^IIIIPP,. #& :-:.:>v.•■■'.;■■■ v *?%. ^ **L /^N fh yksEfc> \ v < V CA , t- i V ^^^ ^^ / ^ ^^,CL THE INSTITUTES OF MEDICINE. MARTYN PAINE, A.M., M.D., LL.D., PROFESSOR OF THE INSTITUTES OF MEDICINE AND MATERIA MEDICA IN THE UNIVERSITY OF NEW YORK; AUTHOR OF THE "MEDICAL AND PHYSIOLOGICAL COMMENTARIES," " A TREATISE ON THE SOUL AND INSTINCT," " THERAPEUTICS AND MATERIA MEDICA," ETC., ETC. ; CORRESPONDING MEMBER OF THE ROYAL VEREIN FUB HEILKUNDE IN PBEUSSEN ; CORRESPONDING MEMBER OF THE ROYAL MEDICO - CHIRURGICAL ACADEMY OF TURIN ; CORRESPONDING MEMBER OF THE GESELLSCHAFT FUR NATUR UND HEILKUNDE ZU DRESDEN ; MEMBER OF THE MEDICAL SOCIETY OF LEIPSIC ; OF THE MEDICAL SOCIETY OF SWEDEN; HONOBABY MEMBER OF THE IMPEBIAL UNIVERSITY PHYSICO - MEDICAL SOCIETY OF MOSCOW; OF THE MONTREAL NATURAL HISTORY SOCIETY ; AND OF MANY OTHER LEARNED SOCIETIES. All are but parts of one stupendous whole, Whose body Nature is, and God the soul. Pope. Theory is only common sense applied to calculation—La Place. eighth edition, revised NEW YORK: HARPER & BROTHERS, PUBLISHERS, FRANKLIN square. 186 8. LONDON: SAMPSON LOW, SON & CO., american and european booksellers, 47 Ludgate Hill. / W0 V\AU I8C8 I (ho no. 11 N£j Entered, according to Act of Congress, in the year one thousand eight hundred and sixty-five, by HARPER & BROTHERS, in the Clerk's Office of the District Court of the Southern District of New York. ^ T HI S W 0 R K Us reepecUullj) ©etrtcatefc TO THE MEDICAL PROFESSION OF THE UNITED STATES, BY THEIR. OBEDIENT, HUMBLE SERVANT, THE AUTHOR. PREFACE TO THE FIRST EDITION. The Author of this Avork has endeavoured to keep before him the difficult objects of adapting it to the student in medicine and to the more advanced. For the advantage of the former, therefore, he has aimed at such method as he might command, and such illustration as might not seem irksome to the latter. With a view to the former, also, he has endeavoured to indicate the intimate manner in which all the topics embraced in the work are related to each other, and their mutual dependences, by constant references from one part to others; and, what is unusual, the Author has made these connecting refer- ences in a prospective as well as retrospective manner. With a view, also, to the same objects, the Author had designed a more copious Index; but as the stereotype Avas completed as long ago as the mid- dle of November, and as the state of his health, and other avocations, have not permitted him to complete the Index, in its regular order, beyond the 125th page, he has concluded to print it as it now stands, and to extend it in a future edition. Many subjects, however, throughout the work, are now incidentally carried out in the Index; but many of the most important receive only a general reference, ex- cepting as they are related to others which are more amply noticed. New York, Jan. 1, 1847. PREFACE TO THE FOURTH EDITION. Three Editions of these Institutes, the first of which was pub- lished in 1847, having been# exhausted, the Author now submits a fourth to his medical brethren, in which he has endeavoured to incor- porate, in an Appendix, the most important of the recent discoveries in Physiology, Pathological Anatomy, Therapeutics, Organic Chem- istry, and Microscopy that are relative to the principles about which this work is interested, and he has connected the Appendix intimate- ly with the main body of the work by copious references to the sec- tions embraced in the former, while the same system is carried out reciprocally in the latter. It is also gratifying to the Author to pay his humble tribute of admiration particularly to the immense labors of the microscopist, who, through the great improvements of the in- strument, is now enabled to analyze Avith surprising accuracy the ul- timate and varying conditions of the solids and fluids. The Author has also fulfilled his design, as expressed in the Preface to the first edition, of extending the original Index, a second one being now added, in Avhich he has endeavoured to present an epitome of the Avhole work. It is proper, however, to suggest that the Reader will find an advantage in consulting simultaneously the original Index, as it is more particularly analytical. An Essay upon the Soul and In- stinct forms a part of the Appendix. New York, November, 1857. PREFACE TO THE FIFTH EDITION. The preceding Edition of 1857 having become exhausted, the Au- thor presents another, in Avhich some remaining typographical errors are corrected, numerous references to sections introduced, and a Sup- plemeot added. Another Preface enables him, also, to express his sense of obligation for the generous opinions which have recently ap- peared in the Medical Press of his \rarious professional Avritings. It is especially gratifying that this tribute has been rendered with great unanimity in his own country, and he desires no greater reAvard for his toil and anxiety. But he by no means intends to imply that his doctrines haA-e been ahvays accepted, although they have been very generally allowed to be logically sustained. And the Author feels it his right to say that, in all the critical revieAvs which have fallen un- der his observation, A\Those object has been to affect his Avritings in- juriously, such reviews have consisted altogether of falsifications and perversions of his statements and opinions. Nor is this unqualified assertion made without a full knowledge that all the objections al- leged have been critically examined, and the results placed upon rec- ord, and from a belief, also, that it is due to the interests of medicine. Some of the false and ungenerous reviews the Author thought it worth while, many years ago, to expose in elaborate articles. But his particular motive for referring now to the subject is to express his thankful acknowledgments to his friend Professor Charles A. Lee, M.D., and to Professor James B. M'CaAv, M.D., the distinguished Editor of the Virginia Medical Journal, for having, with great ability and disinterestedness, performed a similar labor in his behalf. But he Avould not, therefore, have it inferred that he supposes his writings are invulnerable, and he would much honor the critic who would employ himself fairly in refuting any doctrines or opinions that may be open to objection.—See Note W p. 1127. The Supplement which is added to the present edition embraces observations that go to corroborate some of the Author's principal \riews in medical philosophy; but he is not aware of any discoveries in Physiology, or of any neAV facts in Pathology, or of any improve- ments in Therapeutics since the late edition to affect adversely any of his doctrines. Indeed, as a Avork of principles, and as a consistent whole, should any doctrine of importance be shown to be fallacious, the entire fabric must be abandoned. But if, on the contrary, its principles be founded in Nature, they can not be affected by any fu- ture accumulation of facts—no more than the laAV of gravitation was \riii PREFACE TO THE FIFTH EDITION. rendered more absolute by the successful calculation of the periodic time of Halley's comet. That achievement was simply a corrobora- tion of a great discovery. It is of no importance, therefore, to the essential objects of this work to introduce neAV discoveries till some one or more may present themselves, that, like chlorine, iodine, &c, in their relation to Lavoisier's theories of oxygen, shall invalidate the system of medical philosophy herein embraced; by which the Author means such facts as can be undeniably showrn to contradict that phi- losophy. This, it is true, will appear strange to those (and of such there are many) who look upon principles as "liable to exceptions" —as having no stability—exposed to daily fluctuations—as consisting even of isolated facts; such philosophers, particularly, as see no dis- crepancy between the conflicting laws of organic and inorganic be- ings, and Avho, therefore, are ever ready to engraft them indiscrim- inately upon organic philosophy, or as one or the other may have its chance in the irresistible pronunciations of organic life, or in the spu- rious analogies of simple matter. To multiply facts in this work Avhich merely contribute to the validity of its principles, or to incor- porate others that may be speciously arrayed against those principles, would constitute a defect for the most ordinary criticism. Never- theless, some things, both of the former and latter nature, have been admitted into the Appendix, although precisely parallel facts occur in the body of the work. But they were said to be new, and the Author yielded to this general belief, though he concedes that the facts are more fully displayed in the latter than in the former cases, and that he therefore contemplated an advantage from their corrob- orating effect. But their exclusion would not have otherwise affected the work, though it might have been regarded by some as a defect. The same may be also affirmed of the Supplement, where, for exam- ple, some late observations relatiATe to absorption by the intestinal A'illi are stated, although they simply confirm Avhat had been long ago ascertained; but they are more precise and complete, and place the doctrine in these Institutes beyond question. Again: Richard- son's late experiments tending to show that the blood's fluidity is owing to ammonia Avere not admitted into the Appendix, as the Au- thor believed that they were contradicted by the general philosophy of life; but reference is made to them in the Supplement because they have been contradicted by other and later observations. It Avould be superfluous to add that it would haATe been irrelevant to the objects of the Avork to have gone into the minutiae of histology, to have even introduced the discovery of Avhite globules in the blood, or the late observations upon the supposed tributary influences of the spleen and thymus upon the blood, &c, since they have no bearing upon a Avork of general principles (§ 83 c). New York, Avgust, 1859. PREFACE TO THE SIXTH EDITION. A careful attention has been bestowed upon this sixth edition, as AA'ill be sufficiently manifest in the numerous references which have been added to the sections wherever the subjects under consideration are allied to other parts of the Avork and may derive illustration through this re- lationship. These new references (which occupy mostly the former va- cant spaces at the end of sentences) are prospective as well as retro- spective, and amount to more than seventeen hundred ; and the Indexes ha\'e been impro\red in a similar manner. The Author has also en- deavored to simplify the exposition of some of the most difficult prob- lems, and to thus render them of more easy comprehension by the young medical student. For this purpose he could have equally desired great- er amplification, and especially to protect himself against misapprehen- sion or misrepresentation (from the latter of which, however, he is not so unwise as to hope for escape); but the vastness of the field, the immensity of the labyrinth which he has explored, has rendered it necessary to em- ploy as much brevity as such variety and intricacies Avould admit, and he has considered it most expedient to carry into the Appendix and Supplement the same compactness that characterizes the body of the work. Of the Supplejjent it is said that " it is very brief, but speaks a volume." But whatever advantages in respect to detail and perspicuity may at- tend a work upon the principles of medicine as founded in Nature, it can have but little chance with other systems unless the student be ambitious of knowledge, and disposed to grapple at the very beginning of his career Avith the difficulties of truth as distinguished from the fascinating sim- plicity of error. The latter once impressed upon his imagination, or once productive of mental indolence, fetters his aspirations and decides his destiny. Hence the incalculable importance of a right beginning. Whatever the apparent obstacles, they may be soon surmounted. The task will ha\e been the best possible mental discipline for the young in- quirer. He will have learned the important art of thinking for himself; and Avhen once inducted into the true philosophy of medicine he can not help thinking, and into the very depths of that philosophy. He will have also shielded himself against the seductions of artificial systems. He will quickly distinguish Avhat is true in Nature from factitious analogies. He is not, however, to be discouraged from informing himself of spurious doctrines; and Avith this object in view the Author of these Institutes has incorporated in the Avork a copious exposition of the offsprings of X preface to the sixth edition. error. But, as he has also endeavored to indicate their fallacies, the student has the double advantage of learning the inventions of art and at the same time the infirmities which are so apt to commend them to our natural indolence. The Author's method, therefore, if he be right in his premises, is not open to the objection alleged by Burke (but on the contrary defeats it), that—" When education takes in error as a part of its system there is no doubt that it will operate with abundant ener- gy and to an extent indefinite." Much has been recently said by a few writers upon the recuperative law of Nature, and presented in such a manner as to convey an impres- sion that now, for the first time, the old doctrine of the vis medicatrix na- tural has been distinctly announced. The Orator, for example, of the Lon- don Hunterian Society for the present year remarks that—" From time immemorial the professors of the healing art, Avith one or two exceptions, seem to have known nothing of the course and termination of diseases, save in connection with, and as modified by, special therapeutical agents. Nearly all their reasoning upon the action of medicines has, in conse- quence, been based upon comparisons of one method of treatment with another. They seem never to have thought of taking as the basis of their reasoning the curative resources of Nature herself, as ascertained by study of the natural course of disease." It is evident that they who have lately written in the foregoing man- ner haATe had their attention diverted from Hippocrates, Celsus, Galen, &c, and if they will turn to the mottoes at page 661 of this work they will find that those early masters "took as the basis of their reasoning" what is supposed to be of such very recent origin. And the Author of these Institutes, umvilling to be excluded, may be permitted to assure these reformers that throughout the work he has " taken as the basis of his reasoning the curative resources of Nature herself, as ascertained by study of the natural course of disease." It is the absolute foundation of all his Therapeutics, and the foregoing mottoes were employed to in- dicate the fact. But these reformers have, also, nearly as large a reli- ance upon Nature as the homoeopath, Avith much less regard for the noble science, and appear to be of Magendie's opinion that "the nurse can prescribe equally well" (§ 744); and perhaps this may be Avhat is intended by claiming for the honor of the present age the discovery of the vis medicatrix natura. In that aspect of the subject the Author of these Institutes does not sympathize (excepting as it respects a feAv " self- limited" diseases, and multitudinous cases in which there is no profound derangement, results of mechanical injuries, &c), although he endeavors to expose the errors of excessive medication, and agrees Avith the abor- tive disciples of Nature that Avherever this practice obtains (as it does with the mass of the profession) the whole work of cure is supposed to devolve upon art; and this, he maintains, is the inevitable effect of the chemical and humoral doctrines. PREFACE TO THE SIXTH EDITION. xi Such is a glance at some of the objects of this work, and to which the Author invites especially the impartial attention of the young student of medicine, and Avith the assurance that he will meet with no timid or un- fair concealment of doctrines that are opposed to those of fbe Institutes. There remains to be noticed what may seem to be an isolated subject, but which is essentially relative to physiology—the essay upon the Soul and Instinctive Principle (incorporated in the Appendix), in which the Author endeavors to demonstrate the substantive existence and self-act- ing nature of the Soul and Instinct upon strictly physiological principles. If this have been accomplished by the Author, Avho believes the demon- stration to be conclusive, then is there an end to materialism; and even he who doubts not the probabilities of the metaphysical inductions, or relies with greater confidence upon Revelation, must realize a new sat- isfaction in that tangible proof Avhich no ingenuity can invalidate, no misrepresentation pervert, and no sophistry evade. As to the Author's reference to his essay upon " Theoretical Geology" (p. 908, 927), it will be seen that the work embraces many facts that are allied to organic philosophy; but it is now his object to state that the discussion proceeds upon recognized grounds in natural philosophy, chem- istry, geology, &c, and without departing from the rules prescribed by !: positive science ;" and as the Author's aim. is simply the development of truth, he entertains the hope that the essay may be scrutinized accord- ing to its supposed philosophical premises. The issue must ultimately turn upon this mode of investigation, not upon the usual ground of geo- logical hypotheses, which, indeed, are the very things in question. It must be decided in the open field of those various sciences which consti- tute the physiology of Nature; since the near affinities among the facts in geology constantly bring them under the collective interpretation of the different departments of knowledge, and no one who has not direct- ed his attention to the Avhole circle of the sciences is qualified to grapple with the subject. Neav York, September, 1860. BOKMMK^BM PREFACE TO THE EIGHTH EDITION. A seatentii edition of this Avork Avas published in 1861, which, as stated in a Preface, " is distinguished from the preceding editions by the addition of several brief foot-notes and some other improve- ments." In 1862 appeared another edition, but under the designa- tion of the seventh edition, though distinguished from that by the addition of tAventy pages of Notes appended at the end of the Sec- oid Index, and by frequent references to them in the text, and also by the addition of several brief foot-notes, and by many references to sections throughout the Avork. Doubtless it had been better to have entitled that edition the eighth. The present edition is distinguished from the last particularly by an extension of the Notes at the. end of the Second Index, and by numerous references to them in the text. Several of the former Prefaces are reproduced as memoranda of the progressive condition of the work. In the Preface to the seventh edition, which is noAV omitted, there occurs the following explanatory statement: " The author embraces this opportunity to say (Avhat may not be obvious to all) that the fractions Avhich appear in many of the numerical des- ignations of the sections, as § 303^ a, are intended for sections that Avere made after the original completion of the manuscript, by Avhich the labor of a revision of the entire work Avas saved. The addition of letters to a series of figures of the same denomination indicates distinct sections, but that they are either closely allied, or are intend- ed as substitutes for fractional parts." The foregoing Preface, Avjth the edition to Avhich it refers, ap- peared in the year 1865. In 1867 there Avas printed an '■'■Eighth Edition Revised" and the present is'a reprint of that Edition, in which improvements had been made. New York, 1868. TABLE OF CONTENTS, PRELIMINARY REMARKS 1-15 PHYSIOLOGY.....15-412 Composition......23-49 Structure......50-73 Vital Principle and its Properties .... 73-125 Vital Principle .... 73-89 Irritability......89-100 Sensibility......100-103 Mobility......103, 104 Vital Affinity..... 105 Vivification...... 105 Nervous Power .... 108-111 General Remarks upon the Philosophy of Life. . 111-122 The Mind and Instinct, and their Properties . . 122-125 Functions, Common . . . 125-280 Motion.......126-128 Absorption......128-134 Assimilation..... 134 Distribution.....207-217 Appropriation.....217-227 Excretion......227-234 Calorification.....234-279 Generation......279, 280 Functions, Peculiar . . . 280-362 Sensation......280-283 Sympathy......283-362 Its general relations to the nervous system . 284-295 Experiments illustrative of.......295-321 Varieties or kinds of. . 321-335 Laws of, applied patho- logically and therapeu- tically ..... 335-353 In its relation to special tissues and organs . 353-362 Relative to the Mental Prin- ciple and Instinct . . 362 Vital Habit......363-372 Age ......... 373-383 Infancy.......373-375 Childhood......375,376 Youth.......376-380 Manhood......380,381 Old Age......382, 383 Temperament, Constitu- tion, Idiosyncrasy . . 383-391 The Sanguine.....386, 387 The Melancholic .... 387-389 The Choleric..... 389 The Phlegmatic .... 389, 390 The Nervous..... 390 Physiology—continued. Races of Mankind . . . . 391-393 Sex . ........393,394 Climate ....... 394-396 Habits and Usages . . . 396,397 Relations of Organic Be- ings to External Ob- jects ....... 398-400 Death........401-404 Summary Conclusion in Physiology, or its Uni- ty of Design .... 405-412 PATHOLOGY......413-540 Remote Causes .... 414-427 Pathological or Proximate Cause ...... 427-434 Symptoms...... 134-455 The Pulse...... 443^48 The Tongue.....448-450 Secretions and Excretions . 450-455 Morbid Anatomy .... 456-463 Inflammation ..... 464-489 Description of.....464—480 Remote Causes of . . . 480,48] Pathological Cause of" . . 482-489 Active and Passive . . . 486-489 Fever........489-499 Description of.....489-497 Remote Causes of . . . 497—498 Pathological Cause of . . 498-499 Venous Congestion . . . 500-513 Humoralism......514-540 THERAPEUTICS .... 541-777 General Consideration of 541-563 Cathartics......563-570 Astringents......570-578 Tonics and Diffusible Stim- ulants ....... 583-590 Antispasmodics.....590-593 Cinchona, and its Alka- loids ....... 593-607 Arsenic.......607-612 Iodine ........ 612-G20 Ergot........620-628 Emmenagogues.....628, 629 Diuretics.......630-633 Expectorants . . . . . 633-642 Counter-irritants . . . 642-660 Remedial Action, its Gen- eral Philosophy . . . 661-689 The Scton......679-681 Local Sedatives, Warm Poultices, SfC.....681-683 Genito-urinary Agents . . 683-689 Uterine Agents . . . .683 -G89 table of contents. Page Therapeutics— continued. Bloodletting ..... 690-777 Leeching......692-698 General Bloodletting. . . 698-702 Cupping......702-703 The Nervous Power in its Relation to the Effects of Loss of Blood .... 703-711 General and Practical Obser- vations upon .... 711-777 General Extent of Bloodlet- ting ....... 711-724 In Congestive Fevers . 724-732 In the recognized Forms of Inflammation .... 732-736 In Simple Continued and Therapeutics—continued. Bloodletting—continued. Simple Intermittent Fe- ver ....... 736-739 In the Cold Stage of Fever 739-741 In Apoplectic Affections . . 741-747 Experience and Opinions of distinguished Physicians as to Bloodletting in In- flammatory, Congestive, and Febrile Diseases . . 747-766 In the Diseases of Infancy and Old Age ... . 768-770 Spontaneous Hemorrhage . 770-772 Misapplied and Excessive . 772-776 General Conclusions as to . 776-777 CONTENTS OF APPENDIX. Progress of Physiological and Pathological Chemistry .... 779-802 Production of Animal Sugar..............783-794 Progress of Physiology................801-816 Structure of Organs..................801-803 Of the Spinal Cord..................802-803 The Nervous Power and Organic Properties..........803-806 Animal Heat in its connexion with the Nervous System......807-812 The Primordial Cell..................812-814 The Boundary-line between Animals and Plants........ 815 Hybrid Animals................... 816 Absorption and Circulation in Plants...........817-824 Experiments to ascertain whether the quantity of Blood circulat- ing in the Brain may be reduced artificially.......824-828 Sedatives—a farther exposition of their uses and of the philosophy relative to their effects.................... 828-835 Alteratives—their uses and mode of action considered practically, &c. . 835-851 Jalap, p. 851-853—Saline Cathartics, p. 853-854—Rhubarb, Scammony, Aloes, Colocynth, Senna, Colchicum, p. 855-862. Of the action of Chloroform and analogous agents in producing Insensibility when inhaled..............882-864 Of the Influence of the Mind upon the Action of Remedial Agents 865-868 Have Diseases undergone Changes of Type within the last forty Years, or have new ones appeared'?...........868-872 Physiology of the Soul and Instinct, or Demonstration of their substantive existence and self-acting nature.......873-911 Rights of Authors..................912-920 SUPPLEMENT. Correlation of Forces.—The Glycogenic Function of the Liver.—The Cause of the Blood's Fluidity.—Modus Operandi of Remedies.—Absorption by the Skin.—Transfusion of Remedies.—Intestinal Absorption and Lacteal Circula- tion.—The Forces which circulate the Blood...........921 Indexes 93i NOTKS 1111 INSTITUTES OF MEDICINE. PRELIMINARY REMARKS. " Until it is proved that the forces which, in a living body, interrupt the play of the natu ral chemical affinities, maintain a proper temperature, and preside over the various actions of organic and animal life, are analogous to those admitted by natural philosophy, we shall act consistently with the principles of that science, by giving distinct names to these two kinds of forces, and employing ourselves in calculating the different laws they obey."—Andral's Pathological Anatomy. See, also, Medical and Physio- logical Commentaries, vol. i., p. 626-632. "Oui*notion of life involves something more than mere reproduction, namely, the idea of an active power, exercised by virtue of a definite form, and production and genera- tion in a definite form. The production of organs, the co-operation of a system of organs, and their power not only to produce their component parts from the food presented to them, bat to generate themselves in their original form and with their properties, are characters belonging exclusively to organic life, and constitute a form of reproduction in- dependent of chemical powers. This vital principle is only known to us through the peculiar form of its instruments; that is, through the organs in which, it resides. Its laws most be investigated just as we investigate those of the other powers which effect motion and changes in matter."—Liebig's Organic Chemistry applied to Physiology, p. 355. "Simple views, whether of health or disease, however ingenious, can seldom be just. They have their origin in the spirit of system, not in the careful study and faithful enu- meration of the complicated circumstances which concur in the production of all vital phe- nomena."—Thompson, on Inflammation. 1, a. Solidism and vitalism will form the basis of these Institutes. If consistent in all their parts, without a violation of facts, it is, prima facie, a proof of their foundation in Nature. To show this consist- ency, and to develop the great principles and laws of organic beings, and erect a substantial fabric of Institutes Avhich shall guide the hand of art, we must ascend, progressively, along the fundamental facts in physiology, pathology, and therapeutics; till, at last, we proceed to convert the great system to practical uses, in the preservation of health, and a just, intelligible, and philosophical application of the materia medica to morbid states of the body. To render this work, therefore, most practical, and to simplify as far as possible the highest department of knowledge, I shall adopt an analytical method. I have also endeavored to arrange the various topics in their most natural order, or as each successive one may ap- pear to emanate from, or to depend upon, the preceding. The stu- dent, therefore, to understand the last, must comprehend all the pre- ceding, and so of each in succession. We have thus a connected link throughout; a difficult achievement, and the more difficult as it is the first effort that has been made to prepent the natural relations of my whole subject in their just order, to point out the affinities, and to ex- hibit throughout the important laws and essential foundations of vital- ism and solidism, and to maintain throughout a consistency of facts and of laws that shall stamp the whole as the Philosophy oj Medicine. In making this claim for the Institutes, I am prepared, as in the case of the Commentaries, to invite the most rigid scrutiny.* If there be any where a collision in principles or facts, or any contradictions of myself, let them be pointed out. My aim is truth, and I desire * Mf.dical and Physiological Commentaries, New York, 1840. A 2 INSTITUTES OF MEDICINE. nothing for myself which I do not yield to others. If there be minor imperfections I would gladly know them. Many of the original doc- trines which appear in this work are presented in various connections in the Medical and Physiological Commentaries. The spirit of the Commentaries will pervade the Institutes, as being, in my judgment, the only stable foundation* 1, b. In the farther prosecution of this Avork it will still be my object to speak of such errors as have usurped the rights or blighted the interests of rational medicine. It is not now the time for a simple expression of facts, of experience, and of philosophical doctrines. The errors which surround them must be also exposed and refuted, or the foe of truth, or the ambitious aspirant, or the lover of indolence, will gain something from an indulgence which they know how to seek and appropriate. Nor is any one more aware of the tendencies of free discussion or unsparing of physiologists than he who has been most successful in the propagation of error, or who would sooner stifle inquiry into factitious systems. Thus, it is said by Liebig, that " It is too frequently forgotten by physiologists that their duty really is, not to refute the experiments of others, nor to show that they are erroneous, but to discover truth, and that alone."—Liebig's Organic Chemistry applied to Physiology, fyc. Now this obvious sophistry betrays its motive, since it is utterly at variance with the habits of him who would enjoin the fiction upon others. Truth should be, indeed, the ultimate object of pursuit; but the first and most important step toward its attainment is the removal of obstacles that may lie in its way (§ 820). It is allowed, indeed, by one of Liebig's most zealous advocates, the editor of the London Lancet, that " the removal of error claims a place next to the establish- ment of truth" (Dec, 1844); and it has grown into a proverb, that "it is more difficult to subdue a prejudice than to build a pyramid." Although, therefore, the contemplated method must be sometimes argumentative and controversial, it has the advantage of leading more immediately to a knowledge of the truth upon disputed questions, than any other which is not demonstrative. There can be no doubt, indeed, that the "establishment of truth" in medical philosophy can be effected only by a simultaneous refutation of the errors which sur- round it. The mind will not surrender a favorite doctrine, however false, to the force of truth alone. Even its practical disasters, as we every where witness, are an inadequate demonstration. But, when error and truth are presented in forcible contrast, it is the pride of reason to embrace the latter. What is also important, the reader will have been presented, as in the Commentaries, with the great rival doctrines in medicine, and in their proper relations to each other (§ 3501). 2, a. The Institutes of Medicine are natural inductions of principles and laws from the healthy and morbid phenomena of living beings. They relate to Physiology, Pathology, and Therapeutics, and to noth- ing else. All other systems, therefore, must be spurious. The sub- stitutes have no depth, no principle, no laws, and are recommended alone by their naked simplicity. " Gentlemen," says Bacon, "nature is a labyrinth, in which the very haste with which you move will make you lose your way." 2, b. The immediate objects of physiology are a critical analysis of * The author has seen no reason to modif}' this statement, made twenty j-ears ago PRELIMINARY REMARKS. 3 the vital conditions and results of organic beings, as manifested in different organs, and in their relations to each other. It contemplates organic nature, therefore, in its natural state; and the. laws which it obeys are its highest end. Pathology is to the physician the great final object of physiology. It investigates the causes which disturb the physiological conditions, and inquires into the phenomena, and the nature of the vital and structural changes. These, in connection form the ground-work of Therapeutics, which considers the indica- tions to be fulfilled, and the means and the manner by which they are to be accomplished, and nature thus aided in the process of cure. The Materia Medica comes last, and is the subordinate object of all the rest. It investigates the composition and physical character of the material objects by which the therapeutical intentions are fulfilled, and interrogates especially their relations, as vital and alterative agents, to pathological conditions. Disease, being a modification of the phys- iological or natural condition, produces new relations between the properties of life and the natural, morbific, and remedial agents; and these are ascertained by observation of their effects upon morbid states alone. It is thus that remedies become beneficial when they would be morbific in health; and what is salubrious in health is ren- dered morbific by diseased conditions. The principle is in beautiful harmony with the instability of the vital properties; and the final cause of this instability is the preservation of organic-being (§ 133, c, 153-156, 638). 2, c. Nevertheless, each of the four great departments of medicine possesses so many peculiar characters that they may be severally con- sidered as constituting, to a large extent, distinct parts of one great symmetrical whole (§ 83, c). Pathological conditions could never have been inferred, a priori, from any extent of physiological inquiries, nor could the effects of therapeutical agents, or the natural termina- tion of disease in health or in death, from any knowledge of anatomy, physiology, or pathology. The whole is originally the work of ob- servation ; and we come to learn the relations of the four great branches of medicine by comparing the phenomena which are pre- sented under the various conditions of health and disease, and as these phenomena may be affected by artificial influences. Anatomy, however, affords no such standard of comparison. And yet it is obvious, as will more distinctly appear hereafter (§ 83-163), that anatomy is the basis of medicine. It is, hoAvever, of the system of organic life that I mainly speak. All, at least, that is superficial in animal life, the voluntary muscles, &c, abstracted from their rela- tions to the organic condition, belongs to the domain of surgery, and is, therefore, of little importance to the physician. 2, d. Notwithstanding, therefore, the foregoing qualifications, it will be seen, in our inquiries into the great fundamental points, that the science of medicine is, throughout, a perfectly connected chain; beginning with the laws which govern the modes in which the ele- ments of matter are combined in organic beings,—advancing to the union of organic compounds into cells and tissues,—to the laws which respect the various processes which are conducted by these tissues, and by the organs into which they are combined,—to those laws as affected by the contingencies of disease,—and, lastly, to the laws which regulate the changes through which the morbid states return to I INSTITUTES OF MEDICINE. the natural conditions of life. All are connected together by intimate dependencies, and are determined by the natural or by the varying states of the-vital properties in their operation through material parts. The ground-work of the whole is, evidently, perfectly simple; since the laA\'s by which the whole is regulated are established upon the constitution of the organic properties (§ 169, f, 638). 2, e. To the eye of the philosopher, therefore, Nature, in her or- ganic department, as in every other, appears in an aspect of astonish- ing simplicity, when he contrasts her forces and laws with the diver sity of their phenomena; nor does he confound the principles and laws which distinguish the different departments of nature. To every other eye the phenomena of life appear confused, and seem referable to no common powers or laws. But he who has obtained the key to the true philosophy of life, by a wide observation of nature, lays open at once the apparent secrets of all its results, whether in health or disease. Whatever he sees has its individuality, and stands in re- lief from all the rest. He knows at a glance from whence this or that springs, how it is related to others, and he traces the whole directly up to a few simple principles. To all but such an eye, howeA7er, the phenomena of life, and more especially of life diseased, appear as does a field to all but the botanist. The common observer sees nothing but a confused assemblage of grasses, and probably will tell you there is but one species where the botanist will as instantly discover fifty. Each species has to the latter a distinct individuality, and he cannot regard them in that state of confusion which is seen by the ignorant. He has studied each plant, knows its specific characters, its relations to others, its habits, &c. By these modes of observation he has also acquired the knowledge that nature has pursued a common plan of organization, and linked the whole, by close analogies, throughout the vegetable kingdom. Were the botanist, therefore, to range simulta- neously among the 100,000 species of plants, he would see nothing but individuality, and the greatest simplicity in the principles upon which the whole are constituted. And just so it is with a philosophi- cal observation of the healthy and morbid phenomena of the animal kingdom. 3. The organic and inorganic kingdoms have, respectively, their peculiar properties and laws. Such as appertain to life, in its nat- ural, as well as morbid aspects, are denoted by an incomparably greater variety of phenomena than those of the external world ; and as their only intelligible foundation is the phenomena evinced, we attain our knowledge of either according to the extent and variety of the phenomena. We know nothing more of matter itself. Without a comprehensive knowledge of the properties and func- tions of living beings, and especially of the laws by which they are governed in their healthy and morbid states, the practice of medicine is mere empyricism. The ignorant, alone, undervalue causes and principles, and depend upon unconnected facts. 4, a. In medicine, therefore, we must concern ourselves with some- thing besides effects. We must understand the laws under which they take place, and, as far as possible, trace up the effects to the pri- mary causes. This is always done in other sciences and in the arts. Why, then, should it be neglected in that science whose practical ap- plication relates to the highest welfare of man % PRELIMINARY REMARKS. 5 The human mind will have its theories upon all subjects; and cho whole history of medicine is a perpetual exemplification that in no inquiries do theory and hypothesis abound so universally as in the healing art (§ 819, 960). This arises, m part, from the intricacies of the subject, but mostly so from the constitution of the mind itself. The Almighty designed it for theoretical conclusions, and set us the example in those stupendous theories upon which the universe, and all it contains, are founded. And what else are, or should be, our inquiries and our theories, than finding out and adopting those of which He is the author 1 What other theory in the natural world can there be than such as are instituted by the Almighty Being l And shall we hesitate to embrace, and to act upon such theories ? And yet it is one of the pretended improvements of the day to insist upon nothing but facts, and to denounce all principles in medicine ; as if the Almighty had not ordained principles and laws as well as facts, which are mere emanations from the former. 4, b. The ignorant pretender will tell us that all this is unimport- • ant; though no one is so much directed by hypothesis, or theory, as this very pretender himself (§ 884). Does not every empiric in the land prescribe his drastic cathartics for the purpose of cleansing the blood of its supposed impurities % Are they not exactly on a par, in their doctrines, and in their practice, with the most speculative of our enlightened humoralists ] Nay, have the ignorant portion of that sect, our Brandreths, our Morrisons, et id omne genus, any reference whatever to facts or experience 1 Is it not all hypothesis, and, there- fore, all a reckless waste of human life 1 Mount up the scale, and you shall find at every step of your ascent, from him who prowls about the outskirts of the profession, to him who directs the all-potent drug with the most consummate skill, that each and all rely mainly upon their conceptions of the philosophy of disease. But you shall also find, that in proportion as Nature has been taken for their guide, and as medical principles are founded upon the absolute phenomena of life, in their healthy and morbid aspects, there will always be the greatest reference to facts and experience. Hence, again, the importance of looking well to our theories, and of seeing that they are established on well-grounded facts, or on the analogy to which they conduct us. Could we, as we cannot, direct the treatment of disease without principles, we never should; and it should therefore be the business of the practitioner to enlighten his mind upon the philosophy of medicine, or his unavoidable disposition to theorize may prove a scourge to mankind. Of this, indeed, the records of medicine abound with examples (§ 801, b, 819, &c, 960, 1005, 1068).—Notes F p. 1114, Ee p. 1133, Ff p. 1135, Go p. 1138. It will therefore be my agreeable task to expose, in these Insti- tutes, the fallacies of the prevailing physical doctrines of life and dis- ease, as well as to inculcate principles which exalt our science above the mere world of matter, render it consistent in all its details, and present it to the profession as a department of knowledge fundament- ally distinct from all other pursuits.—See Rights &c. p. 912. Differences of opinion on questions of great moment to mankind are apt to be strongly conveyed, and apparent error to be censured in no measured terms. This, perhaps, is often admissible, considering the obstinacy of error, and so long as it is the doctrine and not its an- 6 INSTITUTES OF MEDICINE. tiior, which is assailed. We may revere the names of Voltaire, of Hume, and of Gibbon, yield them a proud rank in the scale of intel- lect, and gratefully acknowledge the rich legacies they have left be- hind. But, who of us would hesitate to speak of their infidelity ac- cording to its nature and tendencies 1 This is even demanded by what we belieA'e of the precepts of religion. And so of the principled! of medicine, which hold as high a relation to the temporal interests of man as do the precepts of religion to his spiritual welfare. The high- est order of intellect is often devoted to the dissemination of error, and perhaps more frequently in religion and medicine than in any other of the great interests of mankind. This must be fully and firm- ly met, not only by evidences of the truth, but by an exposure of its perversions and corruptions. 4|, a. The physiological world has been lately divided into three schools. One of these sects virtually regards organic nature as a part only of inorganic, endowed with the same properties and governed by the same laws. It maintains, in short, that there is no essential dif- ference between a man and a stone. At the head of this school stands • Liebig, the distinguished and able chemist. It is a great and poAver- ful school, but is falling, daily, beneath the weight of its vast errors and corruptions. It is denominated the chemical school of medicine. 4£, b. Contrasted with this is the school of vitalism, which regards organic and inorganic nature as distinct in their most essential attri- butes. It supposes that each department is governed by properties and laws peculiar to itself. It regards the organic being as funda- mentally distinct from the inorganic in its elementary constitution, in the aggregation of its molecules, in the structure of its parts, in its condition as a whole, and in every phenomenon which it evinces. It sees design in every part of the living being—eloquent even in the dry bones of a skeleton; a design peculiar to every part, while all concur together to the common ends of the more universal designs of procuring the means of sustenance, of maintaining life, of perpetua- ting the species, &c. On the other hand, this school discerns no cor- responding design in the constitution, or in the condition of inor- ganic matter. It sees nothing here but mere vis inertice, which, however, is supposed by the chemical school to be capable of evolv- ing from simple matter every variety of organization, with all its spe- cific designs, even instinct and reason, while, at the same time, we hear from the depth of materialism that " organic nature is the mys- tery of mysteries"—the Creator being the only "mystery" about it. Again, the vitalists, in consideration of the facts now stated, main- tain, in the language of Liebig, the great head of the school of mere physics, " the existence of a principle distinct from all other powers of nature, namely, a vital principle;" which organizes and governs all living beings, and which is the fundamental cause of all their phe- nomena in health and disease. I say, in the language of Liebig, "a principle distinct from all other powers of nature;" for this mere chemist, in his conflicts with living nature, concedes the existence of such a principle as at the foundation of all vital phenomena, yet, in the same general manner, and on all specific questions where he had introduced its direct and exclusive agency, he as unequivocally de- clares that there is no such principle, and that every result of life and disease, even thought itself, are entirely oAving to chemical agencies. PRELIMINARY REMARKS. 7 His whole system, as set forth in his " Organic Chemistry applied to Physiology," and in his "Animal Chemistry" as applied to Pathol- ogy and Therapeutics, is a tissue of similar contradictions, and of the boldest assumptions. Yet, Avith deep mortification I say it, he has been hailed with an enthusiasm before unknown in the annals of med- icine, as the only true expounder of physiology and of medical phi- losophy. The Avorld, however, is fast awaking from its spell-bound delusion, and the doctrines of this " reformer" will soon be mingled with the same and more original chimeras which did their part in •'the dark ages of science" (§ 350, 1029, 1030, 1034). 4i, c. Finally, the third school, or that of chemico-vitalism, en- deavors to form, as it were, a bond of union between the schools of pure vitalism, and of pure chemistry; though such an alliance be as unnatural as human brains in a block of granite. The chemico-phys- iologist makes a compromise with philosophy, and takes for his rule " in medio tutissimus ibis." It is as regardless as the school of pure chemistry of the universal consent with which physiology has been hitherto restricted to the condition, functions, results, and laws of liv- ing beings, and chemistry to the condition and laws of dead matter. This school, therefore, mingles the doctrines of vitalism and chemis- try ; allotting to the former one half of the phenomena of life, and the other half to the latter. This is the school to which the young student has the greatest chance of becoming the victim; for it is apparently recommended by the conciliatory principle which I have stated in the form of its motto, and by many of the most distinguished members of our profession. 41, d. I have said that it is a remarkable characteristic of the medi cal school of pure chemistry, that its doctrines are in perfect conflict with each other, as shown in a work (Liebig's "Animal Chemistry") which is assumed as the basis of the chemical philosophy of life—as the great foundation on which the school itself has been erected. And how could it be otherwise, seeing that this school, and this writer, are constantly employed about tAvo subjects which have no affinities; that is to say, the philosophy of life and the philosophy of chemistry ] I shall think it of sufficient importance to substantiate the foregoing fact by many proofs in the course of this work; and, as an example of the whole, I shall adduce the contradictory views which are put forth upon the most important principles which lie at the foundation of organic life, and at the basis of medical science. On the very subject of a vital principle itself the genius of the school is as flatly contra- dictory as on the most unimportant doctrine; for at one moment he avows the existence of such a principle " distinct from all other pow- ers of nature," and calls it "the vital principle," which, he says, gov- erns all the processes of living beings (§ 59, 60), and at the next moment he asserts that, " in the animal body Ave recognize, as the ultimate cause of all force, only one cause, the chemical action Avhich the elements of the food and the oxygen of the air mutually exercise on each other. The only known ultimate cause of vital force, either in animals or in plants, is a, chemical process." He renders, as will be seen by ensuing quotations (§ 350), what he assumes as an original fundamental cause of life the indispensable source of another cause, which he avows to be equally original and fundamental; and what is yet more indicative of the chaotic state of 8 INSTITUTES OF MEDICINE. the chemical speculations relative to living beings, this author (as I have shown in the Medical and Physiological Commentaries of many others) assumes, at one time, the chemical force to be the sole cause of all vital processes and results, while, at another time, he regards the vital principle as the only power concerned in the same phenomena. It will be gratifying to curiosity, for example, to observe how Liebig entangles his reader, as it respects the physiology of digestion, by making that process to depend on a purely chemical action, and to evolve that vital principle which he as unequivocally declares to be the only power concerned in chymification (§ 350, nos. 3, 17, 51, 58). 5. Chemical and mechanical philosophy, as we have already seen, are strangers to the philosophy of medicine. There is a natural con- flict between the subjects of each. They have no relationship, no sym- pathies, but carry on a perpetual hostility. The organic being is for- ever converting to its own uses the inorganic, and changing its very nature into its own. The inorganic is fruitless in resistance and in assault, till the former is passive. It then lays waste the fabric by which it had been wrought into a great system of designs, and de- grades the whole to its own level. Chemistry, therefore, begins where physiology ends ; and physiology begins Avith organic influences upon the elements of matter, or where chemistry leaves off. No depart- ment of medicine has any thing to hope from chemistry beyond its power of analysis (§ 1029, 1030). And yet do the labors of chemists aspire at a substitution of the ever-fluctuating principles of chemical science for all that has been hitherto founded upon the phenomena of life and disease. Their oft repeated effort to carry a science which is mainly analytical and me- chanical into that which is eminently intellectual and overflowing with the most sublime institutions, and distinguished by the most pro- found principles and laws of nature, and therefore seductive to an am- bition which is restif under the practical manipulations of the labor- atory, would raise no inquiry as to motive, or end, did not the proper guardians of the science not only abandon their old and rich domain at the very approach of the enemy, but, with most unnatural distrust of self, invite the destroyer (§ 349, d, 433, p. 719, § 960, a). The late publication of Liebig's " Animal Chemistry" has abund- antly proved the truth of what I sufficiently established in the " Med- ical and Physiological Commentaries," that the recent application of chemistry to physiology and medicine is not a partial, but a complete substitution of that science. In justification of all this, we are noAv told that the means of investigation, of analysis, and of creation, have received an extension of which our predecessors had no knowledge. Such, however, has always been the pretext of chemistry for its inva- sions upon the science of life. Take, for example, the words of Fourcroy, who wrote more than sixty years ago, and who, like Lie- big and his school, attempted to substitute chemistry for physiology, and to rear up a fabric of medicine upon that imaginary foundation; and this, too, in the case of either of the masters, without having ever read a medical book, or having ever prescribed for a disease. The language of Fourcroy is exactly such as we now hear from the lips of Liebig and his followers; who cheerfully allow that nothing flow- ed from the labors of Fourcroy to illuminate the dark ways of organ- ic life (§ 1029, 1030). ft PRELIMINARY REMARKS. Q So identical are the language, and ambition, and hope or confi- dence, and the visionary speculations, of the older and recent chem- ists, that a space may be well assigned to this exposure of chemical pretensions. We read, then, in Fourcroy, what we read in the Avorks of Liebig and his cotemporary chemists. Thus : " The errors of the chemical physicians of the last century, and the indifference many practitioners of the present time seem to have for chemistry, have produced a disadvantageous opinion in the minds of many persons, which time alone can remove. If the enthusiasm of those physicians, who cultivated chemistry, misled them, it does not follow that any conclusion can be drawn from thence that may be ap- plied to the present time. The exactness which the moderns have introduced into every part of experimental philosophy ought to re- move the apprehensions of such as, for want of acquaintance with the subject," are apt to imagine that chemistry is still the dark, mysterious science it was a century ago." " It is chemistry alone that can throw any light on the composition of the fluids, and the changes they under- go by the processes that are carried on during life. We cannot avoid having recourse to this science, in our endeavors to discover the true mechanism of the animal functions ; the properties of the fluids separ- ated by the different viscera; or the alterations such fluids undergo." " It will be necessary to enlarge and multiply these researches on subjects of different age, size, and temperament, in various climates and seasons, and to pursue them among the different classes of ani- mals," &c. " We think it equally necessary to examine the solids, by chemical methods, as well in the sound as in the diseased state, and by a comparison of their properties, endeavor to discover to which of the fluids they owe their formation ; and this being known, we may proceed to conjecture, in morbific dispositions, the solid or fluid that has suffered a change. " If it be thus established that the theory of medicine is capable of receiving the most essential advantages from chemistry, it is equally certain that the practice is no less in need of the same assistance; since both must of necessity accompany each other, and are promoted by the same means." " Nothing can be more evident than that the choice of aliments, and of air, cannot be made with any certainty, but in consequence ofchemical researches into the nature of foods, and the properties of the atmospheric fluid" (§ 18).—Fourcroy's Medical Chemistry, 1782.—Also, Appendix § 1028-1030, 1034, Lehmann. I have said, in the Commentaries, that " a prosperous harvest" was promised from Fourcroy's reformation. But, again I reiterate, where is the evidence ] since which time, also, chemistry has made greater advances than any other science, has had its unmolested sway, and Fourcroy's example has been followed with a corresponding diligence. Can you point to a solitary instance in which organic chemistry, ex- cept in a negative sense, has advanced the science of life or disease ? Do not the very chemists of this day incidentally allow the perfectly abortive nature of their science in relation to physiology and medi- cine 1 Consult the quotations in section 350, b, 1, &c, and 350i— 350|. Or take the affirmations of the distinguished Mulder (§ 350f), which go, with the rest, to establish the truth of my former assertion, that "chemistry has been a perfect incubus upon medicine; and the time is not distant when it will have proved, by its own showing, its want of 0 10 INSTITUTES OF MEDICINE. relation to our subject, if it have not done so already."—Comment., vol. i., p. 5S6, note.— See Appendix § 1028-1030. 5], a. I agree with the chemical physiologist that "facts are stub- born things," and, with the analogy which reposes upon them, are at the foundation of all philosophy ; but it does not equally follow that facts are always philosophically or even honestly applied, nor that he who devotes himself to the laboratory is the best qualified to apply his own facts to organic nature. " We can have no very high idea of experiments made by gentlemen," says Hunter, " who, for want of anatomical knowledge, have not been able to pursue their reasoning even beyond the simple experiment itself." Least of all can the chemist be permitted to charge upon the vitalist a neglect of chemical facts; since it is as well by these as by the phenomena of life that the vitalist overthrows the artificial system (§ 350-350|). Nor let it be forgotten that it is purely by an appeal to certain false analogies, and by a disregard of the phenomena of living beings, that the physical and chemical hypotheses of life and disease have obtained their ascendency (§ 733, d). All our theories and principles in medicine, it cannot be too often reiterated, should rest upon well-ascertained facts. The great diffi- culties with which truth has had to contend since the restoration of the proper method of observing nature consists in the mistaken nature of facts, or of false conclusions from admitted facts. What is often assumed to be fact is just otherwise, and, where the premises are sound, they have frequently led to spurious theories (§ 3502-350|, 433, &c, 493, 823, &c). 5\, b. The phenomena of nature are the facts about which all phi- losophy is concerned, and therefore form the substantial ground of* all intellectual acquirements. As they relate to organic beings, to their laAvs, their properties, their functions, whether morbid or healthy, they are to be found in the organic being himself, not in the work- shops of the chemist or of the mechanical philosopher. But, even where the mind admits this proposition, if prone to speculation, it too often regards each fact by itself, and rears up hypotheses wrong in themselves, and in conflict with each other. Facts should therefore be compared before they are reduced to theory ; or, where they may conflict with acknowledged principles they should remain in an iso- lated state till their true nature may be better understood, or till the principles which they appear to contradict may be shown to be erro- neous. Should some fact, for example, appear to indicate the depend- ence of life upon chemical or any other physical forces, the evidence to the contrary is so various and conclusive, that that fact must be considered as deficient in some of its elements, which, if known, Avould readily bring it under a well-established principle in physiology. These absent elements are some other facts which escape our obser- vation ; and thus what is truly fact, in an abstract sense, is made the ground-work of important error. 5±, c. It is the peculiar misfortune of science to generalize too hastily; and it often happens that the explosion, or the introduction, of one error, is the parent of many others. It is also astonishingly true that a few phenomena are abstracted from the whole, of which they may be only sequences of the others, and are made the ground of conflicting doctrines, and substitutes for the theories that are insti- PRELIMINARY REMARKS. 11 tuted upon the more fundamental facts ; and thus a blind disregard of consistency is permitted to prevail till a most incongruous series of assumptions, as in Liebig's Animal Chemistry, is presented to us as the science which Nature teaches. Again, there is a proneness of the human mind to admit of no real- ities but such as make a strong demonstration upon the senses; and hence it is that the physical and chemical philosophers of life prefer the facts of the laboratory to such as are supplied by organic beings. The former are therefore assumed as the foundation for principles and laws in physiology and medicine ; and when it is considered how large a proportion of mankind have not the ability to distinguish the true from the false, especially when the latter is set forth in a confi- dent and dogmatic manner, it ceases to be remarkable that what is comparatively simple, and comes plausibly recommended by the tangi- ble and visible attributes of matter, should command their confidence beyond those realities which can be appreciated only by an exercise of the understanding in connection with the revelations of sense, and Avhich form the ground-work of principles of difficult penetration. There are few, indeed, who are capable of reasoning beyond their senses and the facts themselves, and this is equally true of the chem- ist, both as to the facts of the laboratory and the phenomena of living beings, Avhenever he attempts an exposition of the properties and laws of a department of nature which lies not within his sphere of investi- gation. " Truth, whether in or out of fashion, is the measure of knowledge and the business of the understanding. Whatever is be- side that, however aufhoi-ized by consent or recommended by variety, is nothing but ignorance or something worse'* (§ 1034). 5\, d. It cannot but be conceded, that, as knowledge advances, and the subjects of inquiry become more or less exhausted, ambition is likely to depart from an observation of nature to seek gratification and renown in artificial expedients. This is becoming a prevailing propensity in medicine; and many have left, and are leaving, the bul- wark of knowledge to rear up hypotheses upon distortions of nature, which, for their better success, they dignify by the name of " experi- mental philosophy" (§ 1085).—Note Pp p. 1142. 5\, e. In medicine, at least, there is but one kind of experimental observation, which consists in the simple study of the phenomena of nature. Or, if art be applied to giA-e them a fuller development, the means must be such as shall elicit results conformable to the institu- tions of nature. But aside from chemistry, it has been the fatality of the physiological department of medicine to have been encumbered with rude experiments, giving the wildest distortions to the features of nature. When we consider the wonderful susceptibility of the properties of life, how readily their actions and re§ults are influenced by natural agents, how a drop of hydrocyanic acid, or of the alcoholic extract of nux vomica, applied to the tongue of an animal, will ex- tinguish life in an instant; or that the same may be done by thrust- ing a needle into the medulla oblongata; or how concentrated mias- ma may almost as instantly induce an attack of fever; or how a. little excess in eating may bring on an attack of apoplexy as immediately fatal as a blow on the region of the stomach—fatal, perhaps, in either case, as the artillery of the clouds; or how simple irritations of a nerve may be followed by death from tetanus; or how all the veg- 12 INSTITUTES OF MEDICINE. etable and animal poisons, as well as all things else which do not pos- sess natural relations to the properties of life, will variously change those properties and all their results,—Avhen, I say, we consider all these things, we may well imagine the difficulty of imitating nature by the most cautious experiments, or of developing her laws by mutila- ting the structure of organic beings, or of illustrating those modifica- tions which spring up in disease, by resorting to processes which are foreign to natural influences. Even the greatest experimentalist in modern times, he who has performed more vivisections than any other man, has placed it upon record, that it is one of the most diffi- cult things in physiology to perform an experiment that shall not be liable to objection. Yet no man ever ventured more hastily upon conclusions from such experiments, and none has thrown greater ob- stacles, in consequence, in the way of physiology and pathology. *>\,f The limits which restrain the interposition of art are very narrow; and when organic nature is brought under the influence of arti- ficial causes with a proper reference to these limits, the resulting phe- nomena may form a safe ground of reasoning as to the laws by which organic beings are governed. Much has been accomplished, in this way, as to the physiological connections of the nervous system with organic actions, the part which it takes in the morbid processes, the sympathetic communications which it establishes throughout the or- ganization, and the interpretation which it supplies of the operation of remedial agents. Nevertheless, the most important part of our knowledge upon these great and intricate questions is abundantly supplied by the natural phenomena of life, as manifested under the varying conditions of health and disease. And that this is so, is suffi- ciently evident from the fact, that but little practical information of the foregoing nature has been added, by recent experiments, to what had been known centuries ago. The late experiments, however, upon the nervous system have confirmed what had been deduced from the more natural process of observation, and have developed some useful facts Avhich it might have been impossible to have known by any other method. Such, for example, is the difference of function be- tween the component parts of the spinal nerves ; one part being de- signed for the transmission of sensation and sympathetic influences, the other for the operation of the will and the development of motion. And yet, if analogy were allowed its proper weight in physiological inquiries, as it must be in reality the great basis of medical science,— if there had been less pertinacity as to the necessity of abstract facts for every conclusion, we might have come, by a process of analogy founded upon ultimate facts, to a knowledge of the constitution of the compound nerves. This could have been inferred from their complex functions as evinced by their phenomena, and by associating them with the simple elements of cerebral nerves, where it is plainly seen that some of the nerves have, individually, a specific function, and whose phenomena are destitute of complexity. b\, a. But the reign of " experimental philosophy" which so lately appeared in the mutilations of animals to discover their natural func- tions ; in the injection of corrosive and putrid substances into the cir- culatory apparatus of animals to illustrate the pathology of human disease; in the transfusion of remedial agents into the same order of beings, and even into plants, to ascertain the virtues of remedies, their PRELIMINARY REMARKS. IS modus operandi as curative agents, and the right treatment of human maladies, has given place to an " experimental philosophy" in which organic life has no participation. This is the " philosophy" against which the observer of nature is now called upon to contend; fraught with far greater evils than the spurious systems which it has so sud- denly surprised and superseded. It is impossible to calculate the mischief which must result to mankind from its unrestrained popular- ity. Something may be gathered from its former effects when chem- istry was young; and something from the progress of error under the fresh spur of Liebig's Animal Chemistry (§ 350-350|, 821). We all know how common the enthusiastic belief that this " Reformer" had overthrown all former systems in every department of medicine ; and we may take the following editorial passage from the London Lancet as expressing a very common opinion of the profession as to the ap- plication of chemistry at the bedside of disease : " As organic chemistry marches on the basis of an improved system of medical practice," says the veteran editor, " it will prove impera- tive that a rigorous examination of the products of the animal frame, the several humors and excretions of the body, should be employed in the investigation of disease. The period approaches when it will be incumbent on us, not perhaps invariably, but still very often, in pre- scribing,—say, for typhus, or purpura, or any of the numerous vari- eties of cutaneous affections, that by a chemical analysis we should first ascertain the constituents and proportions of the proximate elements of the urine, the saliva, the expired breath, the perspired matter, per- haps the blood, the faeces of the patient, before applying our remedies; and this process may have to be gone through not once only, but sev- eral times in the progress of the malady." " The time is, we repeat it, approaching when the foundation of practice on the laws of Organic Chemistry will form the distinction between the enlight- ened physician and the mere pretender" (§ 851, 863, e; 883, b).— London Lancet, April 29, 1843. (Also, § 1029, 1030.) 5i, b. In the foregoing quotation we have essentially what is noAv extensively denominated " the progress of medical science," and the nature of the doctrines to which these Institutes are opposed. These Institutes will be found mainly, so far as physics are alleged to be concerned, by the side of all the most illustrious physiologists from Hippocrates to us, Avhose general views are thus summarily express- ed by Bichat: "The organic chemistry of the laboratory," says Bichat, "is the dead anatomy of the fluids, not a physiological chemistry. The physiology of the fluids should be composed of the innumerable variations which they experience according to the different (vital) states of their respective organs." " The instability of the vital pow- ers is the quicksand on which have sunk the calculations of all the physicians of the last hundred years. The habitual variations of the living fluids, dependent on the instability of the powers of life, one would think, should be no less an obstacle to the chemical physicians of the present age." " Again, had physiology been cultivated by men before physics, I am persuaded that many applications of the former would have been made to the latter. Rivers would have been seen to flow from the tonic action of their banks, crystals to unite from the excitement M institutes of medicine. which they exercise upon their reciprocal sensibilities, and planets to move because they mutually irritate each other at vast distances. All this Avould appear unreasonable to us, who think of gravitation only in consideration of these phenomena. And Avhy should we not, in fact, be as ridiculous when we come with this same gravitation, with our chemical affinities and chemical compositions, and with a language established upon their fundamental data, to treat of a sci- ence with which they have nothing whatever to do 1"—Bichat's Gen- eral Anatomy and Physiology. 6. We may now readily perceive the reason Avhy chemistry has undergone changes within a few years, while all that relates essen- tially to the properties and laws of organic beings may have been long since known. The chemist operates, and makes all his discov- eries, through the forces and laws of inorganic matter. These he may carry into his laboratory, turn into his test glasses, or involve in his crucible. He can therefore oblige nature to form the same inor- ganic compounds as she forms spontaneously. He can then separate the elements again, and again oblige nature to recombine them after their original manner. But, can he do the same thing with organic beings 1 He cannot form the most simple organic compound—can- not even recombine the elements when they are once separated;— although he has then the necessary elements, and in their exact pro- portions. The reason is obvious. The chemist has not at his com- mand in this case, as in the other, the necessary powers; or, as the chemist expresses it, " he cannot place them in the same circumstan- ces as Nature does." It is clear, therefore, that while the laboratory is the proper place for the study of the inorganic kingdom, we must go to the organic being itself to learn the nature of the powers and laws by Avhich it is governed. These, then, are the reasons why the laws of organic be- ings have been long so much better understood than those of chemis- try. Every thing is artificial in the laboratory, so far as experiments are concerned; and, if these be not the right ones, or be imperfectly conducted, they will either fail to represent nature correctly, or will give her a wrong interpretation. Hence the great instability of this science; and yet we are told that every new theory in chemistry is applicable to physiology and medicine. But, it is quite otherAvise with organic beings. Here all the ex- periments are carried on by Nature herself, and they cannot deceive. The various results and phenomena are seen in the being itself, and can be seen nowhere else. They must, therefore, be the true guide, and the only guide, to the powers and laws by which organic beino-s are governed. These phenomena, too, are astonishingly multiplied in any given being, and new ones are presented as the being may come under neAV influences. But, this variety is extended almost to infinity when we consider that every distinct species of plants and animals has its peculiar manifestations of life. It is also true that each one of this endless variety is utterly different from any of the phenomena of the inorganic world. And when we take all the phe- nomena of organic beings in connection, and find a perfect harmony among the whole, the nature of the proof is so various and immenst as to conduct us to a right knoAvledge of the principles and laws of life in all their aspects. PHYSIOLOGY. 15 Now all this variety has been perpetually before the observation of mankind, and always presented to our observation by nature her- self. It therefore ceases, I say, to be remarkable that the science of life had so greatly outstripped that of chemistry; and it will proba- bly forever remain better understood; since nature is the experi- ' menter in one case, and man in the other. PHYSIOLOGY. • 7. The sensible world is composed of animate and inanimate be- ings, Avhich, with their difference in composition and structure, has led to their division into the organic and inorganic or mineral kingdoms. 8. The relations between the tAvo great kingdoms of nature, and their contradistinctions, render a general reference to the inorganic indispensable to our physiological and higher branches of inquiry. 9. Animals and plants, which make up the organic kingdom, are essentially dependent on the inorganic; but the latter kingdom is per- fectly independent of the organic. 10. The beginning of organization is in plants, which are the pri- mary source of nourishment to animals. 11. From the foregoing law arises the great fundamental distinc- tion between plants and animals—that the former subsist on the ele- ments of matter, while the latter are nourished by those elements in an organic state. It appears, therefore, that vegetables are more creative than animals (§ 303). 12. All organic substances are compounds of the simple elements of matter. They are combined by the vital poAvers, while inorganic compounds are produced by chemical forces. 13. As organization begins in vegetables, it is obvious that a de- compounded organic substance can be restored to an organic state only by that vegetable kingdom which was created for the specific purpose of organizing the mineral kingdom, for the ultimate final cause of supplying food to animals. The plant reduces, the animal consumes (§ 303).—Notes N R pp. 1121, 1123. 14, a. If an animal compound be decompounded, the reunion of the elements into an animal substance requires the agency of both vegetable and animal organization; and, not only so, but nothing can reproduce any given animal compound but the precise part of the same species of animal which gave origin to the part so decompound- ed (§ 12).—Note R p. 1123. 14, b. Owing to this universal law, by which the animal is rendered so perfectly dependent on the vegetable kingdom, the Creator has given a striking perfection to the grand design in the institution of an invisible Avorld of animalcula for the consumption of that vast pro- portion of organic matter which is passing through the process of maceration to its elementary state. Thus arrested by these econo- mists of nature, it advances through an ascending series of animals, till, at last, it becomes the food of man (§ 151, 1052). The foregoing distinction is fundamental in nature; and here, at tbp very threshold, we are met by a barrier which the chemist and 16 INSTITUTES OF MEDICINE. physical philosopher cannot pass from one side, nor the physiologist from the other (§ 1052). 14, c. I may also say, that it is no small proof of a Creator, that the elements of all combinations which are generated by animals and plants are derived from the inorganic kingdom, Avhich will be allowed to be less productive than the organic. And since, especially, no or- ganic being can generate any elementary substance, nor the ele- ments unite, of themselves, into organic compounds, it follows that the whole was created by a Being of greater power. We can go no farther back than the elements of matter. Here the atheist himself pauses in dismay. They proclaim a God, and reason submits to this limit of its powers. ■ I may also propose another, and perhaps greater proof of the error of spontaneous generation. The kingdoms of nature are governed by inherent powers, and the organic possess powers peculiar to them- selves ; but the existence of matter, whether organic or inorganic, is also indispensable to their respective forces. These forces, therefore, did not create matter; and since matter cannot create matter, and therefore did not create itself, it follows that its associate powers did not create themselves. Whence it is obvious that some greater Power exists by which the powers of nature were created in union Avith matter (1079 J/1083, 1085).—Notes Pp p. 1142, GIq p. 1145. These arguments, therefore, may be taken in connection with those which I formerly adduced for the purpose of exposing the fallacy of the doctrine implied by Carpenter, Pritchard, Fletcher, and others, by assuming that the vital properties exist in the elements of matter, and that, therefore, the elements are capable of arranging themselves into organic beings. (See my Examination of Reviews, p. 37, and my Notice of Reviews. Also, § 1051, 1052.) 15. Exact analyses are readily made of mineral compounds, and the elements may be recombined into the same or other mineral com- pounds. The precise analysis of the most simple organic compound, solid or fluid, as fibrin or albumen, is very difficult, and always liable to doubt. 16. Excepting the earths, plants subsist upon the atmosphere and what it contains (§ 303); but they immediately derive much of their nourishment from decaying organic substances that are incorporated with the soil. But, before such compounds can be appropriated by plants, they must be resolved into their elementary state. They can be taken into the organization of plants only in the condition of min- eral substances; and even then the most simple binary compound must be decompounded before organization can begin. All the re- combinations, as constituting parts in the vegetable economy, are es- sentially unlike any substance in the mineral kingdom. 17. If animal organization resolve an organic compound into a min- eral condition, such compound is useless in the animal economy (§ 13, 14). There is never present, therefore, in the animal organization, as a part of, or as a source of supply to that organization, any mineral substance (§ 360). Whatever mutations the materials of supply may undergo, they must always exist in an organic state, or be permanent- ly restored to the mineral kingdom.—Notes N R pp. 1121, 1123. 18, a. We learn from the foregoing premises (§ 17), that food does not lose its organic state during the process of digestion ; and since it PHYSIOLOGY. 1? becomes more and more nearly assimilated to the living solids from the earliest action of the gastric juice, it is evident that chemical agencies have no connection with the transformations to Avhich it is subjected in the alimentary canal (§ 350-376). 18, b. Hence, also, the fallacy of attempting, by chemical analysis, to indicate the proper sustenance of man and animals. " To deter- mine," says Liebig, " what substances are capable of affording nour- ishment, it is only necessary to ascertain the composition of the food, and to compare it with that of the ingredients of the blood.''' He then pro- ceeds to a practical application of this principle by setting forth the chief elements of the blood. The difficult subject, also, of identifying hay with the flesh of animals, and all the vegetable substances which enter the human stomach with the various tissues of the body, is so far disposed of as to require no other interposition between the nutri- ment and its conversion into living animal compounds than the chem- ical forces. This chemical doctrine is thus set forth by Liebig: " The most recent and exact researches have established as a univer- sal fact, to which nothing yet known is opposed, that the nitrogenized constituents of vegetable food have a composition identical with that of the constituents of the blood"—Liebig's Animal Chemistry. 18, c. And such, too, is a common example not only of the assump- tions of this writer, but of that positive manner which has inspired such uniArersal confidence (§ 350£-350£). There are, of course, in nitrogenized vegetable food certain combinations more or less analo- gous to what are called the constituents of the blood, though never the same, and but comparatively feAv in many that are appropriate as means of nourishment; nor could it be doubtful that the elements of the flesh and blood of animals subsisting on vegetables must exist in their food. But the identity of elements in any given vegetable and animal compounds is Arery different from identity of compounds, and this, too, with every imaginary latitude of the isomeric and polymeric problems. Nor have any two chemists agreed, as yet, in their analy- sis of blood, or of any animal compound ($ 1029, 1030,). But we have from the laboratory' most ample admissions of the groundless nature of the preceding statement. Thus, again, Liebig : " As far as our researches have gone, it may be laid down as a law, founded on experience, that vegetables produce, in their organism, compounds of proteine ; and that out of these compounds of proteine the various tissues and parts of the animal body are developed by the vital force, with the aid of the oxygen of the atmosphere and of the elements of water. " Now, although it cannot be demonstrated that proteine exists ready formed in vegetable and animal products, and although the dif- ference in their properties seems to indicate that their elements are not arranged in the same manner, yet the hypothesis of the pre-exist- ence of proteine, as a point of departure in developing and comparing their properties, is exceedingly convenient. At all events, it is certain that the elements of these compounds assume the same arrangement when acted on by potash at a high temperature" ! !—Liebig's Animal Chemistry. Nor is this the end of the contradiction; for we also read in the same work, that " We cannot, indeed, maintain that the animal organism has no B 18 INSTITUTES OF MEDICINE. power to form other compounds, for we know that it is capable of producing an extensive series of compounds, differing in composition from the chief constituents of the blood" (§ 409, b, and 53, b). But, if the foregoing quotations be conclusive of the specific inqui- ries before us, the following admitted facts not only establish the same conclusions, but prove that chemistry is entirely incompetent to any one of its pretensions as to a proximate analysis of the blood, or of other organic compounds, and that it is strictly limited to a mere ele- mentary decomposition, while they also concede the existence of a vital principle as an " immaterial" governing poAver, Avholly different from any attribute of inorganic nature, and therefore render it certain in another aspect, that the chemist, from want of this agent, can, at most, only effect the elementary analysis of organic compounds. Thus, then, the organic chemist: " If the problem to be solved by organic chemistry be this, namely, to explain the changes which the food undergoes in the animal body; then it is the business of this science to ascertain what elements must be added, what elements must be separated, in order to effect, or, in general, to render possible, the conversion of a given compound into a second or third; but we cannot expect from it the synthetic proof of the accuracy of the views entertained, because every thing in the or ganization goes on under the influence of the vital force, an immate- rial agent which the chemist cannot employ at will."—Liebig's An- imal Chemistry. 18, d. If we now turn to section 409, b, we shall there find that it is in the blood alone that the reputed proximate principles of vegeta- bles are assumed to exist, and that many proximate compounds are allowed by the chemist to be elaborated from the blood to which there is nothing at all analogous in the vegetable kingdom, or even in the blood itself. This, then, is the sum of the whole subject: 1st. The chemist has his favorite doctrine of digestion, as an important foothold for material- ism, forever present, to be extended as far as the obscurities of the subject will admit, and to borr&w an apparent confirmation from these predicated assumptions. The absolute amount of that doctrine is thus expressed by Liebig : " In the natural state of the digestive process, the food only under- goes a change in its state of cohesion, becoming fluid without any other change of properties."—Liebig's Animal Chemistry. 2d. Now, the food undergoing no other change " in the digestive process" than that of becoming " fluid," it is the easiest matter to find it all in the blood just as it was taken into the stomach,—vegetable a& well as animal; while, in so finding it, a pretended confirmation is set up of the " universal fact, to which nothing yet known is opposed, that the nitrogenized constituents of vegetable food have a compo- sition identical with that of the blood," and vice versa. Or, as Liebig also has it, " vegetables produce in their organism the blood of all animals" (§ 350, no. 76). But, 3d. We are assured by chemists, that nothing is more diffi- cult of analysis than the blood, even as it respects its elementary com- position; while it is well known that the analyses of this fluid are always discrepant. Hence the impracticability of instituting unex- ceptionable comparisons between even the elementary composition of PHYSIOLOGY. 19 blood and the nitrogenized constituents of plants; while the very nature of the chemical influences exerted upon a vital compound of 17 or 18 elements with a view to its analysis is conclusive of the arti- ficial condition of all the chemical compounds which may be thus formed out of the homogeneous fluid. And so Lehmann, § 1029,1030. Again, 4th. It is finally said that many substances elaborated from the blood are utterly different from any thing discovered in plants, or in the blood itself (§ 409, b). Here, the composition of the organic sub- stances being simple, readily leads to an exposure of the assumptions which have taken refuge under the greater difficulties, and obscu- rilfts, and disagreements, attending the analysis of the most complex substance known in nature (§ 53). 18, e. But we shall see, farther on, that the chemical school main- tain, through their principal chief, those doctrines of digestion, to suit other hypotheses in organic chemistry, which are fundamentally opposed to each other, and which I shall now arrange in connection, that the reader may see, at a glance, not only the speculative nature of organic chemistry, but the feebleness of the assumption as to the identity of the blood and the nitrogenized constituents of plants Thus A. "In the natural state of the digestive process, the food only undergoes a change in its state of cohesion, becom- ing fluid without any other change of properties."—Lie- big's Animal Chemistry. C. "The most decisive ex- periments of physiologists have shown that the process of chtmification is inde- pendent of the vital force ; that it takes place in virtue of a purely chemical ac- tion, EXACTLY SIMII AR to those processes of decom- position or transformation which are known as putre- faction, fermentation, or decay.''—Liebig's Animal Chemistry. B. " The VITAL FORCE CAUSES A decomposition of the con- stituents of food, and destroys the force of attraction which is continually exerted be- tween their molecules. It alters the direction of the CHEMICAL FORCES in such wise, that the elements of the constituents of the food arrange themselves in an- other form, and combine to produce new compounds. It forces the new compounds to assume forms altogeth- er different from those which are the result of the attraction of cohesion when acting freely, that is, without resistance."—Liebig's Ani- mal Chemistry. It will be therefore seen by the quotations B and C, that the state- ment is admitted to be a mere assumption; while it necessarily fol- lows, by adopting either of the contradictory statements, B or C, that the vegetable substances undergo a radical change during the process of digestion, and, therefore, that we cannot find those sub- stances in the blood, but their elements, only, in new and peculiar combinations. The differences, indeed, are probably often much greater than between calomel and corrosive sublimate (§ 350i). What, also, gives to the whole of this subject its proper interpre- tation is the parallel which is drawn by Liebig between the assimila- tion of the most virulent poisons and the most appropriate food, as set forth in Section 350, Nos. 41 and 42. The looseness of the clos- ing sentence of No. 41, abstracted from all the surrounding evidence of hypothesis, is abundantly conclusive of the conjectural nature of the whole of this pretended mathematical demonstration. There is no difficulty, however, in comprehending the source of the mistake which honest chemists have made in attempting, by 20 INSTITUTES OF MEDICINE. chemical analysis, to indicate the proper sustenance of man and ani mals. It lies in a wrong conception of the economy of vegetable life, and thence reasoning from a mistaken coincidence of princi- ples, which exist in the two departments of the organic kingdom in a strikingly modified state, to their more analogous results (§ 10, 13-17).—Notes N R pp. 1121, 1123. Since, however, plants subsist upon mineral substances, in their elementary state, the chemist may often successfully indicate those inorganic or organic compounds which will yield to any given species of plant (whose general elementary composition may be known) the elements tfiat go especially to its nutritive economy. But, from a fun- damental distinction between plants and animals (§ 11, 13-17), it is ob- vious that no such thing can be done in relation to the latter. No better practical proof of this can be wanted than the perfectly indiges- tible nature of many compounds which contain the requisite elements. Such compounds, upon the chemical philosophy, as I have said, and as admitted by Liebig, include many virulent poisons in the vege- table kingdom, and many inorganic substances whose binary com- pounds embrace numerous elements. We need not, indeed, go any farther than the recent experiments by Dr. Beaumont upon the va- rieties of food, as will be subsequently noticed (366), and Magendie's analogous experiments with the food of animals,* to show that the Avhole of this subject must be left to natural experience. Nor does it appear to have occurred to the chemical physiologist, in the foregoing inquiries, that the elementary composition of animals is greatly alike, at least in all mammalia. It should follow, there- fore, upon the chemical philosophy, that the practical distinctions should not exist between the food of man and animals, but that a common diet should be as universally adapted as atmospheric air. To this conclusion it may be also added, that the same chemical phi- losophy refers chymification to a purely chemical process; or, in the language of Liebig, " it takes place in virtue of a purely chemical action, exactly similar to those processes of decomposition or trans- formation which are known as putrefaction, fermentation, or decay."— Animal Chemistry, p. 16. And since, therefore, chymification is " independent of the vital force" (ibid.), and as chemistry identifies the gastric juice of man and quadrupeds, and even the chyme, it is obvious that chemistry can predicate nothing, upon this subject, of any difference in the vital constitution of man and animalst (§ 409, 350, d). 19. In respect to their general structure, inorganic bodies are ho- mogeneous, organic beings heterogeneous. This applies as well to the elementary constituents in their modes of combination as to the compound structure of the whole being. Each particle of a mineral compound is as much a whole as the greater mass, and has the same combination of elements. Each element is as perfect as the com- pound conditions. Animals have muscles, glands, nerves, vessels, &c, with an endless variety in the elementary combinations in the same individual. All these parts are necessary to make a whole, and depend, mutually, upon each other for their existence. The same * See Medical and Physiological Commentaries, vol. i.. p. 697, &c. t See my article on the foregoing subject in the Boston Medical and Surgical Journal December 27, 1843. physiology. 21 general principle is applicable to plants. Nevertheless, apparent ex- ceptions occur in both animated kingdoms, as in parts of many plants and of polypi. But, in these instances, each part possesses essential- ly the whole apparatus of organic life. 20. Organic beings grow from within by interstitial deposition of molecules derived from the blood or sap, according to the exact na- ture of each part. Inorganic bodies do not grow, but increase only by a superficial juxtaposition of parts, which may, also, be wholly unlike the original crystal, or other nucleus, in their elements. In the process of growth and nutrition the new material is con- veyed within from without, and subjected to many specific changes, till it is resolved into one homogeneous fluid. Atmospheric air is also indispensable to all organic beings. There is nothing analo- gous in the inorganic world; while these, and an endless series of other facts, establish the similitude of the organic life of plants and animals. 21. A peculiar action of certain agents upon the whole organism of plants and animals, called vital stimuli, entirely unlike the action of chemical agents, is necessary to the growth and existence of or- ganic beings. They are both internal and external, and give rise to all the phenomena in organic life, and maintain the whole in one ex- act condition; while the action of agents upon inorganic, or on dead organic, substances, does not elicit one of these multifarious phenom- ena (§ 74, 1881). 22. Every part of an animal or vegetable is forever distinguished by the same vital phenomena and physical results; and the action of vital stimuli is forever the same on each part, respectively, but, like the vital phenomena and physical results, different in each; the whole being liable to invariable modifications at different stages of life, and according to temperament, and according, also, to every other modifying influence. 23. Unlike inorganic bodies, organic beings require the coexist- ence of solids and fluids in their composition. 24. All organic beings have the power of generating motion within all their parts. Mineral compounds have no such endowment. If motion take place in their internal constitution, it depends upon in- fluences which have no existence in living beings. Nor is this all; for motion is always generated in living beings by the operation of a power implanted in their constitution, and this power is brought into action by the mind, and by internal and external physical agents. 25. The solids and certain fluids of organic beings act upon each other. But the fluids act only upon the organic properties of the solids, while the solids transmute the most important fluid into their own substance. The stimulant action of the blood upon the organic properties, and the reaction of the solids upon the blood, are design- ed for a common end. The concurrence of the whole fabric is ne- cessary to these, as to all other, results. There is nothing analogous in the mineral kinsrdom. 26. When external or internal agents produce motion m organic beings, they do not affect the composition, in the natural state. It ia quite otherwise with inorganic or dead organic compounds. 27. Organic beings are perpetually subject to a vital decomposition and removal of old parts, while the old are exactly replaced by new 22 INSTITUTES OF MEDICINE. ones. It is essential to mineral compounds that they remain \\ ithout change. Any disturbance of their molecules deranges their structure or composition. While, therefore, inorganic compounds are forever the same, or- ganic beings are subject to an unceasing loss of identity as respects their present component parts. 28. The external forms of plants and animals are variously and greatly contradistinguished from those of inorganic bodies. The condition of one, also, is uniform; that of the other, even when crys- talized, is variable. 29. " The only character," says Muller, " that can be possibly compared in organic and inorganic bodies, is the mode in which sym- metry is realized in each; that is to say, the character which miner- als possess in their state of crystalization." Yet there is not, in this respect, the slightest analogy; since no true organic compound ever approaches the condition of a crystal. Here Ave may trust the au- thority of Liebig, who says of the " vital principle of the animal ovum, as well as the seed of a plant," that, " Entering into a state of motion or activity, it exhibits itself in the production of a series of forms, which, although occasionally bounded by right lines, are yet widely distinct from geometrical forms, such as we observe in crystalized minerals. This force," he goes on, " is the vital force, vis vitae, or vitality." 