrane, dependent upon the subjacent third lobe of the prostate gland, which, in old people, is frequently enlarged, and occasions difficulty in passing the catheter. The neck of the bladder penetrates the prostate gland, but, at its commencement, it is surrounded by loose cellular tissue, containing a very large and abundant plexus of veins. The internal layer of muscular fibres is here transverse; and they cross and intermix with each other, in different directions, forming a close, compact tissue, which has the effect of a particular apparatus for retaining the urine, and has been called the sphincten. Anatomists have not usual'ly esteemed this structure to be distinct from the muscu- lar coat at large; but Sir Charles Bella asserts, that if we begin the dissection by taking off the inner membrane of the bladder from around the orifice of the urethra, a set of fibres will be dis- covered on the lower half of the orifice, which, being carefully dissected will be found to run in a semicircular form around the urethra ' These fibres make a band of about half an inch in breadth, particularly strong on the lower part of the opening ; and having ascended a little above the orifice, on each side, they dis- pose of a portion of their fibres in the substance of the bladder. » Anatomy and Physiol. 5th Amer. Edit., by Dr. Godman, ii. 375, New York, 1829 See, also, on this subject, Dr. Horner, Special Anatomy and Histology, vol. ii., 6th edit., Philad. 1843; and Dr. Goddard, in Wilson s Anatomist's Vade Mecuni, Amer. Edit!, p. 531, Phila'd. 1843. 288 SECRETION. A smaller and somewhat weaker set of fibres will be seen to com- plete their course, surrounding the orifice on the upper part. The arteries of the bladder proceed from various sources, but chiefly from the umbilical and common pudic. The veins return the blood into the internal iliacs, They form a plexus of considerable size upon each side of the bladder, particularly about its neck. The lymphatics accompany the principal veins of the bladder, and, at the under part and sides, pass into the iliac glands. The nerves are from the great sympathetic and sacral. The urethra is the excretory duct of the bladder. It extends, in the male, from the neck of the bladder to the extremity of the gland ; and is from seven to ten inches in length. In the female it is much shorter. The male urethra has several curvatures in the state of flaccidity of the penis; but is straight, or nearly so, if the penis be drawn forwards and upwards, and if the rectum be empty. The first portion of this canal, which traverses the pros- tate gland, is called the prostatic portion. Into it open, — on each side of a caruncle, called the verumontanum, caputgallinaginis or crista urethralis, — the two ejaculatory ducts, those of the prostate, and a little lower, the orifice of Cowper's glands. Between the prostate and the bulb is the membranous part of the urethra, which is eight or ten lines long. The remainder of the canal is called the corpus spongiosum or spongy portion, because sur- rounded by an erectile spongy tissue. It is situate beneath the corpora cavernosa, and passes forward to terminate in the glans ; the structure of which will be considered under Generation. At the commencement of this portion of the urethra is the bulb of the urethra, Fig. 206; the structure of which resembles that of the corpora cavernosa of the penis — to be described hereafter. The dimensions of the canal are various. At the neck of the bladder, it is considerable ; behind the caput gallinaginis it contracts, and immediately enlarges in the forepart of the prostate. The mem- branous portion is narrower; and, in the bulb, the channel en- larges. In the body of the penis, it diminishes successively, till it nearly attains the glans, when it is so much increased in size as to have acquired the name fossa naviculars. At the apex of the glans it terminates by a short vertical slit. Mr. Shawa has de- scribed a set of vessels, immediately on the outside of the internal membrane of the urethra, which, when empty, are very similar, in appearance, to muscular fibres. These vessels, he remarks, form an internal spongy body, which passes down to the membra- nous part of the urethra, and forms even a small bulb there Dr Horner," however, says, that this appeared to him to be rather the cellular membrane connecting the canal of the urethra with the corpus spongiosum. The whole of the urethra is lined by a very vascular and sensible mucous membrane, which is continued from * Manual of Anatomy, ii. 118, Lond. 1822. b Lessons in Practical Anatomy, 3d edit. p. 272, Philad. 1836 ; and Amer Journ of the Medical Sciences, p. 538, for Feb. 1832. GLANDULAR — OF THE URINE. 289 the inner coat of the bladder. It has, apparently, a certain degree of contractility, and therefore, by some anatomists, is conceived to possess muscular fibres. Sir Everard Home, from the results of his microscopical observations, is disposed to be of this opinion. This is, however, so contrary to analogy, that it is probable the fibres may be seated in the tissue surrounding it. The membrane contains numerous follicles, and several lacunae, one or two of which, near the extremity of the penis, are so large as occasionally to obstruct the catheter, and to convey the impression that a stricture exists. The prostate and the glands of Cowper, being more concerned in generation, will be described hereafter. There are certain muscles of the perineum, that are engaged in the expulsion of the urine from the urethra; and some of them in defecation, and in the evacuation of the sperm likewise ; as the ac- celerators urinas or bulbo-urethrales, which propel the urine or semen forward ;a the transversus perinei or ischio-perinealis, which dilates the bulb for the reception of the urine or semen ; the sphincter ani, which draws down the bulb, and thus aids in the ejection of the urine or sperm ; and the levator ani, which surrounds the extremity of the rectum, the neck of the bladder, the membranous portion of the urethra, the prostate gland, and a part of the vesiculse seminales, and assists in the evacuation of the bladder, vesiculae seminales, and prostate. A part of the levator, which arises from the pubis and assists in inclosing the prostate gland, is called by Sbmmering compressor prostatas. Between the membranous part of the urethra, and that portion of the levator ani which arises from the inner side of the symphysis pubis, a red- dish, cellular, and very vascular substance exists, which closely surrounds the canal, has been described by Mr. Wilsonb under the name compressor urethras, and is termed, by some of the French anatomists, muscle de Wilson. By many, however, it is considered to be a part of the levator ani. Amussat asserts, that the membra- nous part of the urethra is formed, externally, of muscular fibres, which are susceptible of energetic contraction, and Magendie0 con- firms his assertion. With regard to the urinary organs of the female : — the kid- neys and ureters have the same situation and structure as those of the male. The bladder, also, holds the same place behind the pubis, but rises higher when distended. It is proportionally larger than that of the male, and is broader from side to side, thus allowing the greater retention to which females are often necessitated. The urethra is much shorter, being only about an inch and a half, or two inches long, and it is straighter than in the male, having only a slight curve downwards between its extre- » For Dr Horner's views on the origin of the aiceleratores urinse, see his Special Anatomy and Histology 6th edit., vol. ii., Philad. 1843. fc Lectures on the Structure and Physiology of the Urinary and Genital Organs, Lond. 1821. c Precis, &c, ii., 472. vol. II. — 25 290 SECRETION. mities, and passing almost horizontally under the symphysis of the pubis. It has no prostate gland, but is furnished, as in the male, with follicles and lacunae, which provide a mucus to lubricate it. In birds in general, and in many reptiles and fishes, the urine, prior to expulsion, is mixed with the excrement in the cloaca. Nothing analogous to the urinary organs has been detected in the lowest classes of animals, although in the dung of the caterpillars of certain insects, traces of urea have been met with. The urine is separated from the blood in the kidneys ; and it has until recently been the universal belief, that it is secreted from arterial blood; Mr. Bowman, however, in accordance with his views on the minute anatomy of the kidney, already given, (p. 285,) has attempted to show, that it is separated from venous blood. His main conclusions are as follows: — First. The epithe- lium, lining the tubes, is the proper organ that secretes the cha- racteristic products of the urine from the blood; and it does this by first assimilating them into its own substance, and afterwards giving them upon its free surface. Secondly. These proper uri- nous products require for their solution a large quantity of water. Thirdly. This water is furnished by the Malpighian tufts of capil- laries, placed at the extremity of the uriniferous tubes; and Fourthly. A farther use of the Malpighian bodies seems to be that of sharing in regulating the amount of water in the body. He thus makes a striking analogy between the liver and kidneys both in structure and function; and expresses his belief,first, that diuretic medi- cines act specially on the Malpighian bodies, and that many sub- stances, especially salts, which, when taken into the system, have a tendency to pass off by the kidneys with rapidity, in reality escape through the Malpighian bodies; secondly, that certain morbid products occasionally found in the urine, such as sugar, al- bumen, and the red particles of the blood, also, in all probability, pass off through this bare system of capillaries. According to Raspail,a the urine is a kind of caput mortuum, ejected into the urinary bladder by those glands. They separate carbon and ni- trogen from the kidneys, in the form of cyanogen, which unites with oxygen to produce cyanic acid ; and this combines with am- monia— itself a compound of nitrogen and hydrogen — to form urea, which is the characteristic element of the urinary secretion ; and they separate and excrete superfluous fluid from the body.b The proofs of this separation are easy and satisfactory; but with regard to the mode in which the operation is effected, we are in the same darkness that hangs over the glandular secretions in general. The transformation must, however, occur in the cortical part of the organ ; for the tubular portion seems to consist only of a collection of excretory ducts ; and, if we cut into it, urine oozes out. The urinary secretion takes place continuously. If a catheter » Chimie Organique, p. 505, Paris 1833. b Carpenter, Human Physiology, § 668, Lond, 1812. GLANDULAR —OF THE URINE. 291 be left in the bladder, the urine drops constantly; and in cases of exstrophia of the bladder — a faulty conformation, in which the organ opens above the pubes, so that a red mucous surface, formed by the inner coat of the bladder, is seen in the hypogastric region, in which two prominences are visible, corresponding to the openings of the ureters—the urine is seen to be constantly passing out at these openings." After the secretion has been effected in the cortical substance, it flows through the tubular portion, and issues guttatim through the apices of the papillae into the pelvis of the kidney, whence it proceeds along the ureter to the bladder. When the uriniferous cones are slightly compressed, the urine issues in greater quantity, but, instead of being limpid, as when it flows naturally, it is thick and troubled. Hence a conclusion has been drawn, that it is really filtered through the hollow fibres of the medullary or tubular portion. If this were the case, what must become of the separated thick portion ? Ought not the tubes to become clogged up with it ? And is it not more probable, that compression, in this case, forces out with the urine some of the blood that is connected with the nutrition of the organ ? The fresh secretion constantly taking place in the kidney causes the urine to flow along the tubuli uriniferi to the pelvis of the organ, whence it proceeds along the ureter, if we are in the erect attitude, by virtue of its gravity ; the fresh fluid, too, continually secreted from the kidney, pushes on that which is before it; and, moreover, there is not improbably some degree of contractile action exerted by the ureters themselves; although, as in the case of the excre- tory ducts in general, such a power has been denied them. These are the chief causes of the progression of the urine into the blad- der, which is aided by the pressure of the abdominal contents and muscles, and, it is supposed, by the pulsation of the renal and iliac arteries ; but the agency of these must be trivial. The orifices of the ureters form the posterior angles of the trigone vesical, and are contracted somewhat below the size of the ducts themselves. They are said, by Sir Charles Bell,b to be furnished with a small fasciculus of muscular fibres, which runs backwards from the orifice of the urethra, immediately behind the lateral mar- gins of the triangle, and, when it contracts, stretches the orifice of the ureter so as to permit the urine to enter the bladder with facility. As the urine enters, it gradually distends the organ until the quantity has attained a certain amount. It cannot reflow by the ureters, on account of the smallness of their orifices and their obliquity ; and as the bladder becomes filled, — owing to the duct passing for some distance between the muscular and mucous coats, — the sides are pressed against each other, so that the cavity is obliterated. (Fig. 207.) As, however, the ureters have a ten- a See note of a case of this kind, by the author, in Amer. Med. Intelligencer, i. 137 ; and another, by Dr. Pancoast, ibid. p. 147, Philad. 1838. t> Anatomy and Physiology, 5th American Edit., by Godman, ii. 381, New York, 1827. 292 SECRETION. Entrance of the Ureter into the Bladder. A. Cavityof the bladder. B. Ureter. C. Vesical orifice of the ureter. dency to lose this obliquity of insertion, in proportion as the blad- der is emptied, the two bands of muscular fibres which run from the back of the prostate gland to the orifices of the ureters, not only assist in emptying the bladder, but, at the same time, pull down the orifices of the ureters, and thus tend to preserve the obliquity.3 Moreover, when we are in the erect attitude, the urine would have to enter the ureters against gravity. These ob- stacles are so effective, that if an injec- tion be thrown forcibly and copiously through the urethra into the bladder, it does not enter the ureters. On the other hand, equally powerful impedi- ments exist to its being discharged through the urethra. The inferior fundus of the bladder is situate lower than the neck; and the sphincter pre- sents a degree of resistance, which re- quires the bladder to contract forcibly on its contents, aided by the abdomi- nal muscles, to overcome it. Magen- die1* considers the contraction of the levatores ani to be the most efficient cause of the retention of the urine ; the fibres which pass around the urethra pressing its sides against each other and thus closing it. The urine accumulates in the bladder until the desire arises to expel it: the number of times that a person in health and in the middle period of life, discharges it in the twenty-four hours, varies; whilst some evacuate the bladder but twice, others may be compelled to do so as many as twelve or fourteen times. Nine times, according to Dr. Thomas Thomsons is a eommon number. The quantity, too, discharged at a time varies. The greatest quantity observed by Dr. Thomson was 25^ cubic inches, or somewhat less than a pint, the most common quantity being from seven to nine cubic inches. During the stay of the urine in the bladder, it is believed to be deprived of some of its more aque- ous portions by absorption, and to become of greater specific gravity, and more coloured ; it is here that those depositions are apt to take place which constitute calculi; although we meet with them in the kidneys and ureters also. As in every excretion, a sensation first arises, in consequence of which the muscles re- quired for the ejection of the secreted matter are called into ac- tion. This sensation arises whenever the urine has accumulated to the necessary extent, or when it possesses irritating qualities, owing to extraneous substances being contained in, or deposited from it; or if the bladder be unusually irritable from any morbid a Sir C. Bell, op. cit., and in Medico-Chirurgical Transactions, vol. iii. b Precis, &c. edit. cit. ii. 473. = British Annals of Medicine, p. 6, Jan. 1837. GLANDULAR—OF THE URINE. 293 cause, the sensation may be repeatedly—nay, almost inces- santly— experienced. The remarks, that have been made on the sensations accompanying the other excretions, are equally appli- cable here. The impression takes place in the bladder ; such impression is conveyed to the brain, which accomplishes the sensation ; and, consecutively, the muscles, concerned in the ex- cretion, are called into action by volition. Physiologists have differed regarding the power of volition over the bladder. Some have affirmed that it is as much under cerebral control as the muscles of locomotion; and they have urged, in support of this view, that the bladder receives spinal nerves, which are voluntary; that it is paralysed in affections of the spinal marrow, like the muscles of the limbs : and that a sensation, which seems destined to arouse the will, is always the precursor of its action. Others again have denied, that the muscular fibres of the bladder are contractile under the will; and they adduce the case of other reservoirs, — the stomach and the rectum, for example,— whose influence in excretion we have seen to be involuntary ; as well as the fact that we no more feel the contraction of the bladder than we do that of the stomach or intestines; and they affirm, that the action of the bladder itself has been confounded with that of the accessory muscles, which are manifestly under the influence of the will, and are important agents in the expulsion of the fluid from the bladder. The views, last expressed, appear to be most accu- rate, and the catenation of phenomena seems to be as follows: — the sensation to expel the urine arises ; the abdominal muscles are thrown into contraction by volition; the viscera are thus pressed down upon the pelvis; the muscular coat of the bladder is, at the same time, stimulated to contraction; the levatores ani and the sphincter fibres are relaxed, so that the resistance of the neck of the organ is diminished, and the urine is forced out through the whole extent of the urethra, being aided in its course, especially towards the termination, by the contractile action of the urethra itself, as well as by the levatores ani and acceleratores urinae mus- cles. These expel the last drops by giving a slight succussion to the organ, and directing it upwards and forwards ; an effect which is aided by shaking the organ to free it from the drops that may exist in the part of the canal near its extremity. The gradually diminishing jet, which we notice, as the bladder is becoming empty, indicates the contraction of the muscular coat of the organ ; whilst the kind of intermittent jet, coincident with voluntary mus- cular exertion, indicates the contraction of the urethral muscles. When we feel the inclination to evacuate the bladder, and do not wish to obey it, the same muscles, — the levatores ani, the accele- ratores urinae, and the fibres around the membranous portion of the urethra and the neck of the bladder, — are thrown into contrac- tion, and resist that of the bladder. Such is the ordinary mechanism of the excretion of urine. The contraction of the bladder is, however, of itself sufficient to expel 25* 294 SECRETION. its contents. Magendie* affirms, that he has frequently seen dogs pass urine when the abdomen was opened, and the bladder re- moved from the influence of the abdominal muscles ; and he far- ther states, that if, in a male dog, the bladder, with the prostate and a small portion of the membranous part of the urethra, be removed from the body, the bladder will contract after a few moments, and project the urine, with an evident jet, until it is en- tirely expelled. Urine — voided in the morning, urina sanguinis, by a person who has eaten heartily, and taken no more fluid than sufficient to allay thirst — is a transparent, limpid fluid, of an amber colour, saline taste, and a peculiar odour. Its specific gravity is estimated by Chossat at from 1-001 to 1-038; by Cruikshank and Wagner,b from 1-005 to 1-033; by Prout, from 1-015 to 1-025; by Gregory, from 1-005 to 1-033 ;c bv Christison,d on the average, 1-024 or 1-025 ; by F. D'Arcet, from 1-001 to 1-060 [?]e by Rayer/ on the average, 1-018 ; and by Dr. Bostock and Martin Solon,e 1-020; by Elliotson,hfrom 1-015 to 1-025; and Dr. Thomson1 found it in an individual, from 50 to 60 years of age and in perfect health, to be, on the average, 1-013; the lowest specific gravity, during ten days, being 1 004 ; and the highest, 1-026. Dr. Thomson has published some tablesJ showing the quantity of urine passed at different times during ten days by the individual in question, and the spe- cific gravity of each portion. These tables do not accord with the opinion generally entertained, that the heaviest urine is voided on rising in the morning. No generalization can, indeed, be made on this subject. The temperature of the urine when recently voided, varied in one case from 92° to 95°. It is slightly acid, for it reddens vegetable blues. " Although at first quite transparent, it deposits an insoluble matter on standing; so that urine, passed at bed-time, is found to have a light cloud floating in it by the following morning. This substance consists, in part, of mucus from the urinary passages; and, in part, of the super-urate of ammonia, which is much more soluble in warm than in cold water. The following table, drawn up by M. Becquerel as far as 1032, and completed from the observations of Dr. Golding Bird,k exhibits, at a single inspection, the amount of solids and water present in 1000 grains of urine of any particular density ; and from the quan- tity of urine passed in twenty-four hours it is easy to calculate how much solid matter the patient is parting with in that period. a Precis, ii. 474. b Elements of Physiology, by R. Willis, § 200, Lond. 1842. c Burdach, Die Physiologie als Erfahrungswissenschaft, v. 271, Leipz. 1835. <* On Granular Degeneration of the Kidneys, p. 34, Edinb. 1839 ; or Dunglison's American Med. Library edit.. Philad. 1839. e L'Experience, No. Iv., Aug. 1838. f Traite des Maladies des Reins, &c, torn, i., Paris, 1839. s De l'Albuminurie, ou Hydropisie Causee par Maladie des Reins, Paris, 1838. h Human Physiology, p. 293, Lond. 1835. British Annals of Medicine, p. 5, Jan. 1837. j Op. citat. p 6. Lond. Med. Gazette, Feb. 10, 1843, p. 678. GLANDULAR —OF THE URINE. 295 Density. Water in 1000 Solids in 1000 r Density. Water in 1000! Solids in 10:)0 grains. grains. grains. grains. 1001 998-35 1-65 1022 963-7 36-3 1002 996-7 3-3 1029 960-4 39-6 1004 993-4 6-6 1026 957-1 42-9 1006 990-1 9-9 1028 953-8 46-2 1003 986-8 13-2 1030 950-5 49-5 1010 983-5 16-5 1032 947-2 52-8 1012 980-2 19-8 1034 943-9 56-1 1014 976-9 23-1 1036 9406 59-4 1016 973-6 264 1038 937-3 62-7 1018 970-3 29-7 1040 934- 66- 1020 967- 33- 1042 930-7 69-3 1044 927-4 72-6 1046 924-1 75-9 The urine is extremely prone to decomposition. When kept for a few days, it acquires a strong smell, which, being sui generis, has been called urinous; and as the decomposition proceeds, the odour becomes extremely disagreeable. The urine, as soon as these changes commence, ceases to have an acid reaction, and the earthy phosphates are deposited. In a short time, a free alkali make's its appearance ; and a large quantity of the carbonate of ammonia is generated. These phenomena are owing to the de- composition of urea, which is almost wholly resolved into carbo- nate of ammonia. Dr. Henrya affirms, that the following substances have been satisfactorily proved to exist in healthy urine, — water, free phos- phoric acid, phosphate of lime, phosphate of magnesia, fluoric acid, uric acid, benzoic acid, lactic acid, urea, gelatin, albumen, lactate of ammonia, sulphate of potassa, sulphate of soda, filiate of lime,chloride of sodium, phosphateofsoda,phosphateof ammonia, sulphur and silex. One of the most elaborate analyses has been given by Berzelius.b He states it to consist —in 1000 parts —of water, 933-00 ; urea, 30-10 ; sulphate of potassa, 3-71 ; sulphate of soda, 3-16 ; phosphate of soda, 2-94 ; chloride of sodium, 4-45 ; phosphate of ammonia, 1-65; muriate of ammonia, 1-50; free lactic acid, lactate of ammonia, animal matter, soluble in alcohol, and urea not separable from the preceding, 17-14; earthy phos- phates, with a trace of filiate of lime, 1-00 ; lithic acid, 1-00 ; mucus of the bladder, 0-32 ; silex, O-03. Dr. Proutc found 100 parts to con- sist of lithic acid, 90-16 ; potassa, 3-45 ; ammonia, 1-70 ; sulphate of potassa, with a trace of chloride of sodium, -95 ; phosphate of lime, carbonate of lime, and magnesia,-80 ; and animal matter, consisting of mucus and a little colouring matter, 2 94.d M. Ras- a Elements of Experimental Chemistry, vol. ii. b Med. Chirurgical Transact, vol. iii.; and Annals of Philos. ii. 423; and Phe Kidneys and Urine, by J. J. Berzelius, translated from the German, by M. H. Boye, ana r. Learning, M.D., p. 97, Philad. 1843. c Annals of Philos. v. 415. See, also, an analysis by Prof. Thomas Thomson, in Records of General Science, ii. 3. n,„onn. d For the appearances presented by the urine under the microscope, see yuevenne, and Vigla, l'Experience, Dec. 1837, Janvier, 1838, & Mars, 1838; Donne, ibid. Janvier, 296 SECRETION. paila thinks it " possible" that uric acid is merely a mixture of or- ganic matter (albumen) with an acid cyanide of mercury ; so that the results of analysis may differ according as the analyzed sub- stances may have been more or less separated from the organic matter. The physical and chemical characters of uric acid, he thinks, accord very well with this hypothesis. The yellowish-red incrustation, deposited on the sides of chamber utensils, is the uric or lithic acid. This is the basis of one of the varieties of calculi. The quantity of \irine, passed in the twenty-four hours, is very variable. Boissier states it at 22 ounces; Hartmann at 28 ; Dr. Robt. Willisb at from 30 to 40; Prout at 32 ; Robinson at 35 ; Von Gorter at 36 ; Keill at 38 : Rye at 39 ; Bostock at 40 ; Sanc- torius at 44 ; Stark at 46 ; Dalton at 48£ ; Haller at 49 ; Christi- son at from 35 to 50 ; Becquerel at about 46 ; Dr. Thomas Thomson at 53 ; and Lining at from 56 to 59 ounces.0 On the ave- rage, it may be estimated perhaps at two pounds and a half; hence the cause of the great size of the renal artery, which, according to the estimate of Haller, conveys to the kidney a sixth or eighth part of the whole blood. Its quantity and character vary accord- ing to age, and, to a certain extent, according to sex. We have already seen, under the head of cutaneous exhalation, how it varies, according to climate and season ; and it is influenced by the serous, pulmonary, and cellular exhalations likewise : one of the almost invariable concomitants of dropsy is diminution of the renal secretion. Its character, too, is modified by the nature of the substances received into the blood. . Rhubarb, turpentine, and asparagus materially alter its physical properties ; whilst certain articles stimulate the kidney to augmented secretion, or are " diuretics." The urine does not appear to be intended for any local func- tion. Its use seems to be restricted to the removal of the elements of the substances, of which it is composed, from the blood ; hence, it is solely depuratory and decomposing. How this decomposition it accomplished we know not. We have already referred to the experiments, performed by MM. Prevost and Dumas, Segalas, Gmelin, Tiedemann and Mitscherlich, in which urea was found in the blood of animals whose kidneys had been extirpated : an in- quiry has consequently arisen — how it exists there? Prior to these experiments, it was universally believed, that its formation is one of the mysterious functions executed in the intimate tissue of the kidney.d It is proper to add, however, that neither Pre- 1838 ; and for some new researches on Human Urine, see Lecanu, Journal de Phar- macie, Nov. and Dec. 1839 ; Dr. G. Bird, op. cit.; Mandl, Manuel d'Anatomie, gene- rale, p. 504, Paris, 1843; and Prout, on the Nature and Treatment of Stomach and Renal Diseases, 4th edit., p. 517, Lond. 1843. a Op. citat. p. 507. t> Urinary Diseases and their Treatment, Bell's Library Edit., p. 14, Philad.' 1839. e Burdach, op. citat. v. 271. See, also, Semeiotique des Urines, ou Traite des Altera- tions de l'Urine dans les Maladies, &c., Paris, 1841; and Thomson, Chemistry of Animal Bodies, p. 459, Edinb. 1843. i Annales de Chimie, xliii. 64, and Raspail's Chimie Organique, p. 506. GLANDULAR—OF THE URINE. 297 vost and Dumas, Tiedemann and Gmelin nor M. Lecanua could detect the smallest trace of this substance in the blood of animals placed under ordinary circumstances. It is, according to Wohler, a cyanateof ammonia,b and contains a very large proportion of azote, so that, it has been imagined, the kidney may possibly be the outlet for an excess of azote, or for preventing its accumulation in the system—in the same manner as the lungs and liver have been regarded as outlets for superfluous carbon. The quantity of azote, discharged in the form of urea, is so great, even in those animals whose food does not essentially contain this efement, that it has been conceived a necessary ingredient in the nutrition of parts, and especially in the formation of fibrin, which, we have seen, is a chief constituent of the blood, and of every muscular organ. The remarks, made on the absorption of azote during respiration, indicate how it is received into the system ; and it has been pre- sumed, that the superfluous portion is thrown off in the form of urea. The experiments of MM. Prevost and Dumas, and of the other physiologists, would certainly favour the conclusion, that urea may exist ready formed in the blood, and that the great function of the kidney may be to separate it along with the other constituents of the urine. Adelonc ascribes the source of the urea to the products of in- terstitial decomposition. He conceives, that, in this shape, they are received into the blood, and that the office of the kidneys is to separate them. All this is necessarily conjectural, and it must be admitted, that our knowledge of the subject is by no means ample, and that we must wait for farther developments. Cer- tain it is, that the removal of the constituents of the urinary secre- tion from the blood is all-important. Experiments on animals have shown, that if it be suppressed by any cause for about three days, death usually supervenes, and the dangers to man are equally imminent. Yet there are some strange cases of protracted suppression on record. Haller mentions a case in which no urine had been secreted for twenty-two weeks, and Dr. Richardsond one of a lad of seventeen, who had never made any and yet felt no inconvenience. a. Connexion between the Stomach and the Kidneys. In consequence of the rapidity with which fluids, received into the stomach, are sometimes voided by the urinary organs, it has been imagined, either that vessels exist, which communicate directly between the stomach and bladder, or that the fluid passes throush the intermediate cellular tissue, or by means of the anastomoses of a Etudes Chimiques sur le Sang Humain, Paris, 1837. b Berzelius, The Kidneys and Urine, translated by M. H. Boye and F. Learning, M.D., p. 73, Philad. 1843; Graham's Elements of Chemistry, Amer. Edit, by Dr. Bridges, p. 671, Philad. 1843; and Thomson, Chemistry of Animal Bodies, p. 77, Edinb. 1843. « Physiologie de I'Homme, torn, iii., Paris, 1829. d Philos. Transact, for 1713; and Elliotson's Blumenbach's Physiology, 4th edit., Lond. 1828. 298 SECRETION. the lymphatics. In support of the opinion, that a more direct passage exists, the assertion of Chirac, — that he saw the urinary bladder become filled with urine, when the ureters were tied, and that he excited urinous vomiting, by tying the renal arteries, — is adduced. It, has been farther affirmed, that the oil, composing a glyster, has been found in the bladder. Darwin,a having admin- istered to a friend a few grains of nitrate of potassa, collected his urine at the expiration of half an hour, and had him bled. The salt was detected in the urine, but not in the blood. Brande made similar experiments with the prussiate of potassa, from which he inferred that the circulation is not the only medium of communi- cation between the stomach and the urinary organs, without, how- ever, indicating the nature of the supposed medium ; and this view is embraced by Sir Everard Home,b Wollaston, Marcet, and others. Lippi,c of Florence, thinks he has found an anatomical explana- tion of the fact. According to him, the chyliferous vessels have not only numerous inosculations with the mesenteric veins, either before their entrance into the mesenteric glands, or whilst they traverse the glands, but, when they attain the last of those glands, some of them proceed to open directly into the renal veins, and into the pelves of the kidneys. At this place, according to him, the chyliferous vessels divide into two sets; the one, ascending, and conveying the chyle into the thoracic duct; the other, descend- ing, and carrying the drinks into the renal veins and pelves of the kidneys, He affirms, that the distinction between these two sets is so marked, that an injection, sent into the former, goes exclu- sively into the thoracic duct, whilst if it be thrown into the latter it passes exclusively to the kidneys. These direct vessels Lippi calls vasa chylopoietica urinifera. If the assertions of Lippi were anatomical facts, it would obviously be difficult to doubt some of the deductions: other anatomists have not, however,been so for- tunate as he ; and, consequently, it may be well to make a few comments. Some of these chylopoietica urinifera, he affirms, open into the renal veins. This arrangement, it is obvious, can- not be invoked to account for the shorter route,— the royal road to the kidney: the renal vessel is conveying the blood back from the kidney, and every thing that reaches it from the intestines, must, necessarily pass into the vena cava, and ultimately attain the kidney through the renal artery. The vessels, therefore, that end in the renal veins, must be put entirely out of the question, so far as regards the topic of dispute; and our attention be concen- trated upon those that terminate in the pelvis of the kidney. Were this termination proved, we should be compelled, as we have re- marked, to bow to authority; but not having been so, it may be a Zoonomia, xxix. 3. i> Philosophical Transactions, xcviii. 51, and ci. 163, for 1808 and 1811 ; and Lec- tures on Comparative Anatomy, i. 221, Lond. 1814; and iii. 138, Lond. 1823. <• Illustrazioni Fisiologiche e Patologice del Sistema Linfatico-Chilifero, &c Firenz 1825. GLANDULAR — OF THE UI1IXE. 299 stated as seemingly improbable, that the ducts in question should take the circuitous course to the pelvis of the kidney, instead of proceeding directly to the bladder. We know then, anatomically, nothing of any canal existing be- tween the stomach and the bladder; and we have not the slightest evidence,— positive or relative, — in favour of the opinion, that there is any transmission of fluid through the intermediate cellular tissue. We have, indeed, absolute testimony against it. MM. Tiedemann and Gmelin, having examined the lymphatics and cel- lular tissue of the abdomen, in cases where they had administered indigo and essence of turpentine to animals, discovered no traces whatever of them, whilst they could be detected in the kidney. The facts, agaiu, referred to by Chirac, are doubtful. ' If the renal arteries be tied, the secretion cannot be effected by the kidney ; yet, as we have seen, in the case of extirpated kidneys, urea may exist in the blood, and, consequently, urinous vomitings be possible. If the ureters be tied, the secretion being practicable, death will occur if the suppression be protracted ; and, in such case, the secreted fluid may pass in the vessels, and readily give a urinous character to the perspiration, vomited matters, &c, &c. The expe- riments of Darwin, Brande, Wollaston, and others only demon- strate, that these gentlemen were unable to detect in the blood that which they found in the urine. Against the negative results attained by these gentlemen, we may adduce the positive testimony of Fodera,a an experimentalist of weight, especially on those mat- ters. He introduced into the bladder of a rabbit a plugged cathe- ter, and tied the penis upon the instrument to prevent the urine from flowing along its sides. He then injected into the stomach a solution of the ferrocyanate of potassa. This being done, he fre- quently removed the plug of the catheter, and received the drops of urine on filtering paper : as soon as indications of the presence of the salt appeared in the urine by the appropriate tests, — which usually required from five to ten minutes after its reception into the stomach, — the animal was killed; and, on examining the blood, the salt was found in the serum taken from the thoracic portion of the vena cava inferior, in the right and left cavities of the heart, in the aorta, the thoracic duct, the mesenteric glands, the kidneys, the joints, and in the mucous membrane of the bron- chia. Magendie,b too, states, as the result of his experiments, — First. That whenever prussiate of potassa is injected into the veins, or is exposed to absorption in the intestinal canal, or in a serous cavity, it speedily passes into the bladder, where it can be readily recognised in the urine. Secondly. That if the quantity of prussiate injected be'considerable, it can be detected in the blood by reagents ; but if the quantity be small, it is impossible to dis- cover it by the ordinary means. Thirdly. That the same thing a Recherches Experimentales sur l'Absorption et l'Exhalation, Paris, 1824. •> Precis, &c. ii 477. 300 SECRETION. happens if the prussiate of potassa be mixed with the blood out of the body. Fourthly. That the salt can be detected, in every proportion, in the urine. We may conclude, therefore, with Dr. Hale,a who has written an interesting paper on this subject, that the existence of any more direct route from the stomach to the bladder than the cir- culatory system and the kidneys is disproved ; and the absorption of fluids must be considered to be effected through the vessels described under the Absorption of Drinks. Such are the glandular secretions, which we shall consider in this place. There are still two important fluids, the sperm and the milk, whose uses will have to be detailed under the next class of functions. GLANDIFORM GANGLIONS. There are several organs, — as the spleen, thyroid, thymus, and supra-renal capsules, — which are termed glands by many anato- mists ; but which Chaussier has termed glandiform ganglions. Of the uses of these we know little or nothing. Yet it is necessary, that the nature of the organs, and their fancied functions should meet with notice. The offices of the thyroid, thymus, and supra- renal capsules, — being chiefly confined to foetal existence, — will not require consideration here. a. The Spleen. The spleen is a viscus of considerable size, situate in the left hypochondriac region, (Fig, 193, H,) beneath the diaphragm, above the left kidney, and to the left of the stomach. Its medium length is about four and a half inches; its thickness two and a half inches; and its weight about eight ounces.b It is of a soft texture, somewhat spongy to the feel, and easily torn. In a very re- cent subject, it is of a greyish-blue colour; which, in a few hours, changes to a purple, so that it resembles a mass of clotted blood. At its inner surface, or that which faces the stomach and kidney, a fissure exists, by which the vessels, nerves, &c, enter or issue from the organ. The anatomical elements of the spleen are : — 1. The splenic artery, which arises from the cceliac, and after having given off branches to the pancreas and the left gastro-epiploic artery, divides into several branches, which enter the spleen at the fissure, and ramify in the tissue of the organ, so that it seems to be exclu- sively formed by them. Whilst the branches of the artery are still in the duplicature of the gastro-splen'ic omentum, and be- fore they ramify in the spleen, they furnish the vasa brevia to the stomach. * The precise mode of termination of the arteries a Boylston Prize Dissertations for the years 1819 and 1821, Boston, 1821 >> Dr. Gross, Elements of Pathological Anatomy, ii. 344, Boston, 1839. SPLEEN. 301 in the spleen is unknown. The communication of the arteries with the veins does not, however, appear to be as free as in other parts of the body, or the anastomoses between the minute arte- ries as numerous. If, according to Assolant,a one of the branches of the splenic artery be tied, the portion of the spleen to which it is distributed dies; and if air be injected into one of these branches, it does not pass into the other; so that the spleen would appear to be a congeries of several distinct lobes; and in certain animals the lobes are so separated as to constitute several spleens. A similar appearance is occasionally seen in the human subject. 2. The splenic vein arises by numerous radicles in the tissue of the spleen: these become gradually larger, and less numerous, and leave the fissure of the spleen by three or four trunks, which ulti- mately, with veins from the stomach and pancreas, unite to form one, that opens into the vena portae. It is without valves, and its parietes are thin. These are the chief constituents. 3. Lympha- tic vessels, which are large and numerous. 4. Nerves, proceeding from the coeliac plexus : they creep along the coats of the splenic artery, — upon which they form an intricate plexus, — into the substance of the spleen. 5. Cellular tissue, which serves as a bond of union between these various parts ; but is in extremely small quantity. 6. A proper membrane, which envelopes the organ externally ; adheres closely to it, and furnishes fibrous sheaths to the ramifications of the artery and vein: keeping the ramifications separated from the tissue of the organ, and sending prolongations into the parenchyma, which gives it more of a reti- culated than spongy' aspect. 7. Of blood, according to many anatomists; but blood differing from that of both the splenic artery and vein; containing, according to Vauquelin, less colouring matter and fibrin, and more albumen and gelatin, than any other kind of blood. This, by stagnating in the organ, is conceived to form an integrant part of it. Malpighib believed it to be contained in cells; but others have supposed it to be situate in a capillary system intermediate to the splenic artery and vein.c Assolant and Meckeld believe, that the blood is in a peculiar state of combination and of intimate union with the other organic elements of the viscus, and with a large quantity of albumen ; and that this combination of the blood forms the dark brown pulpy substance, contained in the cells formed by the proper coat, and which can be easily demonstrated by tearing or cutting the spleen, and scraping it with the handle of a knife. These cells and the character of the tissue of the spleen are exhibited in the marginal » Recherches sur la Rate, Paris, 1801. b Op. Omnia, part ii. Lond. 1687 ; and Op. Posthum. p. 42, Lond. 1697. <: Seiler, in art. Milz, in Pierer's Anat. Physiol. Wbrterbuch, B. v. s. 322, Alten- burg, 1832. i Handbuch, &c, traduit par Jourdan, iii. 476, Paris, 1825. VOL. II. — 26 302 GLANDIFORM GANGLIONS. Fig. 208. Section of the Spleen. figure. (Fig. 208.) In addition to the pulp, there is an abundance of rounded corpuscles, varying in size from an almost imperceptible mag- nitude to a line or more in diame- ter. By Malpighi, these were con- ceived to be granular corpuscles, and, by Ruysch,a simply convoluted vessels. Andralb affirms, that by repeated washings, the spleen is shown to consist of an infinite num- ber of cells, which communicate on the one hand together, and, on the other, directly with the splenic veins. The latter, when the inner surface of the large subdivisions of the splenic veins are examined, ap- pear to have a great number of perforations, through which a probe passes directly into the cells of the organ. The farther the subdivisions of the vein examined are from the trunk, the larger are these perfora- tions, and still farther on, the coats of the vein are not a continued surface, but are split into filaments, which do not differ from those forming the cells, and are continuous with them.c Recently, M. Bourgery has maintained that the fibrous envelope of the spleen sends off a multitude of lamellae, which penetrate into its interior, forming irregular spaces of unequal dimensions. These short spaces he calls splenic vesicles. In the septa, a num- ber of lymphatic glands exists. The capillaries of the arteries com- municate directly with those of the veins ; but, according to M. Bourgery, there are, in addition, veins with patulous orifices. The interior of the vesicles is filled with a soft substance of a deep red colour, in which the small white corpuscles, discovered by Mal- pighi, are suspended. M. Mandld suggests, that the white corpus- cles may be analogous to the intestinal villi, in which the lympha- tics originate by a caecal extremity. Besides the proper mem- brane, the spleen also receives a peritoneal coat; and, between the stomach and the organ, the peritoneum forms the gastro-splenic » Meckel, op. citat. * Precis, d'Anatomie Pathologique, torn. ii. part i. p. 416, Paris, 1832. c See, also, Sir E. Home's Lectures on Comparative Anatomy, iii. 148 ; Dr. Warner on the Distribution of the Splenic Vein, in the spleen of the ox and sheep, in American Journal of the Med. Sciences, Feb. 1836, p. 541 ; and Weber's Hildebrandt's Handbuch der Anatomie, u. s. w., Band iv.s. 328, Braunschweig, 1822 : and on the Minute Struc- ture of tbe Spleen, Bourgery, Gaz. M£d., Juin 11,1842 ; and Brit, and For. Med. Rev. Oct. 1842, p. 541. <• Manuel d'Anatomie generale, p. 518, Paris, 1843. SPLEEN. 303 epiploon or gastro-splenic ligament, in the duplicature of which are situate the vasa brevia. Lastly: the spleen is capable of distension and contraction; and is possessed of little sensibility in the healthy state. It has no excretory duct. The hypotheses, which have been indulged on the nature of the spleen, are beyond measure numerous and visionary; and, after all, we are in the greatest obscurity as to its" real uses. Many of these hypotheses are too idle to merit notice; such are those, that consider it to be the seat of the soul, — the organ of dreaming, — of melancholy and of laughter, — of sleep and the venereal appetite,— the organ that secretes the mucilaginous fluids of the joints, that serves as a warm fomentation to the stomach, and so on. It was long regarded as a secretory apparatus, for the formation of the atrabilis, — of a fluid intended to nourish the nerves, — of the gastric juice, — of a humour intended to temper the alkaline character of the chyle or bile, &c. The absence of an excretory duct would be a sufficient answer to all these specula- tions, if the non-existence of the supposititious humours were in- sufficient to exhibit their absurdity. MM. Tiedemann and Gmelin3 consider its functions to be identical with those of the mesenteric glands. They regard it as a ganglion of the absorbent system, which prepares a fluid to be mixed with the chyle and effect its animalization. In favour of the view, that it is a part of the lymphatic system, they remark, that it exists only in those ani- mals that have a distinct absorbent system; that its bulk is in a ratio with the development of the absorbent system ; that the lymphatics predominate in the structure of the organ; that its texture is like that of the lymphatic ganglions; and lastly, that, on dissecting a turtle, they distinctly saw all the lymphatics of the abdomen passing first to the spleen, then leaving that organ of larger size, and proceeding to the thoracic duct. In support of their second position, that it furnishes some material towards the animalization of the chyle, they adduce ; — the large size of the splenic artery, which manifestly, they conceive, carries more blood to the spleen than is needed for its nutrition; and they affirm, that, in their experiments, they have frequently found, whilst digestion and chylosis were going on,the lymphatic vessels of the spleen gorged with a reddish fluid, which was carried by them into the thoracic duct, where the chyle always has the most rosy hue; and they add, that a substance injected into the splenic artery, passes readily into the lymphatics of the spleen. Lastly, after extirpating the spleen in animals, the chyle appeared to them to be more transparent; no longer depositing coagula; and the lymphatic ganglions of the abdomen seemed to have augmented in size. Views, similar to these, have been maintained by Sir Everard Home.b * Vereuche iiber die Wege auf welchen Substanzen aus dem Magen und Darmkanal ins Blut gelangen, p. 86, Heidelb. 1820. t> Philosoph. Transactions for 1808 and 1811; and Lect. on Comp. Anatomy, loc. cit. 304 GLANDIFORM GANGLIONS. Chaussier, as we have seen, classes the spleen amongst the glandiform ganglions, and affirms, that a fluid is exhaled into its interior, of a serous or sanguineous character, which, when ab- sorbed, assists in lymphosis. Many, again, have believed, that the spleen is a sanguineous, not a lymphatic ganglion, but they have differed regarding the blood on which it exerts its action; some maintaining, that it pre- pares the blood for the secretion of the gastric juice; others, for that of the bile. The former of these views is at once repelled by the fact, that the vessels which pass from the splenic artery to the stomach, leave that vessel before it enters the spleen. The latter has been urged, of late, by M. Voisin.a He thinks, the principal use of the spleen is to furnish to the liver, blood containing those materials that enter into the composition of the bile ; but this view, also, rests on very uncertain data and,deductions. Since the period of Haller, the blood of the splenic vein has been presumed to differ essentially from that of other veins, which has led to the belief, that some elaboration is effected in the spleen so as to fit the blood for the secretion of the bile. It has been de- scribed as more aqueous, more albuminous, more unctuous, and blacker than other venous blood ; to be less coagulable, less rich in fibrin, and the fibrin it does contain to be less animalized. Yet these affirmations have been denied ; and even were they admit- ted, we have no positive knowledge, that such changes better adapt it for the formation of bile by the liver. The ideas that have existed, regarding its acting as a diverticu- lum for the blood, have been mentioned under the head of Circu- lation. By some, it has been supposed to act as such in the inter- vals of digestion ;b or in other words, to be a diverticulum to the stomach : by others, its agency in this way is believed to apply to the whole circulatory system, so that when the flow of blood is impeded or arrested in other parts, it may be received into the spleen. Such a view was entertained by Dr. Rush.c It has been embraced by many others.*1 It is hard to say which of these speculations is the most inge- nious. None can satisfy the judicious physiologist, especially when he considers the comparative impunity consequent on ex- tirpation of the organ. This was an operation performed at an early period. Pliny affirms that it was practised on runners to render them more swift. From animals the spleen has been re- peatedly removed, and although many of these have died in Gen- ii Nouvel Apercu sur la Physiologie du Foie, et les Usages de la Bile, Paris, 1833. b Dr. W. Stukely, Of the Spleen, its Description and History, Uses and Diseases, &c, Lond. 1722 ; and Dr. G. Dermott, Medical Times, April 3, 1841. c Coxe's Medical Museum, Philad. 1807. See, also, on this subject, art. Milz. in Pierer, op. cit. s. 328 ; and Mr. Hake, Proceedings of the Royal Society, No. 39, June 20, 1839. d Dr. O'Beirne, Dublin Journal of Medical Science, Nov. 1842, p. 219 ; Carpenter, Human Physiology. § 709, Lond. 1842 ; and Dr. Hargreave, Dublin Medical Press, Aug. 10, 1842, p. 81. SPLEEN. 305 sequence of the operation, several have recovered.3 Adelonb re- fers to the case of a man who was wounded by a knife under the last false rib of the left side. Surgical attendance was not had until twelve hours afterwards; and as the spleen had issued at the wound, and was much altered, it was considered necessary to ex- tirpate it. The vessels were tied; the man got well in less than two months, and has ever since enjoyed good health. Sir Charles Bellc asserts, that an old pupil had given him an account of his having cut off the spleen in a native of South America. The spleen had escaped through a wound, and had become gangre- nous. He could observe no effect to result from the extirpation. T. Chapman, Esq. of Purneah, in India, has related a case of ex- cision of a portion of the spleen by Dr. Macdonald of that station. A native, about thirty years of age, was gored in the abdomen by a buffalo, and through the wound, which was about three inches in length, a portion of the spleen protruded. Six days afterwards, the man sought advice from Dr. Macdonald, who removed the spleen with the knife, and the patient rapidly recovered. Dr. O'Brien, in an inaugural dissertation, published at Edinburgh, in 1818, refers to a case, which fell under his own management. The man was a native of Mexico: the spleen lay out, owing to a wound of the abdomen, for two days before the surgeon was ap- plied to. The bleeding was profuse : the vessels and other con- nexions were secured by ligature, and the spleen separated com- pletely on the twentieth day of the wound. On the forty-fifth day, the man was discharged from the hospital, cured ; and he remarked to some one about this time, that " he felt as well as ever he did in his life."e Dulaurens, Kerckring, Baillie/ and others, refer, also, to cases, in which the spleen has been found wanting in man, without any apparent impediment to the functions. The experiments, which have been made on animals, by re- moving the spleen, have led to discordant results. Malpighi says, that the operation was followed by increased secretion of urine ; Dumas, that the animals had afterwards a voracious appetite; Mead, and Mayer, that digestion was impaired, that the evacua- tions were more liquid, and the bile more watery ; Tiedemann and Gmelin, that the chyle appeared more transparent and devoid of clot; Professor Coleman, that the dogs, — the subjects of the experiment,— were fat and indolent. A dog, whose spleen was removed by Mr. Mayo,& became, on recovering from the wound, » J. H. Schulze, de Splene Canibus Exciso, Hal. 1735 : Morgagni, Ani mad. Anat. iii. Animad. xxv. Lugd. Bat. 1741. b Physiol, de I'Homme, 2de edit. torn. iii. Paris, 1829. * Anat. and Physiol., 5th Amer. Edit., by Dr. Godman, ii. 363, New York, 1827. d India Journal of Medicine, vol. viii. p. 1 ; and London Medical Gazette, for May, 20th, 1837, p. 285. * Blundell's Researches, Physiol, and Pathol. Lond. 1825. f Morbid Anatomy, 2d edit. p. 260, Lond. 1797 ; Meckel's Handbuch der Patholo- gischen Anatomie, B. i. s. 608, Leipz. 1812. s Outlines of Human Physiology, 4th edit. p. 107, Lond. 1838; and Outlines of Human Pathology, p. 128, Lond. 1836. 26* 4 306 GLANDIFORM GANGLIONS. fatter than before : in a year's time it had returned to its former condition, and no difference was observed in its appearance or habits from those of other dogs. Similar results followed the ex- periments of Dr. Blundell, Mr. Dobson, and Mr. Eagle ;a and the last gentleman states, that an offer had been made him of a " smart sum of money" by a dealer in Leadenhall Market, if he would tell him his method of fattening animals. Dnpuytren extirpated the spleen of forty dogs on the same day, without tying any vessel, but merely stitching up the wound of the abdomen, — yet no hemorrhage supervened. In the first eight days, half the dogs operated on, died of inflammation of the abdominal * viscera induced by the operation, as was proved by dissection. The other twenty got well without any accident, at the end of three weeks at the farthest. At first they manifested a voracious appetite, but it soon resumed its natural standard. They fed on the same aliment, the same drinks, took the same quantity of food, and digestion seemed to be accomplished in the same time. The faeces had the same consistence, the same appearance, and the chyle appeared to have the same character. Nor did the other functions offer any modification. Dnpuytren opened several of these dogs some time afterwards, and found no apparent change in the abdominal cir- culation,— in that of the stomach, epiploon, or liver. The last organ, which appeared to some of the experimenters to be enlarged, did not seem to him to be at all so. The bile alone appeared a little thicker, and deposited a slight sediment.b These circumstances render it extremely difficult to arrive at any theory regarding the offices of this anomalous organ. It is manifestly not essential to life, and therefore not probably inser- vient to the purposes assigned it by Tiedemann and Gmelin. Its office must evidently be of a supplementary or vicarious nature ; and this would accord best, perhaps, with the notion of its serving as a diverticulum ; the blood speedily passing, after the organ has been extirpated, into other channels ;c a view, which, as elsewhere remarked,11 is somewhat confirmed by the splenic enlargements consequent on repeated attacks of intermittent, — the blood, which has receded from the surface, accumulating perhaps in this organ. It must be admitted, however, that our knowledge of the function is of a singularly negative and unsatisfactory character, and this is strikingly exemplified by the suggestion of Paleye — who was certainly not predisposed to arrive at such a conclusion — that the spleen " may be merely a stuffing, a soft cushion to fill up a vacuum or hollow, which, unless occupied, would leave the pack- age loose and unsteady." > Lond. Lancet, Oct. 8, 1842, p. 58, and Dec. 10, 1842, p. 406, b Adelon, op. cit. c Bostock, Physiology, 3d edit. p. 580, Lond. 1836. See, also, Hodgkin, in Ap- pendix to translation of Edwards, De l'lnfluence des Agens Physiques, &c. Lond. 1833. d Practice of Medicine, vol. i., 2d edit., Philad. 1844. p Natural Theology, c. 11. » GENERATION. 307 BOOK III. REPRODUCTIVE FUNCTIONS. The functions, which we have been hitherto considering, relate exclusively to the individual. We have now to investigate those that refer to the preservation of the species, and without which living beings would soon cease to exist. Although these func- tions are really multiple, it has been the custom with physiologists to refer them to one head —generation — of which they are made to form the subordinate divisions. 'chapter I. GENERATION. The function of generation, much as it varies amongst organized bodies, is possessed by them exclusively. When a mineral gives rise to another of a similar character, it is at the expense of its own existence ; but the animal and the vegetable produce being after being, without any curtailment of theirs. The writers of antiquity considered, that all organized bodies are produced in one of two ways. Amongst the upper classes of both animals and vegetables, they believed the work of reproduction to be effected by a process, which is termed univocal or regular ge- neration, {generatio homogenea, propagatio;) but in the very lowest classes, as the mushroom, the worm, the frog, &c, they conceived that the putrefaction of different bodies, aided by the influence of the sun, might generate life. This has been termed equivocal or spontaneous generation, {generatio heterogenea, asquivoca, primitiva, primigena, originaria, spontanea ;) and is supposed to have been devised by the Egyptians to account for the swarms of frogs and flies, which appeared on the banks of the Nile after its periodical inundations.81 Amongst the ancients, the latter hypothesis was almost universally credited. Pliny unhesi- tatingly expresses his belief, that the rat and the frog are produced in this manner; and at his time it was generally thought, that the bee, for example, was derived, at times from a parent, but at others from putrid beef.b The passage of Virgilc — in which he describes how the shepherd Aristasus succeeded in producing swarms of bees from the entrails of a steer, exposed for nine days to putrefaction — is probably fa- miliar to most readers, and exhibits the same belief. a Fleming's Philosophy of Zoology, i. 24, Edinb. 1822 ; Burdach's Physiologie als Erfahrungswissenschaft, 2te Auflage,i. 8,Leipz. 1835; and Purkinje,in art.Erzeugung, Encyclop. Worterbuch, xi. 512, Berlin, 1834. b " Apes nascuntur partim ex apibus, partim ex bubulo corpore putrefacto." — Varro. De Re Rustica, iii. 16. See, also, Plinii Hist. Natural. « Georgic. lib. iv. 1. 295. 308 GENERATION. The hypothesis of equivocal generation having been conceived, in consequence of the impracticability of tracing ocularly the func- tion in the minute tribes of animals, it naturally maintained its ground uninterruptedly, as regarded those animals, until better means of observation were invented. The difficulty, too, of ad- mitting regular generation as applicable to all animals, was aug- mented by the fact, not at first known to naturalists, that many of the lower tribes conceal their eggs, in order that their nascent larvae may find suitable food; but the existence of evident sexual organs in many of these small species induced physiologists, at an early period, to believe, that they also might be reproduced by sexual intercourse : direct proofs were not, however, obtained until the discovery of the microscope ; after which the investiga- tions of Redi, Vallisnieri, Swammerdam, Hooke, Reaumur, Bon- net and others, clearly demonstrated that many of the smallest in- sects have eggs and sexes, and that they reproduce like other ani- mals. In the case of plants it has been supposed that the growth of the fungi amongst dung, and of the various parasitical plants that appear on putrid flesh, fruit, &c. furnishes facts in support of the equivocal theory; but the microscope exhibits the seeds of many of these plants, and experiments show that they are prolific. The characters, by which the different species and varieties are distin- guished, although astonishingly minute, are fixed, exhibiting no fluctuation, such as might be anticipated did these plants arise by spontaneous generation, or by the fortuitous concourse of atoms. The animalcules, that make their appearance in water in which vegetable or animal substances have been infused or are contained, would seem, at first sight, to favour the ancient doctrine. In these cases, however, the species, again, have determinate characters ; presenting always the same proportion of parts ; and appearing to transmit their vitality to their descendants in a manner not unlike animals and vegetables higher in the scale. The explanation, of- fered by the supporters of the univocal theory for those obscure cases in which direct observation fails us, is that their seeds and eggs are so extremely minute, that they can be borne about by the winds, or by birds ; be readily deposited, and, when they find a soil or nidus, favourable to their growth, can undergo develop- ment. Thus, the soil, in which alone the monilia glanca flourishes, is putrid fruit; whilst the small infusory animal — the vibrio aceti or vinegar eel —requires, for its growth, vinegar that has been for some time exposed to the air.a "That the atmo- sphere," says Dr. Good,b is freighted with myriads of insect eggs, that elude our senses ; and that such eggs, when they meet with a proper bed, are hatched in a few hours into a perfect form, is clear to any one who has attended to the rapid and wonderful effects of what, in common language, is called a blight, upon plantations and gardens. I have seen, as probably many, who may read this work, have also, a hop-ground completely overrun and desolated * Fleming, op. citat. p. 24. b Study of Medicine, CI. i. Ord. 1. Gen. x. Sp. 3. GENERATION. 309 by the aphis humuli or hopgreen-louse, within twelve hours after a honey-dew (which is a peculiar haze or mist, loaded with a poisonous miasm) has slowly swept through the plantation, and stimulated the leaves of the hop to the morbid secretion of a sac- charine and viscid juice, which, while it destroys the young shoots by exhaustion, renders them a favourite resort for this insect, and a cherishing nidus for the myriads of little dots that are its eggs. The latter are hatched within eight-and-forty hours after their de- posit, and succeeded by hosts of other eggs of the same kind ; or, if the blight takes place in an early part of the autumn, by hosts of the young insects produced viviparously ; for in different seasons of the year, the aphis breeds both ways. Now it is highly pro- bable, that there are minute eggs or ovula of innumerable kinds of animalcules floating in myriads of myriads through the atmo- sphere, so diminutive as to bear no larger proportion to the eggs of the aphis than these bear to those of the wren, or the hedge-spar- row; protected, at the same time, from destruction by the filmy in- tegument that surrounds them, till they can meet with a proper nest for their reception, and a proper stimulating power to quicken them into life; and which, with respect to many of them, are only found obvious to the senses in different descriptions of animal fluids. " The same fact occurs in the mineral kingdom : stagnant water, though purified by distillation and confined in a marble basin, will, in a short time, become loaded on its surface or about its sides with various species of confervas; while the interior will be peopled with microscopic animalcules. So, while damp cellars are covered with boletuses, agarics and other funguses, the driest brick walls are often lined with the lichens and mosses. We see nothing of the animal and vegetable eggs or seeds by which all this is effected; but we know, that they exist in the atmosphere, and that this is the medium of their circulation." This view of the extraneous origin of the seeds of the confer- vas, &c, is corroborated by an experiment of Senebier. He filled a bottle with distilled water, and corked it accurately; not an atom of green matter was produced, although it was exposed to the light of the sun for four years; nor did the green matter, considered as the first stage of spontaneous organization, exhibit itself in a glass of common water, covered with a stratum of oil.a It is proper, however, to remark, that the observation of others in- validates the results of this experiment. Burdach,b assisted by Hensche, and along with Professor von Baer, poured water on marble in a glass vessel, the remainder of the vessel being filled with atmospheric air, oxygen or hydrogen, and placed it in the light of the sun, or in warm sand. No green matter was perceptible, but there was a slimy substance with while threads, part of which had a ramified appearance, and part that of coral. On the other hand, pieces of granite, newly broken from the midst of a block, » See, also, Wrisberg, Observ. de Animal. Infusor. b Die Physiologie ale Erfahrungswissenschaft, 2te Auflage, i. 23, Leipz.. 1835. 310 GENERATION. produced — with fresh distilled water, and oxygen or hydrogen, in the sun — green matter, with threads of the confervas; but in the warmth of digestion flocculi only. He next took some mould, which he dug up, and which was inodorous, and apparently free from all foreign matter; boiled it in a considerable quantity of water, and reduced the decoction to the consistence of a thick, partly pulverulent extract. This gave, with common water and atmospheric air — in bottles with ground stoppers, tied over with bladder — in the sun, numerous infusory animalcules and green matter; but with distilled water and oxygen or hydrogen, green matter only appearea at the bottom of the bottles. The subject of intestinal worms has been eagerly embraced by the supporters of the doctrne of equivocal generation, who are of opinion, that the germs need not be received from without; whilst the followers of the univocal doctrine maintain, that they must always be admitted into the system. The first opinion includes amongst its supporters the names of Needham,3 Buffon, Patrin, Treviranus,b Rudolphi,c Bremser,d Himly, and other distinguished helminthologists. The latter comprises those who believe in the Harveian maxim, — omne vivum ex ovo.e To support the latter opinion, it has been attempted to show, that the worms, found in the human intestines, are precisely the same as others that have been found out of the bodjr; but the evidence, in favour of this position, is by no means strong or satisfactory. Linnaeus affirms, that the taenia vulgaris, — of a smaller size, however, — has been met with in muddy springs; and the ascarides vermiculares in marshes, and in the putrescent roots of plants. Gadd affirms, that he met with the taenia articulata plana osculis lateralibus gemi- nis in a chalybeate rivulet; Unzer, taenia in a well; and Tis- sot says, that he found a taenia, exactly like the human, in a river; whilst Linnaeus, Leeuenhoek, Schaffer and others affirm, that they have found the distoma hepaticum in water; but 0. F. Miiller, — who took extraordinary pains in the comparative examination of the entozoa, which infest the human body, with those that are met with in springs, — states, that he has frequently detected the pla- nariae, but never saw one like the distoma hepaticum? On the other hand, the supporters of the equivocal theory have laboured, with a good deal of success, to show, that a difference is always discoverable between the worms found without, and those found within, the body ; but were it demonstrated to a mathema- tical certainty, that such difference exists, it would not be an in- vincible argument against the correctness of the univocal theory ; as difference of locality, food, &c, might induce important changes in their corporeal development, and give occasion to the diversity, » An account of some New Microscopical Discoveries, 8vo., Lond. 1745. b Biologie, torn. ii. 264. • Entozoorum sive Vermium Intestinalium Historia Naturalis, torn. i. p. 370. a Ueber Lebende Wurmer im Lebenden Menschen, Wien, 1819. e See the author's Commentaries on the Diseases of the Stomach and Bowels of Children, p. 20, Lond. 1824. f Rudolphi, op. citat. GENERATION. 311 which is occasionally perceptible amongst these parasites. Yet, if we admit that the germs of the entozoa are always received from without, their occurrence in different stages of development, in the foetus in utero, is a circumstance difficult of explanation. Small, indeed, must be the germ, which, when received into the digestive organs of the mother, can pass into her circulation, be transmitted into the vessels of the foetus, be deposited in some viscus, and there undergo its full development; yet such ceses have occurred, if the theory be correct. Certain it is, — however the fact may be ac- counted for,— that worms have been found in the foetus, by indi- viduals whose testimony cannot be doubted. Eschholz saw them in the egg of the hen. Fromann found the distoma hepaticum in the liver of the foetal lamb ; Kerckring,3 ascarides lumbricoides in the stomach of a fcetus six and a half months old ; Breudel, taeniae in the human fcetus in utero; Heim, taeniae in the new- born infant; Blumenbach, taeniae in the intestine of the new-born puppy; and Goze, Bloch, and Rudolphi, the same parasite in sucking lambs.b Perhaps the conclusion of Cuvier0 is the soundest and most con- sistent with analogy,— that these parasites " propagate by germs so minute as to be capable of transmission through the narrowest passages; so that the germs may exist in the infant at birth." We have seen, that not simply the germs, but the animals themselves have been found at this early period of existence. The scientific world was, at one time, astounded by the assertion of Mr. Crosse, that he had succeeded in forming infusory animalcules from solu- tions of granite, silex, &c. by the aid of galvanism; but the only mode of explaining the phenomenon is, that organized matters, perhaps ova, were existent in the solutions, which became deve- loped under the galvanic influence. The whole matter is involved in insuperable difficulties; yet the univocal theory is,in all respects perhaps, most admissible as regards the whole of the living crea- tion :d still there are many distinguished naturalists who conceive it probable, that spontaneous generation occurs in the lowest divi- sions of the living scale. Amongst these may be mentioned De Lamarck, Raspail, Burdach, Treviranus, Wrisberg, Schweigger, Gruithuisen, Von Baer, and Adelon seems to accord with them. It has been properly remarked by a recent writere on this subject, who is himself inclined to admit the existence of spontaneous generation among some species of cryptogamic plants, infusorial animalcules, and entozoa, that " it must be held in recollection, » Spicilegium Anatom. Obs. lxxix. p. 154, Amstel. 1670. b Stannius, art. Entozoa, in Encyclop. Wbrterb. der Medic. Wissensch. xi. 276, Berlin, 1834 ; also, Gratzer, Die Krankheiten des Foetus, p. 107, Breslau, 1837. c Regne Animal, p. 27. See, also, Ehrenberg, in Nov. Act. Nat. Cur. torn, x.; and Miillev's Physiology, Baly's translation, Part i. p. 14, Lond. 1838. £, be by Human Testis injected with Mercury. a, a. Lobules formed of seminiferous tubes, b. Rete testis, c. Vasa efferentia. d. Plexuses of the efferent vessels passing into the head of the epididymis e e. f. Body of the epididymis. g. Its appendix; its tail or cauda. i. Vas deferens. — (Lauth.) Fig. 212. GENERATIVE APPARATUS — MALE. 319 no means essential. It has been sufficiently demonstrated that individuals, so circumstanced, are capable of procreation. In many animals, the testicles are always internal; whilst, in some, they appear only in the scrotum during the season of amorous excitement. Fodere has indeed asserted, that the crypsorchides or testicondi, or those whose testes have not de- scended, are occasionally remarked for the possession of unusual prolific powers and sexual vigour.a Dr. Marshall states, that in the examination of 10,800 recruits he found 5 in whom the right, and 6 in whom the left testicle was not apparent. He met with but one instance in which both testi- cles had not appeared.b It appears, that there is a set of barbarians at the back of the Cape of Good Hope, who are generally possessed of but one testicle, or are monor chides; and Linnaeus, under the belief, that this is a natural defect, has made them a distinct variety of the human species. Mr. Barrow has noticed the same singularity ; but Dr. Goodc thinks it doubtful, whether, like the want of beard amongst the American savages, the destitution may not be owing to a barbarous custom of extirpation in early life. The deviation is not, however, more singular than the unusual formation of the nates and of the genital organs of the female in certain people of those regions, to which we shall have to refer. The possession of a single testicle appears to be sufficient for procreation. Occasionally three testicles exist.d At times, the testicles are extremely small, but capable of exe- cuting all their functions. Mr. Wilsone was consulted by a gentle- man, on the point of marriage, respecting the propriety of his en- tering into that state, whose penis and testicles very little exceeded in size those of a youth of eight years of age. He was twenty-six years old, but had never experienced sexual desire until he became acquainted with the lady whom he proposed to make his wife; after which he had repeated erections, with nocturnal emissions. He married; became the father of a family; and when he was twenty-eight years old, the organs had increased to the usual size of those of the adult. In certain cases, the testes are drawn up against the abdominal ring so as to encourage the idea, that there are no testes in the scrotum, and Professor Grossf has given the cases of two boys, one fourteen, the other eleven years of age, who were said to have been castrated, and a medical practitioner deposed to the absence of the testes ; which, however, were found to be situate in the groin, a " Ces organes paraissant tirer du bain chaud ou ils se trouvent plonges plus d'apti- tude a la secretion que lorsqu'ils sont descendus au dehors dans leurs enveloppes ordi- nals i» —Traite de JVedecine Legale, i. 370, Paris, 1813. b Hints to Young Medical Officers in the Army, p. 83. c Physiological Proem to class Genetica, Study of Medicine, vol. iv. Special Anat. and Histology. 6th edit. Philad. 1843 ; and Lessons on Practical Anatomy, 3d edit. p. 373, Philad. 1836. GENERATIVE APPARATUS — MALE. 321 nalis communis. The tunica vaginalis or tunica elytrdides is a true serous membrane, enveloping the testicle and lining the scro- tum ; having, consequently, a scrotal and a testicular portion. We shall see, hereafter, that it is a dependence of the peritoneum, passing before the testicle in its descent, and afterwards becoming separated from any direct communication with the abdomen. The vas deferens or excretory duct of the testicle commences at the globus minor of the epididymis, (C, Fig. 210,) which is itself, we have seen, formed of aconvoluted tube. This, when unfolded, according to Monro, measures as much as thirty-two feet. As soon as the vas deferens quits the testicle, it joins the spermatic cord, passes upwards to the abdominal fling, separates from the bloodvessels on entering the abdomen, and descends downwards and inwards to the posterior and inferior part of the bladder, passing between the bas-fond of the latter and the ureter. It then converges towards its fellow along the under extremity of the bladder, at the inner margin of the vesicula seminalis of the same side, and ultimately opens into the urethra near the neck of the bladder. (Fig. 206 and Fig. 213.) Atthe base of the prostate, it receives a canal from the vesicula, and continues its course to the urethra under the name of ejaculatory duct. The vas deferens has two coats, the outermost of which is very firm and almost cartilaginous; but its structure is not manifest. The inner coat is thin, and be- longs to the class of mucous mem- branes. The vesiculas seminales, 19, Fig. 206, and Fig. 214, are considered to be two convoluted tubes,— One on each side, —which are two inches or two inches and a half long, and six or seven lines broad at the fundus, and are situate at the lower fundus of the bladder, between it and the rectum and be- hind the prostate gland. At the anterior extremities they approach each other very closely, being se- parated only by the vasa deferentia. When inflated and dried, they pre- sent the appearance of cells; but Posterior View of Male Bladder. 1. Body of bladder. 2. Fundus. 3. Inferior fundus or base. 4. Ura- chus. 5, 5, Ureters. 6, 6. Vasa deferentia. 7, 7. Vesiculae semi- nales. Triangular area, corre- sponding with trigoiium vesicse through which bladder would be pierced, in puncturing bladder through rectum. The dotted line forming base of this triangular area, marks extent of recto-vesical fold of peritoneum. — (Wilson.) Fig. 214. Section of the Vesicula Seminales, SfC. V. Section of vas deferens. S. Section of vesicula seminalis. E. Section of ejaculatory duct. 322 GENERATION. are generally conceived to be tubes, which, being convoluted, are brought within the compass of the vesicuise. When dissected and stretched out, they are four or five inches long by about one-fourth of an inch in diameter. Amussat,3 however, denies this arrange- ment of the vesiculse : he affirms, that he has discovered them to be formed of a Fig. 215. minute canal of considerable length, various- ly convoluted, the folds of which are uni- ted to each other by cellu- lar filaments, like those of the spermatic ves- sels. At the anterior part, termed the neck, a short canal passes Section of Bladder, Prostate, andPenis. Off, 1. Urachus attached to upper part of fundus of bladder. 2. Recto-vesical fold of peritoneum, at its point of reflection from base of bladder upon Unites anterior surface of rectum. 3. Opening of right ureter. 4. A slight ridge, opi-ifg formed by muscle of ureter, and extending from termination of ureter to tUj_ulc commencement of urethra. This ridge forms lateral boundary of trigo- with the num vesica;. 5. Commencement of urethra; the elevation of mucous , /. membrane immediately behind figure is uvula vesica;. Constriction of deferens which at an angle vas to bladder at this point is neck of bladder. C. Prostatic portion of urethra. forp-. *UP //,//». 7. Prostate gland; difference of thickness of gland, above and below AOI1I1 Hie ultt- urethra, is shown. 8. Isthmus, or third lobe of prostate; immediately fnS ejttCulatO- beneath which ejaculatory duct is seen passing. 9. Right vesicula semi- . rrii nalis; vas deferens is seen to be cut short off, close to its junction with riUS. 1 he Vesi- ejaculatoryduct. 10. Membranous portion of urethra. 11. Cowper'sgland „.,]_, aTO fnvrr. of right side, with its duct. 12. Bulbous portion of urethra: throughout CUIaJ are IOrm- whole length of urethra of corpus spongiosum, numerous lacunae are seen. qA of tWO mem- 13. Fossa naviculars. 14. Corpus cavernosum, cut somewhat obliquely . i to right side, near its lower part. Character of venous-cellular texture is braiieS ; tile shown. J5. Right crus penis. 16. Near upper part of corpus caver- . i nosum, section has fallen a little to left of middle line ; a portion of sep- more external turn pectiniforme is consequently seen. This figure also indicates thick- lilrp that nf thp ness of fibrous investment of corpus cavernosum, and its abrupt termina- ulttl 1 lc tion at base of (17) glans penis. 18. Lower segment of glans. 19. Mea- VaS deferens, tus urinarius. 20. Corpus spongiosum. 21. Bulb of corpus spongiosum.— i ii cwiison.) s and capable of contracting in the act of ejaculation; and an internal lining, of a white, delicate character, a little like that which lines the interior of the gall-bladder, and supposed to be mucous. Although the vesiculse are manifestly contractile, no muscular fibres have been detected in them. They are found filled, in the dead body, with an opaque, thick, yellowish fluid, very different, in appearance, from the sperm ejaculated during life. The prostate gland, (Fig. 206 and Fig. 215,) is an organ of very dense tissue, embracing the neck of the bladder, and penetrated by the urethra, which traverses it much nearer its upper than its lower surface. The base is directed backwards, the point forwards and » Magendie's Precis, &c. ii. 514. GENERATIVE APPARATUS — MALE. 323 its inferior surface rests upon the rectum, so that, by passing the finger into the rectum, enlargements of the organ may be detected. The prostate was once universally esteemed glandular, and it is still so termed. It is, now, generally and correctly regarded as an agglomeration of several small follicles, filled by a viscid whitish fluid. These follicles have numerous minute excretory ducts, which open on each side of the caput gallinaginis. The glands of Cowper are two small, oblong bodies; of the size of a pea; of a reddish colour, and of a somewhat firm tissue. They are situate anterior to the prostate, parallel to each other, and at the sides of the urethra. Each has an excretory duct, which creeps obliquely in the spongy tissue of the bulk, and opens before the verumontanum. The male organ ox penis consists of the corpus cavernosum and corpus spongiosum ; parts essentially formed of an erectile tissue, and surrounded by a very firm elastic covering, which prevents over-distension, and gives form to the organ. The corpora caver- nosa constitute the great body of the penis. They are two tubes which are united and separated by an imperfect partition. Within them a kind of cellular tissue exists, into which blood is poured, so as to cause erection. The posterior extremities of these caver- nous tubes are called crura penis. These separate in the perineum, each taking hold of the ramus of the pubis ; and, at the other ex tremity, the cavernous bodies terminate in rounded points under the glans penis. The anatomical elements of the internal tissue of the corpora cavernosa are, — the ramifications of the cavernous artery, which proceeds from the internal pudic; those of a Vein bearing the same name; and probably, nerves, although they have not been traced so far. All these elements are sup- ported by filamentous prolongations from the outer dense en- velope. A difference of opinion prevails amongst anatomists with regard to the precise arrangement of these prolongations. Some consider them to form cells, or a kind of spongy structure, on the plates of which the ramifications of the cavernous artery and vein and of the nerves terminate, and into which the blood is extravasated. Others conceive, that the internal arrangement con- sists of a plexus of minute arteries and veins, supported by the plates of the outer membrane, interlacing like the capillary vessels, but with this addition, that in place of the minute veins becoming capillary in the plexus, they are of greater size, forming very ex- tensible dilatations and networks, and anastomosing freely with each other. If the cavernous artery be injected, the matter first fills the ramifications of the artery, then the venous plexuses of the cavernous bodies, and it ultimately returns by the cavernous vein, having produced erection. The same effect is caused still more readily by injecting the cavernous vein. J. Muller, who has investigated the structure of the male organ, has discovered two sets of arteries in the organ differing from each other in size, mode of termination, and uses: the first he calls Rami nutritii, which are distributed upon the parietes of the veins and throughout 324 GENERATION. the spongy substance,differing in no respect from the nutritive ar- teries of other parts. The second set he calls arteriae helicinas. They differ from the nutritive vessels in form, size, and distribu- tion. They are short, and are given off from the larger branches as well as from the finest twigs of the artery ; most of them come off at a right angle, and project into the cavity of the spongy sub- stance, either terminating abruptly or swelling out into a clublike process without again subdividing. Almost all these arteries have this character, that they are bent like a horn, so that the end de- scribes half a circle or somewhat more. These arteries have a great resemblance to the tendrils of the vine, whence their name — arteriae helicinas. A minute examination of them, either with the lens or with the microscope, shows, that, although they at all times project into the venous cavities of the corpora cavernosa, they are not entirely naked, but are covered with a deli- cate membrane, which under the microscope appears granular.8 The views of Muller are embraced by Krause and Hyrtl,b but the researches of Valentin0 are not in accordance with them. The result of numerous examinations has convinced him, that the heli- cine arteries are not peculiar vessels, but merely minute arteries that have been divided or torn, and that the real distribution of the vessels of the corpora cavernosa follows in every respect the most simple laws. The investigations of Muller have led him to infer, that, both in man and the horse, the nerves of the corpora caver- nosa are made up of branches pro- ceeding from the organic as well as the animal system, whilst the nerves of animal life alone provide the nerves of sensation of the penis.d Attached to the corpora cavernosa, and running in the groove beneath them, is a spongy body of similar structure, — the corpus spongiosum urethras, — through which the ure- thra passes. It commences, posteriorly, at the bulb of the urethra, — already described under the Secretion of Urine, — and terminates anteriorly in the glans, which is, in no wise, a depend- ency of the corpora cavernosa, but is separated from them by a portion of their outer membranes; so that erection may take place in the one, and not » For a farther description of these vessels, see J. Muller, art. Erectiles Gewebe, Encycl. Wdrterbuch der Medic. Wissench. xi. 452, Berlin, 1834; Handbuch der Physiologie, u. s. w., Baly's translation, Lond. 1838; and Abhandlungen der Konig- lich. Akademie der Wissenschaft. zu Berlin, s. 93, Berlin, 1837; also, Dr. Hart, in art. Erectile Tissue, in Cyclop. Anat. and Physiol, part x.. p. 146, June, 1837. t> Mandl, Manuel d'Anatomie generale, p. 197, Paris, 1843. c Miiller's Archiv. fur Anatomie, u. s. w., and Lond. Med. Gazette, June 23, 1838, p. 543; and Henle, Allgemein. Anatom. s. 485, Leipz. 1841. d Lond. Med. Gazette, April 23d, 1836, and Abhandlung, u. s. w., s. 117. B Section of the Penis. A. External membrane or sheath of the penis. B. Corpus cavernosum. D. Corpus spongiosum urethra?. SPERM. 325 simultaneously in the other; and injections into the corpora ca- vernosa of the one do not pass into those of the other. The glans appears to be the final expansion of the erectile tissue which sur- rounds the urethra. The posterior circular margin of the glans is called the corona glandis, and behind this is a depression termed the cervix, collum or neck. Several follicles exist here, called the glandulas odoriferae Tysoni, which secrete an unctuous humour called the smegma prseputii, which often accumulates largely, where cleanliness is not attended to. The penis is covered by the skin, which forms, towards the glans, the prepuce ox foreskin. The cellular tissue, which unites it to the organ is lax, and never contains fat. The inner lamina of the prepuce being inserted circularly into the penis, some distance back from the point, the glans can generally be denuded, when the prepuce is drawn back. The under and middle part of the prepuce is attached to the extremity of the glans by a dupli- cature, called the frasnum praeputii, which extends to the orifice of the urethra. The skin is continued over the glans, but it is greatly modified in its structure, being smooth and velvety, highly delicate, sensible, and vascular. Lastly. In addition to the accelerators urinae, the transversus perinei, the sphincter ani, and the levator ani muscles, which we have described as equally concerned in the excretion of urine and semen, the erector penis or ischio-cavernosus muscle is largely con- nected with the function of generation. The genital organs of man are, in reality, merely an apparatus, for a glandular secretion of which the testicle is the gland; the vesiculae seminales are sup- posed to be the reservoirs; and the vas deferens and urethra the excretory ducts; — the arrangement which we observe in the penis being for the pnrpose of conveying the secreted fluid into the parts of the female. 1. SPERM. The sperm, sperma or semen is secreted by the testicles from the blood of the spermatic artery, by a mechanism, which is no more understood than that of secretion in general. When formed, it is received into the tubuli seminiferi, and passes along them to the epididymis, the vas deferens, and the vesiculse seminales, where it is generally conceived to be deposited, until it is projected into the urethra, under the venereal excitement. That this is its course is sufficiently evidenced by the arrangement of the excretory ducts, and by the function which the sperm has to fulfil. De Graaf,a however, adduces an additional proof. On tying the vas deferens of a dog, the testicle became swollen under excitement, and ulti- mately the vas deferens gave way between the testicle and the ligature. The causes of the progression of the sperm through the ducts are, — the continuity of the secretion by the testicle, and a 1 De Virorum Organ. Gener. Inserv., in Med. Oper. Ornn. Amstel. 1705. VOL. II. — 28 326 GENERATION. contraction of the excretory ducts themselves. These are the effi- cient agents. It has been a question with physiologists, whether the secretion of the sperm be constantly taking place, or whether, as the func- tion of generation is accomplished at uncertain intervals, the secre- tion may not likewise be intermittent. It is impossible to arrive at any positive conclusion on this point. It would seem, however, unnecessary for the secretion to be effected at all times; and it is more probable, that when the vesiculas seminales are emptied of their contents, during coition, a stimulus is given to the testes by the excitement, and they are soon replenished. This, however, is more and more difficult' in proportion to the number of repetitions of the venereal act, as the secretion takes place at best but slowly. By some, the spermatic and pampiniform plexuses have been re- garded as diverticula to the testes during this intermission of action. The sperm passes slowly along the excretory ducts of the testicle, owing partly to the slowness of the secretion, and partly to the ar- rangement of the ducts, which, as we have seen, are remarkably convoluted, long, and minute. The use of the vesiculse seminales has been disputed. The majority of physiologists regard them to be reservoirs for the sperm, and to serve the same purpose as the gall-bladder in the case of the bile. Others, however, have sup- posed, that they secrete a fluid of a peculiar nature, the use of which may probably be to dilute the sperm; and others, again, infer, that they are both seminal reservoirs, and secreting organs, furnishing mucus, or perhaps some other fluid for admixture with the semen." Dr. John Davy found spermatozoa in the fluid of the vesiculse, but except in two instances no animalcules could be seen in the fluid expressed from the divided substance of the testes. He invariably found, however, extremely minute, dense spherules, which he conjectures to be the ova of the spermatozoa.1* These are manifestly not essential-to the function of generation, as they do not exist in all animals. The dog and cat kind, the bear, opos- sum, sea-otter, seal, &c, possess them not; and there are several in which there is no direct communication between the duct and the vas deferens, which open separately into the urethra. This circumstance, however, with the fact, that they generally contain, after death, a fluid of different appearance and properties from those of the sperm, — with the glandular structure, which their coats seem to possess, in many instances, — is opposed to the view, that they are simple reservoirs for the semen, and favours that which ascribes to them a peculiar secretion. Where this commu- nication between the duct of the vesicles and the vas deferens ex- ists, a reflux of the semen may take place, and an admixture be- tween the sperm and the fluid secreted by them. It is not impro- bable, however, as Adelonc suggests, that all the excretory ducts - Dr. John Davy, in Edinb. Med. and Surg. Journ. for July, 1838, p. 12 ; and Re- searches, Physiological and Anatomical, Dunglison's Amer. Med. Libr. Edit. p. 363, Philad. 1840. *> Ibid., p. 373. c Physiologie de I'Homme, 2de edit. iv. 15, Paris, 1829. SPERM. 327 of the testicle may act as a reservoir; and in the case of animals, in which the vesiculse are wanting, they must possess this office exclusively. If we are to adopt the description of Amussat as an anatomical fact, the vesiculae themselves are constituted of a con- voluted tube, having an arrangement somewhat resembling that which prevails in the excretory ducts of the testes.a That the excretory ducts of the testes may serve as reservoirs is proved by the fact, that impregnation is practicable after thorough castration. This has been doubted both as regards animals and man, but there is no question of the fact as regards the former.b The author's respectable friend, Dr. Pue, of Baltimore, related to him unquestionable instances of the kind. In one case, a boar was observed on one side of a hedge, striving to get at some sows in heat on the other side. The boar was castrated, and no incon- venience being apprehended, he was turned loose into the field with the sows. In five minutes after the operation, he had inter- course with one of the sows, and subsequently with others. The first sow brought forth a litter, but none of the others were im- pregnated. In another case, after a horse had been castrated, it was recollected,that the male organ had not been washed —■ which, it seems, is looked upon as advisable. To save inconvenience, it was suggested, that the same effect might be produced by putting him to a mare, then in the stable, and in heat. This was done, and, in due time, the mare brought forth a foal, unequivocally the result of this sexual union. Mr. Walton Hamilton, — a great breeder of horses, in Saratoga county, New York, — informed the author's friend, Mr. Nicholas P. Trist, United States consul at the Havana, that he, also, had known several instances of impregna- tion after castration.0 It is to be presumed, that the power of procreation can exist for a short time only after the operation; yet a secretion may take place from the lining membrane of the ducts, and vesiculae, and from the prostate and other follicles, but this secretion cannot sup- ply the place of the sperm. Sir A. Cooper gives the case of a man, who stated to him, that for nearly the first twelve months after complete castration, he had emissions in coitu, or the sensation of emissions. Afterwards, he had erections and intercourse at distant intervals, but without the sensation of emission.*1 It has been asked, how does it happen, that the sperm, in its pro- gress along the vas deferens, does not pass directly on into the urethra by the ejaculatory duct, instead of reflowing into the sper- matic vesicles ? This, it has been imagined, is owing to the exist- ence of an arrangement at the opening of the ejaculatory duct into the urethra, similar to that which prevails at the termination of the * Magendie's Precis, &c. ii. 348. b Varro, De Re Rustica, lib. ii. cap. 5. <= See some remarks, by the author, in his American Medical Intelligencer, p. 146, July 15, 1837 ; and by Dr. Warrington, ibid. p. 244, Oct. 1, Annales de Chimie, ix. 64. t Chemische Tabellen des Thierreichs, s. 169, Niirnberg, 1814 ; cited in Burdach's Physiologie, u. s. w., i. 111. d Chimie Organique, p. 386, Paris, 1833. e Adelon, in art. Generation, of Diet, de M£d. torn. x.; and Physiologie de I'Homme, iv. 17. See, also, Burdach's Physiologie, i. 112, for various opinions on this sub- ject; and M. Donne, in Gazette Medicale de Paris, Juin 3, 1837. f Elements of Physiology, translated from the German, by Robert Willis, M.D., par* i. p. 4, Lond. 1841. See, also, Mandl, Manuel d'Anatomie generale, p. 494, Paris, 1843. SPERM. 329 round, granulated bodies may almost always be detected; which are, in all cases, much less numerous than the spermatozoa. 1 nese bodies he distinguishes by the names seminal granules — granula seminis. Both elements of the sperm are suspended in a small quantity of perfectly homogeneous fluid, transparent and clear as water " Pure semen, therefore, in its most perfect state, consists principally of seminal animalcules and seminal granules, both of which are enveloped in a small quantity of fluid." This fluid Wagner calls liquor seminis; and he suggests, in connexion with the discoveries of Schwann Fig. 217. and Schleiden, referred to at page 179 of this volume, whether, in the development of the spermatozoa, the liquor seminis may not be re- garded as a matrix, (Zelle nkeimstotf, cystoblastema, Schwann,) in which the granular nuclei are developed as cytoblasts, which again put forth their covering or cyst as a cellular wall: the finely granular contents would then have to be considered as the cell-fluid. The cytoblasts disappear as soon as the spermatozoa are evolved in their contents, and the cells burst and cast out the animalcules, as the cells of the algse scatter abroad their sporules.a These ani- malcules, however, have been denied to be pecu- liar to this fluid, and have been regarded as infusorv animalcules, similar to those met with Spermatoioa,magnified from in all animal infusions; by others, they have ^*S^ been esteemed organic molecules of the sperm, a man shortly after death. M Virev b__a physiologist, strangely fantastic in a. Fiat surface. 6. Profile J.VI. > liey, apujoiuiugi , tu 11 „ view, margin presenting. his speculations, — conceives, that as tne ponenc. The similar spot on the of vegetables is a collection of small capsules, ^[-XnSa£rS containing within them the true fecundating ^^"^SS^ principle, which is of extreme subtilty, tne pre- it3 b0dy. «. seminal gra- tended spermatic animalcules are tubes contain- nules- in°- the true sperm, and the motion we observe in them is owing to°the rupture of the tubes; whilst Raspail* is led to think, that they are mere shreds, {lambeaux,) of the tissues of the generative organs, ejaculated with the sperm, which describe involuntary movements by virtue of the property they possess of aspiring and expiring. In confirmation of this, he states, that if we open an ovary of the mussel, we may observe, alongside the large ovules, myriadsof moving shreds, whose form and size are infinitely varied, and which possess nothing resembling regular organization They bear evident marks of laceration. Now, these shreds, he con- ceives, may affect greater regularity in certain classes of animals » Wagner, op. cit. p. 27. ., ,„. t . b Art. Generation, in Diet, des Sciences Medicates; and Philosophie d H;&koire Naturelle, Paris, 1835. c °P- cl*at- P- 389- 330 GENERATION. of a more elevated order; but, he concludes, that however this may be, the spermatic animalcules, which have hitherto been classed amongst those incertae sedis, may be provisionally placed in the genus cercaria — that is, amongst infusory, agastric animals having a kind of tail — which Raspail considers the simplest of animated beings,and to live only by "aspiration and expiration." Wagner also remarks, that the expression cercaria seminis, applied to the spermatozoon, can only be a collective title, and that the manifold forms of spermatozoa, which he has found to occur in the seminal fluid of a great number of animals, must be viewed in the light of so many different species. Ehrenberg refers them to the haustellate entozoa.8 The author has examined the sperm with microscopes of high magnifying power, but without being able to satisfy himself, that the minute bodies, contained in it, are animalcular. In a powerful hydroxygen microscope, not the slightest appearance of animal- cules presented itself, but this may have been owing to the great intensity of light. Sir Everard Home and Mr. Bauerb were equally unsuccessful, and they were led to conclude, that the appearance of living animalcules in the semen is not real, but the effect of a microscopic deception. Wagner0 considers, that they are essen- tial elements of the seminal fluid, and bear a specific relation to the generative act, and that they are thus far comparable to the blood-globules; which present themselves in the same manner as essential typically organized constituents of the blood amid the liquor sanguinis, just as the spermatozoa present them- selves amid the liquor seminis. The question of their animality he considers to be undetermined as their internal organization had not been detected. In the appendix, however, to Dr. Wagner's work, Dr. Willisd remarks, that in the examination of the spermatozoa of the bear, Dr. Valentin6 had settled the question of the organiza- tion and consequently the true animal nature of the seminal animal- cule ; but the question is not regarded as settled by this state- ment. Dr. Carpenter/indeed, considers, that there is but little reason to consider them independent animalcules. He esteems them to be bodies having an inherent power of motion, not exceeding in their activity ciliated epithelium cells, and even blood corpuscles; and he thinks there is no evidence,that their function is any higher than that of the pollen-tube of plants, which conveys into the ovulum the germ of the first cells of the embryo. The presence of the spermatozoa, whole or broken into fragments, may aid in detecting nocturnal emissions, and be of assistance in cases of alleged rape.? a For a full account of these animalcules, see Wagner, op. citat. p. 6. b Lect. on Comp. Anat. v. 337, Lond. 1828. <= Op. citat. p. 34. * Ibid. p. 228. e Nov. Act. Acad. C. L. Natur. Curios, vol. xi. 1839.. f Human Physiology, § 733, Lond. 1842 ; or Principles of General and Comparative Physiology, § 607, Lond. 1841; and Todd and Bowman, Physiological Anatomy, &c, of Man, p. 66, Lond. 1843. s J. Muller, Elements of Physiology, translated by Baly, p. 1477, Lond. 1842. GENERATIVE APPARATUS — FEMALE. 33] It would seem that the spermatozoa are not found solely in the sperm; for Mr. Lloyd,a of Saint Bartholomew's Hospital, London, stated recently to the Medico-Chirurgical Society, that in two cases of common hydrocele, in which he examined micro- scopically the fluid withdrawn by tapping, he had found numer- ous spermatozoa. He counted forty of these in one drop of the fluid. Some of them were observed to retain their power of motion for three hours after the fluid had been withdrawn. In the fluid of many other cases of hydrocele, Mr. Lloyd was unable to detect these animalcules. The agency of the sperm in fecundation will be considered here- after. It may be observed, however, that in all examinations of it, whether by the microscope or otherwise, we must bear in mind, the caution to which we have adverted more than once, as appli- cable to the examination of animal fluids in general, — that we ought not to conclude positively, from the results of our observa- tions of the fluids when out of the body, that they possess precisely the same characteristics when in it; and this remark is especially applicable to the sperm, which varies manifestly in its sensible pro- perties a short time after it has been excreted. The sperm being the great vivifying agent, — the medium by which life is communicated from generation to generation,— it has been looked upon as one of the most important if not the most im- portant of animal fluids ; and hence it is regarded, by some physio- logists, as formed of the most animalized materials, or of those that constitute the most elevated part of the new being — the nervous system. The quantity of sperm secreted cannot be estimated. It varies according to the individual, and to his extent of voluptuous excitement, as well as to the degree of previous indulgence in venereal pleasures. Where the demand is frequent, the supply is larger ; although when the act is repeatedly performed, the abso- lute quantity at each copulation may be less.b b. Genital Organs of the Female. The genital organs of the male effect fewer functions than those of the female. They are inservient to copulation and fecundation only. Those of the female, — in addition to parts, which fulfil these offices, — comprise others for gestation and lactation. The soft and prominent covering to the symphysis pubis — which is formed by the common integuments, elevated by fat, and, at the age of puberty, covered by hair, formerly termed tressoria — is called the mons veneris. The absence of this hair has, by the vul- gar, been esteemed a matter of reproach ; and it was formerly the custom, when a female had been detected a third time in inconti- nent practices, in the vicinity of the Superior Courts of Westmin- » Provincial Medical Journal, cited in Medical Examiner, July 22, 1843, p. 168. b Theophrastus, Pliny, and Athenaeus assert, that with the help of a certain herb, an Indian prince was able to copulate seventy times in twenty-four hours ! — Theophr. I. c. v., Plin. 1. xxvi. c. 9, and Athenaeus, 1. i. c 12. See, also, art. Cas rares, in Diet. des Sciences Medicates. 332 GENERATION. ster, to pjunish the offence by cutting off the tressoriaa in open court. Occasionally its growth is excessive. Below this, are the labia pudendi or labia major a, which are two large, soft lips, formed by a duplicature of the common integument, with adipose matter interposed. The inner surface is smooth, and studded with sebaceous follicles. The labia commence at the symphysis pubis, descend to the perinaeum, which is the portion of integument, about an inch and a half in length, between the posterior commissure of the labia and the anus. This commissure is called the fraenum labiorum,fraenulumperinasi or fourchette. The opening between the labia is the vulva ox fossa magna. At the upper junction of the labia, and within them, a small organ exists, called the clitoris or superlabia, which greatly resembles the penis. It is formed of corpora cavernosa, and is terminated anteriorly by the glans, which is covered by a prepuce, consisting of a prolongation of the mucous membrane of the vagina. Unlike the penis, how- ever, it has no corpus spongiosum, or urethra attached to it ; but it is capable of being made erect by a mechanism similar to that which applies to the penis ; and it has two erector muscles, the erectores clitoridis,—similar to the erectores penis. Anciently, if a female was detected a fourth time in incontinence in the vicinity of the Superior Courts of Westminster, the clitoris was amputated in open court.b Extending from the prepuce of the clitoris, and within the labia majora, are the labia minora or nymphas, the organization of which is similar to that of the labia majora. They gradually enlarge as they pass downwards, and disappear when they reach the orifice of the vagina. A singular variety is observed in the organization of those parts amongst the Bosjesmen or Bushmen, the tribe to whose peculiari- ties of organization we have already had occasion to refer. Dis- cordance has, however, prevailed regarding the precise nature of this peculiarity, some describing it as existing in the labia, others in the nymphas, and others again, in a peculiar organization; some deeming it natural, others artificial. Dr. Somerville,0 who had numerous opportunities for observation and dissection, asserts, that the mons veneris is less prominent than in the European, and is either destitute of hair, or thinly covered by a small quantity of a soft, woolly nature ; that the labia are very small, so that they seems at times to be almost wanting ; that the loose, pendulous, and rugous growth, which hangs from the pudendum, is a double fold; and that it is proved to be the nymphas, by the situation of the clitoris at the commissure of the folds, as well as by all other circumstances; and that they sometimes reach five inches below the margin of the labia; Le Vaillantd says nine inches. Cuviere a Chitty's Practical Treatise on Medical Jurisprudence, part i. p. 390, Amer. Edit., Philad. 1836. b Chitty, op. cit. part i. p. 391, Amer. Edit, Philad". 1836! c Medico-Chirurgical Transactions, vii. 157. d Voyage dans l'lnterieur d'Afrique, p. 371. « Memoir, du Museum, iii. 266; and Broc, Essai sur les Races Humiines d. 87. Paris, 1836. ' ' v "• GENERATIVE APPARATUS — FEMALE. 333 examined the Hottentot Venus, and found her to agree well with the account of Dr. Somerville. The labia were very small; and a single prominence descended between them from the upper part. It divided into two lateral portions, which passed along the sides of the vagina to the inferior angle of the labia. The whole length was about four inches. When she was examined naked by the French Savans, this formation was not observed. She kept the tablier, ventrale cutaneum, or, as it is termed by the Germans, S chiirz e ('apron,') carefully concealed, either between her thighs, or yet more deeply ; and it was not known, until after her death, that she possessed it. Both Mr. Barrowa and Dr. Somerville deny that the peculiarity is artificially excited. In warm climates, the nymphse are often greatly and inconve- niently elongated, and amongst the Egyptians and other African tribes, it has been the custom to extir- Fig. 218. pate them, or to di- minish their size. This is what is meant by circumci- sion in the female. The vagina is a canal, which extends between the vulva and the uterus, the neck of which it em- braces. It is some- times called the vul- vo-uterine canal, and is from four to six inches long, and an inch and a half, or two inches, in di- ameter. It is situate in the pelvis, be- tween the bladder before, and the rectum behind; it is slightly curved, with the concavity forwards, and is narrower at the middle than at the extremities. Its inner surface has numerous — chiefly transverse — ruga?, which become less in the progress of age, after repeated acts of copulation, and especially after accouchement. It is composed of an internal mucous membrane, supplied with numerous mucous follicles, of a dense cellular membrane, and, be- tween these, a layer of erectile tissue, which is thicker near the vulva; but is, by some, said to extend even as far as the uterus. It is termed the corpus spongiosum vaginae. It is chiefly situate around the anterior extremity of the vagina, below the clitoris, and » Travels, pp. 279,280 ; see, also, Lawrence's Lectures on Physiology, Zoology, &c. Lond. 1819 ; and Dr. D. D. Davis, in Principles, &c, of Obstetric Medicine, i. 54, Lond. 1836. Lateral view of Pelvic Viscera in the Female. 334 GENERATION. at the base of the nymphse ; and the veins of which it is constituted are called plexus retiformis. The upper portion of the vagina, to a small extent, is covered by the peritoneum. The sphincter or con- strictor vaginas muscle surrounds the orifice of the vagina, and covers the plexus retiformis. It is about an inch and a quarter wide, and ordinarily about six inches in length ; arises from the body of the clitoris, and passes backwards and downwards, to be inserted into the dense, white substance, in the centre of the perineum, which is common to the transversi perinei muscles, and the ante- rior point of the sphincter ani. Fig. 219. Anterior view of the Female Organs. Near [the external aperture of the vagina is the hymen or vir- ginal, or vaginal valve, which is a more or less extensive, mem- branous duplicature, of variable shape, and formed by the mu- cous membrane of the vulva, where it enters the vagina, so that it closes the canal, more or less completely. It is generally very thin, and easily lacerable : but is sometimes extremely firm, so as to prevent penetration. It is usually of a semilunar shape ; some- times oval from right to left, or almost circular, with an aperture in the middle, whilst, occasionally, it is entirely imperforate, and of course prevents the issue of the menstrual flux. It is easily destroyed by mechanical violence of any kind, as by strongly rubbing the sexual organs of infants by coarse cloths, and by ulcerations of the part; hence its absence is not an absolute proof of the loss of virginity, as it was of old regarded by the Hebrews. Nor is its presence a positive evidence of continence. Individuals GENERATIVE APPARATUS—FEMALE. 335 have conceived, in whom the aperture of the hymen has been so small as to prevent penetration. Its general semilunar or cres- centic shape has been considered to explain the origin of the sym- bol of the crescent assigned to Diana — the goddess of chastity.3 Around the part of the vagina, where the hymen was situate, small, reddish, flattened, or rounded tubercles — the carunculas myrtiformes seu hymenales — afterwards exist, which are of vari- ous sizes, and are formed, according to the general opinion, by the remains of the hymen. Beclard and J. Cloquetb consider them to be folds of the mucous membrane. Their number varies from two to five, or six. Fig. 220. Female Organs of Generation. 1. Upper part of vagina. 2, Os uteri, projecting into vagina ; posterior lip is seen to be longef and larger than anterior. 3. Cervix uteri. 4. Body of uterus. 5. Its fundus. 6. Broad ligament of left side, having enclosed between its layers (7) Fallopian tube, and (8) round ligament. On right side broad ligament is removed, so as to bring more clearly into view structures which it contains. 9. Fallopian lube. 10. Its fimbriated extremity. 11. One of its fimbriae attached to ovary. 12. Ovary attached by its ligament to upper angle of uterus. 13. Round ligament.— Wilson.) At either side of the entrance of the vagina, beneath the integu- ment covering its inferior part, as well as the superficial perineal fascia, and the constrictor vaginae muscle, are situate the glands of Duverney. The space they occupy lies between the lower end of the vagina, the ascending ramus of the ischium, the cms clitoridis, and the erector clitoridis muscle. The excretory duct is at the anterior edge of the superior part of the gland, and runs beneath the constrictor vaginae, horizontally forwards and inwards, to the inner face of the nympha, opening in front of the carunculas myr- tiformes, in the midst of a number of small mucous follicles.6 These glands secrete a thick, tenacious, grayish-white fluid, which is emitted in considerable quantity at the termination of sexual in- tercourse,and—it has been suggested—through the spasmodic con- traction of the constrictor vaginas muscle, under which they lie. » Chitty, op. citat. p. 389, and Beck's Medical Jurisprudence, 6th edit., Philad. 1838. For an elaborate description of the Hymen and Caruncles, see Devilliers, Rpvue Medicale, Mai, 1840 ; and Encyclograph. des Sciences Medicales, Join, 1840, p. 65. See, also,Virey, Gazette Medicale, No. xxiii., Paris, 1840. b Dictionnaire de Medecine, &c. art. Caroncule, Paris, 1821. c Mr. Taylor, Dublin Journal of Med. Sciences, vol. xiii. 1838. 336 GENERATION. Fig. 221. The uterus is a hollow organ, for the reception of the fcetus, and its retention during gestation. It is situate in the pelvis, between the bladder — which is before, and the rectum behind, and below the convolutions of the small intestines. Fig. 218 gives a lateral view of their relative situation, and Fig. 219, of their position, when regarded from before. It is of a conoidal shape, flattened on the anterior and posterior surfaces ; rounded at the base, which is above, and truncated at its apex, which is beneath. It is of small size; its length being only about two and a half inches; its breadth one and a half inch at the base, aud ten lines at the neck ; its thickness about an inch. It is divided into the fundus, body, and cervix or neck. The fundus is the upper part of the organ, which is above the insertion of the Fallopian tubes. The body is the part between the insertion of the tubes and the neck; and the neck is the lowest and narrowest portion, which projects and opens into the vagina. At each of the two superior angles are — the opening of the Fallopian tube, the attachments of the ligament of the ovary, and that of the round ligament. The inferior angle is formed by the neck, which projects into the vagina to the distance of four or five lines, and terminates by a cleft, situate crosswise, called os tineas, os uteri or vaginal orifice of the uterus. The aperture is bounded by two lips, which are smooth and rounded in those that have not had children ; jag- ged and rugous in those who are mothers, — the anterior lip being somewhat thicker than-the poste- rior. It is from three to five lines long, and is generally more or less open, especially in those who have had children.3 The inter- nal cavity of the uterus is very small in proportion to the bulk of the organ, owing to the thickness of the parietes, which almost touch internally. It is divided into the cavity of the body, and that of the neck. (Fig. 221.) The former is triangular. The tubes open at its upper angles. The second cavity is more long than broad; is broader at the middle than at either end, and at the upper part, where it communicates with the cavity of the » See, on the Neck of the Uterus in the Young Female, Dr. Marc D'Espine, in Archiv. General, de Medecine, Avril, 1836; and Dunglison's American Medical Intelligencer, i. 103, Philad. 1838. GENERATIVE APPARATUS — FEMALE. 337 body of the uterus, an opening exists, called the internal orifice of the uterus : the external orifice being the os uteri. The inner surface has several transverse rugae, which are not very promi- nent. It is covered by very fine villi, and the orifices of several mucous follicles are visible. The precise organization of the uterus has been a topic of in- teresting inquiry amongst anatomists. It is usually considered to be formed of two parts, a mucous membrane internally, and the proper tissue of the uterus, which constitutes the principal part of the substance. The mucous membrane has been esteemed a pro- longation of that which lines the vagina. It is very thin ; of a red hue in the cavity of the body of the organ ; white in that of the neck. Chaussier, Ribes, and Madame Boivin, however, deny its existence. Chaussier assorts, that having macerated the uterus and a part of the vagina in water, in vinegar, and in alkaline solutions; and having subjected them to continued ebullition, he always observed the mucous membrane of the vagina stop at the edge of the os uteri; and Madame Boivin,— a well-known French authoress on obstetrics, who has attended carefully to the anatomy of those organs during pregnancy, — says, that the mucous mem- brane of the vagina terminates by small expansible folds, and by a kind of prepuce, under the anterior lip of the os uteri. In their view, the inner surface of the uterus is formed of the same tissue as the rest of it.a The proper tissue of the organ is dense, com- pact, not easily cut, and somewhat resembles cartilage in colour, resistance, and elasticity. It is a whitish, homogeneous substance, penetrated by numerous minute vessels. In the unimpregnated state, the fibres, which seem to enter into the composition of the tissue, appear ligamentous and pass in every direction, but so as to permit the uterus to be more readily lacerated from the circumfer- ence to the centre than in any other direction. The precise cha- racter of the tissue is a matter of contention amongst anatomists. To judge from the changes it experiences during gestation, and by its energetic contraction in delivery, it would seem to be decidedly muscular, or at least capable of assuming that charac- ter ; but, on this point, we shall have occasion to dwell here- after. The uterus has, besides the usual organic constituents, — arte- ries, veins, lymphatics, and nerves. The arteries proceed from two sources ; — from the spermatic, which are chiefly distributed to the fundus of the organ, and towards the part where the Fallo- pian tubes terminate ; and from the hypogastric, which are sent especially to the body and neck. Their principal branches are rea- dily seen under the peritoneum, which covers the organ; they are * Velpeau, Traite- Elementaire de l'Art. des Accouchemens, i. 77, Paris, 1829, 2d Amer. Edit, by Prof. Meigs, Philad. 1838; and Adelon, Physiologie de I'Homme, 2de e"dil. iv. 26. VOL. II. — 29 338 GENERATION. very tortuous ; frequently anastomose, and their ramifications are lost in the tissue of the viscus, and on its inner surface. The veins empty themselves partly into the spermatic, and partly into the hypogastric. They are Fig. 222. even more tortuous than the arteries; and, during pregnancy, they dilate and form what have been termed the uterine sinuses. The nerves are derived part- ly from the great sym- pathetic, and partly from the sacral pairs. The uterus is some- times absent.* The appendages of the uterus are : — 1. The ligamenta lata or broad ligaments, which are formed by the pe- ritoneum. This mem- brane is reflected over the anterior and poste- rior surfaces and over the fundus of the uterus; and the lateral duplica- tures of it form a broad expansion, and envelope the Fallopian tubes and ovaria. These expansions are the broad ligaments. (See Fig. 220, and Fig. 219.) 2. The anterior and posterior ligaments, which are four in number and are formed by the peritoneum. Two of these pass from the uterus to the bladder, — the anterior; and two between the rectum and uterus, — the posterior. 3. The ligamenta rotunda or round ligaments, (Fig. 220,) which are about the size of a goose- quill, arise from the superior angles of the fundus uteri, and, pro- ceeding obliquely downwards and outwards, pass out through the abdominal rings to be lost in the cellular tissue of the groins. They are whitish, somewhat dense cords, formed by a collection of tor- tuous veins and lymphatics, of nerves, and of longitudinal fibres, which were, at one time, believed to be muscular, but are now generally considered to consist of condensed cellular tissue. 4. The Fallopian or uterine tubes; two conical, tortuous canals four or five inches in length ; situate in the same broad ligaments' that contain the ovaries and extending from the superior angles of » For a number of such cases, see Dr. Chew, Amer. Journ. Med. Sciences Mav 1840, p. 39. ' '' Nerves of the Uterus. GENERATIVE APPARATUS — FEMALE. 339 vilion. It is trumpet-shaped, fringed, and commonly inclined towards the ovary, to which it is attached by one of its longest fimbria. This fringed portion is called corpus fimbriatum or morsus diaboli. The Fallopian tubes, consequently, open at one end into the cavity of the uterus, and at the other through the peritoneum into the cavity of the abdomen. They are covered externally by the broad ligament, or peritoneum ; are lined inter- nally by a mucous membrane, which is soft, villous, and has many longitudinal folds; and between these coats is a thick, dense, whi- tish membrane, which is possessed of contractility; although mus- cular fibres cannot be detected in it.a Santorini asserts, that in robust females the middle membrane of the tubes has two muscu- lar layers; an external, the fibres of which are longitudinal, and an internal, whose fibres are circular. Recently, a memoir was read by M. Raciborski6 to the Acade- mic Roy ale des Sciences of Paris, in which he states it to be a general rule, that the extremities of the Fallopian tube in domestic animals are so placed during the act of fecundation as to envelope the entire ovary, either directly by means of the open trumpet- shaped extremity, or indirectly by the aid of the fimbriated extre- mity. In women, however, the fimbriated extremity of the tube embraces but a small portion of the ovary; and M. Raciborski thinks, that this anatomical peculiarity is the cause of extra-uterine conception being so much more common in women than in do- mestic animals. In the latter, indeed, it is very rare. The ovaries, (Fig. 224,) are two ovoid bodies, of a pale red colour, rugous, and nearly of the size of the testes of the male. They are situate in the cavity of the pelvis, and are contained in the pos- terior fold of the broad ligaments of the uterus. At one time they were conceived to be glandular, and were called the female testes ; but as soon as the notion prevailed Section of 0vary- » Weber's Hildebrandt's Handbuch der Anatomie, Band. iv. s. 422, Braunschweig 1832. b Gazette Medicale de Paris, 25 Juin, 1842. 340 GENERATION. that they contained ova, the term ovary or egg-vessel was given to them. The external extremity of the ovary has attached to it one of the principal fimbria of the Fallopian tube. The inner ex- tremity has a small fibro-vascular cord inserted into it: this passes to the uterus to which it is attached behind the insertion of the Fallopian tube, and a little lower. It is called the ligament oft the ovary, and is in the posterior ala of the broad ligament. It is solid, and has no canal. The surface of the ovary has many round prominences, and the peritoneum— forming the indusium — envelopes the whole of it, except at the part where the ovary adheres to the broad ligament. The precise nature of its paren- chyma or stroma is not determined. When torn or divided lon- gitudinally, as in Fig. 226, it appears to be constituted of a cel- lulo-vascular tissue. In this, there are from fifteen to twenty spherical vesicles — ovula Graafiana,folliculi Graafiani* ox ovi- capsules. Roedererb asserts that he found in the ovary of one woman thirty, in that of another about fifty. These are filled with an albuminous fluid, which is colourless or yellowish, and may be readily seen by dividing the vesicles carefully with the point of fine scissors. The fluid from the ovary of a mare was examined by Lassaigne, and found to contain albumen, with chlorides of sodium and potassium.0 In the lower animals, the ovarium consists of a loose tissue, containing many cells, in which the ova are formed, and from which they escape by the rupture of the cell-walls; in the higher animals, as in the human female, the tissue of the ovarium is more compact, and the ova, except when they are approaching maturity, can only be distinguished by the aid of a high magni- fying power.^ The microscopic analysis of the ovum has engaged the deep at- tention of modern histologists, who have greatly extended our knowledge in regard to it, although we have still much to learn. In man and the mammalia, the ova, even when advanced, are ex- ceedingly minute, which is owing to the small quantity of vitellus that enters into their composition. The ripest ovum in the ovary of the human subject, and of the mammalia, generally does not measure more than from the fifteenth to the twentieth part of a line in diameter; it rarely happens, that they are as much as T\th of a line. Hence, they are distinguished with difficulty by the naked eye. Under the microscope, the Graafian vesicle is found to consist of an external and internal membrane. The former — the tunic of the ovisac of Dr. Barry — is extremely vascular ; the lat- ter, the ovisac of the same observer — the membrana propria of some — is smooth and velvety, and derives its vessels from the former. The cavity, inclosed by these membranes, is far from » Weber's Hildebrandt's Handbuch der Anatomie, B. iv. 458, Braunschweig, 1832. b Stannius, art. Eierstock, in Encyclop. Wbrterb. x. 188, Berlin, 1836. c Dupuy's Journal de Medec. Veterin. for July, 1826, p. 336, & Carpenter, Human Physiology, § 739, Lond. 1842. GENERATIVE APPARATUS — FEMALE. 341 being filled by the ovum ; it contains, besides, a whitish or yellow- ish albuminous mass, which consists chiefly of granules, from the two hundredth to the three hundredth part of a line in diameter, connected together by a tenacious fluid, and forming the tunica granulosa of Dr. Barry.a Its density is unequal, and, towards some part of the periphery of the vesicle, these granules are accu- mulated in a disk-like form, making a slight prominence, in which there is a depression. The disk is termed by Von Baer discus proligerus; and it has been called discus vitellinus, and stratum proligerum. The prominence is called cumulus. Dr. Barry like- wise observed certain granular cords, resembling both in appear- ance and function the^chalazee of the egg, which he has called retinacula, but which Bischoff does not admit. A small cup-like cavity in the cumulus receives the ovum. The ovum is surrounded by a thick white ring, which has been called zona pellucida, and which has been considered to be a membrane,but, according toMr.T. W. Jones, is now pretty generally acknowledged to be " the optical expression of the circumferential doublingofa thick transparent mem- brane, which incloses the yolk." Within this, is a granular layer — the vitellus, the larger granules of which are superficial and compact; whilst, internally, it is a clear albu- minous fluid almost devoid of gra- nules. Imbedded in the vitellus, but nearer its circumference than its centre, is the germinal vesicle or vesicle of Purkinje, which ap- pears like a clear ring, of very small size, and measures, in man and the mammalia, not more than ?