:^;r )-.y??z.z ■■■&,.'..-..■■-'.•■•-. ^1 Mi^:tz:;,z UNITED STATES OF AMERICA FOUNDED 1836 WASHINGTON, D. C. GPO 16—67244-1 i "\ (\^■/!■ .^ *4 ■ \^\j^ '5. i" W* V AN ESSAY, &c. AN ESSAY ON SUSPENDED ANIMATION. BY SAMUEL JACKSON, HONORARY MEMBER OF THE PHILADELPHIA MEDICAL, AND MEMBER 07 TEE PHILADELPHIA LINNEAN SOCIETIES. Nec tardum opperior, nee praecedentibus insto. Hos-ace.' '* ^lU.KY PRINTED BY SMITH 6? MAXWELL. PHILADELPHIA. 1808. • AN INAUGURAL DISSERTATION, FOR THE DEGREE OF DOCTOR OF MEDICINE, I SUBMITTED TO THE EXAMINATION OF THE MEDICAL PROFESSORS, OF JAMES M'DOWELL, LL. D. PROVOST, AND OF THE TRUSTEES , OF THE UNIVERSITY OF PENNSYLVANIA. • ON THE 28TH DAY OF APRIL, 1808. $*%13'1 \ TO CASPAR WISTAR, M. D. ADJUNCT PROFESSOR OF ANATOMY AND MIDWIFERY IN THE UNIVERSITY OF PENNSYLVANIA; A MAN, WHOSE AMIABLE QUALITIES HAVE ENDEARED HIM TO A LARGE CIRCLE OF ADMIRING FRIENDS; A PHYSICIAN, WHOSE TALENTS HAVE GAINED HIM THE CONFIDENCE AND RESPECT OF A COMMUNITY, THIS EPHEMERAL PRODUCTION IS INSCRIBED, AS A SMALL TRIBUTE OF RESPECT FOR EVERY VIRTUE WHICH ADORNS AND EXALTS THE HUMAN CHARACTEP, AND AS A MARK OF HEARTFELT GRATITUDE, FOR MANY INSTANCES OF ALMOST PARENTAL KINDNESS, EXPERIENCED WHILE UNDER HIS TUTELAGE, BY HIS AFFECTIONATE PUPIL, SAMUEL JACKSON. INTRODUCTION. KJLD Age, if not the only natural outlet of death, as Bacon asserts, before Man forgot the God that made him, and be- came the unrestrained follower of vice, was most probably the principal portal through which life issued. How changed the scene! Existence has become the tenure of uncertainty; each gale bearing on its wings the seeds of destruction, while death suspends its sword each instant o'er our heads. For although youth may lead us exulting with the fulness of life, and bound- ing with joy, along its verdant paths, though Health circles our brow with its rosy wreaths, we are uncertain but that a moment separates us from eternity. This enemy of man lurks in secret around; he appears not always in the horrid garb of disease, to warn us of his approach; but while the soul revels in the luxuries ofanticipatingfancy; while the soft smiling countenance of hope attracts our regards; or ambition, as a dazzling meteor, ab- sorbs attention, his icy hand touches our hearts; we cease, ere our day has run its course, and still warm with imagina- tion's glowing fire, are inclosed in the cold and silent tomb. So enervated has life been rendered, and so numerous are the deathful instruments, which disease now marshals in its ranks, from the follies, the vitious propensities, and the crimes of men ! To diminish this accession to disease, and to guard these ave- nues of death, that man may live nature's originally allotted span, is the object of medical science, the constant, the un- varying effort of every philanthropick physician. But while he regards the more dreadful battalia, he must not neglect the sudden, unexpected, and therefore too frequently fatal attacks X of his watchful foe. Those casualties, which are so often ir- remediable, if they cannot be prevented, he should endeavour to render innocent. Of these, few are a more frequent cause of destruction to existence, than that of drowning. Each year does society lament that it is, by this means, deprived of its proudest boasts, its brightest ornaments, or its humble sup- ports. A family, in a few fatal moments, too frequently loses the support and protection of a father, is precipitated from the comforts of competence, to the distresses of poverty, and left to the cold charity of a pitiless world, from his term of being, pre- maturely,and untimely ending by this too common accident. Of- ten does a fond mother, while distraction paints her looks, de- spair of the coming of her wandering child. He returns no more, or is given to her arms a lifeless corpse, the victim of the rapacious wave. As the physician has not fulfilled his duty, when he has only defended from the aims of death; or stretched forth his hand, and raised a suffering being from a bed of disease, of anguish, and of pain; but as he is to render secure the life he has pro- tected; as he is to make it a blessing to its possessor, that it may not be a burden to a " soul heavy laden" with distress, he is to close this avenue of death, and to dry this source of misery. AN ESSAY, &c. JLN the first dawn of physiological learning, it might perhaps have appeared vain and presumptuous, to at- tempt restoring to animation an apparently dead body- But as we now know that the characteristick signs of life and death, are obscure, (if we except putrefaction) and that no one has been able certainly to pronounce, this is vitality, or that is death; as we are also absolutely certain, that the more obvious appearances of life may be suspended, without its being annihilated, it becomes an act of criminalness to neglect any effort to resuscitate in cases of the sudden suspension of vital action. Shall we refuse to rake the warm ashes for a spark, which may rekindle to a genial blaze, and give new vigor to a sink- ing frame ? That life can exist, as it were, in a latent state, for sometime, and still remain capable of being roused in- to action, and to produce all its phenomena, is establish- ed by facts so numerous and incontestible, as to render the attempt to prove it superfluous. It was, from an ob- servation of the spontaneous recovery of drowned per- sons, which, in Holland, first led to the practice of endeavouring to revive those, who suffered by this acci- 12 dent. The success, which crowned the first attempts, in- duced the philanthropists of that country, to institute humane societies. This laudable example was soon im- itated in the different nations of Europe, by which means,, has humanity frequently gained a triumph over death. It must, however, be acknowledged that all efforts at re- suscitation, are often ineffectual; even in cases in which submersion has not long existed. It becomes, then, a question of much interest and importance, to be an- swered, whether in these instances, the failure is not to be attributed to a defect in the method now employed for recovery, or to a total extinction of life. The Humane Society of this and other cities, and al- so many respectable physicians, appear to be of the opi- nion, that more persons might be recovered, and that a plan of greater efficacy, than the present might be adopt- ed to effect this noble object. Actuated by this senti- ment, the Philadelphia Humane Society, highly to its honour, and with a seal and disinterestedness, which phi- lanthropy ever inspires, has, by offering medals, endea- voured to excite an investigation of this subject; but the result of this commendable spirit is as yet unknown. It is to be feared, however, until that distant day shall ar- rive, when the principle of life will be less obscure, its cause ascertained, or itself made known, all efforts will be fruitless. For it appears to proceed from a difference in thenature of this unknown cause of the phenomena of life, that some persons sooner fall victims to submersion than 13 others, though not remaining inthatstate, a greater length of time, than those who recover; and that some succumb under diseases, which others resist for years. A be- lief in this opinion, might be supposed to preclude all other inquiry, and induce us to rest contented with our present advantages, hopeless of attaining to a greater good. But while an opinion is overshadowed with a doubt, the true philosopher relies not on it fully; he trusts to it, but with the cautious steps of the wanderer of the dark. He would not, by this opinion, be indu- ced to remit an exertion, or let one experiment remain unassayed, which would more illurne the subject, or serve to extinguish that light which twinkled but to de- ceive. In the following pages, I shall treat this interesting subject to the extent of my abilities. If the smallest germe of success should bud from my exertions, to be afterwards nurtured with more refined culture, my ex- pectations will be more than fulfilled, and myself re- warded. I shall occupy them, I; with considering respiration, and as far as our limi- ted views will enable us, in inquiring into the manner in which it supports life; II; with ascertaining the proximate causeof the disease, produced by drowning; examining the state of the vital organs; and the indications of cure, which a know- ledge of these presents; III; with the mode of recovery, founded on these in- dications, promising the greatest success. SECTION I. OF RESPIRATION. Than respiration, no function of the animal economy, is more important," or more interesting: important, as it is connected with life; interesting, as the manner of this connexion is unknown. Until the late discoveries and improvements in che- mistry, which have formed so brilliant an epoch in the history of physicks, the knowledge of respiration, was, in a great measure, vague, conjectural, and uncertain. Ignorant of oxygen, of the composition of the atmos- phere, and its effects on the blood, physiologists, before this time, had no data from which to reason, no guide to direct their steps. Like mariners without the compass, their course was devious and wandering. If sometimes, by the mere force of genius, they approached the con- fines of truth, they were, however, lost more frequently in the mists of error. But although chemistry has elu- cidated many of the phenomena, which before eluded investigation; although its discoveries have been a lumi- nary to respiration, and enabled us to behold with a more extended ken, yet there remains a region of truth to be explored, still is the most useful part of the knowledge of this function unknown, or viewed through the de- lusive medium of conjecture. 15 The manner in which respiration is performed, is well known to every physiologist; it will be, therefore, unne- cessary that it should be here detailed. Its more impor- tant parts demand our consideration. The change which is produced in the air inspired; the alteration of colour in the blood, with the manner by which this change is effected; and what purposes it an- swers to the system, are the points of view in which res- piration attracts attention. Atmospheric air, composed of oxygen 22, azote 78 parts, when inhaled into the lungs, and again expired, is ascertained, on examination, to be in a different state, from that in which it was, when first taken into those vis- cera. The greater part of the oxygen disappears, and in its place, a quantity of carbonic acid gas is found. Mr. Davy has lately published to the world, that part of the azotic portion of the air is also consumed. His experiments, confirmed by those of Priestley, previously made, render the opinion probable, if not certain. Before proceeding to explain the cause of this change in the air inspired, the alteration which is experienced by the blood must be noticed. They are so intimately con- nected, so mutually dependent, that to understand the one, the other must be known. The blood passes into the lungs from the right side of the heart, through the pulmonary artery, of a dark purple or black colour. After having circulated through this artery, which ramifies into almost inconceivable 16 minuteness, and in which it is exposed to the action of the air contained in the lungs, it is returned to the left side of the heart, of a bright vermillion hue, and is thence distributed throughout the system, which it nourishes and supports. The change in the constituents of the air, which I have mentioned, being discovered, and the alte- ration that the blood undergoes in the lungs, into which the air is received, being known, led to the supposition, that the change of the one, was the cause of that of the other. The experiments of Cigna, but more particu- larly those of Priestley, proved this supposition to be correct. They found venous blood, when exposed to atmospheric air, to acquire a bright scarlet colour, and that the air lost its oxygen, while carbonic acid gas was formed; and that oxygen gas produced the same effects, but with more rapidity. Priestley removed all objections which might be urged against this opinion, by showing, that these changes occured, even when the air was se- parated from the blood, by the intervention of a bladder; a demonstrative proof, that the membranes of the lungs could be no hindrance to their mutual action. Having made this advance in the discovery of respi- ration, philosophers endeavoured, next, to render it com- plete, by explaining in what manner these different changes were effected. In these lowly pages, which assume not to the form of a regular treatise, I think it unnecessary to pass in review the various theories on this subject, which have been 17 promulgated, to point out their merits or correct their faults. I shall only consider that, which at the present day, can boast of the most numerous followers, and exa- mine to what degree it merits our assent. Lavoisier, whom Science extols as the most illustrious, while she weeps his fate, as the most unfortunate of her sons, soon after the publication of Priestley's paper* on respiration, presented to the publick, a theory replete with ingenuity, which, for some time, possessed, almost universal sway over the philosophick world, and still retains, perhaps above all others, the greatest number of disciples. Carbonic acid gas, appearing in the air expired* sup- plying the place