30. The foregoing considerations, each and all (§ 8-29), demon- strate a radical difference between the forces and laws of organic and inorganic beings, and a remarkable modification of such as are com- mon to plants and animals. But, as the institutions of organic life lie at the foundation of medical science, they should be still farther sought in the contradistinctions between the organic and inorganic kingdoms, and in those diversified phenomena which indicate a com- mon but modified government of animals and plants. All organic beings possess in common the most essential conditions of life, though existing in the two great departments of living nature under specific modifications or varieties ; not, however, very dissimilar, but inti- mately connected by a gradation of analogies, as we descend along the chain of either, till Ave arrive at their more absolute connecting link in the lowest being of one and the other. Other conditions are superadded to the nobler department, which, with the differences of structure and the modifications of their common properties of life, and their modes of subsistence, distinguish the two living kingdoms from each other. 31. Physiology may be divided into, 1st. The composition of or- ' ganic beings; 2d. Their structure; 3d. Their properties; 4th. Their functions ; 5th. Modifications of properties and functions which arise from sex, temperament, climate, habits, age, &c.; 6th. The relations of organic beings to external objects ; 7th. Death. These several topics will be considered with a special view to the great principles which form the Institutes of Medicine. PHYSIOLOGY.--COMPOSITION. 23 FIBST DIVISION OF PHYSIOLOGY. COMPOSITION. 32. The principal object contemplated by this work in ascertaining the facts relative to the composition of organic beings is to settle the principles and laws upon which such beings are constituted, by tracing them out in the fundamental conditions of organic matter. 33. Composition is subdivided into ultimate or elementary, and the proximate parts ; the latter being compounded of the former. 34. Of the sixty-six known elementary substances, the following seventeen have been found in the composition of plants : carbon, oxy- gen, hydrogen, nitrogen, potassium, calcium, iron, manganese, phos- phorus, sulphur, silicium, magnesium, aluminum, chlorine, sodium, iodine, bromine. 35. The same elements (34), with the addition of fluor, and the probable exception of aluminum, occur in animals. Arsenic is also often found in man.* Although animals are exposed to various sources from which other elements might be derived, they reject ev- ery other elementary principle; or, rather, are incapable of their assimilation.—Notes N R pp. 1121, 1123. 36. The foregoing coincidence in the common nature of the ele- ments of plants and animals supplies no small proof of the peculiar properties and laws of organic beings. Others, however, more stri- king, lie at the foundation, and form, also, contradistinctions with the inorganic world. 37. Animal and vegetable substances are mostly composed of car- bon, oxygen, hydrogen, and nitrogen, four out of the sixty-six ele- ments that go to the formation of inorganic compounds. The main bulk of plants, indeed, such as the cellular and vascular tissues, is probably composed of carbon, hydrogen, and oxygen alone, as the essential elements; though nitrogen is indispensable to many of the products of vegetable organization, and Liebig says it is found in all parts of a plant (§ 62, f, note). The three or four indispensable ele- ments compose 90 or more parts of 100 of all the soft textures of an- imals, and of ali plants. These are selected, universally, by the veg- etable kingdom, as if by instinct. This circumstance increases great- ly the force of the conclusion in the foregoing section (§ 36). 38. The elements of mineral compounds are always united in a binary manner; those of organic in a ternary, quaternary, &c, being always intimately blended with each other. This distinction involves an absolute difference in the powers and laws of the two kingdoms. 39. No two elements, therefore, can form a true organic compound. The rare exceptions which have been made by the chemists are not organic substances, nor can they be rendered such by the animal or- ganization. They belong to the mineral kingdom, from which they cannot be elevated but by the properties of vegetable life (§ 14,16,17). All mineral compounds may be resolved into their elements, which are as perfect minerals as when united. Indeed, the most natural con- dition of a mineral is the state of a simple element. * Whence come the fluor and the arsenic, unless through plants? (§ 14-18.) 24 INSTITUTES OF MEDICINE. 40. What, therefore, is so fundamental in organic beings as ex- pressed in sections 38 and 39, and universally admitted, allows of no introduction of powers, principles, laws, &c, which shall conflict with the powers and laws upon which the simplest organic compound is constituted. In the progress of this work it will be seen that this position is every where substantiated. Unity and harmony prevail throughout each department of nature, respectively; and while the powers and laws of the organic are as fully contradistinguished from those of the inorganic kingdom as are their physical and all other attri- butes, we shall find that the former are apparently embarrassed by a great diversity of phenomena as manifested in health and disease, but that, in reality, all the variety goes to the conclusion that the funda- mental principles are the same throughout (§ 638, 733, d). 41. Again, we may suppose at least some 20,000,000 of distinct or- ganic compounds in the various species of plants, and some 30,000,000 more in the animal kingdom, formed mostly out of four elements (§37), while these same elements yield scarcely a dozen combinations in the mineral kingdom. 42. The foregoing organic compounds are formed in each individ- ual, respectively, out of one common homogeneous fluid, composed of about seventeen elements.* No chemical hypothesis can interpret this universal characteristic of the organic kingdom; while all the relative facts of inorganic chemistry are totally opposed to this almost endless and undeviating variety of neAV combinations out of a common fluid, according to the species of animal or plant, and according to the nature of every particular part. If chemical agencies operated, there would be no uniformity in any secreted product at any two successive moments (§ 741, b, 1052). It is one of the frequent concessions of the distinguished chemico- vitalist, Miiller, that " The opinion that the component principles of the organs exist in the blood in their perfect state cannot be possibly adopted. The com- ponents of most tissues, in fact, present, besides many modifications of fibrin, albumen, fat, and ozmazome, other perfectly peculiar matters, nothing analogous to which is contained in the blood." " Even the fibrin of muscle cannot be considered identical with the fibrin of the liquor sanguinis."—Muller.—So, also, Lehmann, § 1029—1031.. John Hunter also laid down the following doctrine, as expressed by his editor, Mr. Palmer : " It is highly probable that the different proximate principles of vegetable and animal substances hold different ranks in the scale of organized substances, in the same manner that one animal ranks high- er in the scale of organized beings than another."—Hunter. And thus Liebig, as a vitalist, in opposition to himself, as a chemist : " In that endless series of compounds, which begins Avith carbonic acid, ammonia, and water, the sources of the nutrition of vegetables, and includes the most complex constituents of the animal brain, there is NO BLANK, NO INTERRUPTION. TlIE FIRST SUBSTANCE CAPABLE OP AFFORDING NUTRIMENT TO ANIMALS IS THE LAST PRODUCT OF THE CRE- ATIVE energy of vegetables."—Liebig's Animal Chemistry. * It is now conceded by physiologists, generally, that the chyle, lymph, and blood, are each, severally, as expressed by A^agner, "homogeneous fluids, with certain peculiar corpuscles mixed with them."—See Wagner's Elements of Physiology, p. 250. Lon- don. 1842. ' PHYSIOLOGY.--COMPOSITION. 25 43. Although it be generally true that it is the wonderful province of organization to elect only four elements from the homogeneous fluid (§ 42) in the formation of organic compounds, yet there are some com- pounds which embrace a greater number, though unlike the elements of inorganic compounds, in intimate union with each other (§ 38). The blood, indeed, has not less than seventeen or eighteen elements thus united; a circumstance in itself conclusive that other powers than the chemical must preside over the elaboration of the very limited number of elements that go uniformly to the formation of all other organic compounds. And, although the metallic and earthy sub- stances form no part of the essential organs of life, they are yet vitally united with the indispensable organic compounds in particu- lar parts, and are elaborated from the blood or sap by those parts only, and with an astonishingly relative proportion to the other elements, as sulphur by the brain, phosphate of lime by the bones, fluate of lime by the teeth, phosphate of magnesia by wheat, silex by the stem of wheat, and by the skeletons of many poriferi, &c. We shall not regard these substances as accidental, or as introduced by a physical process, but, as contributing a subordinate part with the essential organic elements toward the perfection of an unfathomable system of Designs, whose moving power is only short of the Creative Energy, in being substituted for that Great First Cause, Avith limita- tions that chain it to the fulfillment of secondary ends (§ 847). 44. Organic compounds are forever the same, in health, in any given part of any species of being at each stage of existence, but liable to be more or less modified in an exact manner at the several stages (§ 153-159). And so of disease. The same morbid state of any given part, cete- ris paribus, always produces the same modifications of the organic compounds of which it may be composed, the same alterations of the secreted fluids, and the same new formations. All this is distinctly seen in the phases of scrofula, in 6mall-pox, cow-pox, lues, measles, hy- drophobia, &c. It is opposed to all facts, that any chemical influences can decom- pound a fluid composed of seventeen or eighteen elements, not only up the exclusive manner represented in the last section, but according, also, to the exact vital constitution or vital modification of each part. 45. Nevertheless (§ 44), the general composition of animals is the same, whether they subsist upon grass, or flesh, or whatever be the nature and variety of the food. So of the chyme, the chyle, and the blood. There is nothing in chemistry that will throw any light upon these coincidences (§ 18, 409). 46. Contrary to what has been seen of the variety of organic com- pounds out of four simple elements (§ 41), only a few hundred, at most, of distinct inorganic compounds can be formed out of the 66 elements which compose the mineral kingdom (§37). Those few compounds, however, make up the great mass of the globe, while the organic are only scattered over its surface. Nor is there a globe in the universe that would not be as worthless as space, did it not administer to the purposes of life. 47. Different combinations of carbon, oxygen, hydrogen, and nitro- gen, constitute, mainly, the Avhole vegetable and animal materia medi- 26 INSTITUTES OF MEDICINE. ca; while their inorganic compounds do not contribute on £ remedial agent of any importance. 48. It is evident that the four principal elements of organic com- pounds combine not only in different proportions, but so variously, in respect to the proportions, among themselves, as to bewilder the imagination (§41). Chemistry can give us no light upon these sub- jects but what is purely analytical; while, in respect to their mineral compounds, the same elements unite only in a small number of pro- portions, upon which chemistry throws its light with a brilliancy that may be said to penetrate the unfathomable recesses of their organic compounds. This fundamental distinction is necessarily conceded; and it were .well for science if chemistry did not overstep the limit. But, the chemist shall always speak for himself. Thus Liebig : " 6 eq. tartaric acid, by absorbing 6 eq. oxygen from the air, form grape sugar, Avith the separation of 12 eq. carbonic acid. We can explain, in a similar manner, the formation of all the component substances of plants, which contain no nitrogen, whether they are pro- duced from carbonic acid and water, with separation of oxygen, or by the conversion of one substance into the other, by the assimilation of oxygen and separation of carbonic acid. We do not know in what form the production of these constituents takes place. In this respect the representation of their formation which we have given must not be received in an" absolute sense, it being intended only to render the na- ture of the process more cap/able of comprehension. But, it must not be forgotten, that, if the conversion of tartaric acid into sugar, in grapes, be considered a fact, it must take place under all circumstances in the same proportions" !—Liebig's Organic Chemistry applied to Physi- ology. The reader should never lose sight of the foregoing hypotheses and admissions. They should be ever ready to chasten his credulity as to the chemical interpretation of every organic compound. They stamp the whole " science of organic chemistry," in its synthetical aspects, as one of pretension, and unworthy the confidence of an intel- ligent mind (§ 350-350f). And this is farther confirmed by the statements in the two next following sections. 49. " The particles of matter," says Liebig, "called equivalents in chemistry, are not infinitely small, for they possess a weight, and are capable of arranging themselves in the most various ways, and of thus forming innumerable compound atoms. The properties of these compound atoms differ in organic nature, not only according to the form, but, also, in many instances, according to the direction and place which the simple atoms take in the compound molecules. " When we compare the composition of organic compounds Avith inorganic, we are quite amazed at the existence of combinations in one single molecule, of Avhich ninety or several hundred atoms or equivalents are united. Thus, the compound atom of an organic acid of very simple composition, acetic acid, for example, contains 12 equivalents of simple elements; 1 atom ofkinovic acid contains 33; 1 of sugar, 36 ; 1 of amygdalin, 90 ; 1 of stearic acid, 138 equivalents. The component parts of animal bodies are infinitely more complex even than these."—Liebig's Organic Chemistry, &c. 50. " Inorganic compounds differ from organic in as great a deoreo PHYSIOLOGY.--COMPOSITION. 27 in their other characters as in their simplicity of constitution. Thus, the decomposition of a compound atom of sulphate of potash is aided by numerous causes, such as the power of cohesion, or the capability of its constituents to form solid, insoluble, or, at certain temperatures, volatile compounds with the body brought into contact with it; and, nevertheless, a vast number of other substances produce in it not the slightest change. Now in the decomposition of a complex organic atom there is nothing similar to this."—Liebig's Organic Chemistry &c. 51. " An essential distinction between organic and inorganic com- pounds is, that in organic products the combining proportions of their elements do not observe, as in mineral compounds, a simple arith- metical ratio." 52. An interesting corollary flows from the foregoing facts (§ 22, 41-50), namely, that all animal and vegetable poisons, all remedial agents of an organic nature, and all the varieties of food, depend upon the modes and proportions in which three or four simple elements unite with each other. It is evident, also, from § 41, that no two re- medial agents generated by different species of plants or animals, however similar, can be exactly alike in their morbific or remedial virtues. Hence the differences among cathartics, emetics, &c. As composition, especially of the sap, also varies more or less at ihe dif- ferent ages of plants and at different seasons, and also from unhealthy conditions, so will corresponding differences arise in their remedial and morbific virtues. In all the cases, however, the characteristics of organic products as vital agents are uniformly the same under any given condition of the organic being ; and so of each simple element, and of the physiological effects of all vital agents (§ 188^, d). The precise natural or morbid states of the organic properties lie at the bottom of the whole philosophy, since these properties, through their- instruments of action, combine the elements exactly according to their existing state (§ 650, 741 b). 53, a. From the facts now stated (§ 38-51), it is evident that the organic chemist can do no more than effect an analysis of organic compounds. He can only present each simple element by itself, without the possibility of acquiring a knowledge of the modes and proportions in which they combine with each other. 53, b. So» also, if the aggregate compounds, such as blood, sap, muscle, gastric juice, &c, be, in reality, made up of more simple compounds, or " proximate principles," by the union of compound atoms, chemistry can give us no information as to the conditions in which they naturally exist. Those combinations which are most alike are different from each other in every distinct part of the or- ganic being, and different in the same parts of distinct species. This is so from the first development of the germ; and what is then begun is perpetuated through the life of the individual, and transmitted to all succeeding generations (§ 63-81, 155). The differences, as we have seen, result from the different proportions in which some three or four simple elements are united together, and from the proportions of different compound atoms which may enter into the entire combi- nation, and from the manner in which they and their elements are combined among themselves. It must be obvious, therefore, that we can never reach the secret of these combination?. We should neces- 28 institutes of medicine. sarify expect, even from the shades of elementary distinctions, that chemistry would confound and even identify many compounds that are totally unlike in their nature. And this it actually does, in pre- senting to us sugar, vinegar, starch, gum-arabic, Avood, &c, as the same substance ; and in identifying pus and cheese, and, again, the albumen of eggs, lymph, mucus, and the product of certain cancerous affections. Nor is there generally any agreement among the chem- ists in their analyses of organic compounds. It is as true now, as when Bostock (a chemical physiologist) affirmed, that " every subse- quent attempt to discover the elements of organized substances differs more or less from those that preceded it" (§ 1029, 1030). The moment chemical agencies begin their operation, artificial transformations necessarily ensue, and the nature of the organic com- pound is changed in a corresponding manner. A large proportion of the resulting products are perfectly new formations, particularly all the binary compounds (§ 38, 39). Nor can there be any doubt that the reputed " proximate principles" are intimately incorporated in any given compound, and have no such separate existence as chemistry teaches. It lies at the very basis of chemistry, that all the elaborations are the artificial results of affinities which have been set in motion by the agents employed, and which are employed for that very purpose. This ?have already endeavored to demonstrate in the Medical and Physiological Commentaries (vol. i., p. 674-6S2), even so far as to show that urea may not be formed by the kidneys, but is the result of spontaneous changes after the elaboration of urine, as it is of artificial influences (§ 54, a). But, attentive observation will gen- erally detect the chemist in the admission of facts which are subver- sive of his speculative doctrines (§ 18, 350); and so it is in the case before us. The admission covers the whole ground as to the preten- sions of organic chemistry beyond the most simple elementary anal- ysis. Thus, 53, c. " Were we able to produce taurine and ammonia directly out of uric acid or allantoine, this might perhaps be considered as an additional proof of the share which has been ascribed to these compounds in the production of bile. It cannot, however, be viewed as any objection to the views above developed on the subject, that with the means we possess, Ave have not yet succeeded in effecting these transformations out of the body. Such an objection*loses all its force, when we consider that we cannot admit, as proved, the pre-ex- istence of taurine and ammonia in the bile ; nay, that it is not even probable that those compounds, which are only known to us as the products of the decomposition of the bile, exist ready formed, as ingredients of that fluid. By the action of muriatic acid on bile, we in a manner, force its elements to unite in such forms as are no longer capable of change under the influence of the same re-agent." —Liebig's Animal Chemistry. By the admissions, also, in § 18, 42, and 350, it will be seen that the Utopian nature of organic chemistry is equally established in all its pretensions by its own founders and advocates (§ 1030). 54, a. Organic substances alone undergo fermentation and putre- faction ; and this shows us, also, in the language of Tiedemann, that " even when the life of organic bodies is extinct, we should consider the qualities Avhich they possess, from the time of death to the com- physiology.—composition. 29 plete resolution of organization, as the result of the vital powers which have been active in them." This obvious principle conducts us at once to the whole philoso- phy of those numerous transformations of which organic compounds are susceptible from chemical agencies, while they still retain their elementary combinations, and appear under uniform aspects when subjected to the same chemical influences, and often analogous to the natural condition of the compound. " It is the power of formation," says Tiedemann, " which, after the extinction of the individual life of organized bodies, renders the organic matters, separated from their organization, capable, provided they have not been reduced to their elements by external physical or chemical actions, of assuming new and more simple forms, according to the diversity of external in- fluences, such as heat, light, water, &c, which determine them in taking on this new form. This power appears, therefore, to be a prop- erty inherent in organic matters in general, rendering them able to take other more simple configurations when detached from the com- binations of living bodies " (§ 1029, 1030). Some organic compounds undergo transformations of the foregoing nature as soon as separated from the organic being. The homo- geneous blood is immediately reduced into three principal compounds, which have no natural existence as such. Nor is this all; for there is a fundamental change among the elements and the compound atoms of the entire mass. The changes arise from the loss of the vital properties, and the subsequent operation of chemical influences. Such, too, is the constitution of organic compounds that there may be a remarkable uniformity in the resulting products when the same chemical agents operate upon any given compound; as exemplified in the various transformations to Avhich sugar is liable, and as seen in the uniform production of morphia, narcotina, quinia, cinchonia, &c. 54, b. It is obvious, hoAvever, from the premises which I have set forth, that chemistry can, at most, present but a few compounds as appa- rently distinct from each other in their elementary composition; for, al- though there are many millions of these distinct combinations in organic beings (§ 41), they commonly possess such analogies that chemistry is obliged to confound all but a few which have strong characteris- tics. These few, which are denominated proximate principles, are supposed by the chemist to make up the entire composition of organic beings. But, a greater proportion even of these few are so inscruta- bly different from each other in their elementary combinations, that they are classed under common denominations, not only for the fore- going reason, but on account of certain resemblances in their physical properties; while it is by these last, and by their differences in re- sults as vital agents, Ave come to know that broad distinctions may exist among them. Such, for example, are the various acids, oils, resins, &c. 55. All organic substances, while endowed with life, resist the de- composing influences of all surrounding agents. All inorganic com- pounds yield to these influences. 56. As soon as organic beings are dead, the very agents that had contributed to their growth and nourishment now become the causes of breaking up their elementary combinations, and with a rapidity un- known in the ordinary decomposition of mineral compounds. In the 30 institutes of medicine. former case, it is allowed by Liebig, that the " vital principle op- poses to the continual action of the atmosphere, moisture, and tem- perature, upon the organism, a resistance which is in a certain degree invincible." 51. In the seed and ovum the properties of life are in a state of ac- tion which maintains their elementary combinations against the chem- ical forces. They resist degrees of cold which operate destructively upon their composition Avhen their life is extinct. Those agents, too, as heat and moisture, which speedily resolve the egg and seed, when deprived of life, into their ultimate elements, Avill in the same de- grees of intensity develop from the germ, when alive, a perfectly organized being. In the former case the operation of the principle of life is generally mistaken for " a force in a state of rest." Thus, Lie- big: " In the animal ovum, as well as in the seed of a plant, we recog- nize a certain remarkable force, the source of growth, Sec, a force in a state of rest."—Liebig's Animal Chemistry, first sentence. See, also, my Examination of Reviews, p. 7-2S. 58. It follows, therefore, that the power which resists the decom- posing forces and agents in living beings combined the elements of such beings, and that death is an extinction of that power. The chem- ical forces can have no connection with the combinations, since they are held together by a power in direct opposition to chemical influ- ences. What, therefore, unites the elements and maintains them against the action of chemical agents, being the fundamental power, must ne- cessarily preside over all the processes and results to which organic beings are liable. 59. " The elements of dead organic matter," says Liebig, in his Or- ganic Chemistry, " seem merely to retain passively the position and condition in which they had been placed." " The atoms exist only by the vis inertia of their elements." So, also, Mulder, § 350|, n, and other chemical physiologists. This shows that the original union is effected by other powers than the chemical, which, otherwise, would still operate after death, and prevent decomposition. We also thus learn why dead organic compounds so readily undergo fermentation and putrefaction, and from the slightest influences. All of Avhich, indeed, appears to be abundantly conceded by the chemical philoso- pher when he yields to the force of facts. For what can be more ample than Liebig's affirmation, that " The vital force is manifested in the form of resistance, inas- much as by its presence in the living tissues, their elements acquire the power of withstanding the disturbance and change in their form and composition, which external agents tend to produce ; a power, which, as chemical compounds, they do not possess."—Liebig's Animal Chem- istry. And yet again may I press into the service of truth the organic chemist, when he temporarily loses sight of the laboratory, and con- tradicts those speculations which impart to his writings the zest of novelty. In his Lectures for the winter of 1844, Liebig appears to have been alarmed for the safety of his empire, and we have here an unusual amount of " vitality." The work on Animal Chemistry applied to Pathology and Thera- PHYSIOLOGY.--COMPOSITION. 31 peutics was more of a distillation from the laboratory than its prede- cessor, Organic Chemistry applied to Physiology; and, as many of the most eminent physiologists in Europe, who were inclined to min- gle chemistry Avith vitalism, Avere nauseated by the dose which was last administered, Liebig came out in his Lectures Avith the following placebo for the vitalists, and the chemico-vitalists. Were it not con- tradicted by the lecturer, it should place him in the very front rank of vitalism. The doctrines are of the most fundamental nature, and lie at the basis of these Institutes, and of my " Medical and Physiological Commentaries." It will be seen that they are strictly relative to my present subject, and inculcate all that the most transcendental vital- ist can desire as to the distinct nature of the vital principle, its full con- trol over the processes of life, its extinction at death, and an absolute distinction between vital and chemical processes and results, while those processes and results are, respectively, referred to forces of a totally dis- tinct nature. Thus: "After the extinction of the vital principle," says Liebig, "in or- ganic atoms, they maintain their form and properties, the state into which they have been brought in living organisms, only by reason of their inherent inertia. It is a great and comprehensive law of matter, that its particles possess no self-activity, no inherent power of origin- ating motion, when at rest; motion must be imparted by some exter- nal cause; and, in like manner, motion once imparted to a body can only be arrested by external resistance. " The constituents of vegetable and animal substances having been formed under the guidance and power of the vital principle, it is this principle which determines the direction of their molecular attraction. The vital principle, therefore, must be A motive power, capable of imparting motion to atoms at rest, and of opposing resistance to other forces producing motion, such as the chemical force, heat, and elec- tricity. We are able to reliquefy and redissolve albumen, after it had been coagulated by heat, but the vital principle alone is capable of restoring the original order and manner of the molecular arrangement in the smallest particles of albumen. Coagulated albumen is again converted into its original form, it is transformed into flesh and blood in the animal organism.—Notes N R pp. 1121, 1123. " In the formation of vegetable and animal substances, the vital principle opposes, as a force of resistance, the action of the other forces,—cohesive attraction, heat, and electricity,—forces Avhich ren- der the aggregation of atoms into combinations of the highest order impossible, except in living organisms. " Hence it is, that when those complex combinations which consti- tute organic substances are withdrawn from the influence of the vital force,—when this no longer is opposed to the action of the other dis- turbing forces, great alterations immediately ensue in their properties, and in the arrangement of their constituents. The slightest chemical action, the mere contact of atmospheric air, suffices to cause a transpo- sition of their atoms, and to produce new arrangements ; in one word, to excite decomposition. Those remarkable phenomena take place which are designated by the terms fermentation, putrefaction, and decay ; these are the processes of decomposition, and their ulti- mate results are to reconvert the elements of organic bodies into that state in Avhich they exist before they participate in the processes of life." 32 INSTITUTES OF MEDICINE. The reader, however, will be more astonished to learn that he has not discovered, amid the multitude of conflicting statements and doc- trines, a passage in the work on Animal Chemistry which, even more than the preceding, identifies " the Reformer" with the most exclu- sive vitalists, and completely annuls all his chemical and physical speculations as to organic life, and hi# radical distinctions between plants and animals (§ 350, nos. 12, 15,20). It will be also seen with what pretense he has been denominated " the Reformer," and " the author of a new and the greatest era in physiology." The extract in- culcates the doctrines of an independent vital principle, its identity in plants and animals, the action of stimuli upon that principle, its susceptibility of influences from the nervous power in animals, the absence of that influence in plants, and the dependence of all organic processes and results, equally in plants and animals, upon that prin- ciple. Now these are exactly the doctrines which are also fundamental throughout the Medical and Physiological Commentaries and these Institutes. They are relative to the constitution and processes of organic beings as a whole, while the foregoing quotations from Lie- big's Lectures comprehend the principles by which I have interpret- ed the elementary condition of organic bodies. Thus our author: " The activity of vegetative life manifests itself,in vegetables, with the aid of external influences ; in animals, by means of influences pro- duced within the organism. Digestion, circulation, secretion, are, no doubt, under the influence of the nervous system; but the force which gives to the germ, the leaf, and the radical fibres of the vegetable the same wonderful properties, is the same as that residing in the se- creting membranes and glands of animals, and which enables every animal organ to perform its own proper functions."—Liebig's Ani- mal Chemistry. 60. " The diversity of the transformations and of the resulting products," says an able advocate of Liebig's physical doctrines of life, " indicate most certainly the complexity of an organic product" (§ 41). " The metamorphoses which occur after organic substances are removed from the influence of the vital force, constitute a separa- tion, or splitting up into new and less complex compounds" (§ 54).— Mr. Ancell, in London Lancet, Nov. 26, 1842. Thus, again and again, does the chemical physiologist unavoidably concede that the elements of organic beings are held together by a vital principle, and, therefore, that they are originally united by that principle. Vitalism becomes established in all its aspects, even in what has been denominated " transcendental vitalism," when it may be shoAvn that the elements of organic beings are, in the language of Liebig, " united by a peculiar mode of attraction, resulting from the existence of a power distinct from all other powers of nature, namely, a Vital Principle;" since, as I have said, the powers and laws which regu- late the composition must be at the foundation of all the subsequent results. Concessions of fundamental principles overthrow all oppos- ing "facts," and all secondary doctrines of a conflicting nature. These, therefore, may be advantageously connected with demonstra- tions of the truth. There are few intelligent minds that do not right- ly appreciate those grand phenomena of Nature which conduct us to PHYSIOLOGY.—composition. 33 a knowledge of her fundamental laws, or do not incidentally betrav their conviction of the right, however the enticements of fame mav beguile them into ingenious substitutions. I shall, therefore, as on all former occasions, continue to bring to the aid of my conclusions the powerful concessions of the most eminent men who belong to the adverse schools in organic philosophy. It is manifest that such au- thorities must weigh with the force of demonstration, since it is obvi- ous that their admissions can flow only from convictions that have been obtained in the school of Nature. Among the most illustrious of the adverse school is Liebig, and standing intermediate is the pro- found and erudite Miiller. And having thus referred again to this great philosopher, I will not lose the opportunity of obtaining from him an important contribution to the doctrines of vitalism as they re- late to the very composition of organic beings, and in which he insti- tutes a broad contrast betAveen the affinities which unite the elements of organic and inorganic compounds. Thus : " Chemical substances," says Miiller, " are regulated by the intrin- sic properties and the elective affinity of the substances uniting to form them. In organic bodies, on the contrary, the power which in- duces, and maintains, the combination of their elements, does not consist in the intrinsic properties of those elements, but in something else, which not only counteracts those affinities, but effects combina- tions in direct opposition to them, and conformably to the laws of its OAvn operation."—Muller, Elements of Physiology, p. 4. Liebig, also, variously inculcates the same great principle. Take, in the first place, a demonstration the converse of Midler's. It is the last paragraph in the work on Organic Chemistry. Thus : " The same numerous causes which are opposed to the formation of complex organic molecules, under ordinary circumstances, occasion their decomposition and transformations when the only antagonist POAVER, THE VITAL PRINCIPLE, NO LONGER COUNTERACTS THE INFLU- ENCE of these causes. New compounds are formed in which chem- ical affinity has the ascendency, and opposes any farther change, while the conditions under which these compounds were formed re- main unaltered." Again, we are informed by this chemist, that " The equilibrium in the chemical attractions of the constituents of food is disturbed by the vital principle, as we know it may be by many other causes. But'the union of the elements, so as to produce new combinations and forms, indicates the presence of a peculiar MODE OF ATTRACTION AND THE EXISTENCE OF A POWER DISTINCT FROM ALL OTHER POWERS OF NATURE, namely, the VITAL PRINCIPLE." " If the food possessed life, not merely the chemical forces, but this vi- tality would offer resistance to the vital force of the organism it nourished." " The indiA'idual organs, such as the stomach, cause all the organic substances conveyed to them, which are capable of transfor- mation, to assume new forms. The stomach compels the elements of these substances to unite into a compound fluid for the formation of blood."—Liebig's Organic Chemistry, p. 356, 357, 346, 384. 61. It is a remarkable characteristic of organic beings that they aie composed chiefly of combustible substances, properly so called, and a supporter of combustion; with the principal exception of that anom- aly in the inorganic kingdom, nitrogen gas (§ 37). 34 institutes of medicine. 62, a. The general introduction of nitrogen gas into the constitution of animal compounds, and into many of a vegetable nature, while it is excluded from mineral compounds, is one of the most striking distinc- tions between the two kingdoms of Nature. Upon that distinction I have founded an argument, in my Essay on the " Philosophy of Vital- ity," in proof of the difference in the powers and laws by which the two kingdoms are governed. It appears also appropriate to this work that the proof should be here introduced. 62, b. I have said in the foregoing Essay, that it is abundantly ev- ident that living beings are endowed with properties which protect their elementary composition against all those decomposing agencies which are perpetually separating the elements of all mineral com- pounds. This shows that the properties, by which the elements of living beings are united, are utterly different from such as combine the elements of inorganic compounds. Nevertheless, the living or- ganization is undergoing a systematic change, a perpetual decomposi- tion, surpassing any mutations that are in progress in the surrounding world. These decompositions are, also, of a peculiar nature, govern- ed by established laws, various in different parts of the same individ- ual, yet forever the same in any given part (§ 44). I shall not stop to show how the old are replaced by new materials, and how the pro- cesses go on pari passu, and in opposition to all the philosophy which chemistry teaches, but only say that the decompositions must be effect- ed by properties as peculiar to the living compound as are the results ; and that these results conspire with the peculiar modes in which the elements are combined in proving the existence of specific properties, which are the common cause of all the harmonious phenomena of liv- ing beings (§ 38-42). 62, c. When, however, the organic being dies, a new order of de- composition begins, eminently of a chemical nature, and in forcible contrast with that which concerns the vital process of renewal. This is due to the special element, nitrogen gas, which may be called the principle of dissolution. Wherever present, it gives rise to transfor- mations and disunion of all the other elements after the properties of life have lost their sway. The moment these cease, chemical decom- position begins,—confusedly, violently; and such are the nature and combinations of the elements, that their disruption would go on with no other contribution from surrounding agents than water alone. Hence the more rapid transformations and dissolution of animal than of vegetable tissues, and of sap and other substances which are gen- erated by vegetable organization. 62, d. Liebig says of nitrogen gas, that "there is some peculiarity in its nature, which gives its compounds the power to decompose sponta- neously with so much facility. Now, nitrogen is known to be the most indifferent of all the elements. It evinces no particular attrac- tion to any one of the simple bodies, and this character it preserves in all its combinations; a character which explains the cause of its easy separation from the matter with which it is united." And again, " When those substances are examined Avhich are most prone to fer- mentation and putrefaction, it is found that they are all, without ex- ception, bodies which contain nitrogen."—Liebig's Organic Chemistry applied, &c, p. 241. 62, e. In the inorganic kingdom, nitrogen is mostly confined to the physiology.--COMPOSITION. 35 atmosphere, where it probably exists in a state of simple intermixture with oxygen. " All bodies Avhich have an affinity for oxygen abstract it from the atmosphere with as much facility as if the nitrogen Avere absent altogether ;" and we have striking examples of the disposition of nitrogen to separate from its compounds, " in the easy transposi- tion of atoms in the fulminating silvers, in fulminating mercury, and in all fulminating substances," whose ready explosion is owing to the presence of nitrogen. " All other substances," says Liebig, " con- taining nitrogen acquire the same power of decomposition when the elements of water are brought into play." 62, f. Noav the foregoing characters belong to nitrogen only as it exists in inorganic or in dead organic compounds, while the former, also, are artificial, or due to accidental causes. In living beings, Avhere it abounds,* it adheres to its associated elements with a tena- city Avhich no agent can impair till it destroys the life of the part; or, in other words, till it destroys those vital properties by which the ele- ments Avere truly united. It is then, however, that the forces of chem- istry take possession, and the elements may explode, I had almost said, with the facility of the fulminating compounds. 62, g. " There is," says Liebig, " in the nature and constitution of the (inanimate) compounds of nitrogen, a kind of tension of their component parts, and a strong disposition to yield to transformations, Avhich effect spontaneously the transposition of their atoms on the in- stant that water or its elements are brought in contact Avith them." On the contrary, " it is found that no body destitute of nitrogen pos sesses, when pure, the property of decomposing spontaneously while in contact with Avater."—Liebig. But, although dead animal compounds readily pass into sponta neous decomposition under slight degrees of moisture, yet, composed as they are, in part, of the elements of water, and very largely im- pregnated Avith aqueous substances in their living state, neither those elements, this Avater, nor any other agent, can disturb the exact com- binations. But, Avhen the organic being dies, chemical agencies have their play, and it is then that " The result of the knoAvn transformations of substances containing nitrogen proves," according to Liebig, " that the water does not mere- ly act as a medium in which motion is permitted to the elements in the act of transposition, but that its influence depends on chemical affinity. When the decomposition of such substances is effected with the assistance of water, the nitrogen is invariably liberated in the form of ammonia."—Liebig. In respect to the inorganic Avorld, had nitrogen been incorporated in its compounds, there would have been no stability among them. They Avould have been perpetually undergoing decomposition, until finally the whole of the nitrogen would fly off by itself, and nothing of the original compound would remain ; and it could never be re- combined. 62, h. Besides the disposition of nitrogen to tear asunder the ele- * Nitrogen is well known to abound in all the tissues of animals. Of vegetables, Lie- big says, that, "Estimated by its proportional weight, nitrogen forms only a very small part of plants, but it is never entirely absent from any part of them. Even when it does not enter into the composition of a particular part or organ, it is always to be found in the fluids which pervade it."—Liebig's Organic Chemistry applied to Physiology, &c, p. 4. 36 INSTITUTES OF MEDICINE. ments with Avhich it may be combined, the complexity of these ele- ments in organic beings contributes to the disorganizing results aftei death, and is another principal cause of spontaneous fermentation and putrefaction (§ 38, 41, 46, 48, 52, 53). 62, i. From the foregoing facts, especially from the universality and fixedness of nitrogen in organic beings, I arrive at the conclusion that the elements of their compounds are united by forces as peculiar as the facts which relate to these compounds, and that the forces of chemistry have no agency in combining the elements, or in effecting changes of their combinations during life. It is also abundantly man- ifest from my premises, that Liebig's declaration that " by chemical agency we can produce the constituents of muscular fibre, skin, and hair," is Avithout the slightest foundation (§ 12, 13, 14). 62, k. The whole labyrinth of combinations in organic beings, and their ultimate return to binary compounds, are full of the most stu- pendous design. The final cause of the reduction of the organic being, when its own specific purposes are ended, is that of again supplying the means of growth to vegetables yet alive, that the elements may be again elaborated into ternary and quaternary compounds, to carry out the final purpose of the vegetable kingdom in supplying nutriment to animals (§ 303).—Note C p. 1113. 63. In the Essay to which I have referred in the last section, I have endeavored to deduce the principles of vitalism from the phenomena that attend the development of the* incubated egg, as had been briefly set forth in my " Examination of Reviews." The considerations there made are peculiarly appropriate to the present work, and to die place at which I have now arrived. It was my object to consider, 1st. The constitutional nature of the ovum. 2d. To show by the philosophy of generation, and by the nature of the poAvers which are universally admitted to be alone concerned in developing the germ or ovum, and in forming the organs of the new being, that the same powers are, also, alone concerned in carrying on forever afterward the processes of life, and, of course, that no new powers, or principles, are introduced. 3d. To consider the manner in which the germ is impregnated, or its vital properties so stimulated into action as to result in the devel- opment of the germ, and in unfolding the various attributes of the neAV being. 4th. To show that we may find in the physiology of generation, or the principles through which the ovum is impregnated, the whole phi- losophy of organic life, or the principles through which the actions of life are forever carried on. 5th. To state the manner in which the natural peculiarities of each parent, whether as it respects the properties of life, or the physical conformation, are infused into the germ and combined in the full- grown offspring. 6th. To show that hereditary diseases are transmitted in the same way as those more natural peculiarities which belong to parents. 7th. To show, also, that the principles which are concerned in the transmission of hereditary diseases are the same as concur in the pro- duction of ordinary diseases. 8th. To deduce from the philosophy of generation the vital nature of hereditary diseases; or, in other words, to show that the morbid PHYSIOLOGY.--COMPOSITION. 37 impression is established upon the vital properties of the ovum, and of course, upon those of the new being ; and that the hereditary vitia- tion does not consist in any transmitted impurity to the blood or other fluids of the offspring, as is noAv supposed by the humoralists. If the foregoing propositions be true in relation to man, they will, of course, be equally so of animals, and of the Avhole vegetable king- dom (§ 169/, 1051,1052). 64, a. If it be universally conceded, as a matter of course, that not only the elementary constitution of the ovum, but its whole develop- ment, depends entirely upon a vital principle or vital properties, it will follow that the same principle or properties are forever afterward concerned in organic processes, and alone concerned. Let us hear, in the first place, the most eminent in the school of vitalism, but who are inclined to lean upon chemistry after the full development of the ovum. 64, b. It is said, for example, by Tiedemann, " That it is the vital power, which in the fecundated germinative liquid, brings the molecules of the organic combinations to the solid form, and calls the first lineaments of the vegetable and animal em- bryo into existence. All the parts and tissues that are formed in it, according to a definite order of succession, are products of the power of formation, and on this they depend in all that relates to their first appearance, their development, aggregation, configuration, and ar- rangement. The phenomena exhibited in the act of formation of an smbryo, are placedyjzr above all the mechanical and chemical acts we ibserve in bodies not endowed with life."—Tiedemann, Comparative Physiology. 64, c. By the illustrious Miiller, it is said, " The creative force exists already in the germ, and creates in it the essential parts of the future animal. The germ is potentially the whole animal. During the development of the germ, the essential parts which constitute the actual whole are produced." " The en- tire vital principle of the egg resides in the germinal disk alone; and since the external influences which act on the germs of the most different organic beings are the same, we must regard the simple germinal disk as the potential whole of the future animal, endoAved with the essential and specific force or principle of the fu- ture being, and capable of increasing the very small amount of this specific force and matter which it already possesses, by the assimila- tion of new matter." And again he says, " This force exists before the harmonizing parts, which are, in fact, formed by it during the development of the embryo." " The vital force inherent in organic beings itself generates the essential organs Avhich constitute the Avhole being." " The formative or organizing principle is a creative pow- er, modifying matter blindly and unconsciously;" yet with such won- derful precision that Miiller also says, that " this rational creative force is exerted in every animal strictly in accordance with what the nature of each requires." " The vital principle," he says, " is in a quiescent state in the egg before incubation."—Muller, Elements of Physiology. 64, d. Passing from the chemico-physiological school to that of pure chemistry, we shall find the same admissions as to the exclusive agency of a vital principle in the formation and development of the 38 institutes of medicine. seed and ovum. The extraordinary contradictions, which will aston- ish the reader, necessarily abound in all authors who are employed in identifying two subjects that have no relation to each other. 64, c. Take Liebig, as a first example; and take, in the first place, his chemical doctrine of life. " In the animal body," he says, " we recognize, as the ultimate cause of all force, only one cause, the chemical action which the ele- ments of the food and the oxygen of the air mutually exercise on each other. The only known ultimate cause of vital force, either in ani- mals or in plants, is a chemical process. If this be prevented, the phenomena of life do not manifest themselves. If the chemical action be impeded, the vital phenomena must take new forms." And yet only a few sections before, and in the very first sentence of Liebig's work on " Animal Chemistry applied to Physiology and Pathology," we read, " In the animal ovum, as well as in the seed of a plant, we recog- nize a certain remarkable force, the source of growth or increase in the mass, and of reproduction, or of supply of the matter consumed; a force in a state of rest.* By the action of external influences, by impregnation, by the presence of air and moisture, the condition of static equilibrium of this force is disturbed. Entering into a state of motion or activity, it exhibits itself in the production of a series of forms, &c. This force is called the vital force, vis vita, or vitality." —Liebig's Animal Chemistry. Turning back to the same author's work on " Organic Chemistry applied to Physiology," we meet not only with a similar contradiction of his grand doctrine of the entire dependence of life upon chemical processes (and as we had before seen in respect to digestion, section 60), but with that which is particularly apposite to my present inquiry. " Our notion of life," says Liebig, " involves something more than mere reproduction, namely, the idea of an active power exercised by virtue of a definite form, and production and generation in a definite form (§ 59). The production of organs, the co-operation of a system of organs, and their power not only to produce their component parts from the food presented to them, but to generate themselves in their original form and with their properties, are characters belonging ex- clusively to organic life, and constitute a form of reproduction inde- pendent of chemical poavers. The chemical forces are subject to the invisible cause by avhich this form is produced. This vital principle is only known to us through the peculiar form of its instru- ments; that is, through the organs in which it resides. Its laws must be investigated just as we investigate those of the other pow- ers which effect motion and changes in matter."—Liebig's Or- ganic Chemistry, &c, p. 355. 64, f Roget, of high authority, maintains that, " However the laws which regulate the vital phenomena may ap- pear, on a superficial view, to differ from those by which the physical changes taking place in inorganic matter are governed, still there is really no essential difference between them." " It may, in like man- ner, be contended, that the affinities which hold together the elements of living bodies, and which govern the elaboration of organic products, are the same with those which preside over inorganized compounds." * See my Examination of Reviews p. 7-28. physiology.—composition. 3y " Hence it becomes every day more and more probable that the forces immediately concerned in the production of chemical changes in the body are the same as those Avhich are in constant operation in the inorganic world; and that Ave are not warranted in the assertion that the operations of vital chemistry are directed by distinct laws, and are the results of new agencies." " However natural it may be to conceive the existence of a single and presiding principle of vitality, we should recollect that this, in the present state of our knowledge, is only a fiction of the mind, not warranted by the phenomena themselves."—Roget's Outlines of Physiology. Let us noAv hear this able writer on the subject of foetal development. " A portion of the vital poaver of the parent," lit! says, " is for this purpose employed to give origin and birth to the offspring. The ut- most solicitude has been shoAvn in every part of living nature to se- cure the perpetuity of the race, by the establishment of laws, of which the operation is certain in all contingent circumstances." Roo-et ultimately describes, in his usual felicitous manner, the de- velopment of the ovum; and here we have nothing from our author but the agency of the vital powers. " The foundations of the edifice," he says, " are laid in the homo- geneous jelly by the efforts of the vital poavers." " At first, all the energies of vitality are directed to the raising of the fabric, and to the extension of those organs, which are of greatest immediate util- ity ; but still haAdng a prospective view to farther and more impor- tant ends,"—and so on throughout the chapter; the whole work of developing and fashioning the fcetal organs being assigned, exclu- sively, to " the efforts of the vital powers," and to the " energies of vi- tality."—Roget's Animal and Vegetable Physiology, Bridgewater Treatise. 64, g. Finally, let us hear, also, Dr. Carpenter, who advocates the chemical doctrines of life so far as to lay down the following princi- ple no less than twice within six pages, and in nearly the same words. Thus: " Reason," he says, "has been already given for the belief that the affinities which hold together the elementary particles of organized structures are not different from those concerned in the inorganic world; and it has been shoAvn that the tendency to decomposition after death bears a very close relation with the activity of the CHANGES WHICH TAKE PLACE IN THE PART DURING LIFE."--CARPEN- ter's Principles of General and Comparative Physiology, p. 140 ; also, p. 146. . . Now the authority of such a Avriter, and a prominent leader in the purely chemical school of physiology, must be allowed to be impor- tant when any unavoidable concession is made to vitalism. Let us then hear him in the matter of the ovum: "Organization, and vital properties," he says, " are simultaneously communicated*to the germ by the structures of its parent. Those vital properties confer upon it the means of itself assimilating, and thereby organizing and endoaving with vitality the materials supplied by the inorganic world."—Carpenter's Principles, &c, p. 1 oo And again, this mere chemist, in his general views of the philosophy of life, observes, that 40 institutes of medicine. "The agency of vitality, as Dr. Pro ut justly remarks, does not change the properties of the elements, but simply combines them [the elements] in modes avhich ave cannot imitate."—Carpenter's Principles, &c, p. 146. 64, h'. Dr. Prichard is strictly of Dr. Carpenter's school (see my " Examination," &c, p. 37), between whom there is a point of agree- ment which is worth noticing in its connection with the subject noAv before us, and to which I have referred in a former work, in its rela- tion to Dr. Carpenter. Both of these writers see so much of peculiar design in organic nature, and find it so impossible to interpret the phenomena of organic beings upon the chemical and physical princi- ples which they have so strenuously set forth, and in their aversion to any other principles, and to the obvious rule of analogy as to second causes, that, in the end, they assign the functions and phenomena of life to the immediate action of the Deity. " The theory of a vital principle," says Dr. Prichard, " has been applied in a different manner, to account for the phenomena displayed at the beginning of life in animals and vegetables, and to get rid of the mystery which attends the gradual evolution of organic structure from ova and germs. Here the vital principle is no longer considered a chemical agent, but assumes the character of a plastic and formative power," &c. Now Dr. Prichard " cuts the knot" and " gets rid of the mystery" after the following manner: " We may," he says, " if we choose to do so, term the cause which governs the organization and vital existence a plastic principle; but it is a principle endoaved avith intelligence and design [ ! J It is, in fact, nothing more than the Energy of the Deity." "The devel- opment of forms, according to their generic, specific, and individual diversities, not less in the vegetable than in the aninial world, can only be accounted for by ascribing it to the universal energy and wisdom of the Creator."—Prichard's Review of the Doctrine of a Vital Principle. See, also, Paine's Commentaries, vol. i., p. 10, 25; and his Examination of Reviews, p. 37, 41, 43, 44. This is a far greater admission than the vitalist can desire; since, if the development and growth of the germ depend immediately upon Almighty Power, so must all the analogous processes of the living being at all stages of its existence, and science would be merged in the direct manifestations of that Power. But, while this doctrine is utterly exclusive of all the assumed chemical agencies at all periods of life, and overlooks the analogy between the development of the germ and the subsequent processes, there can be no hesitation as to the disposition which should be made of it, without any reference to its prevaricating nature (§ 175 d, 699 c, 740). 65. HaA-ing now before us a plain statement of our necessary prem- ises as they respect the exclusive agency of the " vital principle," or " organic force," or " creative power," or " vital properties," or "vital powers," or "vitality" (whichever term may be'preferred), in carrying out the full development of the embryo, it may be interesting to know the details of that development and growth, which is thus allowed, on all hands, to be conducted by powers utterly distinct from the chemical and physical, and in which these have no agency. " The development of the separate parts," says Miiller, " out of PHYSIOLOGY.—composition. 4] the simple mass, is observable in the incubated egg. All the parts of the egg, except the germinal membrane, are destined for the nu- trition of the germ. The simple germinal disk is the potential whole of the future animal, endowed Avith the essential and specific force, or principle of the future being, and this germ expands to form the germinal membrane, Avhich grows so as to surround the yolk; and by transformation of this germ, the organs of the future animal are pro- duced. The rudiments merely of the nervous and vascular systems, and of the intestinal canal, are first formed ; and from these rudi- ments the details of the organization are afterward more fully devel- oped ; so that the first trace of the central parts of the nervous sys- tem must be regarded neither as brain nor as spinal marroAV, but as still the potential Avhole of the central parts of the nervous system. In the same manner, the different parts of the heart are seen to be developed from a uniform tube; and the first trace of the intestinal tube is more than the mere intestinal tube; it is the potential whole, —the representative of the entire digestive apparatus; for, as Baer first discovered, liver, salivary glands, and pancreas, are, in the far- ther progress of the vegetative process, really developed from that which appears to be merely the rudiment of the intestinal canal. It can be no longer doubted that the germ is not the miniature of the future being, with all its organs, as Bonnet and Haller believed, but is merely potentially this being, Avith the specific vital force of which it is endowed, and which it becomes actually by develop- ment, and by the production of the organs essential to the active state of the actual being. A high magnifying power is not necessary to distinguish the first rudiments of the separate organs, Avhich, from their first appearance, are distinct and very large, but simple. So that the later complicated state of a particular organ can be seen to arise by transformation from its simple rudiment. These remarks are noAA' no longer mere opinions, but facts; and nothing is more dis- tinct than the development of glands from the intestinal tube, and of the intestinal tube itself from a portion of the germinal membrane." —Muller, ibid — ($ 1051,1052). Such, then, is the history of the development of the germ in birds, and in all the higher animals; and the whole work is ascribed by physiologists of every denomination exclusively to principles un- known in the inorganic world, and wholly distinct from any of a chemical nature. They are called, indiscriminately, vital properties, vital powers, vital principle, organic force, creative force, &c, to distin- guish the principle, or properties, from every thing that has any known existence in inorganic substances, or as the source of any in- organic results. But, physiologists of the chemical school stop here, and ascribe all organic compounds after the being is fully formed to chemical agencies. It is remarkable, however, that it has not occur- red to these philosophers, that precisely the same elementary combi- nations, the same formation into tissues, and the same secretions, take place at all stages of the rudimentary development as at all future periods of life, and that the rudimentary development consists in these formations of simple compounds and their union into tissues; and if the early or rudimentary growth of the being, all its secreted products, all its elementary combinations, be determined by the vital properties, so are the same results determined by the same properties 42 institutes of medicine. or powers forever afterward. To call in the agency of chemical or physical forces, to accomplish precisely the same results at any future stage of the organic being as are admitted to be performed in the de- velopment of the "essential parts" of that being by the "vital prin- ciple" or " vital properties" alone, is a violation not only of the plain- est rule in philosophy, but of the clearest facts (§ 41, 42, 55-58). 66. We have thus before us a peculiar order of powers by which the organic being is developed, fashioned, and forever exclusively governed. It is these powers about which physiology, pathology, and therapeutics, are essentially concerned. We may, therefore, seek in the composition of organic beings, and in the laws of their development,ybr the great rudimentary principles of medicine. The vital principle has also the extraordinary task of laying out, in the ovum, the whole organization of the future being; so that its subse- quent labor must be comparatively simple, and it is then, least of all, that it can require any help from the forces of the inorganic king- dom, or that it would permit a violation of the great principle in na- ture of avoiding an unnecessary multiplication of causes. 67. It may be farther shown by the incipient development of the ovum, that the vital powers, or properties, are more concerned in the growth, nutrition, and all the subsequent physical results, throughout the whole existence of the being, than is generally supposed by even the exclusive vitalists. The usual supposition is that the vessels or instruments of action, which are moved by the vital.powers, perform the work of decomposing the blood and other parts, and recombining them again in other proportions and forms, according to the particu- lar organization of parts, and the modification of their vital states. It has been the doctrine of most physiologists till a recent day, that the ovum, in its germinating part, is a mere organic fluid, destitute of vessels, and all other parts of the future apparatus. Later re- searches, hoAvever, have disclosed the existence of a rudimentary cell; and it is said by Miiller (1835) that " in the incubated egg the sole material for the first formation of blood is the substance of the germ or germinal membrane, Avhich itself grows by assimilation of the fluid of the egg, or the yelk. It may be distinctly observed that the blood is generated in the germinal membrane before the vessels are formed ;"* from Avhichit appears that t'he first "assimilation of neAV matter" must take place without the agency of vessels, or of any parts which are subsequently formed ; and, therefore, the same powers Avhich enabled the cell to generate vessels, nerves, &c, con- tinue to make the same conversion out of blood ; and as all this Avas originally done without the aid of vessels, so must the same poAvers be forever operative with their subsidiary agency only. As the ovum possesses the potential whole, it is equivalent to the mature structure. We see, therefore, that Miiller, reasoning upon other grounds, may not have been altogether hypothetical in his inference that the " vital prin- ciple exerts its influence even beyond tlje surface of an organ, as shown by its effects on the chyle, in maintaining the fluidity of the blood," &c. By the same rule, it may be at once shoAvn that the only ingenious chemical hypothesis ever invented to interpret organic results,—the catalytic,—is purely an assumption; since this hypothesis is predica- * Kolliker states that " the membrane of animal cells, the largest of which are yelk. cells, exhibit no structure of any kind."—Microscopical Anatomy, Wurzburg, 1852. PHYSIO LOGY.--COMPOSITION. 43 ted of the blood-vessels. But, if there be no vessels in the germ, the first vessels must, of course, be produced without the supposed chem- ical influence of vessels, and, by my showing, therefore, as to the subsequent formation of vessels and other parts, the supposed agency of the catalytic forces is a mere assumption (§ 41, 42, 1051; also, Medical and Physiological Commentaries, vol. i., p. 74-76). On this subject, too, chemistry must abide by admissions which are made in the very face of consistency; so imperative is fact, and so imbecile is hypothesis. Thus, it is said by the distinguished chemico- physiologist, Dr. Prout, that " The most determined sceptic cannot assert that there is any ne- cessary relation, or, indeed, anv relation whatever, between the mechanical arrangements and the chemical properties to Avhich they- administer. There is no reason Avhy the chemical changes of or- ganization should result from the mechanical arrangements by which they are accomplished [! ]; neither is there the slightest reason Avhy the mechanical arrangements, in the formation of organized be- ings, should lead to the chemical changes of which they are the instru- ments" !—Dr. Prout's Bridgewater Treatise.—Such is the proof which chemistry offers. 68. The question then arises as to what is the particular office of those vessels Avhere the elementary combinations and decompositions take place] Simply this: to convey, and eliminate through the agen- cies of the vital properties, those parts from the blood out of which the vital properties effect the new elementary combinations, whether solid or fluid,—to aid in arranging the neAv molecules, and to carry forward those fluid products which may be destined for other ends. 69. But, have not the nerves an indispensable agency in effecting the elementary combinations and decompositions % Certainly not, as I shall endeavor to show. But the sympathetic nerve exerts an influence upon all organic functions, and impresses a special condition upon all organic compounds, and this physiological laAV is extensively involved in" pathology and therapeutics (§ 226, 232, 233, 399, 446 a, 461, 46fi 488i 489, 512, 639, 746 c). 70. But, all the A'essels, and all the solid parts of the organism, have their various specific offices. Here, in every part, reside the vital properties, Avhich had been fully developed in the ovum, and here are they modified according to the exact nature of the organization and the peculiar final causes of "the properties of the vital principle" in each part. Hence they manifest peculiarities in parts that are apparently alike. The modifications vary, for instance, in the serous membranes, and more remarkably in the mucous, as known by the influence of foreign agents, their phenomena, their products, &c. The vital properties differ in different parts of one and the same con- tinuous tissue, as in the mucous tissue of the nose, lungs, stomach, &c. Hence one of the important objects of studying the structure of organs, and the nature of their tissues; for, as the vital properties are naturally modified in different parts, so will their alterations in the same disease be different in different tissues of one organ, and, for the same reason, even of different parts of one continuous tissue. These natural modifications of the vital properties in different parts have, at least, three great final causes. The first is what I have al- ready stated, namely, to separate from the blood, through the agency of the capillary vessels, that exact part which is to be decompounded 44 INSTITUTES OF MEDICINE. at any given point; the second is, by these modifications, to enable " the properties of the vital principle" to decompound and recombine the elements according to the exact nature of the combinations which belong to the part; and the third, to qualify the properties, through the medium of the capillary vessels, to shape and unite the new mole- cules to the old. It is easy to apply this principle, under its different aspects, to all other vessels, as the veins, the secretory and excretory vessels of the glands, and the absorbents. 71. Now, at the first start of the development of the germ, " the properties of the vital principle" (as they are well designated by Miil- ler) are but very imperfectly, if at all, aided by any of the foregoing physical means, though they come into operation at the moment they are successively produced. " The properties of the vital principle," therefore, must exist in that potential cell in a modification, and with a formative energy which they do not possess in any of the new de- velopments ; and herein it will have been seen that the very chemist has come to this conclusion (§ 64 f, 190 b). 72. The process of generation presents a varied and most impres- sive illustration of the peculiarities of the vital properties, and of the manner in which they are liable to be impressed and permanently modified in their nature. It results in the production of organic be- ings similar to those which exercise the generative faculty. This fac- ulty is therefore manifested with as many specific modifications as there are different species of organic beings. If we allow to the globe one million of distinct species of animals, the specific modifications of the germinal product will be as numerous, and these are more or less influenced by the semen of the male. The seminal or productive principle of the male exerts its special influences upon the living prop- erties of the germ, and according to the special constitution of the ovum directs their operation in such a maimer that none but beings of the same kind with the parents, where both are of the same species, are produced. That the various modifications which distinguish each species are determined by both parents is fully demonstrated in hybrid animals, and is sufficiently obvious in the transmission of the peculiar- ities of the male or female, where the individuals are of the same spe- cies. And, notwithstanding our supposed million of distinct species of animals, and the specific variations in all the parts of each species (§ 41), this almost endless variety is made up by successive deposi- tions of elementary compounds out of mainly four simple substances (§ 37, 42, 46), three of which are gaseous, united in modes unknown to chemistry (38-40, 48), and which chemistry cannot detect, and for- ever uniting in different modes and proportions according to the ex- act nature of every part (§ 43, 44). The act of generation establishes the essential modifications which are to be continued, without varia- tion, throughout the life of the new being; and this new individual, be- coming in its turn the agent of procreation, perpetuates all the specif- ic modifications which appertain to itself and to its ancestors. The intermingling of species, which results in hybrid animals, proceeds upon the same plan. It must therefore necessarily be, that the vital properties of the ovum are so impressed by the exciting influences of the semen that those peculiar elementary combinations and ao-orega- tions are started which ultimately make up the hybrid. " These vital properties," says Dr. Carpenter, " confer upon it the means of itself PHYSIOLOGY.--COMPOSITION 45 assimilating, and thereby organizing, and endowing with vitality, the materials of the inorganic world ;" leaA'ing it, also, clear to all minds that the action of the semen must be exerted directly upon the vital properties of the ovum (§ 189, 1051). That this important question as to the direct action of the semen upon the vital properties of the ovum, and its capability of establish- ing certain modifications of these properties, and that the humoral in- terpretation of transmitted peculiarities is an unfounded assumption, may be definitively settled, I will also add, ," The well-known fact, that when the Earl of Morton's Arabian mare Avas covered by the quagga, not only did the mule so begotten partake of the character of the sire, but when the mare was subsequently sub- mitted to an Arabian stallion, by whom she had three foals at differ- ent times, the first two continued to exhibit some of the distinctive peculiarities of the quagga conjoined with the characters of the Ara- bian breed."—Montgomery, on the Signs and Symptoms of Pregnan- cy, p. 17. This should overthrow the whole fabric of humoralism* The author of the foregoing statement supposes that the semen " may influence several ova, and so continue to manifest its effect in the offspring of subsequent conceptions Avhen impregnation has been effected" by males of another species. The reader will also not fail to remark that the history of this case is in direct conflict with the late attempts to revive the old doctrine of referring the germ to the male parent (§ 67, 1051, 1052, 1078). 73, a. The semen, then, is a vital stimulus, and so far on a par with the ordinary stimuli of life. These may be natural, like air, food, heat, &c.; or they may be morbific, like malaria, poisons, &c.; or cu- rative, like medicines. In all the cases, their action is upon the vital properties ; and it is in consequence of these influences that the ovum is developed, that life is maintained, health preserved or impaired, or disease removed. The ova of oviparous animals show the analogy in respect to stimuli, and the principles involved, more impressively than those of viviparous ; since by an admirable design, in respect to the former, the impression of the semen has a limited operation, when the vital properties of the ovum return to their quiescent state, but may be again roused into action by the simple stimulus of heat. (See Med. and Phys. Comm., vol. i., p. 21, &c.) 73, b. The action of the semen upon the properties of the vital prin- ciple of the germ is a type of all the influences that are produced upon the same vital properties during the life of the animal, and from which all its organic actions, and all their results, arise. And so of the ger- mination and growth of plants; which, by-the-way, evinces the com- mon nature of the principle of life, and of organic actions, in the two departments of the animated kingdom (§ 188J, d). It is the whole es- sential philosophy of physiology. It is the alterations produced in the vital properties which constitutes the philosophy of disease, and in which, indeed, all disease virtually consists. It is the art of finding out the remote causes, and the nature of the alterations they produce, and of adapting to the altered condition of the properties of life such agents as shall establish new impressions upon them, and thus enable them to return to their natural state, which forms the basis of thera- peutics in its connection with pathology. 74. a. Here I shall digress for a moment, to consider certain anal- * The same is stated of Sir G. Ousley's mare and a zebra, and of a mare and an ass, and the subsequent foals by stallions. 46 INSTITUTES OF MEDICINE. ogies in the development of special organs, through the influence of specific stimuli, with that general evolution of the organic fabric which is started by the action of the seminal principle upon the germ. These analogies are to be found in the organs of animal life. The senses, for example, sometimes manifestly require for their full de- velopment the prolonged operation of the stimuli which are natural to each. This is habitually observed in the young of some animals, and is seen conspicuously in the subterranean fish of Kentucky. In this last instance organic life is perfectly developed; but, owing to the exclusion of the natural stimulus of the eye from the very outset* of life, that organ remains in its rudimentary state. A fortiori, therefore, the reputedly first inhabitants of this globe, such as the trilobite, attest the existence of the same light at their crea- tion as is enjoyed at the present day; geologists to the contrary not- withstanding (§ 1079, b). Superficial observers of nature, either through inattention to the moral consequences, or through infidelity, are apt to believe that phys- ical agents are the real creative forces of organic beings, from ob- serving that particular parts are clearly dependent for their develop- ment upon the action of certain specific stimuli. But, in all these cases, the rudiment is there, and has been perpetuated ever since the original species came from the Hand of Creative Power. That Power is en- titled to all the praise, as the Author of the rudiment, of its endow- ment with peculiarly modified properties of life, of the existence of the physical agents, and of the mutual adaptation of these modified properties of the rudiment and the virtues of the physical causes, so that the operation of the latter upon the former shall result, for exam- ple, in vision, and, under certain circumstances, as when the ovum is developed and matured out of the body, the physical agent, in the ex- ample supposed, shall be necessary to the development of the rudi- mentary organ of sight (§ 350|, A-350f, 1). The principle is much the same as that which applies to the necessity of external heat and light to the development and growth of plants. The specific stimu- lus of light by which the vital properties and actions of the leaf are enabled to decompound carbonic acid, and to assimilate the carbon, is manifestly a parallel example Avith my supposed influence of light in developing an animal organ in which the nervous system is extensive- ly incorporated for the final cause of the Avhole organ ; although it be certainly true that, in the case of the eye as of the leaf, the essential influences of light are exerted upon the organic properties of either part, and that the nervous system, in the former case, is only a medi- um of transmitted influences to the organic properties (§ 188, 188£, 189, 202, 203, 222, 223, 226, 227, 514 k, 1072 a, note). It would be an interesting inquiry to ascertain whether, by a total exclusion of light from the ovum of fish, after fecundation, the pecu- liarity of the Kentucky wonder may not be established in the first generation; and whether, also, an exclusion of light for a series of years would not be followed by a failure of the balance of absorption and nutrition in the eyes, and consequently a wasting of those organs. The general law of absorption operates universally, without the aid of any specific stimulus; while it is clearly otherwise in respect to nutrition, and especially in regard to certain organs. The voluntary muscles become emaciated from want of the stimulus of exercise, &c PHYSIOLOGY.--COMPOSITION. 47 We see, therefore, hoAv it happens that fishes with and without eyes may exist together in subterranean caverns as extensive as that of Kentucky; the latter inhabiting the dark regions, while the former exist in springs near the crevices of the cave (§ 136, 137,548 a, 649 d, 733 b). 74, b. Such, then, is my philosophy of this subject, and such the full extent of the ground upon which infidelity would plant its standard. Nor will I dismiss this subject without referring, now and hereafter, to the calm indifference with which this infidelity is regarded even by the religious world, by adducing not a few of the present popular treatises on theoretical geology (v 350|, g-k, 1085). 75. Let us now see if the beginning of individual existence does not supply a key to the whole philosophy of disease, as it does to that of physiology. We have seen that all the actions, and all the results of life, are merely effects which arise from the operation of the vital properties through their organic instruments (§ 65-67, 133, &c, 188, &c). These properties must be constantly excited into action by foreign agents, as by food, blood, &c, or the properties will become extinct, and, of course, the effects will cease (§ 188^, b). Now, the actions in disease are nothing more than the altered actions of health, and the same rule applies to all the morbid products. It follows, therefore, that the properties of life, upon Avhich these altered condi- tions depend, are modified or altered in a corresponding manner. As a consequence of this, it also results that the vital properties have been varied from their natural state by agents or causes capable of producing: the change. These agents make their impressions in the same way as the natural stimuli of life, only the morbific agents at the same time affect the nature of the vital properties, and bring them into a new condition. This new condition constitutes disease. 76. The type of all this may be found in the impregnated ovum. The properties which animate the germ before conception are deter- mined entirely by the vital constitution of the female parent. But we have seen that the new being may partake of the physical characters of the male as well as of the female, and it happens not unfrequently that the characteristics of the male are predominant. Hence it fol- lows that the semen so far establishes changes in the original consti- tution of the vital properties of the germ. Since, therefore, all the foetal developments, all their physical pe- culiarities, depend upon the precise modifications and actions of the vital properties (§ 70), and since these properties in the unimpregnated ovum are determined entirely by the female parent, their nature after impregnation must be more or less affected, and assimilated to the peculiar nature of the male parent in all the cases where the offspring manifest any of the male characteristics. This is entirely analogous, in principle, to the modifications which are produced in the properties of life by morbific causes ; but with this difference in contingencies: in the case of the impregnated ovurn the modifications are perma- nently established, and can never be altered, so far as the vital prop- erties, in either parent, upon which the modifications depend, are fun- damental in their nature. In the case of the morbific agent, or the cause of disease, the vital properties are diverted from the healthy state, and from such modified conditions they commonly possess the ability of escape, and of returning again to their natural standard (§ 48 INSTITUTES OF MEDICINE. 853, 858, 898). In the case of the impregnated ovum a modifying agent operates, whose properties are intended to confer on the ne\v being a stable condition, however they may modify the exact consti- tution of the impregnated germ. This vital stimulus, the semen, therefore, in virtue of its specific properties, bestows upon the corre- sponding vital properties of the ovum the peculiarities which belong to itself; and these being natural, vital, and determinate, the trans- mitted peculiarities should be equally so. Or, where the male parent enjoys a perfectly natural constitution, the innate predispositions to disease depend upon special peculiarities in the vital state of the ovum, which may be as permanently established, through the modified con- stitution of the female parent, as any of the natural characteristics. In the case of disease, however, the morbific agents have none of the properties of life which are natural to the fecundating semen, and the modifications, therefore, which they may determine may be different, even if we suppose them to act, as in the case of the germ, upon the whole constitution. Whatever modifications, therefore, may arise from their action, they must consist of deviations from the standard of health. But, it does not necessarily follow that certain artificial modifications may not be as permanent as the natural ones; and it is from observation alone, that we learn that they are so, or nearly so; as in the case of artificial " temperaments," the effects of domestica- tion upon animals, the changes.Avhich are wrought in the vegetable kingdom by cultivation and by change of climate (§ 535, &c). 77. In the case, however, of the formation of temperaments by change of climate, and the more remarkable alterations produced in animals by domestication, and in plants by cultivation, &c, the results are brought about by the new and habitual influences to which the properties of life are exposed; and, in all these cases, a radical, and often permanent modification is established, approximating closely the modifications Avhich are bestowed upon the germ by the fecunda- ting semen. Now, it is also true, that what is denominated predispo- sition to disease is entirely analogous, in principle, to the permanent temperaments of Avhich I have just spoken. Both are results of phys- ical agents, modifying the properties of life ; and this chain of analo- gies conducts us to those predispositions to disease which are im- pressed upon the germ by the fecundating semen, and by which I show that the philosophy of the operation of morfibic causes is vari- ously, and even exactly exhibited in the impregnation of the germ (§ 63, 75, 535, 539, 559). 78. Take the scrofulous subject as supplying an example of hered- itary predisposition to disease. If it exist in the female, her ova will partake of this peculiar modification of the vital properties, and it is in this way that her progeny inherits the scrofulous diathesis (§ 144- 147). In this case, as in all transmitted predispositions to disease, the peculiarities induced in the parent have arisen, originally, from the operation of deleterious agents—imbuing the ovum with the mod- ifications belonging to the female, or imparting to the semen the whole concentrated force of what may have been the slow work of numerous causes upon the male parent. Here, then, we see illustrated in the very ovum, even before im- pregnation, the Avhole principle which concerns artificial tempera- ments, and those influences of morbific agents which establish predis- PHYSIOLOGY.--COMPOSITION. 49 positions to disease in the full-grown subject. It frequently happens also, that this natural diathesis is so great, that it results in actual dis- ease before the birth of the offspring, as manifested by tuberculous affections of the lungs in still-born infants. 79. But, to make the philosophy of this subject more obvious, let us consider the germ when it derives its scrofulous diathesis from the male parent. Before impregnation its vital condition is perfectly natural. The semen of the male parent establishes upon it the modification which constitutes the predisposition to scrofula, just as malaria deter- mine those modifications which result in fever, &c. And here we may readily detect a perfect analogy between the alterative influences of the semen and of remedial agents, and come to understand how it is that the latter produce their effects (§ 904, d). We have only to observe those instances where some of the offspring inherit the scrof- ulous diathesis of the female parent, while others are as entirely ex-. empt as the male parent; the natural condition of the semen having altered the vital constitution of the ovum in the latter case, and im- pressed a disposition to a development of the new being in its perfect state. 80. The subject may be pursued under a variety of aspects, and with various illustrations, whether physiologically or pathologically. Other exemplifications will occur under the subjects of vital habit and the temperaments. The same principle is concerned throughout, whether in respect to the physiological conditions impressed upon the ovum by the seminal fluid, or as those conditions are modified in he- reditary scrofula, gout, &c, or whether it concern the temperaments and other permanent changes that are induced by climate, domestica- tion, &c, or as malaria may establish their peculiar modifications of the properties of life. Nor can such conclusions be unexpected to those who duly consider the simplicity of nature in her elementary principles and laws (§ 561). 81. Could the doctrine entertained by Walker, Elliotson, and oth- ers, that the imagination of the parents influences the physical organ- ization of the offspring, be shown, the philosophy which I have set forth, though not rendered more clear, would be yet fortified. But, this is at best but speculation. I could, however, turn to the myste- rious production of the soul. This remarkable principle is doubtless developed at the very outset of fcetal life, as evinced by its often com- bining the intellectual peculiarities of both parents, or, again, of man- ifesting chiefly those of the male. But here we have no other fact to guide us, and all beyond has been involved in an impenerJtble mys- tery by the great Creator. Here it is a pride and a help of philoso- phy to rest on faith alone (§ 433). 82. For an examination of vital phenomena, and relative facts, in proof of the existence of properties peculiar to organic beings, and of the abstraction of such beings from the laws of the inorganic world, see Essay on the " Vital Pc wers," in Medical and Physiological Com- mentaries, vol. i. D 50 INSTITUTES OF MEDICINE. SECOND DIVISION OF PHYSIOLOGY. STRUCTURE. 83. a. There are certain details in respect to the structure of or- gans Avhich must be stated, now and hereafter, to enable us to com- prehend the laAVS which govern the healthy and morbid states of man Perhaps few things can impress us more forcibly with the impor- tance of a correct analysis not only of the physical organization of all parts of the body, but more especially of the vital characteristics of each part, than the continued propagation from high sources of doc- trines like the folloAving; while they equally prove my position as to the appropriate sources of knowledge (§ 5\-5\, &c), and the tenden- cies of the microscope.* 83, b. The errors in doctrine to which I have referred are revealed sufficiently in the following extract from an article by the distinguish ed Mr. Paget, contained in the 27th volume of the Transactions of the Royal Medical and Chirurgical Society, London, 1844. The article is entitled "An Account of the Examination of a Cyst containing Seminal Fluid;" in the course of which Mr. Paget observes, " If, with the aid of these observations, we endeavor to find an ex- planation of the occurrence of spermatozoa in the fluid of cysts con- nected Avith the testicle, we may suppose either that the fluid part of the semen has permeated from the seminal tubes into the cysts, and been farther organized in them ; or, that the cyst itself secretes a fluid in Avhich the organic structures of the semen may be developed." " The most probable explanation of these cases, therefore, seems to be, that certain cysts, seated near the organ which naturally secretes the materials for semen, may possess a power of secreting a similar fluid"t ($ 251). I cannot doubt that before I shall have parted with the reader in what I shall have said of die peculiarities of structure, and the more remarkable modifications of vital properties and functions, there will be a disposition to concede the importance of the subject, and that this importance is rendered more manifest by the prevalence of opin- ions analogous to those in the foregoing extract. 83, c. As I have already intimated, however (§ 2, c), anatomical science can lead, originally, to no conceptions of the properties and functionSof life, and therefore to none of their modifications in dis ease. The most that we can infer, abstractedly, from a knowledge of structure, are certain general results that are denoted by the constitu- tion of organs, or assemblages of organs, upon the known principles * See Medical and Physiological Commentaries, vol. i., p. 699-712. Also, my Exam- ination of Reviews, p. 6, 89, 90. t The Medico-Chirurgical Review for January, 1845, quotes this paragraph, and ob- serves of it, that " Mr. Paget's explanation of the vicarious appearance of the spermatozoa, which has of late so much puzzled the members of the society, has the merit of being in- genious and original."—I cannot acquiesce in this decision. The doctrine is old, though recently, for the first time, enforced by the deceptive report of the microscope. It is thus noticed in the Medical and^ Physiological Commentaries : " True, we know that the an- cient belief is even maintained at this day, by Sir A. Cooper, and others, that the testis is of no special use, but that the semen is the product of those simple reservoirs, the vesi- culae seminales. But, what does this show ?" &c. See, also, my comments on this sub- ject, in vol. i., p. 588, and on the supposed vicarious secretion of milk, urine, <£c.. p. 601- 603. PHYSIOLOGY.--STRUCTURE. 51 of Design. The construction of the eye, for example, evinces some great final cause relative to light; that of the urinary apparatus, that a fluid is produced by the kidneys, and conveyed to a receptacle where it accumulates, and is finally evacuated through the urethra; and so of many other parts. We thus infer, also, the uses of each part, individually, from their relations to each other as a system of Design. In other cases the function of a part may be inferred from the known uses of other parts to which it is related ; as the valves of the veins, for example, were supposed by Harvey to be designed for giving the blood a direction toward the right cavities of the heart; and this induction from anatomical Design conducted him to a full exposition of the circulation. But, in respect to the great processes' of life, no conclusions can be originally drawn but through their phe- nomena, nor does structure denote even the principle of vision ($ 251). Having, however, acquired a knowledge of structure in a particular species of animal, as man, for example, and learned the uses of each particular part by a study of its phenomena, so perfect is the system of Design throughout organic nature, and so harmonious are the anal- ogies of function among organs that bear certain resemblances of structure, or of relations to each other, in all species of animals, al- though the differences in respect to structure, particularly, may be very great (§ 107, 409, e), yet illustrated by greater analogies of relation, we may generally infer, by this analogical process (§ 5^), the absolute uses of every part in any species of animal that may be, for the first time, subjected to the knife of the anatomist. And this process of in- duction may be carried to a great extent from an established standard of comparison in the animal to the vegetable kingdom. But the prin- ciple is equally comprehensive in respect to plants, when, as with an- imals, a complex being is marked out, as a standard, in all its struc- tures and functions. The same is also true, though in a far more limited extent, of the modifications of structure, and the corresponding modifications of func- tion, at the different eras of life (§ 153-162). And when we come to the variations of function in morbid states, though unattended by any appreciable alteration of structure, and consider how various must be the treatment according to the nature of the affected tissue, we are deeply impressed with the indispensable importance, to the physician, of an accurate knowledge of all that is relative to the sensible organ- ization of the material part of organic life (§ 2, c). Though the struc- ture, itself, reflect no light upon pathology, excepting through its mor- bid alterations, an observation of its morbid phenomena leads us to a knowledge of the parts diseased, and this knowledge is important to a just interpretation of the phenomena, and to a right method of treat- ment (§ 131). 