ANIMAL CHEMISTRY. 
 
BIOLOGY 
 
 LIBRARY 
 
 6 
 
 ^ WE OCPT. 
 
 Entered according to Act of Congress, in the year 1842, by 
 
 JOHN OWEN, 
 in the Clerk's Office of the District Court of the District of Massachusetts 
 
 CAMBRIDGE: 
 METCALF, KEITH, AND NICHOLS, 
 
 PRINTERS TO THE UNIVERSITY. 
 
ADVERTISEMENT 
 
 TO THE CAMBRIDGE EDITION 
 
 THIS edition of the admirable work of Dr. 
 Liebig is published in compliance with the 
 wishes both of the author and of the translator, 
 and is the only American edition authorized by 
 them. It contains valuable matter which is not 
 in the English edition. 
 
 There have been fewer deviations in the 
 body of the work from the London edition than 
 were at first contemplated. After a consider- 
 able part of that edition had been printed, it 
 was deemed advisable to introduce new matter, 
 which, without deranging the whole work, 
 could only be done by withdrawing portions 
 and substituting the new matter. Both the 
 portions withdrawn and those substituted, to- 
 gether with various corrections, and matter for 
 a* 
 
 6692G2 
 
Vi ADVERTISEMENT. 
 
 which room could not be conveniently obtained, 
 were forwarded by the translator for use in pre- 
 paring the present edition. From these mate- 
 rials alone, partly in manuscript, this edition has 
 been arranged, revised, and printed. The editor 
 availed himself of the permission given him to 
 incorporate the new matter in the body of the 
 work, to introduce it in the form of notes, or to 
 omit it altogether, as he might deem most advis- 
 able, convenient, or useful. He had decided to 
 incorporate the whole in the body of the work, 
 but on the arrival of a complete copy of the 
 London edition, he concluded to make as little 
 variation from that as possible. Some of the 
 less important materials were therefore not used, 
 and others were condensed and introduced as 
 notes. 
 
 After the arrival of the copy of the London 
 edition, it was found to contain important er- 
 rors, some in the body of the work, but more 
 in the Appendix. Many of these must have 
 arisen from the distance at which the translator 
 was from the press ; and others from the haste 
 with which it probably became necessary to 
 finish the work in time for the publication of 
 
ADVERTISEMENT. Vll 
 
 this translation prior to the meeting of the 
 British Association ; when an Abstract of the 
 original, was read by Dr. Lyon Playfair.* 
 
 Great care has been bestowed upon the cal- 
 culations and estimates, which form so impor- 
 tant a feature in the body of the work, and in 
 the analytical results, which constitute the Ap- 
 pendix, upon the vast accumulation of which 
 the whole force of the reasoning depends. 
 Without presuming that the present edition is 
 perfect, or that some errors will not be found 
 in it, it is believed, that it contains fewer than 
 any other, and the editor has the satisfaction of 
 feeling that no pains have been spared to effectu- 
 ate this object. Those only, who may have lei- 
 sure and patience to go through all the calcula- 
 tions can estimate the time and labor they have 
 required. For the ready and able cooperation 
 of Professor Peirce, Dr. Samuel L. Dana, and 
 especially, Mr. Thomas Hill of this University, 
 in the laborious examination and revision of the 
 tables and analytical results, the editor is bound 
 to record his grateful acknowledgments. 
 
 * The abstract occupies two pages of the Athenaeum of July 
 3d. 
 
ADVERTISEMENT. 
 
 The contemplated republication of this work 
 was, several months ago, announced by Messrs. 
 Carey and Hart of Philadelphia, from whose 
 press it would undoubtedly have appeared in a 
 manner acceptable both to the author and the 
 public ; but, on learning the wishes of the 
 author and translator, those gentlemen at once 
 courteously relinquished their undertaking. 
 
 The printing of this edition had been com- 
 menced, and, notwithstanding the wishes of 
 those most interested in the favorable reception 
 of the work had been publicly announced, a 
 reprint from a New York press made its ap- 
 pearance, with all the errors of the English 
 press, and with additional ones. The friends 
 of Science and the admirers of the indefatigable 
 author, will regret, that any occurrence should 
 have diminished the hope, that the reception 
 of the present edition would have afforded to 
 him and the translator, grateful evidence of 
 the value and interest with which the fruits 
 of the profound researches of the former are 
 here welcomed. 
 
 The reception of Dr. Liebig's volume on the 
 continent of Europe, prior to the appearance of 
 
ADVERTISEMENT. i x 
 
 this translation, was enthusiastic, and fully sus- 
 tained the high encomiums and anticipations ex- 
 pressed by the translator in one of his letters to 
 the editor ; in whose opinion it would mark the 
 commencement of a new era in physiology. In 
 translating it, he expresses himself, as having ex- 
 perienced the highest admiration of the profound 
 sagacity, which enabled the author to erect so 
 beautiful a structure on the foundation of facts, 
 which others had allowed to remain for so long 
 a time utterly useless, and of the logical structure 
 and extreme cogency of his arguments, . the 
 brightest light being shed upon almost every 
 point in physiology accessible to chemistry, 
 the true path having been opened, leading to 
 the anticipation of the most astonishing results. 
 Dr. Gregory undertook the translation at the 
 express request of the author, and from long 
 and very intimate knowledge of the mind and 
 thoughts, as well as the style of his friend, in 
 addition to his well known acquirements as a 
 chemist and physiologist, was peculiarly fitted 
 for this act of friendship ; with the faithful per- 
 formance of which Dr. Liebig has expressed 
 his high satisfaction. 
 
Xll MEMOIR OF THE AUTHOR. 
 
 By an Essay on the nature of Fulminic Acid 
 (Knallsaeure), which he offered to the Acad- 
 emy, he gained the attention and friendship of 
 Alexander von Humboldt, who recommended 
 him to Gay-Lussac. That eminent chemist 
 opened to him his laboratory, which had never 
 before been accessible to pupils, and here Lie- 
 big finished his labors on the fulminic acid. 
 Immediately after his return from Paris, the 
 young chemist, probably through the recom- 
 mendation of Humboldt, was appointed to an 
 extraordinary professorship at Giessen. As 
 early as 1826 he received the appointment of 
 ordinary Professor of Chemistry in the same 
 University, and the Medical Faculty honored 
 him with its Doctorate. 
 
 Among his independent scientific works, may 
 be mentioned his " Anleitung zur Analyse or- 
 ganischer Koerper," (Introduction to the Analy- 
 sis of Organic Bodies,) Brunswick, 1837, and 
 his " Practical Pharmacy," as a part of the new 
 edition of the "Manual of Pharmacy of Geiger," 
 Heidelberg, 1839, which was printed again as 
 a separate work in 1840. In partnership with 
 Dr. Poggendorf, in Berlin, he commenced a 
 
MEMOIR OF THE AUTHOR. 
 
 " Dictionary of Chemistry," which is not yet 
 completed. The chief organ of his communica- 
 tions to the public has been the " Annals of 
 Pharmacy," and which is now, chiefly through 
 his labors, the principal journal for Organic 
 Chemistry. 
 
 Dr. Liebig is without doubt one of the most 
 eminent chemists of Europe, and in organic 
 chemistry he may be called without hesitation 
 the first living authority. His labors are the 
 more important inasmuch as they are not con- 
 fined to researches in one department, but, like 
 those of Berzelius, embrace the whole science 
 of Chemistry. His investigations of organic 
 bodies should, however, be particularly noticed^ 
 as they have roused a spirit of greater activity 
 in all who are engaged in chemical pursuits. 
 
 Almost from the beginning Liebig has ex- 
 ercised in his labors a very severe criticism. 
 This criticism was the more useful, as it was 
 an experimental one, refuting experiments by 
 experiments, for which he was particularly dis- 
 tinguished by Berzelius in his " Jahresberich- 
 ten " (Annual Reports). We must not omit to 
 
 observe, however, that the severity of his criti- 
 b 
 
XJV MEMOIR OF THE AUTHOR. 
 
 cisms, especially of his later ones, has been 
 thought bj some to be occasionally tinged by 
 personal and even ambitious motives. 
 
 The beneficial effects of the labors of Liebi 
 
 o 
 
 were soon visible in Germany and in the 
 neighboring countries. The French chem- 
 ists were led to show more respect to Ger- 
 man Chemistry than ever before, and this re- 
 spect is now established in the place of for- 
 mer disregard, for " the French now acknowl- 
 edge," as Liebig himself once remarked, "that 
 Germany is the real seat of public opinion in 
 chemical affairs." In Germany his criticism 
 w T as efficacious, because it attacked with merci- 
 less severity all that was false, and showed at 
 the same time the right method of coming at 
 correct results, and which not only commanded 
 the attention of neighboring countries, but in- 
 creased and secured it. 
 
 This may be said, however, only in respect 
 to the department of Organic Chemistry ; for, 
 when Liebig commenced his researches, Inor- 
 ganic Chemistry had reached such a degree of 
 perfection, that it was partly through contrast 
 with it, that the imperfections of the former 
 
MEMOIR OF THE AUTHOR. XV 
 
 were perceptible, partly, also, because a true 
 basis on which it should be fomided was want- 
 ing. 
 
 To this design of recreating, as it were, Or- 
 ganic Chemistry, in his native country, Liebig 
 was always faithful ; and, though he no longer 
 stands alone as a distinguished promoter of 
 that department, yet no one can overlook the 
 influence he has had upon his colleagues and 
 pupils. This influence operates in Germany 
 and England to urge on the science, in France 
 more to moderate its progress ; that is, to keep 
 theory within its proper limits. The conse- 
 quence has been that, whereas, before, many 
 chemical students repaired to the laboratories 
 of Paris, the young chemists of all nations are 
 now assembled in the little town of Giessen, 
 to profit by the instructions of this great mas- 
 ter. In the present year there are around 
 him one hundred and thirty-five foreigners. 
 The British chemists are looking with eager- 
 ness to Germany, and to undervalue Ger- 
 man Chemistry at the present day, would be 
 ridiculed even in France. We know very well, 
 that Dr. Liebig has not produced this effect 
 
XVI MEMOIR OF THE AUTHOR. 
 
 alone, but who can tell, how soon it would 
 have happened without him ? 
 
 By his unwearied efforts to simplify Organic 
 analysis and to make it more accessible, he has 
 been rendering invaluable services to the young 
 chemist. He has also jimplified the apparatus, 
 and his improvements in it are now extensively 
 known and employed, having already superseded 
 much that was formerly in use ; and in this too 
 he has conduced to the great advances in his 
 favorite department of science. 
 
 From the commencement of his brilliant ca- 
 reer, Dr. Liebig has been an unflinching op- 
 ponent of traditional authorities, and has never 
 hesitated to attack the weaker parts of the old 
 school. It may be asked, does he not in the 
 place of old authorities set up his own ? Has 
 he not been too ambitious of founding a new 
 school ? We think not, unless we should honor 
 with his name, the school of all who are in- 
 spired with the love of truth and the ambition 
 of attaining the best methods of research. 
 
 It cannot be wondered at, that a man like 
 Liebig should concentrate about him a circle 
 of young men, many of whom are blind to all 
 
MEMOIR OF THE AUTHOR. XVli 
 
 other merit, but that of their master, and who 
 extend it even to external preparations, for ex- 
 ample, to single parts of his apparatus, &c. 
 But they may be excused, after the proofs he 
 has given, how fully equal he is to his task, 
 by a series of experiments always so chosen, 
 that they have aided in the promotion of his 
 general object, while he has aroused in so many 
 others the true spirit of research, already re- 
 warded by most valuable results. 
 
 From among the many examples of the skill 
 and sagacity of Liebig, we may mention his 
 examination of the Platinum-black (Platin- 
 schwarz), of Chloral, of Aldehyde * ; his the- 
 ory of Alcohol and of Ether, and that of the 
 formation of Acetic Acid (Essigbildung), of 
 Alkaloids, of the analysis of Organic Elements 
 (Organische Elementar-Analyse), on all of 
 which he has left the impress of his analytical 
 tact. Nor should we overlook his investigation 
 of the products of the decomposition of the 
 Sulphocyanates (Schwefel-Cyan), of the con- 
 
 * Though not the discoverer of Aldehyde, Liebig was the 
 first to insulate it, and describe its properties. 
 6* 
 
XV111 MEMOIR OF THE AUTHOR. 
 
 stitution of the Organic Acids, and his experi- 
 ments performed in connexion with Mr. Wohler 
 on the Oil of bitter Almonds, on Cyanic Acid, 
 and on the products of Decomposition of Uric 
 Acid. These are but a few of his many im- 
 portant researches. 
 
 Dr. Liebig, young as he is, has attained a 
 reputation which secures to him one of the first 
 places in the history of Chemistry, notwith- 
 standing the great opposition which his criti- 
 cisms have excited, and will continue to excite 
 as he advances. A few years since, Professor 
 Liebig was selected by Dr. Turner, to aid him 
 in the completion of the sixth edition of his Ele- 
 ments of Chemistry. To Liebig was committed 
 the department of Organic Chemistry. On the 
 decease of the lamented author, the work was 
 continued by Liebig and Dr. Gregory of Aber- 
 deen. The manner in which they have thus 
 far proceeded with their undertaking, has shown 
 that it could not have be.en placed in abler 
 hands. And the choice of Professor Liebig, 
 says his accomplished coadjutor, "has been rati- 
 fied by the unanimous voice of European chem- 
 ists, by whom he is admitted to be the first 
 
MEMOIR OP THE AUTHOR. x lx 
 
 living authority in Organic Chemistry." The 
 translation of the First Part of Dr. Liebig's Re- 
 port on Organic Chemistry,* which has passed 
 to a third edition in this country, and of which 
 the present work is a continuation, has made 
 the name of the author familiar to us ; and the 
 appearance of a new work from the laboratory 
 of Giessen will be no less welcome on this side 
 the Atlantic, than it was on the continent of 
 Europe. 
 
 CAMBRIDGE, June, 1842. 
 
 * " Chemistry in its Application to Agriculture and Physiology. 
 By Justus Liebig, M. D., Ph. D., F. R. S., M. R. I. A., Professor 
 of Chemistry in the University of Giessen, etc., etc., etc. Edited 
 from the Manuscript of the Author by Lyon Play fair, Ph. D. 
 Third American, from the second London edition, with very 
 numerous additions, a new chapter on Soils, Notes, and Appen- 
 dix, by John W. Webster, M. D., Erving Professor of Chemistry 
 in Harvard University. Cambridge : Published by John Owen. 
 1842." 
 
TO 
 
 THE BRITISH ASSOCIATION 
 
 FOR THE 
 
 ADVANCEMENT OF SCIENCE. 
 
 AT the meeting of the British Association in 
 Glasgow, in 1840, I had the honor to present 
 the first part of a report on the then present 
 state of Organic Chemistry, in which I en- 
 deavored to develope the doctrines of this 
 science in their bearing on Agriculture and 
 Physiology. 
 
 It affords me now much gratification to be 
 able to communicate to the meeting of the As- 
 sociation for the present year, the second part 
 of my labors ; in which 1 have attempted to 
 trace the application of Organic Chemistry to 
 Animal Physiology and Pathology. 
 
 In the present work, an extensive series of 
 phenomena have been treated in their chemical 
 relations ; and, although it would be presump- 
 tuous to consider the questions here raised as 
 being definitely resolved, yet those who are 
 
XX11 DEDICATION. 
 
 familiar with chemistry will perceive, that the 
 only method which can lead to theiT final reso- 
 lution, namely, the quantitative method, has 
 been employed. 
 
 The formulae and equations in the second 
 part, therefore, although they are not to be 
 viewed as ascertained truths, and as furnishing 
 a complete, or the only explanation of the vital 
 processes there treated of, are yet true in this 
 sense ; that, being deduced from facts by logi- 
 cal induction, they must stand as long as no 
 new facts shall be opposed to them. 
 
 When the chemist shows, for example, that 
 the elements of the bile, added to those of the 
 urate of ammonia, correspond exactly to those 
 of blood, he presents to us a fact which is in- 
 dependent of all hypothesis. It remains for 
 the physiologist to determine, by experiment, 
 whether the conclusions drawn by the chemist 
 from such a fact be accurate or erroneous. 
 And, whether this question be answered in the 
 affirmative or in the negative, the fact remains, 
 and will some day find its true explanation. 
 
 I have now to perform the agreeable duty of 
 expressing my sense of the services rendered 
 to me, in the preparation of the English edition 
 by my friend Dr. Gregory. The distinguished 
 station he occupies as a chemist ; the regular 
 education which he has received in the various 
 
DEDICATION. XX111 
 
 branches of medicine; and his intimate ac- 
 quaintance with the German language, all 
 these, taken together, are the best securities, 
 that the translation is such as to convey the 
 exact sense of the original ; securities, such as 
 are not often united in the same individual. 
 
 It is my intention to follow this second part 
 with a third, the completion of which, however, 
 cannot be looked for before the lapse of two 
 years. This third part will contain an investi- 
 gation of the food of man and animals, the an- 
 alysis of all articles of diet, and the study of 
 the changes which the raw food undergoes in 
 its preparation ; as, for example, in fermenta- 
 tion (bread), baking, roasting, boiling, &c. 
 Already, it is true, many analyses have been 
 made for the proposed work; but the number 
 of objects of investigation is exceedingly large, 
 and in order to determine with accuracy the 
 absolute value of seed, or of flour, or of a spe- 
 cies of fodder, &c., as food, the ultimate analy- 
 sis alone is not sufficient ; there are required 
 comparative investigations, which present very 
 great difficulties. 
 
 DR. JUSTUS LIEBIG. 
 GIESSEN, 3d June, 1842. 
 
PREFACE. 
 
 BY the application to Chemistry of the meth- 
 ods which had for centuries been followed by 
 philosophers in ascertaining the causes of natu- 
 ral phenomena in physics, by the observation 
 of weight and measure, LAVOISIER laid the 
 foundation of a new science, which, having 
 been cultivated by a host of distinguished men, 
 has, in a singularly short period, reached a high 
 degree of perfection. 
 
 It was the investigation and determination of 
 all the conditions which are essential to an ob- 
 servation or an experiment, and the discovery 
 of the true principles of scientific research, that 
 protected chemists from error, and conducted 
 them, by a way equally simple and secure, to 
 discoveries which have shed a brilliant light on 
 those natural phenomena, which were previous- 
 ly the most obscure and incomprehensible. 
 
 The most useful applications to the arts, to 
 industry, and to all branches of knowledge re- 
 lated to chemistry, sprung from the laws thus 
 
XXVI PREFACE. 
 
 established ; and this influence was not delayed 
 till chemistry had attained its highest perfec- 
 tion, but came into action with each new ob- 
 servation. 
 
 All existing experience and observation in 
 other departments of science reacted, in like 
 manner, on the improvement and development 
 of chemistry ; so that chemistry received from 
 metallurgy, and from other industrial arts, as 
 much benefit as she had conferred on them. 
 While they simultaneously increased in wealth, 
 they mutually contributed to the development 
 of each other. 
 
 After mineral chemistry had gradually attain- 
 ed its present state of development, the labors 
 of chemists took a new direction. From the 
 study of the constituent parts of vegetables and 
 animals, new and altered views have arisen ; 
 and the present work is an attempt to apply 
 these views to physiology and pathology. 
 
 In earlier times the attempt has been made, 
 and often with great success, to apply to the 
 objects of the medical art the views derived 
 from an acquaintance with chemical observa- 
 tions. Indeed, the great physicians, who lived 
 towards the end of the seventeenth century, 
 were the founders of chemistry, and in those 
 days the only philosophers acquainted with it. 
 The phlogistic system was the dawn of a new 
 
PREFACE. 
 
 day ; it was the victory of philosophy over the 
 rudest empiricism. 
 
 With all its discoveries, modern chemistry 
 has performed but slender services to physi- 
 ology and pathology ; and we cannot be de- 
 ceived as to the cause of this failure, if we 
 reflect that it was found impossible to trace 
 any sort of relation between the observations 
 made in inorganic chemistry, the knowledge 
 of the characters of the elementary bodies, and 
 of such of their compounds as could be formed 
 in the laboratory, on the one hand, and the 
 living body, with the characters of its constitu- 
 ents, on the other. 
 
 Physiology took no share in the advancement 
 of chemistry, because for a long period she re- 
 ceived from the latter science no assistance in 
 her own development. This state of matters 
 has been entirely changed within five and 
 twenty years. But during this period physi- 
 ology has also acquired new ways and methods 
 of investigation within her own province ; and 
 it is only the exhaustion of these sources of 
 discovery, which has enabled us to look for- 
 ward to a change in the direction of the labors 
 of physiologists. The time for such a change 
 is now at hand ; and a perseverance in the 
 methods lately followed in physiology would 
 now, from the want, which must soon be felt, 
 
XXV111 PREFACE. 
 
 of fresh points of departure for researches, 
 render physiology more extensive, but neither 
 more profound nor more solid. 
 