of the oxygen, which has disappeared from the air inhaled, and this gas being known to consist of carbon and oxygen, its formation in the lungs, Lavoi- sier thought, would satisfactorily explain the source of the consumption of oxygen; and the carbon being ex- tracted from the blood, would account for the change, which that fluid sustains. In some accurate experiments, at a period subsequent to the publication of this theory, he ascertained that more oxygen is lost to the air inspi- red, than is necessary to the formation of the carbonic acid gas, which is found in the air expired. To obviate the powerful objections, which might be argued against his doctrine, from this fact, he now, for the first time, noticed the elimination of water from the lungs, which * Philosophical Transactions, Vol. 66, part 1; C 18 before he had treated with neglect. His discovery of the constituent parts of this fluid, which has impressed on his name the seal of immortality, came now with friend- ly aid to relieve him from this difficulty. Influenced undoubtedly by this discovery, and never having admit- ted that oxygen entered into the blood, he concluded in- stantly the portion of this gas, for the disappearance of which, he was to account, united to hydrogen thrown out from the blood, and with it, formed the water contained in the air of expiration. This theory, simple, plausible, and ingenious, was for a while supposed to have com- pletely explained the phenomena of respiration; accoun- ting for the consumption of oxygen, the formation of the carbonic acid gas, and the change in the colour of the blood. But this hypothesis, though specious in appear- ance, and the authority of a name so commanding as that of Lavoisier, could not entitle it to universal adoption, unexamined and uninvestigated. It has passed the ordeal of publick opinion, and has been found defective. It lives in remembrance, not from its own intrinsick worth, but from the merits of its author. Lavoisier fell into an error, at his commencing the consideration of respiration, which affected all his future reasonings. After appearing undecided, whether oxygen is absorbed into the blood, or united to carbon, in the cavity of the lungs, he finally adopted the latter opinion as correct; and believed that the change in the blood, is produced by the loss of carbon and hydrogen, which are 19 rejected from the vessels, uniting to the oxygen ex- teriorly thereto, forming carbonic acid gas and water. Bostock, in his very valuable essay on respiration, con- tests this opinion; and his arguments must prove it fal- lacious. He very justly concludes, as also does Burdin,* that there are no solid grounds, on which to rest the opi- nion, that water is formed in the lungs. The supposi- tion of hydrogen in the blood, is entirely gratuitous, no one fact, but the escape of water from the lungs, countenan- cing the notion, and this is to be explained on another principle, more analogous to the general operations of the ceconomy, than to that of the union of its constituent parts, in these viscera. For we find every cavity of the body, moistened continually by a watery, or serous fluid, to preserve them pliable and soft, to obviate the bad effects which friction would otherwise occasion; and we must suppose the same fluid would be secreted on the surface ofthe bronchice. The air, carrying part of this off in so- lution, or in vapour, explains its appearance in expiration. We are no more authorized to conclude, that hydrogen and oxygen unite to form water in the lungs, than that they do so in the cavity of the abdomen; for we findj when opened, while the animal heat yet remains, a watery vapour exhales from it. Crawford was led into the same error, from a mistake under which he laboured, owing to the nascent state of Chemistry in his day. He says, there are two kinds of * Medical Studies, Vol. Ill, page 341. 20 inflammable air, one obtained from metals, the other from animal and vegetable substances, which he calls lambent inflammable air. This last produces carbonic acid gas in its combustion. He supposed this air was extricated from the blood, united to oxygen, and produ- ced the carbonic acid gas. But as water is the product also of the union of oxygen and hydrogen, it must therefore result, that water is formed in respiration ;* such is the train of reasoning he pursues. This lam- bent inflammable air, of which he speaks, is carbonated hydrogen gas ; but that it exists in the blood, or is ejected into the lungs, is an opinion not founded on fact, and discarded by reason. Lavoisier and Crawford, were not more correct in their belief, that oxygen did not enter the blood, and that its loss was owing to its uniting with carbon and hydrogen, in the lungs. The numerous and decisive proofs of its absorption into the blood, are indicated, 1st, By some experiments of Girtanner,who found ar- terial blood to evolve oxygen; for this blood being expo- sed to azote, and hydrogen airs, and this gas, being dis- coverable in them afterwards, it must have escaped from the blood; these experiments are confirmed by others of Priestley; f 2, Mr. Davy, when he exposed arterial blood to heat, informs us that carbonic acid gas and oxygen, or " phos oxygen," as he terms it, were driven off, • Crawford, on Animal Heat, page 15 3-4. J Priestley on air, Vol. Ill, P« 76-7. 21 3d, From the fact that air is separated from the blood, in the living body. It must of course be a secretion from the arterial blood, and is the separation of air contained in, or held in solution by it; for it is impossible, for a mo- ment, to entertain the idea that it proceeds from a decom- position of the blood, or of any part of the system. Hunter mentions several circumstances in support of this belief;* and also the case of a tumor, from which air was dis- charged, f In the disease called Tympanitis, a vast quan- tity is at times secreted. No account has as yet been published of this air having been examined, we there- fore cannot determine of what kind it is; but in the sword-fish, the air bladder is ascertained to contain oxy- gen, while in the carp, it is found to be azote. 4th, Morgagni mentions his having inflated the lungs of a subject, in consequence of which, air passed into the pulmonary veins.J Bichat relates an experiment he performed on a living dog, which must place the fact beyond all dispute. He inflated, with some force, the * lungs, and on dividing the crural artery, the blood is- sued forth, mixed with bubbles of air. He distended, afterwards the lungs of another dog, with hydrogen gas, and while the air escaped from the crural artery, as in the preceding experiment, he inflamed it with a taper. § * See Animal Economy. Observations on digestion, p. 164-5. t Same, p. 166-7. \ Vol. 1, p. 117. § Recherches Physiologiques, sur la Vie et la Mort,p. 354-5 22 5, From the fact that air has been found in the vessels after death. Morgagni in his dissections gives several in- stances of this circumstance, which occurred to him- self and others, that render it incontestible.* I had an op- portunity of witnessing this incident, in the bodies of two men, whose deaths were sudden and violent; ha- ving been destroyed by strangulation. The right side of the hearts of each, were considerably distended; and on making an opening into them, air rushed out with the blood. The coronary veins of one were perfectly trans- parent, from the air, which they contained. It was also detected in the brain of the other, in the vena galena. The diaphragm in the agonies of death had been raised to a considerable height, and compressed the lungs. It may be supposed, as it was by a person present at the examination of the bodies, that the air proceeded from putrefaction. I will not assert it did not; indeed I must confess there proceeded from one of the subjects, a fetor; but the viscera did not exhibit signs of putrefaction, and I am confident I have dissected, and seen dissected and examined, subjects much farther advanced in putres- cence than these were, yet have not before seen or heard of this appearance. But if the oxygen does not enter the vessels, what I would ask, becomes of that portion of it, which Lavoi- sier has found, is lost to the air, more than is necessary, to the formation of the carbonic acid, which is produced. It does not certainly unite to hydrogen, as he supposes, | Morgagni on Diseases, Vol.1, Letter s. 23 • to form the aqueous vapour. If we do not admit that it enters the blood, we cannot account for its disappearance; and as we find facts, which so strongly countenance the opinion that it does, so we cannot hesitate to believe it true, or confess it plausible. It more readily meets our assent, we are impelled on to conviction, when we know that air, in a certain quantity, can be injected into the vessels, without injury to the animal. Dr. Hartshorne, mentions in his inaugural thesis, that he injected 1-8 of a cubic inch of oxygen gas, into the femoral artery of a dog, which suffered from it, no inconvenience. I repeated this ex- periment, on the jugular vein of a dog, to the amount of the 1-4 of a cubic inch of oxygen, with a similar result. Girtanner met, indeed, with very different effects in his experiments; almost instant death being induced; but he employed a " considerable quantity," so that the heart must have been acted on by a powerful and unaccusto- med stimulus ; for the distance, from the place at which the air was injected, and the heart, being but small, and the quantity considerable, the air must have been emptied into the right auricle and ventricle, unmixed with the blood. Now it is not my intention to contend, that air, in any quantity, not in union with the blood, can circu- late without injury to the animal; but that it is received into the blood, in the capillary vessels of the lungs, and circulates with it, either held in solution, or minutely divided. 24 An opinion has lately been advanced by Mr. Thomp- son, that all the component parts of the air are absorbed into the blood, and that the greater part of the azote, is again rejected from it, while the oygen is retained. It appears, that he was led to this supposition, to account for the disappearance of a portion of the azote, which is lost in respiration, ascertained by Priestley and Davy. This occurrence, is however satisfactorily explained by Bostock, without admitting this solution; and as it is sup- ported by no other circumstance, I place no confidence in its truth. It is, on the contrary, invalidated by the facts ; 1st, That between blood and azote, as Mr. Thompson informs us expressly himself, there is no affinity. 2nd, That a strong affinity exists, between blood and oxygen. I have ascertained, that blood exposed to oxy- muriatic acid gas, becomes oxygenated as rapidly as in atmospheric air, and reduces it to the state of common muriatic acid gas. 3d, That it has never been observed, in the numerous • experiments which have been made, by exposing blood, drawn from the system, to atmospheric air, that any of the azotic portion disappeared. This opinion, cannot be admitted, then, unsustained by any decisive facts. I believe, on the other hand, that the oxygen is solely absorbed, but owing to the affinity, existing between oxygen and azote, there is carried along with it, into the blood, a small portion of this last air. 25 From the facts which have been enumerated, and the arguments which have been inferred from them, it is concluded 1st, That the oxygen gas of the air disappears, by entering into the blood, in the pulmonary vessels. 2nd, That the carbonic acid gas is generated in the lungs, by the oxygen, combining with, what Allen* calls, an oxide of carbon, formed during the circulation, from the oxygen forsaking the blood, to unite intimately, with the carbon it contains: and 3rd, That the water of expiration, arises from the exhalation of the pulmonary secretion. This theory of Respiration, nearly that of La Grange, as modified and improved by Allen,f appears to me to possess more plausibility, and a greater support from facts, than any other of the many which have been con- structed. It then follows, that the change induced in the air by respiration, is produced; 1st, By the oxygen uniting to, or entering into the blood. 