83£. We have now seen that the composition of organic beings is formed by properties peculiar to organic structure, and that what is thus at the foundation presides over all, and is the cause of all that is superinduced upon that composition. The structure of organic be- ings, which is comprehended under our second division of physiology, is therefore dependent on the same creative cause. 84. The greatest physical characteristic of organized structure is supposed to be its arrangement into cells. Here all analogy with in- organic substances disappears entirely. The chemico-physiologists 32 INSTITUTES OF MEDICINE. imagine that the contradistinction betAveen organic and inorganic be- ings commences at this step in the ascending series of organic results (§ 42). But we have seen sufficiently that all that relates to the com- position of plants and animals is equally significant of a radical dis- tinction between the simplest organic compound and those of an inor- ganic nature ; the same powers being equally concerned in the forma. tion of organic compounds as in their arrangement into tissues. 85. The general structure of organic beings is made up of tissues. A knowledge of the vital characteristics of the different compound tis- sues, of the same tissue in separate parts, of the different parts of one r and the same continuous tissue as it may pass through different com- pound organs, of the whole as they may be combined into complex organs, of their vital relations to each other, and of all parts to each other, is indispensable to a knowledge of the laws in physiology, pa- thology, and therapeutics. 86. Bichat analyzed the tissues more ably than others, and arranged them as follows: 1. Cellular. 2. Nervous 3. Muscular i cerebro-spinal. ( ganglionic. ( involuntary. ( voluntary. ( arterial. 4. Vascular . . . . < venous. 5. Osseous. ( lymphatic. ( fibrous. ( dermoid. 7. Erectile. 8. Mucous. 9. Serous. 10. Synovial. 11. Glandular. 12. Epidermous, or corneous. 87. Until the era of Bichat, the tissues were limited to three as designated by Haller; namely, the cellular, muscular, and nervous. The cellular Avas supposed to form a large proportion of other tissues. 88. There Avas a great error, physiological and pathological, in the foregoing limitation (§ 87), since it took ho note of the modifications of the vital properties, and of the particular functions of the tissues as arranged by Bichat.* 89. The several tissues are distinguished by differences of internal structure, as well as by modifications of their properties and func- tions. They are called simple organs, when considered in their func- tional character; and when two or more go to the formation of more complex parts, they are called compound organs. Certain compound organs, which concur together in some general function, are called an apparatus ; as the urinary, the digestive, the circulatory, &c. As the whole exist in the universal body, they are called an organism. Each tissue, collectively, is also a system; as the mucous, serous muscular, &c * For practical purposes Bichat's analysis has not been improved, nor probably can be—1860. PHYSIOLOGY.--STRUCTURE. 5S 91. The simple tissues rarely occur in a separate state, but are more or less connected together into complex organs. 92. The simple textures are, themselves, compound organs, so far as their organization is made up of various tissues. The union of tissues, therefore, in the simple textures, is quite different and far more intricate than when the simple textures form what is called, specifically, a compound organ. 93. The structure of the general body, and of its different parts, is radiated. The ray Destined for Avaste. ) Conveying the means ) of repair. The Arrangement of Organs according to their relative Functions. ( Brain and cerebral nerves. 1. Nervous System. < Spinal cord and its nerves. ( Sympathetic ganglia and sympathetic nerve ^ Heart and its Pericardium. Arteries. Veins. Lymphatics. Lymphatic glands Lacteals. Lacteal glands. Mouth, stomach, intestine Salivary glands and pancreas. Liver. Spleen. Larynx and vocal system. Trachea. L ungs. Diaphragm. I Muscles of thorax and abdomen 5. System of voluntary muscles. C Derma, or main portion. 6. Cutaneous Sys- J Papillary tissue. rem. ] Rete mucosum. (^ Epidermis. f Kidneys. ~ tt • c . Ureters. ,. Urinary System. 1 B]adder | Urethra. Organ of hearing. " sight. " smell. Bones. Cartilage. Ligaments. Synovial capsules. Testes. ~) Ductus deferens. Seminal vesicles. Prostate gland. Penis. Muscles of perinasum Ovaries. Fallopian tubes. Uterus. Vagina. Hymen. Clitoris. Nymphae. Labia. Constrictor vaginae, j »Mammae,—accessory parts. j 8. Special Sensitive System. 9. Osseous System. 10 Genital System. « > Formative. > Copulative. > Formative. •CopulatiAre. r Male. Female. 58 INSTITUTES OF MEDICINE. 126. .The organic and animal functions are also naturally subdivi< ded into, 1st. Those which operate from without inward, as in digestion ; and, 2d. Those Avhich operate from within outward, as in circulation, se- cretion, &c. 127. There are generally two sets of organs for the animal func- tions, having a harmony of action in their natural and healthy states. 128. When the organs of organic life are in pairs, as the kidneys, concerted action is not necessary; and here one organ may supply the place of both (§ 109). 129, a. The whole assemblage of organic viscera act together in concert; but the animal organs, as a general system, act more or less independently of each other. 129, b. The mutual relations which subsist between the various or- gans and their several functions are of two principal kinds; namely, the vital, and the mechanical. 129, c. The first class of relations may be distributed into three dif- ferent orders. The first order consists of the relations between the organs of sense. The second order embraces those between the brain and voluntary muscles. The third order comprises the relations which are especially maintained by sympathy. It is the last subdi- vision, mostly, which is relative to our present subject. It concerns, therefore, the organization by which organic life is carried on in ani- mals, and depends upon the nervous power in its function of sympa- thy, and upon a principle independent of the nervous power, called continuous sympathy, and which is probably also an important princi- ple in plants (§ 111-113, 222, 233, 495-500, 638J, 818^).—Note U. 129, d. The vital relations of a general nature evince the highest order of Design. They refer to the mutual co-operation of distinct systems of organs in the production of particular results, and of these various systems in the maintenance of universal life; while the sev- eral individual organs possess distinct and specific offices that are more or less dependent upon the principle of sympathy (§ 222-233, 455), that is, reflex action of the nervous system. 129, e. The sympathetic relations are most strongly pronounced among organs Avhich concur together in the performance of special functions, as the circulatory, the digestive, the urinary, the sexual systems, &c. (§ 124). Other special relations subsist between the brain and the organs of animal life through the medium, in part, of the mental functions. Such is seen between the brain and voluntary muscles in the production of voluntary motion (§ 500, d). Thus, also, the senses aid each other; the sight being most independent. In this way, too, a concurrence is established between the teeth, mus- cles, eyes, nose, &c, in procuring food and supplying the stomach; each individual part having been also constituted with a reference to the nature of the food, and the mode of obtaining it (§ 323). 129, f. Plants are devoid of all that intimate association of parts Avhich is owing to reflex nervous influence in animals, as well as to peculiarities of structure and special modifications of the common properties of life. But, a general relation of functions obtains to a certain extent in plants through the law of continuous sympathy, which, as I have endeavored to show, depends upon the organic properties and which 1 would designate as continuous influence (§ 498). PHYSIOLOGY.--STRUCTURE. 59 129, g- The sympathetic relations in organic life are of the very highest moment in medicine. Disease is propagated, is maintained, and removed, very greatly, through these natural relations. 129, h. The sympathetic relations are variously modified by dis- ease, and are often more strongly pronounced than in health, though more or less diverted from their natural condition. Remedies also operate with greater effect through these modified relations, as well as through the greater susceptibility of the organic properties (§ 137, d). For the same reason, natural stimuli, as food, oftan prove morbific in diseased conditions (§ 152, b). The sympathies Avhich grow out of morbific agents depend upon the natural principle, of* which they are only modifications. And so of those which spring from remedial agents; these agents giving rise to greater influences in consequence of the morbid state of sympathy and of the organic properties, as well as in consequence of their own intrinsic virtues (§ 718, 901). 129, i. It appears, therefore, to be a most important law, that mor- bid states call into operation reflex nervous actions among organs, which, in their natural state, manifest but feeble, and perhaps no di- rect relations whatever; and that, in consequence of morbid changes, remedial agents will operate sympathetically through the stomach, &c, upon remote parts, Avhen they Avould have no such effect in the healthy state of the organs. This principle is demonstrated in every case of disease, and constitutes our first position against the humoral pathology, and the doctrine of the operation of remedial agents by absorption (§ 819, &c). New vital relations being developed by disease, our remedies continue to operate through those acquired re- lations so long as they exist; while, also, the remedies themselves may institute analogous sympathetic relations, and thus simultane- ously induce reflex nervous actions of a salubrious nature in organs not morbidly affected (§ 74, 117, 137, 143, 155, 156, 3S7, 422, 514 h, 524 d, 525, 528, 733 b, 905, 980). 129, k. The mechanical relations are equally common to plants and animals. They are maintained by the motion of matter from one or- gan, or part, to another; as the transmission of blood from the heart through the blood-vessels, sap from the roots to the leaves of plants, food through the intestinal canal, urine from the kidneys to the blad- der, and from the bladder through the urethra, &c. But, the move- ment of the matter is effected by the vital properties operating through the various organs. 130. Every part is a perfect labyrinth, anatomically considered. It is a labyrinth, also, of perfect designs; Avhile the harmonious con- currence of these designs in the aggregate organs and tissues is too profoundly complex for any exact analysis. The deep intimacy of parts in each tissue corresponds with the union of the whole, with the dominion of common laAVs, and with that concerted action of all parts, which, in a popular sense, makes up the life of the organic being. 131. It has already been stated, that a knowledge of the minuteness of structure which is supplied by the microscope is practically use- less, while the deceptions of that instrument have led to many im- portant errors in physiology and pathology (§ 83). It cannot be de- pended upon, especially, in exploring soft structures. If it lead to unimportant facts, it is equally liable to betray us into error and fal- 60 INSTITUTES OF MEDICINE. lacious hypotheses. The whole history of that instrument, so far afl physiology is concerned, has gone to confirm the foregoing conclu- sions, Avhich were originally advanced in another work, and has con- clusively sustained the opinion of one of the most profound observers of the present age. Thus : " Authors," says Bichat, " have been much occupied with the in- timate structure of glands. Let us neglect all these idle questions, in which neither inspection nor experiment can guide us. Let us begin the study a§ anatomy where the organs can be subjected to the senses." " No methodical mind will attend to the minute nature of the muscular fibre, upon which so much has been written. The ex- act progress of the sciences in this age is not accommodated to those hypotheses, which made general anatomy and physiology a frivolous romance in the last." Microscopical information, so far as correct, goes to the amount of human knowledge, and to the perfection of science, though it may not contribute to useful ends. But experience shows us that we may not depend, as it respects the microscope, upon the vision of oth- ers, especially where a high magnifying power is required. Each must observe for himself; and, as allowed by Ehrenberg, long prac- tice, alone, can assure him of any general accuracy. The laborious student may attend to this accomplishment. But, vita brevis, ars longa; and he will be likely to live the subject of deluded sense rather than of enlightened understanding. " Enough is left besides to search and know. But knowledge is as food, and needs no less Her temperance over appetite, to know In measure what the mind may well contain j Oppresses else with surfeit, and soon turns Wisdom to folly, as nourishment to wind."—Milton. The following is another example in illustration of Milton's prin- ciple, and another instance* of the revolutionary spirit of the micro- scopic observers. I quote from Wagner's " Elements of Physiology for the Use of Students." " The study," he says, " of the varieties of form presented by the seminal animalcules ought not to be held as any trifling matter, or as tending to accumulate superfluous details. Most important phys- iological conclusions may be based on the information thus ac- quired" (§ 83, b). It is one of the few correct physiological conclusions to be found in the writings of Liebig, that " The most exact anatomical knowledge of the structure of tissues cannot teach us their uses ; and from the microscopical examination of the most minute reticulations of the vessels, we can learn no more as to their functions than we have learned concerning vision from counting the surfaces on the eye of a fly."—Liebig's Animal Chem- istry.—■(§ 83 c, 251, 699 c and d). When we consider, therefore, the constant deceptions of the micro- scope, especially in all explorations of soft substances, and the abso- lute uselessness of any knowledge it may convey as to the recesses of organization, it may be reasonably expected that the time is not * See article on the Microscope, in Medical and Physiological Commentaries, vol. i., p 699-712; and my Examination of Reviews, p. 6, 89; also, this work, § 515. PHYSIOLOGY.--STRUCTURE. 01 distant when all this lumber will be excluded from practical Avorks on physiology, and turned, at least, into a channel by itself. 132. Each simple texture, when united into compound organs, has as much its own specific function as the aggregate compound. It is even more important, in a pathological sense, to regard the individ- ual textures than the compound organ which they may form. 133, a. A consideration of the tissues in respect to their special character and functions, as well as their obvious anatomical differen- ces, being of the very highest importance to the physiologist and phy- sician, they can be studied advantageously only in these several as- pects. Much must, therefore, be now anticipated as to what will be subsequently stated more circumstantially in regard to the properties and functions of life. The student must be prepared with that anal- ysis before he can approach the tissues with any hope of enlightened knowledge. A simple statement of their apparent anatomical charac- teristics and relations, and of their products, would present a barren field. Nor is it alone their vital attributes which should most engage the attention of the medical philosopher, but he should be equally and simultaneously employed in learning how these conditions are modified in disease. Such, therefore, is my projected plan in relation to the tissues (§ 83, c). 133, b. Every distinct tissue, and often the same tissue as it occurs in different places and connections, and even the different parts of one and the same continuous tissue, possess, respectively, special modifi- cations of the vital properties and functions. Upon these modifica- tions depend the variety of the natural vital phenomena, as, also, very greatly, those which are morbid. 133, c. But there would be no disease were there not another im- portant condition iu the constitution of the vital properties; and this is their mutability. Its final cause is the well-being of organic nature ; since, as organization changes in the progress of the plant or of ani- mals to a state of maturity, so must there be an antecedent change in the properties which conduct the development of organs, &c. The same principle is displayed in gestation, lactation, &c. It is this, in connection with the susceptibility of the properties of life to the action of blood and other vital agents, which renders them liable to morbid changes when other causes operate. Such, therefore, is a necessary consequence of the final cause of the adaptation of the properties of life to the influence of salutary agents, and to the varying exigencies of organic nature. Nor would there be any recovery from disease, but for the same mutability of the organic properties, and their liability to other chan- ges when yet other causes operate (§ 177, &c, 901). 134. Owing to the peculiarities in the vital constitution of the dif- ferent tissues, a common disease, as inflammation, is characterized by many peculiarities of symptoms, &c, in the several tissues, respect- ively. Differences also arise in their constitutional influences, and they may require corresponding variations of treatment (§ 718). This is even true of different parts of a continuous tissue, as the alimentary and pulmonary mucous membrane ; where inflammation of this mem- brane in the nose, larynx, trachea, lungs, fauces, stomach, and intes- tines, is distinguished by almost as striking peculiarities in the vital signs, and in their constitutional influences, as arc the physiological 62 INSTITUTES OF MEDICINE. functions of the different compound organs which it traverses (§ 140 752-754, 780, 783). 135, a. The special modifications of the vital properties in differ- ent parts of one and the same continuous tissue is often strikingly de- noted by the character of the natural product of the several portions. respectively; as in the tissue last mentioned. Nothing, for example, can be more unique than the gastric juice, a product of all complex animals, while it can be generated by nothing but the mucous tissue of the stomach. Again, in the lungs we meet with this tissue per- forming the office of excretion; being the only example in which an organ eliminates truly effete matter from venous blood. And here an important analogy occurs to show that the elaboration of carbon is a vital process (§ 316, 419, 827 b). In the uterus the same membrane appears as an organ of excretion in relation to the arterial blood, but for the uses of the uterus alone; nor is there any thing else in nature that is capable of generating a similar product. But, in all the cases, the analogy which is indicated by the coincidence of anatomical struc- ture is farther confirmed by the universal production of mucus by this remarkable tissue. The anatomical differences are microscopical. 135, b. All the foregoing is delicately exemplified by the great variety of formations which are generated by the granulations that Bpring from ulcers; since, although in all the cases the granulations appear to be identical in character, we know from their production of parts analogous to such as had been removed by the ulcerative pro- cess, that, in every instance, the granulations must have been endow- ed, respectively, with specific modifications of the organic properties and shades of difference in organic structure (§ 733 c). 13Q. In consequence, also, of the foregoing peculiarities of vital con- stitution, every tissue, and often continuous parts of a tissue (as in the last example), are determined in their results by special vital influ- ences, as Avell as by any peculiarities of organization. This is denoted by the phenomena Avhere structures are most alike. Owins;, also, to the general coincidence in the vital constitution of all parts "there are certain general stimuli adapted to the whole, especially the stimulus of heat. The blood has been regarded as a universal stimulus ; but, it is only so in relation to the sanguineous system. This fact, it may be now remarked, evinces, what is shown by diseases, a near identity in the vital constitution of all that part of the arterial system which conveys red blood; Avhile, on the other hand, the difference between arterial and venous blood shows a difference in the oro-anic proper- ties of the arterial and venous systems. This has its deep foundation in the whole physiological condition of man and animals, and I may also add, in the whole vegetable tribe (§ 847, c). While every sur- face has some secreted product adapted to its own special modifi- cation of irritability, many of these products may be offensive to other parts. Again, the special irritability of one part may be exactly suited to some product of another part, and this may or may not be a natural vital stimulus, and perfectly inoffensive, to the second part while it may excoriate all other parts. Bile, for instance, is the nat- ural stimulus of the intestine, but Avill injure other parts. Venous blood is harmless in the veins, and excites them, more or less, to a contractile action ; but is rapidly fatal within the arteries (§ 849), Urine is the natural stimulus of the bladder, but will excoriate most other parts (§ 74, 188* d, 475J, 500 m, 514/, 647J, 650, 847 e). PHYSIOLOGY.--STRUCTURE. 63 137, a. In this relative sense the animal is filled with poisons; each one of which, however, in its proper place, is not only inoffen- sive, but indispensable. Here is the principle. 137, b. It is, also, upon the foregoing organic constitution of differ- ent parts, and Avhich gives rise to a mutual relation of the different vital agents and products of organs and of the various parts of the or- ganism, that the difference in the effects of remedial as Avell as mor- bific agents upon different parts is essentially founded. Wine in- flames the mucous tissue of the bladder, &c, but may be good for the stomach. Tobacco smoke is inoffensive when inspired in the or- dinary mode; but it is a violent poison when introduced Avithin the alimentary canal. Other agents affect the stomach, or intestines, or liver, or uterus, or bladder, &c, each organ more than the others, and more than other parts (§ 233f, 872 c, 838.) 137, c. From not duly regarding these important facts, or from an ignorance, or a disregard of physiology, many agents which have a specific relation to the vital constitution of some tissue in a particular part of the body, as the mucous, for example, are supposed to have the same relation to the tissue in all other parts. Hence the oil of turpentine, copaiva, naphtha, &c, haAre been abortively or injuriously employed in pulmonary catarrh, phthisis even, diarrhoea, dysentery, &c, mostly for the reason that they exert a specific effect upon the mucous tissue of the urinary organs. This great law of adaptation is so universal as to extend through- out the whole domain of* medicine, reaching as fully into pathology and therapeutics as it is conspicuous in physiology. If the blood be rendered morbid by morbid states of the solids it never becomes morbific, since there is a progressive adaptation of the vital changes in the solids to such as the solids induce in the blood. And so of va- rious morbid secretions in relation to the parts by which they may be produced. These results, in which the vital properties of the solids are always concerned as the primary cause, are founded in an all- pervading law of the animal economy, and by which, and which alone, nature is enabled to throw off disease (§ 524 d, 944 c, 847 a-h). 137, d. Again, it is one of the most important laws in medicine, that the susceptibility of tissues and organs to the action of remedial agents is more or less affected by disease. Many agents which oper- ate powerfully in certain morbid states, and in certain doses, both lo- cally and sympathetically, may be perfectly inert in the natural states of the same organs. And so of the natural agents of life. The great- ness of the effects, also, will depend very much upon the nature and intensity of disease. The same principle applies to the impressions which are made by many remedial agents upon existing states of dis- ease, or upon organs in their state of integrity; by which the diseased or healthy parts are increased in their susceptibility to the subsequent action of the same or other remedies, or to morbific causes (§ 143, c). 137, e. It is, therefore, one harmonious system of laws throughout. Were it, indeed, otherwise, remedial agents could have no existence, and disease, of course, could receive no help from art. These, also, are the beginning of a long series of facts which show us that the effects of all agents, whether morbific or remedial, may be traced to the peculiar impression which they exert upon parts with which they come in contact; and by which, also, we overthroAV the whole system 64 INSTITUTES OF MEDICINE. of chemical physiology, the humoral pathology, and the doctrines of debility, and of cure by the absorption of remedies (§ 847, e). 138. The natural modifications of the vital properties and functions, or the special vital constitution, of any particular tissue, or parts ol a continuous tissue, and, therefore, their special modifications in any given disease, conform to the general nature of the complex organ of which the tissue may form a component part. Certain tissues of a compound organ are far more liable to disease than its other tissues. Thus, the mucous tissue of the stomach is quite liable, the serous rarely, and the muscular more rarely (§ 764, a) 139. Disease of any particular tissue, or parts of a tissue, is apt to be most severe, in its local and general character, according to the importance of the functions of the compound organ of Avhich it may form a component part. This, however, is less true of the constitu- tional influence, than of the local intensity of disease. 140. The sympathetic influences of disease are also greatly deter- mined by the nature of the affection, especially the constitutional ef- fects. Inflammation of the serous, venous, and ligamentous, tissues, disturb the constitution far more than the same-degrees of inflamma- tion affecting the mucous, arterial, and muscular, tissues. But much, also, as already said, will depend upon the nature of the compound organ with which the tissue, or part of a continuous tissue, may be associated ; though sometimes, where the compound organ is compar- atively unimportant, inflammation of one of its tissues may give rise to great constitutional disturbances. Such, for example, is true of some inflammatory affections of the mucous tissue of the throat; and few diseases are more intractable than laryngitis. Much, also, will often depend upon the special modification of disease; as in acute articular rheumatism (§ 525-530). 141, a. Tissues of the same organization are most allied in their vital properties, and hence are most liable to sympathize with each other in their diseases. 141, b. When a tissue of an organ becomes diseased the proper- ties and functions of the others are more or less disturbed ; though the primary disease is not apt to be propagated to them from the tis- sue first affected. It continues rather in the tissue first invaded. In- flammation, for example, beginning in the mucous tissue of the stom- ach, Avill extend along that tissue, so far at least as its connection relates* to the stomach, without being often propagated to the other tissues of the compound organ. This principle has a broad founda- tion, and is owing to the general coincidence in the vital constitution of all parts of the same tissue, and to the differences between the vital states of that and the associated tissues. Exceptions, howeArer occur more frequently in some parts than in others; as in the lungs, where pleuro-pneumonia is not unfrequent. Nevertheless, in these cases the simultaneous affection of two distinct tissues of a compound or- gan may be rather owing to a general predisposition effected by some remote cause than to morbific influences exerted by one tissue upon the other. In other cases, especially of specific inflammation, the dis- ease is propagated directly from one tissue to another, as in scrofula rheumatism, &c.; but in most other instances by reflex nervous action. 142. For reasons stated in § 133-136, morbific agents may readily excite disease in one part of a continuous tissue when they would have PHYSIOLOGY.--STRUCTURE. 65 no effect on another part of it; or may operate more profoundly on one part than on another. And this holds true of the action of reme- dial agents. The same is also true of the sympathetic influences which may be exerted by disease ; and a like principle applies to cer- tain sympathies that fall upon special parts which are immediately continuous with each other, but which are determined, also, by cer- tain special vital relations of the different parts. Thus, the vital rela tions of the tongue to the alimentary canal being far greater than to the lungs, and as the canal readily sympathizes with other chylopoi- etic viscera, the tongue is far more sensitive to abdominal than to pul- monary derangements (§ 129 c, i, 6S9 i, 694f). 143, a. Again, there may be varying susceptibilities of the differ- ent parts of a continuous tissue (arising from numerous causes not positively morbific), when the same morbific, or remedial, cause will affect one part or the other more in conformity with the acquired sus- ceptibilities, than with the natural modifications, of the vital proper- ties in the several parts, respectively. This is also more applicable to the tissue as it occurs in compound organs not anatomically con- nected, and to tissues which differ in their organization (§ 783). 143, b. Hence it fo^ws, that, if all the organs be rendered preter- naturally susceptible, a general explosion of disease may follow the operation of some cause, which, in sounder health, would be harm- less. Under these circumstances, however, disease is most apt to spring up more or less sympathetically, and successively, in one part after another, till all parts may ultimately be brought into some, though variable, forms of disease (§ 514 h, 660, 666, 905). But, in these cases, it generally happens that some of the morbid states abate, or subside, as new ones come forward, the new ones, perhaps, subduing sympathetically the older in the series (§ 804, 905). The system, therefore, is rarely universally invaded by disease, except in idiopathic fever (§ 148, 783). Reflected nervous action applies in all the cases. Nevertheless, it probably does not often, if ever happen, except in fever, that the primary is the efficient predisposing cause of universal disease, but that disease of one organ proves the predisposing of dis- ease in another; and as one organ after another becomes affected in this manner, they co-operate together in rendering other parts suscep- tible of disease (§ 644, &c, 715-719). 143, c. In proportion, therefore, as the susceptibility of the system at large is increased by morbid changes, or predisposed by morbific influences, so, in a general sense, will the alterative action of reme- dial agents be felt in a corresponding manner (§ 137 d, 152 b, 715). By the law of adaptation as set forth in the Medical and Physiological Commentaries (vol. i., p. 649, 653-655, &c), and in various parts of the present work, the sympathetic influence of any local disease which is felt by distant organs modifies the vital states of those parts in a manner that institutes harmonious relations to the part more pro- foundly affected; and thus remedial agents will extend their salutary alterative action to such distant parts, and render them the source of salutary effects upon the essential seats of disease (§ 73,80,117,129 i, 133-137, 140, 155,156,169/ 387, 399, 422, 514 h, 524 d, 525, 528, 638, 649 d, 811, 848, 902/ 905). When the whole system is inva- ded by disease, as in idiopathic fever, the alterative action of rem- edies is felt over the universal body (§ 148, 152 i, 222-232, 500, E 66 INSTITUTES OF MEDICINE. 904 d). It is owing, also, to the same law of adaptation, the same universal, however partial modifications of the vital states which local diseases often induce, that parts remote from the direct seat of dis- ease are protected against all morbific effects from any changes which the blood may undergo as a consequence of morbid action (§ 845, &c). Independently, however, of any increased susceptibility of organs, the action of numerous agents upon the stomach may determine influences upon distant parts whose natural state is unimpaired, and these influ- ences may become the source of other impressions upon other parts. Circles of reflex nervous action may be thus engendered universally, by which all parts shall concur in the effects of the gastric irritation which the remedies may institute. In this manner a cathartic or an emetic may bring the whole organism to bear Avith favorable influences upon some slight inflammation of the throat which had exerted no mod- ifying effects upon other parts (§514 h, 692 a, 902 g). 143, d. Again, there are some remedial agents possessing general vital relations to the whole body, especially the several preparations of mercury, and others whose specific relations are more limited, like cantharides, which will affect profoundly the entire organization, or certain individual parts, and alter the conditio of their vital states, in the most healthy conditions. These agents, therefore, approach most nearly the truly morbific ones, Avhile they possess the grand charac- teristic of the Materia Medica of instituting morbid changes which are of transient existence (k 1059, 854 d). 144. Many acquired conditions may be transmitted from parents to child, which may thus form a constitutional predisposition to disease; being a permanent and more or less universal modification of the vital properties (though of some parts more than others), which does not properly belong to them; as in scrofula. Here, the absolute remote cause has operated upon the ancestor (§ 75-80, 661). 145. Subjects thus constituted (§ 144) are liable to morbific influ- ences which the more natural do not feel; and such causes as Avould produce in the natural subject common inflammation of the nose, trachea, &c, will excite scrofulous inflammation in the lungs of the acquired constitution (§ 650, 659). 146. Hereditary predisposition to disease manifests itself in certain tissues and organs more than in others, according to the nature of the transmitted constitution ($ 143, a). 147. Sympathetic diseases may spring up in unusual constitutions, when they would not in the more natural. Thus, in certain heredi- tary conditions indigestion gives rise to scrofulous, rheumatic, and gouty inflammation of parts distant from the chylopoietic viscera. The same principle is also in operation when the vital constitution of parts is modified by habits, climate, age, the development of the gen- erative organs, &c. (§ 542), all depending upon reflex nervous action. 148. Certain causes appear to be capable of affecting, directly and indirectly, all the tissues of the body, as in idiopathic fever; though, in these cases the primary morbific effect is on particular parts, from which it is disseminated by morbific reflex nervous action (§ 649, 665, 666, 760). In these cases, however, it appears not to be a posi- tive state of disease in the part upon which the morbific agents may exert their primary effects, as on the mucous surfaces, which brings the .est of the system into a predisposition to disease; but a predis- PHYSIOLOGY.--STRUCTURE. 67 position being established in those primary parts, the impression is of such a nature as to be propagated sympathetically over the universal body; just as when many remedial agents acting upon the mucous surface of the stomach exert powerful influences upon remote organs, but without inducing disease in the gastric mucous membrane. It is, therefore, in idiopathic fever, as well as in numerous local affections,' that the parts on Avhich the morbific agents exert their direct effects may not manifest any signs of disease till the explosion of fever takes place ; or as when pneumonia, or catarrh, is induced by the action of cold upon the skin; Avhile it often happens that the parts thus origin- ally, but imperceptibly impressed, become sympathetically the seats of absolute disease by the reacting influence of the diseases which had been sympathetically produced through these parts. Very complex circles of reflex nervous action may thus arise. These general af- fections may be also broken up by the action of a single remedy, as by an emetic, or mercury, &c. (557, 559, 712, 715-719). 149. It is a great and important law, resulting from the physiolog- ical considerations now made (§ 133-148), that morbific causes, ex- ternal or internal, determine disease upon the tissues of one com- pound organ or another according to the particular virtues of the morbific causes, and in accordance, also, with the natural modifica- tions of the vital properties in every part, and the susceptibilities which they may acquire from other causes (§ 642 b, 722 d, 725, 794, 795, 808). Hence it follows that many of the natural stimuli of 'ife may become morbific. 150, a. It is a great fundamental law, that a general coincidence exists betAveen the natural susceptibilities of the properties of life to their ordinary stimuli (§ 136), and to those of a morbific, and of a re- medial, nature, according to the natural modifications of the vital properties, whether in a general sense (§ 148), or in their relation to particular parts (§ 136); the influences produced conforming, of course, to the natural modifications of the properties of life and the special virtues of the several agents, though modified by the tran- sient or permanent influences which spring from other sources, espe- cially from disease (584, 644-674, 772 c, 826, &c, 847 e, 904). Such is the inevitable result of the constitution of the properties of life (§ 177). It is, as it were, the great focal point from which all di- verges that is embraced in medicine; the bond which unites every branch of the science. 150, b. All that is here said, and in § 149, is equally applicable to the nervous power, in all its modifications, as an agent in the produc- tion and cure of disease, as to agents of a physical nature (§ 222- 233f, &c). 151. It is through the foregoing laAV (§ 150) that the natural stim- uli of life maintain all parts in their precise conditions; through which, also, morbific agents alter those conditions in certain uniform ways, and through which remedial agents establish certain other changes which enable the properties and actions of every part to re- turn spontaneously to their natural states. The law involves an im- mense range of facts in physiology, pathology, and therapeutics, and groups many other fundamental principles. It should be the point of departure in all our medical researches and reasonings; for it is, as it Avere, the polar star which will guide us safely upon our difficult and dangerous voyage ($ 794, 795. &c). \ 68 INSTITUTES OF MEDICINE. 152, a. It follows, therefore, from § 150, 151, that the operation of all things upon the living organism, Avhether food, heat, cold, blood poisons, the nervous power, or remedies for disease, is upon one com- mon principle, which is relative to the natural constitution of the or- ganic properties. Food stimulates the stomach, and throws a genial sympathetic influence over the whole organism, warming the cold surface as soon as it enters its appropriate receptacle; blood main- tains, in the same way, the actions of all parts ; poisons and morbific agents, put into the stomach, affect the vital properties of that organ injuriously, when, unlike thecase of food, pernicious reflex nervous ac- tions are determined upon other parts, or the same food in excess may do the same. We then introduce into the same organ another class of morbific agents that are less profound in their operation, and which prove remedial in certain doses, and therefore establish, through the same principle, a salutary change in the same properties which other poisons had affected injuriously (§ 638, 642 b, 854). 152, b. It is also worthy of repetition, that such is the analogy be- tween morbific and remedial impressions, that the' organs which sus- tain the former are thus rendered susceptible of the latter, when they might be otherwise insensible to the same remedial agents, in their appropriate remedial doses. Such is the harmony of the laws of na- ture ; such their great final causes (§ 524, no. 3, d). For the same reason, also, many of the natural agents of life, such as the ordinary kinds of food, may be intensely morbific in most of the diseases of man (§ 849). Or, again, the agents Avhich heal in their remedial doses may establish severe forms of disease when administered in health. 153. Through the law of development, the tissues undergo natural modifications in their structure and vital endowments at many periods of life. In infancy, the organs are imperfectly developed, though the properties and functions of organic life, unlike those of animal life, are strongly pronounced in many of the viscera. A relation obtains, however, in organic life, between the properties and functions and the relative size of organs (§ 159). In childhood, there is another well-marked change. In adoles- cence, another; when the organs become mature. In old age, an- other; when life is naturally on the decline. 154. The foregoing stages of development (§ 153) are not sudden, but gradually progressive. 155. The changes of organization (§ 153, 154) are preceded by corresponding changes in the vital properties, upon which the former depend (§ 445,/). This principle, too, like all others which relate to organic life, whether in health or disease, is universally true under any given combination of circumstances. It is true of the develop- ment of All tissues and all organs, and all other products, from the be- ginning of conception to the end of life. Hence, also, the variety in the remedial or morbific virtues of many plants, at different stages of their growth. As structure varies, the vital properties have under- gone modifications, in conformity with that order of Design which was instituted, that where one specific end is accomplished, and others are to be fulfilled, the powers by which these final causes are to be ac- complished shall haAre their necessary adaptations. And while, also the vital properties, under all their natural modifications, are so con- stituted as to receive certain exact impressions from the natural stim- PHYSIOLOGY.--STRUCTURE. 69 uli of life, that vital actions may be determined according to the pur- poses ordained, so also will morbific and remedial agents be varied in their influences (§ 129 i, 387, 980). 156, a. The foregoing variations (§ 153-155), therefore, give rise to new dispositions to disease in many parts, and are productive of modifications of former diseases, or the latter disappear. This, as Ave have seen, is a necessary consequence of the physiological chan- ges, since the same properties Avhich carry on nutrition and growth carry on all diseases. The relations of vital and morbific agents move on, pari passu, with the natural changes in the properties of life ; and remedial agents undergo corresponding modifications of action. 156, b. The great law of adaptation is forever present to the eye of the naturalist; and when the same subjects are contemplated in a moral sense, the same evidences of Design meet him at every glance of the mind. Take an example of a compound nature, a universal physiologico-moral phenomenon in which our present topic is involv- ed. Thus, no sooner was man created than he was doomed to obtain his subsistence by the sweat of his brow. Roots, grains, fruits, &c, were, therefore, as far as the wants of animals would allow, created mostly in an unedible condition, but rendered susceptible of the re- quisite improvement by cultivation; and to carry out the great pur- pose, the nature of soils, air, water, &c, Avere made subservient (§ 74, 80, 117, 137,143, 155, 169/ 266, 384, 385, 387, 399, 409/ 422 514 h, 524 d, 525, 526 d, 528, 638, 733 b, 847 g). 157. Organs are softest and most fluid at the beginning of their de- velopment, and increase, progressively, in density through life. The animal ovum is scarcely more than an organic fluid (§ 67). 158. Vascular action is promoted by the greater fluidity of or- gans, and vice versa (§ 142). Inflammation is in part, therefore, more intense and rapid in infancy and childhood than at later peri- ods, which, with other causes, gives rise to the necessity of great promptitude of remedies. Other causes attending the vital condi- tions of old age render equally important a decisive treatment of the severe diseases that may befall that age (§ 574, &c, 1009, &c). 159. The proportional size of organs varies at different stages of life. The cerebro-spinal system, for example, is largest in child- nood. Hence a greater development of the organic properties in those parts, and a greater consequent liability of the brain to inflammatory and congestive affections, and to hydrocephalus. The large propor- tional size of the nervous and arterial systems affects the physiolog- ical and pathological condition of all other parts; giving activity to nutrition, and susceptibility and intensity to disease. The glandular tissue of the liver has the largest proportional size in infancy; but not so the venous system of the liver. Hence, again, •be glandular function of that organ is especially liable to derange- ment in infancy, and its venous tissue to congestion at more advanced ages. It is also important to understand, that the veins, in a general sense, " have a real inferiority as it respects the arteries, during the first periods of life."—Bichat. There are some exceptions, espe- cially in the brain. 160. What has now been said of the modifications of the vital con- Btitution of different tissues and organs may be illustrated by the re] 70 INSTITUTES of medicine. ative liability of different tissues, and parts of common tissues, ta some given disease, by the relative danger of that disease as it may affect the different parts, and by the effects of some remedial agent upon the various parts, respectively. The remedy may be loss of blood, and the supposed disease inflammation. The statement may be conveniently made in a tabular form, Avhile, also, it may be con- verted to practical uses (§ 711). 161. The tables are intended in a general sense, and suppose the constitution to be naturally sound. If hereditary predispositions to disease exist, as in scrofula, or if the constitution be affected by in- temperance, or by previous diseases, &c, the order of liabilities to inflammation, &c, as marked in the first table, will be more or less affected. In the scrofulous constitution, for example, instead of the mucous, the lymphatic tissue may be most liable. 162. The tables will be more or less modified by age. Thus, the veins of the pia mater are more liable to congestion in infancy and childhood than any other part of the venous texture. This liability afterward decreases, and returns at the age of fifty and upward, re- sulting in cerebral hemorrhage (§ 805). PHYSIOLOGICAL AND PRACTICAL SUGGESTIONS. Tissues most liable to disease, especially to inflammation, in the order of arrangement: 1. Mucous. 2. Venous (venous congestion). 3. Cellular. 4. Serous. 5. Ligamentous and dermoid (fibrous). 6. Glandular. 7. Lymphatic. 8. Nervous. 9. Synovial. 10. Periosteum (fibrous). 11. Osseous. 12. Tendons, cartilage, dura mater, and pericardium (fibrous'). 13. Muscular. 14. Arterial. TABLE 11. 1 of the nose. " lungs, fauces. " eyes. ( Ilium, " small intestine, } Jejunum, ( Duodenum. " stomach. " large intestine. " uterus and vagina. " bladder. 1. Mucous texture PHYSIOLOGY.— STRUCTURE. 71 2. Venous texture (form- ing, mostly, venous congestion)..... 3. Cellular texture . 4. Serous texture 5. Glandular texture 6. Lymphatic texture , 7. Fibrous texture . . . . < 8. Nervous texture . . 9. Synovial texture . . LO. Osseous texture . . . C of pia mater, in infancy and childhood. " liver. " small intestine. " pia mater of adults. " rectum (piles). " uterus (phlebitis). " lungs (congestive asthma). " lower extremities (varix). " spermatic cord (circocele). sub-cutaneous. of the lungs. " pia mater. " voluntary muscles. of the lungs. " parietes of thorax. " parietes of abdomen. " liver. " small intestine. " large intestine. " heart and pericardium. " cerebral ventricles. " kidneys. " stomach. lymphatic glands. . mammae (puerperal). salivary glands. liver. testis. lacteal glands. kidney. thyroid gland (goitre). thymus gland. pancreas. of the lower extremities. " upper extremities. " uterus (see Comm., vol. ii., p. 470) others rarely. ligaments. dermoid. periosteum. cartilage. tendons. pericardium. dura mater. brain. nerves. ganglia of sympathetic. spinal cord. of the knee-joints. " ankle. " joints of upper extremities. spongy bone. solid bone. 72 INSTITUTES OF MEDICINE. f of the brain. 11 a *~ • i * I arch OI" aorta. 11. Arterial texture. . . .< J extremities. (_ rare in other parts. TABLE III. Relative danger of high inflammation affecting the tissues of di£ ferent organs, according to the order of arrangement: 1. All textures of the brain. 2. All textures of the heart and pericardium. 3. Venous and lymphatic textures of the womb, iliac and other veins. 4. Peritoneum of abdomen (puerperal women). 5. Serous membrane of small intestine. 6. Veins of the liver (venous congestion in congestive fevers). 7. Parenchyma of lungs. 8. Glandular texture of liver. 9. Mucous texture of small intestines. 10. Mucous texture of stomach. 11. Serous texture of large intestine. 12. Textures of kidney. 13. Mucous texture of large intestine. 14. Serous texture of lungs and thorax. 15. Serous texture of liver. 16. Serous texture of abdominal parietes (common inflammation). 17. Veins of lungs (low, or sub-active, forming congestive asthma. See Comm., vol. ii., p. 494). 18. Textures of bladder. 19. Mucous texture of uterus. 20. Ligaments. 21. Bone and cartilage. 22. Lymphatics of extremities. Tissues which require the greatest extent of general blood-lettino-, when affected with high inflammation,—according to the organs in which they are associated, and in the order of arrangement. The remedy is supposed to be applied early. 1. All textures of the brain. 2. All textures of the heart and pericardium. 3. Serous texture of small intestine. 4. Peritoneum of abdomen (inpuerperal women). NoteHp. 1117. 5. Parenchyma of lungs. 6. Serous texture of stomach. 7. Serous texture of large intestine. 8. Veins and lymphatics of uterus. (Early.) 9. Serous and glandular texture of liver. 10. Venous texture of liver. (Sub-acute, congestion in congestive fever. Often more largely.) 11. Mucous texture of small intestine. 12. Uterus. 13. Textures of kidney. PHYSIOLOGY.--VITAL PROPERTIES. 73 14. Mucous texture of stomach. 15. Mucous texture of large intestine. 16. Serous texture of lungs and chest. 17. Serous texture of abdominal parietes. (Common inflammation.) 18. Ligaments. (Often more largely.) 19. Bladder. 20. Mucous texture of bronchiae. 21. Mamma, testis, parotid gland. 22. Absorbents of extremities. 163. In the treatment of disease, therefore, we should consider the precise pathology of each affected tissue, the natural vital peculiari- ties of the affected tissue in the compound organ, its general character as well as that of the compound organ in the animal economy, the in- fluences which its morbid state exerts upon the other tissues in a compound organ, its own morbific influences and the combined influ- ences of the compound organ upon other parts, and hoAv the remote sympathizing parts may react, or shed an influence on yet other parts. And then follows not only the general plan of treatment, but all that nice discrimination of cathartics, emetics, alteratives, and other groups of agents possessing, in their individualities, respectively, analogous virtues, their combinations, alternations, precise dose, frequency of repetition, &c. (§ 675, 685, 686). The same variety of considerations are to be made when the condition of diseased parts may undergo changes, favorable or unfavorable, from the operation of remedial agents. We are mostly assisted in the foregoing inquiries by comparisons of the morbid with the natural vital phenomena and physical products of each part, and the whole collectively. We also acquire much of our knowledge of the natural constitution of individual parts by ob- serving the deviation of their phenomena when acted upon by mor- bific or remedial agents. The phenomena are then more strongly pronounced than in health, or new ones are developed. Indeed, it is sometimes through morbid conditions only that we acquire a knowl- edge of some of the important physiological conditions ; as, for ex- ample, the existence of common sensibility in all parts. Hence a corollary, that none but an observer of disease can expound the nat- ural conditions and laws of life (§ 685, 686, 848). THIRD DIVISION OP PHYSIOLOGY. PROPERTIES OR POWERS OF LIFE. 164. A vital, or peculiar governing principle or power, in organic beings, has been recognized by all the most distinguished medical philosophers at all ages of the science. It is the fundamental cause of growth, nutrition, and of all other phenomena of organic beings. It is, in all but the vulgar acceptation, synonymous with the term life; and life, therefore, is a cause, and not an effect, as has been assumed by many distinguished physiologists, and as taught by chemistry. 74 INSTITUTES OB MEDICINE. 165, a. " Until it is proved," says Andral (the rastorer of the hu- moral pathology), " that the forces which, in a living body, interrupt the play of the natural chemical affinities, maintain a proper temperature, and pieside over the various actions of organic and animal life, are analogous to those^admitted by natural philosophy, we shall act con- sistently with the principles of that science, by giving distinct names to those two kinds of forces, and employing ourselves in calculating the different laws they obey."—Andral's Pathological Anatomy. _ And, to the same effect, the distinguished organic chemist, Liebig, the chief of the school of pure chemistry (§ 4|): " There is nothing to prevent us from considering the vital force as a peculiar property, which is possessed by certain material bodies, and becomes sensible when their elementary particles are combined in a certain arrangement or form. This supposition takes from the vital phenomena nothing of their wonderful peculiarity. It may, therefore, be considered as a resting point from which an investi- gation into these phenomena, and the laws which regulate them, may be commenced; exactly as we consider the properties and laws of light to be dependent on a certain luminiferous matter or ether, which has no farther connection with the laws ascertained by investi- gation."—Liebig's Animal Chemistry. So, also, Carpenter, Roget, and other eminent chiefs of the physical school (§ 64). And thus, the eminent Miiller, who leads in the school of chemico- vital physiology : " The only character that can be possibly compared in organic and inorganic bodies, is the mode in which symmetry is realized in each." " Whether the vital principle is to be regarded as imponderable mat- ter, or as a force or energy, is just as uncertain as the same question in reference to several phenomena in physics. Physiology, in this case, is not behind the other natural sciences; for the properties of this principle in the functions of the nerves are nearly as well known as those of light, caloric, and electricity, in physics."—Muller's Physi- ology. Finally, we have the pure vitalist, teaching the same doctrine; though, with greater consistency. Thus : " Physiology," says Bichat, " would have made much greater prog- ress, if all those who studied it had set aside the notions which are Dorrowed from the accessory sciences, as they are termed. But, these sciences are not accessory ; they are wholly strangers to physiology, and should be banished from it wholly." " To say that physiology is made up of the phjfcics of animals, is to give a very absurd idea of it. As well might we say that astronomy is the physiology of the stars."—Bichat's General Anatomy, fyc. Tiedemann, too, was right in saying that, " All the qualities of organic bodies should be looked upon as the effects of the vital powers. Even those phenomena seen in them, which they exhibit in common with inorganic bodies, undergo modifi- cations of their specific action, and should be considered subordinate to the vital powers."—Tiedemann's Physiology, Sfc. There is not, indeed, in the whole range of medical literature, one author, hoAvever devoted to the physical and chemical views of life, who does not eAince the necessity of admitting a governing vitalprin- PHYSIOLOGY.--VITAL PROPERTIES. 75 ciple as a distinct entity, distinct from all other things in nature. I say, there cannot be produced one author of any consideration, who does not summon to the aid of his discussion a vital principle whenever he touches upon the abstract phenomena of life. And this I have abun dantly shown by an extensive range of quotations in my various pub- lications (Except § 1034). 165, b. We are constantly asked, how we know the existence of the vital properties or powers ] Again, I say, precisely by the same means as the advocates of the chemical and physical philosophy of life defend their knowledge of the forces which govern the inor- ganic world. The question is important, as implying that physiolo- gists either do not arrive at their knowledge of causes through their effects, or, that there is nothing different in the phenomena of organic and inorganic beings. What would the metaphysician say, were Ave to ask him for any other demonstration of mind than its manifesta- tions ; or the mechanical or chemical philosopher, should we demand any other evidence of gravitation, magnetism, chemical affinity, &c, than the effects Avhich they supply 1 And do we not distinguish one from the other, and regard them as wholly distinct forces, by the dif- ference in their effects ] The proof is clear and tangible, in all the cases. Where the results of power differ so materially from each other, it is as good a ground of argument, that the phenomena depend upon specific powers in one case as in the other; and, if it be " a cloak of ignorance" in either case to assume the existence of powers, it must surely appertain to him who attempts an explanation of the phenomena by assuming forces with which such phenomena have no known connection (§ 175, bb, 1085). 166. Many of the eminent ancient physicians considered the vital principle an intelligent agent; and even Hunter has been supposed, though erroneously, to have been of that opinion. Some distinguish- ed physiologists, of the present day, are inclined to regard the soul as that agent. Others confound it with the Deity ;* while yet others, confounding the Deity Avith Nature, fall into a labyrinth of absurdi- ties.t Others suppose the vital functions alone to constitute life.| The ancient physicians generally distinguished the vital principle from the soul, and regarded both as immaterial (§ 175 d, 350| k). 167, a. The vital principle was early known underthe names of An- ima and Calidum Innatum. It was greatly lost sight of in the " dark ages," but reappeared among the earliest restorers of learning, when it took the name of Anima Vegetans, as significant of its organizing power in plants and animals. The eccentric philosopher, Paracelsus, substituted the name of Sidereal Spirit, to suit his dogmas of plane- tary and demoniac influence. Then came Van Helmont with his in- novation of a Spiritus Archaus, an immaterial principle, which he lo- cated in the upper orifice of the stomach. It presided over the body in a general sense, and had under its command several subordinate spirits (one for each organ), to execute the orders of the great spirit. But, like Paracelsus, he expounded much of his physiological results upon chemical principles, and had no definite conceptions of the office of his Archaeus. Stahl followed Van Helmont with his Rational Soul, * See my article on the " Vital Powers," in Medical and Physiological Commentaries roL i.; and my " Essays on the Philosophy of Vitality." t See my " Examination of Reviews,' p. 43. X Comm., ut supra 76 INSTITUTES OF MEDICINE. and Lord Bacon had entered the field in defense of a vital principle Then came Haller, with his great philosophical and practical distinc- tion of the Vis Insita and Vis Nervea. Here we enter into the midst of the profound theories of irritability and sensibility, which had been suggested by Galen (§ 476, b). Glisson, too, had forced his way into the laws of irritability; and Baglivi had already dealt his fatal blows upon the humoral pathology. We may, therefore, date the progress- ive and substantial foundation of vitalism and solidism from Baglivi to Haller; a period of about one hundred years. 167, b. Whytt modified the Stahlian doctrine; and the visionary Des Cartes led the way in rejecting altogether, for awhile, the vital powers, in which he was aided by the hypothesis of a nervous fluid, which appeared about his time. The doctrine then followed, as a consequence, that matter acquires vitality in virtue of a peculiar or- ganization, and this became an easy step to the atheistical doctrine of spontaneous generation. Then came up the view as set forth by Monro, Sir Humphrey Davy, and others, analogous to the Cartesian, that a living principle pervades the universe, and governs all things. Some of this school suppose the universal principle to be subordinate to the Deity; but a greater number, like Carpenter, Prichard, and especially many of our present geologists, as Lyell, &c, regard it as the Deity Himself, whereby the latter, either directly or by implica- tion, confound nature with God. The doctrine becomes, here, either atheistical or of a direct atheistical tendency; and we have, as a re- newed consequence, the assumption of spontaneous generation.* 167, c. Those great luminaries, Hunter and Bichat, came forward in good time to rescue the philosophy of medicine from the degrada- tion with which it was threatened by chemistry and physics, and have left an impregnable shield to all future ages. 167, d. Tiedemann, too, soon after appeared with his " Physiology of Man," in which the doctrines of life are ably expounded, and which must be ranked as one of the productions of an original mind. Tiede- mann could not believe that there was any sincerity in the absolute rejection of a peculiar governing principle of living beings. " How- ever different," he says, " may be the names chosen by physiologists and physicians to designate this power, however various the ideas they attach to it, yet all must agree on the essential point, that of re- garding it as intended to maintain living bodies, vegetable and animal, and all their parts, during a certain space of time, in a state of integ- rity, in the composition, organization, and vital properties that are peculiar to them, and to render those bodies capable, at a certain pe- riod of their existence, of producing beings of the same species as themselves, which beings are confined to the same determinate mode of formation and development, and exhibit similar phenomena." " We are bound, therefore, to consider the principle which presides over those different acts, as a power inherent in all parts of livino-be- ings, and we cannot assume that, either in vegetables or animals, it is limited to any one part or parts. All the parts of a plant, the roots, stem, branches, leaves, flowers, wood, and bark, are nourished. Nu- trition takes place in all the tissues and organs of animals. The con- * See Medical and Physiological Commentaries, vol. i., p. 25, and vol. ii., p. 124-140. Also, "Examination of Reviews," p. 43; "Notice of Reviews," p. 4; "Essays on Vital' ity," &e„ p. 17. PHYSIOLOGY.--VITAL PROPERTIES. 71 tinual tendency of this power to preserve the individual and all its parts, forms the prominent character of individual life, and is present- ed to us as the most importanp internal condition of life. This power not only converts the alimentary matters, drawn from without, into nu- tritive fluids, endowed with special properties and assimilated by it, but it also introduces them into the solid organic form, determines and reo-ulates the composition, the organization, and the vitality of parts. Every living body is exposed to external influences, which urge it to manifestations of activity. Every one, however, under certain exter- nal circumstances, retains its form, its composition, and activity. Cer- tain external impressions, however, of a mechanical or chemical na- ture, and divers organic matters, vegetable and animal poisons, are able to annihilate this power* and thus to cause the death of the living bodies on which they operate." 167, e. Next came the illustrious Miiller to aid in arresting the al- most universal onslaugh, in Europe, that seemed to threaten the ex- tinction of every sage in medicine from Hippocrates to the exit of Bichat. Under the magic wand of Andral the venerable doctrine of humoralism reared its portentous form; while Louis substituted mor bid anatomy for the science of pathology, and Liebig, and his school Avith fire and acids, overrun the whole domain of medicine. Although Miiller employs the language of Stahl, in relation to a vital principle, I think it rather designed as a forcible mode of ex- pression, than as imputative of intelligence. Thus, uthis rational cre- ative force," he says, " is exerted in every animal strictly in accordance with what the nature of each part requires." The fact is truly stated; but it reposes on great laws of organization, not upon intelligence. That such is Midler's view appears from another expression, that, " the formative or organizing-principle is a creative power, modifying matter blindly and unconsciously." The radical fault of this philoso- pher consists, like that of Van Helmont, Stahl, Hoffmann, and Para- celsus, in referring many vital results of organic beings equally to a "A'ital creative principle" and to chemical forces.—See Muller's Physiology. 167,/ So remarkably different, however, are all the results of life from those of dead matter, that some of the shrewdest physiologists, of our own day, can scarcely avoid the chimerical theory of Van Hel- mont. Thus, even Marshall Hall: " The principle of action in the cerebral system," he says, "is the rpvx?], or the immortal soul. Upon the cerebrum the soul sits en- throned, receiving the embassadors, as it were, from without, along the sentient nerves; deliberating and willing, and sending forth its emissaries and plenipotentiaries, which convey its sovereign mandates, alon°- the voluntary nerves, to muscles subdued to volition."t—(Hall * See "Examination of Reviews," p. 26-28 ; also, this work, § 189 h, 350| b. t I have somewhere seen it suggested that the doctrines of vitalism may be applied in support of animal magnetism. But, while vitalism is fundamentally opposed, even to speculative theory, and rests alone on the absolute phenomena of organic beings, it is not less true that, with rare exceptions, the medical advocates of animal magnetism are, as in ancient times, among the physical theorists of life (§ 844). Dr. Elhotson is of that de- nomination. (See Med. and Phys. Comm., vol. ii.. p. 137, 138.) And, although I have, m the foregoing work (vol. i., p. 632), expressed my opinion of the countenance which has been given to this imposture by distinguished members of the medical profession, I will add my entire concurrence in the following sentiments by Hannah More. In a letter to Hor- ace Walpole, dated 1788, she remarks, " I give you leave to be as severe as you please on the demoniacal mummery which has been acting in this country; it was, as usual with 78 institutes of medicine. on the Nervous System.) Here I suppose the " emissaries and pleni- potentiaries" to be nothing more than the nervous power, a property prodigies, the operation of fraud upon folly. In vain do we boast of the enlightened eigh- teenth century, and conceitedly talk as if human reason had not a manacle left about her, but that philosophy had broken down all the strong-holds of prejudice, ignorance, and su- perstition ; and yet, at this very time, Mesmer has got a hundred thousand pounds by animal magnetism in Paris. Mamaduc is getting as much in London. There is a fortune teller in Westminster who is making little less. The divining rod is still considered as oracular in many places. Devils are cast out by seven ministers. Poor human reason, when wilt thou come to years of discretion!" (0 844.) I may also add the foliowiug extract from the New York Journal of Medicine for March, L845: " New York, Feb. 14, 1845. "Mr. Editor, " Dear Sir—In a letter of the 11th inst, addressed to myself, you desire me to state what I witnessed of the firmness of a young gentleman, upon whom the operation of ex- section of the inferior maxillary bone was performed by Prof. Mott, ' and the reflections to which it gave rise, as bearing on the subject of alleged surgical operations without pain in the mesmeric state.' "The case to which you refer is briefly reported in the January number of the New York Journal of Medicine, by some person, who, like myself, was present at the opera- tion. The subject is there stated to have been 'afine intelligent young man, whose he- roic deportment greatly facilitated the operation.' "Perhaps it is enough that I should have quoted the expressive language of. one, who appears to have looked on with the same admiration as myself; though these examples of ' heroic deportment' are common enough in the walks of surgery, especially among females; and that, too, without mesmeric imposture. The same eminent surgeon, who operated in the case which is the subject of these remarks, will tell you that he has extirpated many breasts, rendered highly sensitive by carcinomatous disease, without observing any evi- dence of pain. But there was something in the case of Mr. Baker, which certainly better deserved the encomium of' heroic,' than any thing I had ever before seen, or heard of, or even imagined as within the compass of human fortitude. " This case, therefore, is interesting at this moment, as evincing a perfect capability of enduring the most intense, and sudden, and prolonged pain, without emotion, and as form- ing a test by which ' the subject of alleged surgical operations without pain in the mes- meric state,' will receive the explanation which you seek. "The case is also physiologically interesting, and interprets the composure of those or- ganic movements, under similar conditions, which has been set forth in behalf of animal magnetism. "To appreciate properly the 'heroic deportment' of young Baker, you must imagine yourself to have been a spectator; follow the able surgeon in all the capital steps, and in all the minor details of the operation, and watch attentively the ' deportment' of the sub- ject. He was laid at a convenient elevation upon a table, his feet crossed upon each other, and his hands lapped. I mention this position, because he did not move his feet, nor displace his hands during the operation. "Now observe the operator; first, making a long and deep incision among the muscles of the neck, and then tearing his way down to the carotid artery, and throwing and tying the ligature. It was, in itself, one of the most capital operations in surgery; but, owing to the dexterity with which it was performed, and with an operation still before us far more difficult, and tedious, and dangerous, this grand step toward the exsection of the jaw lost much of its usual interest to the spectator. But it was not the less painful to the sufferer; who, however, sustained it without betraying the slightest evidence of pain. " Next came the circular incision, reaching all the way from the joint of the maxillary bone, down along its lower edge, up to the middle of the chin. This was done by one rapid, immense sweep of the knife; but there remained the same imperturbable compo- sure of the patient. Not a sigh, not a groan escaped, no muscle moved—the very eye did not wink. And then followed, as you may well suppose, a prolonged, tedious, painful dis- section, in which it became necessary to exasperate the suffering by securing many bleed- ing vessels; till, finally, the operator was ready for his saw. But nothing had yet hap- pened to elicit a single manifestation that the patient was not in a profound slumber, ex- cepting that his eyes were open, and that he occasionally swallowed. " But, before sawing the bone at the middle of the chin, it was necessary to remove one of the incisor teeth, and this was so firmly rooted that a straight forceps slipped in the hand of a capable assistant. Another pull, however, brought with it the tooth; but in neither attempt was there any more indication of suffering than in drawing a nail from a board. " Then came the process of sawing, and this was calculated to greatly annoy the patient from a slight accident which happened to the saw, and which prolonged this part of the operation. Still, however, the same ' heroic deportment" distinguished the patient for- bearance of the sufferer, the same unexampled complacency continued to mark every lin- eament of his face, his very eye displaying nothing but gentleness, softness, and calm resignation. PHYSIOLOGY.--VITAL PROPERTIES. 79 of the vital principle of animals, and whose modus operandi in devel- oping voluntary motion I have endeavored to expound in sections 233, 245, 500, d, and references there. 167, g. For the proof of the existence of a vital principle, and of the government of organic beings by laws peculiar to themselves, as derived exclusively by myself from their composition, see that divis- ion of this Avork, and my Essays on the Philosophy of Vitality; and for the proof which I have offered as founded on the phenomena of life, see Essay on the Vital Powers, in Medical and Physiological Commentaries, vol. i., p. 1-119.—Also, Rights of Authors, p. 912. 168. It is practically useless to investigate the nature of the vital principle. That nature, hoAvever, may be as well inferred through the medium of its phenomena, as the nature of the most tangible ob- jects. The opinion of Miiller commends itself to every right-thinking mind. "Whether the Arital principle," he says, "is to be regarded as im- ponderable matter, or as a force or energy, is just as uncertain as the same question is in reference to several important phenomena in physics. Physiology, in this case, is not behind the other natural sci- ences ; for the properties of the vital principle are as well known in the functions of the nerves, as those of light, caloric, and electricity in physics." " But, Avithout, in the remotest degree, Avishing to com- pare the vital and mental principles with the imponderable agents, we must express our conviction that there is nothing in the facts of natural science which argues against the possibility of the existence of an immaterial principle independent of matter, though its powers be manifested in organic bodies—in matter."—Muller's Physiology. " The bone being separated at the chin, the dissection was resumed among the impor- tant parts, and though conducted with all possible skill and rapidity, it was necessarily tedious, as well as hopelessly painful, and, therefore, still calculated to try the firmness of the stoutest heart. A great extent of all kinds of tissues was divided, and, of course, no small proportion of nerves. Bleeding vessels continued to be secured, the difficult divis- ion of the articulating ligaments performed witn as much facility as its difficulties would admit; and after the removal of the jaw, remaining portions of diseased muscle, &c, were cut away, and which tended not a little to embarrass that ' heroic deportment' which had marked every stage of this great and triumphant operation. From its beginning to its ending, which occupied one hour and a half after the first incision till the final extirpation of all the diseased mass, the sufferer did not manifest the slightest evidence of^Rin, or of impatience, or of fatigue, either by language, gesture, expression of countenance, winking groaning, sighing, or any other imaginable method by which the mesmerite might be dis- posed to evade the overwhelming rebuke which the recital of this case cannot fail to in- flict on his love of the marvelous, or his love of mischief, or his yet more culpable designs on human credulity. " I have said that there was something physiologically interesting in the foregoing case Deyond its simple merit of an 'heroic deportment,' and that it goes to the very depths of mesmeric assurance and duplicity. It was this : " On feeling the pulse of the patient twice during the operation (the last time after the lapse of an hour), I found it calm, undisturbed, and with about the same frequency it had before the operation was begun. This proves to us what I have before expressed, that it is not pain, but the consequent mental emotions which affect the organs of circulation, whether the heart or blood-vessels. "Thus ended an operation, unequaled in the annals of surgery; alike triumphant to the surgeon, to American Genius, to the admirable subject, to the cause of truth, of moral- ity, and of sound religion. " If you desire it, you may publish the foregoing statement, to which I should add some comments had I not already contributed my part, in a medical work, toward the sup- pression of one of the greatest nuisances that has yet infected the moral and reflecting part of the community. I have, however, some developments in reserve, which will prob- ably see the light when the parties interested may be beyond the reach of greater re- proof or mortification. " I remain, very truly, ycur friend and obedient servant, " Marttn Paine." 80 INSTITUTES OF MEDICINE. In the language of Liebig, " In regard to the nature and essence of the vital force, we can hardly deceive ourselves, when we reflect, that it behaves, in all its manifestations, exactly like other natural forces; that it is devoid of consciousness, or of volition, and is subject to the ac- tion of a blister" (§ 165, a). 169, a. We know, however, but little of the nature of the princi- ple of life, and as little of the most obvious material substances; but, while this proposition is sufficiently plain, it is extensively ar- gued that the vital principle, or organic force, has no existence, be- cause it is not obvious to the senses. Thus neglecting its infinite phenomena (our only knowledge of the most sensible existences), the age has run into a materialism that takes in its way the soul itself. Our great interest lies in the phenomena of nature. Through these phenomena their causes may be sought; their nature but very imperfectly. We can only describe matter by its manifestations; and so of the soul, and the principle of life. Of the nature of the soul, however, we have, as it respects its spirituality and some other important attributes, a special Revelation. 169, b. If organized beings possessed a principle of life that could, like light, be seen, they would then be allowed to be governed by this agent, and we should be relieved of the encumbrance of the phys- ical and chemical hypotheses. But, though no such principle ad- dress itself to the sight like electricity or light, its existence is far more variously attested by other phenomena, and more so than all the other powers of nature; and these phonomena being wholly dif- ferent from such as appear in the inorganic world, it is prima facie evident that powers or properties which are predicated of them carry on the processes of health and disease; while the scrutiny of ages has never produced a fact in opposition. 169, c. Indeed, with so much light upon our subject, so much of fact to substantiate our conclusions, it would seem highly probable that all the facts which may be raised in opposition have no relative bearing, and that they are brought forward in the spirit of hypoth- esis. 169,. d. The more comprehensive a law may be, the more readily is it l#own and determined, and the less likely is it that apparently conflicting facts will arise. Whenever such are produced, it is ow- ing to a proper want of investigation. The facts are examined su- perficially; and the speculative or the credulous mind seizes upon some prominent characteristic, and pushes its opposition to nature under the spur of novelty, or the delight of discovery, or the goad of ambition. (See Correlation of Forces, p. 921, § 1085.) Since, also, we seek, alone, for the existence and the nature of causes by means of their phenomena, he is no philosopher who refu- ses an inquiry into causes from want of other means of information. The objection has never been raised in any science excepting medi- cine ; but here we are told by many that we have no means of reaching even the existence of the properties of life as contradistin- guished from those of inorganic matter. It is this blindness, in part, which refuses to apply to the science of life the universal fact, that the phenomena are the only index to the forces which govern the inor- ganic world, that has embarrassed the progress of medicine, and en- cumbered it with a spurious philosophy. PHYSIOLOGY.--VITAL PROPERTIES. 81 169, e. Conscious, then, that I have taken my stand upon ground which true philosophy will recognize as her own, I shall go on with an investigation of the properties of life, as the source of all vital phenomena, of all morbid conditions, and which constitute life itself, and lie at the foundation of medicine. I shall enter far more exten sively into an analysis of those properties than any other writer, shall set forth original views as to the character and office of the nervous power, and as to the mode in which this power participates in the operation of remedial and morbific agents, and endeavor to show, also, that, in proportion as philosophy may depart from the deduc- tions which are founded on the phenomena of living beings, so must all such philosophy be fundamentally false, and become the unavoid- able cause of practical errors of the highest moment (Rights &c, p. 912). 169,/ Nor is it a small part of the proof that vitalism is founded m nature, that it is consistent throughout; seeking no multiplication of causes, but serving as an impregnable and universal foundation for every fact and every rational principle in physiology, pathology, and therapeutics; and, therefore, uniting all the principles relative to life, health, disease, and the art of medicine, into one consentane- ous, harmonious Avhole. What a contrast with the mechanical and chemical speculations, or those commingled with vitalism! What a boundless source of stupendous philosophy for the votaries of one ; what unmitigated confusion, and corruption of knowledge, and mis- application of mind, for the disciples of the other! How truly, and with what sublimity on the one hand, and imbecility on the other, is here exemplified the great distinction between man and his Creatoi, that the former devises in parts that may have no congruity, while the latter perfects the whole and all together (§ 63, &c, 74, 80, 117, 137, 143, 155, 156, 266, 323-326, 387, 399, 514 h, 524 d, 526 d, 638)! 170, a. The vital principle is a Avhole, in respect to its substantial nature, and is common to vegetables and animals. Organic matter, or an organized substratum, is necessary to its existence; and, since the perpetuity of organic matter depends upon the vital principle, it is manifest that both were brought into being without the agency of each other. The vital properties cannot be generated by matter, since upon them the existence of organization depends, nor is there a single phenomenon that indicates their presence in inorganic sub- stances ; nor can they be produced by the forces of physics, since they are perfectly incapable of restoring the structure, or even its elementary composition, after the organized matter is decomposed, or, of reanimating the machine before decomposition has begun ; while, on the other hand, these are the forces which lay waste the structure, and only so, after the signs of the vital properties shall have totally •disappeared (§ 1079 b, 1085).—Notes Pp p. 1142, GU p- 1145. This unavoidable deduction goes far in confirming the Mosaic ac- count of the different steps observed by the Almighty in the creation of living beings; that the sensible structure was first produced, and the spiritual and vital existences superadded* The rudiments of that organization have been perpetuated in connection Avith the prop- erties of life since they came from the hands of the Creator, and are the present source of all animated beings. Any doctrine adverse to • See Medical and Physiological Commentaries, vol. i., p 86-92. 82 INSTITUTES of medicine. this is not only atheistical, but is opposed to all the suggestions of reason* (§ 74, 350| k). Nor is this' all. The varieties in the differ- ent tissues of each animal, and of every plant, all the modifications of the vital properties in each species of animals and plants, in each tissue, and in every part, as already set forth (§ 133, &c), and to be yet expounded, all the various functions that correspond to the mod- ified structure and vital properties, all the secretions, even to the od- or of flowers, &c, are exactly the same now as at the day they were called into being. This shows us that the properties and laAVS by which organic beings are governed, though infinitely varied, are as precise as the principle and laws of gravitation, as the conditions of the solar beam and the laws which they obey.—Note Pp p. 1142. 170, b. Again, the moment inorganic matter is brought into a state to receive the vital principle, however low in degree or energy, it must be exalted to an organic condition. If chyle, blood, semen, the gastric juice, &c, possess life, so, also, must they possess an or- ganic state. This, indeed, is obvious from what we have seen of tho manner in which their elements are united. 170, c. The living principle appears, therefore, to be neither the result of organic compounds, as supposed by Hunter and others, nor, as stated by Prout, Millengen, and others, the primary cause of organic conditions. Both have coexisted since they were the prod- uct of Creative Power, both are necessary to the vivification of dead matter, and the co-operation of both to the farther development of each. 171. The vital principle appears entire in parts when separated from their connections, if such parts be constituted with the requisite structure for independent nutrition (§ 304). Hence the development of the egg, the germination of seeds and flower-buds, the growth of shoots, and the multiplication of polypi from portions of the animal. Miiller, and others, suppose the vital principle to be divisible in such cases; but this construction regards the principle too much in the light of ordinary matter, and too little in that of a specific sub- stance endowed with a variety of properties. These properties, so far as necessary to organic life, are implanted in every part, and each part may be regarded as a whole as it respects its own organic con- dition. In simple beings, therefore, where no great complexity of organs is necessary to the great final cause, nutrition, many parts of such beings may be capable of carrying on the process independent- ly of the rest (§ 299, 302, 304, 322). It is probable, therefore, that the vital principle, in the foregoing cases, is no more "divided" than the soul or instinct as implanted in the ovum.—Medical and Physio- logical Commentaries, vol. i., p. 85, 87. 172. The principle of life, or life itself, may be summarily defined as a cause, consisting of certain specific properties, appertaining to organic matter, capable of being acted upon by external and internal physical agents, by the nervous power, and by mentalcauses, and of thus being brought into a state of action itself, and in no other Avay. Its action is exerted upon the organism, and upon certain external sub- stances, as upon food. In the former case its action gives rise to mo- tion, upon which all the functions depend ; in the latter its operation * See Med. and Physio. Comm., vol. ii., p. 123-140. Also, "Examination of Reviews ' p. 43; and "Notice of Reviews," p. 2, tec, in "Med. and Physiolog. Comm.," vol iii. -Also, $ 1079 b, 1085. PHYSIOLOGY.--VITAL PROPERTIES. 83 is through the medium of the gastric juice in animals, but is more obscure in vegetables. The principle is creative so far as it combines the elements of matter in peculiar modes, and arranges the compound molecules into tissues and. organs, and in modes identical with those which came originally from the Creative Energy of God, Who thus far imparted to the principle of life a formative endowment. The principle is capable of protecting the matter which it endows against the decomposing influences of all the physical agents by which it is nat- urally surrounded, while the extinction of the principle exposes the or- ganic substance to an intestine chemical dissolution, and to the decom- posing action of surrounding agents, which proceeds with a rapidity without parallel in the natural state of the inorganic world. The principle is also susceptible of certain limited changes from the in- fluence of causes, mental and physical, which constitute the essence of disease; while other causes are capable of modifying the morbid changes in such wise that the principle of life takes on a restorative energy, through which it recovers its normal condition. The prop- erties of the vital principle are variously and naturally modified in different parts, and undergo natural modifications at certain stages of life, giving rise to changes of organization, &c. (§ 62, 64, 133, &c). These natural modifications will be farther explained in all the detail which is demanded by one of the most important topics in physiolo- gy; and I now proceed to the various specifications relative to the principle of life. 173. It is the special province of the vital principle in plants to combine the elements of matter into organic compounds ; while in an- imals it can only appropriate compounds of an organic nature. This is a fundamental distinction between the two departments of the or- ganic kingdom; from which it appears that plants are indispensable to the existence of animals (fy 1052). 174. The vital principle is subject to extinction, and this consti- tutes death. When speaking of the composition of organic beings I adverted to the manner in which they resist the decomposing effects of chemical agents, and how the seed and egg are capable of being converted into complex living beings, or the whole animal and vege- table kingdom of being resolved into their ultimate elements, by the action of heat, air, and moisture. The same structure remains in either case when life is suddenly destroyed, and the exact difference which arises in the two cases, from the influence of the same causes, can be owing only to the presence of peculiar poAvers in one case which have disappeared in the other. The cessation of the phenom- ena of life is the consequence of death ; and, there is nothing to die (certainly not the forces of chemistry) hut the principle of life upon which the phenomena depended, and which held the elements of structure in vital union (§ 584, 633). 175, a. As set forth in the Medical and Physiological Commentaries, " I believe the vital principle, vital power, organic force, organic power, are one substance, whether material or immaterial; and they refer, with me, to a universal cause of animal and vegetable life, or, rather, as constituting life itself. I believe, also, that this principle has vari- ous attributes, common or generic, and partial or specific; or perhaps I should call the former distinct properties. Thus, of the generic, we have irritability, mobility, sensibility, &c, and the modifications of S4 INSTITUTES OF MEDICINE. each of these in the same or different tissues form the specific or pai- tial variations. These properties are also constantly varied in dis- ease, and these variations I call changes in kind. The partial modifi cations in their natural state I designate as variations in kind" (§ 133 163, 171). 175, b. The vital principle has certain analogies with the mind or soul, and Avith the instinct of animals (§ 241). Each is inherent in or- ganic matter, and the operations of each are through the medium of that matter. Each, respectively, is one substance, and each possesses certain distinct attributes or properties. Each is not only capable of acting by means of organized structure, but of being acted upon, and modified in its nature, and only so in conjunction with that structure (§ 189, 191, 234/ 241, 566-568). Even in the inorganic world Ave meet Avith a substance which is not without its light in the way of analogy. This substance is light itself. It is apparently one homogeneous, imponderable, substance, yet said to consist of distinct component parts, each of which is endowed with specific attributes. These component parts would thus be distinct entities, which I do not recognize in relation to the properties of the vi- tal principle, or of the soul. But the distinction is not important to my present purpose, and I should also add that it is indifferent wheth- er we here regard the corpuscular or the more probable Avave theory of light (§ 234 e), as the individuality operates in either case. 175, bb. It has been well said by Professor Draper, that " Just in the same way that I am willing to admit the existence of forty different simple metals, so, upon similar evidence, I am free to admit the existence of fifty different imponderable agents, if need be Is there any thing which should lead us to suppose that the imponder- ables are constituted by Nature on a plan that is elaborately simple, and the ponderables on one that is elaborately complex % That the former are all modifications of one primordial ether, and the latter in- trinsically different bodies, more than a quarter of a hundred of which have been discoArered during the present century V (§ 1085). " We are thus forced to admit that rays of light, rays of heat, ti- thonic rays, phosphoric rays, and probably many other radiant forms, have an independent existence, and that they can be separated, by proper processes, from each other."—Draper's Treatise on the For- ces which produce the Organization of Plants, p. 70, 71. Organic life, however, needs only a single principle, or " imponder- able," till it be shown that its supposed properties are individual ex- istences (§ 165, by 175, c. I have presented in the Commentaries, in the Essays "on the Vital Powers" and " Spontaneous Generation," and my " Notice qf Reviews," certain facts which go to the conclusion that the mind or soul is a distinct immaterial substance, and that the instinctiAre principle of animals is equally a distinct substance from the brain. I will now add a few words, physiologically, in respect to the main ar- gument of the materialists, drawn from analogy, that the mind like the gastric juice, the urine, &c, is only a product of the functions of the brain (§ 1076, c). The analogy is fictitious. Both the mind and instinct are entirely wanting in every known attribute of the product of other organs and are sui generis in all their characteristics. This is sufficiently obvi- PHYSIOLOGY.--VITAL PROPERTIES. S5 ous. But there are other considerations which establish the distinc- tion more fully, though they appear not to have engaged the attention of physiologists. What, for example, is the efficient cause of the pro- duction of bile, urine, &c.! Certainly the blood, in connection Avith organic structure and organic actions, and while these actions go on, bile, urine, &c, are uninterruptedly secreted ; or, if arrested, it is from the failure of the organic processes. But, it is just otherwise in re- spect to the mind and the instinctive principle. These are completely suspended in all their manifestations during sleep, and often so with great instantaneousness. And yet there is every reason to believe that the organic functions of the brain continue to move on as per- fectly as those of the liver, the kidneys, &c.; especially when it is con- sidered that sleep may happen in almost the twinkling of an eye. Indeed, were any change to befall the brain, it should be more or less manifested by some consequent modification of all the organic actions ; particularly as those of animal life undergo complete suspension. Again, other peculiarities which contradistinguish the mind and instinct from every organic product are the quick transitions from sleeping to Avaking, and the occurrence of the change without any change in the organic functions of the brain. Take in connection the act of sleeping and the act of waking,—the instant suspension and the instant reproduction of the intellectual operations, and in all their isolated aspects, and the most obtuse understanding must concede not only the entire want of analogy Avith any other phenomena of nature, but that there must be a unique cause for such perfectly unique effects. But, again, suppose some change in the organic condition of the brain as the cause of sleep; what is it, I say, that so instantly rein- states its functions Avhen Ave pass from the sleeping to the waking state 1 What rouses the organ to its wonted secretion of mind ] Are there any analogies supplied by the fiver, the kidneys, &c. (§ 241)? What is it, I say, that brings the great nervous centre into operation in all the acts of volition, in all the acts of intellection ? This ques- tion must be answered consistently, or in some conformity with the argument drawn from analogy. If that can be done, then it must be conceded that the analogy is forcible, and that the argument in favor of materialism is logically taken. So, on the other hand, should the ar- gument fail in this indispensable requisite, materialism must stand convicted of sophistry, insincerity, and a leaning to infidelity (§ 14, c). The premises are perfectly simple. They are also sound so far as it respects all organic actions and results. The blood, as with all other organs, is the natural stimulus of the brain, and here' as there all the organic phenomena are distinctly pronounced. They proceed, in all parts, with uniformity, and without interruption. Nothing can suspend them or modify them in the brain, or elsewhere, during their natural condition. So far the analogy is complete. Now, as it can- not be the blood, according to the analogy, which rouses the brain to action in willing, reflecting, &c, I ask the materialist the nature of the stimulus which operates upon the brain in eliciting the phenomena of mind ? And again, I say, if he can sustain his answer by analogy, such is the consistency of Nature in organic philosophy, such the har- mony of Design, that it might be difficult to oppose Revelation itself to what is so fundamental in Nature. (Continued at p. 882, § 1076). 