\yth part of a line in diameter. Upon a particular part of the germi- nal vesicle is observed the macula germinativa or germinal spot, which presents itself as a rounded granular formation attached to the inner wall of the germinal vesicle. All these parts are repre- sented in the marginal figure. Wagnerb thinks the germinal vesicle may be viewed as a cell — a primary cell — of which the germinal spot forms the nucleus, and that it would perhaps be well to style the germinal spot the germinal nucleus. The experiments of Carusc have shown, that the vesicles exist a Philos. Transact, for 1838. b Human Physiology, translated by R. Willis, p. 43, Lond. 1841. See, also, the works of the various ovologists referred to hereafter, and especially an elaborate report on the ovum of man and the mammalia before and after fecundation, by Mr. T. W. Jones, in Brit, and For. Med. Rev., Oct. 1843, p» 513. c Gazette Medicale de Paris, Aug. 12, 1837. 29* Ripe Ovum of Rabbit, taken from the Graafian Vesicle. a, a. Proligenous disks, the edges of which are ragged and irregularly notched, the clear parts, b, b, being pale oil-globules, c. The zona pellucida. d. The vitelline membrane. e. Vitellus. /. Germinal vesicle, g. Germi- nal spot.— (Wagner.) 342 GENERATION. Fig. 226. even in the foetus. In these vesicles, we shall see hereafter, the ovum is contained. The arteries and veins of the ovaries belong to the spermatics. The arteries pass between the two layers of the broad ligament to the ovarium, assuming there a beautiful con- voluted arrangement, very similar to the convoluted arteries of the testis. These vessels traverse the ovary nearly in paral- lel lines, as in the marginal figure, form- ing numerous minute twigs, which have an irregular knotty appearance, from their tortuous condition, and appear to be chiefly distributed to the Graafian vesi- cles.3 The nerves of the ovaries, which are extremely delicate, are from the renal plexuses ; and their lym- phatics communicate with those of the kidneys. Such is the anatomy of the chief organs concerned in the func- tion of generation. Those of lactation we shall describe hereafter. Longitudinal Division of the Ovary. 1. MENSTRUATION. Before proceeding to the physiology of generation, there is one function, peculiar to the female, which will require consideration. This consists in a periodical discharge of blood from the vulva, occurring from three to six days in every month, during the whole time that the female is capable of conceiving, or from the period of puberty to what has been termed the critical age. This discharge is called the catamenia, menses, flowers, &c, and the process men- struation. It seems to be possessed by the human species alone.b MM. Geoffroy St. Hilaire, and F. Cuvier, however, assert, that they have discovered indications of it in the females of certain animals; but it is usually denied that this is any thing more than the exudation of a bloody mucus.0 In some females, menstruation is established suddenly, and without any premonitory symptoms; but, in the greater number, it is preceded and accompanied by some inconvenience. The female complains of signs of plethora, or general excitement, — indicated by redness and heat of skin, heaviness in the head, oppression, quick pulse, and pains in the back or abdomen ; whilst the discharge commences drop by drop, but continuously. During the first twenty-four hours, the flow is not as great as afterwards, and is more of a serous character ; but, on the following day, it becomes more abundant and sanguineous, and gradually subsides, leaving, in many females, a whitish, mu- cous discharge, technically termed leucorrhcea, and, in popular language, the whites. a E. Rigby, System of Midwifery, Amer. Edit. p. 23, Philad. 1841. b Blumenbach, De Gener. Human. Variet. ed. 3, p. 51, Gotting. 1795. e Dr. Allen Thomson, art. Generation, in Cyclop, of Anatomy and Physiology, part xiii. p. 441, Feb. 1838. MENSTRUATION. 343 The quantity of fluid lost, during each menstruation, varies greatly, according to the individual and to the climate. Its average is supposed to be from six to eight ounces in temperate climes. By some, it has been estimated as high as twenty, but this is an exaggeration. The fluid proceeds from the interior of the uterus, and not from the vagina. At one time, it was believed, that in the intervals between the flow of the menses, the blood gradually * accumulates in some parts of the uterus, and when these parts attain a certain degree of fulness, they give way and the blood flows. This office was ascribed to the cells, — which were con- ceived to exist in the substance of the uterus between the uterine arteries and veins, — and, by some, to the veins themselves, which, owing to their great size, were presumed to be reservoirs, and hence were called uterine sinuses. The objection to these views is,— that we have no evidence of the existence of any such accumula- tion ; and that when the interior of the uterus of one who has died during menstruation is examined, there are no signs of any such rupture as that described : the enlarged vessels exist only during pregnancy or during the expanded state of the uterus; the veins, in the unimpregnated uterus, being extremely small, and totally inadequate for such a purpose. The menstrual fluid is a true exhalation, effected from the inner surface of the uterus. This is evident from the change in the lining membrane of the organ during the period of its flow. It is rendered softer and more villous, and exhibits bloody spots, with numerous pores from which the fluid may be expressed. An injection, sent into the arteries of the uterus, also readily transudes through the lining membrane. The appearance of the menstrual fluid in the cavity of the uterus, during the period of its flow ; its suppression in various morbid conditions of the organ; and the direct evidence, furnished to Ruysch, Blundell,a Sir C. Clarke,b and others, in cases of prolapsus or of inversio uteri, where the fluid has been seen distilling from the uterus, likewise show that it is a uterine ex- halation. It has been a question, whether the fluid proceeds from the arteries or veins; and this has arisen from the circumstance of its being regarded as mere blood; but it is in appearance not much like blood ; and it may be distinguished from it by the smell, which is sui generis, and also by not being coagulable. " It is," says Mr. Hunter, " neither similar to blood taken from a vein of the same person, nor to that which is extravasated by acci- dent in any other part of the body, but is a species of blood, changed, separated, or thrown off from the common mass by an action of the vessels of the uterus, similar to that of secretion, by which action the blood loses the principle of coagulation and, I suppose, life." The principle of coagulation does not exist, owing, accord- » Principles and Practice of Obstetricy, Amer. Edit. p. 49, Washington, 1834. b On Diseases of Females, attended with Discharges, Amer. Edit. Philad. 1824 ; see, also, Dr. D. Davis, in Principles, &c, of Obstetric Medicine, i. 256, Lond. 1836. 344 GENERATION. ing to Lavagna,aToulmouche, and J. Muller,b to absence of fibrin, Retzius0 asserts, that he has detected in it free phosphoric and lactic acids, by the presence of which, he conceives, the fibrin is kept in a state of solution and prevented from coagulating. The fluid has the properties, according to Brande, of a very concentrated solu- tion of the colouring matter of the blood in a dilute serum.d Dr. Burowe examined twelve ounces of menstrual blood, which had been retained in the uterus by an imperforate hymen. The fluid was of a dirty reddish brown colour, of the consistence of syrup, very adhesive, and entirely devoid of odour. It abounded in albu- men, and was very little susceptible of putrefaction. When ex- amined with the microscope, almost all the blood-globules were found to have lost their regular form, and to resemble the granules, observed in pus which has been for a long time exposed to the air, or retained within the cavity of an abscess. These blood-globules were suspended in a transparent fluid. On stirring the blood for a considerable time, no perceptible change was produced to the eye, but under the microscope numerous delicate transparent lamellae were seen floating in the serum, which Dr. Burow re- garded as portions of fibrin, a substance sparingly present — as has been remarked — in menstrual blood. The red colour of the menstrual fluid was found by Remakf to be owing to the presence of blood-globules, and the intensity of the colour to their number. M. Bouchardate has recently undertaken a new analysis of the - menstrual fluid, obtained from a female who permitted a speculum to remain in the vagina for ten hours in order that an ounce might be procured. Without this precaution, the fluid becomes mixed with vaginal mucus, and urine, as the presence of ammo • niaco-magnesian phosphate demonstrates. The following were the results of the analysis : — Water, 90-8 ; fixed matters, 6-92. The fixed matters were composed of—fibrin, albumen, and colour- ing matter, 75-27; extractive matter, 0-42; fatty matter, 2-21; salts, 5-31 ; mucus, 1679. The female was a patient of M. Briere de Boismont, who considers, that the large proportion of water was due to the delicacy of her frame, and to her subsisting on vegetable diet (?). Another specimen of menstrual fluid, examined by M. Donne, presented the following appearances under the microscope. 1. Abundance of the ordinary corpuscles of the blood. 2. Vaginal mucus, formed of epidermic scales from the mucous membrane. 3. Mucous globules, furnished by the neck a Brugnatelli, Giornale di Fisica, &c. p. 397,1817 ; Desorme'aux, in Dict.de Medec xvi. 181. b Handbuch der Physiologie, Baly's translation, p. 256, Lond. 1837, and p 1481 Lond. 1842. c Ars Berattelse af Setterblad, 1835, Seite 19 — quoted in Zeitschrift fiir die Ge- sammte Medicin. Marz, 1837, S. 390. d Philos. Transact, cii. 113 ; and Blundell, op. cit. p. 46. e Miiller's Archiv. No. vii. 1840 ; and Brit, and For. Med. Rev., July, 1840 p 287 f Medicinische Zeitung, Dec. 25, 1839. See, also, Mr. Ancell, Lectures'on the Physiology and Pathology of the Blood, April 25, 1840, p. 149. g Briere de Boismont, De la Menstruation, &c, Paris, 1842 ; and Provincial Med Journal, July 30,1842. MENSTRUATION. 345 of the uterus (?). So far, therefore, as these examinations go, they would show, that there is a resemblance between the catamenial discharge and arterial blood. The fact of injections, sent into the arteries, transuding through the inner lining of the uterus is in favour of the exhalation taking place from the arteries, and the analogy of all the other exhalations is confirmatory of the position. Still there are many eminent physiologists and obstetricians who regard the discharge as a monthly hemorrhage. The efficient cause of menstruation has afforded ample scope for speculation and hypothesis.* As its recurrence corresponds to a revolution of the moon around the earth, lunar influence has been invoked ; but, before this solution can be admitted, it must be shown, that the effect of lunar attraction is different in the vari- ous relative positions of the moon and earth. There is no day- in the month, in which numerous females do not commence their menstrual flux, and, whilst the discharge is beginning with some, it is at its acme or decline with others. The hypothesis of lunar influence must therefore be rejected. In the time of Van Hel- mont,b it was believed, that a ferment exists in the uterus, which gives occasion to a periodical intestine motion in the vessels, and a recurrence of the discharge ; but independently of the want of evidence of the existence of such a ferment, the difficulty remains of accounting for its regular renovation every month. Local and general plethora have been assigned as causes, and many of the circumstances, that modify the flow, favour the opinion. The fact of, what has been called, vicarious menstruation has been urged in support of this view. In these cases, instead of the men- strual flux taking place from the uterus, hemorrhages occur from various other parts of the body, as the breast, lungs, ears, eyes, nose, &c. It does not seem, however, that in any of these cases, the term menstruation is appropriate; inasmuch as the fluid is not menstrual, but consists of blood periodically extravasated. Still, they would appear to indicate, that there is a necessity for the monthly evacuation ox purgation, R e in i g u n g, as the French and Germans term it; and that if this be obstructed, a vicarious hemorrhage may be established ; yet the loss of several times the quantity of blood from the arm, previous to, or in the very act of, menstruation does not always prevent, or interrupt the flow of the catamenia; and in those maladies, which are caused by their ob- struction, greater relief is afforded by the flow of a few drops from the uterus itself, than by ten times the quantity from any other part. Some of the believers in local plethora of the uterus have maintained, that the arteries of the pelvis are more relaxed in the female than in the male, and the veins more unyielding; hence, that the first of these vessels convey more blood than the second return. It has been also affirmed, that whilst the arteries of the head predominate in man, by reason of his being more dis- » Dr. D. Davis, op. cit. i, 259. i* Opera, edit. 4, p. 440, Lugd. Bat. 1667; and Haller, Elementa Physiologic, vii. 1, 346 GENERATION. posed for intellectual meditation, the pelvic and uterine arteries predominate in the female, owing to her destination being more especially for reproduction. Setttng aside all these gratuitous as- sumptions, it is obvious, that a state, if not of plethora, at least of irritation, must occur in the uterus every month, which gives occa- sion to the menstrual secretion ; but, as Adelona has properly re- marked, it is not possible to say, why this irritation is renewed monthly, any more than to explain, why the predominance of one organ succeeds that of another in the succession of the ages. The func- tion is as natural, as instinctive to the female, as the development of the whole sexual system at the period of puberty. That it is con- nected most materially with the capability of reproduction is shown by the fact, that it does not make its appearance until puberty, — the period at which the young female is capable of conceiving,— and that it disappears at the critical time of life, when conception is impracticable. It is arrested, too, as a general rule, during pregnancy and lactation ; and in amenorrhoea or obstruction of the menses, fecundation is not readily effected. In that variety, indeed, of menstruation, which is accomplished with much pain at every period, and is accompanied by the secretion of a membra- nous substance having the shape of the uterine cavity, conception may be esteemed impracticable. Professor Hamilton, of the Uni- versity of Edinburgh, was in the habit of adducing this, in his lectures, as one of two circumstances — the other being the want of a uterus — that are invincible obstacles to fecundation. Yet, in the case of dysmenorrhea, of the kind mentioned, if the female can be made to pass one monthly period without suffering, or without the morbid secretion from the uterine cavity, she may become pregnant, and the whole of the evil be removed: for, the effect of pregnancy being to arrest the catamenia, the morbid habit is usually got rid of during gestation and lactation, and may not subsequently recur. Gallb strangely supposed, that some general, but extraneous cause of menstruation exists,— not the influence of the moon ; and he affirms, that, in all countries, females generally menstruate about the same time ; that there are, consequently, periods of the month in which none are in that condition; and he affirms, that all females may, in this respect, be divided into two classes : — the one comprising those who menstruate in the first eight days of the month, and the other, those who are " unwell" — as it is termed by them, in some countries — in the last fortnight. He does not, however, attempt to divine what this cause is. We are satisfied, that his positions are erroneous. Attention to the matter has led us to the knowledge, already expressed, that there is no period of the moon, at which the catamenial discharge is not taking place in some ; and we have not the slightest reason for supposing, that, on the average, more females are menstruating 1 Physiologie de I'Homme, 2de e*dit. iv. 48, Paris, 1829. b Sur les Fonctions du Cerveau, iv. p. 355. MENSTRUATION. 347 at any one part of the month than at another.8 It would seem, however, that there are circumstances in the economy, which, as in the case of fevers, give occasion to something like periodicity at intervals of seven days ; — for example, Mr. Roberton,b of Man- chester, England, asserts, that of 100 women, the catamenia re- turned every fourth week in 6S; every third week in 28; every second week in 1 ; and at irregular intervals in 10; these varie- ties usually existing as family and constitutional peculiarities. It is scarcely necessary to notice the visionary speculations of those who have regarded menstruation-as a mechanical conse- quence of the erect attitude ; or the opinion of Roussel,0 that it originally did not exist, but that being produced artificially by too succulent and nutritious a regimen, it was afterwards propagated from generation to generation; or, finally, that of Aubert, who maintained, that if the first amorous inclinations were satisfied, the resulting pregnancy would totally prevent the establishment of menstruation. The function, it need scarcely be repeated, is instinctive, and forms an essential part of the female constitution. Of late, M. Gendrind has revived a view entertained by Mr. Cruikshank,e Dr. Power/ and others, that menstruation is depen- dent upon changes occurring periodically in the ovary. Many cases have been observed by Cruikshank, Robt. Lee,s Gendrin and others, in which, on the dissection of females who have died during menstruation, evidences have been afforded of the rupture of an ovarian vesicle, and of a small ir- Fig. 227. regular rupture or cicatrix in the coats of the ova- rium, as repre- sented in the marginal figure, which communi- cated with the re- mains of a Graaf- ian vesicle :h whence it has been inferred, that during the whole of that period of life 1 See art. Generation, by Dr. Allen Thomson, in Cycl. Anat. and Physiol., part xiii. p. 440, Feb. 1838. »> Edinb. Med. and Surg. Journal, xxxviii. 237. c Systeme Physique, &c, de la Femme, p. 13, Paris, 1809. d Traite Philosophique de Mddecine Pratique, Paris, 1838-9. • See Brit, and For. Med. Review, Oct. 1840, p. 592. f An Essay on the Periodical Discharge, &c, Lond. 1832. e M. Negrier, cited in Dunglison's Amer. Med. Intelligencer, July 15,1840, p. 121. See, also, Dr. Robt. Lee, art. Ovaria, Cyclopaedia of Pract. Medicine; Dr. Laycock, on the Nervous Diseases of Women, p. 42, Lond. 1840 ; and Dr. R. Willis, in note to Wagner's Elements of Physiology, p. 69, Lond. 1841. h Churchill, Theory and Practice of Midwifery, Amer. Edit, by Prof. R. M. Huston, p. 71, Philad. 1843. Ovary of a Female dying daring Menstruation. 348 GENERATION. when the capability of conception continues, there is a constantly successive development of vesicles and their contained ovules in the ovary, and that, at each epoch of menstruation, a vesicle having reached the surface of the ovary becomes the foyer of a peculiar organic action, in which all the organs of generation par- ticipate ; and that the result of this action is the rupture of the vesicle, and the loss of the infecund ovum, either by expulsion from the uterus or by destruction in the ovary. Still more recently, M. Raciborski,3 in a letter to the Academie Roy ale de Medecine of Paris, has maintained, as the result of his researches on menstrua- tion—First. That there exists the most intimate connection between the Graafian vesicles and menstruation. When these vesicles arrive at their full development, menstruation commences, and when they are destroyed, it ceases. Secondly. At each menstrual period, a follicle projects like a nipple on the surface of the ovary, where it afterwards bursts, without requiring for that purpose any venereal excitement. Thirdly. The rupture of the follicles in general appears to take place at the period when the menstrual discharge is stopping; and Fourthly. The ovaries do not act al- ternately, as has been affirmed : in this respect not seeming to be under any fixed law. It must be admitted, then, that there cer- tainly would seem to be a close and intimate relation between the number of cicatrices on the surface of the ovaries, and the num- ber of times a female has menstruated.11 The age, at which menstruation commences, varies in individuals and in different climates. It has been esteemed a general law, that the warmer the climate, the earlier the discharge takes place, and the sooner it ceases; but there is reason for doubting the correct- ness of this prevalent belief.0 With us, the most common period of its commencement is from thirteen to seventeen years. Mahomet is said to have consummated his marriage with one of his wives, " when she was full eight years old."d Of 450 cases, observed at the Manchester Lying-in Hospital, in England,e menstruation com- menced in the eleventh year in 10 ; in the twelfth in 19; in the thirteenth in 53; in the fourteenth in 85 ; in the fifteenth in 97 ; in the sixteenth in 76 ; in the seventeenth in 57 ; in the eighteenth in 26 ; in the nineteenth in 23 ; and in the twentieth in 4. Men- struation commonly ceases in the temperate zone at from forty to fifty years. These estimates are, however, liable to many excep- tions. In rare cases, the catamenia have appeared at a very early age, even in childhood; and again, the menses, with powers of fecundity, have continued, in particular instances, beyond the ages that have been specified: some of these protracted cases have had regular catamenia; in others, the discharge, after a long suppres- sion, has returned. Of 77 individuals, they ceased in 1 at the age » Bullet, de l'Academ. Royal, de Med. Jan. 1843 ; and Edinb. Med. and Surg. Journ April, 1843. b See, on this subject, Mr. Girdwood, London Lancet, March 4, 1843, p. 825. c Dr. A. Thomson, op. citat. p. 442. <> Prideaux's Life of Mahomet, p. 30, Lond. 1718. e Roberton, op. citat. MENSTRUATION. 349 of 35 ; in 4 at 40; in 1 at 42 ; in 1 at 43 ; in 3 at 44 ; in 4 at 45 ; in 3 at 47 ; in 10 at 48 ; in 7 at 49 ; in 26 at 50 ; in 2 at 51 ; in 7 at 52 ; in 2 at 53 ; in 2 at 54; in 1 at 57 ; in 2 at 60; and in 1 at 70. Of the 10,000 pregnant females, registered at the Man- chester Hospital, 436 were upwards of 40 years of age ; 397 from 40 to 45; 13 in their 47th year; Sin their 48th; 6 in their 49th ; 9 in their 50th; 1 in her 52d; 1 in her 53d; and 1 in her 54th. Mr. Roberton asserts, that as far as he could ascertain, — and es- pecially in the three cases above 50 years, — the catamenia con- tinued up to the period of conception.3 The following table has recently been published by M. Briere de Boismont.b It is founded on the results of 2352 cases. It will be seen from it, that by far the greatest number of women begin to menstruate during the 14th or 15th year. Age. 5 Paris, 1200 cases by Meniers. Paris, 85 cases by Marc D'Es-pine. Lyons, 432 cases by Petrequin. Marseilles, 68 cases by Marc D'Es pine. Manchester, 450 cases by Roberton. Gottingen, 137 cases by Osiander. 1 0 0 0 0 0 7 1 0 0 0 0 0 8 2 0 t o 0 0 0 9 10 1 0 0 0 0 10 29 0 5 0 0 0 11 93 3 14 6 10 0 * 12 105 14 26 10 19 3 13 132 6 47 13 53 8 14 194 18 50 9 85 21 15 190 14 70 16 97 32 16 141 7 79 8 76 24 17 127 6 58 4 57 11 18 90 5 38 2 26 18 19 35 8 21 0 23 10 20 30 3 9 0 4 8 21 8 0 5 0 0 1 22 8 0 1 0 0 0 23 4 0 0 0 0 1 24 0 0 3 0 0 0« Mr. Robertond has attempted, and successfully, to show, that the age of puberty is as early in the cold, as in the tropical regions of the earth ; and, that were marriages to take place in England, at as juvenile an age as they do in Hindusthan, instances of very early fecundity would be as common in England as they are in that country. He is of opinion, that early marriage and early in- tercourse between the sexes, where found prevailing generally, " are to be attributed, not to any peculiar precocity, but to moral and political degradation, exhibited in ill laws and customs, the enslavement more'or less of the women, ignorance of letters, and a See Montgomery, on the Signs and Symptoms of Pregnancy, p. 160, Lond. 1837. b De la Menstruation, &c, Paris, 1842. c For a similar table, formed from 5062 cases, see Dr. W. A. Guy, Principles of Forensic Medicine, part i. p. 79, Lond. 1843. d Edinb. Med. and Surg. Journal, Oct. 1832, and July, 1842 ; and Lond. Med. Gaz., July 21, 1843. VOL. II. — 30 350 GENERATION. impure or debasing systems of religion." He has also shown, from statistical evidence, that menstruation does not occur more early in the negress than in the white female. In the statement sent to Parliament by Bartholomew Mosse, when endeavouring to procure a grant for the Dublin Lying-in Hospital, he mentions, that 84 of the women delivered under his care were between the ages of 41 and 54; 4 of these were in their 51st year, and 1 in her 54th. A relation of Haller had two sons after her fiftieth year ; and children are said to have been born even after the mother had attained the age of sixty.3 Holdefreund re- lates the case of a female, in whom menstruation continued till the age of seventy-one ;b Bourgeois till the age of eighty ; and Hagen- dorn till ninety; however, it is probable that these were not cases of true menstruation, but perhaps of irregularly periodical dis- charges of true blood from the uterus or vagina.6 As a general rule, the appearance of the menses denotes the capability of being impregnated, and their cessation the loss of such capability. Yet, females have become mothers without ever hav- ing menstruated.*1 Foder6e attended a woman, who had men- struated but once —in her 17th year, — although 35 years of age, healthy, and the mother of five children. Morgagni instances a mother and daughter, both of whom were mothers before they menstruated. Sir E. Homef mentions the case of a young woman, who was married before she was seventeen, and having never menstruated, became pregnant; four months after her delivery, she became pregnant again; and four months after the second delivery, she was a third time pregnant, but miscarried: after this she menstruated for the first time, and continued to do so for several periods, when she again became pregnant; and Mr. Har- rison,^ at a meeting of the Westminster Medical Society remarked, that he knew an instance in which the mother of a large family had never menstruated; — yet Dr. Deweesh and Dr. Campbell' assert, that there is not a properly attested instance on record, of a female conceiving, previous to the establishment of the cata- menia : the latter gentleman admits, however, that when an indi- vidual has once been impregnated, she may conceive again, seve- ral times in succession, without any recurrence of the catamenia between these different conceptions, — because he has known a case of this kind, but not of the other! During the existence of menstruation, the system of the female * See-a case of this kind in Transylvania Journal, ix. 185, Lexington, 1836, b See a case by Dr. Strassberger, of recurrence of menstruation at 80, after it had ceased at 42 years of age, in Medicin. Zeitung, s. 248, Nov. 30, 1836. e Dr. D. Davis, Principles, &c. of Obstetric Medicine, i. 239, London, 1836 • and C. W. Mehliss, Leber Virilescenz und Rejuvenescenz Thierischer Kbrper, s. 75, Leipz. 1838. d Churchill, op. cit. e Medecine Legale, i. 393, Paris, 1813.' f Philosoph. Transact, cvii. 258; and Lect. on Comp. Anat. iii. 298. s Lond. Lancet, Jan. 19, 1839, p. 619. '• (Jompend. System of Midwifery, 8th edit. Philad. 1836. : Introduction to the Study of Midwifery, Edinb. 1833. SEXUAL AMBIGUITY. 351 is more irritable than at other times; so that all exposure to sud- den and irregular checks of transpiration should be avoided, as well as every kind of mental and corporeal agitation, otherwise the process may be impeded, or hysterical and other troublesome affections be excited. The sacred volume exhibits the feeling en- tertained towards the female, whilst performing this natural func- tion. Not only was she regarded " unclean" in antiquity ; she was looked upon, as Dr. Elliotson has remarked,3 as mysteriously deleterious. In the time of Pliny,b a female, during menstruation, was considered to blight corn, destroy grafts and hives of bees, dry up fields of corn, cause iron and copper to rust and smell, drive dogs mad, &c, &c; and it is firmly believed by many, in England, that meat will not take salt if the process be conducted by a female so circumstanced. The temperature of the vagina does not appear to be affected by menstruation or pregnancy.0 c. Sexual Ambiguity. The sexual characteristics, in the human species, are widely separate ; and the two perfect sexes are never, perhaps, united in the same individual. Yet such an unnatural union has been supposed to exist; from the fabulous son of 'e^»c and a^wi, — Mercury and Venus, — to his less dignified representative of mo- dern times: — " Nee foemina dici, Nee puer utpossent, neutrumque et utrumque videntur."— OvidA We have already remarked, that in the lower animals, and in plants, such hermaphrodism is common ; but, in the upper classes and especially in man, a formation, which gives to an individual the attributes of both sexes has never been witnessed." Monstrous formations are occasionally met with; but if careful examination be made, it can usually be determined to what sex they rather be- long. Cases, however, occur, in which it is extremely difficult to decide, although we may readily pronounce that the being is totally incapable of the function of reproduction. The generality of cases are produced by unusual development of the clitoris in the female, or by a cleft scrotum in the male. Only two instances of this kind have fallen under the observation of the author, both of which were females, as they usually are. One of these has been described by the late Professor Beclard, of Paris, whose de- tails we borrow.f 1 Elliotson's Blumenbach, p. 465, Lond. 1828. •> Histor. Natural, xxvii. « Fricke, Zeitschrift fur die Gesammte Medicin, Nov. 1838. i " Both bodies in a single body mix, A single body with a double sex." — Addison. e Dr. Willis, in Wagner's Elements of Physiology, part i. p. 55, Philad. 1841. See a case of supposed hermaphrodism, by Robt. Perry, with the dissection, by Sir Astley Cooper, in Guy's Hospital Reports, for April and October, 1840. f Art. Hermaphrodite, in Diet, de Medecine, torn, xi. 352 GENERATION. Marie-Madeleine Lefort, aged sixteen years, seemed to belong to the male sex, if attention were paid merely to the proportions of the trunk, limbs, shoulders, and pelvis ; to the conformation and dimensions of the pelvis; to the size of the larynx ; the tone of the voice, the development of the hair ; and to the form of the urethra, which extended beyond the symphysis pubis. An atten- tive examination, however, of the genital organs showed, that she was of the female sex. The mons veneris was round and covered with hair. Below the symphysis pubis was a clitoris, resembling the penis in shape, twenty-seven millimetres, or about an inch long, in the state of flaccidity ; and susceptible of slight elongation during erection; having an imperforate glans, hollowed beneath by a duct or channel, at the inferior part of which were five small holes, situate regularly on the median line. Beneath and behind the clitoris, a vulva existed, with two narrow, short and thin labia, furnished with hair, devoid of any thing like testicles, and extend- ing to within ten lines of the anus. Between the labia was a very superficial cleft, pressure upon which communicated a vague sensation of a void space in front of the anus. At the root of the clitoris was a round aperture,"through which a catheter could not be passed into the bladder. It could be readily directed, how- ver, towards the anus, in a direction parallel to the perineum. When the catheter was passed a little backwards and upwards to the depth of eight or ten centimetres, it was arrested by a sensible obstacle, but no urine flowed through it. It seemed to be in the vagina. At the part where the vagina stopped, a substance could be distinguished through the parietes of the rectum, which ap- peared to be the body of the uterus. Nowhere could testicles be discovered. She had menstruated from the age of eight years ; the blood issuing in a half coagulated state through the aperture at the root of the clitoris. She experienced, too, manifest inclina- tion for commerce with the male, and a slight operation only would probably have been necessary to divide the apron, closing the vulva from the clitoris to the posterior commissure of the labia. The urethra extended in this case for some distance beneath the clito- ris, as in the penis. From all the circumstances,M. Beclard concluded that the person, subjected to the examination of the SocUte de Medecine of Paris, was a female; and that she possessed several of the essential organs of the female ; — the uterus and vagina__ whilst she had only the secondary characters of the male ;__as the proportions of the trunk and limbs; that of the shoulders and pelvis ; the conformation and dimensions of the pelvis; the size of the larynx; the tone of the voice; the development of the hair • the urethra extending beyond the symphysis pubis, &c. In the year 1818, an individual was exhibited in London, who had a singular union of the apparent characteristics of the two sexes. The countenance resembled that of the male, and she had a beard, but it was scanty. The shape, however, of the body and limbs was that of the female. The students of the Anatomical SEXUAL AMBIGUITY. 353 Theatre of Great Blenheim Street, London, of whom the author was one, offered her a certain sum, provided she would permit the sexual organs to be inspected by the veteran head of the school — Mr. Brookes : to this she consented. She was, accordingly, ex- posed before the class; and her most striking peculiarities exhibit- ed. The clitoris was large, but not perforate. Mr. Brookes, desirous of trying the experimentum crucis, passed a catheter into the vagina, and attempted to introduce another into the ure- thra ; but fearing discovery, and finding that the mystery of her condition was on the point of being unveiled, she started up and defeated the experiment. No doubt existed in the mind of Mr. Brookes, that there were two distinct canals, — one forming the vagina ; the other the urethra, — and that she was consequently female. One of the most complete cases of admixture of the sexes was laid by Rudolphi before the Academy of Sciences of Berlin, at the sitting of Oct. 22, 1S25.11 It was met with in the body of a child, which died, it was said, seven days after birth, but the development of parts led to the supposition, that it was three months old. The penis was divided inferiorly ; the right side of the scrotum con- tained a testicle ; the left side was small and empty. There was a uterus, which communicated at its superior and left portion with a Fallopian tube, behind which was an ovary destitute of its liga- ment. On the night side, there was neither Fallopian tube, nor ovary, nor ligament, but a true testicle, from the epididymis of which arose a vas deferens. Below the uterus was a hard, flat- tened ovoid body, which, when divided, exhibited a cavity with thick parietes. The uterus terminated above in the parietes of this body, but without penetrating its cavity. At its inferior part was a true vagina, which terminated in a cul-de-sac. The urethra opened into the bladder, which was perfect; and the amis, rectum and other organs were naturally formed. Rudolphi considered the ovoid body, situate beneath the uterus, to be the prostate, and vesiculae seminales in a rudimental state. A curious case of doubtful sex was seen by the author's friend — Dr. Pue, of Baltimore. It occurred in a negro, who had the ap- pearance of a woman, and passed for such. On examination, at the request, of her owner, Dr. Pue found no signs of female organs of generation. There was a penis of some development — the size of a boy's, 12 or 14 years old. The glans was well formed, but the urethra did not terminate at the extremity of the organ. It opened at the frsenum. There was some appearance of scrotum, but no testes were perceptible. Menstruation took place regularly, but with great pain, the fluid passing through the urethra. During this period, the breasts— which were natural, and the size of a girl's of 14 — became tender and swollen, and she had at this time only a desire for copulation. The pubes was well covered with hair. Dr. Pue's impression was, that her inclinations were for the a Amer. Journ. of the Med. Sciences, p. 499, Feb. 1832. 30* 354 GENERATION. male. A very interesting case has likewise been described by Professor Mayer« of Bonn. The mixed attributes of male and female were well marked. On the one hand, there was a testicle slightly atrophied, a penis and a prostate gland; on the other, a vagina and uterus, with its Fallopian tubes, and on the left side a body analogous to an ovary. Cases like the above, — and we have such on the authority of Baillie, Verdier, Giraud, Ackermann, Handy, Sir E. Home, Pinel, Maret, Sue, Bouillaud, and others,— have led to the belief, that hermaphrodism is possible.b This is the opinion of Tiedemann, Meckel, and many other physiologists, but it does not rest on any observed examples. The varieties of these sexual vagaries are extremely numerous ; and form occasionally the subject of medico- legal inquiry. Instances of animals being brought forth, whose organs of gene- ratior/are preternaturally formed, sometimes occur, and they also have been commonly called hermaphrodites ; but such examples have been rarely investigated. Monstrous productions, having a mixture of the male and female organs, seem to occur most fre- quently in neat cattle, and have been called free-martins. When a cow brings forth twin calves, one a male and the other appa- rently a female, the former always grows up to be a perfect bull, but the latter appears destitute of all sexual functions, and never propagates. This is the free-martin. It was th^e opinion of Mr. Hunter, that the free-martin never exhibits sexual propensities; but this has been controverted by Mr. AUnatt.c A clergyman of great respectability informed that gentleman, that he had bred a free-martin upon his estate, which had not only shown the natural desire for the male, but had actually admitted him — of course, ineffectually. Mr. Allnatt farther remarks, that he had seen, the day before, working in harness, a true, apparently female, adult free-martin, which occasionally manifested its male propensities in an intelligible manner. When the cows amongst which this free- martin is kept, exhibit their inclination for the male, the creature — unlike the spayed heifer or common ox — is peculiarly on the alert, and has been observed to leap the cows like the entire male. A gentleman of Mr. Allnatt's neighbourhood had a true free-martin, which had received the bull several times, but had never propa- gated. After death the animal was examined. Scarcely a ves- tige of uterus could be discovered. From Mr. Hunter's observa- tions'1 it would seem, that in all the instances of free-martins, which he examined, no one had the complete organs of the male and * Gazette Medicale de Paris, Sept. 24,1836 ; and Philadelphia Med. Examiner Anril 10, 1841, p. 232. ,-npni t> Dr. Simpson, art. Hermaphroditism, Cyclop, of Anat. and Physiol, vol. ii. • Marc art. Hermaphrodisme, Diet, de Medecine, 2de edit. xv. 241, Paris, 1837; Beck Med' Jurisprud. 6th edit. vol. i. Philad. 1838; Mr. Pilcher, Lancet, March 17, 1838 p' 915 • and W. A. Guy, Principles of Forensic Medicine, part i. p. 36, Lond. 1843. ' c London Medical Gazette for July 2d, 1836. i Animal Q2conomy, edit, by Mr. Owen, Lond. 1838. PHYSIOLOGY OF GENERATION. 355 female, but partly the one and partly the other ; and, in all, the ovaria and testicles were too imperfect to perform their functions. In noticing this phenomenon, Sir Everard Home" remarks, that it may account for twins being most commonly of the same sex; "and when they are of different sexes," he adds, "it leads to in- quire whether the female, when grown up, has not less of the true female character than other women, and is incapable of having children." " It is curious," says Sir Everard, " and in some mea- sure to the purpose, that, in some countries, nurses and midwives have a prejudice, that such twins seldom breed." The remark of Sir Everard is signally unfortunate, and ought not to have been hastily hazarded, seeing that a slight examination would have exhibited, that there is no analogy between the free-martin and the females in question; and, more especially, as the suggestion accords with a popular prejudice, highly injurious to the prospects and painful to the feelings of all who are thus circumstanced. In the London Medical Repository,0 Mr. Cribb, of Cambridge, England, has properly observed, that the external characters and anatomical conformation of the free-martin are totally unlike those of the human female. In external appearance, the free-martin differs considera- bly from the perfectly formed cow ; —the head and neck, in par- ticular, bearing a striking resemblance to those of the bull. Mr. Cribb has, however, brought forward the most decisive evidence in favour of the fallacy of the popular prejudice, by the history of seven cases, which are of themselves sufficient to put the matter for ever at rest. Of these seven cases, which are all that he had ever known, of women, born under the circumstances in question, having been married, — six had children. The case of an orang-outang, described by Dr. Harlan,c affords the nearest approach to a complete union of the sexes in the same individual, which has been recorded. It possessed ovaries, Fallo- pian tubes, uterus and vagina, and also testes, epididymis, vasa deferentia, and a highly erectile penis. 1. PHYSIOLOGY OF GENERATION. In man and the superior animals, in which each sex is possessed by a distinct individual, it is necessary, that there should be a union of the sexes, and that the fecundating fluid of the male should be conveyed within the appropriate organs of the female, in order that, from the concourse of the matters furnished by both sexes, a new individual may result. To this union we are incited by an imperious instinct, established within us for the preservation of the species, as the senses of hunger and thirst are placed within us for the preservation of the individual. This has been termed the desire or instinct of reproduction; and for wise purposes, its grati- fication is attended with the most pleasurable feelings, which man * Philosoph. Transactions for 1799 ; and Lectures on Comparative Anatomy, iii. 311, Lond. 1823. b Sept. 1823, and ibid. 1827. c Medical and Physical Researches, p. 22, Philad. 1835. g^g GENERATION. or animals can experience. Prior to the period of puberty, or whilst the individual is incapable of procreation, this desire does not exist; but it suddenly makes its appearance at puberty, per- sists vehemently during youth and the adult age, and disappears in advanced life, when procreation becomes again impracticable. It is strikingly exhibited in those animals, in which generation can only be effected at particular periods of the year, or whilst they are in heat; — as in the deer, during the rutting season. The views, which have been entertained, regarding the seat of this instinct — whether in the encephalon or genital organs — were considered under the head of the mental and moral manifestations. It was there stated, that Cabanis and Broussais make the internal impressions to proceed from the genital organs, but to form a part of the psychology of the individual ; and that Gall assigns an en- cephalic organ— the cerebellum — for its production, and ranks the instinct of reproduction amongst the primary faculties of the mind. In farther proof of the idea, which refers it to the ence- phalon, it may be remarked, that the instinct has been observed in those, who, owing to original malformation, have wanted the principal part of the genital organs, whilst it has continued in the case of eunuchs not castrated till after the age of puberty. In opposition to this view, it has been urged, that simple titillation of the organs will excite the desire. This, however, may be entirely dependent upon association, in which the brain is largely con- cerned. In many cases, the desire is produced through the agency of vision; when the brain must necessarily be first excited, and, through its influence the generative apparatus. The cause of the desire has, by some, been ascribed to the presence of sperm, in the requisite quantity, in the vesiculse seminales; but in answer to this, it is urged, that eunuchs, under the circumstances above mention, and females, in whom there is no spermatic secretion, have the desire. The fact is, we have no more precise knowledge of the nature of this instinct, than we have of any of the internal sensations or moral faculties. We know, however, that it exhibits itself in various degrees of intensity, and occasionally assumes an opposite character — constituting anaphrodisia. a. Copulation. — In the union of the sexes, the part performed by the male is the introduction of the penis, — the organ for the conveyance of the sperm to the uterus, — and the excretion of that fluid, during its introduction. In the flaccid state of the organ this penetration is impracticable; it is first of all necessary, that under the excitement of the venereal desire, the organ should attain a necessary state of rigidity, which is termed erection. In this state the organ becomes enlarged, and raised towards the abdomen ; its arteries beat forcibly ; the veins become tumid • the skin more coloured, and the heat augmented. It becomes also of a triangular shape, and these changes are indicated by an inde- scribable feeling, of pleasure. Erection is not dependent upon voljtion. At times, it manifests itself against the will ; at others COPULATION. 357 it refuses to obey it; yet it requires, apparently, the constant ex- citement of the encephalic organ concerned in its production; — the slightest distraction of the mind causing its cessation. The modest and retiring spouse is, at times, unable to consummate the marriage for nights, perhaps weeks; yet, he is only temporarily impotent; for the inclination and the consequent erection super- vene sooner or later. Pills of crumb of bread, and a recommen- dation to the individual not to approach his wife for a fortnight, whatever may be his desire, have, in almost all cases, removed the impotence ! The state of erection is not long maintained, ex- cept under unusual excitement; the organ soon returning to its ordinary flaccidity. Its cause is a congestion of blood in the erec- tile tissue of the corporacavernosa, urethra, and glans. Swammer- damm and De Graaf cut off the penis of a dog during erection, and found the tissue gorged with blood, and that the organ returned to its flaccid condition, as the blood flowed from it. The same fact, according to Adelon,a has been observed in the human subject, where erection has continued till after death. Mr. Callaway,b of Guy's Hospital, London, has described the case of an individual, who,inastate of inebriation, had communication three times with his wife the same night, without the consequent collapse succeed- ing, although emission ensued each time. This condition persisted for sixteen days, notwithstanding the use of appropriate means : at this time, an opening was made with a lancet into the left cms of the penis, below the scrotum, and a large quantity of dark, gru- mous blood, with numerous small coagula escaped. By pressing the penis, the corpora cavernosa were immediately emptied, and each side became flaccid ; the communication by the pecten or sep- tum penis permitting the discharge of the contents of both corpora by the incision into the left cms. After recovery, the person remained quite impotent, the organ being incapable of erection, probably owing, as Mr. Callaway suggests, to the deposition of coagulable lymph in the cells of the corpora cavernosa preventing the admission of blood, and the consequent distension of the organ. Artificial erection can, likewise, be induced in the dead body by injections, so that but little doubt need exist, that the enlargement and rigidity of the penis, during erection, are caused by the larger quantity of blood sent into it. The great difficulty has been, to account for this increased flow. The older writers ascribed it to the compression of the internal pudic vein against the symphysis pubis, owing to the organ being raised towards the abdomen by the ischio-cavernosi muscles ; and as the cavernous vein empties its blood into the internal pudic, stagnation of blood in the corpora cavernosa ought necessarily to result from such compression, and consequent distension of the organ ; whilst the cavernous arteries, being firmer, could not yield to the compression, and would, there- fore, continue to convey the blood to the penis. It is obvious, how- * Physiologie de I'Homme, edit, citat. iv. 57. b London Medical Repository, for April, 1824. 358 GENERATION. ever, that here, — as in every case, where the erectile tissue is con- cerned, — the congestion must be of an active kind: the beating of the arteries and the coloration of the organ indicate this ; and, be- sides, compression of the pudic vein cannot precede erection; it must, if it occurat all,be regarded rather as a consequence of erection than as its cause. The case of the female nipple affords us an instance of erectility, where no compression can be invoked, and where the distension must be caused by augmented flow of blood by the arteries. If the nipple be handled, particularly whilst the female is under voluptuous excitement, it will be found to enlarge, and to become rigid, or to be in a true state of erection. The cor- rect opinion is, that irritation of this erectile tissue is the first link in the chain of phenomena constituting erection. The feeling of pleasure is certainly experienced there, prior to, and during erec- tion ; and this irritation, like every other, solicits an increased flow of blood into the erectile tissue, which, by organization, is capable of considerable distension. The erectile tissues of the corpora cavernosa, and of the corpus spongiosum urethrse,,and glans, are all concerned in the process ; but in what precise man- ner, physiologists are not entirely agreed. Some have supposed, that the blood is effused into the cells, and is consequently out of the vessels. Another view, supported by some of the most eminent anatomists and physiologists, is, that the blood simply accumu- lates in the venous plexuses of the corpora cavernosa. Such seems to have been the opinion of Tiedemann, Stieglitz, and J. Miiller,a and of Cuvier, Chaussier, and Beclard, from their injec- tions ; and the rapidity, with which erection disappears, favours the notion. The discovery of the helicine arteries of the penis by Professor Muller, described at page 324 of this volume, has led to the inference that the peculiar arrangement may be con- cerned in the function in question, but in what manner the circulation in the male organ or its erection is modified by them is not appreciated :b Valentin, indeed, — as we have seen,__ denies their existence. It has been asked again, whether this accumulation of blood be, as we have remarked, an increased afflux by the arteries, or a di- minished action of the veins ; or these two states combined.0 The last opinion is probably the most correct. The arteries first respond to the appeal; the organ is, at the same time, raised by the appropriate muscles; its tissue becomes distended, the plexus of veins turgid, and the return of blood impeded. In this way the organ Requires the rigidity, necessary for penetrating the parts of the female. The friction, which then occurs, keeps up the » Art. Erection, in Encyclop. Wbrterb. der. Medicin. Wissenschaft. xii. 460, Berlin 1834. ' ' b Wagner, Elements of Physiology, translated by R. Willis, p. 75, London, 1841 See, on the Causes of Erection, Krause in Miiller's Archiv. H. i. 1837 • and Ton,!™' Med. Gazette, for Aug. 1837. ' ^onaon c Chaussier and Adelon, in art. Erection, Diet, des Sciences Mgdicales xi 461 Berlin, 1834 ; also, Adelon's Physiologie de I'Homme, iv. 57. > • » COPULATION. 359 voluptuous excitement, and the state of erection. This excitement is extended to the whole generative system; the secretion of the testicles is augmented; the sperm arrives in greater quantity in the vesiculse seminales ; the testicles are drawn up towards the abdominal rings by the contraction of the dartos and cremaster, so that the vas deferens is rendered shorter, and, in the opinion of some, the sperm filling the excretory ducts of the testicle, is in this manner forced mechanically forwards towards the vesicles. When these have attained a certain degree of distension, they contract suddenly and powerfully, and the sperm is projected through the ejaculatory ducts into the urethra. At this period the pleasurable sensation is at its height. When the sperm reaches the urethra, the canal is thrown into the highest excitement ; and the ischio- cavernosus and bulbo-cavernosus muscles, with the transversus perinei, and levator ani, are thrown into violent contraction; the two first holding the penis straight, and assisting the others in pro- jecting the sperm along the urethra. By the agency of these muscles and of the proper muscular structure in the urethra, the fluid is expelled, not continuously, but in jets, as it seems to be sent into the urethra by the alternate contractions of the vesiculse seminales. These muscular contractions are of a reflex character, being independent of the will, and incapable of being controlled by any exertion of it. They are induced, as in deglutition, by a spe- cial excitant, — the food in one case ; the sperm in the other. The quantity of sperm discharged varies materially according to the circumstances previously mentioned: its average is estimated at about two drachms. Along with the true sperm, the fluids of the prostate and of the glands of Cowper are discharged; so as to constitute the semen as we meet with it. When the emis- sion is accomplished, the penis gradually returns to its ordinary state of flaccidity ; and it is usually impracticable, by any effort, to repeat the act without the intervention of a certain interval of repose, to enable the due quantity of sperm to collect in the sper- matic vessels, and vesicles. In some persons, however, the ex- citability is so great, and the secretion of sperm so ready, that little or no interval is required between the first and second attempt. This comprises the whole of the agency of the male in the func- tion of gestation. In man the emission of sperm is soon effected ; but in certain animals it is a long process. In the dog, which has no vesiculae seminales, the penis swells so much, during copulation, that it cannot be withdrawn until the emission of sperm removes the erection. In the female, during copulation, the clitoris is in the same state of erection as the penis ; as well as the spongy tissue, lining more especially the entrance of the vagina; and it is in these parts, particularly in the clitoris, that pleasure is experienced during sexual desire, and during copulation. This feeling persists the 360 GENERATION. whole time of coition, and ultimately attains its acme, as in the case of the male, but without any spermatic ejaculation. It is not owing to the contact of the male sperm, — for it frequently occurs before or after emission by the male, but is dependent upon some inappreciable modification in the female organs, — in the ovaries or Fallopian tubes, it is supposed by some physiolo- gists. In most —if not in all — cases,an increased discharge sud- denly takes place, during the orgasm, from the mucous follicles of the vagina and vulva, but chiefly from the glands of Duverney, the admixture of which with the male sperm is supposed to have some connection with impregnation, and to be perhaps the vehicle for the fecundating principle of the sperm. After the kind of con- vulsive excitement into which the female is thrown, a sensation of languor and debility is experienced, as in the male, but not to the same extent,—and, in consequence of no. spermatic emission taking place in her, she is capable of a renewal of intercourse more speedily than the male, and can better support its frequent repetition. b. Fecundation. — An admixture having, in this manner, been effected between the materials furnished by the male and those of the female ; after a fecundating copulation conception ox fecunda- tion results,and the rudiments of the new being are instantaneously constituted. The well-known fact, that, after the removal of the testicles, the individual is incapable of procreation although the rest of the genital organs may remain entire, is of itself sufficient t<5 show, that the fecundating fluid is the secretion of those organs, and that this fluid is indispensable. Physiologists have not, how- ever, been satisfied with this fact. Spallanzani3 examined frogs with great attention, whilst in the act of copulation, both in and out of water ; and he observed, that, at the moment when the female deposited her eggs, the male darted a transparent liquor through a tumid point which issued from its anus. This liquor moistened the eggs, and fecundated them. To be certain that it was the fecundating agent, he dressed the male in waxed taffeta breeches; when he found, that fecundation was prevented, and that sperm enough was contained in the breeches to be collected. This he took up by means of a camel's hair pencil, and all the eggs which he touched with it were fecundated. Three grains of this sperm were sufficient to render a pound of water fecundating; and a drop of a solution which could not contain more than the 2,994,6S7,500th part of a grain was enough for the purpose. To diminish the objection, that the frog is too remote in organization from man to admit of any analogical deduction, Spallanzani took a spaniel bitch, which had engendered several times; shut her up some time before the period of heat, and waited until she exhibited evidences of being in that condition, which did not happen until after a fortnight's seclusion. He then injected into the vagina and uterus, by means of a common syringe warmed to 100° ofFahren- * Sur la Generation, parSenebier, Genev. 1783. FECUNDATION. 361 heit, nineteen grains of sperm obtained from a dog. Two days afterwards she ceased to be in heat, and, at the ordinary period, she brought forth three young ones, which not only resembled her but the dog from which the sperm had been obtained. This ex- periment has been repeated by Rossi, of Pisa, and by Buffolini, of Cesena, with similar results.8 The success of an analogous expe- riment on the human species rests on the authority of John Hunter. He recommended an individual, affected with hypospadias, to in- ject his sperm by means of a warm syringe. His wife afterwards became p'regnant.b In some experiments on generation, Prevost and Dumas fecun- dated artificially the ova of the frog. Having expressed the fluid from several testicles, and diluted it with water, they placed the ova in it. These we're observed to become tumid and developed; whilst other ova, placed in common water, merely swelled up, and in a few days became putrid. They observed, moreover, that the mucus, with which the ova are covered in the oviduct, — the part corresponding to the Fallopian tube in the mammalia, — assists in the absorption of the sperm, and in conducting it to the surface of the ovum ; and that in order to succeed in these artificial fecunda- tions, the sperm must be diluted: if too much concentrated its action is less. They satisfied themselves likewise, that the chief part of the sperm penetrates as far as the ova, as animalcules could be detected moving in the mucus covering their surface, and these animalcules they conceive to be the active part of the sperm. It is not, however, universally admitted, that the positive contact 'of sperm with the ovum is indispensable to fecundation. Some phy- siologists maintain, that the sperm proceeds no further than the upper part of the vagina ; whence it is absorbed by the vessels of that canal, and conveyed through the circulation to the ovary. This is, however, the most improbable of all the views that have been indulged on this topic; for if such were the fact, impregna- tion ought to be effected as easily by injecting sperm into the bloodvessels, — the female being, at the time, in a state of volup- tuous excitement. It has been directly overthrown, too, by the experiments of Dr. Blundellc on the rabbit, who found, that when the communication between the vagina and the uterus was cut off, impregnation could not be accomplished, although the animal ad- mitted the male as many as fifty times, generally at intervals of two or three days or more. Yet, it is evident— Dr. Blundell re- marks — that much of the male fluid must have been deposited in the vagina, and absorbed by veins or lymphatics.*1 Others have presumed, that when the sperm is thrown into the vagina, a hali- » Adelon, Physiologie de I'Homme, iv. 66, Paris, 1829 ; and Wagner, Elements of Physiology, by Dr. R. Willis, p. 68, Lond. 1841. >> Sir E. Home, Lect. on Comp. Anat. iii. 315 ; and Burdach's Physiologie,, u. 3. w. i. 506. e Principles and Practice of Obstetricy, Amer. Edit., Washington, 1834. i See an experiment with a similar object, by Dr. Harlan, Medical and Physical Researches, p. 627, Philad. 1835. VOL. II. — 31 362 GENERATION. tus or aura — the aura seminis — escapes from it, makes its way to the ovary, and impregnates an ovum. Others, again, think, that the sperm is projected into the uterus, and that in this cavity it undergoes admixture with the germ furnished by the female ; whilst a last class, with more probability in their favour, maintain that the sperm is thrown into the uterus, whence it passes through the Fallopian tube to the ovary, the fimbriated extremity of the tube, at the time, embracing the latter organ. The late Dr. De- wees,* suggested, that after the sperm is deposited on .the labia pudendi or in the vagina, it may be taken up by a set of vessels — which, he admitted, have never been seen in the human female — whose duty it is to convey the sperm to the ovary. This conjec- ture he conceives to have been in part confirmed by the discovery of ducts, leading from the ovary to the vagina, in the cow and sow, by Dr. Gartner, of Copenhagen. The objections that may be urged against his hypothesis, Dr. Dewees remarks, " he must leave to others." We have no doubt, that his intimate acquaint- ance with the subject could have suggested many that are pertinent and cogent. It will be obvious, that if we admit the existence of the ducts, described by Gartner, it by no means follows, that they are certainly inservient to the function in question. Independently, too, of the objection that they have not been met with in the human female, it may be urged that if we grant their existence, there would seem to be no reason, why closure of the os uteri, after impregnation, or interruption of the vulvo-uterine canal, by divi- sion of the vagina— as in the experiments of Dr. Blundell on rabbits — or division of the Fallopian tubes, should prevent subse- , quent conception, in the first case during the existence of preg- nancy; in the two last, for life. These vessels ought, in both cases, to continue to convey sperm to the ovary, and extra-uterine pregnancies or superfoetation ought to be constantly occurring. MM. Prevost and Dumasb are amongst the most recent writers, who maintain that fecundation takes place in the uterus, and they assign the following reasons for their belief. First. That in their experiments, they always found sperm in the comua of the uterus, and they conceive it natural, that fecundation should be operated only where sperm is. Secondly. That in those animals, whose ova are not fecundated until after they have been laid, fecundation must necessarily be accomplished out of the ovary; and Thirdly, that in their experiments on artificial fecundation, they have never been able to fecundate ova taken from the ovary. In reply to the first of these positions it has been properly remarked by Adelonc that the evidence of MM. Prevost and Dumas, with regard to the presence of sperm elsewhere than in the uterus, is only of a nega- tive character; and that, on the other hand, we have the positive * A Compendious System of Midwifery, 7th edit. Philad. 1835 b Annales des Sciences Naturelles, iii. ] 13. c Physiologie de I'Homme, 2de edit. iv. 68, Paris, 1829. FECUNDATION. 363 testimony of physiologists in favour of its existence in the Fallo- pian tubes and ovary." Haller asserts, that he found it there ; and MM. Prevost and Dumas afford us evidence against the position they have assumed respecting the seat of fecundation. They affirm, that on the first day after copulation, the sperm was discoverable in the cornua of the uterus, and that it was not until after the lapse of twenty-four hours, that it had attained the summits of the cornua. Once they detected it in the Fallopian tubes ; — a cir- cumstance which is inexplicable under the view, that fecundation is accomplished in the uterus. Leeuenhoek and Hartsbker also found it in some cases in the Fallopian tube; and still more re- cently, Bischoff, Wagner,3 and Dr. M. Barryb have discovered spermatozoa in the fluid collected from the surface of the ovary, and within the capsular prolongations of the Fallopian tubes that enclose the ovaria; and recently, Dr. Barry0 has found, in two cases, spermatozoa within the ovum of the rabbit taken from the Fallopian tube. They were within the thick transparent mem- brane —zona pellucida — brought with the ovum from the ovary. In reply to the second argument it may be remarked, that analo- gies drawn from the inferior animals are frequently very loose and unsatisfactory, and ought consequently to be received with caution. This is peculiarly one of these cases; for fecundation, in the case adduced, is always accomplished out of the body, and analogy might with equal propriety be invoked to prove, that in the human female fecundation must also be effected externally. In answer to the third negative position of MM. Prevost and Dumas, the positive experiments of Spallanzani may be adduced, who suc- ceeded in producing fecundation in ova, that had been previously separated from the ovary. The evidence, that conception takes place in the ovary, appears to us convincing. Ovarian pregnancy offers irresistible proof of it, Of this, Mr. Stanley of Bartholomew's Hospital has given an instructive example ;d and a still more extraordinary instance is related by Dr. Granville.e Other varieties of extra-uterine preg- nancy are confirmative of the same position. At times, the fetus is found in the cavity of the abdomen, — the ovum seeming to have escaped from the Fallopian tube when its fimbrated ex- tremity grasped the ovary to receive the ovum and convey it to the cavity of the uterus. At other times, the foetus is developed in the Fallopian tube, — as in the marginal figure, (Fig. 228) —some impediment having existed to the passage of the ovum from the ovarium to the uterus. This impediment can, indeed, be excited artificially so as to give rise to tubal pregnancy. Nuck applied a * Elements of Physiology, translated by Dr. R. Willis, p. 66, Lond. 1841. b Philosophical Transactions for 1839, p. 315. c Proceedings of the Royal Society, Dec. 8,1842 ; and Lond. Med. Gazette, April 7, 1843, p. 73. o Medical Transactions, vol. vi. e Philosophical Transactions, for 1820. 364 GENERATION. ligature around one Fig. 228. of the cornua of the Raspail asserts, that he once met with an ovule, still attached to the ovary, which contained an embryo.b It is obvious, then, from these facts, either that fecundation occurs in the ovarium, or else that the ovum, when fecundated in the uterus, travels along the Fallopian tube to the ovarium, and from thence back again to the uterus, which is not probable.*5 Besides, that the ovaries are indispensable agents in the function of generation is shown by the well-known fact, that their removal, by the operation of spaying, not only precludes reproduction but takes away all sexual desire. A case is detailed of a natural de- fect of this kind in an adult woman, who had never exhibited the slightest desire for commerce with the male, and had never menstruated. On dissection, the ovaria were found deficient; and the uterus was not larger than an infant's.d But, to prevent impregnation, it is not even necessary that the ovaries should be removed. It is sufficient to deprive them of all immediate communication with the uterus, by simply dividing the Fallopian tubes. On this subject, Haightone instituted numerous experiments, the result of which was, that after this operation a fcetus was in no instance produced. The operation is much more simple than the ordinary method of spaying by the removal of the ovaries, and it has been successfully practised, at the recommenda- tion of the author, on the farm of his friend Thomas Jefferson Ran- dolph, Esq. of Virginia. It does not seem that the simple division of the Fallopian tubes takes away the sexual desire, as Haighton supposed. Dr. Blundell has proposed this division of the tubes, and even the removal of a small portion of them, so as to render them completely impervious, when the pelvis is so contracted as not to admit of the birth of a living child in the seventh month- and he goes so far as to affirm, that the operation is much less dangerous than delivery by perforating the head, when the pelvis * De Ovi Mammalium et Hominis Genesi, Lips. 1827. b Chimie Organique, p. 262, Paris, 1833. * Granville's Graphic Illustrations of Abortion, p. iii. Lond. 1834 t Philosoph. Transactions for 1805. . Philosoph. Transact, for 1797. FECUNDATION. 365 is greatly contracted. We have already remarked, that sperm has been found in the cavity of the uterus, and even in the Fallopian tubes. Fabricius ab Acquapendente maintained, that it could not be detected there; and Harvey contended, that in the case of the cow, whose vagina is very long, as well as in numerous other animals, the sperm cannot possibly reach the uterus, and that there is no reason for supposing that it ever does. In addition, however, to the facts already cited, we may remark, that Mr. John Huntera killed a bitch in the act of copulation, and found the semen in the cavity of the uterus, conveyed thither, in his opinion, per saltum, Ruyschb discovered it in the uterus of a woman taken in adultery by her husband and killed by him ; and Hallere in the uterus of a sheep killed forty-five minutes after copulation. An interesting case, in relation to this point, has been published by Dr. H. Bond,d of Philadelphia. A young female, after having passed a part of the night with a male friend, destroyed herself early in the morning, by taking laudanum. On cutting open the uterus, it was found to be thickly coated with a substance having the appearance, and the strong peculiar odour, of the sperm. One of the Fallopian tubes was laid open, and found to contain, apparently, the same mat- ter, but it was not ascertained whether it possessed the seminal odour. More recently, Bischoff,e in his investigations, found few or no spermatozoa in the vagina of bitches and rabbits, after coitus, but the uterus was quite full. Blumenbachf supposes, that, during the venereal orgasm, the uterus sucks in the sperm. It is impossible to explain the mode in which this is accomplished, but the fact of the entrance of the fluid into the uterus, and even as far as the ovarium seems unques- tionable. This Dr. Blunder admits, but he is disposed to think, that, in general, the rudiments from the mother, and the fecundat- ing fluid meet in the uterus; as, in hjs experiments on rabbits, he found — from the formation of corpora lutea, the development of the uterus and the accumulation of water in the uterine cavity — that the rudiments may come down into the uterus, without a previous contact of the semen. His experiments, however, appear to us to prove nothing more, than that infecund ova may be dis- charged from the ovarium, and that if they are prevented from passing externally, owing to closure of the vagina or cervix uteri, the uterine phenomena, alluded to, may occur. They do not in- validate the arguments already adduced to show, that the ovum must be fecundated in the ovarium. It.has been suggested by Dr. * Philosoph. Transact, for 1817. b Thesaur. Anat. iv.; and Adversaria Anat. Med. Chirurg. Dec. 1. <= Element. Physiol, viii. 22. d American Journal of the Medical Sciences, No. xxvi. for February, 1834, p. 403. e Entwickelungsgeschichte des Kaninchen-Eies, u. s. w. Leipz. 1842 ; cited by Mr. T. W. Jones, in Brit, and For. Med. Rev., Oct. 1843, p. 513. f Elements of Physiology, by Elliotson, 4th edit. p. 467, Lond. 1S28. s Principles, &c, of Obstetricy, Amer. Edit. p. 56, Washington, 1834. 31* 366 GENERATION. Bostock,3 that the ciliary motions, which have been observed by Purkinje, Valentin,b and others in the mucous membranes of the air-passages, and which have been likewise detected in the gene- rative organs, and whose office appears to be to propel substances along them, may have something to do with the propulsion of the sperm towards the ovary; and J. Muller0 affirms, that "the mode, in which the semen is conducted so far through the female genera- tive organs, is no longer a problem requiring solution; for the discovery of the ciliary motion affords a solution of it." Dr. Sharpey,d however, remarks, that the direction of these motions, in those organs, is from within outwards, so that he conceives it to be difficult to assign any other office to them than that of convey- ing outwards the secretion of the membrane, unless we suppose that they also bring down the ovum into the uterus. Prof. Wag- ner6 considers, that the sperm reaches the ovary, partly by the ciliary motions, which begin in the cervix uteri; partly by the contractions of the tubes, and partly by the motility of the sper- matozoa. Future observations may shed farther light on this subject. Granting, then, that conception occurs in the ovarium, and that sperm is projected into the uterus, with or without the actions referred to ; in what manner does the sperm exert its fecun- dating agency on the ovarium? It is manifestly impossible, that the force of projection from the male can propel it, not only as far as the cornua of the uterus, but also through the narrow media of communication between the uterus and ovary by the Fallopian tubes. This difficulty suggested the idea of the aura seminis or aura seminalis, which, it was supposed, might readily pass into the uterus, and through the tubes to the ovary. Haighton, indeed, embraced an opinion more obscure than this, believing, that the semen penetrates no farther than the uterus, and acts upon the ovaria by sympathy; and this view has been adopted by some distinguished individuals. In opposition to the notion of the aura seminis, we have some striking facts and experiments. In all those animals, in which fecundation is accomplished out of the body, direct contact of the sperm appears necessary. Spallanzani, and MM. Prevost and Dumas found, in their experiments on artificial fecundation, that they were always unsuccessful when they simply subjected the ova to the emanation from the sperm. Spallanzani took two watch-glasses, capable of being fitted to each other, the concave 1 Physiology, 3d edit. p. 654, Lond. 1836. » Miiller's Archiv. B. i.; and translation in Dublin Journal of Med. and Chem Science, May, 1835 ; and in Edinb. New Philos. Journal, for July, 1835. c Elements of Physiology, translated by Baly, p. 1491, Lond. 1842. <* Art. Cilia, Cyclop, of Anat. and Physiology, part vii. p. 633, July, 1836 See also, Muller, Elements of Physiology, by Baly, p. 857, Lond. 1838 ; Todd and Bow- man, Physiological Anat. and Physiol, of Man, p. 62, Lond. 1843 ; and vol. i. p. 472* of this work. ' " *' e Elements of Physiology, translated by R. Willis, part i. p. 72, Lond. 1841 FECUNDATION. 367 surface of the one being opposed to that of the other. Into the lower he put ten or twelve grains of sperm, and into the upper about twenty ova. In the course of a few hours, the sperm had evaporated, so that the ova were moistened by it; yet they were not fecundated,but fecundation was readily accomplished by touch- ing them with the sperm that remained in the lower glass. A similar experiment was performed by MM. Pr6vost and Dumas. They prepared about an ounce and a half of a fecundating fluid from the expressed humour of twelve testicles, and as many vesi- culse seminales. With two and a half drachms of this fluid they fecundated more than two hundred ova. The remainder of this fluid was put into a small retort, to which an adopter was attached. In this, forty ova were placed, ten of which occupied the hollowest part, whilst the rest were placed near the beak of the retort. The apparatus was put under the receiver of an air-pump, and air suffi- cient was withdrawn to diminish the pressure of the atmosphere one-half. The rays of the sun were now directed upon the body of the retort, until the temperature within rose to about 90°; after the lapse of four hours, the experiment was shopped, when the following were the results. The eggs, at the bottom of the adopter, were bathed in a transparent fluid, the product of distillation. They had become tumid as in pure water, but had undergone no development. The eggs, near the beak of the retort, were similarly circumstanced, but all were readily fecundated by the thick sperm, which remained at the bottom of the retort. No aura, no emana- tion from the sperm consequently appeared to be capable of im- pregnating the ova. Absolute contact was indispensable.8 This is probably the case with the human female, and if so, the sperm must proceed from the uterus along the Fallopian tube to the ova- rium.1' The common opinion is, that during the intense excite- ment at the time of copulation, the tube is raised, and its digitated extremity applied to the ovarium. The sperm then proceeds along it, — in what manner impelled we know not, — and attains the ovary. According to Blundell and others, during the time of in- tercourse, the whole of the tube is in a state of spontaneous move- ment. Cruikshank pithed a female rabbit, when in heat, and ex- amined the uterine system very minutely. The external and internal parts of generation were found black with blood; the Fal- lopian tubes were twisted like writhing worms, and exhibited a very vivid peristaltic motion ; and the fimbriae embraced the ovaria, like fingers laying hold of an object, so closely and so firmly as to require some force, and even slight laceration to disengage them. Haller states, that by injecting the vessels of the tube in the dead body, it has assumed this kind of action. De Graaf, too, affirms, that he has found the fimbriated extremity adhering to , a Rudolphi, art. Aura Seminalis, in Encyclopad. Wbrterbuch der Medicinisch. Wissenschaft, B. iv. s. 452, Berlin, 1830 ; and Hiiter, art. Empfangniss, ibid. x. 628, Berlin, 1834. b Dr. Allen Thomson, art. Generation, in Cyclop, of Anat. and Physiol, part xiii. p. 462, Feb. 1838. 368 GENERATION. the ovary, twenty-seven hours after copulation; and Magendie, that he has seen the extremity of the tube applied to a vesicle. As excitement would appear to be necessary to cause the digi- tated extremity of the Fallopian tube to embrace the ovary, it would seem probable, that a female could not be impregnated without some consciousness of the sexual union. This may be imperfect, as during sleep, or when in a state of stupor — either from spirituous liquors or narcotics — but still some feeling must probably be engendered in order that fecundation may take place. As the aura seminis appears to be insufficient for impregnation, it is obviously a matter of moment, that the sperm should be pro- jected as high up into the vagina as possible. It has been often observed, that where the orifice of the urethra does not open at the extremity of the glans, but beneath the penis, or at some dis- tance from the point, the individual has been rendered less capa- ble of procreation. In a case, that fell under the care of the author, the urethra was opened opposite the corona glandis by a sloughing syphilitic sore, and the aperture continued, in spite of every effort to the contrary. The individual was married, and the father of three or four chilclren ; but after this occurrence he had no increase of his family. Many medico-legal writers have considered, that when the urethra terminates at some other than its natural situa- tion, impotence is the necessary result, — and that although copu- lation may be effected, impregnation is impracticable. Zacchias,3 however, gives a positive case to the contrary. Belloc,b too, as- serts, that he knew of a person, in whom the orifice of the urethra terminated at the root of the frasnum, who had four children that resembled the father, two having the same malformation ; and Dr. Francis refers to the case of an inhabitant of New York, who, under similar circumstances, had two children. Many such cases are, indeed, on record.0 We cannot, therefore, regard it as an ab- solute cause of impotence, but the inference is just, that if the semen be not projected far up into the vagina, and in the direction of the os uteri, impregnation is not likely to be accomplished; a fact, which it might be of moment to bear in mind, where the rapid succession of children is an evil of magnitude. Yet, not- withstanding this weight of evidence, it has been affirmed by Pro- fessor Heim,d that impregnation may take place by the simple contact of the sperm with the lower part of the abdomen. The answer to this view, by D'Outrepont,e appears to us, however, over- whelming. Heim relies on statements made by the parties that no » Qusstiones Medico-Legales, Lugd. 1674. b Cours de Medecine Legale, p. 50, Paris, 1819. c Beck's Elements of Medical Jurisprudence, 6th edit. p. 71, Philad. 1838; and Traill's Outlines of a Course of Lectures on Med. Jurisprudence, p. 26, Edinb. 1840, or American Edition, by the author, Philad. 1841; and W. A. Guy, Principles of Forensic Medicine, part i. p. 44, Lond. 1843. d Wochenschrift fur die Gesammte Heilkunde ; and Gazette Medicale, Sept. 26, 1836. a Neue Zeitschrift fur Geburtskunde, von Busch, d'Outrepont und Ritgen, B. iv. H. ii., Berlin, 1836; or Dunglison's Amer. Med. Intelligencer, p. 275, Nov. 1, 1837.' FECUNDATION. 369 penetration existed; but D'Outrepont properly observes, that when- ever this has been alleged in a case of pregnancy, he has found, when the parties were strictly questioned, that one or both of them admitted, that the male organ might have been in the vagina, or at least within the vulva. The part, then, to which the sperm is applied is the ovary, and probably, according to Bischoff, the liquor sanguinis is the sub- stance that passes through the parietes of the follicle by imbibi- tion, in order to reach the ovum. Mr. Jones states, that although he is not prepared to deny this, yet when he takes into considera- tion all the evidence on the subject, he is of opinion, that there is no proof, that fecundation takes place until the ovum has escaped from the Graafian follicle, and comes into direct contact with the sperm.a Let us now inquire into the changes experienced by this body after a fecundating copulation. Fabricius ab Acquapendente,b having killed hens a short time after they had been trodden, exa- mined their ovaries, and observed,— amongst the small yellow, round granula, arranged racemiferously, whiclf constitute those organs, — one having a small spot, in which vessels became deve- loped. This increased in size, and was afterwards detached, and received by the oviduct; becoming covered, in its passage through that tortuous canal and the cloaca, by particular layers, especially by the calcareous envelope; and being ultimately extruded in the form of an egg. Harvey,c in his experiments on the doe, made similar observations. He affirms, positively, that the ovary fur- nishes an ovum, and that the only difference, which exists amongst animals in this respect, is, that, in some, the ovum is hatched after having been laid, whilst, in others, it is deposited in a reservoir — a womb — where it undergoes successive changes. De Graafd instituted several experiments on rabbits, for the purpose of de- tecting the series of changes in the organs from conception till delivery. Half an hour after copulation, no alteration was per- ceptible, except that the cornua of the uterus appeared a little redder than usual. In six hours, the coverings of the ovarian vesicles or vesicles of De Graaf seemed reddish. At the expiration of a day from conception, three vesicles in one of the ovaries, and five in the other, appeared changed, having become opaque and reddish. After twenty-seven, forty, and fifty hours, the cornua of the uterus and the tubes were very red, and one of the tubes had laid hold of the ovary; a vesicle was in the tube, and two in the right cornu of the uterus. These vesicles were as large as mustard seed. They were formed of two membranes, and were filled by a limpid fluid. On the fourth day, the ovary contained only a species of envelope, called, by De Graaf, a follicle ; this appeared to be the capsule, which had contained the ovum. The ovum itself was a T. W. Jones, Report on the Ovum of Man and the Mammifera, in Brit, and For. Med. Rev., Oct. 1843, p. 525. b Opera., Lips. c De Generatione, p. 228. <» Tom. i. 310. 370 GENERATION. in the cavity of the uterus, had augmented in size, and its two envelopes were very distinct. Here it remained loose until the seventh day, when it formed an adhesion to the uterus. On the ninth day, De Graaf observed a small opaque point, a kind of cloud, in the transparent fluid that filled the ovum. On the tenth day, this point had the shape of a small worm. On the eleventh, the embryo was clearly perceptible ; and from this period, it un- derwent its full development, until the thirty-first day, when deli- very took place. Malpighia and Vallisnierib also observed, in their experiments, that after a fecundating copulation, a body was developed at the surface of the ovary, which subsequently burst, and suffered a smaller body to escape. This was laid hold, of by the tube, and conveyed by it to the uterus. It is not, however, uni- versally admitted, that this body is the impregnated ovum ; some affirming, that it is a sperm similar to that of the male ; and others, that it is an amorphous substance, which, after successive develop- ments, becomes the new individual.0 Haller exposed the females of sheep and of other animals to the males on the same day ; and killed them at different periods after copulation, for the purpose of detecting the whole series of changes by which the vesicle is detached from the ovary and conveyed to the uterus. Half an hour after copulation, one of the vesicles of the ovary appeared to be prominent; to have on its convexity a red, bloody spot, and to be about to break ; in an hour or more, the vesicle gave way, and its interior seemed bleeding and inflamed. What remained of the vesicle in the ovary, and appeared to be its envelope, gradually became inspissated, and converted into a body of a yellowish colour, to which Haller gave the name corpus luteum. The cleft, by which the vesicle escaped, was observable for some time, but, about the eighth day, it disappeared. On the twelfth day, the corpus luteum became pale and began to diminish in size. This it continued to do until the end of gestation ; and ultimately became a small, hard, yellowish or blackish substance, which could al- ways be distinguished in the ovarium, by the cicatrix left by it. Its size was greater, the nearer the examination was made to the period of conception. In a bitch, for example, on the tenth day, it was half the size of the ovary; yet it proceeded, in that case, from one vesicle to the other. In multiparous animals, as many corpora lutea existed as foetuses. The experiments of Hallerd have been frequently repeated and with similar results. Magendie,e whose trials were made on bitches, observed, that the largest vesicles of the ovary were greatly augmented in size, thirty hours after copulation ; and that the tissue of the ovary, surrounding them, had acquired greater consistence, had changed colour, and become of a yellowish-gray. This part » De Formatione Pulli in Ovo, Lond. 1673 ; and De Ovo Incubato, Lond. 1686. b Istoriadella Generazione dell'Uomo, Discorsi Academ. iv. Venez. 1722-1726. c Adelon, Physiologie de I'Homme, iv. 74. a Element. Physiologies, xxix. • Pre'cis de Physiologie, edit, citat. ii. 534. FECUNDATION. 371 was the corpus luteum. It, as well as the vesicles, increased for the next three or four days ; and seemed to contain, in its areolae, a white, opaque fluid, similar to milk. The vesicles now succes- sively ruptured the external coat of the ovary, and passed to the surface of the organ, still adhering to it, however, by one side. Their size was sometimes that of a common hazlenut, but no germ was perceptible in them. The surface was smooth, and the inte- rior filled with fluid. Whilst they were passing to the uterus, the corpus luteum remained in the ovary, and underwent the changes referred to by Haller. In similar experiments, instituted by MM. Prevost and Dumas,8 no change was perceptible in the ovary dur- ing the first day after fecundation ; but, on the second day, seve- ral vesicles enlarged, and continued to do so for the next four or five days, so that from being two or three millimetres in diameter, they attained a diameter of eight. From the sixth to the eighth day, the vesicles burst, and allowed an ovule to emerge, which often escaped observation, owing to its not being more than half a millimetre in diameter, but was clearly seen by MM. Pre- vost and Dumas by the aid of the microscope.* This part they term ovule, in contradistinction to that developed in the ovary, which they call vesicle. The latter has the appearance, at its sur- face, of a bloody cleft, into which a probe may be passed ; and in this way it can be shown, that the vesicle has an interior cavity, which is the void space left by the ovule after its escape from the ovarium into the Fallopian tube. On the eighth day, in the bitch, the ovule passes into the uterus. All the ovules do not, however, enter that cavity at the same time ; —an interval of three or four days sometimes occurring between them. When they attain the uterus, they are at first free and floating ; and if examined with a micro- scope magnifying twelve diameters, they seem to consist of a small vesicle, filled with an albuminous, transparent fluid. If examined in water, their upper surface has a mammiform appearance, with a white spot on the side. This is the cicatricula. These ovules speedily augment in size, and, on the twelfth day, foetuses can be recognised in them. Similar experiments, with like results, have been made by Von Baer,b Seiler,c and others; and much minute attention has been paid to the subject by recent histologists, — by Wagner, Barry, Bischoff and T. W. Jones more especially. The subject, however, is altogether in a transition state ; and it is difficult to say positive- ly what is the condition of the ovum from the period post coitum until it leaves the ovary. After the intercourse of the sexes, an increased flow of blood takes place to the ovaries; the vascular membrane of the Graafian vesicle enlarges; the granules, mingled a Annales des Sciences Naturelles, iii. 135. b De Ovi Mammalium, &c. Epist. Lips. 1827. <■ Das Ei und Die Gebarmutter des Menschen, Dresd. 1832; Burdach's Physiologie als Erfahrungswissenschaft, Th. ii. Leipz. 1828; and Purkinje, art. Ei, in Encyclop. Wdrterb. der Medicin. Wissensch. x. 107, Berlin, 1834. 372 GENERATION. with its contents, become greatly developed, and changed; and thickening and general increase of its walls, particularly of the base and sides supervene; the ovum and other contents of the follicle are by this pressed forwards, or against that aspect of the follicle, which is in contact with the peritoneum, and which now becomes thinner and thinner, and finally bursts, so that the ovum escapes, and a cavity is left in the ovary, which is soon obliterated by the growth on all sides of the inner membrane of the follicle ; a reddish, fleshy-looking mass sprouts from the walls towards the shrinking cavity, and the rent by which the ovum had escaped is finally closed. The follicle, thus altered, constitutes the corpus luteum—to be described presently. Such is the description of Wagner.3 From the above facts, then, we may conclude, that the sperm excites the vesicles in the ovaries to development; that the ova, within the germinal part, burst their covering, are laid hold of by the Fallopian tube, and conveyed to the uterus, where they re- main during the period of gestation. In the passage of the ova along the Fallopian tube it has gene- rally been believed that they experience but little change. They carry off, according to Wagner,b a small portion of the granular stratum of the vesicle with them, which appears hanging to them at first as an irregular, ragged discoidal appendage ; but this is soon detached. The ovum gains a little in size; but there is still no trace of any special spot where the embryo arises. It would seem, however, from the researches of British embryologists, that the outer membrane of the ovum, which it acquired in the ovary, becomes swoln with moisture in the tube, and assumes the ap- pearance of a thick, gelatinous-looking membrane — the proper chorion ; and by and by, the zona pellucida having disappeared, the newly-formed chorion comes to be the only investment of the yolk.c All the observations on the ovum in the Fallopian tubes have, however, been made on animals. Of the human ovum whilst in these tubes, nothing is known.d The exact time, required by the ovum or ova to make their way into the uterus, has not been accurately determined. Cruikshanke found, that in rabbits forty-eight hours were necessary. Haigh- tonf divided one of the Fallopian tubes in a rabbit; and, having exposed the animal to the male, he observed that gestation occurred only on the sound side. On making this section after copulation, he found, that if it were executed within the two first days, the descent of the ovules was prevented; but if it were delayed for sixty hours, the ovules had passed through the tube and were in the cavity of the uterus. A case, too, is quoted by writers on » Elements of Physiology, translated by R. Willis, p. 136. Lond 1842 ■> R.Willis, Ibid. p. 138. 'Ibid! p. 142 a T. W. Jones, Brit, and For. Med. Rev., Oct. 1843, p. 542. Philosoph. Transactions, for 1797. f j^ lxxxvji 304. FECUNDATION. 373 this subject, on the authority of a surgeon named Bussieres, who observed an ovoid sac, about the size of a hazlenut and contain- ing an embryo, half in the Fallopian tube and half adherent to the ovary.a The minuteness of the calibre of the Fallopian tube is not as great a stumbling-block in the way of understanding how this passage is effected, as might appear at first sight. The duct is, doubtless, extremely small in the ordinary state ; but it admits of considerable dilatation. Magendieb asserts, that he once found it half an inch in diameter. Moreover, the size of the ovum, as we have just seen, is only -^oth part of an inch. The period that elapses between a fecundating copulation and the passage of the ovum from the ovarium to the uterus, is dif- ferent in different animals. In the sheep it occurs, according to Haller0 and Kuhlemannd on the seventeenth day. In rabbits, it is uncertain, but occurs generally on the third or fourth day after copulation ;e in bitches on the fifth, according to some, but not till after the lapse of ten or twelve days, according to others ;£ and in the human female, perhaps about the same time; yet Mr. Burns infers from analogical evidence, that we should be more justified in the belief that the ovum, in the human female, does not enter the uterus until at least three weeks after concep- tion.s Maygrier refers to a case of abortion twelve days after copulation; the abortment consisting of a vesicle, shaggy on its surface and filled by a transparent fluid. One of the most in- structive cases that we possess on this subject is given by Sir Everard Home,h and although, as Dr. Granville1 has remarked, it has lately been the fashion to doubt the accuracy of the case, or to esteem it morbid,J there is reason to believe it correct, from the circumstance of Mr. Bauer's microscopic examination of the ovu- lum, and description of its structure corresponding with the more recent discoveries of Professor Boer. A servant-maid, twenty- one years of age, had been courted by an officer, who had pro- mised her marriage, in order that he might more easily accomplish his wishes. She was but little in the habit of leaving home, and had not done so for several days, when she requested a fellow- servant to remain in the house, as she was desirous of calling upon a friend, and should be detained some time. This was on the 7th of January, 1S17. After an absence of several hours, she returned 1 Adelon, Physiologie de I'Homme, edit. cit. iv. 77. b Precis, &c. edit. cit. p. 536. c Element. Physiol, viii. 59. d Observ. quaedam circa Negotium Generationis in Ovibus fact. Gotting. 1753. 8 Recherches sur la Generation des Mammiferes par Coste, suivies de Recherches sur la Formation des Embryons, par Delpech et Coste, Paris, 1834. f Wagner, Elements of Physiology, by Willis, p. 137, Lond. 1841. % The Principles of Midwifery, &c. 3d edit. p. 132, Lond. 1814. h Philosophical Transactions for 1807, p. 252 ; and Lectures on Comparative Ana- tomy, iii. 288, Lond. 1823. • Graphic Illustrations of Abortion, &c, p. vii. Lond. 1834. j Weber's Hildebrandt's Handbuch der Anatomie, iv. 465, Braunschweig, 1832; Dr. Allen Thomson, in art. Generation, Cyclop, of Anat. and Physiol. P. xiii. p. 454, Feb. 1838 ; and Dr. John Davy, Researches, Physiological and Anatomical, Dungli- son's Amer. Med. Libr. Edit., p. 379, Philad. 1840. VOL. II. — 32 374 GENERATION. with a pair of new corsets, and other articles of dress which she had purchased. In the evening she got one of the maid-servants to assist her in trying on the corsets. In the act of lacing them, she complained of considerable general indisposition, which disappeared on taking a little brandy. Next day, she was much indisposed. This was attributed to the catamenia not having made their ap- pearance, although the period had arrived. On the following day, there was a wildness in her manner, and she appeared to suffer great mental distress. Fever supervened, which confined her to her bed. On the 13th, she had an epileptic fit, followed by deli- rium, which continued till the 15th, when she expired in the fore- noon. On making inquiries of her fellow-servants, many circum- stances were mentioned which rendered it highly probable, that on the morning of the 7th, when she was immediately on the point of menstruating, her lover had succeeded in gratifying his desires ; and that she had become pregnant on that day, so that, when she died, she was in the seventh or eighth day of impregnation. Dis- section showed the uterus to be much larger than in the virgin state, and considerably more vascular. On accurately observing the right ovarium, in company with Mr. Clift, Sir Everard no- ticed, upon the most prominent part of its outer surface, a small ragged orifice. This induced him to make a longitudinal incision in a line close to this orifice, when a canal was found leading to a cavity filled with coagulated blood, and surrounded by a narrow yellow margin, in the structure of which the lines had a zigzag appearance. The cavity of the uterus was then opened, by mak- ing an incision through the coats from each angle; and from the point where these incisions met, a third incision was continued down through the os uteri to the vagina. The os uteri was found completely blocked up by a plug of mucus, so that nothing could have escaped by the vagina ; the orifices leading to the Fallopian tubes were both open, and the inner surface of the cavity of the uterus was composed of a beautiful efflorescence of coagulable lymph resembling the most delicate moss. By attentive exami- nation, Sir Everard discovered a small, spherical, transparent body concealed in this efflorescence, which was the impregnated ovum. This was submitted to the microscopic investigations of Mr. Bauer, who made various drawings of it, and detected two projecting points, which were considered to mark out, even at this early period, and before the ovum was attached to the uterus, the seat of the brain and spinal marrow. This case shows, that an ovum had left the ovarium, and that it was in the interior of the uterus, prior to the seventh or eighth day after impregnation. Weber and Von Baer have each recorded a case in which there was an op- portunity for examining the embryo, probably eight days after a fecundating copulation ; but no ovum was detected either in the uterus or tubes. On comparing the degree of advancement of the fcetus in the ovum, described by different observers, with that of the fcetus in FECUNDATION. 375 the dog, cat, and sheep, at known periods, Dr. Allen Thomson3 hazards the opinion, that the human ovum does not arrive in the uterus before the eleventh or twelfth day after conception. Valen- tin, indeed, thinks the twelfth or fourteenth day. From this dis- crepancy, however, amongst observers, it is manifest that our knowledge on the matter is by no means fixed or definite. But, it has been asked, is it a mere matter of chance, which of the ovarian vesicles shall be fecundated; or are there not some that are riper than the rest, and that receive, by preference, the vivifying influence of the sperm ? MM. Prevost and, Dumas have shown, that such is the case with oviparous animals. They found, in their experiments, that not only were the vesicles of the ovaries of frogs of different sizes, but that the largest were always first laid, whilst the smallest were not to be deposited until subsequent years. In all the animals, whose eggs were fecundated externally, they seemed evidently prepared or maturated.b We have, too, the most indubitable evidence that birds — although unquestion- able virgins — may lay infecund eggs. Analogy would lead us to believe, that something similar may happen to the viviparous animal, and direct observation has confirmed the position. In all cases in which an ovum has escaped, a cavity of course is left in the ovarium, which is filled up, in the manner already mentioned, by a growth from the inner membrane of the Graafian follicle, which, thus altered, constitutes the corpus luteum? Not longer ago than the year 1808, the existence of the corpora lutea in the ovaria was held to be full proof of impregnation. In that year, Charles Angus, Esq., of Liverpool, England, was tried at the Lancaster Assizes, for the murder of Miss Burns, a resident of his house.d The symptoms previous to her decease, and the appearances observed on dissection, were such as to warrant the suspicion that she had been poisoned. The uterine organs were also found to be in such a state as to induce a belief, that she had been delivered a short time before her death, of a foetus, which had nearly arrived at maturity. It was not, however, until after the trial, that the ovaria were examined, in the presence of a num- ber of physicians, and a corpus luteum was distinctly perceived in one of them. The uterus was taken to London and shown to several of the most eminent practitioners there, all of whom appear to have considered that the presence of a corpus luteum proved the fact of pregnancy beyohd a doubt.'1 Such, indeed, is the posi- tive averment of Haller,e an opinion which was embraced by Haighton/who maintained that theyfurnish " incontestable proof" of previous impregnation. It was this belief,— coupled with the a Art. Generation, in Cyclop, of Anat. and Physiol. P. xiii. p. 454, Feb. 1838. b Hiiter, art. Empfangniss, in Encyclopad. Wbrterb. der Medicin. Wissensch. x. 629, Berlin, 1834. c F. Renaud, Lond. and Edinb. Monthly Journal of Medical Science, June, 1842. d Edinb. Med. and Surg. Journal, v. 220. e Beck's Medical Jurisprudence, 6th edit. i. 247, New York, 1838. • f Element. Physiolog. xxix. 1. s Philosoph. Transact, lxxxvii. 159. 37C GENERATION. fact, that division of the Fallopian tubes, in his experiments, pre- vented impregnation, whilst corpora lutea were found, notwith- standing, in the ovary, — which led him to the strange conclusion, that the semen penetrates no farther than the uterus, and acts upon the ovaria by sympathy. Sir Everard Homea affirms, that corpora lutea exist indepen- dently of impregnation. Upon examining," said he, 4' the ovaria of several women, who had died virgins, and in whom the hymen was too perfect to admit of the possibility of impregnation, there were not only distinct corpora lutea, but also small cavities around the edge of the ovarium, evidently left by ova, that had passed out at some former period;" and he affirms, that whenever a female quadruped is in heat, one or more ova pass from the ova- ria to the uterus, whether she receives the male or not. This view of the subject appears to have been first propounded by Blu- menbach,1' who remarks that the state of the ovaria of females, who have died under strong* sexual passion, has been found simi- lar to that of rabbits during heat; and he affirms, that in the body of a young woman, eighteen years of age, who had been brought up in a convent, and had every appearance of being a virgin, Val- lisnieri found five or six vesicles pushing forward in one ovarium, and the corresponding Fallopian tube redder and larger than usual, as he had frequently observed in animals during heat. Bon- net, he adds, gives the history of a young lady, who died vehe- mently in love with a man of low station, and whose ovaria were turgid with vesicles of great size. It has been already re- marked, under Menstruation, that the periodical recurrence of that function has been supposed to consist in the production and deve- lopment of vesicles in the ovary, that is, of a matured ovum which is periodically brought forward either to be expelled with the men- strual flux, or to be destroyed in the ovary ; a view which Was en- tertained by Cruikshank, and has been recently urged strongly by Gendrin. Buffon, again, maintained, that instead of the corpus luteum of Haller being the remains of the ovule, it is its rudiment; and that the corpus exists prior to fecundation, — as he also found it in the virgin. Lastly, Dr. Blundellc states, that he has in his possession a preparation, consisting of the ovaries of a young girl, who died of cholera under seventeen years of age, with the hymen, which nearly closed the entrance of the vagina, unbroken. In these ovaries, the corpora lutea are no fewer than four; two of them being a little obscure, but easily perceptible by an experienced eye. The remaining two are very distinct, and differ from the corpus luteum of genuine impregnation merely by their more diminutive size and the less extensive vascularity of the con- a Philosoph. Transact, for 1817 and 1819; and Lectures on Compar. Anat. iii 304 b Comment. Soc. Roy. Scient. Gotting. ix. 128; and Elliotson's edit of Bliimeii* bach's Physiology, 4th edit., p. 468, Lond. 1828. c Researches, Physiol, and Pathological, p. 49, Lond. 1825. FECUNDATION. 377 Fig. 229. tiguous parts of the ovary. " In every other respect," says Dr. Blundell, " in colour and form, and the cavity which they contain, their appearance is perfectly natural, indeed, so much so, that I occasionally circulate them in the class-room, as accurate specimens of the luteum upon the small scale." Mr. Stanley8 confirms the fact of the corpora lutea of virgins being of a smaller size than those that are the consequences of impregnation; and Dr. Mont- gomery6 says, that he has seen many of these virgin corpora lutea, " as they are unhappily called," and has preserved several speci- mens of them, but not in any instance, did they present what he would regard as even an approach to the assemblage of charac- ters belonging to the true corpus luteum,—the result of impreg- nation ; from which, according to him, they differ in the following particulars:__1. There is no prominence or enlargement of the ovary over them. 2. The external cicatrix is almost always wanting. 3. There are often several of them found in both ova- ries, especially in subjects who have died of tubercular diseases, such as phthisis, in which case they appear to be merely depositions of tubercle, and are frequently without any discoverable connection with the Graafian vesicles. 4. They present no trace whatever of vessels in their substance, of which they are in fact entirely destitute, and of * u ;„i„~*~A c T1!-.^^ Corpus Luteum in the third month — course cannot be injected. 5. 1 neir (Montgomery.) texture is sometimes so infirm, that it seems to be merely the remains of a coagulum, and at* others appears fibro-cellular, like that of the internal structure of the ovary; but never presents the soft, rich, ta- bulated, and regularly pearance, which Hunter press, when he described der and friable like glandular flesh." 6. In form they are often triangular, or square, or of some figure bounded by straight lines ; and 7. They never pre- sent, either the central cavity, or the radiated or stelliform white line, which results from its closure.0 Figures 229 and 230 represent the corpus luteum in the third, and at the end of the ninth month, respectively. a Transactions of the Royal College of Physicians of London, vol. vi. b An Exposition of the Signs and Symptoms of Pregnancy, &c, p. 245, Lond. 1837, or Dunglison's Amer. Med. Lib. Edit., Philad. 1839 ; and art. Signs of Pregna»cy and Delivery, in Cyclop, of Pract. Medicine, Lond. 1833. c See Dr. E. Rigby, System of Midwifery, American Edit., p. 27, PWad. 1841 ; and Dr. R. Paterson, Edinb. Med. and Surg. Journ. Jan. 1840. 32* Fig. 230. glandular ap- rneaiit to ex- them as " ten- Corpus Luteum at the end of tbe ninth month. — (Montgomery.) 378 GENERATION. Recently, however, Dr. William Davidson," of Edinburgh, has published three dissections of females — not one of whom was pregnant — and in each, corpora lutea were found. They all pos- sessed the characters assigned them by Dr. Montgomery,—a central cavity, or fibrous coagulum; an oval shape, and a radiated white cicatrix in the centre, just about the central body ; — the body being at the same time immediately under the peritoneal coat. This last point is dwelt upon by Dr. Robert Lee, who maintains, that false corpora lutea are never observed in immediate connection with the peritoneum, a small portion of stroma intervening. One of the females had been in a weakly condition for some years, and had no children ; another was unmarried, and had menstruated three days previous to her death ; of the third, there was no his- tory, but all the organs were healthy, and the Fallopian tube and uterus were in every respect natural. Dr. Davidson expresses his confident opinion, that in none of the cases had there been im- pregnation prior to the appearance of these bodies; and he refers to Professors Alison, Allen Thomson, John Reid, and Mr. Goodsir, in proof of the accuracy of his statement, and of their perfect resem- blance to true corpora lutea. Dr. Davidson states, as the result of his investigations, that he is led to believe, that impregnation cannot take place without the appearance of a true corpus luteum, but that a true corpus luteum may appear independently of impreg- nation. It is not yet decided at what period the central cavity disap- pears or closes up to form the stellated line. Dr. Montgomery thinks he has invariably found it existing up to the end of the fourth month. He has one specimen in which it was closed in the fifth month, and another in which it was open in the sixth, but later than this he has never found it. The structure of the corpus luteum is of a peculiar kind, and is not distinctly seen in small animals, or in those that have numerous litters; but in the cow, which commonly has only one calf at a birth, it is so large, according to Sir Everard Home,b that, when magnified, the structure can be made out. It is a mass of thin con- volutions, bearing a greater resemblance to those of the brain than to any other organ. Its shape is irregularly oval, with a central cavity, and in some animals, its substance is of a bright orange- colour, when first exposed. The corpora lutea are found to make their appearance immediately after puberty, and they continue to succeed each other, as the ova are expelled, till the period arrives when impregnation can no longer be accomplished Sir Everard's theory, regarding these bodies, is, that they are glands formed purposely for the production of ova, — and a similar view is entertained by Seiler,c—that they exist previous to, and are uncon- 1 L&id. and Edinb. Monthly Journal of Med. Science, Dec. 1841 b Leo, on Comp. Anat. iii. 303. c Us 2j und die Gebarmutter des Menschen,u. s. w., Dresd. 1832 ; and Stannius, FECUNDATION. 379 Fig. 231. nected with, sexual intercourse,— and, when they have fulfilled their office of forming ova, they are remov- ed by absorption, whether the ova be fecundated or not. Figures, 231, a and b, afford an external and internal view of a human ovary, that did not contain the ovum, from which a child had been deve- loped. It was taken immediately after the child was born. The corpus luteum is nearly of the full size, a and b, Fig. 232, afford an external and internal view of the ovarium, in which the impregnated ovum had been formed. The latter figure ex- hibits how much the corpus luteum had been broken down. In it we see a new corpus luteum forming. From all these facts, then, we are perhaps justified in concluding with Sir Everard Home,3 and Messrs. Blundell, Saumarez,b Cuvier, and others,0 that something resembling a corpus luteum may be produced independently even of sexual inter- course, by the mere excitement of high carnal desire, during which it is probable, that the digitated ex- tremity of the Fallopian tube em- braces the ovary, a vesicle bursts its covering, and a yellow body remains. The ovule is conveyed along the tube into the uterus, but, being infecund, it undergoes no far- ther development there ; so that unimpregnated ova may, under such circumstances, be discharged, as we observe in the oviparous animal. When pregnancy is over, the corpus luteum gradually diminishes in size and disappears. Dr. Montgomery remarks, that the ex- act period of its total disappearance he is unable to state, but art. Eierstock, in Encycl. Wbrterb. der Medicin. Wissensch. x. 193, Berl. 1834. See also, Weber's Hildebrandt's Handbuch der Anatomie, iv. 464, Braunschweig, 1832. a Op. cit. iii. 304. b A New System of Physiology, i. 337; see Granville's Graphic Illustrations of Abortion, part vi. Lond. 1834 ; and Dr. Allen Thomson, in art. Generation, Cyclop. Anat. and Physiol, part. xiii. p. 450, for Feb. 1838. c For a history of the opinions entertained at various times regarding the corpus luteum, see Dr. Paterson, Edinb. Med. and Surg. Journal, April, 1841, p. 402. Corpora Lutea.—(Sir E. Home 380 GENERATION. Fig. 232. that he has found it distinctly vi- sible so late as the end of five months after delivery at the full time, but not beyond this period. It would appear, therefore, that in a few months after the termination of pregnancy, all traces of the corpus luteum are lost, and that, consequent- ly, it will be impossible to decide how frequently impregnation has taken place, merely by examining the ovaries.a c. Theories of Generation. — We have now endeavoured to demon- strate the part performed by the two sexes in fecundation. We have seen that the material furnished by the male is the sperm ; that afforded by the female an ovum. The most difficult topic of inquiry yet remains, — how the new individual results from their commixture ? Of the na- ture of this mysterious process we are indeed profoundly ignorant; and if we could make any comparison between the extent of our ignorance on the different vital phenomena, we should be disposed to decide, that the function of generation is, perhaps, the least intelligible. The new be- ing must be stamped instantaneously as by the die. From the very mo- ment of the admixture of the ma- terials, at a fecundating copula- tion, the embryo must have within it the powers necessary for its own formation, and under impulses communicated by each parent — as regards likeness, hereditary predisposition, &c. From this moment the father has no communication with it; yet we know, that it will resemble him in its features and in its predispositions to certain morbid states, — whilst the mother probably exerts but a slight and indirect control over it afterwards, her office being chiefly to furnish the homunculus with a nidus, in which it may work its own formation, and with the necessary pabulum. We have seen, that even so early as the seventh and eighth day after fecundation, two projecting points — it has been asserted — are a Rigby, op. cit. p. 27, Philad. 1840. See, also, T. W. Jones, in Brit, and For. Med. Rev., Oct. 1843, p. 528. THEORIES — EP1GENESIS. 381 observed in the ovum, which indicate the future situations of the brain and spinal marrow. Our want of acquaintance with the precise character of this impenetrable mystery will not, however, excuse us from passing over some of the ingenious hypotheses, that have been entertained on the subject. These have varied according to the views that have prevailed respecting the nature of the sperm; and to the opinions indulged regarding the matter furnished by the ovary. Drelincourt,3 who died in 1697, collected as many as two hundred and sixty hypotheses of generation; but they may all, perhaps, be classed under two, — the system of epi- genesis and that of evolution. 1. Epigenesis. — According to this system, which is the most ancient of all, the new being is conceived to be built up of materials furnished by both sexes, the particles composing those materials having previously possessed the arrangement necessary for con- stituting it, or having suddenly received such arrangement. Still, it is requisite that these particles should have some controlling agent to regulate their affinity, different from any of the ordinary forces of matter; and hence a force has been imagined to exist, which has been termed cosmic, plastic, essential, nisusformativus — the Bildungstrieb of the Germans—force of formation,^,. Hippocratesb maintains, that each of the two sexes possesses two kinds of seed, formed by the superfluous nutriment, and by fluids constituted of materials proceeding from all parts of the body, and especially from the most essential, — the nervous. Of these two seeds, the stronger begets males, the weaker females. In the act of generation, these seeds become mixed in the uterus, and by the influence of the heat of that organ, they form the new indi- vidual— by a kind of animal crystallization — male or female; according to the predominance of the stronger or the weaker seed. Aristotle0 thought, that it is not by seed that the female partici- pates in generation, but by the menstrual blood. This blood he conceived to be the basis of the new individual, and the principles furnished by. the male to communicate to it the vital movement, and to fashion it. Empedocles, Epicurus, and various other ancient physiologists, contended, that the male and female respec- tively contribute a seminal fluid, which equally co-operate in the generation and development of the foetus, and that it belongs to the male or female sex, or resembles more closely the father or the mother, according as the orgasm of the one or the other pre- dominates, or is accompanied by a more copious discharged Lac- tantius, in quoting the views of Aristotle on generation, fancifully affirms, that the right side of the uterus is the proper chamber of 1 Novem Libelli de Utero, Conceptione, Foetu, &c, Lugd. Bat. 1632. b Trifi yov»c; in Oper. Omnia, edit. A. Fo'e'sio. Genev. 1657-1662. c De Generatione Animalium, &c. i. 19. d " Semper enim partus duplici de semine constat; Atque utrique simile est magis id quodcumque creatur." Lucret. lib. iv. 382 GENERATION. the male foetus, and the left of the female, — a belief, which ap- pears to be still prevalent amongst the vulgar, in many parts of Great Britain. But he adds, if the male or stronger semen should, by mistake, enter the left side of the uterus, a male child may still be conceived; yet as it occupies the female department, its voice, face, &c, will be effeminate. On the contrary, if the weaker or female seed should flow into the right side of the uterus, and a female foetus be engendered, it will exhibit evidences of a mascu- line character. The idea of Aristotle, with regard to the men- strual blood, has met with few partisans, and is undeserving of notice. That of Hippocrates, notwithstanding the objections, which we now know to apply to it, — that the female furnishes no sperm, and that the ovaria are probably in no respect analogous to the testes of the male, — has had numerous supporters amongst the moderns, being modified to suit the scientific ideas of the time, and of the individual. Descartes, for example, considered the new being to arise from a kind of fermentation of the seed furnished by both sexes. Pascal, that the sperm of the male is acid, and that of the female alkaline; and that they combine to form the embryo. Maupertuis3 maintained, that, in each seed, parts exist, adapted for the formation of every organ of the body, and that, at the time of the union of the seed in a fecundating copulation, each of the parts is properly attracted and aggregated by a kind of crys- tallization.b The celebrated hypothesis of the eloquent but too enthusiastic Buffon0 is but a modification of the Hippocratic doctrine of epige- nesis. According to him, there exists in nature two kinds of mat- ter,— the living and the dead; the former perpetually changing during life, and consisting of an infinite number of small, incorrup- tible particles or primordial monads, which he called organic molecules. These molecules, by combining in greater or less quantity with dead matter, form all organized bodies ; and without undergoing destruction, are incessantly passing from vegetables to animals, in the nutrition of the latter, and are returned from the animal to the vegetable by the death and putrefaction of the former. These organic molecules, during the period of growth, are appro- priated to the development of the individual; but, as soon as he has acquired his full size, the superfluous molecules are sent into depot in the genital organs, each molecule being invested with the shape of the part sending it. In this way he conceived the seed of both sexes to be formed of molecules obtained from every part of the system. In the commixture of the seeds, during a fe- cundating copulation, the same force that assimilates the organic molecules to the parts of the body for their nourishment and in- crease, causes them, in this hypothesis, to congregate for the for- mation of the new individual; and, according as the molecules of a Venus Physique, Paris, 1751. b Adelon, Physiologie de I'Homme, iv. 85, Paris 1829 <= Histoire Naturelle, torn. xvii. &c., Paris, 1799. THEORIES — EPIGENESIS. 383 the male or female predominate, so is the embryo male or female. The ingenuity of this doctrine was most captivating; and it ap- peared so well adapted for the explanation of many of the pheno- mena of generation, that it had numerous and respectable votaries. It accounted for the circumstance of procreation being impracti- cable, until the system had undergone its great development at puberty.. It explained why excessive indulgence in venery occa- sions emaciation and exhaustion; and why, on the other hand, the castrated animal is disposed to obesity, — the depot having been removed by the mutilation. The resemblance of the child to one parent rather than to the other was supposed to be owing to the one furnishing a greater proportion of organic molecules than the other; and as more males than females are born, the circumstance was ascribed to the male being usually stronger, and therefore fur- nishing a stronger seed, or more of it. Prior to this hypothesis, Leeuenhoeka had discovered what he considered to be spermatic animalcules in the semen ; but Buffon contested their animalcular nature, and regarded them as his vital particles or organic molecules; whilst he looked upon the ovarian vesicle as the capsule that contained the sperm of the female. The opinions of Buffon were slightly modified by Blumenbach,b and by Darwin.c The former, like Buffon, divided matter into two kinds, possessing properties essentially different from each other ; — the inorganic and the organized ; the latter possessing a peculiar creative or formative effort, which he called B i 1 d u n g s t r i e b or nisus formativus, — a principle in many respects resembling gravitation, and endowing every organ, as soon as it acquires structure, with a vita propria. This force he conceived to preside over the arrangement of the materials, furnished by the two sexes in generation. Darwin preferred to the term organic molecules that of vital germs, which he says are of two kinds, according as they are secreted or provided by male or female organs, whether ani- mal or vegetable. In the subdivision, however, of the germs the term molecule is retained ; but it is limited to those of the female; the vital germs or particles, secreted by the female organs of a bud or flower, or the female particles of an animal, being denominated by him molecules with formative propensities ; whilst those secreted from the male organs are texmedfibrils with formative appetencies. To the fibrils he assigns a higher degree of organization than to the molecules. Both, however, he asserts, have a propensity or appetency to form or create, and " they reciprocally stimulate and embrace each other and instantly coalesce ; and may thus popu- larly be compared to the double affinities of chemistry." Subtile as these hypotheses are, they are open to forcible objec- tions of which a few only will suffice. The notion of this occult a Arcana Naturse, Lugd. Bat. 1685. b Ueber den Bildungstrieb, Gotting. 1791 ; Comment. Societat. Gotting. torn. viii.; and ENiotson's Blumenbach's Physiology, 4th edit. p. 490, Lond. 1828. c Zoonomia, Lond. 1796. 384 GENERATION. force is identical with that, which, we shall see hereafter, has pre- vailed as regards life in general, and it leaves the subject in the same obscurity as ever. What do the terms plastic, cosmic, or vegetative force, orBildungstrieb express, which is not equal- ly conveyed by vital force, — that mysterious property, on which so many unfathomable processes of the animal body are dependent, and of the nature or essence of which we know absolutely nothing ? The objection, urged against the doctrine of Hippocrates, — that we have no evidence of the existence of female sperm, —applies equally to the hypotheses that have been founded upon it; and even were we to grant, that the ovarium is a receptacle for female sperm, the idea, that such sperm is constituted of organic molecules, derived from every part of the body, would still be entirely gra- tuitous. We have no facts to demonstrate the affirmative ; whilst there are many circumstances, that favour the negative. The in- dividual, for example, who has lost some part of his person — nose, eye, or ear, or has had a limb amputated, still begets perfect children; yet whence can the molecules, in such cases, have been obtained ? It is true, that if the mutilation affect but one parent, the organic molecules of the lost part may still exist in the seed of the other; but we ought, at least, to expect the part to be less perfectly formed in the embryo, which it is not. Where two docked horses are made to engender, the result ought, a fortiori, to be imperfect, as the organic molecules of the tail could not be furnished by either parent, yet we find the colt, in such cases, per- fect in this appendage. An elucidative case is also afforded by the fcetus. If we admit the possibility of organic molecules constitu- ting those parts that exist in the parents, how can we account for the formation of such as are peculiar to foetal existence. Whence are the organic molecules of the navel-string, or of the umbilical vein, or of the ductus venosus, or the ductus arteriosus,;or the um- bilical arteries obtained? These and other objections have led to the abandonment of the theory of Buffon, which remains merely as a monument of the author's ingenuity and elevation of fancy. 2. Evolution. — According to this theory, the new individual pre-exists in some shape in one of the sexes, but requires to be vivified by the other, in the act of generation ; after which it com- mences the series of developments or evolutions, which lead to the formation of an independent being.3- The great differences of sentiment, that have prevailed under this view, have been owing to the part, which each sex has been conceived to play in the function. Some have considered the germ to exist in the ovary, and to require the vivifying influence of the male sperm to cause its evolution. Others have conceived the male sperm to contain the rudiments of the new being, and the female to afford it merely a nidus, and pabulum during its development. The former class of physiologists have been called ovarists ; — the latter sperma- * C. Windischmann,art.EvolutionsTheorie, Encyclopad. Wbrterb. der Medicinisch Wissensch. xi. 615, Berlin, 1834. THEORIES — EVOLUTION. 385 lists, seminists, and animalculists. The ovarists maintain, that the part furnished by the female is an ovum from the ovary; and this ovum they conceive to be formed of an embryo and of par- ticular organs for the nutrition and first development of the em- bryo ; and adapted for becoming, after a series of changes or evolutions, a being similar to the one whence it has emanated. The hypothesis was suggested by the fact, that in many ani- mals but a single individual is necessary for reproduction ; and it is easier, perhaps, to conceive this individual to be female than male; as well as by what is noticed in many oviparous animals. In these, the part, furnished by the female, is mani- festly an ovum or egg ; and in many, such egg is laid before the union of the sexes, and is fecundated, as we have seen, externally. By analogy, the inference was drawn, that this may happen to the viviparous animal also. The notion is said, but erroneously, to have been first of all advanced by Joseph de Aromatariis.3; It was developed by Harvey,b who strenuously maintained the doctrine omne vivum ex ovo. The anatomical examinations of Sylvius, Vesalius, Fallopius, De Graaf,c Malpighi,d Vallisnierie and others, — by showing, that what had been previously regarded as female testes, and had been so called, were organs containing minute vesicles or ova, and hence termed, by Steno, ovaria, — were strong confirmations of this view, and startling objections to the ancient theory of epigenesis; and the problem appeared to be demonstrated, when it was discovered, that the vesicle or ovum leaves the ovarium, and.passes through the Fallopian tube to the uterus. The chief arguments that have been adduced in favour of this doctrine are: — First. The difficulty of conceiving the formation, ab origine, of an organized body, as no one part can exist without the simultaneous existence of others. Secondly. The existence of the germ prior to fecundation in many living beings. In plants, for example, the grain exists in a rudimental state in the flower, before the pollen, which has to fecundate it, has attained matu- rity. In birds, too, the egg must pre-exist, as we find that those, which have never had intercourse with the male, can yet lay. This is more strikingly manifest in many fishes, and in the batra- cia or frog kind; where the egg is not fecundated until after ex- trusion. Spallanzani, moreover, asserts, that he could distin- guish the presence of the tadpole in the unfecundated ova of the frog ; and Haller, that of the chick in the infecund egg ; at least he has seen them containing the yolk, which, in his view, is but a dependence of the intestine of the fcetus, and if the yolk exist, the chick exists also. Thirdly. The fact, before referred to, that in certain animals, a single copulation is capable of fecun- » Epist. de Generatione Plantarum ex Seminibu?, Venet. 