 No one will venture to maintain, that the 
 knowledge of the forms and of the phenomena 
 of motion in organized beings is either unne- 
 cessary or unprofitable. On the contrary, this 
 knowledge must be considered as altogether 
 indispensable to that of the vital processes. But 
 it embraces only one class of the conditions 
 necessary for the acquisition of that knowledge, 
 and is not of itself sufficient to enable us to 
 attain it. 
 
 The study of the uses and functions of the 
 different organs, and of their mutual connex- 
 ion in the animal body, was formerly the chief 
 object of physiological researches ; but lately 
 this study has fallen into the back-ground. 
 The greater part of all the modern discoveries 
 has served to enrich comparative anatomy far 
 more than physiology. 
 
 These researches have yielded the most val- 
 uable results in relation to the recognition of 
 the dissimilar forms and conditions to be found 
 in the healthy and in the diseased organism ; 
 but they have yielded no conclusions calculated 
 to give us a more profound insight into the 
 essence of the vital processes. 
 
 The most exact anatomical knowledge of the 
 
PREFACE. XXIX 
 
 structure of the 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 count- 
 ing the surfaces on the eye of the fly. The 
 most beautiful and elevated problem for the 
 human intellect, the discovery of the laws of 
 vitality, cannot be resolved, nay, cannot even 
 be imagined, without an accurate knowledge 
 of chemical forces ; of those forces which do 
 not act at sensible distances ; which are mani- 
 fested in the same way as those ultimate causes 
 by which the vital phenomena are determined ; 
 and which are invariably found active, when- 
 ever dissimilar substances come into contact. 
 
 Physiology, even in the present day, still 
 endeavors, but always after the fashion of the 
 phlogistic chemists (that is, by the qualitative 
 method), to apply chemical experience to the 
 removal of diseased conditions ; but with all 
 these countless experiments we are not one 
 step nearer to the causes and the essence of 
 disease. 
 
 Without proposing well-defined questions, 
 experimenters have placed blood, urine, and 
 all the constituents of the healthy or diseased 
 frame, in contact with acids, alkalies, and all 
 sorts of chemical reagents; and have drawn, 
 c* 
 
XXX PREFACE. 
 
 from observation of the changes thus produced, 
 conclusions as to their behavior in the body. 
 
 By pursuing this method, useful remedies or 
 modes of treatment might by accident be dis- 
 covered ; but a rational physiology cannot be 
 founded on mere reactions, and the living 
 body cannot be viewed as a chemical labo- 
 ratory. 
 
 In certain diseased conditions, in which the 
 blood acquires a viscid consistence, this state 
 cannot be permanently removed by a chemical 
 action on the fluid circulating in the blood- 
 vessels. The deposit of a sediment from the 
 urine may, perhaps, be prevented by alkalies, 
 while their action has not the remotest tendency 
 to remove the cause of disease. Again, when we 
 observe, in typhus, insoluble salts of ammonia 
 in the faeces, and a change in the globules of 
 the blood similar to that which may be artifi- 
 cially produced by ammonia, we are not, on 
 that account, entitled to consider the presence 
 of ammonia in the body as the cause, but only 
 as the effect of a cause. 
 
 Thus medicine, after the fashion of the Aris- 
 totelian philosophy, has formed certain concep- 
 tions in regard to nutrition and sanguification ; 
 articles of diet have been divided into nutri- 
 tious and non-nutritious ; but these theories, 
 being founded on observations destitute of the 
 
PREFACE. XXXI 
 
 conditions most essential to the drawing of just 
 conclusions, could not be received as expres- 
 sions 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 quantitative 
 method of research ! 
 
 When a lean goose, weighing 41bs., gains, 
 in thirty-six days, during which it has been 
 fed with 241bs. of maize, 51bs. in weight, and 
 yields 3^ Ibs. of pure fat, this fat cannot have 
 been contained in the food, ready formed, be- 
 cause maize does not contain the thousandth 
 part of its weight of fat, or of any substance 
 resembling fat. And when a certain number 
 of bees, the weight of which is exactly known, 
 being fed with pure honey, devoid of wax, 
 yield one part of wax for every twenty parts 
 of honey consumed, without any change being 
 perceptible in their health or in their weight, 
 it is impossible any longer to entertain a doubt 
 as to the formation of fat from sugar in the 
 animal body. 
 
 We must adopt the method which has thus 
 led to the discovery of the origin of fat, in 
 the investigation of the origir* and alteration of 
 the secretions, as well as in the study of all 
 the other phenomena of the animal body. 
 
XXX11 PREFACE. 
 
 From the moment that we begin to look earn- 
 estly and conscientiously for the true answers 
 to our questions ; that we take the trouble, 
 by means of weight and measure, to fix our 
 observations, and express them in the form of 
 equations, these answers are obtained without 
 difficulty. 
 
 However numerous our observations may be, 
 yet, if they only bear on one side of a ques- 
 tion, they will never enable us to penetrate the 
 essence of a natural phenomenon in its full 
 significance. If we are to derive any advan- 
 tage from them, they must be directed to a 
 well-defined object ; and there must be an or- 
 ganized connexion between them. 
 
 Mechanical philosophers and chemists justly 
 ascribe to their methods of research the greater 
 part of the success which has attended their 
 labors. The result of every such investigation, 
 if it bear in any degree the stamp of perfec- 
 tion, may always be given in few words ; but 
 these few words are eternal truths, to the dis- 
 covery of which numberless experiments and 
 questions were essential. The researches them- 
 selves, the laborious experiments and compli- 
 cated apparatus, are forgotten as soon as the 
 truth is ascertained. They were the ladders, 
 the shafts, the tools, which were indispensable 
 to enable us to attain to the rich vein of ore ; 
 
PREFACE. XXxiil 
 
 they were the pillars and air passages which 
 protected the mine from water and from foul air. 
 
 Every chemical or physical investigation, 
 however insignificant, which lays claim to at- 
 tention, must in the present day possess this 
 character. From a certain number of obser- 
 vations it must enable us to draw some conclu- 
 sion, whether it be extended or limited. 
 
 The imperfection of the method or system 
 of research adopted by physiologists can alone 
 explain the fact, that for the last fifty years 
 they have established so few new and solid 
 truths in regard to a more profound knowledge 
 of the functions of the most important organs, 
 of the spleen, of the liver, and of the numerous 
 glands of the body ; and the limited acquaint- 
 ance of physiologists with the methods of re- 
 search 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. 
 
 Before the time of Lavoisier, Scheele, and 
 Priestley, chemistry was not more closely re- 
 lated to physics than she is now to physiology. 
 At the present day chemistry is so fused, as 
 it were, into physics, that it would be a diffi- 
 cult matter to draw the line between them 
 distinctly. The connexion between chemistry 
 and physiology is the same, and in another half 
 
PREFACE. 
 
 century it will be found impossible to separate 
 them. 
 
 Our questions and our experiments intersect 
 in numberless curved -lines the straight line 
 that leads to truth. It is the points of inter- 
 section that indicate to us the true direction ; 
 but, owing to the imperfection of the human 
 intellect, these curve lines must be pursued. 
 Observers in chemistry and physics have the 
 eye ever fixed on the object which they seek 
 to attain, one may succeed, for a time, in 
 following the direct line ; but all are prepared 
 for circuitous paths. Never doubting of the ul- 
 timate success of their efforts, provided they ex- 
 hibit constancy and perseverance, their eager- 
 ness and courage are only exalted by difficulties. 
 
 Detached observations, without connexion, 
 are points scattered over the plain, which do 
 not allow us to choose a decided path. For 
 centuries chemistry presented nothing but these 
 points, although sufficient means were available 
 to fill up the intervals between them. But per- 
 manent discoveries and real progress were only 
 made when chemists ceased to make use of 
 fancy to connect them. 
 
 My object in the present work has been to 
 direct attention to the points of intersection of 
 chemistry with physiology, and to point out 
 those parts in which the sciences become, as it 
 
PREFACE. XXXV 
 
 were, mixed up together. It contains a col- 
 lection of problems, such as chemistry at pres- 
 ent requires to be resolved ; and a number of 
 conclusions, drawn according to the rules of 
 that science, from such observations as have 
 been made. 
 
 These questions and problems will be re- 
 solved : and we cannot doubt, that we shall 
 have in that case a new physiology and a ra- 
 tional pathology. Our sounding line, indeed, 
 is not long enough to measure the depths of 
 the sea, but is not on that account less valuable 
 to us. If it assist us, in the mean time, to 
 avoid rocks and shoals, its use is sufficiently 
 obvious. In the hands of the physiologist, or- 
 ganic chemistry must become an intellectual 
 instrument, by means of which he will be en- 
 abled to trace the causes of phenomena invisi- 
 ble to the bodily sight ; and if among the re- 
 sults which I have developed or indicated in 
 this work, one alone shall admit of a use- 
 ful application, I shall consider the object for 
 which it was written as fully attained. The 
 path which has led to it will open up other 
 paths ; and this I consider as the most impor- 
 tant object to be gained. 
 
 JUSTUS LIEBIG. 
 
 GIESSEN, April, 1842. 
 
NOTE. 
 
 AT the end of the Appendix will be found an interesting 
 paper by Keller (see page 315), confirming the very im- 
 portant observation of A. Ure, Junior, as to the conversion 
 of benzoic acid into hippuric acid in the human body, and 
 the more recent confirmation of the same by M. Garrod, 
 from the London and Edinburgh Philosophical Magazine 
 for June, 1842. The reader will perceive, that this fact 
 strengthens materially the argument of the Author on the 
 action of remedies. 
 
 It has been deemed advisable to retain in this edition, the 
 notes on page 76, which will not be found in the English 
 edition. They were removed, after the pages were in type, 
 to make room for extending the statement, on page 77, that 
 phosphoric acid " is employed in forming brain and nervous 
 matter, to which it is essential, and, also, no doubt, in con- 
 tributing to the supply of the earthy part of the bones. It 
 is probable, however, that the greater part of the earth of 
 bones is obtained by the direct assimilation of phosphate of 
 lime, while the soluble phosphates are better adapted for the 
 production of nervous matter." And, " The phosphoric 
 acid which, by the change of matter, is separated in the 
 uncombined state, is not expelled from the body as phos- 
 phate of soda ; but we find it in the solid excrements in the 
 form of insoluble earthy phosphates." 
 
 tCJ* For an explanation of the formula; and equations 
 employed in this work, see the Introduction to the Appen- 
 dix, page 267. 
 
 For Tables of corresponding Hessian and English weights, 
 &c., see Organ. Chem. in its Application to Agriculture, 
 3d edition, page 416. 
 
 ERRATA. 
 
 Page 76, line 17, for venous " read " arterial." ' 
 " 110, line 12, for <; circulation " read " cellular tissue." 
 " 271, line 11, for " manuel" read " Manual." 
 
CONTENTS. 
 
 PART I. 
 
 PAGE 
 
 Vital force, vis vitse, or vitality ... . . . 1 
 
 Distinction between animal and vegetable life ... 2 
 Assimilation the result of chemical forces ... 4 
 Vitality independent of consciousness .... 6 
 
 Laws of the vital force 8 
 
 Conditions of animal life 9 
 
 Nutrition depends on chemical changes .... 10 
 Amount of oxygen inspired by an adult man . . .12 
 It combines with carbon and hydrogen in the body . 13 
 The consumption of oxygen varies . . . . .15 
 
 Effect of heat on these variations 16 
 
 The mutual action of oxygen and carbon in the body is the 
 
 true source of animal heat 17 
 
 The amount of oxygen regulates that of food . . .20 
 
 Effects of climate on the appetite 22 
 
 The process of starvation 24 
 
 Cause of death in starvation and chronic diseases . . 26 
 Nerves and muscles not the source of animal heat . . 28 
 
 Amount of animal heat 32 
 
 Nervous and vegetative life . . . . . .36 
 
 Nutrition depends on the constituents of blood . . 38 
 
 Identity of organic composition in fibrine and albumen 39 
 d 
 
XXXV111 CONTENTS. 
 
 Nutrition in the carnivora the most simple 
 
 In the herbivora, depends on the azotized products of veg- 
 etables ......... 
 
 These products identical with the constituents of blood 
 
 The blood of animals is therefore formed by vegetables . 
 
 Uses of the non-azotized ingredients of food 
 
 Changes of the food in the organism of carnivora . 
 
 Carbon accumulates in the bile 
 
 Nitrogen in the urine 
 
 The carbon is consumed or burned . . . . 
 
 True function of the bile 
 
 Amount of bile secreted ....... 
 
 Assimilation more energetic in the young animal . 
 
 The butter, sugar, &c., of its food support respiration 
 
 The same is true of the class of herbivora 
 
 Waste of matter very rapid in carnivora .... 
 
 Importance of agriculture to population .... 
 
 Assimilation less energetic in the carnivora 
 
 Origin of fat in domesticated animals .... 
 
 Its formation is a source of oxygen . . . . 
 
 It is formed when oxygen is deficient, and is a source of 
 animal heat 86 
 
 Elements of nutrition and of respiration . . 92 
 
 <5elatine incapable of serving for nutrition, strictly so called 93 
 
 But it may serve to nourish the gelatinous tissues . . 94 
 
 PART II. 
 THE METAMORPHOSIS OF TISSUES. 
 
 Discovery of proteine 10] 
 
 It is formed by vegetables alone 102 
 
 Theory of chymification 104 
 
 Uses of the saliva 108 
 
CONTENTS. XXXIX 
 
 Source of the nitrogen exhaled from the lungs and skin . 109 
 
 Composition of proteine 116 
 
 Composition of the animal tissues 120 
 
 Gelatine contains no proteine, although formed from it 122 
 The secretions contain all the elements of the blood . 126 
 Formula of blood and metamorphoses of bile . . 127 
 Metamorphoses of blood and flesh . . . . 130 
 The constituents of the urine derived from the metamor- 
 phosed tissues 131 
 
 Relation of blood or flesh and proteine to the secretions 
 
 and excretions 133 
 
 Formation of gelatine ....... 135 
 
 Origin of bile in the carnivora . . ... . 137 
 
 Orfgin of bile in the herbivora 140 
 
 Origin of hippuric acid ....... 142 
 
 Formation of the chief secretions and excretions . . 144 
 
 Soda essential to the bile 146 
 
 Relation of urine to bile 148 
 
 Relation of starch to bile . ..... . 150 
 
 Uses of common salt 153 
 
 Certain remedies take a share in the vital transformations 161 
 
 Chief qualities of the blood 163 
 
 Modus operandi of organic remedies .... 165 
 
 All organic poisons contain nitrogen .... 168 
 
 Theine identical with caffeine 170 
 
 Relation of theine and caffeine to bile . . . . 170 
 
 Theory of their action 171 
 
 Theory of the action of the vegetable alkalies . . 173 
 
 Composition and origin of nervous matter . . . 174 
 
 It is related to that of the vegetable alkalies . . 176 
 Theory of the action of the latter . . . . .178 
 
 Phosphorus seems essential to nervous matter . . 180 
 
Xl CONTENTS. 
 
 PART III. 
 
 1. The phenomena of motion in the animal organism . 185 
 
 2. The same subject, with particular reference to the waste 
 
 and supply or change of matter .... 221 
 
 3. Theory of disease 242 
 
 4. Theory of respiration . . . . . . . 253 
 
 APPENDIX. 
 
 Containing the analytical evidence referred to in the sec- 
 tions in which are described the chemical processes 
 of respiration, nutrition, and the metamorphosis of 
 
 tissues 265 
 
 
 On the conversion of benzoic acid into hippuric acid in the 
 
 human body, by W. Keller ..... 315 
 
 Exosmose and endosmose ...... 319 
 
 Action of the heart 320 
 
 Excretion of carbon . . . . . . . 321 
 
 INDEX 323 
 
ORGANIC CHEMISTRY 
 
 APPLIED TO 
 
 PHYSIOLOGY AND P,ATHOLO;GpY. 
 
 I. IN the animal ovum, as well as in the seed of a 
 plant, we recognise a certain remarkable force, the 
 source of growth, or increase in the mass, and of re- 
 production, or of supply of the matter consumed ; a 
 force in a state of rest. By the action of external in- 
 fluences, 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, which, although occasionally bounded by 
 right lines, are yet widely distinct from geometrical 
 forms, such as we observe in crystallized minerals. 
 This force is called the vital force, vis vitce or vitality. 
 
 The increase of mass in a plant is determined by the 
 occurrence of a decomposition which takes place in 
 certain parts of the plant under the influence of light 
 and heat. 
 
 In the vital process, as it goes on in vegetables, it 
 is exclusively inorganic matter which undergoes this 
 decomposition ; and if, with the most distinguished mm- 
 1 
 
VEGETABLE AND 
 
 eralogists, we consider atmospherical air and certain 
 other gases as minerals, it may be said that the vital pro- 
 cess in vegetables accomplishes the transformation of 
 mineral substances into an organism endued with life ; 
 that the mineral becomes part of an organ possessing 
 vital force. , , 
 
 The increase xxt'hiass in a living plant implies that 
 .eertaijt sopipotieint ;parts ef its nourishment become 
 component parts of the plant ; and a comparison of the 
 chemical composition of the plant with that of its nour- 
 ishment makes known to us, with positive certainty, 
 which of the component parts of the latter have been 
 assimilated, and which have been rejected. 
 
 The observations of vegetable physiologists and the 
 researches of chemists have mutually contributed to es- 
 tablish the fact, that the growth and development of 
 vegetables depend on the elimination of oxygen, which 
 is separated from the other component parts of their 
 nourishment. 
 
 In contradistinction to vegetable life, the life of ani- 
 mals exhibits itself in the continual absorption of the 
 oxygen of the air, and its combination with certain com- 
 ponent parts of the animal body. 
 
 While no part of an organized being can serve as 
 food to vegetables, until, by the processes of putrefac- 
 tion 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 or- 
 ganisms. 
 
ANIMAL LIFE. 3 
 
 Animals are distinguished from vegetables by the fac- 
 ulty of locomotion, and, in general, by the possession 
 of senses. 
 
 The existence and activity of these distinguishing 
 faculties depend on certain instruments which are never 
 found in vegetables. Comparative anatomy shows, that 
 the phenomena of motion and sensation depend on 
 certain kinds of apparatus, which have no other relation 
 to each other than this, that they meet in a common 
 centre. The substance of the spinal marrow, the 
 nerves, and the brain, is, in its composition, and in its 
 chemical characters, essentially distinct from that of 
 which cellular substance, membranes, muscles, and skin 
 are composed. 
 
 Every thing in the animal organism, to which the 
 name of motion can be applied, proceeds from the ner- 
 vous apparatus. The phenomena of motion in vegeta- 
 bles, the circulation of the sap, for example, observed 
 in many of the characeae, and the closing of flowers and 
 leaves, depend on physical and mechanical causes. A 
 plant is destitute of nerves. Heat and light are the 
 remote causes of motion in vegetables ; but in animals 
 we recognise in the nervous apparatus a source of 
 power, capable of renewing itself at every moment of 
 their existence. 
 
 While the assimilation of food in vegetables, and the 
 whole process of their formation, are dependent on cer- 
 tain external influences which produce motion, the 
 development of the animal organism is, to a certain 
 extent, independent of these external influences, just 
 
4 ASSIMILATION THE RESULT 
 
 because the animal body can produce within itself that 
 source of motion, which is indispensable to the vital 
 process. 
 
 Assimilation, or the process of formation and growth, 
 in other words, the passage of matter from a state 
 of motion to that of rest, goes on in the same way 
 in animals and in vegetables. In both, the same cause 
 determines the increase of mass. This constitutes the 
 true vegetative life, which is carried on without con- 
 sciousness. 
 
 The activity of vegetative life manifests itself, in 
 vegetables, with the aid of external influences ; in ani- 
 mals, by means of influences produced within their 
 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 rad- 
 ical fibres of the vegetable the same wonderful proper- 
 ties, is the same as that residing in the secreting mem- 
 branes and glands of animals, and which enables every 
 animal organ to perform its own proper function. It is 
 only the source of motion that differs in the two great 
 classes of organized beings. 
 
 While the organs of the vital motions are never 
 wanting in the lowest orders of animals, as in the im- 
 pregnated germ of the ovum, in which they are devel- 
 oped first of all, we find, in the higher orders of ani- 
 mals, peculiar organs of feeling and sensation, of con- 
 sciousness and of a higher intellectual existence. 
 