175, d. It is assumed by many late physiologists, as Drs. Carpen 66 INSTITUTES OF MEDICINE. ter, Prichard, &c, after admitting and denying the existence of vita) properties, and contending for their existence in the elements of matter, and the organizing agency of the forces of chemistry, that, nevertheless, all the results of organic beings are owing to the im- mediate acts of the Almighty (§ 64, /*). This, therefore, as with the author of the "Vestiges of Creation," is only a circuitous method of confounding nature with God (§ 350? h-350% I). Let us, Iioav- ever, suppose that there is a Supreme Being in their opinion, who is the Author of nature, and that He is the PoAver who presides in or- ganic beings, and regulates all their processes, and we shall see that the doctrine abounds with absurdities. Its advocates generally carry this sophistry so far as to affirm that the particles of matter are con- stantly maintained in union by Almighty Power, that chemical affini- ties are nothing but manifestations of that Power, that gravitation is only a constant emanation of the Deity, that digestion, circulation, secretion, excretion, &c, are only immediate acts of God. It is plain, therefore, that they can allow no other God than nature. But, let us now look physiologically at this pantheism. Organic beings are made up of matter, which, it will be conceded, is distinct from God, if we alloAv his existence as distinct from matter. It is therefore perfectly consistent to suppose that this matter is endowed with distinct forces for its own government (§ 14, c). If we regard, next, the results of vital stimuli, we have a palpable proof that they elicit actions and physical results through principles Avhich possess the power of acting, or we must take up the absurdity of supposing that they act on God himself. The same may be affirmed of the poisons, medicinal agents, &c. But this will not hold either in religion or philosophy. Nevertheless, it is evident that some active agent is op- erated upon. If stimulants are applied to the nose, the heart may be thrown, on the instant, into increased action. Of course, it cannot be entertained that God is the agent acted upon in such a case, any more than when prussic acid destroys life with the same instantaneousness ; and, therefore, He cannot be assumed as the cause of the healthy and natural functions (64 h, 241 d, 350f g-350% o, 376i, 733 d). In my " Exam, of Reviews" (in Comm., vol. iii.) I have shown that the doctrine of " the properties of life in the elements of matter" is thoroughly material as it respects the soul (§ 14 c, 189 b, 350| I, m). 176. Besides an organized substratum and a principle of life, there is something still beyond not less important to all the great purposes of life. This consists of the actions and various results of life. If all animated beings existed in the state of the seed and ovum, the whole universe would be nearly without any other apparent anima- tion than what is elicited by the forces of physics and chemistry. The movements of the heavenly bodies would be the principal de- monstrative source of power. Although, therefore, the actions and phenomena of organic beino-s, like the motions of the heavenly orbs, are merely the effects of a pe- culiar power which Ave call life, they are, nevertheless, the only at- tendants of life that interest our senses beyond the physical struc- ture. Hence, it is not remarkable, considering how liable the senses are to take the lead of the understanding, that even the soundest minds have supposed that life consists of its results alone, and have overlooked the great efficient cause or power upon which the results PHYSIOLOGY.--VITAL PROPERTIES. 87 depend (§ 234 g, 247). Had they considered for a moment, however, the analogy which subsists between the motions of organic beings and those of the heavenly orbs, and that the latter depend upon a power which is called gravitation, and without which all the orbs would suffer the stillness of death, the conclusion would have been unavoidable that celestial motion is merely an effect, and, therefore, that all organic motions and their results depend upon moving pow- ers. They should have seen, too, that when a drop of prussic acid, or of the spirituous extract of nux vomica, is applied to the tongue, all the phenomena of life are instantly extinguished, that nothing can reproduce them although the organized structure remains unimpair- ed, and that the whole being is immediately resolved into its ultimate elements (§ 1042). • 177. The properties of life are the fundamental cause of all healthy and morbid phenomena. They are liable to be more or less diverted from their natural state by a variety of causes, and these new condi- tions constitute the most essential part of disease. This instability of the properties of life is at the foundation of all disease, and even of therapeutics (§ 642, b). Other causes, acting upon these morbid conditions, alter them in yet other ways, and contribute to their res- toration to the natural standard. This is the aim of all our remedies ; and the recuperative tendency of the properties of life (the vis medi- catrix natures), when they are driven by morbific causes from their healthy state, enables them to recover spontaneously from the artifi- cial conditions which are substituted by remedial agents for the more intensely morbid (§ 172, 851 a, 853, 854, 893, 900, 901, 905, 1059). 178. Notwithstanding the natural instability of the properties of life, they have a definite character in every part of the body, accord- incr to the nature of each part, at every hour of existence (§ 153-156). 179. The exact nature of disease depends mostly upon the forego- ing definite conditions (§ 178), and upon the particular virtues of the morbific agents. The salutary changes produced by remedial agents involve the same principles. But, these definite changes, and the ac- tion of morbific and remedial agents, are liable to contingent influen- ces from habits, &c.; as set forth under the fifth division of Physiol- ogy. Our calculation of results is thus embarrassed according to the nature and extent of the contingent influences (§ 756, b). 180. The vital properties are without renovation, or mutation in health, except as they are liable to certain natural modifications at different periods of life, or during gestation, or from the slow opera- tion of external agents, as in the artificial temperaments. They must remain without renewal, to be forever ready for the work of nutri- tion, &c. (§ 237, 570-630). 181. The permanency of the vital properties enables us to under- stand the nature of predisposition to disease, artificial temperaments, and hereditary diseases, which many refer to the ever-changing blood (§ 238, 666). 182, a. -According as the vital properties may be modified, either in the foregoing manner (§ 181), or as in disease (§ 177), so will be the condition of the elementary combinations, and other physical products. 182, b. Nevertheless, the properties of life never undergo any rad- ical change till they shall have passed the limit of their recuperative 88 INSTITUTES OF MEDICINE. power (§ 177), and are therefore approaching a state of extinction. Hence, essentially, in connection with the nature of the remote causes, the analogies among diseases (§ 670, 756). 183. In their highest development, the properties of the vital prin- ciple are six ; namely, irritability, mobility, vital affinity, vilification, sensibility, and the nervous power (§ 175). They are called vital prop- erties, vital powers, and vital forces; but are clearly attributes of a common principle, just as judgment, perception, the will, &c, are properties of the soul. They will be examined according to then- nearest relations to each other in the most perfect beings, and their practical application. 184, a. The first four properties (§ 183) are common to plants and animals, and reside in all the tissues.' They may be properly called organic properties, as they carry on the organic processes (§ 476-492, 516 a). The last two are peculiar to animals. This ^nultiplication of vital properties in the animal kingdom harmonizes with the intro- duction of tissues and organs which have no existence in plants (§ 201, 222,232, 450, &c, 500). 184, b. The nervous power has been considered a principle by itself, and often regarded by eminent physiologists as the galvanic fluid, generated by the brain, or other organs, and conducted by the nerves (Med. and Phys. Comm., vol. i., p. 65-68, 107-119). Its phe- nomena, hoAvever, declare it to be entirely distinct in its nature from all things else ; while its analogies to the other properties of life show it to be an element of the vital principle (§ 227-232). If it be diffi- cult for the limited comprehension of man to surmise how this prop- erty should prove an agent to others with Avhich it is associated, the difficulty is no greater than the admitted fact that the will may con- trol other properties of the mind, and the passions. Nevertheless, it is unimportant in a practical sense, and in the institution of principles, whether the nervous power be considered a property of the vital principle, or a principle by itself (§ 175 bb, 186, 226, 1072 b). 185. Although the organic properties which are common to plants and animals are essentially the same, they possess greater modifica- tions throughout than will have been seen to appertain to the same properties in the different parts of animals. But all the variations in the two organic kingdoms are intimately connected by close analo- gies ; just as they are in the different animal tissues (§ 133, &c). Much of the difference in the general vital constitution of the two kingdoms is owing to the presence in one, and the absence in the oth- er, of the nervous system, and those corresponding properties which play so important a part in the animal tribes (§ 733,/). In both de- partments of organic nature, however, there is, essentially, the same principle of life, its great organic elements, and the same great func- tions over which they preside. Hef e, too, in the vegetable kingdom, in the modifications of structure and of the organic properties and functions, and of the laws which they obey, we witness the greatest simplification of life. The vegetable tribes, being also exempt from most of those secondary influences which so constantly embarrass our inquiries in more complex organization, especially from the compli- cations that arise from nervous influence, are better subjects for the experimental researches which concern the philosophy of life; and the facts, therefore, Avhich they supply may be earned up, for the PHYSIOLOGY.--VITAL PROI ERTIES. 89 same general purpose, as sound analogies, to more complex beinms (§ 191 a, 409, 733, 853,1052). 186. The mental property, perception, is necessary to the exercise of" specific and common sensibility, and the will to that of mobility as modified in the function of voluntary motion (§ 194, &c, 226, 241 243, 500 e). Here we hav-e not only other analogies between the in- tellectual and vital principles, but each is brought into direct action with the other (§ 175, 184 b). 187. The vital properties co-operate together in their functions, more or less, as they exist in any given being. 187|. The conditions now mentioned as to the principle of life, as well as all those to be hereafter stated, and the phenomena of which they are predicated, form other groups of facts, which, individually and collectively, contradistinguish the principle of life from all the forces of inorganic nature (§ 1041). IRRITABILITY. 188, a. Irritability belongs to all tissues, and is the property upon which all vital agents, external and internal, physical and mental, nat- ural, morbific, and remedial, produce impressions in organic life; ex- cept as sensibility is concerned in reflex nervous actions (§ 201-203, 226), and as the nerves, from being incorporated in other tissues, take a subordinate part in organic functions, independently of reflex action (§461, 492). All actions or motions, in animal as Avell as organic life, are brought about by impressions on irritability (§ 205, 233, 257, 486, 500 d). This may be either by the direct action of the agent, or by the indirect action of the nervous power (§ 222, &c). When vital agents affect the organic functions in a direct manner, it is by direct action upon the irritability of the parts Avhich perform the functions. This is true, in part, of the natural excitants of organs ; as blood acts directly upon the irritability of the heart and blood-ves- sels, bile upon that of the intestines, food upon that of the stomach, &c. In these cases, however, influences are also transmitted through sympathetic sensibility to the nervous centres, and thence reflected upon the muscular tissue of the organs (§ 201, 514/). So, also, re- medial agents operate upon the irritability of parts to which they are applied, and thus affect their functions in a direct manner. But their influences are commonly more extensive, and then they call into ope- ration the nervous power by their action upon sensibility (§ 201), thus giving rise to reflex nervous actions (§ 222, &c, 475-1-, 500). When mental emotions affect the organic functions it is by determ- ining the nervous power upon the irritability of the parts (§ 226, 227). And, although sensibility receives the primary impressions in the func- tion of sympathy, the resulting influences upon organic actions are brought about by a determination of the nervous power upon the irri- tability of the affected organs (§ 201, 226, 227, 475i 647^ 1041). 188, b. When vital agents act upon specific sensibility the results of their impressions are merely their propagation to the nervous centres, and a consequent action upon those parts (§ 194-204, 222-234). 188, c. I shall endeavor to show that the doctrine is entirely unfound- ed Avhich supposes that vital agents produce their effects in organic life by direct impressions upon the nervous system, excepting so far as explained above (§ 188 a). This demonstration, indeed, AA'as made in 90 .NSTITUTES OF MEDICINE. the Commentaries, but mainly by other processes than will be present- ed in the Institutes. The fact alone, however, should be adequate, that plants have no nervous system, yet carry on all the essential or- ganic processes that exist in animals; Avhile they are alike liable to corresponding results from the operation of morbific and remedial agents. 188-J, a. Every thing which is capable of affecting irritability, and sensibility, is a vital agent. These agents are either natural to the body, as blood, heat, bile, &c, or external, as food, air, heat, light, electricity, &c. Irritability is perpetually alive to the stimulus of blood in all parts of the sanguiferous system, as it is to that of the sap wherever it circulates- (§ 136). This shows the exquisite suscep- tibility of the property. 188|, b. Many vital agents, those just mentioned, are indispensable to the maintenance of organic processes, either in animals or plants. Hence, from maintaining the organic powers in constant action, they are called vital stimuli. Those of a morbific or remedial nature are knoAvn by these epithets, though, in a philosophical sense, they are vital agents. They are distinguished by very different characteristics from the natural agents of life ; even all those which-are stimulant to the organic processes; for they not only excite the properties of life, but are capable, also, of affecting their intrinsic nature. But, there are others, whose effect, in certain degrees of intensity, is directly the reverse of the foregoing, as hydrocyanic acid, tobacco, &c.; and these, when thus operating, are vital depressants (§ 441 d, 650, 743). 188^, c. Some of the vital stimuli which are natural to the body, as blood, and bile, and also food, subserve other purposes than that alone of rousing the action of organs. They are also acted upon and appropriated to the uses of the system. This is more extensively true of animals than of plants. In the latter case there are certain external stimuli which are indispensable to vegetation, and whose only operation is that of excitants, but Avhich are comparatively un- important to animals. These agents are particularly light and heat, and perhaps electricity. The heat which is most important to animals is generated by the living organism. 188\, d. An important error has prevailed among chemists, from their necessary want of physiological knowledge, in regarding the imponderable agents as the causes of life, and not as mere stimuli to those real causes Avhich are implanted in the organization itself, and by which, of course, all the actions and results are determined. This vitiation of philosophy has beset, especially, the functions of animals as it regards their assumed dependence on electricity, and the func- tions of plants in their obvious dependence upon light. The fallacy of the former hypothesis is shown extensively in the Medical and Physiological Commentaries (Essay on the Vital Powers and its Ap- pendix). Of the latter I will noAv say, that in all the relations of light to plants we have the most distinct analogies with other vital stimuli to guide us to the same certain conclusion, that, like other stimuli, it does but rouse the properties of life to certain special modes of ac- tion, by which they decompose carbonic acid gas, carry on the work of appropriation, &c. (Parallel Columns, nos. 64, 65, 66, 68, 74).* But, thanks to my colleague, Professor Draper, whose name in early life glows upon the sunbeam, organic science is supplied with * See Correlation of Forces, p. 921, § 1085. PHYSIOLOGY.--V.TAL PROPERTIES, 91 an adornment which vies in delicacy, yet sublimity, witn the capa- bilities of the nervous power (§ 222, &c, 234 e). The professor has obligingly furnished me with the following statu ment of the progress, and nature, of the discoveries in relation to the solar beam. Thus : " Until the time of Sir Isaac Newton, it was universally supposed that light was a simple elementary body, and therefore incapable of decomposition. " The great optical discovery of Newton consisted in proving that the Avhite light of the sun, or of day, is in reality made up of many colored varieties. He fixed the number at seven: red, orange, yel- low, green, blue, indigo, violet. He indisputably established that that which Ave commonly call light is made up of, and therefore con tains, the seven prismatic rays. They differ not only by impressing the organ of vision with different sensations, but also in intrinsic brill- iancy or illuminating power. It is to be remarked that of these the yellow is the brightest. " It Avas the opinion of Newton, and his folloAvers, that Avhen light falls upon bodies and disappears, it is converted into heat; or, in oth- er Avords, that heat is extinguished light. Sir W. Herschel, the as- tronomer, proved the separate and distinct nature of these principles. The proof chiefly depends on the fact that the brightest ray is not the hottest, and that in the sunbeams there exist rays in abundance which are Avholly invisible, but which can rapidly raise a thermometer. That Avhich Ave cannot see we should scarcely call light. Moreover, a vessel of hot Avater in the darkest place is invisible; yet common observation shows it is emitting calorific emanations. The independ- ence of light and heat may therefore be considered as established. " Some of the alchemists discovered that certain of the white salts of silver (the chloride) turned black under the influence of the sun- shine. Toward the dose of the last century it was shown that the rays Avhich produced this effect Avere invisible, and therefore could not be regarded as rays of light. At a later period I showed that they could not disturb a thermometer, or communicate to our organs the impression of warmth, and therefore must be distinct from heat. From the circumstance that they are ahvays accompanied by light, I gave them the provisional name of Tithonic rays, from the fable of Tithonus and Aurora. " The same species of modification which light exhibits (as colors) has been traced by Melloni for the rays of heat, and by me for the Tithonic rays. But, as both these classes of rays are invisible, their coloration must be necessarily so too, and is known to us only by in- direct facts. We speak of it, therefore, as ideal or imaginary. There are seven colors for heat and the chemical rays, as there are seven for light. " It is worth remarking how complex the constitution of light is now understood to be, when contrasted with the opinion held by the predecessors of Newton (§ 183, &c). " I have established, as respects some of these rays, that they dis- charge extraordinary functions. It is the yellow ray of light which has control of the evolution of plants. Under its influence their leaves effect the decomposition of carbonic acid gas in the atmosphere, set- ting free its oxygen and fixing its carbon. This wonderful phenom- • 92 INSTITUTES OF MEDICINE. enon is unquestionably the first step in the production of organized matter, such as starch, woody fibre, &c, from inorganic gases. The carbon is first fixed under the form of chlorophyll in the leaf. Chloro- phyll occurs under remarkable circumstances as the coloring matter of bile. "Extended investigations have shoAvn that each particular ray of these principles exerts specific powers. The compounds in which silver enters are affected by those of a violet color; chlorine is most acted on by the indigo; and carbon by the yellow. It is for this rea- son, as I have shown, that to the animal eye the yellow ray is bright- est. If nature could have formed a retina of which silver was the basis, the indigo would have been the most brilliant ray. All our conceptions of beauty in colors depend, therefore, on the physical pe- culiarities of the carbon atom. And it is a beautiful and interesting fact, that the ray which evokes from atmospheric air the multitude of forms composing the vegetable world has charge of the process of vision in all animals (p. 797, 798, $ 1034). " Dr. Gardner discovered that the movements of plants are chiefly directed by the indigo rays of light. They grow in the direction in which it falls upon them; and the blue color of the sky is one of the causes of the upright growth of stems. " Besides the three classes of rays which I have mentioned, there is a fourth, of which much less is known; the phosphorogenic rays. These take their name from the fact that when they fall on certain bodies, such as the diamond, Canton's phosphorus, &c, they cause them to gloAV with a pale or splendid light. The extraordinary pecu- liarity they possess is, that glass is opaque to them. " The advance of chemical optics has sufficiently proved that each of the constituent rays of the sunbeam, or of light derived from arti- ficial sources, has capabilities of its own. Thus, each of the seven rays of light impresses our minds with special sensations. The yel- low, moreoArer, controls the growth of plants, the indigo their move- ments. Of the Tithonic rays, the blue is the one concerned in Da- guerreotype portrait taking, and the red can bleach paper blacked with oxide of silver. The same peculiarities will undoubtedly be discovered as respects the rays of heat." Professor Draper's analysis of the sunbeam, by subjecting plants to the various elements of the solar spectrum, demonstrates, what was still conjectural, the individuality of its component parts, and estab- lishes their rank as distinct physical and vital agents. Analogy justi- fied this demonstration; and had the professor proceeded upon the basis of analogy, and applied the spectrum to the philosophy of life, it would have been one of the most splendid achievements of the hu- man mind. But, like Philip and Miiller, in respect to the nervous power, he lost the opportunity; but in losing it, he reared another beacon upon the quicksands of chemistry (§ 476, 493, 5141 b). The chemical properties of the solar spectrum having been an- nounced by other philosophers, it only remained to infer that, like all other things, the integral parts of the spectrum which had manifested peculiar agencies in the physical world Avould probably, if each were specifically distinct, exhibit greater diversities in organic life (§ 52 136,175 bb). This would appear to settle the individuality of the numerous rays. The results of sensation, the test of the thermometer, and even • PHYSIOLOGY.--VITAL PROPERTIES. 93 of chemistry, with their united force, established only probabilities. Nature may have supplied the unerring, the " indisputable"' requisite, in the Vital Principle. And, although discoA'ery is probably only he- gun, the principles of individuality, and of organic relations, are as well determined by the properties of one ray as by those of a dozen. That others than such as are knoAvn belong to the class of vital ao-ents, there can be little doubt. The physical capabilities of other rays sup- ply a strong analogy for this conclusion. But the doctrine of individ- uality is unimportant to our purpose, since, if the homogeneous nature of light and the elegant wave theory become established, each prismat- ic ray will be as much distinguished by peculiar properties as if every ray Avere an entity (§ 175 bb, 234 e). It will be now observed that every tangible substance yields an overwhelming analogy in corroboration of the doctrine which I ad- vance as to the vital relations of the solar spectrum; while the coin- cidence in the specific influences of its component parts upon organic life Avith every other distinct agent, equally in its own turn, surrounds the spectrum with a vital philosophy. Nor is this alone the importance to organic philosophy of the rich discovery. The individual parts of the spectrum not only affect sen- sibility and irritability in modes peculiar to each, but, in beautiful harmony with all tangible substances, each part, respectively, affects certain organs only, according to their special modifications of irrita- bility or sensibility, and according to its own peculiar virtues (§ 133 b, 136, 137 b, 150 a, 188 a, 190, 194, 199, 203). Here, also, it will be seen, is another analogical proof of the vital nature of the influences of light upon organic beings (§ 74 a, 303 e). Much, also, may be found in Professor Draper's oAvn conclusions to show the vital nature of the agency of light. Take, for example. the statement that the "indigo ray controls the movements of plants," and that " the blue color of the sky is one of the causes of the upright growth of plants." Noav what intelligible explanation can chemistry offer of those phenomena in their undoubted relation to light? The unavoidable answer supplies an indisputable analogy for the vital in- fluences of the yellow ray, &c. As to the decomposition of carbonic acid gas, it is the only phenomenon in organic life, and I may add animal, which Liebig abstracted, unequiA'ocally, from chemical agen- cies (§ 350, nos. 66, 68). If we noAv carry the foregoing analogies along in comparing the effects of heat and electricity with those of light upon vegetable or- ganization, we shall readily see that a common philosophy attends the operation of the whole, and that light, in its relation to vegetable life, is nothing but a vital stimulus, adapted to the peculiarly modified vital properties of the leaf, as blood is to the sanguiferous system, sap to the circulatory system of plants, bile to the intestine, semen to the ovum, pollen to the germen, &c. (§ 133, &c). Consider, too, the analogy which is supplied, in the foregoing aspect, by the action of light upon the retina (§ 234, e), and how it contributes to the produc- tion of various hues of the skin, and how, on the other hand, the skin becomes blanched, like the plant, by the exclusion of light. And the analogy may be extended to the motions produced in the iris by the action of light upon the "carbon atom" of the retina (§ 514, k). Nay, more, the action of light, as I have shown, by its absence, at 94 INSTITUTES OF MEDICINE. least, reaches far beyond the peculiarly modified sensibility of the retina (§ 199); since, by its long privation, the entire organ of vision ceases to be developed (§ 74). Again, by what chemical philosophy shall we interpret not only the painful effect of light upon an inflamed eye, but its aggravation of the disease 1 And here, by-the-way, its simultaneous action upon the sensibility of animal life and the irri- tability of organic life concur together in the demonstration. And now to continue the analogies with electricity and galvanism. Either will promote the growth of plants which no degree or modifi- cation of light can exert. So will they, also, promote nutrition in muscles that are wasted in paralysis; and if the pneumogastric nerve be divided, the transmission of galvanism through the inferior portion will rouse the stomach to the production of the true gastric juice and partially restore digestion. And here I may stop to say, that the co- incidence in the effects of galvanism upon vegetable and animal organ- ization is one of the many facts which establish the general identity of the properties of life in both departments of the animated king- dom, while it proves that galvanism and the nervous power are .per- fectly distinct, though each be a vital agent (§ 73 b, 74, 185, 226). Again, also, galvanism is a remedial agent, affecting morbid functions after the manner of other remedies, which, with its analogy to light in promoting the growth of plants, shows farther that the latter is, in the same sense, only a peculiar stimulus to organic functions (§ 74, 303). What is said by Professor Draper in the foregoing abstract on the subject of the yellow ray in its connection with sensation deserves a critical inquiry, not only for the sake of the facts, but as contributing light upon organic philosophy. The chemical doctrine of vision is so clearly fallacious, that any specific relations which may be shoAvn between particular rays of light and the sensibility of the retina, may advance our knowledge, analogically, of the connection of the rays with organic functions, through irritability. But I see not how it is shoAvn that the yellow ray " has charge of the process of vision in all animals," since " each of the seven rays of light impresses our minds with special sensations" (p. 797-798, § 1034). Moreover, if the yellow ray give rise to sensation by its action on the carbon atom, or by any chemical influence, then, also, do each of the remaining six, and each one in modes peculiar to itself, and in all the cases upon distinct bases. Nay, more, when the retina feels the united rays, each of the seven must simultaneously exert their specific chemical actions. Besides, how are those invisible ravs employed which operate chemically upon inorganic compounds ? 'What means the important distinction between the visible and invisible rays that the former act upon organic beings, the latter upon inorganic ?- From the close analogies between the relation of physical ao-ents to sensibility in animal life and irritability in organic life, if their action in the former case be not chemical, but vital, so is it equally in the lat- ter, and vice versa. It is either vital throughout, or chemical altogether. But, organic philosophy, through its analogies, should be able to explain what chemistry cannot as to the resulting sensation when the united rays of the sunbeam fall upon the retina. One example will do it. Thus, every distinct agent of positive virtues produces distinct impressions in organic life. But, by uniting tAvo or more together either mechanically or chemically, a new agent is created. Avhich op- PHYSIOLOGY.--VITAL PROPERTIES. 95 erates either in an individual sense, or if by several virtues, as an en- tire whole. So, in respect to vision, the united virtues of the numer- ous rays of the sunbeam acting upon the sensibility of the retina give rise to sensation attended by a white light (§ 136, 188, 193, 199, 650, S72 a, 1054). In organic life they equally act separately or unitedly. The intelligent reader may now test the foregoing philosophy by what is perpetually observed within himself, and bring to its illustration the exact analogies which I have indicated as being supplied by the different passions of the mind; how anger stimulates the whole vascu- lar system,—how fear depresses it,—how shame acts upon the capilla- ries of the face alone,—how joy acts upon the heart and kindles the eyes in,its own peculiar way, or its antagonist, grief, seeks the lachry- mal gland, or expectation of food the parotids,—how fear, again, rouses the kidneys, or bathes the skin with perspiration,—how love poises its aim at the genital organs (§ 227, 234 g, 509, 512, &c). If, therefore, light do not affect organic actions, and influence organic results as supposed of the foregoing mental causes, and as imputed, also, to all vital agents, but, on the contrary, its Operations upon plants, and therefore upon animals, be of a chemical nature, then, by the clear- est analogy, all other agents of life, the mind and its passions, every act of intellection, every voluntary movement, belong equally to the same category (§ 175 c, 349 e, 1072). 189, a. Where physical views of life obtain, their advocates sup- pose that vital agents operate directly upon the structure. This is one of the first steps in materialism. Many of the chemical school imagine, as Liebig expresses it, that " every motion, every manifesta- tion of force, is the result of a transformation of the structure, or of the substance of parts;" that "every thought, every mental affection, is the result of a change in the composition of the substance of the brain." And so of every pulsation of the heart (§ 350). Others, again, Avho belong to the school of vitalism, to accommodate their lan- guage to the physical conceptions of the day, speak of the action of vital agents " upon the structure through the medium of the vital properties." This difference among vitalists is only verbal; since, by admission, the structure can only be affected " through the medi- um of its vital properties," upon which, therefore, the impression must be made. Hence, distinguished vitalists, Professor Caldwell, for example, who defend the semi-physical mode of expression, often fall into the simple realities of their philosophy. Thus the professor, in his " Outlines of a Course of Lectures" observes that " irritability and sensibility can be acted on by stimulants alone." " Purgative medicines act chiefly on our irritability," &c. (p. 185, 187). And so it ever happens withinquirers after truth. They cannot adhere even to ambiguities of language ; and others who see the truth, but build upon hypotheses, are often betrayed into fatal contradictions (§ 64, 236, 345-350, 350£ n, 699 c, 740, 819 b). 189, b. But, Avhat is more remarkable, the most absolute physical phi- losophers of life, they who deride the existence of the " vital proper- ties," and speak of their " destruction" as an absurdity, not only fall into the language of the vitalists, but unaA'oidably contradict their whole system of materialism, wheneArer they approach the realities of life. This is true even of Dr. Carpenter, who, in his review of my Com- mentaries attempted their overthrow by satirizing the supposed exist- 96 INSTITUTES OF MEDICINE. ence of " vital properties," and particularly the supposition that prop erties could be "destroyed." Thus, then, Dr. Carpenter, at a subse- quent time, and in a work of great professional popularity. The cap- itals and italics are mine : " It is a fact of some importance, in relation to the disputed question of the connection of muscular irritability with the nervous system, that when, by the application of narcotic substances to the nerves, their vital properties are destroyed, the irritability of the muscle may remain for some time longer; and the latter must, therefore, be independent of the former. Hence we should conclude that contrac- tility [mobility, of these Institutes, § 205] must be a property really inherent in muscular tissue, which may be called into action by va- rious stimuli applied to itself, and which may be weakened by vari- ous depressing agents applied to itself ; and that the nerves have the power of conveying the stimuli which call the property into action, but have little or no other influence on it."—Carpenter's Human Physiology, Section 376.—See, also, this work, § 175 d, 167 d, 291, 350J b ; and Examination of Reviews, p. 8-12, 26-43. It is important to the great objects of medicine, that I should now say, that the foregoing is only an example of numerous palpable con- tradictions of the physical vieAvs which form the fundamental philoso- phy of life in the foregoing work, and, I may add, of most others which are devoted to the propagation of medical materialism. It will be seen that enough is admitted in the preceding quotation to substantiate every doctrine advanced in these Institutes. There are the vital prop- erties, in all their individuality, called into action by stimuli, and " act- ing" of themselves even beyond the doctrine of vitalists, or, ao-ain, " weakened by various depressing agents," and liable to be " de- stroyed;" though I do not allow, as affirmed in the quotation, that 11 contractility" is the property acted upon ($206). Finally, we have ad- mitted, " that the nerves have the power of conveying the stimuli which call the property [contractility, or mobility} into action ;" and which is all that is necessary to the whole doctrine Avhich I have propounded as to the nervous power (§ 222-233|, 500, &c, 512, &c, 893-905). 189, c. The impressions which are made on the vital properties be come the causation of the changes which may ensue in the actions, or structure, of the solids, where the impression is made. No vital agents elicit actions, or a single phenomenon of life, when applied to an in- organic compound, not even from an organic being just dead from in- stant destruction by hydrocyanic acid, or by a pin thrust into the me- dulla oblongata. On the contrary, indeed, all the agents which had before contributed to the maintenance of life, now carry out the work of destruction, and more speedily resolve the organic fabric into its ultimate elements than any inorganic compound ($ 62). It follows, therefore, that agents do not elicit the actions of life by operating upon the organized structure; but upon those properties which hydrocy- anic acid, &c, may extinguish in an instant of time ; nor do they op- erate upon the functions, since those are merely effects (§ 176). And is it not a greater paradox that hydrocyanic acid, or aconite, &c, should destroy life in a second of time by its action upon the mere structure than upon that living principle which imparts to the organic kingdom all its peculiar characteristics'? Or, as the blood, or joy, or fanger, rouses the heart, or as fear brings on perspiration, micturition PHYSIOLOGY.--VITAL PROPERTIES. 97 &c, or as the want of air throws into action the respiratory muscles, or as odors, light, &c, produce their sensations 1 By facts of the foregoing nature, and by all those considerations which have been made in relation to the differences in the vital con- stitution of the different tissues, and of different parts of one and the same continuous tissue (as of the alimentary and pulmonary mucous membrane, § 133, &c), it becomes perfectly obvious that the proper- ties of life are something ^?er se, something besiires organization itself, or organic functions, and upon Avhich the agents of life exert their im- mediate impressions (§ 1029, 1030, 1034, 1041). There can, therefore, be no appreciation of the laws of organic be ings, of the modus operandi of natural, morbific, or remedial agents, of healthy or morbid processes, of voluntary or involuntary muscular motion, of the results of the operation of the nervous power and sen- sibility, or even of perception, without a critical reference to the prop- erties of life as the efficient causes, and as receiving the impressions which may be exerted by external and internal agents (§ 872). 190, a. Irritability, and other vital properties, are naturally modi- fied, in kind and degree, in the different tissues, in tissues of the same order, and in different parts of one and the same continuous tissue (§ 133, &c, 199, 203, 227-232, 525-529). These natural modifications are shown in all parts by the peculiar action of the natural stimuli of life; as blood upon the heart and blood-vessels, food on the stomach, bile on the intestines, urine on the bladder, the will, through the nervous power, upon the voluntary muscles (§ 215, 227, 486), and by the differences that arise from their action on parts to which they are not peculiar. And so of the diversi- fied effects of external agents on different parts. 190, b. There are remarkable modifications of irritability in the ova of oviparous and viviparous animals, and in seeds. Semen is the only natural stimulus of the former, in their absolute state of ova; while in the ova of viviparous animals, the actions, after being roused by the stimulus of semen, must go on to a full development of the organ- ic being, and in undisturbed connection with the parent; but, in the oviparous, when the ovum has acquired a certain development, the actions cease spontaneously, the properties of life no longer obeying the vital stimuli as in the other case. These properties then become dormant (and in the seed, also), and nature, having fulfilled her final cause, the ovum is expelled from the body, and the seed cast off, that they may be subjected to new agents. Semen will not now act upon the egg, but heat and atmospheric air become necessary to restore • the actions, and carry out the process originally instituted by the spe- cific stimulus of semen. There are certain oviparous animals that present other peculiarities; and other changing modifications, of irritability in respect to their ova. At certain seasons their ova undergo a partial development from the influence of season, and from the stimuli supplied by the female pa- rent. These influences, however, finally cease to operate, and the ovum is expelled to undergo the action of semen in the external world. This action again modifies irritability, and adapts it to other vital stimuli. Again, it may be affirmed of many oviparous animals, e.g. birds, that a partial development of the ovum takes place, though imperfectly, G 98 INSTITUTES OF MEDICINE. through stimuli supplied by the female parent, and the ovum is ulti- mately expelled as when incipient development is brought about by the stimulus of semen, hut that these ova are insusceptible of renewed actions, either from the stimulus of semen, or other vital agents (§ 71-73, 1051). 191, a. The variations in kind and degree of irritability (§ 190) adapt each part to be acted upon by peculiar natural agents, Avhile the same agents may have a pernicious effect on other parts, in the great plan of organic life (§ 133, &c). The same principle governs the operation of morbific, and, more or less, of remedial agents, and is one of the main causes of disease, and of the determination of dis- ease upon one part in preference to another (§ 149-151). The prin- ciple is, therefore, very comprehensive, and refers as well to the kind, energy, and degree of the operating causes or agents, as to the kind and degree of irritability (§ 150). And so, also, of sensibility (§ 194). The principle is not only seen in all parts of the organic being, but every distinct species of animal and plant has, in a collective sense, its own-special modification of irritability, through which its organic habits as to food, composition, nutrition, &c, are specifically regula- ted. It is this which renders what is poisonous to one animal or plant salubrious or inoffensive to another. And this lets us into a knowledge of the reason why certain atmospheric influences induce the "milk-sickness" in the kine of the Western States, and probably in no other animal. It reveals to us how it is that the stately plata- nus occidentalis and the common peach tree have been dying out over extensive regions of country, and why the potato-crop is cut off, year after year, in vast regions of Europe and America, while every other tree and herb escape the epidemics (§ 150). These very facts de- monstrate, also, the principle as to the natural modifications of the properties of life, and establish, alone, the fundamental identity of the vital properties in the two departments of the organic kingdom (§ 185). 191, b. Again, more remarkable modifications of irritability, or changes in kind, are artificially effected by morbific and remedial in- fluences, external and internal, physical and moral; and these, far more than a mere increase and depression of this property, constitute an essential part of disease. These affections of irritability give rise to new series of influences, from every variety of agent, and often very different from such as are exerted under circumstances of health (§ 542). Hence it is that ordinary food, &c, becomes morbific in diseased conditions, remedial agents operative, either for p-ood or for evil, when otherwise they might fail of any effect (§ 226), and, upon this mutability, and varying susceptibility of the property now under* consideration, is greatly founded the art of medicine. It is, especial- ly, these varying conditions of irritability which demand so much critical reference to the exact nature of remedial agents, their doses, &c. (§ 857, 871, 878), and to the mutability of the property is partic- ularly due the salubrious influences which are exerted (§ 901). 191, c. And here we have striking analogies in the manner in which the properties of the mind are modified in their character and again restored to their integrity when the organic properties of the brain become affected in the foregoing manner (§ 175). 191, d. Remote analogies prob&bly exist even in the inorganic kingdom; though we have apparently nothing there in this respect FHYSIOLOGY.--VITAL PROPERTIES. 99 which transcends other affinities between the two great kino-Joms of nature. We do not find that dead matter is endowed with proper- ties as specifically distinct from the matter itself as the livino- beino- and the properties by which it is governed. And, so far as this analogy extends to dead matter, its properties do not appear to be liable to any mutations in kind, but only in degree ; and here it would seem that the analogy should end, since we do not find that instability in the mineral world Avhich, in the organic, grows out of the mutability of the properties of life. What I ha\re thus said of the analogies between the properties of living and dead matter is sustained by the late researches of chemists. Thus, on the allotropism of simple bodies, it is said by Prof. Draper, that, " to a certain extent, the views of M. Berzelius coincide with those Avhich have offered themselves to me from the study of the prop- erties of chlorine. They are not, however, altogether the same. M Berzelius infers that elementary bodies can assume, under varying cir- cumstances, different qualities. The idea which it is attempted to communicate in this memoir is simply this,—that a given substance, such as chlorine, can pass from a state of high activity, in which it possesses all its well-known properties, to a state of complete inac- tivity, in which even its most energetic affinities disappear. And that, between these extremes there are innumerable intermediate points. Be- tween the two views there is, therefore, this essential difference: From the former, it does not appear what the nature of the newly-assumed •properties may be ; from the latter, they must obviously be of the same character, and differ only in intensity or degree, diminishing from stage to stage until complete inactivity results."—Draper, on Allotropism of Chlorine as Connected with the Theory of Substitutions. 1845. 192. Irritability stands as a sentinel at all the openings and pores of the body, and betAveen the capillary and extreme vessels of the ar- terial system ; admitting and excluding according to its natural mod- ifications in different parts. Thus, all but chyme is excluded from the duodenum by the pyloric orifice of the stomach, and all but atmo- spheric air by the glottis. The globules of blood are vastly smaller than the visible capillaries which carry only white blood, from which they are excluded by the peculiar irritability of these vessels.* When admitted, as in inflammation, it arises from a morbid alteration of irri- tability. And so Avhen the lacteals absorb deleterious agents, or the pylorus allows the escape of undigested food. There is no analogy between a set of inert tubes and the living ducts. And yet are Ave presented with tubular instruments of glass, &c, to demonstrate the laws which govern the circulation of the blood and of sap, and sponges and lamp-wick to exemplify the process of absorption as carried on by the lymphatics and lacteals (§ 289, 291). 193. Bichat confounded irritability with sensibility, by calling the former organic sensibility, and the latter animal sensibility. He made, also, a greater mistake in supposing that irritability and sensibility are only different degrees of one property. This fact derives its impor- tance from the high authority of the French philosopher, and the er- rors into which, he has thus led a multitude of others. The coincident functions between plants and animals, and organic actions being carried on in parts of animals after the greatest possible destruction of the nervous communications, evince the clearest distinc- * A few are said to be admitted, but are visible only through the microscope. 100 INSTITUTES OF MEDICINE. tion between irritability and sensibility, however close their,analogies in respect to the operation of physical agents. Nor c?fn the nervous influence act as a stimulus in such cases, though the nerves may form a channel for other stimuli (§ 461, 476-i c, 489, 490). 2. SENSIBILITY. 194. Sensibility, which is peculiar to the vital principle of animals, resides exclusively in the nervous system. That which gives rise to true sensation is mainly limited to the cerebro-spinal system (§ 184, 523). 195. Through sensibility we learn the existence and nature of ex- ternal objects. These objects make their impressions upon this prop- erty as we have seen of other agents in respect to irritability (§ 1S8, &c). Another important function is also performed by sensibility, which consists in the transmission of impressions to the cerebro-spinal axis, as a part of the great function of sympathy, or reflex nervous action. All the modifications of sensibility are designed for the transmission of impressions from the circumference to the nervous centres (§ 450, 451). The sympathetic neiwe contributes centres in organic life. 196. The nerves are the organs of sensibility, and the brain and spinal cord the recipients of impressions transmitted by this property through the medium of the nerves. Perception is also necessary to the recognized modifications of sensation ; and, therefore, the perfect exercise of the poAver, in its function of true sensation, requires a healthy state of the foregoing elements (§ 523, no. 3). 197. Sensibility is said to be of two kinds, common and specific. I shall distinguish it into a third kind, which may be called sympathetic sensibility ($ 1037, b). 198. Common sensibility is the source of pain, and resides in all the nerves. It is generally dormant in the organs of organic life, but may be greatly roused by disease. The best examples of this latent state occur in the ligaments and bones. Its development by disease is a clear illustration of the light which is reflected upon natural phys- iological conditions by their morbid changes (§ 137, d). 199. Specific sensibility is peculiar to the senses, where it mani- fests very striking peculiarities. Light, alone, will affect the specific sensibility of the retina, the intrinsic A'irtues, only, of various substan ces give rise to tasting and smelling, certain mechanical impressions to hearing, &c. This proves a difference, or modification, of specific sensibility in the several organs of sense, by which, as in the case of irritability (§ 190, 191), it is adapted, in various parts, to the action of special stimuli, according to the predetermined uses of each part. 199£. The impressions transmitted by common and specific sensi- bility are received by the brain alone, or its equivalent. The spinal cord is only a medium of communication. These, also, are the kinds of sensibility which require for their operation the exercise of per- ception (§ 451, 523, nos. 1,2); and it is these upon which true sen- sation depends. Whenever brought into operation, the mind takes cognizance of the transmitted impressions (p. 864, note). 200. The foregoing (§ 197-199) are coincident with what Ave have seen of differences in irritability (§ 133, &c, 190, 191), though more strongly pronounced, and are clear examples of what is meant bv PHYSIOLOGY.--VITAL PROPERTIES. 101 natural modifications of the vital properties; and illustrate those mod- ifications which constitute the essence of disease (§ 133, &c, 191). The three principal kinds of sensibility, and the several modifica- tions of the specific kind, as shown by the special causes which, re- spectively, give rise to seeing, tasting, smelling, &c, also illustrate the principle which governs the special relations of different agents, natural, morbific, and remedial, to irritability as modified in different parts ; and this, also, reciprocally illustrates the characteristics of sen- sibility. A harmony of laws prevails universally (§ 133-138). Like irritability, sensibility is also liable to artificial modifications from the action of external and internal causes; and, as will be seen, the ner- vous power is susceptible of even more remarkable influences (§ 226- 232, 725). 201, a. The last section leads me to consider the third kind of sen- sibility, or what I have denominated sympathetic sensibility (§ 197). Its office will explain the qualifying term sympathetic, which appears to be necessary to avoid the confusion which prevails in the applica- tion of the general term to the distinct offices of exciting acts of in- tellection and of influencing organic motions, and of producing invol- untary motion in animal life. There Avas a radical objection to Bi- chat's designation of irritability.as organic sensibility (§ 193); but in the present term there seems to be a peculiar advantage (§ 451, d). "Impressions," says Miiller, "conveyed by the sensitive nerves to the central organs are either reflected by them upon the origin of the motor nerves,' without giving rise to true sensations, or are conducted to the sensorium, the seat of consciousness." When light produces vision, or odors give rise to agreeable sensa- tions, it is due to specific sensibility. The mind perceives, and the effect goes no farther; there is no extension of the impressions be- yond the sensitive nerves. Again, the light or mechanical irritants are productive of pain, and the effect is limited in the same manner. But here there is no specific sensation. It is the same in all the or- gans of sense. This, therefore, is due to common sensibility. At another time, however, the light induces a paroxysm of sneezing, or the odor syncope or disease. Here is a perfectly new train of re- sults, the principal of which are in parts distant from the direct seat of the impressions. The primary influences have been propagated upon various organs by the nervous centres through the system of motor nerves. These influences, therefore, have called into action another modification of sensibility, and that is the sympathetic (§ 450, &c, 464, 514 k-m, 902).—Note D p. 1114. 201, b. This variety of the common property, like specific sensi- bility, belongs tacertain parts only of the nervous system, and is the medium through which impressions upon all parts are transmitted to the cerebro-spinal axis, in the function of sympathy. Perception, and true sensation, therefore, which is rarely an attendant phenomenon, are not necessary to the office of this modification of sensibility, nor is a continuity of the nerves with the brain. Reflected motion may be as readily excited through the spinal cord as through the brain; "and we are in possession," says Miiller, "of no facts which prove that the spinal cord, when separated from the brain and medulla ob- longata, can be the seat of true sensation. The reflected motions ex- cited by the irritation of the surface in decapitated frogs are no proof of this." The ganglia of the sympathetic nerve are, also, centres. 102 INSTITUTES OF MEDICINE. 201, c. Sympathetic sensibility appertains to what are denominated the sensitive nerves, and the sensitive fibres of compound nerves, which are also, in part, the instruments of common sensibility. But, a remarkable anatomical distinction, and which goes far to sustain the variety of sensibility which is here indicated, is found in the sen- sitive fibres of the sympathetic and pneumogastric nerves; which possess, in the most exalted degree, the power of transmitting organic impressions to the nervous centres, but which are nearly destitute of common sensibility. Indeed, it is through this .system of sensitive fibres that the whole organic department maintains the specific rela- tions of its several parts (§ 129, 523, nos. 1, 2, 3, 6, 1037, b). 201, d. The impressions transmitted through sympathetic sensibility may be receiA'ed either by the brain, spinal cord, or certain parts of the ganglionic system (§ 520); and either connectedly or independ- ently of each other. When thus received by the nervous centres, they give rise to a development and transmission of the nervous pow- er through what are called the motor nerves, and terminate in those influences which complete the function of sympathy, by giving rise to sensible or insensible motions, or modifying such as had existed. 202, a. The manner in which sympathies are brought about through the medium, in part, of sensibility, and the failure of impressions upon common and specific sensibility to generate sympathy, or to excite the influence of the motor nerves, and the absence of sensation in the former case, and the admissible absence of the brain, as well as other peculiarities, prove, abundantly, the existence of this third kind of sensibility. Besides, also, the prominent demonstrations to the fore- going effect which occur in disease, this modification of sensibility is in universal operation in healthy states of the body; as manifested in respiration, and in the concerted action with which the various organs carry on their respective functions. Through this modification all parts transmit to the cerebro-spinal axis special influences that are relative to their existing conditions, and these influences are propa- gated through motor nerves, and maintain a harmony of movements. These reflex nervous actions are, therefore, universal and perpetual. The special function of this kind of sensibility, and its co-operation with the nervous power in the function of sympathy, will be farther considered along with that function, and the function of motion, and again under the laws of sympathy, and the modus operandi of reme- dial agents (§ 1037, b). 202, b. It may be now said, however, that when sympathetic sen- sibility contributes to motion, whether in organic or animal life or Avhether sensible or insensible, it is through impressions received and transmitted by this property to the cerebro-spinal axis, or to the centres of the sympathetic Avhen a medium of reflex action, and a consequent development of the nervous power, Avhich power then op- erates, through motor nerves, upon the organic irritability of parts Avhich are brought into motion. 203. Like specific sensibility (§ 199), and the organic property, ir- ritability (§ 190-192), sympathetic sensibility is variously modified in different parts, by which it is adapted to the reception of impressions from agents of particular virtues, and for their transmission to the nervous centres, and for the ultimate generation of true sympathy; while the same agents fail of these effects in other parts (§ 133, fcc.) PHYSIOLOGY.--VITAL PROPERTIES. 103 204. Another manifest contradistinction between sympathetic, and common and specific sensibility, is seen in the general failure of im- pressions made on sympathetic sensibility to act upon the mind, and therefore in the ordinary absence of all sensation. If sensation be an attendant phenomenon, it then arises from impressions simultaneously made upon common sensibility (§ 445, 464-467, 473, no. 5, 474, no 4 523, 1.037, b). 3. MOBILITY. 205, a. Mobility is the property by which all motions are carried on in animals and plants. It is peculiar to the solids, though some late physiologists have ascribed it to the globules of blood, while oth- ers have mistaken the globules for entozoa (§ 233, 253, &c). 205, b. Sensible and insensible contractility, as employed by Bichat, and muscular power, are bad substitutes for the name mobility. They lead to erroneous conclusions ; since the heart, blood-vessels, and other muscular organs dilate or elongate, as well as contract, through the same vital property; and motion occurs in various tissues.—(Med. and Physiolog. Comm., vol. i., p. 150, 379-391.) The terms sensible and insensible contractility limit the law of mo- lion to simple contraction, while there must be often a correspond- ing active* dilatation, or the part would always remain in a state of tonic spasm. Elasticity will never explain the dilatation of the heart, of the veins, &c.—(Med. and Physiolog. Comm., vol. ii., p. 147-156, 175, 176, 399-402, where this is fully examined). 206. The philosophical Macbride remarks that, " as irritability ne- cessarily implies mobility of the animal fibres, this does not require to be considered a distinct property." If, then, the existence of mo- bility be thus implied, it is a distinct property; and when the phenom- ena of irritability and mobility are duly considered, it will be seen that they should be regarded in a separate sense. Irritability is cer- tainly necessary to the exercise of mobility; but the former may be greatly exalted without a corresponding increase of motion. The distinctions are numerous and of great practical importance (^ 500, d). 207. The existence of mobility in plants is abundantly shown by the motion of their fluids, which no mechanical principle can inter- pret, by their secretions, and by other results analogous to those which depend, in part, on this property in animals. It is also manifested by the sensible movements of the leaves, blossoms, stamina, &c.; and from these we may reason analogically, and infer insensible motions of the sap-vessels, the secretory apparatus, &c, as is also done in an- imals (§ 1054). Mobility, therefore, gives rise to sensible and insensible motions. They are generally sensible in animal life, and of either kind in or- ganic (§ 476-492, 516, no. 2 ; also, Medical and Physiological Com- mentaries, vol. ii., p. 150, 379-391). 208. Mobility is brought into operation through impressions made on irritability, whether by vital stimuli in organic life, or by the ner- vous power in either organic or animal life (§ 188). The philosophy of this will be considered along with the attributes of the nervous power, the function of sympathy, and the laws of sympathy. 209. If sensation apparently give rise to motion, it may be occa- sioned by the action of external or internal causes upon sensibility; 101 INSTITUTES OF MEDICINE. but this impression is imparted to irritability and then to mobility, before motion can follow (§ 195); or, from the intimate associations and analogies between irritability and sensibility, the two properties may be simultaneously affected by the same agents. Where, how- ever, sensation is accompanied by motion as an apparent effect of im- pressions upon common sensibility, it probably arises in all cases from a simultaneous impression upon sympathetic sensibility (§ 198, 201, 202). This exact analysis is indispensable to our subject. 210. Irritability may be increased through an exalted state of sym- pathetic sensibility, and organic motions may be thus increased through sensibility; which is nearly the same as the foregoing law (§209). 211. It is doubtful whether parts may be irritated without exciting mobility (§ 202); but it is otherwise with common and specific sensi- bility, as in seeing, tasting, &c, and in pain. 212. Mobility, like irritability and sensibility, may be in a passive or dormant state, as in the ovum and seed, or as sensibility exists in the organic life of animals. All are roused by appropriate agents, and could not be roused were they not already present. Certain an- imals, such as the wheel, and the sloth animalcula, may have all appa- rent traces of life extinguished, maybe completely exsiccated, and be speedily revived by heat and moisture.* The first impression of semen, or of heat, &c, upon the ovum, or seed, is made on irritability, through which, as the next step in the process, mobility is roused into action. Then follow the new ele- mentary combinations. We thus learn, in part, that life is a cause, not an effect.—(Med. and Physiolog. Comm., vol. i., p. 9, et seq.) 213. Sensible mobility is especially manifested in the compound organs, taken as a whole (§ 205). Insensible mobility occurs in the small vessels (§207). But, the palpable evidences of a special law of motion in the small vessels are apt to be sacrificed to the negative fact that the motion itself is not of a a isible nature. As well might we deny the existence of microscopical animals. 214. The insensible motions in organic life are the most important that occur, especially such as take place in the extreme capillary ves- sels ; since these are the instruments of all the most essential actions and phenomena of life, and of disease. 215. Voluntary motion is brought into exercise by the will and nervous power, as will be set forth under my consideration of the lat- ter property and the function of motion (§ 222-233f, 500 d). The essential difference, therefore, between the motions in animal and or- ganic life lies in the nature of the stimuli; voluntary motion requiring the exercise of the will, while the organs of organic life rarely obey the stimulus of the nervous power when excited by the will ($ 500 e). It is probable, also, that mobility has a peculiar modification in the muscular tissue of animal life. Notwithstanding mobility, in animal life, is always subject to the nervous power, motion is here, as in organic life, independent of the nervous system,excepting as supplying a stimulus ($483, 486). * See Spali.a\zani's Experiments in Opusculi di Fisca Animate, Opere, tvi, p. 482-556. PHYSIOLOGY.--VITAL PROPERTIES. 105 4. VITAL AFFINITY. 216. It has been seen that the elements of organic compounds are very differently combined from those of inorganic (§ 32, &c). Hence has arisen the term vital affinity, as denoting a property peculiar to plants and animals, by which all their elements are united and main- tained in combination. When death takes place, chemical affinities operate, and resolve the organic into inorganic compounds, or into their simple elements (§ 174). 217. Vital affinity exists in modified states in the two departments of organic nature ; since, in plants, it unites the simple elements into organic compounds, while in animals, it can operate only upon com- pounds of this complexity. Vegetable organization is, therefore, more of a crearive nature than animal (§ 13). 5. VIVIFICATION. 218. By vivification, in conjunction with vital affinity, life is bestow- ed upon dead matter. The elements of matter are, essentially, com- bined into organic compounds by vital affinity; but there is a pro- gressive vitalization of the organic compounds till they become united with the solids. This shows that vital affinity must have an associate power of vivification. 219. Vivification belongs, particularly, to the assimilating organs, though its energy must be great in the gastric juice. It has natural modifications in all parts, and presents distinctions between plants and animals. 220, a. Vital affinity and vivification, like the other properties of life, are susceptible of morbid changes. This gives rise to changes in the general vital character, and in the composition, of the solids and fluids. These changes in composition are inferred upon principle, as well as from observation (§ 666, b). No chemical analysis can detect them, unless it be an alkalescence or an acidity of the secreted fluids, or changes in the urine; and even these imperfect results are often sur- rounded by objections (§ 5£ b, 53, 1029, 1030). 220, b. Changes in some of the secretions, as in the milk, may be brought about by temporary influences, and independently of disease, as by emotions of the mind, the action of cathartics, &c. These also affect the condition of organs and their products in the various states of disease; and upon this depends the art of medicine (§ 852, &c). 220, c, The alterations which take place in the solids and fluids are always the same in any given condition of the affected properties of life. They are, therefore, constantly liable to variations during the . progress of disease, and are various in different diseases, and accord- ing, also, to the nature of remedial influences, and'of those other causes by which they are affected independently of disease (§ 672). 221. The changes which arise in the solids and fluids from morbid conditions never approximate the condition of dead matter (§ 674). 221i. Changes in organic compounds may be the result of the di- rect action of physical agents, but are generally owing to alterative in- fluences of direct or reflex nervous action leading to disease, and some- thing to the natural l»v that the nerves impress a special condition upon animal compounds, both solid and fluid (§ 69, 226, 399, 405, 446 a, 455, 456 a, 461, 485, 488-1, 489, 512, 740, 952). 106 INSTITUTES JF MEDICINE. 6. THE NERVOUS POWER--ITS DIRECT AND REFLEX ACTION. 222, a. The analysis which I shall make of sympathy establishes so clearly its functional character, that I shall remove it from among the properties peculiar to animals, where it has been hitherto placed. In defining this function, generally regarded as a property, 1 shall introduce the nervous power, upon which, in connection Avith sensi- bility, the function depends (§ 201). This is reflex nervous action. 222, b. The philosophy of the operation of the nervous power in producing motion, under all its various aspects, as manifested m its natural regulation of organic functions (§ 202), or by its ether reflex actions as induced by morbific and remedial agents, or by the influ- ences of disease, in the motions which are generated in the organs of organic life by the passions and analogous affections of the mind, in the movements of the voluntary muscles, in the production of sudden death from all causes, as well as the solution of other relative prob- lems, and the physiological interpretation of the recognized laws of sympathy and their general introduction into pathology and thera- peutics, were originally attempted by myself in the Medical and Physiological Commentaries, and subsequently, and more extensively, in my Essay on the Modus Operandi of Remedial Agents* Should the exposition there and now set forth prove to be well founded, it must necessarily result, sooner or later, in the overthrow of all the mechanical and chemical hypotheses in physiology, consign to its well-merited oblivion the humoral pathology, and place upon its true foundation the operation of remedial agents.—See Eights, &c, p. 912. 223. The nervous power appertains to the vital principle, resides exclusively in the nervous systems, and is, therefore, peculiar to ani- mals (§ 184, b). It gives rise, however, to results in organic as well as animal life. These results, also, are far more numerous and impor- tant in the organic than the animal mechanism, while sensibility is es- pecially designed for the latter. Unlike sensibility, also, in its func- tion of sensation, perception is not necessary to the operations of the nervous power, nor does the latter, like sensibility in its office of pro- ducing sensation, require a continuity of the nerves with the brain for reflex or direct action, especially in organic life (§ 209, 507). The nervous power is constantly, though, for the most part, in in- sensible operation throughout the organic mechanism, modifying tho actions and annualizing the products of all parts. For this special reason 1 have endeaA'ored to show that the nervous power is super- added to the vital principle of animals, and that the complexity of or- gans and functions which it is designed to subserve, and the absence of its phenomena in plants, afford a substantial proof that the proper- ty belongs to animals alone (§ 1041.) 224. The nervous power is exerted, especially, through what are denominated the motor nerves and the motor fibres of compound nerves, or "nerves of motion;" these nerves, however, being mainly dependent for the nervous power upon the brain and spinal cord (§ 201). Nevertheless, there is reason to suppose that the nervous power is implanted in the motor nerves, as well as in the brain and spinal cord. The phenomena of contiguous sympathy, as when inflammation of the liver, the lungs, &c, is relieved by blisters, over the region of the * Med. and Phys. Comm., 1840.—Essay, cfc., 1842. PHYSIOLOGY.--VITAL PROPERTIES. 107 affected organs, cannot be traced through the cerebro-spinal system, excepting in its connection Avith the ganglionic, which supplies, in such cases, the immediate centres of reflex nervous action (§ 893). There exists a great fundamental distinction between the cerebro-spinal and ganglionic systems, the former of Avhich is allotted especially to animal life, the latter to organic (§ 113); and, although the cerebro-spinal be associated in function with the ganglionic, purely cerebro-spinal nerves exert no influences upon the organic functions, not even the pneumo- gastric till independent life begins, Avhile the ganglionic supplies the stimulus to organic muscles, combines the organic viscera, and determ- ines exciting and modifying effects upon all their actions, by which the secretions are variously increased or diminished, and the organic prod- ucts imbued with the peculiarities that distinguish them from the or- ganic compounds of plants ; and Avhat is of vast practical importance, it is oAving to those physiological differences that morbific and reme- dial agents operate, essentially, through the sympathetic system (§ 113, 409 h, 422, 461-461|, 4751, 500 g, 524 a, no. 7, 89H g, k, 8931). 225. Like irritability, sensibility, and the other properties of life, the nervous poAver is capable of being acted upon by external and internal causes, both mental and physical, of being increased, or diminished, or altered in kind, according to the nature of the causes (§ 200, 203, 258). 226. The nervous power possesses the remarkable characteristic of being a vital agent to the property irritability (§ 184 b). It is also li- able to artificial modifications from the operation of physical and mental causes upon the nenous system ; and its influences upon irritability will correspond with the nature of its modifications ; being thus rendered a vital stimulus, or a vital depressant, or a vital alterative (§ 150). When, therefore, this power operates in any unusual manner, organic and an- imal motions, whether sensible or insensible, Avill be variously modified, or produced, by calling mobility into exercise, according to the nature of the influences exerted upon the power, and products Avill vary ac- cordingly. This grows out of the natural office of the nervous system of exciting and modifying organic actions and their results (§ 461). 227. The nervous power is brought into unusual operation very va- riously, according to the seat and nature of the exciting cause (§ 1)51). 1st. Its operation is excited in a direct manner by irritants, &c, ap- plied to the brain, to the spinal cord, and to the motor nerves. It is also excited directly by cerebral or spinal disease, by the passions, men- tal emotions, imagination, intense reflection, and by the will. This I call direct nervous action (§ 222 a). In all the cases, the nervous poAv- er Avill be rendered stimulant, or depressant, or alterative to the or- ganic properties and functions, and variously energetic according to the nature of the operating cause, and the intensity and suddenness Avith which it may operate (§ 480, 743, 951). In blushing, the poAv- er is rendered stimulant; by fear, depressant; by grief, anger, hope, &c, alterative (§ 844). These effects are also commonly very sud- den, especially the physiological. Even such as are morbific are oft- en almost instantaneous; and this rapidity of change ceases to be re- markable when we regard their near coincidence Avith the natural re- sults, and that the same principle is involved in voluntary motion. A close analogy subsists between all the foregoing direct causes and all the physical agents of life, whether natural, morbific, or reme- dial, as the latter may develop the nervous power through sensitive nerves. These analogies will have been variously illustrated. They 108 INSTITUTES OF MEDICINE. eA'ince the simplicity of fundamental principles and the relationship and perfect harmony Avhich prevail among the whole, even those which are especially relative to mind and instinct as superadded to the simple condition of the vegetable kingdom (§ 323-325, 818J). 2d. The reflex action of the nervous power is excited through the medium of sympathetic sensibility (§ 201-203). This complex process results in the true function of sympathy. Impressions are made by physical and mental causes, by disease, &c, upon the foregoing varie- ty of sensibility, which I call sympathetic from the office of the sensi- tive conductors in this function of reflex nervous action. The impres- sions are then communicated to the cerebro-spinal axis, or to other central parts of the nervous system, and there bring into operation. and variously modify, the nervous power (§ 224). The power, thus developed, thus influenced, or so modified in kind that it partakes of the nature of the transmitted impressions, which are more or less co- incident with the virtues of the remote causes, is then exerted, through the motor system of nerves, upon the organic properties of distant parts, or of the nervous system itself (§ 208, 209, 462-469), by which those properties, and their resulting functions and products, are vari- ously affected according to the foregoing circumstances. From this fact it also results, that the modified conditions which are brought about by the nervous power, when the preternatural operation of this power depends upon external causes, whether morbific or remedial, are more or less analogous to those changes in the organic conditions which are wrought in parts by the direct operation of the same causes (§ 188, 657 b, 503-505, 891J k 893 e, 902, 904 a, 951 c, 990^). 228, a. It thence follows, that there is imparted to the nervous power, by the foregoing means (§ 227), more or less of the charac- teristic virtues of the remote causes, but under the influence of its own nature, by which the nervous power is substituted for those causes, and thus reaches, with its acquired attributes, and their various effects, every part of the organization, and, often, with great instantaneous- ness. It appears, therefore, that this constitution of the nervous pow- er is wonderfully suited to the various exigencies of life ; while, as will be seen in section 232, it grows out of its physiological nature as a regulator of organic actions (§ 1057, 1075, 481 d). 228, b. It is also an important law that the nervous power is vari- ously influenced in its morbific and remedial action by slight vari- ations in the intensity of the operating causes, whethermental orphys- ical; though a determination is simultaneously given to its action by the numerous other conditions already mentioned, and which may happen to be present. Thus, an impression from cold, as a blast of air, or a drop of cold water, upon the skin in syncope, will rouse the respiratory organs. Another impression from the same, and under other circumstances, will excite catarrh, or pneumonia, or articular rheumatism. One degree of impression upon the stomach by tartar- lzed antimony will determine the nervous power upon the respiratory muscles (as will cantharides upon the bladder, or mercury upon the salivary glands), and vomiting is the consequence; while it simul- taneously reflects the same power upon the skin, and other organs, and of which perspiration, &c, is a consequence. In smaller doses, the respiratory movements are not affected, but only the condition of the skin, &c, and in lesser degrees. But, these examples embrace PHYSIOLOGY.--VITAL PROPERTIES. 109 only certain parts of the influences in each case ; while in others they are far more complex, one sympathetic result becoming the cause of* others, till, through a single impression upon the skin, various circles of morbific or remedial reflex nervous actions may be instituted. 229. When disease operates in the foregoing manner in exciting the nervous power, and determining it with alterative effects upon re- mote parts, or upon the nervous system itself, it often imparts to it a modification by which a similar condition of disease is generated in the parts upon which the power is thus determined. Hence the con- secutive inflammations which are often springing up, sympathetically, in various parts. But, this depends, more or less, upon the nature of the organs secondarily affected, upon their precise condition as divert- ed more or less from their healthy states by other causes, upon tem- perament, age, sex, &c. When, therefore, the nervous power is de- veloped by disease, other conditions varying more or less from the primary affection are observed among the common effects. For the same reasons, also, when morbific and remedial agents operate through the medium of the nervous power, the results may be very various. 230. If the nervous power be brought into preternatural operation in a direct manner (§ 227), as Avhen impressions are made upon the brain, or spinal cord, or the trunks of nerves, or by cerebral disease, or when the mind or passions develop its operation, it is also liable to modifications, and corresponding effects, as when the impressions are communicated through the medium of the sensitive conductors. Thus alcohol, applied to the brain or spinal cord, increases the action of the heart and capillary blood-vessels, and so do anger, joy, hope, love, imagination. But, a watery infusion of opium or of tobacco, applied in like manner, depresses those actions, and so do fear, grief, and anx- iety. We see, also, various other organic functions affected in a cor- responding manner (§ 480-485, 489-492, 943, 945). In these cases, the nervous power is often determined, with more or less effect, di- rectly upon the organic properties of the brain, and may extinguish them instantly. A sudden explosion of anger may, in this manner, induce apoplexy, while in other cases the destructive influence of the nervous power is expended mainly upon the heart. Inflammation of the brain determines the nervous power directly upon the cerebral vessels which carry on the morbid process, and thus increases its force and obstinacy. So with many morbific and remedial agents of a physical nature, Avhich, when applied to the stomach, excite the ner- vous power indirectly, or through the medium of the sensitive fibres of the pneumogastric and sympathetic nerves, but in which cases the nervous poAver is reflected upon the organic properties of the brain, or of the spinal cord, or of the individual nerves, as well as upon those of other parts. Such is the case with all the narcotics, strych- nine and analogous substances, prussic acid, aconite, &c, which bear specific relations to the nervous system ; either exciting or removing morbid states of the brain or nerves (§ 487 g, 526 d). 231. It is not alone the general functions of tissues and of com- pound organs which are affected by the nervous power in the fore- going manner (§ 227-230), but equally, also, those of the intimate or- ganization of all parts, upon Avhich nutrition, vital decomposition, &c, depend. It always acts upon minute structure (§ 395, 1040). 232. The modifications of the nervous power now described (§ HO INSTITUTES OF MEDICINE. 227—230) are analogous to those which Ave have seen to be exerted upon irritability and sensibility (§ 191, 200), and they spring from that physiological constitution of the nervous power which is design- ed for great natural purposes in the animal economy. This poAver is manifestly associated with the vital principle of animals (§ 184, b) as a regulator of their multifarious parts, by Avhich the whole are main- tained in harmonious action, or by which the varying changes and failures of some shall institute vital changes in other parts that shall contribute to the restoration of the former, or exempt the general or- ganism from the evils which would otherwise arise (§ 455). Volun- tary motion (§ 215, 486), respiration, a permanent contraction of the sphincters, are also other final causes of the institution of the nervous power. The power is in perpetual operation in fevery part of the animal organization, though more obviously pronounced in some of its results than in others, as in the function of respiration, the perma- nent contraction of the sphincters, the motions of the iris, &c. It is, however, not less constantly operative, though with less intensity, in all organic processes, bestoAving important conditions upon all pro- ducts of an organic nature, solid or fluid, and forever stretches its universal sway, as a harmonizing power, over the whole organic mechanism. This power, therefore, is rendered exquisitely suscepti- ble to the most astonishing variety of physical, vital, and mentalcauses ; and, that it may feel and transmit the influences of the vital changes that may befall one part or another to other parts, for the maintenance of the great balance of functions, and to fulfill the office of restoration as well as of conservation, there is imparted to it, as to the other prop- erties of life, a partial mutability in its nature, conformable to the va- rious impressions exerted upon it, and by which it is rendered vari- ously and usefully alterative to morbid conditions; and since, also, such alterative effects as are demanded by morbid states could not be exerted by a natural vital agent in its unmodified condition. Thus we have, in the obvious constitution of the nervous power, as manifest in its common functions, a principle of interpretation for all the vari- ety of changes that are not less obviously exerted upon it by morbific and remedial agents than are plain its reflex and direct actions. 233. The nervous power does not generate motion either in animal or organic life (§ 476-492, 516, nos. 2, 7). It only influences the or- ganic property mobility, upon which all motion depends, through the medium of irritability (§ 188, 205, 208, 209, 226). Even voluntary motion is entirely independent of the nervous system, excepting as the nervous power is a stimulus to irritability. In the production of this complex function several elements are concerned : 1st. The will, operating as a stimulus upon the brain, develops the nervous power; 2d. This power is then transmitted to the voluntary muscles, where it acts as a stimulus upon irritability (§ 226); 3d. Mobility is thus called into exercise, the immediate result of which is voluntary motion (§ 205, 206, 208, 209, 245, 256, 476 c, 486, 487, 492, no. 7, 500 d). However complex, and destitute of analogies in the world of mere physics, this phenomenon may be, I have no doubt that the solution which I have offered will bj received by every philosophical mind which may attentively consider the nervous pcwer in its connections with the motor nerves, and the experiments of Wilson Philip (§ 464, &c, 476, &c, 1041). PHYSIOLOGY.--VITAL PROPERTIES. Ill Since, also, the nervous power has no existence in plants, their ac- tions are alone influenced by the physical agents of life ; and, having no sympathetic relation of parts, the diseases of one part are felt by other parts only through the common laws of nutrition, while, also, remedial agents are curative by their local action alone. 233|. The nervous power, in a manner analogous to its determina- tion upon the sphincter of the bladder after the evacuation of the urine, may be propagated upon distant parts, with morbific or curative effects, long after the removal of the agent by which it was originally excited. This is owing to the continued change, or impression, wrought upon the part to which the agent was applied (§ 514 g, 516, no. 6). 233J-. One of the most remarkable laws of the nervous power ia that of its determination through particular nerves upon certain parts, according to the nature of the exciting cause, whether mental or phys- ical, whether natural, morbific, or remedial, and equally so in animal and organic life; passing over, in the fulfillment of this law, various intermediate nerves of more direct anatomical connection. This is remarkably exemplified in many musical performances and feats of agility. This special determination of the nervous power is most in conformity with the special influences that may bring it into operation, in healthy conditions of the body; but in diseased states, or where or- gans are but partially diverted from their natural state, a direction is more or less given to the determination of the power by these acquired susceptibilities (§ 500^', k, 871). This peculiar attribute of the ner- vous power distinguishes it from the direct action of remedial and morbific agents, which, if taken into the circulation in efficient quan- tities, would often derange the universal body. But the same physi- ological constitution of the nervous power which renders it obedien; to the will in its transmissions to particular muscles, or to the passions in its effects on special organs in organic life, renders the power, when modified by remedial or morbific agents, and according to its pre- cise modification and susceptibility of parts, equally determinate and circumscribed in its operation (§ 150-152, 838, 844). There is noth- ing in Nature more wonderful and paradoxical than this attribute of the nervous power; and while the facts which it supplies in connec- tion with the operation of the Avill and the passions bear with the strongest analogical force upon the philosophy which respects the in- fluences of morbific and remedial agents upon all parts distant from the seat of their application, that analogy is corroborated by the limitation of the morbific or remedial effects to certain parts of the organism. 2331. It appears, therefore, that the nervous influence, reflex or di- rect, is generally the immediate remote cause of all changes beyond the seat of the direct action of other causes (§ 644-647^, 889 k). GENERAL REMARKS UPON THE PHILOSOPHY OF LIFE. 234, a. Notwithstanding all the laws of sympathy, that are neces- sary to the full interpretation of the remote effects of morbific and re- medial agents, are as well established as any laws in physics, they have not been applied to these important objects ; but, on the contra- ry, those philosophers who have contributed most to their critical ex- position overlook their pathological and therapeutical bearings, and cling to the doctrines of humoralism, and of the operation of remedial agents by absorption ; nor have they applied, in the least, the nervous 112 INSTITUTES OF MEDICINE. power in a philosophical manner to an exploration of the natural phe- nomena of sympathy. The oscillations of Newton, the contractions of Darwin, the vibrations of Hartley, the secretions of Galen, the gal- vanism of Galvani, the destructive forces of the chemist, and the caloric and the magnetism of wilder imaginations, continue to be adopted, and show as well by their great incongruity as by their failure, that the hypotheses are founded on imaginary data, and that each has neglected the phenomena of life (§ 189 b, 785, 1085). 234, b. I say nothing of those who still refuse their assent to the well-ascertained laws of sympathy, as manifested in the natural states of the body. These they have yet to study and to learn; but it may be well objected that their ignorance shall prove an obstacle to the progress of knowledge (§ 905f). He, indeed, must have been a very imperfect spectator of human events, who anticipates the acquiescence of ignorance or prejudice, or the ready concurrence of inferior minds, in the intricate problems which relate to the laws of the vital functions. The demonstrations of Philip have become obsolete in all but their abstract nature; and the discoveries of Prochasca, Sir Charles Bell, Miiller, Hall, Valentin, and others, in the functions of the nerves, are either unknown, or un- appreciated, by all but the erudite student or such as aim at erudition; and the very anatomical medium of reflex actions, through which the operations of the nervous power and the phenomena of sympathy ap- peal, as it were, to the senses as well as to the understanding, is apt to be regarded as an accidental or as a superfluous appendage of the body, or thrown in to embarrass inquiry by multiplying the complex ities of organic beings (§ 1039).—Rights of Authors, p. 912. Coming to the different kinds of irritability and sensibility, or as these are modified by morbific and remedial agents, or by other phys- ical causes, as well as the analogous modifications of the nervous power, and its remarkable attributes as a vital agent, its direct action as such when developed by causes acting directly upon the nervous system, or when brought into operation indirectly through the medi- um of sympathetic sensibility (§ 227), and other analogous facts which are equally substantiated by an endless variety of phenomena, they are pronounced by a no small number of the profession, even by wri- ters who appear in the character of expounders of medical philosophy, as metaphysical speculations, or as imaginary hypotheses. Even life itself is regarded as a subtlety of the schools, or as a phantom of less reputable claims. " For my part," says Magendie, " I declare boldly that I look upon these ideas about vitality, and the rest of it, as noth- ing more than a cloak for ignorance and laziness"* (§ 1034). 234, c. If, then, you object to the existence of a principle of life, why not to the existence of mind, to the imponderables, or to tangible matter itself (§ 168, 169, 175 bb) % Do you deny its several well- attested properties 1 Then why not deny the properties of the mind 1 Have you not, for the aid of the senses, a tangible analogy in the solar beam (§ 1881 d, 234 e)1 Do you cast aside all the phenomena of irritability and sensibility, and maintain that the action of internal and external causes, the mind and its passions, is exerted upon the struc- ture alone, because you cannot see the properties (§ 169, 189) ] Can * See Medical and Physiological Commentaries, vol. i., p. 397, 511. 512, 514, 515, as to Magendie. PHYSIOLOGY.--VITAL PROPERTIES. 113 you see the Maker of the eye, or did the eye make itself (§ 74) 1 Do the muscles move without a moving power 1 Are you not amazed at what you cannot deny, that the mutual co-operation of the mind and the brain, which results in willing, is limited in its action upon the body to exactly those parts where its operation can be alone useful to the animal, namely, the voluntary muscles; nay, more, that the will elects of these muscles such only as are precisely necessary to its present purpose, and bestoAvs every imaginable degree of force with- in the limit of its poAver, and variously, also, on the several muscles which it may throw into simultaneous action (§ 233|, 349 e, 500 i) 1. Is there nothing as improbable in all this as in the propositions of the vitalist 1 Consider hoAV, on the other hand, those other acts of the mind, called the passions, so near akin to the will, judgment, reflec- tion, are clearly ordained to operate in organic life for the moral and physical good of the being ; or, if they be also the causes of pain and disease, the analogy of Nature shines out even here in placing them on a par with the morbific agents of the external world. If this be so, or a single fact conceded, how will you disregard the multitudi- nous phenomena of irritability and sensibility, or their various natu- ral and artificial modifications (§ 64, f) 1 Will you consider an ar- gumentum ad hominem ? Do you, then, deny that you possess judg- ment, reflection, and the ability to discover truth 1 If you object not to this, you must concede the philosophy of these Institutes as to the foregoing properties of life, and by the same demonstration upon which that philosophy rests you must admit the imputed attributes of the nervous power, -which are far more clearly and variously attested than judgment, reflection, or the ability to discover truth. Look at the experiments by Wilson Philip, Hall, Miiller, Bell (§ 464, &c, 476, &c). Look at the nervous system, and there you shall absolutely see. Or, do you require other aid for your senses, look, again, at the analo- gies which are supplied by the solar beam, by electricity, by galvan- ism, by magnetism. Consider how they astonish you in their over- powering influences upon all things but the living being. And yet you can not see how these destructive effects are exerted. You give up your senses when the needle traverses the compass, and stand in mute astonishment, gazing at the north for some sign that shall help the un- derstanding as to the nature of the mysterious agent. But you see and feel nothing. Nor is this all; for the dismay of sense becomes inexpressible, when imagination surveys the interval of thousands of miles, through which the unseen force exerts its mystic sway. And so of gravitation. But the effects are strongly pronounced upon the sense of vision, and their frequent repetition begets an acknowledg- ment that there is something besides the tangible and visible qualities of matter which, operating through vast distances, maintains the nee- dle in one everlasting direction, and the heavenly orbs in their unde- viating rounds. And here, in the perpetual operation of magnetism, there is something to aid your conception of an equally unintermit- ting exercise of the nervous power (§ 1034). 234, d. Do you object to what I have propounded as to the artifi- cial and temporary modifications of the nervous power (§ 227-232)1 Can you state an objection, farther than that which has been just con- sidered 1 Do not the infinite phenomena of sympathy mutually con- spire together, without a contradictory fact, in proving the occurrence H 114 INSTITUTES OF MEDICINE. of such modifications; and is there a single effect of morbific and remedial agents, operating through the nervous systems, which cannot be clearly, perfectly, explained by the doctrines which I have pro- pounded in relation to the nervous power ? Can a like affirmation be made of any other thing 1 But, you cannot sec the modifications of the nervous power. Neither can you see the modifications of the electric fluid, as manifested under the conditions of electricity and galvanism; but, the effects of the latter make a strong impression upon sense, Avhich grows into the belief that physical causes do, in re- ality, alter the conditions of electricity and turn it to galvanism, and those effects have actually engendered the expression of "modification of electricity." Here, then, is something for the senses, to aid them in their survey of the less tangible, but not less precise, and infinitely diversified, phenomena, that mark the artificial modifications of irrita- bility, sensibility, and the nervous power. And, should you require a like assistance as to the natural modifications of irritability and sen- sibility, or even the existence of the different properties which apper- tain to the vital principle, you have only to regard the solar beam, and the solar prism, and try experiments with each prismatic color (§ 188i, d). 