1625. b Exercitationes de Generatione Animalium, Lond. 1651. c De Organis Mulierum, &c. Lugd. Bat. 1672. d Append, ad Opera Omnia, Lugd. Bat. 1687. e Istoria della Generazione deH'Uomo, Discorsi Acad, i.-iv., Venez. 1722-1726. VOL. II. — 33 386 GENERATION. dating several successive generations. In these cases, it is argued, the germ of the different generations must have existed in the first. Fourthly. The fact of natural and accidental encasings, inclusions, or emboitements ; as in the bulb of the hyacinth, in which the rudiments of the flower are distinguishable.; in the buds of trees, in which the branches, leaves, and flowers, have been detected in miniature, and greatly convoluted ; in the jaws of certain animals, in which the germs of different series of teeth can be detected ; in the volvox, a transparent animal, which exhibits several young ones encased in each other ; in the common egg, which occasion- ally has another within it; and in the instances on record, in which human foetuses have been found in the bodies of youths, of which there is a striking example in the Museum of the Royal College of Surgeons, of London; and a similar case in a boy of four- teen years of age, has been related by Dupuytren. A most singular case of the kind occurred to M. Velpeau.3 A tumour was removed from the scrotum of a young man aged 27, which was found to contain almost all the elements of a human body. Its exterior was evidently tegumentary, and the greater part of its substance was a mixture of lamellae and fibres like cellular, adipose, muscular and fibrous tissues. In the interior, there were two cysts filled with a substance like albumen or the vitreous humour : another cyst, as large as a partridge's egg, contained a greenish semi-fluid matter like meconium; and a fourth contained a dirty yellow grumous mass surrounded by hairs: the mass consisted of sebaceous matter and scales of epidermis; the hairs had no bulbs. A tuft of hair, which protruded externally from a kind of ulcer at the posterior part, — and which, with the fact of the tumour being congenital, induced M. Velpeau to con- sider it to be foetal,— proceeded from the cyst that contained the meconium-like substance, and gave the opening into it somewhat the appearance of an anus. In the midst of all these, numerous perfectly organized portions of a skeleton were found, consisting of bones resembling more or less the clavicle, scapula, humerus', sphenoid bone, sacrum, portions of vertebra?, and others whose names could not be determined. A peculiarity of this case of monstrosity by inclusion was, that the second foetus did not act as a foreign body in the other, but had a separate and independent existence and power of growth within itself. The tumour had its own colour and consistence, and a sensibility entirely independent of the person to whom it was attached. The man himself pierced it several times with a knife without feeling the least pain • and yet, all the wounds that were made in it bled, inflamed and cica- trized like those of any othej: part of the body. Perhaps the ex- planation of these extraordinary cases by Dr. Blundellb is' as phi- losophical as any that could be devised. A seed or egg, he re- a Gazette Medicale, Fev. 15,1840. •> Principles and Practice of Obstctricy, edited by Dr. Castle, Lond. 1834; American edition, Washington. ' ^uiencan THEORIES — EVOLUTION. 387 marks, though fecundated, may lie for years without being evolved. A serpent may become inclosed under the eggshell of the goose ; the shell probably forming over it as the animal lies in the oviduct of the bird. These facts Dr. Blundell applies to the phenomenon in question. When the boy was begotten, a twin was begotten at the same time,—but, while the former underwent his development in the usual manner, the impregnated ovum of his companion lay dor- mant,and,unresistingly,became closed up within the fraternal struc- ture, as the viper in the eggshell. For a few years, these living rudi- ments generally lie quiet within the body, and ultimately become de- veloped so as to occasion the death of both. "The boy," he remarks — speaking of one of the cases — " became pregnant with his twin brother, his abdomen formed the receptacle, where, as in the nest of a bird, the formation was accomplished." Cases of this kind of arrest of development occasionally occur, where two or more ova are fecundated at the same time, or in succession. To this we shall refer under Superfoetation.' Fifthly. The fact of the various metamorphoses that take place in certain animals. Of these we have the most familiar instances in the batracia, and in insects. The forms which they have successively to assume are evidently encased. In the chrysalis, the outlines of the form of the future butterfly are apparent; and in the larva we observe those of the chrysalis. The frog is also apparent under the skin of the tadpole. Sixthly. The fact of artificial fecundation, which has been regarded, by the ovarists, as one of the strongest proofs of their theory; the quantity of sperm employed, as in the experi ments of Spallanzani, already detailed, being too small, in theii opinion, to assist in the formation of the new individual, except as a vivifying material. Lastly. They invoke the circumstance of partial reproduction, of which all living bodies afford more or less manifest examples ; —as the reproduction of the hair and nails in man; of the teeth in the rodentia; of the tail in the lizard; of the claw in the lobster ; of the head in the snail, &c.,&c. All these phenomena are, according to them, owing to each part possessing, within itself, germs destined for its reproduction, and requiring only favourable circumstances for their development. The par- tisans of the doctrine of epigenesis, however, consider these last facts as opposed to the views of the ovarists; and they maintain, that, in such cases, there is throughout a fresh formation. The chief objections, that have been urged against the hypothesis of the ovarists, are ; — First. The resemblance of the child to the father — a subject which we shall refer to presently. The ovarists cannot of course r'eny that such resemblance exists; and they ascribe it to the modifying influence exerted by the male sperm, but without being able to explain the nature of such influence. They affirm, however,that the likeness to the mother is more frequent and i See a case of" Abdominal Enadelphia or Monstrosity by Inclusion," by M. Roux, du Var, with reflections by M. Geoffroy Saint-Hilaire, in Gazette Medicale de Paris, No. 35, Aout27,1836 ; and Researches on Monstrosity by Inclusion in Animals, sug. gested by a case of the kind in a Human Fcetus, by M. Charvet, in Archives Gene- rales de Medecine, Nov, 1838. 388 GENERATION. evident. Certain cases of resemblance are, indeed, weighty stum- bling blocks to ovism, or to the doctrine of a pre-existent germ in the female. It is a well-known fact, that six-fingered men will beget six-fingered children. How can we explain this upon the principle of the pre-existence of the germ in the female, and of the part played by the male sperm being simply that of a vivificative agent; and must we suppose, in the case of monstro- sities, that such germs have been originally monstrous ? Secondly. The production of hybrids is one of the strongest counter-argu- ments. They are produced by the union of the male and female of different species. Of these, the mule is the most familiar in- stance— the product of the ass and the mare. This strikingly participates in the qualities of both parents, and, consequently, the pre-existing germ in the female must have been more than vivified by the sexual intercourse. Its structure must have been altogether changed, and all the germs of its future offspring anni- hilated as the mule is seldom fertile. If a white woman marry a negro, the child is a mulatto, and if the successive generations of this woman be continually united to negroes, the progeny will ultimately become entirely black ; or, at least the white admixture will escape recognition. As a general rule, the offspring of differ- ent races has an intermediate tint between that of the parents: and the proportions of white and black blood, in different admix- tures, have even been subjected to calculation, in countries where negroes are common. The following table represents these pro- portions, according to the principles sanctioned by custom. Parents. Negro and white, White and mulatto, Negro and mulatto, White and terceron, Negro and terceron, White and quarteron, Negro and quarteron, The two last are considered to be respectively white and black; and of these the former were white by law, and consequently free', in the British West India Islands.3 All these cases exhibit the' influence exerted by the father upon the character of the offspring, and are great difficulties in the way of supposing that the male sperm is simply a vivifier of the germ pre-existing in the female.u Thirdly. The doctrine of the ovarists does not account for the greater degree of fertility of cultivated plants and of domesticated animals. Fourthly. The changes, induced by the succession of ages on the animal and vegetable species inhabiting the surface of » Lectures on Physiology, Zoology, and the Natural History of Man p 299 Loni 1819. . ' b Rudolphi, Grundriss der Physiologie, u. s. w. B. i. s. 54, Berl. 1823 • Burdach Physiologie als Erfahrungswissenschaft, u. s. w., B. i. a. 516 : and Berndt art R««' tardthiere in Enc. Wbrterb. u. s. w., B. v. s. 53, Berl. I83Q. * * *"*' Offspring. ] degree of Mixture. mulatto, i a white, 5 black. terceron, 3 — i — griffo or zambo, r i 3 or black terceron, C 4 ? -- quarteron, i 8 — 1 5 — black quarteron, 1 8 — 7 8 --' quinteron, 15 T5" — 1 black quinteron, i IT — 15 __ rs — THEORIES — EVOLUTION. 389 the globe, have been adduced against this hypothesis. In exa- mining the geological character of the various strata that compose the earth, it has been observed by geologists that many of these contain imbedded the fossil remains of animals and vegetables Now, those rocks on which others rest are the oldest, and the suc- cessive strata above these are more and more modern, and it has been found that the organic fossil remains in the different strata differ more and more from the present inhabitants of the surface of the globe in proportion to the depth we descend ; and that the remains of those beings, that have always been the compa- nions of man, are found only in the most recent of the alluvial deposits, — in the upper crust of the earth. In the older rocks the impressions are chiefly of the less perfect plants — as the ferns and reeds ; and of the lower animals — the remains of shells and corals ; whilst fish are uncommon. In the more recent strata, the remains of reptiles, birds and quadrupeds are apparent, but all of them differ essentially from the existing kinds, and in none of the formations of more ancient date has the fossil human skeleton been met with. The pretended human bones, conveyed by Spallanzani from the Island of Cerigo — the ancient Cythera—are not those of the human species any more than the bones of the Homo diluvii testis of Scheuchzer; and the skeleton of the savage Galibi, conveyed from Guadaloupe and deposited in the British Museum, is imbedded in acalcareous earth of modern formation. Hence it has been concluded, that man is of a date posterior to animals in all countries where fossil bones have been discovered.3 These singular facts, furnished by modern geological inquiry, have been attempted to be explained by the supposition, that the present races of animals are the descendants of those whose remains are met with in the rocks, and that their difference of character may have arisen from some change in the physical constitution of the atmosphere, or of the surface of the earth, producing a corresponding change in the forms of organized beings. It has been properly remarked, however, by Dr. Fleming,5 that the effect of circumstances on the appear- ance of living beings is circumscribed within certain limits, so that no transmutation of species was ever ascertained to have taken place, whilst the fossil species differ as much from the recent kinds, as the last do from each other ; and he adds, that it remains for the abettors of the opinion to connect the extinct with the living races, by ascertaining the intermediate links or transitions. This will probably ever be impracticable. The difference, indeed, be- tween the extinct and the living races is in several cases so extreme, that many naturalists have preferred believing in the occasional formation of new organized beings. Linnaeus was bold enough to affirm, that, in his time, more species of vegetables were in ex- istence than in antiquity, and hence, that new vegetable species » Principles of Geology, by Charles Lyell, Esq., F. R. S. i. 241,4th edit. Lond. 1835. b Philosophy of Zoologv, i. 26, Edinb. 1822. 33* 390 GENERATION. must necessarily have been ushered into being; and Wildenow embraced the views of Linnaeus. De Larmack,3 one of the most distinguished naturalists of the day, openly professes his belief, that both animals and vegetables are incessantly changing under the influence of climate, food, domestication, the crossing of breeds, Sac and he remarks, that if the species now in existence appear to us fixed in their characters, it is because the circumstances that modify those species demand an enormous time for action, and would consequently require numerous generations to establish the fact. The manifest effect of climate, food, &c, on vegetables and animals, he thinks, precludes the possibility of denying those changes on theoretical considerations ; and what we call lost spe- cies axe, in his view, only the actual species before they experienced modification. It is proper, however, to observe, that the repre- sentations on the wall of one of the sepulchres in the valley of Beban el Molook, at Thebes, which are regarded by Champollion as having been executed upwards of two thousand years before the Christian era, enable the features of the Jew and of the negro, amongst others, to be recognised as easily as the representations of their descendants of the present day ; so that, for the space of at least three thousand eight hundred years, no modification of the kind referred to by Lamarck seems to have occurred in the human species. Another explanation has been offered for these geological facts, and for the rotation, which we observe in the vegetable occupants of particular soils in successive years. It has been supposed, that as the seeds of plants and the ova of certain animals are so exces- sively minute as to penetrate wherever water or air can enter ; and as they are capable of retaining the vital principle for an indefinite length of time, of which we have many proofs, and of undergoing evolution whenever circumstances are favourable, the crust of the earth may be regarded as a receptacle of germs, each of which is ready to expand into vegetable or animal forms, on the occurrence of conditions necessary for their development. This is the hypothesis of panspermia or dissemination of germs, according to which the germs of the ferns and reeds were first expanded, and afterwards those of the staminiferous or more per- fect vegetables ; and, in the animal kingdom, first the zoophyte, and gradually the being more elevated in the scale ; the organized bodies of the first period flourishing, so long as the circumstances, favourable to their development, continued, and then making way for the evolution of their successors, — the changes effected in the soil by the growth and decay of the former probably favouring the evolution of the latter; which, again, retained possession of the soil so long as circumstances were propitious.b The changes ■ Philosophic Zoologique, edit. cit. torn. i.; and Lyell's Principles of Geolotrv ii. 407. s'r' m,\.F.lenS?' °P- °uitat- Kll;«" ?■Pu1roln,je' art* ErztuSunS. in Encycl. Wbrterb. der Median. Wissensch. xi. 537, Berlin, 1834. THEORIES — EVOLUTION. 391 that take place in forest vegetation are favourable to this doctrine. If, in Virginia, the forest trees be removed so as to make way for other growth, and the ground be prepared for the first cultivation, the Phytolacca decandra ox poke, which was not previously per- ceptible on the land, usurps the whole surface. When Mr. Madi- son went with Gen. Lafayette to the Indian treaty, they disco- vered, that wherever trees had been blown down by a hurricane, in the spring, the white clover had sprung up in abundance, al- though the spot was many miles distant from any cleared land ; and it has often been remarked, that where, during a drought in the spring, the woods have taken fire and the surface of the ground has been torrefied, the water-weed has made its appearance in immense quantities, and occupied the burnt surface. The late Judge Peters, having occasion to cut ditches on his land, in the western part of Pennsylvania, was surprised to find every subterra- neous tree that was met with, different from those at the time occupying the surface ; and President Madison informed the author, that in the space of sixty or seventy years, he had noticed the following spontaneous rotation of vegetables : — 1. Mayweed ; 2. Blue centaury ; 3. Bottle-brush-grass ; 4. Broomstraw; 5. White clover ; 6. Wild carrot; and the last is now giving way to the blue grass.3 The doctrine of panspermia is, however, totally inapplicable to the viviparous animal, in which the ovum is hatched within the body, and which, consequently, continues to live after the birth of its progeny; and the facts furnished by geology seem clearly to show,that the development of the animal kingdom has been succes- sive, not simultaneous; but, under what circumstances the differ- ent animals were successively ushered into being, we know not. Lastly, as regards the ovarists themselves; — they differ in es- sential points: whilst some are favourable to the doctrine of the dissemination of germs, believing, as we have seen, that ova or germs are disseminated over all space, and that they only undergo development under favourable circumstances, as when they meet with bodies capable of retaining them, and causing their growth, or which resemble themselves ; others assert, that the germs are inclosed in each other, and that they are successively aroused from their torpor, and called into life, by the influence of the seminal fluid; so that not only did the ovary of the first female contain the ova of all the children she had, but one only of these ova con- tained the whole of the human race. This was the celebrated system of emboitement des germes or encasing of germs, of which Bonnetb was the propounder, and Spallanzani the promulgator. Yet how monstrous for us to believe, that the first female had, within her, the germs of all mankind, born, and to be born; or to conceive, that a grain of Indian corn contains within it all the seed, 1 Prichard, Researches on the Physical. History of Man, i. 39; and Carpenter, Principles of General and Comparative Physiology, 2d edit. Lond. 1841. b Considerat. sur les Corps. Organises vol. i. and ii., Amst. 1762. 392 GENERATION. that may hereafter result from its culture. In this strange hypo- thesis — as Professor Elliotsona observes — there must have been an uncommon store of germs prepared at the beginning, for the ovaria of a single sturgeon have contained 1,467,500 ova.b Many of the ovarists, again, and they alone have any thing like pro- bability in their favour, believe, that the female forms her own ova, as the male forms his own sperm, by a secretory action ; and; so far as the female is concerned in the generative process, we shall find that this is the only philosophical view ; but it is im- perfect in not admitting of more than a vivifying action in the materials furnished by the male. About the middle of the seventeenth century, Hamme or Van Hammen, Leeuenhoekc and Hartsoker,d discovered a prodigious number of small moving bodies in the sperm of animals, which they regarded as animalcules.e This gave.rise to a new system of generation, directly the reverse of that of Harvey, — that of gene- ration ab animalculo maris. As, in the Harveian doctrine, the germ was conceived to be furnished by the mother and the vivify- ing influence to be alone exerted by the male, so, in this doctrine, the entire formation was regarded as the work of the father, the mother affording nothing more than a nidus, and appropriate pa- bulum for the homunculus or rudimental foetus.f The spermatic doctrine was soon embraced by Boerhaave, Keill, Cheyne, Wolff, Lieutaud, and others.^ The pre-existing germ was accordingly now referred exclusively to the male ; and, by some, the doctrine of emboitement or encasing was extended to it. In support of this hypothesis, the spermatists urged, — that the animalcules they dis- covered were peculiar to the semen, and that they exist in the sperm of all animals capable of generation ; that they differ in dif- ferent species, but are always identical in the sperm of the same animal, and in that of individuals of the same species; that they are not perceptible in the sperm of any animal until the age at which generation is practicable, whilst they are wanting in infancy and decrepitude; that their number is so considerable, that a drop of the sperm of a cock, scarcely equal in size to a grain of sand contains 50,000; and lastly, that their minute size is no obstacle to the supposition, that generation is accomplished by them • — the disproportion between the trees of our forest and the seed pro'ducini? them being nearly if not entirely as great as that between the animalcule and the being it has to develope. Leeuenhoek esti mated the dimensions of those of the frog at about the l-10,000th a Blumenbach's Physiology, by Elliotson, 4th edit. p. 494 Lond 1828 b Petit, Memoir, de l'Academ. des Sciences, 1733. c Oper. iii. 285, and iv. 169, Lugd. Bat. 1722. i Journal des Scavans, pour 1678 ; and Essai de Dioptrioue d 227 P«;= ico* e Haller, Element. Physiol, vol. vii. 27 ; Rudolphi, artAnimaS 8™i ? Encyclopad. Wbrterb. der Medecin. Wissenschaft, ii. 597, Berhn 1828 «n?£ ' T Histoire de Medecine, par Jourdan, iv. 309, Paris, 1815. ' d SPrenSel> f Mohrenheim, Nova Conceptions atque Generations Theoria R„T;„m ,,Q, b Bostock's Physiology, 3d edit. p. 642, Lond. 1836. g °m' 179i< THEORIES — EVOLUTION. 393 part of a human hair, and that the milt of a cod may contain 15,000,000,000,000,000 of them. The difficulty with the sperma- tists or animalculists was to determine the mode in which the ho- munculus attains the ovary, and effects the work of reproduction. Whilst some asserted it to be only requisite, that the sperm should attain the uterus, whither it attracted the ovum from the ovarium ; 'others imagined, that the animalcule travelled along the Fallopian tube to the ovary; entered one of the ovarian vesicles; shut itself up there for some time, and then returned into the cavity of the uterus, to undergo its first development, through the medium of the nutritive substance contained in the vesicle : and a celebrated pupil of Leeuenhoek even affirmed, that he not only saw these animalcules under the shape of the tadpole, as they were generally described, but that he could trace one of them, bursting through the envelope that retained it, and exhibiting two arms, two legs, a human head and a heart !a Although this doctrine was extremely captivating, and, for a time, kept the minds of many eminent philosophers in a state of delusive enthusiasm ; insomuch that Dr. Thomas Morgan,b in a work, pub- lished in 1731, thus expresses himself regarding it: — " That all ge- neration is from an animalculum pre-existing in semine maris, is so evident in fact, and so well confirmed by experience and obser- vation, that I know of no learned men, who in the least doubt^of it;" it was, subsequently, strongly objected to by many ; and the great fact on which it rested — the very existence of the spermatic animalcules — was, and is, strenuously contested. Linnseusc dis- credited the observations of Leeuenhoek. Verheyen denied the ex- istence of the animalcules, and undertook to demonstrate, that the motion, supposed to be traced in them, was a mere microscopic delusion: — whilst Needhamd and Buffon regarded them as or- ganic molecules.e Of late years, MM. Prevost and Dumasf have directed their attention to the subject; and their investigations, as on every other topic of physiological inquiry, are worthy of the deepest regard. The results of their examinations led them to confirm the existence of these animalcules, and likewise to con- sider them as the direct agents of fecundation. By means of the microscope they detected them in all the animals, whose sperm they examined, and these were numerous. Whether the fluid were' observed after its excretion" by a living animal, or after its death, in the vas deferens or in the testicle, the animalcules were detected in it with eqtial facility. They consider these bodies to be cha- racteristic of the sperm, as they found them only in that secretion ? being wanting in every other humour of the body, even in those 1 Adelon, Physiologie de I'Homme, edit. cit. iv. 94. b Mechanical Practice of Physic, Lond. 1735. c Bostock's Physiology, 3d edit. p. 643, London, 1836. i New Microscopical Discoveries, Lond. 1745. e Haller, Element. Physiologic, xxvii. f Mem. de la Societe Physique de Geneve, i. 180, and Annales des Sciences Na* turelles, torn. i. and ji. og. GENERATION. that are excreted with the sperm, as the fluids of the prostate, and of the glands of Cowper; and although similar in shape, and size, and in the character of their locomotion in the individuals of. the same species, they are of various shapes and dimensions in differ- ent species. In passing through the series of genital organs these animalcules experience no change, being as perfect in the testicle as at the time of their excretion; and they controvert the remark of Leeuenhoek, that they are met with apparently of different ages. The animalcules were manifestly endowed with spontaneous mo- tion, which gradually ceased, —in the sperm obtained during life by ejaculation, in the course of two or three hours ; in that taken from the vessels after death, in fifteen or twenty minutes, and in eighteen or twenty hours, when left in its own vessels after death. In farther proof of the position,-that these animalcules are the fecun- dating agents, MM. Prevost and Dumas assert, that they are only met with whilst reproduction is practicable : — that, in the human species, they are not found in infancy or decrepitude ; and, in the majority of birds, are only apparent in the sperm, at the periods fixed for their copulation ; facts which, in their opinion, show, that they are not mere infusory animalcules. MM. Prevost and Dumas moreover affirm, that they appear to be connected with the physiological condition of the animal furnishing them ; their rriotions being rapid or languishing, according as the animal was young or old, or, in a state of health or disease. They state, also, that in their experiments on the ova of the mammiferous animal, they observed animalcules filling the cornua of the uterus, and remaining there aiive and moving, until the ovule descended into that organ, when they gradually disappeared ; and they argue in favour of the influence of these animalcules, — that the positive contact of the sperm is necessary for fecundation, and that the aura seminis is totally insufficient; that the sperm, in twenty-four hours, loses its fecundating property, and it requires about this length of time for the animalcules to gradually cease their movements and perish ; and, lastly, that having destroyed the animalcules in the sperm, the fluid lost its fecundating property. One of these experi- ments consisted in killing all the animalcules inaspermatised fluid__ whose fecundating power had been previously tested, — by re- peated discharges of a Leyden phial: another consisted in placing a spermatized fluid on a quintuple filter, and repeating this until all the animalcules were retained on the filter ; when it was found, that the fluid, which passed through, had no fecundating power,' whilst the portion retained by the filter had the full faculty; a re'- sult that had been obtained by Spallanzani, who found, besides that he was capable of effecting fecundation with water in which the papers, used as filters, had been washed. M. Donnea has in- vestigated the mode in which the zoospermes are affected in the blood, the milk, the vaginal and uterine mucus in the healthy state in the purulent matter of chancres, and of blennorrhoea in the » Gazette Medicale de Paris, No. xxii., 3 Juin, 1837. THEORIES — EVOLUTION. 395 saliva, urine, &c. He observed these animalcules continue to live, and to move in some of those fluids, whilst in others they died in- stantaneously. For instance, the blood, the milk and pus did not affect them : in the mucus of the vagina and uterus they generally lived well; but in the saliva and urine they died almost instanta- neously. M. Donne, too, affirms, that there are cases in which the mucus of the vagina and uterus acquires properties that are deleterious to the zoospermes, and he is of opinion, that this is a cause of sterility. This deleterious property, according to M. Donne, occasionally resides in the vaginal mucus ; but at others, in a still higher degree in the mucus of the uterus; and he en- deavoured to discover, whether the mucus of the two membranes presented any peculiar characters or signs of disease, and he affirms, that he particularly noticed the excessive acidity of the one, and the marked alkaline character of the other. The mucus cecreted by the vagina as far as the orifice of the os uteri differed from that which flowed from within the cervix uteri, independently of its physical characters, by a different reaction, M. Donne found the vaginal mucus always acid — the uterine always alkaline, and he thinks, that the deleterious influence exerted by them on the zoo- spermes depended on excess of acidity in the one, and excess of alkali in the other. All this, however, it need scarcely be said, t requires substantiation. Professor Wagner,3 who has entered at great length into the consideration of the spermatozoa, accords with the general conclusions of M.Donne: some of his experiments, however, instituted for the most part on the spermatozoa of the lower animals, led him to different conclusions. He found, for example, that they almost always lived in saliva; also in urine when it was kept warm and was not too concentrated. He has repeatedly detected them in the urine of persons, whom he sus- pected of masturbation. Dr. John Davyb affirms, that on examin- ing the fluid from the urethra after stool in a healthy man, he had alvyays detected spermatozoa in it; and Dr. Robt. Willisc asserts, that under the same circumstances, and even after the mere eva- cuation of the bladder, he has several times discovered sperma- tozoa in the fluid of the urethra ; but the subjects of his observa- tion were never strong or healthy men ; they mostly laboured under anomalous nervous symptoms, which, he thinks, were irf all like- lihood connected with an irritable or disordered state of the vesi- culae seminales and prostate part of the urethra. MM. Prevost and Dumas, and Rolando, conjecture, that the sper- matic animalcule forms the nervous system of the new being, and that the ovule furnishes only the cellular framework in which the organs are formed; but this is mere hypothesis. The essays of these ingenious experimenters would seem to prove the existence of peculiar animalcules in the sperm, and their apparent agency * Elements of Physiology, translated by Dr. Willis, p. 20, Lond. 18,41. b Edinburgh Medical and Surgical Journal, vol. i. c Wagner, op. citat. p. 21, (note.) 396 GENERATION. in the generative process; yet, as we have before seen, (page 330 of this volume,) all this has been questioned, and Raspail" is dis- posed to regard the fancied animalcules as mere shreds of the tissues of the generative organs ejaculated with the sperm. It is scarcely necessary to remark, that all the objections, which were urged against the system of the ovarists, as regards the proof in favour of an active participation of both sexes in the work of reproduction, are equally applicable to the views of those animal- culists, who refer generation exclusively to the spermatic ani- malcule.11 Such are the chief theories that have been propounded on the subject of generation. It has been already observed, that the par- ticular modifiations are almost innumerable. They may all, how- ever,-be classed with more or less consanguinity under some of the doctrines enumerated. Facts and arguments are strongly against any view that refers the whole process of formation to either sex. There must be a union of materials furnished by both, otherwise it is impossible to explain the similarity in conformation to both parents, which is often so manifest. Accordingly, this modified view of epigenesis is now adopted by most physiologists : — that at a fecundating copulation, the secretion of the male is united to a material, furnished by the ovarium of the female ; that from the union of these elements the embryo results, impressed, from the very instant of such union, with life, and with an impulse to a greater or less resemblance to this or that parent, as the case may be ; and that the material, furnished by the female, is as much a secretion resulting from the. peculiar organization of the ovarium, as the sperm is from that of the testicle, — life being susceptible, in this manner, of communication from father to child, without a necessity for invoking the incomprehensible and revolting doctrine of the pre-existence of germs. This admixture of the materials furnished by both sexes accounts for the likeness that the child may bear to either parent, whatever may be the difficulty in un- derstanding the precise mode in which they act in the formation of the fcetus. It has been attempted, however, by some, to maintain, that the influence of the maternal imagination during a fecundat- ing copulation may be sufficient to impress the germ within her with the necessary impulse ; and the plea has been occasionally urged in courts of justice. Of this we have an example in a well-known case, tried in New York, between 30 and 40 years ago. A mulatto woman was delivered of a female bastard child, which became chargeable to the authorities of the city. When interro- gated, she stated that a black man of the name of Whistelo was the father, who was accordingly apprehended, for the purpose of being assessed with the expenses. Several physicians, who were summoned before the magistrates, gave it as their opinion that it was not his child, but the offspring of a white man. Dr. S. * Chimie Organique, p. 389, Paris, 1833. b Burdach's Physiologie als Erfahrungswissenschaft, 2te Auflage, i. 112, Leipz. 1835. THEORIES — EVOLUTION. 397 Mitchill, however, who, according to Dr. Beck, seemed to be a believer in the influence of the imagination over the foetus, thought it probable that the negro was the father. Owing to this difference of sentiment, the case was carried before the mayor, recorder, and several aldermen. It appeared in evidence, that the colour of the child was somewhat dark, but lighter than the generality of mulattos, and that its hair was straight, and had none of the peculiarities of the negro race. The court very properly decided in favour of Whistelo, and of course against the testimony of Dr. Mitchill, who, moreover, maintained, that as alteration of complexion has occasionally been noticed in the human subject, — as of negroes turning partly white, — and in.animals, so this might be a parallel instance.* The opinion does not seem entitled to much greater estimation than that of the poor Irishwoman, in a London police report, who ascribed the fact of her having brought forth a thick-lipped, woolly-headed urchin to her having eaten some black potatoes during her pregnancy ! It is obvious, that the effect of the maternal imagination can only be invoked — by those who believe in its agency on the future appearance of the foetus — in the case of those animals in which copulation is a part of the process. Where the eggs are first extruded and then fecun- dated, all such influence must be out of the question ; and even in the viviparous animal, we have seen, experiments on arti- ficial impregnation have shown, that not only has the bitch been fecundated by sperm injected into the vagina, but that the result- ing young have manifestly resembled the dog, whence the sperm had been obtained.b But the strongest case in favour of the influence of the maternal imagination is given by Sir Everard Home.c An English mare was covered by a quaga,— a species of wild ass from Africa, which is marked somewhat like the zebra. This happened in the year 1815, in the park of Earl Morton, in Scotland. The mare was only covered once ; went eleven months, four days, and nineteen hours, and the produce was a hybrid, marked like the father. The hybrid remained with the dam for four months, when it was weaned and removed from her sight. She probably saw it again in the early part of 1816, but never afterwards. In February, 1817, she was covered by an Arabian horse, and had her first foal — a filly. In May, 1818, she was covered again by the same horse, and had a second. In June, 1S19, she was covered again, but this year missed ; but in May, 1821, she was covered a fourth time, and had a third; — all being marked like the quaga. Similar facts have been alluded to by other writers. Hallerd remarks, that the female organs of the mare seem to be corrupted by the unequal copulation with » Beck's Medical Jurisprudence, 6th edit. i. 500, Philad. 1838. See, also, for some ridiculous stories of this kind, Demangeon, Du Pouvoir de l'Imagination sur de Phy- sique et le Moral de I'Homme, p. 201, Paris, 1834. b See page 360 of this volume. « Philosoph. Transact, for 1821, p. 21; and Lectures on Comparative Anatomy, iii. 307. <» Element. Physiol, viii. 104. VOL. II.— 31 398 GENERATION. the ass, as the young foal of a horse from a mare, which previ- ously had a mule by an ass, has something asinine in the form of its mouth and lips; and Beefier3 says, that when a mare has had a mule by an ass, and afterwards a foal by a horse, there are evi- dently marks, in the foal, of the mother having retained some ideas of her former paramour, — the ass; whence such horses are commended on account of their tolerance and other similar quali- ties. It has been even affirmed, that the human female, when twice married, bears children occasionally to the second husband, which resemble the first both in bodily structure and mental powers.b The mode in which the influence is exerted, in this and similar cases, is unfathomable ; and the fact itself, although indis- putable, is astounding. Sir Everard Homec thinks, that it is one of the strongest proofs of the effect of the mind of the mother upon her young that has ever been recorded. Although we are totally incapable of suggesting any satisfactory solution, it appears to us more probable, that the impression must have been made in these cases on the genital system, and probably upon the ovarian vesicle, rather than upon the mind of the animal.d d. Conception. —Conception usually occurs without the slight- est consciousness on the part of the female; and hence the diffi- culty of reckoning the precise period of gestation. Certain signs, as shivering, pains about the umbilicus, &c, are said to have occa- sionally denoted its occurrence ; but these are rare exceptions, and the indications afforded by one are often extremely different from those presented by another. In those animals, in which genera- tion is only accomplished during a period of generative excitement, the period of conception can be determined with accuracy ; for, in by far the majority of such cases, a single copulation will fecun- date, — the existence of the state of heat indicating, that the gene- rative organs are ripe for conception. In the human female, where the sexual intercourse can take place at all periods of the year, conception is by no means as likely to follow a single intercourse ; for, although she may be always susceptible of fecundation, her genital organs are perhaps at no one time so powerfully excited as in the animal during the season of love. It is not for the phy- siologist to inquire into the morbid causes of sterility in either male or female ; nor is it desirable to relate all the visionary notions which have prevailed regarding the circumstances that favour con- ception. It would certainly seem more likely to supervene when the venereal orgasm occurs simultaneously in both parties; and » Physic. Subterran. Lips. 1703. b See art. Generation, by Dr. Allen Thomson, Cyclop. Anat. and Physiol P xiii p. 468, for Feb. 1838. c Lectures, &c. iii. 308. d See, on the Theories of Generation, Buffon, Nat. Hist. vol. ii. chap. 5 • Kurt Sprengel's Hist.de la Medecine, Jourdan's translation, i. 231, Paris, 1815 • Dr A Thomson, op. cit. p. 427 ; Adelon, Physiologie de I'Homme, 2de edit p 81 Paris' 1829; Meigs, Philadelphia Practice of Midwifery, p. 83, Philad. 1838 ; and Seiler art' Erzeugung, in Pierer, Anat. Phys. Wbrterb. ii. 802, Leipz. und Altenb. 1818 -'and Breschet, in l'Art de Procreer les Sexes a Volonte, par Millot, Paris 1829 ' CONCEPTION. 399 when the sperm is thrown well forwards towards the mouth of the uterus. We have already shown, that preternatural openings of the urethra, which interfere with this projection of the sperm in the proper direction, render fecundation less probable. It has been generally affirmed by writers, that conception is apt to take place more readily immediately after menstruation ; either, it has been imagined, because the uterus continues slightly open, so as to admit the sperm more easily into its cavity, or because the whole apparatus is in a state of some excitement. This opi- nion is problematical; and, accordingly, a female is in the habit of reckoning from a fortnight after her last menstrual period ; for as she might have fallen with child immediately after one menstrua- tion, or not until immediately preceding the following menstruation, a difference of three weeks might occur ; and she, therefore, takes the middle point between those periods ; that is, ten days or a fort- night after her last menstruation, or, what is the same thing, ten days or a fortnight before the first obstructed menstruation. Sir Everard Home,a however, differs on this topic from the generality of physiologists, — affirming that, in the human species, the fulness of the vessels of the womb, prior to menstruation, corresponds with the state of heat in the female quadruped, and shows that, at that period, the ova are most commonly fit for impregnation. " The females in India," he observes, " where from the warmth of the climate, all the internal economy respecting the propagation of the species goes on more kindly than in changeable climates, reckon ten months as the period of utero-gestation.h In the Apocrypha, the wisdom of Solomon, chap. vii. v. 2, — ' And in my mother's womb was fashioned to be flesh in the time of ten months.' This circum- stance seems to prove, that immediately before menstruation, when all the appendages of the womb are loaded with blood, the ova and ovaria are more frequently ready for impregnation in the climates most congenial for propagation; and therefore the mode of reckoning is from the previous menstruation, which is ten months before the birth." Dr. Carpenter thinks it is " quite certain" that there is a greater aptitude for conception immediately before and after menstru- ation, than there is at any intermediate period. There is no subject, however, which is less certain ; Raciborski states, that of fifteen women, who specified accurately the period of their last menstrua- tion, as well as that of their last sexual commerce, conception took place in five from two to four days before the period at which the catamenia were due. In seven, it dated from a union two or three days after menstruation ; in two, it took place during the period; and in one only as long as ten days after. Nor is the author pre- pared to agree with Dr. Carpenter, that there is good reason to believe, that in women the sexual feeling becomes stronger at the menstrual period.0 ■ Lectures on Comparative Anatomy, iii. 297. b These were of course lunar months; although Sir Everard clearly does not think so. c Carpenter, Human Physiology, Amer. Edit, by Dr. Clymer, § 742, Philad. 1843. 400 GENERATION. It has been attempted to ascertain what age and season are most prolific. From a register kept by Dr. Bland, of London, it would appear, that more women between the ages of twenty-six and thirty years, bear children than at any other period. Of two thou- sand one hundred and two women delivered, eighty-five were from fifteen to twenty years of age ; five hundred and seventy-eight from twenty-one to twenty-five ; six hundred and ninety-nine from twenty-six to thirty ; four hundred and seven from thirty-one to thirty-five ; two hundred and ninety-one from thirty-six to forty ; thirty-six from forty-one to forty-five ; and six from forty-six to forty-nine. At Marseilles, according to Raymond, women con- ceive most readily in autumn,and chiefly in October; next in sum- mer ; and lastly in winter and spring, — the month of March having fewest conceptions. Morand says, that July, May, June, and August, are the most frequent months for conception; and No- vember, March, April, and October, successivel}*', the least frequent. At the Havana, according to tables by the author's friend, Don Ramon de la Sagra,a-the monthly number of births, amongst the white population, during a period of five years,— from 1825 to 1829 inclusive — was in the following order:—October, September, November, December, August, July, June, April, May, January, March, and February. February, January, March and April are, therefore, the most frequent months for conception at the Havana — June, July, May and September the least so. Mr. Burnsb as- serts, that the register for ten years of an extensive parish in Glas- gow renders it probable that August and September are most favourable for conception. M. Villerme, from an estimate founded on eight years' observations in France, comprising 7,651,437 births, makes the ratio of conceptions as follows ; — May, June, April, July, February, March and December, January, August, November, September and October:—and lastly, Dr. Gouver- neur Emerson,0 who has employed himself most profitably on the Medical Statistics of Philadelphia, has furnished a table of the number of births, during each month, for the ten years ending in 1830; according to which, the numbers are in the following order: December, September, January, March, October, August, Novem- ber, February, July, May, April and June, —the greatest number ofconceptions occurring, consequently, in April, January, and May, — the least in October, August and September. The human female is uniparous, — one ovum only, as a general rule, being fecundated : numerous other animals are multiparous, or bring forth many at a birth. The law, however, on this subject is not fixed. Occasionally, the human female will brin<* forth twins, triplets, or quadruplets, whilst the multiparous animal is not always delivered of the same number. It is impossible to account for those differences. The ovarists refer them to the female • the » Historio Economico-Politica y Estadistica de la Isla de Cuba Hahan* lass * b Principles of Midwifery, 3d edit. p. 126, Lond. 1814. "a^na, 1833. e Amer. Journ. of the Med. Sciences, for Nov. 1831. CONCEPTION. 401 animalculists to the male; and facts have been found to support both views. Certain females, who have been frequently married, have been muciparous with each husband; and analogous facts have occurred to males under similar circumstances. Menage cites the case of a man, whose wife brought him twenty-one children in seven deliveries ; and the same individual having impregnated his servant-maid, she brought forth triplets likewise. In 1755, it is asserted, a peasant was presented to the Empress of Russia, who was seventy years of age, and had been twice married. His first wife had fifty-seven children at twenty-one births. In four de- liveries she had four children at each; in seven, three; and in six, two. This appears to be the neplus ultra of such cases ! In the Hospice de la MaterniU, of Paris, it has been observed, that twins occur once in about eighty cases. In the Westminster Hospital, the same ratio has been found, to prevail. In the British Lying-in- Hospital, the proportion was not greater than 1 in 91; whilst in the Dublin Lying-in Hospital, the cases were nearly twice as fre- quent, or about 1 in 57. Dr. Collins9 properly remarks on the singular circumstance, that in Ireland, the proportional number of women giving birth to twins is nearly a third greater than in any other country of which he had been able to obtain authentic re- cords. He states the proportion in France to be one in every 95 births; in Germany, one in 80; in England, one in 92 ; in Scot- land, one in 95; and in Ireland, one in 62. Of 129,172 women delivered in the Lying-in Hospital, Dublin, 2062 gave birth to twins; 29 produced three at a birth, which is in the proportion of one in 4450 ; and one only gave birth to four. In this country, the average, according to Dr. Dewees, is about 1 in 75. Triplet cases were found to occur in the Hospice de la Maternit'e, of Paris, about once in 9000 times; and in the Dublin Hospital once in 5050 times; the balance being largely in favour of the prolific powers of the Irish. Dr. Dewees affirms, that in more than 9000 cases, he has not met with an instance of triplets. Of 36,000 cases in the Hospice de la Maternite not one brought forth four children; yet there are cases on record where five have been born at a birth.b Beyond this number the tales of authors ought perhaps to be esteemed fabulous. In referring to the following table, it will be found to prevail, as a general rule, amongst quadrupeds, that the largest and most for- midable bring forth the fewest young, and that the lower tribes are unusually fruitful; the number produced compensating, in some measure, for their natural feebleness, which renders them constantly liable to destruction. On the other hand, were the larger species to be as prolific as the smaller, the latter would a A Practical Treatise on Midwifery, Lond. 1835 : republished in Bell's Select Library, Philad. 1838. b Dr. Garthshore, in Philos. Transact, for 1787, Kleinert's Repertorium, cited in Amer. Journ. of the Med. Sciences, Feb. 1838, p. 459 ; also, Bulletino delle Scienze Mediche, Agosto e Settembre, 1838, cited in Brit, and For. Med. Rev., Oct. 1839,, p. 564. 34* 402 GENERATION. soon be blotted from existence. What would have been the condition of animated nature, if the gigantic mastodon, once the inhabitant of our plains, could have engendered as frequently and as numerously as the rabbit. For wise purposes, it has also been ordained, that the more formidable animals seldom begin the work of reproduction until they have nearly attained their full size : whilst those that bring forth many commence much earner. Lastly, there is some correspondence, likewise, between the dura- tion of gestation and the size of the animal. Animals. Duration of ges-tation. Number of young. Animals. Duration of ges-tation. Number of young. Ape - - about 9 months, 1 Lioness - 4 or 5 Bat - - . 2 Tigress . 4 or 5 Rat - - 5 or 6 weeks, 5 or 6 Cat - - 8 weeks, 4 or 5 Mouse - - . 6 to 10 Seal - - . 2 Hare - - 30 days, 4 or 5 11 months"^ Rabbit- - Do. Do. Mare - - and some V 1 Guinea-pig 3 weeks, 5 to 12 days, 3 Squirrel - 6 weeks, 4 or 5 Ewe - - 5 months, 1 or 2 Mole - - . 4 or 5 Goat - - 4^ months, 1, 2, or 3 Bear - - ... 2 or 3 Cow - 9 months, 1 or 2 Otter - - 9 weeks, 4 or 5 Reindeer - 8 months, 2 Bitch - - 9 weeks, 4 to 10 Hind - - Do. 1 or 2 Ferret - - 6 weeks, 6 or 7 Sow 4 months, 6 to 12 ) and more $ Wolf - - 10 weeks, 5 to 9 Opossom - . 4 or 5 Camel - - 12 months, 1 Kangaroo - . 1 Walrus - 9 months, 1 Jack-all . 6 to 8 Elephant - 2 years, 1 Fox - - 10 weeks, 4 or 5 Whale - 9 or 10 months, ----1----------- 1 or 2* Conception being entirely removed from all influence of voli- tion, it is obviously impracticable, by any effort of the will, either to modify the sex of the fcetus, or its general physical and moral characters. Yet idle and absurd schemes have been devised for both one and the other. The older philosophers, as Hippocrates and Aristotle, believed that the right testicle and ovary furnished rudiments of males; and the same organs, on the left side, those of females : some of the old writers, de Re Rusticd, assert that this was the result of their experiments with the ram. These state- ments gave rise to a pretended " art of procreating the sexes at pleasure," which has even been seriously revived in our own time. Mr. John Hunter published an experiment in the Philoso- phical Transactions, which was instituted for the purpose of deter- mining whether the number of young be equally divided between the ovaria. He took two sows from the same litter, deprived one of an ovarium, and counted the number of pigs each produced during its life. The sow with two ovaria had one hundred and sixty-two : the spayed sow only seventy-six. Hence he inferred, that each ovarium had nearly the same proportion. In this expe- riment, he makes no mention of the interesting fact re^ardino- the » See, on this subject, Dr. Laycock, on the Nervous Diseases of Women d 48 Lond. 1840. ' V' ' CONCEPTION. 403 proportion of the males in the two cases, and whether they were not all of the same sex in the sow that had been spayed. Had his attention been drawn to this point, the results would have been sufficient to arrest the strange hypothesis brought forward by Millot,a who boldly affirmed that males are produced by the right ovarium, and females by the left; asserting, that he could so manage the position of the woman during copulation, that she should certainly have a boy or girl, as might have been deter- mined upon : and he published the names of mothers, who had followed his advice, and had succeeded in their wishes! A case, related by Dr. Granville, of London, to the Royal Society,b has completely exhibited the absurdity of this doctrine. ^ A woman, forty years of age, died at the Hospice de la Maternite of Paris, — six or seven days after delivery,—of what had been supposed to be a disease of the heart. The body was opened in the presence of Dr. Granville, and the disease was found to be aneurism of the aorta. On examining the uterus, it was discovered to be at least four times the size of what it is during the unimpregnated state. It had acquired its full development on the right side only, where it had the usual pyriform convexity ; whilst the leftformed a straight line scarcely half an inch distant from the centre, although it was more two inches from the same point to the outline of the right side. The Fallopian tube and the ovarium, with the other parts on the right side, had the natural appearance ; but they were not tobefoundon the left. Yet this woman had been the mother of eleven children of both sexes; and a few days before her death had been delivered of twins;—one male and one female.0 M. Jadelot, too, has given the dissection of a female, who had been delivered of several children — boys and girls ; yet she had no ovary or Fallopian tube on the right side. Lepelletierd asserts that he saw a similar case in the Hospital of Mans, in 1825, and the Recueils of the Societe de Medecine, of Paris, contains the his- tory of an extra-uterine gestation, in which a male fcetus was contained in the left ovary. Independently of these decisive cases, it has been found, that when one of the.ovaries has been entirely disabled by disease, the other has conceived of both sexes. In rabbits, an ovary has been removed ; yet both male and foetuses have subsequently been en- gendered ; and if the gravid uterus of one of those animals be exa- mined, male and female foetuses will be found in the same cornu of the uterus, all of which, owing to peculiar construction of the uterus, — the cornu forming the main part of the organ, — must manifestly have proceeded from the corresponding ovary. We are totally unaware, therefore, of the circumstances that give rise to the jsex of the new being, although satisfied that it is in no respect influenced by the desires of the parents. We shall see, » Millot, l'Art de Procreer les Sexes a Volonte ; nouvolle edit., par M. Breschet, Paris, 1829. " Philos. Transact, for 1808, p. 308. c Sir E. Home, Lect. on Comp. Anat. iii. 300. ■» Physiologie Medicale et Philosophiciue, iv. 333, Paris, 1833. 404 GENERATION. hereafter, that some distinguished physiologists believe, that the sex is not settled at the moment of conception, and that it is determined at a later period, after the embryo has undergone a certain development. It is an ancient opinion, which seems to be in some measure confirmed by what we notice in certain animals, that the charac- ter of the offspring is largely dependent upon the moral and physical qualities of the parent ; and a Dr. Robert, of Paris, in a dissertation under the pompous title of Megalanthropogenesis, has fancifully maintained, that the race of men of genius may be per- petuated by uniting them to women possessed of the same facul- ties. Similar views are maintained by Claude Quillet.a It is, also, an old opinion, that the procreative energy of the parents has much to do with the mental and corporeal activity of the offspring. Hence it is, that bastards have been presumed to excel in this respect. Such is the view of Burton,b and the same idea is put, by Shakspeare, into the mouth of Edmund.0 This, we have no doubt, is erroneous. Much depends upon the condition of the parents as regards their organization and strength of constitution. The remark — " fortes creantur fortibus et bonis" — is true within certain limits; but we have no proof, that the ardour of the pro- creative effort can have any such influence; and the ratio of in- stances of bastards, who have been signalized for the possession of unusual vigour — mental or corporeal — to the whole number of illegitimates, is not greater than in the case of those born in wed- lock.'1 It would appear, too, that the number of male children is greater in cases of legitimate than of illegitimate birth. Mr. Bab- bagee has compared the ratio in different countries, from which he has deduced the following table : — Legitimate Births. Number of Births observed. Illegitimate Births. Number of Births observed. Females. 10,000 10,000 10,000 10,000 10,000 Males. Females. Males. France, Naples, Prussia, Westphalia, Montpellier, 10,657 10.452 10,609 10,471 10,707 9,656,135 1,059,055 3,672,251 151,169 25,064 10,000 10,484 10,000 10,267 10,000 10,278 10,000 10,039 10,000: 10,081 673,047 51,309 212,804 19,950 2,735 Mean, 10,000 10,575 10,000 | 10,250 From the statistics of the Gebaranstalt, the Imperial Lying-in 1 Quilleti Callipaedia, sive de Pulcrme Prolis Habendae Ratione, &c. Lond. 1708. b Anatomy of Melancholy, vol. ii. " Why brand they us With base 1 with baseness 1 bastardy ? base 1 base 1 Who in the lusty stealth of nature take More composition and fierce quality Than doth, within a dull, stale, tired bed Go to the creating a whole tribe of fops Got 'tween sleep and wake!" — King Lear, i.2. d Elliotson's Blumenbach's Physiology, 4th edit. p. 496, Lond." 1828. <■ Brewster's Journal of Science, New Series, No. 1; and Quetelet, Sur I'Homme, i. 47, Pans, 1835. CONCEPTION. 405 i Hospital of Vienna, which is the great receptacle of illegitimate conceptions, it would seem that the number of female children born actually exceeds there that of the males. Of 21,212 children born there in the seven years prior to 1838, the sexes were in the propor- tion of 10,584 males to 10,628 females.3 To elucidate the effect of the condition of the parent on the future progeny, M. Girou de Bnzareinguesb gave a violent blow to a bitch, whilst lined, in consequence of which she was para- plegic for some days. She brought forth eight pups, all of which, except one,had the hind legs wanting, malformed, or weak. It has been attempted to show, also, that the corporeal vigour of the parents has much to do even with the future sex. M. Girou instituted a series of experiments on different animals, but especially on sheep, to discover, whether a greater number of male or female lambs may not be produced at the will of the agricul- turist. The plan, adopted to insure this result, was to employ very young rams in that division of the flock whence it was desired to obtain females ; and strong and vigorous rams, of four or five years of age, in that from which males were to be procured. The result would seem to show, that the younger rams begat females in greater proportion, and the older, males. M. Girou asserts, that females commonly predominate amongst animals, that live in a state of " polygamy," and it is asserted, that the same fact has been observed, in Turkey, and Persia, in our own species; but statistical facts are wanting on this subject. From the re- searches of Hofackerc and Sadler,d it would seem, that, as a general rule, when the mother is older than the father, fewer boys are born than girls, and the same is observed where they are of equal age, but the greater the excess of age on the part of the father, the greater will be the ratio of boys born.e The fact de- duced from the observations of these gentlemen, has been charac- terised by a recent writer as " one of the most remarkable contri- butions that have yet been made by statistics in physiology/ The followin0- table gives the average results obtained by them; the numbers indicating the proportion of male births to 100 females. Hofacker. Sadler. Father younger than mother, 906 Father younger than mother, 86-5 Father and mother of equal age, 90-0 Father and mother of equal age, 94-8 Father older by 1 to 6 years, 103-4 Father older by 1 to 6 years, 103-7 6 to 9 124-7 6 to 11 126-7 9 to 18 143-7 11 to 16 147-7 18 and more, 200 0 16 and more, 163-2 » Austria : its Literary, Scientific and Medical Institutions, by W. R. Wilde, p. 22, Note, Dublin, 1843. b Memoire sur les Rapports des Sexes, &c. Paris, 1836 ; and a farther Memoir, in Revue Medicale, 1837 ; and Encyclograph. des Sciences Medicales, Janv. 1838. See, also, a notice of the first Memoir by Dr. G. Emerson, in Amer. Journ. of the Medical Sciences, p. 171, May, 1837. c Annales d'Hygiene, p. 537, July, 1829. a The Law of Population, ii. 343, Lond. 1830 ; and Quetelet sur I'Homme, i. 53, Paris, 1835. e See, on this subject, Mr. A. Walker, Intermarriage, Amer. Edit., p. 219, New york, 1839. f Carpenter, Human Physiology, § 771, Lond. 1842. 406 GENERATION. It appears, that the general proportion of males born to the females is every where pretty nearly the same. The calculations of Hufe- land give the numbers in Germany as 21 to 20 ; those of Girou, in France, make the proportions as 21 to 19-69 ; and in Paris as 21 to 20-27; and the census of Great Britain, taken in 1821, estimates them as 21 to 20-066. In the Dublin Lying-in Hospital, during ten years, the ratio was as 21 to 19-33 ; and in the Eastern Dis- trict of the Royal Maternity Charity of London, during the year 1830, it was as 21 to 19-64. In Philadelphia, according to the tables of Dr. Emerson,3 the proportion from 1821 to 1S30, was as 21 to 19-43. In the whole of Europe the proportion is estimated as 106 to 100.b Although, however, a greater number of males may be born, they seem more exposed to natural or accidental death ; for amongst adults the balance is much less in their favour, and, indeed, the number of adult females rather exceeds that of the males. Dr. Emerson0 states, that of the children born in Phi- ladelphia, during the ten years included between 1821 and 1830, amounting, according to the returns made to the Board of Health, to 64,642, there were 2,496 more males than females. But, not- withstanding the males at birth exceeded the females about lh per cent., the census of 1830 shows, that by the fifth year, the male excess is reduced to about 5 per cent., and at ten years to only 1 per cent.; and that reduction still going on, the females between the ages of 10 and 15, exceed the males about 8 per cent.; and between 15 and 20, 7-3 per cent. ; facts, which clearly authorize the deduction of Quetelet,d that during the early stages of life there are agencies operating to reduce the proportion of the male sex. Dr. Emerson's investigations exhibit clearly, that the greater lia- bility of males to accidents did not furnish a sufficient reason for their greater mortality ; — the deaths, reported in the Philadelphia bills, under the head of casualties, constituting but a small propor- tion of the whole mortality; and this — when burns and scalds are included — being more considerable in the case of the female. The gross male mortality under the twentieth year, for the three years above mentioned, exceeded the female in the ratio of 7-94 per cent. The diseases, which seemed to be particularly obnoxious to the male sex, were, according to the Philadelphia bills, the following — arranged in the order of their decreasing mortality : — Inflamma- tion of the brain, inflammation of the bowels, bronchitis croup inflammation of the lungs, fevers of all kinds (except scarlet) con- vulsions, general dropsy, dropsy of the head, and small-pox To these sources of mortality may be added those under the head of a Amer. Journ. of the Med. Sciences, for Nov. 1835 b Quetelet, Sur I'Homme, i. 43 Paris, 1835. See, also, Transactions of the Statistical Society of London vol. i part i. Lond. 1837 ; and a notice of the volume by Dr Emer- son, in American Journal of the Medical Sciences, p. 444 for Feb 1838 • D All Thomson, art. Generation, Cyclop. Anat. and Physiol, part xiii. p 478 Feb' \wS. and Burdach s Physiologie als Erfahrungswissenschaft, i.587,2te AufWe'Lei™ wwV c American Journal of the Medical Sciences, for Nov 1835 n 56 '^"'P*1 iao°- ■» Sur I'Homme, i. 156, Paris, 1835. ' ' V' CONCEPTION. 407 casualties, and others vaguely designated debility, decay, &c. The few cases in which the deaths of females predominated were — consumptions, dropsy of the chest, scarlet fever, burns and scalds, and hooping-cough.a It would appear that about one infant in twenty is still-born. The cause of this is a difficult inquiry; as well as that of the greater ratio — double—in cities than in the country; in some cities than in others ; amongst male infants rather than females ; in the win- ter than in the summer ; amongst the illegitimate rather than the legitimate. It is an interesting topic of investigation for the medical statistician.13 The following table, embracing the statistics of the Im- perial Lying-in Hospital of Vienna, which, as before remarked, is the great receptacle for illegitimate conceptions, is interesting on account of the number of cases observed. It is given by Mr. Wilde,c who states, that it was collected and arranged with much care> from the unpublished records of the hospital for the eight years ending Dec. 31, 1840, and exhibits the results of 25,906 deliveries, and 26,149 births. NUMBER OF DELIVERIES, 25,906. C Single births, 25,638 Children, < Twins, 248 times, 496, or 1 in 105-43 ( Triplets, 5 „ 15, or 1 in 5229-8 Total births, 26,149. -, • „„„„,.,. C Boys, 11,717? Proportion of Males feex in 23,413 births, £ Qi^ ufiQ6 £ t0 100 Females, 100-17 r Bovs, 48 -\ Sex of still-born children \ Girls, 45 / Proportion of Males in 2201 births, ") — f to 100 Females, 10666 ( Total, 93) Total still-born in 23,413 births, 939, or 1 in 24-92 Died before the ninth day in 23,222, 1482, or 1 in 15-66 CBoys, 49 ~) Proportion of Males Sexes in 95 of these, | Girlg> 46 £ t0 100 Females, 106 52 Abortions and premature deliveries ? 674; or j jn 33.13 in 25, 705, S It will be observed, that the ratio of still-born is smaller than the average ; yet it is much higher than in the whole of the Aus- trian dominions,in which the proportion, according to Mr. Wilde, is 1 in 30-62. It is difficult, however, to believe, that his statistics can be accurate, when we observe the ratio in Linz stated to be 1 in 155-35 onlv!d * See, on this subject, W. Farr, in Third Report of the Registrar-general of Births, Deaths and Marriages in England, p. 72, Lond. 1841. f See an article on this subject by the author, in American Med. Intelligencer, tor Sept. 1, 1837, p. 203, and ibid. Oct. 1, 1836, p. 252 ; Dr. Avery, m Transact of the Med. Society of the State of New York, iii., part ii. p. 179, Albany, 1837 ; Quetelet, Sur I'Homme, p. 122, Paris, 1835 ; Brit, and For. Med. Review, July, 183/, p. M* , Dr. Emerson, in American Journ. of the Medical Sciences, Feb. 1838, p. 444; ana Prof. Rau, of Bern, Ueber die UnnatUrliche Sterblichkeit der Kinder m ihrem ersten Lebensjahre, B-rn, 1836, cited in Brit, and For. Med. Rev. April, 1839, p. 593; and Wilde's Austria. . , < Austria, &c, &c, p. 223, Dublin, 1843. d Ibid. p. 225. 408 GENERATION. e. Superfoetation.—It has been an oft agitated question, whether, after an ovule has been impregnated and passed down into the cavity of the uterus, another ovule may not be fecundated ; so that the products of two conceptions may undergo their respective de- velopments in the uterus, and be delivered at an interval corres- ponding to that between the conceptions. Many physiologists have believed this to be possible, and have given it the name of superfcetation or superfecundation. The case, cited from Sir Everard Home, of the young female, who died on the seventh or eighth day after conception, exhibits that the mouth of the womb is at an early period completely obstructed by a plug of mucus ; and that the inner surface of the uterus is lined by an efflorescence of coagulable lymph, the nature of which will be described under the next head. When such a change has been effected, it would seem to be impossible for the male sperm to reach the ovary; and accordingly, the general belief is, that superfoetation is only practicable prior to these changes, and where there is a second vesicle ripe for impregnation. Of this kind of superfoeta- tion it is probable, that twin and triplet cases are often, if not always, examples; one ovule being impregnated at one copula- tion, and another at the next." It seems also to be common in animals. The dog-breeders have often remarked, that a bitch, after having been lined, will readily admit a dog of a very differ- ent kind to copulate with her ; and where this has occurred, two different descriptions of puppies have been brought forth, — some resembling each of the fathers. Sir Everard Homeb states, that a setter bitch was lined in the morning by a pointer. The bitch went out with the game-keeper, who had with him a Russian setter of his own, which also lined her in the course of the afternoon. She had a litter of six puppies; two only of which were preserved. One of these bore an exact resemblance to the pointer, the other to the Russian setter, — the male influence being predominant in each. Of this kind of superfoetation or double conception we have se- veral instances on record, of which the following are amongst the most striking, the male parents of the respective foetuses having differed in colour. The first is the well-known case, cited by Buf- fon,0 of a female at Charleston, South Carolina, who was delivered in 1714 of twins, within a very short time of each other. One of these was black, the other white. This circumstance led to an inquiry when the woman confessed, that on a particular day, im- mediately after her husband had left his bed, a negro entered her room, and compelled her to gratify his wishes, under threats of murdering her. Several cases of women in the West India Islands having had, at one birth, a black and a white child, are recorded ; and Dr. Moseley* gives the following case, which is very analo- • Art. Zwillinge, in Pierer's Anat. Physiol. Real. Wbrterb. Band viii., Altenb 1829 Lee . on Comp Anat. m. 302. c Hist. Nat. de I'Homme pJaJS ■* A 1 reatise on Tropical Diseases, p. 111. "uiuie, J. uoerie. SUPERFfJiTATION. 409 gous to that described by Buffon. A negro woman brought forth two children at a birth, both of a size, one of which was a negro, the other a mulatto. On being interrogated, she said, that a white man, belonging to the estate, came to her hut one morning before she was up, and that she received his embraces soon after her black husband had quitted her. Sir Everaid Homea likewise asserts, that a particular friend of his " knows a black woman, who has two children now alive, that are twins and were suckled together; one quite black, the other a mulatto. The woman herself does not hesitate in stating the circumstances : one morning just after her husband had left her, a soldier, for whom she had a partiality came into her hut, and was connected with her, about three or four hours after leaving the embraces of her husband." One of the author's pupils, Dr. N. J. Huston, then of Harrisonburg, Virginia, also com- municated to him the case of a female who was delivered, in March, 1827, of a negro child and a mulatto on the same night. Where negro slavery exists, such cases are sufficiently numerous.11 So far, therefore, as regards the possibility of a second vesicle being fecundated, prior to the closure of the os uteri by the tena- cious mucus and the flocculent membranous secretion from the interior of the uterus, or by the decidua, no doubt, we think, can be entertained; but, except in cases of double uterus, it would seem to be impracticable afterwards; although cases have been adduced to show its possibility. Still, these may perhaps be ex- plained under the supposition, that the uterine changes, above re- ferred to, may not be as rapidly accomplished in some cases as in others; and, again, the period of gestation is not so rigidly fixed, but that children, begotten at the same time, or within twenty-four hours, may still be born at a distance of some weeks from each other. A case happened to the author in which nearly three weeks elapsed between the birth of twins, in whose cases the ova were probably fecundated either at the same copulation or within a few hours of each other. It may happen, too, that although two ova may be fecundated, both embryos may not undergo equal development.0 One, indeed, may be arrested at an early stage, although still retaining the vital principle. In such a case, the other will generally be found larger than common. A case of this kind occurred in the practice of Professor Hall, of the University of Maryland. On the 4th of October, 1835, a lady was delivered of a female foetus, 2 inches and 10 lines in length. This occurred about half-past eight in the morning; and, at two o'clock on the following morning, she was delivered of a second child, which weighed 9£ pounds. The foetus, whose development was arrested, was seen by the author. a Op. citat. >> See, for an enumeration of cases, Beck's Medical Jurisprudence, 6th edit. i. 222 ; and Dr. Allen Thomson, in Cyclop. Anat. and Physiol., part xiii.p.469,forFeb. 1838. c Wagner, Elements of Physiology, by Willis, p. 79, Lond. 1841. VOL. II.-- 35 410 GENERATION. When first extruded, it gave no evidences of decay, and in colour and general characters resembled the fostus of anordinary abortion.8 f. Pregnancy. — When the fecundated ovum has been laid hold of by the fimbriated extremity of the Fallopian tube, and through this channel, — perhaps by the contraction of the tubes and the ciliary motions of its lining membraneb— has reached the cavity of the uterus, it forms a union with this viscus, to obtain the nutritive fluids, that may be required for its development, and to remain there during the whole period of pregnancy or utero-ges- tation ; — a condition which will now require some consideration. Immediately after a fecundating copulation, and whilst the chief changes are transpiring in the ovary, certain modifications occur in the uterus. According to some, it dilates for the reception of the ovum. Bertrandi found this to be the case in extra-uterine pregnancy, and in females whom he opened at periods so near to conception, that the ovum was still floating in the uterus. Its substance appeared at the same time redder, softer, less compact, and more vascular than usual. In the case to which we have more than once alluded from Sir Everard Home,c the lining of the uterus was covered by a beautiful flocculent appearance, about the seventh or eighth day after impregnation. The soft flocculent membrane, which forms in this way, is the membrana caduca seu decidua, decidua externa, first described by Hunter; the epicho- Fig 233. n'on °f Chaussier; the tunica exterior ovi, t. ca- duca, t. crassa; membrana cribrosa ; membrana ovi materna, membrana mucosa; decidua cellu- laris et spongiosa, of others. In a case, observed by Von Baer at a very early The da"k shade, period, when the decidua was still in a pulpy state, ?,ver „an? .1?et":ee" me villi of the lining membrane of the uterus, which the villi, is the deci- ... D, , ' ~ dua. The uterine in the unimpregnatedstate are very short, were found tending InuTth" le- to be remarkably elongated ; and between the villi, ■ u>ops there.-(£« arid Passing over them, was a substance not orga- Baer.) nized, but merely effused, and evidently the deci- dua at an extremely early age.d Others have supposed, that the decidua is composed of the inner portion of the mucous membrane itself, which undergoes a considerable change in its character.e The arrangement of this membrane has given rise to some dis- cussion/ The opinions of most of the anatomists of the present * For similar cases, of which many are on record, see Dr. Samuel Jackson, formerly of Northumberland, Pa., now of Philadelphia, in American Journal of the Medical Sciences, May 1838, p. 237, and May, 1839, p. 256 ; also, Dr. J. G. Porter, ibid. Aug. 1840, p. 307 ; and Mr. Streeter, Lond. Lancet, Oct. 30, 1841. b Wagner op. citat. p. 137. c Lect. on Comp. Anat. iii. 209, Lond. 1823. i Von Baer, op. citat; and Wagner's Physiology, by Willis, p. 184, Lond. 1841. e Weber and Sharpey, cited in Muller, Elements of Physiology by Baly n 1574 Lond. 1842. J " v' t Weber's Hildebrandt's Handbuch der Anatomie, iv. 486 & 515 1832 • Pur- kinje, art. Ei, Encyclop. Wbrterb. der Medicin. Wissensch. x. 107, Berlin, 1834 • W. Hunter's Anatomical Description of the Human Gravid Uterus and its Contents Lond. 1794 ; and Carus, Zur Lehre von der Schwangerschaft, u. s. w., Abth. ii. s. 5.' PREGNANCY. 411 day are in favour of one of two views. It is maintained by some, that one of the first effects of conception is to cause the secretion of a considerable quantity of a sero-albuminous substance from the inner surface of the uterus; so that the organ becomes filled with it. At first, when the ovum arrives in the uterus, it falls into the midst of this secretion, gradually absorbing a part by its outer sur- face for its nutrition. The remainder is organized into a double membrane, one corresponding to the uterus, the other adhering to the ovum. This sero-albuminous substance has been assimilated, both to the white, with which the eggs of birds become invested in passing through the oviduct, and to the viscid substance, that en- velopes the membranous ova of certain reptiles. It is conceived by some to plug up both the orifices of the Fallopian tubes, and that of the uterus ; and according to Krummacheraand Dutrochet,b it has been seen extending into the tubes; whilst the remains of that, which plugged up the os uteri, has been recognised in the shape of a nipple on the top of the aborted ovum. To this sub- stance, Breschetc has given the name Hydropirione. By others, it is held, that the decidua is slightly organized even prior to the arrival of the ovum, lining the whole of the cavity and being de- void of apertures; so that when the ovum passes along the tube and attains the cornu of the uterus, it pushes the decidua before it; the part so pushed forwards constituting the tunica decidua reflexa or ovuline, and enveloping the whole of the ovum except at the part where the decidua leaves the uterus to be reflected over it. This is the seat of the future placenta. Such is the opinion of Velpeau,d Wagner,e and others. An objection to it, however, is the difficulty of so small a body pushing the decidua before it; and a still stronger is the assertion of Professor Shar.pey, that the structure of the decidua and of the decidua reflexa is different/ Hence, it has been thought more probable, that the latter is almost entirely a new production, the growth of which is simultaneous with the enlargement of the ovum, and that the decidua vera has no more share in its formation, than as supplying, through its vessels, the necessary materials.^ At the point of reflection of the decidua re- flexa, there is a thick stratum of a substance precisely similar to the decidua reflexa, which attaches the ovum to the side of the uterus,and which blends intimately on the outer side of the reflex * Diss. Sistens Observationes quasd. Anatom. circa Velamenta Ovi humani. Duisb. 1790. b M£m. de la Societe Medicale d'Emulation, viii. P. i. 1817. c Etudes Anatomiques, Physiologiques, et Pathologiques, de l'GEuf dans l'Espece Humaine, &c, Paris, 1832. * Traite Elementaire de l'Art des Accouchemens, i. 231, Paris, 1829, or Prof. Meigs's translation, 2d edit. 246, Philad. 1838; also, Velpeau, Embryologie ou Ovo- logie Humaine, Paris, 1833 ; or a copious Analysis of the same, by the author, in Amer. Journ. Med. Sciences, Aug. 1834, p. 389. • Op. citat. p. 188. f Muller, op. cit. s Carpenter, Human Physiology, § 748, Lond. 1842. 412 GENERATION. Fig. 234. Fig. 235. fold with the decidua vera. This thick stratum is termed the decidua serotina, from its appearing to have been formed at a later period. It is represented in big. 236. The view of Mr. Burns3 dif- fers from this in supposing that the decidua consists of two layers, the innermost of which has no aperture, so that the ovum on attaining the cornu of the uterus pushes it for- wards, and forms the decidua pro- trusa or decidua reflexa. Im- pregnation, Velpeau says, occasions a specific excitation in the uterus, promptly followed by an exhala- tion of coagulable matter. This section gf m uterus abovt eight days after im-concxetes, and is soon transformed pregnation. int0 a kind 0f cyst or ampulla, filled a. Cervix. 6, J. Orifices of Fallopian tubes, . J i'„u*l,. »«„,. c. Decidua vera. d. cavity of uterus. — (Wag- with a transparent or sligntry rose- ner) coloured fluid. This species of cyst is in contact with the whole surface of the uterine cavity, and sometimes extends into the com- mencement of the tubes, and most frequently into the upper part of the cervix uteri, in the form of solid, concrete cords ; but is never, he says, perforated naturally, as ■f Hunter, Bojanus, Lee and others have maintained. The decidua uteri, according to Velpeau, retains a pretty considerable thickness, es- pecially around the placenta, until the end of gestation : the decidua reflexa, on the contrary, becomes insensibly thinner and thinner, so that at the full period it is at times of extreme tenuity. Towards the third or fourth month — a little sooner or later — they touch and Section of the Uterus when the Ovum is entering TiXeSS Upon each Other, and Xe- its Cavity. • • , r Ovum,/, surrounded by its chorion^, a. maH1 1Q a m0™ 0r leSS PerfeCt Cervix, b, b. Fallopian tubes, c. Decidua State of COtlliguitV, Until the eX- vera. d. Cavity of the uterus, e. Decidua re- i • c ., * -, ■ , riexa—(Wagner.y pulsion of the secundmes ; but, Velpeau asserts, they are never confounded ; and such appears to be the view of Bischoff.b The de- cidua — the true as well as the reflected — is esteemed by Vel- peau a simple concretion — a layer without regular texture__the agPrinciples of Midwifery, 3d edit. p. 147, Lond. 1814. b Wagner, op. citat. p. 190(note). PREGNANCY. 413 Fig. 236. product of an excretion from the lining mem- brane of the uterus ; on this account, he terms it, "anhistous membrane^ (from *v, privative, and »Vto{, " a web") or " membrane without texture." There has, indeed, been a striking dissatisfaction with the name "decidua." Be- sides the appellatives already given, Dutro- chet has proposed to call it epione, Breschet, perione, Seiler, mem- brana uteri interna evo- luta and Burdach, ni- damentum.'1 A difficulty exists in understanding how the decidua is formed con- tinuously over the ori- fice of the Fallopian tubes, and over the up- per surface of the cer- vix uteri. A new pro- duction must evidently take place there. By SOme, however, it is not Section of the Uterus with the Ovum somewhat adoanced. tippcnmod tr\ evict in the> a. Muco gelatinous substance, blocking up os uteri. 6, b. picsuuieu iu tJAiai in mc Fa|lopian tllbes. Ci c. Decidua vera, prolonged at c 2, into latter Situation* but a Fallopian tube. d. Cavity of uterus, almost completely occu- ,,...' pied by ovum (compare with Fig. 235). e, e. Angles at which plUg Of gelatinOUS mat- decidua vera is reflected. /. Decidua serotina. g. AUantois. tor io f/Minrl thoro qq in h- Umbilical vesicle, i. Amnion, k. Chorion, lined with ttU li> 10UI1U mere, a.S ill outer fold of serous tunic. —(Wagner.-) Fig. 236, a. The use of the decidua is, in Velpeau's opinion, to retain the fecundated ovum tb a given point of the uterine cavity ; and if his views of its arrangement were correct, the suggestions wovdd be good. In favour of this arrangement, a good deal might be said. If there were apertures in the decidua corresponding to the Fallo- pian tubes, it would seem, that the ovum ought more frequently to fall into the serous-albuminous matter about the cervix uteri, and attachment of the placenta over the os uteri ought, perhaps, to occur more frequently than it is known to do. Under M. Velpeau's doctrine, the attachment of the placenta ought to be near the a Burdach, Die Physiologie als Erfahrungswissenschaft, B. ii.; Bojanus, Isis, 1821, H. iii.; and Dr. Robt. Lee's Remarks on the Pathology and Treatment of some of the most important Diseases of Women, London, 1833. 414 GENERATION. cornu of the uterus, which is, in fact, the case. Of 34 females, who died in a state of pregnancy at the Hbpital de Perfectionne- ment, an examination of the parts exhibited, that, in twenty, the centre of the placenta corresponded to the orifice of the Fallopian tube ; in three, it was anterior to it; in two, posterior ; in three, beneath; and in six, near the fundus of the uterus. It is not so easy to subscribe to his assertions regarding the " anorganic" nature of the decidua. Many excellent observers have affirmed, not only that this membrane exists between the placenta and the uterus, which M. Velpeau's view, of course, renders impossible, but that numerous vessels pass between it, the uterus, and the placenta. We know, too, that the safest and most effectual mode of inducing premature labour is to detach the decidua from the cervix uteri, or, in other words, to break up the vessels that form the medium of communication between it and the lining membrane of the uterus. It may be said, indeed, that the mere separation of the "anorganic pellicle" —as M. Velpeau designates it — is a source of irritation, and may excite the uterus to the expulsion of its con- tents, and this is possible; but he affirms, that no tissue attaches Ihe decidua to the uterus ; and that it adheres to the inner surface of the organ merely in the manner of an excreted membraniform shell {plague). The views of Lepelletiera and Raspailb coincide with those of Velpeau as to the decidua being an excretion ; but those of Raspail are modified by his peculiar opinions. He main- tains, that the surfaces of an organ — whether external or internal — having once fulfilled their appropriate functions, become de- tached and give place to the layer beneath them; and we have before remarked, that he considers the secretions of the mucous :md serous membranes to be constituted of the detritus of those membranes. Now, that which happens to the intestinal canal and the bladder must likewise happen, he affirms, to the uterus, and as, at the period of gestation, it surpasses in development, elabora- tion, and vitality, every other living organ, it ought necessarily to cast off its layers, in proportion as they have executed the work of elaboration. These deciduous layers constitute the decidua, on which, he says, traces of a former adhesion to the parietes of the uterus, and of the three apertures into the organ, may be met with. But the very existence of a decidua reflexa has been denied. It is so by Ji3rg,c Samuel," and by Dr. Granville, who affirms, that it is now scarcely admitted by one in ten of the anatomists of the European continent/8 He refers to a specimen of an impregnated uterus in the Museum of the Royal College of Surgeons of London, which exhibits distinctly a round ovum, suspended naturally within the decidua, as a globe may be supposed to hang from some point a Physiologie Medicale et Philosophique, iv. 339, Paris, 1833. b Chimie Organique, p. 270, Paris, 1833. c Das Geb'arorgan des Menschen, u. s. w. Leipz. 1808. ■■ De Ovorum Mammal. Vclament. Wirceb. 1816 ; and art. Ei. in Enrvrl WHr terb. der Med. Wissensch. x. 107, Berlin, 1831. ^ncyci. vv or- <• Sea, also, Dewees, Compendious 8ystem of Midwifery. PREGNANCY. 415 of the interior of an oblong sac; and to two specimens, in the col- lection of Sir Charles Clarke, exhibiting an ovulum, which has already penetrated about an inch into the cavity of the uterine decidua ; but neither in these, nor in the specimen of the Royal College, is any part of the uterine decidua pushed forward. The ovum appears to have its natural covering ; and, in the College specimen, there is a large space between them and the deciduous lining of the uterus. Dr. Granville regards the decidua reflexa to be the external membrane of the ovum, to which Professor Boer, of Konigsberg, gave the name " cortical membrane," and which Dr. Granville terms cortex ovi.a It has received various names. By Albinus, it was termed involucrum membranaceum ; by Ho- boken, membrana retiformis chorii; by Roederer, membrana filamentosa; by Blumenbach, membrana adventitia; and by Osiander, membrana crassa.h To this membrane — and to the decidua uteri, as connected with the placenta —we shall have to refer hereafter. Such is the uncertain state of our information on this interesting topic of intra-uterine anatomy. Fig. 237. Extra-Ulerinc Pregnancy. a. The uterus, its cavities laid open. b. Its parietes thickened, as in natural pregnancy, c. A portion of decidua separated from its inner surface, d. Bristles to show the direction of the Fallo- pian tubes, e. Right Fallopian tube distended into a sac which has burst, containing the extra- uterine ovum. /. The foetus, g. The chorion, h. The ovaries ; in the right one is a well marked corpus luteum. i. The round ligament. The decidua manifestly does not belong to the ovum ; for it not only exists prior to the descent of the ovum, into the uterus, but is » Graphic Illustrations of Abortion, &c. p. v. Lond. 1834. b Burdach, Physiologie als Erfahrungswissenschaft, ii. 75, who refers to the various views on the subject of the decidua reflexa. See, also, Velpeau, in op. cit.; and Pur- kinje, art. Ei, in Encyclop. Wbrterb. der Medicin. Wissensch. x. 107, Berlin, 1834. i 416 GENERATION. even formed, according to Breschet,8 in all cases of extra-uterine pregnancy. (See Fig. 237.) Chaussier saw it in several cases of tubal gestation. It existed in a case of abdominal pregnancy, cited by Lallemant, and, according to Adelon,b Evrat affirms, that one is secreted after every time of sexual intercourse, — which is apocryphal. Recently, Dr. Robert Leec has shown, that the decidua is not formed within the uterus in all cases of.extra-uterine gestation. In ten cases detailed by him, and in one other cited from Chaussier, the decidua was seen distinctly surrounding the ovum in the Fallopian tube. When the ovum attains the interior of the uterus, which it does in the first five or six days after conception, it forms, in a short space of time, a connexion with the uterus by means of the pla- centa, in the mode to be mentioned hereafter. During the deve- lopment of the embryo, it is requisite that the uterus should be correspondently enlarged, in order to afford room for it, as well as to supply it with its proper nutriment. These changes in the ute- rine system will engage us exclusively at present. In the first two months, the augmentation in size is not great, and chiefly occurs in the pelvis ; but, in the fourth, the increase is more rapid. The uterus is too large to be contained in the pelvis, and consequently rises into the hypogastrium. During the next four months, it in- creases, in every direction, occupying a larger and larger space in the cavity of the abdomen, and crowding the viscera into the flanks and the iliac regions. At the termination of the eighth month, it almost fills the hypogastric and umbilical regions ; and its fundus approaches the epigastric region. After this, the fun- dus is depressed and approaches the umbilicus, leaving a flatness above, which has given rise to the old French proverb :—En ventre plat enfant y a. During the first five, months of utero-gesta- tion, the womb experiences but little change, maintaining a conoi- dal shape. After this, however, the neck diminishes in length, and is ultimately almost entirely effaced. The organ has now a decidedly ovoid shape, and its bulk is, according to Haller and Levret, eleven and a half times greater than in the unimpreg- nated state. Its length, at the full period, has been estimated at about a foot; its transverse diameter at nine inches; its circum- ference on a level with the Fallopian tubes, at twenty-six inches; and, at the uterine portion of the cervix uteri, thirteen inches. Its weight, which, prior to impregnation, was from fourteen to eigh- teen drachms, is, at this time, from a pound and a half to two pounds. Whilst the uterus is undergoing expansion, the size and situa- tion of the parts attached to it also experience modification. The broad ligaments are unfolded ; the ovaries and Fallopian a Repert. General d'Anatomie, p. 165, pour 1828. b Physiologie de I'Homme, 2de edit. iv. 110, Paris, 1829. c Lond. Med. Gazette, June 5, 1840. PREGNANCY. 417 tubes are raised a little, but are subsequently applied against the sides of the uterus. The vagina is elongated. The round liga- ments yield to the elevation of the organ as far as their length will permit; but, ultimately, they draw the uterus forward, so that the great vessels of the abdomen are not injuriously com- pressed. The parietes of the abdomen are so much distended that the cuticle yields ; hence, an appearance of cicatrices always exists on the abdomen of one who has borne children; and occa- sionally, the fasciculi of the abdominal muscles separate so as to give rise to ventral hernia. The changes, produced in the uterus, are not limited to simple dilatation of its tissue. Its condition has experienced various alterations, dependent upon the new mode of nutrition it has as- sumed. The whole organ has undergone, not only extension, but inspissation of its parietes. In its unimpregnated condition, it is about four lines thick ; in the third month of utero-gestation, five. Its arteries enlarge as well as its veins, which latter form large dilatations at the inner surface. These have been called Fig. 238. Arteries of the Impregnated Uterus. uterine sinuses. Its nerves are greatly increased in size, as well as its lymphatics ; and its proper tissues from being hard, whitish, and incontractile, has become red, soft, spongy, and capable of energetic contraction. A difference of sentiment has existed with regard to the nature of the new tissue of the uterus ; some com- paring it to the middle coat of arteries; other describing it as partly cellular and partly muscular; but an immense majority esteeming it to be muscular. The respectable name of Blumen- bach3 is in the minority. The facts in favour of its muscularity appear to us overwhelming. It is clearly muscular in the mam- * Instit. Physiol. § 547. See, also, Dr. Ramsbotham, Edinb. Med. and Surg. Journal, xxxix. 456. 418 GENERATION. miferous animal. Thus, in the rabbit, the muscularity- of the uterus, according to Blundell,* is far more conspicuous than that of the intestines; the fibres can be seen coarse and large, and their motion can be observed, if they be examined immediately after the rabbit is killed. The same acute physiologist remarks, that, when developed by pregnancy, the muscularity of the organ is so clear, that if you take a portion of it, and show it to any anatomist, asking him what its nature is, he will unhesitatingly reply — it is muscular. This experiment, he says, he once made himself. He took a portion, of the impregnated uterus, showed it to Mr. Green and Mr. Key — " excellent judges on this point," — and, without mentioning the womb, he asked them to tell him what was the structure, when they immediately declared it to be muscular. A similar experiment had previously been made upon Mr. Else, who had made up his mind as to the non-muscularity of the uterus. A small portion was taken to him for his opinion of the precise nature of the tissue submitted to him. It was from the uterus at an advanced period of utero-gestation. After carefully examining it, he gave for answer, that in his opinion it was muscular; but as it was detached from its natural locality, he could not say to what part of the body it belonged. When told, however, that it was a piece of the uterus, he examined it again, and then said that it could not be muscle, for there were no muscular fibres in the uterus.b The arrangement of the fibres is not clearly understood. Gene- rally, perhaps, they are described as running externally, in a lon- gitudinal direction, from the fundus to the neck: beneath this plane is another with circular fibres ; but within this the fibres are interlaced in inextricable confusion. Some anatomists, however, enumerate as many as seven superposed planes. The fibres are of much lighter colour than those of ordinary muscles, are more like those of the bladder and intestines, and are collected in very flat and loose fasciculi.0 The development of this structure would not seem to be limited to the pregnant condition. It appears to occur whenever the uterus in increased in size, as has been re- marked by Dr. Horner,d and by Lobstein.e The muscular layers are thickest at the fundus uteri. At the cervix uteri, they are extremely small and indistinct. After the ovum has attained the interior of the uterus, and en- tered the flocculent decidua, it becomes connected, in process of time, with the uterus, by means of a body to be described hereafter, called the placenta, which is attached to the uterus, and commu- nicates with the foetus by a vascular cord that enters its umbilicus. The seat of the attachment of the placenta — we have seen__ a Principles and Practice of Obstetricy, Amer. Edit. p. 67, Washington, 1834. b Dr. D. Davis's Principles and Practice of Obstetric Medicine, ii. 850,Lond.'l836. c D6sormeaux, art Grossesse, in Diet, de Med. x. 380, Paris 1824. & Lessons in Practical Anatomy, p. 304, Philad. 1836. e Fragment d'Anatomie Physiologique sur l'Organisation de la Matrice dans l'Espece Humaine, Paris, 1803. SIGNS OF PREGNANCY. 419 is not always the same. Frequently, it is near one of the cornua of the uterus ; but occasionally it is implanted over the os uteri. The diversity of position has given occasion to difference of opinion re- garding the causes that influence it. By some, it has been pre- sumed, that, in whatever part of the uterus the ovum lodges, when it quits the Fallopian tube, there an adhesion is formed. By others, it has been said, that as the ovum pushes the decidua at the mouth of the Fallopian tube before it into the uterus, the attach- ment of the placenta must be near the orifice of the tube. Such would, indeed, appear to be the fact in the majority of cases, but we see so many irregularities in this respect, as to preclude us from assigning any very satisfactory reason for it. g. Aligns of Pregnancy. — Along with the changes that super- vene in the generative apparatus during pregnancy, the whole system commonly sympathises more or less in the altered condi- tion. Some females, however, pass through the whole course of gestation with but very slight or no disturbance of the ordinary functions ; whilst, with others, it is a period of perpetual suffering. One of the earliest and most common signs is suppression of the catamenial discharge ; but, of itself, this cannot be relied on, as it may result from disease. Soon after impregnation, the digestive and cerebral functions exhibit more or less modification. The female is affected with nausea and vomiting, especially in the, morning after rising; the appetite is most fastidious; substances, which previously excited loathing being at times desired or longed for with the greatest avidity; whilst on the contrary, cherished articles of diet can no longer be regarded without disgust. The sleep is apt to be disturbed; the temper to be unusually irritable, even in those possessed of signal equanimity on other occasions. The mammae enlarge, and become knotty, and sometimes lancina- ting pains are felt in them; and a secretion of a whitish serum can often be pressed from the nipple. The areola around the nipple becomes of a darker colour in the first pregnancy than it is in the virgin state ; and it is darker during each successive preg- nancy, than when the female is not pregnant. There is, also, a puffy turgescence, net alone of the nipple, but of the whole of the surrounding disk, with a development of the small follicles around the nipple.a These appearances constitute one of the best single proofs of the existence of pregnancy ; but it is obvious, that for accurate discrimination, it is necessary to be aware of the hue in each particular case in the unfecundated state ; and, moreover, in- stances are on record of a well-marked areola occurring in persons who are not pregnant, as well as of an entire absence of areola in those who are. Dr. Guy remarks, that Dr. J. Reid showed him a case of enlarged mammae, with distinct areolas and mucous folli- cles, in a female who had never been, and was not at that time, * Montgomery's Exposition of the Signs and Symptoms of Pregnancy, &c, p. 62, Lond. 1837, or Dunglison's Amer. Med. Libr. Edit. Philad. 1839; and Hamilton's Practical Observations on Midwifery, \mer. Med. Libr. Edit. p. 44, Philad. 1837. 420 GENERATION. pregnant.* The author has had numerous opportunities for appre- ciating the insufficiency of these evidences when taken singly. It has been affirmed by Dr. Kluge, of Berlin, and by M. Jacque- min, of Paris, that a bluish tint of the vagina, extending from the os externum to the os uteri, is a sure test of pregnancy. Accord- ing to Kluge, this discoloration commences in the fourth week of utero-gestation, increases until the time of delivery, and ceases with the lochia. M. Jacquemin, on examining the genitals of prostitutes, in compliance with the police regulations of Paris, observed the same peculiarity of colour in the same situation in those that were pregnant: he describes it as a violet colour, or like lees of wine, and so distinct as never to deceive him, being sufficient of itself, and independently of the other signs of pregnancy, to determine the existence of that state. Parent-Duchate!etb affirms, that he was present when M. Jacquemin's accuracy in this matter was success- fully put to the test: in the investigation, he examined no less than 4500 prostitutes. , Dr. Montgomery,0 however, — from limited observation it is true, — found, that whilst in some cases the bluish colour was very obvious, in others it was so slight as to be scarcely, if at all, perceptible. There is nothing more probable, than that the capillary circulation of the mucous coat of the vagina may be mo- dified along with that of the interior of the uterus during preg- nancy, so as to give occasion to a change of colour, like that men- tioned by those eminent observers; but it may be doubted whether the test can often be available, especially in private practice. Attention has been paid to the condition of the urine during utero- gestation,*1 but although a difference has appeared to exist between it and the urine of an unimpregnated female, it has not gene- rally been esteemed distinctive.e M. Donne,f indeed, affirms, that during pregnancy it contains less uric acid and phosphate of lime than in the natural state, a difference explicable on considering the elements that are necessary for the formation of the organs of the foetus. The crystallization of the salts of the urine is thus so remarkably modified, that by simple inspection, without examining the females, he has in more than thirty cases recognized the state of pregnancy at different periods. Of late years, the urine of the pregnant female has been found to contain a peculiar substance, which, when it is allowed to stand, separates and forms a pellicle on the surface. To observe this, the urine must be allowed to stand from two to six days, when minute opaque bodies are ob- served to rise from the bottom to the surface of the fluid, where they gradually agglomerate and form a continuous layer over the sur- • See Dr. J. Reid, Lond. Lancet, Dec. 22, 1838 ; and Dr. W. A. Guv Principles of Forensic Medicine, p. 72, Lond. 1843. b De la Prostitution dans la Ville de Paris, i. 217, 218, Paris 1837 « Op. citat. p. vi. Lond. 1837. d Galen and Savanorola, cited by Fodere, M£d. Legal, i. 435, Paris 1837 e Montgomery, op. cit. p. 157, E. Rigby, System of Midwifery, p. 57 Lond 1841 f Gazette Medicale de Paris, 29 Mai, 1841. * ' SIGNS OF PREGNANCY. 421 face, which is so consistent, that it may be almost lifted off the urine by raising it by,one of its edges. To this pellicle the name kiestein, or more properly kyestein, has been given. It is whitish, opalescent, slightly granular, and may be compared to the fatty substance, which swims on the surface of soups, after they have been allowed to cool. When examined by the microscope, it has the aspect of a gelatinous mass without determinate form : at times, cubical crystals are observed in it, but this appearance is only seen when it has stood for a long time, and may be esteemed foreign to it. The kiestein remains on the surface for several days; the urine then becomes turbid, and small opaque masses become de- tached from the kiestein and fall to the bottom of the fluid ; the pellicle then soon becomes destroyed. Various experiments have been made on this matter by Nauche,a Eguisier,b Dr. Golding Bird,c Mr. Letheby,dDr. Stark,eand the author'sfriend Dr. E. K. Kane,f of Philadelphia, now physician to the Chinese Embassy; and, at the author's request, by Drs. McPheeters and Perry,s resident physi- cians at the Philadelphia Hospital. They show, that when taken in conjunction with other phenomena, the appearance of the kiestein is certainly a great aid in the diagnosis of pregnancy. Mr. Letheby found unquestionable evidence of kiestein in 48 out of 50 cases between the 2d and 9th month of utero-gestation, and was unable to account for its absence in the two exceptions. The result of Dr. Kane's observations, which the author had an oppor- tunity of examining from time to time, and for the accuracy of which he can vouch, was deduced by Dr. Kane as follows. First. Kiestein is not peculiar to pregnancy, but may occur whenever the lacteal elements are secreted without a free discharge from the mammas. Secondly. Although it is sometimes obscurely deve- loped and occasionally simulated by other pellicles, it is generally distinguishable from all others. Thirdly. Where pregnancy is possible, the exhibition of a clearly defined kiestenic pellicle is one of the least equivocal proofs of that condition ; and Fourthly. When this pellicle is not found in the more advanced stages of supposed pregnancy, the probabilities, if the female be otherwise healthy, are as 20 to 1 (81 to 4) that the prognosis is incorrect. The author has distinctly noticed in some of the cases the cheesy odour of kiestenic urine described by Dr. Bird. Along with the above signs, the uterus gradually enlarges; and, about the end of the fourth calendar month or the eighteenth week, sooner or later, quickening, as it is usually but erroneously termed, takes place, or the motion of the child is first felt. Prior to this, — from the moment, indeed, of a fecundating copulation, — the » La Lancette Francaise, and Lond. Lancet, No. clxvii, p. 675. b La Lancette Franchise, Fevrier 21, 18'39. See, also, L'Experience, Juillet 25, 1839. c Guy's Hospital Reports, April, 1840. * Lond. Med Gazette, Dec. 24, 1841. e Edinb. Med. and Surg. Journal, Jan. 1842. f American Journal of the Med. Sciences, p. 37, Philad. 1842. t Amer. Med. Intelligencer, March 15, 1841, p. 369. vol. ii. — 36 v 422 GENERATION. Fig. 239. Fig. 240. Cervix uteri at six months. female is quick with child, but it is not until this period that the fcetus has undergone the development neces- sary for its movements to be perceptible. This occurrence establishes the fact of gestation, whatever doubts may have previously existed. Where there is much corpulence, or where the fluid, surrounding the fcetus is in such quantity as to throw obscurity around the case, it may be necessary, for the purpose of verifying the existence of pregnancy, to insti- tute an examination per vaginam. This can rarely afford much evidence, prior to the pe- cervix uteri at three months. rjoci 0f quickening ; but, after this, the ex- amination, by what the French term the mouvement de ballotte- ment, mayindicate the presence or the contrary of a foetus in the womb. This mode of examination consists in passing the forefinger of one hand into the vagina, — the female being in the erect attitude, — and in giving the foetus a sudden succussion by means of the other hand placed upon the abdomen. In this way, a sen- sation is communicated to the finger in vagina, which is often of an un- equivocal character. During the latter months, the cervix uteri ex- hibits the changes depicted in Fis-241, the marginal figures. Of late years3 the application of the stethoscope has been used as a means of discrimina- tion in doubtful cases. By ap- plying this instrument to the abdomen of a pregnant female, after the fifth month, the pul- sations of the heart of the foetus are audible. This instrument may also exhibit when the pregnancy is multiple, by indicating the pulsations of two or more distinct hearts, according as the concep- tion is double, triple, &c. It would appear, however, that aus- cultation affords but two main signs of pregnancy, — the pulsa- tions of the foetal heart, and a murmur, which, according to some, should, correctly speaking, be designated the " uterine souffle or murmur." This murmur has been supposed to take place in the uterine artery, which serves for the nutrition of the placenta, and * Dr. E. Kennedy's Observations on Obstetric Auscultation, &c, Dublin, 1833 ; De Kergaradec, Memoire sur l'Auscultation Appliqu£e a I'Etude de la Grossesse, &c. Paris, 1822 ; Dr. J. C. Ferguson, in Hays's Select Medico-Chirurgical Transactions, p. 172, Philad. 1831; Montgomery, op. cit. p. 120, Lond. 1837 ; and Nagele, Die geburtshiil- fliche Auscultation, Mainz, 1838; noticed in Brit, and For.Med. Rev. Oct. 1839, p. 368. Cervix uteri at eight months. SIGNS OF PREGNANCY. 423 even to indicate the situation of the placenta :a others have con- sidered, that it is is not connected with the pla- centa, but depends upon the increased vascularity and peculiar arrange- ment of the uterine ves- sels during the gravid state;b but it has been questioned whether it be ever produced except by pressure on the vessels of the mother. It is, in- Cervix uteri at nine months. deed, positively stated, that the sound has been heard in cases of uterine and other tu- mours where there was no pregnancy.0 In one case of fibrous tumour of the uterus, the author heard it distinctly. In addition to the placental or uterine murmur and the sounds of the foetal heart, a third sound is occasionally to be heard, and one which is considered to be seated in the umbilical cord. This has been termed the " funic bellows' sound." It is of the bellows species, is synchronous with the first sound of the foetal heart, and appears to depend upon diminution of the caliber of the umbilical arteries, either through pressure, or stretching of the funis, or both combined."1 It is affirmed, too, by Prof.'* Nagele, that the move- ments of the fcetus may be distinguished by the stethoscope at a very early period of pregnancy. The pulsations of the foetal heart vary, according to a number of observers, from 120 to 180 in the minute. Nagele,e however, affirms, that he has occasionally found them, but momentarily, to sink as low as 50 or 60. Professor Hamilton*" refers to various cases, in which Drs. Sidey and Moir attended particularly to the action of the foetal heart previous to breathing, in all of which it was 60 or less in a minute, before the establishment of respiration. Professor Hamilton affirms, that almost half a century has elapsed since he remarked, that in infants who did not breathe upon birth, but in whom the pulsation of the cord continued, the action of the heart did not exceed sixty pulsations in the minute till breathing took place, when it became so frequent that it could not be num- bered. This led him to take every opportunity — when he had » Dr. Doherty, Dublin Journal of Med. Science, March, 1840. b E. Rigby, System of Midwifery, Amer. Edit., p. 90, Philad. 1841. « Raciborski, Manual of Auscultation, translated by Fitzheibert, p. 145, Lond. 1835 ; E. Rigby, System of Midwifery, p. 54, Lond. 1841; Dr. Hope, Treatise on Diseases of the Heart, Amer. Edit, by Dr. Pennock, Philad. 1842;. and Prof. Huston, in Churchill, System of Midwifery, Amer. Edit., p. 136 (note). Journal of the English Agricultural Society, part ii. 1839. c Dr. Hall, Lond. Med. Gazette, May 6, 1842. DURATION OF PREGNANCY. 427 to a particular bull belonging to him, carried their calves about four days longer than cows in calf to any other bull; — the average period of gestation being in them 290i days. In a case detailed by Dr. Dewees,a an opportunity occurred for dating with precision the time of fecundation. The case is like- wise interesting in another respect, as demonstrating, that fecunda- tion does not necessarily arrest the succeeding catamenial discharge. The husband of a lady, who was obliged to absent himself many months, in consequence of the embarrassment of his affairs, return- ed one night clandestinely; his visit being known only to his wife, her mother, and Dr. Dewees himself. The lady was, at the time, within a week of her menstrual period; and, as the catamenia ap- peared as usual, she was induced to hope, that she had escaped impregnation. Her catamenia did not, however, make their ap- pearance at the next period ; the ordinary signs of pregnancy supervened ; and in nine months and thirteen days, or in two hundred and ninety-three days from the visit of the husband, she was delivered.11 In his evidence before the House of Peers, in the case before alluded to, Dr. Granville stated his opinion, that the usual term of utero-gestation is as we have given it; but he, at the same time, detailed the case of his own lady, in whom it had been largely protracted. Mrs. Granville passed her menstrual period on the 7th of April, and on the 15th of August following she quickened; — that is, four months and six or seven days after- wards. In the early part of the first week in January, her con- finement was expected, and a medical friend desired to hold him- self in readiness to attend. Labour pains came on at this time, but soon passed away ; and Mrs. G. went on till the 7th of Fe- bruary, when labour took place, and the delivery was speedy. The child was larger and stronger than usual, and was considered by Dr. Granville, — as well as by Dr. A. T. Thomson, Professor of Materia Medica in the University of London, — to be a ten months' child. Now, if, in this case, we calculate, that conception occurred only the day before the interruption of menstruation, three hundred and six days must have elapsed between impregna- tion and birth; and if we take the middle period between the last menstruation and the interruption, the interval must have been three hundred and sixteen, or three hundred and eighteen days. The limit, to which the protraction of pregnancy may possibly extend, cannot be assigned. It is not probable, however, that it ever varies largely from the ordinary period. The University of Heidelberg allowed the legitimacy of a child, born at the expira- tion of thirteen months from the date of the last connubial inter- course ; and a case was decided by the Supreme Court of Friesland, by which a child was admitted to the succession, although it was » A Compendious System of Midwifery, 7th Edit. Philad. 1835. b See a case of protracted gestation communicated by Dr. James R. Manley to Dr. T. R. Beck, in Amer. Journ. of the Medical Sciences, Jan. 1831, p. 59 ; and the case of Innes v. Innes, cited by Dr. Beck, in Amer. Journal of the Medical Sciences, July, 1841, p. 235. See, also, Dr. W. A. Guy, Principles of Forensic Medicine, part L p. 167, Lond. 1843. Aao GENERATION. 428 not born till three hundred and thirty-three days from the husband's death ; or only a few days short of twelve lunar months. These are instances of the ne plus ultra of judicial philanthropy, and, perhaps we might say, credulity. Still, although extremely im- probable, we cannot say that they are impossible. I his much, however, is clear, that real excess over two hundred and eighty days is by no means frequent; and we think, in accordance with the civil code now in force in France, that the legitimacy of an in- fant born three hundred days after the dissolution of marriage may be contested; although we are by no means disposed to affirm, that if the character of the woman be irreproachable, the decision should be on the side of illegitimacy. Professor Hamilton, indeed, says he is « quite certain," that the term allowed by the French code is too limited, and, he is inclined to regard ten calendar months, which he believes to be the established usage of the Con- sistorial Court of Scotland, as a good general rule, liable to excep- tions, upon satisfactory evidence that menstruation had been ob- structed for a certain period.3 Much uncertainty exists as to the earliest period at which a child is viable or capable of carrying on an independent existence. The period is generally fixed at near the end of the seventh month, but children have lived for some time, which have been born earlier. Much evidence was brought forward in a recent case in Scotland, to show that it is possible for a child to live some months, which has been born at the conclusion of 24 weeks of utero-gesta- tion. In that case, the Presbytery decided in favour of the legiti- macy of an infant born alive within 25 weeks after marriage. The difficulty, in such cases, of fixing the exact date of conception must necessarily render ail computation in regard to the precise age of the child uncertain.6 i. Parturition. —At the end of seven months of utero-gestation, and even a month earlier, the fcetus is capable of an independent existence ; provided, from any cause, delivery should be hastened. This is not, however, the fall period, and although labour may occur at the end of seven months, the usual course is for the foetus to be carried until the end of about nine calendar months. If it be extruded prior to the period at which it is able to maintain an inde- pendent existence, the process is termed abortion or miscarriage ; if between this time and the full period, it is called premature labour. From certain records, abortion or premature labour has been estimated to occur, on the average, once in 7S£ cases.0 In the Gebaranstalt of Vienna, the inmates of which are chiefly unmar- ried, the ratio appears to be more than double, or 1 in 38-13.d With respect to the causes, that give rise to the extrusion, we are in utter darkness. It is in truth as inexplicable as any of the * Op. cit., Amer. Med. Library edit. p. 59. * See Beck's Medical Jurisprudence, 6th edit., Philad. 1838; Carpenter, Human Physiology,"§ 755, Lond. 1842; and Dr. W. A. Guy, Principles of Forensic Medicine, Parti, p. 177, Lond. 1843. c Churchill, Theory and Practice of Midwifery, Amer. Edit, by Prof. Huston, p. 167, Philad. 1843. d Wilde, Austria, &c. p. 222, Dublin, 1843." PARTURITION. 429 other instinctive operations of the living machine. Yet although this is generally admitted, the discussion of the subject occupies a considerable space in the works of some obstetrical writers.* Our knowledge appears to be limited to the fact, that when the foetus has undergone a certain degree of development, and the uterus a corresponding distension, its contractility is called into action, and the uterine contents are beautifully and systematically expelled. Nor can we always fix upon the degree of distension, that shall give occasion to the exertion of this contractile power. Sometimes, it will supervene after a few months of utero-gestation so as to pro- duce abortion; at other times, it happens when the foetus is just viable ; and at others, again, and in the generality of cases, it is not elicited until the full period. In cases of twins, the uterus will admit of still greater distension before its contractility is aroused. In regard to the action of the muscles specially concerned in the process, it would seem, that the diaphragm and abdominal muscles are excited to action through an excitor influence con- veyed from the uterus to the spinal cord ; whilst the contractions of the uterus take place independently of all connection with the ner- vous centres, — like the peristole of the intestines, and the systole of the ventricles of the heart. The fcetus has been observed to be expelled after the cessation of the respiratory movements of the mother. This, as has been suggested,5 has probably occurred in con- sequence of the uterine fibres retaining their power of contraction longer than those of the muscles supplied by the cerebro-spinal nerves. A day or two pre- ceding labour, a dis- Fig. 243. ■ charge is occasionally observed from the va- gina of a mucous fluid more or less streaked with blood. This is termed the show, be- cause it indicates the commencement of some dilatation of the neck, or mouth 0/the womb,—the forerun- ner of labour or tra- vail. The external organs, at the same time, become tumid and flabby. The ori- fice of the uterus, if an examination be made, is perceived to be enlarging ; and its edges are thinner. Along with this,slight • Dewees, Comp. of Midwifery. Natural Labour. b Carpenter, Human Physiol, p. 153, Lond. 1842. 430 GENERATION. grinding pains are experienced in the loins and abdomen. After an uncertain period, pains of a very different character come on, which commence in the loins, and appear to bear down towards the os uteri. These are not constant, but recur, at first after long intervals, and subsequently after shorter, —the body of the uterus manifestly contracting with great force, so as to press the ovum down against the mouth of the womb, and to dilate it. In this way, the membranes of the ovum protrude through the os uteri with their contained fluid, the pouch being occasionally termed the bag of waters. Sooner or later, the mem- branes give way, the waters are discharged, and the uterus con- tracts so as to embrace the body of the child, which was previously impracticable, except through the medium of the liquor arnnii. At the commencement of labour, the child's head has not entered the pelvis,the occiput being generally towards the left acetabulum ; but, when the uterine contractions become more violent, and are accompanied by powerful efforts on the part of the abdominal muscles, the head enters the pelvis, the mouth of the womb be- comes largely dilated, and the female is in a state of agitation and excitement, owing to the violence of the efforts, and the irresistible desire she has of assisting them as far as lies in her power. When the head has entered the pelvis, in the position described, in which the long diameter corresponds to the long diameter of the pelvis, it describes, laterally, an arc of a circle, the face passing into the hollow of the sacrum, and the occiput behind the arch of the pubis. By the continuance of the pains, the head presents at the vulva. The pains now be- Fig. 244. come urgent and for- cing. The os coc- cygis is pushed back- wards, and the peri- neum is distended, — at times so con- siderably as to threat- ten, and even to ef- fect laceration ; the anus is also forced open and protruded; the nymphas and carunculae of the va- gina are effaced; the labia separated, and the head clears the vulva, from the occi- put to the chin, ex- periencing a vertical rotation as depicted in Fig. 244. When Rotation of the Head. the head isextruded the shoulders and C+B PARTURITION. 431 rest of the body readily follow on account of their smaller dimen- sions. The child, however, still remains attached to the mother by the navel-string, which has to be tied, and divided at a few fingers' breadth from the umbilicus. After the birth of the child, the female has generally a short in- terval of repose; but after a time, slight bearing down pains are experienced, owing to the contraction of the uterus for the se- paration of the placenta, and of the membranes of the ovum, called the secundines or afterbirth. The process of parturition is accomplished in a longer or shorter time in different individuals, and in the same individual in differ- ent labours, according, to the particular conditions of the female and foetus. The parts, however, when once dilated, yield much easier afterwards to similar efforts, so that the first labour is generally the most protracted. After the separation of the secundines, the female is commonly left in a state of debility and fatigue ; but this gradually disappears. The uterus also contracts; its vessels become tortuous, small, and their orifices are plugged up. For a short time, blood continues to be discharged from them; but as they become obliterated by the return of the uterus to its usual size, the discharge loses its sangui- neous character, and is replaced by one of a paler colour, called the lochia, which gradually disappears, and altogether ceases in the course of two or three weeks after delivery. For a day or two after delivery, coagula of blood form in the in- terior of the uterus, especially in the second and subsequent labours, which excite the organ to contraction for their ex- pulsion. These contrac- tions are accompanied with pain, and are called after-pains ; and as their object is the removal of that, which interferes with the return of the uterus to its proper di- mensions, it is obvious that they ought not to be officiously interfered with. Whilst the uterus is contracting its dimen- sions, the other parts gra- dually resume the condi- tion they were in prior to delivery ; so that, in the course of three or four weeks, it is impracticable to pronounce positively, whether delivery has recently taken place or not. Breech Presentation. 432 GENERATION. in charges Labour, as thus accomplished, is more deserving of the term in the human female than in animals; and this is partly owing to the large size of the fcetal head, and partly to the circumstance, that in the animal the axis of the pelvis is the same as that of the body, whilst in the human female, the axis of the brim, as repre- sented by the dotted straight lines in Fig. 244, ferms a considera- ble angle with that of the outlet. In rare cases, the child is ex- truded without labour-pains. The author was called in the night, to a female, who declared to him, that she was awoke by a slight abdominal uneasiness, when she found both the child and secundines expelled •, and other cases of a like kind are on records These facts should be borne in mind of infanticide. The position of the child — with the face behind and the occiput before — constitutes the usual presentation in natural labour. Of twelve thousand six hundred and thirty-three chil- dren, born at the Hospice de la Mater nit e" of Paris, twelve thousand one hundred and twenty, according to. M. Jules Clo- quet, were of this presentation; sixty-three had the face turned forward; one hundred and ninety-eight were breech presen- tations ; (see Fig. 245 ;) in one hundred and forty-seven cases the feet presented; Fig. 246. and in three, the knees. All these, however, are cases in which la- bour can be effected without assistance ; the knee and feet pre- sentations being iden- tical as regards the process of delivery with that of the breech. But, whenever any other part of the fcetus presents, the position is unfavourable, and requires that the hand should be introduced into the uterus, with Arm Presentation. the vieW of bringing tU . down the feet, and converting the case into a foot presentation. The marginal figure of a presentation of the right superior extremity, sufficiently shows, that labour could no be accomplished without the efforts of art The following table, drawn up from data furnished by Veloeau will show the comparative number of presentations, according to the experience of the individuals mentioned. * T. Lewis, Lond. and Edinb. Monthly Journ of MWI «„• .. » . Rawson, Lond. Lancet, Nov. 27, 1841. * Med* Science' July> ^42 ;_Mr. PARTURITION. 433 TABLE EXHIBITING THE RATIO OF PRESENTATIONS IN 1000 CASES. According to Merri-man. Bland. Mde. Boivin. Mde. Lacha-pelle. Niigele. Lovati. Hospital of the Paculte. Boer. Regular, or of the vertex, 924 944 969 933 933 911 980 I. Occipito anterior, 908 944 910 895 a. Occipito-cotyloid (left) 760 717 537 Do. (right) 179 209 b. Occipito-pubian, 0-29 II. Occipito posterior, 9-4 9 a. Fronto-cotyloid (left) 53 7-3 b. Do. (right) 4-4 2-9 Face presentation, 2-2 2-6 3-6 4-6 8-8 Mento-iliac (right) 2-6 Of the pelvis, 36 28 29 36 47 29 Of the foot, 12-7 94 14 10-3 Of the knees, 0-19 0-40 ' Of the breech, 23 13 18 22 19 Of the trunk, 4-6 5-3 4-8 Requiring Forceps, 6-6 4-7 4-6 3-4 36 5-7 ---------Turning, 16 4-7 7-8 7-2 5-9 ---------Cephalotomy, 33 5-2 4-77 0-53 2-4 1-5* It is found, that the period of the twenty-four hours has some influence upon the process of parturition ; about five children being born during the night for four during the day.b The parturient and child-bed condition is not devoid of danger to the female ; yet the mortality is less than is generally, perhaps, imagined. In some of the great lying-in institutions it has been, however, enormous,0 and in the Gebaranstalt, of Vienna, it is still estimated at 1 in 30-87 ! The number of deaths, during labour and subsequently, connected therewith, has been stated to be in Berlin as 1 in 152 ;d in Konigsberg, as 1 in 168 ; and in Wirtemberg, as 1 in 175 ; a proportion much less than during the last century. Dr. Collinse states, that of 16,414 women, delivered in the Dublin Lying-in Hospital, 164 died, or in the proportion of 1 in 100; and if, he observes, from this number we deduct the deaths from puer- peral fever, which may be considered accidental, the proportion becomes greatly diminished, viz. to 1 in 156 deliveries ; and again, * Velpeau, Traite Elementaire de l'Art des Accouchemens, Paris, 1829 ; or Meigs's translation, 2d edit. Philad. 1838. See, also, on the same subject, Dr. Collins, Prac- tical Treatise on Midwifery, Lond. 1835; Churchill, Theory and Practice of Mid- wifery, Amer. Edit, by Prof. Huston, Philad. 