 Pathology informs us, that the true vegetative life is 
 in no way dependent on the presence of this apparatus ; 
 
OF CHEMICAL FORCES. 5 
 
 that the process of nutrition proceeds in those parts of 
 the body where the nerves 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 incapable of exerting any influence on the 
 contractions of the heart, on the motion of the intes- 
 tines, or on the processes of secretion. 
 
 The higher phenomena of mental existence cannot, 
 in the present state of science, be referred to their 
 proximate, and still less to their ultimate causes. We 
 only know of them, that they exist ; we ascribe them to 
 an immaterial agency, and that, in so far as its manifes- 
 tations are connected with matter, an agency entirely 
 distinct from the vital force, with which it has nothing in 
 common. 
 
 It cannot be denied, that this peculiar force exercises 
 a certain influence on the activity of vegetative life, 
 just as other immaterial agents, such as Light, Heat, 
 Electricity, and Magnetism do ; but this influence is not 
 of a determinative kind, and manifests itself only as an 
 acceleration, a retarding, or a disturbance of the pro- 
 cess of vegetative life. In a manner exactly analogous, 
 the vegetative life reacts on the conscious mental ex- 
 istence. 
 
 There are thus two forces, which are found in activity 
 together ; but consciousness and intellect may be ab- 
 sent in animals as they are in living vegetables, without 
 their vitality being otherwise affected than by the want 
 of a peculiar source of increased energy or of disturb- 
 1* 
 
6 VITALITY INDEPENDENT 
 
 ance. Except in regard to this, all the vital chemical 
 processes go on precisely in the same way in man and 
 in the lower animals. 
 
 The efforts of philosophers, constantly renewed, to 
 penetrate the relations of the soul to animal life, have 
 all along retarded the progress of physiology. In this 
 attempt men left the province of philosophical research 
 for that of fancy ; physiologists, carried away by ima- 
 gination, were far from being acquainted with the laws 
 of purely animal life. None of them had a clear con- 
 ception 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. 
 
 For the purpose of investigating the laws of vital 
 motion in the animal body, only one condition, namely, 
 the knowledge of the apparatus which serves for its 
 production, was ascertained ; but the substance of the 
 organs, the changes which food undergoes in the living 
 body, its transformation into portions of organs, and its 
 re-conversion into lifeless compounds, the share which 
 the atmosphere takes in the processes of vitality ; all 
 these foundations for future conclusions were still 
 wanting. 
 
 What has the soul, what have consciousness and 
 intellect, to do with the development 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 
 
OF CONSCIOUSNESS AND INTELLECT. 7 
 
 those phenomena of life which are not psychological ; 
 and let us beware of drawing conclusions before we 
 have a groundwork. 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 must 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, however, the laws which regulate 
 their motion and rest, because these are manifested in 
 phenomena. In like manner, the laws of vitality, and 
 of all that disturbs, promotes, or alters it, may certainly 
 be discovered, although we shall never learn what life 
 is. Thus, the discovery of the laws of gravitation and 
 of the planetary motions led to an entirely new concep- 
 tion of the cause of these phenomena. This concep- 
 tion could not have been formed in all its clearness 
 without a knowledge of the phenomena out of which it 
 was evolved ; for, considered by itself, gravity, like 
 light to one born blind, is a mere word, devoid of 
 meaning. 
 
 The modern science of physiology has left the track 
 of Aristotle. To the eternal advantage of science, and 
 to the benefit of mankind, it no longer invents a horror 
 vacui, a quinta essentia^ in order to furnish credulous 
 hearers with solutions and explanations of phenomena, 
 
9 LAWS OF THE 
 
 whose true connexion with others, whose ultimate cause, 
 is still unknown. 
 
 If we assume, that all the phenomena exhibited by 
 the organism 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 condi- 
 tion ; if, therefore, we regard the vital force as an in- 
 dependent force, then, in the phenomena of organic 
 life, as in all other phenomena ascribed to the action of 
 forces, we have the statics, that is, the state of equilib- 
 rium determined by a resistance, and the dynamics, of 
 the vital force. 
 
 All the parts of the animal body are produced from a 
 peculiar fluid, circulating in its organism, by virtue of 
 an influence residing in every cell, in every organ, or 
 part of an organ. Physiology teaches, that all parts of 
 the body were originally blood ; or that at least they 
 were brought to the growing organs by means of this 
 fluid. 
 
 The most ordinary experience further shows, that at 
 each moment of life, in the animal organism, a continued 
 change of matter, more or less accelerated, is going on ; 
 that a part of the structure is transformed into unorgan- 
 ized matter, loses its condition of life, and must be 
 again renewed. Physiology has sufficiently decisive 
 grounds for the opinion, that every motion, every mani- 
 festation 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 
 
VITAL FORCE. 9 
 
 thought, every sensation, is accompanied by a change in 
 the composition of the substance of the brain. 
 
 In order to keep up the phenomena of life in animals, 
 certain matters are required, parts of organisms, which 
 we call nourishment. In consequence of a series of 
 alterations, they serve either for the increase of the 
 mass (nutrition), or for the supply of the matter con- 
 sumed (reproduction), or, finally, for the production of 
 force. 
 
 II. If the first condition of animal life be the assimi- 
 lation of what is commonly called nourishment, the 
 second is a continual absorption of oxygen from the 
 atmosphere. 
 
 Viewed as an object of scientific research, animal 
 life exhibits itself in a series of phenomena, the con- 
 nexion and recurrence of which are determined by the 
 changes which the food and the oxygen absorbed from 
 the atmosphere undergo in the organism under the influ- 
 ence of the vital force. 
 
 All vital activity arises from the mutual action of 
 the oxygen of the atmosphere and the elements of 
 the food. 
 
 In the processes of nutrition and reproduction, we 
 perceive the passage of matter from the state of motion 
 to that of rest (static equilibrium) ; under the influence 
 of the nervous system, this matter enters again into a 
 state of motion. The ultimate causes of these different 
 conditions of the vital force are chemical forces. 
 
 The cause of the state of rest is a resistance, deter- 
 
10 NUTRITION AND REPRODUCTION 
 
 mined by a force of attraction (combination), which 
 acts between the smallest particles of matter, and is 
 manifested only when these are in actual contact, or at 
 infinitely small distances. 
 
 To this peculiar kind of attraction we may of course 
 apply different names ; but the chemist calls it affinity. 
 
 The cause of the state of motion is to be found in a 
 series of changes, which the food undergoes in the or- 
 ganism, and these are the results of processes of de- 
 composition, to which either the food itself, or the 
 structures formed from it, or parts of organs, are sub- 
 jected. 
 
 The distinguishing character of vegetable life is a 
 continued passage of matter from the state of motion to 
 that of static equilibrium. While a plant lives, we 
 cannot perceive any cessation in its growth ; no part of 
 an organ in the plant diminishes in size. If decompo- 
 sition occur, it is the result of assimilation. A plant 
 produces within itself no cause of motion ; no part of 
 its structure, from any influence residing in its organism, 
 loses its state of vitality, and is converted into unorgan- 
 ized, amorphous compounds ; in a word, no waste 
 occurs in vegetables. Waste, in the animal body, is a 
 change in the state or in the composition of some of 
 its parts, and consequently is the result of chemical 
 actions. 
 
 The influence of poisons and of remedial agents on 
 the living animal body evidently shows, that the chemical 
 decompositions and combinations in the body, which 
 manifest themselves in the phenomena of vitality, may 
 
DEPEND ON CHEMICAL CHANGES. 
 
 be increased in intensity by chemical forces of analogous 
 character, and retarded or put an end to by those of 
 opposite character ; and that we are enabled to exercise 
 an influence on every part of an organ by means of sub- 
 stances possessing a well-defined chemical action. 
 
 As, in the closed galvanic circuit, in consequence of 
 certain changes which an inorganic body, a metal, un- 
 dergoes when placed in contact with an acid, a certain 
 something becomes cognizable by our senses, which we 
 call a current of electricity ; so, in the animal body, in 
 consequence of transformations and changes undergone 
 by matter previously constituting a part of the organism, 
 certain phenomena of motion and activity are perceived, 
 and these we call life, or vitality. 
 
 The electrical current manifests itself in certain phe- 
 nomena of attraction and repulsion, which it excites in 
 other bodies naturally motionless, and by the phenom- 
 ena of the formation and decomposition of chemical 
 compounds, which occur everywhere, when the resist- 
 ance is not sufficient to arrest the current. 
 
 It is from this point of view, and from no other, that 
 chemistry ought to contemplate the phenomena of life. 
 Wonders surround us on every side. The formation 
 of a crystal, of an octahedron, is not less incompre- 
 hensible than the production of a leaf or of a muscular 
 fibre ; and the production of vermilion, from mercury 
 and sulphur, is as much an enigma as the formation of 
 an eye from the substance of the blood. 
 
 The first conditions of animal life are nutritious mat- 
 ters and oxygen, introduced into the system. 
 
12 OXYGEN REQUIRED 
 
 At every moment of his life man is taking oxygen 
 into his system, by means of the organs of respiration ; 
 no pause is observable while life continues. 
 
 The observations of physiologists have shown, that 
 the body of an adult man, supplied with sufficient food, 
 has neither increased nor diminished in weight at the 
 end of twenty-four hours ; yet the quantity of oxygen 
 taken into the system during this period is very consid- 
 erable. 
 
 According to the experiments of Lavoisier, an adult 
 man takes into his system, from the atmosphere, in one 
 year, 746 Ibs., according to Menzies, 837 Ibs. of oxy- 
 gen ; yet we find his weight, at the beginning and end 
 of the year, either quite the same, or differing, one way 
 or the other, by at most a few pounds, (i)* 
 
 What, it may be asked, has become of the enormous 
 weight of oxygen thus introduced, in the course of a 
 year, into the human system ? 
 
 This question may be answered satisfactorily : no 
 part of this oxygen remains in the system ; but it is 
 given out again in the form of a compound of carbon or 
 of hydrogen. 
 
 The carbon and hydrogen of certain parts of the 
 body have entered into combination with the oxygen 
 introduced through the lungs and through the skin, and 
 have been given out in the forms of carbonic acid gas 
 and the vapor of water. 
 
 At every moment, with every expiration, certain 
 quantities of its elements separate from the animal or- 
 
 * The Numbers refer to the Appendix. 
 
AS WELL AS FOOD. 13 
 
 ganism, after having entered into combination, within 
 the body, with the oxygen of the atmosphere. 
 
 If we assume, with Lavoisier and Seguin, in order 
 to obtain a foundation for our calculation, that an adult 
 man receives into his system daily 32| oz. (46,037 cu- 
 bic inches = 15,661 grains, French weight) of oxygen, 
 and that the weight of the whole mass of his blood, of 
 which 80 per cent, is water, is 24 Ibs. ; it then appears, 
 from the known composition of the blood, that, in order 
 to convert the whole of its carbon and hydrogen into 
 carbonic acid and water, 64,103 grains of oxygen are 
 required. This quantity will be taken into the system 
 of an adult in four days two hours. (2) 
 
 Whether this oxygen enters into combination with 
 the elements of the blood, or with other parts of the 
 body containing carbon and hydrogen, in either case 
 the conclusion is inevitable, that the body of a man, 
 who daily takes into the system 32| oz. of oxygen, must 
 receive daily in the shape of nourishment, as much car- 
 bon and hydrogen as would suffice to supply 24 Ibs. of 
 blood with these elements ; it being presupposed that 
 the weight of the body remains unchanged, and that it 
 retains its normal condition as to health. 
 
 This supply is furnished in the food. 
 
 From the accurate determination of the quantity of 
 carbon daily taken into the system in the food, as well 
 as of that proportion of it which passes out of the body 
 in the faeces and urine, unburned, that is, in some form 
 in which it is not combined with oxygen, it appears that 
 2 
 
14 OXYGEN COMBINES WITH 
 
 an adult, taking moderate exercise, consumes 13.9 oz. 
 of carbon daily, (s) 
 
 These 13 T 9 oz. of carbon escape through the skin 
 and lungs, as carbonic acid gas. 
 
 For conversion into carbonic acid gas, 13 T 9 oz. of 
 carbon require 37 oz. of oxygen. 
 
 According to the analyses of Boussingault (Ann. de Ch. 
 et de Ph. LXXI. p. 136), a horse consumes in twenty- 
 four hours 97| oz. of carbon, a milch cow 69 T 9 S oz. 
 The quantities of carbon here mentioned are those given 
 off from the bodies of these animals in the form of 
 carbonic acid ; and it appears from them that the horse 
 consumes, in converting carbon into carbonic acid, 
 13lbs. 3| oz. in twenty-four hours, and the milch cow 
 11 Ibs. 10| oz. of oxygen in the same time. (4) 
 
 Since no part of the oxygen taken into the system is 
 again given off in any other form but that of a com- 
 pound of carbon or hydrogen ; since, further, the car- 
 bon and hydrogen given off are, in a normal condition 
 of health, replaced by carbon and hydrogen supplied in 
 the food, it is clear, that the amount of nourishment re- 
 quired for its support by the animal body must be in a 
 direct ratio to the quantity of oxygen taken into the 
 system. 
 
 Two animals, which in equal times take up by means 
 of the lungs and skin unequal quantities of oxygen, 
 consume quantities of the same nourishment, which are 
 unequal in the same ratio. 
 
 The consumption of oxygen in equal times may be 
 expressed by the number of respirations ; it is clear 
 
THE CARBON OF THE FOOD. 15 
 
 that, in the same individual, the quantity of nourishment 
 required must vary with the force and number of the 
 respirations. 
 
 A child, in whom the organs of respiration are natural- 
 ly in a state of great activity, requires food oftener, and in 
 greater proportion to its bulk, than an adult, and bears 
 hunger less easily. A bird, deprived of food, dies on 
 the third day, while a serpent, which, if kept under a 
 bell-jar, hardly consumes in an hour so much oxygen as 
 that we can detect the carbonic acid produced, can live 
 without food three months and longer. 
 
 The number of respirations is smaller in a state of 
 rest than during exercise or work. The -quantity of food 
 necessary in both conditions must vary in the same ratio. 
 
 An excess of food is incompatible with deficiency 
 in respired oxygen, that is, with deficient exercise ; just 
 as violent exercise, which implies an increased supply 
 of food, is incompatible with weak digestive organs. In 
 either case the health suffers. 
 
 But the quantity of oxygen which an animal takes up 
 by the lungs, depends not only on the number of respi- 
 rations ; it is also affected by the temperature and densi- 
 ty of the atmosphere. 
 
 The capacity of the chest in an animal is a constant 
 quantity. At every respiration a quantity of air enters, 
 the volume of which may be considered as uniform ; but 
 its weight, and that of the oxygen it contains, is not 
 constant. Air is expanded by heat, and contracted 
 by cold, and equal volumes of hot and cold air contain 
 unequal weights of oxygen. In summer air contains 
 aqueous vapor, in winter it is dry ; the space occupied 
 
16 EFFECT OF HEAT ON THE OXYGEN CONSUMED. 
 
 by vapor in warm air is filled by air itself in winter ; it 
 contains, for the same volume, more oxygen in winter 
 than in summer. In summer and in winter, at the pole 
 and at the equator, we respire an equal volume of air ; 
 the cold air warmed during respiration in the air passages 
 and pulmonary cells, acquires the temperature of the 
 body. To introduce into the lungs a given volume of 
 oxygen, less expenditure of force is necessary in winter ; 
 and for the same force, more oxygen is inspired. 
 
 In an equal number of respirations we consume more 
 oxygen at the level of the sea than on a mountain. The 
 quantity both of oxygen inspired and of carbonic acid ex- 
 pired, must therefore vary with the height of the barometer. 
 
 The oxygen taken into the system is given out again 
 in the same forms, whether in summer or in winter ; 
 hence we expire more carbon in cold weather, and when 
 the -barometer is high, than we do in warm weather ; 
 and we must consume more or less carbon in our food 
 in the same proportion ; in Sweden more tnan in Sicily ; 
 and in our more temperate climate a full eighth more in 
 winter than in summer. 
 
 Even when we consume equal weights of food in 
 cold and warm countries, infinite wisdom has so ar- 
 ranged, that the articles of food in different climates 
 are most unequal in the proportion of carbon they con- 
 tain. The fruits on which the natives of the south 
 prefer to feed do not in the fresh state contain more 
 than 12 per cent, of carbon, while the bacon and train 
 oil used by the inhabitants of the arctic regions contain 
 from 66 to 80 per cent, of carbon. 
 
 It is no difficult matter, in warm climates, to study 
 
SOURCE OF ANIMAL HEAT. 17 
 
 moderation in eating, and men can bear hunger for a 
 long time under the equator ; but cold and hunger united 
 very soon exhaust the body. 
 
 The mutual action between the elements of the 
 food and the oxygen conveyed by the circulation of the 
 blood to every part of the body is THE SOURCE OF AN- 
 IMAL HEAT. 
 
 III. All living creatures, whose existence depends 
 on the absorption of oxygen, possess within them- 
 selves a source of heat independent of surrounding 
 objects. 
 
 This truth applies to all animals, and extends, be- 
 sides, to the germination of seeds, to the flowering of 
 plants, and to the maturation of fruits. 
 
 It is only in those parts of the body to which arterial 
 blood, and with it the oxygen absorbed in respiration, is 
 conveyed, that heat is produced. Hair, wool, or feath- 
 ers do not possess an elevated temperature. 
 
 This high temperature of the animal body, or, as it 
 may be called, disengagement of heat, is uniformly and 
 under all circumstances the result of the combination of 
 a combustible substance with oxygen. 
 
 In whatever way carbon may combine with oxygen, 
 the act of combination cannot take place without the 
 disengagement of heat. It is a matter of indifference 
 whether the combination take place rapidly or slowly, at 
 a high or at a low temperature ; the amount of heat 
 liberated is a constant quantity. 
 
 The carbon of the food, which is converted into car- 
 2* 
 
18 RESPIRATION. 
 
 bonic acid within the body, must give out exactly as 
 much heat as if it had been directly burnt in the air or 
 in oxygen gas ; the only difference is, that the amount 
 of heat produced is diffused over unequal times. In 
 oxygen, the combustion is more rapid, and the heat 
 more intense ; in air it is slower, the temperature is not 
 so high, but it continues longer. 
 
 It is obvious that the amount of heat liberated must 
 increase or diminish with the quantity of oxygen intro- 
 duced in equal times by respiration. Those animals 
 which respire frequently, and consequently consume 
 much oxygen, possess a higher temperature than others, 
 which, with a body of equal size to be heated, take into 
 the system less oxygen. The temperature of a child 
 (102) is higher than that of an adult (99-5). That 
 of birds (104 to 105-4) is higher than that of quad- 
 rupeds (98-5 to 100-4), or than that of fishes or am- 
 phibia, whose proper temperature is from 2-7 to 3-6 
 higher than that of the medium in which they live. All 
 animals, strictly speaking, are warm-blooded ; but in 
 those only which possess lungs is the temperature of the 
 body quite independent of the surrounding medium. (5) 
 
 The most trustworthy observations prove that in all 
 climates, in the temperate zones as well as at the equa- 
 tor or the poles, the temperature of the body in man, 
 and in what are commonly called warm-blooded animals, 
 is invariably the same ; yet how different are the cir- 
 cumstances under which they live ! 
 
 The animal body is a heated mass, which bears the 
 same relation to surrounding objects as any other heated 
 
UNIFORM TEMPERATURE OF THE ANIMAL BODY. 19 
 
 mass. It receives heat when the surrounding objects 
 are hotter, it loses heat when they are colder, than 
 itself. 
 
 We know that the rapidity of cooling increases with 
 the difference between the temperature of the heated 
 body and that of the surrounding medium ; that is, the 
 colder the surrounding medium the shorter the time re- 
 quired for the cooling of the heated body. 
 
 How unequal, then, must be the loss of heat in a 
 man at Palermo, where the external temperature is 
 nearly equal to that of the body, and in the polar re- 
 gions, where the external temperature is from 70 to 
 90 lower. 
 
 Yet, notwithstanding this extremely unequal loss of 
 heat, experience has shown, that the blood of the in- 
 habitant of the arctic circle has a temperature as high as 
 that of a native of the south, who lives in so different a 
 medium. 
 
 This fact, when its true significance is perceived, 
 proves that the heat given off to the surrounding medi- 
 um is restored within the body with great rapidity. 
 This compensation takes place more rapidly in winter 
 than in summer, at the pole than at the equator. 
 