234, e. Do you marvel at the rapidity with. which the nervous power moves in its operations % Consider, then, the incomprehensi- ble velocity of light,—200,000 miles in a second of time ; or the more rapid apparent motion of the electric fluid. Or, take the more prob- able doctrine of the undulations of light, and this will be yet more con formable to what is probably true of the nervous power. Of the un- dulations, then, we have not less than 458,000,000,000,000, for the red ray ; 535,000,000,000,000, for the yellow ray ; 727,000,000,000,000, for the violet ray, in a second of time. I say, when we think of the physical effects of electricity, galvan- ism, magnetism, and of light, and more especially when we attempt to think of the inconceivable rapidity with which the undulations of li edit are propagated, we shall have no difficulty with what I have attrib- uted to the nervous power in resolving the phenomena of sympathy, voluntary motion, &c. v and when, also, we reflect that those very un- dulations, according to their variety, produce on the retina all the im- pressions that are requisite for every phenomenon of vision, and that every impression, which is thus produced, must be transmitted to the brain, before the sense of vision can be excited (§ 188^ d, 500 k). If, also, the retina be thus sensitive to the undulations of a substance which is so imponderable that it is doubted by many whether the sub- stratum of light be actually material, we shall have no difficulty, I say, by the aid of this plain analogy, in making the same philosophical use of the vastly more numerous and unique facts that are supplied by an- imal life, or in apprehending that the virtues of more substantial agents, whether morbific or remedial, may, in like manner, exert pow- erful impressions upon the properties of every part, both nervous and organic, and that such influences may, equally with the impressions of light, be transmitted to the brain and spinal cord, and establish im- pressions upon the parts in conformity with the virtues of each acent (§ 503). The undulations of light are excited by the various objects from which they proceed. And so of the nervous power. It is not in tran- PHYSIOLOGY.--VITAL PROPERTIES. 115 situ, a movable substance, but, like the principle of light, is every where diffused through its appropriate medium, and, like that princi- ple, is brought into operation by exciting causes. Is it difficult, how- ever, to imagine how the nervous power can move with the velocity of light in parts so dense as the nerves 1 It is less difficult than the comprehension of the admitted fact that light traverses the diamond as rapidly as it does ethereal space (§ 175 b, 188|- d). Do you still marvel as to how the nervous power should induce or subvert diseases? Were you not equally in the dark as to the modus operandi of the so- lar beam in its various agencies upon inorganic compounds, till a few obscure phenomena led to the hypothesis of undulations 1 But, what have you gained by the undulations 1 Can you tell us how these in- conceivably small motions operate, without a resort to absolute as- sumptions ] Are you any more convinced than before, that the phe- nomena of light are realities, or have you been aided a whit, by these discoveries, as to your former knowledge of the laws of light % You tell us that not only the well-known colors of the solar spectrum possess, individually, specific properties, but that " each of these com- prises rays differing in constitution, and differing in refrangibility, and that, doubtless, to each one specific effects are due."* You show the physiologist a few positive results, and he believes the analysis, and the existence of the several rays; though he may greatly dis- credit your philosophy of the effects as manifested in a department of nature which you study only under influences supplied by the labora- tory (§ 188-£, d). But, you tell him, also, that the solar ray embraces "other principles Avhich are invisible," and you call upon him to ad- mit the existence of these, notwithstanding he cannot see them (§ 175, bb). The physiologist, however, readily admits their existence upon the strength of the few facts which imply the operation of an in- visible agent; and he does so because he is a physiologist. But, ta- king your own rule of judgment as to a vital principle and its several properties, you were doubtful whether he might demand more tangi- ble proof; and, accordingly, you prepare him for an admission of your premises by a mode of reasoning which you reject, contemptu- ously, when the physiologist sets forth his endless series of facts which prove, each one, the existence of properties peculiar to living beings. You prejudge the case, as it were, by impugning his understanding, unless the induction be conceded. You tell him, that, "just in the same way that I am willing to admit the existence of forty simple metals, so, upon similar evidence, I am free to admit the existence of fifty different imponderable agents, if need be" (§ 175 bb). The phys- iologist requires you to admit but one, and, with this one he explains, with perfect consistency, all the processes of living beings, all the phenomena in physiology, in pathology, and therapeutics, while no one of them can be interpreted without the agency of such a principle. 234,/ But again, I say, what have we gained in a practical sense, or as to the modus operandi, or the laws of light and heat, or of the constituents of the solar ray, by the discovery of the undulations, or by any supposed decision of the question as to distinct rays or modi- fications of a common ray, or even by the prismatic colors 1 Nothing whatever; no more than has been gained, in a useful sense, by mi- croscopic explorations in physiology, but with the greater advantage • Draper's Treatise on The Foi-ces which produce the Organization of Plants, p. 103. 116 INSTITUTES OF MEDICINE. of more precision, and more accomplishment to science, and without the pernicious hypotheses of the latter. And can the same affirma- tion be made of our knowledge of the properties of the vital princi- ples, and of their natural modifications in different parts, and those which are induced by morbific and remedial agents 1 On the contrary, we see this knowledge every where converted to the most important uses of organic beings, not only in a direct practical sense, but in un- folding the great laws by which they are governed. This knowledge, indeed, is the great foundation of physiology and of the healing art. Do you object to the relation which sympathetic sensibility bears to the nervous power (§ 201), and the relation of the nervous power to irritability (§ 226), in the phenomena of motion 1 Have you any better data for your conceptions of the relation of the magnetic pole to the needle; and to explain that relation, do you not admit a pecu- liar imponderable, invisible agent, which acts upon the properties of the needle ? Do you understand any better, or have you any bettei facts respecting, the relation of physical agents to the mind, in the phe- nomena of sensation ? You obtain your ideas of matter through the operation of physical agents upon the intellectual part; and how will you explain the access of those physical means to the spiritual sub- stance unless you also admit the physiological property, sensibility 1 What intelligible connection is there between the properties of mind and the motions of the brain ] What intelligible connection between the stimulus of the blood and the motions of the heart, or those mo- tions which attend the generation of bile and all other organic products, unless you admit a principle of life ] The forces of life are concerned about sensation in a peculiar manner, and there would be a violent interruption of the law of analogy were there not something interme- diate between mind and matter, a bond of union, as it were, through which impressions upon the senses should reach the spiritual existence. We may fancy it to be electricity, or the chemical forces; but, this no more aids our comprehension, through the known phenomena sup- plied by these causes, as to the communications from matter to the immaterial, thinking existence, than if we regard the nerves, per se, as the only medium. We therefore turn our reason to the special phenomena, and find a property in universal operation throughout the body, as the medium through which certain kinds of impressions from physical agents are transmitted to the mind. But, we find, also, an- other analogous series of phenomena which force us to the conclusion that these depend, also, upon a certain modification of the same prop- erty as that through which impressions are made upon the mind by external objects. We see, also, that these transmitted impressions give rise to another endless series of peculiar results, which have their point of departure in the nervous centres; and we see, too, that each one corresponds with, and confirms the others, in the several series respectively. We learn, besides, that those of the last series are anal- ogous to the direct effects of vital agents, healthy, morbific, and re- medial, upon the organs which are the immediate seat of their opera- tion. Hence, we conclude, inevitably, that there exists what is de- nominated the nervous power, with all the capabilities which I have as- cribed to it, and that it is brought into operation through the same channel of sympathy as the mind when sensible objects exert their effects. The mind, and the nervous power, are, therefore, so far on a PHYSIOLOGY.--VITAL PROPERTIES. 117 par. Each is an agent, each gives rise to sensible and insensible mo- tions, and modifies variously the ordinary results when themselves are affected in an unusual manner, and each is brought into opera- tion by analogous causes. The mind, through the properties of life, forms a special bond of union between itself and certain parts of the organization; the nervous power, another special bond between the same properties of the vital principle and other parts of the organi- zation, and by which, and by the perpetual operation of that power, the whole organic mechanism of animals moves on in a well-balanced, concerted action. Thus are the properties of the mind, the proper- ties of the vital principle, and the sensible mechanism, all mutually related to each other, and bound together by laws as precise as those more simple ones which rule in the inorganic world. 234, g. We need not, therefore, inquire into the intrinsic nature of the nervous power, or of the organic properties. It would be as ab- surd as to interrogate the nature of gravitation, or of any other prop- erty of mere matter, or even matter itself; though we may well say what the nervous and organic powers are not, and tmis save much speculation and its resulting practice. It is enough that we know their existence and the laws they obey. This is all that can be philo- sophically or practically useful. With these we are about as well acquainted as we are with the laws of gravitation, or of light. An ignorance of the nature of the principles or causes affects in no respect our study of their laws, of their modes of operating, or of the influ- ences to which they may be liable. Their laws, like the laws of gal- vanism, or of optics, must remain the same, whatever theory may be adopted as to the nature of the causes. Inquiries, therefore, so obviously beyond our reach as the absolute nature of the vital principle, or any of its properties, should never raise our curiosity, much less receive our attention. Their pursuit vitiates the judgment, diverts the mind from practical and useful in- quiries, and renders it prone to speculation. But again, I say, we know enough of the whole of this subject for the purposes of philosophy, and for the good of mankind, by the phe- nomena alone; and since the phenomena of organic beings are far more diversified than those which relate to inorganic matter, so also should we be as contented with the former as with the latter, and ap- ply them in the same philosophical and practical manner. We also knoAV enough of physics to marvel at nothing in organic beings which may be utterly different from the constitution, the phenomena, and the laws of inorganic matter; and, if it seem mysterious that such an agent as the nervous power should exist, Avith the characteristics which I have assigned, it will become less Avonderful when we reflect upon the phenomena of the immaterial mind in its connection with organization, as in muscular motion, blushing, palpitation, syncope, apoplexy, &c, or even upon the velocity of light, the inconceivable rapidity of its undulations, its laws, its effects, &c. All that we can know of the nature of any substance, material or immaterial, is by the phenomena it manifests. Where these are the same, or closely allied, as in electricity and galvanism, we may be sure that the essential causes are the same. But, where great and striking differences exist, and more especially where there are no analogies in the phenomena, as between the nervous power, or the 118 INSTITUTES OF MEDICINE. organic properties, and all inorganic agents, substances, or causes, we may be equally certain that the agents, substances, causes, or powers, are as different from each other, in their essence, as in their phe- nomena (§ 1085). It follows, therefore, that the nervous power, and the organic prop- erties, are, respectively, sui generis ; having no analogies in the inor- ganic world. The phenomena which different agents, powers, or causes, manifest, are so unlike each other, that different modes of investigation must be pursued to arrive at a knowledge of each; and the phenomena will be just as conclusive of the nature of one substance or poAver as of another. A stone, for instance, affects the sight, and touch; it ap- pears of a certain size, shape, color, &c, or it is hard or soft; if an- alyzed, it is found to be composed of several distinct substances, each of which manifest other phenomena; and this is all we know of the nature of a stone. And so of magnetism, galvanism, light, heat, and whatever else appertains to the inorganic world. We examine their manifestations^ and compare them together, and distinguish different things from each other by the manifestations or phenomena of each. But, there are groups of phenomena which have certain general re- semblances, and these we arrange into genera or families, as the sev- eral earths, metals, gases, &c.; but the specific distinctions ahvays remain, so that by the phenomena peculiar to each species we can always distinguish one from another. Just so it is in respect to the physical and chemical powers. The means of knowledge are of the same nature in all the cases, and the proof is as good in one case as in another. Coming to plants and animals, a general survey of their phenomena shows us that they have no other analogies, of any importance, Avith the inorganic world, than in the elements of which they are composed. These are derived from the inorganic kingdom; and here the simili- tude ends. If we investigate the phenomena analytically, they come upon us in a profusion wholly surpassing those of inorganic beings, and without the most remote resemblance. Here, therefore, Ave ap- ply the same rule as to inorganic beings, and we learn by the same process of observation as much of the nature and powers of one class of beings as of the other, and the proof is as good in one case as in the other, though more conclusive in respect to organic beings, in- asmuch as their phenomena are more various. By the same rule, also, we attain all the knowledge we possess of the soul, and, beyond that of Revelation, all that is relative to a Supreme Being; and we distin- guish each from all the others, or bring them into relationship, in the same way.—See Correlation of Forces, § 1085. The same mode of reasoning is, of course, applicable to what I have said of the modifications of the nervous power (§ 227-229), and of the organic properties (§ 133-156, 188-215). 234, h. We are, however, so much the creatures of sense, that the majority will probably still go on explaining every thing appertaining to life by some tangible or visible cause, or by some laws with which Ave fancy ourselves to be better acquainted. I have already cited sev- eral examples ; and if we take up any writer, indifferently, it is more than an equal chance that the authorities will be increased. Thus, here is Sir Gilbert Blane's excellent work on " Medical Logic" PHYSIOLOG V.--VITAL PROPERTIES. 119 " The changes," he says, " accomplished by the actions of life may be conceived to be effected through the agency of some imponderable fluid; such- as electricity, light, or magnetism. We may conceive, for instance, that each gland may be furnished with a sort of voltaic apparatus for effecting its specific change." The same doctrine has been adopted by a host of medical philosophers of our own times. But, did any of the foregoing agents ever produce, out of the organic being, a single one of the phenomena of life 1 Did they ever give rise to one of those phenomena in a dead subject, although the organ- ized structure remain unimpaired; as in cases of instant death from hydrocyanic acid, nux vomica, or from a needle thrust into the medul- la oblongata 1 Is not the whole hypothesis contradicted by all that is known of the effects of those agents ] It is the merest assumption to sustain an unintelligible and absurd hypothesis to affirm that struc- tural derangement is necessary to death. If galvanism, the chemical forces, &c, be the immediate cause of the deposition which constitutes the interstitial growth, what bestows vitality (or life, if it be preferred) on the new-formed matter 1 Or, if this vitality be imparted by spe- cific powers of the formative instruments, why should not those pow- ers be adequate to the entire work (§ 64) 1 Why so .great a violation of the most common rule in philosophy as to introduce other forces, whose great office is to pull down, and whose results are confusion 1 234,'-/. The whole art of medicine consists in producing certain im- pressions upon properties or powers that are wholly unlike those which rule in the inorganic world. It will not answer to talk of mod- ifying the operation of galvanism, magnetism, gravitation, light, chem- ical affinity, &c, by an emetic or cathartic. It must, however, come to this, if you will have it that those forces preside over organized beings, or even if they be allowed to have a subordinate agency (§ 175, d, 360, 409 k, 446 a, 488^, 493 cc, 500 nn, 893 a, 893£). 235. Finally, the phenomena of life are as easily comprehended as those of inorganic matter, and denote as clearly, and even more so, the nature of the causes. Who will demonstrate the nature of those physical properties by which foreign agents produce their impression on the properties of life 1 And yet so accurate is our discrimination among them, as prompted by the vital signs which they produce, that it is one of the most important objects of the physician to select from the multitude of cathartics, emetics, &c, a certain species whose properties shall correspond with the modified signs of the properties of life ; and, it is no unusual phenomenon, that, of the whole range before him, he decides with accuracy that there is only one medicine which is well suited to the case. And his conceptions of the specific properties of the agent, and of those of the organization, even in the modified state of the latter, are so comprehensive that he may foretell their united result. He knoAvs as much of the properties of life as of the remedial agent. He knows them far better; and that he admits their existence and specific nature is manifest from his deliberate ac- tion. Whoever .prescribes for disease upon any other ground is a mere charlatan. Who, again, will define the nature of cohesion, gravitation, chem- ical affinities, &c. 1 Like the properties of life and of spirit, and their relations to matter, their existence is only inferred from certain uni- form phenomena, and from such, alone, we deduce their relations to 120 INSTITUTES OF MEDICINE. objects of more sensible demonstration; and this is all we know of the sensible objects themselves. We reach the connection "between common matter and its properties, between the vital properties and organized structure, between the intellectual and moral faculties and the nervous system, the concurrence between them in the production of certain effects, and the differences in the nature of the several prop- erties, by a common process of observation. There are mysteries at- tending the same conditions of the whole which must be left to the sole comprehension of the Author Who intended the whole to sub- serve the purposes in which we are alone interested; Who has wise- ly secured to Himself the nature and control of primary causes; and Who has thereby restricted our inquiries to the only useful end of knowledge, the existence of the causes, and their various phenomena and laws. These may be so employed as to answer the wants, the conveniences, and the Ararious exigencies of intelligent beings. Those are the springs of action which it might be unsafe for man to under- stand. 236. From what I have hitherto said on the subject of life it must evidently be regarded, in a philosophical sense,, as a cause, not as an effect. The functions and other phenomena are the effects. This con- struction, which I have also set forth in my Essay on the " Vital Pow- ers" in other demonstrative aspects, is indispensable to any sound principles in medicine. All effects have their causes; and this simple principle obliges us to look for a cause of the phenomena of life. It is with the conditions of that cause, ascertained through the medium of its effects, that all physiology and medicine are concerned. 237. The powers by which living beings are governed, ceteris par- ibus, are always as precise in their operation, and bring about results as precise, as gravitation itself. But the properties of life are con- stantly liable to variations, and, therefore, there will be correspond- ing variations in their phenomena. Gravitation, and other physical forces, on the other hand, are immutable, and there are, therefore, no variations in the results of their operation. But it is also equally true that any given condition of the properties of life, connected with any given influences, is equivalent to the unvarying state of the physical forces. That particular condition, in conjunction with the supposed influences, always determines the same results, whether in health or disease. Every power in nature, when operating under given circum- stances, always terminates in uniform effects. The uncertainties, therefore, to which the science of medicine is liable, or any other which has nature for its foundation, are owing to our inability to understand all the facts. If any remedial agent produce an effect at one time which it does not at another it is because the properties of life have been differently affected in the different. cases ; and there may have been, also, a concurrence of many other different influences. Never- theless, in each case, the medicine operates according to established laws, and the modifications depend upon the difference of circumstan- ces. Each combination of circumstances, however; aHvays gives a uniform determination to the laws which govern the effects. Where the conditions are the same, the remedy in a certain dose will always produce the same results. Although gravitation is immutable in its nature, we yet see some- thing analogous to the foregoing influences upon the properties of PHYSIOLOGY.--VITAL PROPERTIES. 12l life in the manner in Avhich the revolution of the heavenly bodies may be affected by their interference, in relation to each other, with the power as exercised by the sun ; as seen in the erratic movement of comets. In either case the incidental influences may be calculated, and the results foretold,—conforming, in one case, to the laws of grav- itation, and in the other to those of the vital force. The sameness of the physiological conditions enables us to calculate not only what will happen to-day, but through all future time. But, the vital conditions are subject to precise modifications at the several great eras or stages of life ; but, being marked by uniformity, the results are forever the same, at each era respectively. The fundamental changes enable us, also, to foresee how the modified properties of life will be differ- ently affected by vital stimuli, the new sympathies that will spring up, the different relations of sensibility to the faculties of the mind, the difference in the acquisition of knowledge, &c, at the several eras. From these natural and uniform modifications of the vital states, we may turn to those of a fluctuating and accidental nature, which grow out of the influence of climate, habits, employments, &c, and which may be not only as lasting as the individual, but may be transmitted to his posterity. As at the different eras of life, we here find, also, variable influences from the natural, the morbific, and the remedial' agents, variable sympathies, &c, among organs, according to the arti- ficially-modified condition of the properties of life. These conditions, however, are rarely exactly the same in any two individuals; but, they are strictly analogous in principle to the natural ones which dis- tinguish the several stages of life, and, so far as they may be known in any given case, we may calculate, with great approximation to the truth, what will be the special characteristic phenomena that will mark the organic, the animal, and the intellectual existence of that in- dividual (§ 153-156, 535, &c, 574, &c). Thus we have a series of analogies, in respect to the mutability of the properties of life, and corresponding results, which bring us upon the confines of disease; which consists, also, in certain modifications of the vital properties, but more profound, more various, and more tran- sient (§ 176-182). Here lie the difficulties of medicine ; difficulties attending our knowledge of the modifying causes, the influences they produce, the complications of sympathy, and other contingent circum- stances. All these conditions must be known in any given case, to foresee, with certainty, any immediate or more remote result either of disease or of the action of any medicine, or of any natural vital agent. But, the properties of'life being never very greatly varied from their natural character, we may come, by a careful observation of their varying phenomena, to a knowledge of their conditions, and to foresee the results, or such as may spring from the operation of medicine, from the different kinds of food, &c, with sufficient accura- cy for all useful purposes. With this knowledge, we get at the most important laws of disease, general and specific, and build up princi- ples which are more valuable in practice than ages of disconnected experience (§ 149, 150). 238. I have said, that although instability is a prominent character- istic of the properties of life, and lies at the foundation of disease and therapeutics, these properties never undergo any radical change till they shall have lost their recuperative tendency. They are the only 122 INSTITUTES OF MEDICINE. attributes of organic beings that do not undergo absolute change and renewal. These properties must be forever present, without essential change of their nature, to carry on the work of decay and renewal, which are in perpetual progress in all the solids and fluids over which the properties preside. Hence an important law, that all hereditary predispositions to dis ease, and all impressions from morbific agents, which do not produce their manifest effects till the blood shall have undergone a renewal (as in hydrophobia, fevers, &c), must be primarily exerted'upon the properties of life, and that all the subsequent changes in the fluids and solids must be due to that original modification of the vital prop- erties. To perpetuate the primary influences something of a perma- nent nature must receive the impression. Analogy, alone, would as- sure us that this must be also equally true of the effects of all mor- bific and remedial agents (§ 666). 239. There is nothing more important to be known and appreci- ated than the endowment of the properties of life with a tendency to return from diseased to their natural states. This is the vis medica- trix natura, and is the immediate foundation of therapeutics. This, and this alone, has given rise to the art of medicine; since, by no ar- tificial means can the diseased properties and functions of life be con- verted into their healthy state. It is also remarkable that the most efficient remedial agents institute their favorable effects by establish- ing new pathological conditions ; which farther shows that it is nature alone which cures, and through the foregoing principle. That prin- ciple consists in the controlling influence of physiological laws, and, Avithout it, organic nature would become extinct (§ 853). 240. Connected with the foregoing law is another not less funda- mental, and which shows the fallacy of reasoning from the effects of remedial agents upon healthy to morbid conditions. It is, that the susceptibility of all parts to the action of remedies, physical or mental, is very different in disease from what it is in health, and the nature and the results of the influences are greatly different in the two con- ditions. Take many of the most powerful agents, arsenic, tartarized antimony, iodine, &c, and when administered in certain small and repeated alterative doses they bring about the cure of the most ob- stinate and formidable conditions of disease; while the same doses may not manifest any action upon the system, or on any part of it, un- der circumstances of health. This manifestly depends upon an in- creased susceptibility of the organic properties, in their diseased con- ditions, to the action of foreign agents, and upon an increased dispo- sition to undergo changes. And here we have opened a grand dis- play of infinite Design, Wisdom, and Goodness, to mitigate the pen- alties of disease, and to preserve the human race. This law, which unfolds a principle latent in health, and by which morbid organic properties acquire susceptibilities to salutary influences from agents which in health would either produce no effects, or lead to untoward results, and its ally, the great recuperatiA'e principle (§ 239), impose the highest obligation on physicians to become medical philosophers. 7. THE MIND AND ITS PROPERTIES. 241, a. Reason and instinct belong to man; instinct alone to ani- mals. Mind is commonly regarded as synonymous with reason, and PHYSIOLOGY.--MENTAL PROPERTIES. 123 instinct a principle by itself. The latter is undoubtedly true of ani- mals ; but I Avould consider instinct, in relation to man, as a property of the soul; Avhile in animals it is shorn of the great distinguishing attribute of man, the rational, immortal faculty. Independently of the specific facts which go to this conclusion, it has the strong ground of analogy in the more complex condition of the principle of life as it exists in animals than in plants (§ 184, 185). 241, b. To simplify the discussion of this intricate subject, the word mind, Avith the foregoing explanation, and mental properties, so far as perception, the will, and the understanding, are concerned, may be applied indiscriminately to man and animals. Judgment and reflec- tion are the great characteristics of reason; but, contrary to the usual representation, the understanding belongs as well to the instinct of animals as to the human mind. Many, again, may be disposed to consider the understanding a function, rather than a property; but this construction Avould suppose the operation of judgment and reflec- tion, Avhich do not belong to animals. The term is also employed in other acceptations than the present. 241, c. The abstract manner in which metaphysicians have consid- ered all the operations of the mind, Avhile no one of them is performed without the co-operation of the brain, or a principal nervous centre, and originally elicited through the corporeal senses, proves to us that physiologists are best qualified to analyze the phenomena of the soul and of instinct, and to indicate their relations to the body, and the laws which they observe. There is also a mysterious affinity between the soul of man and the instinct of animals, of which metaphysicians take but little or no cognizance. This alliance is shown by the cor- responding manifestations of perception, of understanding, and of the will in animals; by the amazing precision with which their habits are regulated ; by the evidence of common passions ; by the coincidence in the external senses of man and animals, through which they alike acquire a knowledge of external things; by the parallel in the ana- tomical structure of the brain of man and of animals Avhich stand high in the scale ; and by other analogies, which denote an affinity between the soul and instinct So great and various, indeed, are the evidences of the foregoing nature, that the special attributes of instinct are as- sociated with the human mind; thus forming a connecting link, through the moral faculties, between rational and irrational beings. Nevertheless, the phenomena of the human mind are infinitely su- perior to those of instinct, while the operations of instinct in animals greatly surpass any of its manifestations in man. Many special pecu- liarities concur, also, in demonstrating an absolute distinction between the rational mind and instinct. The latter, for instance, ahvays moves, in each individual species of animal, in a particular, unvarying path, but differently in each species of animal* It never diverges to im- prove its original endowments, or to add a gain which it did not pos- sess in its infant condition. It is then nearly as perfect in its opera- tions as at mature age; nor does one generation of animals gain upon its predecessors. Hoav different Avith reason, and with the instinct of man ! He passes through early infancy without a trace of the for- mer, and with only that helpless development of the latter which ena- * Here I may say that analogy proves that there is but one species of mankind, since tht manifestations of reason and instinct are the same in all. 124 INSTITUTES OF MEDICINE. bles him, with the foreign aid of reason, to imbibe the sustenance re- quired by organic life. Unlike the instinct of animals, however, the corresponding manifestations become greatly multiplied as age ad- vances ; but it remains always far more circumscribed and imperfect, and often plunging itself, and leading reason, into violations of their natural functions. And what a contrast between the limitations of in- stinct and the progress and grasp of the human mind; the latter for- eArer ranging through all the labyrinths of nature, investigating their phenomena, developing their powers, their subsidiary causes, and their laws, turning in upon itself and multiplying its knowledge, and en- larging its powers by its own independent efforts, laying up the gains of the past as a fruitful source of present good and of farther acquisi- tions, distinguishing good from evil, from which results the sense of moral responsibility, investigating its own attributes, and attempting even its own nature, and tracing up its existence to a Higher Power, as the Author of the Universe which was made for the contemplation and the enjoyment of mind (§ 175 c). 241, d. It is not an object, however, of the Institutes to investigate the philosophy of mind beyond those physiological considerations which are relative to the properties and functions of life, however it may have been important to their interests to contradistinguish the Maker from His works (§ 14 c, 175, 350f h-l). Perception and the will are the only mental properties which concur, more or less, in the phenomena of animal life. 242. Perception is always necessary to true sensation, and therefore to the exercise of all the senses. The mind, or instinct, must per- ceive an impression made upon sense, and consciousness must operate before the impression can be realized. The phenomena of sympa- thy in their connection with sensibility, in the ordinary processes of life, are not relative to sensation, but depend on a special modification of sensibility and on the nervous power. 243. The will, another property of the mind, upon which volition depends, exemplifies yet farther the complexity of the principles which obtain in the animal kingdom; and its phenomena admonish us to pause over that materialism which sees nothing but the demon- strations of physical and chemical power in the equally unique mani- festations of irritability, sensibility, mobility, the nervous power,—the entire organic force (§ 215). The will presides in animal life. It governs the movements not only of the voluntary muscles, but even the operations of the other mental faculties. In producing muscular motion, the operations of judgment and perception are often associated, and even bring the will into action. All muscular movements with which the mind, or in- stinct, is not connected, depend upon other causes than the will. Vol- untary motion is, therefore, as dependent on the will as true sensation is upon perception (§ 1072, b). The will has very little operation in organic life (§ 500, e); though the passions operate Avith power upon the heart, the abdominal viscera, &c. This peculiarity is founded in consummate Design ; since great- er latitude to the will would be incompatible with animal existence; while, on the other hand, other elements of the mind are allowed, for useful purposes, to stretch their influences to the deep recesses of life. 244. The will, a property of the mind, like the nervous poAver a PHYSIOLOGY.--FUNCTIONS. 125 property of the vital principle, is, therefore, a vital stimulus to the brain, whose chief office is the production of voluntary motion, by bringing into action the nervous power. 245. When the will gives rise to voluntary motion the philosophy is the same as when motion is developed in the organs of organic life by the nervous power (§ 205-215). The latter may take place through impressions transmitted to the nervous centres (§ 227, 500), or by impressions exerted in a direct manner upon these centres (§ 227, 230, 477). The will operates in the direct manner, develops the nervous power, and transmits it to the irritability of the voluntary muscles, by which mobility is brought into operation (§ 233). When the passions affect the movements in organic life it is exactly in the same way as with the will in animal life (§ 500 h, 1040, 1072 b). 246. Thus it appears that the unity in the great plan of the ner- vous power, in its relations to both organic and animal life, to mind as well as to matter, and the perfect concurrence of all the facts, and the obvious nature of the whole, which declare a harmony of principles and laws throughout all the immense variety relative to the nervous power, continue to unfold a grandeur of the subject which invites an unprejudiced attention to the expositions I have made of this brilliant institution of Nature (§ 1069-1082). FOURTH DIVISION OF PHYSIOLOGY. FUNCTIONS. 247. Our fourth grand division of Physiology comprehends the functions of organic beings. They are carried on by the properties of life in their connection with organized structure (§ 170, 175, 177), and of which the functions are the great final causes, or effects (§ 176). They are, indeed, the only useful ends of life; since, otherwise, all organic beings would exist in the condition of the seed and egg (§ 235, 236). The terminating series of the capillary vessels are the im- mediate instruments of all the essential processes in organic life, and therefore, also, of all diseases (§ 109, 410, 411, 668, 679). 248. The functions are common and peculiar. 249. The common functions belong to all organic beings. They consist of, 1st. Motion; 2d. Absorption; 3d. Assimilation; 4th. Dis- tribution; 5th. Appropriation, or nutrition and secretion; 6th. Excre- tion; 7th. Calorification; 8th. Generation. The first seven are in- dispensable to animals and plants. The eighth appertains only to the species, and has no essential part in the organic economy (§ 97, 118-123, 153-156, 237, 578). 250. The peculiar functions belong to animals only. They are, I. Functions of relation ; comprehending, 1st. Sensation; 2d. Sym- pathy, or reflex nervous action. II. Voluntary motion, and functions by which the mind and instinct act on external objects. III. Other mental and instinctive functions. 126 INSTITUTES OF MEDICINE. I. COMMON, OR ORGANIC FUNCTIONS. 251. Organs which perform similar functions are very variable in structure in different orders of animals. The liver, for example, " is represented in one case by simple caeca, or blind sacs; in another by tufts of casca; in a third by bunches of cells ; in a fourth by a spongy mass; in a fifth by branched ducts ending in feather-like terminal twigs ;" and so on, up to the complication of the most perfect animals. Nevertheless, they all secrete a very analogous fluid. And so of oth- er organs and functions. A due regard for the preceding facts must unavoidably reconcile every mind to what I have said as to microscopical explorations of the minuteness of structure (§ 131, 304, 306, 409, e). 252. Though structure be very various, there is a great analogy in the vital functions and their immediate products,—even between plants and animals. This is remarkably true of every individual part in the different races of animals, whatever its simplicity or complexi- ty (§ 251). Hence, it becomes more and more manifest that the properties of life have a greater agency in the formation of organic products than the structure itself (§ 67-69). 1. MOTION. 253. Motion is the immediate result of the action of mobility or contractility, and was necessarily explained in describing that prop- erty (§ 205-215). It is the function by which all things acquire their movement in organic beings. 254. Motion may be remotely mechanical, as the movement of the blood, ingesta, &c.; but the power and the actions of parts which gen- erate the mechanical movements are purely vital. 255. Motion belongs, of course, to every tissue in which its mani- festations occur; and it is therefore an error, hoAvever common, to limit this function to the muscular tissue. 256. The great offices of motion in organic life are to supply the system with useful materials, and to remove such as are useless. 257. In animal life this function appears under the aspect of loco- motion or some analogous result, and I have associated the considera- tion of this modification of the function with that which is common to the organic life of animals and plants, on account of their common na- ture. 258. Voluntary motion proceeds from the action of the will upon the great nervous centre, by Avhich the nervous power is developed and transmitted to the irritability of the voluntary muscles (§ 188, 208, 233, 476 c). Here the excitation of the nervous power is direct, as in the experiments by Wilson Philip (§ 486, 487). If the motion be involuntary, as in the ordinary movements of respiration, the develop- ment of the nervous power is indirect, according to the usual process when organic actions are influenced by the nervous power (§ 222, &c, 500). When other involuntary motions affect the muscles of animal life, as convulsions, &c, the development of the nervous power may be direct, as in diseases, and concussions, of the brain, or indirect, as in teething, and intestinal irritation. The philosophy, however, re- specting the production of motion in all these cases, is exactly the same. Whether the movements be voluntary or involuntary, the PHYSIOLOGY.--FUNCTIONS. 127 movements depend upon the action of the nervous influence upon mo- bility through the property irritability. The mind does not, as has been supposed, leave the brain to enter the muscles in voluntary mo- tion. The difficulties of explanation are not only multiplied by this supposition, but it is shown to be erroneous by the analogous move- ments which may be excited through the spinal cord, or through the nerves, after the soul and instinctive principle are separated from the body by the removal of the head. This philosophy is also coincident with that which I have propounded as to influences of the nervous power in organic life. Each illustrates and sustains the other (§ 500). 259. It is now important to repeat, that the nervous power never generates motion, per se (§ 222-232). The function always depends immediately upon the organic property mobility, which is brought into action through impressions made upon irritability (§ 188). The ner- vous power is only a stimulus to irritability. But, it is much more im- portant to motion in animal than organic life; since it is the only nat- ural stimulus of the voluntary muscles, while blood, and other agents, operate upon the tissues Avith Avhich they are in contact in organic life, and thus excite reflex nervous actions, and render them tributary as an exciting cause of muscular motion and in increasing or diminishing and otherwise affecting the secreted products (§ 224, 226, 475-1-, 893-L). 260. Very important laws grow out of the foregoing distinction be- tAveen the relation of the nervous power to the function of motion in animal and organic life, and its essential independence of that power in either life (§ 475J, 476, 498, 500 m, 893\, 1042). 261. That motion does not depend upon the nerves is shown by the sensible and insensible motions of plants; by that of their leaves, stems, stamens, by their absorption, nutrition, secretion, &c. (§ 455, c). The analogies in results prove this independence of the nerves, and the near identity of the function in plants and animals. Indeed, the chemists will have it that all the essential compounds of the animal are formed by vegetable organization (§ 18, 409). Such analogies are always sound,being based on great fundamental laws. But there may be great variety of mechanism. Where nerves exist, and in connection with centres capable of generating a stimulus, they are so far tributary to muscular and other motions, and voluntary motion is wholly depend- ent upon that stimulus, as also natural involuntary muscular motion. 262. " The heart of a frog continues to beat with its ordinary rhythm even when the entire base of the organ, when the ventricles, as far as their juncture with the auricles, are cut away" (p. 346, § 516 d, no. 8). In the same way, " the peristaltic movements of the intestinal canal continue not only when the intestine is removed from the trunk to- gether with the mesentery and ganglionic plexus, but also when the intestine itself is isolated from the plexifs by being separated from the mesentery at the line of its insertion."—Muller's Physiology. 263. Dr. M. Hall tied a ligature around the root of the heart and lungs, and then separated them from the body. " The action of the heart was still such as to carry on, in a slight degree, and for a short period, the circulation of the blood through the pulmonary artery, and a few of the capillary Aressels." He adds his belief, " that the actual circulation of the blood has not been before seen proceeding entirely and independently of the sympathetic system."—Hall. 264. Now, in the last two of the foregoing cases there may have 128 INSTITUTES OF MEDICINE. been local nervous centres, ganglia, perhaps, or some other part of the sympathetic nerve to supply the requisite stimulus through reflex ac- tions ; the air and the injuries operating as remote exciting causes of the nervous influence (§ 475-i). But in the case of the mutilated heart the nature of the injury precludes the supposition that there could have been any radiating focus of reflex actions, which is probably equally true of the case in § 498 e; so that in those instances the air and the mechanical irritation were alone the exciting causes. Note A p. 1111. 265. Motion, therefore, whether voluntary or involuntary, is carried on through properties inherent in the various tissues, and the nervous influence is only a remote exciting cause, and in that respect on com- mon ground Avith other vital agents, Avhile also, as will be seen, it is an indispensable regulator of the organic mechanism of animals, and trib- utary to the perfection of their organic compounds (§ 222-233|, 500). 266. The nervous power, in developing motion in either organic or animal life, as a stimulus to the organic properties, does not follow the nerves according to their regular order of distribution from the nervous centres. On the contrary, its entire want of uniformity in that respect—operating simultaneously, at one time, through a nerve or nerves proceeding from the cranium and some inferior part of the spinal canal, while it passes over all intermediate nerves—or, at an- other time, electing, without any regularity in respect to order of ar- rangement, two or more of those-intermediate spinal nerves—this entire want of respect to anatomical order is so familiar to all that it has not appeared as one of the most difficult and sublime problems of nature. This very extraordinary attribute of the nervous power is rendered the more remarkable by our knowledge of the fact that its* operation is determined through particular nerves either by an act of the will, or, in organic life, by particular passions, by their intensity of operation, and by the special nature and intensity of physical agents which may transmit their influences to the nervous centres through some other part; and, in the cases relative to organic life, according, also, to the existing susceptibility of the various parts of the organism (§ 137 d, 143, 148-152, 233|, 500, 8921 v, 893, 905, 1059). 267. All the foregoing are established facts, of perpetual occurrence; and they should be taken in connection with the doctrines which I have advanced as to artificial modifications.of the nervous power, and the modus operandi of morbific and remedial agents (§ 224-233|, 497-500, 503, 506, 889 a, 891-1- k, 892 aa, 893-905). 2. absorption. 268. Absorption is performed, in animals, by the lacteals and lym- phatics ; those vessels being very similar in their constitution and function. There are corresponding means for the office of absorption in the roots and leaves of plants. 269. Magendie, and others who have copied from him, have fallen into the error of attributing the office of absorption to the veins. He was led into the mistake by an ignorance of the fact that the lymphat- ics terminate variously in small veins.* Fallacies of that nature should be apparent upc n principle alone—at least to such as recog- nize a unity of design, and a simplicity in the great institutions of nature. Every system of vessels, so far as known, has but one func- * See Medical and Physiological Commentaries, vol. ii., p. 170, note, 380, 394-396. PHYSIOLOGY.--FUNCTIONS. 129 don, however that may be modified in different parte, as seen in the lymphatics and lacteals, in the terminal series of the capillary arter- ies in all parts, &c. The distinction depends either upon structure connected with the modifications of common vital properties, and their relative adaptations to the physical properties of different fluids, or, structure may be apparently less concerned than the organic prop- erties ; which is one of the most universal and important principles in physiology (§ 133-150). 270. The lacteals perform the office of absorbing, and introducing into the organization of animals, foreign nutritive matter. 271. The lymphatics, in greater part, are destined for the vital de- composition of the body, and for the removal of waste parts, which are conveyed by the lymphatics into the torrent of blood to be ulti- mately cast out of the system, or again to undergo, in part, the process of sanguification. May absorb from surfaces, but not nutritive matter. 272. By these vessels, also, the solids are removed in the ulcerative process of inflammation, and mortified parts are detached from the sound,* and foreign substances which are introduced into the body are taken up and removed. 273. Hence it is obvious that the lacteals and lymphatics are antag- onizing systems, and that beings so endowed are the constant subjects of waste as Avell as of nutrition ; the balance being maintained through the inlet supplied by the lacteals, and the outlet provided by the lym- phatics (§ 180-182, 286). Notwithstanding, therefore, the coincidence in the general function of these two systems of vessels, the office of one is creative, thatrof the other destructive. During the period of growth nutrition overbalances waste; but, when growth ceases, nutrition and vital decomposition must be in equilibrio. 274. No substances but such as exist in a fluid or very attenuated state are taken up by the lacteals and absorbents. 275. The intestinal villi have been shown by Cruikshank, Bleuland, and others to possess open orifices,! though this is denied by the mi- croscopists; and I have shown that the modifying influence of the ganglionic nerves upon all the organic functions and products contra- dicts the hypotheses of catalysis and endosmose and exosmose (§ 1089). 276. Different substances are absorbed with various degrees of ra- pidity, both in animals and plants. This depends on their peculiar virtues, and on the manner, therefore, in which they affect irritability; thus showing the vital nature of the process (§ 149, 188, &c, 207). The same conclusion is also inferable from experiments, as well upon plants as animals. 277, a. Again, the lacteals, in virtue of their special modifications of irritability, exclude every thing but chyle. Bile is not taken up either by the lacteals or lymphatics; cathartics pass off; emetics are rejected. The principle is every Avhere; is shown in the larynx, pylorus, &c, in the sparseness of the red globules in the lymph vessels, though their diameters be many times larger than the globules of blood (§ 399). The principle lies in the virtues of the agents and the special modification of irritability which belongs to each part (§ 135). It is designed for the conservation of every part, and of the * See Med. and Physiolog. Comm., vol. ii., p. 168,169, 171-173. t Ibid., vol. i., p. 683-690, 699-712. 130 INSTITUTES OF MEDICINE. whole. Had not the lacteals and lymphatics been endowed in this wonderful manner, or were absorption a mere physical process, or ca- pillary attraction, or endosmose, all foreign substances would have free access to the internal parts of the organization, and organic beings would have had no continued existence. They would have perished as soon as created. Hence, are the vital properties so modified in all these millions of inlets into the labyrinth of organization that they shall be not only vigilant seritinels, but recognize, at once, every one of the thousand offenders that may endeavor to steal its way into the sanctum sanctorum (§ 192). 277, b. Some of the most important laws in medicine are founded on the special modifications of irritability in different parts (§ 149, 150); and as it respects the lacteals and lymphatics, the principle not only contradicts the assumption of the operation of medicines by absorption, but confirms, in a beautiful manner, the laws of sympathy. 278. It is only when the lacteals and lymphatics become morbidly affected, or their irritability essentially modified by the morbific action of agents offensive to the organization, that those agents are at all ad- mitted, and then only very sparingly. The principle is the same as when undigested food escapes the pyloric orifice in indigestion, or the red globules of blood gain admittance to the serous vessels in in- flammation (§ 14, 74, 117, 137,143, 155, 156, 169/, 266, 3031 a, 306, 310, 313, 325, 387, 399, 409/, 422, 514 h, 524 d, 525, 526 d, 528 c, 638, 649 d, 764 b, 811, 847 c, 848, 902/ 905). 279. If, therefore, foreign agents affectthe absorbent vessels in the foregoing manner, so also do they affect the condition oflthe other tissues of the part. This is the beginning of disease, which may now go on accumulating without any farther agency of the exciting cause; or, if the offending cause gain admission into the circulation, it may con- tinue, per se, to exasperate disease. But, even in this case of the con- tinued operation of morbific or remedial agents after their absorption, I have shown that solidism and vitalism can alone explain their effects (§ 819, &c). 280. I have also shown that when morbific or remedial agents are taken into the circulation the quantity is so small, their dilution by the blood and other fluids so great, and their elimination by the kid- neys so rapid (at least in a general sense), that little or nothing is likely to be contributed in this way to the morbific or remedial effects. The rapidity with which agents that are not morbific, but useless to the system, are elaborated by the kidneys, is a proof, upon the prin- ciple of Design, that a provision exists for the exclusion of deleterious agents from the circulation. But, since they may, under special cir- cumstances, pass the great sentinel (§ 278), the kidneys are provided as other guards to the general organism, to expel the offenders at once. Just so with the lungs. If offensive objects pass the larynx, all the muscles of respiration, through a beautiful system of Design, imme- diately set at work to get rid of the intruder. The intelligent reader will readily carry this principle to more recondite processes, as the institution of abscesses, and the curious steps that attend their progress from deep-seated parts toward the surface (§ 733). 281. It may be also added, that I know of no critical attempt having been made to invalidate the facts and the reasoning set forth in my Essay on the Humoral Pathology, which has for its object the ex- PHYSIOLOGY.--FUNCTIONS. 131 posure of that pathology and the defense of solidism and vitalism; and, although that work has been now six years before the public, I know not that I have omitted the investigation of one essential fact or experiment that has been alleged or instituted in behalf of humoralism. If such omission has occurred, let it be shown.* 282. Many distinguished men have been led into the error of sup posing that noxious substances are taken readily into the circulation because the skin is deeply tinged with yellow, in jaundice ; or because the bones become red when madder is eaten; or the urine is colored by rhubarb, or manifests the odor of turpentine, of garlic, &c. But, let it be considered, that the inoffensive coloring matter of the bile is alone absorbed, as is also that of madder and rhubarb, &c.; Avhile the thousandth part of a grain of spirits of turpentine, or of garlic, is enough to impart all the odor to the urine that has been ever observed to at- tend that product. 283. If remedial and morbific agents be absorbed, it devolves upon the mechanical philosophers to show the fact, which they have failed of doing in regard to many of the most important (§ 826 c) ; but should their assumptions become realities, I shall have demonstrated by a mul- titude of analogies where absorption is out of the question, and in va- rious other ways, that the modus operandi of the whole rests upon the philosophy of the natural physiological laws (§ 1088-1089). 284. Although a very limited operation of morbific and remedial agents, through their absorption into the circulation, be not incompat- ible with solidism and vitalism (§ 277, 278, 283, 827/), the usual in- terpretation of their effects, according to the doctrines of humoralism, would compel us to abandon the application of physiology to medicine, whether pathologically considered, or in respect to the operation of curative agents. The laws of disease would be totally unlike the laws of health; or, rather, disease would be Avithout laws, and there would, therefore, be no general principles in medicine. Practice would be a blind empyricism. Diseases would be just as various and un- certain as every chemical change in the blood, and these changes, upon the ground of humoralism, would have no resemblances to each other. 285. The properties of life lie at the foundation of physiology. It is a knowledge of their character, and of the laws which they obey, that enables us to conform our habits, at all ages, in the best way for the maintenance of health. But, what is disease 1 It is a deviation from the state of health; and, therefore, if there be any consistency in nature, disease should consist primarily and essentially in modifi- cations of those vital properties, which, in a different state, constitute the important conditions of health. In this way, therefore, medicine takes the rank of an intelligible and important science. Physiology is the ground-work throughout. Pathology becomes nothing more than physiology modified. And, coming to therapeutics, it is still physiology applied to the cure of diseases; or, in other words, the application of such agents to the morbid properties of life as shall aid their restoration to their natural physiological state. The whole is thus bound together. No new elements come into operation; but, throughout the whole series of changes, the same powers are in action and carry on all the processes. Nor are there any new laws intro- duced. The powers and actions being fundamentally the same, *In Medical and Physiological Comm. vol. i. 1840.—Now 25 years, and no attempt made. —1865. 132 INSTITUTES OF MEDICINE. so are the laws, of health and disease, as are those, also, by which diseased are converted to healthy conditions. But, the powers or properties of life being modified in disease, and again modified in other ways by the action of remedial agents, so are the laws, under which all these results happen, varied in a corresponding manner. The laAvs are only the conditions under which effects take.place ; and, as those effects have always a direct reference to the state of the vital properties, they must be fundamentally of the same nature under all the various conditions of life, since, also, the vital properties never lose their fundamental character (§ 1, 639). 286. When, therefore, I may speak of the laws of health and the laws of disease, I must not be understood as meaning something entirely different in the two cases. And yet, their modifications are always precise, and the results of each are always determined in one uniform manner. This is necessarily so, because the changes in the vital properties are .always precise, and according to the nature of the in- fluences by which the changes are effected (§ 149, 150). 287. In this sense, therefore (§ 286), the laws may be assumed to be, in each individual modification, of a specific nature. 288. Laws may be said to be general and specific; which, how- ever, is only another mode of considering the foregoing principle (§ 285). Thus, it is a general law that the absorbents, whether in health or disease, do not take up foreign substances of a deleterious nature; but, it is a specific law, that when the irritability of the lacteals or lymphatics is modified in a certain way, they will admit a small pro- portion of the noxious agent by which the alteration is produced (§ 277, 278). 289. Those mechanical physiologists who have not, or will not have, just conceptions of the properties and actions of life, refer the process of absorption to capillary attraction, or that mechanical principle which determines the ascent of oil in the wick of a lamp (§ 277). The chemists belong to this class of reasoners; even such of them a« allow the existence of a vital principle. Thus, for example, Liebig has it, that, " A cotton wick inclosed in a lamp, which contains a liquid satura- ted with carbonic acid, acts exactly in the same manner as a living plant in the night. Water and carbonic acid are sucked up by capil- lary attraction, and both evaporate from the exterior part of the wick." Again, "All substances in solution in a„soil are absorbed by the roots of plants exactly as a sponge imbibes a liquid, and all it con- tains, without selection."—Liebig's Organic Chemistry applied to Physiology and Agriculture. Now all this might be very good philosophy for a common agricultu- rist; but it evinces an unaccountable disregard of facts, and of the plain- est suggestions of nature. And yet it is a common doctrine now-a- days; a part of the " new experimental philosophy." In the first place, hoAvever, it is not true that the roots of plants imbibe their nourish- ment " without selection." When plants are cultivated in glass ves- sels containing distilled water, their roots will even decompose the glass, and select its silica, or alkali, or take them both, and assimilate them to themselves, and in the absence of any known chemical affini- ties or influences. Absorption is nearly as exact in plants as in ani- mals ; and so is appropriation. Like animals, their absorbent system PHYSIOLOGY.--FUNCTIONS. 133 is naturally repulsive of every thing that is offensive and not suitable to their economy. If poisons, when artificially applied, get admission, it is by inflicting a violence on the radicles of plants (§ 278). And what is thus prompted by reason, by analogy, by common experience, is fully confirmed by the chemists themselves, in those analyses of all parts of a plant, even the sap, which are designed as standards of the composition which shall serve for any particular part of any given species of plant, as Avell through all future time as at the hour when the analyses were made (§ 1052, 1053,1054). 290. The simile of the " lamp-wick," and of the " sponge" (§ 289), show us how far astray our friends are from the path of truth. It is not alone the complex mechanism of the root which the absorbed ma- terials traverse, but a labyrinth of highly organized and living tubes, passing through the whole trunk of the plant, till the materials finally reach the leaves. In those respiratory organs, the pabulum vita is farther subjected to the action of another complicated, unique, and living system of vessels. And what is the " Avick of a lamp ]" A mere bundle of dead, disorganized fibres, broken upon the card, and spun upon the wheel (§ 350^ n, o, 826 c). 291. But, the foregoing degrading doctrine of life (§ 289) is not pe- culiar to the chemists. Some reputedly profound physiologists apply it not only to plants, but to animals, and, like Liebig, identify the same vital and physical processes. One example, in a distinguished quarter, will suffice. Thus, Dr. Carpenter: " It Avill be hereafter shown that the absorption of nutritious fluid is probably due to the physical $>ower of endosmose. A continued absorption may be produced by a physical contrivancSkvhich imitates the effects of vital action ; [ ! ] as in the wick of a lamp, which draws up oil to supply the combustion above, but will cease to do so when the de- mand no longer exists" ! (§ 64 g, 175 d).—Carpenter's Comparative Physiology. The Avork, a standard one, from Avhich the foregoing is quoted, abounds with analogous doctrines. They are, of course, fatal to physiology and to all medical science. 292. Immediately after the quotation from Liebig, in the preceding section, that author proceeds to reprobate physiologists for their ex- clusion of chemistry from organic life, and charitably regards it as a prejudice arising from our ignorance of the science (§ 350, a). This, however, is quite an untenable position; for, wherever medicine is cultivated chemistry is justly made a fundamental part of education. It is, indeed, the knowledge which the soundest physiologists possess of chemical science that enables them to institute the necessary con- trasts, and which convinces them that chemistry, in its proper ac- ceptation, has no connection with the processes of living beings. This, indeed, I have abundantly shown to be the real opinion of the chemists themselves (§ 350, &c). Bold in assumption, inapt in illus- tration, and, at last, like Liebig, contradicting the whole by an ac- knowledgment that " vitality, in its peculiar operations, makes use of a special apparatus for each function of an organ," and that "in the living organism we are acquainted with only one cause of motion ; and this is the same cause which determines the growth of living tis- sues, and gives them the power of resistance to external agencies. It is the vital force."—Liebig (§ 350, nos. 26, 27, 28, 71-77, &c). 134 institutes of medicine. 293. Looking at other facts attending the process of absorption in plants, we shall find them all concurring with what I have already stated as to the dependence of this function upon vital actions ; and, if vital here, we need not look for other proof of a similar law in an- imals. Thus, Van Marum demonstrated that absorbed fluids could rise only eight inches by capillary attraction. Hales, Walker, Mirbel, Chevreuil, and others, have shoAvn that the sap moves with such ve- locity and force in plants, that it must be propelled by vital contrac- tions and dilatations of the vessels. We have examples of this sur- prising rapidity of the circulation in grape-vines. Don and Barbieri affirm that they saw the movements of the vessels. Again, the motion of sap is increased by light, heat, and other stim- uli, which have no effect on capillary attraction. And this is the opin- ion even of Liebig, who says that " the functions of plants certainly proceed with greater intensity and rapidity in sunshine, than in the diffused light of day; but it merely accelerates in a greater degree the action already existing;" "an action," he says, "which de- pends on the vital force alone." It was shown by La Place, that, if the sap rose by capillary attrac- tion, it should not, as it does, flow from the openings made in the ves- sels. But, again, the sap will not flow from the openings, if the plants be poisoned with prussic acid. The effect is the same as upon the circulation of the blood; and it would be equally absurd, in either case, to suppose that the poison acts upon any physical force. As- tringents, and various other substances, applied to the openings, avert the flow of sap, which can only be ^lone through the foregoing prin- ciples (§ 278-1^4, 1054). 294. Here is another fact, and which appears to be conclusive of the vital nature of absorption, and of the discrimination observed by the radicles of plants (§ 289, 291). It is, that the sap of the root is unlike any thing which it absorbs from the earth. All the substances are decompounded at the moment of entering the roots, just as the carbonic acid is by the leaves. Their elements are then also united according to the modes which prevail in organic compounds (§ 38, 42). 295. Equally unfounded as the doctrine of capillary attraction are the supposed processes of endosmose and exosmose. They are gen- erally predicated of experiments upon dead matter, and are then car- ried, by way of analogy, to the living organism, and in defiance of all the contradictory phenomena of life.* Having entered extensively into a refutation of the hypothesis of endosmose and exosmose in the Medical and Physiological Commentaries, I shall not now resume the subject (§ 1052, 1053, 1054). 3. assimilation. 296. By the function of assimilation subslances taken into the body are converted into the homogeneous blood, and identified in com- position and vital properties Avith all parts of the body. It is there- fore especially concerned in the process of growth, and in supplying the waste which is constantly in progress. It is the function, there- fore, by which the properties of life are communicated to dead matter. 297. All dead matter, before its reception into the body, is subject to the forces of chemistry. The operation of these forces is arrest- ed in the alimentary canal of animals, and in the absorbing vessels of plants. * Violence is inflicted in the experiments upon living tissues. PHYSIOLOGY.--FUNCTIONS. I35 298. The nutriment of vegetables consists always of inorganic sub stances, or is reduced to the condition of inorganic matter before its appropriation. The food of animals is always organic. The former exists in an elementary or in a state of binary combination, the latter of ternary, quaternary, &c. It is the work of vegetable assimilation to overthrow the chemical combinations, and to unite the elements in those very different modes which constitute organic compounds. This is the most remarkable and comprehensive System of Design of which we have any knowledge (§ 1052).—Notes NR pp. 1121,1123. 299. Assimilation, therefore, devolves especially upon the proper- ties vivification and vital affinity (§ 216, 218); though it be certainly true that all the organic powers and functions are necessary to each other, and concur together in producing every result. But, in every result there are some more interested than others. 300. Animals, being incapable of organizing inorganic substances, are dependent upon the vegetable kingdom as their ultimate source of supply (§ 13, 14). Such, indeed, is the final cause of vegetable life. But the food of animals must be dead before it can begin to un- dergo the action of the vital properties in another being. The gas- tric juice, for instance, has no effect upon any living substance. 301. No organic compound ever undergoes chemical decomposi- tion, or any approximation toward such decomposition, to fit it for the purposes of animal life. On the contrary, every such tendency places the appropriate nutriment of animals, more or less, beyond their as- similating endowments. It is the province of animal life, and of all its provisions for assimilation, not to carry back toward their inorganic condition the peculiar compounds generated by the vegetable king- dom for the foreordained uses of the animal, but to carry them for- ward to yet higher degrees of life and organization. This is one of the most fundamental laws of nature, and is conclusive against all the chemical speculations with which physiology has been so unhappily visited (§ 356 6-376).* The argument belongs to me (§ 1084). 302, a. The assimilating organs in vegetables are more simple than in animals, and the complexity increases in animals according to their rank in the scale of life. It would appear, therefore, that organiza- tion bears a ratio more or less proportionate to the endowment of or- ganic compounds with the properties of life (§ 301, 409). 302, b. The process of converting inorganic into organic compounds begins in two orders of vessels, one of which are the radical absorb- ents of plants, the other analogous vessels in the leaves. The matter absorbed by the roots ascends through the stem to the leaves, where, by the operation of a series of vessels, variously mod- ified in different species, it is converted, along with that absorbed by the leaves, into a juice, which, like the blood, is thus fitted for the purposes of nutrition. This juice then descends through other ves- sels, to be appropriated to all parts, and to form the source of all the various products of vegetable organization. 303, a. We come, therefore, to a conclusion as remarkable as it is comprehensive, that the atmosphere is not only essential to plants and animals in its usual acceptation, but that it supplies the great means of nutriment to both organic kingdoms: directly to the vegetable, and indirectly to the animal department (§ 298-300). Mineral compounds appertaining to the earth must yield the less important elements, and * Chemists are beginning to adopt this conclusion, as appears in Note at p. 196.—1860. 136 INSTITUTES OF MEDICINE. even some proportion of oxygen through the decomposition of rocks and metals and the appropriate combinations that may ensue; but we must look especially to the atmosphere and what it contains for the four great elements which compose organic beings. The oxygen and the nitrogen of the air, the oxygen and the hydrogen of the vapor which the air contains, and the carbon of the carbonic acid, are as much at this day the great source of nutriment to plants, as before the " mist" went up from the seas, or animals yielded ammonia. Oxygen and nitrogen, therefore, as it respects atmospheric air, are appropri- ated by plants in their elementary condition. Upon organic com- pounds thus formed is animal existence, in the main, dependent. Ammonia certainly contributes to the nourishment of plants. But this is an incidental means, at least if there be any truth in Moses. And that his Record is true, is plain enough upon the principle of Design; since it is impossible that Providence should have created the animal kingdom, which yields the ammonia, before he brought forth that kingdom upon which animals depend for their existence. 303, b. As it respects absorption, the leaves and the roots of plants appear to have a common office, though the former are designed es- pecially for assimilation. The carbonic acid, and the oxygen and the nitrogen of the air, are precipitated along with the vapor, and thus reach the organs which are principally devoted to absorption. In no other way can we primarily reach the materials of all organic beings. Before their absorption can have begun, the most essential elements must have been embraced originally in the atmosphere, and in the simple conditions which I have stated. Nor is it a difficult process to follow out that circuit of causes and effects in which revolves the economy of nature in making the waste of organic beings during their own existence a subsidiary supply of nourishment to themselves, or to others of their own day, or to generations in the womb of time; or, Avhen consigned " to the dust," how their elements, from one genera- tion to another, form an endless round of materials for reproduction and growth, either in the form of gases and vapor diffused in the air or as imbodied Avith the earth. 303, c. Although it be the special object of the radical fibres to carry on the function of absorption, this office is more or less perform- ed by the leaves of plants, but in various degrees, according to the nature of the species. In arid climates, the leaves have this function strongly pronounced; and many plants, like the sempervirens, will grow as well when suspended by a string, as when connected by theit roots Avith the soil. 303, d. The leaves of plants absorb carbonic acid mostly during the day, decompound it through a vital process, and otherwise prepare it as an important source of nourishment. Light is necessary to this func- tion of the leaves, and without it the plant languishes and dies. As an attendant result oxygen gas is evolved into the atmosphere. The process is, therefore, suspended during the absence of light, and some proportion of carbonic acid is regenerated and escapes along with the vapor which is exhaled by the leaves. It has been also supposed that more or less oxygen is absorbed at night; but this opinion appears not to be sustained by later and better observations. It is most proba- ble, indeed, that the temporary absence of light occasions scarcely more than a suspension of the assimilating process. Light acts as a vital PHYSIOLOGY.--FUNCTIONS. 137 stimulus to the leaves, by which their organic properties are tendered capable of overthrowing that most refractory compound, carbonic acid (§ 188£ d, 350, nos. 64, 66, 68-76,) 303, e. The leaves of plants being the great organs of assimilation, and light the vital stimulus by which the function is maintained (§ 1881, d), it appears from what has been now said that light holds the first rank among the requisites of life. It was therefore brought into existence before the creation of the vegetable kingdom; and beino thus indispensable to all living beings, we see the fallacy of a common tenet in theoretical geology, that the most thrifty period of vegetation was through a great cycle of total darkness, and an atmosphere of carbonic acid (§ 74, 1079 b). 303J, a. One of the most interesting facts in vegetable physiology is the immediate necessity of plants to animal life during their very growth; their final cause, in this respect, being the abstraction of car- bonic acid from the atmosphere, and the renewal of its oxygen. Ani- mals, too, as we have seen, incidentally contribute carbon to the vege- table kingdom, in the form of carbonic acid, and nitrogen in the form of ammonia. There is this remarkable subserviency of the organic kingdoms to each other, though there be not a reciprocal dependence. Vegetables, indeed, preceded animals, and are, therefore, essentially independent, while animals derive all they possess from vegetable creation (§ 303, a). Plants are the producers, animals the consumers. The former directly, and the latter indirectly, live upon the air and what it contains. The plant dies and becomes food for the animal; but it seems scarcely less important in its living state to the exigen- cies of animal life. And so the animal, living and dead, yields back its all to the atmosphere; and thus are the inorganic, and the two de- partments of the organic, kingdoms united (§ 1052, 1053). 303^, b. But, we have seen, as I originally indicated in the Essay on the Philosophy of Vitality, that the supply of ammonia to the atmo- sphere is only a contingent result of the creation of animals, and there fore not indispensable to vegetation (§ 156 b, 303 a). Liebig, how- ever, reverses the order of Creation, and affirms that " We haA'e not the slightest reason for believing that the nitrogen of the atmosphere takes part in the process of assimilation of plants and animals." " These facts are not sufficient to establish the opinion that it is ammonia which affords all vegetables, without exception, the nitrogen which enters into the composition of their constituent sub- stances. Considerations of another kind, however, give to this opin- ion a degree of certainty which completely excludes all other views of the matter."—Liebig's Organic Chemistry, &c, p. 70, 71. 303£, c. The same mistake has arisen with the chemists as to the reciprocal dependence of animals and plants, in regard to the excre- tion of carbon by one and oxygen by the other. However true it may be that animals are dependent on plants for oxygen gas, it is certainly an assumption that the vegetable kingdom is alike dependent on the animal for its carbonaceous element. If the primary creation of plants be admitted, that is sufficient; and to those avIio reject the Mosaic Record, and the concurring testimony of geologists, I may repeat the admitted fact that vegetables are the ultimate source of supply to all animals. The former, therefore, are essentially independent, the latter dependent; while this universal fact corroborates, also, 138 INSTITUTES OF MEDICINE. the original account of the primary creation of the A^egetable kingdom (§303]). As to the relations of the living plant to organic life, it is computed by Saussure, and allowed by others, that the atmosphere contains about i-oVo th part of its weight of carbonic acid. The atmosphere must be also losing, through the processes of respiration, combustion, &c, a proportion of its oxygen. It is estimated, also, that the present num- ber of human beings would, alone, double the existing quantity of car- bonic acid in the air in 1000 years; and, in 303,000 years would ex- haust its oxygen. It is also found that atmospheric air of the present day does not contain less oxygen than that which is found in jars buried for 1S00 years in the ruins of Pompeii. From all this it is inferable that there is a universal cause in oper- ation, by which the carbonic acid of the air is consumed, and oxygen supplied; and, from the various well-known, and indispensable uses Df the vegetable kingdom to the animal, which declare its creation for the benefit of the latter, and, therefore, its antecedent or simultaneous creation, we should naturally be prompted, by analogy, to look to this subordinate provision as the universal source through which the great purposes of respiration are maintained unimpaired. Chemistry has here elegantly illustrated this great element in the final causes of the vegetable kingdom, and the contingent aid which it derives from the animal; while it enlarges our view of the vast conceptions of Unity of Design. 303^. It is also worth our while to observe of these important laws, as we go along, how they are perverted by the ignorant in physiolo- gy, and how incapable the chemist is constantly proving himself of " pursuing his reasoning," as said of him by Hunter, " even beyond the simple experiment itself." Vegetables, as we have seen, are composed mainly of carbon, oxy- gen, hydrogen, and nitrogen (§ 37, 303). The carbonic acid of the air (as well as of the soil) is absorbed by plants, and appropriated to their nourishment and growth. This gaseous substance, therefore, is decomposed by vegetable organization, the carbon vivified and ap- propriated, and a part of the oxygen thrown off to replenish the at- mosphere. It is incorrectly said, however, by Liebig, that " the at- mosphere must receive by this process a volume of oxygen for every volume of carbonic acid which has been decomposed." It may be meant, however, that an equivalent or atom of oxygen for every equiv- alent of carbon is given off to the atmosphere; but even this construc- tion is invalidated by the multiplicity of sources from Avhich plants are, supplied with that important element. But enough is known to ren- der it certain that a large proportion of the oxygen of carbonic acid is retained by plants and combined under a new form along with the car- bon and other elements. Liebig's hypothesis of capillary attraction led him, not improbably, to overlook the fact that the water which is absorbed by plants is actually decompounded, and its elements com- bined with others according to the laws which determine organic com- pounds. It is water, indeed, Avhich yields, far more than ammonia, the hydrogen which abounds in plants (§ 303, b). Water, therefore, being composed of oxygen and hydrogen, furnishes a source of the supply of that oxygen which goes to the increase of vegetables ; and, for aught that can be said to the contrary, it may form a part of what is evolved into the air. PHYSIOLOGY.--FUNCTIONS. 139 We have seen, also, that plants derive a part of their oxygen from mineral compounds appertaining to the earth, and probably by means of the roots from the atmospheric air which is held in solution by water, when the gas may be thus appropriated, notwithstanding its. elementary condition in the latter case. Although, doubtless, more or less carbonic acid is reproduced in the leaves and escapes at night along with the va- por exhaled, the probabilities are against the supposition that a propor- tion is also then generated and emitted by plants in a manner analogous to the respiration of animals, and having for its object, in part, the separation of carbon from some of the vegetable constituents. 303f. But let us come to philosophy:— " At night," says Liebig, " a true chemical process commences, in consequence of the action of the oxygen of the air upon the sub- stances composing the leaves, blossoms, and fruit. This process is not at all connected with the life of the vegetable organism, because it goes on in the dead plant exactly as in a living one" ! Here, in the first place, is an important fallacy in the premises from which the induction is made; since the processes have not the least analogy in the living and dead plant. In the former, the oxygen is taken into the organization, and goes to form organic compounds. In the dead plant, it is an agent of chemical decomposition, by which the organic compounds are destroyed, and the structure broken up. Noav we shall always find that authors who reason in the foregoing manner perpetually contradict themselves. In the case before us, a contradiction necessarily arises from the fundamental differences be- tween the processes of organic and inorganic beings, and the laws by which they are governed. A little farther on from the quotation I have just made, Liebig affirms that " the laws of life cannot be investi- gated in an organized being which is diseased or dying." Here, then, is a contradictory opinion, which inculcates as great an error in physi- ology as that of identifying the effects of oxygen on " living beings" and on such as are actually dead. Here is an absolute denial of any analogies between the laws which govern living " diseased beings" and the "laws of life." But, this declaration of the chemist, devoid of truth as it is, is universally applicable where he would be least disposed to see it operate. Such an application, too, is an irresistible sequitur ; since, if " the laws of life cannot be investigated in an organ- ized being which is diseased or /lying," it certainly follows that the laws which relate to dead, or inorganic beings, and the forces upon which those laws depend, can have no agency in living beings. Such, however, is the material which is now-a-days denominated " experimental philosophy," and " the progress of medical science." And, if the reader will now turn to the parallel columns (§ 350), ho will see yet other contradictions directly relative to the foregoing quotation (§ 1052, 1053). But, it may, perhaps, be well enough, before dismissing this sub- ject, to say, that, although " the laws of life cannot be investigated in an organized being which is dying," the laws which govern diseased actions and their results are only slightly modified " laws of life," and often reflect great light upon their strictly healthy condition. We are, or should be, constantly reasoning in this manner in all cases of disease; and it is only by comparisons of the modifications, which constitute disease, with the natural conditions of life, that we can have 140 INSTITUTES OF MEDICINE. any just knowledge of diseases. In proportion, however, as the indi- vidual approximates a state of death all this reasoning fails; and, when actually dead, no such comparisons can be instituted. Here, then, it is that the foregoing admission of the chemist applies with all the force of truth (§ 639 a). 304. The greater complexity of the organs of assimilation in ani- mal life gives rise to a variety of subordinate functions in animals not found in plants; such, for example, as digestion by the gastric juice, saliva, bile, &c.; then a farther advancement of the process in the lacteals, in the blood-vessels, in the lungs, &c. Some of these subor- dinate functions, however, have their analogies in plants ; such as the action of the sap-vessels upon the circulating fluid, the imbibiticn and exhalation of gaseous substances by the leaves, &c. But, in all the cases, the extreme vessels which perform the office of nutrition are the main instruments of organic life. All the functions which are carried on by compound structures are subsidiary only to that of the nutritive vessels (§ 171). 305. The organs of assimilation in animals are more or less com- plex according to the nature of the food. Probably every animal has a stomach, or some analogous organ, and a mouth, and anus, which would form, as supposed by Aristotle, a fundamental distinc- tion between plants and animals (§ 11). The analogies which are supplied by the higher orders of animals would prompt this conclu- sion in respect to the most inferior, or some equivalent arrangement. 306. In vertebrated animals the stomach is generally an expand- ed portion only of the intestinal canal. In fishes the intestine is commonly short; but this is often compensated by folds in the mu- cous membrane. In birds there is a complexity of the alimentary organs which does not exist in fishes, amphibia, or reptiles. In mam- malia the digestive organization is still different; and here it is more remarkably various according to the nature of the food, and as the necessity of supplies may be felt at short or at longer intervals. The more, also, the phenomena of animal life are multiplied the greatei is the development of the digestive system (§ 107, 251, 353). Its complex nature has an intimate relation to the qualities of the food, and these relations have an affinity with that principle of instinct which directs animals in the selection of food. The more dense and tough the food, and the more removed from the nature of the body which it is destined to nourish, the more complex are the organs of* digestion. And so, on the contrary, the softer the food, and the more it is like the animal in its composition, the more simple are the assim- ilating organs. Animals, therefore, which live on hay have these or- gans much more complex than such as are nourished by animal food ; especially that part of the organization which is destined to make the first and greatest change. 307. The principal agent in the assimilating process, in animals, is the gastric juice; a vital organic fluid, which is secreted by the inter- nal coat of the stomach (§ 135 a, 316, 419, 827 b). This secretion is especially promoted by the stimulus of food, which is dissolved and altered in its elementary constitution by the vital influences of the juice. This is the first and greatest step in the process of assimilation. It is here that dead matter receives its first impressions from the prop- erties vivification and A'ital affinity (§ 216, 218). The chemists tell us PHYSIOLOGY.--FUNCTIONS. 141 that the process is a chemical one; and that, notwithstanding the va- rious, and unique, and astonishing devices of nature for the elaboration of the gastric juice, they would persuade physiologists into the belief that many different processes of the laboratory will generate a gastric juice Avith all the unique properties that appertain to the fluid as elab- orated from the blood by^the various modifications of organization which were instituted by Almighty Power for these specific objects. And having been thus regardless of the most sublime and profound institutions of that Power, they proceed to assume that the product of these artificial compounds, in their action upon food, is the homoge- neous chyme of living nature, and Avhich is apparently the same in all animals, whatever the kind or the variety of food. But the chemist is met at the very threshold by the fact, that there is nothing in or- ganic nature itself that can elaborate that fluid from the blood but that particular part of the great system of mucous membranes which forms a component part of the stomach (§ 135, a).—Notes N R. 308. The foregoing relates to complex animals; but analogy, as well as observation, renders it evident that the inferior races possess an or- ganization which is equivalent to the stomach (§ 251). 309. In most animals that consume food of a solid nature, there are preparatory organs which assist mechanically, by dividing the food. The construction of these organs of mastication, both as to their osse- ous and muscular parts, has a strict reference to the kind of food upon which the animal is destined to subsist. Animals of prey are furnish- ed with organs for the destruction of life and organization; since no substance which possesses life can undergo digestion, and all solids must be divided to admit of a free access of the gastric juice and saliva. 310. The organs of mastication are more various than any other parts; yet so uniform in each species, so allied among numerous spe- cies, that naturalists have taken these characters not only as signifi- cant of the species, but as the foundation of a systematic distribution of the species into genera, and of genera into orders. 311. Where the usual organs of mastication are deficient in ani- mals, the species is often supplied with means in the stomach itself for reducing the aliment to a soft substance, so that it may be pene- trated by the gastric juice. The stomach of the armadillo, which sub- sists on insects, and of the granivorous birds, is endowed with a pow- erful muscle -for crushing, or grinding the food. The stomachs of other animals are armed with bony or horny parts, as in many insects 312. The food is moved about in the stomach by the muscular ac- tion of the organ; but so peculiar and exquisite is the modification of irritability of the pyloric orifice, the food is not permitted to pass this outlet till it is converted into chyme (§ 278). Much of the aque- ous portion, however, is early and rapidly absorbed by the stomach. 313. When, however, as we have seen, the irritability of the pylo- rus is artificially modified, as in disease, it will often allow undigested food to pass, more or less readily, into the duodenum (§ 278). But it is more remarkable that it will suffer many hard, indigestible sub- stances to escape, while it detains such as are most congenial to its nature. The passage of indigestible substances is effected gradually by repeatedly presenting themselves at the pylorus, and thus so habit- uating the irritability of that orifice to their own irritant effects, but not to those of digestible food, that they are alloAved to pass, while 142 INSTITUTES OF MEDICINE. the latter is detained; the stomach thus electing what is most conge- nial to its nature and to the wants of life (§ 188, &c, 539 a, 543, 551). 314. The saliva, bile, and pancreatic juice are auxiliary to the gas- tric juice, though how far is considered problematical. The liver is found, under a great variety of forms, in all animals whose structure can be made the subject of ocular demonstration, and it is known to generate bile in all instances. The pancreas and salivary glands oc- cur in all the mammifera, birds, and reptiles, and in many fishes, mol- lusca, and insects. From the general occurrence, therefore, of the foregoing organs, it cannot be doubted, independently of the more direct facts, that the fluids which they secrete have an important vital agency in the pro- cess of assimilation. 315. Animals which live on vegetables have larger salivary glands than such as feed on animal substances ; and, since vegetables require greater assimilating means than animal food, it is a just inference from final causes that the saliva answers a far more important object than, as is commonly imputed to it, of moistening the food and facili- tating its passage to the stomach. On the other hand, however, it has been with still less reason imagined by others that it contributes more than the gastric juice to the conversion of food into chyme. But here, as on all speculative questions, some distinguished chemists re- fer the agency of the saliva in the process of digestion to the atmo- spheric air it conveys to the stomach, while others of equal renown attribute this high office to its own specific virtues. 316. The bile and pancreatic juice mingle with the chyme in the upper part of the duodenum, where it is probable that the latter fluid contributes an assimilating influence analogous to that of the saliva; while the disappearance of some of the components of the bile, and other relative facts, show a direct connection of this fluid with the process of assimilation. The bile also separates the excrementitious from the nutritious part of the chyme; the former portion occupying the centre of the canal, and the latter the parietes (417, b). Connected with these important uses of the bile is its well-known function of maintaining peristaltic action. Such, therefore, being its great final causes, we may safely reject the hypothesis of the mechan- ical theorists, that the liver, like the lungs, is designed to depurate the blood. The injury consequent on the failure of the liver, by ex- periment or otherwise, to perform its function, no more proves its supposed depurating office than a like contingency befalling the stom- ach would place that organ in the same category.—See § 1031-1033. 317. The intestinal tube, like the roots of plants, is supplied with absorbing vessels, which are called lacteals in animals of complex or- ganization. The nutritive part of the chyme is taken up by these vessels, where it undergoes a farther assimilation, and receives the name of chyle. Nothing is absorbed by the lacteals which is offensive to their exquisitely modified irritability, excepting under the circumstances already set forth (§ 278). 318. In the higher animals the chyle is transmitted by the lacteals to the thoracic duct, and by this vessel to the left subclavian vein, where it mingles with the general mass of blood. Thence it passes to the right cavities of the heart to be sent to the lungs, where it re- PHYSIOLOGY.--FUNCTIONS. 143 ceives another important impress of vivification, parts, for the first time, with a portion of its carbonaceous matter, and undergoes a de- velopment of its coloring principle. From the lungs, it passes with the old blood, with which it is now fully incorporated, to the left cav- ities of the heart, to be transmitted to all parts of the body to under- go the last act of assimilation. 