1843; and Wilde, Austria, &c, &c, p. 223, Dublin,1843. b Quetelet, Sur I'Homme, i. 102, Brux. 1835 ; Dr. Buek, Nachricht von dem Ge- sundheits-zustande der Stadt Hamburg, von N. H. Julius, s. 157, Hamburg, 1 829; and Dunglison's Amer. Med. Intelligencer, Sept. 1, 1837, p. 213. c See an article on the subject, by the author, in his Amer. Med. Intelligencer, Sept. 1, 1837, p. 264. d Casper, Beitrage zur Medicinisch. Statistik, u. s. w. Berl. 1825; and Elements of Medical Statistics, by Dr. B. Hawkins, Lond. 1829. See, also, Quetelet, i. 130. e Op. citat. p. 366. vol. ii. — 37 434 GENERATION. if we subtract the deaths from causes not the results of childbirth, the mortality, from effects arising in consequence of parturition, is vastly reduced, viz. to 1 in 244. In the year 1839, childbirth was fatalto 2915 women throughout England and Wales. Of 1,000,000 females living, 36S died from this cause in 1838, and 372 in 1839. About 5 births in 1000, it was estimated, were fatal to the mother.8 In 1840, the ratio was greater, about 1 in 187.b The further details of this subject belong more appropriately to obstetrics. j. Lactation. — When the child has been separated from the mother, and continues to live by the exercise of its own vital powers, it has still to be dependent upon her for the nutriment adapted to its tender condition. Whilst in utero this nutriment consisted of fluids placed in contact with it, but, after birth, a secre- tion serves this purpose, which has to be received into the stomach Fig. 247. Milk Ducts in Human Mamma. The ducts are filled with wax. — (Sir Astley Cooper.) and undergo the digestive process. This secretion is the milk. It is prepared by the mammse or breasts, the number, size, and situa- » W. Farr, in Third Annual Report of the Registrar-general of Births, Deaths and Marriages in England, p. 74, London, 1841. b W. Farr, in Fourth Annual Report, &c, &c, p. 219, Lond. 1842. LACTATION. 435 tion of which are characteristic of the human species. Instances are, however, on record of three or more distinct mammae in the same individual.* Two such cases are described by Dr. G. C. M. Roberts, of Baltimore.5 At times, two nipples are met with on one breast. Three cases of the kind are given by Tiedemann, and one recently, by Dr. Chowne.c In some instances, the supernumerary breasts have been on other parts of the body.d Each breast contains a mammary gland, surrounded by the fat of the breast, and resting on the pectoralis major muscle. It is formed of several lobes, united by a somewhat dense cellular tissue, and consisting of smaller lobules, which seem, again, composed of round granula- Fig. 248. tions, of a rosy-white colour, and of about the size of a poppy seed. These granula or acini, according to Reil,e cannot be dis- tinguished in the mammae of the virgin. The glandular granula give origin to the excretory ducts, called tubuli lactiferi or galactOnhoH, Which are tortUOUS,extensible, Commencement of milk ducts, j x ftii ii -x as exhibited in a mercurial m- and transparent. 1 hese enlarge and unite jection. -(sirAsthy cooper.) with each other, so that those of each lobe remain distinct from, and have no communication with, the ducts of any other lobe. All these finally terminate in sinuses, or reser- voirs, near the base of the nipple, which are fifteen or eighteen in number, and open on the nipple, without having communication with each other. The size and shape of the breast are chiefly caused by the cellu- lar tissue in which the mammary gland is situate : this is covered by a thin layer of skin, which is extremely soft and delicate, and devoid of folds. In the middle of the breast is the tubercle, called the nipple,mammella, or teat,— a prominence consisting of an erec- tile spongy tissue, differing in colour from the rest of the breast. The nipples do not project directly forwards, but forwards and outwards, for wise purposes, which have been thus depicted by Sir Astley Cooper :f — " The natural obliquity of the mammella or nipple forwards and outwards, with a slight turn of the nipple up- wards, is one of the most beautiful provisions in nature both for the mother and her child. To the mother, because the child rests upon her arm and lap, in the most convenient position for sucking ; » Dr. Robt. Lee, London Medioal Gazette, Jan. 20,1838; Medico-Chirurg. Transact. vol; xxi., Lond. 183S; and Mr. Thursfield, Lond. Med. Gaz. March 3, 1328, p. 898. b Baltimore Medical and Surgical Journal, ii. 497, Baltimore, 1834. c Lond. Lancet, July 2, 1842, p. 465. i Art. Cas Rares, in Diction, des Sciences Medicates; Journal de Physiologie, par Magendie, Janv. 1827 ; Hedenus, art. Brust (weibliche,) in Encyclop. Worterbuch der Medicin. Wissenschaft. vi. 352, Berlin, 1832 ; art. Brustwarze, ibid. p. 406 ; Davis's Principles and Practice of Obstetric Medicine, ii. 777, Lond. 1836; Petrequin, in Gazette Medicale de Paris, No. xiii. Avril 1, 1837 ; and Chowne, op. cit. e Schlemm, art. Briiste, in Encyclop. Wbrterb. der Medicin. Wissenschaft. vi. 332, Berlin, 1831. f On the Anatomy of the Breast, p. 12, London, 1810. 4o6 GENERATION. for if the nipple and breast had projected directly forwards, the child must have been supported before her in the mother's hands in a most inconvenient and fatiguing position, instead of its re- clining upon her side and arm. But it is wisely provided by na- ture, that when the child reposes upon its mother's arm, it has its mouth directly applied to the nipple, which is turned outwards to receive it, whilst the lower part of the breast forms a cushion upon which the cheek of the infant tranquilly reposes." The erection of the nipple, which is so manifest during the pro- cess of suckling, and can be readily produced by handling it, has been supposed to be owing .to an arrangement similar to that of the corpora cavernosa penis, or to a venous circle surrounding the nipple ;a but Sir Astley Cooper attributes it simply to an afflux of blood into the capillaries of the part. Around the nipple is the areola, which is of a rosy hue in youth, but becomes darker in the progress of life, and the capillary system of which is so delicate as to blush, like the countenance, under simi- lar emotions. The changes, produced on the areola by gestation, have been already described. The skin, at the base of the nipple, and on its surface, is rough, owing to the presence of a number of sebaceous follicles, called by Sir Astley Cooper the "tubercles of the areola," which secrete a fluid for the lubrication of the part, and for defending it from the action of the secretions of the mouth of the infant during lactation. Numerous arteries, veins, nerves and lymphatics, — the anatomical constituents of organic textures in general,—also enter into the composition of the mammae and nipples.b The mammary gland of the male is analogous to that of the female, but much smaller. The secretion of milk is liable to longer intermissions than any other function of the kind. In the unmarried and chaste female, although the blood, whence milk is formed, may be constantly pass- ing to the nipple, no secretion takes place from it. It is only during gestation and some time afterwards, as a general rule, that the necessary excitation exists to produce it. Yet although largely allied to the generative function, — the mammae undergoing their chief development at puberty and becoming shrivelled in old age,— the secretion may arise independently of impregnation ; for it has been witnessed in the unquestionable virgin, in the superannuated female, and even in the male sex. The fact as regards the unim- pregnated female is mentioned by Hippocrates. Baudelocquec states, that a young girl at Alengon, eight years old, suckled her brother for the space of a month. Dr. Gordon Smithd refers to a manuscript in the collection of Sir Hans Sloane, which gives an a Prof. Sebastian, Tijdschrift voor Natuurlijke Gesehiedenis en Physiologie door J. Van der Hoeven en W. H. de Vriese, 2de Deel, bl. i., Amsterdam, 1835. * See, on the intimate structure of the Mammary Glands, Sir Astley Cooper op. cit.; Mr. Solly, art. Mammary Glands, Cyclop, of Anatomy and Physiology part xxL April, 1841 ; and Dr. Carpenter, Human Physiology, § 681, Lond. 1842 « Art. d'Accouchement, j. 188, Paris, 1822. d Forensic Medicine p 48i LACTATION. 437 account of a woman, at the age of sixty-eight, who had not borne a child for more than twenty years, and who nursed her grand- children, one after another.3 Professor Hall, of the University of Maryland, related to the author the case of a widow, aged fifty, whom he saw giving suck to one of her grandchildren, although she had not had a child of her own for twenty years previously. The secretion of milk was solicited by putting the child to her breast during the night, whilst weaning it. Dr. Francis, of New York, describes the case of a lady, who, fourteen years previously, was delivered of a healthy child after a natural labour. " Since that period," he remarks, " her breasts have regularly secreted milk in great abundance, so that, to use her own language, she could at all times easily perform the office of a nurse :" and Dr. Ken- nedy,b of Ashby-de la Zouch, has described the case of a woman, who menstruated during lactation, suckled children uninterruptedly through the full course of forty-seven years, and, in her eighty- first year, had a moderate, but regular supply of milk, which was rich, and sweet, and did not differ from that yielded by young and healthy mothers. In a note, with which the author has been favoured by Dr. Samuel Jackson — formerly of Northumberland county, Pa., now of Philadelphia—a case is described, of a lady, certainly above sixty-five years of age, who nursed one of her daughter's twins. She had not borne a child for many years, and was suddenly endowed with a full flow of milk. A lady of Northumberland observed to Dr. Jackson, " that she could not but admire the beautiful fulness and contour of her bosom."c Dr. Richard Clarke,d of Union Town, South Alabama, gives the case of a lady, who had never borne a child, and who was requested to take charge of an infant, during the illness of its mother. In the course of the night, the infant became restless and fretful, and the lady — to quiet it — put her nipple into its mouth. This was done from time to time, until the milk began to flow. An interesting fact, connected with this case was, that some time afterwards she conceived, and at the expiration of the usual term was delivered of a fine child. Dr. Clarke refers to other cases, which would ap- pear to show, in another form, the intimate and mysterious sym- pathy that exists between the mammas and the uterus. But these, and cases of a similar nature, of which there are many on record,6 do not possess the same singularity as those of the function being executed by the male. Yet we have the most unquestionable authority in favour of the occurrence of such instances. A Bishop of Corkf relates the case of a man who suckled his child after the » See a similar case, by Mr. Temple, in North of England Med. and Surg. Journal, '• 23°- . . b Medico-Chirurgical Review for July, 1832. c A similar case is given by Audubert, in Journal de la Societe de Medecine, Pratique de Montpellier; and Encyclographie des Sciences Medicales, Fevrier, 1841, p. 299. d Dunglison's American Medical Intelligencer, April 16, 1838, p. 19. e Elliotson's Blumenbach, 4th edit. p. 509, Lond. 1828. f Philos, Trans, xii. 813, 37* 438 GENERATION. death of his wife. Humboldt adduces one of a man, thirty-two years of age, who nursed his child for five months on the secretion from his breasts; Captain Franklin* gives a similar instance ; and Professor Hall, of the University of Maryland, exhibited to his obstetrical class, in the year 1827, a coloured man, fifty-five years of age, who had large, soft, well-formed mammae, rather more conical than those of the female, and projecting fully seven inches from the chest; with perfect and large nipples. The glandular structure seemed to the touch to be exactly like that of the female. This man/according to Professor Hall, had officiated as wet-nurse, for several years, in the family of his mistress, and he repre- sented, that the secretion of milk was induced by applying the children, entrusted to his care, to the breasts, during the night. When the milk was no longer required, great difficulty was ex- perienced in arresting the secretion. His genital organs were fully developed.b It appears, therefore, that the secretion of milk may be caused, independently of a uterus, by soliciting the action of the mam- mary glands, but that this is a mere exception to the general rule, according to which the secretion is as intermittent as gestation itself. We have noticed, as one of the signs of pregnancy, that the breasts become enlarged and turgid, denoting the aptitude for the formation of the fluid; and it not unfrequently happens, that, towards the middle and latter periods of pregnancy, milk will distil from the nipples. This fluid, however, as well as that which flows from the breasts during the first two or three days after de- livery, differs somewhat from milk, containing more serum and butter, and less caseum, and it is conceived to be more laxative, so as to aid the expulsion of the meconium. This first milk is called colostrum,protogala, &c, and, in the cow, constitutes the biestings or beastings. Generally, about the third day after con- finement, the mammae become tumid, hard, and even painful, and the secretion from this time is established, the pain and distension soon disappearing. It is hardly necessary to discuss the views of Richerand,c who considers the milk to be derived from the lymph ; of others, who derive it from the chyle; of Raspail, who is disposed to think, that the mammary glands are in connexion, by media of a com- munication yet unknown, with the mucous surface of the stomach, and that they subtract, irom the alimentary mass, the salts and a Narrative of a Journey to the Polar Sea, p. 157. » For similar cases, see C. W. Mehliss, (leber Virilescenz und Reiuvenescenz thierwcher Korper, s. 41 & 71, Leipz. 1838; Belloc, Cours de M^dec. Legale p 52 P^1^1^F^de>r6',TIrait<5lle M6decine ^gale, i. 440; Coxe's Medical Museum, i. 267 ; Beck s Medical Jurisprudence, 6th edit. i. 188, Philad. 1838 ; and Montgomery on the Signs and Symptoms of Pregnancy, p. 70, London, 1837, or Dunglison'! Amer. Medical Library Edition, Philadelphia, 1838. c Niveau* Elpmens de Physiologie, 7eme edit., Paris, 1817. LACTATION. 43*9 organizing materials which enter into the composition of the milk ; or of Girard of Lyons, who gratuitously asserts, that there is in the abdomen an apparatus of vessels, — intermediate between the uterus and mammas,— which continue inactive, except during gestation, and for some time after delivery, but, in those condi- tions, are excited to activity.2 All these notions are entirely hypo- thetical, and there is no reason for believing, that this secretion differs from others, as regards the kind of blood from which it is separated. The separation takes place in the tissue of the gland, and the product is received by the lactiferous ducts, along which it is propelled by the fresh secretion continuously arriving, and by the contractile action of the ducts themselves, the milk remain- ing in the ducts and sinuses, until the mammae are, at times, con- siderably distended and painful. The excretion of the milk takes place only at intervals. When the lactiferous ducts are sufficiently filled, a degree of distension and uneasiness is felt, which calls for the removal of the con- tained fluid. At times, the flow occurs spontaneously ; but, com- monly, only when solicited either by sucking or drawing the breast, the secretion under such circumstances being very rapid, and the contraction of the galactophorous ducts such as to project the milk through the orifices in a thready stream. Milk is a highly azoted fluid, Composed of water, caseum, sugar of milk, certain salts, — as chloride of sodium, phosphate, and acetate of potassa, with a vestige of lactate of iron and earthy phosphate,— and a little lactic acid. According to Berzelius,b cow's milk consists of cream, and milk properly so called, — the cream consisting of butter, 4-5 ; cheese, 3-5 ; whey, 92-0 ; —and the whey, of milk and salt, 4-4 ;—the milk containing water, 928-75; — cheese, with a trace of butter, 28-01 ; sugar of milk, 35-00; chloride of potassium, 1-70; phosphate of potassa, 0-25; lactic acid, acetate of potassa, and lactate of iron, 6-00; and phos- phate of lime, 0-30.c Raspaild defines milk to be an aqueous fluid, holding albumen and oil in solution by means of an alkali, or alkaline salt, which he suggests may be the acetate of ammonia, — and, in suspension, an immense number of albuminous and oleaginous globules. The following table exhibits the discrepant results of the investiga- tions of Brisson, Boyssou, Stipriaan Luiscius and Bondt, Schu- bler, and John, in 1000 parts of the milk of different animals — as given by Burdach.e * Adelon's Physiologie de I'Homme, 2de edit. iv. 141, Paris, 1839. b Medico-Chirurgical Transactions, vol. iii. « See, on the Microscopic Examination, &c. of the Milk, Donne, Du Lai, et en particulier de celui des Nourrices, &c, Paris, 1837, or notice thereof in Brit, and For. Med. Rev., July, 1838, p. 181. See, also, Donne, Comptes rendus, Sept. 18, 1839, or Dunglison's Amer. Med. Intelligencer, Jan. 1, 1840, p. 306; and Nasse, Miiller's Archiv. 1840, Heft iii., or Brit, and For. Med. Rev., Jan. 1841, p. 228. d Chimie Organique, p. 345, Paris, 1833. • Physiologie als Erfahrungswissenschaft, B. ii. and v. 2te Auflage, s. 259, Leipz. 1833. See, also, Carpenter, Human Physiology, § 684, Lond. 1842. 440 GENERATION. Observers. Specific gravity. Butter. Cheese. Sugar of milk. Water. Extract. s r Brisson, \ Boyssou, j Luiscius, ' John, 10409 10350 38-24 58-12 54-68 51-26 153-75 31-25 20-73 41-87 3906 886-19 746-25 875-00 345 s o O f Brisson, i Boyssou, J Luiscius, I SchUbler, (^ John, 10324 10280 24-88 26-87 24-00 23-43 39-40 89-37 50-47 93-75 31-33 3062 77-00 3906 900-92 853-12 848-53 84375 3-45 £ o C Brisson, 3 Boyssou, y Luiscius, C John, 10341 10360 29-95 45-62 11-71 52-99 91-25 105-45 20-73 43-75 23-43 892-85 819-37 849-39 3-45 S n r Brisson, j Boyssou, j Luiscius, ' John, 10364 10450 0-57 0-00 000 18-43 16-25 64-84 32-25 87-50 35-15 938-36 896-25 900-00 10-36 g < r Brisson, \ Boyssou, j Luiscius, ' John, 10355 10230 0-92 0-00 0-00 19-58 3312 11-71 39-97 4500 46-87 932-60 921-87 . 941-40 691 Brisson, Boyssou, Luiscius, John, 10203 10250 32-25 30-00 23-43 11-52 26-87 1562 4608 73-12 3906 903-92 870-00 921-87 6-91 a From this table, an approximation may be made, as to the main differences between the milk of those animals, but it is not easy to explain the signal discrepancy amongst observers as to the quan- tity of the different materials in the milk of the same animal. Much, of course, may be dependent upon the state of the milk at the time of the experiment, but this can scarcely account for the whole discrepancy. From a great number of experiments, MM. Deyeux and Par- mentierb classed six kinds of milk, which they examined, according to the following table, as regards the relative quantity of the ma- terials they contained. Caseum. Butter. Sugar of Milk. Serum. Goat. Sheep. Cow. Sheep. Cow. Goat. Woman. Ass. Mare. Ass. Woman. Mare. Cow. Goat. Sheep. Ass. Woman. Woman. Ass. Mare. Mare. Cow. Goat. Sheep. * See, also, MM. O'Henry and A. Chevalier, Journal de Pharmacie, Juin et Juillet, 1839 ; M- Lecanu, ibid., Avril, 1839 ; MM. D'Arcet et Petit. Revue Medicale, Fev. ou Mars, 1839; and Sir Astley Cooper and Dr. G. Bird in Sir Astley Cooper' on the Anatomy of the Breast, Lond. 1840. b Precis d'Exp£r., &c. sur les diflerentes especes de Lait, Strasbourg, an vii. 1790. LACTATION. 441 Human milk, therefore, contains more sugar of milk and less cheesy matter than that of the cow; hence it is sweeter, more liquid, less coagulable, and incapable of being made into cheese. It has also albuminous, oleaginous, and saccharine ingredients combined, so as to adapt it admirably as an aliment for the young; and of all the secreted fluids it appears to be most nearly allied to blood in its composition.* M. Romanetb has lately affirmed, that the globules in cow's milk are wholly formed of butter, which exists as a pulp, enve- loped in a white, translucent, elastic and resistent pellicle; and that the cyst is broken in churning, by which the butter escapes, and the pellicles floating about separately constitute the white particles that give consistence to buttermilk. When human milk is first drawn, it is of a bluer colour than that of the cow. It resembles rather whey, or cow's milk much diluted with water. If allowed to rest, it separates, like the milk of other animals, into cream and milk, — the quantity of the cream being one-fifth to one-third of that of the milk. The milky portion, however, appears semitransparent like whey, instead of being white and opaque like that of the cow. During the first days of its remaining at rest, abundance of cream and a little curd are se- parated, and lactic acid is developed. The specific gravity of human milk was found by Dr. Rees to be 1-0358, and the solid contents 12 per cent. The specific gravity of the cream was l-021.c Casein — the azoted constituent of milk — is distinguished from fibrin and albumen by its great solubility, and by not coagulating when heated. This is regarded by Liebigd as " the chief consti- tuent of the mother's blood. To convert casein into blood no foreign substance is required, and in the conversion of the mother's blood into casein no elements of the constituents of the blood have been separated." The quantity and character of the milk differ according to the quantity and character of the food,—a circumstance, which was one of the greatest causes of the belief, that the lymphatics or chyliferous vessels convey to the mammas the materials for the secretion. The milk is, however, situate in this respect like the urine, which varies in quantity and quality, according to the amount and kind of solid or liquid food taken. The milk is more abundant, thicker, and less acid, if the female lives on animal food, but possesses the opposite qualities when vegetable diet is used. It is apt, also, to be impregnated with heterogeneous matters, taken up from the digestive canal. The milk and the butter of cows in- dicate unequivocally the character of their pasturage, especially if they have fed on the turnip, wild onion, &c. Medicine, given to » Dr. G. 0. Rees, art. Milk, Cyclop, of Anat. and Physiol. •> Comptus rendus, Avril, 1842. e Sir Astley Cooper, op. cit. i Animal Chemistry, Amer. Edit. p. 51, Cambridge, 1842. 442 GENERATION. the mother, may in this way act upon the infant.8 Serious — almost fatal — narcotism was induced in the infant of a profes- sional friend of the author, by a dose of morphia administered to his wife. It would seem, that occasionally the secretion of the two glands differs. A case has been related in which the milk of the right breast had a distinctly salt taste, whilst that of the opposite breast was of the ordinary sweetness.b The quantity of milk secreted is not always in proportion to the bulk of the mammae : a female whose bosom is of middle size often secretes more than another in whom it is much more developed'; — the greater size being usually owing to the larger quantity of adipous tissue surrounding the mammary gland, and this tissue is in nowise concerned in the function. The ordinary quantity of milk that can be squeezed from either breast at any one time, and which must consequently have been contained in its tubes and reservoirs, is about two ounces.0 The secretion of milk usually continues until the period when the organs of mastication of the infant have acquired the neces- sary development for the digestion of solid food : it generally ceases during the second year. For a great part, or the whole of this time, the menstrual flux is suspended; and if both the secretions, — mammary and menstrual, — go on together,the former is usually impoverished, and in small quantity. This, at least, is the general opinion. Some, however, think, that no general rule can be esta- blished on the subject; and that the condition of the child's health ought to be the only guide. M. Gendrin would on no account per- mit a woman to continue nursing after the catamenia had returned. The subject has recently been closely investigated by M. Raci- borski,*1 who laid the results before the Academie Royale de Mede- cine on the 31st of May, 1843. The inferences are, —that, con- trary to generally received opinions, the milk of nurses who men- struate during suckling does not differ sensibly, in physical, chemi- cal or microscopic characters, from that of nurses whose catamenia are suspended ; — that the only difference, which can be detected between these two kinds of milk, is, that in most cases the milk of menstruating nurses contains less cream during the menstrual periods than in the intervals between those periods ; hence arises trie bluish appearance presented occasionally by such milk • — and that a nurse should never be rejected merely because 'she Whilst lactation continues, the female is less likely to conceive ; a See on this subject, and also for an analysis of the Milk, Simon, Journal de Phar made, Jum, 1839, and Sir Astley Cooper on the Anatomy of the Breast Lond 184? b Hartmann, m Mittheilungen aus dem Archiv. der Gesellschaft practischer Aerzt'e r^s. iut^ss- Le^x^a^ssxs fsuvrS EMBRYOLOGY. 443 and hence the importance, — were there not even more weighty reasons, — of the mother's suckling her own child, in order to pre- vent the too rapid succession of children. From observations, made at the Manchester Lying-in Hospital, on one hundred and sixty married women, Mr. Robertona concludes, that in seven out of eight women, who suckle for as long a period as the working classes in England are in the habit of doing — about fifteen and a half months on the average — there will be an interval of fifteen months between parturition and the commencement of the subse- quent pregnancy ; and that, in a majority of instances, when suck- ling is prolonged to even nineteen or twenty months, pregnancy does not take place till after weaning. When menstruation recurs during suckling, it is an evidence that the womb has, again, the organic activity, which befits it for impregnation. 'CHAPTER II. FCETAL EXISTENCE.--EMBRYOLOGY. The subject of fcetal existence forms so completely a part of the function just considered, that its investigation naturally succeeds thatofthe part performed by the parents in its production, and more especially as the development of the ovum is synchronous with the uterine changes that have been pointed out. 1. SPECIAL ANATOMY AND HISTOLOGY OP THE FCETUS. a. Dependencies of the Foetus.—These are the parts of the ovum, that form its parietes, attach it to the uterus, connect it with the fcetus, and are inservient to the nutrition and development of the new being. They are generally conceived to consist,— First, of two mem branes, according to common belief, which constitute the parietes of the ovule, and which are concentric ; the outermost, called the chorion, — the innermost, filled with a fluid, in which the fcetus is placed, and called the amnion or amnios. By Boer and Gran- ville,5 a third and-outer membranehasbeen admitted, — the cortical membrane or cortex ovi. Secondly, of a spongy, vascular body, situate without the chorion, covering about one-quarter of the ovule, and connecting it with the uterus, — the placenta. Thirdly, of a cord of vessels, — extending from the placenta to the fcetus, the body of which is penetrated at the umbilicus, by the vessels, called the umbilical cord or navel string; and lastly, of three vesicles — the umbilical, allantoid, and erythroid, which are con- sidered to be concerned in fcetal nutrition. » Edinb. Med. and Surg. Journal, Jan. 1837. See, on the same subject, Mr. Lay- cock, Dublin Med. Press, Oct. 26, 1842, or Amer. Journ. Med. Sciences, Jan. 1843, p. 184. b Graphic Illustrations of Abortion, Lond. 1834. 444 EMBRYOLOGY. 1. The chorion — which has received various names3 — is the outermost of the membranes of the ovum. About the twelfth day after conception, according tofVelpeau,b it is thick, opaque, resist- ing, and flocculent at both surfaces. These flocculi, in the part of the ovum that corresponds to the tunica decidua reflexa, aid its adhesion to that membrane; but, in the part where the ovum corresponds to the uterus, they become developed to constitute the placenta. At its inner surface, the chorion corresponds to the amnion. These two membranes are, however, separated during the earliest period of foetal existence, by a gelatinous or albumi- nous fluid ;L but at the expiration of three months, the liquid dis- appears and they are afterwards in contact. By many anatomists, the chorion is conceived to consist originally of two laminas; and by Burdachd these have been distinguished by different names; the outer lamina being called by him exochorion ; the inner endo- chorion. Velpeau denies this, and asserts, that he has never been able to separate them, even by the aid of previous maceration.e As the placenta is formed on the uterine side of the chorion, the membrane is reflected over the fcetal surface of that organ, and is' continued over the umbilical cord, as far as the umbilicus of the fcetus, where it is confounded with the skin, of which it conse- quently appears to be a dependence. As pregnancy advances, the chorion becomes thinner, and less tenacious and dense, so that at the full period, it is merely a thin, transparent, colourless mem- brane, much more delicate than the amnion. Haller, Blumenbach and Velpeau affirm it to be devoid of vessels; but, according to Wrisberg, it receives some from the umbilical trunks of the fcetus, and, according to others, from the decidua. Dutrochet conceives it to be an extension of the fcetal bladder. Its vascularity, accord- ing to Dr. Granville, is proved by its diseases, which are chiefly of an inflammatory character, ending in thickening of its texture ; and he affirms, that there is a preparation in the collection of Sir Charles Clarke, which shows the vessels of the chorion as evi- dently as if they were injected. 2. The amnion lines the chorion concentrically. It is filled with a serous fluid, and contains the fcetus. In the first days of fcetal existence, it is thin, transparent, easily lacerable, and somewhat resembling the retina, At first, it adheres to the chorion only by a point, which corresponds to the abdomen of the fcetus ; the other portions of the membranes being separated by the fluid already mentioned, called the false liquor amnii. Afterwards the membranes coalesce, and adhere by very delicate cellular fila- " "al'er.'.E^ment- ^Ti0l-ViU- 188; Burdach's Physiologie als Erfahrungswis- senschalt, n. 57 ; and Velpeau, Embryologie, Paris, 1833. b Embryologie ou Ovologie Humaine, Paris, 1833 «C ,PUrS?' ^ Ei' Encycl°Pad- Worterbuch der Medicinisch. Wissenschaft x 149 Berlin, 1834. d q . .. ',1' "' e See, also, Weber's Hildebrandt's Handbuch der Anatomie, iv ^llln^hwi. Be'un^r^^6' ^ ^ * EnCyd°P- ^'^ *" Med^' ™™£S I ™% DEPENDENCIES OF THE FCETUS. 445 ments; but the adhesion is feeble, except at the placenta and um- bilical cord. In the course of gestation, this membrane becomes thicker and tougher; and, at the full period, it is more tenacious than the chorion, elastic, semitransparent and of a whitish colour. Like the chorion, it covers the fcetal surface of the placenta, enve- lopes the umbilical cord, passes to the umbilicus of the fcetus, and commingles there with the skin.a It has been a question, whether the amnion be supplied with bloodvessels. Velpeau denies it: Haller and others have main- tained the affirmative. Haller asserts, that he saw a branch of the umbilical artery creeping upon it. The fact of the existence of a fluid within it, which is presumed to be secreted by it, would also greatly favour the affirmative. But, admitting that it is supplied with bloodvessels, a difference has existed with regard to the source whence they proceed ; and anatomical investigation has not succeeded in dispelling it. Monro affirms, that on injecting warm water into the umbilical arteries of the fcetus, the water oozed from the surface of the amnion. Wrisberg asserts, that he noticed the injection to stop between the chorion and amnion; and Chaus- sier obtained the same results as Monro, by injecting the vessels of the mother. The amnion contains a serous fluid, the quantity of which is in an inverse ratio to the size of the new being; so that its weight may be several drachms, when that of the fcetus is only a few grains. At first, the liquor amnii, — for so it is called, — is trans- parent ; but, at the full period, it has a milky appearance, owing to fiocculi of an albuminous substance held in suspension by it. It has a saline taste, a spermatic smell, and is viscid and glutinous to the touch. Vauquelin and Bunivab found it to contain, water, 93-8 ; albumen, chloride of sodium, soda, phosphate of lime, and lime, 1*2. That of the cow, according to these gentlemen, con- tains amniotic acid; but Prout, Dulong, and Labillardiere and Lassaigne were not able to detect it. Dr. Rees analysed several specimens. He found its specific gravity to be about 1-007 or 1-008, and its mean composition in two cases at 1\ months to be as follows: water, 986-S; albumen (traces of fatty matter), 2-S; salts soluble in water, 3-7; albumen from albuminate of soda, 1-6; salts soluble in alcohol, 3-4 ; lactic acid, urea, 1-7. Total, 1000, The salts consisted of chloride of sodium, and carbonate of soda, with traces of alkaline sulphate and phosphate.0 Dr. Vogtd analyzed it at two different periods of pregnancy, at 3% months and 6 months, and found the constituents to vary as follows: 1 Velpeau, Embryologie, &c. Paris, 1833. b Annales de Chimie, torn, xxxiii.; and Memoir, de la Societe Medicale d'Emula- tion, iii. 229. c Ancell, Lectures on the Physiolog/and Pathology of the Blood, April 25,1840, p. 154. d Miiller's Archiv.; and Brit, and For. Med. Review, July, 1838, p. 248. VOL. II. — 3S 446 EMBRYOLOGY. 3i Months. 978-45 6 Months. 990-29 3-69 0-34 5-95 10-79 0-14 2-40 6-77 0-30 1000- 1000- Water - - Alcoholic extract, consisting of uncertain animal matter and lactate of soda Chloride of sodium - Albumen (as residuum) - Sulphate and phosphate of lime, and loss Specific gravity......1-0182 - - 1-0092 No inferences can, however, be drawn from these cases as to the proportion of solid matters at different periods of utero-gestation, inasmuch as the subject of the first case died of an inflammatory disease ; the other in a state of cachexia. Prouta found some sugar of milk in the liquor amnii of the human female; Berzelius de- tected fluoric acid in it; Scheele, free oxygen ;b and Lassaigne,c in one experiment, a gas resembling atmospheric air ; in others, a.gas composed of carbonic acid and azote. J. Miiller,d however, was never able to detect oxygen in it. The chemical history of this substance is, consequently, sufficiently uncertain, nor is its origin placed upon surer grounds ; — some physiologists ascribing it to the mother, others to the fcetus; — opinions fluctuating, according to the presumed source of the vessels, that supply the amnion with arterial blood. It has even been supposed to be the transpiration of the fcetus, or its urine. One reply to these views is, that we find it in greater relative proportion when the fcetus is small. Meckel thinks, that it chiefly proceeds from the mother, but that, about the termination of pregnancy, it is furnished in part by the fcetus. The functions, however, to which, as we shall see, it is probably inservient, would almost constrain us to consider it a secretion from the maternal vessels; and what perhaps favours this notion is the fact, that if a female be made to take rhubarb for some time prior to parturition, the liquor amnii will be found tinged with it.e It is interesting, also, to recollect, that, in the ex- periments of Dr. Blundell, — which consisted in obliterating the vulvo-uterine canal in rabbits, and, when they had recovered from the effects of the injury, putting them to the male, — although impregnation did not take place, the wombs, — as in extra-uterine pregnancy, — were evolved, and the waters collected in the uterus. The fluid, consequently, must, in these cases, have been secreted from the interior of the uterus. May not the liquor amnii be secreted, in this manner, throughout the whole of gestation, and pass through the membranes of the ovum by simple imbibition ? and may not the fluid secretions of the fcetus, which are discharged into the liquor amnii, pass through the membranes, and enter the system of the mother, in the same way ? * Annals of Philosophy, v. 417. b Dissert, de Liquoris Amnii Arteriae Aspera Fcetuum Humanorum Natura et Usu &c, Copenh. 1799. c Archiv. G^n^ral. de Med. ii 308 ' * Handbuch der Physiologie, i. 305, Berlin, 1833. * Granville, Graphic Illustrations of Abortion, p. xxi., Lond. 1834. DEPENDENCIES OF THE FCETUS. 447 The quantity of the liquor amnii varies in different individuals, and in the same individual at different pregnancies, from four ounces to as many pints. Occasionally, it exists to such an amount as to throw obscurity even over the very fact of pregnancy. An instance of this kind, strongly elucidating the necessity of the most careful attention on the part of the practitioner in such cases, oc- curred in the practice of a respectable London practitioner, — a friend of the author. The abdomen of a lady had been for some time enlarging by what was supposed to be abdominal dropsy: fluctuation was evident, yet the case appeared to be equivocal. A distinguished accoucheur, and a surgeon of the highest eminence, were called in consultation, and after examination the latter de- clared, that" it was an Augean stable, which nothing but the trocar could clear out." As the lady, however, was even then com- plaining of intermittent pain, it was deemed advisable to make an examination per vaginam. The os uteri was found dilated and dilating, and in a few hours after this formidable decision, she was delivered of a healthy child, the gush of liquor amnii being enor- mous. After its discharge, the lady was reduced to the natural size, and the dropsy, of course, disappeared. 3. The cortical membrane or cortex ovi is, according to Boer and Granville,a the one, which is usually regarded as a uterine production, and denominated the decidua reflexa. It surrounds the ovule when it descends into the uterus, and envelopes the shaggy chorion. This membrane is destined to be absorbed dur- ing the first months of utero-gestation, so as to expose the next membrane to the contact of the decidua, with which a connexion takes place in the part where the placenta is to be formed. In that part, Boer and Granville consider, that the cortex ovi is never altogether obliterated, but only made thinner; and in process of time it is converted into a mere pellicle or envelope, which not only serves to divide the filiform vessels of the chorion into groups or cotyledons, in order to form the placenta, but also covers those cotyledons. This Dr. Granville calls the membrana propria. 4. Placenta. — This is a soft, spongy, vascular body, formed at the surface of the chorion, adherent to the uterus, and connected with the fcetus by the umbilical cord. The placenta is not in ex- istence during the first days of the embryo state ; but its formation commences, perhaps, with the arrival of the embryo in the uterus. In the opinion of some, the flocculi, which are at first spread uni- formly over the whole external surface of the chorion, gradually congregate from all parts of the surface into one, uniting with ves- sels proceeding from the uterus, and traversing the decidua, to form the placenta ; the decidua disappearing from the uterine sur- face of the placenta about the middle of pregnancy, so that the latter comes into immediate contact with the uterus. In the opinion of others, the placenta is formed by the separation of the layers of the chorion, and by the development of the different vessels, that * Graphic Illustrations of Abortion, part iv. Lond. 1835. 448 EMBRYOLOGY. creep between them. Velpeau3 maintains, that the placenta forms only at the part of the ovule, which is not covered by the true decidua, and which is immediately in contact with the uterus ; and that it results from the development of the granulations that cover this part of the chorion ; these granulations or villi, according to Velpeau, being gangliform organs containing the rudiments of the placentafvessels. Others, again, regard it as formed by the growth of the vessels of the uterus into the decidua serotina. The mode in which the placenta is attached to the uterus has always been an interesting question with physiologists ; and it has been revived, of late, by Messrs. Lee,b Radford,0 and others. A common opinion has been, that the large venous canals of the uterus are uninterruptedly continuous with those of the placenta. Wharton and Reuss,d and a number of others, conceive that, at an early period of pregnancy, the part of the uterus, in contact with the ovum, becomes fungous or spongy, and that the fun gosities, which constitute the uterine placenta, commingle and unite with those of the chorion so intimately, that laceration necessarily oc- curs when the placenta is extruded ; and Dubois goes so far as to consider milk fever as a true traumatic disease, produced by such rupture ! The opinion of Messrs. Lee, Radford, Velpeau and others is, that the maternal vessels do not terminate in the placenta ; but that apertures—portions scooped out, as it were, —exist, in their parietes, which are closed up, according to the two first gentlemen, by the true decidua ; — according to Velpeau, by a membranule or anorganic pellicle, which he conceives to be thrown out on the fungous surface of the placenta, or by some valvular arrangement, the nature of which has not been discovered; but these apertures have no connexion, in his opinion, with any vascular orifice, either in the membrane or the placenta. The mode, therefore, in which these authors consider the placenta to be attached to the uterus is, so far as it goes, somewhat unfavourable to the idea generally en- tertained, that the maternal vessels pour their fluid into the mater- nal side of the placenta, whence it is taken up by the radicles of the umbilical vein. Whatever blood is exhaled must necessarily pass through the decidua, according to Lee and Radford ; or through the pellicle, according to Velpeau. More recently, Dr. Leee has somewhat modified his views, and now believes, that the circula- tion in the human ovum, in the third month of gestation, is carried on in the following manner : — The maternal blood is conveyed by the arteries of the uterine decidua into the interstices of the placenta and villi of the chorion. The blood, which has circulated in the placenta, is returned into the veins of the uterus by the oblique a Embryologie ou Ovologie Humaine, p. 63. b Philosoph. Transactions for 1832 ; and Remarks on the Pathology and Treatment of some of the most important Diseases of Women, Lond. 1833. c On the Structure of the Human Placenta, Manchester, 1837. i Novae quasdam Observationes Circa Structuram Vasor. in Placent H™ culiarem hujus cum Utero Nexum, Tubing. 1784. -numan. et pe- e London Medical Gazette, Dec. 1838; ox Amer. Journ. of the Med Soi™™; May, 1839, p. 189. "= mea. sciences, DEPENDENCIES OF THE FCETUS. 449 openings in the decidua covering the placenta. The blood, which has circulated between the villosities of the chorion, passes through the openings in the decidua reflexa into the cavity between the two deciduous membranes, whence it is taken up by the numerous apertures and canals that exist, according to him, in the uterine de- cidua, and so passes into the Veins of the uterus. Biancini* main- tains, that a number of flexuous vessels connect the uterus directly with the placenta, whichare developed immediately after the period of conception. These utero-placental vessels, he says, are not pro- longations of the uterine vessels, but a new production. Recently, Dr. John Reidb has carefully examined into this point of anatomy. On separating the adhering surfaces of the uterus and placenta, cautiously under water, he satisfied himself, but not without con- siderable difficulty, of the existence of the utero-placental vessels described by the Hunters. After a portion of the placenta had been detached in this manner, Dr. Reid's attention was attracted towards a number of rounded bands passing between the uterine surface of the placenta and the inner surface of the uterus, several of which could be drawn out in the form of tufts from the mouths of the uterine sinuses. On slitting up some of the uterine sinuses' with the scissors, these tufts could be seen ramifying in their inte- rior. These were ascertained to be prolongations of the fcetal placental vessels, and to protrude into the open mouths of certain of the uterine sinuses, and in those placed next the inner surface of the uterus only. These tufts were surrounded externally by a soft tube, similar to the soft wall of the utero-placental Fig. 249. vessels, which passed between ^^^h^y^t ,v <^^^^-<*sr.<» #&*>. the margin of the open mouths ^M^^^^^yf^^t^M^ of the uterine sinuses and the "gPSST JpfeK? edges of the orifices in the de- ; yy cidua through which the tufts """~~~~ife~~*ITt " -?**.-.*& DrOtrudedintO the sinUSeS. On Transverse Section of the Uterus and Placenta. pvaminino thp tnff<5 a« thpu a and J. Uterine sinuses with tufts of foetal placen- UJLd.IIlUllUg Ulc lulls, d& iuey tal vessels prolonged into them. c. Curling artery lav in the SinUSeS, it Was evi- Pa*sinS through the decidua vera, d Decidua vera. J ' e. Tufts of placental vessels.—(J. Reid.) dent, that though they were so far loose, and could be floated about, yet they were bound down firmly at various points by reflections of the inner coat of the venous system of the mother upon their outer surface. Dr. Reid farther satisfied himself that the interior of the placenta is composed of numerous trunks and branches, each including an artery, and an accompanying vein, every one of which, he be- lieves, is closely ensheathed in prolongations of the inner coat of the vascular system of the mother, or at least in a membrane con- tinuous with it. According to this view of the structure of the placenta, the inner coat of the vascular system of the mother is prolonged over each individual tuft, so that when the blood of the a Sul Commercio Sanguigno tra la Madre e il Feto, Pisa, 1833. b Edinb. Med. and Surg. Journal, Jan. 1841, p. 4. 38* 450 EMBRYOLOGY. mother flows into the placenta through the curling arteries of the uterus, it passes into a large sac formed by the inner coat of the vascular system of the mother, which is intersected in many thou- sands of different directions, by the placental tufts projecting into it like fringes, and pushing its tbin wall before them in the form of sheaths, which closely envelope both the Fig. 250. trunk and each individual branch composing these tufts. From this sac, the maternal blood is returned by the utero-placental veins with- out having been extravasated, or without hav- ing left the maternal system of vessels. Into this sac in the placenta, containing the blood Connection between the Ma- 0f the mother, the tufts of the placenta hang tCTTlCll 0.71(1 bCEZOil rCS&CLS* I O a. curling artery, b. like the bronchial vessels of certain aquatic utedne vein, c Placenta. animals,to which they have a marked analogy. a. Placental tufts with in- ' J °J ner coat of vascular system This sac is protected and strengthened on the of the mother enveloping r . i c c ^ t v ., , • them.-{j. Reid.) foetal surface of the placenta by the chorion, on the uterine surface by the decidua vera, and on the edges or margin by the decidua reflexa. In this view, the ' fcetal and maternal portions are every where intimately intermixed with tufts of minute placental vessels, their blunt extremities being found lying immediately under the chorion covering its fcetal sur- face, as well as towards its uterine surface. The discovery of the prolongations of the foetal placental -vessels into some of the ute- rine sinuses, Dr. Reid thinks, is principally valuable, as it presents us with a kind of miniature representation of the whole structure of the placenta; and the reason why the placental tufts are not perceptible on the uterine surface of the placenta expelled in an accouchement is, that they are so strongly bound down by the re- flection of the inner coat of the uterine sinuses that they are torn across. Professors Alison, Allen Thomson, and J. Y. Simpson in- spected the preparations of Dr. Reid, and expressed themselves satisfied that the placental tufts were prolonged into the uterine sinuses, and that the inner coat of the veins was prolonged upon them. Dr. Sharpey, too, confirms the views of Dr. Reid from his own observation of impregnated uteri; and Dr. Churchilla states, that in a recent visit to Edinburgh, Dr. Reid showed him one of the portions of uterus and placenta on which his investigations were made, and there was no difficulty in demonstrating the tufts dipping into the uterine sinuses. " No doubt," he adds, " farther observations are necessary for the perfect elucidation of the sub- ject ; but I certainly think, that as far as our knowledge extends it is in favour of the opinion adopted by Dr. Reid and the later physiologists." ProVsT Webl?.^ Vi6W t0 that °f ^ Reid is e»tert^ed by Fhiltmf017 "^ Pra°tiCe °f Midwifer*' Amer« E^t. by Prof. Huston, p. 110, b Hildebrandt's Handbuch der Anatomie des Menschen.iv. 496, Braunschweig 1812 • Wagner, op. cit. p. 201, and Dr. Reid, op. cit. p. 11 See also M?% . , Medico-Chirurg. Transactions, vol. xxv. L?nd 1842 ' ' M" DalrymPle> DEPENDENCIES OF THE FffiTUS. 451 In whatever manner originally produced, the placenta is distin- guishable in the second month, at the termination of which it covers two-thirds, or at the least, One-half of the ovum ; after this, it is observed to go on successively increasing. Prior to the full, term, however, it is said to be less heavy, more dense, and less vascular, owing — it has been conceived — to several of the ves- sels that formed it having become obliterated and converted into hard, fibrous filaments ; a change, which has been regarded as a sign of maturity in the fcetus, and a prelude to its birth. At the full period, its extent has been estimated at about one-fourth of that of the ovum ; its diameter from six to nine inches; its circumference twenty-four inches; its thickness from an inch to an inch and a half at the centre, but less than this at the circumference; and its weight, with the umbilical cord and mem- branes, from twelve to twenty ounces. All this is subject, however, to much variation. It is of a circular shape, and the cord is usually inserted into its centre. It may be attached to any part of the uterus, but is usually found towards the fundus. two surfaces, that which corresponds to the uterus Fig. 252. is divided into irregularly rounded lobes or cotyle- dons, and it is covered by a soft and delicate cel- lulo-vascular membrane, which by many is consi- dered to be the decidua vera.b Wrisberg,0 Lob- stein,d and Desormeaux,et however, who consider, that the decidua disap- pears from behind the pla- centa about the fourth or fifth month, regard it as a new membrane ; and Bo- * Burdach's Physiologie als Erfahrungswissensch. ii. 403. »> See Dr. John Reid, Edinb. Med. and Surg. Journal, Jan. 1841, p. 8. e Observ. Anat. Obstetric, de Structura Ovi et Secundinar. Human. &c. Gotting. 1783- d Essai sur la Nutrition du Foetus, Strasbourg, 1802. e Art. CEuf Humain, in Diet, de Medecine. Uterine Surface of the Placenta. Of its Fcetal Surface of the Placenta. 452 EMBRYOLOGY. janus, believing it to be produced at a later period than the decidua vera, gives it the name of membrana decidua serotina* (See Fig. 236, page 413 of this volume.) Breschet,again, maintains that two laminae — decidua vera and decidua reflexa — are found in- tervening between the uterus and placenta,5 whilst Velpeau main- tains that the true decidua never exists there! The fcetal or umbilical surface is smooth, polished, covered by the chorion and amnion, and exhibits the distribution of the um- bilical vessels, and the mode in which the cord is attached to the organ. The following are the anatomical constituents of the placenta, as usually described by anatomists. First. Bloodvessels, from two sources, the mother and the fcetus. The former proceed from the uterus, and consist of arteries and veins, of small size but con- siderable number. The vessels, which proceed from the fcetus, are those that constitute the umbilical cord ;—viz. the umbilical vein, and the umbilical arteries. These vessels, after having pene- trated the fcetal surface of the placenta, divide in the substance of the organ, so that each lobe has an arterial and a venous branch, which ramify in it, but do not anastomose with the vessels of other lobes. Secondly. Expansions of the chorion, which are de- scribed by some as dividing into cellular sheaths, and accompany- ing the vessels to their final ramifications;—an arrangement which is, however, contested by others. Thirdly. White fila- ments, which are numerous in proportion to the advancement of pregnancy, and which seem to be obliterated vessels. Fourthly. A kind of intermediate cellular tissue, serving to unite the vessels together, and which has been regarded, by some anatomists, as an extension of the decidua accompanying those vessels. Lastly. A quantity of blood poured into this intermediate cellular tissue, which may be removed by washing. In addition to these consti- tuents, a glandular structure has been presumed to exist in it; as well as lymphatic vessels.0 Fohmann,d affirms, that the umbili- cal cord, in addition to the bloodvessels, consists solely of a plexus of absorbents, which may be readily injected with mercury. This has been done also by Dr. Montgomery, of Dublin. These lymphatics of the cord communicate with a network of lympha- tics, seated between the placenta and the amnion, the termination of which Fohmann could not detect, but he thinks they pass to the uterine surface of the placenta. These vessels proceed to the umbilicus of the child, and chiefly unite with the subcutane- ous lymphatics of the abdominal parietes ; follow the superficial veins ; pass under the crural arches; ramify on the iliac glands ; and terminate in the thoracic duct. Lobstein and Meckel say that they have never been able to detect lymphatics in the cord. 1 Isis, von Oken, fur 1821. *> Memoir, de l'Academ. Royal, de Medec. torn. ii. Paris, 1833. c Granville, op. citat. p. xix. d sur les Vaisseaux Absorbans du Placenta, &c. Liege, 1832; and Amer. Journ. DEPENDENCIES OF THE F02TUS. 453 Chaussier and Ribes,a and Mr. Csesar Hawkinsb describe nerves in the placenta proceeding from the great sympathetic of the fcetus. The uterine and the fcetal portions of the placenta are gener- ally described as quite distinct from each other, during the two first months of fcetal life ; but afterwards they constitute one mass. Still, the uterine vessels remain distinct from the fcetal; the ute- rine arteries and veins communicating freely with each other, as well as the fcetal arteries and veins; but no direct communication existing between the maternal and fcetal vessels. Until of late, almost every obstetrical anatomist adopted the division of the pla- centa into two parts, constituting — as it were — two distinct pla- centae,— the one maternal, the other fcetal. Messrs. Lee, Rad- ford, and others have, however, contested this point, and have affirmed, with Velpeau, that the human placenta is entirely fcetal. The very fact, indeed, of the existence of a membrane, or — as M. Velpeau calls it — a " membranule," between the placenta and the uterus, would destroy the idea of any direct adhesion be- tween the placenta and uterus, and make the placenta wholly fcetal. Yet the point is still contested, — by those especially, who consider that the maternal vessels ramify on one surface of the placenta, and the fcetal on the other.0 It is generally supposed, that the placenta is most frequently attached to the right side of the uterus, but Nageled found the op- posite to be the fact in his examinations. In six hundred cases, which he carefully auscultated, the placenta was found in two hundred and thirty-eight cases on the left side, and in one hundred and forty-one on the right. 5. Umbilical cord.— From the fcetal surface of the placenta a cord of vessels passes, which enters the umbilicus of the fcetus, and has hence received the name umbilical cord, as well as that of navel string. It forms the medium of communication between the fcetus and the placenta. During the first month — Pockelse says the first three weeks — of fcetal existence, the cord is not perceptible ; the embryo appearing to be in contact, by the ante- rior part of its body, with the membranes of the ovum. Such, at least, is the description of most anatomists ; but Velpeauf says it is erroneous. The youngest embryo he dissected had a cord. At a fortnight and three weeks old, the length is three or four lines; and he thinks his examinations lead him to infer, that at every period of fcetal development, the length of the cord is nearly equal to that of the body, if it do not exceed it a little. » Journal Universel des Sciences Medicales, i. 233. b Sir E. Home, Lect. on Comp. Anat. v. 185, Lond. 1828; Lond. Lancet, June, 1833; and Messrs. Mayo and Stanley, Report on the Preparations of Impregnated Uteri in the Hunterian Museum, Lancet, June 22, 1833. c See Weber's Hildebrandt's Handbuch der Anatomie, iv. 495, Braunschweig, 1832. d Die Geburtshulfliche Auscultation, Mainz, 1838 ; cited in Brit, and For. Med. Rev., Oct. 1839, p. 371. « Neue Beitrage zur Entwickelungsgeschichte des Menschlichen Embryo, in Isis, von Oken, 1825. ' Embryologie, ou Ovologie Humaine, Paris, 1833. 454 EMBRYOLOGY. Fig. 253. Knotted Umbilical Cord. In an embryo, a month old, Beclard8 observed vessels creeping, for a certain space, between the membranes of the ovum, from the abdomen of the fcetus to a part of the chorion, where the rudiments of the future placenta were visible. During the fifth week, the cord is straight, short, and very large, owing to its containing a portion of the in- testinal canal. It presents, also, three or four dilatations, separated by as many contracted portions or necks; but these gradually disappear; the cord lengthens, and be- comes smaller, and occasionally it is twisted, knotted, and tuberculated in a strangely in- explicable manner. (Fig. 253.) After the fifth week it contains — besides the duct of the umbilical vesicle — the omphalo-mesentcfric vessels, and a portion of the urachus, or of the allantoid, and of the intestines. At about two months, the digestive canal enters the abdomen: the urachus, the vitelline canal — to be mentioned presently — and the vessels become obliterated, so that, at three months, as at the full period, the umbilical cord is composed of three vessels,— the umbilical vein, and two arteries of the same name, — of a pe- culiar jelly-like substance, and it is surrounded, as we have seen, by the amnion and chorion. The vessels will be more particularly described hereafter. They are united by a cellular-tissue, contain- ing the jelly of the cord, or of Wharton,a thick albuminous secre- tion, which bears some resemblance to jelly, and the quantity of which is very variable. In the fcetus, the cellular tissue is conti- nuous with the sub-peritoneal cellular tissue ; and in the placenta, it is considered to accompany the ramifications of the vessels. The length of the cord varies, at the full period, from eight inches to fifty-four. The most common length is eighteen inches." kin h'lr a]Tdy *emar,ked>that Chaussier, Ribes, and Haw- far as Z S?^™ f the ^reat sympathetic of the fcetus as and othersP ' "^ haS been done ^ Durr>c Rieck>d 6 Umbilical vesicle. - This vesicle, called-also vesicula alba and intestinal vesicle, appears to have been first carefully ^served * Embryologie, ou Essai Anatomique sur le F£tus Humain P*.; iqoi <> Dr. Churchill, in Dublin Journal of Med Science mS'i «£ ' 1821" c Dissert. Sistens Funicul. Umbilic. Nervis Ca^e Tubint' 1815 ' Utrum Funiculus Umbilicalis Nervis polleat aut ^TubLg 1816 DEPENDENCIES OE THE FCETUS. 455 by Albinus.a Dr. Granville," however, ascribes its discovery to Bojanus,c whilst others have assigned it to Diemerbroeck.d It was unknown to the ancients ; and, amongst the moderns, is not uni- versally admitted to be a physiological condition. Osiander and Dollinger class it amongst imaginary organs; and Velpeau remarks, that out of about two hundred vesicles, which he had examined, in foetuses under three months of development, he had met with only thirty in which the umbilical vesicle was in a state, that could be called natural. Under such circumstances, it is not easy to understand how he could distinguish the physiological from the pathological condition. If the existence of the vesicle be a part of the physiological or natural process, the majority of vesi- cles ought to be healthy or natural; yet he pronounces the thirty in the two hundred to be alone properly formed; and, of conse- quence, one hundred and seventy to be morbid or unnatural. This vesicle is described as a small pyriform, round or spheroidal sac; which, about the fifteenth or twentieth day after fecunda- tion, is of the size of a common pea. It probably acquires its greatest dimensions in the course of the third or fourth week. Fig. 254. Diagram of the Foztus and Membranes about the sixth week. a. Chorion b. The larger absorbent extremities, the site of the placenta, e. AUantois. d. Am- nion. «. Urachus. e. Bladder. /. Vesicula umbilicalis. g. Communicating canal between the vesicula umbilicalis and intestine, h. Vena umbilicalis. ii. Arterifeumbilicales. 1. Vena omphalo- meseraica. k. Arteria omphalo-meseraica. n. Heart, o. Rudiment of superior extremity, p. Rudi- ment of lower extremity.—{Carus.) After a month, Velpeau always found it smaller. About the fifth sixth or seventh week it is about the size of a coriander seed. ' Annotat. Academic, lib. i. p. 74. b Graphic Illustrations of Abortion, p. xii. Lond. 1834. « Meckel's Archiv. iv. s. 34; and Journ. Complement du Diet, des Sciences Medi- cales, ii. 1818, p. 84. d Opera, p. 304, Ultraject, 1672; see, also, Mackenzie, in the Edinburgh Medical and Surgical Journal for January, 1836, p. 46. For a list of those who have described it, see Purkinje, in art. Ei, of Encyclopad. Medicin. Wbrterb. x. 156, Berlin, 1834 ; and Weber's Hildebrandt's Handbuch der Anatom. Band. iv. 456 EMBRYOLOGY. After this, it becomes shrivelled and disappears insensibly. It seems to be situate between the chorion and amnion, and is com- monly adherent either to the outer surface of the amnion, or to the inner surface of the chorion, but, at times, is situate loosely between them. It is seen in Fig. 236 and Fig. 254. The characters of the vitelline pedicle, as Velpeau terms it, which attaches the vesicle to the embryo, vary according to the stage of gestation. At the end of the first month, it is not less than two, nor more than six lines long, and about a quarter of a line broad. Where it joins the vesicle, it experiences an infundibuliform ex- pansion. Its continuity with the intestinal canal appears to be undoubted.3 Up to twenty or thirty days of embryonic life, the pedicle is hollow, and, in two subjects, M. Velpeau was able to press the contained fluid from the vesicle into the abdomen, with- out lacerating any part." Generally, the canal does not exist longer than the .expiration of the fifth week, and the obliteration appears to proceed from the umbilicus towards the vesicle. The parietes of the vitelline pouch — as M. Velpeau also calls it, from its analogy to the vitelline or yolk-bag of the chick — are strong and resisting ; somewhat thick, and difficult to tear. As the umbilical vesicle of brutes has been admitted to be con- tinuous with the intestinal canal, anatomists have assigned it and its pedicle three coats. Such is the view of Dutrochet. Velpeau has not been able to detect these in the human fcetus. He admits, however, a serous surface, and a mucous surface; The vesicle is evidently supplied with arteries and veins, which are generally termed omphalo-mesenteric or omphalo-mesaraic, but, by Velpeau, vitello-mesenteric, or, simply, vitelline. The common belief is, that they communicate with the superior mesen- teric artery and vein; but Velpeau says he has remarked, that they inosculate with one of the branches of the second or third order of those great vessels (canaux), — with those, in particular, that are distributed to the caecum. These vessels he considers to be the vessels of nutrition of the umbilical vesicle. The fluid, contained in the vesicle, which Velpeau terms the vitelline fluid, has been compared, from analogy, to the vitellus or yolk of egg. In a favourable case for examination, Velpeau found it of a pale yellow colour; opaque ; of the consistence of a thickish emulsion; different in every respect from serosity, to which Albinus, Boerhaave,c Wrisbergd and Lobsteuv3 compared it, and from every other fluid in the organism; and he regards it as a nutritive sub- stance — a sort of oil — in a great measure resembling that which constitutes the vitelline fluid of the chick in ovoS 7. Mlantoid vesicle or allantois. — This vesicle__called also » Purkinje, art. Ei, in op. cit. x. 157. b See, also, R. Wagner, Elements of Physiology, translated by Robert Willis M D p. 194, Lond. 1841. = Haller. Elementa Physiol, viii. 208. i Descript. Anat. Embryonis, Gotting. 1764. e Op. cit. p. 42. f See, on this and other topics of Embryology, Von Siebold's Journal fur Gebiirt- shiilfe, xiv. Heft 3, Leipz. 1835; and Brit, and For. Med. Review, i. 241, Lond. 1836. DEPENDENCIES OF THE FffiTUS. 457 membrana farciminalis and membrana intestinalis — has been alternately admitted and denied to be a part of the appendages of the human fcetus, from the earliest periods until the present day. It has been seen by Emmert, Meckel, Pockels, Velpeau, Von Baer, Burdach and others a It is situate between the chorion and am- nion, and communicates, in animals, with the urinary bladder by a duct called urachus. It has been observed in the dog, sheep, cow, in the saurian and ophidian reptiles, birds, &c. M. Velpeau" was never able to detect any communication with the bladder in the human subject, and he is compelled to have recourse to analogy to infer, that any such channel has in reality existed. From all his facts — which are not numerous or forcible — he " thinks him- self authorized to say," that from the fifth week after conception till the end of pregnancy, the chorion and amnion are separated by a transparent colourless, or slightly greenish-yellow layer. This layer, instead of being a simple serosity, is lamellated, after the manner of the vitreous humour of the eye. It diminishes in thickness, in proportion to the development of the other membranes. The quantity of fluid, which its meshes inclose, is, on the contrary, in an inverse ratio with the progress of gestation. Becoming gradually thinner, it is ultimately formed into a homogeneous and pulpy layer, by being transformed into a simple gelatinous or mu- cous layer (enduit), which wholly disappears, in many cases, be- fore the period of accouchement. Between the reticulated body, as Velpeau terms it, and the allantoid of oviparous animals, he thinks, there is the greatest analogy. Yet the fluid of the allantoid is very different from the urine, which is supposed, by some, to exist in the allantoid of animals. This fluid, we shall find, has been considered inservient to the nutrition of the new being, but, after all, it must be admitted, that our ideas regarding the vesicle, in man, are far from being determinate. ' 8. Erythroid vesicle. — This vesicle was first described by Dr. Pockels, of Brunswick, as existing in the human subject. It had been before observed in the mammalia. According to Pockels,0 it is pyriform; and much longer than, though of the same breadth as, the umbilical vessel. Within it, the intestines are formed. Velpeau, however, asserts, that he has never been able to meet with it; and he is disposed to think, that none of the embryos, depicted by Pockels, and by Seiler,d were in the natural state. Such, too, is the opinion of Weber,e and it is not noticed by the later embryologists. According to most obstetrical physiologists, when pregnancy is 1 Purkinje, art. Ei, in Encyc. Wort, der Medicin Wissensch. xi. 151, Berlin, 1834. i> Embryologie ou Ovologie Humaine, Paris, 1833. See, also, Burdach, Die Physio- logie als Erfahrungswissenschaft, ii. 530; Weber's Hildebrandt's Handbuch der Ana- tomie, iv. 509, Braunschweig, 1832 ; and Meckel's Handbuch, u. s. w., Jourdan and Breschet's French translation, iii. 768, Paris, 1825. c Isis, von Oken, p. 1342, 1825. d Das Ei und Die Gebarmutter des Menschen, u. s. w., p. 24, Dresd. 1832. « Weber's Hildebrandt's Handbuch der Anatomie, iv. 518, Braunsch. 1832. vol. ii.— 39 458 EMBRYOLOGY. multiple, the ova in the uterus are generally distinct, but contigu- ous to each other. By others, it has been affirmed, that two or more children may be contained in the same ovum, but this appears to require confirmation. The placenta of each child, in such mul- tiple cases, may be distinct; or the different placentas may be united into one, having intimate vascular communications with each other. At other times, in twin cases, but one placenta exists. This gives origin to two cords, and at others to one only, which afterwards bifurcates, and proceeds to both foetuses. Maygrier,3 however, affirms unconditionally, that there is always a placenta for each fcetus ; but that it is not uncommon, in double pregnan- cies, to find the two placentas united at their margins; the circu- lation of each fcetus being distinct, although the vessels may anas- tomose. This was the fact in a case of quadruple pregnancy, communicated by M. Capuron to the Academie Royale de Mede- cine, in Jan. 10th, 1837. b. Development of the Ovum. — Prior to the consideration of the development of the human ovum, it may be well to refer to the changes that the egg undergoes during incubation ; in which we have an opportunity of observing the transmutations at all periods of fcetal formation, independently of any connexion with either parent. The subject has engaged the attention of physiologists of all ages ; but it is chiefly to those of more modern times—as Hunter, Cuvier, Dutrochet,b Pander,0 Rolando, Sir Everard Home, Prevost and Dumas, Von Baer, Kuhlemann,d Dollinger, D'Alton, Oken,e Purkinje/ Rathke, C. F. Wolff, Bres- chet, Burdach, Reichert, Cams, Krause, Seiler, Bojanus, Meckel, E. H. Weber, Bernhardt and Valentin, Coste, Owen, Sharpey, Velpeau, Flourens, Allen Thomson, T. W. Jones, Bischoff, Schwann and Schleiden, J. Muller, Rudolph Wagner and Martin Barry, the two last of whom received, about the same time, medals for their researches, the former from the Institute of France, and the latter from the Royal Society of London — that we are indebted for more precise information on the subject; although, unfortu- nately, they are by no means of accordance on many points. The investigations of Sir Everard Home, aided by those of the excel- lent microscopic observer, Mr. Bauer,& are accompanied by en- gravings, some of which we shall borrow in elucidation of the fol- lowing brief description. The egg of a bird, — of a hen for example,—consists of two de- scriptions of parts : —those which are but little concerned in the development of the new being, and which remain after the chick is hatched, — as the shell and the membrane lining it,__and such as * Nouvelles Demonstrations d'Accouchemens, Paris, 1822-26. b Journal de Physique, p. 88, for 1819. c Beitrage zur Entwickelungsgeschichte des HUhnchcns im Ei, Wurzb 1817 d Observ. quaedam circa Negotium Generationis in ovibus fact. Gotting. 1753." f Symbolae ad Ovi Avium Historiam ante Incubationem, p. 16 Wratislav 1825- and art. Ei, in Encyclopad. Wbrterb. der Medicin. Wissenschaft. Band x 107 Berl' 1834, s Sir E- Home's Lectures on Comp. Anat. iii 427s DEVELOPMENT OF THE OVUM — CHICK IN OVO. 459 undergo changes along with those of the chick and co-operate in its formation, —as the white, the yolk, and the cicatricula or mole- cule. The shell is porous, to allow of the absorption of air through it; and of the evaporation of a part of the albumen or white. In the ovarium it is albuminous, but in the cloaca becomes calcareous. The membrane, membrana testae, that lines the shell, is of a white colour, and consists of two layers, which separate from each other at the greater end of the egg, and leave a space filled with air, owing to the evaporation of the white and the absorption of air. This space is larger the older the egg, and is called the folliculus aeris or air-chamber. The albumen or white does not exist whilst the egg is 'attached to the ovary. It is deposited between the yolk and the shell, as the egg passes through the oviduct. Of the white there are two distinct kinds; — the outermost, thin and fluid, which evaporates in part, and is less abundant in the old than in the fresh laid egg> and another, situate within the last, which is much denser, and only touches the shell at the smaller extremity of the egg by a prolongation of its substance, which has been called the liga- ment of the white. Fig. 255. The yolk or yolk-ball, vitellus, seems to be at first sight a semifluid mass without organi- zation ; but on closer examination, it is found to consist of a yolk-bag, two epider- mic membranes, which envelope it as well as the cicatricula or mole cule. Two prolonga dons of these mem- branes, knotty, and terminating in a floc- culent extremity in the albumen, called cha- lazse or poles, are at- tached to the two ends of the egg and thus suspend it. It is also surrounded by a pro- per membrane; and lastly, under the epi- dermic coals of the yolk, and upon its proper coat lies the cicatricula, macula, tread of the cock, ox gelatinous molecule from which the future embryo is to be formed. It is found before the yolk leaves the ovarium. Ovarium of the laying Hen; natural size. The Ova at differ- ent stages of increment.— CSir E. Home.) 460 EMBRYOLOGY. Fig. 256. The external membrane of the yolk, when it quits the yolk-bag, is very thin and delicate ; its surface is studded over with red dots, which disappear in its passage along the oviduct. When this membrane is removed, there is a natural aperture in the thick, spongy covering under it, through which is seen the cicatricula or molecule, surrounded by an areola, halo, or circulus. On examination, this areola proves to be nothing more than that part of the surface of the yolk, which is circumscribed by the margin of the aperture. The molecule or cicatricula itself, (Fig. 256,) has a granulated appear- ance ; and, according to Sir Everard Home,a is made up, in the centre, of globules ^oth part of an inch in diameter, surrounded by circles of a mixed substance; about two-thirds consisting of the same small glo- bules, and one-third of larger oval globules, about T^th part of an inch in diameter ; the last resembling in shape the oval red globules of the New laid Egg ^^Moiecuie, fcc.-csir blood in the bird. Besides the glo- E Home) bules, there is some fine oil, which appears in drops, when the parts are immersed in water. Oval globules and oil are also met with in the yolk itself, but in small proportion and devoid of colour. If the ovum, according to Valentin,6 be lacerated and its contents minutely examined, the cicatricula is found like a grayish white disk, which in its whole periphery is dense, granular and opaque, but in the centre presents a clear non-granular, and perfectly diapha- nous point. Purkinje found, that when he removed the dark granular mass, by suction with a small tube, there remained a perfectly transparent vesicle, filled with a pellucid lymph, which had a decidedly spherical form, but, being extremely deli- seca0nofahen^ggwithinthe cate, was very easily lacerated, and its a. The granular membrane form fluid escaped. As he found this, which VMic^rpu?Se°irnbeeddnd\kn the" 'ater naturalists have named — after cumulus, c. Vitellary membrane, its dlSCOVerer--the ' Purkinip/in wnirlp ' d. Inner and outer layers of the cap- *l'UIOly " UJ °» llJC Jr ur/tlltjeanveSlCie, iuie of the ovum. e. indusium of the in the ova of the ovarv, but could not see ovary. _ (T. W. Jones.) ^ m ^ ^^ ^ ^^ ^^ ±Q » Op. cit. iii. 426. b Handbuch der Entwickelungsgeschichte de.« Menschen, u. s. w. Berlin 1S35 ' Edinburgh Med. and Surg. Journ. April, 1836, p. 393; and Bernhardt, Symbols ad ovi Mammalium Historiam ante Pragnationem. Wratisl. 1S34. See also Dr A Fig. 257. DEVELOPMENT OF THE OVUM— CHICK IN OVO. 461 oviduct, he gave it the name " germinal vesicle." The granular membrane, — its thickened portion, the so called cicatricula, — and the germinal vesicle, constitute those parts of the ovum, which pass immediately into the original foundation of the embryo, the blastoderma or " germinal membrane." When the egg leaves the ovarium, (Fig. 255,) the ovarial yolk-bag gives way at the median line, and the yolk drops into the commencement of the oviduct. The yolk-bags are exceedingly vascular, the outer membrane of the yolk being connected to them by vessels and fasciculi of fibres, but being readily separable from them. During the first hours of incubation no change is percepti- ble in the egg, but, about the seventh, the molecule is evidently enlarged, and a membrane, containing a fluid substance, is obser- vable. This membrane is the Amnion, Colliquamentum, Saccu- lus Colliquamenti, Nidus puHi, Areola pellucida Wolffii, trans- parent pellucid area. At this time, a white line is perceptible in the molecule, which is the rudimental fcetus ; and, even at this early period, according to Sir Everard Home,a the brain and spinal marrow can be detected. The areola has extended itself; and the surface, beyond the line which formed its boundary, has acquired the consistence of a membrane, and has also a distinct line by which it is circumscribed. This Sir Everard calls the outer areola. In the space between these two areolae are distinct dots of an oily matter. In twelve hours the rudiments of the brain are more distinct, as well as those of the spinal marrow. A dark line or primitive trace or streak may now be discovered in the cicatricula towards the centre of the transparent area, lying in the transverse axis of the egg, and swollen at the extremity, which lies to the left when the smaller end of the egg is turned from us. The larger extremity indicates the place where the head is afterwards form- ed, and occupies nearly the centre of the transparent area. As incu- bation proceeds, the whole cicatri- cula expands: towards the twelfth or fourteenth hour the germinal membrane divides into two layers „....., n T v . , . , . Egg thirty-six hours after Incubation.— of granules, the uppermost being (&> e. Home.) entitled the serous or animal layer ; the lower the mucous or vege- Thomson, art. Generation, in Cyclopsed. of Anatomy and Physiology, Feb. 1838, part xiii. p. 452; Burdach, Physiologie als Erfahrungswissenschaft, 2te Auflage, i. 87, Leipz. 1835 ; Mr. Thomas Wharton Jones, on the First Changes in the Ova of the Mammi- fera, in Philos. Transact, part ii. for 1837, p. 339 ; and Dr. Martin Barry, Philosoph. Transact. 1838, pp. 301,341 ; 1839, p. 307, and 1839-40. * Lectures on Comparative Anatomy, iii. 426. 39* 462 EMBRYOLOGY. tative layer, — the former being more extended than the latter. In a few hours later, the separation of the germinal membrane be- comes more distinct, and between the serous and the mucous layers there appears a new layer, called the vascular. In one or other of the three primitive layers — serous, mucous, or vascular — is contained the germ of all the tissues and organs of the body, and it is conceived, that their histogeny admits of a distinct group- ing. The serous layer, for example, is presumed to give origin to the organs of animal life — the brain, spinal marrow, the organs of the senses, the skin, muscles, tendons, ligaments, cartilages, and bones; from the mucous layer originate the organs of vegetative life — the intestinal canal, hings, liver, spleen, pancreas, and other glands; and from the vascular layer the heart and vascular system are presumed to arise. It is not decided to which layer the repro- ductive system should be assigned. According to Dr. Barry,3 however, there does not occur in the mammiferous ovum any such phenomenon as the splitting of a germinal membrane into the " so called serous, vascular, and mucous laminae. Nor is there any structure entitled to be denominated a germinal membrane, for it is not a previously existing membrane, which originates the germ, but it is the previously existing germ which, by means of a hollow process, originates a structure having the appearance of a mem- brane." In thirty-six hours, the head is turned to the left side. The cere- brum and cerebellum appear to be distinct bodies. The iris is per- ceptible through the pupil. The intervertebral nerves are nearly formed ; those nearest the head being the most distinct. A portion of the heart is seen. At this period, under the inner areola, appa- rently at the termination of the spinal marrow, a vesicle begins to protrude, which is seen earlier in some eggs than in others. The white of egg is found to be successively absorbed by the yolk, so that the latler is rendered more fluid and its mass augmented. The first appearance of red blood is discerned on the surface of the yolk- bag towards the end of the second day. A series of points is ob- served, which form grooves; and these closing constitute vessels, the trunks of which become connected with the chick. The vascu- lar surface itself is called figura venosa, area or area vasculosa; and the vessel, by which its margin is defined, vena terminalis, and circulus venosus. The trunk of all the veinsjoins the vena portae, whilst the arteries, that ramify on the yolk-bag, arise from the me- senteric artery of the chick, and have hence been called omphalo- mesenteric. In two days and a half, the spinal marrow has its posterior part inclosed ; the auricles and ventricles of the heart are perceptible, and the auricles are filled with red blood. An arterial trunk from the left ventricle gives off two large vessels, — one to the right side of the embryo, the other to the left, — sending branches over the whole of the areolar membrane, which is bounded on each side by a large trunk carrying red blood; but the branches of the two trunks * Op. cit.; and Wagner's Elements of Physiology, p. 153, (note,) Lond. 1841. DEVELOPMENT OF THE OVUM — CHICK IN OVO. 463 do not unite, there being a small space on one side, which renders 'the circle incomplete. This Sir Everard Home calls the areolar circulation. In three days, the outer areola has extended itself over one-third of the circumference of the yolk, carrying the marginal arteries along with it to the outer edge, but diminished in size. The brain is much enlarged ; the cerebellum being yet the larger of the two. The spinal marrow and its nerves are most distinctly formed; and the eye appears to want only the pigmentum nigrum. The right ventricle of the heart contains red blood ; the arteries can be traced to the head ; the rudiments of the wings and legs are formed, and the vesicle is farther en- larged, but its vessels do not carry red blood. It has forced its way through the external covering of the yolk, and opened a commu- nication through this slit, by which a part of the albumen is admitted to mix itself with the yolk, and gives it a more oval form. At this period, the em- bryo is generally found to have changed its position and to be wholly turned on the left side. In four days, the vesicle is more enlarged, and more vascular, its vessels containing red blood. The optic nerve and pigmentum ni- grum of the eye are visible. The outer areola extends half over the volk, with which a larger portion of the white is now mixed. In five days, the vesicle has acquired a great size and become exceedingly vascular; the yolk, too, has become thinner, in con- sequence of its admixture with more of the albumen. In six days, the vascular membrane of the areola has extended farther over the yolk. The vesicle, at this time, has suddenly expanded itself in the form of a double night-cap over the yolk, and its coverings are beginning to inclose the embryo, the outer- most laver being termed the chorion, the innermost the middle membrane. The amnion contains a fluid in which the embryo is suspended by the vessels of the vesicular membrane. The brain has become enlarged so as to equal insize the body of the embryo. Its vessels are distinctly seen. The two eyes equal the whole brain in size. The parietes of the thorax and abdomen have begun to form; and the wings and legs are nearly completed, as well as the bill. At this period muscular action has been notice^. In seven days, the vesicle —having extended over the embryo, — has begun to inclose the areolar covering of the yolk, ana a pulsation is distinctly seen in the trunk that supplies the vesicular ; opened three days after Incubation.—{Sir E.Home.) Egg' 464 EMBRYOLOGY. bag with blood. The pulsations were, in one case, seventy-nine in a minute, whilst the embryo was kept in a temperature of 105°; but when the temperature was diminished, they ceased, and when again raised to the same point, they were reproduced. The mus- cles of the limbs now move with vigour. In eight days, the anastomosing branches of the vesicular circu- lation have a strong pulsation. In nine days, the vesicle has nearly inclosed the yolk. In ten days, no portion of the yolk is observable on the outside of the vesicle. The embryo being taken out of the amnion, — now become full of water,— the thorax is found to be completely formed, and the roots of the feathers very distinct. The contents of the egg, during the formation of the embryo, be- come much diminished in quantity, and the void space is gradually occupied by a gas, which was ex- amined by Mr. Hatchett, and found to be atmospheric air deposited at the great end of the egg between the layers of the membrane lining the shell. Even prior to incuba- tion, there is always a small por- Egg five days after Incubation.-(.Sir E. Home.) tion of air ill this place which is supposed to be emploved in aerat- ing the blood, from the time of its first acquiring a red colour, till superseded in that office by the external air acting through the egg-shell upon the blood in the vessels of the vesicular membrane, with which it is lined. Between the period of fourteen and eighteen days, the yolk be- comes completely inclosed by the areolar membrane; and, at the expiration of the latter period, the greater part of the yolk is drawn into the body, as in Fig. 263. At twenty days, the chick is com- pletely formed, the yolk is entirely drawn in, and only portions of the membrane belonging to. the vesicle are seen externally. The yolk- bag has a narrow tube, ductus vi- tellanus, ductus vitelli intestinalis Egg ten days after Incubation.-(&V£.flttm«.) se" apophysis, half an inch Jong connecting it with the intestine^ DEVELOPMENT OF THE OVUM — CHICK IN OVO. 465 Embryo of the Egg. Showing the opening in the abdomen, from which •eight inches above the open- Fig. 262. ings of the caeca into the gut. The whole of these changes, which, in the viviparous ani- mal, are effected within the womb of the mother, take place in the incubated chick by virtue of its own powers; and without any assistance except that of the atmosphe- ric air and of a certain degree of warmth. In the course of incubation, the yolk becomes constantly thinner and paler, by the admixture of the white; and, at the same time, innu- merable fringe-like vessels, with flocculent extremities, of a singular structure, form on the inner surface of the yolk- Un~ n^A U-,-,,-, ."^.f^ *U~ ,t~\U portions of the vesicular and areolar membranes and Dag, ana nang into llie yOlK. turns of tne intestines are protruding. Magnified The Office Of these is presumed two diameters. - (Sir E. Home.) to be, to absorb the yolk and to convey it into the veins of the yolk- bag, where it is assimilated to the blood and applied to the nutrition of the new being. Blumenbach states, that in numerous and varied microsco- pical examinations of the yolk-bag, in the latter weeks of incubation, he thinks he has observed the actual pas- sage of the yolk from the yellow floc- culent vessels of the inner surface of the bag into the bloodvessels which go to the chick. He has, at all events, seen manifest yellow streaks in the red blood contained in those veins. When the chick has escaped from the shell, the yolk, we have seen, is not exhaust- ed, but is received into the abdomen, and as it communicates with the intes-' tinal tube, it is, for some time, a source of supply to the young animal, until its strength is equal to the digestion of its appropriate food. The highly vas- cular chorion is manifestly, an organ of aeration, like the placenta of the mammalia.* » For a minute and recent account of the development of the chick in ovo, illustrated by numerous engravings, see R. Wagner, Elements of Physiology, translated by R Willis, p. 80, Lond. 1841; also, Burdach, Die Physiologie als Erfahrungswissenschaft,. 2te Band, 2te Auflage, Leipz. 1837; Towne, Guy's Hospital Reports, Oct. 183 9, p. 385 ; and T. W. Jones, Brit, and For. Med. Rev., Oct. 1843, p. 513. Embryo eighteen days old. Half the natu- ral size. — (Sir E. Home.) 466 EMBRYOLOGY. The development of the mammalia greatly resembles that of the bird ; and it is in the former, that the histogeny of the impreg- nated ovum, at the earliest periods of intra-uterine existence, has been studied. There can be no doubt, as Wagner has remarked,* that researches on the mammalia, carefully conducted and used with discretion, are much better calculated to throw light on the primary formation of the human embryo than any amount of ne- cessarily unconnected observations on human ova cast off at an early period, and in the great majority of cases obviously diseased. In treating the whole of the subject, Wagner considers the deve- lopment of the chick to be the safest guide, and he consequently refers to it continually in his interesting description of the deve- lopment of the mammiferous ovum. In the higher oviparous ani- mals, the germinal membrane absorbs the nutritious matter from the yolk, and prepares it for the use of the embryo itself, by con- verting it into blood ; but after the yolk has been exhausted, the yolk-bag is taken into the body, and is gradually removed by ab- sorption. In the mammalia, the quantity of yolk, laid up for the nutrition of the embryo, is comparatively inconsiderable, and it is only required until the ovum has contracted a union with the ute- rus ; after which the yolk-bag is separated from the embryo, and thrown off as useless. Still, as Dr. Carpenterb has remarked, " the early processes are the same in mammiferous as they are in ovipa- rous animals ; and the development of man, of a bird, of a reptile, or of a fish, takes place, up to a certain point, upon the same gene- ral plan." The human ovum certainly does not reach the uterus until to- wards the termination of a week after conception. On the seventh or eighth day, it has the appearance referred to in the case so often cited from Sir Everard Home ; the future situations of the brain and the spinal marrow being recognisable with the aid of a powerful microscope. On the thirteenth or fourteenth day, according to Maygrier, the ovum is perceptible in the uterus, and of Fig. 264. about the size of a pea, —according to Pockels, of a *^%. Spanish nut,c containing a turbid fluid, in the midst of ;-f <■--§ wmch an °Paque point is suspended, the punctum ^$W saliens. Fig. 264 represents an ovum, which is figured by Velpeau, and could not have been more than fourteen days old, unless the midwife, who gave it to him, and who was herself the subject of the miscarriage, deceived him, and she appeared to have had no reason for so doing. Good descriptions and representations of the human ovum within the first month from conception are, however, as Wagnerd has remarked, very scarce, and many of the accounts appertain to diseased ova, or to monstrous or distorted embryos thrown off by abortion. Its weight has » Op. cit. b Human Physiology, § 758, Lond. 1842 « Ism, von Oken December, 1825; and Granville's Graphic Illustrations of Abortion part vn., Lond. 1834. *♦ Gken und Kieser, Beitrage zur Vergleichend. Zoologie, Anatomie und Physiologie, H. i. p. 74 Bamberg und Wurzburg, 1806; and Rathke, in Weber's Hildebrandt's Handbuch der Anatom. iv. 440. Valentin, op. citat. p. 380. Corpora Wolffiana, with Kidney and Testes, from Embryo of Birds. a. Kidney. *, b. Ureters, c. Corpus Wolffianum. d. Its ex- . cretoryduct. e, e. Testicles. At IS perceptible in the pavilion DEVELOPMENT OF THE FffiTUS. 469 which began to be observable in the preceding month, is now dis- tinct ; and slight, almost imperceptible, movements begin to mani- fest themselves. The length of the fcetus is, at the end of one hundred and twenty days, five or six inches ; the weight four or five ounces. During the fifth month, the deve- lopment of every part goes on; but a distinction is manifest amongst them. The mus- cular system is well-marked, and the movements of the foetus unequi- vocal. The head is still very large, compared with the rest of the body, and is covered with small, silvery hairs. The eyelids are glued together. Length, seven to nine inches; weight six or eight ounces. If the foetus be born at the end of five months, it may live for a few minutes. In the sixth month, the derma begins to be distinguished from the epidermis. The skin is delicate, smooth, and of a purple colour; especially on the face, lips, ears, palms of the hands and soles of the feet. It seems plaited, owing to the absence of fat in the subcutaneous cellular tissue. The scrotum is small, and of a vivid red hue. The vulva is prominent, and its lips are separated by the projection of the clitoris. The nails appear, and towards the termination of the month, are somewhat solid. Should the foetus be born now, it is sufficiently developed to breathe and cry, but it dies in a few hours. Length, at six months, ten or twelve inches. Weight under two pounds. During the seventh month all the parts are better proportioned. The head is directed towards the orifice of the uterus, and can be felt by the finger introduced into the vagina, but it is still very movable. The eyelids begin to separate, and the membrane, which previously closed the pupil — the membrana pupillaris — to disappear. The fat is more abundant, so that the form is more rotund. The skin is redder, and its sebaceous follicles are formed, which secrete a white, cheesy substance—the vernix caseosa — vol. ii. — 40 Fig. 270. Foetus at three months, in its membranes. 470 EMBRYOLOGY. which covers it; and the testicles are in progress to the scrotum. The length at seven months is fourteen inches; the weight under three pounds. In the eighth month, the foetus increases proportionably more in breadth than in length. All its parts are firmer and more formed. The nails exist; and the child is now certainly viable or capable of supporting an independent existence. The testicles descend into the scrotum ; the bones of the skull, ribs, and limbs are more or less completely ossified. The length is sixteen inches ; the weight four pounds arid upwards. At the full period of nine months, the organs have acquired the development necessary for the continued existence of the infant. Length eighteen or twenty inches ; weight six or seven pounds. According to Dr. Granville, length 22 inches ; weight from five to eight pounds. Dr. Deweesa says the result of his experience, in this country, makes the average weight above seven pounds. He has met with two ascertained cases of fifteen pounds, and seve- ral, which he believed to be of equal weight. Dr. Moore, of New York, had several cases,where the weight was twelve pounds; and a case occurred in that city in 1821, of a fcetus, born dead, which weighed sixteen and a half pounds. Dr. Traill11 once weighed a child at the moment of birth, which weighed 14 pounds; Mr. Park, of Liverpool, found another to weigh 15 pounds; and a case has been recorded by Mr. J. D. Owens, in which a still-born child measured 24 inches in length, and weighed seventeen pounds twelve ounces.0 Recently, Dr. Storer,d of Bos- ton, has published the following results of observations. Of 30 children, 14 females weighed 112 pounds, or averaged 8 pounds each; and 16 males weighed 145i pounds, or averaged 8h pounds each. The largest child seen by Dr. Storer was a male, and weighed 13 pounds: the next in weight was 12! pounds. One weighed 11, one 10£, and two 10 pounds each. Where there are twins in utero, the weight of each is usually less than in a uniparous case, but their united weight is greater. M. D.uges, of Paris, found that in 444 twins the average weight was four pounds, and the extreme weights three and eight pounds. The whole of this description amounts to no more than an ap- proximation to the truth. The facts will be found to vary greatly in individual cases, and, therefore, according to individual experi- ence ; arid this accounts, for the great discordance in the state- ments of different observers.e This discordance is strongly exem- plified in the following table containing the estimates of the length » Compendious System of Midwifery, 8th edit. Philad. 1836. Outlines of a Course of Medical JurTsprudence, 2d edit. p. 16, Edinb. 1840, or Amer. Edit, with notes by the author of this work, p. 27, Philad 1841 « Lond. Lancet, Dec. 22, 1838. * New England Quarterly Journal of Medicine and Surgery, July, 1842 n. Vn?vH w\iT iTm ,Erfa\u"gswi-enschaft, Band ii.; Valentin, art. Foetus, m Encycl Worterb. der Medicin. Wissensch, xii. 372, Berlin, 1835 ; and Trattato Generale di Ostetncia, di Dr. Asdrubali, 2de edizione, i. 152, Roma, 1812. DEVELOPMENT OF THE FOETUS. » 471 and weight of the foetus at different periods of intra-uterine exist- ence, as deduced by Dr. Becka from various observers, and as given by Maygrierb on his own authority, and by Dr. Granville0 as the averages of minute and accurate observations made by Autenrieth, Sommering, Bichat, Pockels, Carus, &c, confirmed by his own ob- servations made on several early ova, and many foetuses examined in the course of seventeen years' obstetrical practice. It is proper to remark, that the Paris pound, poids de marc, of sixteen ounces, contains 9216 Paris grains ; whilst the avoirdupois contains only 8532-5 Paris grains; and that the Paris inch is 1 065977 English inch. At 30 days, 2 months, 3 do. 4 do. 5 do. 6 do. 7 do. 8 do. Beck. Maygrier. Granville. Beck. Maygrier. Granville. Length. Weight. 3 to 5 lines 2 inches 3£ do. 5 to 6 do. 7 to 9 9 to 12 12 to 14 16 10 to 12 lines 4 inches 6 do. 8 do. 10 do. 12 do. 14 do. 16 do. 1 inch 3 inches 9 inches 12 do. 17 do. 2 ounces 2 or 3 ounces 4 or 5 do. 9 or 10 do. 1 to 2 pounds 2 to 3 do. 3 to 4 do. 9 or 10 grains 5 drachms 2J ounces 7 or 8 do 16 ounces 2 pounds 3 do. 4 do. 20 grains 1£ ounce 1 pound 2 to 4 pounds 4 to 5 do. The difficulty must necessarily be great in making any accurate estimate during the early periods of fcetal existence ; and the changes in the after months are liable to considerable fluctuation. Chaussier affirms, that after the fifth month, the fcetus increases an inch every fifteen days, and Maygrier adopts his estimate. The former gentleman has published a table of the dimensions of the fcetus at the full period, deduced from an examination of more than fifteen thousand cases. From these we are aicjed in forming a judgment of the probable age of the foetus in the latter months of utero-gestation ; — a point of interest with the medico-legal inquirer. At the full period, the middle of the body corresponds exactly with the umbilicus, or a very little below it; at eight months, it is three-quarters of an inch, or an inch higher. At seven months it approaches still nearer the sternum; and at six months it falls exactly at the lower extremity of that bone ; hence, if we depend upon these admeasurements, should the middle of the body of the foetus be found to fall at tlie lower extremity of the sternum, we may be justified in concluding that the foetus is under the seventh month, and consequently not viable or rearable. The following are the results of some observations made by Mr. Taylor, Lecturer on Medical Jurisprudence at Guy's Hospital, and Dr. Geoghegan, Professor of Medical Jurisprudence in the Royal College of Surgeons in Ireland. * Medical Jurisprudence, 6th edit. i. 276, Philad. 1838. See, also, Dr. W. A. Guy, Principles of Forensic Medicine, Part i. p. 100, Philad. 1843. b Nouvelles Demonstrations d'Accouchemens, Paris, 1822-26. « Graphic Illustrations of Abortion, &c, p. xi., Lond. 1834. See Seiler, art. Em- bryo, in Anat. Phys. Real Wbrterb. ii. s. 530, Leipz. und Altenb. 1818. 472 EMBRYOLOGY. Case. Whole length. 1 - 18$ 2 . 20 3 - m 4 - ]-6i 5 . 19 6 . 17 7 . 18 8 - 17 9 - 20f 10 - m 11 ■ 18| Attachment of the Umbilical Cord. A quarter of an inch below the centre. Half an inch Do. Half an inch nearly Do. Half an inch Do. Do. Do. A little below the centre. Exactly at the centre. Do. Do. A little below the centre. Do. Do. Exactly at the centre.* A striking circumstance connected with the development of the fcetus, is the progressive diminution in proportion between the part of the body above the umbilicus and that below it. At a very early period of foetal life, (see Figs. 267, and 268,) the cord is attached near the base of the trunk; but the parts beneath be- come gradually developed, until its insertion ultimately falls about the middle of the body.b The following table of the length and weight (French), and cen- tral point of the fcetus at different ages is given by M. Lepelletier.c It still farther exhibits the discordance to which we have alluded above. Month. Length. Weight. Central point. 1 5 or 6 lines 9 to 15 grains at the junction of the head and trunk. 2 18 to 20 lines 6 to 8 drachms at the upper part of the sternum. 3 2 to 3 inches 2 or 3 ounces at the upper extremity of the xiphoid cartilage. 4 5 to 6 inches 10 to 16 ounces at the middle of the xiphoid carti-lage. 5 7 to 9 inches 1 to 2 pounds at the lower extremity of the xiphoid cartilage. 6 9 to 12 inches 2 to 3 pounds several lines below the xiphoid car-tilage. 7 12 to 15 inches 3 to 4 pounds equidistant between the cartilage and the umbilicus. ! s" 15 to 18 inches 4 to 6 pounds an inch above the umbilicus. 9 16 to 20 inches 6 to 8 pounds at the umbilicus. ! Extremes, Extremes, 12 to 15 inches 2 to 16 pounds (Millot.) (Voistel.) The position of the foetus in utero, and the cause of such posi- tion at various periods of utero-gestation, have been topics of some interest. In the early weeks, it seems to be merely suspended by the cord ; and it has been conceived, that because the head is heavier, it is the lowest part. It is difficult, however, to admit this as the cause of the position assumed in such an immense ma- jority of cases, or to fancy, that the nice adaptation of the fcetal » T. R. Beck, Amer. Journ. of the Med. Sciences, Oct. 1842, p. 489 b See Carus, Lehrbuch der Gynakologie, Th. ii. s. 29, Leipz'. 1828 c Physiologie Medicale et Philosophique, iv. 451, Paris, 1833. DEVELOPMENT OF THE FCETUS. 473 position to the parts through which the child has to pass is simply dependent upon such a mechanical cause. Gravity can afford us no explanation why the face in 12,120 cases out of 12,533, has been found turned to the right sacro-iliac synchondrosis, and the occiput to the left acetabulum; and in the 63 of these cases in which the face was turned forwards, and in the 198 breech presentations, are we to presume, that the whole effect was owing to mere difference of weight in those parts that were lowest ? The common position of the fcetus, at the full period, is exhibit- ed in the next illustration. The body is bent forward, the chin resting on the chest, the occiput towards the brim of the pelvis, the arms approximated in front, and one or both lying upon the face ; the thighs bent upon the abdomen, the knees separated, the legs crossed, and drawn up, and the feet bent upon the anterior surface of the legs ; so that the oval, which it thus forms, has been estimated at about ten inches in the long diameter; the head, at the full period, resting on the neck, and even on the mouth, of the womb, and the breech corresponding to the fundus of the organ. From the first moment of a fecundating copulation, the minute matters, furnished by both sexes, when commingled, commence the work of forming the embryo. For a short time, they find in the ovum the neces- sary nutriment, and subsequently obtain it from the uterus. The mode in which this action of formation is accomplished is as mysterious as the es- sence of generation itself. When the im- pregnated ovum is first seen, it seems to be an amphorous, ge- latinous mass, in which no distinct or- gans are perceptible. In a short time, how- ever, the brain and spinal marrow, and bloodvessels, make their appearance; but which of these is first developed is unde- cided. Sir Everard Home,a a Lect. 40* Fig. 271. Full period of Utero-Gestation. on Comp. Anat. iii. 292, and 429. 4?4 EMBRYOLOGY. — from his observations of the chick in ovo, as well as from the microscopic appearances, presented by the ovum in the case of the female who died on the seventh or eighth day after impregna- tion, in which a rudimental brain and spinal marrow were percep- tible, — decides, that the parts, first formed, bear a resemblance to brain, and that the heart and arteries are produced in consequence of the brain having been established. Malpighi, Brera, Pander, Tiedemann, Prevost and Dumas, Velpeau, Rolando, and Schroder van der Kolk,a also assign the priority to the nervous system. Meckel, however, admits no primitive organizing element, but believes, that the first rudiments of the foetus contain the basis of every part. On the other hand, the researches of Serres, on the mode of development of the nervous system, have induced him to be in favour of the earlier appearance of the bloodvessels,1" and this view appears to be supported by the fact, that if an artery of the brain be wanting, or double, the nervous part to which it is usually distributed is also wanting, or double. The acephalous fcetus has no carotid or vertebral arteries; whilst the bicephalous or tricephalous have those vessels double or treble : with these views Dr. Granville0 accords, and he lays it down as a law, that the nerves invariably appear after the arteries vvhich they are intended to accompany. A like discordance exists in the views regarding the precedence in formation of the bloodvessels. The blood is clearly formed before the heart. It appears at distinct points from it, and acquires a motion independently of it. The veins are formed first ; the heart next, and lastly the arteries. This is the view of the generality of physiologists,*3 but a distin- guished Italian physiologist— Rolando — assigns the precedency to the arteries. Farther experiments are demanded on these in- teresting, but intricate points of organogenia.e Messrs. Geoffroy Saint-Hilaire,f Meckel,^ Serres,h Tiedemann,1 and others are of opinion, that the development of the embryo takes place from the sides towards the median line — from the circumference to- wards the centre ; but Velpeau) considers, that the median lihe is first formed.k The spinal marrow is the first portion of the ner- vous system which appears ; and this system, he thinks, precedes every other. Histogeny, or the development of the different tissues, is a topic of deep interest to the student of general anatomy, and has en- » Observationes Anatom. Pathol, et Pract. Argum. 8vo. Amstel. 1826 ; cited in Edinb. Med. and Surg. Journal, for April 1, 1836. b See, also, Medici, in Bulletino delle Scienze Mediche, Dicembre, 1836, p. 389; and Richerand, Nouveaux Elements de Physiologie, 13eme edit, par M. Berard aine\ § 206, Bruxelles, 1837. c Op. cit. i See Von Baer, Ueber Entwickelungsgeschiehte der Thiere, u. s. w., Kbriigsberg, 1837 ; also, Prof. R. J. Graves, in Lond. Med. Gaz. for June 30th, 1838, p. 591. * Adelon, Physiologie de I'Homme, 2de edit. iv. 353, Paris, 1829. f Philosophic Anatomique, Paris, 1818-22. s Handbuch der Anatomie, Band, i. *> Recherches d'Anatomie Transcendante, &c. Paris, 1832. I Anatomie du Cerveau, traduit par Jourdan, Paris, 1823. i Embryologie ou Ovologie Humaine, Paris, 1833. k See, also, H. Mayo's Outlines of Physiology, p. 385, Lond. 1833 ; and GranTille, Uraphic Illustrations of Abortion, p. xii. Lond. 1834. PECULIARITIES OF THE FffiTUS. 475 gaged the attention of some of the most excellent anatomists of modern times. Amongst these, Rolando, Tiedemann, Ackermann, 9 Serres, Velpeau, Walther, Beclard, Rosenmuller, Geoffroy Saint- Hilaire, Meckel', Burdach, Rudolph Wagner, Valentin, Bischoff, Schwann and Schleiden, are especially conspicuous. The nature and limits of this work will preclude us, however, from entering into this investigation any farther than to point out some of the most striking peculiarities of foetal life.3 The fullest treatise on the subject is that of Burdach,b and one of the most recent that of Rudolph Wagner.c c. Peculiarities of the Foetus. — The head of the fcetus is large in proportion to the rest of the body, and the bones of the skull are united by membrane; the sagittal suture extends down to the nose, so as to divide the frontal bone into two por- tions ; and where this suture unites with the coronal, a quadrangular space is left, filled up by membrane, which is called the anterior fonta- nelle or bregma. Where the poste- rior extremity of the sagittal suture joins the lambdoidal, a triangular space of a similar kind is left, called the posterior fontanelle or posterior bregma. It is important for the ob- stetrical practitioner to bear in mind the shape of these spaces, as they indicate to him whether the anterior or posterior part of the head is the presenting part. The pupil of the eye, in a very young fcetus, is en- tirely closed by a membrane, called membrana pupillaris, which arises from the inner margin of the iris, and continues there till the seventh month, when it gradually vanishes by absorption. It is a vascular sub- stance, and, like the iris, to which it is attached, separates the two cham- bers of the eye from each other. Wachendorffd first described it in * Weber's Hildebrandt's Handbuch der Anatomie, iv. 467, Braunschweig, 1832 ; Purkinje, art. Ei, Encyclop. Wbrterb. der Medicinisch. Wissensch. xi. 107, Berlin, 1834-5 ; Valentin, art. Fcetus, ibid. xii. 255, Berl. 1835. An abstract of the views of Serres, is given in Amer. Journal of the Med. Sciences, Feb. 1837, p. 473. See, also, Fletcher's Rudiments of Physiology, part i. Edinb. 1836. b Die Physiologie als Erfahrungswissenschaft, 2ter Band. 2te Auflage, Leipz. 1837. c Elements of Physiology, translated by Willis, Lond. 1841. i Commerc. Litterar. Noric. 1740 ; and Valentin, art. Fcetus, Encycl. Wbrterb. n. B.w., xii. 376. Fig. 272. Fcetus at full term. a, a- Divided integuments. c,c. Divided ribs and intercostal muscles, e, e. Lobes of thymus gland g, g, A, A. Lungs, i. Right auricle of the heart, k. Right ven- tricle, n, o. Right and left lobes of the liver, p. Stomach. q, q. Small intestines. r. The colon, s. Bladder of urine inflated. t. The urachus. u, u. The umbilical arte- ries, v. The umbilical vein. w. The umbilicus, x. The collapsed umbilical cord. 476 EMBRYOLOGY. 1738 ; and both he and Wrisberg detected vessels in it. Its vas- cularity was denied by Bichat, but it has been satisfactorily de- monstrated by J. Cloquet.3 The membrane is manifestly con- nected with the process of formation of the delicate organ to which it is attached; and according to Blumenbach,5 it keeps the iris expanded, during the rapid increase of the eyeball. In the upper part of the thorax of the foetus, a large gland, or rather glandiform ganglion exists, called the thymus, and by Joseph Frank, corpus incomprehensibile. It is situate in the superior me- diastinum, and lies over the top of the pericardium and the arch of the aorta. It has two long cornua above, and two broad lobes below. Its appearance is glandular, and colour very variable. In the progress of age it diminishes, so that in the adult it is wasted, and in old age can scarcely be discovered amongst the cellular tissue. Krausec states, that he has found it in almost all indi- viduals between twenty and thirty years of age, and very often larger than in young children. It is surrounded by a thin, cellular capsule, which sends prolongations into its interior, and divides it into lobules of unequal size, in which several vesicles are distin- guishable, filled with a milky Fig. 273. fluid. Sir Astley Cooper states, that the lobules may be drawn out and separated from each other in the man- ner of a string of beads, when their enveloping capsule has been removed. The ordinary weight of the thymus has been estimated at half an ounce, but this is probably above the average. Dr. Roberts,** of New York, found the ^verage weight in the full grown foetus to be 229 grains. The thymic arteries proceed from the inferior, thyroid, internal mammary, bronchial, mediastinal, &c. The nerves proceed from the pneumogastric, diaphragma- tic, and inferior cervical ganglia. It has no excre- tory duct; and is one of the * Memoir sur la Membrane Pupillaire, Paris, 1817. b Institut. Physiolog. § 262. See, also, Elliotson's Translation, and Weber's Hildebrandt's Handbuch der Anatomie, iv. 84. vveDers c Miiller's Archiv. Heft 1, 1837. * Amer. Journ. of the Med. Sciences, Aug. 1837, Nov. 1838, and Oct. 1841 ; New York Journ. of Med. and Surg., Jan. 1840 ; and New York Med. Gaz., July 21 184* See, also, Dr. C. Lee, m Amer. Journ. of the Med. Sciences, Jan. 1842 p 138' Section of the Thymus Gland at the Eighth Month. 1. Cervical portions of the gland ; independence of two lateral glands is well marked. 2. Secretory cells seen upon cutsurface of section ; these are observed in all parts of section. 3,3. Pores or openings of secretory cells and pouches ; they are seen covering whole in ternal surface of great central cavity or reservoir Continuity of reservoir in lower or thoracic portion of gland with cervical portion, is seen in the figure__ {Sir dstley Cooper.) PECULIARITIES OF THE FffiTUS. 477 most obscure, in its physiology, of any organ of the body, although, like the lymphatic glands, probably connected with the function of nutrition.8 The thyroid gland, which has been described in another place, and whose functions are equally obscure, is also largely developed in the foetus; as well as the supra-renal capsules. The lungs, not having received air in respiration, are collapsed and dense, containing no more blood than is necessary for their nutrition. They are of a dark colour, like liver, and do not fill the cavity of the chest. Their specific gravity is greater than that of water, and consequently they sink in that fluid. On cutting into them, no air is emitted, and no hemorrhage follows. The absolute weight, however, of the lungs is less; no more blood, as we have seen, being sent to them than what is necessary for their nutriment; whilst, after respiration is established, the whole of the blood passes through them : the vessels are consequently filled with blood, enlarged, and the organs themselves increased in ab- solute weight. Ploucquet asserts, from experiments, that the weight of the lungs of a full-grown fcetus, which never respired, is to that of the whole body, as 1 to 70 ; whilst, in those, in which respiration has been established, it is as 1 to 35; the absolute weight being thus doubled. These numbers cannot, however, be con- sidered to afford a satisfactory average,— the exceptions being numerous ; but they show that, as might be expected, the abso- lute weight is less, prior to the establishment of respiration. Care- ful and extended observations have satisfactorily shown, that although an increase in the weight of the lungs is generally found after respiration has been completely established, it is by no means the case when the inspirations have been feeble, as they often are for some hours and days after birth; and, on the other hand, it is not unusual to meet, in infants that have not breathed, with lungs as heavy as in the average of those that have respired.1* The sub- ject is one of great interest, connected with infanticide, and has been treated in a competent manner, by Dr. J. B. Beck, in Beck's Elements of Medical Jurisprudence, — decidedly, in our opinion, one of the best medico-legal works in existence.0 It is, however, in the circulatory system of the fcetus, that we meet with the most striking peculiarities. The heart is propor- tionably larger and more conical than in the adult. The valve of Eustachius — at the left side of the mouth of the inferior vena cava, where this vessel joins the sinus venosus, — is larger than at an after period, and is supposed to direct the principal part of the blood of that cava directly through the opening which exists be- tween the right and left auricle. This opening, which is called the foramen ovale ox foramen of Botal, is in the septum between the 1 Gulliver, in Gerber's General Anatomy, p. 100, Lond. 1842. b Dr. Guy, Edinb. Med. and Surg. Journ., vol. lvi. and lvii. e See, also, J. B. Beck, Researches in Medicine and Medical Jurisprudence, New York, 1835. 478 EMBRYOLOGY. Fig. 274. Circulatory Organs of the Faztus. 1. Umbilical cord, consisting of umbilical vein and two umbilical arteries ; proceeding from pla- centa (2). 3. Umbilical vein dividing into three branches; two (4,4) to be distributed to liver; and one (5), ductus venosus, which enters infe- rior vena cava (6). 7. Portal vein returning blood from intestines, and uniting with right hepatic branch. 8. Right auricle ; course of blood is denoted by arrow, proceeding from 8 to 9, left auricle. 10. Left ventricle; blood following ar- row to arch of aorta (11), to be distributed through branches given off by arch to head and upper ex- tremities. Arrows 12 and 13,represent return of blood from head and upper extremities through jugular and subclavian veins, to superior vena cava (14), to right auricle (8), and in course of arrow through right ventricle (15), to pulmonary artery (16). 17. Ductus arteriosus, which appears to be a proper continuation of pulmonary artery, the offsets at each side are right and left pulmo- nary artery cut 'off; these' are of extremely small size as compared with ductus arteriosus. Ductus arteriosus joins descending aorta (18, 18), which divides into common iliacs, and these into in- ternal iliacs, which become umbilical arteries (19), and return blood along umbilical cord to placenta; while other divisions, external iliacs (20), are continued into lower extremities. Ar- rows at termination of these vessels mark return of venous blood by veins to inferior cava.— (Wilson.) auricles, and is nearly equal in size to the mouth of the inferior cava. It is situate obliquely, and has a membrane, forming a distinct valve, and somewhat of acrescentic shape, which allows part of the blood of the right auricle to pass through the opening into the left auricle, but prevents its return. The pulmonary artery, in- stead of bifurcating as in the adult, divides into three branch- es ; — the right and left going to the lungs of the corresponding side, whilst the middle branch, — to which the name ductus arteriosus has been given,— opens directly into the aorta; so that a great part of the blood of the pulmonary artery passes directly into that vessel. From the internal iliac arteries, two considerable vessels arise, called the umbilical arteries. These mount by the sides of the blad- der, as in Fig. 272, on the out- side of the peritoneum and per- forate the umbilicus in their progress to the umbilical cord and placenta. The umbilical vein, which is also a constituent of the cord, and conveys the blood from the placenta to the fcetus, arises from the substance of the placenta by a multitude of radicles, which unite together to form it. Its size is consider- able. It enters the umbilicus, (Fig. 272,) passes towards the inferior surface of the liver, and joins the left branch of the vena porta hepatica. Here a vessel arises called the ductus venosus, which opens into the vena cava inferior, or joins the left vena hepatica where that vein enters the cava. A part only of the blood of the umbilical vein goes PECULIARITIES OF THE FffiTUS. 479 directly to the vena cava ; the remainder is distributed to the right and left lobes of the liver, especially to the latter. The digestive apparatus exhibits few peculiarities. The bowels, at the full period, always contain a quantity of greenish, or deep black, viscid faeces, to which the term meconium has been applied, owing to their resemblance to the inspissated juice of the poppy (fAHKuy, " a poppy"). It appears to be a compound of the secre- tions from the intestinal canal and bile, and frequently contains down or fine hairs mixed with it. The liver is very large ; so much so as to occupy both hypochondriac regions ; and the right and left lobes are more nearly of a size than in the adult. Prior to birth it would seem to be the only decarbonizing organ ; the lungs being inactive, but as soon as respiration is established, less blood is sent to the liver; and the diminution takes place with great rapidity, and is usually evidenced a short time after birth by the comparative paleness of its substance. Hence it has been sup- posed that the weight of the liver might aid in the determination of the question, whether a child had breathed or not. It has been shown, howeyer, that although the liver, as a general rule, weighs less after respiration has been established, it by no means exists when the inspiration has been feeble for hours or days after birth ; and, on the other hand, it is not uncommon to meet, in infants that have not breathed, with livers as light as in the average of those that have.a The urinary bladder is of an elongated shape, and extends almost to the umbilicus. The muscular coat is somewhat thicker and more irritable than in the adult, and it continues to possess more power during youth. The common trick of the schoolboy — of sending the jet over his head — is generally impracticable in more advanced life. From the fundus of the bladder, a ligament of a conical shape, called the urachus, (Fig. 272,) ascends between the umbilical arteries to the umbilicus ; becoming confounded in this place with the abdominal aponeuroses, according to Bichat, and forming a kind of suspensory ligament to the bladder. It is some- times found hollow in the human fcetus, but such a formation Bichat considers to be preternatural. In the foetal quadruped, it is a lar^e canal, which transmits urine to the allantois, of which, as well°as of other foetal peculiarities, we have previously treated. Lastly, the genital organs require some notice. The successive development of this part of the system has given rise to some sin- gular views regarding the cause of the sex of the foetus. During the first few weeks, the organs are not perceptible ; but, about the termination of the fifth week, a small, cleft eminence appears, which is the rudiment of the scrotum or the vulva, according to the sex. In the sixth week, an aperture is perceptible, common to the anus and genital organs, in front of which is a projecting tubercle. In the seventh and eighth weeks, this tubercle seems to » Guy, op. cit.; and Carpenter, Human Physiology, § 661, Lond. 1842. 480 EMBRYOLOGY. be tipped by a glans, and grooved beneath by a channel which extends to the anus. In the eleventh and twelfth weeks, the pe- rineum is formed and separates the anus from the genital organs. In the fourteenth week, the sex is distinct; but there still remains, for some time, a groove beneath the clitoris or penis, which be- comes closed in the former, and is made into a canal in the latter. The striking similarity between the male and female organs has led Tiedemann* to conclude, that the female sex is the male, ar- rested at an inferior point of organization. In his view, every embryo is originally female ; the cleft, described above, being the vulVa, — the tubercle, the clitoris; to constitute the male sex,.the cleft is united so as to form a raphe, the labia majora are joined to form the scrotum, the nymphse to form the urethra, and the clitoris is transformed into a penis. In support of this .opinion, Tiedemann asserts, that the lowest species of animals are almost all females; and that all the young acephali and aborted fcetuses, which have been examined, are of that sex. Others, again, assert, that the sexes are originally neuter, and that the future sex is determined by accidental circumstances, during the first week of fcetal life ; whilst Velpeau is disposed to believe, that they are all male ; the infrapubic prolongation existing in every embryo, although there may be neither labia majora nor scrotum. But admitting that the embryo belongs to either the one or the other sex, or is neutral, we must still remain at a loss regarding the influences that occasion the subsequent mutations ; and it seems impossible not to admit, that although an apparent sexual identity may exist amongst different embryo's, there must be an impulse seated somewhere, which gives occasion to the sex being ultimately male or female, as it causes the young being to resemble one or other parent in its outward form, or internal configuration : and if our means of observation were adequate to the purpose, a distribution of arteries or nerves might probably be detected, which could satisfactorily account, ad initio, for the resulting sex. In the absence of such positive data, Geoffroy St. Hilaire has suggested, thatjhe difference of"sex may be owing to the distribution of the two branches of the spermatic artery. If they continue in approximation, proceeding together, — the one to the testicle, the other to the epididymis, — the indi- vidual is male ; if they separate, — the one going to the ovary, the other to the cornu of the uterus, — the individual is female. The degree of predominance of the cerebro-spinal system, he thinks, determines the approximation or separation of the two arterial branches. This predominance being greater in the male, the sper- matic arteries are more feeble and consequently in greater proxi- mity ; and conversely in the female.b * Anatomie der Kopflosen Missgeburten, p. 54, Landshut, 1813. b Adelon, Physiologie de I'Homme, 2de.edit. iv. 375 ; J. Muller, Bildungsgeschichte der Genitalien, Berlin, 1830; E. H. Weber's Hildebrandt's Anatomie, iv. 446; Va- lentin, art. Foetus, Encycl. Wbrterb. der Medicin. Wissensch. xii. 381, Berlin, 1835; Coste, Annales d'Anatomie et de Physiologie, tom.ii. No. ii.,Mars, 1838 ; and London Medical Gazette, May 12, 1838, p. 304. PECULIARITIES OF THE FffiTUS. 481 Leaving these phantasies of the generalizing anatomists on a sub- ject regarding which we must, probably, ever remain in the dark, let us inquire into the phenomena of the descent of the testes in the fcetus. In the early months of foetal life, the testicle is an abdominal viscus, being seated below the kidney. About the middle of the third month of utero-gestation, it is about two lines long, and is situate behind the peritoneum, which is reflected over its ventral surface. At this time, a sheath of peritoneum may be observed, passing from the abdominal ring to the lower part of the testicle, and containing a ligament, called gubernaculum testis, which is considered to be formed of elastic cellular tissue, proceeding from the'upper part of the scrotum, and from the part of the general aponeurosis of the thigh near the ring, and of some muscular fibres coming from the internal oblique and transversalis muscles. Fig. 275. Fig. 276. Descent of the Testicle. A. Testicle.- 6. Peritoneal covering or tunica vaginalis testis. C. Peritoneum of the loins. D. Peritoneum descending before the testicle. F. Peritoneum lining the abdomen. Descent of the Testicle. A. Testicle in the scrotum. B. Prolongation of the peritoneum. C. Peritoneum lining the abdomen. D. Peritoneum forming the tunica vaginalis. E. Cavity of the peritoneum. F. Kidney. The head of the foetus in utero being the lowest part, the testis has necessarily to ascend into the scrotum, and consequently some force must be exerted upon it. This is supposed to be effected by the contraction of the gubernaculum testis, yet it does not contain any fibrous structure, until after the descent of the testis has com- menced. About the seventh month, the testes are in progress towards the scrotum, and have attained the inner ring. Fig. 275 exhibits one leaving the abdomen and entering the scrotum, into which it generally passes in the ninth month. In this descent, the organ abandons successively one portion of the peritoneum to pass behind another immediately below, until the lowest part of the pouch, formed by the peritoneum, around the testicle, as in Fig. 276, VOL. II.— 41 482 EMBRYOLOGY. becomes the tunica vaginalis testis; whilst the portion of perito- neum, that descended before the testicle, becomes, when the testicle has fully descended, the second coat or tunica vaginalis. As soon as the testicle has reached the lower part of the scro- tum, the neck of the pouch approaches a closure, and this is com- monlv effected at birth.' Sometimes, however, it remains open for a "time, the intestines pass down, and congenital hernia is thus induced.51 The testes have not always descended into the scrotum at birth, even at the full period; of 97 new-born infants, Wrisberg found both testes in the scrotum in 67 : one or both in the canal in 17; one testis in the abdomen in 8 ; and both testes were in the cavity of the abdomen in 3. Sometimes, as has been remarked elsewhere, one or both testes remain through life in the abdomen, a condition which is natural in the ram.b 2. PHYSIOLOGY OF THE FffiTUS. In investigating this interesting point of human physiology, we shall inquire into the functions, in the order we have adopted respect- ing the functions of the adult. Over many of the topics that will have to engage attention, the deepest obscurity rests; whilst the hypotheses, indulged regarding them, have been of the most fanci- ful and mystical character. a. Jinimal Functions. — The external senses in general are manifestly not in exercise during foetal life ; of this there can be no doubt, a| regards the sense of sight; and the same thing pro- bably applies to the taste, smell, and hearing. With regard to tact, however, we have the best reason for believing, that it exists, particularly towards the latter periods of utero-gestation. The cold hand, applied over the abdomen of the mother, will instantly elicit the motions of the child. The brain and nervous system of the foetus must, therefore, have undergone the development necessary for the reception of the impression made through the medium of the mother; to convey such impression to the percipient organ, and to accomplish perception. The existence of most of the internal sensations ox wants would of course be supererogatory in the fcetal state, where the func- tions, to which they minister after birth, are themselves wanting. It is probable, that there is no digestion except of the mucous secre- tions of the tube; no excretion of faeces or urine, and certainly there is no pulmonary respiration. It is not unlikely, however, that internal impressions, originating in the very tissue of the organs, may be communicated to, and appreciated by, the brain. a See Oesterreicher, De Gubernaculo s. d. Hunteriano, 1828 ; and Neue Darstellung der Lehre der Ortsveranderung der Hoden, 1830 ; also, Rathke, Abhandlungen zur Bildungs und Entwickelungsgeschichte des Menschen, u. s. w., Th. i., 1832 — cited by Valentin, art. Foetus, in Encyclop. Worterbuch der Medicin. Wissenschaft. xii. 381, Berlin, 1835 ; and J. B. Curling, on the Structure of the Gubernaculum and on the Descent of the Testis, in London Lancet, April 10, 1841, p. 70; and in Practical Treatise on the Diseases of the Testes, &c, p. 32, Lond. 1843. b Comment. Soc. Reg. Scient. Gotting. 1778 ; and Curling, op. cit. p. 66. PHYSIOLOGY OF THE FOZTUS. 