 Now, in different climates the quantity of oxygen 
 introduced into the system by respiration, as has been 
 already shown, varies according to the temperature 
 of the external air ; the quantity of inspired oxygen in- 
 creases with the loss of heat by external cooling, and 
 the quantity of carbon or hydrogen necessary to com- 
 
20 UNIFORM TEMPERATURE OF THE ANIMAL BODY. 
 
 bine with this oxygen must be increased in the same 
 ratio. 
 
 It is evident, that the supply of the heat lost by cool- 
 ing is effected by the mutual action of the elements of 
 the food and the inspired oxygen, which combine to- 
 gether. To make use of a familiar, but not on that 
 account a less just illustration, the animal body acts, in 
 this respect, as a furnace, which we supply with fuel. 
 It signifies nothing what intermediate forms food may 
 assume, what changes it may undergo in the body, the 
 last change is uniformly the conversion of its carbon into 
 carbonic acid, and of its hydrogen into water ; the un- 
 assimilated nitrogen of the food, along with the unburned 
 or unoxidized carbon, is expelled in the urine or in the 
 solid excrements. In order to keep up in the furnace 
 a constant temperature, we must vary the supply of fuel 
 according to the external temperature, that is, according 
 to the supply of oxygen. 
 
 In the animal body the food is the fuel ; with a proper 
 supply of oxygen we obtain the heat given out during 
 its oxidation or combustion. In winter, when we take 
 exercise in a cold atmosphere, and when consequently 
 the amount of inspired oxygen increases, the necessity 
 for food containing carbon and hydrogen increases in the 
 same ratio ; and by gratifying the appetite thus excited, 
 we obtain the most efficient protection against the most 
 piercing cold. A starving man is soon frozen to death ; 
 and every one knows, that the animals of prey in the 
 arctic regions far exceed in voracity those of the torrid 
 zone. 
 
QUANTITY OF FOOD REGULATED. 21 
 
 In cold and temperate climates, the air, which inces- 
 santly strives to consume the body, urges man to labori- 
 ous efforts in order to furnish the means of resistance to 
 its action, while, in hot climates, the necessity of labor 
 to provide food is far less urgent. 
 
 Our clothing is merely an equivalent for a certain 
 amount of food. The more warmly we are clothed the 
 less urgent becomes the appetite for food, because the 
 loss of heat by cooling, and consequently the amount 
 of heat to be supplied by the food, is diminished. 
 
 If we were to go naked, like certain savage tribes, or 
 if in hunting or fishing we were exposed to the same 
 degree of cold as the Samoyedes, we should be able 
 with ease to consume 10 Ibs. of flesh, and perhaps a 
 dozen of tallow candles into the bargain, daily, as warm- 
 ly clad travellers have related with astonishment of these 
 people. We should then also be able to take the same 
 quantity of brandy or train oil without bad effects, be- 
 cause the carbon and hydrogen of these substances 
 would only suffice to keep up the equilibrium between 
 the external temperature and that of our bodies. 
 
 According to the preceding expositions, the quantity 
 of food is regulated by the number of respirations, by 
 the temperature of the air, and by the amount of heat 
 given off to the surrounding medium. 
 
 No isolated fact, apparently opposed to this statement 
 can affect the truth of this natural law. Without tem- 
 porary or permanent injury to health, the Neapolitan 
 cannot take more* carbon and hydrogen in the shape of 
 food than he expires as carbonic acid and water ; and 
 
22 QUANTITY OF FOOD REGULATED. 
 
 the Esquimaux cannot expire more carbon and hydrogen 
 than he takes into the system as food, unless in a state 
 of disease or of starvation. Let us examine these states 
 a little more closely. 
 
 The Englishman in Jamaica sees with regret the dis- 
 appearance of his appetite, previously a source of fre- 
 quently recurring enjoyment ; and he succeeds, by the 
 use of cayenne pepper and the most powerful stimulants, 
 in enabling himself to take as much food as he was ac- 
 customed to eat at home. But the whole of the carbon 
 thus introduced into the system is not consumed ; the 
 temperature of the air is too high, and the oppressive 
 heat does not allow him to increase the number of res- 
 pirations by active exercise, and thus to proportion the 
 waste to the amount of food taken ; disease of some 
 kind, therefore, ensues. 
 
 On the other hand, England sends her sick, whose 
 diseased digestive organs have in a greater or less de- 
 gree lost the power of bringing the food into that state 
 in which it is best adapted for oxidation, and therefore 
 furnish less resistance to the oxidizing agency of the 
 atmosphere than is required in their native climate, to 
 southern regions, where the amount of inspired oxygen 
 is diminished in so great a proportion ; and the result, 
 an improvement in the health, is obvious. The dis- 
 eased organs of digestion have sufficient power to place 
 the diminished amount of food in equilibrium with the 
 inspired oxygen ; in the colder climate, the organs of 
 respiration themselves would have been consumed in 
 
IMPORTANCE OF HYDROGEN. 23 
 
 furnishing the necessary resistance to the action of the 
 atmospheric oxygen. 
 
 In our climate, hepatic diseases, or those arising from 
 excess of carbon, prevail in summer ; in winter, pul- 
 monic diseases, or those arising from excess of oxygen, 
 are more frequent. 
 
 The cooling of the body, by whatever cause it may 
 be produced, increases the amount of food necessary. 
 The mere exposure to the open air, in a carriage or on 
 the deck of a ship, by increasing radiation and vaporiza- 
 tion, increases the loss of heat, and compels us to eat 
 more than usual. The same is true of those who are 
 accustomed to drink large quantities of cold water, 
 which is given off at the temperature of the body, 98'5. 
 It increases the appetite, and persons of weak constitu- 
 tion find it necessary, by continued exercise, to supply 
 to the system the oxygen required to restore the heat 
 abstracted by the cold water. Loud and long continued 
 speaking, the crying of infants, moist air, all exert a 
 decided and appreciable influence on the amount of food 
 which is taken. 
 
 IV. In the foregoing pages, it has been assumed, that 
 it is especially carbon and hydrogen, which, by com- 
 bining with oxygen, serve to produce animal heat. In 
 fact, observation proves that the hydrogen of the food 
 plays a not less important part than the carbon. 
 
 The whole process of respiration appears most clear- 
 ly developed, when we consider the state of a man, or 
 other animal, totally deprived of food. 
 
24 EFFECTS OF STARVATION. 
 
 The first effect of starvation is the disappearance of 
 fat, and this fat cannot be traced either in the urine or 
 in the scanty faeces. Its carbon and hydrogen have 
 been given off through the skin and lungs in the form 
 of oxidized products ; it is obvious, that they have 
 served to support respiration. 
 
 In the case of a starving man, 32| oz. of oxygen 
 enter the system daily, and are given out again in com- 
 bination with a part of his body. Currie mentions the 
 case of an individual who was unable to swallow, and 
 whose body lost 100 Ibs. in weight during a month ; 
 and, according to Martell (Trans. Linn. Soc., vol. xi. 
 p. 411), a fat pig, overwhelmed in a slip of earth, lived 
 160 days without food, and was found to have dimin- 
 ished in weight, in that time, more than 120 Ibs. The 
 whole history of hybernating animals, and the well- 
 established facts of the periodical accumulation, in vari- 
 ous animals, of fat, which, at other periods, entirely 
 disappears, prove that the oxygen, in the respiratory 
 process, consumes, without exception, all such substan- 
 ces as are capable of entering into combination with it. 
 It combines with whatever is presented to it ; and the 
 deficiency of hydrogen is the only reason why carbonic 
 acid is the chief product ; for, at the temperature of the 
 body, the affinity of hydrogen for oxygen far surpasses 
 that of carbon for the same element. 
 
 We know in fact, that the graminivora expire a vol- 
 ume of carbonic acid equal to that of the oxygen in- 
 spired, while the carnivora, the only class of animals 
 whose food contains fat, inspire more oxygen than is 
 
EFFECTS OF STARVATION. 25 
 
 equal in volume to the carbonic acid expired. Exact 
 experiments have shown, that in many cases only half 
 the volume of oxygen is expired in the form of carbonic 
 acid. These observations cannot be gainsaid, and are 
 far more convincing than those arbitrary and artificially 
 produced phenomena, sometimes called experiments ; 
 experiments which, made as too often they are, without 
 regard to the necessary and natural conditions, possess 
 no value, and may be entirely dispensed with ; especial- 
 ly when, as in the present case, nature affords the op- 
 portunity for observation, and when we make a rational 
 use of that opportunity. 
 
 In the progress of starvation, however, it is not only 
 the fat which disappears, but also, by degrees, all such 
 of the solids as are capable of being dissolved. In the 
 wasted bodies of those who have suffered starvation, 
 the muscles are shrunk and unnaturally soft, and hav& 
 lost their contractility ; all those parts of the body 
 which were capable of entering into the state of motion 
 have served to protect the remainder of the frame from 
 the destructive influence of the atmosphere. Towards 
 the end, the particles of the brain begin to undergo the 
 process of oxidation, and delirium, mania, and death 
 close the scene ; that is to say, all resistance to the 
 oxidizing power of the atmospheric oxygen ceases, and 
 the chemical process of eremacausis, or decay, com- 
 mences, in which every part of the body, the bones 
 excepted, enters into combination with oxygen. 
 
 The time which is required to cause death by starva- 
 tion depends on the amount of fat in the body, on the 
 3 
 
26 DEATH CAUSED BY RESPIRATION. 
 
 degree of exercise, as in labor or exertion of any kind, 
 on the temperature of the air, and finally, on the pres- 
 ence or absence of water. Through the skin and lungs 
 there escapes a certain quantity of water, and as the 
 presence of water is essential to the continuance of the 
 vital motions, its dissipation hastens death. Cases have 
 occurred, in which a full supply of water being accessi- 
 ble to the sufferer, death has not occurred till after the 
 lapse of twenty days. In one case, life was sustained 
 in this way for the period of sixty days. 
 
 In all chronic diseases death is produced by the same 
 cause, namely, the chemical action of the atmosphere. 
 When those substances are wanting, whose function in 
 the organism is to , support the process of respiration ; 
 when the diseased organs are incapable of performing 
 their proper function of producing these substances ; 
 when they have lost the power of transforming the food 
 into that shape in which it may, by entering into combi- 
 nation with the oxygen of the air, protect the system 
 from its influence, then, the substance of the organs 
 themselves, the fat of the body, the substance of the 
 muscles, the nerves, and the brain, are unavoidably con- 
 sumed. * 
 
 The true cause of death in these cases is the respira- 
 tory process, that is, the action of the atmosphere. 
 
 A deficiency of food, and a want of power to con- 
 vert the food into a part of the. organism, are both, 
 
 * For an account of what really takes place in this process, I refer 
 to the considerations on the means by which the change of matter is 
 effected in the body of the carnivora, which will be found further on. 
 
RESPIRATION TENDS TO CONSUME THE BODY. 27 
 
 equally, a want of resistance ; and this is the negative 
 cause of the cessation of the vital process. The flame 
 is extinguished, because the oil is consumed ; and it is 
 the oxygen of the air which has consumed it. 
 
 In many diseases substances are produced which are 
 incapable of assimilation. By the mere deprivation of 
 food, these substances are removed from the body with- 
 out leaving a trace behind ; their elements have entered 
 into combination with the oxygen of the air. 
 
 From the first moment that the function of the lungs 
 or of the skin is interrupted or disturbed, compounds, 
 rich in carbon, appear in the urine, which acquires a 
 brown color. Over the whole surface of the body oxy- 
 gen is absorbed, and combines with all the substances 
 which offer no resistance to it. In those parts of the 
 body where the access of oxygen is impeded ; for ex- 
 ample, in the arm-pits, or in the soles of the feet, 
 peculiar compounds are given out, recognisable by their 
 appearance, or by their odor. These compounds con- 
 tain much carbon. 
 
 Respiration is the falling weight, the bent spring, 
 which keeps the clock in motion ; the inspirations and 
 expirations are the strokes of the pendulum which regu- 
 late it. In our ordinary time-pieces, we know with 
 mathematical accuracy the effect produced on their rate 
 of going, by changes in the length of the pendulum, or 
 in the external temperature. Few, however, have a 
 clear conception of the influence of air and temperature 
 on the health of the human body ; and yet the research 
 
28 NERVES AND MUSCLES 
 
 into the conditions necessary to keep it in the normal 
 state, is not more difficult than in the case of a clock. 
 
 V. The want of a just conception of force and 
 effect, and of the connexion of natural phenomena, has 
 led chemists to attribute a part of the heat generated in 
 the animal body to the action of the nervous system. 
 If this view exclude chemical action, or changes in the 
 arrangement of the elementary particles, as a condition 
 of nervous agency, it means nothing else than to derive 
 the presence of motion, the manifestation of a force, 
 from nothing. But no force, no power can come of 
 nothing. 
 
 No one will seriously deny the share which the ner- 
 vous apparatus has in the respiratory process ; for no 
 change of condition can occur in the body without the 
 nerves ; they are essential to all vital motions. Under 
 their influence, the viscera produce those compounds, 
 which, while they protect the organism from the action 
 of the oxygen of the atmosphere, give rise to animal 
 heat ; and when the nerves cease to perform their func- 
 tions, the whole process of the action of oxygen must 
 assume another form. When the pons Varolii is cut 
 through in the dog, or when a stunning blow is inflicted 
 on the back of the head, the animal continues to respire 
 for some time, often more rapidly than in the normal 
 state ; the frequency of the pulse at first rather increases 
 than diminishes, yet the animal cools as rapidly as if 
 sudden death had occurred. Exactly similar observa- 
 tions have been made on the cutting of the spinal cord, 
 
NOT THE SOURCE OF ANIMAL HEAT. 29 
 
 and of the par vagum. The respiratory motions con- 
 tinue for a time, but the oxygen does not meet with 
 those substances with which, in the normal state, it 
 would have combined ; because the paralyzed viscera 
 will no longer furnish them. The singular idea, that the 
 nerves produce animal heat, has obviously arisen from 
 the notion, that the inspired oxygen combines with car- 
 bon, in the blood itself ; in which case the temperature 
 of the body, in the above experiments, certainly, ought 
 not to have sunk. But, as we shall afterwards see, 
 there cannot be a more erroneous conception than this. 
 
 As, by the division of the pneumogastric nerves, the 
 motion of the stomach and the secretion of the gastric 
 juice are arrested, and an immediate check is thus given 
 to the process of digestion, so the paralysis of the or- 
 gans of vital motion in the abdominal viscera affects the 
 process of respiration. These processes are most in- 
 timately connected ; and every disturbance of the ner- 
 vous system or of the nerves of digestion reacts visibly 
 on the process of respiration. 
 
 The observation has been made, that heat is pro- 
 duced by the contraction of the muscles, just as in a 
 piece of caoutchouc, which, when rapidly drawn out, 
 forcibly contracts again, with disengagement of heat. 
 Some have gone so far as to ascribe a part of the 
 animal heat to the mechanical motions of the body, as 
 if these motions could exist without an expenditure of 
 force consumed in producing them ; how then, we may 
 ask, is this force produced ? 
 
 By the combustion of carbon, by the solution of 
 3* 
 
30 SOURCES OF HEAT. 
 
 a metal in an acid, by the combination of the two 
 electricities, positive and negative, by the absorption 
 of light, and even by the rubbing of two solid bodies 
 together with a certain degree of rapidity, heat may 
 be produced. 
 
 By a number of causes, in appearance entirely dis- 
 tinct, we can thus produce one and the same effect. 
 In combustion and in the production of galvanic elec- 
 tricity we have a change of condition in material par- 
 ticles ; when heat is produced by the absorption of 
 light or by friction, we have the conversion of one 
 kind of motion into another, which affects our senses 
 differently. In all such cases we have a something 
 given, which merely takes another form ; in all we have 
 a force and its effect. By means of the fire which 
 heats the boiler of a steam-engine we can produce 
 every kind of motion, and by a certain amount of mo- 
 tion we can produce fire. 
 
 When we rub a piece of sugar briskly on an iron 
 grater, it undergoes, at the surfaces of contact, the 
 same change as if exposed to heat ; and two pieces 
 of ice, when rubbed together, melt at the point of 
 contact. 
 
 Let us remember, that the most distinguished author- 
 ities in physics consider the phenomena of heat as 
 phenomena of motion, because the very conception of 
 the creation of matter, even though imponderable, is 
 absolutely irreconcilable with its production by me- 
 chanical causes, such as friction or motion. 
 
 But, admitting all the influence which electric or 
 
SOURCE OF ANIMAL HEAT. 31 
 
 magnetic disturbances in the animal body can have on 
 the functions of its organs, still the ultimate cause of 
 all these forces is a change of condition in material 
 particles, which may be expressed by the conversion, 
 within a certain time, of the elements of the food into 
 oxidized products. Such of these elements as do not 
 undergo this process of slow combustion, are given off 
 unburned or incombustible in the excrements. 
 
 Now, it is absolutely impossible that a given amount 
 of carbon or hydrogen, whatever different forms they 
 may assume in the progress of the combustion, can 
 produce more heat than if directly burned in atmos- 
 pheric air or in oxygen gas. 
 
 When we kindle a fire under a steam-engine, and 
 employ the power obtained to produce heat by friction, 
 it is impossible that the heat thus obtained can ever 
 be greater than that which was required to heat the 
 boiler ; and if we use the galvanic current to produce 
 heat, the amount of heat obtained is never, in any cir- 
 cumstances, greater than we might have by the combus- 
 tion of the zinc which has been dissolved in the acid. 
 
 The contraction of muscles produces heat ; but the 
 force necessary for the contraction has manifested itself 
 through the organs of motion, in which it has been ex- 
 cited by chemical changes. The ultimate cause of 
 the heat produced is, therefore, to be found in these 
 chemical changes. 
 
 By dissolving a metal in an acid, we produce an 
 electrical current ; this current, if passed through a 
 wire, converts the wire into a magnet, by means of 
 
32 GREAT AMOUNT 
 
 which many different effects may be produced. The 
 cause of these phenomena is magnetism ; the cause of 
 the magnetic phenomena is to be found in the electrical 
 current ; and the ultimate cause of the electrical current 
 is found to be a chemical change, a chemical action. 
 
 There are various causes by which force or motion 
 may be produced. A bent spring, a current of air, the 
 fall of water, fire applied to a boiler, the solution of a 
 metal in an acid, all these different causes of motion 
 may be made to produce the same effect. But in the 
 animal body we recognise as the ultimate cause of all 
 force only one cause, the chemical action which the 
 elements of the food and the oxygen of the air mu- 
 tually exercise on each other. The only known ulti- 
 mate cause of vital force, either in animals or in plants, 
 is a chemical process. If this be prevented, the phe- 
 nomena of life do not manifest themselves, or they 
 cease to be recognisable by our senses. If the chem- 
 ical action be impeded, the vital phenomena must take 
 new forms. 
 
 According to the experiments of Despretz, 1 oz. of 
 carbon evolves, during its combustion, as much heat as 
 would raise the temperature of 78*15 oz. of water at 
 32 to 212, that is, by ISO degrees ; in all, therefore, 
 78-15 times 180= 14067 degrees of heat. Conse- 
 quently, the 13-9 oz. of carbon, which are daily con- 
 verted into carbonic acid in the body of an adult, 
 evolve 13-9 X 14067= 195531-3 degrees of heat. 
 This amount of heat is sufficient to raise the tempera- 
 ture of 1 oz. of water by that number of degrees, or 
 
OF ANIMAL HEAT. 33 
 
 from 32 to 195563-3; or to cause 67-9 Ibs. of wa- 
 ter at 32 to boil; or to heat 184-3 Ibs. of water to 
 98-3 (the temperature of the human body) ; or to 
 convert into vapor 11-4 Ibs. of water at 98-3. 
 
 If we now assume, that the quantity of water vapor- 
 ized through the skin and lungs in 24 hours amounts to 
 48 oz. (3 Ibs.), then there will remain, after deducting 
 the necessary amount of heat, 144137-7 * degrees of 
 heat, which are dissipated by radiation, by heating the 
 expired air, and in the excrementitious matters. 
 
 In this calculation, no account has been taken of the 
 heat evolved by the hydrogen of the food, during its 
 conversion into water by oxidation within the body. 
 But if we consider, that the specific heat of the bones, 
 of fat, and of the organs generally, is far less than that 
 of water, and that consequently they require, in order 
 to be heated to 98-3, much less heat than an equal 
 weight of water, no doubt can be entertained, that when 
 all the concomitant circumstances are , included in the 
 calculation, the heat evolved in the process of combus- 
 tion, to which the food is subjected in the body, is 
 amply sufficient to explain the constant temperature of 
 the body, as well as the evaporation from the skin and 
 lungs. 
 