319. Assimilation advances progressively from the first conversion of food into chyme till the nutritive matter becomes vitally united with the solid parts. At each step of the process, in the stomach, in the duodenum, through the lacteals, in the lungs, and at its final des- tination, the degree and kind of assimilation is forever the same, at' each of its stages, in every species of organic beings ; thus denoting specific powers and laws by which all this unvarying exactness is maintained (§ 42). Assimilation is more simple in animals low in the scale of organi zation ; but close analogies prevail throughout: 320. The chyle is found to exhibit globules under the microscope, of which some are reddish. It is said, also, that they have been seen in the chyme ; but Miiller thinks that impossible, as the lacteals, accord- ing to him, have no open orifices, and, therefore, the globules could not be admitted through the " invisible pores" of the closed lacteals. These vessels, however, have open terminations by the villi of the in- testines (§ 275, 1089). These questions as to the existence and shape of the globules of blood, chyle, milk, &c, are of very little practical importance and are apt to lead to much waste of time, and encumber medicine with specu- lation and false doctrine; while the instrument, through the aid of Avhich the imagination is thus sent upon its airy flight, is also the im. bodyment of a thousand falsehoods in the path of truth (§ 131, 251). 321. Since, however, no one doubts that the nutritive part of the chyme undergoes a very positive change in the lacteals (§ 320), and a higher degree of assimilation, the proof is the same here, as in absorp- tion by plants, that the fluid is not taken up and carried forward by capillary attraction (§ 289-291). 322. Looking back upon the variety of parts which are concerned in the work of assimilation; their exact adaptation to each other; their peculiarities in different species of animals according to the na- ture of their food—varying, indeed, more or less in every species, yet always alike in all individuals of the same species; the prevalence of four specific digestive fluids, and each of these analogous in all an- imals, notwithstanding the variety in the structure of the secreting or- gans, yet only generated, respectively, by one special part, their pro- duction in unusual quantities, especially of the gastric juice, to meet the exigencies of digestion; the apparently exact similarity in the composition of the chyme of all animals, whatever the nature and the variety of the food; it appears to be one of the highest absurdities to suppose that all this complexity of parts, all this magnificence and variety in Design, should be merely intended to subserve a chemical reduction of food in the stomach, especially, too, as all that is known of chemistry is in conflict with every part of this stupendous whole. And when we pursue the other steps through which the great end of digestion is attained, and steadily regard each individual part forever giving rise to certain unvarying results, each part in its anatomical 144 INSTITUTES OF MEDICINE. and vital relations to all the rest, the necessity of every part to every step in the process of assimilation, the necessity of the whole to every secreted solid and fluid, the derivation of the whole unique and for- ever exact variety (millions upon millions, § 41-46) from four ele- ments mainly, out of a homogeneous fluid which embraces yet fourteen other elements, the necessary co-operation of many of the secreted fluids toward their own formation individually, and toward every for- mation in the complex animal—when, I say, we duly consider this labyrinth of complexities, moving on in one unvarying round of har- monious action and results, moved by a power within which has no "known analogy in the world where chemical results obtain, we may reconcile unbelief in all this Design with a yet higher order of infi- delity, but certainly not with the ordinary promptings of reason, 01 with the plainest rules of evidence (§ 638). But, let us analyze, in another section, the great plan of nature for the maintenance of organic life in animals. 323. Let us analyze, after the manner of Cuvier, the constitution of animals in respect to the subserviency of the various parts of the fabric to the single function of digestion, and according to the nature of each species of animal; and when we shall have reflected upon the principles which determine the coincidences, and see that no one of them can be explained by any of the forces and laws of the inor- ganic world, let us cast from us, as unworthy a thoughtful mind, the supposition that the final act, or that of digestion, is a chemical pro- cess ; and let us also apply the same induction to every other process of living beings. ' " Every organized being," says Cuvier, " forms a whole, a unique, and perfect system, the parts of which mutually correspond, and con cur in the same definite action by a reciprocal reaction. None ol those parts can change without the whole changing; and, consequent ly, each of them, separately considered, points out and marks all the others. Thus, if the intestines of an animal are so organized as only to digest flesh, and that fresh, it follows that the jaws of the animal must be constructed to devour prey, its claws to seize and tear it, its teeth to eat and divide it, the whole structure of the organs of motion such as to pursue and catch it, its perceptive organs to discern it at a distance. Nature must have even placed in its brain the necessary instinct to know how to conceal itself and lay snares for its victims. That the jaw may be enabled to seize, it must have a certain-shaped prominence for the articulation, a certain relation between the posi- tion of the resisting power and that of the strength employed with the fulcrum; a certain volume in the temporal muscle, requiring an equiv- alent extent in the hollow which receives it, and a certain convexity of the zygomatic arch under Avhich it passes. This zygomatic arch must also possess a certain strength to give strength to the masseter muscle. That an animal may carry off its prey, a certain strength is requisite in the muscles which raise the head; whence results a de- terminate formation in the vertebrae and muscles attached, and in the occiput where the muscles are inserted. That the teeth may cut the flesh, they must be sharp, and they must be so more or less according as they will have more or less exclusively flesh to cut. Their roots should be more or less solid, as they have more and larger bones to nreak. All these circumstances will, in like manner, influence the de- PHYSIOLOGY.--FUNCTIONS. I45 velopment of all those parts which serve to move the jaw. That the claws may seize the prey, they must have a certain mobility in the talons, a certain strength in the nails; whence will result determinate formations in all the claws, and the necessary distribution of muscles and tendons. It will be necessary that the forearm have a certain facility in turning, whence, again, will result certain determinate for- mations of the bones which compose it. But, the bone of the fore- arm, articulating in the shoulder-joint, cannot change its structure without this also changes." Again, observe what may be inferred from some other given part, as from the shape of the bones : " The formation of the teeth bespeaks that of the jaw; that of the scapula that of the claws; just as the equa- tion of a curve involves all its properties. So the claw, the scapula, the articulation of the jaw, the thigh-bone, and all the other bones separately considered, require the certain tooth, or the tooth requires them, reciprocally; and, taking any one of them, isolated from the skel- eton of an unknown animal, he who possesses a knowledge of the laws of organic economy, could expound every other part of the animal. Take the hoof, for example. We see, very plainly, that hoofed ani- mals must all be herbivorous, since they have no means of seizing upon prey. We see, also, that having no other use for their fore- feet than to support their bodies, they have no occasion for a power- fully-framed shoulder; whence we infer, what is the case, the absence of the clavicle and acromion, and the straightness of the scapula. Not having any occasion to turn their fore-legs, their radius will be solidly united to the ulna, or, at least, articulated by a hinge-joint, and not by ball and socket, with the humerus. Their herbivorous diet will require teeth with a broad surface to crush seeds and herbs. This breadth must be irregular, and for this reason the enamel parts must alternate with the osseous parts. This sort of surface compelling hor- izontal motion for grinding the food to pieces, the articulation of the jaw cannot form a hinge so close as in carnivorous animals. It must be flattened, and correspond with the facing of the temporal bones. The temporal cavity, which will only contain a very small muscle, will be small and shallow," &c. (§ 169,/). 324. An intestine, claw, tooth, hoof, or other bone, therefore, of an unknown animal being given, we may construct a skeleton that shall be nearly true to nature in all its parts. We may then proceed to cover it with muscles; and, lastly, we can tell from that tusk, or claw, or hoof, or other bone, what was the structure of the digestive appa- ratus, and to what kind of food the gastric juice was specifically adapt- ed, and what were the peculiar instinct and habits of the animal,—so special is the adaptation of all other parts of the organization, both in animal and organic life, and all the habits and instincts of animals, to the peculiarities of the digestive organs in every species (§ 18). 325. Now the whole of the foregoing mutual concurrence of all parts of the body, the adaptation of each part to the others in structure and use, being directly designed to subserve the purposes of diges- tion, and since it cannot be seriously entertained that any physical or chemical force is concerned in such a labyrinth of harmonious struc- ture and actions, and so distinguished throughout by a multitude of the most consummate Designs, and all conspiring to one common end, it is manifestly absurd to imagine that digestion, the final caute of the 146 INSTITUTES OF MEDICINE. whole, is carried on by agencies which have no connection with the va- rious subordinate means (§' 14, 74, 80, 117, 129 i, 133-137, 143, 155, 156, 169/ 266, 3031 a, 306, 318, 336, 387, 399, 422, 514 h, 524 d, 525, 526 d, 528 c, 638, 649 d, 733 b, 764 b, 811, 847 c, 848, 902/ 905). 326. What we have now seen of fundamental Design in'the con- struction and subservience of all parts to the function of assimilation, and of the exact concurrence of the whole toward the incipient step, may well prepare the mind to realize the same Design throughout the whole system of organic processes, the same exact foundation in an- atomical structure, and in vital properties, the same precise and ever- lasting laws (§ 169,/). Do we look again, therefore, at the stupen- dous fabric upon which, and its special vital endowments, the laws of sympathy depend 1 Astonishment abates, and unbelief yields as well to the force of analogy as to direct demonstration. 327. The philosophy of assimilation applied pathologically, and in conformity with the doctrines of solidism, is the following : The func- tion of assimilation, being performed by the organic properties through their media of action, there will be a corresponding change in the elementary combination of the new compounds which are added to the parts affected, and the same morbid condition of the A7ital proper- ties will be imparted to the new compounds. 328. If the stomach be diseased, then the nature of the gastric juice will be altered according to the manner in which the properties of the stomach may be affected. If, also, we allow, in this case, that the chyme will have a corresponding variation, and-that this will in itself affect the whole character of the circulating mass of blood, so that the new elementary combinations, those of the solids and secreted fluids, will be more or less modified in all parts, we shall in no respect com- promit the consistency of nature, or the fundamental principles of physiology (§ 44, 52, 78, 153-155, 218-220). However such admis- sion may look like humoralism, it has no affinity with it. The whole process resolves itself into a primary disease of the solids j and the modified condition of the blood, which I am now supposing, does not derange the vital properties and actions of the system (§ 156 b, 845, &c). But when chylification is affected by diseased states of the stomach, reflex nervous actions are then so exerted by that organ upon other parts, that their vital states do actually sustain a change, and often a far greater one, from that sympathetic cause. This more gen- eral modified condition of the solids contributes still farther to modify the new combinations, and to give rise to what are called vitiated se- cretions. The most striking examples are seen, of course, when di- gestion fails altogether, and the solids become universally affected by disease, as in fever (§ 143 c, 148, 657 b, 776, &c). 329. If the heart and vascular system at large feel, mainly, the in- fluence of gastric or some other local disease, the blood is always more or less affected in its composition, and assimilation is otherwise va- riously modified in all other parts, not only in consequence of the change in the blood, but of the affection of all the organs and fluids which are concerned in assimilation. Nothing affects the composition of the blood so rapidly as disturbances of the vital conditions of the heart and blood-vessels; or, perhaps, I should rather say of the ex- treme capillary blood-vessels. Nothing can prove more distinctly the truth of solidism and the fallacies of humoralism; especially those PHYSIOLOGY.--FUNCTIONS. 147 more instantaneous changes which are effected in the entire circula- ting mass of blood by abstracting only an ounce of it from the arm (§ 845, &c, 952). 330. Now, suppose, instead of treating disease upon some broad principles, we were to undertake the specific object of the humoralists in any of the foregoing cases (§ 327-329); that is to say, the resto- ration of the blood in its composition and nature. The humoral pa- thologist would attempt its direct medication, in the vain hope that his drugs can produce, by their direct action upon the fluid, that natural combination of its elements, and that natural state of its vital properties, for doing which Nature has provided the whole system of the great vital organs, and many living secretions (§ 845, &c). Since, there- fore, the humoralist has not a physiological principle for his govern- ment, he has departed wholly from nature. The duty of cure thus devolves upon the solidist, Avho proceeds to restore assimilation by re- establishing the natural condition of the various tissues and organs whose functions had become deranged and had been the cause of the altered condition of the blood; and this is effected according to the manner set forth in my chapter on the modus operandi of remedial agents. There, too, you shall find, as well as in my disquisitions upon the philosophy of solidism, that the living solids are the only agents which can possibly effect any salutary changes in the pabulum vita, and, therefore, that when the former are diseased along with the latter, they must take the initiating step both in the morbid and healthy processes. Just in proportion, therefore, as the solidist improves the condition of the diseased organs, assimilation will approximate its natural state, and the blood be regenerated according to established physiological laws.—Note R p. 1123. 331. The condition, therefore, of the blood and of the products elaborated from it, in all cases of disease, should be regarded only as more or less significant of the morbid changes which may affect the solid parts. 332. Having now gone over the general philosophy relative to as- similation, I shall proceed to consider its principal element, or what is denominated THE PHYSIOLOGY OF DIGESTION. In my investigation of this subject I shall enter rather extensively upon the ground of Organic Chemistry, in all its applications to the science of medicine ; since it is here, especially, as said in the Com- mentaries, that chemistry has reared its batteries, and from whence it sends forth its artillery into the various dominions of organic life. A contrast will be instituted under the general designations of Physiol- ogy and Organic Chemistry, in their relation to healthy and morbid processes. 333. The doctrines of life, as hitherto expounded, should be appli- cable to all the problems in organic beings which may seem to a su- perficial observer to fall under the laws of chemistry, or of physics. Such problems are especially presented by digestion, respiratiqs, and the production of organic heat; and these are the main intrenchments of chemistry. If the philosophy, therefore, which I have thus far pro- pounded lie at the foundation of the foregoing results, it is probable that chemistry must be abortive in facts, and wild in conclusions; and 148 INSTITUTES OF MEDICINE. the more so as it advances to the greater obscurities in physiology pathology, and therapeutics. Such are the realities; and their expo- sure is the overthrow and the perpetual doom of organic chemistry. 334. Human physiology has been greatly vitiated, in recent times, by experiments upon animals, and conducted under the most unnat- ural circumstances. They haA-e been extensively made, in a physio- logical aspect, without any view to the differences in organization and vital constitution between animals and man, and often with a ref- erence to more functions than belong to any organic being. When prompted by pathological and therapeutical considerations the ex- periments have been liable not only to the foregoing objections, but to the greater one of assuming that there is no difference in the sus- ceptibility of organs to the action of natural, morbific, and remedial agents in the varying states of health and disease (§ 149, 150, 240). These experimental fallacies, and the vast errors to which they have led and are still leading, I have considered extensively in my Essay on the Humoral Pathology.—See p. 839, § 1058 b, note. In a physiological sense, the greatest evil attending the foregoing experiments consists in neglecting the fact that the constitution of man is different from that of animals when applying the results of such otherwise unnatural experiments to explain the vital laws which gov- ern the functions of the human species. The disparity increases between the natural laws and results of the human and those of vegetable organization, and others, again, of chemical affinities, just in the ratio of the difference between the va- rieties of organization and vital constitution, and the attributes of the inorganic kingdom. 335. What, then, shall be said of those experiments which are con- ducted in the laboratory of the chemist to determine the physiology of the highest function of life, but in which organization takes no part, and the whole process is carried on by artificial " mixtures" and chemical reagents ] This is now the almost universal philosophy, and therefore demands an investigation which shall lead either to its con- firmation or to its overthrow (Rights of Authors, p. 912). 336. It is in the stomach that vitality is exemplified in its most im- pressive and astonishing aspects, and where unequivocal demonstra- tions abound that fluids, as well as solids, are endowed with the prin- ciple of vital operations, " a principle distinct from all other powers of nature" (§ 64, 339). It is here, especially, that nature has illus- trated her distinction between the animate and inanimate world, and established her chain of connection. It is here, in the incipient change of dead into living matter, that we witness a full display of those powers which operate in the most elaborate organization, and an equal exclusion of the forces which appertain to dead matter. It is here the line of separation begins abruptly; but where analogies are pre- sented in the conversion of dead into living matter, through new modes of combining the same elements; and admiration increases, as we mount along the entire function of assimilation, and find, at eachftep of the ascending series, that the whole agency is committed to forces that have no existence in the inorganic world; that the whole is the harmonious result of a principle which may form an interme- diate link betAveen spirit and matter; and that there is no power with- in our control by which we can determine the nature of the changes. PHYSIOLOGY.--ORGANIC CHEMISTRY--FUNCTIONS. 149 Casting a glance at the vegetable world, we find the connection con- tinued, by other analogous links, with elementary matter itself; but here, as in the higher department of nature, the line of separation is equally defined, however low in the scale of analogy may be the prop- erties of life which have their beginning in vegetable organization. It is here, then, at the threshold of life, as in the propagation of the species, that we especially witness a substitution for Creative Power ; and, as all that appertains exclusively to the organic world was per- fectly distinct in its Creation from the inorganic, so are the substituted processes of generation, and of the conversion of dead into living mat- ter, equally distinct from the causes and results of inorganic processes (§ 32, &c, 63, &c). For conducting that connected series of changes which make up the process of assimilation in animals, a complex apparatus has been provided, whose beginning in the vegetable kingdom, and whose pro- gressive development in the higher kingdom, have been contrived upon consummate principles of Design, that the elements of matter shall be gradually brought into those perfectly new conditions, both as to composition and properties, which contradistinguish the organic from the inorganic kingdom, and thus as in all things else in the nat- ural world, that abrupt transmutation of inorganic into organic matter which distinguished the Creative Act shall be avoided, and remain a characteristic of Creative Power (§ 14, 172, 325). 337. In the early part of this work, I set forth some general facts which evince an incongruity of doctrines that clearly divides the physi- ological world into three schools; one of them (pure chemistry) mak- ing no distinction between the properties and laws of organic and in- organic beings; a second (pure vitalism) contradistinguishing the two kingdoms in those fundamental conditions; and the third (chemico- vitalism) blending the doctrines of chemistry and vitalism (§ 4£, 820 c). Each of these denominations has interpreted the philosophy of di- gestion according to the general doctrines of life which are peculiar to each. 338. Beginning with pure chemistry, we find the great leader set- ting forth the process of digestion in the following language in his late work on Animal Chemistry applied to Pathology and Therapeutics " Chymification," he says, " is independent of the vital force. It takes place in virtue of a purely chemical action,—exactly sim- ilar to those processes of decomposition and transformation which are Known as putrefaction, fermentation, or decay" (§ 365). It will be also seen from the foregoing quotation, that the chemist s regardless of his own rules of philosophy, and of the fundamental principles of chemistry; since he identifies the organizing act, or that which combines the elements of matter into complex organic com- pounds, with the chemical process that resolves these compounds into their ultimate elements. We are told, indeed, that this is " experi- mental philosophy," and that, therefore, we must submit to it (§ 350). 339, a. I shall now set forth the exact doctrine of the vitalists rela- tive to the physiology of digestion, in the language of the same dis- tinguished " reformer" whom I have quoted in the preceding section. It is true, the doctrines are as fundamentally opposed as contradiction can possibly make them. But, as will have been abundantly seen, the most remarkable characteristic of the writings of this distinguished 150 INSTITUTES OF MEDICINE. man are their palpable contradictions. Nor can there bt any proof so conclusive of the radical distinction between the philosophy of life and the philosophy of chemistry, about which " the reformer" was simultaneously concerned. But, I will go back for a conflicting doctrine to the treatise "on Organic Chemistry applied to Physiology," published a year or two antecedently to his work " on Animal Chemistry ;" by which we shall learn the extent of the confusion which pervades his writings, and the tardiness with which it is discerned by his medical disciples. In that work he says, " The equilibrium in the chemical attractions of the constituents of food is disturbed by the vital principle. The union of its ele- ments, so as to produce new combinations and forms, indicates the presence of A peculiar mode of attraction, and the existence of k POWER DISTINCT FROM ALL OTHER POWERS OF NATURE, namely, THE vital principle." " If the food possessed life, not merely the chem- ical forces, but this vitality would offer resistance to the vital force of the organism it nourished."—Liebig. Such, then, is exactly the doctrine of the vitalist and solidist, mis- taken by the chemist for his own, when he happened to be reasoning according to the promptings of organic nature. 'The same views are presented in the work on Animal Chemistry (§ 350). 339, b. And here, perhaps, it may be worth our while to say that the resuscitated chemical doctrine (§ 338) is apparently too Avide a de- parture from fact even for that part of the British medical profession who have received most of the sayings of Liebig as oracular revela- tions ; for we read in the late edition of the " Pharmacologia" now devoted to the authorized philosophy (§ 349 d, 676 b), that, " According to the experiments of Spallanzani, and still more re- cently of Dr. Beaumont, if, after putrefaction has actually advanced, a substance in such a condition be introduced into the living stomach, the process is immediately checked, and no signs of putrefaction are presented by the digested food, although were the same substances left at the temperature of 99° F., they would soon evince evidence of its progress. It is therefore clear that the vital poavers of the di- gestive organs must, in such cases, reverse or suspend the ordinary chemical affinities" (§ 676, b).—Paris's Pharmacologia, p. 148. Lon- don, 1843. And such, in reality, is one of Liebig's conflicting state- ments. \ And why should not the " vital powers reverse or suspend the ordi- nary chemical affinities" in all other cases of food, where it is far more obvious that such*resistance does happen ; and why may we not con- clude that the law in relation to digestion has a wide foundation in liv- ing beings ] Why does not the blood putrefy 1 Why not any other animal or vegetable fluid 1 Why not any living animal or vegetable solid ] 340. Let us now hear the student of organic nature upon the phys- iology of digestion. What says John Hunter, of whom it is said by one, that "he stands alone in our profession;" that, "in his immense career, every thing bore reference to one great idea,—the discovery and elucidation of nature's laws ;" " who," says another, " was neither anatomist, physiologist, surgeon, nor naturalist, alone, but the most rema-kable combination of all these which the Avorld has yet seen;,J PHYSIOLOGY.--ORGANIC chemistry—FUNCTIONS. 151 for, " where," says another, " in the calendar of time, shall we look for an equal in the compass, the variety, and the depth of his researches into the mysteries of animal life, or for consequences such as those that have resulted from his labors to universal pathology;" while an- other apostrophizes, " how humble do any of the men of the present day appear when placed by the side of Hunter!" " The genius of Hunter," says another, " long ago explained the objections to othei theories of digestion. These have been turned into ridicule to smooth the way for hypotheses that have no better foundation." Well may we ask, what says John Hunter on the physiology of di gestion 1 "Digestion," he says, "is an assimilating process. It is a species of generation ; but the curious circumstance is its converting both veg- etable and animal matter into the same kind of substance or com- pound, which no chemical process can effect. Those who took it up chemically, being ignorant of the principles of the animal economy, have erroneously referred the operations of the animal machine to the laws of chemistry." 341. The illustrious George Fordyce, after a thorough experiment al investigation of the subject, comes to the conclusion that, " The changes which take place in the substances capable of giving nourishment, and, therefore, of being converted into the essential parts of the chyle, are totally different from those changes which take place any where but in the stomach, duodenum, and jejunum, when alive. Therefore, no experiment made any where, excepting in these intestines of the living animal, can in the smallest degree influence the doctrine of digestion." "Food placed in all the chemical circum- stances that can be conceived similar to those in which it is placed in the living animal, will neArer be converted into chyme, but will under- go other changes totally different." He finally adds, as the result of his own experiments out of the stomach, that, "whether we employ the gastric juice, or bile, or saliva, in no case has chyle, or any thing like it, ever been produced." The reason is, that the gastric juice, like the blood, loses its vitality as soon as abstracted from the stomach. Hunter arri\-ed at exactly the same conclusion from his observations (§364)^ _ 342. It is the opinion of Tiedemann, another distinguished inquirer into the nature of digestion (§ 340, 341), that, "All the phenomena of digestion and assimilation, and which are only observed in living bodies, appear to rest, as to their foundation, on the vital property which organized liquids possess of producing, under certain circumstances, in other organic matters, similar changes that cause these bodies to acquire the properties themselves are en- dowed withal." Again: " It cannot be mistaken that digestion is an operation exclusively the property of living bodies, and is in no way to be compared with the changes of composition which general physical forces and the play of chemical are capable of producing in inorganic matters. It must be considered as a vital act, as an effect of life." As to assimilation by vegetables, Tiedemann holds the same doc- trine as Hunter, Fordyce, and all other physiologists whose opinions have survived the day on which they were promulgated. Thus : " On the subject of the material changes which vegetable parts un- 152 INSTITUTES OF MEDICINE. dergo in nutrition, chemistry has hitherto given us no satisfactory in- formation, simply because, being effects of life, such changes arc beyond the domain of chemical science. All that we are authorized to admit is, that the changes of composition that occur during the nutrition of vegetables are the consequence of vital manifestations of activity, and not the effects of chemical affinities, such as are observed in inorganic bodies." "All the attempts," he goes on, " of the iatro-mechanicians and ia- tro-chemists to reach this point (assimilation) have failed; and it is well ascertained that such ideas are both unsatisfactory and erroneous. We are therefore under the necessity of regarding them as effects, sui generis, as vital manifestations, founded on a power peculiar to, and inherent in, organic bodies."—Tiedemann's Physiology. 343. Turning to the greatest of French physiologists, we hear^om him the same general protest against the corruption of medicine by ingrafting upon it the physical sciences (§ 5\, b). 344. In considering farther the physiology of digestion, I shall in- troduce, in the first place, a series of general conclusions which have been derived from chemistry, both as to digestion and other organic processes, and when in this respect and otherwise prepared, I shall state the remaining grounds upon which I rely more specifically for establishing the vital doctrine. 345. Let us hear, then, the distinguished chemist, Dr. Prout, as the representative of those who mingle chemistry with vitalism. "First," says Dr. Prout, "the stomach has the power of dissolving alimentary substances, or, at least, of bringing them to a semi-fluid state. This operation seems to be altogether chemical. " 2d. The stomach has, within certain limits, the power of changing into one another the simple alimentary principles," and "this part of the operation of the stomach appears, like the reducing process, to be chemical; but not so easy of accomplishment. It may be termed the converting operation of the stomach. " 3d. The stomach must have, within certain limits, the power of organizing and vitalizing the different alimentary substances." " It is impossible to imagine that this organizing agency of the stomach can be chemical. Its agency is vital, and its nature completely unknown." 346. Such, then, is the doctrine of digestion as entertained by the chemico-vitalist (§ 345). But, from what we shall have seen of the absolute contradictions which abound in the writings of those who at- tempt the application of pure chemistry to the functions and results of organic life, we may expect that the chemico-vitalist will be equally inconsistent when he applies himself, at one time, to the phenomena of living beings, and, at another, reasons from the results of the labor- atory to those phenomena. Accordingly, we find within a few pa°-es of the foregoing doctrine of the chemico-physiologist, that he broadly affirms that " There is no relation avhatever between the mechanical ar- rangements and the chemical properties to which they administer," " There is no reason why the chemical changes of organization should result from the mechanical arrangements by which they are accom- plished; neither is there the slightest reason, why the mechanical arrangements in the formation of organized beings should lead to the chemical changes of which they are the instruments" ! PHYSIOLOGY.--ORGANIC CHEMISTRY—FUNCTIONS. 153 Here, then, in a single sentence, are not only the strangest contra- dictions, but a full admission that there is not the " slightest reason" for the application of chemistry to any process, function, or result of living beings. 347. Nor is that all. For the chemico-vitalist, the same eminent chemist whom I have just quoted, goes on to say, that " with the liv- ing, the animative properties of organic bodies, chemistry has not the smallest alliance, and probably will never, in any degree, elucidate those properties. The phenomena of life are not even remotely anal- ogous to any thing we know in chemistry as exhibited among inorganic agents." And, as if to complete the overthrow of the chemical part of the philosophy of digestion, the same reasoner observes that, " the means by Avhich the peculiarities of composition and structure are produced, which is so remarkable in all organic substances, like the results themselves, are quite peculiar, and bear little or no resem- blance to any artificial process of chemistry ;" that "those who have attempted to apply chemistry to physiology and pathology have split on a fatal rock by hastily assuming that what they found by experi- ment to be wanting, or otherwise changed, in the animal economy, Avas the cause of particular diseases, and that such diseases were to be cured by supplying, and adjusting artificially, the principle in error. But the scientific physician will soon discover that Nature will not al- low him to officiate as her journeyman, even in the most trifling de- gree"—Dr. Proct's Bridgewater Treatise. 348. And, to the same effect may be quoted Dr. Carpenter, one of the foremost, as we have seen, in the school of pure chemistry (§ 64, g-). " The agency of vitality," says this reasoner, in his Comparative Physiology, Avhere he generally ridicules the term and all that is rela- tive to it, " the agency of vitality, as Dr. Prout justly remarks, does not change the properties of the elements, but simply combines the elements in modes which we cannot imitate" ! So, also, Dr. Roget, alike distinguished in the school of chemico- vitalism (§ 64,/) : "Vital chemistry" he says," is too subtle a poaver for human science to detect, or for human art to imitate." And thus the eminent Wagner, not less arrayed on the side of chemistry: " The existence of one or more powers, commonly called vital powers, is not, however, denied. The final cause of the secretion of the gastric juice lies in the nature of the animal organism, and is unknown to us."—Wagner's Physiology, London, 1842, p. 346. And yet this distinguished observer is one of the manufacturers of gas- tric juice. 349, a. Thus might I go on with one after another, till I should have exhausted the whole that have attempted to confound the science of life with the science of chemistry, and prove by their own state- ments that there is not the slightest intelligible connection between them. Indeed, I have already, in the Medical and Physiological Commentaries, pointed out this universal admission (§ 626 b). The ground of chemistry being thus virtually abandoned to the vi- talist, it would seem superfluous to pursue an adversary who is al- ways upon the retreat. But, as he flies, he is forever shooting from behind, and his Parthian weapons fall thickly and heavily upon the vast multitude. He must therefore be subdued into a practical acqui- 154 INSTITUTES of medicine. escence Avith those consistent principles of nature which exact his com sent, but not his compliance. 349, b. Perhaps no author has supplied so many examples of con- tradictions in great fundamental principles, and in so small a compass, as he who has so lately taken captive the physiological world. In the Preface to the Essays " On the Philosophy of Vitality and the Modus Operandi of Remedial Agents" I had occasion to say of the article on " Poisons, Contagions, and Miasma," in Liebig's " Organic Chemistry applied to Agriculture and Physiology," that " it is certainly the most stupendous exhibition of perverted facts, of combinations of conflict- ing doctrines, and of the rudest system of pathology and therapeutics, that can be found in the records of dreamy speculation." It was objected by the editor of the London Lancet, that I did not prove my allegations (§ 5\, a). Nor was it in any respect the object of that work to do so. I was satisfied with calling attention to the facts, and with what I had already published in the Medical and Phys- iological Commentaries. Since that day, the work on " Animal Chem- istry" has appeared ; and it is now my purpose to sustain the allega- tions of the " Preface," and this more especially from the objections alleged by Liebig against physiologists (§ 350, mottoes, a, b, c, and d). I say, therefore, that we meet on the same page a purely chemical and a purely vital philosophy of digestion; and equally so of other important organic processes. That each is laid down without quali- fication, and with the dictum of a master, who is conscious that the preponderance he gives to the purely chemical philosophy of life will establish his Empire in that philosophy with an age more prone than ever to the doctrines of materialism. 349, c. Let us, therefore, not be deceived; for, however this very extraordinary and successful pretender in medicine may beguile us with words, and seem to persuade rather than to rule, let us remem- ber that, at most, he does but invalidate his own edicts by counter- mands, and that in the end he tells us that these apparently adverse decrees are, in their absolute import, one and the same ; that they are consistent laws delivered from the laboratory, though apparently in conflict on account of the opposing forces, the attraction and repul- sion, which preside in the chemistry of nature; that, however, in re- ality, there is no difference whatever in the seemingly two great prin- ciples which lie at the foundation, which are one and identical, since " the mysterious vital principle can be replaced by the chemical forces ;" and since, also, " the vital force unites in its manifestations all the pe- culiarities of the chemical forces, and of the no less wonderful cause which we regard as the ultimate origin of electrical phenomena." And again, " in the processes of nutrition and reproduction, the ultimate cause of the different conditions of the vital force are chemical forces" (§ 64, e). —Liebig's Organic Chemistry ; and Animal Chemistry. 349, d. It is painful to speak thus of one so highly endowed, so devoted in mind, so accomplished in chemistry; but science and hu- manity demand the sacrifice. But, again, I wish to be understood, that neither here, nor in any other case, is it the individual of whom I speak, but of his doctrines alone (§ 1 b, 4 b). Nor yet would the doctrines of an individual become the subject of extended remark, did they not represent the existing state of the three high branches of medicine. The gigantic physical school had too much of the Pro- PHAS10LOGY.--ORGANIC CHEMISTRY--FUNCTIONS. 155 tean character, too little unity of purpose, and demanded greater sta- bility. The learned men of a great Nation, The British Associa- tion for the Advancement of Science, united in the object, and be- Btowed the honor of achieving the enterprise upon a foreign Chemist. The note of proscription has been sounded in high quarters, in due conformity (§ 5\ a, 350| kk), and medical philosophy has nothing to hope even from a spirit of toleration. The subject, therefore, must be brought to the test of observation and reason, and he who arraigns the authorized doctrines will cheerfully abide an unsuccessful issue (§ 1 b, 676 b, 709, note). I shall therefore dwell upon the conclusions of those who have engendered the corruptions, and shall array them in all the force demanded by the magnitude of my subject, that we may the better realize the shallowness of that pretended philosophy which has so lately swept, like a hurricane, over the intellectual world, that we may see, in the system of contradictions, the equal fallacy of that school who endeavor, with great sincerity, to mingle the conflict- ing principles, and that we may the better cultivate and enjoy the simple and consistent philosophy which nature teaches. Nor will I yet leave this general reference to that stupendous system of assump- tion and contradiction which was so lately hailed by physiologists as the harbinger of a total revolution in medical science, ay, in the very practice of medicine, without showing you the depth of the material- ism in which it was founded. I say nothing now of the avowed infidelity to Avhich it has led. Examples of that disregard of instinct- ive faith I have already placed in their proper connection with my subject.* But, I will merely present, in relief, from Liebig's revolu- tionary work, a doctrine of the chemical school, from which, if I mis- take not the ambition of intellectual and immortal beings, the very impulse of nature will turn the most indifferent with a loathing aver- sion. We shall see from it, also, how entirely degraded to the rank of the merest matter is every thing relating to organic life ; even man himself. Thus, then, " the Reformer," in behalf of the school of chemistry: 349, e. " Physiology has sufficiently decisive grounds for the opin- ion that every motion, every manifestation of force, is the result Of a transformation of the structure or of its substance; that every concep- tion, every mental affection, is followed by changes in the chemical nature of the secreted fluids; that every thought, every sensation, is accompanied by a change in the composition of the substance of the brain." " Every manifestation of force is the result of a trans- formation of the structure or of its substance"—See p. 158, no. b\. And now may it not be reasonably asked, what is the cause of those chemical changes in the cerebral substance which give rise to " every conception, every mental affection, every thought, and every sensa- tion" (§ 175 c, 500 n, 1054, 1076 a) those "manifestations of force"? Many organic chemists, however, are disposed to admit a spiritual part, and they should therefore recollect that the existence of a prin- ciple of life is not less substantiated by facts than the existence of the soul, which they are so ready to concede when inviting our attention to the physical doctrines of life. 350. I have just said that I would present such an array of contra- * See Medical and Physiological Commentaries, vol. ii., p. 122-140. Also, the Essay on the Vital Powers, in vol. i. Also Tacitus' Dialogue Concerning Oratory. 156 INSTITUTES OF MEDICINE. dictory opinions on the physiology of digestion, and the general phi- losophy of life and disease, from the two brief National Essays by Liebig (§ 349, b), as should induce physiologists to retrace their steps, and thus make some atonement to the science which was surrendered with an acclamation that had been worthy the original institution of medicine. In the first place, however, with a view to the cause which I advo- cate, and in justice, also, to able and independent philosophers, I shall quote the following remarks from a letter addressed to myself by a distinguished writer, of Manchester (England) : "Manchester, May 5, 1846. " Dear Sir, " I made your pamphlet (a Lecture on Digestion) the subject of a Paper which I read before the Manchester Literary and Philo- sophical Society, and which provoked a discussion two nights. The result was almost unanimously in favor of your views in reference to the Philosophy of Digestion. lam, &c, "Charles Clay, M.D." I shall now exhibit, in parallel columns, the new philosophy which forms the present science of medicine, preceded by some appropriate mottoes. a. "Animal and vegetable physiologists institute experiments without being ac- quainted with the circumstances necessary to the continuance of life—with the qualities and proper nourishment of the animal or plant on which they operate—or with the nature and chemical constitution of its organs. These experiments are considered by them as convincing proofs, while they are fitted only to awaken pity" (no. 50). b. " All discoveries in physics and in chemistry, all explanations of chemists [! ] must remain without fruit and useless, because even to the great leaders in physi- ology, carbonic acid, ammonia, acids, and bases, are sounds without meaning, words without sense, terms of an unknown language, which awaken no thoughts, and no asso- ciations. They treat these sciences like the vulgar, who despise a foreign literature in exact proportion to their ignorance of it."'—Liebig's Organic Chemistry applied to Phys- iology, &c. [See no. 2.]— ($ 1034). c. "None of them (the most distinguished physiologists) had a clear conception of the process of development and nutrition, or of the true cause of death. They professed to explain the most obscure psychological phenomena, and yet they were unable to say what fever is, and in what way quinine acts in curing it" (no. 2. 42). The oft-reiterated conclu- sion folbws, that it is reserved for chemistry to resolve these problems. d. "Thus medicine, after the fashion of the Aristotelian philosophy, has formed certain conceptions in regard to nutrition and sanguification. Articles of diet have been di- vided into nutritious and non-nutritious ; but these theories [! ] being founded on observations destitute of the conditions most essential to the drawing of just conclusions, could not be received as expressions of the truth. How clear are now to us the relations of the different articles of food to the objects which they serve in the body, since organic chemistry has applied to the investigation her quantative method of research" ! (§ 18, 409.) e. "The limited acquaintance of physiologists with the methods of research employed in chemistry will continue to be the chief impediment to the progress of physiology, as well as a reproach which that science cannot escape."—Liebig's Animal Chemistry. f. " AVhat has the soul, what have consciousness and intellect to do with the develop- ment of the human foetus, or the foetus in a fowl's egg ? Not more, surely, than with the development of the seeds of a plant. Let us first endeavor to refer to their ultimate causes those phenomena of life which are not psychological; and let us beware of drawing con- clusions before we have a ground-work. We know exactly the mechanism of the eye; but neither anatomy nor chemistry will ever explain how the rays of light act on conscious ness, so as to produce vision. Natural science has fixed limits which cannot be passed, and it mast always be borne in mind that, with all our discoveries, we shall never know what light, electricity, and magnetism are in their essence, because, even of those things which are material, the human intellect has only conceptions. We can ascertain, how- ever, the laws which regulate their motion and rest, because these are manifested in phe nomena. In lire manner, the laws of vitality, and of all that disturbs, pro motes, or alters vitality, may certainly be discovered, although we shall never leans what life is" (§ 168). — Liebig's Animal Chemistry. PHYSIOLOGY.---ORGANIC CHEMISTRY---FUNCTIONS. 157 g. " For years past a tribunal has been established at Giessen, before which Liebig is at the same time accuser, witness, public prosecutor, advocate, and judge."—Mul- der's Reply to Liebig. Translation, London, 1846. h. " Chemists and natural philosophers, accustomed to study the phenomena over which the physical forces preside, have carried their spirit of calculation into the theories of the vital laws."—Bichat's General Anatomy, vol. ii., p. 54. i. " Let a man be given up to the contemplation of one sort of knowledge, and that will become every thing. The mind will take such a tincture from a familiarity with that ob- iect, that every thing else, how remote soever, will be brought under the same view. A metaphysician will bring ploughing and gardening immediately to abstract notions ; the history of nature will signify nothing to him. A chemist, on the contrary, shall reduce divinity to the maxims of his laboratory, explain morality by sal, sulphur, and mercury and allegorize the Scripture itself, and the sacred mysteries thereof, into the philosopher's stone."—Locke, on the Human Understanding. k. " Mr. Locke, I think, mentions an eminent musician, who believed that God created the world in six days, and rested on the seventh, because there are but seven notes in music. I myself knew one of that profession who thought there were only three parts in harmony, to wit, base, tenor, and treble, because there are but three persons in the Trin- ity."—Reid, on the Powers of the Human Mind, vol. ii., Essay 6, c. viii. I. " When education takes in error as a part of its system, there is no doubt that it will operate with abundant energy, and to an extent indefinite" (J) 433).—Burke. CHEMICAL DOCTRINES. VITAL DOCTRINES. 1. " My object has been, in the 47. " A rational physiology present work, to direct attention to cannot be founded on mere re- the points of intersection of chem- actions, and the living body cannot istry with physiology, and to point be viewed as a chemical labor- out those parts in which the sci- atory." ences become, as it were, mixed " The study of the uses of up together. It contains a collec- the functions of different organs, lion of problems, such as chemis- and of their mutual connection try at present requires to be re- in the animal body, was formerly solved, and a number of conclu- the chief object in physiological sions drawn according to the rules researches; but lately this study of that science. These questions has fallen into the back-ground." and problems will be resolved; —Liebig's Animal Chemistry.— and we cannot doubt that we shall (See motto c.) have in that case a new physiol- 48. " With all its discover- ogy and a rational pathology." ies, Modern Chemistry has per- —Liebig's Animal Chemistry. formed but slender services to 2. " In earlier times, the attempt physiology and pathology."—Lie- has been made, and often with big, ibid. great success, to apply to the ob- 49. " Physiology still endeavors jects of the medical art the views to apply chemical experiments to derived from an acquaintance the removal of diseased conditions; with chemical observations. In- but, with all these countless ex deed, the great physicians, who periments, we are not one step lived toward the end of the 17th nearer to the causes and essence of century, were the founders of disease."—Liebig, ibid. chemistry, and in those days 50. "Mechanical philosophers the only philosophers ac- and chemists justly ascribe to quainted with it."—Liebig's their methods of research the Animal Chemistry. (See mottoes greater part of the success which b, e.) has attended their labors."—Lie- big's Animal Chemistry (a). 3. "In the animal body we rec- 51. "In the animal ovum, aa ognize as the ultimate cause of all well as in the seed of a plant, 158 • INSTITUTES OF MEDICINE. CHEMICAL DOCTRINES. force only one cause, the chemic vl action which the elements of the food and the oxygen of the air mutually exercise on each other. The only known ultimate cause of vital force, either in animals or in plants, is a chemical process. If this be prevented, the phenom- ena OF LIFE DO NOT MANIFEST themselves. If the chemical ac- tion be impeded, the vital phenom- ena must take new forms." " All vital activity arises from the mutual action of the oxygen of the atmosphere and the elements of the food."—Liebig's Animal Chemis- try. 4. " The life of animals exhib- its itself in the continual absorp- tion of the oxygen of the air, and its combination with certain parts of the animal body."—Liebig's Animal Chemistry. 5. " Physiology has sufficiently decisive grounds for the opinion, that EVERY MOTION, EVERY MANI- FESTATION OF FORCE, IS THE RE- SULT OF A TRANSFORMATION OF THE STRUCTURE OR OF ITS SUB- STANCE ; that every conception, ev- ery mental affection, is followed by changes in the chemical nature of the secreted fluids; that every thought, every sensation, is accom- panied by a change in the composi- tion of the substance of the brain"! —Liebig's Animal Chemistry (no. 41.18J). 51. That our Author's intent cannot be doubtful appears from his unequivocal statement that— " The higher phenomena of men- tal existence cannot, in the pres- ent state of science, be referred to their proximate, and still less to their ultimate causes. [Of course, therefore, not to a Soul.~] We only know of them that they exist." Again—"The efforts of philoso- phers, constantly made to pene- trate the relations of the soul to vital doctrines. we recognize a certain remark- able FORCE, THE SOURCE OF growth, or increase in the mass, and of reproduction, or of supply of the matter consumed ; a force in a state of rest. By the ac- tion of external influences, by im- pregnation, by the presence of air and moisture, the condition of static equilibrium of this force is disturbed. Entering into a state of motion or activity, it exhibits itself in the production of a series of forms, which, al- though occasionally bounded by right lines, are yet widely distinct from geometrical forms, such as we observe in crystalized miner- als. This force is called the vi tal force, vis vita?, or vitality." " The increase of mass is effect- ed in living parts by the vital force."—Liebig's Animal Chem- istry. (See my Essays on Vitali- ty, &c, p. 13-18.) 514;. " The oxygen of the at- mosphere is the proper, active, ex- ternal cause of the waste of mat- ter in the animal body. It acts like a force which tends to disturb and destroy the manifestations of the vital force at every moment. But its effect as a chemical agent (in producing waste), the disturb- ance proceeding from it, is held in equilibrium by the vital force."—Liebig's Animal Chem- istry. 52. " The vital force is manifest- ed in the form of resistance, in- asmuch as by its presence in the living tissues their elements acquire the power of withstanding the dis- turbance and change in their form and composition which external agencies tend to produce : a pow- er which, as chemical com- pounds, they do not possess." —Liebig's Animal Chemistry. 53. " The vital principle must be a motive power, capable of physiology.—ORGANIC chemical doctrines. animal life, have all along retard- ed the progress of physiology. In this attempt men have left the province of philosophical research for that of fancy" (p. 182-183, § 350f gy, p. 924-925, § 1085).— Liebig's Animal Chemistry, 6. " In the processes of nutri- tion and reproduction, we per- ceive the passage of matter from the state of motion to that of rest (static equilibrium). Under the in- fluence of the nervous system, this matter enters again into a state of motion. The ultimate causes of these different conditions of the vi- tal force are chemical forces." 7. " The cause of the state of motion is to be found in a series of changes which the food under- goes in the organism, and these are the results of processes of decomposition, to which either the food itself, or the structures formed from it, or parts of organs, are subjected" (§ 1054). 8. " The change of matter, the manifestation of mechanical force, and the absorption of oxygen, are, in the animal body, so closely con- nected with each other, that we may consider the amount of mo- tion and the quantity of living tissue transformed, as propor- tional to the quantity of ox- ygen inspired and consumed in a given time by the animal."—Lie- big's Animal Chemistry (no. 3, 4). 9. " If we employ these well- known facts as means to assist us in investig-atino- the ultimate cause of the mechanical effects in the an- imal organism, observation teaches us that the motion of the blood \ND OF THE OTHER ANIMAL FLU- chemistry—functions. 159 vital doctrines. imparting motion to atoms at rest, and of opposing resistance to other forces producing mo- tion, such as THE chemical force, heat and electricity."—Liebig's Lectures for 1844. " Every thing in the organism goes on under the influence of the VITAL FORCE, AN IMMATERIAL agent, which the chemist cannot employ at will."—Liebig's Ani- mal Chemistry. 54. " There is nothing to pre- vent us from considering the vital force as a peculiar property, which is possessed by certain ma- terial bodies, and becomes sensi- ble when their elementary parti- cles are combined in a certain ar- rangement or form. This suppo- sition takes from the vital phenom- ena nothing of their wonderful pe- culiarity. It may, therefore, be considered as a resting point from which an investigation into these phenomena, and the laws which regulate them, may be com menced; exactly as we considei the properties and laws of light to be dependent on a certain lu- miniferous matter or ether, which has no farther connection with the laws ascertained by investigation." —Liebig's Animal Chemistry. 55. " Every thing in the ani- mal organism, to which the name of motion can be applied, pro- ceeds from the nervous appara- tus." " In animals we recognize in the nervous apparatus a source of power capable of renewing itself at every moment of then existence." — Liebig's Animal Chemistry. 56. " We may communicate motion to a body at rest by means of a number of forces, very differ- ent in their manifestations. Thus, a time-piece may be set in motion by a falling weight (gravitation), or by a bent spring (elasticity). 160 institutes of medicine. CHEMICAL DOCTRINES. ids proceeds from distinct organs, which, as in the case of the heart and intestines, do not generate THE MOVING POWER IN THEM- SELVES, BUT RECEIVE IT FROM OTH- ER quarters."—Liebig's Animal Chemistry (no. 3, 4). 10. " Now, since the phenome- na of motion in the animal body ARE DEPENDENT ON THE CHANGE of matter, the increase of the change of matter in any part is fol- lowed by an increase of all the motions. Consequently, if, in con- sequence of a DISEASED TRANS- FORMATION OF LIVING TISSUES, a greater amount of force be gener- ated than is required for the pro- duction of the normal motions, it is seen in the acceleration of ALL OR SOME OF THE INVOLUNTARY motions, as well as in a higher TEMPERATURE OF THE DISEASED part."—Liebig's Animal Chem- istry. [Such, with § 3504;, i, and no. 11, is the chemical substitute for the medical aphorism, " ubi irrita- tio ibi ajfuxus." It will be also seen from the foregoing nos. 7, 8, 9, that Liebig considers the circula- tion of the blood due to the agen- cies of oxygen, and not at all to the action of the heart.] 11. "The power to effect trans- formations does not belong to the vital principle. Each transforma- tion is owing to a disturbance in the attraction of the elements of a compound, and is, consequently, a purely chemical process." — Liebig's Organic Chemistry ap- plied to Physiology, &c. 12. " The combinations of the chemist relate to the change of matter, forward and backward,ro the conversion of food into the various tissues and secretions, and to their metamorphosis into lifeless compounds ; his investiga- tions ought to tell us what has vital doctrines. Every kind of motion may be pro- duced by the electric or magnetic force, as well as by chemical at traction; while we cannot say, as long as we only consider the man- ifestation of these forces m the phe- nomenon or result produced, which of these various causes of change of place has set the objects in mo- tion. In the animal organism we are acquainted with only one cause of motion, and this is the same cause which determines the growth of living tissues and gives them the power of resistance to ex- ternal agencies. It is the vital force."—Liebig, ibid. 57. " In order to attain a clear conception of these manifestations of the vital force, so different in form, we must bear in mind, that every known force is recog- nized by two conditions of activi- ty," &c.—Liebig's Animal Chem- istry. 58. " Our notion of life involves something more than mere repro duction, namely, the idea of an ao tive power exercised by virtue of a definite form, and production and generation in a definite form. The production of organs, and their power not only to produce their component parts from the food presented to them, but to gen- erate themselves in their orig- inal form and with all their prop- erties, are characters belonging exclusively to organic life, and constitute a form of reproduction independent of chemical pow- ers. The chemical forces are sub- PHYSIOLOGY.--ORGANIC CHEMISTBY--FUNCTIONS. 161 CHEMICAL doctrines. taken place and what can take place in the body."—Liebig's Animal Chemistry. 13. " How beautifully and admi- rably simple, with the aid of these discoveries (chemical), appears the process of nutrition in animals, the formation of their organs," &c. M. " In the hands of the physiolo- gist, organic chemistry must be- come an intellectual instrument, by means of which he will be enabled to trace the causes of phenomena invisible to the bodily sight."— Liebig's Animal Chemistry. 14^. "Since, in different indi- viduals, according to the amount of force consumed in producing voluntary mechanical effects, une- qual quantities of living tissues are wasted, there must occur in every individual, unless the phenomena of motion are to cease entirely, a condition in which all voluntary motions are completely checked; in which, therefore, these occasion no waste. This condition is called sleep."—Ibid. 15. " The self-regulating steam- engines furnish no unapt image of what occurs in the animal body." " The body, in regard to the pro- duction of heat and force, acts just like one of these ^machines."— Liebig's Animal Chemistry. 16." The vital force unites in its manifestations all the peculi- arities of chemical forces, and of the not less wonderful cause which we regard as the ultimate origin of electrical phenomena." —Liebig's Animal Chemistry. 17. " The mysterious vital vital doctrines. ject to the invisible cause bv which this form is produced. Of the existence of this cause itself we are made aware only by the phenomena which it pro duces. Its laws must be inves- tigated^^ as we investigate those of the other powers which effect motion and changes in matter."— Liebig's Organic Chemistry ap- plied to Physiology, &c. 59. " It is not the true chemist who has endeavored to apply to the animal organism his notions derived from purely chemical pro- cesses. He has not had the re- motest intention of undertaking the explanation of any really vital phenomenon upon chemical prin- ciples. The only part which chemistry now, or for the future, can take in the explanation of the vital processes, is limited to a more precise designation of the phenom- ena, and to the task of control- ling the correctness of inferen- ces, and insuring the accuracy of all observations by number and weight. Although the chemist is able to analyze organic bodies, and tell us their ultimate elements, he does not claim the power of syn- thesis, or of producing them again by the union of these elements" !! ! —Liebig's Lectures for 1844 (§ 350|-350|).—See no. 39. 60. " In what form or in what manner the vital force pro- duces mechanical effects in the animal body is altogether unknown, and is as little to be ascertained by experiment as the connection of chemical action with thf phenomena of motion, which we can produce with the galvanic battery. We know not how a certain invisible something, heat, gives to certain bodies the power of exerting an enormous pressure on surround- ing objects. We know not even 162 1NSTI1TTES BF MEDICINE. CHEMICAL DOCTRINES. principle can be replaced by the chemical forces."—Liebig's Or- ganic Chemistry applied to Phys- iology, &c. 17-|. "The animal body is a heated mass, which bears the same relation to surrounding objects as any other heated mass. It receives heat when the surrounding objects are hotter, it loses heat when they are colder than itself." — Liebig's Animal Chemistry. (See § 350f, 440 c, 1044 a, b, 1046-1050.) 17f. " The high temperature of the animal body is uniformly and under all circumstances the result of the combination of a combusti- ble substance with oxygen." " The carbon of the food, which is converted into carbonic acid within the body, must give out ex- actly as much heat as if it had been directly burned in the air, or in oxygen gas. The only difference is, that the amount of heat pro- duced is diffused over unequal times." " By the combination of oxygen with the constituents of the met- amorphosed tissues, the tempera- ture necessary to the manifes- tations of vitality is produced in the carnivora."—Liebig's Ani- mal Chemistry (§ 440, nos. 17 and 18). 18. " The nerves which accom- plish the voluntary and involunta- ry motions in the body (no. 7-9) are, according to the preceding exposition, not the producers, but only the conductors of the vital force (§ 59). They permit VITAL DOCTRINES. how this something itself is pro- duced when we burn wood 01 coals. " So it is with THE VITAL FORC1 and with the phenomena exhibit- ed by living bodies. The cause of these phenomena is not chem- ical force ; it is not electricity, nor magnetism. It is a peculiar force, because it exhibits mani- festations which are formed by NO OTHER KNOWN FORCE." 61. "In regard to the nature and essence of the vital force, we can hardly deceive ourselves, when we reflect, that it behaves, in all its manifestations, exactly like other natural forces; that it is devoid of consciousness or of vo- lition, and is subject to the action of a blister." — Liebig's Animal Chemistry. 6\\. " Certain other constitu- ents of the blood may give rise to the formation of carbonic acid in the lungs. But, all this has no connection with that vital pro- cess by which the heat necessa- ry for the support of life is gen- erated in every part of the body." —Liebig's Animal Chemistry. 61f. Nevertheless — "In the animal organism two processes of oxydation are going on; one in the lungs [the union of oxygen with an ' organic compound of iron'], the other in the capillaries [the union of the absorbed oxygen with car- bon, &c.]. By means of the former, in spite of the degree of cooling, and of the increased evaporation which takes place there, the constant temperature of the lungs is kept up, while the heat of the Rest of the body is supplied by the latter" !—Liebig's Animal Chemistry. 62. " In the present state of our knowledge, no one, probably, will IMAGINE that ELECTRICITY is tO be considered as the cause of the phenomena of motion in the body." " Every thing in the ani- mal organism to which the name physiology.—organic chemical doctrines. the current to traverse them, and present, as conductors- of elec- tricity, ALL THE PHENOMENA WHICH THEY EXHIBIT AS CONDUCT- ORS OF THE VITAL FORCE" !--LlE- big's Animal Chemistry. [Com- pare with no. 55.] 18j. " If CHEMICAL ACTION be excluded as a condition of nervous agency, it means nothing else than to derive the presence of motion, the MANIFESTATION OF FORCE, FROM NOTHING. BUT NO FORCE, NO POW- ER, CAN COME FROM NOTHING"! — Liebig's Animal Chemistry (no. 5). 19. " By means of the nerves, all parts of the body receive the moving force which is indispen- sable to their functions, to change of place, to the production of me- chanical effects. Where nerves are not found, motion does not occur. [In plants, for example 1] The excess of force generated in one place is conducted to other parts by the nerves. The force which one organ cannot produce in itself is conveyed to it from other quar- ters, [! ] and the vital force which is wanting to it, in order to furnish resistance to external causes of disturbance, it receives in the form of excess from another organ, an excess which that organ cannot consume in itself"!—Liebig's An- imal Chemistry (§ 422, 423, 733 e). 20. " The phenomena of motion in vegetables, the circulation of the sap, for example, observed in many of the characeae, and the closing of flowers and leaves, de- pend on physical and mechanical causes. Heat and light are the REMOTE CAUSES of MOTION in VEG- ETABLES ; but in animals we rec- ognize in the nervous apparatus a source of power, capable of re- newing itself at every moment of their existence."—Liebig's Ani- mal Chemistry. 21. "While the assimilation CHEMISTRY--FUNCTIONS. 163 VITAL DOCTRINES. of motion can be applied proceeds from the nervous apparatus. In animals we recognize in the ner- vous apparatus a source of pow- er,'capable of renewing itself at every moment of their exist- ence."—Liebig's Animial Chem- istry (no. 55). 62-^. "But all this (formation of carbonic acid) has no connection with that vital process by which the heat necessary for the support of life is generated in every part of the body." — Liebig's Animal Chemistry. 63. " Pathology informs us that the true vegetable life is in no way dependent on this apparatus (the cerebro-spinal); that the pro- cess of nutrition proceeds in those parts of the body where theNERVES of sensation and voluntary motion are paralyzed, exactly in the same way as in other parts where these nerves are in the normal condi- tion ; and, on the other hand, that the most energetic volition is inca- pable of exerting any influence on the contractions of the heart, on the motion of the intestines, or on the processes of secretion."—Lie- big's Animal Chemistry. 64. "Although plants require light, and, indeed, sun light, it is not necessary that the direct rays of the sun reach them. Their functions certainly proceed with greater intensity and rapidity in sunshine, than in the diffused light of day; but it merely accelerates in a creater degree the action ALREADY EXISTING." -- LlEBIG's Organic Chemistry applied tr Physiology, &c. 65. " The vital principle is only known to us through the pe- culiar form of its instruments ; 164 institutes of medicine. CHEMICAL DOCTRINES. of food in vegetables, and the WHOLE PROCESS OF THEIR FORMA- TION, are dependent on certain EXTERNAL INFLUENCES which Vro- duce motion, the development ofthe animal organism is, to a certain extent, independent of those exter- nal influences, just because the animal body can produce within ITSELF THAT SOURCE OF MOTION WHICH IS INDISPENSABLE TO THE vital process."—Liebig's Ani- mal Chemistry. 22. " Neither the emission of carbonic acid nor the absorption of oxygen (by plants) has any con- nection with the process of assim- ilation ; nor have they the slight- est relation to each other. The one is purely a mechanical, the other a purely chemical process. A cotton wick, inclosed in a lamp, which contains a liquid sat- urated with carbonic acid, acts ex- actly in the same manner as a liv- ing plant in the night."—Liebig's Organic Chemistry applied to Physiology, &c 23. " At night, a true chemical process commences, in conse- quence of the action of the oxygen of the air upon the substances composing the leaves, blossoms, and fruit. This process is "not at all connected with the life of the vegetable organism, because it goes on in the dead plant exact- ly as in a living one" ! Nevertheless, 23|. "What value can be at- tached to experiments, in which all those matters which a plant requires in the process of assim- ilation, besides its mere nutri- ment, have been excluded with THE GREATEST CARE ] Can the laws of life be investigated in an organized being which is dis- eased or dying1?"—Liebig's Or- ganic Chemistry applied, &c.—Or, can those laws be investigated in VITAL DOCTRINES. that is, through the organs in which it resides. Hence, what- ever kind of energy a substance may possess, if it is amorphous and destitute of organs from which the impulse, motion, or change, proceeds, it does not live. Its energy depends, in THIS CASE, On a CHEMICAL ACTION. Light, heat, electricity, or other influences [justly considered here by Liebig as vital stimuli and not forces] may increase, diminish, or arrest this action ; but they are not its efficient cause." " The vital principle opposes to the continual action ofthe atmosphere, moisture, and temperature, upon the organism, A resistance which is, in a certain degree, invincible. It is by the constant neutralization and renewal of these external in- fluences that life and motion are maintained." — Liebig's Organic Chemistry applied to Physiology, &c. (§ 188£, d). 66. " An abnormal productior of certain component parts of plants presupposes a power and capabil- ity of assimilation, to which the most powerful chemical action cannot be compared. The best idea of it may be formed, by con- sidering that it surpasses in power the strongest galvanic battery, with which we are not able to separate the oxygen from carbonic acid, as is done by the leaves of plants," " and without the direct solar rays." 67. " All that we can do is to supply those substances which are adapted for assimilation by the power already present in the or- gans ofthe plant."—Liebig's Or- ganic Chemistry applied to Phys- iology, &c. 68. " The living part of a plant acquires the whole force and di- rection of its vital energy from the absence of all conductors of force. By this means the leaf it PHYSIOLOGY.—organic CHEMICAL DOCTRINES. " a cotton wick, inclosed in a lamp V And so of animals. 24. " The permeability to gases is a mechanical property, common to all animal tissues; and is found in the same degree in the living as in the dead tissue" !— Liebig's Animal Chemistry (§ 350^, n, and Medical and Phys- iological Commentaries, vol. i., p. 565, 569, notes, 683-690). 24^. " The surface of the body is the membrane from which evap- oration goes constantly forward. In consequence of this evapo- ration ALL THE FLUIDS OF THE BODY, IN OBEDIENCE TO ATMOS- PHERIC PRESSURE, EXPERIENCE MO- TION in the direction toward the evaporating surface. This is ob- viously the chief cause of the passage of the nutritious fluids through the walls of the blood-ves- sels [strained off], and the cause of their distribution through the body. We know now what important function the skin fulfills through evaporation" ! —Liebig's Researches on the Chemistry of Food, «fec, American Journal of Science and Arts, May, 1848, p. 415.— See contradiction in nos. 5, 6, 7, 8, 9, 10, 69-75. Also § 350^ n. 25. "Analogy, that fertile source of error, has unfortunately led to the very unapt comparison of the vital functions of plants with those of animals."—Liebig's Or- ganic Chemistry applied to Physi- ology, &c. 26. "All substances in solu- tion in a soil are absorbed by the roots of plants, exactly as 4 sponge imbibes a liquid, and all that it contains, without SELECTION," and " THEIR ASSIMI- LATION is a PURELY CHEMICAL PRO- CESS."—Ibid. (no. 22, § 289-291). Nevertheless, CHEMISTRY--FUNCTIONS. 165 VITAL DOCTRINES. enabled to overcome the strongest chemical attractions, to decompose carbonic acid, and to ASSIMILATE the elements of its nourishment." —Liebig's Animal Chemistry. 69. " In vegetable physiology, a leaf is regarded in every case merely as a leaf, notwithstanding that leaves generating oil of tur- pentine or oil of lemons, must pos- sess a different nature from those in which oxalic acid is formed. Vitality, in its peculiar operations, makes use of a special apparatus for each function of an organ. Veg- etable physiologists, in the study of their science, have not directed their attention to that part of it (the laws of vitality) which is most worthy of investigation."—Liebig's Organic Chemistry applied to Phys- iology, &c. 70. "In the living plant, the in- tensity of the vital force far ex- ceeds that of the chemical action of oxygen. We know, with the utmost certainty, that, by the in- fluence of the VITAL force, oxy- gen is separated from elements to which it has the strongest affinity; and that it is given out in the gas- eous form, without exerting the slightest action on the juices of the plant." — Liebig's Animal Chem- istry. 71. " The animal organism n A HIGHER KIND OF VEGETABLE." " Assimilation, or the process of formation and growth, goes on in the same way in animals and in vegetables. In both the same cause determines the in- crease of mass. This constitutes the true vegetative life."—Lie big's Animal Chemistry. 72. " The constituents of VEG etable and animal substances are formed under the guidance and power of the vital principle, which determines the direction of their molecular attraction " " Iv 166 INSTITUTES OF MEDICINE. CHEMICAL DOCTRINES. 26£. " When roots find their more appropriate base in suffi- cient quantity, they will take up less of another."—And, again (in opposition to the simile of the " sponge" and " lamp-wick") : "It is thought very remarkable, that those plants of the grass tribe, the seeds of which furnish food for man, follow him like the domestic animals. But saline plants seek the sea-shore ox saline springs, and the Chainopodium the dung- hill from similar causes. Saline plants require common salt, and plants which grow on dung-hills, only, need ammonia and nitrates, and they are attracted whither these can be found, just as the dung-fly is to animal excrements." " The roots of plants are con- stantly engaged in collecting from the rain those alkalies which form- ed part of the sea-water, and also those ofthe water of springs which penetrates the soil." 27. " Each new radical fibril which a plant acquires may be re- garded as constituting, at the same time, a mouth, a lung, and a stomach. The roots perform the functions of the leaves from the first moment of their formation ; they extract from the soil their proper nutriment, namely, the car- bonic acid generated by the hu- mus."—Liebig's Organic Chem- istry applied to Physiology. 28. [" Nature speaks to us in a peculiar language, in the language of phenomena. She answers, at all times, the questions which are put to her ; and such questions are exper- iments. An experiment is the ex- pression of a thought. We are near- er the truth, when the phenom- enon, elicited by the experiment, corresponds to the thought; while the opposite result shows that the question was falsely sta- ted, and that the conception was VITAL DOCTRINES. the formation of vegetable and an- imal substances, the vital prin- ciple opposes, as a force of re- sistance, the action of the other forces," &c.—Liebig's Lectures for 1844.—See p. 31, § 59. 73. " The force which gives tu the germ, the leaf, and the radi- cal FIBRES of the VEGETABLE THE SAME WONDERFUL PROPERTIES (di- gestion, circulation, and secretion), is the same as that residing in the secreting membranes and glands of animals, and which en- ables every animal organ to per- form its own proper functions."— Liebig's Animal Chemistry. 74. " In the animal organism the vital force exhibits itself as in the plant, in the form of growth, and as the means of re- sistance TO EXTERNAL AGENCIES." —Ibid. 75. " If we assume that all the phenomena exhibited by the or- ganism of plants and animals are to be ascribed to a peculiar cause, different in its manifestations from all other causes which produce MOTION Or CHANGE OF CONDITION ; if, therefore, we regard the vital force as an independent force (no. 3), then, in the phenomena of organic life, as in all other phe- nomena ascribed to the action of forces, we have the statics, that is, the state of equilibrium determ- ined by a resistance, and the dy- namics OF THE VITAL FORCE" !-- Ibid. 76. " Vegetables produce in their organism the blood of all animals."—Liebig, ibid. To occupy space, nos. 26£ and 27 are contrasted with nos. 25 and 26 in the same column. And so with 5\, 23£. But here is more in the more appropriate place, upon this fundamental point. Thus : 77. " When it is considered, that sea-water contains less that physiology.—organic chemistry—functions. 167 chemical doctrines. vital doctrines. erroneous." — Liebig's Organic Toooooo of its own weight of io- Chemistry, &c. (§ 1052,1054). dine, and that all combinations of [I pause in my quotations for the pur- iodine with the metallic bases of pose of indicating the important bearing of alkalies are highly soluble in wa- the "chemistry of plants" upon the chem- .. • • . -7 ical philosophy of digestion in animals as ter'some provision must necessarily carried on by the gastric juice. Now, if be supposed to exist IN THE organ- in the latter case the agencies be of a chem- IZATION of sea-weed and the dif- ical nature, there should be some analogy c , . 3 a~ , , . , , between the supposed chemical transform- terent kinds ot torce by which they ation of organic compounds by the gastric are enabled, DURING THEIR LIFE, iuice and the transformation of inorganic „„__„______» „ .-i r- ? substances into organic compounds fs ef-#TO EXTRACT IODINE in the form of fected by plants, especially considering a soluble salt from sea-water, and that "vegetables produce in their organ- t0 ASSIMILATE IT IN SUCH A MAN- lsm the blood of all animals (no. 76). i_ • • • ■> Chemistry is prodigal of experiments, and NER that it is not again restored to of supposititious agents from pepsin to the surrounding medium. These chlorine, in resolving digestion by ani- nlarir<, arp Cmr vermis nv Tnmvi? mals, but vouchsafes scarcely a word in Plants are COLLECTORS OF IODINE, behalf of that "creative function" by which JUST AS LAND PLANTS ARE OF AL "the blood of all animals" is generated by KALIES ; and they yield us this el- plants out of the elements of matter. Will „ . J J , Chemistry explain (§ 301, 360) ?] ement IN QUANTITIES such as we could not otherwise obtain from the water without the evaporation of whole seas." — Liebig's Or- ganic Chemistry applied to Physi- 29. " The most decisive exper- ology, &c.—(§ 1054). iments of physiologists have shown 78. "The equilibrium in the that the process of chymification chemical attractions of the constit- is independent of the vital force; uents of food is disturbed by the that it takes place in virtue of a vital principle ;" and " the un- PURELY CHEMICAL action, EXACTLY ION of its ELEMENTS, SO as tO pro- similar to those processes of de- duce new combinations and forms composition or transformation indicates a peculiar mode of at- which are known as putrefac- traction, and the existence of A POWER DISTINCT FROM ALL OTHER powers of nature, namely, the vital principle." — Liebig's Or- ganic Chemistry applied to Physi- ology, &c. 79. " The vital force causes a decomposition ofthe constituents TION, FERMENTATION, Or DECAY. —Liebig's Animal Chemistry. " Those remarkable phenom- ena, FERMENTATION, PUTREFAC- TION, and decay, are the pro- cesses of Decomposition, and their ultimate results are to re- convert the elements of organic of food, and destroys the force of bodies into that state in which they attraction which is continually ex- exist before they participate in the erted between their molecules. It processes of life."—Liebig's ice- alters the direction ofthe chemi- turesfor 1844. cal forces in such wise, that the 30. " The second part of the elements of the constituents of work will treat of the chemical the food arrange themselves in an- processes which effect the com- other form, and combine to pro- plete destruction of plants and duce new compounds. It forces animals after death, such as the the new compounds to assume forms peculiar modes of decomposition altogether different from those usually described as fermentation, which are the result ofthe attrac- futrefaction, and decay."—Lie- tion of cohesion when acting free- 168 institutes of medicine. chemical doctrines. big's Organic Chemistry applied to Physiology, &c. 31. "In the same way as mus- cular fibre, when separated from the body, communicates the state of decomposition existing in its elements to the peroxide of hydro- gen, so a certain product, arising by means of the vital process, and by consequence of the transposition of the elements of parts ofthe stom- ach and of the other digestive or- gans [! ] while its own metamor- phosis is accomplished in the stom- ach, acts on the food. The in- soluble matters are digested" !— Liebig's Animal Chemistry. 32. " Is it truly vitality, which generates sugar in the germ for the nutrition of young plants, or which gives to the stomach the power to dissolve and to prepare for assimilation all the matter in- troduced into it 1 A decoction of malt possesses as little power to reproduce itself, as the stomach of a dead calf. Both are, un- questionably, destitute of life. But, when starch is introduced into a decoction of malt, it changes, first into a gummy matter, and lastly into sugar. Hard-boiled albumen, and muscular fibre, can be dis- solved in a decoction of a calf's stomach, to which a few drops of muriatic acid have been added, precisely as in the stomach it- self."—Liebig's Organic Chemis- try, &c. (no. 11). 33. " All substances which can arrest the phenomena of fermen- tation and putrefaction in liquids, also arrest digestion when taken into the stomach" !—Liebig's An- imal Chemistry. 34. " In the natural state of the digestive process, the food only undergoes % change in its state of cohesion, becoming fluid without any other change of properties."— Liebig's Animal Chemistry. VITAL DOCTRINES. ly, that is, without resistance."— Liebig's Animal Chemistry. 80. " It is well known that in many graminivorous animals, where the digestive organs have been overloaded with fresh juicy vegetables, these substances un- dergo IN THE STOMACH THE SAME decomposition as they would at the same temperature out of the 'body. They pass into fermenta- tion and putrefaction, whereby so great a quantity of carbonic acid gas and of inflammable gas is generated, that these organs are enormously distended, and sometimes even to bursting."— Liebig's Animal Chemistry. 81. " The vital force appears as a moving force or cause of mo- tion, when it overcomes the chem- ical forces, cohesion and affini- ty, which act between the con- stituents of food, and when it changes the position or place in which their elements occur. The vital force is manifested as A cause of motion in overcoming the chemical attraction of the constituents of food, and is, far- ther, THE CAUSE WHICH COMPELS them to combine in a new arrange- ment, and to assume new forms." —Liebig's Animal Chemistry. 82. " It will be shown in the second part of this work, that all plants and vegetable structures undergo two processes of decom- position AFTER DEATH. One of these is named fermentation, the other decay or putrefaction."— Liebig's Organic Chemistry ap- plied to Physiology, &c, (§ 349, c, e). 83. " The individual organs such as the stomach, cause all the organic substances conveyed tc them, which are capable of trans- formation, to assume new forms, The stomach compels the ele- physiology.—organic chemistry--FUNCTIONS. 169 CHEMICAL doctrines. vital doctrines. 35. Although "the process of ments of these substances to unite chymification is independent of into a compound fitted for the for- the vital force, and takes place in mation of the blood."—Liebig's virtue of a purely chemical action, Organic Chemistry, &c. exactly similar to those processes 84. " The first substance ca- of decomposition which are known pable of affording nutriment to an- as putrefaction, fermentation, imals is the last product of the or decay ;" nevertheless, " Inor- creative energy of vegetables." ganic compounds differ from or- —Liebig's Animal Chemistry. gaxic in as great a degree as in 85. " The special characters of their simplicity of constitution."— food, that is, of substances fitted for Liebig's Animal Chemistry, and assimilation, are absence of ac- Organic Chemistry. tive chemical properties, and the capability of yielding to trans- formations." — Liebig's Organic Chemistry applied to Physiology &c. 36. " The power of elements to 86. " All experience proves that unite together, and to form pecu- there is in the organism only one liar compounds which are genera- source of physical power ; and ted in animals and vegetables, is this source is the conversion of liv- chemical affinity." — Liebig's ing parts into lifeless, amorphous Organic Chemistry applied to compounds." — Liebig's Animal Physiology, &c. Chemistry. 86^. " It is only with the com- mencement of chemical action that the separation of a part of an or- gan in the form of lifeless com- pounds begins." — Liebig's Ani- mal Chemistry. 37. " We should not permit our- 87. "When a chemical com selves to be withheld, by the idea pound of simple constitution is in- of a vital principle, from consid- troduced into the stomach, its ering in a chemical point of view, chemical action is, of course, op- the process of transformation of posed by the vital principle the food, and its assimilation by The results produced depend upon the various organs. This is the the strength of their respective ac- more necessary, as the views hith- tions. Either an equilibrium of erto held have produced no re- both powers is attained, a change suits, and are quite incapable of being effected without the destruc- useful application."—Liebig's Or- tion ofthe vital principle ; in which ganic Chemistry applied, &c. case a medicinal effect is occa- 38. "We know that an organ- sioned. Or, the acting body yields ized body cannot generate sub- to the superior force of vital- stances, but only change the mode ity, that is, it is digested. Or of their combinations, and that its lastly, the chemical action ob- sustexance and reproduction tains the ascendency and acts as depend upon the chemical trans- a poison." — Liebig's Organic formation of the matters which are Chemistry applied to Physiology, employed as its nutriment, and &c. which contain its own constituent * 87^. "The vital power in veg ♦ /70 institutes of medicine. chemical doctrines. elements. Whatever we regard as the cause of these transforma- tions, the act of transformation is a PURELY CHEMICAL PROCESS. It will be shown, when considering the processes of fermentation and 'putrefaction, that any disturbance of the mutual attraction subsist- ing between the elements of tt body gives rise to a transforma- tion."—Liebig's Organic Chem- istry, &c. 39. " By CHEMICAL AGENCY We can produce the constituents of muscular fibre, skin, and hair" ! " We are able to form, in our la- boratories, formic acid and urea, &c, all products, it is said, of the vital principle. We see, there- fore, that this MYSTERIOUS VITAL principle can be replaced by the chemical forces" !!—Lie- big's Organic Chemistry (no. 16, 51,59, § 53). 40. " The influence of poisons and of remedial agents on the liv- ing animal body evidently shows that the chemical decompositions and combinations in the body, WHICH MANIFEST THEMSELVES IN THE PHENOMENA OF VITALITY, may be increased in intensity by chem- ical forces of an analogous char- acter, and retarded or put an end- to by those of opposite character" VITAL DOCTRINES. etables accomplishes the trans FORMATION of MINERAL substancea into an organism endowed with life." — Liebig's Animal Chem- istry. 87f. "The cause of waste of matter is the chemical action of oxygen. This waste of matter oc- curs in consequence ofthe absorp- tion of oxygen into the substances of living parts. This absorption of oxygen occurs only when the resistance which the vital force oj living parts opposes to the chem ical action ofthe oxygen is weak- er than that chemical action."— Liebig's Animal Chemistry (nos. 3, 4, 7, 8, 11, 86i). 88. " The constituents of VEG- ETABLE and animal substances HAVING BEEN FORMED Under THE GUIDANCE AND POWER of the VITAL principle, it is this principle which determines the direction of their molecular attraction." " The vi- tal principle alone is capable of restoring the original order and manner of the molecular arrange- ment in the smallest particles of albumen."—Liebig's Lectures for 1844 (§ 48-50). " We cannot expect from oi- ganic chemistry the synthetic proof of the accuracy ofthe views entertained, because every thing in the organism goes on under THE INFLUENCE of the VITAL FORCE, AN IMMATERIAL AGENT [!] which the chemist cannot employ at will." —Liebig's Animal Chemistry. 89. " From the theory of dis- ease developed in the preceding pages, it follows, obviously, that a diseased condition once establish- ed, in any part of the body, can- not be made to disappear by the chemical action of a remedy."— Liebig's Animal Chemistry. 90. " The vital force is sub- ject to the action of a blister." —Ibid. PHYSIOLOGY.--ORGANIC CHEMISTRY--FUNCTIONS. 171 CHEMICAL DOCTRINES. and that we are enabled to exer- cise an influence on every part of an organ by means of substances possessing a well-defined chem- ical action."—Liebig's Animal Chemistry (mottoes a-e). 41. " It is singular that we find medicinal agencies all depend- ent On CERTAIN MATTERS, which differ in composition [moral emo- tions, heat, cold, change of air, ex- ercise ?]; and if, by the introduc- tion of a substance, certain abnor- mal conditions are rendered nor- mal, it will be impossible to reject the opinion, that this phenomenon depends on a change in the com- position ofthe constituents ofthe diseased organism [no. 5], a change in which the elements of the REMEDY TAKE A SHARE SIMILAR TO THAT WHICH THE VEGETABLE ELE- MENTS of food have taken in the formation of fat, of membranes, of the saliva, ofthe seminal fluid, &c. [!] Their carbon, hydrogen, or ni- trogen, or whatever else belongs to their composition, are derived from the vegetable organism ; and, after all, the action and effects of quinine, morphia, and the vegeta- ble poisons in general, are no hypotheses" ! — Liebig's Animal Chemistry (§ 18, and motto d). 42. " With respect to the action of quinine, or the alkaloids of opi- um, &c, physiologists and pathol- ogists entertain no doubt that it is exerted chiefly on the brain and nerves. If we reflect that this ac- tion is exerted by substances which are material, tangible, and ponder- able ; that they disappear in the organism; that a double dose acts more powerfully than a single one; that, after a time, a fresh dose must be given if we wish to pro- duce the action a second time; all these considerations, viewed chem- ically, [!] permit only one form of explanation; the supposition, VITAL DOCTRINES. 91. " The vital force in a liv- ing animal tissue appears as a cause of growth in the mass, and of resistance to those external agencies which tend to alter the form, structure, and composition of the substance of the tissue in which the vital energy resides"— Liebig's Animal Chemistry. 92. " The slightest action of a chemical agent upon the blood ex- ercises an injurious influence. Even the momentary contact with the air in the lungs, although ef- fected through the medium of cells and membranes, alters the color . and other qualities of the blood." —Liebig's Organic Chemistry ap- plied to Physiology, &c. 93. " Every substance may be considered as nutriment, which loses its former properties when acted on by the vital principle, and does not exercise a chemical action upon the living organ. An- other class of bodies change the direction, the strength, and inten- sity of the resisting vital principle and thus exert a modifying influ- ence upon the functions of its or- gans. These are medicaments. A third class of compounds are called poisons, when they possess the property of uniting with or- gans or with their component parts, and when their power of ef- fecting this is stronger than the re- sistance offered by the vital princi- ple."—Liebig's Organic Chemis- try, &c. 93-i. "Death is the condition in which all resistance on the part of the vital force entirely ceases. So long as this condition is not established the living tissues con- tinue to offer resistance." — Lie- big's Animal Chemistry. 172 INSTITUTES of medicine. CHEMICAL DOCTRINES. namely, that these compounds, by means of their elements, take a share in the formation of new or the transformation of existing brain and nervous matter" !,!— Liebig's Animal Chemistry. 43. " Owing to its volatility and the ease with which its vapor per- meates animal tissues, alcohol can spread throughout the body in all directions" !--LlE- big's Animal Chemistry (§ 350£, »).—Notes N R pp. 1121, 1123. 44. " It is impossible to mistake the modus operandi of putrefied sausages, or muscle, urine, cheese, cerebral substance, and other mat- ters, in a state of putrefaction." " It is obvious that they communi- cate THEIR OWN STATE OF PUTRE- FACTION TO THE SOUND BLOOD, from which they were produced, exactly in the same manner as glu- ten in a state of decay or putrefac- tion causes a similar transforma- tion in a solution of sugar" ! 45. " The mode of action of a morbid virus exhibits such a STRONG SIMILARITY TO THE ACTION of yeast upon liquids containing sugar and gluten, that the two processes have been long since compared to one another, although merely for the purpose of illustra- tion. [They have often been rep- resented as identical.] But, when the phenomena attending the ac- tion of each respectively are con- sidered more closely, it will in re- ality be seen that their influence depends upon the same cause." " Ordinary yeast, and the virus of human small-pox, effect a violent tumultuous transformation, the for- mer in vegetable juices, the latter in the blood" ! " The action ofthe virus of cow-pox is analogous to that of low yeast [ / ] It commu- nicates its own state of decomposi- tion to A matter in the blood, and from a second matter is itself re- * This is contradicted by French chemist; but assert that it exists hi the body in a fre VITAL DOCTRINES. [The next following (94) is con- firmed by other observations, showing that Alcohol, Opium, and Tobacco are not absorbed, but act through the nervous system, p. 301-310, § 481- 484. Alcohol is digested.] 94. " According to all the obser- vations hitherto made, neither the expired air, nor the perspiration, nor the urine, contains any trace of alcohol, after indulgence in spirituous liquors."—Liebig's An- imal Chemistry* 95. " The vivifying agency of the blood must ever continue to be the most important condition in the restoration of a disturbed equilibrium, and the blood must, therefore, be considered and con- stantly kept in view, as the ulti- mate and most powerful cause of lasting vital resistance, as well in the diseasrd as in the un- affected parts of the body."