483 We have strong reason for believing, that pain may be experienced by the foetus ; for if it be destroyed by any sudden influence in the latter periods of pregnancy, death will generally be preceded by irregular movements which are manifest to the mother, and fre- quently lead her to anticipate the result. Adelon asks, whether it may not be affected, under such circumstances, with convulsions, similar to those that animals experience when they die suddenly, especially from hemorrhage ? It is impossible to reply to this ques- tion, but that the child suffers appears evident. The most elevated of the functions of relation — the mental and moral faculties — would seem to be needless to the foetus, and consequently little, if at all, exercised. Bichat and Adelon,8 considering that its existence is purely vegetative, are of opinion that they are not exerted at all. Cabanis,b however, suggests, that imperfect essays may, at this early period, be made by virtue of the same instinct that impels animals to exercise their organs prior to the period at which they are able to derive service from them ; as in the case of the bird, which will shake its wings before they are covered with feathers, and when yet incapable of bearing them. It is difficult to deny to the foetus all intellectual and moral manifestations. They must doubtless be obscurely rudimental; still, we may conceive that some may exist, if we admit that the brain is in a state for the perception of impressions, that tact is practicable, and instinct in full activity. We find, moreover, that the power of motion, voluntary as well an involun- tary, exists certainly after the fifth month, and probably much earlier, could it be appreciated. During the latter months of utero-gestation, the motion of the fcetus appears to be almost incessant, and can be distinctly felt by placing the hand upon the abdomen. At times, indeed, it is manifest to the sight. The cause of these movements is by no means clear. It is probable, that they are instituted for the purpose of inducing a change in posi- tions, which may have become irksome, and for assuming others; for we have already remarked, that the foetus readily appreciates any sudden succussion given to it through the mother, — hence that it possesses tact, and, as we can readily understand, may ex- perience fatigue from the maintenance of an inconvenient posture. This impression is conveyed to the brain, which sends out voli- tion to the appropriate muscles, and the position is changed. All this proves, that the cerebral functions are exerted, but for a few definite objects only. The function of expression is of course almost, if not entirely, null in the fcetus. There are cases upon record, where children are said to have cried in utero, so as to be heard distinctly,not only by the mother, but by those around her. Indeed, the objection, that an infant may respire before it is born, and yet not come into the world alive,—in which case there will be buoyancy and dilatation of the lungs, has been brought forward against the doci- » Physiologie de I'Homme, 2de edit. iv. 420, Paris, 1829. b Rapport du Physique et du Moral de I'Homme, Paris, 1802. 484 EMBRYOLOGY. masia pulmonum or lung-proof of infanticide. We would not be understood as believing these cases to be mere fabrications, or the phenomenon impossible, — except, indeed, whilst the mem- branes are in a state of integrity. When they have given way, and the child's mouth presents towards the os uteri, breathing and the vagitus may be ' practicable and may have occurred; but very positive and unexceptionable testimony is required to esta- blish such an astounding event.a b. Functions of Nutrition. — These functions are not as numer- ous in the foetus as they are in the adult. Their object is, however, the same ; — the formation of the various parts of the organized machine, and their constant decomposition and renovation. One of the least tenable hypotheses, that have been entertained regarding the embryo at its first formation, is — that, for the first month—and why the period is thus limited is not apparent — the vitality of the fcetus is not independent, but is a part,—an offset, as it were, — of that of the mother; that it has no separate powers of existence ; no faculty of self-evolution ; and that its organs are nourished by the plastic materials, which it incessantly derives from the maternal blood.b It appears manifest, that from the very moment of the union of the materials furnished by both sexes at a fecundating copulation, the elements of the new being must exist; and it must possess, within itself, the faculty of self- evolution ; otherwise, how can we understand the phenomena that take place in the ovarium after fecundation ? It is admitted that this last organ furnishes the unfecundated ovum ; and that the sperm must come in contact with this ovum ; after which, fecundation is accomplished, and immediately the ovum under- goes a farther development; escapes, in due time, from the viscus in which it was formed ; is laid hold of by the Fallopian tube; passes through that canal, and is deposited in the interior of the uterus, with which it ultimately contracts adhesions. But all this requires time. The ovum does not probably reach the uterus, in the human female, until about the end of a week ; and some time must still elapse before such adhesions are effected; and, consequently, before any thing like maternal blood, whence the plastic materials are derived, according to the view in question, could be sent to it. During the whole of this time, the embryo doubtless derives its nourishment from the albuminous matters with which it is surrounded in the ovum itself, in the same man- ner as the young of the oviparous animal obtains the nutriment necessary for its full development, during incubation, from the matters surrounding it; in which case the supply of fresh plastic materials, derived from the maternal blood, is obviously impossi- ble.c But, in due time, after it has attained the interior of the uterus, it is compelled to absorb appropriate nutriment from the * See a case of this kind by Dr. Collins, in his Practical Treatise on Midwifery &c. Lond. 1835; also, Beck's Medical Jurisprudence, 6th edit. Philadelphia, 1838 t Geddings, art. Acephalous, Amer. Cycl. of Pract. Medicine, P. ii n 142* Philn delphia, 1833. P' **' rnua c Granville's Graphic Illustrations of Abortion, p. vii., London, 1834. NUTRITION OF THE FOZTUS. 435 mother; the minute quantity existing in the ovum, at this early period, being totally insufficient for the development which the foetus is destined to attain. In this last respect, the human ovum differs from the eggs of oviparous birds, which are hatched out of the body, and contain sufficient nutriment for full foetal evolution. In treating of this subject, Dr. Granville has the following re- marks—" What stronger proof need be required of the exist- ence of an adherent life principle in the ovulum, which is, at one time at least, indeed, I suspect throughout the period of gestation, independent of any connexion with the parent mother. Yet none of the earlier writers who adopted the ovarian theory of genera- tion have ever asked themselves this question — what supports, the vitality of a fecundated ovulum after it has left the ovarium, and previously to its becoming connected with the womb ? In fact, the subject had never been mooted, before the more modern physiologists took it up and satisfactorily explained it:" — and he adds in a note, " the whole of the English physiologists, writers on midwifery and lecturers, whether ancient or modern, are en- tirely silent on this important stage of embryonic life." It is a topic, however, discussed at length in the first edition of this work, and much expanded in the subsequent edition.* Since the time of Hippocrates, Aristotle, and Galen, different anatomists and physiologists have asserted, that the umbilical vein is the only channel through which nutriment reaches the foetus, or, in other words, that the whole of the nourishment which the fcetus receives is from the placenta : but the facts, to which allusion has already been made, are sufficient to overturn this hypothesis. It is impossible, that the placenta can have any agency until it is in esse. Such an explanation of the process of fcetal nutrition could only hold good after the first periods, and then, as we shall see, it is sufficiently doubtful. Accordingly, some of the most distin- guished of modern physiologists, who have devoted their attention to embryology, have completely abandoned the idea of placental agency during the first months; and they, who have invoked it at all, have usually done so, as regards the after periods only. On all this subject, however, we have the greatest diversity of views. Lobstein,b for example, affirms, that the venous radicles of the rudimental placenta obtain nutritive fluids from the mother during the first days only, until the period when the arteries are formed; but that, after this, all circulation between the uterus and pla- centa ceases, and the fluid of the umbilical vesicle, the liquor amnii, and the jelly of the cord, are the materials of nutrition. Meckel0 thinks the placenta is never the source of nutritive mate- rials. He regards it as an organ for the vivification of the blood of the foetus, analogous to the organ of respiration in the adult; and nutrition is, in.his opinion, accomplished by the matter of the » Human Physiology, 1st edit. ii. 365, Philad. 1832, and 2d edit. ii. 413, Philad. 1836. b Essai sur la Nutrition du Fcetus, Strasbourg, 1802. '•Handbuch, u. s. w., Jourdan and Breschet's French translation, iii. 784, 41* 4S6 EMBRYOLOGY. umbilical vesicle in the beginning, by the liquor amnii until mid- term, and by the jelly of the cord until the end. According to Beclard,3 nutrition is effected during the first weeks, by the fluid of the umbilical vesicle; afterwards by the liquor amnii, and the jelly of the cord; and as soon as the ovum becomes villous, and developes the placenta, by that organ. Dr. Montgomery11 has described several " decidual cotyledons," as he terms them, which are best seen about the second or third month, and are not to be found at the advanced period of gestation. These are small cup- like elevations on the external surface of the decidua vera, having the appearance of little bags, the bottoms of which are attached to or embedded in its substance ; they then expand a little, and again grow smaller towards their outer or uterine end, which, in by far the greater number of them, is an open mouth when separated from the uterus; how it may be when adherent he does not profess to say, nor does he offer any de- cided opinion as to their precise nature or uses; but from having on more than one occasion observed within their cavity a milky or chy- lous fluid, he is disposed to con- sider them reservoirs for nutrient fluids separated from the maternal blood, to be thence absorbed for the support and development of the ovum. " This view," says Dr. Montgomery, "seems strength- ened when we consider, that at the early periods of gestation, the ovum derives all its support by imbibition, through the connexion existing between the decidua and the villous processes covering the outer surface of the chorion." Adelon0 is of opinion, that two sources of nutrition ought alone to be admitted, — the umbilical vesicle, which is the sole agent for nearly two months, and the placenta for the remainder of the period. M. Velpeaud equally thinks, that the nutriment of the ovum is derived from different sources at different periods of intra-uterine existence. The em- bryo, he says, is at first but a vegetable, imbibing the surrounding humours. The villi of its circumference, which are true cellular spongioles, obtain nutritive principles in the Fallopian tube and the uterus, to keep up the development of the vesicles of the em- bryo ; after which the new being is nourished like the chick in ovo, or rather like the plantule, which is, at first, altogether deve- » Embryologie, ou Essai Anatomique sur le Fetus Humain, Paris, 1821. b Signs and Symptoms of Pregnancy, p. 133, Lond. 1837. c Physiologie de I'Homme, 2de edit., iv. 397, Paris, 1829. a Embryologie ou Ovologie, &c, Paris. 1833 ; and Traite Elementaire de 1'Art des Accouchemens, Professor Meigs's translation, 2d edit. p. 213, Philad. 1838 See also Broussais, Traite de Physiologie, &c, Dr.*. Bell and La Roche's translation 3d Amer' edit. p. 535, Philad. 1832. Decidual Cotyledons. —(Montgomery.) NUTRITION OF THE FCETUS. 487 loped at the expense of principles inclosed in its cotyledons. It gradually exhausts the vitelline substance contained in the umbi- lical vesicle. The emulsive substance of the reticulated sac of the allantoid pouch is also gradually absorbed. The end of the second month arrives ; the vessels of the cord are formed, and the pla- centa is developed ; by its contact with the uterus, this organ ob- tains reparatory materials, elaborates them, and forms from them a fluid more or less analogous to blood, and this fluid is absorbed by the radicles of the umbilical vein. We find, consequently, some of the most distinguished physiolo- gists of the age denying — as it would seem that every one ought to deny — that the nutrition of the foetus takes place solely by means of blood sent by the mother to the foetus. If we search into the evidence afforded us by transcendental anatomy, we find that amidst the various singular monstrosities met with, there would appear to be but one thing absolutely necessary for fcetal develop- ment, — an absorbing surface, surrounded by a nutritive substance capable of being absorbed. Head, heart, —every thing, in short, except organic nervous system, vessels, and cellular tissue, —may be wanting, and yet the foetus may grow so as to attain its ordi- nary dimensions. We have the most incontestable evidence, that neither the placenta nor umbilical cord is indispensably necessary for foetal development. Adelon disposes of this in the most sum- mary manner, by affirming, that "there is no authentic instance of a foetus, devoid of umbilical cord and placenta, attaining full ute- rine growth." The case is not, however, got rid of so easily. The marsupial animals breed their young without either placenta or cord. The embryos are inclosed in one or more membranes, which are not attached to the coats of the uterus, and are supplied with nourishment from a gelatinous matter by which they are sur- rounded. Thomas Bartholin, moreover, during his travels in Italy, saw an individual, forty years old, who was born without anus, penis, or umbilicus; and M. Velpeau cites cases from Ruysch, Samson, Chatton, Rommeil, Denys, Fatio, V. Geuns, Sue, Penchie- nati, Franzio, Desgranges, Kluyskens, Pinel, Mason, Osiander, Die- trich, Von Froriep, and Voisin ; but as these cases militate against his views of embryotrophy, he attempts to diminish their force by affirming, that the observations, which he had made, satisfy him, that all the foetuses thus born had died in utero, in consequence of the destruction of the cord, or the closure of the umbilicus ; or else, that the umbilicus existed, but was hidden or lost in the ex- troversion of the bladder, almost always remarked in those that lived. Now, passing by the singular deduction of M. Velpeau, that his observations have satisfied him of the incorrectness of ob- servations made by men, many of whom have long since passed away, — long before he existed, — as well as the facts relating to the marsupial animal, and that the fcetus, in extra-uterine preg- nancies, has frequently no placenta, — with the case cited by Dr. Good, from Hoffmann, of a foetus born in good health and vigour, with the funis sphacelated and divided into two parts; and one 488 EMBRYOLOGY. by Stalpart Van der Wiel,a of a living child, exhibited without any umbilicus as a public curiosity, — a case, observed by Dr. Goodb himself, appears to us to be impregnable. The case in question occurred in 1791. The labour was natural; the child, scarcely less than the ordinary size, was born alive ; cried feebly once or twice after birth, and died in about ten minutes. The organization, both internal and external, was imperfect in many parts. There was no sexual character whatever; neither penis nor pudendum ; nor any interior organ of generation. There was no anus, no rectum, no funis, no umbilicus. The minutest inves- tigation could not discover the least trace of any. With the use of a little force, a small, shrivelled placenta, — or rather the rudi- ment of a placenta, — followed soon after the birth of the child, without a funis or umbilical vessels of any kind, or any other appendage by which it appeared to have been attached to the child. In a quarter of an hour afterwards, a second living child was protruded into the vagina and delivered with ease, being a perfect boy, attached to its placenta by a proper funis. The body of the first child was dissected in the presence of Dr. Drake of Hadleigh, and of Mr. Anderson of Sunbury, to both of whom Dr. Good appeals for the correctness of his statement. In the stomach, a liquor was found resembling the liquor amnii. How could nu- trition have been effected, then, in this case ? Certainly not by blood sent from the mother to the child, for no apparatus for its conveyance was discoverable; and are we not driven to the ne- cessity of supposing, that the food must have been obtained from the fluid within the ovum? This case, — with the arguments already adduced,—seems to constrain us to admit, that the liquor amnii may have more agency in the nutrition of the new being than is generally granted. Professor Monro,0 amongst other rea- sons,— all of which are of a negative character, — for his disbelief in this function of the liquor amnii, asserts, that if the office of the placenta be not that of affording food to the embryo, it becomes those, who maintain the contrary doctrine, to determine what other office can be allotted to it, and that till this is done, it is more consistent with reason to doubt the few and unsatisfactory cases, at the time brought forward, than to possess ourselves with facts directly contradictory of each other. The case given by Dr. Good, since Professor Monro's remarks were published, is so unanswer- able, and so unquestionable, that it affords a positive fact, of full or nearly full foetal development, independently of placenta and umbilical cord ; and the fact must remain, although our ignorance of the functions of the placenta be « dark as Erebus." The following case, with which the author was obli^in^ly favoured by his friend, Dr. Wright, of Baltimore, has an instruc- a Observat. Rar. Med. Chirur. cent. ii. p. 1, Obs. 32. »> Case of Preternatural Fcetation, with Observations, read before the Medical Society of London, Oct. 20, 1794 ; and Study of Medicine, in Physiological Proem to Cbi / Genetlca- c Edinburgh Medical Essays, ii. 1C2. " NUTRITION OF THE FCETUS. 489 tive bearing upon the subject. The condition of the placenta was such as to lead that intelligent observer to conclude, that any cir- culation between the mother and the foetus, through the placenta, was impracticable. " Baltimore, September 2Gth, 1835. " Dear Sir, — In compliance with your request, I offer you the following plain and short statement of a case, which occurred in my practice, at the date indicated. " On the 6th of December, 1833, I was requested to visit Mrs. T----, of this city, — a young woman of large form, good constitution, and generally excellent health. She had been married about fifteen months, and I was now called to attend her first labour. She had felt occasional labour pains through the day, and was delivered of a fine, vigorous, female infant, in about four hours from the time of my call. The labour was, in all respects, natural, and as easy as is common —or consistent— with a first parturition. After the birth of the child, an hour, perhaps, was passed in waiting for secondary pains to effect the expulsion or favour the removal of the placenta, but no movement of this kind having then occurred, a gentle examination was made to ascertain whether that body might be easily and properly taken away. The vagina contained nothing more than the funis, — the outlet of the uterus was open, soft and extensible. The cord was gently followed into the uterine cavity, and the cake found near its fundus, retaining a«lose connexion with the uterus. The placental mass was large and firm, presenting to the touch a peculiar feeling — as of a dense sponge, full of coarse, granular or gravelly particles. Deeming it now proper to relieve the patient fully, a cautious effort was made to detach the placenta from the uterus, in order to its manual extrac- tion. In pursuing this design, it was found, that the adhering surface of the former consisted of a uniform calcareous lamina or plate, rough to the finger, and exciting such a sensation or feeling, as would be caused by a sheet of coarse sand-paper. When the mass was detached, and brought away, the laminar surface, just referred to, was found to be a calcareous plate, uniformly covering the whole of the attached portion of the cake, — the entire surface of the utero-placental connexion. The calcareous matter, thus distributed, was thin, and readily friable, but, as before remarked, it appeared to constitute a uniform and superficial covering. The correspondent uterine surface — the part from which the placenta had been separated — felt rough, but comparatively soft, imparting nothing distinctly of the calcareous or gritty feel. Out of the body, the placenta felt heavy, and eminently rough throughout. When compressed or rubbed together, the large amount of nodular or granular matter, dispersed through its sub- stance, was not only manifest to the touch, but a very audible crepitation or grating sound could be thus elicited from any, and every part of the mass. " In this uncommon instance of placental degeneracy, both the mother and child were perfectly healthy and well. The latter, indeed, was remarkable for its fine size, perfect nutrition and vigour. From the condition of the cake, and the character of its adhesion to the uterus, I apprehended a more than ordinary liability to secondary affec- tion, in the form of puerperal fever, —and whether influenced or not by the circum- stances detailed, secondary fever did ensue on the third day from delivery, attended by the usual signs of puerperal hysteritis, which affection, however, was happily subdued by general and topical bleeding, calomel, &c. " With sincere regard, yours, » T. H. WRIGHT. " Professor Dunglisox. « p,s.__The child, referred to, is living, and, from its birth to the present, has con- siderably exceeded the common bulk of children at the same age. The mother is now far advanced in her second pregnancy."» Since this letter was written, the same lady has been delivered of another healthy child ; and although the maternal surface of the placenta was of the same calcareous character, the deposition was not to the same extent as in the first pregnancy. A similar » See an analogous case by Madame Buisson Dauthez, in Gaz. Med. de Pans, Juillet, 1842. 490 EMBRYOLOGY. case has been described by Mr. Gilbert, of Beaminster, Eng- land.3 Amongst those physiologists, who admit the liquor amnii to be a fluid destined for foetal nutrition, a difference prevails, regarding the mode in which it is received into the system. Osiander,b Brug- mans,c Van den Bosch, Fohmann, Carusd and others think, that it is absorbed through the skin. In the foetal state, the cuticle is extremely thin ; and, until within a month or two of the full period, can be scarcely said to exist. There is consequently not that im- pediment to cutaneous absorption, which, we have seen, exists in the adult. The strong argument, however, which they offer in favour of such absorption is the fact, that the fcetus has been de- veloped, although devoid of both mouth and umbilical cord; and Professor Monro, in opposing the function ascribed to the liqour amnii, refers to cases of monstrous formation, in which no mouth existed, nor any kind of passage leading to the stomach. Others, as Hallere and Darwin/ are of opinion, that the fluid enters the mouth and is sent on into the stomach and intestines; and in sup- port of this view they affirm, that the liquor amnii has been found in these viscera; — that it has been shown to exist in the stomach and pharynx. Heister, on opening a gravid cow, which had perished from cold, found the liquor amnii frozen, and a continuous mass of ice extending to the stomach of the fcetus.s The physiologists, who believe that the liquor amnii is received into the stomach, differ as to what happens to it in that organ. Some suppose, that it is simply absorbed without undergoing diges- tion ; others, that it must first be subjected to that process. Ac- cording to the former opinion, it is simply necessary, that the fluid should come into contact with the mucous membrane of the ali- mentary passages; and they affirm, that if digestion occur at all, it can only be during the latter months. Others, however, con- ceive that the waters are swallowed or sucked in, and that they undergo true digestion. In evidence of this they adduce the fact of meconium existing at an early period in the intestinal canal, which they look upon as evidence that the digestive function is in action; and in farther proof of this, they affirm, that on opening the abdomen of a new-born infant the chyliferous vessels were found filled with chyle, which could not, they say, have been form- ed from any other substance than the liquor amnii; and lastly, that fine silky down has been found in the meconium, similar to that which exists on the skin of the foetus, and which is conceived to have entered the mouth along with the liquor amnii. These rea- » Lancet, for Dec. 16, 1837, p. 418. b Handbuch der Entbindungskunde, torn. i. p. 237. c De Natura et Utilitate Liquoris Amnii, Ultraject. 1792. d Lehrbuch der Gyn'akologie, Th. ii. s. 27, Leipz. 1828. e Elementa Physiologic, viii. 205. f Zoonomia, vol. i., London, 1796. See Meckel's Handbuch, u.s.w. Jourdan and Breschet's translation, iii. 784, Paris, 1825. s Adelon, Physiologie de I'Homme, iv., 389, Paris, 1829. NUTRITION OF THE FCETUS. 491 sons have their weight, but they cannot explain the development in the cases above alluded to, in which there was no mouth; and of course they cannot apply to the acephalous foetus. Moreover, it has been properly remarked, that the presence of meconium in the intestinal canal — admitting that it is the product of digestion, which is denied by many — merely proves that digestion has taken place, and the same may be said of the chyle in the chyliferous vessels : neither one nor the other is a positive evidence of the digestion of the liquor amnii. Both might have proceeded from the stomachal secretions. It has also been affirmed, that meco- nium exists in the intestines, of the acephalous foetus; and in those in which the mouth is imperforate. Lastly, with regard to the down discovered in the meconium, it has been suggested as possible that it may be formed by the mucous membrane of the intestine, which so strongly resembles the skin in structure and functions. Others have supposed that the liquor amnii is received through the respiratory passages, from the circumstance, that, in certain cases, the fluid has been found in the trachea and bronchia ; some presuming, that it readily and spontaneously enters at the nostrils and passes to the trachea and bronchia ; others, that it is forced in by the pressure of the uterus ; and others, again, that it is intro- duced by the respiratory movements of the foetus. Views have differed in this case, also, regarding the action exerted upon it after introduction ; some presuming that it is absorbed imme- diately ; others, that it is inservient to a kind of respiration; and that, during foetal existence, we are aquatic animals, — consuming the oxygen or atmospheric air, which Scheele,8 Lassaigne,b and others have stated to exist in the fluid. It is scarcely necessary to oppose seriously these gratuitous speculations. The whole ar- rangement of the vascular system of the fcetus, so different from that which is subsequently established, and the great diversity in the lungs, prior and subsequent to respiration, would be sufficient to refute the idea, had it even been shown, that the liquor amnii always contains one or other of these gases, which is by no means the fact. The case of the acephalous foetus is also an obstacle to this view as strong as to that of the digestion of the liquor amnii. As if to confirm the remark of Cicero — " nihil tam absurdam, quod non dictum sit ab aliquo philosophorum," — it has been ad- vanced by two individuals of no mean pretensions in science, that the liquor amnii may be absorbed by the genital organs or by the mammas. Lobsteinc supports the former view ; Okend the latter. He asserts, that the fluid is laid hold of by the mammae, is elaborated by them, and conveyed from thence into the thymus 1 De Liquoris Amnii Utilitate, Copenhag. 1795. b Archiv. General, de Med. ii. 308. » Essai sur la Nutrition du FcEtus, p. 102, Strasbourg, 1802. <* Zeugung, p. 162, Bamberg, 1805. 492 EMBRYOLOGY. gland, the thoracic duct, and the vascular system of the fcetus! Hence, in this opinion, the necessity of both sexes possessing nip- ples before birth.a Of these various opinions, the one that assigns the introduction of the fluid to the agency of the cutaneous absorbents appears to carry with it the greatest probability. It must be admitted, how- ever, that the whole subject is environed with obscurity, and requires fresh, repeated, and accurate experiments and observa- tions to enlighten us. But it may now be asked, with Monro, what are the nutritive functions performed by the placenta? We have before alluded to the different views, entertained regarding the connexion between the placenta and the uterus. Formerly, it was universally main- tained, that vessels pass between the mother and the maternal side of the placenta, and that others pass between the foetus and the foetal side, but that the two sides are so distinct, as to justify their being regarded as two placenta?, — the one maternal, the other fcetal, — simply united to each other. At one time, again, it was supposed, that a direct communication exists between the maternal and fcetal vessels, but this notion has long been exploded. We have decisive evidence, that the connexion is of the most indirect nature. Wrisberg made several experiments, which showed that the fluid of the fcetal circulation is not drained when the mother dies from hemorrhage. It has been affirmed, too, that if the uterine arteries be injected, the matter of the injection passes into the ute- rine veins, after having been effused into the lobes of the placenta. If, on the other hand, the injection be thrown into the umbilical arteries, the matter passes into the umbilical vein, and is effused into the foetal side of the placenta, but does not pass into the uterine vessels. When, however, an odorous substance, like cam- phor, is injected into the maternal veins of an animal, the fcetal blood ultimately assumes a camphorated odour, and when ani- mals have been fed on madder during gestation, the colouring matter has been found in the foetus ;b also when the human female has taken rhubarb, evidence of it has been found in the liquor amnii, in the serum of the blood of the umbilical vessels, and in the first urine of the infant.0 Magendied injected this substance into the veins of a gravid bitch, and extracted a fcetus from the uterus at the expiration of three or four minutes : the blood did not exhibit the slightest odour of camphor; whilst that of a second foetus, extracted at the end of a quarter of an hour, had a decidedly camphorated smell. This was the case, also, with the a Hedenus in art Brust (weibliche,) Encyclopad. Wbrterb der Medicinish. Wis- ITlon pH351',Berl1?' ,8H3L See-especially, on the whole subject of fcetal nutrition, Adelon, Physiologie de I'Homme, 2de edit. iv. 383, Paris, 1829; and Meckel's Hand- from'the Frlm/h? pjEi^S? tranSlati°n' ^ ^ ? °' IW' B"«B* «™**» b Dr. Musey, in Amer. Journ. of the Med. Sciences, for November, 1829 c Granville's Graphic Illustrations of Abortion, &c. p. xx. Lond. 1834 d Precis Elementaire, ii. 552. NUTRITION OF THE FCETUS. 493 other foetuses. Such communication may, however, have been owing to the same kind of transudation and imbibition, of which we have spoken under the head of absorption, and may conse- quently be regarded as entirely adventitious; and the fact of the length of time, required for the detection of the odorous substance favours this idea ; for if any direct communication existed between the mother and the foetus, the transmission ought certainly to have been effected more speedily. The transmission of substances from the foetal to the maternal placenta is yet more difficult. Magendie was never able to affect the mother by poisons injected into the umbilical arteries and directed towards the placenta ; and he remarks, in confirmation of the results of the experiments'of Wris- berg, that if the mother dies of hemorrhage, the vessels of the fcetus remain filled with blood. They who consider, that there is no mater- nal and foetal portion of the placenta, or, rather, tbat it is all fcetal, of course believe, where the matter of injection, thrown into the uterine vessels, has passed into the cells of the placenta, that it has been owing to the rupture of parts, by the force with which the injection has been propelled. Another fact, that proves the indirect nature of the connexion which exists between the parent and child, is the total want of cor- respondence between the circulation of the foetus and that of the mother. By applying the stethoscope to the abdomen of a pregnant female, the beating of the fcetal heart is observed to be twice as frequent as that of the mother. (See p. 422 of this volume.) Again, examples have occurred in which the foetus has been extruded with the placenta and membranes entire.3 In a case of this kind, which occurred to Wrisberg, the circulation continued for nine minutes; in one described by Osiander,b for fifteen minutes; in some, by Professor Chapman, from ten to twenty minutes; and in one, by Professor Channing, of Boston, and Dr. Selby, of Tennessee, where a bath of tepid water was used to re-susci- tate the foetus, for an hour.c Marsond and Flajani relate cases in which life continued for the same time: Dr. Nehr,e of Rehau, in Bavaria, has given a case in which the circulation of the child was unequivocal for seven hours after the sudden and decided death of the mother; and other cases are referred to by D'Outrepont in his comments on this one.f In other cases of a similar kind, where the child could scarcely breathe and was in danger of perishing, the life of the placenta was maintained by keeping it in water of a temperature nearly equal to that of the body, and the child has been saved. All these facts prove demon- stratively, that the foetus carries on a circulation independently of » Granville, op. cit. part x. Lond. 1834. t> Annalen, torn. i. p. 27. c Horner's Special and General Anatomy, 5th edit. ii. 277, Philad. 1839. d Lond. Med. Gazette, August, 1833. • IN cue Zeitschrilt fur Geburtskunde, von Busch, D'Outrepont und Rit^en, Band. iv. Heft l,s. 58, Berlin, 1836. ' Ibid. s. 60. See, also, Diction, des Sciences Medicates, torn. xvii. p. 442 ; and Osiander's Handbuch der Entbindungskunde, B. iii. Abth. 2, s. 157. VOL. II. — 42 AnA EMBRYOLOGY. 494 that of the mother; and whatever passes between the fetal and maternal vessels is probably exhaled from the one and absorbed Z the other, as the case may be. The fluid sent to the foetus is supposed by some,-indeed by most physiologists—to be the maternal blood, modified or unmodified. Schreger,* however and others maintain, that the communication of any nutritious fluid trorn the mother to the foetus, and conversely, takes place by means ot lymphatics, and not by bloodvessels ; and that the maternal vessels exhale into the spongy tissue of the placenta the serous part of the blood, which is taken up by the lymphatics of the foetal portion, and conveyed into the thoracic duct. It has been before remarked, that Lobsteinb and Meckel' sup- pose that the gelatinous substance of the cord is one of the mate- rials of foetal nutrition. This opinion they found on the circumstance of the albuminous nature of the substance, and the great size which it gives to the cord at the earlv periods of foetal life, as well as on the great development of the absorbent vessels of the foetus, that proceed from the umbilicus to the anterior mediastinuni; whilst others invoke, also, the fluids of the umbilical and allantoid vesicles. All these speculations regarding the various sources of nutritive matter are sufficient evidence of the uncertainty that prevails on this interesting topic. It is manifest, however, that we cannot re- gard as nutritive matters those substances which are secreted by the foetus itself. It is impossible, that'any development can occur without the reception of materials from without. We have seen, that when the ovum passes from the ovarium to the uterus, it con- tains within it, a molecule, and fluids which are probably destined for the nutrition of the new being, and which afford the necessary pabulum for the increase, that occurs,between the period ol im- pregnation and that at which an adhesion is formed between the ovum and the inner surface of the uterus. The mother, having furnished the nutritive material in the ovum, she must continue to provide it in the uterus ; and as soon as the vascular communi- cation is formed between the exterior of the ovum and the interior of the uterus, nutritive elements are doubtless received by the em- bryo;__for otherwise it would perish from inanition. What then can be the nature of these elements ? Do they consist of maternal blood, laid hold of by the foetus at this early period, when no circulatory system is apparent; or are the bloodvessels distri- buted to the membranes of the ovum, to enable them to continue the secretion of that nutritive matter which they took with them from the ovarium, and which must necessarily have had a mater- nal origin ? The latter certainly is the more probable supposition, and it is, as we have seen, an argument in favour of the amnion being supplied with blood from the uterus^ rather than from the fcetus ; for, if we admit it to be in any manner inservient to nutri- tion, its production must be extraneous to the body which it has * De Functione Placentae Uterinae, Erlang. 1795. •> Essai sur la Nutrition du Fcetus, Strasbourg, 1812.. c Handbuch, u. s. w., Jourdan and Breschet's translation, iii. 785, Paris, 1825. NUTRITION OF THE FCETUS. 495 to nourish. These observations apply equally to the jelly of the umbilical cord, which is probably secreted by the membranous * envelopes, and may consequently be regarded as a nutritive mate- rial derived from the parent. Both, it is true, might be secreted by the foetus from fluids furnished by the mother, and be placed in depot, as the fat is in after existence. Transcendental anatomy, then, instructs us, that the placenta and umbilical cord are not indispensable to foetal nutrition ; and com- pels us to infer with Meckel4 — one of the most eminent of modern anatomists and physiologists — that the human placenta may have no direct agency in embryotrophy. We are, therefore, necessarily driven to the conclusion, before laid down, — that, in order for a foetus to be developed in utero, it is but necessary, that there shall be an absorbing surface, surrounded by a nutritive substance, which will admit of being absorbed. Now, the cutaneous envelope of the foetus — monstrous or natural — is such a surface, and the liquor amnii such a fluid; and the matter of the umbilical vesicle, with the jelly of the cord, when these parts exist, and possibly some material derived through the placenta — after it exists — may lend their aid; but the participation of these last agents is — to say the least — doubtful. The function of the placenta probably is, to admit of the fcetal blood being shown to that circulating in the ma- ternal vessels, so that some change may be effected in the former, which may better adapt it for serving as the pabulum, whence the secretions, from which the foetal organs have to be elaborated, may be formed. According to Dr. Reid,b the blood of the mother, con- tained in the placental sac already described (p. 450 of this volume), and the blood of the fcetus contained in the umbilical vessels, can readily act and react on each other, through the spongy and cel- lular walls of the placental vessels and the thin sac ensheathing them, in the same manner as the blood in the branchial vessels of aquatic animals is acted upon by the water in which they float. If we admit this, however, it is obvious, that the nutritive fluid, when received into the system, will have to be made into blood by the action of the fcetus, in a manner, bearing some analogy to what occurs in the adult, or in the simplest of living beings, in which the nutritive fluid is absorbed at the surface of the body. Of the mode in which such conversion is effected we are in the same darkness that envelopes all the mysterious processes which are esteemed organic and vital; but that the foetus is capable of effecting it we have irrefragable proof in the oviparous animal, where there can be no communication, after the egg is laid, be- tween the embryo and the parent. Yet we find it forming its own blood from the yolk surrounding it, and undergoing its full and regular development from causes seated in itself alone. Of those physiologists, who consider that the mother sends her blood to the placenta, to be taken up by the foetal vessels, all do not conceive that it is in a state adapted for the nutrition of the » L.op. citat. b Edinb. Med. and Surg. Journ. Jan. 1841, p. 8. 496 EMBRYOLOGY. new being: some are of opinion that the placenta, or the liver, or both, modify it, but in a manner which they do not attempt to explain. In favour of such an action being exerted by the pla- centa, they state that it is clearly the organ which absorbs the fluid, and that every organ of absorption is necessarily one of ela- boration ;— a principle which we have elsewhere proved to be unfounded; and, moreover, that the blood conveyed to the fcetus by the umbilical vein, differs essentially in colour from that con- veyed to it by the umbilical arteries, — a fact, which, we shall see, can be accounted for more satisfactorily. In support of the view, that a second change is effected in the liver, they affirm, that a great part of the foetal blood ramifies in the substance of that organ before it reaches the heart; a part only going by the ductus veno- sus ; and that the great size of the liver, during foetal life, when its function of secreting bile can be but sparingly exerted, is in favour of this notion.a The opinion, that some change is effected upon the blood in the liver, is certainly much more philosophical and probable than the belief of Haller, that the object of its passage through that organ is to deaden the force with which the mother projects the fluid into the foetal vessels. We have seen, that it is extremely doubtful, whether she transmit any ; and that if she does, the communication is very indirect. M. Geoffroy Saint-Hilaireb appears to think, that the blood of the mother, which he conceives to be sent through the placenta to the foetus, is unfitted for foetal life, before it has undergone certain modifications. The blood, according to him, which leaves the placenta, proceeds in part to the liver, and the remainder to the heart. In the liver it forms the material of the biliary secretion, or at least of a fluid, which, when discharged into the intestines, irritates them, and provokes a copious secretion from the mucous or lining membrane. This mucus, according to M. Saint-Hilaire, is always met with in the stomach and intestines of the foetus ; and the presence of meconium, and of other excrementitious mat- ters in the intestines, shows, that digestion must have taken place. This digestion he considers to be effected upon the mucus, secreted in the manner just mentioned ; and, in support of its being inser- vient to sanguification, he, affirms, that its quantity is too great for the simple purpose of lubricating the parts ; that mucus is the first stage of all organic compounds ; that it predominates in all young beings ; is the foundation of every organ ; more capable of assimilation than any other substance, &c. But independently of the whole of this view being entirely hypothetical, it cannot be esteemed probable, that the foetus is nourished by one of its own secretions. All secretions must be formed from blood Blood must, therefore, pre-exist in the foetal vessels, and the process, in- dicated by Saint-Hilaire, be unnecessary. .224,ephnadT1838. ^ ^ *** AcCouchemens5 or Meigs's translation, 2d edit b Philosophie Anatomique, Paris, 1818-22. NUTRITION OF THE FCETUS. 497 Allusion has alreadybeen made to the opinions of Schreger on the nutrition of the foetus. These were developed in a letter, written by him, in 1799, to Sommering.a He considers, that all communication of nutritious matter between the mother and fcetus occurs through the lymphatics which he has described as existing in considerable numbers in the placenta and umbilical cord. The red blood, flowing in the maternal vessels, is too highly charged with carbon, and with other heterogeneous substances, he thinks, to serve for the nutrition of the foetus. Its serous part, which is purer and more oxygenized, is therefore alone exhaled. The uterine arteries pour this serum into the spongy texture of the placenta, whence it is taken up by the lymphatics of the foetal portion. These convey it along the umbilical cord to the thoracic duct, whence it passes into the left subclavian, vena cava superior, right auricle and ventricle, ductus arteriosus, and aorta; and, by the umbilical arteries, is returned to the placenta. In this course, it is mixed with the blood, and becomes itself converted into that fluid. When it attains the placenta, the blood is not poured into the cells of that organ, to be transported to the mother, but it passes into the umbilical vein, the radicles of which are continuous with the final ramifications of the umbilical arteries. Lateral pores, however, exist in the latter, which suffer fluids to escape, that cannot be elaborated by the foetus, or that require again to be submitted to the maternal organs, before they are fitted for its support. These fluids, according to Schreger, are not absorbed by the veins of the uterus, but by the lymphatics of that viscus, which are so apparent in the pregnant state, and have been in- jected by Cruikshank, Meckel, &c. In his view, therefore, the conversion of the serous fluid into blood is chiefly effected in the lymphatic system, and it has been a favourite hypothesis with many physiologists, that those organs, regarding whose functions we are so profoundly ignorant, and whose development is so much greater during intra-uterine than extra-uterine existence, — as the thymus, and thyroid glands, and the supra-renal capsules, — are, *in some way, connected with the lymphosis or haematosis of the foetus. We have already referred to the conjectures, that these organs are diverticula for the blood of those parts, the functions of which are not exerted until an after period of existence. Brous- saisb makes the thyroid a diverticulum to the larynx ; the thymus a diverticulum to the lungs, and the supra-renal capsules to the kidneys. Notwithstanding these ingenious speculations, however, our darkness, with regard to the true functions of these singular organs, is not the less impenetrable. To conclude. The most plausible opinion we can form on this intricate subject is, that the mother secretes the substances, which 1 Epistol. ad S. Th. Sbmmering, De Functione Placentae Uterinaj, Erlang. 1799. See, also, Richerand, op. cit., 13eme £dit. § ccvi. b Commentaires des Propositions de Pathologic, &c. Paris, 1829, or Drs. Hays and Griffith's translation, p. 214, Philad. 1832. 42*= 498 EMBRYOLOGY. are placed in contact with the foetus, in a condition best adapted for its nutrition; that in this state they are received into the sys- tem, by absorption, as the chyle or the lymph is received in the adult,—undergoing modifications, in their passage through the foetal placenta, as well as in every part of the system where the elements of the blood must escape for the formation of the various tissues. With regard to the precise nutritive functions executed in the fcetal state, and first as concerns digestion, it is obvious, that this cannot take place to any extent, otherwise excrementitious matter would have to be thrown out, which, by entering the liquor amnii, would be fatal to its important functions, and probably to the very existence of, the foetus. Yet, that some digestion is effected, is manifest from the presence of. meconium in the intes- tines, which is probably the excrementitious matter, arising from the digestion of the mucous secretions of the alimentary canal. 2. Respiration, as accomplished by lungs, does not exist; and we have already seen, that the idea of the fcetus possessing the kind of respiration of the aquatic animal is inadmissible. An analogous function to the respiration of the adult, however, occurs, as respects the changes effected upon the blood. It is probable, that the blood is sent to the placenta to be aerated there, as it is in the lungs, in extra-uterine existence. Such was the opinion of Sir Everard Home, of Girtanner, Stein,a and we may say, such is the opinion of many of the most enlightened physiologists of the present day. The chief arguments adduced in support of this opinion are, — the absolute necessity for aeration to every living being, animal or vegetable ; the no less necessity for a free circu- lation of blood — along the umbilical cord to and from the pla- centa to the life of the foetus; and the analogy of birds, in which the umbilical vessels are inservient to respiration by receiving the external air through the pores of the shell, so that if the shell be greased, respiration is prevented, and the chick dies.b The sensible evidences of these changes being effected by the placenta are not like those, which we possess regarding the aera- * tion of the blood in its passage through the lungs of the adult, where the venous differs so essentially from the arterial blood. It is indeed asserted, in works of anatomy, that «the effete blood of the umbilical arteries becomes regenerated in the pla- centa assumes a brighter hue, and is returned to the foetus by the umbilical vein," but this is not in accordance with experiment ana observation. Bichat' made numerous dissections of young lft2^eM^'8'H.andb,UC^ U> s" T-,J°Urdan and Bres<*et's Fr. translation, iii. 793, Paris, 182o , Meigs s translation of Velpeau, edit. cit. p. 225 ; and Granville's Graphic Illus trationsof Abortion, p. xviii. Lond. 1834. "Mpmc inus ■> Varnishes of organic animal matters, as albumen, gelatin, &c., have no effect in Ke,Tl85 UanSmiSS10n °f air' See Mr' Towne, Guv's Hospital Re^Oa et iJ^t"^! ParU'1818 5 3nd ReSCarCheS ******>» - ^ Vie RESPIRATION OF THE FOZTUS. pigs whilst yet in utero,. and he uniformly found the \)lood of the arteries and veins presenting the same appearance and resem- bling the venous blood of the mother. Not the slightest difference was observed between the blood of the aorta and that of the vena cava, or between that of the carotid artery and of the jugular vein. He made the same observations in three experiments of a similar kind on foetuses of the dog. He also frequently examined human foetuses that had died in utero, and always found the same uniformity between the arterial and venous blood: hence he con- cludes, that there is no difference between the arterial and venous blood of the fcetus, at least in appearance. Similar experiments by Autenrietha furnished like results. Dr. Granville, too, affirms, that he has never been able to detect the least difference between the arterio-umbilical and venous-umbilical blood in the many cases he has examined,b and it is important to bear this fact in mind, inasmuch as it may be received as one of the evidences that a foetus has not respired. The apparent identity, however, between the blood passing to the placenta by the umbilical arteries and that returning by the cord cannot be real. The slightest reflection will show, that they must be different, and such is the opinion, from observation, of Bostock,c Jeffrey,d and others. It isfrom the blood, carried by the umbilical vein and distributed over the body, that all the organs of the fcetus have to derive the materials of their nutrition and development; and being deprived of these mate- rials, the fluid must necessarily be different in the umbilical arte- ries from what it was in the umbilical vein. The researches of more modern chemistry have not been directed to the foetal blood, but Fourcroye analyzed it, and found it to differ materially from the blood of the child that had respired. He asserts, that its colouring matter is darker, and seems to be more abundant; that it is desti- tute of fibrin and phosphoric salts, and is incapable of becoming florid by exposure to the influence of atmospheric air. It has been found, too, that the globules of the foetal blood do not resemble those of the blood of the mother. The fact, however, of the similarity in appearance between the arterial and venous blood of the foetus, is no evidence that respiration is not one of the foetal functions, inas- much as the same thing is observed in fishes. Under the head of circulation it was remarked, that the coloration of the blood is per- haps of no farther importance than as indicating that the vital change of aeration has taken place in the lungs. In this case, we have the vital change effected without any such coloration. Yet » Dissertatio Sistens Experimenta circa Calorem Fcetus, et Sanguinem Ipsius In- stituta, Tubing. 1799 ; also, Velpeau, by Meigs, p. 224. b Graphic Illustrations, &c, p. 20. See, also, J. Miiller's Handbuch, u. s. w., Baly's translation, p. 318, Lond. 1837; Richerand, Elemens de Physiologie, 13eme edit, par Berard ain6, § ccviii.; Cuvier, Legons d'Anatomie Compared, iv. 298, Paris, 1799 ; and Adelon, Physiologie de I'Homme, 2de edit. iv. 405. « Op. cit. System of Anatomy. 3d edit, edited by Dr. Horner, a. 76, Philad. 18-44. « Precis Elementaire de Physiologie, 2de edit. ii. 550, Paris, 1825. EMBRYOLOGY. 50« batier regarding the use of the valve of Eustachius and the non-ad- mixture of the blood of the two cavse in the right auricle. In their opinion, the two bloods do commingle ; but — owing to the existence of the foramen ovale, and the arrangement of the valve of Eustachius — the left auricle is filled simultaneously with the right; and, consequently, the same kind of blood must be distributed to both the upper and lower portions of the body. The uses of the foramen ovale and ductus arteriosus are explained as follows. As the left auricle receives but little blood from the lungs, it could furnish but a small quantity to the left ventricle, did it not receive blood through the foramen ovale ; and again, as the lung is exert- ing no function, during the state of foetal life, the blood is sent along the pulmonary artery and ductus arteriosus into the aorta, so that the contraction of both ventricles is employed in propelling the blood along the aorta to the lower parts of the body and to the placenta. Without this union of forces, it is conceived, that the blood could not be urged forward as far as the placenta. Experiments, by Dr. John Reid,a favour the views of Wolff and Sabatier. He took a foetus of about seven months, and threw simultaneously a red-coloured injection up the vena cava inferior, and a yellow-coloured one down the vena cava superior. On tracing the red injection upwards, it was found to have passed through the foramen ovale and to have filled the left side of the heart, without any intermixture with the yellow, except very slightly at the posterior part of the right auricle. Not a drop of the yellow appeared to have accompanied the red into the left side of the heart. From the left side of the heart it ascended the aorta, and filled all the large vessels going to the head and upper extre- mities. The injection, in all these vessels, had not the slightest tinge of yellow. On tracing the yellow injection downwards, he found it rilling the right auricle and the right ventricle, whence it proceeded along the pulmonary artery, and filled the ductus arte- riosus, and branches going to the lungs. On entering the aorta, it passed down that vessel, filling it completely without any ad- mixture of red, so that all the branches of the thoracic and abdo- minal aorta were filled with the yellow. From this and other experi- ments of a similar kind, Dr. Reid infers, that the blood, returning from the placenta; passes principally to the head and upper extre- mities ; and that the lower part ^f the body is principally supplied t by blood returning by the vena cava superior; or, in other words, by blood which has already gone the circuit of the body. Recent observations by Dr. T. Williamsb have convinced him, notwithstanding the opposing experiments of Dr. Reid, that the Eustachian valve is mechanically inefficient as a means for pre- serving the individuality of the two currents from the vena cava as they traverse the right auricle ; and he affirms, that at the period of its diastole, when the auricle has attained a moderate limit of » Edinb. Med. and Surg. Journal, xliii. 308. b Lond. Med. Gazette, March 31, J843. MONSTROSITIES. 503 distension, it may be readily demonstrated, that the two streams must freely intermingle. Hence it is not true — he infers — that the difference of quality is so great, as is generally taught by ana- tomists, between the blood that is distributed to the two portions of the body in the foetus. After all, the great difference between the adult and foetal circu- lation is,— that in the former, a part of the blood only proceeds to the organ of sanguification ; that the aerated blood is poured into the right auricle instead of the left; that, instead of proceeding through the lungs, a part of the blood gets at once to the left side of the heart, whence it is sent to the head and upper extremities, and the remainder goes directly from the pulmonary artery into the aorta ; and that a part of the aortic blood proceeds to the lower extremities, and the remainder goes to the placenta, from which it is returned into the inferior cava. 4. With regard to the nutrition, (properly so called,) of the foetus, it is doubtless effected in the same manner as in the adult; and our ignorance of the precise nature of the mysterious process is equally great. During the whole of foetal existence, it is energetically exerted, and especially during the earlier periods. Sommering has asserted, that the growth of the foetus fluctuates ; that in the first month it is greatest; in the second, less; in the third, greater; less, again, in the fourth; and then greater until the sixth, when it diminishes until birth. There is, by the way, a singular circumstance connected with the nutrition of the foetus, which cannot be passed over without a slight notice, although, in its details, it belongs more properly to pathological anatomy. Owing to inappreciable causes, the different parts of the fcetus, or some particular part, may be preternaturally developed, or b,e defective, so as to give rise to anomalies of con- formation, or what have been termed monstrosities. Three kuids of monsters may be considered to exist. The first comprises such as are born with an excess of parts, as with two heads on one trunk, two trunks to one head; with four arms and four legs; twins with a band uniting them, as in the case of the Siamese twins, &c. The second includes those in which parts are defec- tive, as acephali, anencephali, &c.; and the third, those in which there is perversion of the formative process, so as to produce various modifications in the direction and situation of organs, — as where the heart is on the right side, the liver on the- left, &c.; where, in other words, there is transposition of the viscera. In these cases there is — to use the language of the German pathologists—super- abundant, defective, ox perverted action of the force of formation __the Bildungstrieb — to which we have more than once alluded. The hypotheses, that have been advanced to account for these formations, as well as for those in which the parts are irregularly developed, may be reduced to three; the others, that have been entertained, having no probability in their favour. First. They 504 EMBRYOLOGY. have been attributed to the influence of the imagination of the mother over the foetus in utero. Secondly. To accidental changes experienced by the fcetus at some period of uterine existence ; and Thirdly. To some original defect or fusion of the germs. The first of these causes has been a subject of keen controversy amongst physiologists, at all periods. We have seen, that the mother trans- mits to the foetus the materials for its nutrition ; and that, to a certain extent, the nutrition is influenced by the character of the materials transmitted; so that if these be not of good quality or in due quantity, the foetus will be imperfectly nourished, and may even perish. Any violent mental emotion may thus destroy the child, by modifying the quantity or quality of the nutritive matter sent to it. Small-pox, measles, and other contagious diseases can also be unquestionably communicated to the foetus in utero; so that the life of the fcetus is indirectly but largely dependent upon the condition of the mother. But the maternal influence has been conceived to extend much beyond this ; and it has been affirmed, that the excited imagination of the mother may occasion an altera- tion in the form of particular parts of the foetus, so as to give rise to nsevi, and to all kinds of mother's marks, as they have been termed. These may consist of spots resembling raspberries, grapes, &c.; or there maybe deficient formation of particular parts,— and some of the cases that have been adduced in favour of their having been induced by impressions, made upon the mother during pregnancy, are sufficiently striking. There are numerous difficul- ties, however, in the way of accepting the cause assigned. If a child be born with nsevi of any kind, the recollection of the mother is racked to discover whether some event did not befall her during gestation to which the appearance may be referred, and it is not often difficult to discover some plausible means of explanation. Cases have occurred in which the mother, when a few months advanced in pregnancy, has been shocked by the sight of a person who had lost a hand, and the child has been born with the same detect. A young female, a few months gone with child, visited a brother in one of the hospitals of London, who was wounded in the side His condition affected her extremely. Her child was hrZZ1 ™P PIt in the Same Part that was wounded in the hfl Th,ese ar? samPles of the thousands of cases that have ™Zt < ' °u that haVe °CCUn'ed to'different individuals.- Si- Sp PTtr^nfe8 T QVen been related of the inferior animals- In don 11 To Jn°rf the mmUu b°°k °f ,he Linnean Society of Lou- ff '. ffu 1S ^n, by Mr. George Milne, F.L.S, of the noon whttM^M3!1011 ^T^ Cat°» her young One after- noon, whilst Mr. Milne and his family were at tea a vouno- female breamed violent ,/h r ^u'' tro-d ""'* heavi|y °" bit mil; she screamed violently, and from the noise emitted, it was evident, lha. ruLt^^" P°°VOir "e "-i""*- -'I. Pulque etteMoraU. MONSTROSITIES. 505 a considerable degree of terror was mingled with the feeling from the injury. From so common a circumstance no extraordinary result was expected; but, at the full time, she dropped five kittens, one of which was perfect, but the other four had the tail remark- ably distorted; and all distorted in the same manner.8 Are we to consider these and similar cases of malformation or monstrosities to be dependent upon the influence of the maternal imagination upon the foetus in utero ? Or are we to regard them as coincidences, the cause being inappreciable, but such as we find to give occasion to vicious organization, where no coincidence with excited imagination can be discovered ? Under the head of genera- tion we have combated the notion, that the mother's fancy can have any effect—as to sex or likeness—during a fecundating copulation. Let us see, then, what we have to admit in a case where a female is, we will suppose, four months advanced in pregnancy, when she is shocked at the appearance of one who has] lost his arm, and the child is born with a like defect. It has been seen, that the com- munication between the mother and the foetus is of the most in- direct character; that the circulation of the foetus is totally distinct from that of the mother; and that she can only influence the foetus through the nutritive material she furnishes—whatever be its character — and, consequently, that such influence must be exerted upon the whole of the fcetus, and not upon any particular part. Yet7 in the supposititious case we have taken, the arm must have been already formed, and the influence of the mother's fancy must have been exclusively exerted upon its absorbents, so as to cause them to take up again that which had been already deposited ! The case we have assumed is not environed with more difficulty than any of the kind. It is a fair specimen of the whole. Yet how impracticable for us to believe, that the effect can be in any way connected with the assigned cause, and how much more easy to presume, that the coincidence, in such cases, has been accidental. Cases of hare-lip are perpetually occurring, yet we never have the maternal imagination invoked ; because, it is by no means easy to discover any similitude between the affection and common extra- neous objects. Moreover, in animals of all kinds — even in the most inferior, as well as in plants — monstrous formations are in- cessantly happening where maternal imagination is out of the question. As a cause of monstrosities, therefore, the influence of the maternal imagination has been generally regarded as an inadmis- sible hypothesis. By many, it has been esteemed ridiculous ; yet it manifestly receives favour with Sir Everard Home ;b and Pro- fessor Elliotson,0 and Burdachd appear inclined to favour it; but on the whole we are justified in adopting the opinion of Dr. Blundell, 1 Fleming's Philosophy of Zoology, vol. i. Edinb. 1822. b Philos. Transactions for 1825, and Lect. on Compar. Anat. v. 190, Lond. 1828. c See his translation of Blumenbach's Physiology, 4th edit. p. 497, Lond. 1828. d Die Physiologie als Erfahrungswissenschaft, B. ii,; see, also, Pierquin, in Ma- gendie's Journal de Physiologie, x. 364. VOL. II. — 43 506 EMBRYOLOGY. which has been embraced by Drs. Allen Thompson* and Wag- ner,b that it is contrary to experience, reason and anatomy, to believe, that the strong attention of the mother's mind to a deter- minate object or event can cause a determinate or a specific im- pression upon the body of her child, without any force or violence from without; and that it is equally improbable, that, when the imagination is operating, the application of the mother's hand to any part of her own body, will cause a disfiguration or specific impression on a corresponding part of the body of the child ! The third hypothesis, with regard to defective germs, we have already canvassed under Generation, and attempted to prove it insuffi- cient. The second, consequently, alone remains, and is almost universally adopted. Independently of all disturbing influences from the mother, the fcetus is known to be frequently attacked with spontaneous diseases, such as dropsy, ulceration, gangrene, cutaneous eruptions, &c. Some of these affections occasionally destroy it before birth. At other times, it is born with them ; and hence they are termed connate, or congenital* The following table, drawn up by Mr. Wilde,dfrom the records of the Gebdranstalt, of Vienna, exhibits the malformations observed there in 23,413 births. Clubfoot . . 16 cases, or once in 1463-31 Hare lip - • 20 - . 1170-65 ------simple - . 9 . . 2601-44 ------with cleft palate ■ - 11 - . 2128-45 Spina bifida . ■ 5 . . 4682-6 Hydrocephalus - ■ 6 . - 3902-16 Six fingers - - 3 . - 7804-33 Inperforate anus - - 2 . ■ 11706-5 Hemicephalus - - 1 ■ ■ 23413 Acephalus . . 1 . . 23413 Umbilical hernia - . 1 . . 23413 Without eyes - - . 2 . . 11706-5 Wanting superior part of vertex - 1 . . 23415 Lenticular cataract - - 1 . . 23413 Wanting one upper extremity - 2 . . 11706-5 With plurality of fingers ; md toes - 5 . . 4682-6 Hydrocephalus with spina bifida, and closed anus I . . 23413 Clubfoot and closed anus - . 1 . . 23413 In a population, consequently, chiefly illegitimate, 88 deviations from the natural type occurred in 23,413 births, or about 1 in every 266 eases. According to the last census of the United States, (1840,) the proportion of deaf and dumb, amongst the whites, was 1 in 2123; amongst the coloured, 1 in 2933.e Where a part has been wanting, the nerve, or bloodvessel, or » Art. Generation, Cyclop, of Anat. and Physiol. P. xiii. p. 477, February, 1838. b Elements of Physiology, transl?*«d by Dr. Willis, p. 227, note, Lond. 1841. c J. Gr'atzer, Die Krankheiten des Foetus, Berlin, 1837, and Dr. W. C. Roberts, Amer. Journ. of the Med Sciences, Aug. 1840, and Oct. 1841. by many ob- servers, whose contributions are well worthy of perusal. Amongst the most important are those of Frankel, Raschkow, Retzius, Ar- * nold, Goodsir,0 Owen, and Nasmyth ;d and a recent writer has » The Anatomy, Physiology, and Diseases of the Teeth, Lond. 1829. See, also, Dr. Ashburner, Lectures on Dentition, Med. Gaz. 1833-34. b See M. Trousseau, Gaz. Med. de Paris, 4 F6v. 1842; and Amer. Journ. of the Med. Sciences, July, 1842, p. 165. c Edinb. Med. and Surg. Journ. Ii. See, also, for an account of his views, Car- penter, Human Physiology, § 632, Lond. 1842. d J. Muller, Elements of Physiology, by Dr. Baly, p. 391, and part iv. chap. 2, appendix; and Nasmyth, Researches upon the Development and Structure of the Teeth, London, 1839 and 1841; Mr. Robert Nasmyth, in Lond. and Edinb. Monthly Journal of Med. Science, Jan. 1843, p. 40; and R. Owen, Odontography, part i. Lond. 1840. See, also, Brit, and For. Med. Rev., July, 1839, p. 158, and Oct. 1841, p. 491. 2. The separate temporary Teeth of each Jaw. SECOND PERIOD OF mFANCT. 519 remarked, that in no organs have the results of recent microscopic researches been so unexpected or so brilliant.3 These researches have shown the teeth to be composed of three main constituents. 1. The crusta petrosa, which differs in its minute structure in no respect from common osseous tissue. It forms the outermost layer of the teeth, visibly surrounds the whole fang, and extends, ac- cording to Mr. Nasmyth, in a very thin layer over the enamel of the crown. 2. The enamel, which invests only the crown of the teeth, and is composed of solid prisms or fibres about ^Voth °f an inch in thickness-set side by side upright on the ivory ; and 3. The dentine or ivory, which forms the chief mass and body of the teeth, which is composed of a fibrous basis, traversed by very fine, branching, cylindrical tubuli, which run in an undulating course from the pulp cavity on the interior of which they open towards the adjacent part of the exterior of the tooth. The basis of the intertubular substance, according to Henle, is composed of bun- dles of flat, pale, granular fibres, the course of which is parallel to that of the tubules. Dentition is necessarily a physiological process, but it is apt to be a cause of numerous diseases. The whole period of its con- tinuance is one of great nervous susceptibility, — so that the sur- geon never operates during it, unless compelled, — and we can understand, that the pressure, exerted by the tooth on the gum, and the consequent inflammation and irritation, may lay the foundation for numerous diseases. More are doubtless ascribed to the process than it is entitled to, but still they are sufficiently numerous; and all require in their management the free division of the distended gum, so as to set the presenting part of the tooth at liberty. Whilst the teeth are appearing,the muscular structure of the body generally is acquiring strength, and the salivary organs are described by anatomists as becoming much more developed. The food of the child is now diversified, and it begins to partici- pate in the ordinary diet of the table. The excrementitious matters are consequently altered in their character, particularly the alvine, which become firmer, and acquire the ordinary faecal smell; the urea is still, however, in the generality of cases, in less proportion than in the adult. The other functions require no par- ticular mention. The number of deaths, during this period, is great. The bills* of mortality of London, as has been elsewhere remarked, show, that the deaths, under two years of age, are nearly thirty per cent. of the whole number. In Philadelphia, during a period of twenty years ending with 1826, the proportion was rather less than a third. The cholera of infants is the great scourge of our cities during the summer months, whilst in country situations it is com- paratively rare ; and it is always found to prevail most in crowded alleys, and in the filthiest and impurest habitations. There is » Mr. Paget, Brit, and For.Med. Rev., July, 1842, p. 270. 520 AGES. something in the confined and deteriorated atmosphere of a town, which seems to act in a manner directly unfavourable fo human life, and to the life of the young especially. This is not confined to man. It is applicable also to the animal. Experiments were instituted by Jenner, and since him by Dr. Baron,a which show that a privation of free air and of their natural nourishment has a ten- dency to produce disorganization and death. Dr. Baron placed a family of young rabbits in a confined situation, and fed them with coarse green food, such as cabbage and grass. They were perfectly healthy when put up. In about a month, one of them died,— the primary step of disorganization being evinced by a number of transparent vesicles on the external surface of the liver. In another, which died nine days after, the disease had advanced to the formation of tubercles in the liver. The liver of a third, which died four days later, had nearly lost its true structure, so completely was it pervaded by tubercles, Two days afterwards, a fourth died ; a number of hydatids was attached to the lower surface of the liver. At this time, Dr. Baron removed three young rabbits, from the place where their companions had died, to another situation, dry and clean, and to their proper accustomed food. The lives of these were obviously saved by the change. He obtained similar results from experiments of the same nature performed on other animals.b c. Third period of Infancy. — This requires no distinct consi- deration ; — the growth of the child and activity of the functions going on as in the preceding period, but gradually acquiring more and more energy. Within this period, a third molar tooth appears, which is not, however, temporary, but belongs to the per- manent set. During the whole of infancy, the dermoid texture — both skin and mucous membranes — is extremely liable to be morbidly affected ; hehce, the frequency of eruptive diseases, and of diar- rhoea, aphthae, croup, bronchitis, &c, many of which are of very fatal tendency. Owing, also, to the susceptibility of the nervous system, convulsions, hydrocephalus, and other head affections are by no means infrequent. 2. CHILDHOOD. • Childhood may be considered to extend from the seventh to the fifteenth year, or to the period of puberty ; and it is particularly marked by the shedding of the first set of teeth, and the appear- ance of the second. It is manifest, that in the growth of the jaws with the rest of the body, the teeth, which, for a time, may have been sufficient in magnitude and number, must soon cease to be » Delineations of the Origin and Progress of various changes of Structure which occur in Man, and some of the inferior Animals, Lond. 1828. b See the author's Elements of Hygiene, p. 138, Philad. 1835; and art. Longevity, in American Quarterly Review, viii. 380, Philad. 1830. CHILDHOOD. 521 Fig. 280. so ; hence, the necessity of a fresh set, which may remain per- manently. The process for the formation of the permanent teeth is similar to that of the milk or temporary teeth; yet it presents some remarkable points of difference ; and it affords us another surprising instance of the wonderful adaptation of means to defi- nite objects, of which we have so many in the human body. This process is well described by Mr. Bell,a whose opportuni- ties for observation have been unusually numerous, and whose zeal and ability in his profession, as well as in the prosecution of natu- ral science, are well known. The rudiments of the permanent teeth are not original, and inde- pendent, like those of the temporary. They are derived from the latter, and continue, for a considerable time, attached to, and inti- mately connected with them. At an early period in the forma- tion of the temporary teeth, the investing sac gives off a small pro- cess or bud, containing a portion of the essential rudiments, namely, the pulp covered by its proper membrane. This constitutes the rudiment of the permanent tooth. It commences in a small thickening on one side of the parent sac, which gradually becomes more and more circumscribed, and at length as- sumes a distinct form, though still connected with it by a pedicle. For a time, the new rudiment is contained within the same alveolus as its generator, which is exca- vated by the absorbents for its reception. It is not, according to Mr. Bell, in consequence of the pressure of the new rudiment upon the bone, that this absorp- tion is occasioned, but by a true process of anticipa- tion ; for he states, that he has seen, in the human sub- ject — and still more evidently in the foal — the com- mencement of the excavation before the new sac was formed, and, consequently, before any pressure could have taken place on the parietes of the socket. The absorption does not, indeed, begin in the smooth sur- face of the socket, but in the cancelli of bone immedi- Temporary t00th atelv behind it. Bv degrees, a small recess is thus and permanent } , . ■ /. ■ ii • i - i ^u rudiment.— (1- formed in the paries of the alveolus, in which the new BeU.) rudiment is lodged, and this excavation continues to increase with the increasing size of the rudiment; whilst, at the same time, the maxillary bone becomes enlarged, and the tem- porary tooth, advancing in its formation, rises in the socket. The new cell is thus gradually separated from the other, both by being itself more and more deeply excavated in the substance of the bone, » The Anatomy, Physiology, and Diseases of the Teeth, Lond. 1829. 44* o. Permanent rudiment given off from the temporary in an incisor. b. Permanent rudiment given off from the temporary in a molaris. — (T. Bell.) 522 AGES- and also by the formation of a bony partition between them, as seen in the marginal figure, 2S1, which exhibits the connexion be- tween the temporary tooth and the permanent rudiment, as it exists after the former has passed through the gum. As the temporary tooth grows and rises in the jaw, the connecting cord or pedicle elongates, and although the sac, from which it is derived, is gradu- ally absorbed, it still remains attached to the neck of the temporary tooth. The situation of each permanent rudiment, when its cor- responding temporary tooth Fig- 282. nas made its appearance , \ through the gum, is deeper in the jaw and a little behind the latter, as represented in the marginal illustrations, (Figs. 282 and 283,) of the upper and lower jaw after the whole of the temporary teeth have passed through the gum. From these, it will be understood, how the (^^/PoraryTeeth and Permanent Rudiments-- upper part of the sac of the permanent rudiment, being, by means of the cord connected with the gum, gradually assumes the same relation to the gum as was originally sustained by the temporary rudiment. The ossification of the permanent teeth commences from The permanent teeth, during their formation, are crowded to- gether in the jaw ; but, as soon as they have advanced to a cer- tain point, and can no longer be contained within their own alveoli, absorption of the anterior parietes of those cavities takes place, and the teeth are allowed to come in some measure for- wards. In consequence of such absorption, it frequently happens, that not only the socket of the corresponding temporary tooth, but that of the tooth on each side is opened to the permanent one. Absorption now occurs in the root of the temporary tooth, — generally at the part nearest its successor, and this gradually pro- ceeds as the latter advances, until the root is completely removed, %m %^- CHILDHOOD. 523 when the crown falls off, leaving room for the permanent tooth to supply its place. It does not seem, that this Fig. 284. absorption of the root f yy—{^ /'—' is produced by pressure ^^p (^ on the part of the per- \^-~*^V'r " manent tooth, as it flfe''";^' ■■'V T%^#p■ ■» , often happens, accord- />'^'*/'?/>;/•* » ^'2kl*mJ ) r ing to Mr. Bell, that yjj iM'ikW^Uk ' the root of the tempo- t&MWfM I WliM rary tooth is wholly ab- |#;< J[g§f sorbed, and the crown f /if W' '■ falls out spontaneouslv, ^y^y^l long before the succeed- M f T jj[ JEr, Jfo*v«| fi ing tooth has approach- \j flPlrti ed the vacant space. As 1 j a general rule, however, l||a l4Llit:v^^&v^"' the actions must be re- ^^M^--^^^^^^ " garded consentaneous; ifff^yir and Mr. Bell thinks, fiigW that this absorption re- 1L, '/-■ ii *u * i j ^ywiiiiinyy sembles that, already referred to, for the for- mation of a new cell ^Tu.>and '°wer Te to receive the perma- . . nent pulp, and that it may be termed, like it, a " process of antici- pation." In both instances, the existence, though not the pressure, or even the contact, of the new body is necessary to excite the action of the absorbent vessels ; and we, accordingly, find, that in those cases, by no means unfrequent,in which the temporary teeth retain their situation in the mouth, with considerable firmness, until adult age, the corresponding permanent ones have not been formed. , The following are the periods at which the permanent teeth generally make their appearance. They are extremely irregular, however, in this respect: the estimate must, consequently, be re- garded as a general approximation only. Anterior or first great molares,..... °2 years. Middle incisors, ------- Lateral incisors, ----- Anterior bicuspids, or first lesser molares, - - - » Posterior bicuspids, or second lesser molares, - - " ,, ,„ /,-... , ... 11 or 12 Lanine teeth, ----- Second great molares, ----- I7t20 Third great molares or dentes sapiential, - - - * 17 to <«u When these have all appeared, the set is complete, consisting of thirty-two teeth, sixteen in each jaw,— the number of temporary teeth having been onlv twenty. Fig. 284 represents the uppei ana lower permanent teeth in their alveoli or sockets, the external alveolar plate having been removed to show the mode in wtiicn they are articulated. Fig. 285 represents the same teeth removed from the socket. Fig. 285. b e d e f S a b e d e f g Upper and lower Teeth. a, a. Central incisors. J, 6.Lateral incisors, c, c. Canine teeth. d, d. First bicuspidati. e, e. Second bicuspidati. //.First molares. g,g. Second molares. A, A. Third molares or dentes sapienlia. While the jaws are becoming furnished with teeth and increasing in size, they undergo a change of form, and the branches become more vertical, so as to favour the exertion of force[during mastica- tion. When the teeth issue from the gums, they are most favour- ably situate for the act of mastication ; the incisors are sharp, the canine pointed, and the molares studded with conical asperities; but, in the progress of age, they become worn on the surfaces, which come in constant contact. During the occurrence of these changes, which embrace the whole of the period we are considering, and extend, at times, into the two next, the animal functions, especially that of sensibility, become surprisingly developed, and the intellectual and moral re- sults of a well adapted system of education are strikingly apparent. The nutritive functions are, likewise, performed with energy, the body not yet having attained its full growth ; and, towards the end of the period, the organs of reproduction commence that de- velopment, which we have to describe under the next period. The teeth appear with sufficient regularity to permit some infer- ence to be drawn with regard to the age of the individual, and accordingly it has been proposed by Mr. Saunders8 to make them a test for age in reference to the children employed in the factories of Great Britain. 3. ADOLESCENCE. The commencement of this age is marked by one of the most extraordinary developments, which the frame experiences, and its » The Teeth, a Test for Age, considered with reference to the Factory Children. Addressed to the Members of both Houses of Parliament, Lond. 1837. ADOLESCENCE. 535 termination by the attainment of full growth in the longitudinal direction. The period of the former of these changes is termed puberty ; that of the latter the adult age. The age of adolescence has been considered to extend from fif- teen years to twenty-five, in men ; and from fifteen to twenty-one, in women; but this is only an approximation, like the other divi- sions of the ages, all of which are subject to great fluctuations in individual cases. During the periods we have already considered, no striking dif- ference exists between the appearance of the male and female, except as regards the generative organs; but, about the age of puberty, essential changes occur, that modify the characteristics of the two sexes in a manner, which they maintain through the remainder of existence; and these changes affect the whole of the > economy to a greater or less degree. In the male, the skin loses more or less of its delicacy and whiteness; the hair becomes darker, the cellular tissue condensed, and the muscles more bulky, so that they are strongly marked beneath the surface ; the beard appears, as well as hair upon the pubes, chest, and in the axillae. The different parts of the body become developed in such manner that the centre of the frame now falls about the pubes. The en- cephalon has increased in size, especially at the posterior and inferior part, the cerebellum, and has become firmer. The ossi- fication of the bones, in the direction of their length, terminates towards the end of the period. The muscles become more red and fibrinous, losing the gelatinous character they previously pos- sessed, and, in the animal, exhibiting those striking changes which we see — from veal to beef, from lamb to mutton, &c. The larynx undergoes great augmentation, and the glottis particularly is elon- gated and widened. The jaws complete their growth, and the dentes sapientiae appear so as to make up the full complement of sixteen teeth in each jaw. The changes in the nutritive organs are not great, consisting chiefly in their development to correspond with the increased size of the frame. The greatest modification is produced in the organs of reproduction, which are now in a state to exercise their important functions. The testicles, at the period of puberty, suddenly enlarge so as to attain twice the diameter they previously possessed ; and the secretion of sperm is accom- plished. The penis is also greatly increased in size ; and, accord- ing to Adelon,a "becomes susceptible of erection." The suscep- tibility, however, exists long before this age. It may be noticed even in the first period of infancy. The scrotum assumes a deeper colour. Such are the chief changes that supervene in the male. In the female, they are not quite so striking; — the general habit remaining much the same as during childhood. The skin pre- serves its primitive whiteness; and, instead of the cellular tissue * Physiologie de I'Homme, 2de edit. iv. 448, Paris, 1829. 526 AGES. becoming more condensed, and the muscles more marked, as in the male, fat is deposited in greater quantity between the muscles, so that the form becomes more rotund. New hair appears on the organs of reproduction and in the axillae, whilst that of the head begins to grow more rapidly. The development'of the genital organs is as signal as in the male. The ovaries attain double their previous dimensions; the uterus enlarges ; and a secretion takes place from it which has been elsewhere described — the menstrual flux ; the mons veneris and labia pudendi are covered with hair; the labia enlarge and the pelvis has its dimensions so modified as to render labour practicable. At an early age, the long diameter of the brim is from before to behind; but it now assumes the opposite direction, or from side to side; and the bosom, which prior to this age, could scarcely be distinguished from that of the male, becomes greatly augmented ; fat is deposited so as to give the mammae their rotundity ; the mammary gland is en- larged ; and the nipple of greater size; — changes fitting the female for the new duties which she may be called on to exercise. The functions undergo equally remarkable modifications, under the new and instinctive impulse, which animates every part of animal life. The external senses attain fresh, and peculiar acti- vity ; the intellectual faculties become greatly developed, and this is the period during which the mental character is more modified and improved by education than any other. It embraces the whole time of scholastic application to the higher studies. Prior to the end of the period, the male youth enters upon the avocation which is to be his future support, and both sexes may become established in life in the new relations of husband and wife, and of parent and child. It is during this age that an indescribable feeling of interest and affection is experienced between individuals of the two sexes; and that the boldness of the male contrasts so strikingly with the captivating modesty of the tender female, — " That chastity of look, which seems to hang A veil of purest light o'er all her beauties." The muscles, having acquired their strength and spring, the severer exercises are now indulged, and mechanical pursuits of all kinds, — military or civil, — are undertaken with full effect. The ex- pressions participate in the altered condition of the mental and moral manifestations, and indicate vivacity, energy, and enthu- siasm. The voice of the male acquires a new character, and becomes graver, for reasons assigned elsewhere; whilst that of the female experiences but slight modification. The nutritive functions of digestion, absorption and respiration experience but little change ; but nutrition, strictly so called, is evidently modified, • from the difference which we notice in the development and struc- ture of the various organs. The muscles contain more fibrin; the blood is thicker and richer in globules ; and the excretions mani- VIRILITY OR MANHOOD. 527 fest a higher degree of animalization. Urea has usurped the place of benzoic acid in the urine; and the cutaneous transpiration has lost its acidulous smell, and become rank and peculiar. Lastly, the sexual functions are now capable of full and active exercise, and appear to be intimately connected with the energy and deve- lopment of many parts of the economy. If the genital organs do not undergo the due change at puberty, or if the testes of the male or the ovaries of the female be removed prior to that age, con- siderable modification occurs. This is more manifest in the male, inasmuch as the ordinary changes, that supervene at puberty, are in him more marked than in the female. The removal of the testicles, prior to puberty, arrests those changes. The beard does not appear, nor the hair in the axillae or on the pubes, as in the entire male; and if those animals in which the males are distin- guished by deciduous horns, as the stag, — or by crests and spurs, as the cock,— be castrated before their appearance, such appen- dages never present themselves. If, however, they be castrated after puberty, they retain these evidences of masculine character. The eunuch, likewise, who becomes such after the appearance of the beard, preserves it, although to a less extent than usual. The development of the larynx is arrested by castration, so that the voice retains, with more or less change, the treble of the period prior to puberty ; and hence this revolting operation has been had recourse to for the sake of gratifying the lovers of music. In the course of age, we find that, during the progressive evo- lution of the organs, one set will be liable to morbid affections at one period, and another set at another. In the early ages, the mucous membranes and the head are peculiarly liable to disease; and, at the period we are now considering, affections of the respi- ratory organs become more prevalent. It is, indeed, the great age for pulmonary consumption, — that fatal malady, which, it was supposed by Sydenham, destroys two-ninths of mankind. In the female, whose proper feminine functions do not appear at the due time, or are irregularly exercised, the commencement, — indeed the whole of this period, — is apt to be passed in more or less sickness and suffering. 4. VIRILITY OR MANHOOD. Halle" has divided this age into three periods, — crescent, con- firmed, and decrescent virility. The first of these extends from the age of twenty-five to that of thirty-five in the male, and from twenty-one to thirty in the female; the second from thirty-five to forty-five in the male, and from thirty to forty in the female. Neither of these will require remark, the whole of the functions throughout this work, — when not otherwise specified, — being described as they are accomplished in manhood. Owing to the particular evolution of organs, however, the tendency is not now - so great to morbid affections of the respiratory function. It is more especially the age for cephalic and abdominal hemorrhage ; 528 AGES. accordingly, apoplexy and hemorrhoidal affections are more fre- quent than at any previous period. In decrescent virility, — in which Hall6 comprises the period of life between forty and fifty in the female, and between forty-five and sixty in the male, — signs of decline are manifest. The skin becomes shrivelled and wrinkled; the hair is gray, or white and scanty; the teeth are worn at the top, chipped, loose, and many, perhaps, lost. The external senses, especially the sight, are more obtuse, partly owing to a change in the physical portions of the organ, so that powerful spectacles becomes necessary, and partly owing to blunted nervous sensibility. Owing to the same cause, the intellectual faculties are exerted with less energy and effect, and the moral manifestations are more feeble and less ex- citable. Locomotion is less active, owing to diminution in the nervous power, as well as probably to physical changes in the muscles, so that the individual begins to stoop,— the tendency of the body to bear forwards being too great for the extensor mus- cles of the back to counteract. The expressions participate in the condition of the intellectual and moral acts, and are, consequently, less exerted than in former periods. The nutritive functions do not exhibit any very remarkable change, and will even remain active until a good old age. The functions of reproduction show the greatest declension, especially in the female. The male may preserve his procreative capabilities much longer than this period, but in the female the power is, usually, entirely lost, the loss being indicated by the cessation of menstruation. After this, the ovaries shrivel, the uterus diminishes in size, the breasts wither, the skin becomes brown and thick, long hairs appear on the upper lip and chin, and all those feminine points are lost, which were previously so attractive. The period of the cessation of the menses is liable to many different disorders, which are the source of much annoy- ance, and are, at times, attended with fatal consequences. Prior to their total disappearance, they generally become extremely irre- gular in their recurrence, sometimes returning every fortnight, de- bilitating by their frequency, and by the quantity of the fluid lost, and laying the foundation, in many cases, for uterine or other dis- eases of a serious character. Cancerous affections of the mammae or labia, which had been previously dormant or not in existence, now arise or become developed, and at times with extreme rapi- dity. In consequence of the great liability to such affections, this has been called the critical age, critical period or critical time of life or turn of life. The danger to the female is not, however, so " critical" at this period as \he epithet might suggest, — the statistical researches of De Chateauneuf and of Lachaise, Finlai- sona and others having shown, that between the ages of forty and fifty no more women die than men.b M. Constant Saucerotte has, indeed, attempted to show by statistics on a great scale, that the » Reports on the Evidence and Elementary Facts on which the tables on Life An- nuities are founded, Lond. 1829. b Dr. D. Davis, in Principles, &c, of Obstetric Medicine, i. 290, Lond. 1836. OLD AGE. 529 mortality amongst women is* greater between the ages of thirty and forty than between forty and sixty ; and Jvluret, in his statis- tics of the Pays du Vaud, did not find between forty and fifty a more critical age than between ten and twenty.* 5. OLD AGE. This is the age when every thing retrogrades. It is the prelude to the total cessation of the functions, where the individual expires, — which is but rarely the case,— from pure old age. This period, has been divided into three stages : —'- incipient or green old age, reaching to seventy years; confirmed old age or caducity, to eighty-five years ; and decrepitude, from eighty-five years upwards. In incipient or green old age, the declension, which had oc- curred in the period of decrescent virility, is now more evident. The intellectual and moral manifestations exhibit more marked signs of feebleness; and the muscular powers totter, and require the aid of a support, —as well to convey a part of the weight of the body to the ground, as to enlarge the base of sustentation. The muscles of the larynx participate in this general vacilla- tion ; the " Big manly voice. Turning again towards childish treble, pipes And whistles in the sound," and is broken and tremulous. The appetite is great, and the powers oftdigestion are consider- able; but mastication is largely deteriorated. In the first place, the teeth fall out, in consequence of the constant deposition of fresh layers in the dental cavities, which ultimately close them, and obliterate the vessels that pass to the internal papillae for their nutrition. As soon as the teeth have fallen out, the alveolar processes, which supported them, waste away by absorption, and the depth of the jaw is thus greatly lessened. On these accounts, the jaws only approach each other at the forepart; the chin projects, and the angle of the jaw is thrown more forward. As the teeth and the sockets disappear, the alveolar margins become thin and sharp, and the gum hardens over them ; the chin and nose necessarily approach (Figs. 286 and 287), the lips fall in, and the speech is inarticulate. We can thus understand the peculiari- ties of the mastication of the aged. They are compelled to bite with the anterior portions of the jaws; for which reason, as well as owing to the greater obliquity of the insertion of the levator muscles of the lower jaw, but little force can be exerted ; and owing to the too great size of the lips, the saliva cannot be re- tained. Respiration is not as readily accomplished, partly owing to the complete ossification of the cartilages of the ribs, but » Churchill, Outlines on the Principal Diseases of Females ; Dunglison's American Medical Library Edit., p. 82, Philad. 1839; or Professor Huston's edit., Philad. 1842. VOL. II. —45 530 AGES. Skull of the Aged. —(Sir C. Bell.) chieflv to diminished muscular powers. The valves of the heart and many of the bloodvessels, especially of the extremities, be- come more or less ossified, and the pulse is somewhat slow and intermittent, but generally perhaps faster than in the adult. Of ' 255 women — between Fig. 286. the ages of 60 and 96 — examined by MM. Hour- mann and Dechambre8 — the average number of pulsations in the mi- nute was 82-29 ; of re- spirations, 21-79. Nutri- tion is effected to such a degree only as to keep the machine in feeble ac- tion ; and animal heat is formed to an inadequate extent, so that the indi- vidual requires the aid of greater extraneous warmth : in many cases, the powers of reproduction in the male are completely lost. In confirmed old age, the debility of the various functions goes on augmenting. The mental and corpo- real powers almost totter to their fall, and often a complete state of dementia or dotage exists. Fre- quently, however, we are gratified to find full intellectual and moral enjoy- ment prevailing even after this period, with the possession of considerable cor- poreal energy. The author has had the honour to enjoy the friendship of two illustrious individ- uals of this country, who had filled the highest office in the gift of a free people, both of whom are now no more ; each of these gentlemen exhibited, after the lapse of * Archiv. General, de Me"dec. 1825. Physiognomy of the Aged.—(Sir C. Eell.) OLD AGE. 531 eighty-three summers, the same commanding intellectual powers and the same benevolence that ever distinguished them. In this stage, locomotion becomes more difficult; the appetite is considerable, and the quantity eaten at times prodigious, the diges- tive powers being incapable of separating the due amount of chyle from a quantity of aliment, which was sufficient in the previous ages. Difficulty, however, sometimes arises in defecation, the muscular powers being insufficient to expel the excrement. From this cause, accumulations occasionally take place in the rectum, which may require the use of mechanical means, — as injections, the introduction of an instrument to break them down, &c. Gene- ration is, usually, entirely impracticable, erection being impossible ; and during the whole of this and the next stage, the urinary organs are liable to disorder — irritability about the neck of the bladder, and incontinence of urine, being frequent sources of annoyance. The density of the lungs — together with the quantity of blood they admit — diminishes with the progress of age ; the thorax itself is gradually accommodated to the change; it becomes atrophied as the lungs are atrophied ; it contracts as they contract, and the diminution in their vascularity, which is always in a ratio with the diminution in texture, shows the direct proportion between the weakened chemical power and the diminished mechanical forces. (Magendie, and MM. Hourmann and Dechambre.) Finally, to this stage succeeds that of decrepitude, so well de- scribed by Shakspeare : " Last scene of all, That ends this strange, eventful history, Is second childishness, and mere oblivion; Sans teeth, sans eyes, sans taste, sans every thing." As You Like It, ii. 7. The loss of power, mental and corporeal, becomes progressively greater; and, in addition to the abolition of most of the external senses — especially those of sight and audition — the intellectual faculties are, perhaps, entirely gone ; all muscular motion is lost, and paralysis requires constant confinement to the bed, or to the easy chair; the excretions are passed involuntarily; sensibility becomes gradually extinct, and life finally flits away as impercep- tibly as the twilight merges in the shades of night. M. Quetelet,3 of Brussels, hasdeduced from extensive observations the relative heights and weights of both sexes at different periods of existence. The results are exhibited in the subjoined diagram. (Fig. 288.) The increase in height is most rapid in the first year, and afterwards diminishes very gradually: between the ages of 5 and 16, the annual increase is very regular. The difference ' Annales d'Hygiene publique, vi. 89 ; and in his work, Sur I'Homme, ct le Deve- lopment de ses Facultis, Bruxelles, 1835; or translation of the same, p. 63, Edinb. 1842. 532 AGES. between the height of the male and female at birth continues to increase during infancy and growth; but it is not very marked until about the 15th year, after which the female grows at a climi- nished rate ; whilst the male goes on in nearly the same degree until about the age of 19. The female, consequently, attains her full height earlier than the male ; — the full height of the latter not being generally attained until about the age of 25. At about 50, Fig. 288. Curves indicating the development of the heights and weight of man and woman at different ages.—(Quetelet.) both sexes experience a diminution of stature, which continues during the latter part of existence. The average heights of the male and female who have obtained their full development are about 3^ times those of the new-born infant of the sexes re- spectively. The relative weight of the sexes corresponds pretty nearly with the height. The preponderance exhibited by the male at birth increases gradually during the first few years ; but towards the period of puberty the proportional weight of the female in- creases; and about the age of 12 there is but little difference between the sexes. After this, however, the weight of the male increases much more rapidly, especially between 15 and 20 : after this, there is not much increase on the"part of the male, although his maximum is not attained until the age of 40; and there is an absolute diminution on the part of the female, whose weight re- mains less during nearly the whole period of child-bearing. After this, however, her weight again experiences an increase, and its maximum is attained about 50. In old age, the weight of both sexes undergoes a diminution in nearly the same degree. The average weights of the male and female who have attained their OLD AGE. 533 full development are twenty times those of the new-born infant of the sexes respectively.3 Such is a brief description of the chief changes, that befall the body in the different ages. To depict them more at length would be inconsistent with the object and limits of this elementary work. It is clear, that, although the divisions, which we have adopted from Halle, are entirely arbitrary, must run into each other, and be liable to numerous exceptions ; — certain well-marked changes occur about the commencement or termination of many of them, aud singular diversity takes place in the successive evolutions of organs : whilst some are predominant at one time, they fall behind others at a previous or subsequent period; and such changes may lay the foundation for morbid affections at one age, in certain organs, which do not prevail at another. The ancients, who believed that great mutations occur at particular intervals, — every three, seven or nine years for example, as the particular number might be at the moment in favour, — compared these periods to knots uniting the different stages of life, and giving the economy a new direction. These knots they called the climateric ox.climacteric years, and they conceived the body to be especially liable to disease at the periods of their occurrence. The majority assigned them to the number seven and its multiples; and the fourteenth and twenty-first years especially were conceived to be replete with danger. Others applied the time climacteric to years resulting from the multiplication of seven with an odd number, and especially with nine ; the sixty-third year being regarded, by almost all, as the gland climacteric. The error, with the ancients, lay, in considering that the numbers exerted any agency. Every one admits the influence of particular evolutions on the health ; and, at the present day, the word climacteric is gener- ally restricted to certain periods of life, at which great changes supervene, independently of any numerical estimate of years; — such as the period of puberty in both sexesj — that of the cessation of the menses, or the critical time of life in the female, &c. It need hardly be remarked, that the different ages we have described, instead of extending through the protracted period of eighty-five years and upwards, may be varied by original consti- tution, climate, habits of life, &,c, so that the stages may be shorter than usual, and all the signs of decrepitude occur many years earlier; and, on the other hand, the period of decrepitude may, through strength of original conformation, and other causes, be largely postponed. » Carpenter, Human Physiology, § 772, Lond. 1842.. 45* 534 SLEEP. CHAPTER II. SLEEP. The difference between the two classes of animal and nutritive functions is strikingly exhibited in the phenomena we have now to consider. Whilst the former are more or less suspended, the latter continue their action with but little modification. The func- tions of sensibility, voluntary motion, and expression, cannot be indulged for any length of time, without fatigue being induced, and a necessity arising for the reparation of the nervous energy which has been expended during their action. After a time,—the length of which is somewhat influenced by habit, — the muscles have no longer power to contract, or the external senses to receive impres- sions; the brain ceases to appreciate; mental and moral manifesta- tions are no longer elicited ; the whole of the functions of relation become torpid, and remain in this state until the nervous system has been renovated, and adapted for the repetition of those func- tions, which, during the previous waking condition, had been ex- hausted. This state constitutes sleep; which, consequently, may be defined — the periodical and temporary suspension of all, or most, of those functions that connect us with the universe. The suspension occurs in those functions and in those only; and hence the consideration of sleep, in many physiological treatises, has im- mediately followed that of the functions of relation. The nutritive functions continue regularly in action from the earliest period of foetal formation ; before mental manifestations exist in the embryo, and during sleep. For them there is no cessation, and scarcely any declension of activity, until the decadency of the frame affects them along with the whole of the machinery. Sleep, in the lan- guage of poetry, has been compared to death ; and Dr. Good8 has stated, that the resemblance between them is not less correct upon the principles of physiology, than it is beautiful among the images of poetry. " Sleep is the death or torpitude of the voluntary. organs, while the involuntary continue their accustomed actions. Death is the sleep or torpitude of the whole." Physiologically, the difference appears to us considerable. During the whole of sleep a process of renovation is probably going on in the organs of animal life, which adapts them for subsequent activity, and contrasts signally with the state of annihilation that constitutes death ; hence the important difference between healthy sleep, and the state of coma induced by any morbid cause ; from which the patient is aroused languid and exhausted, instead of active and recruited.b The foetus in utero is also described by some as being in a perpetual sleep, until aroused by the new actions established » Book of Nature, ii. 226, Lond. 1826. b See the author's Therapeutics, p. 401, Philad. 1836 ; and his General Therapeutics and Materia Medica, vol. ii. Philad. 1843. SLEEP. 535 at birth ; but it appears to us, that there must be, even in this case, alternations of activity and suspension in the nervous functions. We have seen elsewhere, that they are manifestly more or less exerted during intra-uterine existence ; nervous energy must there- fore be expended; and renovation, — to a much less extent, it is true, than in the new-born child, — be necessary. Linnaeus," under the term somnus plant arum, expresses a peculiar state in the con- stitution of many plants during the night, as evinced by a change of position, generally a drooping or folding together of their leaves or leaflets; such a change being occasioned by the withdrawal of the stimulus of light, and, probably, it has been conceived, consti- tuting a state of rest to their vital functions ; but it is obvious, that there can be no similitude between this condition and that of the sleep of animals, which is confined to the functions of relation,— functions that do not even exist in the vegetable. The approach of sleep is indicated by signs, that are unequivo- cal, and referable to the encephalon. The great nervous centre of animal life, feeling the necessity for rest and renovation, an internal sensation arises in it, as well as in the whole of the nervous system over which it presides, termed sleepiness or the sensation or want or desire of sleep, which, provided the waking state has been pro- tracted, ultimately becomes irresistible, and often draws on sleep in spite of every effort to the contrary. It is affirmed, that boys, exhausted by exertion, dropped asleep amid the tumultuous noise of the battle of the Nile; and the fatigued soldier has often gone to sleep amid discharges of artillery. An engineer has been known to fall asleep within a boiler whilst his fellows were beating it on the outside with their heavy hammers. Noises will at first prevent sleep, but the desire is ultimately so invincible, that they cease to produce any effect. In the noisy inns of large towns, where the per- petual arrivals and -departures of travellers keep up an incessant din and confusion, sleep may be for a time withheld, but it ulti- mately supervenes, although the tumult may be even tenfold ; and if the noise should, from any cause, suddenly cease, the individual will probably awake. It is reported of the proprietor of some vast iron-works, who slept close to them, notwithstanding the noise of sledge-hammers, forges and blast-furnaces, that he would imme- diately awake if any interruption occurred during the night. This effect of habit is seen in the infant, which has been accustomed to the cradle. The moment the motion and noise of the cradle, or the sound of the nurse's voice —if she have been in the custom of singing the child to sleep —ceases, it awakes. When the desire for sleep sets in vigorously, the animal func- tions become more obtuse, until they progressively fail to be exerted. The cessation does not occur in allsimultaneously. The power of volition is gradually lost over the muscles ; the eyes cannot be kept open ; the upper eyelid falls, and if we attempt to a Amcenitat. Academ. torn, iv ; and Choulant, in art. Schlaf, Pierer's Anat. Phys. Heal Wbrterb. vii. 257, Altenb. 1S27. SLEEP. raise it again, it appears to be weighed down, the eyeball is directed upwards, and the pupil is contracted ;a the arms fall where gravity would take them ; the extensor muscles of the back, deprived of volition, cease to contract, and the head falls suddenly forwards, occasioning nodding, which rouses the brain to momen- tary action, to be again lost, however. If the individual be in the erect attitude, his limbs bend under him; and if in the sitting posture, the head gradually falls upon the chest; the extensors of the trunk no longer contract with sufficient force to obviate its tendency to fall forwards ; and the attitude, unsupported, cannot be maintained. The same gradual suspension occurs in the mus- cular movements, concerned in speech and in the production of the voice, which becomes feeble, confused, broken, and ultimately lost. In short, all the strictly voluntary muscles have their action suspended, if we except the orbicularis palpebrarum muscle, which, according to Broussais,b now contracts to close the eye and shut off the stimulus of light. If we determine to resist the desire for sleep, we yawn and stretch, for the reasons elsewhere assigned, and endeavour to arouse the functions to renewed activity. If the state of wakefulness have not been long protracted, we are suc- cessful ; but all our endeavours fail, if the nervous system be so far exhausted as to render reparation indispensable. From the commencement of sleepiness, the action of the senses is enfeebled, and gradually suspended. The sight yields first, the closure of the eyelids preventing the organ from being impressed by its special irritant. The smell yields after the taste ; the hearing after the smell; and lastly, the touch sleeps ; although the appropriate irritants may continue to reach the organs of these senses. All the internal sensations, hunger, thirst, &c, as well as the morbid sensation of pain, are no longer appreciated. The intellectual and moral manifestations exhibit, from the commencement of the feel- ing of heaviness, the languor which pervades the frame. The will gradually ceases to control the functions that are under its dominion, until ultimately the power of volition is lost. In the less perfect kind of sleep, or in slumber, the ideas flit in a disor- derly manner, constituting a kind of delirium; but when sleep is complete, the whole encephalic organ appears to be at rest, and perceptions are no longer accomplished : special irritants may be applied to the external senses, but they excite no sensation. Many physiologists affirm, that the internal functions of nutrition acquire more energy during sleep ;c but Broussaisd properly disputes the affirmation, and maintains, that the want of action in the senses, muscles, and intellect, must necessarily occasion diminished energy in the nutritive functions. During sleep, circulation and respira- tion appear to be retarded : perspiration is less active, and diges- » Mojon's Leggi Fisiologiche, &c, translated by Skene, p. 34, Lond. 1827. b Traite de Physiologie, &c.; or Drs. Bell and La Roche's translation, 2d Amer. Edit. Philad. 1832. <= Mojon, op. cit., p. 89, Lond. 1827. ' d Qp. citat. p. 183. SLEEP. 537 tion more tardy than in the waking condition. The difference in the last respect is so great, that, as Broussais remarks, the appe- tite recurs many hours before the usual time where long watching is indulged, and an additional meal becomes necessary; proving the truth of the old French proverb, — " qui dor/ dine" —" who sleeps dines." Secretion, nutrition, and calorification are also less energetically performed than usual. Absorption alone, according to some, is more active ; but there seems not to be sufficient reason even for this assertion. This notion of the greater activity of the nutritive organs is as old as Hippocrates, and has'been acquiesced in by almost all subsequent writers without examination, espe- cially as it seemed to show a kind of alternation and equipoise be- tween the respective periods of activity of animal and organic life. During sleep, then, all the animal functions are suspended, and the body generally remains in a state of semiflexion, the one which, as we have elsewhere seen, requires little natural effort. To this, however, there are numerous exceptions depending upon habit. The easiest position for the body is perhaps on the back. It is the one assumed in extreme debility, when the prostration is so great that the individual sinks down in the bed like a dead weight; but the extensor muscles of the thigh and leg, under such circum- stances, become fatigued, and relief is obtained by drawing the feet upwards so as to elevate the knees. This is a common atti- tude in the most debilitating maladies, and is often maintained until within a short time prior to dissolution. Sleep can persist with the exercise of certain muscles. Couriers, on long journeys, will nap on horseback ; and coachmen on their boxes. The author has seen a servant boy erect and asleep in the intervals between the demand for his services at the table. During the first sleep, the suspension of the animal functions is the most complete ; but, towards morning, some of them become less asleep, or more excitable than others. The intellectual and moral faculties are frequently inordinately active, giving occasion to dreams, which, with some individuals, occupy a great portion of the period allotted to rest. The sense of tact, too, is easily roused. If we lie in a position which is disagreeable, it is soon changed; the limbs are drawn away, if irritated in any manner; the clothes are pulled up, if the air is disagreeably cold,&c. The sense of sight and the voluntary motions are least readily aroused, so that those functions, which fall asleep the last, are most easily awakened, and they gradually resume their activity in the order in which they lost it. After six or eight hours of sleep, — more or less according to circumstances, — the individual awakes, not generally at once, however; a state of slumber, like that which preceded sleep, now succeeds it. The organs, which are the last to resume their acti- vity, require to be excited to the performance of their functions. The eyes are rubbed ; stretching is indulged, which recalls the nervous influx to the muscles; and sighing and yawning arouse the muscles of respiration, and compensate, in some measure, for the minor degree of aeration of the blood accomplished during sleep. The urine is discharged, and the phlegm, which may have collected in the air-passages, is expectorated: these excretions have accu- mulated during sleep, because, owing to diminished sensibility, the call for their evacuation has not been as urgent. In cases of catarrh, accompanied by copious mucous secretion, and in phthisis pulmonalis, the fluid will collect in surprising quantity in the air- passages during sleep, and it is expectorated as soon as the brain is sufficiently aroused to respond to the sensation. When the individual is fully awake, the energy, with which the animal functions are exercised, exhibits that the nervous system must have entirely recruited during its state of comparative inaction. The period of sleep, necessary for this purpose, varies in different individuals, and at different ages.' Some require eight or ten hours; others not more than three or four; and others are said to have been contented, throughout the course of a long life, with not more than one or two. Men of active minds, whose attention is engaged in a series of interesting employments, sleep much less than the lazy and the listless. General Pichegru informed Sir Gil- bert Blane,a that in the course of his active campaigns he had, for a whole year, not more than one hour of sleep, on an average, in the twenty-four hours. The great Frederick of Prussia, and the yet more great Napoleon, are said to have spent a surprisingly short time in rest; but with respect to the latter, the fact is contro- verted by one,b who had excellent opportunities for observation. It is probable, that in these cases the sleep is more intense, and that such of the animal functions, as require rest indispensably, are com- pletely suspended during the whole period consigned to it. These are the functions of voluntary motion more particularly; the intellectual and moral faculties requiring a much shorter period of repose, as is manifest by their incessant activity during dreaming,— a condition, which, with some, continues through almost the whole night. The same individual, too, will spend a shorter time in sleep, when strongly interested in any pursuit, than in the mono- tonous occurrences of ordinary life, and, when any subject occu- pies us intently, it will frequently keep us awake in spite of our- selves ; but although the period of sleep may be protracted much beyond the accustomed hour by unusual excitation, the effect of the stimulus becomes insufficient, and sleep comes on under circumstances, which appear most unfavourable to it. The lunatic affords us a wonderful example of powerful resistance to sleep and fatigue, or rather of the short period, which is necessary for the renovation of the nervous system, kept almost incessantly upon the stretch, as it is, in many of these distressing cases. It has been a common remark, that women require more sleep than men, and Georget0 assigns them a couple of hours more,— * Medical Logic, 2d edit. p. 83; see, also, Macnish, Philosophy of Sleep, Amer. Edit. p. 35, New York, 1834; and Elliotson's Human Physiology, p. 602. b Bourrienne, Private Memoirs of Napoleon Bonaparte, Amer. Edit. Philad. 1831. • De la Physiologie du Systeme Nerveux, &c, Paris, 1821. DREAMS. 539 allotting to men six or seven hours, and to women eight or nine; but Dr. Macnisn3 judiciously doubts, whether the female constitution require more sleep than the male : at least, he says, it is certain, that women endure protracted wakefulness better than men, "but whether this may result from custom is a question worthy to be considered." The fact is, however, too general to allow custom to be invoked. It would seem, indeed, that the female frame, although far more excitable than that of the male, is longer in having that excitability exhausted, and that the recu- perative powers are greater, so that the excitability, when ex- hausted, is more readily restored. The notion, that the female needs more rest than the male, appears to be traditionary, and like most traditions, to have been handed down from one indivi- dual to another, without due examination. The degree of mus- cular and mental exertion, to which the male is accustomed, would seem to indicate that a longer period of rest ought to be required by him to admit of the necessary restoration of excita- bility.5 In infancy and youth, where the animal functions are extremely aciive, the necessity for sleep is greatest; in mature age, where time is more valued and the cares are more numerous, it is less indulged; whilst the aged may be affected in two oppo- site ways; they may be either in a state of almost constant somno- lency, or their sleep may be short and light. Sleep has been divided by the physiologist into complete, and incomplete. The former is characterized by suspension of all the animal functions; a state, the existence of which has been doubted by many. Certain it is, that it. can occur but rarely, and only when all the organs have stood in equal need of rest and re- novation ; and when none have preserved, from the preceding state of waking, a peculiar susceptibility for action. The nearest approach to it occurs in the first hours of repose ; after this, it be- comes incomplete; some of the functions are not equally sound asleep, and consequently respond to excitants with different de- grees of facility; and the various organs do not require the same time for reparation, and therefore awake at different intervals; hence, dreams arise, which occur chiefly towards morning, or after the sleep has become incomplete ; that is, when some of the animal functions are more or less actively, but irregularly, exer- cised. 1. DREAMS. Anciently, dreams were regarded as supernatural phenomena, under the control of the children of Somnus or Sleep,— Morpheus, Phobetor or Icelos, and Phantasos. These three children, ac- cording to Ovid,c were capable of transforming themselves into any form ; the employment of Morpheus being to counterfeit the » Op. citat. p. 280. ., ,. b See, on the Hygienic Relations of Sleep, the Author's "Elements of Hygiene, from p. 444 to 455 inclusive, Philad. 1835. <= Metamorphos. xi. v. 592 ad 645. 540 SLEEP. forms of men ; Phobetor imitated the likeness of brutes and ob- jects of terror ; and Phantasos that of inanimate creatures. For a long time dreams were supposed to reveal future events by types and figures ; as when Hecuba dreamed she had conceived a fire- brand, and Caesar that he should lie with his mother; which was interpreted, that he should enjoy the empire of the earth, — the common mother of all living creatures. Oneiromancy was an encouraged art, and ministered largely to the credulity and super- stition of the people. Strange to say, there are yet those, who look upon dreams to be typical and instructive, and consequently supernatural ! Mr. Baxtera and Bishop Newton openly main- tained this doctrine. They divide dreams into two kinds, — good and evil, — and conceive, that two kinds of agents, good and evil spirits, are concerned in their production ; they consequently ac- count for the one or the other sort of dreams, according as the one or the other kind of agents obtains a predominancy !b It is not necessary to combat these views,— which ought of coursetfo be as applicable to animals as to man, — especially as they are uni- versally discarded. Dreaming is now properly considered to be an irregular action of the brain, in which the great controlling power of the will has suspended its agency, and allowed the me- mory and imagination unlimited sway, so that the most singular and heterogeneous ideas are formed, — still kept, however, some- what in train by the force of association. At times, indeed, this influence is so great, that every part of the dream appears to go on in the most natural and consistent manner. We witness scenes that have occurred during our waking hours; and seem to see, hear, walk, talk, and perform all the ordinary offices of life. The mind reasons, judges, wills, and experiences all the various emotions. Generally, the whole process is confined to the brain, but, at times, the muscles are thrown into action, and the expression of the feel- ings and emotions occurs, as in the waking state. The dreamer moves, speaks, groans, cries, sings,&c.,and if the dream concern the generative function, the external organs respond, and emission takes place in the male to such an extent, occasionally, as to constitute a true disease, or to be the cause of such, — the paroniria salaz of Good,c the gonorrhoea dormientium,ox night pollution of others. During the prevalence of a passion, too, the nutritive organs, in which its effects are experienced whilst awake, may be equally concerned during sleep. The respiration is short and interrupted, and sighs, groans, or laughter, according to the character of the emotion, are elicited ; the heart beats with more or less violence, and this state of excitement often continues after the individual has been completely aroused. The nightmare, ephialtes, or in- cubus affords us an example of suffering as intense as could well be experienced during our waking moments. A sensation of dis- * An Inquiry into the Nature of the Human Soul, &c, Lond. 1730. b Good's Book of Nature, ii. 13, Amer. Edit., Bost. 1826. ' Physiological System of Nosology, cl. iv. ord. 1, gen. v. sp. 3. DREAMS. 