2nd, By its acquiring carbonic acid gas, from a por- tion of the oxygen, combining with an oxide of carbon, in the pulmonary vessels, from which it is eliminated. * I am not certain I am correct, in mentioning this as Mr. Allen's opinion. The work he has published on this subject, cannot be obtained here; but I am led to believe, this is the modificatioiv of La Grange's theory by Mr. Allen, of which Bostock speaks, page 115. t See note, page 29. D 26 3d, By its losing a small portion of azote, which is absorbed into the blood, in consequence of the affinity? between it and the oxygen. The cause of the alteration of colour, which the blood experiences in the lungs, comes now to be consi- dered. By Crawford, Lavoisier, and the generality of phy- siologists, it is attributed to the escape of hydrogen and carbon, from the blood. As no proof of the existence of hydrogen in the blood can be advanced, it becomes needless to consider how far its absence, may have this effect. It only remains to demonstrate that it cannot be ex- plained on the supposition of the ejection of the carbon from this fluid. If the deprivation of carbon to the blood, have the ef- fect of changing its colour to the vermilion hue, it must follow, that it would not lose this tint, when once ac- quired until it should be again impregnated with carbon. How does this accord with fact? Arterial blood exposed- to the air, whence it could derive no carbon, will, after sometime, lose its vermilion colour, which proceeds from the oxygen more closely combining with the car- bon, which the blood still contains. If blood, which has this colour be exposed to an air, which does not contain oxygen, or be placed in vacuo, in neither of which si- tuations, it can possibly receive carbon, it takes on, how- ever, the dark colour of venous blood; and if again ex- 27 posed to oxygen, or atmospheric airs, it again assumes the vermil hue. It might be objected to these well-known facts, that the blood is not in a natural state, and of course, they cannot be depended on to draw any conclusions of what occurs, in the living body. To obviate this objection, of little force, we have only to refer to the experiment of Hunter, which proves that arterial blood, confined in the arteries, becomes as black as venous blood. It is also a fact, familiar to every surgeon, that the blood, which first flows from an artery in an operation, after the circulation has been prevented in it by the tourniquet, for a short time, is perfectly black. It will be in vain to assert, that here the blood might have received carbon. No well-informed physiologist, at this day, will support the opinion of Crawford, which his warmest admirers have deserted, that the blood receives its carbon, in the capillary vessels. The only medium, by which it can en- ter the vessels, is the absorbents, and of course, it is ut- terly impossible any could have been carried to the caro- tids, on which Hunter experimented, or to any artery, secured with a tourniquet. This fact alone, that the blood receives its carbon by means of the absorbents only, which is perfectly un- deniable, and which Lavoisier himself was obliged to confess true, completely refutes his doctrine. Bostock decisively proves, from it, that Crawford and Lavoisier 28 are in error.* For as the blood, according to these phi- losophers, becomes black only in consequence of ac- quiring carbon, (for hydrogen is put out of the question) and as it gains the bright red colour, in the lungs, charac- teristick of arterial blood, by the loss of this principle, then, it should follow, that the blood having passed the lungs, would retain this colour, until it arrived at the junction of the right and left subclavian veins, with their respective jugulars; for it is at this place alone, that the absorbents of the system pour their contents into the blood vessels. Now, as the blood cannot obtain carbon, until it comes to this situation, it should not before then, acquire the black colour. This is known, however, to the world, not to be fact. The alteration of the co- lour of the blood, during the circulation, is not, then, de- pendant on the presence or absence of carbon. When under certain circumstances, we behold a certain effect produced invariably and universally, the human mind almost involuntarily and most justly, attributes those circumstances as the cause. It is not, then, without surprize, we find that so much difficulty and dispute, have existed for so long a period,on this subject. For as blood becomes always of a florid red colour, when oxygen is present; as it always loses this colour, when deprived of contact with this air; as this colour when lost is restored again by exposing the * Essay on Respiration, p. 111-12. 29 blood to this gas; as the gas is always found diminished in quantity, or entirely consumed, according to the great- er or less space of time they have been in contact; and as the degree of the colour of the blood always corresponds with the quantity of oxygen present, or consumed; it would appear to be unquestionably proved, that the ab- sorption of oxygen, was the cause of the blood's florid co- lour. The preceding portion of this section, established the fact that oxygen was absorbed into the blood, and as it is now shown, that the change of the blood's colour in the lungs, is not the consequence of the escape of carbon from it; and also, that this effect occurs whenever oxygen is present, the conclusion is, the combination of oxygen with the blood, is the cause of its vermilion hue. The gradual change of this colour, to the purple or black of venous blood, is the event of the oxygen com- bining gradually, with the carbon of the blood, and forming an oxyde of carbon; and thus, by the loss of ox- ygen to the blood,* and perhaps the peculiar state of the carbon, produced by its combination with the oxygen, is the dark colour to be attributed.! * Bostock, p. 115-6. t This theory, which Bostock mentions, as that of La Grange, modified by Allen, appears to me to be sup- ported by strong and conclusive proofs. The facility with which it explains the hitherto anomalous facts of animal heat, inexplicable by any other, must tend greatly to its establishment and recep- tion. ' 30 As the change of colour in the blood, to the bright vermilion, is produced by an absorption of oxygen; and it being a well-established and incontestible fact, that death is the speedy and unavoidable consequence of the defect of this change, it remains to inquire into the manner in which oxygen supports life. I have now approached a part of my subject, which, like a rugged, desolate, untrodden tract, appearing af- ter a passage through a land meliorated by the hand of industry, almost deters from traversing its bounds. I paused on its borders, as the wandering youth, when first he meditates to forsake the beaten way; tempted by lux- uriant fruit----- " And unknown regions dares descry," like him, I may return, gladdened with the object of my pursuit, or roam lost in mazy windings. A strong conviction, that thebranch of medical sci- ence I am treating, can alone be improved by an eluci- dation of this part of physiology, impels me to this un- dertaking. Too long have those, who are best calculated to penetrate its deepened gloom, and overcome the ob- stacles of its ways, avoided the arduous task. They have proceeded on, and neglected, or viewed it with" a cursory glance, leaving its wide extent to be explored by feebler steps. Yet ere Elysium can be gained, must 31 Acheron be passed. A few, however, have entered and have sought the riches of the soil. Where some be- fore have trodden, I may, then, be permitted to wan- der, nor suffer reprehension. Perhaps some sparkling gem, whose " mild and modest ray," lay concealed from their view, may meet my more fortunate eye. Drawn from its obscurity, and polished by a master's hand, the long neglected and once worthless stone, becomes the valued jewel. r, As the oxygen combines gradually with the carbon of the blood, its caloric is eliminated, and it is thus, the cause of the phenomenon of animal heat. But does it not perform some other office to the system, more immediately conducive to life ? I believe it does. I found this belief, 1st, On th^ absolute necessity, of the continual oxy- genation of the blood, in every class of animals which is known. 2nd, On the sudden suspension of the actions, and phenomena of life, in animals, cut oft'from communica- tion with this gas. For if it produce no other effect, but merely the pro- duction of animal heat, those animals and insects, Avhose animal heat is not greater than that of the surrounding medium, ought not to be readily, if at all, destroyed, when deprived of oxygen. For as the heat of their bodies, is not superior to that of the circumambient air, and sometimes not so great, it could not be lost, and cf 32 course, the animal would continue to live : and if oxy- gen only supported, and was only connected with life, by producing animal heat, this principle, quality, or whatever it be, should not be so suddenly destroyed, as we find it is, especially in warm blooded animals, when they cannot obtain oxygen; for death is mostly induced, before the animal heat is diminished. If this were also, the only connexion between them, we would find a man, or any other animal, deprived of oxygen, in a tempera- ture warmer than their animal heat, would require a great- er length of time, in which to be destroyed, than when placed in a cold medium, under similar circumstances. Yet we find no difference produced in the period, in which life ceases, in these two conditions. 3rd, From the same necessity existing in the foetus, as in the adult, of the uninterrupted oxygenation of its blood—Situated as the foetus is, it is securely guarded against any change of its temperature being effected, by external causes. In truth, it scarcely seems necessary, it should in its own system evolve any caloric, and of course, if oxygen be only intended to produce this effect, it is here perfectly superfluous. And Surely, as the animal heat of the foetus Cannot be lost, even when it no longer receives oxygen, it would continue to live, if oxygen were not necessary to its existence in some other manner. But can the foetus exist better than the child which breathes, independent of oxygen ? No, not more cer- 33 tain does night succeed day, than death follows the ces- sation of this effect on the blood. The sad experience of every accoucheur tells, how fatal are the consequences to the child, of compression on the umbilical cord, which prevents the foetus from receiving oxygenated blood. Neither is the opinion of Goodwyn, that it is thus needful to life, by stimulating the left side of the heart, more correct. The arguments of Coleman, and the experiments of Bishart, have con- signed this theory to the number of those, which are to be held in remembrance as having been, but are no more. In what manner, then, is the oxygenation of the blood connected with life? This is the club of Hercules. While physicians believed, and were the advocates for the doctrine of a self-existing power, an " anima medica," presiding over the system, we are not astonish- ed, that the slightest shadow of suspicion never crossed their minds, that life was supported, much less pro- duced, by any external cause. But since this opi- nion has been held from the pale of physiology, and ex- cluded from communion with medicine; and as the the- ory of the forced state of life, founded on fact, supported by reason, and countenanced by analogy, has extended its empire over the fairer portion of the medical world, we cannot but admire, a circumstance so obvious as this must be, has been neglected, nor met with that attention, which its importance, surely commands. For if excitabi- lity, that quality on which stimuli act, and produce E the actions of life, is ever varying, and seldom rests at one point, according to the difference, in the number or strength of the stimuli acting upon it, there must be some source within the system, from which it may be generated when deficient. It cannot be, the system is en- dowed with a certain quantity, at the commencement of existence, and that this is to continue during life: if so, a portion once exhausted, is irretrievably lost, and exis- tence has suddenly hastened to its termination. But we well know, each hour witnesses in it, some accumulation or diminution. It is far from being my intention to assert confident- ly, that oxygen is the principle, from which is produced the excitability; I presume not thus; I forget not that I am one, whose step is yet scarce o'er the threshold of the temple of medicine, on whose head, experience but now begins to shed its illuminating rays; and whose ac- quaintance with the phenomena of life, as exhibited in health and disease, is contained within a circumscribed bourne. This opinion, however, advanced by Girtan- ner, has been silently acquiesced in by some, while it has been openly denied but by a few. The theory which he has connected with it, the doctrine of Brown, travesty with a chemical garb, has deterred many from bestowing on it that attention, to which, perhaps, it is entitled. Yet it becomes philosophers, more especially medical philosophers, not to reject hastily, even a con- jecture, somewhat patronized by facts. Medicine con- 35 tains within its records many truths, which were once but suppositions, and which are now confirmed facts. And if we but for a moment reflect on the continually fluctua- ting state of excitability, itmust be evident, it is originated in the system; and if so, there must be some source, from which it can be discovered to proceed. Is the brain, as some suppose, this fountain of life ? If the ex- citability be secreted in that organ, there must still be some principle, from which it is formed. This, how- ever, can be conveyed to the brain, by the blood alone. But it is blood in a peculiar state only, which can circu- late to the brain, without causing the destruction of its function, and the extinction of life, and which of course, can alone produce the excitability; and this blood is ar- terial. As blood, then, which contains oxygen is alone proper to generate this principle, and as no other kind of blood will answer for this purpose, it still does not, if this theory be true, invalidate the opinion of Girtanner, which therefore, begins to appear less improbable, than it did at first glance. But the brain is not the organ, which produces or se- cretes excitability. The fact is well known, that when the communication between this viscus, with parts not vital, is cut off, those parts still retain their excitability, and irritability, for although their sensation and voluntary motions are destroyed, yet they are alive to the action of stimuli. 