—' Liebig's Animal Chemistry. Nevertheless, " No other component part of the organism can be compared to the blood, in respect of the fee- ble resistance which it offers to exterior influences." " The chem- ical force and the vital principle hold each other in such perfect equilibrium, that every disturb- ance, however trifling, or from whatever cause it may proceed, EFFECTS A CHANGE IN THE BLOOD." —Liebig's Organic Chemistry ap- plied, &c. But, again, nevertheless, " It is obvious, moreover, that in all diseases where the forma- tion of contagious matter and of exanthemata is accompanied by fe- ver, two diseased conditions simul- taneously exist, and two process- es are simultaneously completed; and that the blood, as it were, bv reaction, that is, fever, becomes a means of cure."—Liebig's An- imal Chemistry. i, who deny, also, that alcohol is " burned " e state.—1861. PHYSIOLOGY.--ORGANIC CHEMISTRY--FUNCTIONS. 173 CHEMICAL DOCTRINES. generated" ! " The susceptibility of infection by the virus of human small-pox must cease after vacci- nation, FOR THE SUBSTANCE tO the presence of which this suscepti- bility is owing has been removed from the body by a peculiar pro- cess of decomposition artificially excited" ! " Cold meat is always in a state of decomposition. It is possible that this state may be communicated to the system of a feeble individual, and may be one of the sources of consump- tion" !! (§ 821)—Liebig's Organ- ic Chemistry applied to Physiology, &c " From the unequal degree of the conducting power in the nerves, we must deduce those conditions which are termed paralysis, syncope, and spasm"!—Liebig's Animal Chem- istry. 46. " In all chRonic diseases, death is produced by the same cause, namely, the chemical action of the atmosphere." " The true cause of death is the RESPIRATORY process, [! ] that is, the chemical action of the at- mosphere." — Liebig's Animal Chemistry (§ 674-676). *#* The quotations from " Liebig's Organic Chemistry applied to Physiology" are do- rived from Mr. Playfair s edition, London, 1840; those from " Liebig's Animal Chemis- try" are taken from Professor Gregory's edition, reprinted New York, 1842. The italics and capitals are mine. 350\. To carry out the full object of the foregoing section, I shall devote another to a farther exhibition ofthe pathological and thera- peutical doctrines which have been deduced by the author ofthe " new era in medicine" from his chemical and physiological elements, as their resulting compounds. This more extended display of theoret- ical and practical doctrines, as they came to us from the laboratory, will reflect a broad light upon the chemical hypotheses of digostion, nutrition, &c, as set forth in the preceding section, and show us, also, the extent of the probabilities which relate to the analysis of food and of the conclusions which are predicated of that analysis (§ 18, 409, 676 b), and, in brief, enable us to comprehend the nature and amount of the service which organic chemistry has rendered to the science of medicine (§ 5, 5-1 a, 376£, 1029, 1030, 1034). This otherwise isolated subject will be farther interesting, as I shall embrace in the quotations the whole science of medicine as founded VITAL DOCTRINES. 96. "It is only by a just appli- cation of its principle that any theory can produce really bene- ficial results."—Liebig's Animal Chemistry. 97. " We can have no very high idea of experiments made by gen- tlemen (chemists, with reference to digestion) who, for want of ana- tomical knowledge, have not been able to pursue their reasoning even beyond the simple experi- ment itself." — John Hunter's Observations on Digestion. 98. " Whenever the chemist for- sakes his laboratory for the bedside, he forfeits all his claims to our re- spect, and his title to our confidence. It is amusing to see the ridiculous errors into which the chemist falls when he turns physician."—Paris' Pharmacologia. London, 6th ed., 1825. 174 INSTITUTES OF MEDICINE. on chemistry and physics, and thus place in contrast the systems of the two rival schools, and enable the reader to adjust their relative mer- its. To do this work of consigning chemistry to its legitimate pur- suits the more effectually, I shall also expose, in an appropriate place, the chemical doctrine of animal heat in the language of him who is supposed to have settled the philosophy of that subject (§ 433-450, 676, 1043-1050). And before proceeding to a farther exposition of the vital and chemical doctrines of digestion, I shall, in consideration of the gen- eral surrender of this subject to the laboratory ofthe chemist, exhibit the corroborating testimony ofthe distinguished Mulder that physiol- ogy and medicine have nothing to hope from observations conducted out ofthe living body (§ 350, nos. 48,49, also Lehmann, §1029,1030). By the method now contemplated obstacles may be removed, and the reader better disposed to consider maturely the grounds upon which I have placed the vital doctrine of digestion, and come the more willingly to the conclusion that none are so imperfectly qualified to interpret the properties and laws of organic beings as they who can reason alone from the slender and deceptive analogies supplied by in- organic nature, and artificial expedients. It is certainly remarkable that this systematic exposure should be necessary at the middle of the nineteenth century, when arts and all other sciences, though more so the arts, are making a steady, some- times an astonishing progress. I may be mistaken in the importance which I have attributed to the innovations which have been made by organic chemistry upon medi- cal philosophy. I know that I am but feebly sustained by others in my conclusions; though now and then a blaze of mind assures me that deep volcanic action is in smothered progress (§ 376|). 350^, O" We have, then, from the authorized works of Liebig (§ 349, d), in the first plmce, the following inductions, in the order of their occurrence, of Pathological Principles, or " Theory of Disease" (350, no. 59). " Every substance or matter, every chemical or mechanical agency, which changes or disturbs the restoration of the equilibrium between the manifestations of the causes of waste and supply, in such a way as to add its action to the causes of waste, is called a cause of dis- ease. Disease occurs when the sum of the vital force, wdiich tends to neutralize all causes of disturbance, in other words, when the re- sistance offered by the vital force, is weaker than the acting cause of disturbance ;"—with the reservation, nevertheless, that " the cause of disturbance, or chemical force and the vital force, are one and identical." 350£, b. " Death is the condition in which all resistance on the part of the vital force entirely ceases. So long as this condition is not es- tablished, the living tissues continue to offer resistance." • 350£, c. " To the observer, the action of a cause of disease exhibits itself in the disturbance of the proportion between waste and supply which is proper to each period of life. In medicine, every abnormal condition of supply or of waste, in all parts, or in a single part of the body, is called disease." 350%, d. " It is evident that one and the same cause of disease will produce in the organism very different effects, according to the period PHYSIOLOGY.--ORGANIC CHEMISTRY--FUNCTIONS. 175 of life. A cause of disease which strengthens the causes of supply, either directly or indirectly, by weakening the action of the causes of waste, destroys, in the child and in the adult, the relative normal state of health ; while in old age it merely brings the waste and supply into equilibrium. 350£, e. " A child, lightly clothed, can bear cooling by a low exter- nal temperature without injury to health. [! ] The force available for mechanical purposes and the temperature of its body increase with the change of matter which follows the cooling; while a high tempera- ture, which impedes the change of matter, is followed by disease." 350^, f " A deficiency of resistance, in a living part, to the causes of waste, is, obviously, a deficiency of resistance to the action of the oxygen ofthe atmosphere. 3501, g, " When, from any cause whatever, this resistance dimin- ishes in a living part, the change of matter increases in an equal de- gree. 3501, Ji. " Now, since the phenomena of motion in the animal body are dependent on the change of matter, the increase of the change of matter in any part is followed by an increase of all motions. According to the conducting power of the nerves, the available force is carried away by the nerves of involuntary motion alone, or by all the nerves together. [! ] 3501, j. " Consequently, if, in consequence of a diseased transforma- tion of living tissues, a greater amount of force be generated than is required for the production ofthe normal motions, it is seen in an ac- celeration of all or some of the involuntary motions, as well as in a higher temperature of the diseased part. This condition is called fever. 3501, j. "When a great excess of force is produced by change of matter, the force, since it can only be consumed by motion, extends itself to the apparatus of voluntary motion. This state is called a febrile paroxysm. 3501, k. " In consequence of the acceleration of the circulation in the state of fever, a greater amount of arterial blood, and, consequent- ly, of oxygen, is conveyed to the diseased part, as well as to all other parts; and, if the active force in the healthy parts continue uniform, the whole action of the excess of oxygen must be exerted on the dis- eased part alone (§ 350, no. 10). 3501, I. "According as a single organ, or a system of organs, is af- fected, the change of matter extends to one part alone, or to the whole affected system. 3501, m. " Should there be formed, in the diseased parts, in conse- quence of the change of matter, from the elements of the blood or of the tissue, new products, which the neighboring parts cannot employ for their own vital functions ; should the surrounding parts, moreover, be unable to convey these products to other parts, where they may un- dergo transformation, then these new products will suffer, at the place where they have been formed, a process of decomposition analogous to fermentation or putrefaction" ! 3501, n. " If we consider the fatal accidents which so frequently occur in wine countries from the drinking of what is called feather white wine, we can no longer doubt that gases of every kind, wheth- er soluble or insoluble in water, possess the property of permeating ant- 176 institutes of medicine. mal tissues, as water penetrates unsized paper [! ] (§ 350, no. 24). This poisonous wine is wine still in a state of fermentation, which is in- creased by the heat of the stomach. The carbonic acid which is dis- engaged penetrates through the parietes ofthe stomach, [!!J through the diaphragm, [!!! ] and through all the intervening membranes, [!!!! J into the air-cells of the lungs, [!!!!!] out of which it displaces the at- mospherical air. [!!!!!!] The patient dies with all the symptoms of asphyxia caused by an irrespirable gas, [! ] and the surest proof of the presence of carbonic acid in the lungs is the fact, that the inhalation of ammonia, which combines with it, is recognized as the best antidote against this kind of poisoning" !—(§ 1055). " No doubt a part of these gases may enter the venous circula- tion through the absorbent and lymphatic vessels, and thus reach the lungs, where they are exhaled ; [! ] but the presence of membranes offers not the slightest obstacle to their passing directly into the cavity ofthe chest" ! (§ 349 d, 447 b, 827 h). 3501, o. " It is known that in cases of wounds ofthe lungs a pecu liar condition is produced, in which, by the act of inspiration, not only oxygen but atmospherical air, with its whole amount of nitrogen, pen- etrates into the cells ofthe lungs. This air is carried by the circula- tion [! ] to every part of the body, [!! ] so that every part is inflated or puffed up with the air, as with water in dropsy. [! ] This state ceases, without pain, as soon as the entrance of the air through the wound is stopped." 3501, p. " The frightful effects of prussic acid, which, when in spired, puis a stop to all the phenomena of motion in a few seconds, are explained in a natural manner by the well-known action of this compound on those of iron, when alkalies are present" !! (§ 494 dd, 827 d, 904 b).—Liebig's Animal Chemistry. 350£, q. The foregoing doctrines, with the humoral philosophy as quoted in § 350, nos. 40-45, make up the whole science of pathology as delivered to us from the laboratory; and such, too, are the doc- trines which are hailed as the foundation of " a new and the greatest era of medicine." There can be no doubt, however, that deliberate investigation will satisfy every mind that they are unintelligible, im- practicable, absurd ; and, consequently, that the whole pretended sys- tem of physiology from which they are deduced, is equally unworthy the dignity of reason. 350|, a. T shall now employ the same authorized chemist (§ 349, d) to give the last blow to his baseless fabric, and to scatter its fragments beyond the reach of idolatry itself. This will be done by setting forth, in the language of the author, his deductions from the physio- logical and pathological doctrines of the laboratory, as to The Chemical Treatment of Disease (§ 350, no. 59). " The accelerated change of matter, and the elevated temperature in diseased parts, show that the resistance offered by the vital force to the action of oxygen is feebler than in the healthy state. But this re- sistance only ceases entirely when death takes place (nos. 1, 46). By the artificial diminution of resistance in another part (as by blis- ters, sinapisms, or setons), the resistance in the diseased organ is not, indeed, directly strengthened; but the chemical action, the cause of the charge of matter, is diminished in the diseased part, being direct- PHYSIOLOGY.--ORGANIC CHEMISTRY--FUNCTIONS. 177 ed to another part, where the physician has succeeded in producing a still more feeble resistance to the change of matter, to the action of oxygen. 3501, b. "A complete cure ofthe original disease occurs, when ex- ternal action and resistance, in the diseased part, are brought into equi- librium. Health, and the restoration ofthe diseased tissue to its orig- inal condition, follow, when we are able so far to weaken the disturb- ing action of oxygen, by any means, that it becomes inferior to the re- sistance offered by the vital force, which,"although enfeebled, has never ceased to act; for this proportion between these causes of change is the uniform and necessary condition of increase of mass in the living organism." 350|, c. " In cases of a different kind, where artificial external dis- turbance produces no effect, the physician adopts other indirect methods to exalt the resistance offered by the vital force. He dimin- ishes, by blood-letting, the number ofthe carriers of oxygen (the glob- ules), and, by this means, the conditions of change of matter; he ex- cludes from the food all such matters as are capable of conversion into blood, &c. 3502, d. " If he succeed, by these means, in diminishing the action of oxygen in the blood on the diseased part, so far that the vital force ofthe latter, its resistance, in the smallest degree, overcomes the chem- ical action ; and if he accomplish this without arresting the functions of other organs, then restoration to health is certain. [! ] 350f, e. " Practical medicine, in many diseases, makes use of cold in a highly rational manner, as a means of exalting and accelerating, in an unwonted degree, the changes of matter. This occurs espe- cially in certain'morbid conditions, in the substance ofthe centre ofthe apparatus of motion; when a glowing heat and a rapid current of blood toward the head point out an abnormal metamorphosis of the brain [! ] (350, motto i, nos. 3, 5). When this condition continues beyond a certain time, experience teaches that all motions in the body cease. [! ] If the change of matter be chiefly confined to the brain, then the change of matter, the generation of force, diminishes in all other parts. [ ! j The metamorphosis which decides the issue of the disease is limited to a short period. We must not forget that the ice melts and absorbs heat from the diseased part; that if the ice be removed before the completion of the metamorphosis, the temperature again rises; that far more heat is removed from the head than if we were to surround the head with a bad conductor of heat. There has obviously been liberated, in an equal time, a far larger amount of heat than in the state of health. [That is to say, such is the pathol- ogy of cerebral inflammation, such the remedy, and such its modus operandi.] 35§\,f. "The self-regulating steam-engines, in which, to produce a uniform motion, the human intellect has shown the most admirable acuteness and sagacity, furnish no unapt image of what occurs in the animal body. " Every one knows, that in the tube which conveys the steam to the cylinder where the piston-rod is to be raised, a stop-cock of peculiar construction is placed, through which all the steam must pass. By an arrangement connected with the regulating wheel, this stop-cock opens when the wheel moves slower, and closes more or less completely M 178 INSTITUTES OF MEDICINE. when the wheel moves faster than is required for a uniform motion. When it opens, more steam is admitted (more force), and the motion of the machine is accelerated. When it shuts, the steam is more or less cut off, the force acting on the piston-rod diminishes, the tension ofthe steam increases, and this tension is accumulated for subsequent use. The tension of the vapor, or the force, so to speak is pro- duced by change of matter, by the combustion of coals m the fire- place. The force increases (the amount of steam generated and its tension increase) with the temperature in the fire-place, which de- pends on the supply of coals and of air (§ 433, &c). There are in these engines other arrangements, all intended for regulation. When the tension of steam in the boiler rises beyond a certain point, the passages for admission of air close themselves; the combustion is re- tarded, the supply of force (steam) is diminished. When the engine goes slower, more steam is admitted to the cylinder, its tension di- minishes, the air-passages are opened, and the cause of disengage- ment of heat, or production of force, increases. Another arrange- ment supplies the fire-place incessantly with coals in proportion as they are wanted. , "If we now lower the temperature at any part of the boiler, tne tension within is diminished. This is immediately seen in the regu- lators of force, which act precisely as if we had removed from the boiler a certain quantity of steam, or force. The regulator and the air-passages open, and the machine supplies itself with more coals. " The body, in regard to the production of heat and force, acts just like one of these machines. With the lowering of the external tem- perature, the respirations become deeper and more frequent; oxygen is supplied in greater quantity and of greater density, the change of matter is increased, and more food must be supplied, if the tempera- ture ofthe bodyis to remain unchanged."—Liebig's Animal Chemistry. Here ends the science of therapeutics, as founded upon the prece- ding doctrines in physiology and pathology; and as the whole system is comprehended within the limits of the last three pages, the reader will readily contrast its brevity with the labors of the past, and will not fail to discover in this time-saving, thought-saving attainment of medicine, as well as in the impenetrability of the system itself, and the unequaled confidence with which it is set forth, the main causes of its success. I shall now proceed, as proposed in § 350*, to demonstrate by the farther showing of chemistry itself, that physiology and medicine have little to hope from the laboratory of the chemist. 350^, a. Of the school of pure chemistry, and of an authority ap- proaching to Liebig, is the distinguished Professor Mulder; less in- consistent than Liebig, but compelled to admit the existence of pecu- liar forces in living beings, yet positively denying them. He advo- cates after the manner of Prichard, Carpenter, Fletcher, &c, the existence of all the properties of living beings in the elements of mat- ter which conducts him, like others, to the belief in Equivocal Gen- eration; adopts the Catalytic theory of Berzelius, in which he differs fundamentally from Liebig (§ 409, j); reasons, after the usual manner of the (.physical philosophers of.life, from the results of inorganic pro- cesses' and overlooks entirely, except by admission of their existence, all the unique phenomena of living beings, and, perhaps, more thab PHYSIOLOGY.--ORGANIC CHEMISTRY--FUNCTIONS. 179 any author of merit, is guided in his conclusions as to the processes and results of organic beings by the fallacious analogies which are studiously sought in the inorganic world. The whole system of vital philosophy, as taught by this distinguished Professor of Chemistry, may be so briefly set forth in extracts from his work on " The Chem- istry of Vegetable and Animal Physiology," and they convey so forci- bly the conjectural nature and worthlessness of chemical physiology, that the solection will contribute its important part toward the final expulsion of chemistry from the rich and fascinating domain of or- ganic nature. The quotations will be made in the order of their oc- currence in the work; and we learn from the first the author's opinion of force, which corresponds with my own as employed in the Com- mentaries, and as defended in my Examination of Reviews. Thus : 350f, b. " It is a matter of indifference whether we conceive that the forces slumber in two substances, and are brought into operation by contact; or that these forces were present in the two bodies in an active state, previous to the contact, but produced the phenomena of combination only during the contact. The mode of considering this point is almost a matter of indifference; but we must always bear in mind that it is a power, a force which is exerted by the one, and which acts upon the other."—Mulder. 350f, c. The next quotation is preliminary to the total denial of the Principle of Life, and of all the properties in living beings excepting such as are active or " slumbering" in the elements of matter. Here, too, appears the fallacy of analogies derived from the laboratory of the chemist. Thus: " Adhering to what we observe and know with certainty, we calcu- late that every elementary body is endowed with a great many specific properties, which, to a large extent, are dependent on the same prin- ciple that causes their combination, and thus on the proportion and character of the chemical tendency. If we adopt this idea, we have the advantage of seeing somewhat of vitality in dead matter. [! ] It is an idea derived from the endless series of phenomena which are observed in the laboratory, in daily occurrences, and in nature at large" (§ 175, d).—Mulder.—(§ 1034, Lehmann). 350f, d. After the usual disquisition upon the " catalytic action" of platinum and other inorganic substances, we come next to the same application of catalysis, in connection with the ordinary laws of chem- ical affinity, to the interpretation of organic processes and results, as I hare examined in the " Commentaries" (vol. i., p. 55-78). It com- prehends Mulder's whole theory of life, and is a good specimen of the author's analogical reasoning. Thus : " Platinum possesses chemical tendency in a high degree ; but it is of such a kind, that it does not react upon the platinum. Hence it may be inferred, that we have good reason for distinguishing by a pe- culiar name such actions as proceed from certain substances without reacting upon themselves; and we have to acknowledge that to the introduction, by Berzelius, of the peculiar term catalysis, we are in- debted for a more correct idea of the nature of ordinary chemical action. " What is called the nascent state of substances is that condition of the elements in which they exhibit both analytic and catalytic phenom- ena; in which, being free and unconstrained, not rendered powerless 180 institutes of medicine. either by being agglomerated into masses, or by combination into com pounds, they show themselves in their proper chemical condition; that is, an active one, in which they can operate upon others, excite a slumbering energy, and cause combinations and decompositions, in which they themselves may either participate or not. This nascent State is the real chemical, state of bodies. In that state both the ele- ments and compounds exhibit themselves in their true character. In the organic kingdom the greater number of substances are actually in that condition; and to this nascent state we ought to ascribe the nu- merous peculiar phenomena apparent in organic substances" (§ 409).— Mulder.—($ 1034, Lehmann). . 350J, e. The next quotation sets forth the whole practical applica- tion of the foregoing doctrines, and is a fine example of the chemical reduction of organic nature to the condition of dead matter, and one of the best summary exhibitions of chemistry in all its pretended re- lations to living beings. It begins with the caption " Disturbance of Chemical Equilibrium." "It is a property ofthe chemical forces, when active in any substance, to excite analogous forces in others. We notice this especially in organic nature, and it is nowhere more strikingly illustrated than in the nutrition of animals. Blood, a homogeneous fluid, circulates through very different parts of the body (§ 42). In the muscles it sustains muscles, in the liver it supplies the component parts of the liver, and from it the gall is there secreted; in the kidneys it maintains their various parts, and secretes the urine, &c. None of these secre- tions appear in the blood with their peculiar qualities ; of some of them not even a trace is found. But the four organic elements ofthe whole are to be found in protein and its combinations, in the coloring mat- ter of the blood, &c. The elements of protein might, no doubt, be transposed in the liver, &c, by means of catalysis, and so the compo- nent parts ofthe liver and gall be produced from it. It would only be necessary, then, that the constituent parts of the liver should be put into contact with the component parts of the blood, and the forces of affinity resident in the substance of the liver would not require to influence those in the protein, or to produce any chemical alteration in its component parts. " Other causes, however, ought undoubtedly to be considered. For instance, a change of its component parts takes place in the liver itself, and, from the first, chemical forces actively operate therein. For the continual change of its component parts is a chief character- istic of every living organic substance. These forces may disturb the chemical equilibrium of other substances, and cause the formation of new products. If the constituents of the blood—the combinations of protein, the coloring matter, &c.—enter the liver when it is in a state of action, and are there put in contact with the gall during its secre- tion, and with the substance ofthe liver itself, which is in a state of continual alteration, then the result will be, that this change of their component parts having taken place, the action will be transferred to the elements of the blood, and will maintain the secretion. If, on the other hand, the constituents of the blood are in a state of continual change, then the circle of action in which they are involved will ex- tend to the mass ofthe liver; and so with every organ (§ 18). PHYSIOLOGY.--ORGANIC CHEMISTRY--FUNCTIONS. 18] "We have, however, no more knowledge ofthe manner in which this secretion originally commences—whether it proceeds from the blood or from the secreting organ, [! ] or whether each of these con- tributes its part—than with the manner in which the first germ ofthe whole organ, the liver, is produced, or in which the germ of the ani- mal is converted into an animal. But the continuance of the action— the duration of secretion—entirely corresponds with some other phe- nomena, which we may observe separately, and which therefore throw light upon these animal actions. This is the case especially with fer- mentation, from which Liebig has drawn many illustrations, for the purpose of clearly exhibiting his ideas; and with the same view we shall also avail ourselves of this process. " Yeast changes sugar into carbonic acid and alcohol, and is at the same time changed itself. The latter change causes the former, and is only transferred to the sugar. If we substitute blood for yeast, and the liver for sugar, we may form an idea, more or less distinct, ofthe secretion ofthe gall. [! ] The component parts ofthe blood are con- tinually undergoing change. This constant change ofthe component parts in organic bodies is a chief cause ofthe continuation of their ex- istence. The liver without intermission assumes new parts and loses others. This process we call nutrition. At the same time that the parts of the blood in the substance of the liver are thus undergoing change, chemical forces are excited; these forces are transferred to the elements of the blood, and so are enabled to produce from them the gall. This takes place the more easily, as the blood itself is also in a state of continual alteration, and thus readily yields to the impulse which, in some way or other, is communicated to it. As the impulse varies, so does the effect. Hence that great diversity in the secre- tion of very dissimilar substances, which are in a state of alteration, from the same fluid—that is, the blood, which is itself at the same time in a state of decomposition."—Mulder. 35§\,f. In our next quotation we have an assumption founded on a begging of the very question aj issue; that is to say, whether there be or not a radical difference in the original constitution of organic and inorganic nature. The author having assumed that there is no difference, proceeds, by the force of surmised analogies drawn from the probable constitution of inorganic matter, to repeat the assump- tion already stated that there are no other properties in living beings than such as exist in the elements of matter. Thus : " The idea ofcommunication of forces is unsound ; it is only what is ^substantial that we can communicate. Forces may be excited, they cannot be communicated. Hence it results that every transformation in plants is effected by the molecular forces of carbon, hydrogen, ox- ygen, and nitrogen,—the elements of carbonic acid, water, and am- monia,—the forces being excited in these elements by the plants them- selves." " Any one who imagines that there is any thing else in ac- tion than a molecular force, than a chemical force, sees more than ex- ists. The forces excited in the elements vary with the influence which certain agents—temperature, moisture, light, &c.—exert. By the aid of crucibles and retorts, therefore, compounds can be formed which differ from those produced by the organs of plants; while, from car- bonic acid and water, plants can produce cellulose and oxygen, a result which cannot yet be imitated by art." " To express our idea in 9 182 institutes of medicine. few words:—The elements of the organic kingdom, carbon, hydro gen, oxygen, and nitrogen, are susceptible of endless modifications For that reason they can form, with minute changes, a great diversity of products (§ 41) ; and by the operation of the same primary forces, they stand toward each other in entirely different relations from those assumed by all the other elements ; so that they can produce a pecu- liar scries of bodies, which are called organic substances" !* " Organic substances, whether called germs or food, possess properties of a pe- culiar kind, existing in the four elements of which they are all constituted" !—Mulder. 350f, g. The difficulty, therefore, with the chemists appears to lie in their habits of reasoning exclusively from what they observe of in- organic compounds and their elements, and an indisposition to admit that the Almighty superadded to organic beings a principle of life, while they allow the special creation of mind in animals. Nor does their philosophy permit them to imagine that the former may be as capable of governing all the processes of organic, as the latter is of animal life, and that the principle of life may be supposed, with as much reason as the principle of intelligence, to be imparted by the exact organization perpetuated from the Almighty Hand to new ac cessions to that organization ; while the phenomena of life are far more multifarious and conclusive of the existence of a special princi- ple than such as oblige the chemist to yield his assent to a mental principle distinct from the matter with which it is associated. Why, then, does not the chemist equally maintain the existence of mind, as ofthe properties of life, in the elements of matter, and that its devel- opment is alike owing to a difference of circumstances 1 Does he fear that this stretch of materialism, this act of philosophical consist- ency, or his neglect to abjure the obvious inference, may impair our confidence in the apparently though not really less objectionable scheme of reducing organic life to the virtual condition of the simple elements of matter, and thus fail of inculcating the most dangerous atheism by attributing creative power to those elements (§ 14, c)? 350|, gg. But let us hear the chemist upon this interesting point. And Liebig, first; who, also, shall show that no injustice is done by the preceding remarks. Thus : "The higher phenomena of "Physiology has sufficiently de- mental existence cannot, in the cisive grounds for the opinion that present state of science, be referred every thought, every sensation, is to their proximate, and still less to accompanied by a change in the their ultimate causes. We only composition of the substance of the know of them that they exist, brain; that every motion, every We ascribe them to an immaterial manifestation of force, is the re- agency, and that, in so far as its sult of a transformation of the manifestations are connected with structure or of its substance."—lb. matter, an agency entirely distinct "Thought, sensation," &c, are from the vital force, with which " manifestations of force," and are, it has nothing in common."—Lie- therefore, " the result of," &c. big's Animal Chemistry. See Parallels, p. 158, no. 5-1.) And now the other able and distinguished chief: * See nvy " Notice of Reviews" ut cit., and my " Examination of Reviews" p. 43, 44, in " Commentaries," vol. iii. PHYSIOLOGY--ORGANIC CHEMISTRY--FUNCTIONS. 183 '' I will not venture to raise the veil, by which the action of thk nerves, or the higher functions of the mind, have hitherto been shrouded from observation. As man has an immaterial and immor- tal part, which is identical with his real being, and of which alone he will consist, when the material frame by which he is bound to the earth, shall be dissolved; and, as the inferior animals possess, in'com- mon with man, certain powers of perception, associated with certain appropriate organs, whose functions have no connection with con- sciousness ; so do animals and plants perform in common a great many operations which are distinct from both of those now mentioned, or which, at least, have their origin in distinct causes. " It is only the latter class of which I speak, and to which I apply the general term of organic life. To that subject I shall restrict my remarks."—Mulder, ut cit. Now, I say, 1st. Why not " raise #the veil from the action ofthe nerves" in a professed work on physiology, and a work, too, which would revolutionize the science ] Have you no phenomena to guide you in " raising the veil ]" Do you fear their contact with the phe- nomena of the laboratory1? Is it right to make this declaration, and then to refer a vast series of phenomena exclusively to " organic life," which could have had no existence without the " action ofthe nerves" (see § 350, no. I85) 1 I deny, too, 2d, that " the higher functions of the mind have hitherto been shrouded from observation;" and I am supported by all who truly believe in the independent existence of mind,; in the affirmation that its " functions" are characterized by an infinitely greater variety of unique phenomena than are the processes of inorganic nature. There is no "veil to be raised" in this or the other case. It is, indeed, by the recognition of these phenomena that our author feels obliged to admit the existence of " an immaterial part," however inconsistent the simultaneous declaration that " the functions of the mind have hitherto been shrouded from observation." And, I am alike sustained, also, and by every dictate of philosophy, in the conclusion that, if the phenomena of mind are decisive of the existence of " an immaterial part," so are the far more varied, and numerous, and equally unique phenomena of organic processes, con- clusive of the existence of some not less peculiar force, power, or " immaterial" or material "part," upon which they depend. In any event, however, the physiologist has a right to insist that the chemist shall not reject all considerations relative to the " action of the nerves," when he invades organic nature with retorts, crucibles, acids, &c. " Analogy is," undoubtedly, as Bacon says, " the basis of all the sciences." Nature, throughout, is bound together by analogies. The principle reaches from the Creator to the mind of man, to his " im- material and immortal part." And so it does from the force and the properties of life to those of dead matter. Here is the delusion of the chemist. But, there is even a wider difference between the formative principle of life and destructive chemical affinity, than there is between the Creative Spirit of God and the created, dependent spirit of man (§ 1076). 350|, h. The grand characteristic of organic life is the principle of life, capable of imparting that principle to matter which is destitute of it, and which it retains only while in its proper connection with the being by which it was so endowed. The doctrine which refers the 184 institutes of medicine. properties of life to the elements of matter is atheistical in its applica- tion (§ 14 c, 74, 175); and the recognition, simultaneously, of a "Cre- ative Power," is but another conventional word for nature, or design- ed to protect the doctrine against the fatal imputation of irreligion (§ 64, h). That imputation, however, is indelibly stamped by nature herself. The mode of defense is well shown in the late highly laud- ed and popular work on the " Vestiges of the Natural History of Creation," in which the author considers La Place's infidelity as to the modus operandi of matter in forming the Universe, and the doc- trine of spontaneous generation in its most ample extent. The au- thor's defense of Mr. Crosse's creation of animals out of silex is a good example of the specious reasoning by which so many are cheated into projects which contemplate the worst results to philosophy and relig- ion.* Thus: . 350f, i. " The supposition of impiety arises from an entire miscon- ception of what is implied by an aboriginal creation of insects. The experimentalist could never be considered as the author ofthe exist- ence of these creatures except by the most unreasoning ignorance. The utmost that can be claimed for, or imputed to him, is, that he ar- ranged the natural conditions under which the true creative energy, that of the Divine Author of all things, was pleased to work in this instance. On the hypothesis here brought forward, the Acarus Cros- sii [! ] was a type of being ordained from the beginning, and destin- ed to be realized under certain physical conditions. When a human hand brought these conditions into the proper arrangement, it did an act akin to hundreds of familiar ones which we execute every day, and which are followed by natural results, but it did nothing more." The defense of La Place's system proceeds upon the same specious assumption (p. 910-911, § 1083, p. 921-928, § 1085). Now the foregoing doctrine transcends not only the usual geologi- cal hypothesis of a successive creation of animals, but that, also, of spontaneous generation; both of which are, of course, anti-Mosaic, and regardless of the established order of creation (§ 303 a, 303*). But here we have an exemplification of a strictly atheistical expedi- ent, in the attempt to assign the existence even of organic beings to the merest chance, under the pretext of ascribing to that chance the intrinsic attributes of a Creative Power, and the imposing title of " the Divine Author of all things" ! It is the same with each and all who allow a God, a Creator, &c, yet reject entirely His Revelation as to creation, supported as it is by the most consummate and endless systems of Design. It is the old expedient of the wolf in the disguise of the sheep (§ 14 c, 64 h, 74, 733 d). 350|, k. Nevertheless, the foregoing work is powerfully sustained by able articles in the British and Foreign Medical Review for January, 1845, consisting of twenty-six pages of eulogistic remarks; and in the Medico-Chirurgical Review for the same month, often pages not less congratulatory. The work was published late in 1844, and, although not at all relevant to medicine, it was taken up with avidity by the two leading medical journals of Europe, and an effort * See Medical and Physiological Commentaries, vol. i., p. 707 ; vol. ii., p. 96. In vol. i., Grass is a typographical error for Crosse. It is also possible that the "created animals,' instead of being "crystalized spiculae," were real animals evolved by the action of galvan. sim from ova contained in the water (see § 74. 188J- d). PHYSIOLOGY.--ORGANIC chemistry--FUNCTIONS. 185 made to prepossess the medical profession before the work itself should fall under their observation; observing in this respect the sys- tem which was almost universally pursued by the periodical press even in anticipation of Liebig's work on Animal Chemistry. In my Essay on Spontaneous Generation, embraced in the Medical and Physiological Commentaries, I have had occasion to refer to the charge of infidelity which is often laid against the Medical Profession. [ have there, too, defended that Profession against so great an injus- tice, and have held responsible the proper Sources that have given rise to this imputation. I have also shown that that imputation is greatly due to the cultivation ofthe chemical and physical hypotheses of life, to which the foregoing Reviews have been laboriously devoted. In conclusion of the whole matter I have said that, " The steps are gradual from the incipient errors in natural philos- ophy to a disbelief in the Mosaic Record of Creation. When we have ultimately reached the brink of the precipice, there is but one dreadful plunge, and we are then in the vortex of atheism. We may begin, as I have said, by a simple denial of the living powers of or- ganized beings, when it will become, at last, an easy argument upon this, and analogous premises, that the Almighty had but very little, if any agency, in the most sublime part of existences." " Let philosophy interrogate nature to its fullest satiety, under the direction of its Heaven-born principles; but let it be consistent, and maintain its dignity. And should it sometimes, as it must in its wide range of nature, come in contact with miracle, that is its limit, con- tented that it begins at the confines of Creation; yet still may it stretch into the regions of Eternity, past and to come; but now it is employed in its nobler work of sacrificing its relations to second causes, and in establishing relations with the First Cause of All." —Medical and Physiological Commentaries, vol. ii., p. 140. 350|, kk. It is now my purpose to quote the foregoing Reviews in connection with the " Vestiges of Creation," partly for the object just assigned, and in part to supply other examples in justification of what I have said in behalf of the Profession, and of the tendency of the chemical and physical hypotheses of life and disease to lay the foun- dation of a grosser materialism, and of infidelity in Religion (§ 175). It seems peculiarly appropriate that Reviewers, who wield an exten- sive and powerful sway, and whose occupation it is to defame what- ever molests that dominion, should be used for the. contemplated pur- pose, and this, more especially, as both Reviewers offer defiance to the "Saints," and the "timid religionists." The Reviews are conducted with great diligence and research. Their influence is coextensive with medicine. That influence must be sapped by a display of its tendencies. There can be no difficulty with a defense of the right. The inculpated are able, their means ample, their coadjutors numer- ous and powerful, the public generous, and, as I said on a like occa- sion in the Commentaries, " I am single-handed, and have nothing but facts for my weapons" (vol. i., p. 391).—Note W p. 1127. Infidelity is certainly a term which should be well sustained in its application; better, at least, than when applied to myself by the first of the following journals (see Examination of Reviews, p. 84-88). As it respects the Reviewers, the imputation appears to be invited and expected, as an obvious consequence ofthe doctrines advanced; 186 INSTITUTES of medicine. and, although I do not belong to the denomination of" Saints," or of the " timid religionists," it is not less my duty as a man, and as an ex- pounder of the Institutes of Nature, to bring those institutions to op- erate upon infidelity. There can be no place more appropriate for looking " through Nature up to Nature's God," than in the general survey of organic beings. If ordained in their organization and their laws by a higher Power, that organization and those laws may well be urged in proof of their Origin. Then, too, shall the minister of health realize the importance of the Institutes of Medicine, and the spirit of the Hippocratic maxim, that " a philosophical physician is like a god." I shall quote a passage of general import from each of the forego- ing Reviewers, that no doubt may linger upon the mind of any reader as to the justice of the criticism which I have now exercised in behalf of religion, of morality, ofthe dignity of medicine. The emphasis is mine. And first the elder brother; beginning thus : " This is a remarkable volume, small in compass, but embracing a wide range of inquiry from worlds beyond the visible starry firma- ment, to the minutest structures of man and animals. No name is pre- fixed,—perhaps in order to avoid the snarls of the narrow-minded and bigoted saints of the present day," &c. The middle thus: " For how many millions and millions of years this production and reproduction of animals went on before man made his appearance on the scene, no human being will ever know. [! ] In all probability, countless ages must have elapsed, before this master-piece of creation appeared. Our author's speculations on the how, the why, the when, and the wherefore this great event occurred, will not give satisfaction to the present race of mankind. [! ] His hypothesis is three or four centuries in advance of the times, and will be stigmatized by the modern saints as downright atheism," &c. And the end, thus : " We have dedicated a space to this remarkable work that may in- duce many of our readers to peruse the original. The author is de- cidedly a man of great information and reflection. He will have a host of saints in array against him, and many will join in the cry, from hypocrisy and self-interest. As we said before, his doctrines have come out a century before their time."—Medico-Chirurgical Review, p. 147, 153, 157. London, Jan., 1846. Next, Dr. Forbes, in the British and Foreign Medical Review. " This is a very beautiful and a very interesting book. Its theme is one of the grandest that can occupy human thought,—no less than the Creation of the Universe." "We are also influenced by the abstract desire to place before our readers matter for their contem- plation, which cannot fail at once to elevate, to gratify, and to enrich the mind. It has always been one of the boasts of our noble profes- sion that it touches and blends with every science; and we should be sorry that our humble efforts should at any time be wanting to stimu- late its professors to exertions that might still justify the boast"! Of La Place's nebular hypothesis, he says : " So far from admitting the atheistical tendency which timid relig- ionists have attributed to the nebular hypothesis, we consider it the grandest contribution which Science has yet made to Religion," &c. PH1SI0L0GY.--ORGANIC CHEMISTRY--FUNCTIONS. 187 The reader, therefore, will have no difficulty in understanding the 'conventional" nature of certain phrases in the following remarks by Dr. Forbes. (See h.) " That the Creator formed man out of the dust of the earth, we have scriptural authority for believing, and we must confess our own predi- lection for the idea, [ ! ] that, at a period however remotely antece- dent, the Creator endowed certain forms of inorganic matter with the PROPERTIES REQUISITE TO ENABLE THEM TO COMBINE, AT THE FITTING season, into the human organism, [!!] over that which would lead us to regard the great-grand-father of our common progenitor as a chimpanzee or an orang-outang."—British and Foreign Medical Review, p. 155, 158, 180. London, January, 1846. (See I.) The author of the Vestiges of the Natural History of Creation is thus quoted by Dr. Forbes : " We have seen powerful evidence that the construction of this globe and its associates, and, inferentially, that of all the other globes of space, was the result, not of any immediate or personal exertion ofthe Deity, but of natural laws which are expressions of His will. What is to hinder our supposing that the organic creation is also a result of natural laws which are, in like manner, an expression of His will 1"—Natural History of Creation. Upon the foregoing extract, which is a part of a more extended one of the same nature, Dr. Forbes remarks, that, " The complete accordance of these views with those some time ago propounded by ourselves (vol. v., p. 342), must be evident, we think, to our readers. To the objection which some timid religion- ists may urge against them, that they are inconsistent with the Mo- saic record, we simply reply with our author, that we do not think it right to adbuce that record either in support of, or in objection to, any scientific hypothesis, based upon the phenomena of nature," &c! —British and Foreign Medical Review, p. 167.—Note Ppp. 1142. Dr. Forbes assumes, of course, that all the misapprehensions and perversions of " the phenomena of nature" are paramount to any thing declared in the Mosaic Record (§ 5\, 74, 733 d, 1079 b, 1085). The most superficial reader cannot fail of discerning in the fore- going principles, as in many other analogous instances, the motives which have induced those foremost medical Reviews to lend their powerful aid in propagating the materialism of Carpenter, the absurd- ities of Liebig, the humoralism of Andral, and the putrid anatomy of Louis, and of their respective schools; and why, on the other hand, they have been equally regardless of truth in their vocation as critics on the labors, the researches, and the statements of others.—NoteW 350f, 1. I have already shown in this and other works how conve- nient a matter it is for "the properties of life in the elements of mat- ter" to bring these elements into an organic state. And since I am now on the subject ofthe first and greatest step in the process of vivi- fication, it may be useful, as it is appropriate, to show how the advo- cates of " the properties of life in the elements of matter," and the propagators of spontaneous generation, and eminent geologists who promulgate a successive creation of animals according to their scale in organic nature and in conformity with the development of new physical agencies, ay, and certain eminent vitalists whose otherwise sound philosophy should have enlightened them a? to the Great First 188 INSTITUTES OF MEDICINE. Cause—in view of all these things, I say, it may be conducive tt sound physiology to show how the foregoing schemers of "creation" arrive, in part, at least, at the conversion of organic matter into the complex fabric, after that matter shall have been duly compounded by " the properties of life which reside in the elements." For this purpose I will take the statement of the distinguished vitalist Tiede- mann. Thus, " The most probable hypothesis is, that the substance of organic bod- ies existed primitively in water, as matter of a particular kind, and that it was thereendowed with the plastic faculty; that is to say, with the power of acquiring, by degrees, different simple forms of living bodies, with the concurrence of the general influences of light, heat, and perhaps also of electricity, &c, and of then passing from the sim- ple forms to other more complicated; varying in proportion to the modification occurring in the external influences, until the point when each species acquired duration by the production and manifestation of activity of the genital organs" !—Tiedemann's Physiology of Man. That is the doctrine, candidly avowed by those to whom genius and the conviction of a right discernment of the ways of nature impart a fearless independence, however it may be disguised by others under the " conventional term" of creation. But, Tiedemann is a philosoph- ical vitalist, and did not confound the principle of life with the forces of inorganic matter, nor, like Carpenter, Fletcher, Prichard, Roberton, Forbes, &c, place the properties of that principle in the elements of matter. He started with matter in more or less of an organic state, and leaves it problematical how its elements became united into that peculiar vital compound. He did not even imply that the elements being so endowed could organize themselves, for he adds to the fore- going statement, that, " Although we cannot here answer the question, whence came the water and "he organic matter which it contained, yet this hypothesis is the one which accords best with the facts with which geology has lately been enriched." And again, " If it be asked, whence organic matters proceed, how they are produced, together with the power of formation inherent in them, we are necessitated candidly to confess our ignorance on the subject, inasmuch as the first origin of organic matters and living bodies is altogether beyond the range of experi- ment."—Tiedemann's Physiology of Man, p. 14, 193. It will be thus seen that even Tiedemann's doctrine enjoys " a loop- hole" which cannot be allowed to those who place " the properties of life in the elements of matter," or who endeavor, or propose, to ere ate organic compounds in the laboratory of the chemist; since, in re- spect to the latter, were the production of organic compounds within " the range of experiment," the accidental nature of the origin of such compounds, and, therefore, the incipient being of man, would be established by the laboratory. And now I ask, does not the or- ganic chemist attempt or profess to create organic compounds 1 So says Liebig, § 350, no. 39, and so say most other distinguished chem- ists. • Liebig and his disciples create the compounds ; Crosse and his followers create the animal. Others do but make the attempt; and this is a very numerous class who thus enter into competition with the Original Author of organic compounds. What, therefore, is the difference in principle between him. who pretends to have succeeded PHYSLOLOGi.--ORGANIC CHEMISTRY--FUNCTIONS. 189 in this work of creation, and the other who has attempted the work, but without success % From the physiologist who advocates the existence of " the proper- ties of life in the elements of matter," we hear that, " There is no reasonable ground for doubt that if the elements could be brought together in their requisite states and proportions^ the hand of man, the result (artificial organic compound) would be the same as the natural compound." Again, " that the germs (of parasitic plants and animals in the interior of others) have been conxeyedfrom without into the situations where they are developed, must be held as a very forced supposition" !—Carpenter's Principles of General and Comparative Physiology, p. 146, 395 ; also, this work, § 14 c, 175 c, d, 189 b.—See doctrine of "Development" p. 922, and Note Pp p. 1142. 350f, m. Mulder has the manliness to carry out the obvious ten- dency of his doctrines, which may be expressed in a brief quotation. Thus, " Upon the principles which have been stated, no room is left for the dispute as to equivocal generation and epigenesis." Nevertheless, it is allowed by Mulder that cellular structure " cannot yet be imitated by art." But, waving this conceded difficulty, if the physiological ar- guments which I have advanced in section 14 c, as to a real Creator, can be invalidated, I shall concede that a ground has been obtained for the doctrine of spontaneous generation (§ 1051, p. 922, § 1085). 350|, n. As I shall soon dismiss this author, it may be useful, in consideration of his exalted worth as a chemist, and his authority among physiologists, to show that even one who endeavors to hold a consistent philosophy on the subject of chemical physiology, yet sees in organic beings so much to contradict his chemical doctrines, that he evinces the usual inconsistency of those who have endeavored to con- found the science of life with that of chemistry (§ 4£, d). For this purpose I shall select two passages only, and place them in parallel columns, after the manner adopted in relation to Liebig in section 350. I shall elect, also, for the negative side, a passage which will show, what cannot be too often repeated, that the chemists are absolute- ly regardless of their own fundamental doctrine, of " ascending from phenomena to their causes," by rejecting all the unique phenomena of life as indicative of any peculiar force or laws. The affirmative side, however, is all that the vitalist desires (§ 189). Denial ofthe Vital Principle and Recognition ofthe Vital Principle Vital Properties. and Vital Properties. " Wherever forces are found in " The question is, whether, du- organic nature, there are substan- ring decomposition, the organic ces which are all supplied with forces grow weaker of them- molecular chemical forces. Even selves, permitting the elements to those singular structures, the obey their primary tendency,—or nerves, consist of the same ele- whether causes must exist by ments as the ordinary substances which these organic forces are of the organic kingdom. It is made weaker 1 Neither is im- thus undeniable, that the molecu- probable. Every thing which lar forces act a chief part in the ceases to be subject to the vital organism, so far as a change of principle, becomes incapable of substances takes place therein; being stimulated by the vital « 190 institutes of medicine. and that no general, no vital force, should be assumed as the source of those molecular forces. Such a vital force is irreconcilable with the true principles of science, which require that nothing should be assumed as existing, but that every thing should be sought for in nature; which teach us to as- cend only from an unprejudiced consideration of the phenomena to their causes, and to assign those causes only as we deduce them from the observed phenomena." —Mulder's Chemistry of Vege- table and Animal Physiology, p. 68. 1845. forces ;—it is placed in 6ther circumstances; and as the prod- ucts OF THE VITAL FUNCTIONS ARE DIFFERENT FROM THE PROD- UCTS of inorganic nature, in consequence of the very differ- ence of the circumstances ir. which the elements are placed, sc the products of substances, de- prived of vital influence, must also greatly vary with circum- stances. Hence it may happen, that the forces present in organ- ic substances, when deprived of the vital influence, may disap- pear of themselves. The impres- sion they had at first received is changed, modified, obliterated and therefore the effects can nc longer be the same. A substance persists in the state into which it xv&s first put, according to the law of inertia ; but the maxim, sub- lata causa tollitur effectus, is of equal value."—Mulder's Chem- istryof'Vegetable and Animal Phys- iology, p. 54 (§ 59). I shall conclude with an extract from Mulder, in which it will bt seen that he has adopted the method set forth by myself in my Essay on the Philosophy of Vitality" (1842), of investigating the subject in the development of the germ. It may be useful to place in contrast the purely chemical and the purely vital interpretations of that devel- opment (§ 65). I may also premise that it should be observed that the chemist keeps out of view all the remarkable circumstances at- tending the development ofthe egg which I have set forth as irrecon- cilable with chemical phenomena, and limits himself to statements founded on a supposed analogy with the simple results of chemical affinity as observed in inorganic nature. Thus : " If we review the phenomena of life, caused by change of materi als, we must go back to the original formation of organs—to the growth of an individual from a germ." After illustrating the devel- ment of the germ by " an example from the inorganic kingdom" (the formation of prisms from a solution of the sulphate of soda!), this distinguished chemist proceeds to say, that " Undoubtedly the differences which exist between the particles of the same organic substances are not chemical, in the ordinary gross signification, but are of the nature of those which are connected with polymorphism. The chemist gives us but a rude result—the compo- sition in a hundred parts, frequently not affording us any insight into either the real characters of substances, or into their real differences. Whenever such dissimilar particles come together, a compound must be produced, possessing peculiar forces, which, though dependent upon PHYSIOLOGY.--ORGANIC CHEMISTRY--FUNCTIONS. 191 the molecular forces of the elements, are yet not determined by these alone. The new arrangement causes a modification of those primary forces. Whenever it takes place, they appear modified, and therefore indicate their presence by producing new effects. In sulphate of soda, the whole collected forces of its constituent molecules—those of sul- phur, sodium, and oxygen—are still existent; and upon these alone depend its qualities, composition, and crystaline form. Sulphate of soda cannot possess other qualities—cannot become other in property —than what results from its elements, and exclusively originates in these. " Thus, then, we suppose that the molecules of the substances in the embryo are arranged, in the first place, simply, and afterward more complexly. Not a trace of any organ is as yet perceptible, however; nor of any force, therefore, by which these organs will be governed. By the new arrangement of the particles, the molecular forces are modified anew, and this process is continuous. Although the primary forces, once united with the materials, remain the source of every ac- tion, of every manifestation of phenomena, of every chemical and or- ganic, that is, physical, combination ; they must, nevertheless, produce different effects, as the combinations become more complex. Each existing particle is the germ of a subsequent one, which is more com- plex; and, while the temperature necessary for hatching keeps the primary forces always excited, there is originated in the new arrange- ment of the particles, and also in the forces proceeding from the groups recently formed, a modification of these primary forces, which is constantly on the increase. " The whole material ofthe embryo in the egg is gradually brought in this manner within the circle of action. Then the circle is still more extended, and in its action are comprehended the elements of the yolk, and also of the albumen. These are erroneously called the food of the newly-formed chicken, or its rudiments. In these ele- ments there are forces also conjoined with the materials—chemical forces, analogous to those which exist in the embryo, and contributing to the production of the whole. These forces differ from those found in the embryo, not in nature, but only in direction, or in the mode of manifestation."—Mulder, ut cit, p. 71-73. 351. Having in the preceding sections, as well as at other times, summoned, in behalf of truth, and of the noblest institutions of na- ture, an adverse party, and having shown, not only by the nature of the pursuits which engage the whole practical attention of the leaders of that party, but by an open cross-examination of the acknowledged chiefs, that the entire field of physiology and medicine remains, as ever, in sole possession of those who are employed in its cultivation, and that, by no possible accident, fraud, or conspiracy, can it be trans- formed or transferred into the laboratory of the chemist, I shall pro- ceed to a more critical examination of the philosophy of digestion, both in its vital, and its supposed chemical attributes. 352. All other processes o01iving beings, whether animal or vege- table, and especially the whole work of assimilation after the entrance of the food within the lacteals, being exclusively vital, it follows, as a great analogy of nature, that the first step in the process of assimila- tion is equally due to vital influences (§ 323-326). 353. Since every species of complex animals has some peculiarity of 192 INSTITUTES OF MEDICINE. organization, not only of the alimentary canal, but of the liver, sali- vary glands, pancreas, te 3th, jaw, skeleton, muscles, and also of in- stinct, corresponding with a certain modification of the vital endow- ments of the gastric juice in each species of animal, which shall be exactly, and forever, and undeviatingly suited to the digestion of those kinds of food which were ordained by the Creator for the sustenance of each when He thus wonderfully instituted this almost endless sys- tem of exact Designs; each individual part having its specific final cause, each final cause modified in every species and with correspond- ing peculiarities of organization, and all concurring to one great final cause of subserving those exigencies of life which are fulfilled by the gastric juice, and whose modifications in different species of animals harmonize with the special attributes of all the concurring causes, and so suited by Infinite Wisdom to the nature of the food of every ani- mal, that its incipient change shall be one of assimilation to the nature of the being, yet nearly coincident in all animals from the general co- incidence in all organic compounds; I say, in all this labyrinth of De- signs, so exactly modified in every species, yet correspondent in all, and each and all, in their individuality, their variety, their modifica- tions, and their unity of purpose, having a specific reference to the alimentary material of each species of animal, we see in perpetual progress what is equivalent to a never-ending voice from Heaven, proclaiming that the organic stomach has no parallel in its capabilities and results in the inorganic world, or in the laboratory ofthe chemist. But this is not all; nor will I fail to convert the stupendous whole, as I advance with the details of assimilation, to the fundamental philoso- phy of organic life. 354. The constituent elements of the food having been subjected to special transformations, and imbued with the first gradations of life, by the vital action of the salivary and gastric juice, and perhaps, also, by contact with the stomach, is thus converted, in all animals, into appa- rently one and the same homogeneous product. It is then submitted to the farther organizing effects ofthe bile and pancreatic juice, pass- ed through the wonderfully vivifying lacteals, carried forward and subjected to the whole animating influence of the pulmonary system, perfected in its exalted endowments by the whole labyrinth of the circulatory organs, and, lastly, though not least, the various com- pounds are determined, each and all, from that one homogeneous fluid, and in one everlastingly exact manner, and according to the nature of each part, by Other complex living systems, and thus per- petuated forever in all their exact varieties,—but how, no imagina- tion can form the most remote conception, but through the instrumen- tality of those specific properties of life which were the only power concerned from the beginning to the ending of the astonishing series of unvarying changes (§ 42); and, however it be that each ultimate product is destined for the immediate uses of the individual, it is un- deniable that the great final cause of every step in the assimilating pro- cess, till it results in the formation ofblQd, is the reproduction of gastric juice for the maintenance of an unceasing supply to the exigencies of organic life, and the perpetuation ofthe species (§ 41, 323-326). 355. The gastric juice being designed to prepare the material for the formation of blood has its powers so constituted as to be merely an agent. The blood, being the pabulum vita fully prepared for the PHYSIOLOGY.--ORGANIC CHEMISTRY--FUNCTIONS. 193 regeneration ofthe gastric juice, aa well as of other organic compounds (§ 354), is mostly a substance acted upon by the living solids, or by the ovum-cell, just as the food had been by the gastric juice, while it serves, also, as a stimulus to the vascular parts, and is highly endow- ed with the properties of life to facilitate its conversion into living solids or fluids, and to make its presence in the blood-vessels compat- ible with their life.—Note R p. 1123. 356, a. While we are thus employed in describing the various de- rails of assimilation, attention is unavoidably arrested by the magnifi- cence of its unique philosophy, and by the ultimate aim of every de- tail of all the immense variety (§ 353-355), even excretion itself (§ 412, &c), at the production of gastric juice ! And as we penetrate the more latent, but yet more impressive physiological laws to which that juice is obedient, we rise in admiration of the preliminary means of their fulfillment; and now again addressing myself to the chemist, I ask him as a philosopher, as one who would protect the consistency of his own science, what can be more emphatically significant ofthe abstrac- tion of digestion from chemical agencies than the fact that the nervous power so modifies the vital constitution ofthe gastric juice that it faila of its usual function when a division is made of the pneumogastric nerve 1 Imagination can surmise no connection between the nervous power and the processes of chemistry. And yet do the writings of Liebig, and of other organic chemists, abound with assumptions that the supposed affinities of chemistry, as operative in animals, are sub- ject to the nervous power! though it is conceded that the nearly co- incident processes and results in plants sustain no such nervous influ- ences (§ 500, nn). " The animal organism," says Liebig, truly, " is a higher kind of vegetable." To suppose that such powers operate in harmony together, and that the mind or its passions are capable of in- fluencing, extensively, the operation of chemical forces, in constantly modifying the various secreted products, both as to quality and quan- tity, is a positive violation of the most obvious and universal rules in natural philosophy (§ 455 a, 461, 478 b, 488±, 493 cc, 893 a, c, 893£). 356, b. It is evident that a great difficulty exists with many, who admit a principle of life in relation to the solids, in imagining a fluid to be equally endowed, and alike capable through that principle of acting upon organic matter. But we must take the facts as we find them, nor allow inorganic nature the slightest interference. If analo- gies must be had, let us seek them in the organic being, and we shall be certain of success. In the instance before us we have the admit- ted vitality ofthe blood; but, unlike the gastric juice, it produces no changes in matter. We have, however, the simple ovum, " whose vital properties," in the language of Dr. Carpenter, " confer upon it the means of itself assimilating, and thereby organizing and endowing with vitality the materials supplied by the inorganic world" (§ 64, g). Here, then, the analogy is remarkably forcible, and the more so, as the fact is conceded by the strictly chemical school of digestion. So, of the semen, in another aspect ofthe active condition ofthe principle of life in an organic fluid; this substance, through that principle, being ca- pable of modifying the organic constitution of the ovum in such wise, that the offspring shall inherit the intellectual, vital, and physical pe- culiarities ofthe male parent, with six fingers instead of five (§ 72, 73). 357. One of the most important arguments in favor of vital diges- N 194 INSTITUTES OF MEDICINE. tion consists in the remarkable endowments of the stomach, as mani- fested by its vital signs, and by the sympathies which prevail between this organ and all other parts. The final cause of this peculiar con- stitution ofthe stomach, this lavish supply ofthe properties of life, this subservience of other organs to its dominion, must be sought in its adaptation to the generation of a fluid that may bestow the first and most difficult act of vitalization upon dead matter (§ 356, a). There would also have been something harsh and abrupt in nature to have admitted into the recesses of her living organization mere dead mat- ter. It is opposed to all analogy, and is, therefore, opposed to all reason. But, that a fluid should perform this astonishing office, this first and great step in the ascending series, it must possess in a high degree the principle of life. Mysterious as it may be represented, we must all of us come at last to the admission ofthe existence of a vital principle; yet far less mysterious, and far less difficult of comprehen- sion than the human soul. It is fair, then, to conclude that an organ destined for such a high function should possess that principle, in common with all other parts, as the means on which its function de- pends ; and the best evidences in favor of this analogical inference are to be seen in its diversified manifestations of life. 358. We have seen, also, that it is conceded by philosophers who defend, in extenso, the chemical hypothesis of life, that there may be something appertaining to the stomach totally distinct from the chem- ical powers, and which is capable of imbuing the chyme with vitality and an organic condition ; and it is, therefore, quite a philosophical conclusion that this vital something has an important agency in pre- paring the material for the admitted exercise upon it of the vivifying or organizing power. Nor can there be any valid objection to the supposition that this vitalizing power, which so far transcends the chemical forces in the organizing effect it is allowed to exert, may be fully adequate to any transmutations the food may undergo; and this inference is the more corroborated by the consideration that matter already in an organic state must be better fitted for the process of vivification than it can possibly be after its elements are broken up and recombined by forces with which those of life are in absolute op- position. Besides, the vitality of the gastric juice, or the vital influ- ence ofthe stomach itself, being fully admitted, and even capable of organizing the food anew, should sufficiently protect the alimentary matter against any chemical agencies which have been supposed to operate. That this counteracting power, indeed, prevails to the full extent which I have alleged, appears to be rendered certain by the ordinary absence of any of those chemical changes which take place where numerous substances are mixed together out of the stomach— substances which often possess strong chemical affinities for each other, and whose operation within the stomach would be promoted by its high temperature. On the contrary, whatever the variety, it is uniformly resolved into otie and the same homogeneous substance, ut- terly unlike the results of chemical reactions of one kind of food upon other kinds; and what is also as conclusive as it is astonishing, the chyle is apparently the same substance in all animals. Chemistry must here be consistent with itself, and not renounce, for the sake of hypothesis, those precise laws by which, in its legitimate pursuit, it lays open, with astonishing exactness, what had appeared the arcana PHYSIOLOGY.--ORGANIC CHEMISTRY--FUNCTIONS. 195 of nature. Here, too, upon the chemico-physiological hypothesis, is presented an instance in which it is necessarily assumed that the properties of life and the forces of chemistry act together in concert in converting dead into living matter—one destroying, and at the same moment the other vitalizing! while the assumption is contra- dicted by all that is known of the relation of these forces to each other (§ 301, 338, 360, 436). Nor may we lose sight of the demand of philosophy not to multiply causes where one is perfectly adequate; and especially where it is admitted that all the others are of themselves wholly inadequate. 359. The last remark may be also equally applied to a common as- sumption which is set forth in the following apparently plausible man- ner : " The vitalists," says one of their opponents, " are loath to admit the operation of chemical agents at all, and would seem to consider it derogatory to suppose that any changes, save the subtle ones effected by the powers of life, are worked upon the aliment." " The vital principle" he says, " whatever it may be, incessantly makes use of chemical and mechanical agents for its purposes; and it is no more degrading to it to employ an acid liquid, and a triturating process, in order to digest the aliment, than it was to have recourse to bony lev- ers, cartilaginous pulleys, and tendonous ropes." Here, in the first place, will be observed an entire begging of the question as to digestion by an acid, since that has never been shown, and is the main point at issue. It is a perfectly unfounded and ex- torted inference from the factitious analogy supposed to be seen in the admitted mechanical movement ofthe food in the stomach, bony levers, cartilaginous pulleys, &c. But the pretended analogy, I say, is utterly inapplicable, were it admissible to reason from better prem- ises of this nature to the existence of important facts which have no other foundation. The bony levers, muscles, tendons, heart, and large blood-vessels, are mere instruments acted upon by the vital principle, and have no part in the vital results, except as they are the passive instruments ofthe properties of life. The same distinction exists be- tween the process of digestion, and the mechanical movement of the food in the stomach, or the " trituration" of the food, as it is errone- ously called by the writer just quoted; since food is not triturated h\ the stomach excepting where that organ is designed to supply the place of teeth. There exists, I say, a total want of analogy between that mechanical movement of the food and the assumed action of an acid ; since, in the latter case, a radical change is supposed to be wrought in the alimentary mass, while no such change is wrought by the mere movement, or even by the trituration or grinding of food in the stomach. The contractions of the stomach, which are purely of a vital nature, facilitate the process of digestion; but they do no more than to expose the food freely to the action of the gastric juice, by which, alone, the conversion into chyme is performed. The contrac- tions, or "trituration," are exactly on a par, as auxiliaries to diges- tion, with the teeth, or with the knife, which divide the food. The acid alone applies to the supposed chemical process of chymification. This is the only agent, involving the only force distinct from the vital principle that is supposed to operate, and to take part with the prop- erties of life in the functions which belong to these properties. Nor is this all. Those chemical forces, or an equivalent agent, are sup- 196 INSTITUTES OF MEDICINE. posed to aj. pertain to the gastric juice (a product of the most highly endowed organ in the animal system); and through that product, and by that product, to operate independently of the vital properties, or, under their control. But, here it may be again affirmed that through- out nature there is not an analogical fact to warrant the conclusion; and with equal truth it may be said that there is nothing to aid our conception of the co-operation of the chemical and vital forces, while all that is known of their relations to each other proclaims their ab- solute independence.—Med. Chirurg. Rev. Lond. vol. 29, p. 107. 360. But, again, it is the admitted final cause ofthe gastric juice to bestow life upon dead matter, while it is incontrovertible that inorgan- ic matter is insusceptible of any such influence from gastric action. Every fact proclaims that nature has provided the vegetable kingdom for, the purpose, especially, of determining organic combinations out of inorganic substances for the sustenance of animal life. In the lan- guage of Liebig, " The first substance capable of affording nutriment to animals is the last product of the* creative energy"—ay, "the creative energy," he says, " of vegetables."—(Animal Chemistry.) It is manifest, therefore, that it would be an absurdity on the part of nature to have ordained that chemical agencies should operate even at the very threshold of life, at the very fountain for which she had provided elaborate means to subvert the combinations of chemistry, and to bring them into those entirely new arrangements that approx- imate the changes they are destined to undergo in the animal stom- ach. And far less probable is it, that this fundamental principle should be lost as we ascend from vegetable to animal organization; since every chemical result within the stomach would tend to reduce the aliment to the state of that inorganic matter whose complete re- duction into organic compounds was effected by the vegetable king- dom for the uses of the animal. Such chemical results, therefore, would counteract the great final cause of nature, in either organic kingdom; and, in the animal, would render the means of sustenance more and more indigestible, and progressively liable to the condition of inorganic matter (§ 338).* This is fully allowed by the chief of the school of pure chemistry, as shown in the foregoing parallel quota- tions. Take another summary statement, than which nothing can be more contradictory of the chemical rationale. " While no part of an organized being," says Liebig, " can serve as food to vegetables, un- til, by the process of putrefaction and decay, it has assumed the form of inorganic matter, the animal organism requires, for its support and development, highly-organized atoms. The food of all animals, in all circumstances, consists of parts of organisms."—(Animal Chemistry?) Chemical philosophy should consider that nutriment of an animal na- ture requires but little more than the solvent process, and the bestow- raent of vital properties ; while, in accordance with its crude hypothe- ses, animal compounds must be, more than vegetable, subject to dis- organizing agencies, and thus more completely removed from their original and near approximation to those of the living animal (§ 18 a). 361. But again I say, if the vital principle be " capable of making use of chemical agents," no reason can be assigned why it may not be equal to the whole work of digestion, and of every other process * This argument is adopted by a writer (a distinguished chemist!) in the Amer. Journ. of Science and Arts, May, 1869, who verbally agrees with me that—" The forces of life and inorganic nature act in opposite directions, the former upward, the latter downward."—See § 301, and p. 911, § 1083. Also, p. 236, § 436.—(1860). PHYSIOLOGY.--ORGANIC CHEMISTRY--FUNCTIONS. 19"? of living beings. The simple construction may be comprehended, while the other is utterly unintelligible. The former alone is agree- able to the rules of philosophy, and abolishes the inextricable confu- sion which attends the chemical hypothesis. What, indeed, can be meant, by the vital properties making use of chemical forces 1 Can there be a more glaring absurdity ] more absolute nonsense ? How are those chemical forces brought into use, how held in subjection, how forever maintained in one exact operation in each particular or- ganic process, of which there are multitudes, distinct from each other, going on in the same individual 1 How do they elaborate from one common, homogeneous fluid, either the blood, or the sap, all the va- rious, unique, unchanging, secreted products of the whole organic be- ing'? Products, forever the same in every part, yet differing from each other according to the nature of the part1? Did you ever hear or dream of any thing analogous to this in that inorganic world where chemistry holds its empire ] When do those chemical forces begin to operate, in the living body, what part do they perform, and what is the allotment of the properties of life 1 Is there any known concert of action between the two species of forces 1 On the contrary, is it not every where demonstrated that the properties of life are in direct opposition to the forces of chemistry ] Whatever be the construction, by uniting the two forces (as is done by the only chemical school that is entitled to a respectful notice), we convert what is a simple problem, like all other processes of nature, into the greatest paradox that has been yet devised by the ingenuity of man. It is in vain to say that some one or two of the products of organization, such as carbonic acid, and urea, are such as result from chemical affinities, since these are excrementitious; while chemistry assures us that all organic compounds are utterly different in their el- ementary combinations from any compound of a chemical nature. Thus might I go on to argue this subject upon general principles alone; while at every step of the argument we should see the whole chemical hypothesis of life taking its proper rank as a dream of the imagination, or as a project of ambitious minds. 362. Digestion having been assumed to be more or less, or alto gether, a chemical affair, it rationally followed that it might be imita ted by art. Accordingly, when this ambitious science had succeeded in turning the whole inorganic world into the laboratory, it set itself at the manufacture of organic compounds, and even at the entire ani- mal. It did not, like Alexander, sit down and weep because it had no more worlds to conquer; but, like Shakspeare, having " exhaust- ed worlds, it then imagined new." Even eminent physiologists, who should look with jealousy upon any invasions upon the laws of nature, especially upon such as it is their peculiar province to illustrate, be- gan the manufacture of gastric juice by fire and acids, and metallic salts. We are thus presented by these philosophers with artificial compounds, of a most incongruous nature, and we are told that each one is the gastric juice; that each is capable of the same precise results as that universal product of animals, apparently the same in all, and elaborated from the blood by an organ of the highest vital endowments, and to which there is nothing analogous in all the other products of living beings, each product being, also, equally unique, and all derived from one common source (§ 135 a, 314, 419, 827 b). 198 INSTITUTES OF MEDICINE. 363. A diversity of opinions exists as to the real nature tf the chemical agent supposed to be employed by nature in the process of digestion. Free muriatic acid having been found, or supposed to ex- ist, in the stomach, it has been concluded by many that this must be the great agent; while Dr. Prout, and others, affirm that " free mu- riatic acid more or less retards the process of reduction." Dr. R. Thompson, however, states that, by digesting muscular fibre in dilute muriatic acid, he produced a substance "exactly resembling chyme." This experiment was pretty widely repeated, and many were equally successful with " dilute muriatic acid" as was Dr. Thompson. Oth- ers, on the contrary, declared their failure, and others, like Dr. Prout, maintained that this acid retarded digestion. Eberle had already ad- vanced the hypothesis that mucous membranes, no matter whether of the stomach or the bladder, dissolved either in muriatic or acetic acid, would form the true gastric juice, and perform its wonderful opera- tions. There is now a general bias in favor of one of these com- pounds, though other preparations are supposed by many to form very good gastric juice. Again, it is said that the "digestive mixture," as it has been well denominated by the manufacturers, " retains its sol- vent properties for months," while the gastric juice loses its solvent power soon after its abstraction from the stomach (§ 341). And what equally establishes a total difference between the " mixture" and the gastric juice is the no small circumstance that the chemist may torture and extinguish the artificial "digestive principle" in a variety of ways, and then transmute it back in all its vigor. Thus, according to Schwann and Miiller, the artificial "digestive principle" maybe neutralized by an alkali, and afterward " precipitated from its neutral solution by acetate of lead, and obtained again in an active state from that precip- itate by means of hydro-sulphuric acid." This precipitate, we are told, when thus treated, and thus compounded of principles radically different from the original mixture, is essentially the same as the gastric juice, and that the results of such artificial preparations must be taken as the test of the physiology of natural digestion ; that, aban- doning nature, we must look to the resources of the laboratory for any satisfactory account of her vital processes. Nor do I at all exag- gerate ; for it is distinctly avowed that we knew nothing of digestion till the invention of the artificial mixtures. Thus, it is said of Schwann by one so able and distinguished as Miiller, that he (Schwann) "hav- ing discovered that the infusion of dry mucous membrane with dilute acid, even after it is filtered, still retains its digestive power, the di- gestive principle, therefore, is clearly in solution, and the theory of di- gestion by contact falls to the ground." Here, a most important phys- iological induction is wholly founded upon a process which has not the most remote connection with organized matter. 364. I have said that the experimenters took the hint of manufac- turing gastric juice from the occasional discovery of an acid in the stomach. But, this is undoubtedly a rare phenomenon in a healthy stomach, and where the food has been at all appropriate in quality and quantity. The chemical hypothesis, as I have said, was long ago in vogue, and was put at rest by demonstrative proof. Distinguished observers, Hunter, Haller, Willis, Spallanzani, Fordyce, and more recently Dumas, Schultz, and others, insist that the reputed acid is the result of a true chemical decomposition of vegetable matter. PHYSIOLOGY.--ORGAa C CHEMISTRY--FUNCTIONS. 199 Spallanzani, whose experiments were almost endless, Scopoli, Chev- reuil, and others, rarely succeeded in finding it at all, and in some an- imals never. Spallanzani, indeed, affirms that the gastric juice is neither acid nor alkaline in its natural state. As far back as Haller's day, when this subject was agitated, it is said by this illustrious and accurate observer, that, " although there may be some rare signs of an acid in the stomach, it does not, there- fore, become us to suppose that food is animalized by a chemical process; much less to compare this process with the action of an acid." And, anticipating the modern experiments with the " diges- tive mixture," he declares of analogous proceedings at his own era, "frustra etiam quisquam, imitatus liquores acres chemicos, liquorem corrodentem invenerit, qui carnem in pultem resolvat." And there can be no doubt that Hunter's prophecy holds good to this day, that, " If ever any matter is formed in any of the juices secreted in any part of a vegetable or animal body similar to what arises from fer- mentation, we may depend on it, it arose from that process; but we may also depend on it, that there is a defect of the living principle in these cases." These are not the mere speculations of genius, but the facts and the conclusions of genius after a long, and wide, and experimental survey of nature. And are these observations, nay, our own experi- ence, our own senses, to be set aside to accommodate an hypothesis of'life which identifies dead, even inorganic, with living beings 1 364|. But perhaps even a greater violence, than the foregoing manufacture of gastric juice, has been recently done to physiology, in the alleged conversion, by chemical manipulations, of the secreted products of organs, totally unlike, into each other. It should be con- ceded, however, that this has been generally sanctioned by the jour- nals of the day. Thus, in the London Lancet for July, 1845, is a quotation from the report of MM. Villefranche and Barreswill to the French Academy on the " Chemical Phenomena of Digestion," from which the conclusion is deduced that " Thus, it appears easy to transform-the gastric juice, the pancreatic fluid, and the saliva, into each other, and to make an artificial gastric juice from the pancreatic fluid, and vice versa"! It appears, also, from these late experiments, that the digestive principle depends on an organic matter, that " the said matter may be destroyed by an elevated temperature," and that " its digestive pow- ers vary, according as it is associated with a fluid having an acid or an alkaline reaction." It would seem, therefore, not improbable that a new hypothesis will soon be in vogue, and that the acid principle will be abandonee to satisfy the claims of new aspirants. 365. The assumed identity of the artificial products with the chyme ofthe human and other stomachs has never been shown in the slight- est degree; and that it is the merest assumption is not only proved by what I have already set forth, but is fully admitted by those who advocate the chemical doctrine. The conclusion rests upon the mere appearance which the artificial substance offers to the eye. Thus, it is lately said by Dr. Davy, that " It is impossible to witness the change which takes place in mus- cular fibre, in consequence of putrefaction giving rise to a fluid very 200 institutes of medicine. like chyme in appearance, without asking, may not putrefaction be concerned in digestion itself, according to the earliest theoretical no- tions on the subject," and as now maintained by Liebig, and his fol- lowers (§ 350) ? Farther on, however, in the same work, he says, " twenty different semi-fluids might be mentioned, to which, as far as the eye can judge, this putrid matter bears as close a resemblance as to chyme" (§ 341). 366. " Dr. Beaumont [of St. Martin celebrity] has instituted several experiments with a view to determine the power of acids in dissolv- ing articles of food; and the results which he obtained, although they varied somewhat according to the substances employed in the exper- iments, have nevertheless led him to the conclusion that no other fluid produces the same effect on food which the gastric juice does, and that it is the only solvent of aliment" (§ 341, 373).—Muller's Physiology, p. 589. London, 1839. So far Dr. Beaumont's accuracy may be readily admitted.' But, as his observations upon the natural process of digestion, as carried on in St. Martin's stomach, have become incorporated in most of the subsequent works on physiology, and even in systematic works on diet, where they generally serve as a foundation for some ofthe most important conclusions in the science of life, and have been seized upon with avidity by the supporters of the physical and chemical doctrines, and without any reference to their credibility, or to the un- natural condition of that celebrated stomach, it may be well to show, by their conflict with universal experience, that those observations are not only worthless, but pregnant with the greatest practical er- rors. For this purpose, it is only necessary to present a brief abstract from the tabular view supplied by the author of the average time oc- cupied by different alimentary substances in undergoing digestion. Thus: articles of diet. Mean Time of Chymifiaition. Preparation. h. m. Pigs' feet, Boused ..... boiled. 1 00 Tripe, do. . . . do. 1 00 Salmon trout, fresh . do. 1 30 Apples, sweet .... raw. 1 30 Cabbage, with vinegar raw. 2 00 Hash, meat and vegetables warmed. 2 30 Goose . . . . roasted. 2 30 Cake, sponge . . ' . baked. 2 30 Pig...... roasted. 2 30 Pork, fat and lean, recently salted raw or stewed. 3 00 Pork steak..... broiled. 3 15 Sausage, fresh .... do. 3 20 Dumpling, apple boiled. 3 00 Green corn and beans do. 3 45 Bread, wheat, fresh . baked. 3 30 Do. Indian com . do. 3 15 Eggs, fresh .... boiled. 3 30 Oysters, fresh .... stewed' 3 30 Beef, fresh, lean, rare roasted 3 00 Mutton, fresh . . do. 3 15 Fowls, domestic do. and boiled. 4 00 Potatoes, Irish...... boiled. 3 30 Here, then, we have pigs' feet nearly four times as easy of diges- tion as baked bread, or roasted mutton, or beef, or domestic fowls, or eggs, or oysters; raw cabbage nearly twice as easy of digestion; rnasted pig and goose a third or more easier, &c. And these are PHYSIOLOGY.—organic chemistry--FUNCTIONS. 201 common examples of what is known, in medicine, as " the experi- mental philosophy of the nineteenth century," and " the march of med- ical science" over all former and more rational experience (§ 18). 367. The experiments with pepsin, or the artificial mixtures, have been limited to substances, already animalized, in their simple condi- tions, and in minute proportions. Hay, nuts, onions, and even arrow- root, would be appalling to pepsin; and the quantities of the gor- tnand, or the variety of the epicure, would soon show the nature of this branch of " experimental philosophy." 368. A chemical dilemma presents itself. The supposed chemical agent in digestion should be the same in all animals, to explain, in the least, the identity ofthe resulting products,—and so it is admitted by the advocates of one " mixture," or of another, respectively. But this, on the other hand, is clearly contradicted by the variety of-the " mixtures," and by the vast variety of alimentary substances, con- sumed by different species of animals; while, indeed, if the least re- gard were paid to the laws of chemical affinity, it should be obvious that there would be no small variety of chemical influences in the stomach of omnivorous man. 369. Nevertheless, if the " digestive mixture" be made from the mu- cous tissue of the stomach of a strictly graminivorous animal, or even from its bladder, it will " digest" meat and other substances which form the peculiar food of carnivorous animals, but will refuse to di- gest most ofthe substances common to the animal from whose stomach the " digestive mixture" is prepared. This, therefore, is contrary to nature. 370. Digestion is well performed and often promoted when alkalies are taken into the stomach in sufficient quantities to hold the reputed amount of acid in a neutral state. 371. On the contrary, digestion is always impaired by the introduc- tion of acids into the stomach while the process is going on. 372. Did the supposed acid exist in the gastric juice, it would ren der the medicinal doses of the nitrate of silver, or the acetate of lead, perfectly inert. This principle is also of obvious application to many other substances. Indeed, it would be a perpetual " incompatible" with many remedial agents. 373. If digestion depend on the supposed chemical agencies, the stomach should always undergo more or less of that change after death; especially violent death. It is the rarest phenomenon, however, in man or animals, to witness the slightest change in that organ that can be referable to the gastric juice (§ 366). 