541 tressing weight is felt at the epigastrium, and of impossibility of motion, speech or even respiration ; the dreamer fancies that some horrible form, or some ferocious being is approaching him, and that all chance of escape is precluded; or that he is about to fall, or is falling, from a lofty precipice ; and the anguish which he suffers is indicated by loud groans, or by such painful feelings, ap- parently in the organs to which the emotions are referred, that he awakes. The ideas, at these times, are even more vivid than dur- ing the waking condition ; the perceptions, that predominate, not* being detracted from by extraneous impressions. On many of these occasions, when we awake, the dream is fresh upon the me- mory ; and by resigning ourselves again to slumber, we can at times recall it, should it be of an agreeable character, or dispel it altogether by rousing ourselves thoroughly.11 On account of the greater vividness of the ideas during sleep, and their freedom from all distraction, intellectual operations are sometimes effected in a surprising manner ; difficulties being oc- casionally solved, which have obtained the mastery during waking. To a minor degree, every one must have experienced more or less of this. Composition, poetical or other, is often effected with the greatest facility ; and a clue is occasionally afforded, which leads to the solution of previous difficulties. Cardan .had a notion that he composed one of his works during sleep. Condillac, who at- tended greatly to this matter, remarked particularly, that, whilst engaged with his " Cours a?Etude," he frequently broke off a subject, before retiring to rest, which he developed and finished the next morning according to his dreams. Condorcet saw in his dreams the final steps of a difficult calculation, which had puzzled him during the day; and Dr. Gregory, of Edinburgh, composed thoughts, and clothed them in words, which were so just in point of reasoning, and so good in point of language, that he used them in his lectures, and in his written lucubrations. Voltaire, Lafon- taine, Franklin, Coleridge, and others, have made similar remarks ; and events of the kind must have occurred, in some shape, to al- most every one.b Dr. Good relates a singular instance which hap- pened to a friend of his, who, amongst other branches of science, had deeply cultivated that of music, of which he was passionately fond. He was a man of irritable temperament, ardent mind, and most active and brilliant imagination ; and " was hence," says Dr. Good,c ." prepared by nature for energetic and vivid ideas in his dreams." On one occasion, during his sleep, he composed-a very beautiful little ode, of about six stanzas, and set the same to very agreeable music, the impression of which was so firmly fixed » See, on this subject, the experiments of M. Girou de Buzareingues, in Magendie's Journal de Physiologie, torn. viii. b Dendy, The Philosophy of Mystery, p. 232, Lond. 1841. c Book of Nature, loc. cit. See, also, Abererombie, Inquiries concerning the Intel- lectual Powers, Amer. Edit. p. 234, New York, 1832 ; Macnish, Philosophy of Sleep, Amer. Edit. p. 65, New York, 1834; and Elliotson's Human Physiology, p. 615, Lond. 1840. VOL. II. — 46 542 SLEEP. in his memory, that, on rising in the morning, he copied from his recollection both the music and the poetry. In these cases, the will must direct, more or less, the intellectual process. It is scarcely conceivable, that the train of reasoning could go on so connectedly and effectively by association alone. That the will can, in some degree, be kept awake, or in a condi- tion susceptible of being readily aroused, is shown by the facility with which we awake at a determined hour, and exercise a degree 1 of watchfulness during sleep; as well as by the facts, previously mentioned, regarding the courier who sleeps on his horse, or the coachman on his box. One curious fact, occasionally observed in dreams and likewise in the Mesmeric condition, *vhich is analogous, in many respects, to what is observed in dreaming, is the calling up of impressions, that have been made at an antecedent period, and that may have been entirely forgotten during the waking state. A well- known case of this kind is recorded in the books. A woman, during the delirium of fever, constantly repeated sentences unknown to her attendants and which proved to be Hebrew and Chaldaic. Of these she knew nothing whatever on her recovery ; but on re- ferring to her previous condition, it appeared that she had formerly lived with a clergyman, who had been in the habit of reading aloud sentences in those languages, which had impressed her mind without her knowledge. Dr. Dewar relates the case of a girl, who, when awake, discover- ed no knowledge of astronomy, or other sciences; but when asleep could define the rotations of the seasons, using expressions the most apt to the subject; and Mr. Dendy,a alludes to the case of an Edinburgh lady, who, "during her somnolent attacks, recited some- what lengthy poems;" and it was curious, that each line com- menced with the final letter of the preceding. There is a kind of dreaming, in which the sleep is less profound than during ordinary dreams ; where the body has, consequently, more capability of receiving external impressions, but where the will has a certain degree of power over the muscles of voluntary motion, but imperfectly regulates the thoughts. This is somnam- bulism or sleep-walking. During the continuance of this state, the individual can apparently see, hear, walk, write, paint, speak, taste, smell, &c, and perform his usual avocations, yet remain so soundly asleep, that it is impossible to awake him without making use of violence. Cases are on record, and of an authentic nature, of individuals who have risen from bed asleep, with their eyes closed, and have not only walked about the room or house, going up or down stairs, finding their way readily and avoiding obsta- cles, but have passed with safety through very dangerous places, as windows, or on the roofs of houses. They have executed, too, yet more difficult feats ; such as dressing themselves, going out of « The Philosophy of Mystery, p. 305, Lond. 1841. DREAMS. 543 doors, lighting a fire, bathing, saddling and bridling a horse, riding, composing verses, &c, and executing all the actions of life cor- rectly, and even acutely; yet they have been asleep during the whole of these acts. The eyes have been shut, or if open, have been incapable of perceiving the brightest light held before them ; and the iris has not exhibited its irritability by contracting, so that it is doubtful whether the ordinary functions of the eyes be gene- rally executed during somnambulism ; and the fact of the serious accidents, that occasionally befall the sleep-walker, is in favour of this conclusion. It must be remarked, however, that, in the opi- nion of some physiologists, the sight is awake and employed, and there are cases which strongly favour the idea. A peculiarity of ordinary somnambulism is, that the train of thoughts is usually directed towards one point, and this so profoundly, that notwith- standing the activity of the imagination, and the firm hold it takes on the mind, no recollection is retained of the occurrences during sleep, after the individual awakes, either spontaneously, or by being forcibly aroused. Animal magnetism3 would seem to be capable of inducing a peculiar kind of somnambulism, in which new faculties appear to be acquired, and intellectual operations to be executed, which are of the most astonishing character. The records of the Academic Royale de Medecine, of Paris, contain many such instances. A singular case of somnambulism is. given by Dr. Belden, of Spring- field, Vermont.1* It occurred in a young female, 17 years of age, and the phenomena were attested by numerous observers. One striking circumstance in this case was the astonishingly developed - impressibility of the eye. As an evidence of this, when Dr. Bel- den, in order to test the sensibility of that organ, took one evening a small concave mirror, and held it so that the rays, proceeding from a lamp, were reflected upon her closed eyelid ; when the light was so diffused, that the outline of the illuminated space could scarcely be distinguished, it caused, the moment it fell on the eyelid, a shock equal to that produced by an electric battery. This female could see as well, apparently, when the eyes were closed as when they were open. The details'of this case — and indeed of every case — of somnambulism are full of interest to the mental philosopher. Of late, the various experiments, at one time so much in vogue, when Mesmerism was in fashion, — have been repeated > See, on the subject of Animal Magnetism, Elliotson's Blumenbach, &c. p. 292, Lond. 1828 ; and Elliotson's Human Physiology, p. 660, Lond. 1840 ; Isis Revelata; An Inquiry into the Origin, Progress, and Present State of Animal Magnetism, by J. C. Colquhoun, Esq., Edinb. 1836; Prichard, Treatise on Insanity, p. 410, Lond. 1835; Erfahrungen Uber den Lebensmagnetismus und Somnambulismus—Commissions- Bericht an die Kb'nigl. Med. Akademie zu Paris, von Husson; und Resultate der Praxis einiger Hamburger Aerzte, so wie des Verfassers, J. F. Siemers, Hamburg, 1835. See, also, Brit, and For. Med. Rev., April 1839, p. 301; and an interesting summary by Prof. J. K. Mitchell, in Quarterly Summary of the Transactions of the College of Physicians of Philadelphia, for Aug., Sept. and October, 1842: b American Journal of the Medical Sciencss, No, xxviii. 544 SLEEP. not only by those who are not in the ranks of the profession, but by certain estimable physicians ; and of the reality of certain of the effects ascribed to the manipulations of the animal magnetizer we can entertain no doubt. The whole history of the" art exhibits, that impressible individuals may have irregularities of nervous dis- tribution induced through the medium of the senses, especially through those of vision and touch, — and that somnambulism and hysteric sleep, with other phenomena referable to a like condition of the nervous system, may be engendered ; but that there is any thing like a magnetic fluid or agent, which may be communicated from the magnetizer to the subject of his experiments, is not only not proved but, in the author's opinion, by no means presumable. One of the most curious of the phenomena presented by this sin- gular condition is the greatly developed sensibility to some irritants, and the total insensibility to others. Thus, the author has seen different persons bear without the slightest muscular action the application of a straw or feather to the conjunctiva; the insertion of pointed bodies into various parts of the cutaneous surface ; the extraction of a tooth, &c, and yet start at the least puff of. air made to come in contact with the face. Dr. Carpenter3 considers, that these phenomena must be considered as still doubtful; but they have been so often witnessed as not to admit of disbelief. From what the author has himself seen, he can readily credit the statements affirmed on respectable testimony, that even the major operations of surgery may have been executed, whilst the patient was in this state of Mesmeric sleep — if it may be so termed. As to the H e 11 s e h e n, clairvoyance, or " lucidity of vision," said to have been possessed by the magnetized, could we assign our be- lief to it at all, it would be only on the ground, — " credo quia im- possible est." The causes of imperfect or incomplete sleep, and hence of dreams, are various. The fact, already referred to, of the different organs of the animal functions having their distinct periods of waking and rest, would induce us to suppose, that it ought not to be always equally profound and durable : yet there are individuals whose sleep is nearly complete throughout; but they are not many. The previous occupation of the sleeper exerts great influence. If it have been of a fatiguing nature, all the faculties rest equally long and soundly ; but if the fatigue extend beyond the due point, a degree of excitability of the brain is left which.renders it extremely liable to be aroused. In this way we understand why dreams should bear upon subjects that have long occupied the mind in its waking state; the tension of the mind on those subjects having left con- siderable excitability, as respects them, and a disposition to resume them under the slightest irritation. The presence or aosence of irritants —external or internal—exerts likewise a great effect on the soundness of sleep, and the formation of dreams. The stillness 1 Human Physiology, p. 231, Lond. 1842. DREAMS. 545 of the night and the absence of light are hence favourable to repose : the position, too, must be one devoid of constraint; and the couch soft and equable, and especially such as the individual has been accustomed to use. Sleep is impracticable in a badly made bed ; and everyone must have experienced the antisoporific influence of a strange bed, the arrangement of which, as to size, pillows, &c, differs from that to which he has been habituated. It is not, how- ever, by external irritants that the sleep is usually disturbed. The state of the system itself may react upon the brain, and give occa- sion to broken sleep, and to dreams of the most turbulent character. Irritations, existing in the viscera, are frequently the cause of dreams, — in children more especially ; and a hearty supper, espe- cially if of materials difficult of digestion, may bring on the whole train of symptoms that characterize nightmare. In like manner, any thing that impedes the action of the functions of respiration, circulation, &c, may occasion the wildest phantasies. All these internal impressions are more vividly perceived for the reasons already stated. The nervous system is no longer excited by the ordinary impressions from the external senses ; and if the internal impressions be insufficient to prevent sleep altogether, they may excite dreams. During this incomplete kind of sleep, the external sensations are not wholly at rest; particularly that of touch or tact, which, as it is the last to sleep, is the first to awake. Impressions, made on it, may excite the most exaggerated representations in the brain, in the shape of dreams. The bite of a flea appeared to Descartes the puncture of a sword: an uneasy position of the neck may excite the idea of strangulation : a loaded stomach may cause the sleeper to feel as if a heavy weight,— a house or castle, or some powerful monster,— were on his stomach. A person, having had a blister applied to his head, dreamed that he was scalped by a party of Indians. Moreau de la Sarthe gives the case of a young female, who, from the application of her cold hand against her breast, when asleep, dreamed that a robber had entered her apartment and had seized hold of her. Galen dreamed that he had a stone leg, and, on waking, found that his own was struck with paralysis. Mr. Dugald Stewart3 gives a similar case, to show how an impression made upon the body, during sleep, may call up a train of associated ideas, and thus produce a dream. A gentleman, (Dr. Gregory,) who, during his travels, had ascended a volcano, having occasion, in consequence of indisposition, to apply a bottle of hot water to his feet when he went to bed, dreamed that he was making a journey to the top of Mount iEtna, and that he found the heat of the ground almost insupportable.11 Sir Walter Scottc mentions an analogous instance, which was told him by the nobleman » Elements of the Philosophy of the Human Mind, i. 335, 3d edit. Lond. 1808. b Abercrombie's Inquiries concerning the Intellectual Powers, Amer. Edit. p. 216, New York, 1832; and Elliotson's Human Physiology, p. 625, Lond. 1840. « Letters on Demonology and Witchcraft, Amer. Edit- p. 49, .New York, 183Q. 46* 546 SLEEP. concerned. He had fallen asleep, with some uneasy feelings arising from indigestion, which brought on the usual train of visionary terrors. At length, they were all summed up in the apprehension, that the phantom of a dead man held the sleeper by the wrist, and endeavoured to drag him out of bed. He awoke in horror, and still felt the cold dead grasp of a corpse's hand on his wrist. It was a minute before he discovered that his own left hand was in a state of numbness, and that with it he had accidentally encircled his right arm. If, again, the organ of hearing be wakeful, the dreamer may hear an individual speak, to him and may reply; so that occasionally secret thoughts and feelings may be elicited. The author has himself replied several times connectedly in this man- ner; and he has been able to lead on others, especially children,— whose sleep is often interrupted by the existence of irregular in- ternal impressions,— to answer a few times in the same way. It would seem, that on the loss of any one sense, the dreams, after a lapse of time, will not be referable to it. Darwin has given many instances of this. After blindness had affected certain per- sons,they never dreamed that they saw objects in their sleep; and a deaf gentleman, who had talked with his fingers for thirty-years, invariably dreamed of finger-speaking, and never alluded to his having dreamed of friends having conversed orally wilh him.a In the explanation of the cause of dreaming, we have the most plausible application of the theory of Gall regarding the plurality of organs in the brain. Every explanation,indeed,takes forgranted, that certain faculties are suspended whilst others are active. Gall's viewb is, that, during sleep, particular organs of animal life enter into activity ; and hence, that the perceptions and ideas, which de- pend on these organs, awake ; but, in such case, their activity takes place without any influence of the will; — that when one organ only is in activity, the dream is simple : the dreamer caresses the object of his affection ; he hears melodious music, or fights his enemies, according as this or that organ is exercising its functions; — that the greater the number of organs in activity at the same time, the more confused or complicated will be the dream, and the greater the number of extravagancies; — that, when the organs are exhausted by watching and labour, we generally do not dream during the first hours of sleep, unless the brain is extremely irri- table; but, in proportion as the organs get rid of their fatigue, they are more disposed to enter into activity, and hence, near the time for waking, we dream more and with greater vivacity. " Dreaming, consequently," he concludes, " is only a state of par- tial waking of animal life; or, in other words, an involuntary activity of certain organs, whilst others are resting."0 In many respects, the state of the mind, during dreaming, resem- bles that in the delirium of fever, as well as in insanity. The » Dendy, The Philosophy of Mystery, p. 228, Lond. 1841. b Sur les Fonctions du Cerveau, ii. 506, Paris, 1825. c See, also, Carmichael, in Transactions of the College of Physicians in Ireland, ii. 48. WAKING DREAMS. 547 imagination and memory may be acting with unusual vivacity, whilst the perception or the judgment may be most erroneous; — attimes,the perception beingaccurate and the judgment suspended, so that the individual may be most incoherent; at others, the per- ception being inaccurate and the judgment right, so that the indi- vidual may reason correctly from false premises. As in dreams, too, the delirious may have their ravings modified by impressions made on the external senses. Sir Walter Scott3 cites the case of a lunatic, confined in the Infirmarvof Edinburgh, whose malady had assumed a gay turn. The house, in his idea, was his own, and he contrived to account for all that seemed inconsistent with his ima- ginary right of property : — there were many patients in it, but that was owing to the benevolence of his nature, which made him love to relieve distress. He went little, or rather never, abroad, — but then his habits were of a domestic and rather sedentary nature. He did not see much company, but he daily received visits from the first characters in the celebrated medical school of the city, and he could not, therefore, be much in want of society. With so many supposed comforts around him, with so many visions of wealth and splendour, one thing alone disturbed his peace. " He was curious," he said, " in his table, choice in his selection of cooks, had every day a dinner of three regular courses and a dessert, and yet somehow or other, every thing he ate tasted of porridge." The cause of this was, that the lunatic actually ate nothing but this at any of his meals : and the impression made upon his palate was so strong as to modify his delusion. 2. WAKING DREAMS. Nearly allied to dreams, in its physiology— or more properly, perhaps —pathology, is the subject of hallucinations, spectral illusions, or waking dreams, in which the mind may be com- pletely sound, and yet the cerebral or percipient part of the brain, concerned in the senses, be so deranged as to call up a series of perceptions of objects, which have no existence except in the imagination. Such hallucinations are constant concomitants of insanity, delirium, and dreaming; but they may occur, also, when the individual is wide awake, and in the full possession of reason- ing powers: he may see the phantasm, but, at the same time, totally disbelieve in the existence of any extraneous body. The most common illusions of this kind affect the senses of sight and hearing. . . It has fallen to the lot of the author to meet with some singular and serious cases of this affection ; where, for example, the indi- vidual, wide awake, has heard the doors of his house violently slammed, his windows thrown up and down, the bells set a ringing, himself subjected to personal violence ; yet there has been no slamming of doors, no throwing up and down of windows, no ringing of bells, no personal violence ; the whole has been an Ulu- » Op. citat. p. 26. 548 SLEEP. sion, a waking dream, and of this no one has been more entirely aware than the sufferer himself. A few years ago, the author was consulted by a most respectable citizen of Virginia, regarding his state of health as well as an illusion of this nature. He was one of the Board of Visiters at West Point, where his duty called him to inspect the demonstrations by the pupils on the black-board. For months after his return to Virginia, he saw the black-board with its demonstrations constantly before him. He had previously experienced an attack of paralysis, and, when he applied to the author, he was labouring under marked evidences of predisposi- tion to a farther attack of encephalic mischief, of which the illu- sion in question was doubtless one. One of the most impressive cases, however, is that of Nicolai, the eminent bookseller of Berlin, which has been detailed by Drs. Ferriara and Hibbert,b and by Dr. Haslamc and Mr. Mayo.d Nicolai laid his case before the Philosophical Society of Berlin. He traced his indisposition, for it was manifestly such, to a series of disagreeable incidents that had befallen him. The depression, thus induced, was aided by the consequences of neglecting a course of periodical bleeding to which he had accustomed himself. This state of health brought on a disposition to spectral illusions, and, for a time, he was regularly haunted by crowds of persons entering his apartment, and ad- dressing him or occupied solely in their own pursuits, until, as his health was restored, they gradually disappeared, and ultimately left him entirely. Yet Nicolai, who was a man of unusually strong intellect, was throughout satisfied, that they were mere hallucinations. The cases of this kind, now on record, are many and curious. Every one engaged in extensive practice, or in frequent commu- nion with the world, must have seen or heard of them. Some, of a deeply interesting character, are detailed by Sir David Brewster,e Dr. Abercrombie/ and Dr. Macnish,* but there are none more extraordinary than some that have been related by Sir Walter Scott.h They are signal examples of the illusions that may occur during even our waking moments; and they may, doubtless, account for some of the stories of apparitions, of which so many are upon record. In the hypochondriac, we meet with all kinds of hallucination, and it is one of the most striking of the symptoms of every variety of insanity ; but, in the cases referred, to, notwithstanding the constancy and permanency of the illusion, ' An Essay towards a Theory of Apparitions, Lond. 1813. b Sketches of the Philosophy of Apparitions, Edinb. 1825 c Medical Jurisprudence as it relates to Insanity, in Cooper's Tracts on Medical Jurisprudence, p. 302, Philad. 1819. •f Outlines of Human Physiology, 3d edit. p. 213, Lond. 1833. e Letters on Natural Magic, Amer. Edit. p. 42, New York 183 2 f Inquiries concerning the Intellectual Powers, and the'Investigation of Truth, Amer. Edit. p. 282, New York, 1832. s Philosophy of Sleep, Amer. Edit. p. 214, New York, 1834. * Letters on Demonology, &c, Amer. Edit. p. 34, New York, 1830 WAKING DREAMS. 549 the individual himself has been satisfied that the whole affair had no real existence. Had he believed in the existence of the phan- tom, and acted from a conviction of its reality, he might, with propriety, have been deemed insane, quoad hoc.3- An instance of this kind is told in the Memoirs of the Count Maurepas, of one of the princes of the house of Bourbon, who supposed himself to be a plant, and, having fixed himself in the garden, called upon his servant to come and water him. His belief argued unsound- ness of mind, yet, even here,the hallucination, we are told, appeared to be confined to this subject.b In vouth, when the imagination is extremely vivid, we can call up images in the mind at pleasure, varying them as we may think proper. In the nervous, the delicate, and the imaginative, uneasy sensations can be experienced, when and where the indi- vidual wishes. After sedentary habits, long continued, the author has been able to experience, at will, pain in any part of the system, and to make it shift at pleasure from one organ to another. In the cases of hallucination, referred to above, as well as in every other kind, the cerebral part of the organ of sense is directly or indirectly excited into action ; — often by disease of the brain, or of some distant organ which reacts upon it. Hence it occurs as a precursor of apoplexy, epilepsy or other cerebral affection, or it may accompany, or be aggravated by, disorder of the digestive function. It has been seen, that although the passions or emotions are cerebral phenomena, they are felt in the nutritive organs; ana1 we can understand, how a disordered state of those organs may react upon the brain, and call up all kinds of illusions ; — generally during sleep, but at times even during our waking mo- ments. In this way, we account for the frightful dreams that follow an overloaded stomach, or that accompany impeded re- spiration or circulation. One of the most distressing symptoms of hydrothorax or water in the chest, which interferes more or less with both these vital functions, is the disturbed sleep, and the frightful sense of impending danger, which nightly distress the unfortunate sufferer. It appears, then, that in all cases of hallucination, occurring in those of sound or diseased mind, asleep or awake, the encephalic or percipient part of the organ of the sense concerned is irresistibly affected, so as to call up the memory of objects, or to form others, which have no existence except in the imagination ; but all this is accomplished without any impression being made upon the ex- ternal senses from without, even when these senses appear to be most actively exercised. In dreams, this must manifestly be the case. We see a friend long since dead ; we parade the streets of a town, which we have never visited ; and see, hear, feel and » See, on this interesting subject, the valuable work of Dr. Conolly on Insanity, Lond. 1830. , ,„ , „ . _ " Rush's Lecture on Medical Jurisprudence, Philad. 1811 ; and Cooper s Tracts on Medical Jurisprudence, p. 324, Philad. 1819. 550 SLEEP. touch the different objects. All this must be encephalic ; and not less certainly is it the case in the hallucinations of insanity, or in those that occur in the waking condition. The object which we see is not in existence, yet it is a regularly defined creation ; a cat in one instance, a gentleman-usher in another, and a skeleton in a third. It cannot depend upon any depraved condition of the organ of sense, as in such case the representation of the mind would be amorphous, irregular, or confused ; not a complete metamorphosis, as is invariably the case. Yet we are surprised Sir Walter Scotta should state, that he thinks " there can be little doubt of the proposition, that the external organs may, from vari- ous causes, become so much deranged as to make false representa- tions to the mind; and that, in such cases, men, in the literal sense, really see the empty and false forms, and hear the ideal sounds, which in a more primitive state of society, are naturally enough referred to the action of demons or disembodied spirits. In such unhappy cases, the patient is intellectually in the con- dition of a general, whose spies have been bribed by the enemy, and who must engage himself in the difficult and delicate task of examining and correcting, by his own powers of argument, the pro- bability of the reports, which are too inconsistent to be trusted to." The explanation is poetic, but manifestly untenable. A theory, which has been offered to account for the various spectral illusions, occurring in any of the modes we have mention- ed, is — that, in all the organs of sense, the mind possesses the power of retransmitting, through the nervous filaments, to the ex- pansions of the nerves that are acted upon by external objects, impressions, which these nerves have previously transmitted to the brain, and, that the vividness of the retransmission is proportional to the frequency with which the impressions have been previous- ly transmitted; that these reproduced impressions are in general feeble in the healthy state of the body, though perfectly adapted to the purposes for which they are required ; but, in other states of the body, they appear with such brilliancy as to create even a belief in the external existence of those objects from which the im- pressions were originally derived. " When the mind," says a writer on this subject, " acquires a knowledge of visible objects it is by means of luminous impressions, conveyed to the sensorium from each impressed point of the retina, through the corresponding filaments of the optic nerve ; and when the memory is subsequently called upon, by an act of the will, to present to us an object, that has been previously seen, it does it by retransmission along the same nervous filaments, to the same points of the retina. In the first case, when the presence of the luminous object keeps up a sustained impression upon the nervous membrane, the filaments, which transmit it to the brain are powerfully excited; but, in the process of retransmission by an effort of memory, the action of the nervous filaments is comparatively feeble, and the resultant impres- * Op. cit. p. 40. WAKING DREAMS. 551 sion on the retina faint or transient. When the memory, however, is powerful, and when the nervous filaments are in a state of high excitability, the impression becomes more vivid; and, as in the case of spectral illusions, it has the same strength and distinctness, as if it were produced by the direct action of luminous rays. In one case, the result of the impression and its retransmission to the retina is a voluntary act of the mind, but, in the other, it is invo- luntary, the controlling power being modified or removed, or the nerves being thrown into a state of easy excitation by some un- healthy action of the bodily organs." According to this view, it is indispensable, that the perception, in every case of illusion, shall be referred to the nerves of the organ by which such perception is ordinarily effected ; to the re- tina, if vision be concerned ; to the auditory nerve, if audition ; and so on. But this retransmission along the nerves appears to us to be wholly unnecessary. When an impression is made upon a sensitive surface, as we have elsewhere shown, sensation is not accomplished, until the impression has been conveyed to the brain by an appropriate organ, and the brain itself has acted; and if we interfere in any manner with the cerebral part of the function, perception is not effected. From the moment, however, that the action of the brain has taken place, the idea formed can be re- called by the exercise of memory ; and we have no doubt, that this could take place although the eyes were extirpated. The memory might call up previous perceptions, when the functions of the re- tina are entirely destroyed. Were it otherwise, it would be impos- sible for those, who have lost their sight from paralysis of the retina, of which many cases are constantly occurring, to call up any of the scenes and images, of which the brain took cognizance prior to the supervention of their blindness. In dreams, too, we exert every one of the senses; some with the greatest activity. We see, hear, taste, smell, and feel; and, in addition to this, walk, run, fly, and execute the ordinary acts of life not only without ap- parent difficulty, but with a facility that surprises us. Yet can we suppose, that, in all these cases, the feeling is actually produced by retransmission along the nerves of the organ to which it is referred ? It has been asserted, that when examination is carefully made, it will be found, that the images, recalled by the memory, follow the motions of the head and of the eye ; but, that this is not the case during sleep is manifest. The individual may remain pre- cisely in the same position, and yet he will seem to move about in all directions in his dreams ; will appear to see objects behind as well as before him ; and in situations towards which it is impossi- ble that the motions of his head and eye should be directed. Even in most of the illusions of our waking hours, the remark ought to be reversed. The encephalic action is the first of the links in the chain of phenomena ; and the motions of the head and the eye follow the images recalled by the memory. When the unfortunate subject of one of the cases of hallucination given by Sir Walter 552 SLEEP. Scott, saw the gentleman-usher preceding him into company, and circulating among the assembled guests, — as well as when he ob- served the skeleton at the foot of his bed, — the perception, owing to disease, had so completely taken possession of a part of the ence- phalic organ of vision, that the idea was constantly in the mind ; and volition being actively exercised, the head and the eye were directed towards the phantasm. Yet the perception was not so powerful, as to preclude the reception of impressions from without, as was shown by the skeleton seeming to be shut off by the body of the physician, so that the skull only was seen peering above his shoulder.* Another fact, which shows, that the whole phenomenon may be entirely encephalic, is'the occurrence, familiar to the operative sur- geon, of a patient, whose lower limb has been amputated, com- plaining of an uneasy sensation, as of itching, in a particular toe, and in a particular part of a toe. This is, at times, a symptom of an extremely distressing character. It is obviously impossible, that, in such case, there can be any external impression made on the part to which the feeli.ig is referred ; or that any retransmission can occur from the brain ; the limb having been removed from the body. Broussais asserts, that if a person tells you he suffers in a limb which he no longer has, it is because he experiences irritation in the extremities of the divided nerve, but this, in no respect, re- moves the difficulty. The sensation is referred to a part which has no existence except in the imagination. But, to return to sleep. We have said, that the object of sleep is to repair the loss, which the nervous system has sustained, dur- ing the previous condition of waking. This may, consequently, be regarded as the great exciting cause of sleep ; but we have seen, also, that certain states of the mind may postpone the usual period of its recurrence. If, indeed, we allow the attention to flag, and suspend the due exercise of volition, sleep can be indulged at al- most any hour of the day. In the same manner, any monotonous impression, or action of the brain in thought; the rocking of a cradle, or the song of the nurse to a restless child ; the murmurs of a bubbling brook, &c, may soothe us to rest. A like effect is produced by substances, as narcotics, which, by a specific action on the nervous system, prevent the ordinary sources of irritation from being appreciated, as well as by certain morbid affections of the brain, — compression, concussion, inflammation, &c. In these cases, however, the sleep is morbid, and is an evidence of serious mischief, — often of fatal disease ; whilst true sleep is as natural as the waking state, and is always — " Man's rich restorative ; his balmy bath, That supples, lubricates, and keeps in play The various movements of that nice machine, Which asks such frequent periods of repair!" Young's Night Thoughts. * Sir W. Scott, Letters on Demonology and Witchcraft, Amer. Edit, v 35. New York, 1830. r WAKING DREAMS. 553 Yet Haller,8 Hartley,b and numerous others have supposed, that natural sleep is dependent upon an accumulation of blood or other fluids in the vessels of the head pressing upon the brain, and thus impeding its functions. In support of this opinion, it is asserted, that all the phenomena which attend the sleeping state, seem to prove a determination of blood to the head. The face is flushed ; the head is hotter ; the skin more moist; and it is generally during the night, or when first awake, that bleeding from the nose and apoplexy take place ; the frequency of erection during sleep is affirmed to be owing to the pressure exerted on the cerebellum, which, in the theory of Gall, is the encephalic organ of generation ; and, lastly, it is argued, that narcotics, and vinous and spirituous liquors produce sleep by causing a similar congestion of blood within the cranium. The case, by no means unique, of the beg- gar whose brain was exposed, and in whom a state of drowsiness was induced when the brain was pressed upon, which could be increased by increasing the pressure, until at length he became comatose, has also been cited by Hartley and others. But all these are cases of morbid suspension of the animal functions, and are no more to be assimilated to true sleep, than the drowsiness, which Flourensc found to prevail in his experiments on animals when the cerebral lobes were removed. The believers in the hypothesis, that congestion of the vessels of the brain is the cause of sleep, consider that the heaviness and stupor, observable in those who indulge too much in laziness and sleep, are owing to long-continued pressure injuring the cerebral organs. Other physiologists have assumed the opposite ground, and affirmed, that during sleep the blood is distributed to the brain in less quantity, and is concentrated in the abdomen, to augment the action of the nutritive functions ;d whilst Cabanise holds, that during sleep there is a reflux of the nervous power towards their source, and a concentration in the brain of the most active princi- ples of sensibility. On all these topics our ignorance is extreme. We know nothing of the state of the encephalon in sleep. Its essence is as impenetrable as that of every other vital function. Dr. Bostockf asserts, that it is not more beyond our grasp than the other functions of the nervous system. This we admit: he has, indeed, afforded us in his own work indubitable evidences of our utter want of acquaintance with the essence of all those functions. The state of sleep is as natural, as instinctive, as that of waking; both are involved in mystery, and their investigation, as Mr. Du- * Element. Physiolog. xvii. 3. b On Man, p. 45, Lond. 1791. c Experiences sur le Systeme Nerveux, Paris, 1825. d Blumenbach, Instit. Physiol., and in Elliotson's Human Physiology, p. 610, Lond. 1840. = Rapport du Physique et du Moral de I'Homme, Paris, 1802. See, also, Adelon, Physiol, de I'Homme, 2de £dit. ii. 292, Paris, 1829; and Gall, Sur les Fonctions du Cerveau, ii. 503, Paris, 1825. f Elementary System of Physiology, 3d edit. p. 815, Lond. 1836. VOL. II. — 47 554 SLEEP- gald Stewart3 has suggested, is probably beyond the reach of the human faculties. 3. revert. Revery has been considered to resemble sleep, and, in its higher grades, to be not far removed from the condition of somnambulism. It is characterized by the attention or volition being directed so intently towards particular topics, during wakefulness, that the impressions of surrounding objects are not appreciated. Various grades of this condition of the mind may be traced, from the slight- est degree of absence or brown study to a state of total abstrac- tion in which the attention is entirely wound up, and riveted to a particular subject. Most persons must have experienced more or less of this, when any subject of severe study, or any great grati- fication, anxiety, or distress has strongly occupied the mind. If engaged in reading, they may follow every line with the eye ; turn over leaf after leaf, and at length awake from the revery, which had occupied the imagination, and find, that not the slightest im- pression has been made on the mind, by the pages, which the eye had perused, and the hand had passed over. If walking in a crowded street, they may have proceeded some way under the in- fluence of revery, moving the limbs as usual, performing various acts of volition, winding safely among the passengers, avoiding the posts and other obstacles, yet so exclusively occupied by the conceptions of the mind, as to be totally unconscious of all these acts of their volition, and of the objects they have passed, which must neces- sarily have impressed their senses so as to regulate those actions, but, owing to the attention having been bent upon other topics, the perceptions were evanescent. In elucidation of the power of a high degree of revery to render an individual torpid to all around him, the case of Archimedes, at the time of his arrest, has been quoted by writers. When the Roman army had at length taken Syracuse by stratagem, which the tactics of Archimedes had pre- vented them from taking by force, he was shut up in his closet, and so intent on a geometrical demonstration, that he was equally insensible to the shouts of the victors, and the outcries of the vanquished. He was calmly tracing the lines of a diagram, when a soldier abruptly entered his room, and clapped a sword to his throat. " Hold, friend," says Archimedes, " one moment, and my demonstration will be finished." The soldier, surprised at his unconcern at a time of such extreme peril, resolved to carry him before Marcellus; but as the philosopher put under his arm a small box full of spheres, dials, and other instruments, the soldier, conceiving the box to be filled with gold, could not resist the temp- tation, and killed him on the spot.3 It is to the capability of indulging to the necessary extent in this kind of mental abstraction, that we are indebted for the solution of » Elements of the Philosophy of the Human Mind, i. 327, 3d edit., Lond. 1808. b Liv. 1. xxxv. c. 3. CORRELATION OF FUNCTIONS. 555 every abstruse problem, relating to science or art, and for some of the most beautiful conceptions of the poet. From indulgence, however, in such abstractions, a habit is often acquired, which may be carried so far as to render the individual unfit for society, and to give him a character for rudeness and ill-breeding, of which he may be by no means deserving. Some most amiable and esti- mable men have, from long habits of abstraction, contracted the disease (aphelxia), as Good3 has constituted it, and have found the cure tedious and almost impracticable; at times, indeed, it appears to have terminated in mental alienation. The difference between this state and that of sleep is, that the attention and voli- tion are here powerfully directed to one object, so as to be torpid to the impressions of extraneous bodies; whilst sleep is characterized by a suspension or diminished exercise of these faculties. CHAPTER III. CORRELATION OF FUNCTIONS. The wonderful and complicated actions of the frame are vari- ously correlated to accomplish that astonishing harmony, which prevails in the state of health, as well as to produce the varied morbid phenomena, — often at a distance from the part originally diseased,—which characterize different pathological conditions. It is not, therefore, simply as a physiological question, that the study of the correlation of functions interests the medical inquirer. It is important to him in the study of every department, which concerns the doctrine of fhe healthy or diseased manifestations, and the modes adapted for the removal of the latter. These correlations may be of various kinds ; — mechanical, in which the effect exerted is entirely of a mechanical character; functional, in which the action of one organ is inseparably united to that of another, to accomplish a particular object ; and sympa- thetic, in which there is no physical action or direct catenation of functions; but where an organ, at a distance from one affected, is excited to regular or irregular action in consequence of the con- dition of the latter. 1. MECHANICAL CORRELATIONS. In the description of the different functions, numerous opportu- nities occurred for showing the influence which organs, in the im- mediate vicinity of each other, may mutually exert so as to modify their functions. The action of the muscles, — particularly those that contract the larger cavities, as the abdomen and thorax, —on the parts with which they come in contact, must be entirely me- chanical. In this way, the diaphragm and the abdominal muscles » A Physiological System of Nosology, cl. iv. ord. 1, gen. v. 556 CORRELATION OF FUNCTIONS. act in vomiting and defecation. During the operation of blood- letting, the flow of blood can be augmented by moving the mus- cles of the hand ; and it is probable, that the constant motion of the muscles of respiration impresses a snccussion on different organs, which may aid them in accomplishing their functions, although the effect of this is doubtless exaggerated. Every change of position, either of the whole body or of a part, has likewise some effect in modifying the actions performed by it or by neigh- bouring organs, although such effect may not be easily appreciable. A similar case of mere mechanical influence, which seems to be important to the proper action of certain organs, is exhibited in the pulsation of the different arteries. It has been seen, that a succus- sion is in this way given to the brain, which appears to be neces- sary to it ; for, if this source of stimulation be in any manner withdrawn, fainting is induced. Perhaps, however, the strongest case, that can be offered, of modification of function by mecha- nical causes, is that of the gravid uterus, which, by its pressure, gives rise to numerous symptoms in other organs, that are often the source of annoyance during gestation. 2. FUNCTIONAL CORRELATIONS. The functional correlations or synergies are of much more mo- ment to the physiologist and pathologist. Many of these have also been described in the preceding history : a brief notice of them will be all that is now requisite. For the maintenance of the healthy function we know that certain conditions are necessary, and that if these be materially modified, in the whole or in any partof the body, disease and death may be the result, even although the derangement may, in the first instance, concern only an ap- parently unimportant part of the frame, — the affection, by corre- lation, spreading gradually to more and more essential organs and functions, until the disorder is ultimately too great to allow of a continuance of the vital movements. In this respect, man differs from an ordinary piece of mechanism, in which the various parts are so adapted to each other as to produce a certain result. If one of these parts be destroyed, the whole machine may have its mo- tion arrested; but the effect is owing to the destruction of one part only, the others remaining sound ; whilst death, or the stoppage of the living machine, does not necessarily follow the destruction of any except a few essential organs, and is generally owing to the derangement of many. We shall find, indeed, that except in cases of sudden death, it is extremely difficult to say which of the three truly vital organs has first ceased to act; and that in all such cases death begins in one or other of the organs essential to vitality, and soon extends to the rest. The essentially vital organs are those-of respiration, circulation, and innervation ; but the great use of respiration is to change the blood from venous to arterial; in other words, to induce a con- version in it by its passage through the lungs, without which it FUNCTIONAL. 557 would be inadequate for the maintenance of life in any organ; and the object of the circulation is, to distribute it to the various parts of the frame as the grand vivifying and reparatory mate- rial. If, also, the organs of innervation be destroyed, the nervous influence is no longer conveyed to the different parts of the frame ; and as the presence of this influence every where is indispensable, the functions may cease from this cause; so that we may regard, as essential elements to the existence of the frame and of every part of the frame, the proper supply of arterial blood and of the nervous influence. In the production and distribution, however, of these agencies, a number of functions is concerned, giving rise to the correlation, which is the object of our present inquiry. If, in any manner, the blood do not meet with due aeration, as in •ordinary cases of suffocation, death supervenes, in the order else- where described; and if a slight degree of aeration be accom- plished, but still not enough for the necessities of the system, instead of suffocation, the individual dies more gradually; the functions fail in the same order; dark blood circulates through all the textures; hence lividity, especially of those parts wheje the cuticle is extremely thin, as of the lips, and wherever the mucous membranes commingle with the skin; and the blood gradually becomes inadequate to keep up the action of the brain and nervous system generally, as well as to stimulate the heart, and the individual gradually expires. If, again, the blood, although properly converted in the lungs, be not duly distributed to the . organs/owing to the failure of the circulatory powers,— either from direct or indirect causes, — the organs exhibit their correla- tion in the same manner, and syncope or fainting, or positive death, may be induced. Often.'however, the stoppage of the action of the heart is but for a short time. Owing to some painful impres- sion, sudden emotion, or other cause, the organ ceases to contract, either suddenly, — when the persons falls down as if deprived of life, — or gradually when the connexion of the different functions, and the order in which they fail, are manifest. Of this kind of— what the surgeon calls — morbid sympathy or constitutional irritation, we have a good example in the effect of a trifling operation upon a delicate, and often upon a strong, individual. Bleeding will sometimes induce fainting, both directly, by the ab- straction of fluid from the vessels, so that the brain may cease to act; and indirectly, when the quantity removed cannot be pre- sumed to have exerted any influence. Some, indeed, will faint from the slightest puncture and loss of blood, or even from the sight of that fluid. In these hist cases, if the syncope come on gradually, a feeling of great anxiety and oppression, occasionally of vacuity, exists in the epigastric region ; and perceptions become confused, the sight obscured, tinnitus aurium and dizziness super- vene, the respiration is embarrassed, the face pale, the extremi- ties cold, and the different parts of the body are covered with a cold, clammy sweat, until, ultimately, loss of sensation and motion 47* 558 CORRELATION OF FUNCTIONS. supervenes, and the individual is temporarily dead ; from which state he soon recovers, in the generality of cases, provided he be kept in the recumbent posture, so that the blood may readily pass to the brain. On other occasions, the heart will not cease its pul- sations, but will continue to send blood, in undue quantity, to the brain, so that all the above symptoms may ensue, except the tem- porary privation of vitality. In consequence of the severe pain induced by a displacement of two of the bones of the wrist, by a fall from a carriage, the author remained a considerable time incapable of sight, and at the same time suffering from great anxiety, yet consciousness and the action of the heart never ceased, as in complete syncope. The third vital function, — that of inner- vation, — when suspended or diminished, draws on a train of pathological phenomena, in the order described under the head of Death; suspending respiration and circulation suddenly, if the cause applied be sufficient; more gradually, and with the symp- toms characterizing apoplexy or compression of the brain, if the cause act in a minor degree. All the three vital functions are consequently correlative, and so intimately associated, that if a malign influence act upon one, the effect is speedily extended to the other.3 Owing to the necessity for the blood possessing certain attri- butes, the most important of which are obtained by its circulation through the lungs, we can readily understand, that if the functions of nutrition be not properly exerted, the composition of that fluid may be imperfect, and disorder take place in various parts of the frame from this cause. Thus, if digestion or the formation of chyle be not properly executed, the blood is not duly renovated, and may be so far impoverished, that the play of the functions is interfered with. We have elsewhere shown, that if omnivorous man be restricted to one kind of diet he will fall off, and become scorbutic, and the affection will be removed by allowing him diet of another kind ; — vegetables, if animal food have induced it, and conversely. Enlarged mesenteric glands, consequent, or not, on inflammation of the mucous membrane of the intestine, and the latter affection itself, are cases which may interfere with chylosis, and consequently with the constitution of the blood. In like manner, if nutrition and the various secretions be not duly per- formed in the tissue of the organs, and, especially, if the great "depu- rations be obstructed, the blood may suffer, and although the due change from venous to arterial may be effected in the lungs, its character may not be such as to adapt it for the healthy execution of the various functions. The humorists assigned too much importance to the condition of the humours in the production of disease ; the solidists, on the other hand, have denied it almost all agency. The medium be- tween these exclusionists is probably the nearest to nature. The » Richerand's Elemens de Physiologie, 13eme edit, par Berard ainS, 4 cxcvii. Bruxelles, 1837. • FUNCTIONAL. 559 solitary fact of black blood being unfit to maintain the perfect and continued vitality of any organ sufficiently exhibits its influ- ence. How the arterial blood exerts its agency, independently of its action as a fluid of nutrition, is beyond our knowledge. It appears to effect a necessary action of stimulation, but in what manner, or on what element, we know not : probably, however, its chief influence may be on the nervous tissue, as the privation of arterial blood soon occasions the cessation of the brain's action. In the higher classes of animals, innervation is dispensed from three great centres, — the encephalon, the spinal marrow, and the great sympathetic.3 The presidency, however, may be fairly assigned in man and in the higher animals, to the first of these. If it fail, death soon becomes general. This, however, is liable to great variation in different animals, and likewise in different functions. In man, if the nervous supply be cut off from any part, the part dies. Physical integrity, continuity, and a due supply of arteriat blood, are necessary to the proper exercise of the nervous power. In the former part of this work, the wonderful resistance to death which characterizes the amphibia, and the comparative independence of each portion of the body, in some of the lower order of animals, were pointed out. The polypus may be divided into numerous pieces, yet each may con- stitute of itself a distinct animal. The snail, after decapitation reproduces the head ; and a similar reparatory power is possessed bv other animals. We have elsewhere seen, that volition is seated lower in the inferior than in the superior orders of animals ; and that in man it is chiefly, —some say, wholly, — restricted to the encephalon. It appears, likewise, that the dependence of the rest of the nervous system on the great nervous centres is less in young than in old animals. Edwards regarded the new-born child as re- sembling, in many respects, the cold-blooded animal; and Redi, Rolando and Flourens, and Legallois found, that the tenacity of life, after decapitation, was much greater the nearer to birth. The functions also differ with regard to their dependence upon the encephalon. Disease may attack the animal functions and suspend them for a considerable length of time, —as in apoplexy, __before the organic functions are interfered with. This is a topic, however, which will be discussed under the head of Death. A gifted preceptor of the author, — M. Beclard,b— has defined life to "consist essentially in the reciprocal action of the circulation of the blood and innervation ; death always following the cessa- tion of such reciprocal action." But this conclusion is applicable only to animals; although both circulation and innervation are admitted in the vegetable by some physiologists. Legallois,0 from his experiments, deduced the unwarrantable inference, that " life « Adelon, Physiologie de I'Homme, iv. 146, 2de edit. Paris, 1829 ; and art. Innerva- tion, in Diet de Med. lere, edit. torn. xii. "Elemens d'Anatomie Generale, 2de 6dit. Pans, 1827 ; or Pognos Translation p. 106, Philad. 1830. c Sur le Principe de la Vie, Pans, 1812. 56Q CORRELATION OF FUNCTIONS. is owinsr to an impression made by arterial blood on the brain and spinal marrow, or to the principle, which results from this im- pression ;" — a definition, which would exclude the numerous animals of the lower classes, as well as vegetables, which are defi- cient in both brain and spinal marrow. The conclusion of Beclard is, perhaps, the limit to our knowledge on this subject. Yet some have endeavoured to discover which of the two functions, — cir- culation or innervation, — holds the other in domination. They, who consider the nervous substance to be first formed in the foetus, ascribe the supremacy to it; whilst the believers in the earlier formation of the sanguiferous system look upon it as the prime agent. We know no more than that both " Maintain, With the mysterious mind and breathing mould A co-existence and community." In every important function of the body we find this correla- tion or catenation of organs existing; all working to one end, and all requisite for its perfect accomplishment. How many organs, for example, are required to co-operate in the elevated function of sensibility ! The encephalon, the seat of thought, receives, by the external senses, the various impressions which act upon them from without, and, by the internal sensations, such as arise in the economy, and are generally the indexes of the physical neces- sities or wants. The intellectual and affective faculties enable us to appreciate the various objects that occasion our sensations, and indicate our social and moral wants : under their direction, volition is sent out, which acts upon the various muscles, and produces such movements as may be required for carrying into effect the suggestions of the mind. Between all these acts there is the closest catenation. In like manner, we observe the correlation between the animal, and the nutritive, and reproductive functions. The internal sensation of hunger suggests to the mind the necessity for a supply of aliment; the external senses are called into action to discover the proper aliment; when discovered, it is laid hold of by muscular movements under the direction of volition, is subjected to various voluntary processes in the mouth, and then passed on, by a mixed voluntary and involuntary action into the stomach. In like manner, the desire for sexual intercourse may be excited in the mind through the organs of vision or touch-, the organs of generation are aroused to action, and the union of the sexes is ac- complished by the exertion of muscles thrown into contraction by volition. The same catenation is exhibited after a fecundating copulation ; menstruation, which was previously performed with regularity is now arrested: the breasts become developed ; milk is formed in them, and, whilst the female suckles her child, unless the period is unusually protracted, the non-existence of the men- strual functions continues. Almost all the phenomena of disease are connected with this SYMPATHY. 561 correlation of functions. Derangement takes place in one organ or structure of the body, and speedily all those, that are correlated with it, participate in the disorder. Hence, in part, arises the com- bination of disordered nervous, circulatory, and secretory function, which characterizes general fever; and the various associated morbid actions that constitute disease in general. 3. SYMPATHY. There is another kind of connexion, which distinguishes the ani- mal body from a piece of ordinary mechanism yet more than those we have considered. In this, owing to an impression made upon one organ, distant organs become affected, without our being able to refer the transmission to mechanical agency, or to the associa- tion of functions, which we have just described. This kind of association is called sympathy. A particle of snuff or other irri- tating substance, impinging on the Schneiderian membrane, pro- duces itching there, followed by a powerful action of the whole respiratory apparatus, established for its removal. The sneezing, thus induced, is not caused by the transmission of the irritation through the intermediate organs to the respiratory muscles; nor can we explain it by the mechanical or functional connexions of organs. It is produced by this third mode of correlation:—in other words, it is a case of sympathy. Again, a small wound in the foot will produce locked jaw, without our being able to dis- cover, or to imagine, any greater connexion between the foot and the jaw than there is between the foot and other organs of the body. We say, that it is caused by sympathy existing between these organs, and, so long as we use the term to signify the un- known cause of these connexions, it is well. It must be under- stood, however, that we attach no definite idea to the term; that it is only employed to express our ignorance of the agent or its mode of action ; precisely as we apply the epithet vital to a pro- cess, which we are incapable of explaining by any physical facts or arguments. Of sympathetic connexions, we have numerous examples in the body; at times, inservient to accomplishing a particular function ; but generally consisting of modifications of function produced by the action of a distant organ. Of the sympathetic connexion be- tween the parts of the same organ, for the execution of a function proper to the organ, we have an example in that between the iris and the retina; the former will contract or dilate according to the degree of stimulation exerted by the light on the latter; and the effect is greater when the light is thrown on the retina than when thrown on the iris itself. A similar kind of sympathy exists be- tween the state of the mammae and that of the uterus, during preg- nancy ; although this has been frequently referred to ordinary functional correlation or synergy ; but the connexion is sufficiently obscure to entitle it to be placed under this division. A singular example of the sympathy between these two organs, soon after 562 CORRELATION OF FUNCTIONS. delivery, is the fact of the sudden and powerful contraction which is excited in the uterus, when in a state of inertness, by the appli- cation of the child to the breast.a a. Sympathy of Continuity. — This is such as occurs between various parts of membranes that are continuous. For example, the slightest taste or smell of a nauseous substance may bring on an effort to vomit, — the whole of the first passages being unfavour- ably disposed for its reception. In disease, we have many exam- ples of this kind of sympathy. During dentition, the child is sub- ject to various gastric and intestinal affections. If a source of irri- tation exist in any part of the intestinal or other mucous membrane, no uneasy sensation may be experienced in the seat of irritation, yet it may be felt at the commencement of the membrane or where it commingles with the skin : — thus, itching at the nOse may in- dicate irritation of the digestive mucous membrane ; — itching or pain of the glans penis, stone in the bladder, &c. These facts prove, that, in disease, a sympathetic bond unites the parts con- cerned, and such is probably the case in health also. We have the same thing proved in the effect produced on the action of glands by irritating the orifices of their excretory ducts. The presence of food in the mouth excites the secretion of the salivary glands, and that of chyme in the duodenum augments the secretion of the liver. In the same manner, a purgative, as calomel, which acts upon the upper part of the intestinal canal, becomes a cholagogue ; and duodenitis occasions a copious biliary secretion. These cases, have, however, been considered by many, to belong more appro- priately to functional correlation, as it is presumable, that the pro- pagation of the irritation from the orifice of the excretory duct takes place directly, and along branches of the same nerves as those that supply the glandular organs. It is by this sympathy of continuity that we explain the action of certain medicines. In bronchial irritation, for example, the cough will frequently be mi- tigated by smearing the top of the larynx by a demulcent,— the soothing influence of which extends to the part irritated. b. Sympathy of Contiguity. — A variety of sympathy, differ- ing somewhat from this, is the sympathy of contiguity or con- tiguous sympathy, in which an organ is affected by an irritation seated in another immediately contiguous to it. The association in action between the lining membrane of the heart and the mus- cular tissue of the organ has been adduced as an instance of this kind, and chiefly from the experiments of Bichat and Nysten, which showed, that any direct irritation of the muscular tissue of the heart has not as much influence as that of the membrane which lines it. A similar association is presumed to exist between the mucous and muscular coats of the alimentary canal, and the same kind of evidence is adduced to prove that the connexion is sympa- * Hedenus in art. Brust, (weibliche,) in Encyclop. Worterb. der Medicin. Wissen schaft, vi. 349, Berlin, 1831; Carus, Lehrbuch der Gynakologie, Th. ii. 407, Leipz. 1828 ; and Dr. Rigby, in Lond. Med. Gazette, March, 1831. SYMPATHY OF CONTIGUITY. 563 thetic.3 Other instances of sympathy are, — the convulsive con- traction of the diaphragm and abdominal muscles in vomiting con- sequent on the condition of the stomach, as well as the convulsive action of the respiratory muscles in sneezing, coughing, &c. The general uniformity in the motion of the two eyes has been adduced as an additional instance ; but Adelon has judiciously remarked, that the evidence in favour of this view is insufficient. For clear- ness of vision it is necessary, that the luminous rays should impinge upon corresponding points of the two retinae, and should fall as nearly as possible in the direction of the optic axes. For this pur- pose, the muscles direct the eyes in the proper manner; and sub- sequently, from habit, the balls move in harmony. We constantly hear, also, a fact adduced from pathology as an instance of sym- pathy. A molar tooth is lost on one side of the jaw; and it is found, perhaps, that the next tooth which decays is the correspond- ing molar tooth of the opposite side: — or a tooth has become carious, and we find the one next to it soon afterwards in a course of decay. These have been regarded as evidences of sympathy, — remote and contiguous. This is not probable. The correspond- ing teeth of the two sides are similarly situate as regards the sup- ply of nerves, vessels, and every anatomical element; and expe- rience teaches us, that the molar teeth —and especially the second great molares — decay sooner than the others. If one, therefore, become carious, we can understand, why its fellow of the opposite side should be more likely to suffer. The opinion, that contiguous teeth are likely to be affected by the presence of a carious tooth,. either by sympathy, or by direct contact, is almost universally be- lieved, and promulgated by the dentist. Both views are probably alike erroneous. If the inner side of the second molaris be decayed, we can understand, why the corresponding side of the third should become carious, without having recourse either to the mysterious agency of sympathy, or to the very doubtful hypothesis of commu- nication by contact, — especially as the caries generally begins in- ternally. The contiguous sides of the teeth are situate almost identically, as regards their anatomical elements; and, consequent- ly, if a morbid cause affects the one, the other is next likely to suffer, and is very apt to do so. Extracting the diseased tooth prevents this, because it removes a source of irritation, which could not but act in a manner directly injurious on the functions of the tooth next to it. The fact of the sympathy, which exists between organs of analogous structure and functions, is familiar to every pathologist. That of the skin and mucous membranes is the most intimate. In every exanthematous disease, the danger is more or less depend- dent upon the degree of affection of the mucous membranes; and the direct rays of the sun, beaming upon the body in warm climates, induce diarrhoea and dysentery. Acute rheumatism is a disease of the fibrous structures of the joints; but one of its most serious ex- * Adelon, Physiologie de I'Homme, edit, cit., iv. 267, Paris, 1829. 5G4 CORRELATION OF FUNCTIONS. tensions, or metastases, — whichsoever they may be called — is to the fibrous structure of the pericardium. Barthez,3 a most respect- able writer, gives a case of this kind of sympathy from Theden which is inexplicable and incredible. A patient, affected with paralysis of the right arm, applied a blister to it, which produced no effect, but acted on the corresponding part of the other arm. The left becoming afterwards paralyzed, a blister was put upon it, which also acted upon the other arm, not on the one to which it was applied ! Owing to this sympathy or consent of parts, Broussaisb has laid down the pathological law, — that when an irritation exists for a long time in an organ, the textures that are analogous to the one, which is diseased, are apt to contract the same affection. c. Remote Sympathies. — As examples of the more distant kinds of sympathies, we may cite the effect produced upon the stomach by distant organs, and conversely. Among the earliest signs of pregnancy are nausea, and vomiting: loathing of food ; fastidious appetite, &c. These symptoms are manifestly induced by sympa- thetic connection between the uterus and stomach ; inasmuch as they are not adventitious, but occur more or less in all cases of pregnancy. Their absence, at least, is a rare exception to the rule. Hunger or dyspepsia, again, impresses a degree of langour,— mental and corporeal,— which is proverbial; whilst the reception of food and its vigorous digestion give a character of energy and buoyancy, greatly contrasting with opposite circumstances. In disease, too, we find sympathies existing between the most dis- tant portions of the frame, and although these are not apparent to us in health, we are perhaps justified in considering that an occult sympathy exists between them in health, which only becomes largely developed, and obvious to us, when the parts are affected with disease. It is probable, too, that in the successive evolution of organs at different periods of life, new sympathies arise, which did not previously exist or were not observable. The changes that supervene in the whole economy at puberty, strikingly illustrate this; changes which do not occur in those, who, owing to malfor- mation, are not possessed of the essential parts of the reproductive system, or who have had them extracted prior to this period. d. Imagination. — The effect of the intellectual and moral faculties on the exercise of the functions of other parts is strongly evidenced, especially in disease. The influence of the mind over the body is, indeed, a subject which demands the attention of every pathologist. In health, we notice the powerful effect in- duced by the affective faculties upon every function. All these are caused by sympathetic association with the brain : the action of the organs being in a state of excitation or depression, accord- . «, ing to the precise character of the emotion. The intellectual » Nouveaux Elemens de la Science de I'Homme, Paris, 1806. b Commentaries des Propositions de Patholosie ; and Drs. Hays and Griffith's trans- lation, p. 60, Philad. 1832. REMOTE SYMPATHIES — IMAGINATION. 565 manifestations probably exert their influence in a manner less evi- dent, but not the less certain. The effects of one of them, at least, on the bodily functions are remarkable. We allude to the imagi- nation ; to which we can ascribe most of the cures that are said to have been effected by modes of management, — often of the most disgusting character,— which have been from time to time in vogue, have fretted their hour on the stage, and then sunk into that insignificance from which they ought never to have emerged. We have had occasion to allude to the excited imagination of the maniac, the hypochondriac, and the nervous, and have remarked, that hallucinations may exist in those of sound mind ;— phantoms created by the imagination; pains felt in various bodily organs, &c.; and we can hence understand, that, under particular cir- cumstances, we may have actual disease produced in this man- ner ; and, at other times, the feeling, — which may be as distress- ing to the patient, — of disease, which has no existence except in the imagination. It is to the effect produced by the imagination, that we must ascribe the introduction into medicine of magic, sor- cery, incantations, Perkinism, and other offsprings of superstition or knavery. The enthusiasm, that has attended the application of these last modes of acting upon the imagination in our own times, is most extraordinary,3 and their history leads us to be still more impressed with the extensive influence that may be exerted by the mind over the body : they teach the practitioner the importance of having its co-operation, whenever it can be procured ; and the dis- advantages, which he may expect to ensue, when the imagination. is either arrayed against himself personally, or the plan of treatment which he is adopting. The physician, who has the confidence of his patient, will be successful — if he adopt precisely the same plan of treatment that would be pursued by one who has it not — in cases where the latter would totally fail. The applications of this sub- ject are developed by the author elsewhere.b Again, pathology is invoked as affording us perhaps the best evi- dences of the existence of extensive sympathetic relations between various parts of the frame, which are supposed to be constantly going on unseen during health, but become developed, and more obvious in disease. The case, we have previously given, of the general effects produced upon the system by local irritation of a part, shows the extent of such association. An insignificant portion of the body may become inflamed, and if the inflamma- tion continue, the function of the stomach may be disordered,— as indicated by loss of appetite, nausea and vomiting; the respi- ration hurried, as well as the circulation; the senses blunted; the intellectual and moral faculties obscured ; and languor and lassitude may indicate the nervous irritation and constraint. The moral consideration of sympathy does not concern us. It » Demangeon, Du Pouvoirde l'lmagination, &c. chap. ii. p. 39, Paris, 1834. b GenerafTherapeutics, p. 56, Philad. 1836 ; and General Therapeutics and Materia Medica, vol. i. Philad. 1843. VOL. II. — 48 566 CORRELATION OF FUNCTIONS. is a subject, — and one of interest to the moral philosopher,—to account not only for these secret causes, which attract individuals towards each other, but Which repel them and occasion antipa- thies. To a certain extent, however, it trends into the province of the physiologist. The tender, susceptible individual, from ob- serving another suffering under pain, feels as if labouring under the same inconvenience, and, by a very rapid, yet complex intel- lectual process, constituted of numerous associations, may be so strongly impressed as to sink under their influence :—thus, the sight of blood will so powerfully impress the mind, in this sym- pathetic manner, that fainting may be induced, and the vital func- tions be for a time suspended. The sight and suffering of a woman in labour may cause abortion in another; and hence the propriety of excluding those, who are pregnant, from the chamber of the parturient female. Hysteric and convulsive paroxysms are induced in a similar way; of which the convulsionnaires of all times must be regarded as affording singular and instructive examples. e. Superstitions connected with Sympathy. — Lastly; the mysterious consent, which we observe between various parts of the body, has given rise to some of the most strange and absurd superstitions that can be imagined. It was believed, for instance, almost universally in the fifteenth century, that an intimate sympathy exists, not only between parts of a body forming portions of one whole, but also between any substance that had previously formed part of a body and the body itself: that if, for example, a piece of flesh were sliced from the arm of one person and made to unite to that of another, the grafted portion would accurately sympathize with the body of which it had previously formed part, and undergo decay and death along with it; and it was even proposed to turn this sympathy to account. It was recommended, for instance, that the alphabet should be traced on the ingrafted portion ; and it was affirmed, that when any of the letters, so traced, were touched, the party from whom the piece of flesh had been taken would feel similar impressions; so that, in this manner, a correspondence might be maintained. Some went even farther than this, asserting, that such a miracu- lous sympathy exists between the human body and all that has previously formed part of it, that if a hot iron were run into the excrement of any person, he would feel a sensation of burning in the part whence it had proceeded ! It was also a notion, that grafts of flesh, united to the body of another, die when the person dies from whom they have been taken. In a work on animal magnetism, the case of a man at Brussels is given, who had an artificial nose, formed after the old Taliacotian method, which served every useful purpose, until the person, from whom the graft had been taken, died, when it sud- denly became cold and livid, and finally fell off. Tagliacozzi* himself lived in an era of superstition, when this belief in the syn- * Gasparis Taliacotii Bononiensis De Curtorum Chirurgia per insitionem libri duo. Veaet. 1597. SUPERSTITIONS CONNECTED WITH SYMPATHY. 567 chronous death of the parent and graft was universally credited ; and the folly has not escaped the notice of Butler : — " So learned Taliacotius from The brawny part of porter's bum, Cut supplemental noses, which Would last as long as parent breech ; But when the date of nock was out, Off dropped the sympathetic snout." — Hudibras. Little less singular was the superstition, —that the wounds of a murdered person will bleed afresh, if the body be touched, ever so lightly in any part by the murderer. This idea gave rise to the trial by bier-right, which has been worked up by Sir Walter Scott with so much dramatic skill, in one of his novels, — St. Valentine's Day, or the Fair Maid of Perth. The annals of judicial inquiry furnish us with many instances of this gross super- stition.3 A case of the kind occurred in our own country. It is contained in the attestation of John Demarest, coroner of Bergen county, New Jersey.b The superstition, too, is noticed by many of the older poets. Thus, Shakspeare, — where the Lady Anne reviles Gloster over the corpse of Henry : — " O ! gentlemen, see, see ! dead Henry's wounds Open their congeal'd mouths and bleed afresh ! Blush, blush, thou lump of foul deformity ; For 'tis thy presence that exhales this blood From cold and empty veins, where no blood dwells. Thy deed, inhuman and unnatural, Provokes this deluge most unnatural." Richard III., i. 2. And Webster, in a tragedy published about the middle of the seventeenth century: — "See Her wounds still bleeding at the horrid presence Of yon stern murderer, till she find revenge." Appius and Virginia. The belief in these cases of monstrous superstition, which, it need scarcely be said, are. usually explicable on purely physical principles, or on the excited imagination of the observer, still exists amongst the benighted inhabitants of many parts of Great Britain and° Ireland, and is the main topic of one of the second series of " Traits and Stories of the Irish Peasantry." The superstition, has, indeed, its believers among us. On the trial of Getter, who was executed a few years ago (1833) in Penn- sylvania, for the murder of his wife, a female witness deposed on oath, as follows: —" If my throat was to be cut, I could tell, before God Almighty, that the deceased smiled, when he (the murderer) touched her. I swore this before the justice, and that she bled considerably. I was sent for to dress her and lay her out. » See the case of Philip Stansfield for the Murder of his Father, Sir James Stans, field 7nMargrave's State Trials, iv. 283 ; and in Celebrated Trials of all Ages &c., fi 566? Lond. 1825. * Annual Regrster, for 1767. 568 CORRELATION OF FUNCTIONS. He toubhed her twice. He made no hesitation about doing it. I also swore before the justice, that it was observed by other people in the house." It would be endless to enumerate the various superstitions, which prevailed, a few centuries ago, on topics more or less re- motely connected with this subject. We pass on, therefore, to the interesting, but abstruse, inquiry into the f. Agents by which Sympathy is accomplished.—The opinions of physiologists have, from time to time, rested chiefly ; — on the membranes, the cellular tissue, the bloodvessels, and the nerves ; whilst there have been some, who, in the difficulty of the subject, have supposed sympathy to be devoid of all organic connexion ; and others, again, have presumed, that all the parts we ha,ve mentioned are concerned. The rapidity, however, with which sympathies are evidenced, has led to the abandonment of all those opinibns; and the generality of physiologists of the present day look to the nervous system as the great source and medium of commu- nication of the different irradiations, by which distant organs are supposed to react, in this manner, upon each other. The rapidity, indeed, with which the various actions of the nervous system are executed, — the apparent synchronism between the reception of an impression on an organ of sense, and its perception by the brain, as well as between the determination of the will and its effect upon a muscle, — naturally attracted the attention of physiologists to this system as the instrument of sympathy. The modes, in which it is supposed to be accomplished, are : — either by the parts that sympathize receiving ramifications from the same nervous trunks, or from such as are united by nervous anastomoses ; or, by the nervous irradiations, emanating from one organ, proceeding to the brain, and being thence reflected to every dependency of the system, but so that certain organs are more modified by such reflection than others ; hence, the distinction into what have been termed direct sympathies and cerebral sympathies. Of the direct sympathies we have already given some examples, — as that between the mucous and muscular coats of the intes- tines ; and if our acquaintance with the precise distribution and connexion of the various parts of the nervous system were more intimate, we might perhaps explain many of the cases that are yet quite obscure to us. The researches of Sir Charles Bell, regarding the nerves concerned in respiration, have thrown light on those associations of organs, which we notice in the active exercise of the respiratory function. It has been elsewhere shown, that although the whole of the nerves, composing his respiratory system, may not be apparently in action during ordinary respiration, yet that when the function has been greatly excited, the association be- comes obvious; parts, that are remote in situation, are combined in function, and all the nerves that animate them, he conceives, arise from the same column of the spine. The opinion of Boer- AGENTS OF SYMPATHY. 569 haave, Meckel, and some others, is, that all sympathies are accom-* plished in this direct manner. On the other hand, Haller, Whytt, Georget, Broussais, Adelon, and others, make the majority of sympathies to be produced through the medium of the brain. Bostock3 indeed affirms, that the facts, adduced by Whytt,b are of such a nature as " to prove, that the co-operation of the brain is essential in those actions, which we refer to the operation of sym- pathy." In many cases, this is doubtless the fact; — as in sneez- ing and coughing; but there are others in which such co-opera- tion seems improbable and indeed impossible. Something like sympathy exists in the vegetable; in which if we admit, with some naturalists, a rudimental nervous system, we have no reason for presuming, that there is any thing like a centre for the recep- tion or transmission of impressions, and the case of infants, born devoid of brain and spinal cord, affords evidence of a like de- scription. We find, that the properties of the vital principle are exempli- fied by the formation of a body of a certain magnitude, form, structure, composition and duration, and that this applies to all organized bodies, vegetable as well as animal. Where such ap- pearance of design, consequently, exists, we ought to expect, that, in the vegetable, also, a harmony or consent must reign amongst the various functions, tending to the accomplishment of that uni- formity, which enables us always to recognise the particular varie- ties of the vegetable kingdom, and which has kept them as dis- tinct, probably, in their characters, as when first created by Almighty power. The irritation of a single leaflet of the Mimosa pudica or sensitive plant causes the whole leaf, as well as the footstalk, to contract. Dr. John Sims irritated a leaflet of this plant, taking the greatest pains to avoid moving any other part of the leaf; yet the whole contracted, and the footstalk dropped. In order, however, to be sure, that mechanical motion communicated by the irritation had no share in the contraction, he directed a sun- beam, concentrated by a lens, on one of the leaflets, when the leaf again contracted, and the footstalk dropped. Of this kind of vegetable irritability we have many examples, some of which are alluded to under another head. From these, and other facts of an analogous character, Sir Gil- bert Blanec concludes, that the functions of living nature, in all its departments, are kept up by a mutual concert and correspondent accordance of every part with every other part, that it would be in vain to waste time in endeavouring to account for them by groping among dark analogies and conjectures; and that it is better to assume them as facts, on which are founded the ultimate and inscrutable principles of the animal economy. We have certainly much to learn regarding the agents of sympathies, and the modes in 1 Elementary System of Physiology, 3d edit. 762, Lond. 1836. b An Essay on the Vital and other Involuntary Functions, § xi. Edinb. 1751. ' Elements of Medical Logic, 3d edit., Lond. 1819. 48* 570 INDIVIDUAL DIFFERENCES. which they are operated ; but still we know enough to infer, that in many cases, in animals, the nerves appear to be the conductors; that the brain is, in others, the centre to which the organ in action transmits its irradiations, and by which they are reflected to the sympathizing organ ; and that, in others, again, the effect is caused in the absence of nervous centre, and even of nerves, by vibrations perhaps, but in a manner which, in the present state of our know- ledge, is inexplicable, and is, therefore, supposed to be essentially organic and vital, — epithets, however, as we have more than once said, that merely convey a confession of our total ignorance of the processes to which they are appropriated.* CHAPTER IV. INDIVIDUAL DIFFERENCES AMONGST MANKIND. The differences, which we observe amongst the individuals of the great human family, are as numerous as the individuals them- selves ; but this dissimilarity is not confined to man or to the ani- mal kingdom: the vegetable exhibits the same ; for, whilst we can readily refer any plant to the species and variety, to which it may have been assigned by the botanist, accurate inspection shows us, that in the precise arrangement of the stalk, branches, leaves, or flowers, no two are exactly alike. We shall not, however, dwell on these trifling points of difference, but restrict ourselves to the broad lines of distinction, that can be easily observed, and an attention to which is of some moment to the physician. Such are the temperaments, constitutions, idiosyncrasies, acquired dif- ferences, and the varieties of the human species or the different races of mankind. Of these, the last belongs more especially to the natural historian, and, consequently, will be but briefly noticed. 1. TEMPERAMENTS. The temperaments are defined to be, — those individual differ- ences, which consist in such disproportion of parts, as regards volume and activity, as to sensibly modify the whole organism, but with- out interfering with the health. The temperament is, consequently, a physiological condition, in which the action of the different func- tions is so tempered as to communicate certain characteristics, which may be referable to one of a few divisions. These divi- sions are by no means the same in all physiological treatises. The ancients generally admitted four, —denominated from the respective fluids or humours, the superabundance of which in the economy was supposed to produce them;—the sanguineous, . » See, on the subject of sympathy, Alison, in Edinb. Med. Chirur. Transact ii. 165; Bostock, op. citat.; Adelon, Physiologie de I'Homme, 2de e"dit. iv. 260, Paris, 1829 ; and the author's Therapeutics, p. 72, Philad. 1836 ; and his General Therapeutics and Mat Med. Philad. 1843. SANGUINE TEMPERAMENT. 571 caused by a surplus of blood ; the bilious or choleric, produced by a surplus of yellow bile ; the phlegmatic, caused by a surplus of phlegm, lymph, or fine watery fluid, derived from the brain ; and the atrabiliary ox melancholic, produced by a surplus of black bile, — the supposed secretion of the atrabiliary capsules and spleen. This division was kept up for ages without modification, and still prevails with one or more additional genera. The epithets have been retained in popular language without our being aware of their parentage. For example, we speak of a sanguine, cho- leric, phlegmatic, or melancholic individual or turn of mind, with precisely the acceptation given to them by the Hippocratic school, — the possessors of these temperaments being presumed to be, respectively, full of high hope and buoyancy ; naturally irascible, dull and sluggish ; or gloomy and low-spirited. Metzger admits only two, — the irritable,(x ei z b a r e,) and the dull ox phlegmatic (trage). Wrisberg3 eight, — the sanguine, sanguineo-choleric, choleric, hypochondriac, melancholic, Boeotian, meek, (s a n f t m u- t h i g e,) and the dull or phlegmatic. Rudolphib also eight, — the strong or normal, the rude, athletic or Boeotian, the lively, the rest- less, the meek, the phlegmatic or dull, the timorous, and the melan- cholic ;— whilst Broussaisc enumerates the gastric, bilious, san- guine, lymphatico-sanguineous, ansemic, nervous, bilioso-san- guine, nervoso-sanguine, and melancholic. It is obvious, that if we were to apply an epithet to the possible modifications, caused by every apparatus of organs, the number might be extended much beyond any of these. Perhaps the division most generally adopted is that embraced by Richerand,d who has embodied considerable animation, with much that is fanciful, in his description.' In this division, the ancient terms have been retained, whilst the erro- neous physiological basis, on which they rest, has been discarded. A short account of these temperaments is necessary, rather, for the purpose of exhibiting what has been, and is still, thought by many physiologists, than for attesting the reality of many of the notions that are mixed up with the subject. With this view, the temperaments may be divided into the sanguine, the bilious or choleric, the melancholic, the phlegmatic, and the nervous. a. The Sanguine Temperament. — This is supposed to be dependent upon a predominance of the circulatory system ; and hence is considered to be characterized by strong, frequent, and regular pulse ; ruddy complexion ; animated countenance ; good shape, although distinctly marked; firm flesh; light hair; fair skin ; blue eyes ; great nervous susceptibility, attended with rapid successibilite, as the French term it; that is,— a facility of being impressed by external objects, and passing rapidly from one idea * In his edition of Haller's Grundriss der Physiologie. i> Grundriss der Physiologie, Berlin, 1821. c Traite de Physiologie, Drs. Bell and La Roche's translation, 3d edit. p. 561, Philad. 1832. d Nouveaux Elemens de Physiologie, 13eme edit, par M. Berard aine, § ccxxvm. Bruxelles, 1837. 572 INDIVIDUAL DIFFERENCES. to another ; quick conception ; ready memory ; lively imagina- tion ; addiction to the pleasures of the table ; and amorousness. The diseases of the temperament are generally violent; and are chiefly seated in the circulatory system, — as fevers, inflamma- tions, and hemorrhages. The physical traits of this temperament, according to Richerand, are to be found in the statues of Antinous and the Apollo Belvi- dere : the moral physiognomy is depicted in the lives of Mark An- tony and Alcibiade's. In Bacchus, both the forms and the charac- ter are found ; and no one in modern times, in M. Richerand's opinion, exhibits a more perfect model of it than the celebrated Duke De Richelieu ; — amiable, fortunate and valorous, but light and inconstant to the termination of his brilliant career. If individuals of this temperament apply themselves to labours of any kind that cause the muscles to be greatly exerted, these organs become largely developed, and a subdivision of the sanguine temperament is formed, which has been called the muscular or athletic. This is characterized by all the outward signs of strength; the head is small; the neck strong; the shoulders broad ; the chest large ; the hips solid ; the muscles prominent, and the interstices well marked. The joints, and parts not covered with muscles, seem small; and the tendons are easily distinguished through the skin, by their prominence. The susceptibility to external impres- sions is not great; the individual is not easily roused; but, when he is, he is almost indomitable. A combination of the physical powers, implied by this temperament, with strong intellect, is rarely met with. The Farnesian Hercules is conceived to offer one of the best spe- cimens of the physical attributes of the athletic temperament." b. The Bilious or Choleric Temperament. — This is presumed to be produced by a predominance of the liver and biliary organs in general. The pulse is strong, hard and frequent; the subcuta- neous veins are prominent; the skin is of a brown colour, inclining to yellow ; hair dark ; body moderately fleshy ; muscles firm, and well marked ; the passions violent, and easily excited ; the temper abrupt, and impetuous; great firmness and inflexibility of charac- ter; boldness in the conception of projects, and untiring perseve- rance in their fulfilment. It is amongst the possessors of this tem- perament, that the greatest virtues and the greatest crimes are met with. Richerandb enumerates Alexander, Julius Caesar, Brutus, Mahomet, Charles XII., Peter the Great, Cromwell, Sextus V., and the Cardinal Richelieu. To these, Goodc has added Attila, Charlemagne, Tamerlane, Richard III., Nadir Shah, and Napo- leon. The moral faculties are early developed ; so that vast enterprises may be conceived, and executed at an age when the mind is ordi- narily far from being matured. The diseases are generally com- bined with more or less derangement of the hepatic system. The » Richerand, op. citat. § ccxxix. b Op. cit. § ccxxx. c Book of Nature, iii. 310. TEMPERAMENT. 573 whole of the characters, however, indicate, that an excited state of the sanguiferous system accompanies that of the biliary organs ; so that the epithet cholerico-sanguine might, with more propriety, be applied to it. Where this vascular predominance does not exist, whilst derangement is present in some of the abdominal organs, or in the nervous system, we have the next genus pro- duced. c. Melancholic or Atrabilious Temperament.— Here the vital functions are feebly or irregularly performed; the skin assumes a deeper hue ; the countenance is sallow and sad ; the bowels are torpid, and all the excretions tardy; the pulse is hard and habitually contracted ; the imagination is gloomy, and the temper suspicious. The characters of Tiberius and of Louis XI. are considered to be instances of the predominance of this tempera- ment ; and, in addition to these, Richeranda has enumerated Tasso, Pascal, Gilbert, Zimmermann,and Jean Jacques Rousseau. d. The Phlegmatic, Lymphatic or Pituitous Temperament.— In this case, the proportion of the fluids is conceived to be too great for that of the solids; the secretory system appearing to be active, whilst the absorbent system does not act so energetically as to prevent the cellular texture from being filled with the humours. The characteristics of this temperament are: — soft flesh; pale skin ; fair hair ; weak, slow and soft pulse; figure rounded, but inexpressive ; the vital actions more or less languid; the memory by no means tenacious, and the attention vacillating ; with aversion to both mental and corporeal exertion. Pomponius Atticus — the friend of Cicero — is offered as an example of this temperament, in ancient times; Montaigne, in more recent history. The latter, however, possessed much of the nervous susceptibility that characterizes the more lively temperaments. Dr. Goodb sug- gests the Emperor Theodosius as an example in earlier times; and Charles IV. of Spain, who resigned himself almost wholly into the hands of Godoy, —Augustus, King of Saxony, who equally re- signed himself into the hands of Napoleon, —and Ferdinand of Sicily, who surrendered for a time the government of his people to the British, — as instances in our own day. It would not be diffi- cult to find, amongst the crowned heads of Europe, others that are equally entitled to be placed amongst these worthies. e. The Nervous Temperament. — Here the nervous system is greatly predominant; the susceptibility to excitement from exter- nal impressions being unusually developed. Like the melancholic temperament, this is, however, seldom natural or primitive. It is morbid or secondary, being induced by sedentary life, sexual indul- gence, or morbid excitement of the imagination, from any cause. It is characterized by small, soft, and, as it were, wasted muscles ; and generally, although not always, by a slender form; great vividness of sensation; and promptitude and fickleness of resolu- tion and judgment. This temperament is frequently combined witn • Op. citat. ccxxxi. o Op. citat. iii. 314 ; and Richerand, op. cit. § ccxxxu. 574 INDIVIDUAL DIFFERENCES. some others. The diseases that are chiefly incident to it, are of the hysterical and convulsive kind; or those to which the epithet ner- vous is usually appropriated. Voltaire and Frederick the Great are given by Richerand8 as examples of this temperament. Such are the temperaments, described by most writers. The slightest attention to their reputed characteristics will show the im- perfection of their definition and demarcation ; so imperfect, indeed, are they, that it is extremely rare for us to meet with an individual, whom we could unhesitatingly refer to any one of them. They are also susceptible of important modifications by climate, education, &c, and may be so combined as to constitute innumerable shades. The man of the strongest sanguine characteristics may, by misfor- tume, assume all those that are looked upon as the indexes of the melancholic or atrabilious; and the activity and impetuosity of the bilious temperament may, by slothful indulgence, be converted into the lymphatic or phlegmatic. It is doubtful, and more than doubtful, also, whether any of the mental characteristics, assigned to the temperaments, are dependent upon them. The brain, we have elsewhere seen, is the organ of the mental and moral mani- festations ; and although we may look upon the temperaments as capable of modifying its activity, they cannot probably affect the degree of perfection of the intellect; — its strength being alto- gether dependent upon cerebral conformation. It is even doubtful whether the temperaments can interfere with the activity of the cerebral functions. In disease of the hepatic, gastric or other vis- cera we certainly see a degree of mental depression and diminished power of the whole nervous system ; but this is the effect of a morbid condition, and continues only so long as such morbid con- dition endures. Nor is it probable, that any predominance of the nutritive functions could induce a permanent influence on the cerebral manifestations. Whatever might be the effect for a while, the nervous system would ultimately resume the ordinary action which befitted its primitive organization. Similar reasons to those have induced the author's late friend, M. Georget,b — a young physician of great promise and experience in mental affections, now no more, — to consider the whole doctrine of the tempera- ments as a superstition connected with the humoral pathology, and to believe, that the brain alone, amongst the organs, has the power, by reason of its predominance or inferiority, to modify the whole economy. That a difference of organization exists in different individuals is obvious; but that there is an arrangement of the nutritive organs or apparatuses, which impresses upon individuals all those mental and other modifications known under the name of tempera- ments, is, we think, sufficiently doubtful. The constitution of an individual is the mode of organization proper to him. A man, for example, is said to have a robust, or a delicate, or a good, or a bad constitution, when he is apparently strong or feeble, usually * Op. cit. ccxxxiii. i> De la Physiologie du Systeme Nerveux, &c, Paris, 1821. IDIOSYNCRASY. 575 in good health, or liable to frequent attacks of disease. The varie- ties in constitution are, therefore, as" numerous as the individuals themselves. A strong constitution is considered to be dependent upon the due development of the principal organs of the body, on a happy proportion between those organs, and on a fit state of energy of the nervous system; whilst the feeble or weak constitution re- sults from a want of these postulates. Our knowledge, however, of these topics, is extremely limited, and concerns the pathologist more than the physiologist. 2. OF IDIOSYNCRASY. The word idiosyncrasy is used, by many physiologists, synony- mously with constitution: but it is generally appropriated to the peculiar disposition, which causes an individual to be affected by extraneous bodies, in a way in which mankind in general are not acted upon by the same agents.a In all cases, perhaps, these pe- culiarities are dependent upon inappreciable structure, either of the organ concerned, or of the nervous branches distributed to it; at times, derived from progenitors ; at others, acquired, — often by association,—in the course of existence. Hence arise many of the antipathies to particular animate and inanimate objects, which we occasionally meet with, and of which Broussais relates a singu- lar instance in a Prussian captain, whom he saw at Paris in 1815. He could not bear the sight of a cat, a thimble, or an old woman, without becoming convulsed,and making frightful grimaces ! The associations must have been singularly complicated to occasion an antipathy to objects differing so signally from each other. Wagner,b of Vienna, has collected a multitude of cases of idiosyncrasy ; and the observation of every individual, whether of the medical pro- fession or not, must have made him acquainted with those pecu- liarities, that render a particular article of diet, which is innoxious, and even agreeable and wholesome to the generality of indivi- duals, productive, in some, of the most unpleasant effects. Haller knew a person who was always violently purged by the syrup of roses. A friend of the author is purged by opium, which has an opposite effect on the generality of individuals. Dr. Paris0 says he knew two cases, in which the odour of ipecacuanha always pro- duced most distressing dyspnoea : the author knew a young apothecary, who could never powder this drug without the super- vention of the most violent catarrh. A friend of Tissot could not take sugar without its exciting violent vomiting. Urticaria or nettle-rash is very frequently occasioned, in particular constitutions, • " Some love not <» gaping pig, And others, when the bngpip') sings i' th' nose, Cannot contain their urine lor affection." Shakspeare. b Hufeland and Himly's Journal der Pract. Heilkund., Nov. 1811, § 55.^ See, also, art. Idiosyncrasie, Diet, des Sciences Medicales, toni. xxii.; and Fletcher's Elements of General Pathology, p. 21, Lond. 1842. « Pharmacologia, 4lh Amer. Edit, by J. B. Beck, p. 189, New York, 1831. 576 INDIVIDUAL DIFFERENCES. by taking shell-fish. The same effect is produced on two young female friends of the author by eating strawberries ; and similar cases are given by Roose. M. Chevalier relates the case of a lady, who could not take powdered rhubarb without an erysipelatous efflorescence showing itself, almost immediately, on the skin ; yet she could take it in the form of infusion with perfect impunity. The above idiosyncrasies apply only to the digestive function. We find equal anomalies in that of the circulation. In some, the pulse is remarkably quick, upwards of one hundred in the minute; in others, it is under thirty. That of Napoleon is said to have beaten only forty-four times in a minute.3 It may also be unequal, and intermittent, and yet the individual be in a state of health.5 The senses offer us some of the most striking cases of this kind of peculiarity. Many strong individuals cannot bear the smell of the apple, cherry, strawberry, or of musk, peppermint, &c. Pope Pius VII. had such an antipathy to musk, that, on one occasion of presentation, an individual of the company having been scented with it, his holiness was obliged to dismiss the party almost immediately.0 The idiosyncrasies of taste are also numerous: some of these cases of singular and depraved sense we have de- scribed under the sense of taste. Dejean gives us the case of an indi- vidual of distinguished rank who was fond of eating excrement. Certain animals, again, as the turkey, have an antipathy to the colour of red; and Von Biichner and Tissot cite the case of a boy who was subject to epileptic fits whenever he saw any thing of a red colour. Occasionally, we meet with similar idiosyncrasies of audition. Sauvages relates the case of a young man labouring under intense headache and fever, which could not be assuaged by any other means than the sound of the drum. The noise of water issuing from a pipe threw Bayle into convulsions. The author has a singular peculiarity of this kind, derived from some accidental association in early life. If a piece of thin biscuit be broken in his presence, — nay, the idea alone is sufficient, — the muscles that raise the left angle of the mouth are contracted, and this irre- sistibly. The sense of tact is not free from idiosyncrasies. Wagner cites the case of a person, who felt a sensation of cold along the back, whenever he touched the down of a peach with the point of his finger; or when the down came in contact with any part of his skin. He was remarkably fond of the fruit, yet was unable to indulge his appetite unless a second person previously removed the skin. Prochaska relates the case of a person, who was affected with nausea whenever he touched this fruit. > See some cases of unusual slowness of the pulse, by Mr. H. Mayo, in Lond. Med. Gazette, May 5, 1838, p. 232; and Dunglison's American Medical Intelligencer, July 2, 1838, p. 103. In one case of fatal disease the pulse beat only nine in the minute ! b. Adelon, Physiologie de I'Homme, edit. cit. iv. 511. c Mathew's Diary of an Invalid. PECULIARITIES OF THE FEMALE. 577 It is, of course, all important, that the practitioner should be ac- quainted with these idiosyncrasies,and so far the notion of "know- ing the constitution," — which is apt to be used to the prejudice of the young practitioner, or of any except the accustomed medical attendant, — has some reason in it. It is the duty, however, of the patient to put the practitioner in possession of the fact of such pecu- liarities, so that he may be enabled to guard against them, and not take that for morbid which is. the effect of simple idiosyncrasy. This, however, is a topic which belongs rather to therapeutics.a 3. OF NATURAL AND ACQUIRED DIFFERENCES. 1. Natural Differences. —The temperaments, constitutions? and idiosyncrasies may, as we have seen, either be dependent upon original conformation, or they may be produced by external influ- ences ; hence, they have been divided into the natural and acquired. Under the former head are included all those individual differences, derived from progenitors, which impress upon the individual more or less of resemblance to one or both parents. It has been properly observed, that the individuality of any human being that ever existed was absolutely dependent on the union of one particular man with one particular woman ; and that if either the husband or the wife had been different, a different being would have been ushered into existence. For the production of Shakspeare, or Mil- ton, or Newton, it was necessary, that the father should marry the identical woman he did marry. If he had selected any other wife, there would have been no Shakspeare, no Milton, no Newton. Sons might have been born of other women, but they would not have been the same, either in mental or physical qualities. All this, however, enters into the question of the influence of both parents on the foetus in utero, which we have considered else- where. a. Peculiarities of the Female. — Amongst the natural differ- ences, those that relate to sex are the most striking. In a previous part of this volume, we have described the peculiarities of the sexual functions in both male and female, but other important dif- ferences have not been detailed. All the descriptions, when not otherwise specified, were presumed to apply to the adult male. At present, it will be only necessary to advert to the peculiarities of the female. The stature of the female is somewhat less than that of the male, the difference being estimated at about a twelfth. The chief parts of the body have not the same mutual proportions. The head is smaller and rounder ; the face shorter; the trunk longer, especially the lumbar portion, and the chest more convex. The lower extremities, especially the thighs, are shorter, so that the half of the body does not fall about the pubes, as in man, but higher. The neck is longer; the abdomen broader, larger, and * See the author's Therapeutics, p. 38, Philad. 1836 ; or his General Therapeutics and Mat. Med., Philad. 1843. vol. 11.—49 578 INDIVIDUAL DIFFERENCES. more prominent; and the pelvis has a greater capacity to adapt it for gestation and parturition. The long diameter of the brim is from side to side, whilst, in the male, it is from before to behind ; the arch of the pubis is larger, and the tuberosities of the ischia are more widely separated, so that the outlet of the pelvis is larger than in the male ; the hips are broader, and, consequently, the spaces between the heads of the thigh-bone greater ; the knees are more turned in, and larger than in the male ; the legs shorter, and the feet smaller. The shoulders are round ; but the width across them, compared with that of the hips, is not so great as in man; the arms are shorter, fatter, and more rounded ; the same is the case with the fore-arm ; the hand is smaller, and softer, and the fingers are more delicate. The whole frame of the female is more slender; the bones are smaller, their tissue is less compact, and the prominences and corre- sponding depressions are less marked; the subcutaneous cellular tissue is more abundant, and filled with a whiter and firmer fat; a similar adipous tissue fills up the intervals between the muscles, so that the whole surface is rounder, and more equable, than that of the male ; the skin is more delicate, whiter, better supplied with capillary vessels, and less covered with hair; the hair of the head, on the other hand, is longer, finer, and more flexible ; the nails are softer and of a more red hue; the muscles of the face are less distinctly marked, so that the expression of the eye, and the emo- tions, which occasion elevation or depression of the angles of the mouth,— laughing and weeping, for example,— are more strongly defined. On the whole, the general texture of the organs is looser and softer. The above observations apply to what may be' termed the standard fern ale,—one whose natural formation has not been inter- fered with by employments, which are usually assigned to the other sex. It can be readily understood, that if the female have been ac- customed to the laborious exercise of her muscles, they may become more and more prominent, the interstices between them more and more marked, the projections and depressions of the bones on which they move more distinct; the whole of the delicacy of struc- ture may be lost; and the skeleton of the female, thus circum- stanced, may be scarcely distinguishable from that of the inactive male, except in the proportions of the pelvis, in which the sexual differences are chiefly and characteristically situate. Many of the functions of the female are no less distinctive than the structure. The senses, as a general rule, are more acute, whether from original delicacy of organization, or from habit, is not certain ; — probably both agencies are concerned. The intel- lectual- and moral faculties are also widely different, and this, doubtless, from original conformation, although education may satisfactorily account for many of the differences observable be- tween the sexes. Gall is one of the few anatomists, who have attended to the comparative state of the cerebral system in the sexes ; and the results of his investigations lead him to affirm, PECULIARITIES OF THE FEMALE. 579 that there is a striking difference in the development of different parts of the encephalon in the two, which he thinks may account for the difference observable in their mental and moral manifes- tations. In the male, the anterior and superior, part of* the ence- phalon is more developed ; in the female, the posterior and infe- rior: the former of these he conceives to be the seat of the intel- lectual faculties ; the latter of those feelings of love and affection, which seem to preponderate in the character of the female. We have elsewhere said, that the views of Gall, on this subject, are not yet received as confirmed truths, and that we must wait until farther experience and multitudinous observations shall have ex- hibited their accuracy, or want of foundation. Independently, however, of all considerations deduced from organization, obser- vation shows, that the female exhibits intellectual and moral dif- ferences, which are by no means equivocal. The softer feelings predominate in her, whilst the intellectual faculties have the pre- ponderance in man. The evidences and character of the various shades of feeling and susceptibility, and the influence of educa- tion and circumstances on these developments, are interesting topics for the consideration of the moral philosopher, but admit of little elucidation from the labours of the physiologist. The only inference, to which he can arrive, is, that the causes of the diver- sity are laid in organization, and become unfolded and distinctive by education. The precise organization he is unable to depict, and the influence of circumstances on the mind it is scarcely his province to consider. The function of muscular motion is, owing to organization, more feebly executed in the female. We have already remarked; that the bones are comparatively small, and the muscles more deli- cately formed. The energy of the nervous system is also less ; so that all the elements for strong muscular contraction are by no means in the most favourable condition ; and, accordingly, the power the female is capable of developing by muscular contraction is much less than that of the male. Her locomotion is somewhat peculiar, — the wide separation of the hip-joints, owing to the greater width of the pelvis, giving her a characteristic gait. The vocal organs exhibit differences, which account for the difference in the voice. The chest and the lungs are of smaller dimensions : the trachea is of less diameter; the larynx smaller ; the glottis shorter and narrower; and the cavities, communicating with the nose, are of smaller size. This arrangement causes the female voice to be weaker, softer and more acute. The muscles of the glottis, and the ligaments of the glottis themselves, are apparently more supple, so as to admit of the production of a greater number of tones, and to favour singing. The phenomena of expression, as we have often remarked, keep pace with the condition of the intel- lectual and moral faculties, and with the susceptibility of the ner- vous system. As this last is generally great in the female, the language of the passions, especially of the softer kind, are more marked in her. i 580 INDIVIDUAL DIFFERENCES. The functions of nutrition present, also, some peculiarities. With regard to digestion, less food is generally required; the sto- mach is less ample ; the liver smaller ; and frequently, — at least more frequently than in the male, — the dentes sapiential do not appear.. The desire for food at the stated periods is not so power- ful; and it is generally for light and agreeable articles of diet rather than for the very nutritious ; but the appetite returns more frequently, and is more fastidious, owing to the greater sensibility of the digestive apparatus. This, however, is greatly an affair of habit, and we have more instances of prolonged abstinence in the female than in the male. The circulation is generally more rapid, the pulse being less full, but quicker. Of the secretions, that of the fat alone requires mention, which is usually more abundant and the product firmer. The cutaneous transpiration is less ac- tive, and the humour has a more acidulous odour. The urine is said, by some writers, to be less abundant, and less charged with salts ; whence, it is asserted, there is less disposition to calculous affections. So far, however, as we have had an opportunity for judging, it is secreted in greater quantity, and this may partly ac- count for its seeming to have a smaller quantity of salts in any given amount; but the truth is, the freedom of the female from calculous affections is greatly owing to the shortness and size of the urethra, which admits the calculus to be discharged with com- parative facility ; and it is a common observation, that where the males of a family, hereditarily predisposed to gout, become, owing to their greater exposure to the exciting causes, affected with that disease, the females may be subject to calculous disorders, — the two affections appearing to be, in some respects, congenerous. For the reasons already mentioned, stone rarely forms in the bladder of the female, and the operation of lithotomy is scarcely ever necessary. The desire to evacuate the contents of the bladder occurs more frequently in the female, probably, in part, owing to habit; and, in part, to the greater mobility of the ner- vous system. In addition to these differences as regards the secretions, the female has one peculiar to herself, — menstruation, — a function which has already engaged attention. In the progress of life, too, the glandular system undergoes evolutions which render it especi- ally liable to disease. About the period of the cessation of the menses, — sooner or later,— the mammae frequently take upon themselves a diseased action, and become scirrhous and cancerous so as to require the organs to be extirpated. In the treatment of disease, these sexual peculiarities have to be borne in mind. Owing to the greater mobility of the nervous system in the female, she usually requires a much smaller dose of any active medicine than the male ; and during the period when the sexual functions are particularly modified, as during menstrua- tion, gestation, and the child-bed state, she becomes liable to vari- ous affections, some of which have been referred to elsewhere; HABIT. 581 others belong more appropriately to works on pathology, thera- peutics or obstetrics.a 2. Acquired Differences.— The acquired differences, which we observe amongst individuals, are extremely numerous. The effect of climate on the physical and mental characteristics is strikingly exhibited. The temperate zone appears to be best adapted for the full development of man, and it is there, that the greatest ornaments of mankind have flourished, and that science and art have bloomed in exuberance; whilst in the hot, enervat- ing regions of the torrid zone, the physical and moral energies are prostrated; and the European or Anglo-American, who has entered them full of life and spirits, has left them after a few years' residence, listless and shorn of his proudest characteristics. Nor is the hyperborean region more favourable to mental and cor- poreal development; the sensibility being obviously blunted by the rigours of the climate. The effect of locality is, perhaps, most signally exemplified in the Cretin and the Goitreux, of the Valais, and of the countries at the base of lofty mountains in every part of the globe ; as well as in the inhabitants of our low coun- tries, who are constantly exposed to malarious exhalations, and bear the sallow imprint on the countenance. Not less effective in modifying the character of individuals is the influence of the way of life, education, profession, govern- ment, &c. The difference between the cultivated and the unculti- vated ; between the humble mechanic, who works at the anvil or the lathe, and him whose avocation, like that of the lawyer, and the physician,consists in a perpetual exercise of the organ of in- tellect ; and between the debased subject of a tyrannical govern- ment, and the independent citizen of a free state,— " Lord of the lion heart and eagle eye," is signala nd impressive. 1. Habit. — To the acquired differences in individuals from extraneous or intrinsic causes we must refer habit, which has been defined, — an acquired disposition in the living body, that has become permanent, and as imperious as any of the primitive dis- positions. It is a peculiar state or disposition of the mind, induced by ihe frequent repetition of the same act. Custom and habit are frequently used synonymously ; but they are distinct. Custom is the frequent repetition of the same act; habit is the effect of such repetition. By custom we dine at the same hour every day : the artificial appetite induced is the effect of habit. The functions of the frame are variously modified by this disposi- tion,— being, at times, greatly developed in energy and rapidity, at others, largely dminished. If a function be over and over again exerted to the utmost extent of which it is capable, both as regards energy and activity, it becomes more and more easy of execution ; * See, on the whole of this subject, Weber's Hildebrandt's Handbuch der Anatomie, iv. 527, Braunschweig, 1832. 49* \ 582 INDIVIDUAL DIFFERENCES. the organ is daily better adapted for its production, and is so habituated to it, that it becomes a real want — a second nature. It is in this way, that we accustom the organs of speech, locomo- tion, &c., to the exercise of their functions, until, ultimately, the most varied combinations of the muscular movements of the tongue and limbs can be executed with surprising facility. If, on the con- trary, the organs of any function possess unusual aptitude for ac- complishing it, and we accustom ourselves to a minor degree of Ihe same, we ultimately lose a part of the aptitude, and the organs be- come less inclined, and less adapted to produce it. By custom we may habituate ourselves to receive an unusually small quantity of nutriment into the stomach, so that at length it may become im- practicable to digest more. A similar effect occurs as regards the quantity of the special irritant, which we allow to impinge on any of the organs of sense. If we accustom them to be feebly impressed, yet sufficiently so for the performance of their functions, they become incapable of sup- porting a greater quantity of the special irritant without indicating suffering. The miner can see into the farthest depths of his exca- vations, when, to the eye of one, who has descended from the bright light of day, all seems enveloped in obscurity. In this case, the sensibility of the organ of sight is developed to such an extent, that if the individual be brought into even a feeble light, the im- pression is extremely painful. The nyctalope is precisely so situate. His nerves of sight are so irritable, that, although he can see well in the night, he is incapable of accurate discrimination by day. On the other hand, exposure to intense light renders the sensibility of the visual nerves so obtuse, that objects are not so readily per- ceived in obscurity. The hemeralope, who sees in the day and not in the,night, and who is consequently the antitheton of the nycta- lope, has the nervous system of vision unusually dull, and incapa- ble of excitement by feeble impressions. It may be laid down, as a general principle, that if we gradually augment the stimulus applied to any organ of sense, it becomes less susceptible of appreciating minor degrees of the same irritant; so that, in this way, an augmented dose of the irritant is progres- sively required to produce the same effect. This is daily exem- plified by the use of tobacco, — either in the form of chewing, smoking, or snuffing, which becomes a confirmed habit, and can only be abandoned —without doing great violence to the feelings — by attention to the principle deduced from practice, — that by gradually following the opposite course to the one adopted in ac- quiring the habit — that is, by accustoming the nerve of sense to a progressive diminution in the dose of the stimulus—an opposite habit may be formed, and the evil, in this manner, be removed. When, by habit, we acquire extreme facility in executing any function, it may be accomplished apparently without the direct agency of volition This is peculiarly applicable to ihe voluntary emotions. We have elsewhere shown, that, in this case, habit HABIT. 583 only communicates the facility, and that there is no natural sequence of motions, and consequently, no reason, — as in executing a rapid musical movement, — why one movement of the fingers should follow rather than another, unless volition were the guiding power. Volition, as Dr. Parr has remarked, is not an exertion of the mind, but apparently a simple impulse directed almost necessarily to an end; and it is affected, by custom, nearly like the organs of the body. Thus, a sensation, which excited a perceptible exertion of volition, will, in time, produce it and the correspondent action, without our being sensible of its interference; and so rapid is this process, that we seem to will two ends or objects at the same time, though they are evidently, when examined, distinct operations. But though, by custom, we are no longer sensible of bodily im- pressions, or of the exercise of volition, the corporeal organs, in their several functions, acquire, like those of the mind, peculiar ac- curacy of discrimination. The musician is not, for instance, sensi- ble of his willing any one motion; yet with the most exquisite nicety he touches a particular part of the string of the violin, and executes a variety of the nicest and most complicated movements with the most delicate precision. It is a common remark, that "habit blunts the feeling but im- proves the judgment." To a certain extent this is true ; but the feeling is not blunted unless the stimulant, which acts upon the organ of sense, is too powerful, and too frequently repeated. When moderately exercised, the effect of education, in perfecting all the senses, is strongly exhibited. Sensations, often repeated, cease to be noticed, not because they are not felt, but because they are not heeded; but if the attention be directed to the sensation, custom adds to the power of discrimination. Hence the sailor is able to detect the first appearance of a sail in the distant horizon, when it cannot be perceived by the landsman ; and a similar kind of dis- crimination is attained by the due exercise of the other senses. This greater power of discrimination is doubtless owing to im- provement in the cerebral or percipient part of the visual appara- tus ; but we have no evidence, that the organ of vision has its ac- tion necessarily blunted. It has been presumed,by some physiologists and metaphysicians, that the will, by custom and exercise, may acquire a power over certain functions of the body, which were not originally subject to it; nay, some speculatists have gone farther, and affirmed, that all the involuntary functions were originally voluntary, and that they have become involuntary by habit. Stahl and the other animists, who regarded the soul as the formative and organizing agent in animals, asserted, that it excites the constant movements of the heart, and of the respiratory, digestive and other nutritive organs, bV habits so protracted and inveterate, and so naturalized within us, that these functions can be effected without the aid of the will, and without the slightest attention being paid to tnera. ^P|ra- tion according to them, is originally voluntary ; but, by habit, has i 584 INDIVIDUAL DIFFERENCES. become spontaneous ; so that there is no farther occasion to invoke volition. Respiration goes on night and day, when we are asleep as well as awake; and they regard, as a proof that the action was originally dependent upon free will, that we are still able to acce- lerate or retard it at pleasure, They cite, moreover, the case of Colonel Townshend, related in another part of this work, (p. 124 of this volume,) to show, that the action of the heart is capable of being influenced by the will; and, likewise, the fact that it is ac- celerated or retarded under the different passions. Condillac, Dutrochet, and De Lamarck,3 again, fantastically as- sert, that the different instincts, observed to prevail so powerfully in animals, are mere products of an acquired power, transmitted through successive generations. The views of the last distin- guished naturalist, regarding the effect of habit on organization, which he considers to tend to greater and greater complication, are most singular and fantastic. It is not, he considers, the organs of an animal that have given rise to its habits; on the contrary, its habits, mode of life, and those of its ancestors have, in the course of time, determined the shape of its body, the number and condition of its organs, and the facilities, which it enjoys. Thus the otter, the beaver, the waterfowl, the turtle, and the frog were not made web-footed that they might swim ; but their wants hav- ing attracted them to the water, in search of prey, they stretched out their toes to strike the water, and move rapidly along its sur- face. By the repeated stretching of the toes, the skin, which united them at the base, acquired a habit of extension, until, in the course of time, they became completely web-footed. The camelopard, again, was not gifted with a long flexible neck, be- cause it was destined to live in the interior of Africa, where the soil is arid and devoid of herbage ; but, being reduced, by the na- ture of the country, to support itself on the foliage of lofty trees, it contracted a habit of stretching itself up to reach the high boughs, until its forelegs became longer than the hinder, and its neck so elongated that it could raise its head to the height of twenty feet above the ground ! The objections to all these views are, — that the functions in question are as well performed during the first day of existence as at an after period, and are apparently as free from the exercise of all volition. The heart, indeed, beats through foetal existence for months before the new being is ushered into the world ; and when, if volition be exerted at all, it can only be so obscurely. The case of Colonel Townshend is strange — passing strange — but it is almost unique, and the power of suspending the heart's action was possessed by him a short time only prior to dissolu- tion. All the functions in question must, indeed, be esteemed natural, and instinctive, inseparably allied to organization ; and * Philosophic Zoologique, torn. i. p. 218, and torn. ii. p. 451, edit. 1830 ; Adelon, art. Habitude, Diet, de Medecine, x. 501, Paris, 1824 ; and Physiologie de I'Homme, 2de edit. iv. 517, Paris, 1829. ASSOCIATION. 