 VI. All experiments hitherto made on the quantity 
 of oxygen which an animal consumes in a given time, 
 and also the conclusions deduced from them as to the 
 
 * In the above, the latent heat of vapor at 212 is taken, according 
 to Despretz, at 955.8. 
 
34 AMOUNT OF OXYGEN 
 
 origin of animal heat, are destitute of practical value in 
 regard to this question, since we have seen, that the 
 quantity of oxygen consumed varies according to the 
 temperature and density of the air, according to the 
 degree of motion, labor, or exercise, to the amount and 
 quality of the food, to the comparative warmth of the 
 clothing, and also according to the time within which 
 the food is taken. Prisoners in the Bridewell at Ma- 
 rienschloss (a prison where labor is enforced), do not 
 consume more than 10-5 oz. of carbon daily ; those in 
 the House of Arrest at Giessen, who are deprived of 
 all exercise, consume only 8-5 oz. ; (6) and in a family 
 well known to me, consisting of nine individuals, five 
 adults, and four children of different ages, the average 
 daily consumption of carbon for each, is not more than 
 9' 5 oz. of carbon.* We may safely assume, as an 
 approximation, that the quantities of oxygen consumed 
 in these different cases are in the ratio of these num- 
 bers ; but where the food contains meat, fat, and wine, 
 the proportions are altered by reason of the hydrogen 
 in these kinds of food which is oxidized, and which, in 
 being converted into water, evolves much more heat 
 for equal weights. 
 
 The attempts to ascertain the amount of heat evolved 
 in an animal for a given consumption of oxygen have 
 
 * In this family, the monthly consumption was 151 Ibs. of brown 
 bread, 70 Ibs. white bread, 132 Ibs. meat, 19 Ibs. sugar, 159 Ibs. but- 
 ter, 57 maass (about 24 gallons) of milk ; the carbon of the potatoes 
 and other vegetables, of the poultry, game, and wine consumed, hav- 
 ing been reckoned as equal to that contained in the excrementitious 
 matters, the carbon of the above articles was considered as being 
 converted into carbonic acid. L. 
 
CONSUMED BY ANIMALS. 35 
 
 been equally unsatisfactory. Animals have been al- 
 lowed to respire in close chambers surrounded with 
 cold water ; the increase of temperature in the water 
 has been measured by the thermometer, and the quan- 
 tity of oxygen consumed has been calculated from the 
 analysis of the air before and after the experiment. In 
 experiments thus conducted, it has been found that the 
 animal lost about ^ more heat than corresponded to the 
 oxygen consumed ; and had the windpipe of the animal 
 been tied, the strange result would have been obtained 
 of a rise in the temperature of the water without any 
 consumption of oxygen. The animal was at the tem- 
 perature of 98 or 99, and the water, in the experi- 
 ments of Despretz, was at 47*5. Such experiments 
 consequently prove, that when a great difference exists 
 between the temperature of the animal body and that 
 of the surrounding medium, and when no motion is al- 
 lowed, more heat is given off than corresponds to the 
 oxygen consumed. In equal times, with free and un- 
 impeded motion, a much larger quantity of oxygen 
 would be consumed without a perceptible increase in 
 the amount of heat lost. The cause of these phenom- 
 ena is obvious. They appear naturally both in man and 
 animals at certain seasons of the year, and we say in 
 such cases that we are freezing, or experience the sen- 
 sation of cold. It is plain, that if we were to clothe a 
 man in a metallic dress, and tie up his hands and feet, 
 the loss of heat, for the same consumption of oxygen, 
 would be far greater than if we were to wrap him up in 
 fur and woollen cloth. Nay, in the latter case, we 
 
36 NERVOUS AND 
 
 should see him begin to perspire, and warm water 
 would exude, in drops, through the finest pores of his 
 skin. 
 
 If to these considerations we add, that decisive ex- 
 periments are on record, in which animals were made to 
 respire in an unnatural position, as for example, lying on 
 the back, with the limbs tied so as to preclude motion, 
 and that the temperature of their bodies was found to 
 sink in a degree appreciable by the thermometer, we 
 can hardly be at a loss what value we ought to attach to 
 the conclusions drawn from such experiments as those 
 above described. 
 
 These experiments and the conclusions deduced from 
 them, in short, are incapable of furnishing the smallest 
 support to the opinion that there exists, in the animal 
 body, any other unknown source of heat, besides the 
 mutual chemical action between the elements of the food 
 and the oxygen of the air. The existence of the latter 
 cannot be doubted or denied, and it is amply sufficient 
 to explain all the phenomena. 
 
 VII. If we designate the production of force, the 
 phenomena of motion in the animal body as nervous life, 
 and the resistance, the condition of static equilibrium, 
 as vegetative life ; it is obvious that in all classes of ani- 
 mals, the latter, namely, vegetative life, prevails over 
 the former, nervous life, in the earlier stages of ex- 
 istence. 
 
 The passage or change of matter from a state of mo- 
 tion to a state of rest, appears in an increase of the 
 
VEGETATIVE LIFE. 37 
 
 mass, and in the supply of waste ; while the motion 
 itself, or the production of force, appears in the shape 
 of waste of matter. 
 
 In a young animal, the waste is less than the increase ; 
 and the female retains, up to a certain age, this peculiar 
 condition of a more intense vegetative life. This con- 
 dition does not cease in the female as in the male, with 
 the complete development of all the organs of the body. 
 
 The female in the lower animals, is, at certain sea- 
 sons, capable of reproduction of the species. The 
 vegetative life in her organism is rendered more intense 
 by certain external conditions, such as temperature, 
 food, &c. ; the organism produces more than is wasted, 
 and the result is the capacity of reproduction. 
 
 In the human species, the female organism is inde- 
 pendent of those external causes, which increase the in- 
 tensity of vegetative life. When the organism is fully 
 developed, it is at all times capable of reproduction of 
 the species ; and infinite wisdom has given to the female 
 body the power, up to a certain age, of producing all 
 parts of its organization in greater quantity than is re- 
 quired to supply the daily waste. 
 
 This excess of production can be shown to contain 
 all the elements of a new organism ; it is constantly ac- 
 cumulating, and is periodically expelled from the body, 
 until it is expended in reproduction. This periodical 
 discharge ceases when the ovum has been impregnated, 
 and from this time every drop of the superabundant 
 blood goes to produce an organism like that of the 
 mother. 
 
 4 
 
38 NUTRITION DEPENDS ON THE 
 
 Exercise and labor cause a diminution in the quantity 
 of the menstrual discharge ; and when it is suppressed 
 in consequence of disease, the vegetative life is mani- 
 fested in a morbid production of fat. When the equi- 
 librium between the vegetative and nervous life is dis- 
 turbed in the male, when, as in eunuchs, the intensity 
 of the latter is diminished, the predominance of the 
 former is shown in the same form, in an increased 
 deposit of fat. 
 
 VIII. If we hold, that increase of mass in the ani- 
 mal body, the development of its organs, and the supply 
 of waste, that all this is dependent on the blood, that 
 is, on the ingredients of the blood, then only those sub- 
 stances can properly be called nutritious, or considered 
 as food, which are capable of conversion into blood. 
 To determine, therefore, what substances are capable 
 of affording nourishment, it is only necessary to ascer- 
 tain the composition of the food, and to compare it with 
 that of the ingredients of the blood. 
 
 Two substances require especial consideration as the 
 chief ingredients of the blood ; one of these separates 
 immediately from the blood when withdrawn from the 
 circulation. It is well known that in this case blood 
 coagulates, and separates into a yellowish liquid, the 
 serum of the blood, and a gelatinous mass, which adheres 
 to a rod or stick, in soft, elastic fibres, when coagulating 
 blood is briskly stirred. This is the fibrine of the blood, 
 which is identical in all its properties with muscular 
 fibre, when the latter is purified from all foreign matters. 
 
CONSTITUENTS OF BLOOD. 39 
 
 The second principal ingredient of the blood is con- 
 tained in the serum, and gives to this liquid all the 
 properties of the white of eggs, with which it is identi- 
 cal. When heated, it coagulates into a white elastic 
 mass, and the coagulating substance is called albumen. 
 
 Fibrine and albumen, the chief ingredients of blood, 
 contain, in all, seven chemical elements, among which 
 nitrogen, phosphorus, and sulphur are found. They 
 contain also the earth of bones. The serum retains in 
 solution sea salt and other salts of potash and soda, in 
 which the acids are carbonic, phosphoric, and sulphuric 
 acids. The globules of the blood contain fibrine and 
 albumen, along with a red coloring matter, in which 
 iron is a constant element. Besides these, the blood 
 contains certain fatty bodies in small quantity, which 
 differ from ordinary fats in several of their properties. 
 
 Chemical analysis has led to the remarkable result, 
 that fibrine and albumen contain the same organic ele- 
 ments united in the same proportion, so that two analy- 
 ses, the one of fibrine and the other of albumen, do 
 not differ more than two analyses of fibrine or two of 
 albumen respectively do, in the composition of 100 
 parts. . 
 
 In these two ingredients of blood the particles are 
 arranged in a different order, as is shown by the dif- 
 ference of their external properties ; but in chemical 
 composition, in the ultimate proportion of the organic 
 elements, they are identical. 
 
 This conclusion has lately been beautifully confirmed 
 by a distinguished physiologist (Denis), who has sue- 
 
40 NUTRITION DEPENDS ON THE 
 
 ceeded in converting fibrine into albumen, that is, in 
 giving it the solubility, and coagulability by heat, which 
 characterize the white of egg.* 
 
 * This remarkable experiment was first performed by M. Prosper 
 Denis; but as it confirms, in an unexpected and very interesting 
 manner, the conclusion drawn by Professor Liebig from the researches 
 of Mulder, and from those jnade at Giessen : namely, the identity of 
 the organic part of vegetable fibrine, albumen, and caseine with that 
 of animal fibrine, albumen, and caseine; and as M. Dumas has 
 made a claim to this discovery, as being previously well known to 
 the French chemists, it appears advisable to mention a few circum- 
 stances connected with the history of these researches. 
 
 The opinions of Liebig on this subject were not only detailed in 
 his lectures in the winter session of 1840-41, but communicated to 
 Mailer, Wagner, and Tiedemann, and also among others to M. Ma- 
 rignac of Geneva, a friend of M. Dumas, who shortly after returned 
 from Giessen to Paris, viz., in February, 1841. 
 
 In the mean time, M. Denis, having made his curious researches, 
 found, that they were not received as they ought to have been by 
 the Parisian chemists. On the contrary, he was laughed at for his 
 facts! He then applied to Liebig, who, at once, caused his experi- 
 ments to be repeated, and confirmed his conclusions. To those who 
 know the care with which every new observation is protected in 
 Paris, there can be no stronger proof that no other French chemist 
 had any idea of the truth as it now appears, otherwise it would have 
 been announced and the date taken. 
 
 In a work published by Dumas and Boussingault, on the composi- 
 tion of the air, in the spring of 1841, the ideas in regard to the cause 
 of the uniform amount of oxygen in the atmosphere, are those pre- 
 viously published in Liebig's Organic Chemistry applied to Agricul- 
 ture, published in 1840. 
 
 Further, M. Dumas, in a lecture published by him in the end of 
 August, 1841, consequently long after the views of Liebig were 
 known in Paris, put forth views, coinciding with those of Liebig in 
 regard to the nutrition of animals, and the composition of the azotized 
 vegetable nutritious compounds, without the slightest acknowledg- 
 ment. 
 
 The researches which led to these views were not Parisian ; for 
 M. Dumas had never made researches on vegetable fibrine, albumen, 
 and caseine ; while the researches of Boussingault led to the conclu- 
 sion, that these substances differed in composition from the constitu- 
 ents of blood. Now, during the two preceding years, Mulder had 
 
CONSTITUENTS OF BLOOD. 41 
 
 Fibrine and albumen, besides having the same com- 
 position, agree also in this, that both dissolve in con- 
 published his admirable papers, while Liebig and his pupils at Giessen 
 had confirmed and extended the conclusions of Mulder, and Liebig 
 himself had made the important deductions on which the present 
 work is founded, and had, as we have seen, publicly taught them in 
 the winter of 1840-41. 
 
 It is impossible to speak too highly of the labors of Boussingault, 
 and accordingly, Liebig, in the present volume, has availed himself 
 of them, with the fullest acknowledgment. It is only to be regretted 
 that that eminent chemist, in the work already mentioned, published 
 along with Dumas, should not have done the same justice to his 
 distinguished German contemporary. 
 
 Finally, on a careful review of the above facts, it cannot be doubt- 
 ed, that, as in the case of the Agricultural Chemistry, our author 
 was the first to advance those views, founded as well on the experi- 
 ments of others as on his own, which have for the first time given a 
 consistent shape to Physiological Chemistry. These views being 
 once published, nothing is easier than to attach a meaning to older 
 observations and remarks, which even their authors had allowed to 
 fall into oblivion from not perceiving their true bearing; and every 
 great advance in science is sure to draw on its author similar charges 
 of plagiarism. The voice of posterity, however, never fails to de- 
 clare itself in favor of the true discoverer, and Liebig will not lose 
 the honor to which he is so justly entitled. 
 
 The conduct of the French chemists in regard to the observations 
 of Denis, is a clear proof, that, previous to the time when Liebig's 
 views reached Paris, they had not formed any distinct opinions on 
 these important points. In fact, it is universally known, that during 
 that period, M. Dumas, who now steps forward to claim a share in 
 discoveries, the value of which he, along with all chemists, now fully 
 appreciates, was occupied with researches, interesting indeed, but 
 of far less value and importance, on his favorite theory of substi- 
 tutions. Indeed, up to the publication of the paper on air, with 
 M. Boussingault, in 1841, M. Dumas had not appeared at all in the 
 interesting field now in question ; whereas, previous to that period, 
 the views of Liebig were matured. 
 
 We could easily prove, by the internal evidences of M. Dumas's 
 writings, that his views are borrowed from Liebig ; as, for example, 
 his formula for fibrine and albumen, the origin of which was un- 
 known to him. But we have done enough to show how groundless 
 the charge of plagiarism against Liebig is. 
 
 4* 
 
42 IDENTITY OF ANIMAL 
 
 centrated muriatic acid, 'yielding a solution of an intense 
 purple color. This solution, whether made with fibrine 
 or albumen, has the very same reactions with all sub- 
 stances yet tried. 
 
 Both albumen and fibrine, in the process of nutrition, 
 are capable of being converted into muscular fibre, and 
 muscular fibre is capable of being reconverted into blood. 
 These facts have long been established by physiologists, 
 and chemistry has merely proved, that these metamor- 
 phoses can be accomplished under the influence of a 
 certain force, without the aid of a third substance, or 
 of its elements, and without the addition of any foreign 
 element, or the separation of any element previously 
 present in these substances. 
 
 If we now compare the composition of all organized 
 parts with that of fibrine and albumen, the following 
 relations present themselves : 
 
 All parts of the animal body which have a decided 
 shape, which form parts of organs, contain nitrogen. 
 No part of an organ which possesses motion and life 
 is destitute of nitrogen ; all of them contain likewise 
 carbon and the elements of water ; the latter, however, 
 in no case in the proportion to form water. 
 
 The chief ingredients of the blood contain nearly 
 17 per cent, of nitrogen, and no part of an organ con- 
 tains less than 17 per cent, of nitrogen. (i)* 
 
 The most convincing experiments and observations 
 have proved, that the animal body is absolutely incapa- 
 
 * See Note XXVII. 
 
FIBRINE AND ALBUMEN. 43 
 
 ble of producing an elementary body, such as carbon or 
 nitrogen, out of substances which do not contain it ; 
 and it obviously follows, that all kinds of food fit for 
 the production either of blood, or of cellular tissue, 
 membranes, skin, hair, muscular fibre, &c., must con- 
 tain a certain amount of nitrogen, because that element 
 is essential to the composition of the above-named 
 organs ; because the organs cannot create it from the 
 other elements presented to them ; and, finally, because 
 no nitrogen is absorbed from the atmosphere in the vital 
 process. 
 
 The substance of the brain and nerves contains a 
 large quantity of albumen, and, in addition to this, two 
 peculiar fatty acids, distinguished from other fats by 
 containing phosphorus (phosphoric acid?). One of 
 these contains nitrogen (Fremy) . 
 
 Finally, water and common fat are those ingredients 
 of the body which are destitute of nitrogen. Both are 
 amorphous or unorganized, and only so far take part in 
 the vital process as that their presence is required for 
 the due performance of the vital functions. The inor- 
 ganic constituents of the body are, iron, lime, magnesia, 
 common salt, and the alkalies. 
 
 IX. The nutritive process in the carnivora is seen in 
 its simplest form. This class of animals lives on the 
 blood and flesh of the graminivora ; but this blood and 
 flesh is, in all its properties, identical with their own. 
 Neither chemical nor physiological differences can be 
 discovered. 
 
44 NUTRITION OF GRAMINIVORA. 
 
 The nutriment of carnivorous animals is derived 
 originally from blood ; in their stomach it becomes dis- 
 solved, and capable of reaching all other parts of the 
 body ; in its passage it is again converted into blood, 
 and from this blood are reproduced all those parts of 
 their organization which have undergone change or 
 metamorphosis. 
 
 With the exception of hoofs, hair, feathers, and the 
 earth of bones, every part of the food of carnivorous 
 animals is capable of assimilation. 
 
 In a chemical sense, therefore, it may be said that a 
 carnivorous animal, in supporting the vital process, con- 
 sumes itself. That which serves for its nutrition is 
 identical with those parts of its organization which are 
 to be renewed. 
 
 The process of nutrition in graminivorous animals 
 appears at first sight altogether different. Their diges- 
 tive organs are less simple, and their food consists of 
 vegetables, the great mass of which contains but little 
 nitrogen. 
 
 From what substances, it may be asked, is the blood 
 formed, by means of which their organs are developed ? 
 This question may be answered with certainty. 
 
 Chemical researches have shown, that all such parts 
 of vegetables as can afford nutriment to animals contain 
 certain constituents which are rich in nitrogen ; and the 
 most ordinary experience proves, that animals require 
 for their support and nutrition less of these parts of 
 plants in proportion as they abound in the nitrogenized 
 
VEGETABLE FIBRINE. 45 
 
 constituents. Animals cannot be fed on matters desti- 
 tute of these nitrogenized constituents. 
 
 These important products of vegetation are especially 
 abundant in the seeds of the different kinds of grain, 
 and of pease, beans, and lentils ; in the roots and the 
 juices of what are commonly called vegetables. They 
 exist, however, in all plants, without exception, and in 
 every part of plants in larger or smaller quantity. 
 
 These nitrogenized forms of nutriment in the vegeta- 
 ble kingdom may be reduced to three substances, which 
 are easily distinguished by their external characters. 
 Two of them are soluble in water, the third is insoluble. 
 
 When the newly-expressed juices of vegetables are 
 allowed to stand, a separation takes place in a few min- 
 utes. A gelatinous precipitate, commonly of a green 
 tinge, is deposited, and this, when' acted on by liquids 
 which remove the coloring matter, leaves a grayish 
 white substance, well known to druggists as the deposit 
 from vegetable juices. This is one of the nitrogenized 
 compounds which serves for the nutrition of animals, 
 and has been named vegetable fibrine. The juice of 
 grapes is especially rich in this constituent, but it is 
 most abundant in the seeds of wheat, and of the cerealia 
 generally. It may be obtained from wheat flour by a 
 mechanical operation, and in a state of tolerable purity ; 
 it is then called gluten, but the glutinous property be- 
 longs, not to vegetable fibrine, but to a foreign sub- 
 stance, present in small quantity, which is not found in 
 the other cerealia. 
 
 The method by which it is obtained sufficiently proves 
 
46 ALBUMEN, AND CASEINE. 
 
 that it is insoluble in water ; although we cannot doubt 
 that it was originally dissolved in the vegetable juice, 
 from which it afterwards separated, exactly as fibrine 
 does from blood. 
 
 The second nitrogenized compound remains dissolved 
 in the juice after the separation of the fibrine. It does 
 not separate from the juice at the ordinary temperature, 
 but is instantly coagulated when the liquid containing it 
 is heated to the boiling point. 
 
 When the clarified juice of nutritious vegetables, 
 such as cauliflower, asparagus, mangel-wurtzel, or tur- 
 nips, is made to boil, a coagulum is formed, which it is 
 absolutely impossible to distinguish from the substance 
 which separates as a coagulum, when the serum of blood 
 or the white of an egg, diluted with water, are heated 
 to the boiling point. This is vegetable albumen. It is 
 found in the greatest abundance in certain seeds, in nuts, 
 almonds, and others, in which the starch of the gra- 
 mineae is replaced by oil. 
 