36 If the opinion, of the production of excitability from oxygen, should for a moment be admitted, could a con- jecture, anyways satisfactory, of the place and manner of the production of this quality from oxygen, be given? It evidently receives its existence in the system. Why not, then, trace the streamlet to its source ? The blood passes into the capillary vessels, possessed of oxygen; in these vessels, it is continually changing, being converted into the animal fibre, and returns from them devoid of this principle. Now, what becomes of the oxygen, when the blood is thus deprived of it? It does not return with the superfluous blood, nor does it escape in the form of gas, or we should always be emphy- sematous. Does it not unite to the animal fibre ? Would not its combination with the animal fibre, in a manner yet unknown, but which " dies doceat" possess it with the property or quality, of being susceptible to the ac- tion of stimuli. That this is positively the mode of the origination of excitability, I certainly do not mean to as- sert; but that it arises in the capillaries, and from oxyge- nated blood, can admit of no question, is demonstrably proved by experiment. And we are now familiarized to the singular and won- derful properties, which oxygen gives to different sub- stances, by combining with them. Even a difference in the proportion of the oxygen, united to the same base, endows it with properties wholly unallied and totally dis- tinct. S7 Could we but devest our minds of those habits of think- ing, which were imposed on them in our youthful days, when feeble and just evolving from their germe, they bent before each breath, received each insect touch, and no longer behold life, as a mysterious and ethereal ens, which it is « scire nefas," but view it as exhibited by the wild and daring genius of Brown, the more correct and discerning Rush, as it truly exists—the creature of necessity, the offspring of the world, we shall not start, amazed'at the avowal of a belief, excitability depends on, flows from the combination of oxygen, and the animal fibre. But too frequently does error retain its strong hold of our minds, and like the shirt of Nessus, even Hercules cannot shake it off. Yet no opinion, however plausible it may appear, however much it may tend to supply some deficiencies, in a theory otherwise complete and correct, and, there- fore courting our acceptance, ought to be admitted, or for a moment entertained in the mind, unless supported, in some degree, by facts. Are there any facts, expe- riments, or circumstances, which stamp the opinion with credibility, that oxygen is the source of excitabili- ty. I think it rendered probable, 1st, From the consequences, resulting from, black or unoxygenated blood, circulating in the arteries. When, by any means, respiration is obstructed, so, that the blood no longer receives oxygen, it passes into the arteries of a dark colour, or in the state of venous blood. 38 In warm blooded animals, if this continue for four or five minutes, the actions of life diminish, and are soon entirely destroyed. If the most powerful stimulants, which before this diminution of life has been induced, would have excited the most violent commotions in the system, be now employed, they produce very little and frequently no effect. Coleman mentions, that having injected one drachm of tart. emet. into the stomach of a dog, which he had immersed in water until nearly drowned; it produ- ced no effect for sometime, and then caused vomiting, while the same quantity in another dog, not treated in the same manner, caused, in a few minutes, violent vomiting, inflammation and gangrene of this viscus. Whence could this difference in the effect of the same medicine proceed? It was from the excitability being nearly destroyed in the one, while in the other it remained in a natural state. But to what shall we attribute the loss of the excitability of the first dog? We know it is worn down by the pow- erful, or the long continued action of stimuli; but in this case, there were no powerful or long continued stimuli applied, by which it could be reduced. Nor can I coin- cide in the belief of some, that the exertions made in drowning, could exhaust this quality. The actions of drowning animals are by no means violent, and surely, we each day, make exertions much more powerful, at the same time that other strong stimuli are exciting us, with- out expending the whole of the excitability, though it is diminished. When we examine the system, for an ex- S 39 planation of this fact, the only cause to which it can be attributed, is the blood having circulated through the capillaries, destitute of oxygen ; and of course whatever effect the oxygen there produced must have ceased. But the excitability and irritability, have been suddenly les- sened, or have entirely disappeared. Does this proceed from the want of oxygen in the blood ? No other cause of solution presents itself to our view. In what manner can these qualities of the fibre be generated from oxygen? To throw some gleams of light upon this darkened spot, which may prove that the want of irritability depends on the absence of oxygen, an experiment of Bichat occurs. He injected blood, fresh taken from the veins, into the crural artery of an animal. The motions of the limb be- came very weak, and it was often rendered paralytick.* This probably would have been more frequently the re- sult, but in such an experiment, it is almost impossible to prevent, more or less oxygenated blood passing into the limb, through the anastomosing branches. When this experiment was performed on one of the carotids, instant death was produced. The same effect was caused undoubtedly, by the blood in both cases; but as an indispensable necessity exists; that for the continu- ance of life, the functions of the brain should be perfectly performed, and its vitality remain uninjured, it was, in this experiment, mortal. In what manner did venous * Recherches Physiologiques, p. 327. 40 blood prove thus deadly, and why should it not be as congenial to life, as arterial? We cannot suppose life to be different in the brain* from what it is in other parts. It must be specifically the same, throughout the system, and consist in the pos- session of excitability. In this experiment, the excita- bility disappeared, when venous blood was present in the arteries. This could have occurred but in one of two ways. It must either have been, that the venous blood, by the force of its stimulant action, destroyed the excitabi- lity, or, if this quality proceeds from the blood, it must have been destitute of that principle, on which, excitabi- lity may possibly depend. But it is the universal opinion, founded on observa- tion, that venous blood is not as great a stimulus as ar- terial, of course it could not have ended life in the first mode. May we not conclude, then, that death was pro- duced in the second mode, or that venous blood, was im- proper to form the excitability of the brain, being devoid of that principle from which it is generated. We know of no other principle in the blood, which adapts it for this purpose but oxygen. 2d, From the results, arising from injecting oxygen and other gasses into the blood vessels. The experi- ment of introducing oxygen into the vessels, has been frequently performed, but we have to lament the want of system, with which it has been pursued. A large or a small quantity of oxygen have been employed; the 41 one always effected the destruction of the animal, the other was of no disservice. It would more tend to raise the curtain for discovery, were it to be ascertained, what quantity could be employed without killing the animal, and by careful observation, note the consequences of it in the system. When death has been induced, by a large quantity be- ing forced into the vessels, all agree that the irritability of the heart and of the muscles, is much increased; and that it continues in them a greater length of time, than when death has been suddenly occasioned, by any other cause. If any other air be injected, death is as suddenly, and sometimes more so, produced ; yet the irritability is found to be nearly destroyed, or does not exist. The constant occurrence of these effects, in the experiments, cannot permit them to be doubted. How are they to be explained? Do they not point to a con- nexion, existing between irritability and oxygen? Or why should the irritability be increased by this sub- stance alone, while it is diminished by every other ? 3d, From the fluctuating state of the excitability, most clearly proving it to be generated in the system; and in connexion with this, the variation in the quantity of ox- ygen consumed. That the quantity of oxygen which disappears in respiration is not uniform, is proved by the difference which exists, between the calculations and ex- periments of different physiologists, made to ascertain the amount, which is destroyed by one person. Their F 4.2 contradictions, can only be reconciled upon the principle* that different quantities, are consumed at different peri* ods. It has much tended to retard our progress, in the knowledge of this branch of physiology, that the Eu- ropean chemists, who, from their opportunity of being supplied with every necessary apparatus, are best calcu- lated to pursue this subject, have in their experiments ne- glected to determine, whether disease produced any alte- ration in the quantity of air, used by the system ; whe- ther there were any difference, in different times of the day; and whether the quantity, which disappeared, cor- responded in any degree, with the stimulability of the subject of the experiment. From this inattention, we are obliged to remain in doubt. But we are not entire- ly destitute of some guides, which may direct, though obscurely, our way. For, 1st, during the night, the exci- tability becomes equalized, and is accumulated for this purpose, and also to answer the wants of the coming day. This is the object of sleep, ----repairer of decay, Whose balms renew the limbs to labours of the day. Dryden, In this state of being, more oxygen is consumed, than in an equal space of time when awake.* We are inclined to believe this assertion correct, from observing those who sleep, make full, deep, and long inspirations, com- pletely distending the lungs, by which means, more air * Rush, M. L. 4 3 is brought into contact with the pulmonary vessels. 2d, In the first attacks of violent inflammatory fevers, when the system possesses a superabundance of excita* bility, and more of it is also exhausted, than in a healthy state ; we observe the respiration more full, hurried, and laborious, than usual; and, of course, more oxygen must be absorbed by the blood. 3, In diseases in which the excitability is deficient, and stimuli can with difficulty produce action, the respiration is slow and weak, or performed, with quick and small inspirations and expira- tions. The blood, then, must receive less oxygen, than when in health, from the respiration being different. But the excitability exists in small quantity. Does this arise from the less oxygenation of the blood ? It might be supposed, if this were true, that a contrary effect, ought to be produced. For if the excitability proceed from oxygen in the blood, the deficiency of this quality, should occasion the respiration to be increased, that the con- sumption of oxygen, may be augmented, to answer the exigencies of the system. This reasoning appears cer- tainly specious, and seems to prove, that no connexion, exists between oxygen and excitability. But view it in another light, and it presents a different aspect. When the excitability is exhausted, by any means, the actions of the animal economy are weakened, and the functions of each particular part, are performed in a defective man- ner. The heart propels a less quantity of blood, and with less momentum to the lungs; the muscles of respi- 44 ration are debilitated, and can no longer produce the same enlargement of the thorax, as in a natural state; from these causes, less blood is sent to the lungs to re- ceive the genial influence of the air; and less air is re- spired, than when health diffuses equability of life and strength over the frame. In these states, the respiration or consumption of oxygen, bears a ratio to the excitabi- lity. 4, That when a part, becomes inflamed, in which case, more oxygenated blood circulates through it, than usual, we observe its vital phenomena, which depend on an in- crease of its excitability, to be exalted. Is notthis the con- sequence of the increased quantity of oxygen it receives? 5, That in weak, debilitated habits, in which life seems to be put partially unfolded, syncope is frequently brought on in crowded rooms, where the air is vitiated by the breaths of many persons, and the burning of candles. Our places of worship, and assembly rooms, bear witness to the truth of this remark. This state of the system, is occasioned by a deficiency of excitability. Does not its diminution in these cases, proceed from the Want of oxgen in the air ? 