585 hence differing from the results of habit which is always ac- quired. The opinion of Bichat, on the other hand, was, that habit influ- ences only the animal functions, and has no bearing on the organic or nutritive. But this is liable to objections. We have seen, under Digestion, that if a bird, essentially carnivorous in its nature, be restricted to vegetable food, the whole digestive economy is modified, and it becomes habituated to the new diet. Wre know, also, that where drains are established in any part of the body, they-become, in time, so much a part of the physiological condi- tion of the frame, that they can only be checked with safety by degrees.* In the administration of medicines, habit has always to be at- tended to. The continued use of a medicine generally diminishes its power ; — hence the second dose of a cathartic ought to be larger than the first, if administered within a few days. Certain cathar- tics are found, however, to be exceptions to this. The Cheltenham water and the different saline cathartics are so. The constitution, so far from becoming reconciled to lead by habit, is rendered more and more sensible to its irritation. Emetics, too, frequently act more powerfully by repetition. Dr. Cullen asserts, that he knew a person so accustomed to excite vomiting on himself, that the one-twentieth part of a grain of tartarized antimony was sufficient to produce a convulsive action of the parts concerned in vomiting. As a general rule, however, medicines lose their effect by habit, and this is particularly the case with tonics ; but if another tonic be substituted for a day or two, and then the former be resumed, it will produce all its previous effects.b 2. Association. — Association, employed abstractedly,is a prin- ciple of the animal economy nearly allied to habit. When two or more impressions of any kind have been made upon the nervous system, and repeated for a certain number of times, they may be- come associated; and if one of them only be produced it will call up the idea of the others. It is a principle, which is largely invoked by the metaphysician, and by which he explains many interesting phenomena of the human mind, especially those connected with our ideas of beauty, or the contrary ; our likes and dislikes, and our sense of moral propriety. Darwin0 employed it to explain many complicated functions of the economy; and he laid it down as a law, that all animal motions, which have occurred at the same time or in immediate succession, become so associated, that when one of them is reproduced, the other has a tendency to accompany or succeed it. The principle has, doubtless, great agency in the production of many of the physical, as well as mental, pheno- mena ; but its influence has been overrated; and many of the » Adelon, in Diet, de Med. x. 498; and Physiologie de I'Homme, edit. cit. iv. 525' see, also, Lepelletier, Physiologie Medicale et Philosophique, i. 259, Paris, 1831. b See the author's General Therapeutics, p. 42, Philad. 1836. e Zoonomia, i. 49, Lond. 1794. 586 INDIVIDUAL DIFFERENCES. consecutive and simultaneous actions, to which we have referred under the head of Correlation of Functions, take place, apparently as well the first time they are exerted, as subsequently. Sucking and deglutition are good cases of the' kind. Soon after birth, the muscles of the lips, cheeks, and tongue are contracted to embrace the nipple, and to diminish the pressure in the interior of the mouth ; and, as soon as the milk has flowed to the necessary ex- tent into the mouth, certain voluntary muscles are contracted. These propel the milk into the pharynx, where its farther progress is effected by muscles, associated or connected functionally, but not in the sense we are now employing the epithet; for here one action could not suggest another, according to the definition we have given of association, which requires that the acts should have been executed previously. Many of the cases, in fact, as- cribed by Darwin and Hartley3 to the agency of this principle, are instinctive actions, in which a correlation — as in the case of deglu- tition— exists, but without our being able to explain the nature of such correlation, any more than we can explain other compli- cated actions and connexions of the nervous system, of which this is doubtless one. Some of the most obstinate diseases are kept up by habit, or by accustomed associated motions ; and, frequently, the disease will seem to continue from this cause alone. When- ever intermittent fever, epilepsy, asthma, chorea, &c, have been long established, the difficulty of removing the influence of habit, or the tendency to recurrence, is extreme. In such cases, the principle of revulsion can be invoked with much advantage by the therapeutist.b 3. Imitation. — The principle of imitation falls appropriately under this section. It may be defined — that consent of parts, depending on similar organization, which, under the influence of the brain, enables them to execute acts similar to those executed by the same parts in another individual. Imitation, consequently, requires the action of the brain ; and differs from those actions that are natural or instinctive to organs. For example, speech requires the action of imitation ; whilst the ordinary voice or cry is effected by the new-born, and by the idiot, who are incapable of all observation, and consequently of imitation. The mode in which speech is acquired, offers us one of the best examples of this imitative principle, — if we may so term it. At a very early period, the child hears the sounds addressed to it, and soon attaches ideas to them. It discovers, moreover, that it is capable of pro- ducing similar sounds with its own larynx, and that these sounds are understood, and are inservient to the gratification of its wants ; and, in this way, speech, as we have elsewhere seen, (vol. i., page 442,) is acquired. The difficulty is to understand in what manner this singular consent is produced. Sir Gilbert Blanehas properly remarked, that the imitation of gestures, is, at first sight, less un- * On Man, i. 102, Lond. 1791. b The author's General Therapeutics, p. 42 ; or his General Therapeutics and Mat. Med., Philad. 1843. VARIETIES OF MANKIND. 587 accountable than that of sounds ; as they are performed by mem- bers which are objects of sight, and would seem therefore to be more readily transferable to the corresponding parts of another person : but he probably errs, when, farther on, he remarks, that when children begin to articulate, they first attempt those letters, in the pronunciation of which the motions of the organs are the objects of sight; such as the p and b, among consonants, and the broad a, among the vowels, "giving occasion to a well-known etymology, from the infanjile syllables, expressive of father and mother in all languages." We do not think, that this explanation is happy; and have elsewhere attempted to show, that the com- bination of letters, and the words referred to, are first enunciated, because they are the easiest of all combinations; and that the ex- pressions of mama, papa, &c, are employed long before the child has acquired the power of imitation, and long prior to his attaching the meaning to the words which he is subsequently taught to adopt. It is certainly singular how the child can learn to imitate sounds, where the action of the organs concerned is completely concealed from view. The only possible way of explaining it is to presume, that it makes repeated attempts with its vocal appa- ratus to produce the same sound which it hears; and that it re- collects the sensation produced by the contraction of the muscles when it succeeds, so as to enable it to repeat the contraction of the muscles, and the sensation, at pleasure. This is, however, a case in which volition is actively exerted. We have others, where the action occurs in spite of the individual, as in yawning. We see the action in a second person, and, notwithstanding all our attempts to the contrary, the respiratory organs are excited through the brain, and we accomplish the same act. Nay, even thinking of the action will be sufficient to arouse it. Of a like nature to this is the sympathetic contraction of the uterus, which comes on, where a pregnant female is in the lying-in chamber during the accouchement of another, and to which we have referred under the head of Sympathy.3 Many morbid phenomena are excited in a similar manner:—of these, squinting and stammering are familiar examples. Of 321 cases of squinting, of which the ex- citing causes were investigated, 61 were found to be produced by imitation.b 4. OF THE VARIETIES OF MANKIND. To determine the number of varieties, into which the great human family may be divided, is a subject which has been con- sidered to belong so completely to the naturalist that we shall pass it over with a brief inquiry. If we cast our eye over the globe, although we may find, that mankind agree in their general form and ?'ganlzallon'l{je~ a/re many points in which they differ materially from each other. With those forms, proportions and colours, which we considei so beautiful in the fine figures of Greece,-to use the anguage of ' See Rostock's Physiology, ed. cit. p. 759. - Med. Examiner, July 10,1841, p. 439. 1 5gg INDIVIDUAL DIFFERENCES. Mr. Lawrence, — contrast the woolly hair, the flat nose, the thick lips, the retreating forehead, advancing jaws, and black skin of the negro; or the broad, square face, narrow oblique eyes, beard- less chin, coarse, straight hair, and olive colour of the Calmuck. Compare the ruddy and sanguine European with the jet black African, the red man of America, the yellow Mongolian, or the brown South-Sea Islanders ; the gigantic Patagonian, or the dwarfish Laplander; the highly civilized nations of Europe, so conspicuous in arts, science, literature, in all that can strengthen and adorn society, or exalt and dignify human nature, to a troop of naked, shivering, and starved New Hollanders, a horde of filthy Hottentots, or the whole of the more or less barbarous tribes, that cover nearly the entire continent of Africa ; and although we must refer them all to the same species, they differ so remarkably from each other as to admit of being classed in a certain number of great varieties ; but with regard to the precise number, naturalists have differed materially. Whatever changes have been impressed upon mankind can, of course, apply only to the descendants of Noah. The broad dis- tinctions, we now meet with, could not have existed in his imme- diate family, saved with him at the time of the deluge. They must necessarily have all been of the same race. None of our investigations on this subject can, consequently, be carried back into antediluvian periods. Hence, the region, on which the ark rested, must be looked upon as the cradle of mankind. The ques- tion of the original residence of man has frequently engaged the attention of the philologist. It is one, which could be answered positively by the historian only, but unfortunately the evidence we possess of an historical character is scanty in the extreme, and the few remarks, in the sacred volume, are insufficient to lead us to any definite conclusion. As far back as the date of the most remote of our historical records, — which extend to about two thousand years prior to the Christian era, — we find the whole of Asia and a part of Africa, — probably a large part,— peopled by different nations, of various manners, religion, and language; car- rying on extensive wars with each other; with here and there, civilized states, possessing important inventions of all kinds which must have required a length of time for discovery, improvement, and diffusion. After the subsidence of the deluge, the waters would first recede from the tops of the highest mountains, which would thus be the earliest habitable ; and, in such a situation, the family of Noah probably increased, and thence spread abroad on the gradual recession of the waters. The earliest habitable region was probably the elevated region of middle Asia, — the loftiest in the world,— not the summits, which would be unsuitable,in every respect, for human existence, but some of the lofty plains, such as that, of which the well-known desert Kobi or Schamo forms the highest point, and whence Asia sinks gradually towards the four quarters, and the great mountain chains proceed that intersect VARIETIES OF MANKIND. 5S9 Asia in every direction. This has been suggested by Herder8 and Adelungb as the cradle of the human race. In the declivities of this elevated region, and of its mountain chains, all the great rivers arise that flow on every side through this division of the globe. After the deluge, it would therefore soon become dry, and project, like an extensive island, above the flood. The cold and barren elevation of Kobi would not itself have been well adapted for the continued residence of our second parents, but immediately on its southern side lies the remarkable country of Thibet, separated by lofty ridges from the rest of the world, and containing within itself every variety of climate. Although on the snow-capt summits the severest cold perpetually prevails, sum- mer eternally reigns in the valleys, and well-watered plains. The rice, too, the vine, pulse, and a variety of other productions of the vegetable kingdom, which man employs for his nutrition, are indi- genous there: and those animarls are found in a wild state which man has domesticated and taken along with him over the earth; — the ox, horse, ass, sheep, goat, camel, swine, dog, cat, and even the valuable reindeer,— his only friend and companion in the icy deserts of polar countries. Zimmermann,c indeed, asserts, that every one of the domesticated animals is originally from Asia. Close to Thibet, and immediately on the declivity of this great cen- tral elevation, is the charming region of Kaschemire, the lofty site of which tempers the southern heat into a protracted spring. The probabilities in favour of the cradle of mankind having been situate to the south of the elevated region of middle Asia are considered to be strengthened by the circumstance of the nations in the vicinity possessing a rude, meagre and imperfect language, such as might be imagined to have existed in the infancy of the human intellect and of the world. Not less than two hun- dred millions of people are found there, whose language appears to be nearly as simple as it must have been soon after its formation. Kaschemire, by reason of the incessant changes, which it has ex- experienced in ancient and modern times, has, indeed, kept pace with the rest of the world in the improvement of its language; but not so, apparently, with Thibet —its neighbour—and with China, and the kingdoms of Ava, Pegu, Siam, Tunkin, and Cots- chinschina. All these extensive countries and these alone in the known world, according to Adelung, betray the imperfection of a newly-formed or primitive language. As the earliest attempt of the child is a stammering of monosyllabic notes, so, —says that eminent philologist, — must have been that of the original child of nature ; and, accordingly, the Thibetans, the Chinese, and their two neighbours to the south continue to stammer monosyllabically, as they must have been taught, thousands of years ago, in the infancy of their race. " No separation of ideas into certain a Ideen zur Philosophic der Geschichte der Menschheit, Riga und Leipz. 1785-1792 b Mithridates oder Allgemeine Sprachenkunde, Berlin, 1806-1817 Erster I he.I. Einleitung. c Geograph. Geschichte der Menschen, u. s. w. Leipz. 1778. VOL. II- — 50 590 INDIVIDUAL DIFFERENCES. classes, whence arose the parts of speech in cultivated languages. The same sound, which denotes joyful, signifies joy and to glad- den, and this in every person, number and tense. No art, con- nexion, or subordinate ideas are united to the rude, monosyllabic root, thereby communicating richness, clearness and euphony to their meagre tongue. The rude, monosyllabic, radical ideas are placed, perhaps broken, and detached from each other, the hearer being left to supply the intermediate ideas. As the monosyllable admits of no inflection, the speaker either makes no distinction between cases and iiumbers, or he seeks for aid, in cases of great necessity, in circumlocution. The plural he forms, like the child, either by repetition,— tree, tree, — or by the addition of the words much or more, as tree much, tree more. I much, or I more is the same to him as we." From these and other circumstances, Adelung infers,that these monosyllabic languages are primitive and the honourable ancestors of all others; but the argument is more plausible perhaps than sound. Is has been correctly remarked by the author's distinguished friend, Mr. Duponceau, that, in all lan- guages, there is a strong tendency to preserve their original struc- ture, and that from the most remote period, to which the memory of man can reach, a monosyllabic language has never been known to become polysyllabic, or conversely. Adelung farther infers, that the immediate descendants of Noah originally occupied the favoured region which has been described, and, as population increased, spread into the neighbouring districts, selecting, by pre- ference, the near and charming regions of the south, east, and west. Hence we find, in the countries immediately bordering on Thibet, the earliest formed states, and the oldest civilization. His- tory refers us to the east, for the primordial germs of most of our ideas, arts and sciences, whence they subsequently spread to the countries farther to the west — to Media, Persia, and western Asia. 1. Division of the Races. — It is probable that from western Asia, the sons of Noah, — Shem, Ham and Japheth, — branched off in various directions, so as to constitute the three distinct stocks which are found to have divided the old world from time imme- morial. These three are—l,the White, Caucasian, Arabico-Euro- pean, or European ; 2, the Olive, Mongolian, Chinese, Kalmuck, or Asiatic ; and 3, the Negro, Ethiopian, Africian, Hottentot, &c, each of which has its own principal habitat; — the white being found chiefly in Europe and Asia Minor, Arabia, Persia, and India as far as the Ganges, and in North Africa; the Mongol occupying the rest of Asia, and having its focus on the plateaux of Great Tartary and Thibet; and the negro race covering almost the whole of Africa, and some of the Isles of New Guinea, the country of the Papuas, &c. The white or Caucasian variety are supposed to be the descendants of Japheth (" audax Japeti genus," Horace) ; the Asiatic the descendants of Shem ; whilst Ham is re- garded as the parent of the African. These three races, — the VARIETIES OF MANKIND. 591 Caucasian, Negro, and Mongolian, — are alone admitted by Cuvier.a Blumenbach,b whose classification will serve our pur- pose as well as any of the others to which reference will be made presently, admits four, — the Caucasian, Ethiopian, Mongolian, American and Malay. a. Caucasian Race. — The Caucasian race is chiefly distin- guished by the elegant form of the head, which approxi- Fig. 289. mates to a perfect oval. It is also remarkable for varia- tions in the shades of the com- plexion and colour of the hair. From this variety, the most civilized nations have sprung. The name Cauca- sian was given to it from the group of mountains between the Caspian and the Black Sea, — tradition seeming to refer the origin of this race to that part of Asia. Even at the present day, the peculiar characteristics of the races are found in the highest per- fection amongst the people who dwell in the vicinity of Mount Caucasus, — the .Geor- gians and Circassians, — who are esteemed the handsomest Caucasian variety. natives of the earth. The marginal figure is given by Blumenbach as a specimen of the Caucasian race, near the original residence whence the epithet is derived. It represents Jusuf Aguiah Efendi, formerly ambas- sador from the Porte to London. The Caucasian race has been subdivided into several great na- tions or families: — 1. The .^mos,comprising the Arabs of the desert or the Bedouins, the Hebrews, the Druses and other inhabitants of Libanus, the Syrians, Chaldseans, Egyptians, Phoenicians, Abyssinians, Moors, &e. 2. The Hindoos on the European side of the Ganges ;—as the inhabitants of Bengal, of the coasts of Coromandel and Malabar, the ancient Persians, &c. 3. The Scythians and European Tartars, comprising also the Circassians, Georgians, &c. 4. The Kelts or Celts, a dark-haired race, whose precise origin is unknown, but presumed to be Indian. The de- scendants of this race are the Gauls, Welsh, Rhaetians, &c, &c.; a Regne animal; also, Elemens de Zoologie, par H. Milne Edwards, p. 259, Paris, l8"3 Handbuch der Naturgeschichtes, § 52, Gotting. 1791; and De Generis Hurnani Varietal Nativ., Gotting. 1777. See, also, Bufton, Hist. Nat. tu. 37 ; Beclard, Ele- menfr Anatomie Genlrale, p. 110, 2de edit. Paris,1827 ; Darner..Zoo, 0g,e Ana- lytique, Paris, 1806 ; and Lawrence's Lectures on Physiology, &c, Lond. 1839. 592 INDIVIDUAL DIFFERENCES. and lastly, the Goths, a fair-haired race, the ancestors of the Ger mans, Dutch, Swedes, Danes, &c. That the time of the first peopling of the European countries must have been very remote is exhibited by the fact, that at the dawn of history, the whole of Europe, from the Don to the mouth of the Tagus, was filled with nations of various physical characters and languages, bearing striking marks of intermixture and modifi- cation. At this period, there were, in Europe, at least six great nations. 1st. The Iberians with the Cantabri, in Spain, in a part of Gaul, and on the coasts of the Mediterranean as far as Italy. 2dly. The Kelts, in Gaul, in the British Isles, between the Danube and the Alps, and in a part of Italy. 3dly. The Germaniox Goths, between the Rhine, the Danube and the Vistula. 4thly. The Thracians, with the Illyrians, in the southeast of Europe, and in western Asia. 5thly. The Sclavi, in the north : and 6thly. The Fins in the northeast. It is not improbable, that these different races migrated from Asia in the above order — such at least is the theory of certain historians and philologers, and there is some reason for adopting it. They who migrated first would probably extend their wanderings until they were arrested by some invincible ob- stacle, or until the arrival of fresh tribes would drive them onwards farther and farther towards the west. In this way, they would ultimately reach the ocean, which would effectually arrest their farther progress, unless towards the south and the north. The descendants of the ancient Iberians do now actually occupy the west of Spain, — the residence probably of their forefathers. Nearly about the same time, perhaps, as the Iberians undertook their migration, the Kelts, a populous tribe, migrated from some part of Asia, and occupied a considerable portion of middle Eu- rope. To these succeeded the Goths, to the north, and the Thra- cians to the south; whilst the Sclavi, the last of the Asiatic emi- grants, wandered still farther north. It is not easy to determine the precise link occupied by the Fins in this vast chain of nations, They were first known to history as a peculiar people in the north of Europe ; but whence they proceeded, or whether they occupied their position to the north of the Germani from choice, or were urged onwards by their more powerful neighbours, we know not. So long as there was sufficient space for the nations to occupy, without disturbing the possessions of their neighbours, they proba- bly kept themselves distinct ; but as soon as the land was filled, a contest arose for the possession of more extensive or more eligible regions; wars were, consequently, undertaken, and the weaker gradually yielded their possessions, or their sovereignly, to the stronger. Hence, at the very dawn of history, numerous nations were met with, amalgamated both in blood and language ; — for example, the Kelto-Iberians of Spain ; the Belgae or Kymbri of Gaul and Britain ; the Latins, and other nations of Italy, and pro- bably many, whose manners, characters, and language had become so melted into each other as to leave little or no trace of the origi- 0 nal constituents. The Letti, Wallachians, Hungarians, and Alba- DIVISION OF THE RACES. 593 nians of eastern Europe, are supposed to afford examples of such amalgamation, whilst the mighty Sclavonic nation, has swallowed up numbers of less powerful tribes, and annihilated even their names for ever. This it is, which frequently embarrasses the phi- lological historian ; and prevents him, without other evidence, from deducing with accuracy the parent stocks or the most important components in ethnical admixtures. . Dr. Morton,* in his splendid and valuable contribution to the Natural History of Man, subdivides the Caucasian race into seven families : — the Caucasian, the Germanic, the Celtic, the Arabian, the Libyan, the Nilotic and the Indostanic. b. Ethiopian Race*—The Negro, African, Ethiopian ox Black man of Gmelin occupies a less extensive surface of the globe, em- bracing the country of Africa which extends from the southern side of Mount Atlas to the Cape of Good Hope. This race is evidently of a less perfect organization than the last, and has some charac- teristics, which approximate it more to the monkey kind. The forehead is flattened and retiring; the skull is smaller, and holds from four to nine ounces of water less than that of the European. On the other hand, the face, which contains the organs of sense, is more developed, and projects more like a snout. The lips are large; the cheek bones prominent; the temporal fossa? hollower; the muscles of mastication stronger ; and the facial angle is smaller ; — the head of the negro, in this respect, holding a middle place between the Caucasian and the orang-outang. The nose is ex- panded; the hair short and woolly, very black and frizzled. Skin black. This colour is not, however, characteristic of the race, as the Hottentots and Caffres are yellow. The marginal figure is the head of J. J. E. Capitein, selected by Blumenbach as the representative of his race. He was an intel- ligent negro, and published se- veral sermons and other works Fis- 29°- in Latin and Dutch. His por- trait was taken by Van Dyk. This case of great intelligence in the negro is almost unique; and it exhibits what may be expected from him under fa- vourable circumstances. In almost all situations in which he is found, it is in a state of slavery and degradation, and no inference can be deduced regarding his original grund- k r a f t — as the Germans call it — or intellectual capability. Hayti has afforded numerous examples of the sound judgment, and even distinguished ability 1 Crania Americana, p. 5, Philad. 1839. 50* 594 INDIVIDUAL DIFFERENCES. with which her sable inhabitants are capable of conducting, not only the municipal, but the foreign concerns of a considerable community. It must be admitted, Fig. 291. however, that from organization, this race would seem to be, casleris pari- bus, less fitted for intellectual distinc- tion than the Caucasian," and singular differences have been observed be- tween them and the Caucasian race, when exposed to similar mental and physical inflfiences.b The Ethiopian race- is subdivided by Dr. Morton0 into six families: — the Negro; the Caffrarian; the Hot- tentot ; the Oceanic Negro ; the Aus- tralian, and the Alforian.d c. Mongolian Race. — The Mon- golian', Asiatic, Kalmuck or Chinese race, the brown man of Gmelin, is recognised by prominent and wide cheek bones; flat, square visage; small and oblique eyes ; straight and Mongolian variety. black hair; scanty beard, and olive complexion. The marginal head is from Blumenbach. It is that of Feodor Ivanowitsch, a Kalmuck, given by the Empress of Russia to the hereditary Princess of Baden. He was educated at Carlsruhe, and was a most distinguished painter at Rome. The portrait was sketched by Feodor himself. The Mongols are spread over the central and eastern parts of Asia, with the exception of the peninsula of Malacca. They like- wise stretch along the whole of the Arctic regions, from Russia and Lapland to Greenland, and the northern parts of the American continent, as far as Behring's Straits, — the Laplanders and Esqui- maux being evidently of the same race as the Koriaks, Kamtscha- dales, Japanese, &c, of the Asiatic continent. Dr. Morton includes in this race five families : — the Mongol- Tartar; the Turkish; the Chinese; the Indo-Chinese, and the Polar. a See vol. i., p. 295. b See abstract of a memoir by Dr. B. H. Coates, " on the effects of secluded and gloomy imprisonment on individuals of the African variety of mankind in the produc- tion of disease," in Proceedings of the American Philosophical Society, vol.3, p. 143, Philad. 1843. c Op citat. p. 7. Physiologie Medicale, torn. i. j Essai sur les Races Humaines, p. 25, Paris, 1836. ORIGIN OF THE DIFFERENT RACES. 597 viduals composing each variety are far from being alike. We find ' the greatest diversity, for example, amongst the nations of the Cau- casian variety, and even amongst anv of its subdivisions. The Frenchman can be distinguished from' the German, the Spaniard from the English, &c, and if we were to push the system of subdi- viding, which appears at present to be fashionable, we might con- stitute almost every nation of the globe into a distinct variety.3 2. Origin of the Different Races. — It has been an oft agitated question, whether all the varieties amongst mankind must be re- garded as belonging to the same species, — the differences which we observe having been accomplished by extraneous circum- stances, acting through a long succession of ages ; or whether they must not be regarded as distinct species, ab origine.h By many, the discussion of this subject has been esteemed not only unneces- sary but profane, inasmuch as the sacred historian has unequi- vocally declared, that all mankind had a common origin. We have already remarked, however, that this is not a question, which concerns our first parents, but belongs exclusively to the family of Noah; for, in his descendants, all these varieties must necessarily have occurred. From the part of Asia, previously described, his immediate descendants probably spread abroad to the north and the south, the east and the west; Europe being peopled by the migratory hordes, which proceeded towards the northwest, and Africa by those from southwestern Asia. These migrations pro- bably all took place by land, except in the case of our own continent, where a slight sea-voyage, of not more than thirty-nine miles, across Behring's Straits, even in frail vessels, would be sufficient to transport the emigrants without much risk of misadventure ; and even this short voyage would be rendered unnecessary during the winter seaspn, the strait being solidified into a continuous mass of ice. Europe probably received its inhabitants long before navigation existed to any extent. Subsequently, when a coasting trade was first established, — to which the enterprise of nations would necessarily be limited in the first instance, until by im- proved vessels and a better system of management they were enabled to brave the terrors of the ocean, and undertake their adventurous voyages of discovery, — many of the coasts, especially of the Mediterranean, received swarms of emigrants, a circum- stance, which accounts for the motley population, observable, at an early period, in these regions. Carthage, we know, was set- tled by the Phoenicians, and Southern Italy and Spain, in this manner, received their Greek colonies. Dr. Copland0 has even » Art. Menschen-Varietaten, in Pierer's Anat. Phys. Real Worterbuch, v. 153. b Lawrence, op. citat.; Weber's Hildebrandt's Handbuch der Anatomie, iv. 529, Braunschweig, 1832 ; J. Cloquet, Anatomie de I'Homme, torn. i. pi. 29, Paris, 1821 ; Lacepede, art. Homme, in Diet, des Sciences Naturel. xxi. 382 ; J. E. Doornik, Wysgeerig Natuurkundig Onderzoek aangande den Oorsprongliken Menschen de Oorspronglike Stammen von deszelfs Geslacht. Amsterd. 1828; Elliotson's Human Physiology, 1062, Philad. 1840 ; Prichard, Researches into the Physical History of Mankind, 3d edit. vol. i. Lond. 1836; and Nat. History of Man, Lond. 1843. <■ Notes to translation of Richerand's Physiology. 59S INDIVIDUAL DIFFERENCES. expressed his belief in the view, that this continent was visited " by Phoenician navigators, the greater part of whom settled in it, particularly in Mexico ; and that the imperfect navigation of that era prevented many of the adventurers, if not all of them, from returning." The notion is, however, altogether hypothetical. The greatest difficulty has been,—to comprehend how the Cau- casian and Ethiopian varieties could have originated from the same source. The other varieties of mankind, if we exclude the negro, could be referred, without much hesitancy, to the same primitive stock, — the changes being caused by adventitious circumstances operating for an immense period, — but it has seemed to many naturalists impossible to suppose, that the characters of the negro could, by any process, become converted into those of the Euro- pean, or conversely. The people of antediluvian times probably possessed but few physical differences, — constituting one large family, modified, per- haps, to a certain extent, by circumstances, but not materially; the two antithetical races, — the white and the black, — first arising in postdiluvian periods. If we adopt this view, the question, regarding the difference of species between the white and the black, will require no agitation. But how are we to explain the essential differences as to form and colour, which we notice amongst the nations of the earth ? In the infancy of anthropology, it was asserted, that the white races inhabit the cold and temperate regions of the earth, whilst the tawny and darker races are situate under a more vertical sun. Within certain limits, the sun is doubtless possessed of the power of modifying the colour. The difference between one, who has been for some time exposed to the rays of a tropical sun, and his brethren of the more temperate climates, is a matter of universal observation. The inhabitant of Spain is, in this way, distinguish- able from the French, German, English, &c.; and hence we can understand, why the Southern Asiatic and African women of the Arab race, when confined within the walls of the seraglio-, may be as white as the fairest Europeans. There are many excep- tions, however, to the notion which has prevailed, that there is an exact ratio between the heat of the climate and the blackness of the skin. For example, at the extreme north of Europe, Asia, and America, we find the Laplanders, Samoiedes, Esquimaux, &c, with the skin very brown, and the hair and iris black ; whilst, in the vicinity of the Laplanders, are the Fins, — a people of large stature compared with the Laplanders, with fair skins and bluish- gray eyes. In the same manner, to the south of the Greenlander, — of short stature, brown skin, and dark hair,—is the tall and fair Icelander, The Kelt of Wales, and of the western coast of . Ireland, of the north of Scotland, and of the west of Bretagne, is still distinguished, by his dark hair and eyes, from the light-haired descendants of the Goth, — the German and the Scandinavian. Many distinct tribes exist in the interior of Africa, having a red or copper hue, with lank black hair, and in the midst of the black ORIGIN OF THE DIFFERENT RACES. 599 varieties of their species. A similar fact was observed by Hum- boldt in different parts of South America. Again, the negro race is not always found in the torrid zone. On our own continent, none have ever been met with, except what have been imported : and these, after repeated descents, have still retained their original character ; whilst, as we have seen, negroes are met with in Aus- tralia under a climate as cold as that of Washington. The fact of the slight mutation, effected by ages on the character of a race, is strikingly shown by the circumstance to which we have before referred,—that in some of the monuments of Egypt, visited by Belzoni and Champollion, representations of the negro, presumed to be upwards of three thousand years old, exhibit the features to be almost identical with those of the negro of the present day. The Jew affords an example of the same immutability, as well as the Esquimaux, who strikingly retain the evidence of their Kal- muck origin. Complexion, and, to a certain extent, the figure are doubtless modified by climate, but the essential characters of the organization remain little if at all changed. Volney has fancifully supposed, that the elongated visage of the negro is owing to the wry face habitually made under exposure to the rays of the sun. Independently, however, of the objection, that this would be wholly insufficient to account for the striking peculiarities of the negro head, it has already been remarked, that these peculiarities do not exist among other races, inhabiting equally hot climes; and that the negro himself is not confined to those climates, and ought, consequently, to lose the museau or snout, when the country is so cool as to render the wry face or moue unnecessary.3 It may then, we think, be concluded, that the evidence in favour of the colour of the negro, of the red man, or of the tawny, being produced directly or indirectly by the solar rays, is insufficient to establish the point. One important argument in the negative is the fact, that in all cases, the children are born fair, and would continue so, if not exposed to the degree of solar heat, which had produced the change in their progenitors.11 In addition to the influence of temperature, and climate, that of food, and of different manners and customs has been frequently invoked, but without any precise results being deduced. The effect of difference in manners and customs is shown in the results of domestication on animals,— as in the case of the wild and the disciplined horse ; of the bison and the ox, — which last is regarded as the bison in a state of tameness. The precise cause of such modification we know not. It is not confined to the ani- mal, but is signally evidenced in the vegetable. The flower of the forest, when received into .the parterre and carefully nurtured, will develope itself in such a manner as to be with difficulty re- cognizable. The change seems to be produced by variation of climate and nutrition, but in what precise manner we know not. The powerful modifying influence of locality on the develop- * Art cit. in Diet, des Sciences Mcdicales. b Fletcher's Rudiments of Phys.ology, part in. p. 69, Edinb. 1837. 600 INDIVIDUAL DIFFERENCES. ment of the moral and physical powers has been more than once referred to. Perhaps the most remarkable examples are met with at the base of lofty mountains, particularly of the Alps, and in some of the unhealthy districts of France especially. One of these is cretinism, a singular case of malformation, with which we are happily unacquainted in the United States. This is a state of idiocy, which is remarkable in its subjects being always more or less deformed, and in its appearing to originate from local influ- ences. The crdtin has every characteristic of the idiot; and, in addition, is often distinguished by a large goitre or swelling of the thyroid gland ; by soft flabby flesh ; and by shrivelled, yellowish, or pale and cadaverous skin, covered, at times, with filthy cuta- neous eruptions. The tongue is thick and pendant; the eyelids large and projecting ; the eyes gummy, red and prominent; the nose flat; the mouth gaping and drivelling ; the face puffy, and at times, violet-coloured, and the lower jaw elongated. In seve- ral, the forehead is broad inferiorly, and flattened and retreating above, giving the cranium the shape of a cone rounded towards its smaller extremity. The stature of the cretin is generally small, scarcely ever exceeding four feet and a few inches ; the limbs are frequently malformed, and almost always kept in a state of flexion. All the cretins are not affected with goitre. Some have large and short, whilst others have thin, and long necks. Like the idiot, the cretin does not generally live* long, scarcely ever surviving the thirtieth year. Authors have differed in opinion as to the causes of this deplora- ble condition. It is observed almost exclusively in the deep and nar- row valleys at the foot of lofty mountains, and in mountain gorges. Hence, it is common in that part of the Alps called the Valais or Wallais; in the valley of Aost, La Maurienne, &c. It is met with, too, at the foot of the mountains of Auvergne, the Pyrenees, the Tyrol, &c. De Saussure, Esquirol, Fodere, Rambuteau,— and all who have had an opportunity of observing these misera- ble wrecks of humanity, — believe, that the great cause is the con- centrated, moist, and warm air, which prevails throughout almost the whole of the year, in the valleys and mountain gorges where it is found to exist.3 That it is dependent upon the locality is obvious, but how this acts, we know no more than we do of the causes of other endemic affections, — intermittent fever, pellagra, beriberi, &c, &c.b After all, perhaps, the strongest arguments, — in favour of ex- traneous circumstances occasioning, in the lapse of ages, the dif- ferent varieties, which we observe in the great human family, — are those derived from the changes that must have occurred amongst many of the inferior animals. The dog,in its wild state, has always a Dr. James Johnson, Change of Air, Amer. Edit. p. 61, New York, 1831 ; and Assistant Surgeon J. M'Clelland, in Dublin Journal of Medical and Chemical Sciences, May, 1837, p. 293; De Saussure, Voyages dans les Alpes, ch. xlvii. § 1050; Heeve, in Philos. Transact, for 1808, p. Ill ; Prichard on Insanity, p. 318,Lond. 1835 ; and Hodgkin, Catalogue of Guy's Museum, §v. part ii. Lond. 1829. b See the author's Practice of Medicine, 2d edit., vol. i., Philad. 1844. VARIETIES OF MANKIND. 601 pretty nearly the same characters ; being covered with hair of the same colour; the ears and tail, and limbs, having the same shape ; and it exhibits, apparently, the same powers and tnstincts ; but, on this matter, our knowledge, derived from observation, is neces- sarily limited. Yet what a number of varieties are observed in this animal when it becomes domesticated ; and how different from each other, in shape, colour, character of skin, and instincts, are the spaniel, hound, greyhound, pointer, mastiff, terrier, cur, pug, lapdog, &c.; differences certainly as great as between the varieties of mankind. These differences, it is presumable, may have been produced partly by the occurrence of accidental varie- ties, affecting perhaps a whole litter, — male and female ; so that if these, again, were to be coupled, the variety, thus accidentally caused, might have become permanent. Such accidental varie- ties occasionally occur in the human species, but they are soon lost, in consequence of the wise law that prevents individuals, within certain degrees of consanguinity, from marrying. It is by no means uncommon, for example, for different children of the same family, from some accidental cause, to be born with six fingers. The author has met with two families in each of which more than one individual was thus circumstanced ; and Sir Anthony Carlisle* has detailed the remarkable case of a family from this continent, where the superfluity extended, in the case of a female, to two thumbs on each hand, and to six toes on each foot. She married and had several children, who, in their turn, became parents, and transmitted the peculiarity to the children to the fourth generation. Now, if the members of this family had con- ■ tinned to marry in and in, a new race of individuals might have , been perpetuated, possessing the unnecessary additions in ques- tion. Under existing laws and customs, it must always happen, that where such peculiarity exists in one parent only, it must soon become extinct; yet, as we have seen, it may be pertinacious enough to persist for some generations. Fortunately, also, it happens, that, as a general rule, no change, which occurs acci- dentally in the parent after birth, is liable to be extended to the progeny.1* Were the rule other than it is, it will be at once seen, the most strange and innumerable varieties of races would exist. Where a limb had become distorted or amputated, a stock of one- limbed animals would be formed; the docked horse would pro- pagate a mutilated colt; the operation of circumcision, performed on one parent, ought to be sufficient for the whole of his descend- ants, &c, &c. * Philosoph. Transact, for 1814. See, also, Prichard's Researches into the Physical History of Mankind, i. 245 and 352, Lond. 1836 ; and his Nat. History of Man. Lond. 1843; art. Generation, Cyclop, of Anat. and Physiol. P. xiii. p. 473, Feb. 1838 ; Mo- rand, Memoir.de l'Academ. pour 1780, p. 137 ; Isidore St. Hilaire, Histoire Generale et 1'articuliere des Anomalies de l'Organisation, p. 681, Paris, 1832 ; and Walker, on Intermarriage, Amer. Edit., New York, 1839. b The author has been informed by one who has had ample opportunity for observa- tion, that when two deaf and dumb individuals marry, the delect is rarely, if ever, observed in their progeny : but that the contrary is the case with the born blind. VOL. II. — 51 602 INDIVIDUAL DIFFERENCES. In addition to this mode of accounting for the great number of varieties in animals of the same species, the influence of difference in manners a*d customs, which we have already considered, has been adduced ; and it has been conceived, that the effect of civil- ization and refinement on the human race may be analogous to that of domestication on the inferior animals. This kind of influ- ence is said to be particularly observable amongst the inhabitants of Hindusthan, where, in consequence of the division into castes, the same condition of life, and the same occupation are continued without change through many successive generations. The arti- sans, who are a superior class, are of a manifestly lighter complexion than the tillers of the soil; and in many of the islands of Polynesia, the same difference exists between the classes as in Hindusthan. The believers, then, in the Mosaic account of the creation, and < the deluge, must regard all the varieties of mankind to have de- scended from the same family, — that of Noah, — and the differ- ent changes, which have been impressed upon their descendants, to be results of extraneous influences acting through a long suc- cession of ages, added to the production perhaps of accidental varieties, which may have occurred in the very infancy of postdilu- vian existence, when the intermarriage of near relations was un- avoidable, and when such varieties would necessarily be perpetu- ated. . The race of Ham appears to have been separated, if not wholly, at least in part, from their brethren by the malediction of Noah; and, whether we consider that a physical alteration was comprised in the malediction, or that such alteration might occur accidentally, as in the cases of those with supernumerary toes and fingers, the very fact of intermarriage with the descendants of the . other sons of Noah, being prevented by the curse pronounced on Ham (for many commentators read Ham for Canaan,) would ne- cessarily lead to a perpetuation of the adventitious modification. But, it has been asked, if all mankind have descended from one family, which of the varieties now extant, must be regarded as their representative ? On this we have nothing but conjecture to guide us. It has been supposed, by some, to be more probable, that the changes, induced upon mankind, have been in consequence of the progress from a state of barbarism to one of refinement, than the reverse; and hence, it has been conceived, that the variety ought to be considered primary, which, through all the vicissitudes of human affairs, has remained in the most degraded condition, and which, in its structure, differs most materially from the variety that has uniformly enjoyed the greatest degree of civilization. Upon this principle, the Ethiopian would have to be regarded as the type of our first ancestors, and such is the opinion of Prichard, and of Bostock. Blumenbach, however, maintains the converse view. Bishop Heber, again, suggests, whether the hue of the Hindoo, which is a brownish-yellow, may not have been that of our first parents, whence the transition, he' thinks, to the white and black varieties, might be more easy and comprehensible. Philology oc- VARIETIES OF MANKIND. 603 casionally aids us in our historical deductions, but the evidence, afforded by it, has to be received with caution. The Hebrew names, like all original appellations, in perhaps all languages, are generally expressive, and therefore worthy of consideration in questions of this nature. The Hebrew word Adam, (Q"r^,) is not only the name of the first man, but it signifies man in the abstract, corresponding to the Greek, avfyawm, and the Latin, Homo. We are told, in the sacred volume, that, " in the day that God created man, in the likeness of God made he him; male and female created he them; and blessed them, and called their name Adam, in the day when they were created. The word Adam is derived from a Hebrew root, (Q"TN,) signifying "to be red," and, accordingly, it is not improbable, that the original hue of the first man was of that character. The remarks already made, render it unnecessary to inquire into the mode, in which, according to the notions of Blumenbach," of Dr. S. S. Smith,bor of Dr. Rush, the black colour of the Ethiopian has been produced. Blumenbach imagined, that the heat of the climate gives rise to an excessive secretion of bile ; that in conse- quence of the connexion, which exists between the action of the liver and the skin, an accumulation of carbonaceous matter takes place in the cutaneous vessels, and that this process, being continued for a succession of ages, the black colour of the skin becomes habi- tual. Dr. Smith had a similar opinion; he thought, that the com- plexion in any climate will be changed towards black, in proportion to the degree of heat in the atmosphere, and to the quantity of bile in the skin ; and, lastly, Dr. Rush, in one of the strangest of the strange views, which have emanated from that distinguished, but too enthusiastic, individual, has attempted to prove, " that the colour and figure of that part of our fellow-creatures, who are known by the epithet of negroes, are derived from a modi- fication of that disease which is known by the name of leprosy." The following are his deductions from " facts and principles"0 urged in a communication, read before the American Philoso- phical Society in 1792 : — " 1. That all the claims of superiority of the whites over the blacks, on account of their colour, are founded alike in ignorance and inhumanity. If the colour of negroes be the effect of a disease, instead of inviting us to tyrannize over them, it should entitle them to a double portion of our humanity, for dis- ease all over the world has always been the signal for immediate and universal compassion. 2. The facts and principles which have been delivered, should teach white people the necessity of keeping up that prejudice against such connexions with them, as would tend to infect posterity with any portion of their disorder. This may be done upon the ground I have mentioned without offering violence to humanity, or calling in question the » De Gener. Human. Variet. Nat., edit. 3tia, p. 66, Gotting. 1795. b An Essay on the Causes of the Variety of Complexion and Figure in the Human Species, Philad. 1787. « Transact, of the American Philosoph. Society, vol. iv. 604 INDIVIDUAL DIFFERENCES. s ameness of descent, or natural equality of mankind. 3. Is the colour of the negroes a disease ? Then let science and humanity combine their efforts, and endeavour to discover a remedy for it. Nature has lately unfurled a banner upon this subject. She has begun spontaneous cures of this disease in several black people in this country. In a certain Henry Moss, who lately travelled through this city, and was exhibited as a show for money, the cure was nearly complete. The change from black to a natural white flesh colour began about five years ago at the ends of his fingers, and has extended gradually over the greatest part of his body. The wool, which formerly perforated the cuticle, has been changed into hair. No change in the diet, drinks, dress, employ- ments, or situation of this man had taken place previously to this change in his skin. But this fact does not militate against artificial attempts to dislodge the colour in negroes, any more than the spontaneous cures of many other diseases militate against the use of medicine in the practice of physic. To direct our experi- ments upon this subject I shall throw out the following facts: — 1. In Henry Moss the colour was first discharged from the skin in those places, on which there was most pressure from clothing,' and most attrition from labour, as on the trunk of his body, and on his fingers. The destruction of the black colour was probably occasioned by the absorption of the colouring matter of the rete mucosum, or perhaps of the rete mucosum itself, for pressure and friction, it is well known, aid the absorbing action of the lymphatics in every part of the body. It is from the latter cause, that the palms of the hands of negro women, who spend their lives at a washing-tub, are generally as fair as the palms of the hands in labouring white people. 2. Depletion, whether by bleeding, purging, or abstinence, has been often ob- served to lessen the black colour in negroes. The effects of the above remedies in curing the common leprosy satisfy me that they might be used, with advantage, in that stateof leprosy, which I conceive to exist in the skin of the negroes. 3. A similar change in the colour of the negroes, though of a more temporary nature, has often been observed in them from the influence of fear. 4. Dr. Be.ddoes tells us that he has discharged the colour in the black wool of a negro by infusing it in the oxygenated muriatic acid, and lessened it by the same means in the hand of a negro man. The land-cloud of Africa, called by the Portuguese Ferrino, Mr. Hawkins tells us, has a peculiar action upon the negroes in chang- ing the black colour of their skins to dusky gray. Its action is accompanied, he says, with an itching and prickling sensation upon every part of the body, which increases with the length of exposure to it so as to be almost intolerable. It is probably air of the carbonic kind, for it uniformly extinguishes fire. 5. A citizen of Philadelphia, upon whose veracity I have perfect re- liance,4 assured me that he had once seen the skin of one side of * " Mr. Thomas Harrison." LIFE. 605 the cheek inclining to the chin, and of part of the hand in a negro boy changed to a white colour by the juice of unripe peaches, (of which he ate a large quantity every year,) falling, and resting frequently upon those parts of his body. « To encourage attempts to cure this disease of the skin in ne- groes, let us recollect that, by succeeding in them, we shall produce a large portion of happiness in the world. We shall in the first place destroy one of the arguments in favour of enslaving the negroes, for their colour has been supposed by the ignorant to mark them as objects of divine judgment, and by the learned to qualify them for labour in hot, and unwholesome climates. Secondly, We shall add greatly to their happiness, for however well they appear to be satisfied with their colour, there are many proofs of their preferring that of the white people. Thirdly, We shall ren- der the belief of the whole human race being descended from one pair, easy and universal, and thereby not only add weight to the Christian revelation, but remove a material obstacle to the exercise of that universal benevolence which is inculcated by it." CHAPTER V. OF LIFE. The knowledge of the mode in which the various functions of the body are exercised constitutes the science of life. The mani- festations of life have consequently been considered already. We have seen, that animal and vegetable substances possess the ordi- nary properties of matter, but that these properties are singularly controlled, so that they are prevented from undergoing those changes, that inevitably occur so soon as they become deprived of vitality. The human body is prone to decomposition. It is formed of substances extremely liable to undergo putrefaction, and is kept at a temperature the most favourable for such change ; yet, so long as life exists, the play of the ordinary affinities is prevented, and this constant resistance to the general forces of matter pre- vails throughout the whole of existence, even to an advanced old age, when it might be supposed the vital forces must be enfeebled almost to annihilation. The case of solution of the stomach after death, described in the first volume of this work, is an additional and forcible evidence of such resistance. So long as life continues in the stomach, the gastric secretions exert no action on the organ, but, when life becomes extinct, these secretions act upon it in the same manner as they do upon other dead animal matter. What, then, is this mysterious power, possessed of such astonishing, such incomprehensible properties ? Our knowledge is limited to the fact above stated, that organized matter, in addition to the general physical and chemical forces,possesses one other,— the vitalforce 51* 606 LIFE. or principle, vitality or life? This principle exists, not only in the whole, but in every part, of a living body ; and its existence is evidenced by the unequivocal signs afforded by the various functions, which we have considered, as well as by others to be presently described. Yet it is not equally evinced in all organs ; some appearing to be possessed of more vitality than others, — a result probably produced by diversity of texture, as it would seem irrational for us to admit a different kind of vital principle, when- ever its manifestations appear to be modified. Admitting the existence of this controlling principle, what, it may be asked, are the functions through which it immediately acts in keeping up the play of the living machine ? It has been elsewhere seen, that, in animals, the reciprocal action of innerva- tion and circulation is indispensable, and that if one of these func- tions be arrested, the other quickly ceases. This is only applica- ble, however, to animals; and it has been doubted, whether it applies to all and to every part of them, whilst to the vegetable it is altogether inapplicable, unless we regard it, with some physio- logists, to possess a rudimental nervous system. The function of sensibility exhibits to us the mode in which the nervous system acts in connecting man with the objects around him, through the agency of volition ; but numerous other acts take place within him, altogether uninfluenced by volition, and yet indispensable for the maintenance of existence. These last acts are equally met with in the animal and the vegetable; and hence a division has been made by Bichat,b into animal life and organic life: — the former evidenced by those functions, that are peculiar to animals — sen- sibility and voluntary motion — which require the presence of a great nervous centre, that may receive from, and transmit to, the different parts of the body, the nervous irradiations, — the neces- sary excitant of the different functions: — the latter evidenced by those functions that are common to animals and vegetables, and are inservient to the nutrition of the frame, — as digestion, ab- sorption, respiration, &c, all of which go on without any direct exercise of volition ; and occasionally, it has been believed, inde- pendently of all nervous influence. Physiologists may,on thispoint,bedivided into two classes;—they who consider, that the whole of the organic functions are under the government of the nervous influence ; and they who think, that the nervous influence does not extend to all the organic functions, but only to the principal of them. The supporters of the first opinion believe, that the agents, or conductors of the nervous influence, are less and less dependent upon the nervous centres, when such exist, the lower the animal is situate in the animal kingdom, and the lower the function; but they consider the nervous influence a Fletcher's Rudiments of Physiology, part ii. a, p. 16, Edinb. 1836. See, also, Prichard, on the Vital Principle, Lond. 1829 ; Dr. W. B. Carpenter, in Edinb. New Philosophical Journal, April, 1838 ; Principles of General and Comparative Physiology, Lond. 1839; and art. Life, Cyclop, of Anat. and Physiol. Lond. Sept. 1840. b Recherches Physiologiques sur la Vie et la Mort, Paris, 1800. LIFE. 607 to be indispensable to every living being, and to every part of such being. In support of this opinion, they are of course compelled to believe, either that a nervous system exists in the vegetable, or that there is a system, which appears to exert over every part of it an influence necessary for its life, and which is, consequently, ana- logous to the nervous system of animals. The organ of this in- fluence is, by some botanists, considered to be the medulla ox pith ;a — whence medullary appendages set out, to be distributed to every part of the vegetable, and which are particularly abundant in such parts as are charged with very active functions,— as the flower. Brachetb maintains this idea, and compares the knots of the pith to the ganglions of the nervous system, — destruction of the pith, and especially of these knots occasioning the death of the parts, that receive their filaments from them. Dutrochet, again, con- siders, that nervous corpuscles exist in the pith of vegetables, which constitute the rudiments of a nervous.system ; but in the vegetable, this system is diffused, instead of being collected in a mass, as in the animal. The believers in the earlier formation of the nervous system in the fcetus will necessarily be in favour of the first opinion. The supporters of the second opinion, — that the nervous influ- ence does not extend to all the organic functions, — assert, that it is chiefly exerted on those functions, which, are of the highest moment, — the most elevated in animality ; that it is less and less in the inferior functions, and ultimately ceases in the lowest acts, — those that immediately accomplish nutrition and reproduction ; and the arguments they adduce in favour of their views are, that these lowest acts exist in every living being—vegetable as well as animal : and that in the superior animal, and in man, there are many parts which do not appear to contain nerves. They, more- over, consider the nervous system as one superadded to living beings, not only for life, nutrition and reproduction, but also, where necessary, for sensation, motion, &c, and hence the prolon- gations or extensions of this system ought to be sent to the organs of the internal or nutritive functions, for the purpose of connecting them with the organs of the external or sensorial functions; and that it is in these connexions only that innervation consists. In this view, consequently, the nervous influence arises only from the necessity of connecting the organs ; is but an indirect condition of life ; exists in the upper animals only, and can in no way be invoked to account for vegetable life. The last is, in our view, the most accurate opinion. We cannot, in the present state of knowledge, admit the existence of nerves in the vegetable : cer- tainly no such thing as a nervous centre is discoverable, and yet we find the most complicated acts of nutrition and reproduction exercised by it, and the principle of instinct as strikingly evidenced as in many animals. We are, therefore, irresistibly led 10 the » Sir J. E. Smith's Introduction to Botany, p. 40. . . b Recherches Experimentales sur les Fonctions du Systeme Nerveux Ganglionar &c. Paris, 1830. 608 LIFE. conclusion, that the manifestations of vitality are but little, if at all, connected with nervous influence, and that the nerves are added, in the upper animals and functions, for other purposes than that of directly communicating vital properties to the part. This deduction will be found confirmed by the facts to be here- after mentioned, connected with the independence of the vital property of irritability of the nervous influence. In the introductory remarks to the first volume of this work, the characters, which distinguish organized from inorganic bodies, were pointed out. All the characters of the former result from the influence of the vital principle, which produces a body of a defi- nite magnitude, shape, structure, composition and duration. There is, moreover, a power, possessed by bodies endowed with the living principle, of being acted upon by certain stimuli, and of being thrown into movement without the participation of the will. This has, indeed, by some physiologists, been considered to be the sole vital property, — with what truth we shall see hereafter. An inquiry into its manifestations will aid us materially in determining whether or not the vital principle be effected directly through the medium of the nerves, and will tend to confirm an opinion, which we have already expressed on this subject. Prior to the time of Haller, the nervous system was looked to as the great source of power in the body; and the contractile power of the muscles, — described at length under the head of Muscular Motion,— was considered to be wholly derived from the nerves, which were supposed to transmit the power to the muscular fibre as it was called for, — accurately regulating the quantity supplied. Haller contended for a vis insita, a power of irritability or con- tractility, essentially residing in the muscles themselves, indepen- dently of any condition of the nervous system, and called into action by stimuli, of which, in the case of the voluntary muscles, the nervous influence is one,— contributing, however, like all other stimuli, to exhaust it, instead of furnishing any fresh supply. We have elsewhere shown, that a muscle is capable of being thrown into contraction after a limb has been removed from the body, and for a considerable period after the cessation of respiration, circula- tion, and consequently of innervation, provided the appropriate stimuli be applied, so as to excite the vis insita, which remains in the muscle for some time after dissolution ; and if all the nerves, supplying the limbs of a frog, be divided, and cut out close to the place where they enter, the muscles, the muscles will still retain their contractility in as great a degree as when the nerves were entire. They, who believe that the contractility of muscles is wholly derived from the nervous system, maintain, however, that in such case, the stimulus may still act, through the medium of the portions of nerves that must always remain attached to the muscle, however carefully attempts may have been made to re- move them ; and some have supposed, that these nervous fibres LIFE. 609 may even constitute an essential part of the muscular fibre.3 The most satisfactory reply, that has been made to this argument, is the following experiment of Dr. Wilson Philip.b All the nerves, supplying one of the hind legs of a frog were divided, so that it became completely paralytic. The skin was removed from the muscles of the leg, and salt sprinkled upon them, which, being renewed from time to time, excited contractions in them for twelve minutes : at the end of this time, they were found no longer capa- ble of being excited. The corresponding muscles of the other limb, in which the nerves were entire, and of which, consequently, the animal had a perfect command, were then laid bare, and the salt applied to them in the same way. In ten minutes, they ceased to contract, and the animal had lost the command of them. The nerves of this limb were now divided, as those of the other had been, but the excitability of the muscles to which the salt had been applied was gone. Its application excited no contraction in them. After the experiment, the muscles of the thighs in both limbs were found to contract forcibly on the application of salt. It excited equally strong contraction on both sides. In this experiment, the excitability of the muscles, whose nerves were entire, was soonest exhausted; and hence Dr.- Philip properly concluded, that the nervous influence, far from bestowing excitability on the muscles, exhausts it like other stimuli; and that the excitability or irrita- bility is a property of the muscle itself.0 This is confirmed by the fact, that, when the vital properties of nerves are destroyed by the application of narcotic substances, the irritability of the muscle to which they are distributed may remain for some time longer, so that they must be independent of each, other.d The opinion of J. Muller is, that if muscular irritability be not dependent upon the brain and spinal cord, they supply some in- fluence essential to its exercise, and in confirmation of it he lays much stress on the loss of irritability of muscles within a few weeks after the section of their nerves. This, however, has been shown by. Dr. J. Reide to be owing to the alteration in their nutrition consequent on their disuse. He divided the spinal nerves as they lie in the lower part of the spinal canal in four frogs, and both posterior extremities were thus insulated from their nervous connections with the spinal cord. The muscles of the para- lyzed limbs were daily exercised by a weak galvanic battery; » See J. W. Earle's New Exposition of the Functions of the Nerves, P. i. Lond. 1833. b An Experimental Inquiry into the Laws of the Vital Functions, &c. p. 100, Lond. 1817. c See, on the powers of Life, Dr. W. Philip, in Lond. Med. Gazette, for March 18 and 25, 1837 ; also, a Notice of some Experiments on the Connexion between the Nervous System, and the Irritability of Muscles in Living Animals, by Dr. J. Reid, in the Fourth Report of the British Association, and in Amer. Journ. of Med. Sciences, p. 181, Nov. 1835. d Carpenter, Human Physiology, § 377, Lond. 1842. • Edinburgh Monthly Journal of Med. Science, May, 1841 ; and Longet, Comptes Rendus, Juillet, 1841. 610 LIFE- whilst those of the other limb were permitted to remain quiescent. This was continued for two months; at the end of which time, the muscles of the exercised limb retained their original size and firmness, and contracted vigorously, whilst those of the'quiescent limb had shrunk to at least one half of their former bulk, and pre- sented a marked contrast with those of the exercised limb. The muscles of the quiescent limb still retained their contractility, even at the end of two months ; but Dr. Reid thought there could be little doubt, that, from their imperfect nutrition, and the progress- ing changes in their physical structure, this would in no long time have disappeared, had circumstances permitted the prolongation of the experiment. It seems that this essential characteristic of living bodies is a distinct vital property, not confined, as Haller supposed, to the muscular structure, but existing over the whole body, In favour of its not being dependent upon the nerves, we have the fact of its presence in the vegetable as well as in the animal. Many plants exhibit this power in a remarkable manner, The barberry bush is one of these. In this flower, the six stamens, spreading moderately, are sheltered under the concave tips of the petals, till some extraneous body, as the feet or' trunk of an insect in search of honey, touches the inner part of each filament near the bottom. The irritability of that part is such, that the filament immediately contracts there, and consequently strikes its anther, full of pollen, against the stigma. Any other part of the filament may be touched without this effect, provided no concussion be given to the whole. After a while, the filament retires gradually, and may be again stimulated; and when each petal, with its annexed filament, has fallen to the ground, the latter, on being touched, shows as much irritability as ever. In another plant, — the Cistus helianthemum, dwarf cistus or lesser sunflower, — the filaments, when touched, execute a motion, the reverse of that of the barberry. They retire from the style and lie down, in a spreading form, upon the petals. Owing to the possession of this property, the Apocynum andro- sxmifolium or dogsbane is extremely destructive to insect life. Attracted by the honey on the nectary of the expanded blossom, the instant the trunk of the fly is protruded to feed on it, the fila- ments close, and, catching the fly by the extremity of its proboscis, they detain the insect until its struggles end in death, occasioned apparently by exhaustion alone. The filaments then relax, and the body falls to the ground.a These are only evidences,however,of particular parts possessing an unusual degree of irritability. The property exists in every part of the plant, and, as in the animal, is the essential charac- teristic of the principle of life. Irritability or contractility forms a medium of communication between the various parts of the living machine, and is excited to action by extraneous influences. All its movements, however, * Sir J. E. Smith's Introduction to Botany, p. 211. INSTINCT. 611 appear to* be dependent upon the action of appropriate stimuli, and are, consequently, passively exercised. 1. Instinct.—There is a power, which has been conceived, to be nearly allied to irritability, and is highly characteristic of or- ganized bodies, — vegetable as well as animal,— whose movements or impulsions are active, and most varied. To this power, the term instinct has been appropriated by Virey,a Fleming,53 Good,c and others, It is an extension of the ordinary acceptation of the term, but it enables us to understand the phenomena better than where we restrict it to those manifestations of man, or animals, that bear the semblance of reason. It is this power, which, ac- cording to those gentlemen, regulates the movements, that are requisite to obtain a supply of food, to remove or counteract opposing obstacles, and to fly from impending danger, or repair injuries. In every organized system," says Dr. Good,d " whether animal or vegetable, and in every part of such system, whether solid or fluid, we trace an evident proof of that controlling, and identifying power, which physiologists have denominated, and with much propriety, the principle of life. Of its cause and nature we know no more than we do of the cause and nature of gravi- tation, or magnetism. It is neither essential mind nor essential matter; it is neither passion nor sensation; but though unques- tionably distinct from all these, is capable of combining with any of them; it is possessed of its own book of laws, to which, under the same circumstances, it adheres without the smallest deviation ; and its sole and uniform aim, whether acting generally or locally, is that of health, preservation, or reproduction. . The agency, by which it operates, is that which we denominate or should denominate instinct, and the actions, by which its sole and uni- form aim is accomplished, are what we mean, or should mean, by instinctive actions; or to speak somewhat more precisely, instinct is the operation of the living principle, whenever mani- festly directing its operations to the health, preservation or reproduction of a living frame, or any part of such frame. The law of instinct, then, is the law of the living principle ; instinc- tive actions are the actions of the living principle ; and either is that power, which characteristically distinguishes organized from unorganized matter, and pervades and regulates the former, uni- formly operating by definite means in definite circumstances to the general welfare of the individual system or of its sepa- rate organs, advancing them to perfection, preserving them in it, or laying a foundation for their reproduction, as the nature ot the case may require. It applies equally to plants and to animals, and to every part of the plant, as well as to every part of the ani- mal, so long as such part continues alive. It is this, which main- tains, from age to age, with so much nicety and precision, the dis- » Art. Instinct, in Diet, des Sciences M6dicales, xxv. 367. > Philosophy of Zoology vol. i ".Edinb. 1822. d • Book of Nature, u. 114, Lond. 1826. 612 LIFE- tinctive characters of different kinds and species, which carries off the waste or worn out matter, supplies it with new, and in a thousand instances, suggests the mode of cure, or even effects the cure itself, in cases of injury or disease. It is ' the divinity that stirs within us' of Stahl, the vis medicatrix naturae of Hoffmann and Cullen and the physicians of our day, &c, &c." Of the existence of this instinctive principle we shall adduce a few examples from both the vegetable and the animal kingdom. When the seed of a plant is deposited in the ground, under circumstances favourable for its development, it expands, and the root and stem are evolved. The root descends into the ground, manifestly not from the laws of gravitation, but owing to some inherent force, inasmuch as it penetrates the earth, which is of much greater spe- cific gravity than itself. The stem, too, bursts through the earth, and rises into the air, notwithstanding that the air is of much less specific gravity, until having attained the height to which the action of the vital principle limits it, its upwards development ceases. It rarely happens, however, that the root is capable of procuring nourishment sufficient for its future development in im- mediate contact with it. It, therefore, sends out numerous fila- mentous radicles in all directions to search after food, and to con- vey it to the proper organs. The number and direction of these filaments, and the distance to which they extend, are regulated by the necessities of the plant, and the supply of the soil. A strawberry offset, planted in sand, will send out almost all its run- ners in the direction in which the proper soil lies nearest; and few, and sometimes none, in the direction in which it lies most remote." When a tree, which requires much moisture, has sprung up, or been planted in a dry soil, in the vicinity of water, it has been observed, that a much larger portion of its roots has been directed towards the water, and that, when a tree of a different species, and which requires a dry soil, has been placed in a similar situa- tion, it has appeared, in the direction given to its roots, to have avoided the water, and moist soil. When a tree, too, happens to grow from seed on a wall, it has been seen, on arrivingat a certain size, to stop for a while, and to send down a root to the ground. As soon as this root has been established in the soil, the tree has continued increasing to a large magnitude. The fact has been often noticed with respect to^the ash, —a tree, which in conse- quence of the profusion of its seed, is found more often scattered in wild and singular places, than in any other not propagated by the agency of birds, or conveyed by the winds.b We find, in all cases, that if the" roots of a plant, spreading in search of nourishment, meet with interruption in their course, they do not arrest their progress, but either attempt to penetrate the • Fleming, op. citat. p. 16; and Mayo's Outlines of Human Physiology, p. 14, edit. 4th, 1837. • » Smith's Introduction to Botany, p. 114 ; and the Sacred History of the World, by Sharon Turner, ¥. S. A., Amer. Edit. i. 168, New York, 1832. " INSTINCT. 613 opposing body, or to avoid it by altering their direction. Dr. Fie- « rning* states, that he has repeatedly seen the creeping root of the Triticum repens or couch grass piercing a potato, which has ob- structed its course. It. is well known, too, that roots will pass under a stone wall or a ditch, and rise up on the opposite side. A striking case of this nature was communicated to the author, by his venerable friend, the late Ex-President Madison. The wooden pipes, for the conveyance of water to Mr. Madison's establishment, having become obstructed, they were carefully ex- amined, when it was found, that the roots of a honeysuckle, growing immediately above a plug, made of the wood of the Lirio- dendron tulipifera or American poplar, which is of soft consist- ence, had penetrated the plug in various places to reach the water, and formed an agglomerated mass in the pipe so as to completely preclude the passage of the water along it. The nearest approximation to these manifestations of instinct, in the animal, occurs in the formation of the new being, and in the first actions that take place after birth. From the moment of the admixture of the substances, furnished by the parents at a fecundating copulation, there must be a principle existing in the embryo, which directs the construction and arrangement of its organs after a definite manner, and always according to that peculiar to the species. In the egg, this is seen in the most dis- tinct manner* The germ of the chick is surrounded by the nourishment requisite for its formation. Organ after organ becomes successively evolved, until the full period of incubation is accomplished, when the young animal breaks the shell. At this time, it has within it a portion of nutriment derived from the yolk drawn into the body. This supplies its wants for a short period; but it soon becomes necessary that it should select and collect food for itself, and we observe it throwing its various organs into action for the prehension, mastication, deglutition, &c. of the food, as if it had been long accustomed to the execution of these functions. In the formation of the human foetus in utero the same instinctive action is observable in the successive evolu- tion of organs, and in the limitation of the body to a determinate shape, size, structure, &c. ; and when these requisites have been attained, the child bursts the membranous envelope, and is ex- truded, to maintain thenceforth an existence independent of the mother. More helpless, however, than the young of the animal kino-dom in general, the infant requires the fostering care of the , parent for the purpose of supplying it with the necessary nutri- ment, but as soon as food is conveyed to the lips, the whole ot the complicated process of deglutition is effected for the first time, with the same facility as after long practice. As we descend in the animal kingdom, we find these inward actions coMtituting instinct more and more largely exhibited. In the q^duiped, it ii not necessary, that the nipple should be applied by the » Op. citat. p. 18. vol. n. — 52 - 614 LIFE. ' mother to the mouth of the new-born animal. It is sought for by the latter, invariably discovered, and as invariably seized hold of, by the appropriate organ of prehension, the mouth. The lips are applied; the air is exhausted; and the milk flows according to exact principles of hydrostatics, but without the animal having the least knowledge of the physical process which it accomplishes. Naturalists, indeed, assert, that before the calf has been more than half extruded from the mother, it has been seen to turn around, embrace and suck the maternal teat. As we descend still farther in the scale of creation, we discover the manifestations of instinct yet more signally developed ; until, ultimately, in the very lowest classes of animals, the functions are exercised much in the same manner as in the vegetable ; and appear to be wholly instinctive, without the slightest evidence of that intelligence, which we ob- serve in the upper classes of the animal kingdom, and pre-eminently in man. This, however, applies only to the very lowest classes; for, a short way higher up the scale, we meet with apparent intel- ligence, united with instinct, in a manner that is truly surprising and mysterious. Again, the similarity of the actions of the instinctive principle, in the animal and vegetable, is exhibited by the reparatory power which both possess when injuries are inflicted upon them. If a branch be forcibly torn from a tree, the bark gradually accumulates around the wound, and cicatrization is at length accomplished. The great utility of many of our garden vegetables, — as spinach, parsley, cress, &c.—depends upon the possession of a power to repair injuries, so that new shoots speedily take the place of the leaves that have been removed : similar to this is the reparatory process, instituted in the lobster that has lost its claw, in the water- newt that has lost an extremity, or an eye ; in the serpent deprived of its tail, and in the snail, that has lost its head. These parts are reproduced as the leaves are in the spinach or the parsley. Few animals, however, possess the power of restoring lost parts; whilst all are capable of repairing their own wounds when not excessive, and of exerting a sanative power, when labouring under disease. If a limb be torn from the body, provided the animal should not die from hemorrhage, a reparatory effort is established, and if the severity of the injury does not induce too much irritation in the system, the wound will gradually fill up, and the skin formoverit. To a lesser extent we see this power exerted in the healing of ordi- nary wounds, and in cementing broken bones ; and although it may answer the purpose of the surgeon to have it. supposed, that he is possessed of healing salves, &c, he is well aware, that the great art, in these cases, is to keep the part entirely at rest, whilst his salves are applied simply for the purpose of keeping the wound moist; the edges in due apposition, where such is necessary, and extraneous bodies from having access to it; — his trust being alto- gether placed in the sanative influence of the instinctive power situate in the injured part, as in every part of the frame. INSTINCT. 615 It is to this power, that we must ascribe all the properties, as- signed to the famous sympathetic powder of Sir KenelmDigby,— which was supposed to have the wonderful property of healing wounds, when merely applied to the bloody clothes of the wounded person, or to the weapon that had inflicted the mischief; — a powder, which, at one time, enjoyed the most astonishing reputa- tion. The wound was, however, always carefully defended from irritation by extraneous substances ; and it has been suggested, that the result furnished the first hint, which led surgeons to the improved practice of healing wounds by what is technically called the first intention. It is to this instinctive principle, so clearly evinced in surgical or external affections, but at times, not. less actively exerted in cases of internal mischief, that the term vis me- dicatrix naturse has been assigned; and, whatever may be the objections to the views entertained regarding its manifestations in disease, that such a power exists can no more be denied than that organized bodies are possessed of the vital principle. We have too many instances of recovery from injuries, not only without the aid of the practitioner, but even in spite of it, to doubt for a moment, that there is, within every living body, a principle, whose opera- tions are manifestly directed to the health and preservation of the frame, and of every part of such frame.3 So far, then, it is manifest, that the instinctive actions of the animal and vegetable are exerted according to the same laws, and probably through similar organs. This, at least, applies to the lowest of all animated beings, where the difference between them and the vegetable is small indeed. It ap- plies equally to the human foetus, which can be considered but to vegetate during the greater part of utero-gestation; and even for some time after birth, its actions are purely instinctive, and differ but little from those of the vegetable, except that, owing to the organization of its nervous system, the acts are of a more complicated character. It is only when the brain has become duly developed, and the external senses fully so, that it exhibits so decidedly the differ- ence between those acts, which it had previously accomplished instinctively, and the elevated phenomena of sensibility, which man enjoys so pre-eminently, but which are likewise possessed, to a greater or less extent, by the whole animal creation. The cells of the ordinary honeycomb are intended for the larvae of the different varieties of the occupants of the hive. These cells are usually placed horizontally, with their mouths opening towards the sides of the hive. The bottom of the cells, instead of forming one flat square, is composedofthree lozenge-shaped pieces, so united as to make the cell end in a point; consequently, the whole forms an hexagonal tube, terminating in a pyramidal cavity. If the-two cells had been a single hexagonal tube, intersected in the middle by a flat, instead of a pyramidal, division, not only would the shape » See the author's " General Therapeutics," chap. i. Philad. 1837; art. Autocratia, in Most's Encyclopcidie, Zweite Auflage, Band i. s. 242, Leipz. 1836 ; and Dr. Alison, art. Instinct, Cyclopsedia of Anat, and Physiol, part xix., July, 1840. 616 LIFE. not have answered the purpose of the bees, but more wax would have been expended in its construction. Hence, it would seem, that both the body and the base of the tube are adapted for their object; that the greatest strength and the greatest capacity are ob- tained with the least expenditure of wax in an hexagonal tube with a pyramidal base. Reaumur, when inquiring into the habi- tudes of these industrious animals, requested Konig, an able mathe- matician, to solve the following question : — among all the hexa- gonal tubes with pyramidal bases, composed of three similar and equal rhombs^, to determine that which, having the same capacity, can be constructed with the least possible quantity of matter? Konig not aware of the precise object of Reaumur's inquiry, solved the problem, and found, — that if three rhombs or lozenges were so inclined to each other that the great angles measured 109° 26', and the little angles 70° 34', the smallest possible quantity of matter would be needed. Maraldi measured the angles actually formed at the bottom of a cell, and found that the great angles gave 109° 28', and the little 70° 32'. All this, however, may be ascribed to blind instinct, proceeding uniformly in the same track, without any evidence of the admixture of reason ; but we have innumerable instances, in the same insects, to show, that their ope- rations are varied according to circumstances, and that intelligence is manifestly expended in the adaptation of their means to definite purposes. Of this we shall give but one example. Huber, whose inquiries into this part of entomology have been singularly minute and accurate, having had great ravages committed on his hives by the sphinx atropos or death's head moth, determined to construct a grating, which should admit the bee but not the moth. He did so, and the devastation ceased. He found, however, that in other hives, not protected by his agency, the bees had adopted a similar expedient for their defence ; and these defences were variously constructed in different hives. " Here, was a single wall whose opening arcades were disposed at its higher part; there, were seve- ral bulwarks behind each other, like the bastions of our citadels : gateways, masked by walls in front, opened on the face of the second rows, while they did not correspond with the apertures-of the first. Sometimes, a series of intersecting arcades permitted free egress to the bees, but refused admittance to their enemies. These fortifications were massy, and their substance firm and compact, being composed of propolis and wax." It would be endless, how- ever, and beyond the design of this work, to enumerate the various evidences of intelligence exhibited by the insect tribe, in fulfilling the ends for which they have been destined by the Great Author of nature.* In all our reasonings on the subject of instinct, we must be com- pelled to admit, in the case of most animals at least, a degree of 1 For numerous examples of the kind, see Alison, art. Instinct. Cyclop. Anat. and Physiol. July, 1840. See, also, Swainson, On the Habits and Instincts of Animals, in Cabinet Cyclopsedia, Lond. 1840. INSTINCT. 617 intelligence that strikingly modifies those actions — the impulse to which is doubtless laid in organization. The precise line of demar- cation between instinctive acts and reason cannot, however, be established, and this has led some philosophers to call in question the existence of the former. It is owing to this union of intelligence with instinct, that we find animals accommodating themselves to circumstances, so that if prevented from adopting the habits that belong to the species, they have recourse to others as similar as possible. Thus, if a bird be prevented from building its nest in a particular situation, or from obtaining the material, which birds of its own species employ, it has recourse to other materials and to another situation, as like those that are appropriate to it as is prac- ticable. The rook usually and instinctively builds its nest on the summit of the tallest trees : but Dr. Darwin, — who is one of those that call in question the influence of instinct, — asserts, that in Welbourn churchyard, a rookery was formed on the outside of the spire, and on the tops of the loftiest windows. There had formerly been a row or grove of high trees in the neighbourhood, which had been cut down, and, in consequence, the birds exhibited the union of intelligence with instinct, by building on the lofty spire and windows. In like manner, the jackdaws of Selbourne, accord- ing to Mr. White, not finding a sufficiency of steeples and lofty houses, on which to hang their nests in that village, accommodated themselves to circumstances, and built them in forsaken rabbit burrows.3 By Stahl,b and the animists in general, as well as by more recent philosophers, all the phenomena of instinct have been referred to experience, so obscure as not to be easily traceable, but not the less certainly existent. The insect tribes, however, furnish us with many cases where the young being can never see the parents, and can, of course, derive no benefit from the experience of its proge- nitors ; yet their habits are precisely what they have probably ever been; so uniform, indeed, as to compel us to refer them to some constant impulse connected with their special organization, and, consequently, instinctive. In support of the existence of these na- tural impulsions, the common occurrence of a brood of young ducks, brought up under a hen, has been adduced.0 These little beings, soon after they have broken the shell, and' contrary to all the feelings and instincts of the foster-mother, will seek the water, and suddenly plunge into it, whilst the hen herself does not dare to follow them. By what kind of experience or observation, — it has been asked, — by what train of thought or reasoning has the scarcely fledged brood been able to discern that a web-foot adapts them for swimming ? Any experience they can have derived must have taught them to shun the water; yet, notwithstanding this, * Natural History of Selbourne, with additions, by Sir W. Jardine, Amer. Edit, p. 82, Philad. 1832: Alison, art. Instinct, Cyclop. Anat. and Phys. July, 1840, b Theoria Vera Medica. Hal. 1737. c Good's Book of Nature, ii. 118, Lond. 1826. 52* 618 LIFE. instinct points out to them the habitudes to which they are adapt- ed, and its indications are obeyed in spite of every kind of counter- experience. Attempts have occasionally been made to domesticate the wild turkey of this continent, by bringing the young up under the common turkey, but they have always resumed the way of life to which instincjt has directed them, when opportunity offered; in accordance with the Horatian maxim: " Naturam expellas furoa, tamen usque recurret." Mr. Madison reared, with great care, a young hawk, which, for a long time, associated with the young of the poultry, without exhibiting the slightest carnivorous or migratory propensity, until, on one occasion, whilst some of his friends were admiring its state of domestication, it suddenly arose in the air, darted down, and seized a chicken, with which it flew to a neighbouring tree, and, after it had finished its repast, ,too.k flight, and was never seen afterwards. Instinct, then, is possessed by every organized body, animal and vegetable; whilst intelligence is the attribute of those only, that are endowed with a certain nervous development. They are, therefore, manifestly distinct; — the former predominating oyer the latter in the lower classes of animals ; whilst, in the upper classes, intelligence becomes more and more predominant, until, ultimately, in man, it is so ascendant as to appear to be the main regulator of the functions: indeed, some have altogether denied the existence of instinct in him. Instinct is seated in every part of a living body; is totally independent of the nervous system; occurs in the vegetable and the zoophyte unprovided with nerves, or at least in which nerves have never been discovered; whilst intelligence is always accompanied by a nervous system, without which, indeed, its existence is incomprehensible. How can we, consequently, accord with those physiologists who place the seat of instinct in the organic nervous system ; and that of intelligence in the brain ? Where is the organic nervous system of the zoophyte, and a fortiori of the vegetable ? Or how can we admit the seat of the various instincts, with Gall, to be in the brain, seeing that we have them exhibited where there is neither brain nor any thing resembling one. The acephalous fcetus un- dergoes its full development in other respects in utero, with the same regularity, as to shape and size, as the perfect fcetus, and can we deny it the existence of instinct ? Yet, in the upper classes, of animals especially, many of the manifestations of instinct are effected through the nervous system, which, in them, as we have elsewhere seen, seems to hold in control the various functions of the frame, and to be one of the two great requisites for the exist- ence of vitality. The instinctive action in the appropriate organ, which gives rise to the internal sensations of hunger, thirst, &c, is communicated to the great nervous centres by the nerves, and the brain responds to the impression, and excites, through the VITAL PROPERTIES. 619 medium of the nerves, the various organs into action which are calculated to accomplish the monitions of the instinct. What is the nature of this instinctive property ? Of this we know no more than we do of the principle of life, of which it is one of the manifestations. It is equally inscrutable with the imponderable agents, light, caloric, electricity, or magnetism, or with the mode of existence of the immaterial principle within us, which gives rise to the mental phenomena: we see it only in its results, which are, in many cases, as unequivocal as those produced by the agents just referred to. All, perhaps, that we are justified 'in concluding is— with Dr. Good — that instinct is the operation of the principle of organized life, by the exertion of certain natural powers, directed to the present or future good of the individual, whilst reason is the operation of the principle of intellectual life, by the exercise of certain acquired powers directed to the same object; that the former appertains to the whole organized mass as gravitation does to the whole unorganized ; actuating alike the smallest and the largest portions ; the minutest particles and the bulkiest systems; and every organ, and every part of every organ, whether solid or fluid, so long as it continues alive ; that, like gravitation, it exhibits, under particular circumstances, different modifications, different powers, and different effects; but that, like gravitation, too, it is subject to its own division .of laws, to which, under definite circumstances, it adheres without the slightest deviation; and that its sole and uniform aim, whether acting generally or locally, is that of perfection, preservation or reproduction. In this view, reason demands discipline, and attains maturity ; instinct, on the contrary, neither requires the one, nor is capable of attaining the other. It is mature from the first, and equally so in the infant as in the adult.a 2. Vital Propkrties. — The great cause of all those mysterious phenomena, which characterize living bodies, and distinguish them by such broad demarcations from the dead, has been a theme of anxious inquiry in all ages ; and has ever ended in the sup- position of some special abstract force, to which the epithet vital has been assigned, and which has received various appellations. Hippocrates designated it by the terms &«*•«> and »vop^m ; Aris- totle styled it the animating or motive and generative principle ; Van Helmont, the archteus ; Stahl, anima ; Barthez and Hunter, vital principle, &c, &c. Yet as Dr. Barclayb has correctly ob- served, all physiological writers — ancient and modern — seem to be agreed, that the causes of life and organization are utterly » See, also, on this subject, Fletcher's Rudiments of Physiology, part ii. b, p. 16, Edinb. 1836 ; J. S. Bushnan, The Philosophy of Instinct and Reason, Edinb. 1*61 ; Brit, and For. Med. Rev., Jan. 1841 ; and Flourens, Eloge de F. Cuvier, Pans, 1840. zation See p. 17, Lond. 1842. 620 LIFE. invisible, whether they pass under the name of animating princi- ples, (Aristotle, Harvey, &c.,) vital principles, (Barthez,) indivisible atoms, spermatic powers, organic particles of organic germs, (Buf- fon,) formative appetencies or formative propensities, (Darwin,) formative forces, (Needham,) formative nisus or Bildung- strie b, (Blumenbach,) pre-existing monads, (Leibnitz,) semina rerum, (Lucretius.) plastic natures, (Cudworth,) occult qualities, or certain unknown chemical affinities. " All seem agreed, that whatever they be, they have been operating since the world began, and throughout the world operating regularly, without intermis- sion, in various places at the same time. All seem agreed, that their modes of operation are strictly methodical; that they seem to act on definite plans, and actually exhibit specific varieties of chemical combination, and mechanical structure, which human intelligence cannot comprehend, much less explain. From their mutual dependence, and other relations subsisting between them, all seem to speak as if they were subject to one great cause, which regulates and harmonizes the whole.a All seem to speak of this great cause as if it were eternal, omnipotent, omnipresent; whether it be the element of fire, of air, or of water, or whether it be fate, nature, necessity, or a God." By virtue of this principle of life, every organized tissue is possessed of certain properties, to which the term vital has been assigned. Regarding the precise number of these proper- ties, physiologists are not agreed. Whilst some have reckoned many ; others have admitted but one. All the functions, which we have hitherto considered, are under the influence of life, and are products of rtie vital properties seated in the tissues; but we do not consider them to be directly caused by these properties. Digestion, for example, is executed by a series of organs, all of which are conducive to a certain result, the ag- gregate constituting the function of digestion. The result of the action of the salivary gland is very different from that of the liver, yet both operations are vital, but modified by the different organization of the two glands. We do not ascribe the difference to a difference in the vital properties of the glands. These are probably the same in both; and are seated in the primary tissues, of which all the more compound textures and organs are built up. They are primary or fundamental properties of living matter. Stahl, having observed obscure, oscillatory movements, alternate contraction and expansion in certain parts of the body, either dur- ing the exercise of a function, or on the application of some ex- ternal agent, conceived, that every part of the frame is, at all times, more or less susceptible of similar movements. These movements he called tonic, their effect upon the organs tone, and the property by which they were induced he esteemed peculiar to organization, and termed it tonicity. This vital property, he conceived, in- fluences the progression of the fluids in the vessels; the pheno- * A. F. Hembel, Einleitung in die Physiologie und Pathologie der Menschlichen Organismus, p. 93, Gotting. 1828. VITAL PROPERTIES. 621 mena of exhalation and absorption, and is totally distinct from the properties possessed by inorganic bodies. Hallera admitted two vital properties, very different from each other, which seemed to him to be equally elementary. The one of these is that by which a living part exhibits itself to be sensible, or transmits to the sensorium an impression made upon it, either by an extraneous body, or by its own internal and organic action ; the other, that by which a part contracts in a manner appreciable to the senses, either by the influence of the will, or of some exter- nal or internal stimulus. The first of these he considered to be a special vital property, which he termed sensibility ; and the second to be another property, which he called irritability. Prior to his time the word irritability had been adopted by Glissonb who had noticed the fact, that living matter was acted upon by irritants of various kinds in a mode no wise analogous to physical and che- mical motions, and hence he concluded, that every organ of the human frame possesses an inherent and peculiar force, which pre- sides over it movements, and is requisite for the exercise of its functions. This force he called irritability. De Gorterc subse- quently extended the views of Glisson, and applied them to the vegetable, affirming irritability to be the sole vital property of all organized bodies, vegetable as well as animal. The acceptation, given to the term by Haller, was consequently more limited. He restricted it to those motions of parts which fall under the obser- vation of the senses ; such as the contraction of the voluntary muscles, heart, &c. He made numerous experiments on living animals, for the purpose of discovering what parts are possessed or not of the true properties of sensibility or irritability, and he concluded, that the former resides exclusively in the nervous, — the latter in the muscular, system. Dr. Marshall Halld still em- ploys the term in the restricted sense of Haller. This celebrated theory, which formed so large a part of physio- logical science at one time, and is still an interesting topic to the physiologist, has been referred to in so many parts of this work, as to require but few comments in this place. We have seen that many of the parts, regarded by Haller as insensible, are acutely sensible in disease, and that we cannot pronounce a part to be positively insensible, until we have applied every kind of irritant to it without effect. We have elsewhere defined sensibility to be an exclusive property of the nervous system ; and have at- tempted to show, that irritability is a property of the muscular tissue — a vis insita — totally independent of the nerves, but of which the nervous fluid is an appropriate excitant. As, however, the vital properties of sensibility and irritability were restricted by « Element. Physiol.; and Memoir, sur la Nature Sensible et Irritable des parties du Corps, Lausan. 1756. b De Ventriculo, in Manget. Bibl. Anatom. i. 80, Genev. 1699. e Medicin. Compendium, Lugd. Bat. 1742. *. Art. Irritability, Cyclop, of Anat. and Physiol. July, 1840. 622 LIFE. Haller to the nervous and muscular systems, they were regarded to be insufficient for the explanation of the various living actions of the frame : the next step was to extend them to eveVy part and to every tissue. It was found, for example, that on investigating' the most minute movements of parts, these movements were always preceded by an impression, to which they seemed sensible, and which appeared to excite their actions. This general property, common to every living part, of receiving an impression, was called sensibility ;— thus generalizing the property, which Haller had restricted to perceptivity by the mind. Every part was said to be sensible to the blood sent to it for its nutrition. Again, every part was observed to move in consequence of the impression it received, sometimes in an apparent manner, as the heart; at others, too slightly for its movements to be recognised otherwise than by the results, —as in the case of the glandular organs ; but always in a manner special to organized matter, and not analogous to any physical or chemical process. This motion was, therefore, referred to another force, called motility, which was nothing more than irritability generalized. These two properties are alone admitted by most modern writers. Every organ is said to feel and to move, after its manner, in the performance of its function; — the stomach in digestion; — the heart in propelling the blood; the muscle in contracting, and the nerve in transmitting sensitive impressions to the brain. Many modern physiologists, whilst they admit the properties of sensibility and motility, have reckoned a greater number of vital properties: this is owing to their having observed that each part has its own peculiar mode of sensibility and motility, and when these modes have seemed to differ largely from each other, they have elevated them into so many special vital properties. The chief modern theories on the vital properties are those of Barthez, Blumenbach, Chaussier, Dumas, and Bichat. Barthez" admitted five, which we can do no more than enumerate, — sensibility, force of contraction, force of expansion or active dilatation, force of fixed situation, and tonicity. Blumenbach,b also admitted five ; —- sensibility, irritability, contractility, vita propria or proper force of life nisus formativus, force of formation or Bildungstrieb. Dumasc referred all the living phenomena to four vital properties ; sensibility, motility, force of assimila- tion, and force of vital resistance. The theory of Bichatd on this subject requires a more detailed notice. He, also, admitted five vital properties; organic sensibility, insensible organic contrac- tility,sensible organic contractility,animal sensibility and animal contractility. First. Organic sensibility is the faculty, possessed by every living fibre of receiving an impression, or of being modi- * Nouvcaux Elemens de la Science de I'Homme, Paris, 1806. b Institutiones Physiologicae, Gotting. 1786 ; or Elliotson's translation. c Principes de Physiologie, 2de edit. Paris, 1806. d Anatomie Generale, torn. i.; and Recherches Physiologiques sur la Vie et la Mort, Paris, 1800. VITAL PROPERTIES. 623 fled by contact, so that the modification is restricted to the part that experiences it, and is not transmitted to the brain. The term .sensibility was adopted by Bichat, because already established, and the epithet organic was added, to affirm, that it is the exclu- sive attribute of organized bodies, and common to all. This pro- perty is not only modified in each organ—as the difference in their nutrition and functions demonstrates — but it adapts each organ to its appropriate external stimulant, so that the salivary gland shall be specially influenced by mercury ; the upper part of the small intestine by calomel ; the lower by aloes, &c, &c. Its exercise is continuous, involuntary, known only by its results, and is more marked as we descend in the scale of animal life ; whilst animal sensibility is the contrary. Secondly. Insensible organic contractility is the faculty, possessed by every living part, of moving in an imperceptible manner, in consequence of an impres- sion immediately received, without either the mind having con- sciousness of the motion, the will participating, or the brain in any manner directing it. We have an example of this in the action of the stomach during digestion ; and of every part of the body on the blood sent to it for its nutrition. Bichat applied the term insensible organic contractility to this property, for the following reasons : — contractility, because contraction is the kind of motion which constitutes it; organic, because it is common to all living beings ; and insensible, because the brain has no consciousness of it. Like organic sensibility, it is modified in each organ*. Its exercise is likewise continuous and involuntary; and it also ex- hibits itself more intensely as we descend in the scale of beings. It always co-exists with organic sensibility. Thirdly. Sensible organic contractility is the same motive faculty as the last, with this difference, that the movements induced by it fall under the senses and are recognised independently of their results. This property is likewise modified in each organ; its exercise is also involuntary, and it only differs from the last in degree, — the move- ment that constitutes it being apparent. Thus, the heart contracts independently of the will, but its motions are not imperceptible, as in the cases which belong to the second vital property or insensible organic contractility. Fourthly. Animal sensibility is the pro- perty possessed by certain organs of transmitting to the mind, through the medium of the brain, the consciousness of impressions, which they have received. It is sensibility in the restricted accep- tation of Haller. The epithet animal was given to it by Bichat to distinguish it from the other variety of sensibility, which belongs to all organized bodies, whilst this is exclusively possessed by animals. The whole of the attributes of this property have been detailed, at much length, in the first volume of this work. Fifthly. Bichat admitted a fifth vital property, under the name animal contractility, which comprised voluntary muscular contraction ; — treated of elsewhere as one of the functions of the body. It diners from organic contractility, in its exciting causes not being seated 624 LD7E. in the organ in which it is developed,— that is,in the muscles,— but in the brain; and, moreover, whilst the other varieties of con- tractility are irresistibly connected with, and proportioned to, the. kind of sensibility correspondent to them, this is not the case with animal sensibility, and its play is never continuous. From the distinction we have endeavoured to draw between the fundamental vital properties and the functions, it will be obvious, that the ingenious division of Bichat is susceptible of farther cur- tailment by analysis. A vital property must be one possessed by all living bodies ; it is fundamental in the tissues, and differs according to the precise structure of the tissue. It is found in the vegetable, as well as in the animal. Neither of the two last properties of Bichat, however, corresponds with this definition. They do not exist in the vegetable. They require not only a nervous system, but a brain, that can conceive and will. They are both, indeed, complicated functions, and, as such, have been considered at great length elsewhere. By ultimate analysis, therefore, the five vital properties of Bichat may be reduced to the two we have previously mentioned,—sensibility and motility. Perhaps we ought to rest satisfied with the admission, that every primary tissue is capable of being acted upon by appropriate stimuli, or is sensible ; and that it possesses the additional pro- perty of moving, in consequence of such impression. Physiolo- gists have, however, attempted to simplify the subject still farther, and to reduce the vital properties to one only. Such is the view of Broussais, who considers contractility to be the fundamental vital property of all the tissues. Adelon considers, that sensi- bility is the only living property, that should be admitted, which must carry with it the idea of motion, and is the active, motive faculty of living matter. The term sensibility is, however, unfor- tunate, in consequence of its conveying the notion of mental per- ception, and of such acceptation having been received into phy- siology to designate a function. It has, consequently, been proposed to substitute the term excitability, incitability or irritability, but with the same signification. Rudolphi" prefers incitability, (Erregbarke it,) as not liable to the objection that maybe urged against the others, of having been employed in other sig- nifications. This incitability differs in the different organs and tissues: in the muscles he terms it irritability (M u s k e 1 k r a f t, Reiz b ar keit); in the nerves, sensibility (Ne rv e nkr aft, Em pf indlichkeit); and by some physiologists, in the mem- branous parts, it is called contractility (S pa n nkr af t, Zu- sammenzie hungskraft.)b 3. Life of the Blood.— Such are the phenomena which indi- cate the existence of the vital principle, and such the laws by which » Grundriss der Physiologie. b For various views on the subject of irritability, see Alison, art. Contractility, Cyclop, of Anat. and Physiol, i. 717, London, 1836; Adelon, Physiologie de I'Homme, 2de edit. iv. 547, Paris, 1829; and Dr. Hall, art. Irritation, Cyclop, of Anat. and Physiol., July, 1840. LIFE OF THE BLOOD/ 625 it seems to be governed. By certain physiologists, it is considered to influence solids only ; by others, it has been considered to reside in the fluids also, and especially in the blood. The notion of the vitality of this fluid was espoused by the celebrated John Hunter," and to him we are indebted for many of the facts and arguments adduced in its favour, which have impelled the generality of modern physiologists to admit its existence. The analogy of the egg had demonstrated, that life is not restricted to substances, which are solid and visibly organized. The fresh egg, like other living bodies, possesses the ordinary counteracting powers communicated by vitality, and resists those agents, which act upon the dead egg as on other animal substances deprived of the living influence. The fresh egg may be exposed for weeks, with impunity, to a degree of heat, which would inevitably occasion the putrefaction of the dead egg. During the time of incubation, the egg of the hen is kept, for three weeks, at a heat of 105°; yet when the chick is hatched, the remaining yolk is perfectly sweet. The power of resisting cold is equally great. Dr. Hunter performed several experiments, which show the power of the vital principle in resisting cold, and the influence of cold in diminishing the energy of the principle. He exposed an egg to the temperature of 17° and of 15° of Fahrenheit, and found that it took about half an hour to freeze it. When thawed, and again exposed to a tem- perature of 25°, it was frozen in one-half the time. He then put a fresh egg, and one that had previously been frozen and again thawed, into a cold mixture at 15°; the dead egg was frozen twenty-five minutes sooner than the fresh.b These experiments led to the legitimate inference, that the egg possessed the principle of life, and,although fluid,must have enjoyed the properties, which we have described to be characteristic of vitality,—of being acted upon by an appropriate irritant, and of moving responsive to the irritation. Similar results to those obtained with the egg followed analo- gous experiments with the blood. On ascertaining the degree of cold, and the length of time necessary to freeze blood taken im- mediately from the vessel, he found that, as in the egg, a much shorter period, and a much less degree of cold, were requisite to freeze blood that had been previously frozen and thawed, than blood recently taken from the vessel. The inference, deduced from this, was, that the vitality of recent blood being compara- tively unimpaired, it was enabled to resist the cold longer than blood whose vital energy had already been partly exhausted by previous exposure. It would appear, however, that the vital principle in fishes can resist the action of frost. Those that were caught by Captain Franklin's party in Winter Lake froze as they were taken out of the nets, and became in a short time a solid mass of ice ; yet they were alive when thawed.0 » Treatise on the Blood, &c, p. i. ch. i. t> Philosoph. Transact. 1778, pp. 29, 30. = See page 194 of this volume *, and Dr. W. B. Carpenter, art. Life, Cyclop, of Anat. and Physiol. Sept. 1840. VOL. II. — 53 626 LIFE. The fluidity of the blood, whilst circulating in the vessels, has been regarded as an additional evidence of its vitality. It is ob- vious, that such fluidity is indispensable, seeing-that it has to cir- culate through the minute vessels of the capillary system, and that the slightest coagulum, forming in them, would lead to morbid derangements. Yet the blood is peculiarly liable to become solid by its constitution, and whenever it is removed from its vessels it coagulates. This is not owing simply to the cessation of its circu- lation, for if it be kept at the same temperature as in the living body, and be made to circulate with equal rapidity through a dead tube, it equally becomes solid. The cause, consequently, that maintains its fluidity,is the vital agency ; or, as J. Muller remarks, the proper combination of its elements is maintained so long only as the blood is under the influence of living surfaces, — that is, of the vessels. The experiments of Shroder van der Kolka show, that coagulation takes place with extraordinary rapidity after the brain and spinal marrow have been broken down: even in a few minutes after the operation, coagula were found in the great ves- sels. Mayer observed, that after the application of a ligature to the pneumogastric nerve the blood coagulated in the vessels and death was thus produced. Sir Astley Cooper, on repeating the experiment, found that the conversion of venous into arterial blood in the lungs was prevented. Of four experiments, however, which were performed under the direction of J. Miiller,b --two on dogs and two on rabbits — although the animals were examined im- mediately after death, which resulted from the ligature of the pneu- mogastrics, in two cases only was a small coagulum, of the size of a pea, discovered in the left side of the heart — none in the pulmonary vessels. Another argument in favour of the vitality of the blood is drawn from the facts connected with its coagu- lation,— facts, which show, that the process is but little influ- enced by physical agents, and which have induced Magendiec to infer, with many other physiologists, who are but little dis- posed to invoke the vital agency, " that the coagulation of the blood cannot be ascribed to any physical influence, but must be esteemed essentially vital, and as affording a demonstrative proof that the blood is endowed with life." It has, indeed, been at- tempted to show, that there are certain phenomena, which de- monstrate that the vitality of this fluid increases or diminishes with the vitality of other parts of the body. When blood is drawn from a vessel it does not instantly coagulate or die ; and, by ob- serving the length of time consumed in the process, it has been thought, that we might, in some measure, be able to estimate the degree of vital energy it possesses. In diseases, where the vital action is exalted, — as in inflammation, — the blood is found to » Comment. deSanguin. Coagulat.Groning. 1820; and Diss.sist. Sanguin.Coagulat- Groning. 1820 ; also, J. Miiller's Handbuch, u. s. w., and Baly's translat. p. 97, Lond. J838. . b op. cit. p. 98. • Precis de Physiologie, 2de e"dit. ii. 234, Paris, 1825. LIFE OF THE BLOOD. 627 coagulate much more slowly than in a state of health, and the coagulation itself is more perfect, whilst in diseases, that are de- pendent upon a diminution of the vital energy, the opposite is the fact; because, in the first case, it is presumed, the blood possesses the vital principle in a higher degree than natural, and conse- quently resists, for a longer period, the influence of the physical agents to which.it is exposed ; whilst, in the second case, it pos- sesses the vital principle to a less degree than natural, and there- fore yields sooner to the influence of those agents,—the coagula tion, in all instances, being analogous to the rigidity of the mus- cles, which takes place after dissolution, and indicates the final cessation of vitality or the last act of life.3 The'buffy coat, or inflammatory crust of the blood, called, also, corium phlogisticum, and crusta pleuretica —the nature of which has been investigated before (vol. ii., p. 108,) —is a circumstance connected with the blood's life, which has been invoked by the supporters of this view of the subject. These terms are applied to an appearance of the crassamentum, which is dependent upon its upper portion containing no red particles, but exhibiting a layer of a buff-coloured coriaceous substance, lying at the top, owing to the red particles, during coagulation, sinking to the lower portion of the clot, before coagulation is completed; hence, the colour- iess state of the upper surface. At the same time, the whole of the coagulated portion is much firmer than usual. The red par- ticles, in such case, have time to subside before the coagulation is complete, which takes place more slowly than in health ; and this is conceived to be owing to the blood's possessing a higher degree of vitality, — a view which is confirmed by some experiments of Mr. Thackrah.b These consisted in receiving blood, taken from the vessels of a living arffmal in a full and uninterrupted stream, into different cups, and noting the time at which coagulation com- menced in each. Blood, for example, was taken from a horse at four periods, about a minute and a half being allowed to intervene between the filling of each cup. In the first cup, coagulation be- gan in eleven minutes and ten seconds; in the second cup, in ten minutes and four seconds; in the third cup, in nine minutes and thirty-five seconds; and in the fourth cup, in three minutes and twenty seconds. In another experiment, blood was drawn into three separate cups, from the veins of a slaughtered ox, the first of which was filled in the first flow ; the second, about three minutes afterwards; and the third, a short time before the death of the animal. Coagulation commenced, in the first cup, in two minutes and thirty seconds ; in the second, in one minute and thirty-five seconds ; and in the third, in one minute and ten seconds. In a similar experiment, coagulation commenced » See, on the Evidences of the Life of the Blood, from its self-motion, p. 151, of this volume. „,,,,,. Tr uu ■> ■ -r>- b An Inquiry into the Nature and Properties of the Blood, in Healtu and in Dis- ease, Lond. 1819. 628 LIFE. in the first cup, in two minutes and ten seconds ; in the second, in one minute and forty-five seconds ; and in the third, in thirty-five seconds. Similar phenomena are found to occur in the human subject. Blood, to the amount of about a pint and a half, was taken from the arm of a female labouring under fever. A portion of this, received into a cup on its first effusion, remained fluid seven minutes; a similar quantity, taken immediately before tying up the arm, was coagulated in three minutes and thirty seconds. Of blood, taken as in the last experiment, from the arm of a man, the first portion began to coagulate in seven minutes; the last in four. The vitality of the system, and with it the vitality of the blood, being diminished by each successive abstraction of that fluid, it coagulated or died sooner and sooner in proportion as it was previously more and more enfeebled.2 It is proper to observe, however, that the blood may remain fluid in the vessels and coagulate when removed from them, long after the death of the body. In a case observed by the author, it flowed freely from the vessels of the brain and coagulated fifteen hours after the total cessation of respiration and circulation ;b and many such cases have been observed by others.0 They would seem to show, that the phenomenon of coagulation is wholly physical in its nature."1 It has been elsewhere shown, that each part of the body as regards the cells that compose it may be considered to have a life of its own, — a cellular life ; hence, a minute part may die and be reproduced without the general life of the individual suffering ; and in certain of the lower animals, so little is the organism in general affected by injuries to a part, that when the animal is cut in pieces, each piece may undergo a distinct 4 development, so as to form so many separate beings. In the higher animals, how- ever, this is not the case. In them, the*death and reproduction of every part of the frame is taking place in the function of nutrition ; and it is only when organs, that are intimately associated with each other, and whose association is essential to the life of the whole, have their functions interrupted, that the interruption of other functions, and general death follows. The death which takes place in minute parts has been called molecular, that of the whole body somatic* But granting that some of the above and other arguments lead to a belief in the vitality of the blood, they are equally favourable, » See, on this subject, Fletcher's Rudiments of Physiology, part. ii. a, p. 45, Edinb. 1836 ; Mandl, Archiv. Gener. de Med. Nov. 1840 ; or Encycl. des Sciences Me"d., Dec. 1840, p. 248 ; and Manuel d'Anatomie generale, p. 224, Paris, 1843 ; and Ancell, Lancet, Oct. 26, p. 145, and Dec. 21, 1839, p. 460. b Proceedings of the American Philosophical Society, for May, June, and July, 1840, p. 216; and Amer. Med. Intelligencer, Aug. 1, 1840. • J. Davy, Researches, Physiological and Anatomical, ii. 190, Lond. 1839 ; or Dun- glison's Amer. Med. Lib. Edit., Philad. 1840. d Jt was repeatedly noticed by Professor S. Jackson, in those who died in Phila- delphia of the yellow fever of 1820. « Carpenter, art. Death, in Cyclop, of Anat. and Physiol., vol. i., and in Human Physiology, § 645, Lond. 1842. LIFE OF THE BLOOD. 629 — many of them at least, — to the life of the chyle, which we have seen, accurately resembles the blood in every property, ex- cept in that of coloration ; and if we admit the blood to be pos- sessed of life, a question arises, respecting the part at which the nutritive substances, taken into the system, become converted into the nature of the being they are destined to nourish, and receive the principle of life. This must be either through the admixture of the fluids poured out from the supra-diaphragmatic portions of the alimentary canal, with those of the stomach or small intestine, or owing to the mysterious and inappreciable agency of the chyli- ferous radicles themselves, which separate the same fluid, chyle, from every substance that may be submitted to their action. A reference to what has been said, on these topics, under the heads of Digestion and Absorption, will lead to the opinion", that no vitalizing influence is exerted on the food in the stomach and in- testines, and therefore that the infusion of vitality — if the expres- sion may be allowed — must take place in the chyliferous or san- guiferous vessels. As to the mode in which the blood obtains its vitality, great doubt must necessarily exist. The general opinion, perhaps, is, that it is obtained from the organic nerves, distributed to the inner coats of the vessels, and this idea is confirmed by an experiment of the late Mr. Thackrah, which showed, that blood, received into a dead vessel, is always more speedily coagulated than when it is retained by ligature in a living vessel; and thence he inferred, that the vitality of the vessel affects the blood, and retards its coagulation. Mr. Thackrah denies, indeed, the life of the blood, and ascribes all the evidences of it, which it exhibits, to the influence exerted by the living vessels on their contents. These are the only fluids that have been suspected to be endowed with vitality. None of the others exhibit analogous phenomena, when exposed to similar agencies. On the whole, we are led to the conclusion, that the vital prin- ciple animates both solids and fluids, but all that we seem to know regarding it is — in the language of Dr. Barclay3— " that all the organisms of animals and plants are formed out of fluids, and that in a certain species of fluid, secreted from the parent, and afterwards inclosed in a very thin and transparent vesicle, there is a living organizing principle, which also acts upon the fluid in a' way which we know not, forming out of it a regularly organized system of solids, and forming not only the rudiments of that system, but causing it afterwards to be nourished, and to grow, through the medium of fluids, which are moved and distri- buted under the influence of this organizing animating principle." Our knowledge being limited to this category, we are compelled to study life in its results or manifestations. These, as we have seen, constitute the science of Biology or Physiology. » Inquiry into Life and Organization, Edinb. 