 The third nitrogenized constituent of the vegetable 
 food of animals is vegetable caseine. It is chiefly found 
 in the seeds of pease, beans, lentils, and similar legu- 
 minous seeds. Like vegetable albumen, it is soluble in 
 water, but differs from it in this, that its solution is not 
 coagulated by heat. When the solution is heated or 
 evaporated, a skin forms on its surface, and the addition 
 of an acid causes a coagulum, just as in animal milk. 
 
 These three nitrogenized compounds, vegetable fi- 
 brine, albumen, and caseine, are the true nitrogenized 
 constituents of the food of graminivorous animals ; all 
 
NUTRITION. 47 
 
 other nitrogenized compounds, occurring in plants, are 
 either rejected by animals, as in the case of the charac- 
 teristic principles of poisonous and medicinal plants, or 
 else they occur in the food in such very small propor- 
 tion, that they cannot possibly contribute to the increase 
 of mass in the animal body. 
 
 The chemical analysis of these three substances has 
 led to the very interesting result that they contain the 
 same organic elements, united in the same proportion by 
 weight ; and, what is still more remarkable, that they 
 are identical in composition with the chief constituents 
 of blood, animal fibrine, and albumen. They all three 
 dissolve in concentrated muriatic acid with the same 
 deep purple color, and even in their physical characters, 
 animal fibrine and albumen are in no respect different 
 from vegetable fibrine and albumen. It is especially to 
 be noticed, that, by the phrase, identity of composition, 
 we do not here imply mere similarity, but that even in 
 regard to the presence and relative amount of sulphur, 
 phosphorus, and phosphate of lime, no difference can 
 be observed, (s) 
 
 How beautifully and admirably simple, with the aid 
 of these discoveries, appears the process of nutrition in 
 animals, the formation of their organs, in which vitality 
 chiefly resides ! Those vegetable principles, which in 
 animals are used to form blood, contain the chief con- 
 stituents of blood, fibrine, and albumen, ready formed, 
 as far as regards their composition. All plants, besides, 
 contain a certain quantity of iron, which reappears in 
 the coloring matter of the blood. Vegetable fibrine and 
 
48 NUTRITION. 
 
 animal fibrine, vegetable albumen and animal albumen, 
 hardly differ, even in form ; if these principles be want- 
 ing in the food, the nutrition of the animal is arrested ; 
 and when they are present, the graminivorous animal 
 obtains in its food the very same principles on the pres- 
 ence of which the nutrition of the carnivora entirely 
 depends. 
 
 Vegetables produce in their organism the blood of all 
 animals, for the carnivora, in consuming the blood and 
 flesh of the graminivora, consume, strictly speaking, 
 only the vegetable principles which have served for the 
 nutrition of the latter. Vegetable fibrine and albumen 
 take the same form in the stomach of the graminivorous 
 animal as animal fibrine and albumen do in that of the 
 carnivorous animal. 
 
 From what has been said it follows, that the devel- 
 opment of the animal organism and its growth are de- 
 pendent on the reception of certain principles identical 
 with the chief constituents of blood. 
 
 In this sense we may say, that the animal organism 
 gives to blood only its form ; that it is incapable of 
 creating blood out of other substances which do not al- 
 ready contain the chief constituents of that fluid. We 
 cannot, indeed, maintain, that the animal organism has 
 no power to form other compounds, for we know that it 
 is capable of producing an extensive series of com- 
 pounds, differing in composition from the chief constitu- 
 ents of blood ; but these last, which form the starting 
 point of the series, it cannot produce. 
 
 The animal organism is a higher kind of vegetable, 
 
USES OF THE SUGAR. 49 
 
 the development of which begins with those substances, 
 with the production of which the life of an ordinary 
 vegetable ends. As soon as the latter has borne seed, 
 it dies, or a period of its life comes to a termination. 
 
 In that endless series of compounds, which begins 
 with carbonic acid, ammonia, and water, the sources of 
 the nutrition of vegetables, and includes the most com- 
 plex constituents of the animal brain, there is no blank, 
 no interruption. The first substance capable of afford- 
 ing nutriment to animals is the last product of the crea- 
 tive energy of vegetables. 
 
 The substance of cellular tissue and of membranes, 
 of the brain and nerves, these the vegetable cannot 
 produce. 
 
 The seemingly miraculous in the productive agency 
 of vegetables disappears in a great degree, when we 
 reflect that the production of the constituents of blood 
 cannot appear more surprising than the occurrence of 
 the fat of beef and mutton in cocoa beans, of human 
 fat in olive oil, of the principal ingredient of butter 
 in palm oil, and of horse fat and train oil in certain oily 
 seeds. 
 
 X. While the preceding considerations leave little or 
 no doubt as to the way in which the increase of mass in 
 an animal, that is, its growth, is carried on, there is yet 
 to be resolved a most important question, namely, that 
 of the function performed in the animal system by sub- 
 stances containing no nitrogen, such as sugar, starch, 
 gum, pectine, &c. 
 
 5 
 
50 USES OF THE STARCH. CASEINE. 
 
 The most extensive class of animals, the graminivora, 
 cannot live without these substances ; their food must 
 contain a certain amount of one or more of them, and 
 if these compounds are not supplied, death quickly 
 ensues. 
 
 This important inquiry extends also to the consti- 
 tuents of the food of carnivorous animals in the earliest 
 periods of life ; for this food also contains substances, 
 which are not necessary for their support in the adult 
 state. 
 
 The nutrition of the young of carnivora is obviously 
 accomplished by means similar to those by which the 
 graminivora are nourished ; their development is de- 
 pendent on the supply of a fluid, which the body of the 
 mother secretes in the shape of milk. 
 
 Milk contains only one nitrogenized constituent, known 
 under the name of caseine ; besides this, its chief ingre- 
 dients are butter (fat), and sugar of milk. 
 
 The blood of the young animal, its muscular fibre, 
 cellular tissue, nervous matter, and bones, must have 
 derived their origin from the nitrogenized constituent of 
 milk, the caseine ; for butter and sugar of milk contain 
 no nitrogen. 
 
 Now, the analysis of caseine has led to the result, 
 which, after the details given in the last section, can 
 hardly excite surprise, that this substance also is identi- 
 cal in composition with the chief constituents of blood, 
 fibrine and albumen. Nay, more, a comparison of its 
 properties with those of vegetable caseine has shown 
 that these two substances are identical in all their prop- 
 
USES OF THE BUTTER, &c. 51 
 
 erties ; insomuch, that certain plants, such as peas, 
 beans, and lentils, are capable of producing the same 
 substance which is formed from the blood of the mother, 
 and employed in yielding the blood of the young ani- 
 mal. (9) 
 
 The young animal, therefore, receives, in the form 
 of caseine, which is distinguished from fibrine and al- 
 bumen by its great solubility, and by not coagulating 
 when heated, the chief constituent of the mother's 
 blood. To convert caseine into blood no foreign sub- 
 stance is required, and in the conversion of the mother's 
 blood into caseine, no elements of the constituents of 
 the blood have been separated. When chemically ex- 
 amined, caseine is found to contain a much larger pro- 
 portion of the earth of bones than blood does, and that 
 in a very soluble form, capable of reaching every part 
 of the body. Thus, even in the earliest period of its 
 life, the development of the organs, in which vitality 
 resides, is, in the carnivorous animal, dependent on the 
 supply of a substance, identical in organic composition 
 with the chief constituents of its blood. 
 
 What, then, is the use of the butter and the sugar of 
 milk ? How does it happen that these substances are 
 indispensable to life ? 
 
 Butter and sugar of milk contain no fixed bases, no 
 soda or potash. Sugar of milk has a composition 
 closely allied to that of the other kinds of sugar, of 
 starch, and of gum ; all of them contain carbon and the 
 elements of water, the latter precisely in the proportion 
 to form water. 
 
52 ANIMAL AND VEGETABLE 
 
 There is added, therefore, by means of these com- 
 pounds, to the nitrogenized constituents of food, a cer- 
 tain amount of carbon, or, as in the case of butter, of 
 carbon and hydrogen ; that is, an excess of elements, 
 which cannot possibly be employed in the production 
 of blood, because the nitrogenized substances contained 
 in the food already contain exactly the amount of car- 
 bon which is required for the production of fibrine and 
 albumen. 
 
 The following considerations will show that hardly a 
 doubt can be entertained, that this excess of carbon 
 alone, or of carbon and hydrogen, is expended in the 
 production of animal heat, and serves to protect the 
 organism from the action of the atmospheric oxygen. 
 
 XI. In order to obtain a clearer insight into the na- 
 ture of the nutritive process in both the great classes of 
 animals, let us first consider the changes which the food 
 of the carnivora undergoes in their organism. 
 
 If we give to an adult serpent, or boa constrictor, a 
 goat, a rabbit, or a bird, we find that the hair, hoofs, 
 horns, feathers, or bones of these animals, are expelled 
 from the body apparently unchanged. They have re- 
 tained their natural form and aspect, but have become 
 brittle, because of all their component parts they have 
 lost only that one which was capable of solution, name- 
 ly, the gelatine. Fsces, properly so called, do not 
 occur in serpents any more than in carnivorous birds. 
 
 We find, moreover, that, when the serpent has re- 
 gained its original weight, every other part of its prey, 
 
CASEINE IDENTICAL. 53 
 
 the flesh, the blood, the brain, and nerves, in short, 
 every thing, has disappeared. 
 
 The only excrement, strictly speaking, is a substance 
 expelled by the urinary passage. When dry, it is pure 
 white, like chalk ; it contains much nitrogen, and a 
 small quantity of carbonate and phosphate of lime 
 mixed with the mass. 
 
 This excrement is urate of ammonia, a chemical 
 compound, in which the nitrogen bears* to the carbon 
 the same proportion as in bicarbonate of ammonia. 
 For every equivalent of nitrogen it contains two equiv- 
 alents of carbon. 
 
 But muscular fibre, blood, membranes, and skin, con- 
 tain four times as much carbon for the same amount of 
 nitrogen, or eight equivalents to one ; and if we add to 
 this the carbon of the fat and nervous substance, it is 
 obvious that the serpent has consumed, for every equiv- 
 alent of nitrogen, much more than eight equivalents of 
 carbon. 
 
 If now we assume, that the urate of ammonia contains 
 all the nitrogen of the animal consumed, then at least 
 six equivalents of carbon, which were in combination 
 with this nitrogen, must have been given out in a differ- 
 ent form from the two equivalents which are found in 
 the urate of ammonia. 
 
 Now we know, with perfect certainty, that this car- 
 bon has been given out through the skin and lungs, 
 which could only take place in the form of an oxidized 
 product. 
 
 The excrements of a buzzard which had been fed 
 5* 
 
54 NUTRITION OF CARNIVORA. 
 
 with beef, when taken out of the rectum, consisted, 
 according to L. Gmelin and Tiedemann, of urate of 
 ammonia. In like manner, the faeces in lions and tigers 
 are scanty and dry, consisting chiefly of bone earth, 
 with mere traces of compounds containing carbon ; but 
 their urine contains, not urate of ammonia, but urea, a 
 compound in which carbon and nitrogen are to each 
 other in the same ratio as in neutral carbonate of am- 
 monia. 
 
 Assuming that their food (flesh, &c.) contains car- 
 bon and nitrogen in the ratio of eight equivalents to one, 
 we find these elements in their urine in the ratio of 
 one equivalent to one ; a smaller proportion of carbon, 
 therefore, than in serpents, in which respiration is so 
 much less active. 
 
 The whole of the carbon and hydrogen which the 
 food of these animals contained, beyond the amount 
 which we find in their excrements, has disappeared, in 
 the process of respiration, as carbonic acid and water. 
 
 Had the animal food been burned in a furnace, the 
 change produced in it would only have differed in the 
 form of combination assumed by the nitrogen from that 
 which it underwent in the body of the animal. The 
 nitrogen would have appeared, with part of the carbon 
 and hydrogen, as carbonate of ammonia, while the rest 
 of the carbon and hydrogen would have formed car- 
 bonic acid and water. The incombustible parts would 
 have taken the form of ashes, and any part of the car- 
 bon unconsumed from a deficiency of oxygen, would 
 have appeared as soot, or lampblack. Now the solid 
 
FOOD OF CARNIVORA. 55 
 
 excrements are nothing else than the incombustible, or 
 imperfectly burned, parts of the food. 
 
 In the preceding pages it has been assumed, that the 
 elements of the food are converted by the oxygen ab- 
 sorbed in the lungs into oxidized products ; the carbon 
 into carbonic acid, the hydrogen into water, and the 
 nitrogen into a compound containing the same elements 
 as carbonate of ammonia. 
 
 This is only true in appearance ; the body, no doubt, 
 after a certain time, acquires its original weight. The 
 amount of carbon, and of the other elements, is not 
 found to be increased, exactly as much carbon, hy- 
 drogen, and nitrogen has been given out as was supplied 
 in the food ; but nothing is more certain than that the 
 carbon, hydrogen, and nitrogen given out, although 
 equal in amount to what is supplied in that form, do not 
 directly proceed from the food. 
 
 It would be utterly irrational to suppose that the 
 necessity of taking food, or the satisfying the appetite, 
 had no other object than the production of urea, uric 
 acid, carbonic acid, and other excrementitious matters, 
 of substances which the system expels, and conse- 
 quently applies to no useful purpose in the economy. 
 
 In the adult animal, the food serves to restore the 
 waste of matter ; certain parts of its organs have lost 
 the state of vitality, have been expelled from the sub- 
 stance of the organs, and have been metamorphosed 
 into new combinations, which are amorphous and unor- 
 ganized. 
 
 The food of the carnivora is at once converted into 
 
5(5 CARBON IS ACCUMULATED 
 
 blood ; out of the newly-formed blood those parts of 
 organs which have undergone metamorphoses are repro- 
 duced. The carbon and nitrogen of the food thus 
 become constituent parts of organs. 
 
 Exactly as much carbon and nitrogen is supplied to 
 the organs by the blood, that is, ultimately, by the food, 
 as they have lost by the transformations attending the 
 exercise of their functions. 
 
 What, then, it may be asked, becomes of the new 
 compounds produced by the transformations of the 
 organs, of the muscles, of the membranes and cellular 
 tissue, of the nerves, and brain ? 
 
 These new compounds cannot, owing to their solu- 
 bility, remain in the situation where they are formed, 
 for a well-known force, namely, the circulation of the 
 blood, opposes itself to this. 
 
 By the expansion of the heart, an organ in which 
 two systems of tubes meet, which are ramified in a 
 most minute network of vessels through all parts of the 
 body, there is produced a vacuum, the immediate effect 
 of which is, that all fluids which can penetrate into 
 these vessels are urged with great force towards one 
 side of the heart by the external pressure of the atmo- 
 sphere. This motion is powerfully assisted by the con- 
 traction of the heart, alternating with its expansion, and 
 caused by a force independent of the atmospheric 
 pressure. 
 
 In a word, the heart is a forcing pump, which sends 
 arterial blood into all parts of the body ; and also a 
 suction pump, by means of which all fluids of whatever 
 
IN THE BILE. 57 
 
 kind, as soon as they enter the absorbent vessels which 
 communicate with the veins, are drawn towards the 
 heart. This suction, arising from the vacuum caused 
 by the expansion of the heart, is a purely mechanical 
 act, which extends, as above stated, to fluids of every 
 kind, to saline solutions, poisons, &c. It is obvious, 
 therefore, that by the forcible entrance of arterial blood 
 into the capillary vessels, the fluids contained in these, 
 in other words, the soluble compounds formed by the 
 transformations of organized parts, must be compelled 
 to move towards the heart. 
 
 These compounds cannot be employed for the re- 
 production of those tissues from which they are derived. 
 They pass through the absorbent and lymphatic vessels 
 into the veins, where their accumulation would speedily 
 put a stop to the nutritive process, were it not that this 
 accumulation is prevented by two contrivances adapted 
 expressly to this purpose, and which may be compared 
 to filtering machines. 
 
 The venous blood, before reaching the heart, is made 
 to pass through the liver ; the arterial blood, on the other 
 hand, passes through the kidneys ; and these organs sep- 
 arate from both all substances incapable of contributing 
 to nutrition. 
 
 Those new compounds which contain the nitrogen of 
 the transformed organs are collected in the urinary blad- 
 der, and being utterly incapable of any further applica- 
 tion in the system, are expelled from the body. 
 
 Those, again, which contain the carbon of the trans- 
 formed tissues, are collected in the gall-bladder in the 
 form of a compound of soda, the bile, which is miscible 
 
58 THE CARBON OF THE BILE 
 
 with water in every proportion, and which, passing into 
 the duodenum, mixes with the chyme. All those parts 
 of the bile which, during the digestive process, do not 
 lose their solubility, return during that process into the 
 circulation in a state of extreme division. The soda 
 of the bile, and those highly carbonized portions which 
 are not precipitated by a weak acid (together making 
 T 9 9 ths of the solid contents of the bile), retain the ca- 
 pacity of resorption by the absorbents of the small and 
 large intestines ; nay, this capacity has been directly 
 proved by the administration of enemata containing bile, 
 the whole of the bile disappearing with the injected 
 fluid in the rectum. 
 
 Thus we know with certainty, that the nitrogenized 
 compounds produced by the metamorphosis of organ- 
 ized tissues, after being separated from the arterial 
 blood by means of the kidneys, are expelled from the 
 body as utterly incapable of further alteration ; while 
 the compounds rich in carbon, derived from the same 
 source, return into the system of carnivorous animals. 
 
 The food of the carnivora is identical with the chief 
 constituents of their bodies, and hence the metamor- 
 phoses which their organs undergo must be the same as 
 those which, under the influence of the vital force, take 
 place in the matters which constitute their food. 
 
 The flesh and blood consumed as food yield their 
 carbon for the support of the respiratory process, while 
 its nitrogen appears as uric acid, ammonia, or urea. 
 But previously to these final changes, the dead flesh 
 and blood become living flesh and blood, and it is, 
 
UNDERGOES COMBUSTION. 59 
 
 strictly speaking, the carbon of the compounds formed 
 in the metamorphoses of living tissues that serves for 
 the production of animal heat. 
 
 The food of the carnivora is converted into blood, 
 which is destined for the reproduction of organized tis- 
 sues ; and by means of the circulation a current of 
 oxygen is conveyed to every part of the body. The 
 globules of the blood, which in themselves can be 
 shown to take no share in the nutritive process, serve to 
 transport the oxygen, which they give up in their pas- 
 sage through the capillary vessels. Here the current of 
 oxygen meets with the compounds produced by the 
 transformation of the tissues, and combines with their 
 carbon to form carbonic acid, with their hydrogen to 
 form water. Every portion of these substances which 
 escapes this process of oxidation is sent back into the 
 circulation in the form of the bile, which by degrees 
 completely disappears. 
 
 In the carnivora the bile contains the carbon of the 
 metamorphosed tissues ; this carbon disappears in the 
 animal body, and the bile likewise disappears in the vital 
 process. Its carbon and hydrogen are given out through 
 the skin and lungs as carbonic acid and water ; and 
 hence it is obvious, that the elements of the bile serve 
 for respiration and for the production of animal heat. 
 Every part of the food of carnivorous animals is capable 
 of forming blood ; their excrements, excluding the 
 urine, contain only inorganic substances, such as phos- 
 phate of lime ; and the small quantity of organic matter 
 which is found mixed with these is derived from excre- 
 
60 USES OF THE URINE 
 
 lions, the use of which is to promote their passage 
 through the intestines, such as mucus. These excre- 
 ments contain no bile and no soda ; for water extracts 
 from them no trace of any substance resembling bile, 
 and yet bile is very soluble in water, and mixes with it 
 in every proportion. 
 
 Physiologists can entertain no doubt as to the origin 
 of the constituent parts of the urine and of the bile. 
 When, from deprivation of food, the stomach contracts 
 itself so as to resemble a portion of intestine, the gall- 
 bladder, for want of the motion which the full stomach 
 gives to it, cannot pour out the bile it contains ; hence 
 in animals starved to death we find the gall-bladder dis- 
 tended and full. The secretion of bile and of urine 
 goes on during the winter sleep of hybernating animals ; 
 and we know that the urine of dogs, fed for three weeks 
 exclusively on pure sugar, contains as much of the most 
 highly nitrogenized constituent, urea, as in the normal 
 condition. (Marchaud. Erdmann's Journal fur prak- 
 tische Chemie, XIV. p. 495.) 
 