6, From the state of the. excitability in hibernating animals, during the winter; and the quantity of oxygen, consumed by them, bearing an equal proportion. At this period, the excitability is extremely low, the most pow- erful stimuli, but weakly affecting it, and then, being but small in quantity, it is soon exhausted, and the animal 45 falls a victim, to the curiosity of the experimenter. In these animals, while in this state, the consumption of oxy- gen is extremely small. But soon as the returning spring, revives and animates all drooping nature, they are roused in their hibernal caves by its inciting influence; their respiration becomes stronger; with this, their ex- citability increases, and now they forsake their habita- tions, and wanton in the full possession and vigour of life. Do not these circumstances tend to impress us with a belief, that the two, are connected by an indisso- luble link? 7, From the affections brought on the system by a rarified atmosphere. When the medium, is in this con- dition, the quantity of oxygen, received into the lungs at each inspiration, is much smaller, than when it is dense. In great altitudes, the atmosphere, is in a high degree of rarifaction. The accounts, which bold and enterprising philosophers, relate of their sensations; of the state of their systems; the effects which they suffered; and the symptoms, they exhibited, when on the summits of the most elevated mountains, to which they had ascended, induce the persuasion, that these consequences of a rari- fied atmosphere, were occasioned by a want of excita- bility. These are best described in the words of De Saus- sure. " When we came near the top," (of Mont Blanc) " I could not walk 15 or 16 paces without stopping to take breath ;and frequently perceived myself so faint, that I was under the necessity of sitting down from time to 46 time; and in proportion as I recovered my breath, I felt my strength renewed." A gain he proceeds, "I was obliged almost at every instant, to desist from my labour and turn all my thoughts to the means of respiration." And after- wards, " While I remained perfectly still, I experienced but little uneasiness more than a slight oppression about my heart; but on the smallest bodily exertion, or when I fixed my attention on any object for some moments, and particularly when I pressed my chest in the act of stoop- ing, I was obliged to rest and pant for a few moments." His assistants, in digging into the snow were obliged to relieve one another incessantly, raising a few shovel-fulls completely fatiguing them. They were all affected with great thirst. Spirits and wine, but aggravated their symp- toms. These were, indubitably, signs of a rapid exhaus- tion of the excitability, from the action of moderate stimu- li. But why should this quality be sooner lost in a rare, than in a dense atmosphere ? The mere weight or levity of the air, I am inclined to believe, would have but little influence in producing this effect. And when we reflect, that oxygen is indispensably ne- cessary to life, and as it is on the summits of lofty moun- tains, and in a rarified atmosphere, received in less quantity into the blood, than when the air is dense, we cannot avoid attributing these -symptoms, the conse- quences of a defective excitability, to the diminished quantity of oxygen in the blood. 47 8, From the melancholy phenomena, which are exhi- bited in those persons, who labour under a mal-confor- mation of the heart. The cause of the symptoms, which afflicts these unhappy and irremediable sufferers, is beyond doubt, the want of duly oxygenated blood. Nor do the terrible, awful paroxysms, attacking these wretched victims of Nature's sport, occur, but when some cause stimulates the system, and hurries on the circulation, so rapidly, that the blood cannot receive the same quantum of oxygen, as before, and which merely sufficed to sup- port a flame just quivering to its end. It is then, that con- vulsive actions distort the whole frame, the pulse is weak and tremulous, and the body is of a blue colour; the thorax is greatly agitated, and dilated to produce its greatest enlargement, that the utmost quantity of air, it is capable of containing, may be inhaled. It is not until by such respiration, agonizing to the patient, and dread- ful to the beholders, the blood becoming more oxygena- ted, that the paroxysm declines, and the sufferer, to whom death woul^ have been a blessing, awakes to life; and to be subject to a similar torture, whenever the cir- culation shall again become accelerated. That the resto- ration in this case, is produced by the greater oxygena- tion of the blood, is proved by the colour of the body, which, during the paroxysm, was blue or black, gradu- ally becoming of a more florid hue than usual. 9, By the circumstances of the foetal circulation. If the foetus, in utero, possessed the same quantum of ex- 48 citability as the child which is born, it would scarcely ever behold the light; it would only be removed from its maternal tomb, to be consigned to the dust. For as the stimuli, which can exhaust the excitability of the foetus, are few in number, it would so accumulate, that the smallest adventitious stimuli, or even the action of those, which are natural to it, would excite the most vi- olent commotions in the system, or prostrate it at once into the arms of death. The taper would be extin- guished by a superabundance of its oil. Now, if there be any dependence of excitability on oxygen, it should fol- low, the foetal blood would receive less oxygen, than that of the adult, or a breathing child. It would be an in- sult to my medical readers, were I to inform them this is the fact. Does not this source afford another corroborative fact? When the foetus is born, is given to the world, that moment it is acted on by powerful, and unaccus- tomed stimuli. If then, there be no original within the system, from which excitability is produced, no foun- tain, from which this principle of life flows to supply the deficiency that occurs, and to accommodate it to the force of the stimuli, by which it is suddenly expending, it would quickly be exhausted; and the infant would sink under their agency, and perish. But if the child which is born, breathe, it continues to live, and of course, its excitability, instead of being expended, has been aug- mented. We look around in vain, for any other cause 49 to which we may attribute the instantaneous increase of this quality, when a child is born and respires, than to that of a greater accession to the body of oxygenated blood. As soon as the foetus arrives in the air, it must breathe, or it ceases to exist; even though the circula- tion which continues through the umbilical cord, still affords it a portion of oxygenated blood. How is this to be explained? We see, that if the child does not breathe as soon as it is born, its excitability is quickly expended, and of consequence it dies; but if it breathe, its excitability accumulates, and continues so to do, un- til it equilibriates with the acting stimuli, and life conti- nues, and goes on to be evolved. In what manner does respiration thus produce excitability? Is it by impart- ing to the blood any principle from which the excitability may deduce its origin ? There is no substance received into the blood by breathing, but oxygen. Is not oxy. gen then the matter, from which excitability is created? And on what other principle can we explain the death of the child which expires, as soon as born, if, from some cause or other, it does not respire? If the doctrine I am supporting be true, it affords an easy solution of this difficulty. For as the child becomes acted on immedi- ately by stimuli, of no small force, if its waste of exci- tability be not supplied, it will speedily be expended, and death supervene. As but a small quantity of oxygen, is received (the child not breathing) through the cord, and which was sufficient only in the foetal state, to accommo- G date this quality to the few and weak stimuli which could diminish it, the small portion the foetus thus obtains by the funis could by no means produce excitability suffici- ent to answer the great demand now made upon it, and of course, the infant dies from the total expenditure of its excitability. 10, From the account whieh the Sacred Volumes of Truth, give of man's formation, and his first spring of life. Man, by the hand of the Deity, was made perfect and complete in all his parts and organs; the machine was fitted to act; but until the breath of life was breath- ed into his nostrils, the motions of life were absent. We here behold life beginning its career in the lungs. Was this by the air stimulating them, or entering into and acting on the blood. It could not have been by a mere stimulant action, for a thousand stimuli were operating upon its frame at the time, yet without the aid of breath- ing, could produce no action. But what effect, then, did the air produce on the blood ? Did it endow this fluid with vitality ? Did it render the blood capable of communicating a principle of existence to the system? or in other words, Did it produce the excitability? for no other vital principle can be admitted. It is evident, no excitability was in the system, until air was received into the lungs. We cannot for a moment suppose, that the air was a specifick stimulus, alone calculated to ex- cite the excitability, and to produce action. If this sup- position be rejected, as it must be with contempt, we 51 have no other resource but to believe, that air was the efficient cause of excitability. For as all nature was created, before man rose to being, the stimuli which now propel his wheels of life, then existed, they would have acted on his system, and developed its latent anima- tion, if it had possessed the quality, which gives to it, a capacity for their action. But it was destitute of this quality, until air entered the lungs. Does not this also lead us to infer, the dependence of excitability on oxy- gen? 11, From the irritability of the heart, after the cessa- tion of all the apparent phenomena of life, being suppor- ted, and even increased, by the presence of oxygen. In a late French work, by Berger, on the proximate cause of the disease produced by drowning, a number of ex- periments are related, in which the heart of drowned ani- mals contracted often, when the thorax was opened, for many hours, and never less than two or three. But in a few others, which he details, when the thorax was not immediately opened, but attempts were made to recover them for the space of an hour, and then the sternum was raised, no contraction of the heart was perceptible. A considerable contradiction certainly dbtains, between the results of these experiments, which I was unable to reconcile, unless the contact of the air, was admitted to have had an influence, in supporting the irritability of the heart. To ascertain how far this idea was correct, and whether oxygen was the agent concerned, I instituted the following series of experiments: 52 Experiment 1st. I submerged a kitten 20 minutes after 11 o'clock A. M., and when the signs of life had ceased, I withdrew it from the water, and immediately laid open its thorax, by raising the sternum, and cutting it off. The heart contracted 36 times in a minute. In 15' the contractions of the right auricle and ventricle, were to the number of forty in a minute; the left auricle and ventricle acted more feebly than the right. In 20', the left auricle intermitted for a time, its motion; it being covered by the left lung, which I raised up and permitted the auri- cle to be exposed to the air; when in the course of 4 or 5', it commenced again spontaneously to move. During the experiment, I repeated, several times, covering and ex- posing the auricle, and always found, that when cut off from contact with the air, its contractions ended, and when exposed to it, they again commenced. In 35' the right auricle, the blood of which was evidently of a redder hue than before, appeared to have lost the power of mo- ving ; but in 45 minutes it recommenced, without irrita- tion, to contract, and more forcibly than before, but a few moments terminated its action, and it was not obser- ved again to mov,e. In one hour, the two ventricles were contracting. In 1** 30', the number was 19 in a minute. In two hours, the contractions were nearly the same in number, but weaker. I was now obliged to leave the experiment, and when I returned 25' after 3 P. M., or four hours after the thorax was first opened, the right ventricle was still contracting. It was distinctly percei- ved by the gentleman who assisted me in the experiment. 