1822. 53* 630 OF DEATH. CHAPTER VI. OF DEATH. It has wisely entered into the views of Providence, that the existence of all organized bodies should be temporary. Yet we find considerable difference amongst them in this respect. Whilst some of the lower classes of animals and vegetables are no sooner ushered into being than a process of decay appears to commence; others require the lapse of ages for their various developments and declensions ; and, as a general rule, those, in which the attainment of growth has been slow, have the period of decrease proportionably postponed; whilst, where maturity has been rapidly attained, decay as rapidly supervenes. The ages of man are numerous and protracted. For a time, the parts of the frame, that are concerned in his development, unceasingly deposit the necessary particles, by a process as beau- tiful and as systematic as it is mysterious, until ultimately the growth, peculiar to the species and the individual, is attained. At this point, the preponderance, which previously existed in the action of the exhalants over the absorbents, appears to cease. All is equality; but, ere long, the exhalants fall off in their wonted activity ; the fluids decrease in quantity ; the solids become more rigid ; and all those changes supervene, which we have described as characterizing the decline of life, and the approach of the pheno- menon, which has now to be considered. Death is the necessary, total, and permanent cessation of those functions, by which the presence of life is characterized. This ces- sation may happen at all ages, from accident or disease; a few only ceasing gradually to live by the effects of age alone. Hence, a distinction has been made into that kind of death which is pro- duced by the gradual wear and tear of the organs, and that which cuts off the being prematurely from existence. The former has been termed, by some physiologists, senile or natural, the latter accidental. These differ considerably in their physiology; and will, therefore, require a distinct consideration. 1. Death from Old Age. —The natural period of life is different in different individuals. It varies according to numerous appre- ciable and inappreciable circumstances ; — the original constitution of the individual; the habits of life ; the locality in which he may be situate, &c. Whilst some countries are remarkable for the longevity of their inhabitants, others surprise us by the short period allotted for the natural duration of life..a Blumenbach asserts, that by an accurate examination of numerous bills of mortality, he » See, on this subject, Bellefroid, Bull. Med. Beige, Aout et lSTov. 1839; Lemuel Shattuck, Amer. Journ. Med. Sciences, April, 1841, p. 369 ; and Traill, Outlines of Med. Jurisprudence, Amer. Edit, with notes by the author of this work, p. 30, Philad. 1841. v ) DEATH FROM OLD AGE. 631 has ascertained the fact, that a considerable proportion of Europeans reach their 84th year, but that a few exceed it; whilst, according to Fod6re,a in the insalubrious region of Brenne, in France; nature begins to retrograde at from 20 to 30; and 50 years is the usual term of existence. Hallerb noted one thousand cases of centena- rians ; sixty-two of from 110 to 120 years; twenty-nine of from 120 to 130; and fifteen who had attained from 130 to 140 years. Beyond this advanced age examples of longevity are much more rare and less sufficiently attested ; yet we have some well authen- ticated cases of the kind. Thomas Parr was born in 1635 ; mar- ried when at the age of 120 ; retained his vigour till 140 ; and died at the age of 152, from plethora — it was supposed — induced by change of diet. Harvey dissected him and found no appearance of decay in any organ.0 Henry Jenkins, who died in Yorkshire, in 1670, is an authentic instance of the greatest longevity on record. He lived 169 years.d The following list of instances of very advanced ages has been givene Lived. Age. Apolloniusof Tyana, - - - - A. D. 99 - 130 St. Patrick,......491-122 Attila,.......500-124 Llywarch Hen......500-150 St. Coemgene,......618- 120 Piastus, King of Poland .... 861 - 120 Thomas Parr, -.....1635 - 152 Henry Jenkins, - - - - J - - 1670 - 169 Countess of Desmond, .... 1612 - 145 Thomas Damme,.....1648 - 154 Peter Torton,......1724 - 185 Margaret Patten.....1739 - 137 John Rovin and Wife, .... 1741 - 172 and 164 St. Mongah or Kentigen, .... 1781 - 185 It would not seem that the natural period of life has differed much in postdiluvian periods. The Psalmist writes: — " The days of our years are threescore years and ten ; and if by reason of strength they be fourscore years, yet is their strength labour and sorrow, for it is soon cut off, and we fly away."f And when Barzillai excused himself for not visiting the royal palace at Jerusalem, he observed to the king : — " I am this day fourscore years old, and can I discern between good and evil 1 can thy servant taste what I eat or what I drink 1 can I hear any more the voice of singing men or singing women 1 wherefore then should thy servant be yet a burden unto my lord the king V's The census of the United States has strikingly exhibited the influ- » Traite de Medecine Legale, et d'Hygiene Publique, torn. v. p. 537, Paris, 1813. b Element. Physiol, xxx. 3. c Philos. Transact, iii. 1699. d Art. Lebensdauer, in Pierer's Anat. Physiol. Real Worterbuch, iv. 697, Leipz. 1821,. " Prichard, Researches into the Physical History of Mankind, 2d edit. i. 421, Lond. 1836. Psalm xc. s 2 Samuel, xix. 35. See art. Longevity, by the author, in Amer. Quarterly Re- view, 1835 ler, Element. Phys 632 DEATH. ence of races on longevity in the same country. In 1S30, accord- ing to Professor Tucker,a the proportion of whites over 100 years of age, was 1 in 19,529; of free coloured, 1 in 487 ; and of slaves, 1 in 1410. The census of 1840 confirms this immense difference, — the whites, over 100, were in proportion of 1 in 17,938; the free coloured of 1 in 597; and the slaves of 1 in 1,866. It is not easy to indicate the character of organization, which is most conducive to longevity and to health. It has been supposed, however, and with some probability, that the state of the nervous system is greatly concerned ; for the pathologist looks to this part of the frame as the commencement of most if not all fatal maladies. Generally, the aged individual sinks silently to death, in the manner described under Decrepitude, (p. 529,) totally unconscious of all that surrounds him. At other times, however, he preserves his sensorial powers to the last, and may be capable of locomotion; until, owing to some oppression of one or other of the vital func- tions during sleep, it becomes the sleep of death, — the elasticity of the organs being insufficient to throw off the oppression and resume their functions. At other times, a slight febrile irritation will be the prelude to dissolution. The great characteristic of this kind of death — as pointed out by Bichat in one of the best of his excellent productions11 — is, that animal life terminates long before organic life. Death takes place in detail,— the animal functions, which connect the aged with the objects around him being annihilated, long before those that are concerned in his nutrition; Death, in other words, takes place from the circumference towards the centre, whilst in accidental or premature death, the annihilation of the functions begins in the centre and extends to the circumference. As vitality gradually recedes in the aged from the exterior, one of the great centres of vitality — brain, heart or lungs — stops for an instant. The powers are insufficient to restore the action, and total death necessarily ensues. It has been an interesting inquiry with physiologists to determine the cause of death, thus naturally occurring. Opinions have been various, but such causes as affect the three great vital functions seem to be most entitled to consideration. These have been sup- posed to be; — First, ossification of the arteries, occasioning an obstacle to the free circulation of blood in the parts ; Secondly, ossi- fication of the cartilages of the ribs, and diminution of the capillary system of the lungs, preventing sanguification; and Thirdly, shrivelling and gradual induration of the nervous system, rendering it ultimately unfit for innervation, &c. These are the physical cir- cumstances or changes, which may give occasion to the final cessa- tion of the vital phenomena; but, after all, the difficulty remains, * Progress of the United States in Population and Wealth in fifty years, as exhibited by the Decennial Census, p. 72, New York, 1843. b Recherches Physiologiques sur la Vie et la Mort, Paris, 1800. ACCIDENTAL DEATH. 633 — and one that is insolvable, — to explain the cause why these changes themselves occur in the organs essential to vitality. We say it is insolvable, for, until we have learned the nature of life, which seems far beyond our comprehension in the present state of our knowledge, it is obviously impracticable to understand the phenomena that arise from its gradual declension and final extinc- tion. This kind of death, produced by the gradual declension of the powers of life, is regarded by Dr. W. Philip,a as only the last sleep, characterized by no peculiarity, in which the powers, partly from their own decay, and partly from the lessened sensibility increasing the difficulty of restoring the sensitive system, be- come incapable of the office, and the individual, therefore, wakes no more. We have before remarked, that there appears to us to be a difference between sleep and death, although they may trend closely on the confines of each other.b It is not common, however, for death to occur in this quiet and gradual manner. Man is liable to numerous diseases, from the earliest to the latest period of existence, many of which are of a fatal character. It was admitted by Sydenham, whose estimate cannot be regard- ed as more than an approximation, that two-thirds of mankind die of acute diseases; and that of the remaining one-third, two- thirds, or two-ninths of the whole die of consumption, leaving, consequently, only one-ninth to perish from other chronic maladies, and from pure old age. How small, then, must be the number of those that expire from decrepitude simply ! 2. Accidental Death. —This term has been used, by many physiologists, to include all kinds of death that befall man in the course of his career, and before the natural term ; the cause consist- ing in the supervention of some accidental organic lesion, which arrests the vital movements before they would cease of themselves. This kind of death differs essentially from that we have been considering. The individual is here, perhaps, in the full posses- sion of all his faculties; his organs have been previously, to all appearance, in the most favourable condition for the prolon- gation of life, and his death, instead of being natural, and unper- ceived in its approaches by the individual himself, is usually forced and violent. Every species of sudden death commences by the interruption of the circulation, the respiration, or the action of the encephalon. One of these three functions first ceases, and the others die in succession. Each will demand a few remarks. a. Death beginning in the Heart. —When — owing to fatal syncope, to wounds of the heart or great vessels, or to the rupture of an aneurism — the heart is struck with death, the cessation of the functions is speedy. Sensation and motion are lost; respira- tion is arrested, and death occurs, —if the cause of the cessation of the heart's action be suddenly and sufficiently applied,—almost » Philosophical Transactions for 1834; and an Inquiry into the Nature of Sleep and Death, p. 166, Lond. 1834. " See page 534 of this volume. 634 DEATH. instantaneously. The order, in which death takes place in the different organs, is as follows : — The heart failing to propel its blood, the brain no longer receives the necessary impulse for the continuance of its functions; it therefore ceases to act; the conse- quence of this is the death of all those organs that receive their nervous influx from it; all voluntary motion is annihilated, as well as the action of the respiratory muscles; the mechanical phenomena of respiration are, consequently, arrested ; and the air is no longer received into the chest. From this cause, then, the chemical phe- nomena of respiration would cease, were they not previously ren- dered unnecessary by the cessation of the heart's action. The phenomena of nutrition, secretion and calorification,— functions of the capillaries, —yield last. b. Death beginning in the Brain. — In this case, owing to the loss of innervation, — as in severe injury done to the head, or the worst cases of apoplexy, — the sensorial functions first cease, and the individual lies deprived of all sensation, volition, and mental and moral manifestation. Respiration becomes progressively more irregular and laborious, and ultimately ceases. The order of death is here as follows: — the interruption of the brain's action destroys that of the voluntary and mixed muscles; the mechanical pheno- mena of respiration therefore cease, and then the chemical. This is followed by cessation of the heart's action, owing to the united loss of nervous influx from the brain, and the want of a due supply of blood. To the cessation of the heart's action succeeds the loss of the general circulation ; and lastly, that of the functions of nu- trition, secretion and calorification. c. Death beginning in the Lungs. — The action of the lungs may Jae destroyed in two ways : either the mechanical phenomena of respiration may first cease, as in hanging, strangulation, &c, where the air is prevented from reaching the lungs; or the chemical phenomena may be first arrested, as when air is breathed, which does not contain oxygen, but yet can be respired for a time. In the first case, the order of death is as follows: — the mechanical phenomena cease ; to this succeeds cessation of the chemical phe- nomena, owing to the supply of air being cut off; the blood, not experiencing the necessary conversion in the lungs, soon stagnates in the pulmonary capillaries ; for a time, however, the heart con- tinues to beat, owing to the aeration effected by the residuary air in the minute bronchial ramifications ; but this soon ceases in con- sequence of the want of supply of blood ; the brain dies, and the other parts in succession." Where the chemical phenomena first cease, the suspension of the action of the brain follows for the cause already assigned ; and the mechanical phenomena of respiration are not arrested, until the nervous influx is cut off by the death of that organ- The immediate phenomena of death and the order of their suc- 1 See the article Asphyxia, by the author, in the American Cyclopedia of Practical Medicine and Surgery, part x., Philad. 1836 ; and in his Practice of Medicine, 2d edit vol. i., p. 408, Philad. 1844. ACCIDENTAL DEATH. 635 cession are easily undersood, when one of the great centres of vitality is suddenly destroyed, either from accident or disease ; but when death does not follow immediately, and time is allowed for a series of morbid phenomena to be established, the problem be- comes much more complicated. Some organ or structure is first deranged ; and, owing to the intimate connexion, which we have elsewhere seen to exist between the various functions, general derangement or irritation follows, and the individual dies, worn out by such irritation, but without our being exactly able to under- stand on which of the great centres that dispense vitality the malign influence has been exerted, or whether it may not have affected all equally. In inflammation of the brain, heart, or lungs, we may presume, that the functions of these organs have been respectively annihilated by the diseased action ; and that as such functions are essential to the existence of vitality, death may arise in the manner we have already described ; but we frequently find the bowels affected with inflammation, or the peritoneum lining the interior of the abdomen ; and the case, if neglected, is as surely attended with fatal consequences as the same morbid affection of the organs termed vital; and this in a space of time so short, as not to enable us to understand the nature or the mode of action of the lethiferous agent: but that it must exert its influence on one or more of the great centres of vitality is manifest. In many cases, the heart seems to yield first, not suddenly but gradually; the brain, failing to receive its due impulse, becomes progressively unfit for transmitting the nervous influence to the muscles ; insensibility gradually supervenes, until it has attained such an extent, that no nervous influence is sent to the respiratory muscles, when cessa- tion of their action naturally ensues. Of the nature, however, of the morbid condition of the heart, thus induced by disease, we are totally ignorant. It is fashionable to say, that death is produced by irritation, but this is merely concealing our deficiency of know- ledge under a term, the explanation of the agency of which com- prises the whole difficulty. Adelona thinks, that the brain gene- rally gives way first in these cases ; in consequence of which the respiration is disturbed, the lung becomes engorged, the respira- tion difficult, and death occurs as in a case of gradual asphyxia. There is something extremely obscure in these cases. It often happens, that the intellectual manifestations and the nervous dis- tribution to the muscles of voluntary motion will be executed, even vigorously, until a short time prior to dissolution, whilst the feeble, irregular and intermittent beat of the heart may indicate how greatly its irritability is morbidly implicated. These remarks are chiefly applicable to death, as it arises trom the numerous acute affections, which are so fatal to mankind ; but it may occur, also, from those, that persist for a great length ot time, and destroy after months or years of morbid irritation, as in cases of calculi of the bladder, engorgements of the viscera &c. In these cases, likewise, death must ultimately result trom the • Physiologie de I'Homme, 2de edit. iv. 472, Paris, 1829. 636 . DEATH. destruction of one or other of the vital functions, — respiration, circulation or innervation ; but, in a manner so gradual, that it takes place nearly in the same way as in old age ; except that, in all cases, it proceeds from the cefttre to the circumference ; the great internal functions first ceasing, and afterwards their depen- dencies, — a difference, which explains why we are justified in attempting means of resuscitation in sudden death, whilst it would be the height of absurdity to have recourse to them where, " Like a clock worn out with eating time, The wheels of weary life at last stand still." The renovation could only be effected by the substitution of new, for the worn out, machinery. It has been already shown (vol. i., p. 406) that there are certain causes of death, which affect the two sexes in infancy to a different extent; and the same fact is exhibited when the ratio of deaths of the male and female is taken at all ages. The following table, from the valuable statistical report now annually made by the direction of the British government, shows this in a striking manner.b Causes of Death. Number of Deaths. 1836. 1839. Males. Females. Males. Females. Cancer 620 1828 660 2031 Hooping-cough - 4036 5071 3683 4482 Consumption 27,935 31,090 28,106 31,453 Child-birth - 2811 2915 Violent deaths 8359 3368 8325 3307 Hydrocephalus 4242 3430 4313 3436 Diabetes 152 55 151 63 Convulsions 14,549 11,498 14,245 11,163 Delirium tremens - 167 15 184 22 Tetanus 100 29 102 20 Bronchitis - 1193 874 916 747 Pleurisy 329 253 342 246 Pneumonia - 9887 8112 10,000 8151 Asthma 3359 2386 3092 2091 Pericarditis - 74 50 83 52 Aneurism - 88 31 69 33 Hernia 318 189 299 175 Fistula 82 18 81 22 Stone ... 282 38 274 25 Cystitis 103 25 118 20 Nephritis 113 44 99 82 Gout - 161 46 170 45 Dropsy 5170 7172 5268 6983 Intemperance 125 35 178 40 Starvation by > want, cold, &c. $ 126 41 85 45 » See H. Mayo, Outlines of Human Pathology, Dunglison's Amer. Med. Lib. Edit. Introduct. p. 3, Philad. 1839. <> Mr. W. Farr, in Third Annual Report of the Registrar-general of Births, Mar- riages and Deaths in England, p. 72, Lond. 1841. DEATH. 637 The following diagram from M. Quetelet* exhibits the relative viability of the two sexes deduced by him from numerous statis- tical inquiries. The dotted line represents the viability of the Fig. 293. (i l> 10 15 20 Z5 30 kO 50 60 10 80 SO 70fl Curve indicating the viability or existibility of male and female at different ages. — Quetelet. female: the other that of the male. According to this, the maxi- mum of viability is least at the age of 14 in both sexes. After puberty, it diminishes more rapidly in the female than in the male. It is also less during the period of childbearing, from the 27th to the 45th year. The age of shortest viability is immediately after birth ; that of longest viability immediately before puberty. The viability of the child after the first month of existence, according to M. Quetelet, is greater than that of the man nearly 100 years old. Towards the 75th year, it is scarcely greater than for the infant about the sixth month after birth. For some time before dissolution, — both in death from old age and from disease,— the indications of the fatal event become more and more apparent. The speech grows embarrassed; the ideas are incoherent; the hands, if raised by the effort of the will, fall inertlv into their former position; the laboured respiration occa- sions insufficient oxygenation of the blood, and the distress excites an attempt at respiration, which the debility renders nearly » Op. cit. English edit., p. 32, Edinb. 1843. VOL. II. — 54 - 638 DEATH. ineffectual; distressing yawnings, and gaspings occur to remedy the defective pulmonary action, and the whole respiratory system is in forcible and agitated motion, — the teeth, at times, gnash- ing, and convulsive contractions occurring at the corners of the mouth. The heart becomes gradually unable to propel the blood with the necessary force into the arteries, so that the fluid ceases to reach the extremities of the body — the hands, feet, nose and ears — which grow cold, and a cold clammy moisture oozes from the vessels. In experiments on animals, the blood is found to be gradually driven no farther than to the feet; then to the groin : afterwards it reaches only to the kidneys, and a kind of reflux occurs through the space along which it had previously been urged forwards. The flux and reflux now reach no farther than the diaphragm, and gradually retreat, until the blood flows back upon the heart itself, which now stops for a time, and then makes an effort to free itself from the contained fluid. The heart's action and respiration are imperfectly performed for a few times at irregular intervals, till at length the contractility of the organ is entirely gone. Respiration ceases by a strong expulsion of air from the chest, — often accompanied with a sigh or a groan, and probably arising, partly from the relaxation of the inspiratory muscles, and still more from the elasticity of the cartilages of the ribs. Hence it is that, in common language, to expire is synony- mous with to die. In cases of sudden death, the heart may con- tinue to beat for a time after innervation and respiration have ceased. Under such circumstances, the left ventricle dies first, the obstruction to respiration cutting off its supply of blood. For some time immediately preceding dissolution, there is usu- ally a peculiar mixed expression of countenance, — a compound of apparent mental and corporeal suffering, — which has given occasion to its being called the agony. It is characterized by facial indications, which were, first well described by Hippocrates, and from him called Fades Hippocratica. The nose is pinched, the eyes are-sunken, the temples hollow, the ears cold and re- tracted, the skin of the forehead tense, the lips pendent, relaxed and cold, &c. The eye, during this condition, especially when dissolution approaches, is fixed and slightly elevated, being kept in that position, according to Sir Charles Bell, by the power of the brain over the voluntary muscles of the eye being lost, and the organ being given up to the action of the oblique, which he consi- ders to be involuntary muscles. The word " agony," applied to this condition, in many languages means a violent contest or strife, but its acceptation has been extended so as to embrace what have been termed the " pangs of death" and any violent pain. ' This agony of death, however, physiologically speaking, instead of being a state of mental and corporeal turmoil and anguish, is one of insensibility. The hurried and laboured breathing, the pecu- liar sound on inspiration, and the fixed and turned up eyeball, instead of being evidences of suffering, are now admitted to be DEATH. 639 signs of the brain having lost all, or almost all, sensibility to im- pressions. All the indications of mortal strife are such in appear- ance only : even the convulsive agitations,occasionally perceived, are of the nature of epileptic spasms, which we know to be pro- duced in total insensibility, and to afford no real evidence of cor- poreal suffering. Although, from the moment that respiration and circulation permanently cease, the body may be regarded as unquestionably dead, vital properties still remain in some of the organs, the pre- sence of which is an evidence that vitality has previously and recently existed. The functions, which persist after the animal has become dead to surrounding objects, are those that belong to the organic class. Animal heat, for example, may still be elicited for a time, in the internal organs more especially; and it may re- quire several hours, in death caused suddenly or speedily, by acci- dent or disease, before the whole body becomes cold. Absorption is, also, said to have occurred after death, and the beard and hair to have grown ; but it is more probable, that, in the last cases, the apparent elongation may have been owing to the shrinking of the integuments. The rectum is very frequently evacuated after dissolution ; and cases have occurred where a child has been born by the contraction of the uterus after the death of the mother. The most marked evidence, however, of the continuance of a vital property after dissolution, is in the case of the muscles, which, as we have mentioned in another place, can be made to contract powerfully on the application of an appropriate stimulus, even for an hour or two after death. Nysten,a from his experiments, inferred, that the parts cease to contract in the following order: — the left ventricle, the large intestine, the small intestine, the sto mach, the bladder, the right ventricle, the oesophagus, the iris, the different voluntary muscles, and, lastly, the auricles, particu- larly the right auricle. The body cools gradually at the surface, and especially towards the extremities, .with a rapidity proportionate to the privation of fluids, and the coldness of the atmosphere. Whilst the refrigeration is going on, the blood remains more or less fluid; and owing to the arteries emptying themselves, by virtue of their elasticity, of their contained blood, the fluid generally accumulates in the venas cavae, the auricles of the heart, and the vessels of the lungs. By virtue of its gravity, it collects also in the most depending parts, occasioning cadaveric hyperaemiae, sugillations or livid marks, which might be mistaken for bruises inflicted during life ; but may generally be distinguished from them by attention. It will be readily understood, that the situation of the blood in the vessels may differ somewhat according to the vital organ which first ceases its functions. If the action of the right heart stops, the lung may- be empty ; if the lung or left heart ceases, the lung and the right side of the heart — with the vessels communicating with it — may » Recherches de Physiologie et de Chimie Pathologiques, Paris, 1811. 640 DEATH. be surcharged with blood, whilst the organs of the corporeal circu- lation may be almost empty. During the progress of refrigera- tion, and especially soon after death, the muscles are soft and re- - laxed, so that the limbs fall into that position to which the force of gravity would bring them; the eyes are half open; the lips and lower jaw pendent, and the pupil dilated. When the body, how- ever, is cold, the blood is coagulated, and white or yellowish coagula exist, especially in the cavities of the heart, which were at one time supposed to be morbid formations, and termed polypi. They take the shape, more or less, of the cavity in which they are found. Lastly, the muscles become firmly contracted, so that no part can be moved, without the application of considerable force ; and, in this state, they continue until the natural progress towards putrefaction again softens their fibres. This has been regarded by physiologists as arising from the last exertion of that residue of vital power, which the body retains after the period of apparent dissolution. With more propriety, perhaps, it may be assigned to physical alterations taking place in the organs, owing to the total loss of those powers, which were previously antago- nists to such changes. It has recently been attributed, by M. Briick,a to the coagulation of the liquids in the interior of the tis- sues. He considers, that the fibrin of the muscle coagulates, when the muscular fibre is deprived of life. It might seem from the previous enumeration of the signs of death, that no difficulty could possibly arise in discriminating be- tween a living and a dead body. Cases have, however, occurred, where such difficulty has been great and perplexing. Many of the signs may exist, and yet the person be merely in a state of suspend- ed animation ; and in certain instances it has even been considered advisable to wait for the manifestations of the putrefactive process, before the body should be consigned to the grave. The following case, given by Dr. Gordon Smith,b strongly exhibits the embarrass- ment that may occasionally arise. A stout young man had been subject to epilepsy, which became combined with madness. On this account it was necessary to remove him to a private asylum in the neighbourhood of London, where he died suddenly, in a violent epileptic paroxysm. The body was removed to the residence of his friends soon after death, when the necessary preparations for inter- ' ment were made. On paying attention to the corpse it was found, that the limbs were quite pliable; that the eye was neither collapsed nor glazed; and that the whole features retained their full natural appearance as during life. A surgeon, who, for years, had been in the habit of attending him, was sent for; and although he could find no indications of vitality, he prudently recommended, that the interment should not take place until decomposition had begun to . manifest itself. In the course of two or three days, appearances » Miiller's Archiv. Nov. 1842 ; cited in Edinb. Med. and Surg. Journal, Oct. 1843, p. 492. h b The Principles of Forensic Medicine, 3d edit, Lond. 1827. DEATH. 641 still continuing the same, a physician was called in, who concurred in the recommendation that had been already given. Fifteen days from the supposed time of his death had elapsed, when Dr. Smith's informant had an opportunity of inspecting the body. At this time, the countenance retained the appearance described, but the eye seemed beginning to sink, and some degree of lividity had commenced on the surface of the abdomen. The joints were still flexible. At this time, a very eminent professor of anatomy viewed the body, and, considering the hesitation that had prevailed to be altogether groundless, he appointed the following day to examine it internally. The head was accordingly opened, and a considerable extravasation of blood found in the posterior part of the cranium, between the skull and dura mater and between the membranes and substance of the brain. No serum was detected in the ventricles ; but the brain itself was remarkably hard. This was sixteen days after death. On the following day, the body was interred. A clamour now arose amongst the neighbours, that he had been prematurely handed over to the anatomist. The body was exhumed ; an inquest was held ; and the evidence of the medical gentleman demanded. The jury returned a verdict of "apoplexy." It may hence become a matter of medico-legal inquiry to verify the existence of death, in cases where doubt prevails, owing to the person being in a state of apparent death, — natural'or assumed.3 Perhaps the most singular case on record of suspension of two of the most important of the vital functions occurred to John Hunter. In the year 1769, being then forty-one years of age, of a sound constitution, and subject to no disease except a casual fit of the gout, he was suddenly attacked with a pain in the stomach, which was speedily succeeded by a total suspension of the action of the heart and of the lungs. By violent'exertion of the will he occasionally inflated the lungs, but over the heart he had no control whatever; nor, although he" was attended by four of the chief phy- sicians in London from the first, could the action of either be re- stored by medicine. In about three-quarters of an hour, however, the vital actions began to return of their own accord, and in two hours he was perfectly recovered. "In this attack," says one of his biographers, Sir Everard Home, " there was a suspension of the most material involuntary actions: even involuntary breathing was stopped ; while sensation, with its consequences, as thinking and acting, 'with the will, were perfect, and all the voluntary actions were as strong as ever."b At one period it was universally credited, that substances could be administered, which might arrest the whole of the vital functions, or cause them to go on so obscurely as to escape detection, i nis a See Dr. J. A. Symonds, in art. Death, Cyclopaedia of Anat. and Physiol, i. 791, LTse1e83aUo Ottley's Life of John Hunter, Bell's Med. Lib. Edit p. 38, Philad. 1839 ; and Htrnter 0„ the'Blood, by Palmer, Bell's Edit. p. 189, Philad. 1840. 54* 642 DEATH. erroneous popular notion is exhibited in the description of the action of the drug administered by Friar Lawrence to Juliet.a Death may also be feigned for sinister purposes. The author recollects a body having been brought in a sack to the house of Mr. Brookes, the distinguished anatomist of London, the vitality of which was detected by the warmth of a protruded toe. It was that of a robber, who had chosen this method of obtaining ad- mission within the premises. The celebrated case of Colonel Townshend exhibits the power occasionally possessed over the vital functions; and Dr. Cleg- horn, of Glasgow, knew an individual who could feign death, and had so completely the power of suspending, or at least of diminishing, the action of the heart, that its pulsations were im- perceptible.1* Lastly, the character of the death, as to violence or gradual extinction, is often exhibited in the physiognomy of the dead. Where it has taken place during a convulsion, or by agents that have forcibly and suddenly arrested respiration or innervation, the countenance may be livid, the jaws clenched, the tongue pro- truded and caught between the teeth, the eyes forced, as it were, from their sockets; but usually in death from old age, or even from acute and tormenting disease,, any distortion or mark of suf- fering, that may have existed prior to dissolution, subsides after the spirit has passed, and the features exhibit a placidity of ex- pression, singularly contrasting with their previously excited con- dition. For effect, however, the poet and the painter suit their descriptions of death to the characterof the individual whom they are depicting. The tyrant falls1 convulsed and agonized, whilst the tender and delicate female is described to have progressively withered, till "At last, Without a groan, or sigh, or glance to show A parting pang, the spirit from her past; And they who watched her nearest could not know * " Take thou this phial, being then in bed, And this distilled liquor drink thou off; When presently thro' all thy veins shall run A cold and drowsy humour, which shall seize Each vital spirit: for no pulse shall keep His natural progress, but surcease to beat. No warmth, no breath, shall testify thou liv'st; The roses in thy lips and cheeks shall fade To paly ashes ; the eyes' windows fall Like death, when he shuts up the day of life; Each part, depriv'd of supple government, Shall stiff, and stark, and cold, appear like death : And in this borrow'd likeness of shrunk death, Thou shalt remain full two-and-forty hours, And then awake as from a pleasant sleep." Romeo and Juliet, iv. 1. b See, also, the case of the Hindoo, mentioned at p. 125 of this volume. DEATH. 643 The very instant, till the change that cast Her sweet face into shadow, dull and slow Glazed o'er her eyes — the beautiful, the black, — Oh ! to possess such lustre, and then lack." Byron's Don Juan, canto iv. Warwick's description of the frightful physiognomy of Duke Humphrey, after death from suffocation, exhibits some of this poetical license : — " But see his face is black and full of blood; His eyeballs farther out than when he liv'd, Staring full ghastly like a strangled man : His hair uprear'd, his nostrils stretch'd with struggling : His hands abroad display'd, as one that grasp'd And tugg'd for life, and was by strength subdued. Look on the sheets; his hair you see is sticking: His well proportion'd beard made rough and rugged, Like to the summer's corn by tempest lodged. — It cannot be but he was murdered here : The least of all these signs were probable." King Henry VI., Part ii. Act. 3. How different is this picture from that of the countenance of the young being, who has gradually sunk to death in the manner above described. The beauty is unextinguished, and the pale- ness and lividity of death have taken the place of the colours of life ; yet the wonted physiognomy may remain : — " Hush'd were his Gertrude's lips ! but still their bland And beautiful expression seem'd to melt With love that could not die !" Campbell. Perhaps one of the most beautiful and accurate pictures, drawn by Byron, is his description of the serenity of countenance observable in most fresh corpses; an expression, which, by asso- ciation is deeply affecting, but not without its consolation to the friends of the departed: — He who hath bent him o'er the dead Ere the first day of death is tied ; * * # * Before decay's effacing fingers Have swept the lines where beauty lingers; And mark'd the mild, angelic air, The rapture of repose that's there; The fix'd yet tender traits, that streak The languor of the placid cheek ; And but for that sad, shrouded eye, That fires not, — wins not, — weeps not now; And but for that chill, changeless brow, Where cold obstruction's apathy Appals the gazing mourner's heart, As if to him it could impart The doom he dreads, yet dwells upon: Yes, but for these and these alone, Some moments, ay, one treach'rous hour, He still might doubt the tyrant's power. So fair, so calm, so softly seal'd The first, last look by death reveal'd. Hyron's Giaour. 644 DEATH. An easy death—euthanasia — is what all desire, and fortunately, whatever may have been the previous pangs, the closing scene, in most ailments, is generally of this character. In the beautiful mythology of the ancients, Death was the daughter of Night, and the sister of Sleep. She was the only divinity to whom no sacrifice was made, because it was felt, that no human interference could arrest her arm ; yet her approach was contemplated without any physical apprehension. The representation of Death as a skeleton covered merely with skin, on the monument at Cuma), was not the common allegorical picture of the period. It was gene- rally depicted on tombs as a friendly genius, holding a wreath in his hand, with an inverted torch, — a sleeping child, winged, with an inverted torch resting on his wreath, or as Love, with a melancholy air, his legs crossed, leaning on an inverted torch,— the inverted torch being a beautiful emblem of the gradual self- extinguishment of the vital flame.a The disgusting representations of Death from the contents of the charnel-house would not seem to have been common until the austerity of the 14th century, and are beginning to be abandoned. In more recent times, Death has been portrayed as a beautiful youth, and it is under this form that he is represented by'Canova, on the monument, erected in St. Peter's at Rome, by George the Fourth of England, in honour of the Stuarts. * D'Israeli, Curiosities of Literature, 2d Series, Amer. Edit, vol. ii. p. 44, Boston, 1834. FINIS. INDEX. i. refers to the 1st, and ii. to the 2d volume. Aberration of refrangibility, i. 179 sphericity, i. 178 Abortion, ii. 428 Absence of mind, ii. 554 Absorption, i. 591 accidental, i. 642 of chyle, i. 591 cutaneous, i. 643 decomposing, ii. 172 digestive, i. 592 of drinks, i. 611 of excrementitial secretions, i 639 internal, i. 639 interstitial, i. 172 of lymph, i. 619 organic, ii. 172 of recrementitial secretions, i. 639 of solids, ii. 172 venous, i. 632 Abstinence, deaths from, i. 514 effects of, i. 514 Academiadel Cimento, experiments of the, on the gizzards of birds, i. 487 Acid, acetic, where found, i. 33 benzoic, i. 33 where found, i. 33 carbonic, quantity of, consumed in respiration, ii. 46 where met with, i. 33 lactic, where found, i. 33 lithic, where found, i. 30 muriatic, where found, i. 26 oxalic, where met with, i. 33 phosphoric, where met with, i. 25 sulpho-cyanic, where met with, i. 29 uric, where met with, i. 30 xanthic, where met with, i. 31 Adipocire, how formed, i. 335 Adipous exhalation, ii. 235 Admiration, expression of, i. 465 Adolescence, age of, ii, 524 Aeration, ii. 42 Affections, what, i. 266 African race, ii. 593 After-birth, ii. 431 After-pains, ii. 431 Age, critical, ii. 528 Ages, the, ii. 510 Air, atmospheric, properties of, ii. 22 drawn into the veins, i. 618 expulsion of, from the intestines, i. 578 in the intestines, nature of the, i. 570 in the stomach, nature of the, i. 554 Albino, state of the eyes of the, i. 181 Album graecum, what, i. 573 Albumen, where met with, i. 28 concrete, where met with, i. 28 liquid, where met with, i. 28 Aliments, classification of, i. 507 Allantoid vesicle, ii. 456 Alphabet, how formed, i. 445 Ambiguity, sexual, ii. 341 American race, ii. 594 | Amnion, ii. 444 Anastomoses of vessels, effects of, on the circulation, ii. 155 Jlnatomie vivante, i. 40 Androgynous being, ii. 351 Angle, facial, i. 296 occipital, 298 Anguish with bodily suffering, expression of, i. 464 Angus, Mr., trial of, ii. 375 Anhelation, ii. 41 Animalcules, spermatic, ii. 328, 392 Animalculists, ii. 385, 392 Animality, what, i. 19 646 INDEX. Animals and vegetables, differences be- tween, i. 19 cold-blooded, what, ii. 187 warm-blooded, ii. 187 Antagonism of nerves, i. 357 Antipathies, ii. 575 Apparatus, what, i. 39 Appetite, i. 511 Arabians,the, on the animal spirits, i. 87 Arcus senilis, i. 184 Areola, ii. 436 Arterialization, ii. 42 Arteries, ii. 74 circulation in the, ii. 130 described, ii. 149 locomotion of, ii. 154 Articulation, ii.*341 Asiatic race, ii. 594 Association, effects of, ii. 585 Athemprobe, ii. 33 Atmospherization, ii. 42 Atrabiliary capsules, i. 624 Attitude, i. 395 erect, i. 395 horizontal, i. 401 on one foot, i. 400 on the knees, i. 400 sitting, i. 401 Audition, organs of, i. 138, 152 physiology of, i. 152 Aura seminis, what, ii. 362 insufficient for effecting fecundation, ii. 362, 366 Auscultation, i. 150 Australian race, ii. 595 Axis, cerebro-spinal, i. 50 Azote, sources of, in the food, i. 503 where found, i. 25. See Nitrogen. B. Ballottement, ii. 422 Beaumont, Dr., case by, i. 558 Bearing a load, physiology of, i. 412 Beastings, what, ii. 438 Belching, i. 582 Bewegungssinn, i. 372 Bier-right, ii. 567 Biffin, Miss, her case, i. 107 Bildungstrieb, ii. 173, 381 Bile, ii. 277 colouring principle of the, i. 35 secretion of the, ii. 265 use of, in digestion, i. 567 yellow colouring principle of the, i. 32 Biliary apparatus, ii. 265 Bilin, i. 34 Biliverdin, i. 35 Births, legitimate and illegitimate, ii. 404 Black man of Gmelin, ii. 593 Blastema, ii. 181 Blastoderma, ii. 461 Blood, ii. 88 aeration of the, ii. 42 agency of the, in health and dis- ease, ii. 165 analysis of the, ii. 108 arterialization of the, ii- 42 atmospherization of the, ii. 42 buffy coat of the, 110, 627 clot of the, ii. 98 coagulation of the, ii. 103 coloration of the, ii. 57 fibre of the, ii. 101 forces that propel the, ii. 144 forces that retard the, ii. 153 globules of the, ii. 92 halitus of the, ii. 197 inflammatory crust of the, ii. 110 infusion of substances into the, ii. 166 life of the, ii. 624 quantity of, ii. 89 red colouring principle of the, ii. 31, 101 specific gravity of .the, ii. 91 transfusion of, ii. 166 velocity of the, ii. 157 venous, ii. 91 inspiration of, ii. 145 weight of, in the body, ii. 90 yellow colouring principle of the, i. 82 corpuscles, red, ii. 92 white, ii. 97 Blowing the nose, ii. 37 Body, human, specific gravity of the, i. 408 Bones, i. 36, 337 spongy, use of, in olfaction, i. 132 Borborygmus, what, i. 578 Bosjesman female, generative organs of the, ii. 233 nates of the, ii. 240 Brace, Julia, deaf, dumb, and blind, i. 278 Brain, i. 51 analysis of the, i. 75 circulation in the, i. 77 convolutions of the, an index of the mind, 300 decussation of the, 355 fatty matter of the, i. 32 insensible, i. 81 movements of the, i. 79 of the negro, i. 295 the organ of the mind, i. 268 a plurality of organs, i. 301 protections of the, i. 51 ratio of the weight of the, to the other parts, i. 294 Breasts, ii. 434 Bridgman, Laura, case of, i. 280 INDEX. 647 Brown man, ii. 594 Buffy coat of the blood, ii. 109 Burns, Miss, case of, ii. 375 Byron, Admiral, effects of prolonged hun- ger on, i. 511 C. Circulation, use of the, ii. 165 Circulatory apparatus, ii. 67 Circumcision in the female, ii. 333 Clairvoyance, ii. 544 Climacteric years, ii. 533 Coenajsthesis, i. 261 Cold, effects of severe, ii. 191 Colouring matter of organs, exhalation of the, ii. 243 Colostrum, what, ii- 438 Colours, accidental, i. 224 complimentary, i. 224 harmonic, i. 224 insensibility to, i. 245 opposite, i. 224 Combustibility, preternatural, ii. 100 Combustion, spontaneous, ii. 100 Commodus, his feats, i. 344 Composition of man, i. 24. Compounds of organization, i. 27 Conception, ii. 398 at different ages, ii. 400 at different seasons, ii. 400 double, ii. 408 physiology of, 399 signs of, 419 Concord, i. 152 Condiments, i. 509 Consonants, i- 446 Constitution, ii. 574 Contractility, i. 21, ii. 608 Contractilite de tissu, i. 42 par defaut d'extension, u. 42 Copulation, ii. 313, 356 Cord, jelly of the, ii. 454 umbilical, ii. 453 Corpus luteum, ii. 370 Corium phlogisticum, ii. 109 Corpora Wolffiana, ii. 468 Correlation of functions, ii. 555 Cortical membrane, ii. 447 Cortex ovi, ii. 447. Coughing, ii. 36 Cowper, Spencer, his case, i. 410 Craniological system of Gall, i. 301 Craniology, i. 307 Cranioscopy, i.. 307 Cranology, i. 307 Crassamentum of the blood, ii. 98 Cretinism, ii. 581, 600 Critical age, ii. 528 Cruor of .the blood, ii. 98 Crtiorin, ii. 101 Crusta pleuretica, ii. 109 Cry, i. 440 Crying, i. 440 expression of, i. 463 of animals, ii. 41 Crvpsorchides, ii. 319 Crypts, i. 37, ii. 221 sebaceous, i. 95, ii. 221 Caducity, ii. 529 Calcium, where found, i. 25 Callipsedia of C. Quillet, ii. 404 Caloric, laws of, i. 101, ii. 186 Caloricite of Chaussier, ii. 202 Calorification, ii. 187 circumstances influencing ii. 200 seat of, ii. 202 theories of, ii. 202 Capillary circulation, ii. 136 vessels, ii. 77 Carbon, where found, i. 25 Cartilages, i. 36, 342 Casein, where met with, i. 29 Catamenia, ii. 342 Caucasian race, ii. 591 Cell, germinal, i. 42, ii. 180 -life, ii. 183 Cells, epithelial,!. 100 formation of, ii. 180 Cellular membrane, exhalation of, ii. 235 Cerebellum, i. 59 Chabert, M., his resistance to heat, i. 102 Cheselden's case of the boy restored to sight, i. 255 Chick in ovo, development of the, ii. 459 Childhood, age of, ii. 520 Chinese race, ii. 594 Chlorine, where found, i. 26 Cholesterin, i. 35 Chondrin, i. 30 Chorion, ii. 444 Chyle, i. 599 where formed, i. .528,563 Chylification, i. 563 Chyliferous apparatus, i. 592 Chylosis, i. 592 physiology of, i. 602 Chyme, i. 528 Chymification, i. 527 Ciliary motion, i. 472 Circulation, ii. 66, t\2 in arteries, ii. 130 in birds, ii. 168 capillary, ii. 136 in fishes, ii. 170 in the foetus, ii. 479 in the heart, ii. 114 in insects, ii. 170 in mammalia, ii. 168 in reptiles, ii. 169 in veins, ii. 142 648 INDEX. Curvatures of vessels, effects of the, on the circulation, ii. 154 Cutaneous exhalation, ii. 244 Cutis anserina, i. 468 Cutting, Margaret, her case, i. 438 Cytoblast, ii. 180 Cytoblastema, ii. 179 D. Dazzling, i. 223 Deaf-dumb, intelligence of the, i. 277 and blind, ii. 277 Death, ii. 630 Decapitation, death by, i. 85, 344 Decarbonization, ii. 42 Decidua, ii. 410 reflexa, ii. 412 Declamation, i. 453 Decrepitude, ii. 531 Defecation, i. 575 Deglutition, i. 523 of air, i. 527 Dentition, first, ii. 517 second, ii. 520 Depuration, cutaneous, ii. 244 urinary, ii. 281 Derivation, ii. 144 Desires, instinctive, i. 263 Diastole of the heart, ii. 117 Diet, variety of, necessary for man, i. 505 Differences, acquired, amongst mankind, ii. 581 individual, ii. 570 natural, ii. 577 Digestion, i. 474 buccal, i. 520 in the large intestine, i. 571 in the small intestine, i. 563 oral, i. 520 of solids, physiology of, i. 510 of liquids, physiology of, i. 578 of the stomach after death, i. 548 physiology of, i. 510 theories of, i. 537 theory of, by chemical solution, i. 538 by coction, i. 537 by fermentation, i. 538 by putrefaction, i. 537 by trituration, i. 538 Digestive organs, i. 475 of birds, i. 485 of ruminant animals, i. 484 Dislodging a stake, physiology of, i. 413 Diverticula, ii. 158 Docimasia pulmonum, ii. 33 Dragging a weight, physiology of, i. 413 Dreams, ii. 539 waking, ii. 547 Drinks, i. 508 absorption of, i. 511 Duct, thoracic, i. 598 E. Ear, external physiology of the, i. 153 internal, physiology of the, i. 159 middle, physiology of the, i. 154 musical, i. 163 trumpet, 150 Echo, i. 149 Egg, incubation of the, ii. 459 Elasticity of tissue, i. 42 Elementary structure of animal substances, i. 37 Elements, inorganic, i. 15, 25 organic, i. 15, 27 containing azote, i. 27 not containing azote, i. 32 Emboitement des germes, ii. 386 Embryo, see Fcetus. Embryology, ii. 443 Emotions, i. 266 instinctive expressions of the, i. 469 Encasing of germs, ii. 386 Encephalon, i. 50 Endosmose, i. 44 Engastrimism, i. 435 Epigenesis, ii. 381 Epiglottis, use of the, in deglutition, i. 524 Epithelial cells, i. 100 Epithelium ciliated, i. 100 cylinder, i. 100 pavement, i. 100 tesselated, i. 100 Erectile tissues, ii. 159 Erection, ii. 357 Eructation, i. 582 Erythroid vesicle, ii. 457 Ethiopian race, ii. 593 Evolution, doctrine of, ii. 384 Excitability, ii. 624 Excito-motory nerves, i. 71 Exhalants, ii. 171 Exhalations, ii. 233 adipous, ii. 235 areolar, ii. 244 colouring, ii. 243 cutaneous, ii. 244 external, ii. 244 internal, 234 of the marrow, ii. 241 pulmonary, ii. 254 mucous, ii. 258. synovial, ii. 242 serous, ii. 234 Exosmose, i. 44 ESTDEX. 649 Expansibility, vital property of, ii. 139 Expectoration, ii. 38 Expiration, ii. 32 Expression, i. 414 depressing, i. 462 exhilarating, i. 461 Extensibility of tissues, i. 42 Extract of meat, i. 30 Extractive of meat, i. 30 Eye, achromatism of the, i. 202 accessory organs to the, i. 192 accommodation of the, to distances, i. 229 coats of the, i. 180, 208 diaphanous parts of the, i. 183. dimensions of the, i. 192 insensibility of the, to colours, i. 245 muscles of the, i. 194,211 phosphorescence of the, i. 223 refracting power of the, i. 198 transparent parts of the, i. 183 Eyes, unequal foci of the, i. 239 F. Face, muscles of the, i. 457 Faculties, affective, i. 266, 290 emotive, i. 266, 290 intellectual, i. 285 intellectual and moral, physio- logy of the, i. 266 mental, i. 266 moral, i. 286 of the heart, i. 286 Fffices, properties of the, i. 573 Falsetto voice, i. 453 Fat, exhalation of the, ii. 235 Fear, expression of, i. 465 Fecundation, ii. 360 Feeling, common sense of, i. 261 of life, i. 261. Female, characteristics of the. ii. 577 Fibre, what, i. 39 albugineous, i. 39 cellular, i. 38 elementary, i. 38 laminated, i. 38 life, ii. 183 ^ medullary, i. 39. muscular, i. 38, 326 nervous, i. 39 pulpy, i. 39 Fibres, primary, i. 38 Fibrin, where met with, i. 28 Filament, what, i. 39 Flexibility of tissues, i. 42 Flexors, preponderance of the, i. 395 Fluid, nervous, i. 88 Fluids, division of, i. 40 of the human body, 35, 40 Flying, i. 412 VOL. II. — »>5 Fcetal existence, ii. 443 Foetus, of the, ii. 443, 467 anatomy of the, ii. 443 animal functions of the, ii. 482 calorification of the, ii. 507 circulation of the, ii. 478 dependencies of the, ii. 443 development of the, ii. 458 digestion of the, ii. 470 dimensions of the, ii. 471 effect of maternal imagination on the, ii. 504 expression of the, ii. 483 external senses of the, ii. 482 histology of the, ii. 443 increment of the, ii. 467 intellectual and moral faculties of the, ii. 483 internal senses of the, ii. 482 motion of the, ii. 483 nutrition of the, ii. 503 nutritive functions of the, ii. 484 peculiarities of the, ii. 475 physiology of the, ii. 482 position of the, ii. 473 reproductive functions of the, ii. 509 respiration of the, ii. 498 secretions of the, ii. 508 weight of the, ii. 471 Follicle, i. 37, ii. 221 sebaceous, ii. 260 Follicular secretions, ii. 258 Food, of man, i. 499 prehension of, i. 517 Force of formation, ii. 173, 331 nutritive, ii. 173 plastic, ii. 173, 381 of vegetation, ii. 173 vital, ii. 173 Forces, motive, seat of the, i. 347 Foreshortening, i. 248 Free-martin, ii. 354 Friction of the blood retards it, ii. 153 Functions, animal, i. 50 classification of the, i. 48 correlation of, ii. 555 nutritive, ii. 474. of man, i. 47 of relation, i. 50 reproductive, ii. 307 table of the, i. 48 Galactophorous tubes, ii. 435 Gall's craniological system, i. 301 Galvanism, effects of, on the muscles, i. 369 Ganglions, glandiform, i. 37, ii. 300 nervous, i. 37 650 INDEX. Gaping, ii. 38 Gas animale sanguinis, ii. 97 Gases, permeability of tissues by, i. 45 Gastric juice, i. 541 Gelatin, where met with, i. 28 Gemeingefuhl, i. 261 Gemeinsinn, i. 261 Generation, ii. 307 ab animalculo maris, ii. 393 animalcular, theory of, ii. 393 by spontaneous division, ii. 312 equivocal, ii. 307 fissiparous, ii. 312 gemmiparous, ii. 312 marsupial, ii. 314 oviparous, ii. 313 ovo-viviparous, ii. 314 regular, ii. 307 spontaneous, ii. 307 theories of, ii. 380 univocal, ii. 307 viviparous, ii. 314 Generative apparatus, ii. 315 Genital organs of the female, ii. 331 of the male, ii. 315 Germinal cell, i. 180 Germs, dissemination of, ii. 390 encasing of, ii. 386 vital, Darwin's notion of, ii. 386 Gestation, ii. 410 of animals, ii. 402 Gestures, i. 455 Girandelli, Madame,her resistance to heat, i.102 Gland, described, i. 37, ii. 241 Glandiform ganglions, ii. 300 Glandular secretions, ii. 260 Globular elements of tissues, ii. 177 Globulin of the blood, i. 28, ii. 96, 101 Goitre, i. 624, ii. 600 Granula seminis, ii. 329 Gras des Cimetieres, i. 336 Gravity retards the blood, ii. 184 Greisenbogen, i. 184 Growth of the body, ii. 184 Guillotine, death by the, i. 87, 344 Gustation, i. Ill H. Habit, ii. 581 Hsmadynamometer, ii. 130 HaBmatosis, ii. 42, 49 Hair, i. 95 Halitus of the blood, ii. 97 Hallucinations, ii. 547 Hand, advantages of the, as an organ of touch, i. 106 Harmony, what, i. 152 Hawking, ii. 38 Hearing, i. 138 immediate functions of, i. 163 improved by cultivation, i. 169 nerve of, i. 161 organ of, i. 138 Heart, ii. 67 a double organ, ii. 67 beat of the, ii. 121 circulation through the, ii. 114 fcetal, pulsations of the, ii. 423 impulse of the, ii. 121 sounds of the, ii. 117 suction power of the, ii. 144 weight, &c, of the, ii. 71 Heart's action, cause of the, ii. 123 Heat sense of, i. 92, 261 animal, ii. 186 of different animals, ii. 188 Hemachroin, ii. 101 Hematin, ii. 96, 101 Hematosin, ii. 96, 101 Hepar sanguinis, ii. 98 Hermaphrodism, ii. 351 Hermaphrodite, ii. 351 Honeywell, Miss, her case described, i. 108 Humorists, i. 36 Hunger, i. 510 Hunter, Mr., case of, ii. 641 Hybrids, doctrine of, ii. 388 Hydrogen—where found, i. 26. Hygrometric property, i. 46 Hymen, use of, ii. 335 I. Idiosyncrasy, ii. 575 Illusions, mental, ii. 547 optical, ii. 258 spectral, ii. 547 Imagination, maternal, influence of the, on the foetus, ii. 397, 504 Imbibition, i. 43, 616 Imitation, effects of, ii. 586 Impulses, cerebral, of motion, i. 353 Incitability, ii. 624 Incubation of the egg, ii. 459 Individualitatssinn, i. 261 Infancy, ii. 510 first period of, ii. 510 second period of, ii. 515 third period of, ii. 520 Inflammatory crust, ii. 627 Infusion of medicines into the blood, ii. 166 Inorganic bodies, i. 14 Insalivation, i. 521 Inspiration, ii 27 of venous blood, ii. 145 first, ii. 510 Instinct, ii. 611 INDEX 651 Instincts, i. 284 Instinctive signs, i. 470 Insula sanguinis, ii. 98 Intellect, i. 284 Intercellular substance, ii. 179 Intercostal nerve, great, i. 66 Intermediate system of vessels, ii. 79 Iron, where found, i. 26 Irritability, i. 17, 362, ii. 624 Irritation, constitutional, ii. 557 Itching, i. 262 Jelly of the cord, ii. 454 Joints, i. 341 Joy, expression of, i. 465 K. Kalmuck race, ii. 594 Kiestein, ii. 421 Kidney, royal road to the, ii. 297 Kissing, i. 461 Korpergefuhl, i. 261 Kyestein, ii. 421 L. Labour, ii. 428 premature, ii. 428 Lactiferous tubes, ii. 435 Lachrymal apparatus, i. 195 Lactation, ii. 434 Lacteals, ii. 592 Language, i. 414 artificial, i. 441 natural, i. 440 origin of, i. 443 Larynx, i. 414 Laughing, i. 440, ii. 40 Laughter, ii. 40 broad, i. 461 of animals, ii. 40 Leaping, i. 406 Lebensgejuhl, i. 261 Lebenssinn, i. 261 Lebensturgor, ii. 139 Lenses, various, i. 176 Letters, how divided, i. 445 Life, ii. 605 animal, ii. 606 cell, ii. 183 fibre, ii. 183 of the blood, ii. 629 organic, ii- 606 Ligaments, i. 33, 342 Light, i. 170 Light, colour and decomposition of, i. 177 diffraction of, i. 241 duration of the impression of, on the retina, i. 259 intensity of, i. 172 reflection of, i. 172 refraction of, i. 172 velocity of, i. 171 Likeness of child to parent, remarks on the, ii. 397 Line, facial, i. 296 occipital, i. 298 Liquid, prehension of, i. 580 Liquor amnii, ii. 444 false, ii. 444 sanguinis, ii. 109 seminis, ii. 329 Listening, i. 169 Liver, histology of the, ii. 268 Lochia, ii. 431 Locomotion, nervous system of, l. 348 Locomotility, i. 325 Locomotive influx, i. 347 Longsightedness, i. 234 Lung-proof of infanticide, ii. 34, 477 Lungenprobe, ii. 34, 477 Lymph, i. 624 coagulable, ii. 101 corpuscles, ii. 625 Lymphatic apparatus, ii. 619 Lymphosis, ii. 619, 626 M. Magnetism, animal, ii. 543 Magnesium, where found, i. 27 Malay race, ii. 595 Mamma, ii. 434 Manganese, where found, i. 26 Manhood, age of, ii. 527 Mankind, varieties of, ii. 587 Mantle, i. 95 Mariotte, experiment of, i. 218 Marks, mother's, ii. 504 Marrow, exhalation of the, ii. 241 Mastication, i. 476 Jfuliere extractive du bouillon, i. 28 Mechanical principles, i. 379 Meconium, ii. 509 Medulla oblongata, i. 59 spinalis, i. 61 Megalanthropogenesis, ii. 404 Melody, i. 152 Membrana granulosa, ii. 461 • Membrane, i. 37 compound, i. 37 fibrous, i. 37 germinal, ii. 460 mucous, i. 37, 99 nictitating, i. 193 652 Membrane, serous, i. 37 Menses, ii. 342 Menstruation, ii. 342 vicarious, ii. 345 Mesenteric glands, i. 597 Milk, ii. 436 Mind, not proportionate to the state of the senses, i. 276 seat of the, i. 323 Miscarriage, ii. 428 Mitchell, the boy, case of, i. 277 Molecules, organic, of Buffon, ii. 383 Mongolian race, ii. 594 Monorchides of the Cape of Good Hope, ii. 319 Monstrosities, ii. 503 Moral acts, i. 290 Motility, ii. 662 Motion, ciliary, i. 472 encephalic nerves of, i. 347 involuntary, i. 346 muscular, i. 325 physiology of, i. 343 vibratory, i. 472 voluntary, i. 325 Motive apparatus, i. 325 forces, seat of the, i. 347 Mouvement de ballottement, ii. 422 Movements, locomotive, i. 402, 404 partial, i. 402 Mucous follicular secretion, ii. 238 exhalation of, ii. 258 membranes, i. 99 Mucus, where met with, i. 30 Muscles, i. 36, 325 analysis of, i. 335 colour of, i. 335 contraction of, i. 360 relaxation of, i. 371 simple and compound, i. 334 Muscular contraction, duration of, i. 375 extent of, i. 372 force of, i. 372 motion, i. 325, 343 nervous centre of, i.347 theories of, i. 360 velocity of, i. 376 web, i. 95 Musical tone, i. 150 Muskelsinn, i. 372 Muteosis, i. 455 Myopy, i. 234 N. Nsevi materni, ii. 504 Nails, i. 99 Natural bodies, i. 13 signs, i. 470 Natural state of man, i. 502 Nausea, i. 583 Navel-string, ii. 453 Negro race, ii. 593 Nerves, i. 36,61 composition of the, i. 75 fatty matter of, i. 32 Fletcher's division, ii. 71 Lepelletier's division, ii. 70 M. Hall's division, ii. 71 pneumogastric, effects of the sec- tion of the, on digestion, i. 549 on respiration, ii. 61 sensible and insensible, ii. 81 Sir C. Bell's division of the, ii. 66 Nervi-motion, Dutrochet's views of, i. 43, ii. 607 Nervous system, i. 50 Neurine, i. 75 New Zealander, head of, ii. 185 Nightmare, ii. 545 Nipples, ii. 435 Nisus formativus, ii. 381 Nitrogen, quantity of, consumed in respi- ration, ii. 44. (See Azote.) Norma verticalis of Blumenbach, i. 298 Nose, blowing the, ii. 37 use of the, in smell, i. 131 Nuclei, ii. 180 Nucleoli, ii. 180 Nutrition, ii. 171 force of, ii. 173 Nutritive principle, peculiar, does not ex- ist, i. 502 Nyctalopes,i.203 O. Odours, i. 126 classification of, i. 129 disengagement of, i. 126 divisibility of, i. 128 medicinal properties of, i. 130 nutritive properties of, i. 130 vehicles of, i. 128 Oken's bodies, ii. 468 Old age, ii. 529 Olein, where met with, i. 32 01fnction,i. 122 physiology of, i. 131 Onomatopoeia, i. 443 Optic nerves, decussation of the, i. 189 Organic nerve, i. 66 Organ, i. 39 Organization, i. 16 compounds of, i. 27 Organized bodies, characters of, i. 16 Organology, i. 307 Oscitation, ii. 38 Oscultation, i. 461 Osmazome, where found, i. 30 NDEX. 653 Ovarists, doctrine of the, ii. 384 Ovum, development of the, ii. 458 Oxygen, where found, i. 25 quantity of, consumed in respira- tion, ii. 44 P. Presbyopy, i. 234 Presentations, various, ii. 433 Principle, nutritive peculiar, does not exist, i. 503 vital, ii. 606 Principles, mechanical, i. 379 proximate of animals, i. 27 Proligerous disc, ii. 341 layer, ii. 341 Propelling a body, how effected, i. 412 Property, hygrometric, of tissues, i. 43 physical, of tissues, i. 42 vital, ii. 620 Prosopose, i. 461 Protein, i. 27 Protogala, ii. 438 Puberty, ii. 525 Pulse, doctrine of the, ii. 160 venous, ii. 115 Purgations, ii. 345 Pylorus, use of the, i. 531 Q.. Quickening, ii. 421 R. Races of man, ii. 590 origin of the, ii. 597 Racornissement, i. 43 Rage, expression of, i. 465 Red man, ii. 594 Regurgitation, i. 582 Reinigung, ii. 345 Rennet, i. 545. Reproduction, desire of, ii. 355 functions of, ii. 307 instinct of, ii. 355 Respiration, ii. 13, 26 chemical phenomena of, ii. 42 cutaneous, ii. 60 effects of, on the circulation, ii. 164 of animals, ii. 64 mechanical phenomena of, ii. 27 Respirations, number of, ii. 34 Respiratory organs, ii. 13 Revery, ii. 554 Rubrin,ii. 101 Rumination, i. 583 Running, i. 408 S. Saliva, ii. 261 Sapidity, cause of, i. 113 Sanguification, ii. 42 Pain, i. 265 bodily, expression of, i. 464 Pains, after, ii. 431 Painting, a variety of expression, i. 472 Palpation, i. 92 Palsy, theory of, i. 355 Pancreatic juice, secretion of the, ii. 263 use of, in digestion, i. 567 Pandiculation, ii. 38 Panniculus carnosus, i. 95 Panspermia, ii. 390 Panting, ii. 41 Parturition, ii. 428 Passions, i. 290 expression of the, i. 461 seat of the, i. 274 Pectoriloquy, i. 434 Pepsin, i. 28,544 Peripheral system of vessels, ii. 77 Peristaltic action, i. 532 Peristole, i. 532 Perceptivity of plants, i. 21 Perspective, i. 249 aerial, i. 257 Perspiration, ii. 244 Phonation, i. £14 Phosphorus, where found, i. 25 Phrenologist, cerebral organs of the, i. 307 Phrenology, i. 307 Physical properties of the tissues, l. 42 Physiology, general, of man, i. 23 Picromel, where found, i. 34 Placenta, ii. 447 of the blood, ii. 98 Placental souffle, ii.422 Plasma, ii. 109 . Pneumogastric nerves, effect of the section of the, on digestion, l. 552 on respiration, ii. 61 Poetry, a variety of expression, i. 472 Point, visual, i. 225 Portal system, ii. 87 Potassium, where found, i. 27 Power, sensorial, i. 324 Pregnancy, ii. 410 duration of, u. 425 protracted, ii. 427 signs of, ii. 429 tubal, ii- 364 Prehension, organs of, i. 413 of food, i. 517 of liquids, i. 580 654 INDEX. Savours, i. 113 classification of, i. 114 Schurze of the Bosjesman female, ii. 333 Sea-sickness, i. 584 Sebaceous follicles, i. 195 Secretion, ii. 221, 224 follicular, ii. 258 glandular, ii. 260 Secretory apparatus, ii. 221 Secundines, ii. 431 Selbstgefuhl, i. 261 Self-feeling, i. 261 Semen, secretion of, ii. 325 properties of, ii. 326 Seminal animalcules, ii. 328 granules, ii. 329 Seminists, ii. 385 Sensations, i. 50 external, i. 90 internal, i. 263 morbid, i. 265 organic, i. 263 Sense of individuality, i. 261 locality, i. 261 cold, i. 261 heat, i. 261 hunger, i. 261 thirst, i. 261 life, i. 264 motion, i. 261, pneumatic, i. 261 sixth, of Buffon, i. 261 geometrical, i. 108 regulating, i. 108 Senses, additional, i. 260 Sensibility, i. 50, 82 less in the lower animals, i. 271 vital property of, ii. 621 Sensorial power, i. 324 Serosity of the blood, ii. 98 Serous exhalation, ii. 234 of the cellular mem- brane, ii. 235 Serum of the blood, ii. 98 Sex, doubtful, ii. 351 of the fcetus, ii. 480 Sexes, differences between the, ii. 577 proportion of the, born, ii. 408 art of producing the, ii. 403 Sexual ambiguity, ii. 351 Sheep, fat-buttocked, ii. 240 Short-sightedness, i. 234 Sighing, ii. 38 sound of, i. 440 Sight, sense of, i. 169 Silicium, where found, i. 26 Singing voice, i. 453. Sinuses, nasal, use of, in smell, i. 131 Skeleton, living, exhibited, i. 40 Skin, i. 92 Skin, follicular secretion of the, ii. 259 goose, ii. 468 Skull, i. 53 Sleep, ii. 534 complete, ii. 539 incomplete, ii. 539 walking, ii. 542 Slumber, ii. 536 Smell, i. 122 acuteness of, in animals, i. 137 acuteness of, in the blind, i. 138 immediate function of the, i. 134 improved by education, i. 137 mediate functions of, i. 135 nerves of, i. 124 organs of, i. 123 Sneezing, ii. 38 Sobbing, ii. 41 Sodium, where found, i. 26 Solander, Dr., effects of severe cold on, ii. 192 Solidists, i. 36 Solids, i. 35 compound, i. 39 Somnambulism, ii. 542 Soul, seat of the, i. 324 Sound, i. 147 acute, malappreciation of, i. 166 intensity of, i. 151 reflexion of, i. 149 sympathetic, i. 148 timbre of, i. 152 tone of, i. 152 vehicle of, i. 148 velocity of, i. 149 % Spaying, method of effecting, ii. 364 Spectra, ocular, i. 224 Speech, i. 442 Sperm, ii. 325 Spermatic animalcule, ii. 329, 392 Spermatists, ii. 384, 392 Spermatozoa, ii. 329 Spinal marrow, protection of the, i. 80 structure of the, i. 61 Spirits, animal, i. 87 Spitting, ii. 37 Splanchnic nerve, i. 66 Spleen, ii. 300 Spontaneity of plants, i. 21 Spurzheim's craniological system, i. 310 Squeezing, i. 413 Squinting, i. 240 Standing, i. 395 Stearin, where met with, i. 32 Stethoscope, i. 150 Stillborn, ii. 407 Stomach, digestion of the, after death, i. 548 and kidney, connexion between the, ii. 297 Stout, Mrs., her case, i. 410 INDEX. 655 Strabismus, i. 240 Straining, ii. 35 Stratum proligerum, ii. 341 Stretching, ii. 38 Structure, elementary, of animal substances, ii. 176 Study, brown, ii. 554 Succus intestinalis, i. 566 Sucking, i. 581 Suction power of the heart, ii. 144 Suffering, bodily, expression of, i. 464 Sugar of diabetes, i. 34 milk, i. 33 Sulphur, where found, i. 25 Superfecundation, ii. 408 Superfoetation, ii. 408 Supra-renal capsules, i. 624 Suspicion, expression of, i. 467 Sutures, i. 52 Sweat, what, ii. 252 Swimming, i. 408 Sympathetic, great, i. 66 Sympathy, ii. 561 agents of, ii. 568 cerebral, ii. 568 direct, ii. 568 morbid, ii. 562 of contiguity, ii. 562 of continuity, ii. 562 remote, ii. 564 superstitions connected with, ii. 566 Synergies, ii. 556 Synovia, ii. 242 System, i. 40 nervous, i. 50 nervous, of locomotion, i. 347 Systole of the heart, ii. 117 T. Tablier. of the Bosjesman female, ii. 333 Tact, i. 92 Tapetum, i. 203 Taste, i. 111 diversity of, in animals, i. 120 immediate functions of, i. 119 improvement of, by education, i. 120 mediate functions of, i. 119 organs of, i. 111 physiology, i. 116 Tattooing, ii. 185 Tawny man, ii. 595 Tears," i. 214 secretion of the, ii. 260 use of the, i. 214 Teeth, i. 475 shedding of the, n. 520 Temperament, i. 273, ii. 570 athletic, n. 572 atrabilious, ii. 573 Temperament, bilious, ii. 572 choleric, ii. 572 influence of, on the mind, i. 273 lymphatic, i. 573 melancholic, i. 573 muscular, i. 572 nervous, i. 573 phlegmatic, i. 573 sanguine, i. 571 Temperature, animal, ii. 186 depressed, effects of, ii. 192 elevated, effects of, ii. 195 of animals, table of, ii. 188 of bodies, ii. 186 Terror, expression of, i. 465 Testes, descent of the, ii. 481 Testicondi, ii. 319 Thaumatrope, of Paris, i. 259 Thigh-bone, neck of, advantage of the, i. 398 Thirst, i. 578 sense of, i. 261 Thoracic duct, i. 598 Thymus gland, i. 623, ii. 476 Thyroid gland, i. 623, ii. 417 Tickling, i. 262 Tingling, i. 262 Tissue, i. 39 albugiheous, i. 39 cellular, i. 38 compound, i. 39 laminated, i. 38 medullary, i. 39 muscular, i. 38 nervous, i. 39 primary, i. 38 pulpy, i. 39 Tissues, permeability of, to gases, i. 46 physical properties of the, i. 42 Titillation, i. 262 Toltecan race, ii. 595 Tone, i. 42 Tongue, i. 112 Tonicity, i. 42, ii. 620 Touch, i. 100 immediate functions of, i. 107 mediate functions of, i. 107 regarded the first of the senses, i. 105 Townshend, Col., his case, ii. 124 Transfusion, ii. 166 Transpiration, cutaneous, ii. 244 pulmonary, ii. 259 Transudation, i. 43 Travail, ii. 429 Trisplanchnic nerve, i. 66 Tunica granulosa, ii- 341 Turgor vitalis, ii. 139 Tutamina cerebri, i. 51 oculi, i. 193 Twins, proportion of cases of, ii. 401 656 INDEX. U. Umbilical cord, ii. 453 Umbilical vesicle, ii. 454 Understanding, i. 285 Urea, where met with, i. 30 Urinary organs, ii. 281 Urine, ii. 294 secretion of, 381 Utero-gestation, ii. 410 Uvula, use of the, i. 523 Varieties of mankind, ii. 587 Vasa vasorum, ii. 87 Vegetables and animals, differences be- tween, i. 19 Vegetative nerve, i. 66 Veins, ii. 83 circulation in the, ii. 142 Vena porta, ii. 88 Venous system, ii. 83 blood, ii. 88 Ventrale cutaneum of the Bosjesman fe- male, ii. 333 Ventriloquism, i. 435 Venus, Hottentot, ii. 333 Vesicle, allantoid, ii. 456 erythroid, ii. 457 intestinal, ii. 650 germinal, ii. 341, 460 of Purkinje, ii. 460 umbilical, ii. 454 Vessels, i. 341 Vestiges of the French, what, i. 140 Viability of child, ii. 428 Vibrations, sympathetic, i. 150 Virility, age of, ii. 527 Vis insita, of Haller, ii. 126, 621 mortua, i. 47 medicatrix naturae, ii. 612 Viscus, i. 37 Visible direction, centre of, i. 220 Vision, i. 169 advantages of, to the mind, i. 646 direct, i. 226 direction of bodies appreciated by, i. 246 distance appreciated by, i. 247 distinct, point of, i. 225 requisites for, i. 226 double, i. 235 erect, i. 220 immediate function of, i. 244 improved by education, i. 260 indirect, i. 226 magnitude, appreciated by, i. 247 mediate functions of, i. 246 motion appreciated by, i. 253 Vision, multiple, with one eye, i. 242 nerves of, i. 217 nocturnal, i. 223 oblique, i. 225 organs of, i. 180 phenomena of, i. 216 physiology of, i. 196 position, appreciated by, i. 245 seat of, i. 217 single, i. 237 surface of bodies appreciated by, i. 247 Visual angle, i. 247 Vital force, ii. 606 Vital principle, ii. 606 properties, ii. 619 Vitality, ii. 606 of the blood, ii. 456 Vitelline disc, ii. 341 pedicle, pouch, ii. 456 Vitelline fluid, ii. 456 Vitellus, ii. 456 Vocal apparatus, i. 414 Voiee, i. 414 intensity of, i. 424 native, i. 440 nerves of, i. 418 physiology of the, i. 420 quality of the, i. 432 timbre of the, i. 432 tone of the, i. 424 Volition, seat of, i. 345 Vomiting, i. 583 at pleasure, i. 582 Vowels, i. 438 W. 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Postage on Medical Journals.—It is of the lege 7; College of Physicians anil Surgeons, N. utmost importance to the profession, and indeed Y., 32; Harvard University, Boston, 17; Uni- to the whole community, that every facility versity of Maryland, 38; Ohio Medical Col- should be afforded for the diffusion of Medical, lege 36; Transylvania University, Lexington, Agricultural, and Scientific intelligence. To 59; Medical College of the State of South Caro- accomplish this, medical men, agriculturists and lina, 82; Louisville Medical Institute, 47; Uni- others should unite to induce Congress to reduce versity of the City of New York, 93; Medical the postage on such periodicals to the same rate . College Richmond Va. 24; Jackson Kemper Col- as lint on Newspapers. I lege St. Louis, 27; Medical Department of St. — ; Louis University, 11; Geneva Medical Insti- Duration of the life of Medical Mjii.—M. tution, 44; making a total of 784. Several Insti- Chadwick in his" Sanatory Report" states that tutions are not embraced in the above. The in the medical profession examples are not rare number of young men who have been authorized of the attainment of extreme old age; yet as a to practice medicine during the present year class they bear the visible marks of health be- must be nearly one thousand. low the average. The mortuary registration for \ — . the year 1839, gives the following as the average Falling off of the Eyebrows.—Mr. Robinson see of death of persons in the three professions asserts that in some cases where the hair falls in England:—Clergymen, 59; Lawyers 50, Me- away from the eyebrows, whiskers, &c. the loss dical men 45. Only one medical student was ( being preceded by intense itching and redness of included i'n the registration; had the deaths of the skin, it is due to the presence ot an insect, those who died in their noviciate been included, which is a parasite of the horse-fly. the average age of death would have been much < ... r -.*- lower This corresponds with the results of the ; Milk-sick Literature.—-The Editor of a V> est- resear'ches of Dr. Caspar of Berlin. Yet the ern Journal concludes a complimentary notice medical profession is notoriously the worst paid of an essay on milk sickness with the remark and the worst treated of all the three professions that it " will constitute a valuable addition to the —the public for whose good this awful loss of milk-sick literature of our country."! life is sustained, is utterly regardless of the sac-> —■ rifice Adieu to the Year.—A writer in the French __ Lancet thus bids adieu to the past year:— Prize Essay—-The Academy of Medicine ; "Adieu then, remarkable year 1843! Medi- offered a prize of 1500 francs for the best essay ; cine will long preserve the remembrance ot thee, on oedema of the glottis, in which should be con- -year fruitful of events as strange as unexpected sidered its causes, progress, symptoms, diagno- I —which hath witnessed the death-of homeopathy .is and treatment witlflhe 'advantages and°dis- and the birth of tachytorny, which bath seen chi- advantages of tracheotomy. This prize was romancy expire and hydropathy nourish. awarded to M. Valleix on the 12th December T,nm., Harris ■ ; Naval Medical Bureau.—Dr. 1 nomas Harris _ '< 0f Philadelphia has been appointed to the Bureau .YwJbim.flJ.-A new Journal {Journal fuer,of Medicine and S«rgery; Dj'- fj"^^,!^ KMerkrankheiten) devoted to the diseases of repu.*iuon as a P -mo~X ihU .pJSeiS children, edited by Drs. Behrend ™» »'W«" ^<™£ ,**,* Navy and of advantage to the ser- braiid, has recently been commenced at Berlin, populai in me .>a., a o The first No. contains memoirs on the intermit- vice. _ tent fever of children, on the ^f*™1'0" £ ; Mature of the external Iliac Artery.-Mr. Ihe epithelium of the mucous£?"-v of new B .^Cooper" performed this operation the 5th acute exanthemata, on the seme.ology ot new ,a. , », » a tient in Guy's Hospital born children, and on pleurisy in infants. , o^ ^^ ^eu,.ism. German Medical J0ipl mrv JIulford.^Yte London papers re- England says that he has been, informed! by I . <>- &«.SUd, announce the death of this d,s- fessorNaegele that »bout 200 forged d.^omas ctnt,} '. ;an> purporting to come from the University ol H • tinfcu .«* V 3 __ delberg, are supposed to be current in the Iii i- > _Among the phenomena foretold in a lish dominions!l How many are there in this ^jj/g* *™e *azJe des mpitaux to occur Medical Graduate^-^^X£ \ out alliance oV orthopaedic cures,' PeTmsylvania ^J^ut of Pennsylvania Co}-_============== t^J^i ^—pyTjLA^CHARD,at One Dollar a year,payable in advance. Published MM b^bCe;Jntains 0ne sheet, and will pay newspaper postage. UNIVERSITY OF PENNSYLVANIA.—MEDICAL DEPARTMENT.—SESSION 1844-5 The Lectures will commence on Monday, the 4th day of November, and be continued, under the following arrangement, to the middle of March ensuing:—Practice and Theory of Medicine, by Nathaniel Chapman, M. D.; Chemistry, Robert Hare, M. D.; Surgery, William Gibson, M. D.; Anatomy, William E.Horner, M.D; Institutes of Medicine, Samuel Jackson, M.D; Materia Medica and Pharmacy, George B. Wood, M. D.; Obstetrics and the Diseases of Women and Children, Hugh L. Hodge, M. D. A Course of Clinical Lectures and Demonstrations, in con. nection with the above, is given at the very extensive and convenient Infirmary called the Phila- delphia Hospital. Clinical Medicine, by W. W. Gerhard, M. D.; Clinical Surgery, Drs. Gibson and Horner. Clinical Instruction in Medicine is also given from the 1st day of November to the 1st day of March by Dr. Wood, in the Pennsylvania Hospital, an institution which is well known as one of the largest and best conducted Infirmaries in the United States. The rooms for Practical Anatomy will be opened October 1st, and continued so to the end of the Course. They are under the charge of Paul Beck Goddard, M. D., Demonstrator, with a supervision on the part of Dr. Horner. Extensive cabinets on Anatomy, Materia Medica, Chemistry, Surgery, and Obstetrics exist. The Professor of Materia Medica, besides his Cabinet, has an extensive and well-furnished Conservatory, from which are exhibited, in the fresh and growing state, the native and exotic Medicinal Plants. W. E. HORNER, M. D., April 1st, 1844. Dean of the Medical Faculty, 263 Chestnut Street, Philadelphia. JEFFERSON MEDICAL COLLEGE, SESSION OF 1844-45. The regular Course of Lectures will commence on Monday the 4th of November, and end on the last day of February. Robley Dunglison, M. D., Professor of Institutes of Medinine,&c; Robert M. Huston, M. D., Professor of Materia Medica* and General Therapeutics; Joseph Pancoast, M. D., Professor of General, Descriptive, and Surgical Anatomy; John K. Mitchell, M. D., Professor of Practice of Medicine; Thomas D. Mutter, M. D, Professor of Institutes and Practice of Surgery; Charles D. Meigs, M. D., Professor of Obstetrics and Diseases of Women and Children; Franklin Bache, M. D., Professor of Chemistry. Lectures and Practical Illustra- tions will be given at the Philadelphia Hospital, one of the most extensive and valuable institu- tions in the United States, regularly through the Course, by Dr. Dunglison on Clinical Medicine, Dr. Pancoast on Clinical Surgery, and at the Dispensary of the College, by Professors of the In- stitution. The Dissecting Room will open on the first of October, under the Professor of Ana- tomy, and Clinical Instruction in Medicine and Surgery will be given at the Dispensary of the College. R. M. HUSTON, M. D., Dean of the Faculty. MEDICAL INSTITUTE OF PHILADELPHIA, LOCUST STREET ABOVE ELEVENTH. The Course of Lectures, for 1844, will commence on the first Monday in April, and will con- tinue until the end of the ensuing October, with the exception of a vacation from the 15th of July to the latter part of August. Clinical Instruction in Medicine and Surgery will be given every afternoon during the season, and in order to make it as practical as possible, those students who desire it will be furnished with cases. Clinical Instruction in Midwifery will be given by the lecturer on that branch, and cases of labour provided for students who may wish to attend them. Practical Instruction in Materia Medica and Pharmacy will also be given, and the Students taught to compound prescriptions and prepare medicines. Lectures on Anatomy, by Paul B. Goddard, M. D.; Surgery, Wr. Poyntell Johnson, M. D.; Obstetrics, M. P. Hutchinson, M. D.; Practice of Medicine, Caspar Morris, M. D.; Materia Medica, Joseph Carson, M. D.; Chemistry, James B. Rogers, M. D.; Clinical Medicine, W. W. Gerhard, M. D.; Clinical Surgery, W. P. Johnson, M. D. Fee for the course, including Clinical Instruction, $70. For tickets, apply to PAUL B. GODDARD, Secretary, No. 7 South Ninth Street. Lea & Blanchard have published the following new books and new editions, since their last list, for which see the proper heads, in the following pages. Andral on the Blood, Allison's Pathology, Dunglison's Human Physiology, 5lh edition. Dunglison's Medical Dictionary, 4th ed.; Dunglison's Practice of Medicine, 8vo., second ed; Chapman on the Viscera; Cooper on Hernia; Cooper on Dislocations; Condie on Children; Smith and Horner's Anatomical Atlas; Prout on the Stomach: Williams's Pathology; Watson's Practice; Cyclopedia of Practical Medi- cine, part First, Second, and Third. Harrison on the Nerves; Wilson's Dissector, &c. &c. Messrs. Geo. W. Carpenter and Co., Wholesale Druggists, No. 301 Market Street, Philadel- phia, have recently published a large pamphlet of 96 pages, entitled "Carpenter's Annual Medi- cal Advertiser for 1844." It contains an account of the most popular of the new medicines, Surgical Instruments, Anatomical Preparations, Chemical and Philosophical Apparatus, Medical Books, the improvements in Chemistry, Pharmacy, &c, and is distributed gratuitously to the physicians of the United Slates. Orders for any of the books mentioned in the accompany- ing list, can be executed by them. TO THE MEDICAL, PROFESSION. LEA AND BLANCHARD present a condensed list of books published and preparing for publication by them nd would refer m .t,» „,h«,......,__ K ..^ .. -%fomlatjon f„ rela. publication of ..j, and as low as ttiey can De attorded consistent with correct and well executed editions. The latest editions will always be furnished, and to their present extensive list they will add from lime to time such other good works as the wants of the profession may call for. Their publications may be found at all of the principal Bookstores throughout the Union. r r Anatomical Atlas, by Smith and Horner, imperial 8vo., nearly ready. Arnott's Elements of Physics, in 1 vol.Svo., 520 closely printed pages. American Medical Journal, published quarterly at 85 a year. Fourteen numbers of the new series are now published. Abercrombie on the Stomach, 1 vol. 8vo., 320 pages. Abercrombie on the Brain, a new edition, 1 vol. 8vo, 324 pages. Allison's Outlines of Pathology, in 1 vol. 8vo., 420 pages. Ashwell on the Diseases of Females, complete in 1 vol., ■ 8vo , nearly ready. Andral on the Blood, 120 pages, 8vo. Bell on the Teeth, with plates, 1 vol. 8vo, 351 pages. Buckland's Geology and Mineralogy, 2 vols, ovo., with numerous plates and maps. Berzelius on the Kidneys and Urine, I vol. small 8vo., 179 pages. Biidgewater Treatises, with numerous illustrations, 7 vols. 8vo., 3287 pages. Bartlett on Fevers, &c , 1 vol. 8vo , 393 pages. Billing's Principles of Medicine, 1 vol 8vo., 304 pages. Brodie on Urinary Organs, 1 vol. 8vo , 214 pages. Brodie on the Joints, 1 vol. 8vo ,216 pages. Chapman on Thoracic and Abdominal Viscera, 1 vol. 8vo., 384 pages. Chitty's MedFcal Jurisprudence, 1 vol 8vo , 509 large pages. Carpenter's Human Physiology, 1 vol. 8vo., 618 pages, with cuts. Carpenter's General and Comparative Physiology, 1 vol. 8vo., at. press. Carpenter's Vegetable Physiology, 1 vol. 12mo , with cuts, 300 pages. Carpenter's Animal Physiology to be published here after. Cooper, Sir Astley, his work on Hernia, imperial 8vo , with plates, 428 pages. Cooper on Dislocations and Fractures, 1 vol. 8vo., with cuts, 499 pages. Condieon Diseases of Children, 1 vol. 8vo., 651 pages. Costello's Cyclopsedia of Practical Surgery, to be pub lished hereafter. Churchill on Females, 1 vol 8vo., 595 large pages. Churchill's Theory and Piaclice of Midwifery, 1 vol 8vo., 519 pages, with cuts Cyclopedia of Practical Medicineby Forbes, &c. Edit- ed by Dunglison, in 4 large super-royal vols, at press. Carson's Medical Formulary, in preparation Dewees's System of Midwifery, with plates, 10th edition, 660 pages. Dewees on Children, 8th edition, 548 pages. Dewees on Females, with plates, 8th edition, 532 pages Dewees's Practice of Physic, 1 vol 8vo. 819 pages. Dunglison's Physiology, 5th edition, 2 vols. 8vo, 1304 pages, with 300 cuts Dunglison's Therapeutics and Materia Medica, a new work, 2 vols 8vo , 1004 pages Dunglison's Medical Dictionary, 4th edition, 1 vol.8vo.. 771 very large pages. ..... Dunglison's New Remedies, 5th edition, 1843, 615 pages Dunglison on Human Health, in 1 vol 8 vo, at press Dunglison's Practice of Medicine, 2d edition, 2 vols 8vo, 1322 pages. ... Dunglison' Medical Student, 12mo, a new edition, pre DruatsTvIodern Surgery, 1 voL 8vo. 534 pages. Ellis's Medical Formulary, 7th edition, 1 vol.Svo., 262 pages Harris on the Maxillary Sinus, I vol. small 8vo , 165 pages. Horner's Special Anatomy, 2 vols. 8vo., 6th edition, 1114 pages. Hodge on the Mechanism of Parturition in I vol. 4to., (preparing) with many plates Hope on the Heart, 1 vol 8vo., 572 pages. Harrison on the Nervous System, 1 vol. 8vo., 292 pages. Jones and Todd on the Ear, 1 vol. at press. Kirby on Animals, many plates, 1 vol. 8vo. 519 pages. Lawrence on the Eye, 1 vol. 8vo , 778 pages. Lawrence on Ruptures, 1 vol. 8vo., 480 pages. Maury's Dental Surgery, with plates, a new work, 1 vol. 8vo., 285 pages- Mutter's Surgery, 2 vols. Svo , now in preparation, with cuts. Miiller's Physiology, 1 vol. 8vo., 886 pages. Manual of Ophthalmic Medicine and "Surgery, to be published hereafter. Medical News and Library, published monthly. Manual of Medical Jurisprudence, in preparation. Meigs' Translation of Colombat D'Isere on the Diseases of Females, in preparation, 1 vol. 8vo. Prout on the Stomach and Renal Diseases, 1 vol. 8vo., with coloured plates, 465 pages. Popular Medicine, by Coates,! vol. 8vo., 614 paces. Philip on Protracted Indigestion, 1 vol. 240 pages. Principles of Surgery, a new work, in 1 vol., 8vo. Pereira's Materia Medica, 2 vols 8vo., 1566 very large and closely printed pages. Roget's Animal and Vegetable Physiology, with many cuts, 2 vols 8vo., 871 pages. Roget's Outlines of Physiology, 1 vol. 8vo, 516 pages. Rigby's System of Midwifery, 1 vol 8vo , 491 pages. Ricord on Venereal, 1 vol 8vo , 256 pages. Ramsbotham on Parturition, with numerous plates, 1 vol imperial 8vo , 458 pages. Robertson on the Teeth, 1 vol. 8vo„ 229 pages. Squarey's Agricultural Chemistry, 12mo , 150 pages. Simons' Medical Chemistry, (preparing.) Stewardson on Fevers, 1 vol. 8vo., preparing. Select Medical Essays by Chapman and others, 2 vols. 8vo . 1149 pages, double columns Tweedie's Library of Practical Medicine, 3 vols. 8vo., 2d edition, revised, 2016 large and closely printed Elliouon's Mesmeric Cases, 8vo., 56 gages. SSd^: D^'cSKCompanion, in preparauon. Tweedie on Fevers, Inflammations and Cuta") £<£ neous Diseases, 1 vol. 8vo I ?"g Tweedie on Diseases of the Nervous System, 1 I 5 £ vol 8vo I 0 5> Tweedie on Diseases of the Organs of Respira- ^ -,-3 tion, 1 vol. 8vo . gg Tweedie on the Digestive, Urinary and Uterine g_eo Organs, 1 vol 8vo. fr2, Tweedie on Rheumatism, Gout, Dropsy, Scurvy, g~ &c, 1 vol.8vo. J ? a> Traill's Medical Jurisprudence, 1 vol 8vo , 234 pages. Trimmer's Geology and Mineralogy, with many cuts, 1 vol. 8vo, 527 pages. ,„,.., . 1. Todd's Cyclopedia of Anatomy and Physiology, to be published hereafter. Walshe's Diagnosis of the Diseases of the Lungs, 1 vol. !2mo , 310 pages. . , Watson's Principles and Practice of Physic, 1 vol. 8vo., Wthfon'sryHurnganPTnatomy, with cuts,l vol. 8vo., 576 WuSa Dissector, or Practical and Surgical Anatomy, by Goddard, with cuts, 1 vol. 12mo , 444 pages. Wiison on the Skin, 1 vol. 8vo., 370 pages. Vouait on the Horse, by Skinner, with cuts, 448 pages, VcJuatt andClater's Cattle Doctor, 1 vol. 12mo , with cuts, 282 pages. Williams' faihology, 1 vol. 8vo., 383 pages. They have other works in preparation, not included in this list. S LEA & BLANCHARD'S PUBLICATIONS. CHAPMAN'S NEW WORK. LECTURES ON THE MOKE IMPORTANT DISEASES OF THE THORACIC AND ABDOMINAL VISCERA. DELIVERED IN THE UNIVERSITY OF PENNSYLVANIA. By N. CHAPiWAN, M.D. Professor of the Theory and Practice of Medicine, &c. In one volume, octavo. PHTHISIS PULMONALIS, CYNANCHE LARYNGEA, ASTHMA, ANGINA PECTORIS, GASTRITIS, CHRONIC GASTRITIS, ORGANIC LESIONS OF THE STOMACH, DYSPEPSIA, ENTERITIS, DUODENAL DYSPEPSIA, CHRONIC FLUXES OF THE BOWELS, CONTAINING CONSTIPATIO, HEPATITIS, CONGESTION OF THE LIVER, HEPATICULA, ICTERUS, SPLENITIS, CHRONIC SPLENITIS, ENGORGEMENT OF THE SPLEEN, CHRONIC CONGESTION OF THE SPLEEN, &c. &c. &c. $P3>W° mW4LWTl* THE FIRST OP THE FART CYCLOPEDIA OF PRACTICAL MEDICINE, EDITED BY DRS. TWEEDIE, FORBES, CONOLIrY, AND DUNGLISON. CONTAINING ARTICLES ON ABDOMEN, Exploration op the, Dr. Forbes. ABORTION, ABSCESS (INTERNAL), ABSTINENCE, ACHOR, ACNE, ACRODYNIA, ACUPUNCTURE, AGE, AIR (CHANGE OF), ALOPECIA, ALTERATIVES, APOPLEXY (CEREBRAL) Dr. Lee. Dr Tweedie. Dr. Marshall Hall. Dr. Todd. Dr. Todd. Dr. Dunglison. Dr. Elliotson. Dr Roget. Sir James Clark. Dr. Todd. Dr. Conolly. Dr. Clutterbuck. AMAUROSIS, AMENORRHCEA, ANEMIA, ANASARCA, ANGINA PECTORIS, ANODYNES, ALTHELMINTICS, ANTHRACION, Dr. Jacob. Dr. Locock. Dr. Marshall Hall. Dr. Darwall. Dr. Forbes. Dr. Whiting. Dr. Thomson. Dr. Dunglison. ANTIPHLOGISTIC REGIMEN, Dr. Barlow. ANTISPASMODICS, Dr. Thomson. AORTA, Aneurism op the, Dr. Hope. APHONIA, Dr. Robertson. APHTHJE, . ---------- For further details see the Prospectus, terms, &c, annexed, but the pages are not so well printed there as they are in the work. The pub- lishers are prepared to send a specimen of the work that will exhibit the mechanical execution as well as its professional character. In presenting this as one of the cheapest works that has yet been offered to the pro- fession, the publishers beg leave to state that persons remitting five dollars can have the first ten parts sent them by mail or otherwise, as they may direct. CYCLOPEDIA OE PRACTICAL MEDICINE. LEA AND BLANCHARD, PHILADELPHIA, WILL PUBLISH THE CYCLOPEDIA OF PRACTICAL MEDICINE; COMPRISING TREATISES ON THE NATURE AND TREATMENT OF DISEASES, MATEEIA MEDICA AND THEEAPEUTICS, MEDICAL JURISPRUDENCE, &c. &c. EDITED BY JOHN FORBES, M.D.,F.R.S. Physician in Ordinary to her Majesty's Household, &c. ALEXANDER TWEEDIE, M.D., F.R.S. Physician to the London Fever Hospital, and to the Foundling Hospital, &c. JOHN CONOLLY, M.D. Late Professor of Medicine in the London University, and Physician to the Hanwell Lunatic Asylum, &c. THOROUGHLY REVISED, WITH ADDITIONS, BY ROBLEY DUNGLISON, M.D. Professor of the Institutes of Medicine, &c. in the Jefferson Medical College, Philadelphia, Lecturer on Clinical Medicine, and Attending Physician at the Philadelphia Hospital; Secretary of the American Philosophical Society, &c. TERMS OF PUBLICATION. THE WORK WILL BE PRINTED WITH A NEW AND CLEAR TYPE, AND BE COMPRISED IN TWENTY-FOUR PARTS, AT FIFTY CENTS EACH, FORMING, WHEN COMPLETE, FOUR LARGE SUPER-ROYAL OCTAVO VOLUMES, EMBRACING OVER rrTTHEE THOUSAND UNUSUALLY LAUGE PAGES, T IN DOUBLE COLUMNS. n forwarding Twenty Dollars, free of postage, in Current Funds, will b. entitled tt Any P^CXto work will be completed during the year two copies. * »«> PUBLISHERS* NOTICE TO THE CYCLOPAEDIA OF PRACTICAL MEDICINR This important work consists of a series of Original Essays upon all subjects of Medicine, contri- buted by no less than SIXTY-SEVEN of the most eminent practical Physicians of Great Britain and Ireland, and among them many of the Professors and Teachers in London, Edinburgh, Dublin and Glasgow, whose reputation conveys a high and just authority to their doctrines. Each subject has been treated by a writer of acknowledged eminence, whose particular studies have eminently fitted him for the task ; and all the articles are authenticated with the names of the authors. The Editors are men of elevated attainments, and in the undertaking have spared no personal pains; in the hope, by uniformity of plan, simplicity of arrangement, and the harmony and con- sistency of its several portions, to make the Cyclopsedia represent, fully and fairly, the state of PRACTICAL MEDICINE at the time of its appearance. From innumerable foreign and domestic sources, the scattered knowledge, which has so fast accumulated since the commencement of the present century, has been gathered together and placed at the command of every reader of the English language ; and whilst the great claims of the older cultivators of Medicine have never been forgotten, the labours of the moderns, and more particularly of the French, German, and Italian Pathologists, by which, conjointly with the efforts of British and American Practitioners, the whole face of Practical Medicine has been changed, have attracted the most diligent and thoughtful attention. The Editors affirm, that if the reader will take the trouble to inspect the mere titles of the articles contained in the work, comprising nearly THREE HUNDRED ORIGINAL ESSAYS of known and distinguished authors, and will bear in mind either the leading physiological divisions of disease, or consider them with reference to the Head, the Chest, the Abdomen, the Surface, or the gene* ral condition of the body, as well as the subjects of OBSTETRICAL MEDICINE, MATERIA MEDICA, or MEDICAL JURISPRUDENCE, he will sufficiently appreciate the care bestowed to make the Cyclopsedia satisfactory to all who refer to its pages, and, at the same time, strictly a book of practical reference. No subject, it is believed, immediately practical in its nature or application, has been omitted; although unnecessary disquisition has been, as much as possible, avoided. It entered consistently and properly into the plan of the Editors to admit a far wider range of subjects than appears heretofore to have been considered necessary in works written professedly on the Practice of Medicine, but a range comprising many new subjects of extreme importance to those engaged in practice, or preparing for it. Such are the subjects of ABSTINENCE \ CONTAGION {EXPLORATION OF! PROGNOSIS ACUPUNCTURE \ CONVALESCENCE THE CHEST AND \ PULSE AGE \ COUNTER-IRRITATION ABDOMEN SOFTENING CHANGE OF AIR j CONGESTION AND DE- GALVANISM MEDICAL STATISTICS ANTIPHLOGISTIC) TERMINATION OF HEREDITARY TRANS-? STETHOSCOPE REGIMEN \ BLOOD MISSION OF DISEASE? SUDDEN DEATH ASPHYXIA ^DERIVATION INDURATION \ SYMPTOMATOLOGY AUSCULTATION | DIETETICS IRRITATION \ TEMPERAMENT BATHING | DISINFECTION DEFECTION (TOXICOLOGY BLOOD-LETTING PHYSICAL EDUCATION LATENT DISEASES \ TRANSFORMATION MORBID STATES ELECTRICITY MALARIA AND MIASMA TRANSFUSION OF THE BLOODf ENDEMIC DISEASES PERFORATION < TUBERCLE CLIMATE EPIDEMICS PSEUDO - MORBID AP- VENTILATION COLD |EXPECTORATION i PEARANCES (MINERAL WATERS and those of various general articles on the pathology of organs. It will be found, too, that admirable articles from the best sources have been inserted on the important subjects of DISEASES OF WOMEN AND CHILDREN, AND OF MEDICAL JURISPRUDENCE. In order, however, that the nature and value of the work may be fully understood, a list of the articles, and the names of the contributors, is appended. The excellence of this work on every topic connected with Practical Medicine, has been admitted by all who have had the good fortune of being able to consult it The hope, indeed, expressed by the Editors, has been amply realized — « That they have prepared a work required by the present wants of medical readers, acceptable to the profession in general, and so capable, by its arrangements, of admitting the progressive improvements of time, as long to continue what the general testimony of their medical brethren, as far as it has hitherto been expressed, has already pronounced it to be, «A STANDARD WORK ON THE PRACTICE OF MEDICINE." Such a work, it is believed, will be most acceptable to the members of the profession throughout the Union, as there exists, at this time, no publication on Practical Medicine, on the extended plan of the one now presented. To adapt it to the Practice of this country, and to thoroughly revise the various articles, the atten- tion of PROFESSOR DUNGLISON will be directed ; whose character and established reputation are a sure guarantee that his portion of the work will be carefully executed. CONTENTS OF, AND CONTRIBUTORS TO, THE CYCLOPEDIA OF PRACTICAL MEDICINE. Abdomen, Exploration of, Dr. Forbes. Abortion.....Dr. Lee. Abscess......Dr. Tweedie. Abstinence.....Dr. M. Hall. Achor......Dr. Todd. Acne.......Dr. Todd. Acupuncture : ... Dr. Elliotson. Age.......Dr. Roget. Air, Change of, . . . Dr. Clark. Alopecia.....Dr. Todd. Alteratives.....Dr. Conollt. Amaurosis.....Dr. Jacob. Amenorrhcea . . . . Dr. Locock. Anaemia......Dr. M. Hall. Anasarca.....Dr. Darwall. Angina Pectoris . . . Dr. Forbes. Anodynes.....Dr. Whiting. Anthelmintics .... Dr. A. T. Thomson. Antiphlogistic Regimen Dr. Barlow. Antispasmodics . . . Dr. A. T. Thomson. Aorta, Aneurism of, . Dr. Hope. Aphonia......Dr. Robertson. Aphthae......Dr. Robertson. Apoplexy, Cerebral, . Dr. Clutterbuck. Apoplexy, Pulmonary,. Dr. Townsend. Arteritis......Dr. Hope. Artisans, Diseases of, . Dr. Darwall. Ascites......Dr. Darwall. Asphyxia.....Dr. Roget. Asthma......Dr. Forbes. Astringents.....Dr. A. T. Thomson. Atrophy ...... Dr. Townsend. Auscultation .... Dr. Forbes. Barbiers......Dr. Scott. Bathing......Dr. Forbes. Beriberi......Dr. Scott. Blood, Morbid States of, Dr. M. Hall. Bloodletting .... Dr. M. Ha.ll. Brain, Inflammation of, Jgf; fcKAwmD. Bronchitis . . . ; . Dr. Williams. Bronchocele .... Dr. And. Crawford. Bullce......Dr. Todd. Calculus.....Dr. Thos. Thomson. Calculous Diseases . . Dr. Cumin. Catalepsy.....Dr. Jot. Catarrh......Dr. Williams. Cathartics.....Dr. A. T. Thomson. Chest, Exploration of, . Dr. Forbes. Chicken Pox ... . Ot. Gregory. Chlorosis.....Dr. M. Hall. Cholera......Dr. Brown. Chorea......Dr. And. Crawford. Climate......Dr. Clark. Cold.......Dr. Whiting. „ .. CDr. Whiting. Lo"c......£ Dr. Tweedie. Colica Pictonum ... Dr. Whiting. Coma......Dr. Adair Crawford. Combustion, Spontane- Sj)T. Apjohn. ous Human, . . c. ' _ Congestion of Blood . Dr. Barlow. CDr. Hastings. Constipation . • • £Dr. Streeten. p«„fo^^« . Dr. Brown. Contagion . . • • ' Dr TweeDie. Convalescence . . . g .Adair Crawford Convulsions . • • • _. T n_nric Convulsions, Infantile . Dr. Locock. Convulsions, Puerperal Dr. Lo£<£M3 Coryza......" ' Counter Irritation . . Dr. Williams. Croup......Dr. Cheyne. Cyanosis.....Dr. Crampton. Cystitis......Dr. Cumin. Delirium.....Dr. Pritchard. Delirium Tremens • . Dr. Carter. Dentition, Disorders of . Dr. Joy. Derivation.....Dr. Stokes. Determination of Blood Dr. Barlow. Diabetes.....Dr. Bardsley. Diaphoretics . . . • Dr. A. T. Thomson. _,. , CDr. Crampton. Diarrhoea .... £ Dr. Forbes. Dietetics.....Dr. Paris. Dilatation of the Heart . Dr. Hope. Disease......Dr. Conolly. Disinfection .... Dr. Brown. Diuretics.....Dr. A. T. Thoms-on. Dropsy......Dr. Darwall. Dysentery.....Dr. Bbown. Dysmenorrhcca . . . Dr. Locock. Dysphagia.....Dr. Stokes. Dyspnoea.....Dr. Williams. Dysuria......Dr. Cumin. Ecthyma.....Dr. Todd. Eczema......Dr. Joy. Education, Physical, . Dr. Barlow. Electricity.....Dr. Apjohn. Elephantiasis Arabum . Dr. Scott. Elephantiasis Grsecorum Dr. Joy. Emetics.....; Dr. A. T. Thomson. Emmenagogues ... Dr. A. T. Thomson. Emphysema .... Dr. Townsend. Emphysema of the Lungs Dr. Townsend. Empyema.....Dr. Townsend. Endemic Diseases . . Dr. Hancock. Enteritis......Dr. Stokes. Ephelis......Dr. Todd. Epidemics.....Dr. Hancock. Epilepsy......Dr. Cheyne. Epistaxis.....Dr. Kerr. Erethismus Mercurialis Dr. Burder. Erysipelas.....Dr. Tweedie Erythema Expectorants . . Expectoration . . Favus . . . . Feigned Diseases ' rDr'. -?Dr. (.Dr. Dr. Joy. Dr. A. T. Thomson. Dr. Wilson. Dr. A. T. Thomson Dr. Scott. Forbes. _. Marshall. Fever, General Doctrine of, Dr. Tweedie. Continued, and its CDr Tweedie. Modifications, t m Typhus ... Dr. Tweedie. Epidemic Gastric Dr. Cheyne. Intermittent . . Dr. Brown. Remittent ... Dr. Brown. Infantile Remittent Dr. Joy. " Hectic . " Puerperal . • " Yellow • • Fungus Hcematodes . Galvanism • • • • Gastritis..... Gastrodynia • • • Gastro-Enteritis . . Glossitis . . • • • Glossis, Spasm of the, Gout .... Haemorrhoids . . . Dr. Brown. Dr. Lee. Dr. Gillkrest. Dr. Kerr. Dr. Apjohn. Dr. Stokes. Dr. Barlow. Dr. Stokes. Dr. Kerr. Dr. Joy. Dr. Barlow. Dr. Burns. CONTENTS, &c, OF THE CYCLOF.««IA OF rTiACTiOAii tiitLviyjilx i Headach.....Dr. Burder. Heart, Diseases of the, Dr. Hope. " Displacement of the, Dr. Townsend. Hematemesis .... Dr. Goldie. Hemoptysis .... Dr. Law. Hemorrhage .... Dr. Watson. Hereditary Transmis sion of Disease Herpes..... Hiccup..... Hooping-Cough . . Hydatids.....Dr Hydrocephalus . . . D Dr. Brown. Dr. A. T. Thomson. Dr. Ash. Dr. Johnson. Kerr. Joy. Hydropericardium . . Dr. Darwall. Hydrophobia .... Dr. Bardsley. Hydrothorax .... Dr. Darwall. Hypertrophy .... Dr. Townsend. Hypertrophy of the Heart Dr. Hope. Hypochondriasis . . . Dr. Pritchakd. Hysteria......Dr. Conolly. Icthyosis.....Dr. A. T. Thomson. Identity......Dr. Montgomery. Impetigo.....Dr. A. T. Thomson. Impotence.....Dr. Beatty. Incontinence of Urine . Dr. Cumin. Incubus...... Dr. Williams. Indigestion.....Dr. Todd. Induration.....Dr. Car's well. Infanticide.....Dr. Arrowsmith. Infection.....Dr. Brown. Inflammation Dr. A. Crawford, Dr. Tweedie. Influenza.....Dr. Hancock. Insanity......Dr. Pritciiard. Irritation.....Dr. Williams. Ischuria Renalis . . . Dr. Carter, Jaundice.....Dr. Burder. Kidneys, Diseases of, . Dr. Carter. Lactation.....Dr. Locock. Laryngitis.....Dr. Cheyne. Latent Diseases . . . Dr. Christison. Lepra......Dr. Houghton. Leucorrhcea .... Dr. Locock. Lichen......Dr. Houghton. Liver, Inflammation of, Dr. Stokes. " Diseases of, . .Dr. Venables. Malaria and Miasma . Dr. Brown. Malformations of the Heart Dr. Williams. Medicine, Principles and Cn Practice of, . . d Melsena......Dr. Goldie. Melanosis.....Dr. Cars well. Menorrhagia .... Dr. Locock. Menstruation, Pathology of Dr. Locock. Miliaria, ._.....Dr.'Tweedie. Mortification .... Dr. Carswell. Narcotics.....Dr. A. T. Thomson. Nephralgia and Nephritis Dr. Carter. Neuralgia.....Dr. Elliotson. Noli me tangere, or Lupus Dr. Houghton. Nyctalopia.....Dr. Grant. Obesity......Dr. Williams. (jEdema......Dr. Darwall. Ophthalmia .... Dr. Jacob. Otalgia and Otitis . . Dr. Burne. Ovaria, Diseases of the " Dr. Lee. Palpitation.....Dr. Hope. Pancreas, Diseases of the, Dr. Carter. Paralysis.....Dr. R. B. Todd. Parotitis......Dr. Kerr. Pellagra......Dr. Kerr. Pemphigus.....Dr. Corrigan. Perforation of the Hol-C^ n „„,„,,„ low Viscera . . J Dr. Carswell. Pericarditis and Carditis Dr. Hope. Peritonitis. . . . Dr. M'Adam, Dr. Stokes Persons found Dead . Dr. Beatty. Phlegmasia Dolens . . Dr. Lee. Conolly. Pityriasis.....Dr. Plague......Dr. Plethora . . . . . Dr. Pleurisy, Pleuritis, . . Dr. Plica Polonica .... Dr. Pneumonia.....Dr. Pneumothorax . . . Dr. Porrigo ...... Dr. Pregnancy, &c, Signs of, Dr. Prognosis.....Dr. Pseudo-morbid Appear- C p ances . . . . c. Psoriasis ..... Dr. Puerperal Diseases . . Dr. Pulse.......Dr. Purigo......Dr. Purpura......Dr. Pyrosis......Dr. Rape.......Dr. Refrigerants . ; . . Dr. Rheumatism .... Dr. Rickets......Dr. Roseola......Dr. Rubeola......Dr. Rupia......Dr. Rupture of the Heart . Dr. Scabies......Dr. Scarlatina.....Dr. Scirrhus......Dr. Scorbutus.....Dr. Scrofula......Dr. Sedatives.....Dr. Sex, Doubtful, ... Dr. Small-Pox.....Dr. Softening of Organs . Dr. Somnambulism and Ani- 5 Dr mal Magnetism . c. Soundness, &c, of Mind Dr. Spinal Marrow, Dis-Cpr eases of, ... c Spleen, Diseases of, . Dr. Statistics, Medical, . . Dr. Stethoscope .... Dr. Stimulants.....Dr. Stomach, Organic Dis- eases of, ... Succession of Inherit- ance-Legitimacy, Suppuration .... Dr. Survivorship .... Dr. Sycosis......Dr. Symtomatology . . . Dr. Syncope......Dr. Tabes Mesenterica . . Dr. Temperament .... Dr. Tetanus......Dr. Throat, Diseases of the, Dr. Tonics......Dr. Toxicology.....Dr. Transformations . . . Dr. Transfusion . . . . Dr. Tubercle.....Dr. Tubercular Phthisis . . Dr. Tympanites .... Dr. Urine, Morbid States of, Dr. Urine, Bloody, . . . Dr. Urticaria.....Dr. Uterus, &c. Pathology of, Dr. Vaccination .... Dr. Varicella.....Dr. Veins, Diseases of, . . Dr. Ventilation.....Dr. Wakefulness .... Dr. Waters, Mineral, . . Dr. Worms......Dr. Wounds, Death from, . Dr. Yaws......Dr. Cumin. Brown. Barlow Law. Corrigan. Williams. Houghton. A. T. Thomson. Montgomery. Ash. r. R. B. Todd. Cumin. Hall. Bostock. A. T. Thomson. Goldie. Kerr. Beatty. A. T. Thomson. Barlow. Cumin.' Tweedie. Montgomery. Corrigan. Townshend. Houghton. Tweedie. Carswell. Kerr. Cumin. A. T. Thomson. Beatty. Gregory. Carswell. Pritchard. Pritchard. R. B. Todd. Bigsby. Hawkins. Williams. A. T. Thomson. Dr. Houghton. Dr. Montgomery. R. B. Todd. Beatty. Cumin. M. Hall. Ash. Joy. Pritchard. Symonds. Tweedie. A. T. Thomson. Apjohn. Duesbury. Kay. Carswell. Clark. Kerr. Bostock, Goldie. Houghton. Lee. Gregory Gregory. Lee. Brown. Cheyne. T. Thomson. Joy. B eatty. Kerr. LEA & BLANCHARD'S PUBLICATIONS. 11 DUNGLISON'S PRACTICE, SECOND EDITION. $P1?9 A NEW EDITION, TO 1844, OF THE PRACTICE OF MEDICINE; A TREATISE ON SPECIAL PATHOLOGY AND THERAPEUTIC SECOND EDITION. BY ROBLEY DUNGLISON, M. D., Professor of the Institutes of Medicine in the Jefferson Medical College, Lecturer on Clinical Medicine, Attending Physician at the Philadelphia Hospital, &c. In two large octavo volumes, of over thirteen hundred pages. Notwithstanding the short period in which this work has been before the profession, it is so universally known throughout the country, and so extensively used as a text-book in the Medical Colleges, that, in presenting this new and much improved edition, the publishers have only to call attention to the author's prefaee. "It is scarcely necessary for the author to say, that the extraordinary sale, which the first edi- tion of this work has met with, is most gratifying to him. It sufficiently satisfies him, that the large amount of labouF and reflection, which he bestowed upon it, has been found serviceable to his medical brethren, and more especially so, perhaps, to those who are engaged in the study of their profession. "Grateful for this result, the author has endeavoured to render the present edition still more useful, by adding whatever of importance has transpired in the short period that has elapsed Bince the first edition was published, and by supplying omissions, which were almost inevitable in the first impression of a work in which ee many subjects are treated of. " It has been pleasing to the author to observe the favourable manner in which tlie work has been noticed by almost all the Journals of Medicine, which have received it at home and abroad; and where criticisms have been occasionally made, they have generally been rather against the plan than the manner of execution. That plan was adopted from a full and deliberate convic- tion of its advantages, and it is, therefore, adhered to in the present edition without modification. 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Diseases of the Mouth, Tongue, Teeth, Gums, Velum Palati and Uvula, Pharynx and (Eso- phagus, Stomach, Intestines, Peritoneum, Morbid Productions in the Peritoneum and Intes- tines.—Diseases of the Larynx and Trachea, Bronchia and Lungs, Pleura, Asphyxia.—Morbid Conditions of the Blood, Diseases of the Heart and Membranes, Arteries, Veins, Intermediate or Capillary Vessels,—Spleen,Thyroid Gland, Thymus Gland, and Supra Renal Capsules, Mesen- teric Glands,—Salivary Glands, PancreaB, Biliary Apparatus, Kidney, Ureter, Urinary Bladder. —Diseases of the Skin, Exanthematous, Vesicular, Bullar, Pustular, Papular, Squamous, Tuber- culous, Maculae, Syphilides— Organic Diseases of the Nervous Centres, Neuroses, Nerves.— Diseases of the Eye, Ear, Nose.—Diseases of the Male and Female Organs of Reproduction- _FeVcr —Intermittent, Remittent, Continued, Eruptive, Arthritic, Cachex, Scrofulous, Scorbutic, Chlorotic, Rhachitic, Hydropic, and Cancerous. 12 LEA & BLANCHARD'S PUBLICATIONS. WATSON'S PRACTICE OF MEDICINE. LE CTURE S ON THE PRINCIPLES AND PRACTICE OF PHYSIC. DELIVERED AT KING'S COLLEGE, LONDON. BY THOMAS WATSON, M. D. Fellow op the Royal College of Physicians, Physician to the Middlesex Hospital, b.a. &o. Iii one large octavo volume, of over nine hundred unusually large pages, well bound in leather. Containing ninety lectures. This volume has met with the universal approbation of the medical press, so far as it has yet been expressed, in a manner rarely enjoyed by so comprehensive a w«rk. The publishers submit a few extracts. '•For our parts, we are not only willing that our characters as scientific physicians and skilful practitioners may be deduced from doctrines contained in this volume, but we hesitate not to express our belief, that for sound, trustworthy principles, and good substantial practice, it cannot be paralleled by any similar work in any other country. We would advise no one to set himself down in practice unprovided with a copy."—British and Foreign Medical Review. " We have here the sterling production of a liberal, well stored, and truly honest mind, possessed of all that is currently known and established of professional knowledge, and capable of pronouncing a trustworthy and impartial judgment on those numerous points in which truth is yet obscured by false hypotheses."—Provincial Med Journal. " Open this huge, well furnished volume where we may, the eye immediately rests on something that carries value on its front. We are impressed at once with the strength and depth of the lecturer's views. He gains on our admiration in proportion to the extent of our acquaintance with his profound researches. Whoever owns this book, will have an acknowledged treasure if the combined wisdom of the highest authorities is appreciated." Boston Med. and Surg Journal. " We know of no other-work better calculated for being placed in the hands of ihe student, and for a text- book, and as such we are sure it will be very extensively adopted. On every important point, the author seems to have posted up his knowledge to the day."—American Medical Journal. " We know not, indeed, of any work of the same size that contains a greater amount of useful and interest- ing matter. We are satisfied, indeed, that no physician, well-read and observing as he may be, can rise from its perusal without having added largely to his stock of valuable information."—Medical Examiner. " It is an admirable digest of general pathology and therapeutics. As a text book for medical schools, it can- not be surpassed, and in no other treatise can practitioners find so concise, and at the same time so complete a summary of the present state of the science of medicine."—Baltimore Patriot. "One of the most practically useful books that ever was presented to the student—indeed, a more admirable summary of general and special pathology, and of the application of therapeutics to diseases, we are free to say has not appeared fir very many years. The lecturer proceeds through the whole classification of human ills, a capite ad calcem, showing at every step an extensive knowledge of his subject, with the ability of communicat- ing his precise ideas, in a style remarkable for its clearness and simplicity.""—N. Y. Journal of Medicine, _ .«sc i f jtp vallie It( tlle gurglCal practitioner. As a Ihe Ltmle".t. U must I. •"^'Xpie.e-lew of the"literature of the subject, it stands ,.. the hrst ran*.- 22 LEA & BLANCHARD'S PUBLICATIONS. SIR ASTLEY COOPER ON HERNIA, Jfith One Hundred and Thirty Figures in Lithography, THE ANATOMY ANlfsURGICAL TREATMENT OF By Sir ASTLEY COOPER, Bart. Edited by C. Aston Key, Surgeon to Guy's Hospital, &c. This important work of Sir Astley is printed from the authorized second edition, published in London, in large Buper-royal folio, and edited by his nephew, Professor Key. It contains all the Plates and all the Letterpress- there are no omissions, interpolations, or modifications—it is the complete work in One "Large Imperial Octavo Volume, WITH OVER 130 FIGURES ON 26 PLATES, AND OVER 400 LARGE PAGES OP LETTERPRESS. The correctness of the Plates is guaranteed by a revision and close examination under the eye of a distinguished Surgeon of this city. The value of this Work of Sir Astley Cooper is so universally acknowledged by all medical men, that in presenting this edition to the American Profession, the publishers have only to state that they have used their utmost endeavours to render the mechanical execution of the work worthy its exalted reputation, and to put it in Buch a form and at such a price as to place it within the reach of those who have been prevented from obtaining it by the size and rarity of former editions. SIR ASTLEY COOPER'S WORK. ON FRACTURES AND DISLOCATIONS WITH NUMEROUS WOOD GUTS. A TREATISE ON DISLOCATIONS AND FRACTURES OF THE JOINTS. By SIR ASTLEY COOPER, Bart., F.R.S., Sergeant Surgeon to the King, &c. A new edition much enlarged; edited by BRANSBV COOPER, F.R.S., Surgeon to Guy's Hospital, with additional Observations from Professor John C. Wakren, of Boston. With nu- merous engravings on wood, after designs by Bjgg, a memoir and a splendid portrait of Sir Astley. In one vol. octavo. The peculiar value of this, as of all Sir Astley Cooper's works, consists in its eminently practical character. His nephew, Bransby B. Cooper, from his own experience, has added a number of cases. Beside this, Sir Astley left behind him very considerable additions in MS. for the express purpose of being introduced into this edition. The volume is embellished with ONE HUNDRED AND THIRTY-THREE WOOD CUTS, and contains the history of no less than three hundred and sixty one cases, thus embodying the records of a life of practice of the Author and his various editors. There are also additional Observations from notes furnished by John C. Warren, M.D., the Professor of Anatomy and Surgery in Harvard University. MAURY'S DENTAL SURGERY. A TREATISE ON THE DENTAL ART, FOUNDED ON ACTUAL EXPERIENCE. ILLUSTRATED BY TWO HUNDRED AND FORTY-ONE FIGURES IN LITHOGRAPHY, AND FIFTY- FOUR WOOD CUTS; BY B. F. MAURY, DENTIST OF THE ROYAL POLYTECHNIC SCHOOL. Translated from the French, with Notes and Additions, BY J. B. S A V IE R, D OCTOR OF DENTAL SURGERY. One volume, octavo. This work is used as a Text book in the Baltimore College of Dental Surgery, and commends itself to the Profession from the great reputation of the author, and as embracing the latest information on the subject Its steady demand is the best testimony of the general favour with which the profession has received it. It is di- vided into three parts. Part I.—Dental Anatomy, Physiology and Pathology. Part II.—Dental Hygiene and Therapeutics. Part III.—Mechanical Dentistry in all its various parts and fully illustrated. THE DISEASES OF THE EYE. WITH NUMEROUS CUTS. A TREATISE ON THE DISEASES OF THE EYE. BY W. LAWRENCE, Surgeon Extraordinary to the Queen, Sec, from the last London Edition, with numerous additions, and sixty- seven Illustrations, many of which are from original drawings. BY ISAAC HAYS, M.D., Surgeon to the Wills Hospital, &c. &c, in one volume octavo. The character of this work is too well established to require a word of commendation—it is justly considered the best on the subject. The present is a reprint of the last London Edition, which appeared in 1841, com- pletely revised and greatly enlarged by the author—and to it considerable additions have been made by the edi- tor. Several subjects omitted in the original are treated of in this edition, on which occasion free use has been made of the work of Mackenzie, to which is added the editor's own experience, derived from many years' at- tention to the subject. LEA & BLANCHARD'S PUBLICATIONS. 23 MATERIA MEDICA, THERAPEUTICS, PHARMACY, AND CHEMISTRY. PEREIRA'S MATTrTa MEDICA. WITH NEAR. THREE HUNDRED ENGRAVINGS ON WOOD. THE ELEMENTS OF MATERIA MEDICA AND THERAPEUTICS. COMPREHENDING THE NATURAL HISTORY. PREPARATION, PROPERTIES COMPOSITION EFFECTS, AND USES OF MEDICINES. ^ru»uw«, BY JONATHAN PEREIRA, M. D., F. R. S. and L. S. Member of the Society of Pharmacy of Paris; Examiner in Materia Medica and Pharmacy of the University of London; Lecturer on Materia Medica at the London Hospital, &c. &c. From the Second London Edition, enlarged and improved. WITH NOTES AND ADDITIONS BY JOSEPH CARSON, M. D. In two volumes, octavo. Part I. contains the General Action and Classification of Medicines, and the Mineral Materia Medica. Part II, the Vegetable and Animal Kingdoms, and including diagrams explanatory of the Processf s of the Pharma- copoeias, a tabular view of the History of the Materia Medica, from the earliest times to the present day, and a very copious index. From the Second London Edition, which has been thorouahly revised, with the Introduc- tion of the Processes of the New Edinburgh Pharmacopoeia, and containing additional articles on Mental Reme- dies, Lieht, Heat, Cold, Electricity, Magnetism, Exercise, Dietetics, and Climate, and many additional Wood Cuts, Illustrative of Pharmaceutical Operations, Crystallography, Shape and Organization of the Feculas of Commerce, and the Natural History of the Materia Medica. The object of the author has bpen to supply the Medical Student with a Class Book on Materia Medica, con- taining a faithful outline of this Department of Medicine, which should embrace a concise account of the most important discoveries in Natural History, Chemistry, Physiology, and Therapeutics, in so far as they pertain to Pharmacology, and treat the subjects in the order of their natural historical relations This great Library or Cyclopedia of Materia Medica has been fully revised, the errors corrected, and nume- rous additions made, by DR JOSEPH CARSON, Professor of Materia Medica and Pharmacy in the " College of Pharmacy," and forms Two Volumes, octavo, of near IGOO large and closely-printed pages. It may be fully relit-d upon as a permanent and standard work for the country,—embodying, as it doesrfull references to the U. S. Pharmacopoeia and an account of the Medical Plants indigenous to the United States. ELLIS'S MEDICAL FORMULARY, 7th Edition. THE MEDICAL FORMULARY; Being a Collection of Prescriptions, derived from the Writings and Practice of many of the most eminent physicians in this country and in Europe. To which is added an Appendix containing the usual Dietetic Preparations and Antidotes for Poisons; the whole accompanied by a few brief Pharmaceutic and Medical Observations. BY BENJAMIN ELLIS, M. D. Seventh Edition, revised and extended by Samuel George Morton, M. D. In one volume octavo. GRAHAM'S CHEMISTRY. THE ELEMENTS OF GHEMISTRY, Including the application of the Science to the Arts. WITH NUMEROUS ULUSTRATIONS, BY THOMAS GRAHAM, F. R. S., L. and E. D. Professor of Chemistry in University College, London, &c. &c. With Notes and Additions, BY ROBERT BRIDGES, M. D., &c. &c. In one vol. octavo. The The appearan'ce of a correct and amended American Edition, underlie cwe^Di* Bridges?will prove an acceptable thing to both teachers and students of chemtstry in this country."—Silliman's Journal. 24 LEA & BLANCHARD'S PUBLICATIONS. DUNGLISON'S MATERIA MEDICA, &c. GENERAL THERAPEUTICS AND MATERIA MEDICA. BY ROBLEY DUNGLISON, M. D., Professor of the Institutes of Mi dicine, &c. &c, in the Jefferson Medical College, PhiLda. In two volumes octavo. "A second edition of the work on General Therapeutics, being called for by the publishers, the author has deemed it advisable to incorporate with it an account of the different articles of the Materia Medica. To this he has been led by the circumstance, that the departments of General Therapeutics and Materia Medica are always associated in the Medical Schools The author's great object has been to prepare a work which may aid the Medical Student in acquiring the main results of modern observation and reflection; and at the same lime, be to the Medical Practitioner^ trustworthy book of reference " Throughout, he has adopted the Nomenclature of the last edition of the Pharmacopoeia of the United States, a work which ought to be in the hands of every practitioner as a guide in the preparation of medicines: and he has endeavoured to arrange the articles in each division, as nearly as he could, in the order of their efficacy as Therapeutical agents." " The subject of Materia Medica has been handled by our author with more than usual judgment. He has, very wisely in our opinion given his principal attention to the articles of tin; Materia Medica as medicines. In conclusion, we strongly recommend these volumes to our readers. No medical student on either side of the Atlantic ought to be without them."— Eorbes' British and Fereign Medical Review, Jun 18-14 53" This work is extensively used as a Text Book in many Colleges. DUNGLISON ON NEW REMEDIES, 4th Edition. NEW REMEDIES; PHARMACEUTICALLY MD THERAPEUTICALLY CONSIDERED. Fourth Edition, with extensive modifications and Additions, BY ROBLEY DUNGLISON, M. D, &c. &c. &c. In otic volume octavo. This edition will be found more complete than any of the former. It contains all the new remedies intro- duced since the third edition in 1841. as well as the new matter embodied in the pharmaceutical journals and essays since that period, as well as in the large works of Pereira. Christison, Bouchardat, (.incite and others. The new matter (about sixty or seventy pagfs) thus introduced ihroush the work can only be appreciated on close investigation The principal new articles inserted in this edition are Aluminas Sales, Anthrakokali, Cannabis Indica, Corjlus Rostrata, Ferri Cirras, Ferri et Quiniss Citraa, Fucus Amylaceus, Fuligokali, Giuti- ana Chirayita.Juglans Kegia, Matias, Paullinia, and Plalini Preparata. A new Edition, to 1S4J, or DUNGLISON'S MEDICAL DICTIONARY. DICTIONARY Or MEDICAL SGlfcHO^s CONTAINING A concise Account of the various Subjects and Terms, with the French and other Synonymes, Notices of Climates and of Celebrated Mineral Waters, Formulae for various Officinal and Empirical Preparations, &c. &c. FOURTH EDITION, MODIFIED AND IMPROVED. By ROBLEY DUNGLISON, M.D. Professor in the Jefferson Medical College, etc. In one Volume, royal Octavo, of near 800 large Pages, double columns. This may safely be affirmed to be the most complete Medical Dictionary yet published, containing, as it does, upwards of FORTY TBIOUSAWO WORBS AKD SYIVOXYMES. It has been the author's anxious desire to render this work a satisfactory and desirable, if not indispensable, Lexicon, in which-the student should never be disappointed in his search for any term with which he might meet in the course of his reading. To those unacquainted with the rapid and unceasing progress of medical science, it might seem that no great modi- fication was necessary in the fourth edition of a work like the present, when the third had appeared within two years, and yet it has been found advisable to add no less than TWO THOUSAND WORDS AND TERMS not included in the preceding editions. Some of these are words of recent formation, while others had previously escaped the author. LEA & BLANCHARD'S PUBLICATIONS. 26 SPECIAL TREATISES ON MEDICINE, SURGERY, &c, PROUT ON THE STOMACH. 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Walch's Sketches of Conspicuous Living Characters of France, 1 vol. 12mo. Walpole's Unrivalled Letters. The only complete edition. Containing nearly 300 Letters, with a portrait, in 4 vols. 8vo. extra cloth. 29 THE AMERICAN JOURNAL OF THE MEDICAL SCIENCES ISAAC HAYSAMCnAS^r„ ^w^1)?""? °,f khe Ameri<*" J°»™al of the Medical Sciences, edited by he Am Philos Sn?"f r K- *V 'f Ho*P,taI' «>y«cian to the Philadelphia Orphan Asylum, Member of ,hThi^„?r' ,°aS. w^ l^*^^1?**? "»raS™* ™!'»b°r?L°" » ?»7 section of the Union. cvcuvcrii ycais n hub Deen unner tne editorial direction of Dr. Isaac Hays A New Series was commenced in Jan. 1841. The pages of this Journal contain the records of the experience of the most distinguished members of the Profession in every part of the Union. CONTENTS OF THE NO. FOR APRIL 1844. Memoirs and Cases.—Art. I Observations on the Pathological Relations of the Medulla Spinalis. By Austin Flint, M.D. If. Case of Molluscum, associated with Fibro-Cellular Encysted Tumour and Eucepha- loid Disease. By Washington L. Atlee, M.D. [With a wood cut.] HI. On the Pulse of the Insane. By Pliny Earle, M.D. IV. Statistics and Cases of Midwifery; compiled from the Records of the Philadelphia Hospital, Blockley. By Geo. N. Burwell, M.I). V. On the Congestive Fever of Mississippi, with Cases. By R. G. Wharton, M.D. VI. Enteritis—with Cases, exemplifying the decidedly beneficial effects of Blood let- ting, and the Sedative Treatment. By P. M. Kollock, M D. VII. Case of Inversion of the Uterus, in which Reposition was effected on the tenth day. By Joseph P. Gazzam, M.D. VIII. Ligature of the external Iliac Artery for Aneurism. By W. P. Boling. M.D. IX Eupatorium Perforatum in Epidemic Influenza. By J. F. Peebles, M.D. X. Case of Polypus of the Uterus expelled by the action of Ergot. By Thomas J. Garden, M.D. XI. On the Extraction of Retained Placenta in Abortion. By Henry Bond, M.D. XII. Improved Catheter Bougie. By R. J. Dodd, M D. Rbviews.—XIII. Fcnger's Dissertation on Erysipelas Ambulans. XIV. Drs. MWilliam and Pritchett on African Remittent Fevers. Bibliographical Notices.—XV. Harrison's Theory of the Nervous System. XVI. Hartshorne's Annual Report of the Eastern State Penitentiary. XVII. Kirkbride's Report of the Pennsylvania Hospital for the In- sane. 2 Report of the Ohio Lunatic Asylum. 3. Report of the Managersof the State LunaticAsylum, (New York) 4. Report of the Superintendent of the Maine Hospital. XVIII Paris's Pharmacologia. XIX. Hare's Statistical Report of one hundred and ninety cases of Insanity admitted into the Retreat near Leeds. XX. White's Address on Insanity. XXI. Report of the Surgeon General U. S. Army. XXII. Dunglison's Human Physiology. XXIII. Dunglison's Dictionary of Medical Science. XXIV. Weston some of the more important Diseases of Childhood. XXV. Magendie's Elementary Treatise on Human Physiology. XXVI. Wilson on Spasm, Languor, Palsy, and other disorders termed Nervous, of the Muscular System. XXVII. West's Clin. ical and Pathological Report on the Pneumonia of Children. XXVIII. Cooper on Hernia. XXIX Todd on Rheumatic Gout. Fever, and Chronic Rheumatism of the Joints. XXX. Smith and Horner's Anatomical Atlas. XXXI. Quarterly Summary of the Transactions of the College of Physicians of Philadelphia. XXXII. Chapman's Lectures on the more Important Diseases of the Thoracic and Abdominal Viscera. SUMMARY OF THE IMPROVEMENTS AND DISCOVERIES IN THE MEDICAL SCIENCES. Anatomy and Physiology.—1. Elstesser onthe Period at which the foramen ovale, and the ductus venosus become obliterated. 2. Lacauchie on Absorption. 3. Burrows on Blood in the brain. 4. Erdl on Optic nerves. 5. Spence on Nervus vagus and nervus accessorius. 6. Escape of ova independent of fecundation, and the connection of this with menstruation. 7. Roberton on Age of puberty in girls. 8. Starr on Urachus pervious after birth. Materia Medica and PiiARMacv.—9. Oalleoti on Species of Veratrum. 10. Martens and Oalleoti on Spe- cies of Smilax. 11. Formula for fluid extract of Senna. 12. O'Shaughnessy on Gurjum Balsam. 13. A'in^- don on New preparation of Quinine. Medical Pathology and Therapeutics and Practical Medicine.—14. Prus on Meningeal Apoplexy. 15. Hus3 on Communication between the aorta and pulmonary artery without Cyanosis. 16. Huss's remark- able case of Cyanosis. 17. Pritchard on the connection of Insanity with diseases in the organs of physical life. 18 Fioravente on new treatment of Sciatica. 19. Volt on Ulceration of the Appendix Vermiformis. 20. Bredscheider on Rupture of the Trachea. 21. JVegrier on Epistaxis. 22. Herberger on blood and urine in chlorotic subjects. 23, Black, on Tubercles and Phthisis. 24. Boudin on Antagonism of typhoid and in- termittent Fevers. 25. Taylor on double intussusception. 26. Mackenzie on Epidemic Remittent Fever which prevailed in Glasgow. __ ... Surgical Pathology and Therapeutics and Operative Suroery.—27. Debeney on abortive treatment of Gonorrlirua, by the Nitrate of Silver, and on the employment of caustic injections at all stages of Urethn- tis. 28. Leroy d'Etiolles on Cancerous diatheses. 29. Douglas on Dislocation of the Femur-head of thai bone on the pubes.-fracture of the neck of femur. 30 Tuton on Ovarian dropsy successfully treated with ioduret of Iron. 31. Mackesy on Amputation of the Leg-ressels so diseased as to preclude the use of liga- tures-recovery. 32. Syme on Disarticulation of the ramus ot the lower Jaw, without opening the cavity of he mouth. 33 Lepine on Penetrating wound of the Abdomen-Prolapse of the Stomach-Recover).34. Fife on Ununited Fracture of the Humerus—excision of the fractured extremities-cure. 35. Purefoy on Trismus fol"ow\ng the^extraction of a tooth. 36. Cooper on Extirpation of an Ovarian Cyst 37 -Scoutetten on TVacheo omv in the last stage of Croup. 38 O'Bryen on Diagnosis of Aneurism of the Aorta. 39. -En- Tlehardt on F^nm% tumour mistaken for Aneurism. 40 Rufz on Painful affection of the breast 41 Dan- twin SnunrtSn Perineum performed immediately after delivery. 42 Berard on Cure of encysted Tu- fnouw 43 Segalas'! remarkahlo case of Calculus. 44 Lenoir on Dislocation of the os mnom.natum on the bital cavity. A.,;*.:,,i r„„tnr.> <\f the membranes to accelerate delivery. 54. Elk- M,DwipeRy.-53. Chailly Honors on Artificial ™V^£.™™™eatwl ot compnui„K the aorta in ute- 32 MEDICAL JOLkwal CONTINUED. American Intelligence.—Original Communications.—McClellan on Extirpation of the Parotid Gland. E. Bissell's Cases of Ovarian Disease, with remarks. Eve on Lithotomy—Bilateral operation, with cases. Tracy on the Vegetable Acids as correctives of acidity of stomach. Ludloic's Notice of a new Flexible ate- thoscopL>: Dodd's Improved Cupping Apparatus. Crowell's Unusual case of irregularity of the incisors and canine teeth of the superior jaw, remedied in seventy-six days. Domestic Summary.—Judkins' case of Ovarian Disease. Bedford on Vaginal Hysterotomy. New Medical Works in preparation. Each Number contains ORIGINAL. ESSAYS. EXTENDED REVIEWS OF THE NEW AND MOST IMPORTANT WORKS, BIBLIOGRAPHICAL NOTICES, And a full Summary of Foreign and Domestic Intelligence. The publishers invite especial attention to this last department, which constitutes an important feature in this Journal, comprising the fullest RETROSPECT of the improvements and discoveries made in the Medical Sciences anywhere to he met with, de- rived not only from the BRITISH JOURNALS. but also from those of FRANCE, GERMANY, DENMARK, ITALY, THE EAST INDIES, and our own country. 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