 Differences in the quantity of urea secreted in these 
 and similar experiments are explained by the condition 
 of the animal in regard to the amount of the natural 
 motions permitted. Every motion increases the amount 
 of organized tissue which undergoes metamorphosis. 
 Thus, after a walk, the secretion of urine in man is in- 
 variably increased. 
 
 The urine of the mammalia, of birds, and of am- 
 phibia, contains uric acid or urea ; and the excrements 
 of the mollusca, and of insects, as of cantharides and 
 
AND OF THE BILE. 61 
 
 of the butterfly of the silkworm, contain urate of am- 
 monia. This constant occurrence of one or two nitro- 
 genized compounds in the excretions of animals, while 
 so great a difference exists in their food, clearly proves 
 that these compounds proceed from one and the same 
 source. 
 
 As little doubt can be entertained in regard to the 
 function of the bile in the vital process. When we 
 consider, that the acetate of potash, given in enema, or 
 simply as a bath for the feet, renders the urine strongly 
 alkaline (Rehberger in Tiedemann's Zeitschrift fur 
 Physiologic, II. 149), and that the change which the 
 acetic acid here undergoes cannot be conceived without 
 the addition of oxygen, it is obvious, that the soluble 
 constituents of the bile, prone to change in a high de- 
 gree as -we know them to be, and which, as already 
 stated, cannot be employed in the production of blood, 
 must, when returned through the intestines into the cir- 
 culation, in like manner yield to the influence of the 
 oxygen which they meet. The bile is a compound of 
 soda, the elements of which, with the exception of the 
 soda, disappear in the body of a carnivorous animal. 
 
 In the opinion of many of the most distinguished 
 physiologists, the bile is intended solely to be excreted ; 
 and nothing is more certain, than that a substance con- 
 taining so very small a proportion of nitrogen can have 
 no share in the process of nutrition or reproduction of 
 organized tissue. But quantitative physiology must at 
 once and decidedly reject the opinion, that the bile serves 
 6 
 
62 AMOUNT OF BILE SECRETED 
 
 no purpose in the economy, and is incapable of further 
 change. 
 
 No part of any organized structure contains soda ; 
 only in the serum of the blood, in the fat of the brain, 
 and in the bile, do we meet with that alkali. When the 
 compounds of soda in the blood are converted into mus- 
 cular fibre, membrane, or cellular tissue, the soda they 
 contain must enter into new combinations. The blood 
 which is transformed into organized tissue gives up its 
 soda to the compounds formed by the metamorphoses 
 of the previously existing tissues. In the bile we find 
 one of these compounds of soda. 
 
 Were the bile intended merely for excretion, we 
 should find it, more or less altered, and also the soda it 
 contains, in the solid excrements. But, with the excep- 
 tion of common salt, and of sulphate of soda, which 
 occur in all the animal fluids, only mere traces of soda 
 are to be found in the faeces. The soda of the bile, 
 therefore, at all events, must have returned from the 
 intestinal canal into the organism, and the same must be 
 true of the organic matters which were in combination 
 with it. 
 
 According to the observations of physiologists, a man 
 secretes daily from 17 to 24 oz. of bile ; a large dog, 
 36 oz. ; a horse, 37 Ibs. (Burdach's Physiologic, V. 
 p. 260.) But the faeces of a man do not on an average 
 weigh more than 5| oz. ; and those of a horse 28| Ibs., 
 of which 21 Ibs. are water, and 7| Ibs. dry faeces. 
 (Boussingault.) The latter yield to alcohol only ^th 
 part of their weight of soluble matter. 
 
IN MAN AND ANIMALS. 63 
 
 If we assume the bile to contain 90 per cent, of 
 water, a horse secretes daily 592 oz. of bile, containing 
 59-2 oz. of solid matter ; while 7| Ibs. or 120 oz. of 
 dried excrement yield only 6 oz. of matter soluble in 
 alcohol, which might possibly be bile. But this matter 
 is not bile ; when the alcohol is dissipated by evapora- 
 tion, there remains a soft, unctuous mass, altogether in- 
 soluble in water, and which, when incinerated, leaves no 
 alkaline ashes, no soda. (10) 
 
 During the digestive process, therefore, the soda of 
 the bile, and, along with it> all the soluble parts of that 
 fluid, are returned into the circulation. This soda re- 
 appears in the newly formed blood, and, finally, we find 
 it in the urine in the form of phosphate, carbonate, and 
 hippurate of soda. Berzelius found in 1,000 parts of 
 fresh human faeces only nine parts of a substance similar 
 to bile ; 5 ounces, therefore, would contain only 21 
 grains of dried bile, equivalent to 210 grains of fresh 
 bile. But a man secretes daily from 9,640 to 11,520 
 grains of fluid bile, that is, from 45 to 56 times as much 
 as can be detected in the matters discharged by the 
 intestinal canal. 
 
 Whatever opinion we may entertain of the accuracy 
 of the physiological experiments, in regard to the quan- 
 tity of bile secreted by the different classes of animals ; 
 thus much is certain, that even the maximum of the 
 supposed secretion, in man and in the horse, does not 
 contain as much carbon as is given out in respiration. 
 With all the fat which is mixed with it, or enters into 
 its composition, dried bile does not contain more than 
 
64 THE CARBON OF THE FOOD 
 
 69 per cent, of carbon. Consequently, if a horse 
 secretes 37 Ibs. of bile, this quantity will contain only 
 40 ounces of carbon. But the horse expires daily 
 nearly twice as much in the form of carbonic acid. A 
 precisely similar proportion holds good in man. 
 
 Along with the matter destined for the formation or 
 reproduction of organs, the circulation conveys oxygen 
 to all parts of the body. Now, into whatever combina- 
 tion the oxygen may enter in the blood, it must be held 
 as certain, that such of the constituents of blood as are 
 employed for reproduction, are not materially altered by 
 it. In muscular fibre we find fibrine, with all the prop- 
 erties it had in venous blood ; the albumen in the blood 
 does not combine with oxygen. The oxygen may pos- 
 sibly serve to convert into the gaseous state some un- 
 known constituent of the blood ; but those well-known 
 constituents which are employed in reproduction, cannot 
 be destined to support the respiratory process ; none of 
 their properties can justify such an opinion. 
 
 Without attempting in this place to exhaust the whole 
 question of the share taken by the bile in the vital op- 
 erations, it follows, as has been observed, from the 
 simple comparison of those parts of the food of the 
 carnivora which are capable of assimilation, with the 
 ultimate products into which it is converted, that all the 
 carbon of the food, except that portion which is found 
 in the urine, is given out as carbonic acid. 
 
 But this carbon was ultimately derived from the sub- 
 stance of the metamorphosed tissues ; and this being 
 admitted, the question of the necessity of substances 
 
SUPPORTS RESPIRATION. 65 
 
 containing much carbon and no nitrogen in the food of 
 the young of the carnivora, and in that of the gramini- 
 vora, is resolved in a strikingly simple manner. 
 
 XII. It cannot be disputed, that in an adult carnivor- 
 ous animal, which neither gains nor loses weight, per- 
 ceptibly, from day to day, its nourishment, the waste of 
 organized tissue, and its consumption of oxygen, stand 
 to each other in a well-defined and fixed relation. 
 
 The carbon of the carbonic acid given off, with that 
 of the urine ; the nitrogen of the urine, and the hydro- 
 gen given off as ammonia and water ; these elements, 
 taken together, must be exactly equal in weight to the 
 carbon, nitrogen, and hydrogen of the metamorphosed 
 tissues, and since these last are exactly replaced by the 
 food, to the carbon, nitrogen, and hydrogen of the food. 
 Were this not the case, the weight of the animal could 
 not possibly remain unchanged. 
 
 But, in the young of the carnivora, the weight does 
 not remain unchanged ; on the contrary, it increases 
 from day to day by an appreciable quantity. 
 
 This fact presupposes, that the assimilative process 
 in the young animal is more energetic, more intense, 
 than the process of transformation in the existing tissues. 
 If both processes were equally active, the weight of 
 the. body could not increase ; and were the waste by 
 transformation greater, the weight of the body would 
 decrease. 
 
 Now, the circulation in the young animal is not 
 weaker, but, on the contrary, more rapid ; the respira- 
 6* 
 
66 BUTTER, SUGAR, STARCH, fee. 
 
 tions are more frequent ; and, for equal bulks, the con- 
 sumption of oxygen must be greater rather than smaller 
 in the young than in the adult animal. But, since the 
 metamorphosis of organized parts goes on more slowly, 
 there would ensue a deficiency of those substances, the 
 carbon and hydrogen of which are adapted for combina- 
 tion with oxygen ; because, in the carnivora, it is the 
 new compounds, produced by the metamorphosis of 
 organized parts, which nature has destined to furnish 
 the necessary resistance to the action of the oxygen, 
 and to produce animal heat. What is wanting for these 
 purposes, an infinite wisdom has supplied to the young 
 animal in its natural food. 
 
 The carbon and hydrogen of butter, and the carbon 
 of the sugar of milk, no part of either of which can 
 yield blood, fibrine, or albumen, are destined for the 
 support of the respiratory process, at an age when a 
 greater resistance is opposed to the metamorphosis of 
 existing organisms ; or, in other words, to the produc- 
 tion of compounds, which in the adult state are produced 
 in quantity amply sufficient for the purpose of respira- 
 tion. 
 
 The young animal receives the constituents of its 
 blood in the caseine of the milk. A metamorphosis of 
 existing organs goes on, for bile and urine are secreted ; 
 the matter of the metamorphosed parts is given off in 
 the form of urine, of carbonic acid, and of water ; but 
 the butter and sugar of milk also disappear ; they can- 
 not be detected in the faeces. 
 
 The butter and sugar of milk are given out in the 
 
CONSUMED IN RESPIRATION. 67 
 
 form of carbonic acid and water, and their conversion 
 into oxidized products furnishes the clearest proof, that 
 far more oxygen is absorbed than is required to convert 
 the carbon and hydrogen of the metamorphosed tissues 
 into carbonic acid and water. 
 
 The change and metamorphosis of organized tissues 
 going on in the vital process in the young animal, con- 
 sequently yield, in a given time, much less carbon and 
 hydrogen in the form adapted for the respiratory process 
 than corresponds to the oxygen taken up in the lungs. 
 The substance of its organized parts would undergo a 
 more rapid consumption, and would necessarily yield to 
 the action of the oxygen, were not the deficiency of 
 carbon and hydrogen supplied from another source. 
 
 The continued increase of mass, or growth, and the 
 free and unimpeded development of the organs in the 
 young animal, are dependent on the presence of foreign 
 substances, which, in the nutritive process, have no 
 other function than to protect the newly-formed organs 
 from the action of the oxygen. It is the elements of 
 these substances which unite with the oxygen ; the 
 organs themselves could not do so without being con- 
 sumed ; that is, growth, or increase of mass in the 
 body, the consumption of oxygen remaining the same, 
 would be utterly impossible. 
 
 The preceding considerations leave no doubt as to 
 the purpose for which Nature has added to the food of 
 the young of carnivorous mammalia substances devoid 
 of nitrogen, which their organism cannot employ for 
 nutrition, strictly so called, that is, for the production 
 
63 PROPERTIES OF STARCH 
 
 of blood ; substances which may be entirely dispensed 
 with in their nourishment in the adult state. In the 
 young of carnivorous birds, the want of all motion is 
 an obvious cause of diminished waste in the organized 
 parts ; hence, milk is not provided for them. 
 
 The nutritive process in the carnivora thus presents 
 itself in two distinct forms ; one of which we again 
 meet with in the graminivora. 
 
 XIII. In the class of graminivorous animals, we 
 observe, that during their whole life, their existence 
 depends on the supply of substances having a compo- 
 sition identical with that of sugar of milk, or closely 
 resembling it. Every thing that they consume as food 
 contains a certain quantity of starch, or gum, or sugar, 
 mixed with other matters. 
 
 The most abundant and widely-extended of the sub- 
 stances of this class is amylon or starch ; it occurs in 
 roots, seeds, and stalks, and even in wood, deposited 
 in the form of roundish or oval globules, which differ 
 from each other in size alone, being identical in chemi- 
 cal composition. (11) In the same plant, in the pea, for 
 example, we find starch, the globules of which differ in 
 size. Those in the expressed juice of the stalks have a 
 diameter of from 2 m to T | of an inch, while those in the 
 seed are three or four times larger. The globules in 
 arrow-root and in potato starch are distinguished by 
 their large size ; those of rice and of wheat are remark- 
 ably small. 
 
 It is well known that starch may be converted into 
 
EASILY CONVERTIBLE INTO SUGAR. 69 
 
 sugar by very different means. This change occurs in 
 the process of germination, as in malting, and it is easily 
 accomplished by the action of acids. The metamor- 
 phosis of starch into sugar depends simply, as is proved 
 by analysis, on the addition of the elements of water. (12) 
 All the carbon of the starch is found in the sugar ; none 
 of its elements- have been separated, and, except the 
 elements of water, no foreign element has been added 
 to it in this transformation. 
 
 In many, especially in pulpy fruits, which when un- 
 ripe are sour and rough to the taste, but when ripe are 
 sweet, as, for example, in apples and pears, the sugar 
 is produced from the starch which the unripe fruit 
 contains. 
 
 If we rub unripe apples or pears on a grater to a 
 pulp, and wash this with cold water on a fine sieve, the 
 turbid liquid, which passes through, deposits a very fine 
 flour of starch, of which not even a trace can be de- 
 tected in the ripe fruit. Many varieties become sweet 
 while yet on the tree ; these are the summer or early 
 apples and pears. Others, again, become sweet only 
 after having been kept for a certain period after gather- 
 ing. The after-ripening, as this change is called, is a 
 purely chemical process, entirely independent of the 
 vitality of the plant. When vegetation ceases, the fruit 
 is capable of reproducing the species, that is, the ker- 
 nel, stone, or true seed is fully ripe, but the fleshy cov- 
 ering from this period is subjected to the action of the 
 atmosphere. Like all substances in a state of erema- 
 
7Q. SUGAR OF MILK, GUM, &c. 
 
 causis, or decay, it absorbs oxygen, and gives off a 
 certain quantity of carbonic acid gas. 
 
 In the same way as the starch in putrefying paste, in 
 which it is in contact with decaying gluten, is converted 
 into sugar, the starch in the above-named fruits, in a 
 state of decay, or eremacausis, is transformed into grape 
 sugar. The more starch the unripe fruit contains, the 
 sweeter does it become when ripe. 
 
 A close connexion thus exists between sugar and 
 starch. By means of a variety of chemical actions, 
 which exert no other influence on the elements of starch 
 than that of changing the direction of their mutual at- 
 traction, we can convert starch into sugar, but it is 
 always grape sugar. 
 
 Sugar of milk in many respects resembles starch ; 
 (is) it is, by itself, incapable of the vinous fermenta- 
 tion, but it acquires the property of resolving itself into 
 alcohol and carbonic acid when it is exposed to heat in 
 contact with a substance in the state of fermentation 
 (such as putrefying cheese in milk) . In this case, it is 
 first converted into grape sugar ; and it undergoes the 
 same transformation, when it is kept in contact with 
 acids, with sulphuric acid, for example, at the or- 
 dinary temperature. 
 
 Gum has the same composition in 100 parts as cane- 
 sugar. (14) It is distinguished from the different varieties 
 of sugar by its not possessing the property of being re- 
 solved into alcohol and carbonic acid by the process of 
 putrefaction. When placed in contact with fermenting 
 substances, it undergoes no appreciable change, whence 
 
COMPARED WITH STARCH. 71 
 
 we may conclude, with some degree of probability, that 
 its elements, in the peculiar arrangement according to 
 which they are united, are held together with a stronger 
 force than the elements of the different kinds of sugar. 
 
 There is, however, a certain relation between gum 
 and sugar of milk, since both of them, when treated 
 with nitric acid, yield the same oxidized product, name- 
 ly, mucic acid, which cannot under the same circum- 
 stances, be formed from any of the other kinds of 
 sugar. 
 
 In order to show more distinctly the similarity of 
 composition in these different substances, which per- 
 form so important a part in the nutritive process of the 
 graminivora, let us represent one equivalent of carbon 
 by C (= 75-8), and one equivalent of water by aqua 
 (== 112-4), we shall then have for the composition of 
 these substances the following expressions : 
 
 Starch . . . . s= 12 C -f 10 aqua. 
 
 Cane Sugar . = 12 C + 10 aqua -j- 1 aqua. 
 
 Gum = 12 C -|- 10 aqua -{- 1 aqua. 
 
 Sugar of milk = 12 C -f 10 aqua -f- 2 aqua. 
 Grape Sugar = 12 C -j- 10 aqua + 4 aqua. 
 
 For the same number of equivalents of carbon, starch 
 contains 10 equivalents, cane-sugar and gum 11 equiva- 
 lents, sugar of milk 12 equivalents, and grape-sugar 14 
 equivalents, of water, or the elements of water. 
 
 XIV. In these different substances, some one of 
 which is never wanting in the food of the graminivora, 
 there is added to the nitrogenized constituents of this 
 food, to the vegetable albumen, fibrine, and caseine, 
 
72 GRAMINIVORA REQUIRE 
 
 from which their blood is formed, strictly speaking, only 
 a certain excess of carbon, which the animal organism 
 cannot possibly employ to produce fibrine or albumen, 
 because the nitrogenized constituents of the food al- 
 ready contain the carbon necessary for the production 
 of blood, and because the blood in the body of the 
 carnivora is formed without the aid of this excess of 
 carbon. 
 
 The function performed in the vital process of the 
 graminivora by these substances (sugar, gum, &c.) is 
 indicated in a very clear and convincing manner, when 
 we take into consideration the very small relative 
 amount of the carbon which these animals consume in 
 the nitrogenized constituents of their food, which bears 
 no proportion whatever to the oxygen absorbed through 
 the skin and lungs. 
 
 A horse, for example, can be kept in perfectly good 
 condition, if he obtain as food 15 Ibs. of hay and 4J 
 Ibs. of oats, daily. If we now calculate the whole 
 amount of nitrogen in these matters, as ascertained by 
 analysis (1-5 per cent, in the hay, 2'2 per cent, in the 
 oats), (is) in the form of blood, that is, as fibrine and 
 albumen, with the due proportion of water in blood 
 (80 per cent.), the horse receives daily no more than 
 4 1 oz. of nitrogen, corresponding to about 8 Ibs. of 
 blood. But along with this nitrogen, that is, combined 
 with it in the form of fibrine or albumen, the animal 
 receives only about 14 J oz. of carbon. Only about 
 8 oz. of this can be employed to support respiration, 
 for with the nitrogen expelled in the urine there are 
 
MUCH CARBON. 73 
 
 combined, in the form of urea, 3 oz., and in the form 
 of hippuric acid, 3| oz., of carbon. 
 
 Without going further into the calculation, it will 
 readily be admitted, that the volume of air inspired and 
 expired by a horse, the quantity of oxygen consumed, 
 and, as a necessary consequence, the amount of car- 
 bonic acid given out by the animal, is much greater than 
 in the respiratory process in man. But an adult man 
 consumes daily about 14 oz. of carbon, and the deter- 
 mination of Boussingault, according to which a horse 
 expires 79 oz. daily, cannot be very far from the truth. 
 
 In the nitrogenized constituents of his food, therefore, 
 the horse receives rather less than the fifth part of the 
 carbon which his organism requires for the support of 
 the respiratory process ; and we see that the wisdom 
 of the Creator has added to his food the fths which are 
 wanting, in various forms, as starch, sugar, &c. with 
 which the animal must be supplied, or his organism will 
 be destroyed by the action of the oxygen. 
 
 It is obvious, that in the system of the graminivora, 
 whose food contains so small a proportion, relatively, 
 of the constituents of blood, the process of metamor- 
 phosis in existing tissues, and consequently their resto- 
 ration or reproduction, must go on far less rapidly than 
 in the carnivora. Were this not the case, a vegetation 
 a thousand times more luxuriant than the actual one 
 would not suffice for their nourishment. Sugar, gum, 
 and starch, would no longer be necessary to support life 
 in these animals, because, in that case, the products of 
 the waste, or metamorphosis of the organized tissues, 
 7 
 
74 WASTE OF ORGANIZED TISSUES 
 
 would contain enough of carbon to support the respira- 
 tory process. 
 
 Man, when confined to animal food, requires for his 
 support and nourishment extensive sources of food, 
 even more widely extended than the lion and tiger, be- 
 cause when he has the opportunity, he kills without 
 eating. 
 