53 Being engaged in the next succeeding experiment, par- ticular attention was not paid to its contractions, and when we inspected the heart, 15' afterwards, no motion could be observed. Having thus ascertained a certain period of time, during which the heart of an animal drowned contracts, when exposed to the air, by which the results of the succeed- ing experiments, might be compared; I proceeded to perform Experiment 2nd. A kitten was prepared as the first had been, the heart of which contracted 20 times in a mi- nute. It was conveyed directly into a bottle containing nitrous gas, over water, and in 4' the contractions were 18 and weakened. The blood, which was effused, be- came of a bright vermilion, which created a suspicion in the minds of the gentlemen present, and in my own, that the blood having a great affinity for oxygen, might even take it from the nitrogene, decomposing the nitrous air. If this had been so, the conclusion to be drawn from the experiment, would have been destroyed. The animal was not retained in the gas more than 15'. But in less than an hour after the thorax had been laid open, the heart had entirely ceased acting, nor could it be excited by the application of sulphuric acid. Experiment 3rd. A kitten being treated as those in the preceding experiments, the heart was ascertained to contract 33 times in a minute. It was then placed in a vessel of hydrogen gas. In 5' the contractions were re- 54 duced to 23, in 8' to 15, and were very feeble, in 20' to 9, and in 45' all action had ceased. The auricles ceased the first, the two ventricles ended their action at the same time. It was then taken from the gas, and the heart irrita- ted, but without any motion being excited. Experiment 4. A large cat was drowned. In its strug- gles it twice got its head above the water, and respired. When all appearances of life had disappeared, it was taken out, and the thorax was opened. I observed the muscles possessed more irritability in this animal, than in the kittens; for they contracted powerfully under the knife. When the heart was exposed, the right auricle alone contracted. The fibres of the diaphragm were very irritable and contracted spontaneously. In 10' after opening the thorax, the right ventricle began to contract. The auricle acted very irregularly, now contracting with frequency, and now very slowly. In 20', the right ven- tricle contracted 4 times in a minute, the auricle propelled a wave of blood through its extent 4 or 5 times, and then ceased to move. The right ventricle was acting at the end of an hour. Its actions had been throughout always slow, but sometimes forcible. The left side had not been observed to move once, during the experiment. I had intended to have placed this cat in azote, but as the action of the heart was so very different in this, from what it had been in the other experiments, I thought no correct conclusion could have been inferred from it, and therefore did not pursue my intention. I left the experi- 55 ment at the termination of an hour, and when I returned, which was 4 hours from the time that the chest had been first opened, I touched the right auricle, which to the surprize of those present and myself, now contracted with more force, than any which I have yet seen, except the last experiment, appearing to close completely on itself, and continued to be thus capable of excitement for an hour. Experiment 5. A kitten was drowned, and its thorax was then opened. The heart beat 13 strokes in a minute. I conveyed it into azotic gas. In 5' the right side beat 9 in a minute, the left ventricle the same number, the left auricle was not seen, being hid by the lungs. In 20' the contractions were 6. In an hour they were extremely feeble, appearing to be the motion of one or two fibres. In 1° 10' being taken out of the gas no motion was per- ceptible, nor could any be produced by irritation. Experiment 6th. A kitten was drowned, and opened as in the other experiments. The whole heart was in mo- tion, and contracted 43 times in a minute. The animal was placed in carbonic acid gas. As I had neglected in the foregoing experiments, to increase the temperature of the water, through which I was obliged to pass the animal, with its thorax opened, to place it in the gas, to that of the animal heat, I thought it might perhaps have been a source of error, by the water abstracting heat from the heart; I therefore, obviated, in this and the following experiments, this objection, by raising the heat of the water to the ani- 56 mal temperature. Six minutes after the animal had been in the gas, the contractions were reduced to 27, and were very feeble; in 15'to 14, and still weaker; in 28' both ven- tricles were quiescent, the auricles contracted feebly. In 35', no action was visiblr, nor could any be excited by irritation. To compare with this experiment I instituted Experiment 7th. A kitten from the same litter, from which was obtained the subject of the preceding experi- ment was drowned with it, and permitted to lay in the water until the heart of the first had ceased to act in the gas. The sternum was raised 35' after the kitten was drowned; but no motion could be perceived in the heart. After being exposed 5', the right ventricle began to contract very weakly, the corresponding auricle fol- lowed, and the ventricle and auricle of the left side, next in succession. The contractions increased in force, especially those of the right auricle, which nearly oblite- rated its cavity each time. The left auricle ceased the first, the ventricle of the same side became quiescent, in two hours after the opening of the thorax. At three hours, the auricle and ventricle of the right side were acting with but little diminution of force, though less frequently, being but 4 times in a minute. Night now closing in I was compelled to retire. Experiment 8. A kitten was prepared, as all the pre- ceding had been. When the heart, was first exposed, the two auricles alone contracted, not more than 6 times in a minute, and with but little force. After having 57 waited a few minutes, and having found the ventricle remained quiet, I placed the kitten in a glass vessel, con- taining oxygen gas, over water of 99 or 100°. In the space of 4', the right auricle became perfectly red, from the blood within it, becoming oxygenated. It was of as florid a colour as arterial blood. The left auricle was concealed by a lobe of the left lung; its motion could, however, be perceived by the agitation of the lung. The action of the auricles, became increased a little in fre- quency, but much more in force. For 15', no sign of motion could be seen, in either of the ventricles; once it was thought, there was a slight oscillation of the right, but it was not decisive. Twenty minutes after the animal had been in the gas, both ventricles gave sudden- ly and spontaneously a powerful contraction. At first there was not more than one, in a minute; in 25' they contracted twice in a minute, in 30' 4 times, the auricles also, but 4 times. The contractions of the heart, were now, undoubtedly, and to the conviction of the gentlemen, who witnessed this, as the preceding experiments, much more powerful, than any of the others had been, even when the thorax was first opened. The apex of the heart, was drawn up towards its basis, between one and two lines. The coronary vessels of the ventricles, were of a beautiful scarlet colour. In 40', the ventricles beat 12 times in a minute, and with so much force, that the blood, began to ooze out from the divided vessels of the lungs, the edges of which I had cut off, to expose the heart. H 58 Although I had done this in the preceding experiments, the blood had never been seen to issue from them, ex- cept at the moment of excision. In one hour, the ven- tricles and auricles beat 8 times in a minute, and with a force apparently greater than before. In 1° 20' the ven- tricles beat 32 in a minute, the right auricle 16, the left auricle appeared to have ceased contracting, for the lobe of the lung which covered it, could not be seen to move, as before. In two hours, the ventricles contracted 27 times in a minute, but more feebly, the left contracted the most forcibly. The right auricle appeared to be enfeebled. I was now obliged to leave it, and returned 3° 30' after the animal, had been placed in the air. The ventricles contracted 11 times in a minute, the right with less strength, than the left. The auricle, however, beat much stronger, than when I left it, but only 4 times in a minute. I remained in the room, inspecting the heart of the animal at intervals, until 20' before 7 o'clock, which was precisely 7 hours after the animal had been placed inthegas. The two ventricles were acting feebly, compared to the force of their contractions at first, but much strong- er, than in most of the former experiments, after they had continued a short time. The right auricle contrac- ted slowly, but with force. It growing dark, I was un- der the necessity of leaving the experiment. But I am confident, that, from the manner in which the heart was acting when I retired, it must have continued at least two hours longer, if not more. 59 ■ From considering these facts, circumstances, and ex- periments unrelated, yet coefficient, I cannot avoid conr senting to the belief, that oxygen and excitability, are intimately connected, if the one be not the original of the other. I will not assert, that the manner of its production, at which I have hinted, is true, or in what other mode, they are connected. The task is beyond my limited powers. But life, will not remain forever, the secret ens of nature. The quill of fame, shall enrol upon the page of time, the day, when some medical Newton will be born, whose genius winged by intuition shall pass the barriers, to which this "jealous goddess" limits our research; when its springing shoot shall be disco- vered; and its laws shall be unfolded from the deep, the dark obscurity, with which they are now enveloped. SECTION SECOND. ON THE PROXIMATE CAUSE OF THE DISEASE, &c. There is no subject in the range of medicine, which has more excited the disputes, and contentions of phy- sicians, than that of the proximate causes of diseases. Theory has risen on theory, system has been overthrown by system, until medicine, has appeared the wreck of reason, the Egypt of science, where the works of ge- 60 nius and of ignorance, lay alike mouldering in scarce distinguishable ruins. But this period has passed away, this day of barbarism, when despotick power assumed the right to manacle the godlike faculties of man, and with its iron hand to crush the expanding wing of aspi- ring intellect, has now declined; and its productions, the offspring of cramped and confined minds, which da- red not to deviate from the dictates of authority, to lis- ten to the voice of truth, or to view the form of nature, inviting with " simplex munditiis," but only as repre- sented in the canvass of daubing copists, appear too hi- deous to have had birth, while their existence can scarce command the belief, that they are the children of intel- ligence. But now, that reason roves far as the wide extended realms of nature, uncontrolled by power, un- fettered by adherence to systems, because they are vene- rable from the continued belief of wasted ages, though unsanctioned by truth, our science has emerged from this unintelligible disorder, to lucid method, and arrange- ment. The temple of medicine, from this confused mass, erects its noble front, the proudest boast, the ho- nour of our race. It no longer threatens to overwhelm those who approach it, with cumbrous and tottering magnificence, but invites to its entrance with simple majesty. While disease, within this dome, has now lost the hydra form with which it has been represented, and its proximate cause beheld with piercing ken, is no longer confounded with its effects, but appears as mor- bid excitement. 61 However true the opinion, that morbid excitement is the proximate cause of disease, may be, with respect to maladies in general, yet it cannot be applied to the dis- ease (if it may be so called) in consideration. In other diseases, such as fevers, &c. there is a peculiar action, specifically different from that of health, which is either above or below the natural standard; suddenly reducing the excitability, or slowly wasting it away. But in this disease, there is an almost immediate suspension of the actions of life, from the capacity, which the system pos- sesses, of supporting and preserving them in existence, being suddenly lost. In the one, the wheels of life are worn down by the powers which propel them, in the other, the wheels being abstracted, the machine must cease to move. It, of course, must have a proximate cause peculiar to itself. Almost every author, who has written on suspended animation, has advanced an opinion on this subject. I shall not retard my progress to consider them, for they are all erroneous, having been founded on theories of re- spiration, which are untrue, and are now rejected. They, therefore, could not be correct. This remark is eviden- ced, by the facility with which each author controverted the opinion of the one, who preceded him, while his own became a victim to his successor. It would be ungenerous, it would be criminal, to rake the remains of learning and talents from the dust, to triumph over their errors, for they are now harmless. 62 I would present, with much more hesitation, than I do, an opinion of my own on the proximate cause of this disease, if any investigation had been expressly made into it, since respiration has been better under- stood, and its final cause began to be investigated. I will not undertake to declare I am correct in my notion'; for that which satisfies me, may not content a more discern- ing mind. But if I have gone astray, I hope to be pre- sented with some Mentor's hand, which may restore me from my wandering. If the opinion, I have endeavoured to render probable, in the preceding section, approach the truth, or if it be only admitted, that oxygen, is immediately conducive to life, more than as a mere stimulus, even if it be so, in some manner of which we are ignorant, we shall then have approached to a view of that, which we seek. Believing this opinion to be true, it appears to me, that the proximate cause, consists in the defect, or absence of that principle, or quality, which oxygen bestows upon the system or animal fibre, to which perhaps it unites; or the cessation of that effect, which oxygen produces in the animal economy, immediately and directly connected with life; owing to a want, or a deficiency of oxygen in the arterial or nutritive blood. Or, in other words, if oxygen be the principle which produces excitability, irritability, or any other effect immediately vital, yet hidden from our view, then, the proximate cause, is the absence of either of these from the system, produced by the defect of oxygen in the blood. 