374. It is fundamental in nature that an organ which is designed for the production of an organic fluid does not also generate an inor- ganic substance, especially a simple element like chlorine, for the pur- pose of bestowing organization and life. 375. Again, since it is the mucous tissue of. the stomach alone which, in all animals, secretes a juice capable of producing chyme; and as no other part of any organized being can generate a substance of similar power, how arrogant, therefore, the supposition that art can manufacture a fluid of the same virtues (§ 323-325)! 376. As new aspirants enter the field, novelties, of course, will spring up. They serve, however, to show us the importance of re- garding with suspicion whatever may conflict with the long-estabHsh- 202 INSTITUTES OF MEDICINE. ed conclusions which have been drawn from an observation of the most common phenomena of living beings. This leads me to advert to the experimental researches of Dr. Schultz, the eminent Berlin professor, which, whatever be their foundation, effectually destroy our confidence in all those " digestive mixtures" which have figured, of late years, so conspicuously in nearly all the systematic works od physiology. In the first place, Professor Schultz infers that neither the stomach nor the gastric juice have much agency in digestion, but that this great office is mostly performed by the saliva. This distinguished observer also finds that, 1st. " The secretions of the stomach are always alkaline excepting during the process of digestion." 2d. " No food undergoes digestion without saliva." 3d. " The chyme is not produced by chemical action, but is an or- ganic compound formed by a vital transformation of the food." 4th. " There is no such product as the supposed acid gastric juice; only a sour chyme" (§ 364, Hunter). 5th. " The acid found in the stomach is the result of a chemical de- composition of the food" (§ 364).—Schultz, de Aliment. Concoctiont Also, the Rejuvenescence of Man, &c. 1842. Again, still more recently, M. Blondlot, under the guidance of " ex- perimental philosophy,"* affirms that the saliva is of the nature of mu- cus, little else than the waste of organs (as Liebig regards the gastric juice, § 350), contributing nothing to digestion, and only useful as a shield to the mucous surface (Blondlot, Traite de Analitique de la Digestion, p. 124, 126). 376-|. It appears, therefore, that all the prevailing physical views of digestion, the chemical doctrines of secreted products, the healthy and morbid processes of living beings, the modus operandi of morbific and remedial agents, which completely shuts out the magnificent laws of sympathy, and the whole bathos of the humoral pathology, have been, in recent times, the work of the laboratory. Physiologists and therapeutists, the British especially, appear to have forgotten that it is their business to explore the facts and the laws of organic nature, and to have turned the whole matter over to the chemist (§ 349, d). They have surrendered this high calling to the laboratory, and have bowed in submission to .whatever its acids and crucibles have pretended to reveal as to the processes and laws of living beings. A vast number have thus discarded their lofty pursuits, and have substituted for them ,a most unnatural dependence upon the laboratory ofthe chemist. The chemist has seized the opportunity with avidity; since his em- ployment with inorganic nature is mostly analytical, mostly exhausted, while that which relates to living beings supplies an unbounded field for the institution of great principles and laws, whether true or false, and for the highesj renown in philosophy. It is not remarkable, therefore, considering the prizes are few, the competitors many, that the " race is to the swift, and the battle to the strong," that the ambi- tious chemist should abandon the mere work of analysis, and push his inquiries into that magnificent department of nature where the richest laurels may be gathered. Inorganic chemistry supplies no such op- portunities. Its work is analytical, and its principles few and simple ; * An artificial fistulous opening in a dog's stomach (§ 366). PHYSIOLOGY.--ORGANIC CHEMISTRY—FUNCTIONS. 203 find this, alone, is the legitimate object of organic chemistry. That ob- ject has been lately well expressed by Mr. Hoblyn, in his Manual of Chemistry. Thus: " The peculiar principles which exist in all organized beings arts distinct from those which operate on inorganic matters, and may be denominated organic agents. Their mode of operation is mysterious. The object of organic chemistry is to investigate the chemical history of the products which occur in the vegetable and animal kingdoms, and which are hence called organic substances." I therefore say, let us look well to the doings of the chemist. Let us properly regard his tampering with so profound a subject as phys- iology, whether in its natural or morbid aspects. Let us scrutinize his facts when he assails the experience of all the renowned in medi- cal science through all past time, and declares that experience worth- less (§ 350* mottoes). Let us not, however, indignantly retaliate upon him his attempts to overthrow the great fabric of medicine, or his ef- forts to undervalue the labors and the doctrines of men who have toiled in tfce field of organic nature, and have immolated themselves in the chambers of the sick. Let us rather kindly advise the chemist to cultivate modesty, and tell him, frankly, that, to comprehend the laws and the processes of living beings, they must be perpetually the objects of profound study, both in the natural state of the being and in all the variations to which he is liable from the influences of mor- bific and remedial agents. Let us tell him that he has acted wisely in refraining from all such observations, and in making the laboratory the exclusive theatre of his experimental inquiries. Either science, analytical, and limited in principles and laws, as chemistry may be, is enough for the compass of an individual; and medicine transcends the powers of the most gigantic mind. The physician, therefore, if he aim at the highest practical usefulness, or at the science of medi- cine, will find only the leisure to acquire the outlines of chemistry, and it is equally certain that the chemist who aspires at a profound knowledge of that department must spend his days and his nights within the precincts of his work-shop. And now let us remember, that there is not one name in all the annals of medicine which rests for its distinction on the physical and chemical doctrines of life. On the contrary, in every instance where attempts have been made to carry the science of chemistry into physiology, in all, and every such instance, the individuals who have "been so employed have sunk rapidly into oblivion; unless here and there a name, like Fourcroy's and Liebig's, which is rescued by lofty genius, and by purely chemical labors in the inorganic kingdom. 376f, a. Finally, I will not forego this opportunity of bringing to the support of opinions which I have hitherto advanced the following extract from Judge Story's late address before the Alumni of Har- vard University. It will be seen that the views of this distinguished man are entirely coincident with those which I had expressed in a former work. (See Medical and Physiological Commentaries, vol. i., p. 331-333, 310, 307, 308, 327, 385-400; vol. ii., p. 666-677, 801- 815, 12, 13, 203, 644, &c.) " I have said," says this eminent jurist, " that the tendency in our day is to ultraism of all sorts. I am aware that this suggestion may appear to some minds of an easy good-nature, or indolent confidence. 204 INSTITUTES OF MEDICINE. to be over-wrought, or too highly colored. But unless we choose voluntarily to blind ourselves to what is passing before our eyes in the daily intercourse of life, it seems to me impossible not to feel that there is much which demands severe scrutiny, if not serious alarm. I meddle not here with the bold, and yet familiar speculations upon government and polity, upon the fundamental changes, and even abo- lition of constitutions, or upon the fluctuating innovations of ordinary legislation. These might, of themselves, furnish out exciting themes for public discussion, if this were a fit occasion to introduce them. I speak rather ofthe interests of letters—ofthe common cause of learn- ing—of the deep and abiding principles of philosophy. Is it not pain- fully true that the spirit of the age has broken loose from the strong ties which have hitherto bound society together by the mutual cohe- sions and attractions of habits, manners, institutions, morals, and liter- ature ] It seems to me, that what is old is no longer a matter of reverence or affection. What is established, is not on that account esteemed positively correct, or even salutary or useful. What have hitherto been deemed fundamental truths in the wide rang* of human experience and moral reasoning, are no longer admitted as axioms, or even as starting-points, but at most are propounded only as prob- lems, worthy of solution. They are questioned and scrutinized, and required to be submitted to jealous proofs. They have not even con- ceded to them the ordinary prerogative of being presumed to be true until the contrary is clearly shown. In short, there seems to me, at least, to be abroad a general skepticism—a restless spirit of innova- tion and change—a fretful desire to provoke discussions of all sorts, under the pretext of free inquiry, or of comprehensive liberalism. And this movement is to be found not merely among illiterate and vain pretenders, but among minds of the highest order, which are ca- pable of giving fearful impulses to public opinion. We seem to be borne on the tide of experiment with a rash and impetuous speed, confident that there is no risk in our course, and heedless that it may make shipwreck of our best hopes, and spread desolation and ruin on every side, as well on its ebb as its flow. The main ground, there- fore, for apprehension, is not from undue reverence for antiquity, so much as it is from dreamy expectations of unbounded future intellect- ual progress; and, above all, from our gross over-valuation and in- ordinate exaggeration of the peculiar advantages and excellences of our own age over all others. This last is, so to say, our besetting sin ; and we worship the idol, carved by the cunning of our own hands," with a fond and parental devotion. There are many even among the educated classes, and far more among the uneducated, who imagine that we see now, as men never saw before, in extent, as well as in clearness of vision; that we reason, as men never reasoned before; that we have reached depths and made discoveries, not merely in ab- stract and physical science, but in the ascertainment of the moral and intellectual powers of man, and the true structure and interests of gov- ernment and society, which throw into comparative insignificance the attainments of past ages. We seem to ourselves to be emerging, as it were, from the darkness of by-gone centuries, whose glow-worm lights ' show the matin to be near, and 'gin to pale their ineffectual fires,' before our advancing radiance. We are almost ready to per- suade ourselves that their experience is of little value to us; that the PHYSIOLOGY.--ORGANIC CHEMISTRY--FUNCTIONS. 205 change of circumstances is so great, that what was wisdom once is no longer such; that it served well enough for the day, but that it ought not now to be an object of desire, or even of commendation. " Nay, the comparison is sometimes eagerly pressed of our achieve- ments in literature with those of former ages. Our histories are said to be more philosophical, more searching, more exact, more elaborate than theirs. Our poetry is said to surpass theirs in brilliancy, imag- inativeness, tenderness, elegance, and variety, and not to be behind theirs even in sublimity, or terrific grandeur. It is more thoughtful, more natural, more suggestive, more concentrative, and more thrill- ing than theirs. Our philosophy is not, like theirs, harsh or crabbed, or irregular; but wrought out in harmonious and well-defined pro- portions. Our metaphysical systems and mental speculations are (as we flatter ourselves) to endure forever, not merely as monuments of our faith, but of truth ; while the old systems must fall into ruins, or merely furnish materials to reconstruct the new—as the temples of the gods of ancient Rome serve but to trick out or ornament the mod- ern churches of the Eternal City. Ay, and it may be so. But who will pause and gaze on the latter, when his eyes can fasten on the gi- gantic forms of the Coliseum, or the Pantheon, or the Column of Tra- jan, or the Arch of Constantine ? " May I not stop for a moment, and ask if there is not much delu- sion and error in this notion of our superiority over former ages ; and if there be, whether it may not be fatal to our just progress in litera- ture, as well as to the permanent interests of society 1 I would not ask those who entertain such opinions to accompany me back to the days of Aristotle and Cicero, whose works on the subject of govern- ment and politics alone have scarcely received any essential addition in principles or practical wisdom, down to this very hour. Who, of all the great names of the past, have possessed so profound an influ- ence and so wide an authority for so long a period 1 Jf time be the arbiter of poetical excellence, whose fame is so secure as that of Ho- mer and Virgil ] Whose histories may hope to outlive those of Thu- cydides and Tacitus ? But I would limit myself to a far narrower space, to the period of the two centuries which have elapsed since our ancestors emigrated to America. Survey the generations which have passed away, and let us ask ourselves what have been their lit- erary labors and scientific attainments 1 What the productions of their genius and learning ] What the amount which they have con- tributed to meliorate the condition of mankind—to lay deep and broad the foundations of Theology, and Jurisprudence, and Medicine—to establish and illustrate the principles of free governments and inter- national law—and to instruct as well as amuse the leisure, and to re- fine the taste of social life 1 Unless I greatly mistake, a calm survey of this whole matter would convince every well-balanced mind, that if we may claim something for ourselves, we must yield much to the scholars of those days. We shall find that much of our own fruits have been grafted on the ancient stocks. That much of what we now admire is not destined for immortality. That much which we deem new is but an ill-disguised plunder from the old repositories. And that much which we vaunt to be true consists of old fallacies, often refuted and forgotten, or of unripe theories, which must perish by the way- side, or be choked by other weeds of a kindred growth. 206 INSTITUTES OF MEDICINE. " The truth is, that no single generation of men can accomplish much of itself or for itself which does not essentially rest upon what has been done before. Whatever may be the extent or variety of labors and attainments, much of them will fail to reach posterity, and muah which reaches them will be felt, not as a distinct formation, but only as com- ponent ingredients of the general mass of knowledge. Many of the immortals of one age cease to be such in the next which succeeds it; and, at best, after a fitful season of renown, they quietly pass away, and sleep well in the common cemetery of the departed. What is present is apt to be dazzling and imposing, and to assume a vast im- portance over the distant and the obscure. The mind in its perspect- ive becomes affected by the like laws as those of the natural vision. The shrub in the foreground overtops the oak, that has numbered its centuries. The hill under our eye looms higher than the snowy Alps, which skirt the edge of the horizon. " But let us subject this matter to a little closer scrutiny, and see if the annals of the.last two centuries alune do not sufficiently admonish us of the mutability of human fame, as well as that of human pursuits. What a vast amount of intellectual power has been expended during that period, which is now dimly seen, or entirely forgotten ! The very names of many authors have perished, and the titles of their works are to be gathered only from the dusty pages of some obscure catalogue. What reason can we have to suppose that much of our own labors will not share a kindred fate ] But, turning to another and brighter part of the picture, where the mellowing hand of time has touched with its finest tints the varying figures. Who are there to be seen but Shakspeare, and Milton, and Bacon, and Locke, and Newton, and Cudworth, and Taylor, and Barrow, not to speak of a host of others, whose works ought to be profoundly studied, and should illustrate every library. I put it to ourselves to say, who are the men of this generation to be brought into comparison with these, in the extent and variety of their labors, the powers of their genius, or the depth of their researches ? Who of ourselves can hope to exercise an influence over the human mind as wide-spread as theirs ? Who can hope to do more for science, for philosophy, for literature, for theolo- gy, than they 1 I put the argument to our modesty, whether we can dispense with the products of their genius, and wisdom, and learning; or may cast aside their works, as mere play-things for idlers, or curi- osities for collectors of the antique 1 " I have but glanced at this subject. It would occupy a large dis- course to unfold it in its various bearings and consequences. But the strong tendency of our times to disregard the lessons and the author- ity of the past must have any thing but a salutary effect upon all the complicated interests of literary as well as social life. It not only loosens and disjoints those institutions, which seem indispensable to our common happiness and security, but it puts afloat all those prin- ciples, which constitute, as it were, the very axioms of all sound phi- losophy and literature. In no country on earth is the danger of such a tendency so pregnant with fearful results, as in our own ; for it nurses a spirit of innovation, and experiment, and oscillation, which leaves no resting-place for sober meditation or permanent progress. It was the striking remark of an acute observer of the human mind, that 'he who sets out with doubting, will find life finished, before he PHYSIOLOGY.--FUNCTIONS. 207 becomes master of the rudiments;' and that he who begins by pre- suming on his own sense has ended his studies as soon as he has commenced them."—Judge Story's Address, &c* 376f, b. In parting, for the present, with organic chemistry would again pay my humble tribute to a science of exalted worth, in its vocation of laying open the constitution and laws of inorganic na- ture, and in applying its results to many of the most useful purposes of life. The physiologist venerates the science, does homage to its cultivators, would do battle for its cause. In protecting the great In- stitution which it is his province to illustrate, in preserving unsullied the stupendous philosophy of Medicine, he makes no encroachment on a sister science; but, ever obedient to the voice of Nature, he wor- ships in all her temples (^ 1034). 4. DISTRIBUTION. 377. The fourth function common to.animals and plants is distribu- tion or circulation. In the former, after the food has become so far assimilated as to receive the final act of appropriation, or, in other words, after it is formed into blood, it must be distributed to all parts of the body, for their growth, nutrition, &c. This office is performed by the heart and blood-vessels in all perfect and superior animals, and by the blood-vessels alone in the inferior tribes, and whenever the heart is wanting. In the last instance the means are very similar to those which carry on the circulation in plants. 378. The mechanism of circulation is shown by the function. In the perfect animals the blood is expelled by the left ventricle of the heart into the aorta, and thence distributed to all parts of the body; where it is applied to nutrition and secretion, and undergoes depura- tion by the excretory organs. Such as is not thus appropriated is sent forward to the communicating veins, by which it is conveyed to the right auricle, and from thence to the right ventricle, to be distrib- uted to the lungs through the pulmonary artery, and returned, again, to the left ventricle through the pulmonary veins and left auricle. In the lungs, the venous blood is converted to arterial, and perfected for the various exigencies of organic life, by the joint agency of the pul- monary mucous tissue and atmospheric air (% 419, 827 b). 379. A remarkable exception occurs to the foregoing general plan of the circulation in the transmission of venous blood from the ab- dominal viscera to the liver, through the vena portae. It is also anomalous, that this blood is appropriated, in part, to the formation of an organic fluid, the bile, while the residue is transmitted to the vena cava through the hepatic veins; these veins being also the asso- ciate medium for the return of blood from the hepatic artery (§1031). 380. There are three principal distinctions between the blood sent out by the left ventricle and that which is returned to the right: 1st. The color of venous blood is a modena red; that of arterial a bright scarlet. 2d. Venous blood is more highly charged with carbonaceous matter than the arterial. 3d. Venous blood will not support the life of organs. 381. The blood supplies all parts with their means of nutrition, se- cretion, &c, and is, itself,'the stimulus by which its own circulatory organs are excited to motion, and by which the formative and secre- tory vessels are maintained in their action. The pabulum vitce is, * See a remarkable parallel to the foregoing in Tacitus' Dialogue concerning Ora- tory. The coincidences should admonish us the more. 208 INSTITUTES CT MEDICINE. therefore, remarkably distinguished from all other substances in na- ture, in being equally the stimulus of the whole circulatory system, and the substance acted upon and appropriated according to the na- ture of every part in which it may circulate (§ 136). It is the same with the sap of plants as with the blood; both being alike the pabulum vita. Each is every where converted into the solid organs to which it is distributed, and into fluids and other prod- ucts which have their special allotment in organic life; and nothing is formed which is not derived immediately from the blood or sap (§ 41-44, 847 c, 1053). .» OF THE POWERS WHICH CIRCULATE THE BLOOD.* 382. Much of the philosophy of medicine is involved in a right es- timate of the powers which carry on the circulation of the blood. But, having set forth this subject extensively in the Medical and Physiological Commentaries, I shall now limit my remarks to a state- ment of the most prominent facts (§ 407, a). 383, a. A great error has prevailed of ascribing the circulation of the blood to the propelling power of the heart alone. Another, less common, imputes venous circulation to the action of the capillary ar- teries; while a still greater regards it as a hydrostatic phenomenon dependent on the arterial column of blood. Another, subversive of all principles in medicine, refers the circulation in the capillary ves- sels—those instruments of all the essential organic processes—to cap- illary attraction. Another supposes that the blood is moved in virtue of its own inherent power. Another, that the globular portion is composed of animalcula, which traverse the circulatory system by their locomotive endowment. But, the most obnoxious to objection is the latest speculation which flows from the universal doctrine of Liebig, that " All vital activity arises from the mutual action of the oxygen of the atmosphere and the elements of the food;" that " the life of ani- mals exhibits itself in the continual absorption of the oxygen of the air, and its combination with certain component parts of the animal body;" and that " the cause of the state of motion is to be found in a series of changes which the food undergoes in the organism; those changes being the results of processes of decomposition, to which the food itself, or the structures formed from it, or parts of organs, are subjected." (See § 350, nos. 9, 10, § 1054). This last hypothesis imputes the circulation entirely to the chemical action of oxygen gas upon the tissues and upon the blood itself; re- jects, altogether, the propelling and suction power of the heart, over- looks the respiratory movements, the peristaltic action of the intesti- nal canal, the permanent contraction ofthe sphincters, the motions of the iris, denies all vascular action, even in the face of such phenome- na as blushing, and all other sympathetic movements, nor recognizes a local morbid physiological determination of blood, or a morbid pro- cess, or a physiological influence of therapeutical agents, but con- strues all these unique results upon the same chemical phenomenon. 383, b. A modification, however, of this doctrine concedes an in- strumentality of the heart in circulating the blood. The heart still acts in virtue of the combustive process; and so far the doctrine is ' The term powers, as here employed, comprehends the instruments of circulation. PHYSIOLOGY.--FUNCTIONS. 209 consistent. But it is fundamentally contradicted by the incongruity of the two great sources of power at the apex and at the circumfer- ence of the circulation, when contrasted with the exact balance which prevails between the moving power of the heart and the circulation of the blood in the capillary system. NoJkis there to be found in na- ture two such distinct sources of power ror the accomplishment of a specific effect as that which imputes the circulation of the blood to an associate mechanical impulse by the heart and a chemical process in the capillary blood-vessels (§ 129). 384. There are numerous elements concerned in the circulation of the blood, each one of which I have endeavored to substantiate in a former work.*—See also p. 934, fy 1090. 1st. The heart possesses, through its vital properties, an active power of dilating and contracting (§ 498, e, 1090), 2d. The arteries possess a similar power, though in a far inferior degree. This has been determined by the application of irritants.— (Medical and Physiological Comm., vol. ii., p. 147-152, 375-403.) 3d. The capillary arteries, or the reservoirs of blood to the ex- treme vessels, have the same power, which is much more actively ex- ercised than in the larger arteries. The capillaries are consequently brought into greater action when stimulated by physical agents, as in inflammatory diseases, or by the nervous power, as in blushing (§ 480, 1039), or as it lights up inflammation (§ 647£, 746 c, 973-974). 4th. The extreme vessels, or terminating series of the arterial sys- tem, have, also, a like power of contracting and dilating actively, and in a still greater degree than the capillary arteries (§ 136, 750). 5th. The extreme capillary veins have, also, a special action of the foregoing nature, which aids in transmitting the blood from the arte- rial system to the next larger series of veins. 6th. The larger veins possess the power of dilating and contracting actively, according to the varying quantities of blood transmitted from the arterial system. Their constant conatus to contract on their con- tents assists in the transmission of the blood. 7th. All the cavities of the heart operate upon the principle of an exhausting pump, during their dilatation.—Note Bb p. 1131. 385. All the foregoing powers (§ 384) concur together, according to a consummate Design, in circulating the blood. All are important elements; no one adequate in itself, while each should be studied by itself, as well as in connection with the whole (§ 74, 80, 117, 137, 143, 155, 156, 169/, 266, 303J- a, 306, 310, 311, 387, 399, 409/ 422, 514 h, 524 d, 525, 526 d, 528, 638, 733 b, 750, 764 b, 811, 847 c, 848, 902/, 905, 1054). The Exp. &c. are in the Commentaries.* 386. The contraction and dilatation of the heart and arteries are, respectively, nearly synchronous. Although there be a perfect consent of action between the capillaries, the extreme vessels, and the heart, those vessels are not associated with the movements of the heart, nor with each other, in the same way as the actions of the heart and arteries; and they are modified, also, according to the special func- tions they perform in different parts (133 b, 135 a, 136). The case of blushing shows us the law in regard to the capillaries (§ 476, &c). 387. The final cause of motion in the veins is chiefly that of sub- * Medical and Physiological Commentaries, vol. ii., p. 375-426, 147-152, and the Essay nn the Theories of Inflammation, ibid. 210 INSTITUTES OF MEDICINE. serving the arterial system; and here the consent of action between the veins and arteries is still more illustrative of the profound nature ofthe principles and laws which govern the functions of organic life. It has been, indeed, the universal doctrine that the capacity of the veins is determined in a mechanical manner by the volume of blood transmitted from the arteries ; but I have endeavored to show that the supposed physical distension and elastic contraction of the veins are without foundation, and would form a most serious obstacle to the cir- culation of the blood. On the contrary, it appears that those actions are not only of a vital nature, but that they are a perpetual illustra- tion of sympathy, depending upon sympathetic relations of the veins to the communicating series of arterial capillaries. This peculiar constitution of the veins explains the reason why they collapse when divided ; since their sympathetic relation to the arteries is thus extinguished. The veins, indeed, appear to be not less sus- ceptible of action from the stimulus of sympathy with the capillary arteries than the iris with the retina (§ 514, k), whose phenomena so clearly demonstrate the operation of that principle in developing sen- sible motions; but compounded as to veins of continuous and remote.* The dilatations and contractions of the veins are, therefore, very greatly effected by reflex nervous influences exerted upon them by the varying states of the capillary arteries, as well as by the quantities of blood they are employed in transmitting to the veins. These influ- ences appear to be originally felt by the capillary series of veins, where the organic properties are most strongly pronounced, and thence propagated by continuous sympathy to the larger series (§ 498, and Comm., vol. ii., p. 520, 521, &c), when reflex actions ensue.* Did not a consent of action with the arteries (depending on the principle of sympathy, § 452, 495, &c, 498) exist in the veins, the vi- tal contractility, and the elastic property of the coats, must be me- chanically overcome by the increased quantity of blood transmitted to them. The blood must be forcibly injected into the capillary veins by the vis a tergo, and in numerous parts of difficult penetration by the finest injections of art. This is utterly repugnant to that Uni- ty of Design which prevails in all parts of the organized being, and would be leaving an important function to a fortuitous and inadequate provision. Nor can it be consistently supposed that the phenomena which appertain to one class of vessels are of a vital nature, and those of the other, resulting in an anatomically associated series, mechanical. The veins possess, also, longitudinal fibres, by which they are fit- ted for rapid and uniform motion over an extensive tract; and this action implies a predominance of continuous sympathy (§ 498). It is also proved that the veins, like the heart and arteries, dilate actively on the application of certain stimuli to their external surface.— (Med. and Physiolog. Comm., vol. ii., p. 147-152, 375-401.) 388. Venous circulation is determined principally by the suction . or derivative power of the right cavities of the heart, but is aided by the contractile power of the large veins, by the more specific action of the capillary veins, and by the propelling power of the communi- cating series of arterial capillaries. The contraction of the left ven- tricle of the heart, and that of the large arteries, have little or no agency in venous circulation. Their force is probably exhausted, or * Continuous sympathy is continuous influence of these Institutes (sec. 129 c, /, 498 a) P11YSI0L0GY.--FUNCTIONS. 211 nearly so, when the blood has reached the terminal series of the arte- rial system. The blood is returned from the lungs to the left cavities ofthe heart by the powers just stated. It is not alone the dilatation of the auricles which constitutes the derivative power, as had been supposed till 1 investigated this subject; but equally, also, that o^the ventricles (§ 1090). 389. In the Medical and Physiological Commentaries, I have ex- amined every objection which has been alleged against the imputed dependence of venous circulation upon the dilatation of the cavities of the heart, and atmospheric pressure. One objection had been stated with greater force and apparent plausibility than the rest, by Drs. Philip, Arnott, and other eminent men; namely, that the parietes of the veins should collapse upon the supposed doctrine of suction. To this objection I have replied, that the injecting power of the commu- nicating arterial capillaries maintains the veins in a state of fullness. The perfectly harmonious relation among the powers which circulate the blood establishes a correspondence between the movements in the venous and arterial systems, by which nature has duly provided against so great an evil as apprehended. 390, a. The suction power of the heart, as I have endeavored to show in the " Commentaries," is indispensable to the portal circula- tion, and to that, also, of the lymphatics, lacteals, thoracic duct, and umbilical vein; though, doubtless, the independent action of these vessels contributes to the motion of their contents. 390, b. In the foregoing work I have considered the objection rela- tive to the occasional jet of blood from a vein wounded in venesec- tion in certain conditions of disease; and I purpose now, from its ambiguous relation to my subject, adverting to the causes of the in- termitting pulse that so often attends congested states of the liver. This phenomenon has been long observed; but no substantial cause has been assigned. It is due, I apprehend, to two influences, one of which is sympathetic, the other more or less mechanical. The sympathetic is readily appreciated; the mechanical, and most important, requires explanation. In my Essay on Inflammation, and in the present work, I have endeavored to show that the current of blood is accelerated in the vessels immediately concerned in that morbid process, notwithstanding the enlarged diameters of the vessels (§ 711, &c). But not so in venous congestion, unless the propelling, and therefore, also, the suction power of the heart, be considerably increased. It often happens, however, that the force of the heart, in venous congestions of the liver, is even reduced below its ordinary standard, however there may be an attendant hardness of the pulse (§ 688). Now, therefore, since the veins undergo an enlargement in their congested states, and since, also, the volume of blood which is transmitted to the heart through the portal system is very large, if it enter that organ in an unusual manner, it is highly probable that it would embarrass its action. Such would be the effect of a sluggish or irregular ingress, especially, as will be seen, if not correspondent with the egress of blood. But, it not unfrequently happens that the pulse becomes intermit- tent, for the first time, after the hepatic affection has sensibly yielded. This occurs, however, mostly, if not altogether, in rather intense 212 INSTITUTES OF MEDICINE. forms (£ venous congestion, and where the force of the heart, and therefore its suction power, are manifestly Increased, so much so, indeed, that practitioners, cautious of blood-letting, will venture upon the remedy. An incomplete subsidence of the disease, and the means of treatment, reduce the action of the heart; and the suction power being thus lessened, while the veins remain yet enlarged, the blood moves with a tardy pace in the portalveins, and disturbs the rhythmic action of the heart. ^ There is also another, and important element of this mechanical cause, which consists in an interrupted balance between the blood which enters the heart and that which is projected from it; its en- trance being rendered slow by the state of the portal veins, while its projection is unembarrassed. If the pulse be merely intermittent, and only so after several beats, excitement from exercise, but not from the mind, will often restore, for a short time, the harmony of both ventricles. Mental excitement, on the contrary, through nervous influence, is apt to increase the intermission, and often adds an irreg- ularity (§ 227, 509, &c). But, unlike the simply intermitting, an ir- regular pulse is commonly increased in its irregularity by violent exercise, as well as by excitements of mind. The intermitting pulse, on the contrary, is often most strongly pronounced in the horizontal posture. Reflex nervous influences enact a part in this phenomenon. The nature of the sympathetic cause will be readily appreciated by the accurate observer, when he considers how often intermis- sions or irregularities of the pulse are increased by a full, and some- times a scanty meal (§ 512), through reflex nervous actions. Cerebral inflammation often gives rise to an irregular action of the heart; but here the cause is determined by the nervous power alone (§ 226, &c). In the case of the brain, also, the pulse is apt to be more irregular than intermittent; while in that of the liver it may be both (§ 687, &c). 391. The valves of the veins have been universally supposed to con- tribute essentially to venous circulation, by supporting the column of blood. This, however, I have endeavored to show, is a mistaken opinion ;* for they are always open when the current of blood is pass- ing. Like the valves ofthe heart their great final cause is to prevent the reflux of blood when pressure operates, and to contribute to the like design of the frequent inosculation of the veins. The supposed co-operation of the voluntary muscles in venous circulation is also merely accidental. 392, a. It appears, therefore, that the whole theory of the circula- tion is strictly relative to the properties of life. The pressure of the atmosphere, by which the blood is forced along the returning vessels, is entirely incidental; and, although the transit of blood from one part to another is merely mechanical, its motion originates entirely ir. vital agencies. The facts, of which the foregoing conclusions are predicated, are very numerous, and contribute to some of the most important pathological and therapeutical principles. It may be use- ful to consider yet farther some of the most indisputable, and to re- gard them, at the same time, in their connection with the laws of which they are the foundation. 392, b. Although the vascular system contributes an important part * Medical and Physiological Commentaries, vol. i;., p. 412, 426. PHYSIOLOGY.--FUNCTIONS. 213 toward the common circulation, the heart possesses within itself a general control over this great function of life. Had it been other- wise, " a thousand causes might intervene, over which the organ, so limited in influence, could have no control, to retard or divert the course of the blood ; and which, by occasioning one short delay, might prevent its return forever." It is, therefore, not only the great mo- tive source, through its contractile power, in the universal act of dis- tribution, but, to effect a return of the venous blood, " it is made the centre of atmospheric pressure and gravity, and designates the stage in the circulation in which a deficiency of supply would be the last in being felt. Hence it appears that the functions of the heart are per- formed, and life preserved, notwithstanding long and copious dis- charges of blood, which, upon any other hypothesis, must have been fatal. For, according to these hypotheses, the heart, or at least the auricles, are placed at the end of projection. They mark the highest advance of the tide, and would first be abandoned by the retiring fluid. They would be drained by every profuse hemorrhage, and the heart would expend its energy in fruitless efforts to circulate a fluid that came not within its reach." Upon any other theory, how could what Armstrong calls "the beautiful balance between the right and left sides of the heart" be preserved ] How, otherwise, would the circulation be restored in syncope 1 In respect, also, to the absorbent power, it is farther well said by Carson, that, " though we are not ac- quainted with any data from which the power of the heart can be cal- culated, there must exist, nevertheless, certain limits, within which it must reasonably be supposed to be confined. If we consider that the quantity of blood in circulation is nearly one fifth of the weight of the whole body; that this great mass is spread over an immense surface; that it is therefore subjected to great resistance from friction, espe- cially in the small vessels where each globule is to be rolled over a fixed surface; that the currents, in consequence of anastomosing branches, are perpetually flowing in opposite directions, and that at- traction must powerfully prevail between the blood and small vessels; when we consider the mass moved, the motion with which it is moved, and the resistance opposed, it is impossible to imagine that this labor could have been performed by the propelling power of the ventricle ;" besides the obvious objections of the liability of the curvature of the aorta and the capillary arteries to be ruptured, and the exigencies of the portal, placental, and lymphatic circulation (§ 390). Again, " the two trunks of the ascending and descending cava meet at the heart in such a manner as to form a straight line. The streams of blood which are conveyed by these vessels to the heart are placed at that point in direct opposition. Upon the supposition that the blood is returned to the heart by a vis a tergo, this position of the vessels is the most unfavorable that can be conceived for the office that is as- signed to them. The momentum of blood in one vessel would be de- stroyed by that of the other; or, if the current in the descending was stronger than that in the ascending cava, the blood in the weaker stream would be prevented from ever reaching the heart." 392, c. In the Medical and Physiological Commentaries, especially in the Essays on Inflammation, and the Powers which Circulate the Blood, I have exhibited a great amount of proof establishing the vital actions of the capillary blood-vessels, and showing that the mo 214 INSTITJTLS OF MEDICINE. mentum of the blood, as derived from the left cardiac ventricle, is nearly lost in the capillaries. The opinion of Hunter, Bichat, Philip, and other distinguished observers, to the same effect, being founded upon the most ample investigations, would seem to leave no doubt upon a question of such fundamental importance in the philosophy of" organic life. " Have they," says Wilson Philip, " who maintain that the circulation is supported by the muscular power of the heart alone, made even the rudest calculation of the degree of resistance to be overcome in driving the blood through two capillary systems at such a rate, that, in a given time, the same quantity shall be delivered by the veins, which is thrown into the arteries 1 Have they made any estimate of the strength necessary in the different sets of vessels, and particularly in the larger arteries, to sustain a power capable of overcoming this resistance ? Let them give what imaginable power they will, they cannot make this power greater than the coats of the vessels will bear without rupture" (§ 1054,1056). So completely arrested, indeed, is the momentum of blood when it reaches the arterial capillaries, so manifest are the vital actions of these vessels, and so unaccountably did Philip and Bichat overlook the suction power of the heart, that they ascribed the circulation in the veins entirely to the propelling action of the capillary arteries. Owing to this limited view, Bichat was led to observe, that, " not- withstanding all that has been written as to the cause of venous cir- culation, there is an obscurity in it, in which there are but few rays of light." The circulation of the liver embarrassed him especially; since any general hypothesis which Should fail here must be wholly abandoned ($ 390). He considered it, however, " incontestibly proved, that when the blood has arrived in the general capillary sys- tem, it is absolutely beyond the influence of the heart, and that the left ventricle has no influence in the venous system." 392, d. The demonstrations of a direct nature, to show the inde- pendent action of the blood-vessels (the veins as well as arteries), are too numerous and various' for concentrated observation. They are scattered throughout this work, and many of importance occur only in the Medical and Physiological Commentaries (vol. ii., p. 147- 152, 375-401). The original suggestions of many belong to myself, as, also, their general application to the subjects before me. It has been one of my special objects to demonstrate an active dilatation of all the blood-vessels, as well as their active contraction. The latter, indeed, proves that the dilatation is active and vital. The greater principle lies in the necessity of a counteracting power; since active contraction alternating with dilatation necessarily implies correspond- ing principles of motion, or there would be a permanent state of contraction or tonic spasm. The sanguiferous system, therefore, would be devoid of function, and nothing but " stagnation" would be the great law of organic nature (§ 748, 1039, 1090). 393. The doctrine of venous circulation, as I have expounded it here, and proved it extensively in the " Commentaries," is replete with the most important physiological, pathological, and therapeutical conclusions. It strikes a fatal blow at the whole mechanical hypoth- esis and the stimulant treatment of venous congestion (§ 788-793), as shown in my Essay on that affection. It determines all the great fundamental points which have been in dispute respecting the circu- PHYSIOLOGY.--FUNCTIONS. 215 lation of the blood. It proves that the propelling force of the left ventricle of the heart is lost, or nearly so, in the extreme capillary arteries. It proves, what is of greater importance than all things else in the Institutes of medicine, that the extreme vessels possess an independent vital action ; since otherwise the blood could never be carried forward in the veins by the power of suction (§ 389). But that would not be the greatest oversight in the plan of organic na- ture (§ 1039,1040). 394. The highest practical, as well as philosophical, conclusions are involved in a correct estimate of the powers which determine the circulation of the blood (§ 393). But there are no errors so prolific of evil, and so derogatory to medical philosophy, as that which as- sumes a passive state of the terminal series of the arteries, or that circulation is carried on in that series by capillary attraction, or by their oxydation (§ 383). Were either of these hypotheses true, there could be none of the organic products, as derived from the blood, no secretion, no nutri- tion—not a principle in physiology, pathology, or therapeutics; for all the essential organic functions, and all the processes of disease, are carried on by the terminal series ofthe arteries (§ 481 g, 483, &c). Consider the phenomena of sympathy; contemplate the experi- ments of Philip to determine the laws of the vital functions; study the laws of the nervous power in their relation to organic functions; observe how instantly mental emotions will variously affect the action of the heart, or bring a suffusion of blood to the pallid face, or how stimuli applied to the brain will as instantly produce corresponding results (§ 4 81-485) ; and you will concede that these results ofthe operation ofthe nervous power demonstrate the independent vital ac- tion of the capillary vessels, and overturn the physical and chemical hypotheses of life. 395. The foregoing influence of the cerebro-spinal and ganglionic systems upon the capillaries and extreme vessels is ofthe highest im- portance in pathology, and in the philosophy and treatment of dis- ease. These vessels are not only the instruments of disease, but they sustain all the morbific influences which result in sympathetic dis- eases, and upon these vessels all remedial agents exert their curative effects, whether by their direct action, or through the instrumentality ofthe nervous power (§ 222-233|, 456 a, 1039, Note Bb p. 1131). 396. Nor is it alone an active condition by which the terminal se- ries of arteries is remarkably distinguished. Our various facts estab- lish the no less important principles, that the several orders of term- inal vessels have their vital properties and actions strongly pronoun- ced, and that these properties and actions are peculiarly modified in their natural state, both in a general sense, and in different parts, and that they are liable to various other peculiar modifications from the operation of morbific and therapeutical agents. Hence, all our cura- tive means must have a steady and direct reference to the existing condition of these extreme capillary vessels (§ 149, 150, &c). 397. Ofthe extreme vessels physiologists have supposed, with great reason, that there are at least three series ; one being destined for nu- trition, another for the secretion and excretion of the fluids, and an- other series coinciding with the veins. Without being disposed to submit this question, in the least, to the 216 INSTITUTES OF MEDICINE. microscope (§ 131), there might be allowed, according to Wagner, what has probably been hypothetically suggested by the well-known ■ simplicity of nature, that there is " but one kind of termination in ref- erence to an artery—a passage into a vein through a capillary vessel, and an intermediate net-work." In this case, however, there must either exist lateral projections from the terminal capillary, or there must radiate from the " intermediate net-work" vessels whose office is to distribute the blood from which are eliminated the materials for nutrition, &c. 398. The extreme vessels which are destined for nutrition, secre- tion, and excretion, elect from the blood, contained in their reservoirs the capillary arteries, the precise elements that are necessary to the formation of each peculiar compound throughout the body, and in such uniform proportions and modes of combination as shall forever, and without deviation, render them exactly conformable to the nature of every part, as ordained at the Creation (§ 41-44). This is done in virtue of the peculiarly modified states of irritability and other properties of life, according to the exact office of every part. Yet are these the vessels which are said to be under the sole government of physical and chemical laws (§ 383), and whose morbid state in in- flammation is constituted by a mechanical relaxation of their parietes, and a stagnation and coagulation of their contents (§ 711, &c.) ! 399. In their natural state, the foregoing vessels admit but very few of the red globules of blood, in virtue of their peculiarly modified ir- ritability ; and this, therefore, where the calibre surpasses the diam- eters of the red globules. There is no mechanical "straining off of the finer from the coarser parts ofthe blood" by an inadequate capa- city of those vessels which convey only white blood (§ 493, d). The separation is effected in a homogeneous substance, and by causes which are very foreign to "strainers" and "sieves" (§ 129, 135-138, 266, 750). The same principle interprets the admission of the red globules into those serous vessels, in inflammation. Irritability is there morbidly affected, and the usual process of vital decomposition of the blood is, of course, arrested (§ 327-329). The entire blood then finds its way into the lymph vessels, as they are called; and the organic law by which that result is determined (§ 192, 278) is beautifully illus- trated by two experiments; one by Buniva, the other by Procter The experiments also confirm the doctrines which I have taught as to the character of the nervous power, and its agency in organic actions, while both observers pursuing different routes, and attaining a com- mon end through opposite effects, but by common principles relative to the nervous power, illustrate and confirm the experiments of each (§ 222-233J, 476, &c, 500). Buniva had great difficulty in effecting an injection of an artery of a living dog, till he divided the spinal cord, when, by thus withdraw- ing the stimulus of the nervous power, the capillaries lost their pecu- liar susceptibility, and the contents of the syringe passed freely on.— Buniva ($ 1039,1056). In Procter's experiment, " a horse was killed by dividing the me- dulla, the bowels turned aside, and the branch of the sympathetic nerve, which joins the ischiadic, laid bare; also, one of the arteries of the leg. A wire applied to the positive pole of a galvanic bat- tery, defended with sponge, was applied to the nerve, and the nega- PHYSIOLOGY.--FUNCTIONS. 2n tive wire to the artery. The positive wire was then drawn slowly alonor the plates of a fifty-plate battery and the effect was certainly not only to reproduce the pulsation in the artery, but also clearly to excite circulation in the more minute vessels." A by-stander ex- claimed, " See how that pipe beats when they put on those wires!" —Procter, on the Sympathetic Nerve. 1844. To the foregoing may be added the experiment by Dr. Hall (§ 263), which, it will have been observed, is insuperably opposed to his con- clusions as to the agency of the nervous system in producing organic actions, and as examined in my Essays on " Vitality," &c. (p. 42, note). See, also, Experiments by Kriemer, § 485, and Philip, § 483, and Dr. Parry's case, § £87, gg.—Note Gt p. 1122. 5. APPROPRIATION, OR NUTRITION AND SECRETION. 400. Appropriation, like assimilation, is a comprehensive, though less complex, function. It embraces what are commonly designated as two functions, namely, nutrition and secretion. 401, a. A common fluid being formed, and distributed to the sever- al parts of the animal and vegetable, is then appropriated to their several uses. 401, b. Animals are distinguished by an unceasing change of the materials of which they are composed. The actions of life disturb the composition of parts, which, being thus unsuited for the purposes of organization, and reduced to a fluid state, are' returned to the general circulating mass of blood, where they either again undergo assimilation, or are eliminated and cast off by the excretory organs. To supply this waste is, in part, the office of appropriation, which furnishes new molecules from the blood, in exact conformity with the process of disintegration after growth is completed, but occurring in excess while nutrition is engaged in rearing up the fabric to a state of maturity. Appropriation is also the function through which those secreted fluids, which act as auxiliaries in the processes of life, are renewed in their original character. 402. Appropriation, therefore, whether it refer to the increase and renewal of the solid parts, or to the production of useful fluids, being equally a process of secretion, every organic product, vegetable or animal, is the result of secretion. But appropriation, as applied to the useful fluids that are formed from the blood or sap, is more com- monly known as an act of secretion; and though the next function which will be considered, namely, excretion, is very analogous, yet the final causes of secretion and excretion being entirely different, it is proper that they should be arranged as distinct processes. Since, however, nutrition, secretion, and excretion are very analo- gous processes, secretion is a good generic term for the whole. Each process consists of certain acts by which new formations are gener- ated from the blood. All parts are first eliminated in a fluid state. Such as are destined for nutrition assume the condition of the solids which they supply as soon as eliminated: such as subserve the uses of fluids remain permanently fluid. It is evident, therefore, that ap- propriation, in a philosophical sense, is the highest act of assimila- tion, but may be very properly regarded as a function by itself. 403. Every part ofthe body possesses a secreting apparatus, since every part appropriates the blood to itself (§ 398). 218 INSTITUTES OF MEDICINE. 404. The organs which generate the permanent fluid products are very various, and more complex than such as carry on nutrition. The former are either glands or simple membranes, acting in their com- pound condition (§ 92). The immediate instruments consist of a sim pie series of extreme vessels which pervade every part, and which are every where so constituted, anatomically and vitally, that they elaborate from the common nutritive fluid such compounds as are ex- actly conformable to the nature of each part respectively (§ 41-44, 133, &c, 135 b, 188, &c, 205, Sec., 233, 397, 398). 405. The variety of secreted products, solid and fluid, is greatei, and the quantity more abundant in animals than in plants, and in pro- portion, also, to the complexity of organization. 406. The following products of secretion which remain more oi less fluid occur in the animal kingdom. The first six are common to most animals: 1. Gastric juice. 2. Saliva. 3. Pancreatic juice. 4. Bile. 5. Serous fluids. 6. Mucous fluids. 7. Tears. f Ofthe serous tissues. " cellular tissue. " articular tissues. " chambers ofthe eye. " capsule ofthe lens. I " labyrinth of-the ear. I" Ofthe mucous tissue ofthe mouth. " " " nose. " " " pharynx. " " larynx and trachea. " " " lungs. " " stomach. " " " intestines. " urinary and genital organs. (_ " skin of aquatic animals. Fatty or oily liquids. 9. Fluids of defense. 10. 11. \ Suet, and fat of cellular tissue. Marrow of bones. Liquids in the cryptae of the skin. Cerumen ofthe ear. Fatty fluid of prepuce. I Many other oily products. C Ink of the sepia. j Liquids of insects. j Virus of serpents, &c. [^ Galvanism of torpedo, &c. Humors of the spider, and of other insects, from which theil webs, cocoons, Sec, are formed. f Germinal fluid. Fl "^1 t t-h Semen. r ti Product of vesicuhe seminales. preservation of theo0\, and Lehmann on Chemical Equations, § 1029). 409, k. In respect to the supposed agency of galvanism in the for- mation of animal compounds through the medium ofthe nervous system, the doctrine is consistently applied to the modifications which arise from morbid processes ; but we have just seen (§ 409 hh) that the fun- damental hypothesis is contradicted by the close analogy between the products of plants and animals, and by the absence of the nervous sys- tem in the former, and therefore, a fortiori, galvanism has no connec- tion with morbid products. Galvanism is also alike a stimulus to the secretory functions of plants and animals, which farther establishes its distinction from the nervous power (§ 113, 224, 226, 356 a, 399, 446 a, 461, 475±, 493 cc, 500 nn, 512, 893 a, c, 8931 902).—Note Y. 410. We may therefore well conclude that there is nothing so im- portant in the whole compass of physiology, and in the philosophy and practice of medicine, as a proper understanding of the vital con- stitution, in their properties and functions, of those extreme vessels by which nutrition and secretion are performed. Those are also the instruments of all morbid processes, and those by which all morbid products are elaborated from the blood. And since all healthy prod- ucts are clearly the result of processes to which there is nothing anal- PHYSIOLOGY.--FUNCTIONS. 22? ogous in the world of dead matter, how obviously must all the prod- ucts of disease, all those of inflammatory conditions, which vary but little from the natural standard, be owing to the same vital processes of those formative and secretory vessels somewhat diverted from their natural states, and in which deviations disease must be allowed to con- sist (§ 750, 1039, 1040, 1056). 411. Finally, the function of appropriation is that which evinces, more than any other, the existence of a vital principle. This princi- ple, being admitted as the basis of that function, must be carried to ev- ery other process of living beings. It is by appropriation that the new elementary combinations, in their endless variety, are formed from the blood or sap. By nutrition, which begins at the earliest develop- ment ofthe embryo in the aspect of growth, under the government of a peculiar power, as admitted by all, the organic being is carried for- ward to full maturity, and maintained while life continues. At every stage of his existence, it is the same process as that which was start- ed by the impression ofthe semen upon the germ ; and, since no new results are brought forth, no new powers can be called into opera- tion. The living semen is the first stimulus of the organic properties of the embryo, and in this respect it is analogous to those vital stimuli which forever after maintain the same powers in action, and by which the same nutrition, or the same elementary combinations, are effected at every subsequent stage of existence. By nutrition, through the operation of these vital properties, and according to specific plans in- stituted by the Creator, and to be forever perpetuated by the substi- tuted energy of the vital principle, all those forms of organic beings, which pass by almost insensible gradations from the mushroom up to the gigantic tree, and from the microscopic animalcule to the majesty of man, are maintained in all their exact peculiarities, in all their anal- ogies to each other, in all their vital and moral attributes. It is by nuti'ition, that is to say, by the specific modes in which some three or four principal elements are united together, and joined to pre-existing parts ofthe same nature (§ 41, 42), that each animal or plant, accord- ing to its species, acquires and maintains a specific configuration and organization, exhibiting vital results that are peculiar to each, pro- ducing specific germs that are developed in exact conformity with the nature ofthe parent, and each pursuing forever a certain path which was marked out for itself alone by the Hand which gave it existence. Such, and far more, is the wonderful power, a power substituted for the Creator Himself, which directs capillary circulation, and governs the process of nutrition in the development of the embryo, in the ma- turity of the being, and in the perpetuation of the species. Briefly, then, the whole essential philosophy of organic life, all that is important, or useful, or dignified in medicine, is directly relative to the vital constitution, and the vital actions ofthe formative and secre- tory vessels. Here is the labyrinth of life, here of disease, here the ul- timate aim of medical philosophy (§ 1040).—Note I p. 1118. 6. EXCRETION. 412. Excretion is the sixth grand function common to animals and vegetables. It is analogous to secretion, and is performed by analo- gous organization ; though the differences, in these respects are prob- ably greater than betweei nutrition and secretion, in their ordinary acceptation (§ 402 404). 228 INSTITUTES OF MEDICINE. 413. By excretion useless matter is elaborated from the blood and ejected from the body. The results of this function, therefore, are entirely different from those of secretion, which are destined for use- ful purposes in the animal economy. 414. The terminal series of the arterial system, as with appropri ation, are the immediate instruments of the function of excretion. But, like secretion, a compounded organization is necessary to excre- tion. In this respect there appears to be about the same anatomical variety allotted to secretion and excretion (§ 404). The same tissue, indeed, and even the same part, may perform both functions; as in the lungs, and in the uterus (§ 135). Notwithstanding, however, these coincidences, the final causes of excretion and secretion are so very different (§ 413), the processes which give rise to such opposite results should be regarded as differ- ent functions. 415. The difference between secretion and excretion, as denoted by their respective uses, is confirmed by the elementary constitution of the products of these functions ; those of secretion being organic, those of excretion inorganic. There is also reason to believe that special elementary changes take place in the urine soon after its elim- ination from the blood.* Urea may be also artificially produced; and such is not improbably the fact when chemically obtained from blood, or even from the urine (§ 53, b, 1032 a, Lehmann). 416. The principal excreted substances are, 1st. Carbon ; 2d. Sweat; 3d. Urine. The lungs, skin, and kidneys, are the organs by which they are elaborated. The lungs and skin exercise their function, principally, after nutrition and secretion have been performed, and are, therefore, mainly concerned in excreting the waste parts of the body; though this devolves also upon the kidneys, especially in dis- ease. 417, a. No one ofthe foregoing products is of an organic nature; and the supposed triumph ofthe chemist in manufacturing urea is no more a proof of the dependence of organic compounds on chemical process- es than any other transformation.! The sweat and the urine be- ing liable to transformations as soon as elaborated (§ 415), and more especially as every chemical agent by which their analysis is attempt- ed necessarily changes their composition, their actual condition at the moment of their production can never be known. Such, also, is true of the analysis of every organic compound. The very analysis sup- poses the generation of compounds or of elements in artificial modes; but the original compound being the product of the organic powers, the transformation of its elements, whether spontaneous or effected by the chemist, and through certain agencies, occurs in certain determi- nate modes, and according to the influences which had been impressed by the organs of life (§ 54, a). Besides, it is now fully admitted that many very uniform and remarkable formations out of organic com- pounds, and themselves, too, allied to organic substances, have no such natural existence ; as hydrocyanic acid, narcotin, &c. (§ 42, 409). Even Magendie threw in the way of proximate analyses the conclu- sive fact that, " during the short transit from the vascular tubes to your receiver, the component elements ofthe blood are found to effect a new arrangement" (§ 1032 b, c), * See Medical and Physiological Commentaries, vol. i., p. 526, 585, 602, 675-679. t Leumann says that—"We can hardly any longer enumerate urea among true organic sub- stances.1'—1S50, PHYSIOLOGY.--FUNCTIONS. 229 417, b. When, therefore, I may speak of changes in the " compo- nent parts" of organic compounds, I refer either to such as may be wrought by organic processes, or by influences exerted by less ob- vious causes, as in the case of the bile (§ 316), or to those chemical transformations of a specific nature which depend upon chemical agencies (a). 418. Carbon is the greatest excrement of animals, and is evolved from plants. In the former it is effected by the mucous tissue of the lungs, and often by the skin (§ 135); in the latter by the leaves (§ 303i). 419, a. The excretion of carbon by the lungs is construed by the chemists according to their rules of interpreting other organic actions. But, as I have endeavored, in the " Commentaries," to establish the vital character of this phenomenon, I shall only now advert to its phi- losophy, and in connection with that which respects the production of animal and vegetable heat (§ 433, &c). They are thus associated by myself out of regard to the confusion which has befallen them in the hands of the chemist. But, appealing to him who sees in organic nature its plainest contradistinctions from inorganic, I would, in this place, submit to his understanding whether it be not probable that the same philosophy attends the elaboration of carbon by the lungs and by the skin, and whether that function ofthe skin in many animals be not as much an organic process as the associate secretion of sweat ] 419, b. But, if the foregoing analogies be not sufficiently conclusive, consider, next, the elaboration of that excrementitious matter, the urine; which all but the purely physical philosopher recognize as a vital process. And, again, shall it be admitted that, while nature has constituted the pulmonary mucous tissue, like that of the stomach, intestine, bladder, Sec, upon her universal plan of organization, and endowed it with the vital function of generating mucus, she has depart- ed from it in an isolated part of one and the same continuous tissue to introduce, along with the vital, a chemical function ? It is the same argument as derived from the production of sweat, in its connection with carbonaceous matter; and here the analogy brings into co- operation every product ofthe living being, and establishes the whole upon common principles (§ 447J c, 1032 b). 419, c. There remains, however, a demonstration from analogy which is perfectly irresistible. We have already seen how differently modified in their vital character are not only different tissues, and tis- sues of the same apparent organization, but even different parts of one and the same continuous tissue. We have seen this exemplified in a variety of aspects, and especially by the specific nature of the product of certain parts. We have seen, for example, that there is nothing in nature but that part of the gastro-intestinal mucous tissue which lines the stomach that will generate gastric juice, while, also, it produces mucus (§ 133-136). Now, carry this to another part ofthe same continuous tissue which lines the air-cells, and the inference is plain that if the gastric juice be elaborated by a vital process, so also is the carbonaceous matter. Nor can any objection be urged that other parts of the mucous system do not contribute to the function of decarbonization upon the ground that they are less delicate, and therefore less permeable to the air, than the mucous portion of the lungs, since, in some animals, that dense organ, the skin, performs the same office. Nor is there a better chance for the application of en 230 INSTITUTES OF MEDICINE. dosmose and exosmose, since atmospheric air is often in contact with the mucous tissue of the stomach (§ 447J c). 420. Perspiration or sweat, which is sensible and insensible, being elaborated by an organ of highly complex" organization, is clearly a product of organic actions; and since the skin of some inferior ani- mals, like the mucous tissue of the lungs, eliminates both mucus and carbon, this coincidence of function in two very complex organs may be considered worthy of some regard in forming the logical induction to which the facts in the preceding section may seem entitled. 421. The excretion of urine is the next great source of depuration to the blood. Like the other products of excretion, it contributes to the process of assimilation by its depurating effects (§ 416). It is as- tonishing, too, with what rapidity many substances appear in the urine after their admission into the stomach ; often not more than five or ten minutes intervening. This rapidity of excretion is particularly true of all matter which is offensive to the organization. 422, a. There is a remarkable sympathy subsisting between the kidneys and skin, by which, as it were, they interchange functions with each other. We are all familiar with the fact that the urine is most abundant in cold weather, and the perspirable matter most de- ficient, and vice versa ; and, as a general principle, when one excre- tion abounds, the other is lessened. This is true in disease as in health (§ 129, 1032 a). It depends upon reflex nervous actions. 422, b. For the fulfillment of their final cause the kidneys possess an exquisite susceptibility to the influence of the nervous power (§ 188, &c, 226, 528). Hence arises the rapid and profuse excre- tion of urine when fear and certain other emotions of the mind are in operation. The same affirmation, too, may be made of the skin, though perhaps less extensively. This, too, is the reason why fear so readily induces copious sweats. In either case, the phenomena are owing to the direct development and determination of the nervous power upon the organs, respectively. These phenomena, too, prove the great susceptibility of the skin and kidneys to the influence of the nervous power, and are a key to the whole philosophy of the inter- changes of action between the skin and kidneys (§ 129, 230, 638^). But there are, also, as may be inferred from the facts just stated, great sympathetic relations between the skin and kidneys and many other organs, though these relations are much more manifested by ef- fects which arise sympathetically in the excretory organs than by the influences of these organs upon other parts. This is mostly seen in disease, and during the operation of remedial agents applied to the stomach. So great, indeed, is the snsceptibility of the skin and the kidneys, in their excretory function, to remedial agents, that a large variety have received the denomination of sudorifics, and another class, diuretics. But, owing to the special vital constitution of the skin and kidneys, by which they are rendered sensitive in their ex- cretory function to a thousand slight influences, it is obvious that the foregoing denominations of remedies convey hypotheses that are un- founded, and of injurious tendencies. There are no better sudorifics ■ than fear and hot water; no better diuretic than impending danger (§ 246, 500, 892f, 1040); all through direct or reflex nervous influence. 422, c. In respect to the foregoing principle as shown by diseased conditions the facts are not less familiar. In such cases, an organ PHYSIOLOGY.--FUNCTIONS. 231 which is naturally designed for secretion may sometimes, by a morbid increase of its products, take on the relative function of excretion, and thus, both by morbific reflex nervous actions, and by copious elaborations from the blood, diminish or suspend the excretion of urine. In the cholera asphyxia this excretion would fail entirely, even when the profuse intestinal discharges were unattended by the usual perspiration. But, in the case of the intestinal affection, much was due to the morbific, vital influences; since we often see the urine increased by the active operation of cathartics.* Scarcely a morbid state disturbs the organs of digestion without diminishing or increas- ing the effete products of the kidneys and skin, especially of the for- mer organ. The kidneys, however, being designed for the mere pur- pose of depuration, do not hold a corresponding sway over the great organs of life, but mainly so as it respects their dependence upon those organs (§ 129); while a greater reciprocity of sympathy be- tween the skin and the essential viscera of life, and a predominant sympathy between the skin and kidneys as organs of excretion, evince the wonderful nature of Design in its provisions and limita- tions, according to the final causes which directed the plan of organic life (§ 325).—Illustrated by heart in § 500 m, 687^-688, 694f, 826 cc. 423. How vain the attempt to refer any ofthe foregoing processes and results to any of the forces or laws which rule in the inorganic world! The entire rationale rests upon the peculiar operations of the nervous power, and its laws of reflex action (§ 222, &c, 446, &c, 455 e, 500). A balance of actions and products is thus perpetually maintained, though, of course, with less uniformity and exactness in sickness than in health. But nature, ever provident, has so constitu- ted the properties of life, that when one organ, whether excretory or secretory, becomes morbidly suspended in its function, the evil will be felt by other organs, by reflected nervous action; and they will thus take on, as it were, the work of that suspended organ. If the excretion of urine be wholly arrested, not only the skin, but many other parts, may join in the concerted action of relief. But, no other part will ever excrete urine, no more than the skin will secrete se- men.t The absurdity of this prevailing doctrine is shown, at once, by the fact that urine would excoriate the eliminating vessels of every part excepting those of the kidney (§ 83 b, 133, &c.). Organs of pure secretion, however, may take on, in consequence of the foregoing condition, the office of excretion ; that is to say, they will elaborate, along with their natural fluids, the excrementitious matters, in certain peculiar combinations, which, in the healthy state of the kidneys, would appear in the form of urine (§ 417). 424. The philosophy of all that I have now said in respect to the interchange of offices among the organs of secretion and excretion, and of the dependence of the several products upon special condi- tions of anatomical structure and modifications of the organic proper- ties', is the same that is concerned in the process of lactation after parturition, however different the remote and final causes. The mam- mary glands sympathize with the new change in the uterine system, and produce a fluid which is totally different from the blood, although, like all other products, it is derived from that fluid. And, there * See my work on the Cholera Asphyxia of New York, 1832. t See Medical and Physiological Commentaries, vol. i., p. 526, 588, 603, 608, 680. 232 INSTITUTES OF MEDICINE. would be just as much wisdom in supposing that the reflex nervous action of the womb upon the mammary glands, at this critical junc- ture, is a chemical phenomenon, as there is in referring the elabora- tion of milk to the capricious forces of chemistry, while its reputed filtration from the blood, by others, is equally refuted by the sympa- thetic nature of lactation in every species of mammifera (§ 1031, b). 425. The excretion of urine, more than the products of any other part, may be affected by the absorption of unnatural agents into the circulation. This is because many agents which will excite the ac- tion ofthe kidneys are not offensive to the lacteals nor to the system at large, and are therefore freely absorbed. Such are many saline and alkaline substances, and others, again, which are natural to the body, as aqueous fluids, &c. Those being either unnatural or re- dundant rouse the action of the kidneys, as the proper organs for their elaboration. The quantity of urine is thus increased ; and, while the kidneys are thus stimulated they may be rendered the means of excreting other matters, though in a very different condition from their existence in the blood (§ 408). 426. In morbid states of all the principal organs the urine is remark- ably liable to change. This arises from various causes. If the stom- ach be the primary seat of disease, or, if its condition be disturbed by reflected nervous influences of other diseased organs, as is almost constantly the case, digestion is imperfectly performed, and the chyle, in consequence, becomes more or less unfitted for the purposes of nutrition and secretion. The kidneys, therefore, carry off more than their wonted quantity of excrementitious matter, while this matter ap- pears under conditions more or less varied from the natural product (§ 425). The whole office of appropriation is, also, more or less im- paired, which farther modifies the condition of the blood and the for- mative action of the kidneys; though a part of the office of excretion, under these circumstances, devolves upon the skin and lungs (§ 416). A third great cause of the variableness of the urine consists in un- usual vital decomposition or wasting of the body, or of some of its parts, when it devolves upon the kidneys to co-operate, beyond their natural habit, with the lungs and skin, in removing the redundancy of waste materials. A fourth cause of the urinary changes, and an important one, lies in actual morbid states of the kidneys themselves. The kidneys, however, are not often the seat of morbid affections be- yond those of a simple functional and transient nature, as induced by reflex nervous actions excited by the diseases of other parts; but to whiqh influences the kidneys are extremely liable, and, therefore, to consequent modifications of the urinary product. 427. Briefly, then, every alteration ofthe natural action ofthe kid- neys, whether primary or sympathetic, and every defect in assimila- tion and appropriation, is attended by some change in the urine • while an endless variety is imparted to it by the qualities and quantities of the ingesta. From this circumstance, which should have prompted other conclusions, has arisen the belief that the state of the urine supplies some of the most important signs of pathological conditions, not only of the kidneys themselves, but of remote organs with which they may sympathize. From Hippocrates to our day, elaborate dis- quisitions have appeared concerning the changes ofthe urine as indic- ative of particular forms of disease, of their special seats, of the dif- PHYSIOLOGY.--FUNCTIONS. 233 ferent stages* of their rise and decline, and of their degrees of se- verity and danger. The humoralists were apt to regard the unusual conditions of this product, and other "vitiated secretions," as the disease itself; and in this respect they are imitated by the humoral- ists of the nineteenth century. • Chemistry has been also brought to bear upon the fluctuating states of the urine, and has increased the factitious importance of a symptom which is often as likely to denote some alimentary substance, or divers forms of disease, or imperfect digestion, or some remedial agent, as the source from which it ema- nates. But, coming to the bed-side we find that all these critical obser- vations are relics of the speculative ages of humoralism. Here, we find that all that is practically useful in relation to the urine is gener- ally best ascertained by mere inspection; and upon this subject, we have all, and more than is desirable, from Hippocrates himself. Those philosophers, however, who are employed in interrogating disease by chemical analyses are not often or long in the chambers of the sick. They carry on the investigation of morbid processes in the laboratory of the chemist, and then and there fabricate the appropriate reagents (§ 5J-, a). He who studies organic nature according to the method of solidism and vitalism has neither the leisure for those most diffi- cult, unattainable, and laborious analyses, nor would they have any influence upon his judgment as to the pathology or treatment of dis- ease, in the midst of such a multitudinous variety as is presented by the vital phenomena of disease. Of one thing, also, we may rest as- sured, that nature has supplied all those ready means for interpreting disease that may be necessary for immediate action ; nor can we often delay the treatment of acute disease for consultations with the labora- tory. In respect to the blood, were it even practicable to learn from analysis its variable conditions in disease, it would reflect no light upon morbid states of the organs, since the qualities of that fluid vary with every varying change in the vital conditions of the solids, and there- fore, too, would fail to indicate, in the least, the appropriate remedies. This is also true, in a general sense, of the urine and all other excre- tions, and secretions. The ready sight, their sensible properties, the vital phenomena, physical signs, experience, and general principles, must be our guide. These may be sometimes facilitated by extraor- dinary modes of observation, but which are always within the reach and clear understanding of every practitioner; such as the usual mode of examining the blood in inflammatory diseases, evaporating the urine in diabetes, &c. On the contrary, were the humoral doc- trines correct the teaching and the practice of medicine should be re- stricted to chemists alone; since there is no branch of inquiry so dif- ficult as organic analyses, while their uncertainty would soon imply that the vis medicatrix natures is the only ordination of nature for the maladies of the human race (§ 691, 1033 b). 428. The menstrual fluid is another and a fourth product of excre- tion ; and, from its close resemblance to the blood, in the human spe- cies, it is one of the proofs that capillary hemorrhage is generally the result of a secretory process. In the higher orders of animals, even a clearer index of its origin is supplied by the intermixture of blood with the periodic secretion of mucus, which, in lower orders, occurs without blood. The menses, however, is a product sui generis, and is 234 INSTITUTES OF MEDICINE. specifically determined by the nature of the part (§ 135). Unlike the other products of excretion, it is not essential as an evacuation, though important to the function of generation. It is therefore pe- culiar, also, in exerting important vital influences upon the genera- tive system. 429. At certain periods of the year the female genitals of all ani- mals undergo changes, by which they are developed or prepared for generation ; as, for instance, the ovaria of birds become enlarged, the vagina of rabbits and of other animals is tumefied with blood, increas- ed in its vascular action, and pours out an unusual mucous or bloody fluid. It is only at these periods that they are susceptible of impreg- nation. 430. But woman is capable of impregnation at all times; and that this may happen, her organs must be often developed and prepared for the purpose. The philosophy of the whole of this preparation, however various in different species, and at whatever intervals of time, is the same in all. The several conditions depend upon changes in the yital states of the generative organs, by which the sexual desire is excited, and the germ rendered susceptible to the stimulus ofthe semen. This is the end and the aim of the whole. 431. It follows, therefore, that the periodical excretion ofthe men- strual fluid is only essential to the office of generation, and not to the whole system, excepting so far as this excretion is a healthy function; and the suspension of any function being a morbid condition, the whole system may sympathize with the uterus when the menstrual discharge is suspended. 432. Hence it follows, as a practical result, that all our prescrip- tions for suspended menstruation must proceed upon the principle that this excretion is a vital, and not a mechanical result; and that its suppression is owing to some morbid state of the uterus, either direct, or sympathetic. 7. CALORIFICATION. 433. Calorification is the function by which plants and animals gen- erate the heat which is peculiar to themselves. Chemistry, however, has enjoyed a more undisturbed exposition of the nature of this func- tion than even that of digestion ; nearly all but the most eminent physiologists, such as Hunter and Bichat, having acquiesced in the speculations and assumptions of chemists as setting forth the true phi- losophy of animal, or, rather, organic heat (§ 333). It is obvious, therefore, that few things in medical philosophy have greater demands upon the physiologist than a right interpretation of this great and wonderful function of organic life, that its philosophy may be carried to the illustration of other organic processes, that all may be seen as a system of consistent Designs, and that no foot-hold, in the way of analogy, shall remain to him who would substitute arti- ficial devices for the institutions and laws of Nature. The times have, and always have had, a demand upon the physiologist for a critical exposure of this extensive vitiation of medical philosophy. They urge it upon him now more than at former periods. Nothing has been hitherto done but to express opinions ; and we now witness, as a con- sequence, an almost universal substitution of the chemical and phys- PHYSIOLOGY.--FUNCTIONS. 235 ical theories o! life, disease, and therapeutics, for the promptings of the most obvious phenomena of Nature. Mankind, in masses, in the aspect of Nations, are carried away by the simplicity of the chemical dogmas, and by the confidence with which they are uttered. They have become incorporated in most of our works on Physiology, Med- icine, Hygiene. Nor is this at all limited to the Medical Profession. It is coextensive with society. It is ingrafted upon popular woiks; carried into our colleges, academies, and even public schools. It has become a part of the general plan of elementary education ; and it is now most extensively an object, through voluminous publications, to induce the whole race of mankind to regulate their food by chemical analysis. Banners, I had almost said, are every where paraded, bear- ing the inscription from Liebig's Animal Chemistry, that " To DETERMINE WHAT SUBSTANCES ARE CAPABLE OF AFFORDING NOURISHMENT, IT IS ONLY NECESSARY TO ASCERTAIN THE COMPOSITION OF THE FOOD, AND TO COMPARE IT WITH THE INGREDIENTS OF THE BLOOD." 434. At the very outset of our inquiry, we discern the speculative nature of the chemical philosophy from the vast difference in the sev- eral hypotheses which have been advanced with equal confidence, and which, for awhile, have been received with almost universal fa- vor. The theory of Crawford, which is relative exclusively to the lungs, and to the difference in the capacity for heat of venous and ar- terial blood, will not soon lose its fascinating simplicity nor the plau- sibility of its pretensions. Its elegance will stand forever in forcible contrast with that deformity which is the idol of the present day. Genius and taste will never cease to do their mournful homage to one, while they turn from the other as from the distortions of a Pagan deity. A third hypothesis may be stated as contributing to the improba- bilities of the whole, and which has not yet been fully supplanted by the greater novelty. This is that which ascribes the evolution of or- ganic heat to the passage ofthe common nutritive fluid to a solid state. It has, even more than Crawford's, the merit of philosophical simpli- city, and of an apparent foundation in nature, but far less ofthe spice of genius. 435, a. The first two of the foregoing hypotheses have, as one of their indispensable elements, the union of the oxygen of the air with the carbon of the blood, or with that of the body; though, as [ have endeavored to show in the Medical and Physiological Com- mentaries, neither that act in respiration, nor the excretion of carbon, has any greater connection with the production of animal heat than it has with that ofthe gastric juice, or any other result of organic func- tions. The whole of that subject is investigated so extensively in the work just mentioned, and, I may say, the speculations and assump- tions which have been subsequently put forth by Liebig and his school are, also, so fully considered in the same work, either as already ex- tant, or as likely to ensue, that I shall now limit myself to a statement of the latest and most approved positions of chemistry, and to such remarks and prominent facts as may be necessary to complete the in- tegrity of those fundamental principles which are the main objects of this work, and to show that- nature operates in her several depart- ments, respectively, by general and not by partial laws, and that a 236 INSTITUTES OF MEDICINE. stable and perfect foundation may be thus laid, as it exists in nature for the great superstructure of pathology and therapeutics (§ 2, 892) 435, b. The arguments and the facts which I have employed in the foregoing Essay on Animal Heat must have been oftener approved than avowed, since they have been freely adopted by some subsequent writers without indicating the source from whence they were derived (§ 906, g).—See Rights of Authors p. 919, no. 23. 435, c. I may be also permitted to make the following extract from the Preface to the third volume of the Medical and Physiological Commentaries, published four years subsequently to the first two vol- umes. Thus: " In respect to chemistry, the author may safely affirm that not a fact has been subsequently disclosed that reflects the smallest light upon "physiology or pathology. The whole of that ground, wherever chemistry has obtruded itself upon the science of life and disease, is so amply explained in the former volumes of these Commentaries, that not a substantial fact, nor a vague conclusion, has been put forth by the school of Liebig, which is not there examined, anticipated, and answered, as something which had already an existence, or was like- ly to emerge from the speculative philosophy of the laboratory then in almost universal vogue" (§ 1 b, 350^, 820 c).* 436. What, therefore, I may now say in refutation of this or of other chemical doctrines of organic processes and results, will con- sist, in part, of a summary view of some of the facts and arguments which are arrayed in copious detail in the Medical and Physiological Commentaries. And, truth being my only object, I shall begin the Bubject under consideration with a statement of the opinions of some of the most accurate and distinguished observers, which correspond with my own. But to show, however, that nothing but opinions have been expressed even by those who have comprehended the subject, I shall quote from each author all that I have any knowledge of his hav- ing said upon the question at issue, with the exception of the little which occurs along with Hunter's observations upon the temperature of trees. I will add, also, in proof of the necessity of these inquiries, that no preceding attempt had been made to show the errors of the chemical doctrines of digestion, and that I have incorporated in my prefatory remarks to that investigation all that I could learn from the distinguished authors whom I have there summoned in behalf of philosophy.—See Rights of Authors p. 919, no. 22, 437, a. Let us, then, hear the great French physiologist. " The extrication of caloric," says Bichat, " is a phenomenon exactly analo- gous to those of which the general capillary system is the seat."— " The disengagement of caloric is always subordinate to the state ofthe vital forces."—" The state of respiration has no influence upon the actual heat ofthe body."—" When we place on one side all the phe- nomena of animal heat, and on the other the chemical hypothesis, it * That this opinion is not peculiar to myself appears from critical notices of the Com- mentaries. Thus, for example, it is said by the distinguished author of the " Climate of the United States and its Endemic Influences," that, " It will be seen that Dr. Paine, in fact, anticipates the whole chemical theory of Lie- big, as set forth in his ' Animal Chemistry.' This he does not only in his Essay on Vi- tality, in which he controverts some of the German professor's opinions, advanced in the ' Organic Chemistry applied to Agriculture and Physiology,' but likewise in his Medi cal and Physiological Commentaries, published before the appearance of either of Lie big's works." PHYSIOLOGY.--FUNCTIONS. 237 appears to me so inadequate to the explanation that I think every me- thodical mind can refute it without my assistance."—Bichat's General Anatomy applied to Physiology and Medicine. 437, b. John Hunter, like Bichat, placed the elaboration of organic heat upon the same vital grounds; regarding it as a secreted product. " It is most probable," he says, " that the power of generating heat in animals arises from a principle so connected with life, that it can, and does, act independently of circulation, &c, and is that power which preserves and regulates the internal machine."—Hunter's Observations on Certain Parts ofthe Animal Economy. 437, c. And thus Wilson Philip: "Among the secretions I have ranked the evolution of caloric, although not taking place on any par- ticular surface, because it appeared to be performed by the same power acting on* the same fluid; and because, like secreted fluids, it fails when any considerable part of the influence of the brain or spi- nal cord is withdrawn."—Philip's Experimental Inquiry into the Laws ofthe Vital Functions (§ 446, b). 437, d. And thus the philosophical Moore : " We must allow the bodies of living animals and vegetables to form an original source of heat, as much beyond our power of explaining as the source of the sun's heat."—Moore's Medical Sketches. 437, e. And Miiller thus : " From the experiments of Dulong and Despretz, it results that, even if the chemical theory of respiration be adopted, there must be still some other source of animal heat." "A gen- eral source of animal heat is undoubtedly to be found in the organic ■processes, in which, by the organizing forces on the organic matter, heat is generated not in one, but in every organ of the body." Again, " Since all organic processes are chiefly dependent on the influence exerted by the nerves on the organic mattter of the body, it cannot appear wonderful if the reciprocal action between the organs and the nerves is a main source of animal heat."—Muller's Physiology. 437, f. Tiedemann has the same view of the subject. " The only point," he says, " that can be regarded as placed beyond doubt is, that the evolution of heat is a vital act which depends immediately on the process of nutrition, the conditional and preservative cause of life. The intensity of the evolution of heat, and- the property of maintaining itself at a certain temperature proper to each species, are, in animals, in direct ratio with the composition of their organization, and with the sum and intensity of their manifestations of activity."—Tiede- mann's Physiology. 437, g. Finally, it is even said by the distinguished chemical phys- iologist, Dr. Carpenter, that, " It is evident that the chemical doc- trine in its present form is insufficient to explain the phenomena of animal calorification."—Carpenter's Human Physiology, p. 611. London, 1842. 438, a. The very able Dr. Edwards, in his work on the Influence. jf Physical Agents on Life, maintains that "respiration and animal heat stand related as cause and effect." This doctrine is maintained by Edwards with great ability ; far more so than by all other authors whom I have consulted. I thought it, therefore, important to dispose of his facts and arguments, in my former work, as far as their plausi- bility and my own advantage of the right position would admit. There is much said, in the Commentaries, in refutation of that doc- 238 INSTITUTES OF MEDICINE. trine, which is at the foundation of Liebig's (§ 440), and to which no farther reference will be made in this work ($ 1044). 438, b. Coming to the heterogeneous assumptions which distinguish the school of Liebig, there was no difficulty in anticipating the nature of such as might be relative to former theories. I had set forth the various doctrines in their ample dimensions, and brought them to the test of facts and philosophy. The combustion theory was then in vogue, and nearly in the terms as expounded* by Liebig. In descant- ing upon its peculiarities I took for my guide the most recent and ap- proved phraseology, which, it will be seen, is coincident with the sup- posed novelty; and, although it had numerous and ardent admirers, it passed into such oblivion, in the brief space of two years, that when Liebig promulgated the same hypothesis, and in the same language, it was hailed as one of the most brilliant achievements of that distin- guished man (§ 349, d). The doctrine which had been thus nearly expressed by Billing, in his " Principles of Medicine," was taken for my text, and is now presented again, in its original typography. Thus: " We have in the lungs a charcoal fire constantly burning, and in the other parts a wood fire, the one producing carbonic acid gas, the other carbon ; the food supplying, through the circulation, the veg- etable or animal fuel, from which the charcoal is prepared that is burn- ed in the lungs. It is thus that animal heat is kept up."—Billing, 1838 (§ 447£