63 I shall not consume any of the little time allotted for the preparation of a thesis, in endeavouring to maintain this supposition. It rests upon the truth of the doctrine I have supported, that oxygen is immediately vital, or a sustainer of life, otherwise than as a stimulus. If that be false, this cannot be true; if that should stand the test of reason, it will sanction this. I shall, therefore, with- out delay, proceed to examine the effects of drowning, on the vital organs. When an animal is immersed in water, it immediately throws out air from its lungs, and attempts to inspire, by which means, water passes into the trachea. It then struggles with violence, and endeavours to raise itself to the surface of the water; again ejects air from its lungs and assaying to breathe, receives water again into the trachea, part of which probably passes into the lungs, wiiile some of it goes into the stomach. The animal now becomes more agitated and convulsed, than before; a few bubbles of air escape from its lungs, and it may be seen to expel a small stream of water from its mouth, mixed with, and clouded by mucus. The struggles, then, diminish in force, the head sinks down, the mouth is wide open, the tongue somewhat projecting, the eyes are open and protruding, and the pupils mostly dilated. The animal is now no longer convulsed, but at intervals feebly moves its extremities, and the body curves, which is produced seemingly by a contraction of the diaphragm. These also quickly terminate, and the animal is taken out of the water apparently lifeless. 64 If the thorax be immediately opened, the heart will be found contracting weakly, especially the ventricle and auricle of the right side, whicrlge distended with black blood; while the left contains but a small portion, which through the thin sides of the auricle appears also black. The cava? and all the veins are also distended with black blood. These appearances, show that the circulation has been entirely suspended; and from the blood being collected in the right side of the heart, that a remora had occurred to its passage, through the lungs. These vis- cera are generally found in a state of greater or less col- lapse. At one time, I have observed it to be small, at another great. When they are cut into, a frothy fluid, which seems to fill very nearly, the extreme bronchial cells, escapes; demonstrating that water has penetrated into them. The experiments of Berger, however, de- cide this contested fact. In all his experiments, he found the lungs of animals drowned, in coloured water, to be more or less tinged. The stomach always contains wa- ter ;• sometimes I have found it in considerable quantity. The brain, whose function is early suspended in this af- fection, appears to be nearly natural. A little more con- gestion is observed, in the veins of the pia mater, than in subjects who have died of diseases, which did not materially affect this organ, though not sufficient to have produced any evil consequences. Even in the death from hanging, the brain is not as much engorged with blood, as we might suppose. I assert this from 65 having once had an opportunity, of examining and com- paring the brain of one hanged, with that of a person who had died with disease, between which, but little difference existed. There can be no doubt, that the death, induced, either by drowning or hanging, does not proceed from an affection of the brain, and indeed, I believe death, in either case, to be entirely independent of the brain, and that the greater or less engorgement of this organ, does not hasten or retard it one moment. If the proximate cause of the disease induced by drowning, which I have proposed, be true ; and as the appearances of the system, after death, evince a total stop being put to the circulation, and the vital effects of the blood, there arise, then, from this knowledge, two indications of cure. 1st, To restore the blood to that state, in which it is salutary to the system, and essential to its life, by im^ pregnating it with oxygen. 2d, To restore the circulation, that this effect of oxy- o-enated blood may be produced on the system. The means of fulfilling these indications, form the sub- ject of the next section. SECTION THIRD. THE MODE OF CURE. The practice, which has been adopted, for the reco- very of drowned persons, has varied at different periods. The remedies, which have been employed, have fre- quently tended more to the total extinction of the por- tion of life that might have remained, than to promote the recovery of the patient. It has, indeed, been too often marked by empiricism; the invariable consequence of principle, being deserted or despised in practice. It was my intention to have entered into the conside- ration of the different modes, recommended by authors, and to have pointed out, how far they were beneficial or injurious. But I am obliged to abridge this part of my design. Those remedies, however, they have advised to be employed, which I thought useful, I have adopted, those which I thought injurious, I have rejected. There is, however, a treatment yet pursued, occasion- ally, by the vulgar, which I must notice, and which can- not be too strongly reprobated, nor too quickly prohibi- ted. I allude to the practice of rolling and shaking per- sons just drawn from the water. I have heard of an instance of. suspended animation, which occurred near this city, a short time since, in which this practice was the destruction of a person. It wasa woman, who had sunk but for a few moments, and 67 exhibited manifest symptoms of life, when taken out, but which entirely disappeared, by rolling her on the gravelly bank; while another, who owed her safety to being thought dead, and was therefore permitted to lie on the shore in the sun, recovered. It is therefore the duty of every well informed individual, to discourage a treatment of such an injurious tendency. To fulfil the indications of cure, mentioned in the last section, the remedies divide themselves into, 1, the preparatory,^ or the means to be employed, in preparing the subject, for the further more effectual treatment. 2, those which oxygenate the blood. 3, Those which stimulate the system, and at the same time oxygenate the blood. 4, those which merely stimulate the system. The means under the first head to be resorted to, are those which, from necessity, must be employed by the persons present, when the body is obtained from the water; and consist, merely in conveying the body, with the least motion to it possible, to the nearest habitation, and placing it in an airy room, in which a small fire may be kindled. The clothes are then to be taken off, as speedily as possible, and the body wiped dry, with warm cloths or flannel, but with no more agitation or friction to the body, than is absolutely unavoidable. It is to be placed on a table overspread with blankets, or with a feather bed, and the body is also to be covered 68 .i: With warmed blankets. While these preparations are making, medical assistance should be sought, and the apparatus belonging to the Humane Society, should be brought from the nearest place of deposit. No other treatment should be pursued, until a physi- cian shall be present, if there be a possibility of one be- ing speedily procured. If there be no probability of ob- taining the assistance of a physician in a short time, some careful and judicious person, may endeavour to pursue the directions which are here related. T& the ardent and officious zeal of bystanders, pro- ceeding certainly from the most laudable motives, but ill and fatally directed at the commencement of the process for cure, too often, is every future effort, rende- red unavailing. When a physician has arrived at the spot, he should proceed immediately to fulfil the first indication of cure, by the employment of the 2d class of remedies, which is the oxygenation of the blood; and which is to be obtained by the inflation of the lungs. This is to be considered, 1st, as to the in- struments to be employed : 2d, as to the agent by which accomplished. 1, The apparatus which it appears to me is best calculated to attain the desired object, is the following: There should be a small ivory tube to be introduced into the trachea, curved at the extremity, which goes into the fauces; such a one as Coleman describes; and having 69 the end which passes into t{ie trachea small, and round, or flattened on its sides. I prefer having this of ivory, or any other hard, or smooth substance, as a firm body can be passed with more ease into the trachea, than one which is flexible. The end of this tube, which pro- jects from the mouth, should be made to screw to the end of a leather tube, whose opposite end, is to be made so as to be attached to the pipe of a double bellows. This is more eligible than the common single bellows employed, for with it an artificial respiration, almost as complete as natural, can be supported. But with the single bellows, the use of the tube to enter the trachea cannot be had; for it would be necessary, each time compression is made on the thorax, in order to effect an expulsion of the air it contains, to remove the ivory, or unscrew the leather tube. The inconvenience resulting from this is obvious. And if the tube be not employed, the lungs cannot be so completely, nor so easily inflated; for notwithstanding all our efforts, great part of the air will pass into t'he stomach; and into the whole tract of intestines. This apparatus, I think, can be employed by a physi- cian with ease; and this method of inflation being more complete, than that in common use, I should suppose is certainly to be preferred. The artificial respiration, by this means, makes an approach to the natural; the lungs are fully distended, and again emptied, with little vio- lence to the system; and at each inflation, fresh air is forced into them. 70 But whoever has seen the operation performed with a single bellows, in the common way, must have been struck with its insufficiency. The compression on the thorax, to expel from it any air, must be violent, and even then cannot effect completely the purpose for which it is intended; for the greater part of the air, in the in- flation, does not enter the lungs, but passes into the sto- mach. The irritability of the heart, the last lingering spark of life, would soon be, as I fear it too frequently is, entirely extinguished by this treatment. The principal objection to this apparatus is, that there is some difficulty in introducing, and keeping the tube in the glottis. But a physician who is acquainted with the structure, and situation of the parts, cannot fail suc- ceeding to place it in the situation he wishes; and a lit- tle attention will answer to preserve it there. The fol- lowing directions, however, may assist to attain a knowledge of the proper manner of introducing it. The mouth should be opened to its utmost extent, and the tongue drawn forwards. The epiglottis can then be distinctly perceived. The tongue will mostly remain in this situation, if not, it may be retained by ah assistant. The fore-finger of the left hand, (ifstandingonthe right side) is to be introduced into the fauces, and is to be pla- ced over the epiglottis, which should not be pushed down on the opening of the glottis: then, holding the tube in his right hand, the physician passes it along the finger of the left, until it has passed over the epiglottis; and 71 with the same finger, he can direct and place the extre- mity of the tube, into the opening of the glottis. The tongue is, then, to be put back, into its natural situation. An assistant, standing at the head of the patient, should hold the tube, to prevent its falling from the glottis, and rather push it down and forwards. The flexible leather tube attached to the bellows, should be screwed to the ivory tube, and inflation should be immediately com- menced. That this apparatus may be employed, the Humane Society should have it left, at the different places of de- posit. If this cannot be obtained, necessity will obligate the use of that, which is at hand, and can be directly employed. A common bellows is to be procured, the pipe of which is to be fixed into one of the nostrils, which is to be compressed round it, by an assistant, who with the same hand closes the other nostril; keeping the mouth shut with his other hand. Another assistant presses on the cricoid cartilage, compressing the oesophagus, and thus preventing the air from going into the stomach. A third and fourth, raised on stools, one on each side the pa- tient, are to make compression with their hands on the thorax, whenever it is completely distended; while the physician, or an assistant blows the bellows. The first apparatus, I think, is to be preferred, if it can be ob- tained. 72 2. The agent, which accomplishes the intention of inflation, is atmospheric air, which ought to be as pure as it can be obtained. To this end, no more persons should be permitted to remain in the room, than are wanting for assistance. If it should be night, as few candles should be in the room as are necessary; a patent lamp, if it can be procured, is to be preferred to candles, as it affords no smoke. If the weather be not too cold, the windows may be raised, to permit a free circulation of air. When inflation has been pursued for a short time, so as to render it probable, that the blood, in the -vessels of the lungs, is oxygenated, the second indication of cure is to be fulfilled, by the employment of the two remaining classes of remedies, and of these as the more preferable is the 3d, Consisting of those agents which stimulate the system, and at the same time, oxygenate the blood. They may be considered, 1st, as atmospheric air, impregnated with stimulant fumes, or vapours. Vol. sal. ammon., &c. have been recommended, but the best I believe, is the va- pour of oxygenated muriatic acid gas. This may either be procured, by pouring sulphuric acid on powdered oxid of manganese and salt, in an oil flask; or the muriatic acid, on the manganese, and applying to the flask a gentle heat. The mouth of the flask is to be held under the air- hole of the bellows, which will thus receive the gas as it is discharged. 73 The assistants, to avoid being affected by it, should have their handkerchiefs wetted with Aqua Ammon., passed round their mouths; the gas will thus be neutral- ized, passing into the nostrils. This gas readily parts with its oxygen to the blood,* and at the same time, it powerfully stimulates the lungs, between which, and the heart a sympathy exists. This circumstance points out the utility of this class of reme- dies. No danger need be apprehended from the use of this gas; the low state of the excitability, in persons suffering by submersion, will prevent its usual effects; as also will its being diluted with atmospheric air. I once inhaled a considerable quantity of it, in perfor- ming an experiment, yet to be mentioned. It excited violent coughing for a considerable time, and increased the action of my whole arterial system which continued for some hours attended with headache, This is a proof of its stimulant qualities, and of course of its promising good in this disease; and that when diluted, it may be breathed without much danger. 2. The employment of gasses, unmixed with atmos- pheric air. These however can seldom be used. It is almost impossible, to have the apparatus, necessary to obtain the gasses, at the places of deposit, and indeed if it were, more time would be necessary to procure them, than could be spared; nor can they be kept ready prepa- * See page 24. 74 red, without great difficulty and expense. If they could be had, however, some of them might be of advantage. The first, as the best of these, is oxygen gas. The ra- pidity with which it produces its desired influence on the blood, and the stimulating effects it exerts on the lungs, render it the most efficacious remedy that can be employ- ed ; if means for obtaining it readily and easily could be devised. When this, or the other gasses can be had, they are to be conveyed into a large bladder, or varnish- ed silk bag, fitted with a stop cock, which should be made to screw, into a perforated block of wood, over the air-hole of the bellows. The second is the oxygenated muriatic acid gas. Mr. Potel, in a late French work, which I have not been able to procure, recommends its use. The Annual Register,* gives an extract from it, informing that a number of drowned rats, which lay on a table where this gas was used, were recovered by it; that the experiment was re- peated on other rats with a similar result; and that at last the young chemist " procured the suspension of his apparent animal functions," and was restored by this means. I must confess, the latter part of the information in- clined me to doubt the truth of the whole relation. I, however, determined to make the experiment. For this purpose I drowned a young dog, having first prepared a * Vol. 2, page 259. 75 sufficient quantity of the gas, in a gas-holder. It-was 15 minutes after he was drowned, before the inflation of his lungs could be commenced. For the more sure and easy performance of the experiment, I performed the operation of bronchotomy, and introduced the pipe of a leather flexible tube, which Was connected to the pipe of the bellows, into the trachea. The gas was transferred into a bladder, and retained in it, by a stop cock, which screwed to the air-hole of the bellows. The lungs were distended with the gas, but it escaped in so large a quan- tity from the mouth of the dog, and so much was recei- ved into my lungs, that I was obliged to drop the bel- lows, and run into the air; I however, immediately re- turned, and attempted another bladder-full, when the same circumstance occurring again, in a still greater de- gree, than before, I was obliged precipitately to fly. The coughing it excited, was so violent and long continued, that I could not resume the experiment, nor have I since then been able to repeat it. I cannot fully rely on it, as the dog, for a first experi- ment, remained in the water too long, and besides this he had the appearance of being unhealthy, which might have had an unfavourable effect. The third air which has been recommended, is the nitrous oxid. No experiments, however, having been made with it, its efficacy can only rest on conjecture. Under this class, may be mentioned, injecting air into one of the jugular veins. It would slightly alter the 76 blood, but its principle effect would be to stimulate the heart. The quantity of 1-4, or 1-2 of a cubic inch, or even more, might probably be used, not only with safe- ty, but with advantage. The 4th class, or those which merely stimulate the system, may be employed in conjunction with either of the two preceding classes. When the inflation of the lungs, is supposed to have oxygenated the blood, the earlier the heart is excited into action, the greater success does it promise. As soon, then, as the blood has experienced this effect, this class of remedies may be employed. In their use, re- gard should be had, to the part to which they are applied, as connected with the heart or diaphragm, by sympathy: for on this, in a great measure will depend their salutary influence. The strongest stimuli should be used, for as the exci- tability is extremely deficient, if weak stimulants only be employed, no action will be excited. ' Indeed, in tnis state of the excitability, their employment cannot be ex- cused as doing no injury, for they will, by degrees, ex- haust it, without inducing any marked excitement. They may be divided into, 1st, Internal, and 2d, Ex- ternal. The Internal, are applied to the stomach and intestines; the External, to the skin andnares. The 1st, or Internal, are, 1st, such as are applied to the stomach, as bran- dy, and other spirits, which should be given verv warm, or nearly hot; and also volatile alkali. Laudanum is recommended; but I am doubtful, whe- ther its secondary sedative effects, should recovery be obtained, would not prove injurious; for it might, then oppress the system, the actions of which remain for some time, feeble. Caution is necessary in pouring these fluids down the throat, lest any of them should get into the trachea; but if they be gradually discharged, from a vessel with a spout to it, and the head of the patient be a little eleva- ted, this inconvenience may be avoided : 2d, such as act on the intestines. For this end, dif- ferent kinds of enemata have been recommended; their utility however is questionable. The connexion, which exists, between the heart and intestines, is weak, even in the full possession of life; andin the asphixia from drown- ing, it must be still more feeble, and of course, any ac- tion exerted on them, would not be extended to that or- gan, and therefore it could be of no service, but would produce harm ; for it would exhaust the little remaining excitability they retained, and not, excite the heart. The experiments of Dr. Legare, related in his inaugural the- sis, in some measure authorize this conclusion. He found, that although the peristaltic motion of the intes- tines of drowned dogs, was excited, and the vessels brought into action by the fumes of tobacco, it proved but momentary, and could not afterwards be awakened. If oxygen, or oxy-muriatic acid gas, were to be injec- 78 ted into the intestines, might they not oxygenate the \ blood in their Vessels ? for this principle acts speedily on the blood, through membranes, and even through the sides of the heart;* and as they would stimulate the intes- tines, the blood of whose vessels would also be oxyge- nated by them, tliey might produce partially, beneficial effects. lid, The External, are, 1st, Electricity. A small electrical machine ought to form part of the apparatus, which the Humane Society deposits at different convenient places. The bottle should be discharged so as to affect directly the heart, or diaphragm, to excite them into action. The charge should be powerful from the commencement, and fre- quently repeated. 2d, Frictions to the extremities,- either with or with- out stimulant substances. 3d, heat. The objections of Hunter to this remedy are invalid. They are founded on an opinion, which is not established to be true; and for this reason they are entitled to no weight. 4th, Those which affect the nares, as vol. salts, &c. Sternutatories might be of service, to excite the action of the diaphragm. For if natural respiration can be ex- cited, recovery is almost certain. The most powerful of the sternutatories, should be employed; snuff, to one * See page. 52 & 57: 79 unaccustomed to its habitual use, will answer well, or the assarabacca of our shops. These means should be persisted in, for an hour at least; but their continuance for a greater length of time would be proper. It is impossible to determine accu- rately, the moment when life has entirely ceased, so as to be no.longer recalled. While, therefore the most distant hope, while the faintest glimmer of possibility remains, that life can be restored, it is an act meriting the severist censure, it is a measure, almost rising to a crime, to desist from exertion. For is it not the perfor- mance of a duty, which man owes to man, to society, to his God? And shall he go and leave this duty unfulfilled, shall he depart and become an accessary to the destruc- tion of a being, shall he hasten away and permit a brother to sink to eternity, " unanointed and unaneled." Behold the man, who has been the successful agent in restoring one from asphixia by drowning. Does he not feel the glowing consciousness, of having been the in- strument of safety, from inevitable destruction? for he has snatched a being from the very embraces of death. Does he not hear the prayers, the blessings of a grateful family, " ascending to the recording angel" of heaven, for his prosperity, his happiness, his health? for he has restored to them a brother, a son, a father, a husband. These, physicians, are your rewards! Will they not excite you to exertion ? 80 I cannot terminate this essay, without acknowledging the many obligations, under which, I labour to the Pro- fessors of the University, for the instruction I have de- s. rived from their truly valuable lectures; their willingness ». to impart information; and personal benefits which, from some of them, I have received. That they may long continue the ornaments of the chairs which they now fill, with annually increasing fame to themselves, and advantage to their pupils, is my most ardent, my most fervent wish. Ere I finally lay aside my pen, I must request the kind indulgence of my reader, for the errors which may stain these sheets. Let a shade of oblivion conceal them from remembrance, or the hand of lenity blot them from the page. I thus deprecate the censure of the scrutini- zing eye, from being conscious that many faults seem * be fostered here, from a want of time necessary for their eradication. I should not urge this apology, if it were not, the period is limited, in which a thesis is to be pre- pared, of which the greater part was consumed in the performance of my experiments; nor do I presume, this production merits to be considered in any other light which might induce to the procrastination of its appear- ance. For once, then, may I indulge the hope, that necessity, will plead and will gain a departure from the critick's law, » ----Reprehendite, quod non Multadies et multa coerctiit, atque Praesectum decies non castigavit ad unguem. Hon. IN consequence of the haste, in some measure Unas Voidable, with which this impression proceeded from the IVess, several mistakes have been committedi They are* however contained, with the exception of a fe\v in the Jmnctuationj in the following list of errata; by are* ference to which they can be rectified* Page 14, line 19, add it after behold* 21, —-17, insert analogous before experiment; 23, — 3, dele so. 33j ~ 9, for Bishart read Bichat. 52, — 9, for being read was. 16* — 25* dele to, t... ;*&i -it 'Wl ''Z*# I s */&+'. Med . H ist, J He. \Ut 0^ L .1