 A nation of hunters, on a limited space, is utterly 
 incapable of increasing its numbers beyond a certain 
 point, which is soon attained. The carbon necessary 
 for respiration must be obtained from the animals, of 
 which only a limited number can live on the space sup- 
 posed. These animals collect from plants the con- 
 stituents of their organs and of their blood, and yield 
 them, in turn, to the savages who live by the chase 
 alone. They, again, receive this food unaccompanied 
 by those compounds, destitute of nitrogen, which, dur- 
 ing the life of the animals, served to support the res- 
 piratory process. In such men, confined to an animal 
 diet, it is the carbon of the flesh and of the blood which 
 must take the place of starch and sugar. 
 
 But 15 Ibs. of flesh contain not more carbon than 
 4 Ibs. of starch, (ie) and while the savage with one ani- 
 mal and an equal weight of starch could maintain life 
 and health for a certain number of days, he would be 
 compelled, if confined to flesh, in order to procure the 
 carbon necessary for respiration, during the same time, 
 to consume five such animals. 
 
 It is easy to see, from these considerations, how 
 close the connexion is between agriculture and the mul- 
 
VERY RAPID IN CARNIVORA. 75 
 
 tiplication of the human species. The cultivation of 
 our crops has ultimately no other object than the pro- 
 duction of a maximum of those substances which are 
 adapted for assimilation and respiration, in the smallest 
 possible space. Grain and other nutritious vegetables 
 yield us, not only in starch, sugar, and gum, the carbon 
 which protects our organs from the action of oxygen, 
 and produces in the organism the heat which is essential 
 to life, but also in the form of vegetable fibrine, albu- 
 men, and caseine, our blood, from which the other parts 
 of our body are developed. 
 
 Man, when confined to animal food, respires, like 
 the carnivora, at the expense of the matters produced 
 by the metamorphosis of organized tissues ; and, just 
 as the lion, tiger, hyaena, in the cages of a menagerie, 
 are compelled to accelerate the waste of the organized 
 tissues by incessant motion, in order to furnish the mat- 
 ter necessary for respiration, so, the savage, for the 
 very same object, is forced to make the most laborious 
 exertions, and go through a vast amount of muscular 
 exercise. He is compelled to consume force merely 
 in order to supply matter for respiration. 
 
 Cultivation is the economy of force. Science teaches 
 us the simplest means of obtaining the greatest effect 
 with the smallest expenditure of power, and with given 
 means to produce a maximum of force. The unprofit- 
 able exertion of power, the waste of force in agricul- 
 ture, in other branches of industry, in science, or in 
 social economy, is characteristic of the savage state, or 
 of the want of cultivation. 
 
76 PHOSPHATES ABOUND IN 
 
 XV. A comparison of the urine of the carnivora 
 with that of the graminivora shows very clearly, that 
 the process of metamorphosis in the tissues is differ- 
 ent, both in form and in rapidity, in the two classes 
 of animals. 
 
 The urine of carnivorous animals is acid, and con- 
 tains alkaline bases, united with uric, phosphoric, and 
 sulphuric acids. We know perfectly the source of the 
 two latter acids. All the tissues, with the exception of 
 cellular tissue and membrane, contain phosphoric acid 
 and sulphur, which latter element is converted into sul- 
 phuric acid by the oxygen of the arterial blood. In the 
 various fluids of the body there are only traces of phos- 
 phates or sulphates, except in the urine, where both are 
 found in abundance. It is plain that they are derived 
 from the metamorphosed tissues ; they enter into the 
 venous blood in the form of soluble salts, and are separ- 
 ated from it in its passage through the kidneys. 
 
 The urine of the graminivora is alkaline ; it contains 
 alkaline carbonates in abundance, and so small a portion 
 of alkaline phosphates as to have been overlooked by 
 most observers. * 
 
 The deficiency, or absence of alkaline phosphates in 
 
 * In a series of observations, continued daily during ninety-six 
 days, human urine was found to be, on four occasions, feebly acid in 
 the morning. In almost every observation it was found neutral, 
 or very feebly alkaline. Lactate of urea could never be detected 
 in it. J. L. 
 
 The translator would add to this note, that in numerous experi- 
 ments made by him, the process given by Messrs. Cap and Henry 
 for extracting lactate of urea from human urine, yielded invariably 
 pure urea. W. G. 
 
THE URINE OF CARNFVORA. 77 
 
 the urine of the graminivora, obviously indicates the 
 slowness with which the tissues in this class of animals 
 are metamorphosed ; for if we assume, that a horse 
 consumes a quantity of vegetable fibrine and albumen 
 corresponding to the amount of nitrogen in his daily 
 food (about 4| oz.), and that the quantity of tissue met- 
 amorphosed is equal to that newly formed, then the 
 quantity of phosphoric acid which on these suppositions 
 would exist in the urine is not so small as not to be easily 
 detected by analysis in the daily secretion of urine 
 (3 Ibs. according to Boussingault) ; for it would amount 
 to 0*8 per cent. But, as above stated, most observers 
 have been unable to detect phosphoric acid in the urine 
 of the horse. 
 
 Hence it is obvious, that the phosphoric acid, which, 
 in consequence of the metamorphosis of tissues is pro- 
 duced in the form of soluble alkaline phosphates, must 
 reenter the circulation in this class of animals. It is 
 there employed in forming brain and nervous matter, to 
 which it is essential. 
 
 In the graminivora, therefore, whose food contains so 
 small a proportion of phosphorus or of phosphates, the 
 organism collects all the soluble phosphates produced by 
 the metamorphosis of tissues and employs them for the 
 development of the bones and of the phosphorized con- 
 stituents of the brain. The organs of excretion do not 
 separate these salts from the blood ; and the excrements 
 of the graminivora contain only insoluble earthy phos- 
 phates. 
 
 7* 
 
78 ASSIMILATION IN CARNIVORA. 
 
 XVI. If we now compare the capacity for increase 
 of mass, the assimilative power in the grarninivora and 
 carnivora, the commonest observations indicate a very 
 marked difference. 
 
 A spider, which sucks with extreme voracity the 
 blood of the first fly, is not disturbed or excited by a 
 second or third. A cat will eat the first, and perhaps 
 the second mouse presented to her, but even if she 
 kills a third, she does not devour it. Exactly similar 
 observations have been made in regard to lions and 
 tigers, which only devour their prey when urged by 
 hunger. Carnivorous animals, indeed, require less food 
 for their mere support, because their skin is destitute of 
 perspiratory pores, and because they consequently lose, 
 for equal bulks, much less heat than graminivorous ani- 
 mals, which are compelled to restore the lost heat by 
 means of food adapted for respiration. 
 
 How different is the energy and intensity of vegeta- 
 tive life in the grarninivora. A cow, or a sheep, in 
 the meadow, eats, almost without interruption, as long 
 as the sun is above the horizon. Their system possesses 
 the power of converting into organized tissues all the 
 food they devour beyond the quantity required for mere- 
 ly supplying the waste of their bodies. 
 
 All the excess of blood produced is converted into 
 cellular and muscular tissue ; the graminivorous animal 
 becomes fleshy and plump, while the flesh of the carniv- 
 orous animal is always tough and sinewy. 
 
 If we consider the case of a stag, a roe-deer, or a 
 hare, animals which consume the same food as cattle 
 
LESS ENERGETIC THAN IN HERBIVORA. 79 
 
 and sheep, it is evident, that, when well supplied with 
 food, their growth in size, their fattening, .must depend 
 on the quantity of vegetable albumen, fibrine, or caseine, 
 which they consume. With free and unimpeded mo- 
 tion and exercise, enough of oxygen is absorbed to con- 
 sume the carbon of the gum, sugar, starch, and of all 
 similar soluble constituents of their food. 
 
 But all this is very differently arranged in our domes- 
 tic animals, when, with an abundant supply of food, we 
 check the processes of cooling and exhalation, as we do 
 when we feed them in stables, where free motion is im- 
 possible. 
 
 The stall-fed animal eats, and reposes merely for di- 
 gestion. It devours in the shape of nitrogenized com- 
 pounds far more food than is required for reproduction, 
 or the supply of waste alone ; and at the same time it 
 eats far more of substances devoid of nitrogen than is 
 necessary merely to support respiration and to keep up 
 animal heat. Want of exercise and diminished cooling 
 are equivalent to a deficient supply of oxygen ; for when 
 these circumstances occur, the animal absorbs much less 
 oxygen than is required to convert into carbonic acid the 
 carbon of the substances destined for respiration. Only 
 a small part of the excess of carbon thus occasioned is 
 expelled from the* body in the horse and ox, in the form 
 of hippuric acid ; and all the remainder is employed in 
 the production of a substance, which, in the normal 
 state, only occurs in small quantity as a constituent of 
 the nerves and brain. This substance is fat. 
 
 In the normal condition, as to exercise and labor, the 
 
80 ORIGIN OF FAT IN 
 
 urine of the horse and ox contains benzoic acid (with 
 14 equivalents of carbon) ; but as soon as the animal is 
 kept quiet in the stable, the urine contains hippuric acid 
 (with 18 equivalents of carbon). 
 
 The flesh of wild animals is devoid of fat ; while 
 that of stall-fed animals is covered with that substance. 
 When the fattened animal is allowed to move more 
 freely in the air, or compelled to draw heavy burdens, 
 the fat again disappears. 
 
 It is evident, therefore, that the formation of fat in 
 the animal body is the result of a want of due propor- 
 tion between the food taken into the stomach and the 
 oxygen absorbed by the lungs and the skin. 
 
 A pig, when fed with highly nitrogenized food, be- 
 comes full of flesh ; when fed with potatoes (starch) it 
 acquires little flesh, but a thick layer of fat. The milk 
 of a cow, when stall fed, is very rich in butter, but in 
 the meadow is found to contain more caseine, and in 
 the same proportion less butter and sugar of milk. In 
 the human female, beer and farinaceous diet increase 
 the proportion of butter in the milk ; an animal diet 
 yields less milk, but it is richer in caseine. 
 
 If we reflect, that in the entire class of carnivora, 
 the food of which contains no substance devoid of ni- 
 trogen except fat, the production of fat in the body is 
 utterly insignificant ; that even in these animals, as in 
 dogs and cats, it increases as soon as they live on a 
 mixed diet ; and that we can increase the formation of 
 fat in other domestic animals at pleasure, but only by 
 means of food containing no nitrogen ; we can hardly 
 
DOMESTICATED ANIMALS. 81 
 
 entertain a doubt that such food, in its various forms of 
 starch, sugar, &c., is closely connected with the pro- 
 duction of fat. 
 
 In the natural course of scientific research, we draw 
 conclusions from the food in regard to the tissues or 
 substances formed from it ; from the nitrogenized con- 
 stituents of plants we draw certain inferences as to the 
 nitrogenized constituents of the blood ; and it is quite 
 in accordance with this, the natural method, that we 
 should seek to establish the relations of those parts of 
 our food which are devoid of nitrogen and those parts 
 of the body which contain none of that element. It is 
 impossible to overlook the very intimate connexion be- 
 tween them. 
 
 If we compare the composition of sugar of milk, of 
 starch, and of the other varieties of sugar, with that of 
 mutton and beef suet, and of human fat, we find that in 
 all of them the proportion of carbon to hydrogen is the 
 same, and that they only differ in that of oxygen. 
 
 According to the analyses of Chevreul, mutton fat, 
 human fat, and hog's lard contain 79 per cent, of carbon 
 to 11*1, 11*4, and 11*7 per cent, of hydrogen respec- 
 tively. (ie) 
 
 Starch contains 44-91 carbon to 6-11 hydrogen. 
 Gum and sugar 42-58 to 6-57 ditto. (w) 
 
 It is obvious that these numbers, representing the 
 relative proportions of carbon and hydrogen in starch, 
 gum, and sugar, are in the same ratio as the carbon and 
 hydrogen in the different kinds of fat ; for 
 
 44-91 : 6-11 = 79 : 10-75 
 42-58 : 6-37 = 79 : 11-82 
 
82 ORIGIN OF FAT IN 
 
 From which it follows, that sugar, starch, and gum, by 
 the mere separation of a part of their oxygen, may pass 
 into fat, or at least into a substance having exactly the 
 composition of fat. If from the formula of starch, 
 C 12 H 10 O 10 , we take 9 equivalents of oxygen, there will 
 remain in 100 parts 
 
 C 12 ..80-4 
 
 H 10 10 8 
 
 O 10-8 
 
 The empirical formula of fat, which comes nearest 
 to this, is C^H^O, which gives in 100 parts 
 
 C n 78-9 
 
 H 10 11-6 
 
 O 9-5 
 
 According to this formula, an equivalent of starch, in 
 order to be changed into fat, would lose 1 equivalent of 
 carbonic acid, CO 2 , and 7 equivalents of oxygen. 
 
 Now the composition of all saponifiable fatty bodies 
 agrees very closely with one or other of these two for- 
 mulae. 
 
 If from 3 equivalents of sugar of milk, 3C 12 H 12 O 12 
 = C 36 H 36 O 36 , we take away four equivalents of water 
 and 31 of oxygen, there will remain C 36 H 32 O, a formula 
 which accurately represents the composition of choles- 
 terine, the fat of bile, (is) 
 
 Whatever views we may entertain regarding the origin 
 of the fatty constituents of the body, this much at least 
 is undeniable, that the herbs and roots consumed by the 
 cow contain no butter ; that in hay or the other fodder 
 of oxen no beef suet exists ; that no hog's lard can be 
 found in the potato refuse given to swine ; and that the 
 
DOMESTICATED ANIMALS. 83 
 
 food of geese or fowls contains no goose fat or capon 
 fat. The masses of fat found in the bodies of these 
 animals are formed in their organism ; and when the 
 full value of this fact is recognised, it entitles us to con- 
 clude that a certain quantity of oxygen, in some form 
 or other, separates from the constituents of their food ; 
 for without such a separation of oxygen, no fat could 
 possibly be formed from any one of these substances. 
 
 The chemical analysis of the constituents of the food 
 of the graminivora shows, in the clearest manner, that 
 they contain carbon and oxygen in certain proportions ; 
 which, when reduced to equivalents, yield the following 
 series : 
 
 In vegetable fibrine, albumen, and caseine, there are contained, 
 
 for 120 eq. carbon, 36 eq. oxygen 
 
 In starch 120 100 
 
 In cane sugar 120 110 
 
 In gum 120 110 
 
 In sugar of milk (..';. .... 120 120 
 
 In grape sugar 120 140 
 
 Noio in all fatty bodies there are contained, on an 
 average 
 
 for 120 eq. carb. only 10 eq. oxygen. 
 
 Since the carbon of the fatty constituents of the ani- 
 mal body is derived from the food, seeing that there is 
 no other source whence it can be derived, it is obvious, 
 if we suppose fat to be formed from albumen, fibrine, 
 or caseine, that, for every 120 equivalents of carbon 
 deposited as fat, 26 equivalents of oxygen must be sep- 
 arated from the elements of these substances ; and fur- 
 ther, if we conceive fat to be formed from starch, sugar, 
 or sugar of milk, that for the same amount of carbon 
 
84 THE FORMATION OF FAT. 
 
 there must be separated 90, 100, and 110 equivalents 
 of oxygen from these compounds respectively. 
 
 There is, therefore, but one way in which the forma- 
 tion of fat in the animal body is possible, and this is 
 absolutely the same in which its formation in plants 
 takes place ; it is a separation of oxygen from the ele- 
 ments of the food. 
 
 The carbon which we find deposited in the seeds and 
 fruits of vegetables, in the form of oil and fat, was pre- 
 viously a constituent of the atmosphere, and was ab- 
 sorbed by the plant as carbonic acid. Its conversion 
 into fat was accomplished under the influence of light, 
 by the vital force of the vegetable ; and the greater part 
 of the oxygen of this carbonic acid was returned to the 
 atmosphere as oxygen gas.* 
 
 In contradistinction to this phenomenon of vitality in 
 plants, we know that the animal system absorbs oxygen 
 from the atmosphere, and that this oxygen is again given 
 out in combination with carbon or hydrogen ; we know, 
 that in the formation of carbonic acid and water, the 
 heat necessary to sustain the constant temperature of 
 the body is produced, and that a process of oxidation 
 is the only source of animal heat. 
 
 Whether fat be formed by the decomposition of 
 fibrine and albumen, the chief constituents of blood, or 
 by that of starch, sugar, or gum, this decomposition 
 must be accompanied by the separation of oxygen from 
 the elements of these compounds. But this oxygen is 
 
 * See Appendix, Note 19, on the formation of wax and honey by 
 the bee. 
 
FAT HOW FORMED. 85 
 
 not given out in the free state, because it meets in the 
 organism with substances possessing the property of en- 
 tering into combination with it. In fact, it is given out 
 in the same forms as that which is absorbed from the 
 atmosphere by the skin and lungs. 
 
 It is easy to see, from the above considerations, that 
 a very remarkable connexion exists between the forma- 
 tion of fat and the respiratory process. 
 
 XVII. The abnormal condition, which causes the 
 deposit of fat in the animal body, depends, as was for- 
 merly stated, on a disproportion between the quantity 
 of carbon in the food and that of oxygen absorbed by 
 the skin and lungs. In the normal condition, the quan- 
 tity of carbon given out is exactly equal to that which 
 is taken in the food, and the body acquires no increase 
 of weight from the accumulation of substances contain- 
 ing much carbon and no nitrogen. 
 
 If we increase the supply of highly carbonized food, 
 then the normal state can only be preserved on the con- 
 dition that, by exercise and labor, the waste of the 
 body is increased, and the supply of oxygen augmented 
 in the same proportion. 
 
 The production of fat is always a consequence of 
 a deficient supply of oxygen, for oxygen is absolutely 
 indispensable for the dissipation of the excess of carbon 
 in the food. This excess of carbon, deposited in the 
 form of fat, is never seen in the Bedouin or in the Arab 
 of the desert, who exhibits with pride to the traveller 
 his lean, muscular, sinewy limbs, altogether free from 
 8 
 
86 HEAT DISENGAGED. 
 
 fat ; but in prisons and jails it appears as a puffiness in 
 the inmates, fed, as they are, on a poor and scanty 
 diet ; it appears in the sedentary females of oriental 
 countries ; and finally, it is produced under the well- 
 known conditions of the fattening of domestic animals. 
 
 The formation of fat depends on a deficiency of oxy- 
 gen ; but in this process, in the formation of fat itself, 
 there is opened up a new source of oxygen, a new cause 
 of animal heat. 
 
 The oxygen set free in the formation of fat is given 
 out in combination with carbon or hydrogen ; and 
 whether this carbon and hydrogen proceed from the 
 substance that yields the oxygen, or from other com- 
 pounds, still there must have been generated by this 
 formation of carbonic acid or water as much heat as if 
 an equal weight of carbon or hydrogen had been burned 
 in air or in oxygen gas. 
 
 If we suppose that from 2 equivalents of starch 18 
 equivalents of oxygen are disengaged, and that these 18 
 equivalents of oxygen combine with 9 equivalents of 
 carbon, from the bile, for example, no one can doubt 
 that, in this case, exactly as much heat must be devel- 
 oped, as if these 9 equivalents of carbon had been 
 directly burned. In this form, therefore, the disen- 
 gagement of heat as a consequence of the formation of 
 fat would be undeniable ; and it could only be consider- 
 ed hypothetical, on the supposition that carbon and 
 oxygen were disengaged from one and the same sub- 
 stance, in the proportions to yield carbonic acid. 
 
 If, for example, we suppose that from 2 atoms of 
 
FORMATION OF FAT. 87 
 
 starch, C 24 H 20 O 20 , the elements of 9 equivalents of car- 
 bonic acid are separated, there will remain a compound 
 containing, for 15 equivalents of carbon, 20 of hydro- 
 gen and 2 of oxygen ; for 
 
 C 24 H 20 Oo = C 9 O 18 -f- C 15 H 20 O 2 . 
 
 Or, if we assume that oxygen is separated from starch 
 in the form both of carbonic acid and water, then, after 
 subtracting the elements of 6 equivalents of water and 
 6 of carbonic acid, there would remain the compound 
 C 18 H 14 2 ; for 
 
 C 24 H 20 20 = C 6 12 + H 6 6 + C 18 H 14 O 2 . 
 
 Assuming, then, the separation of oxygen in either 
 of these forms, it remains to be decided whether the 
 carbonic acid and water given off were contained, as 
 such, in the starch, or not. 
 
 If they were ready formed in the starch, the separa- 
 tion might occur without the disengagement of heat ; 
 but if the carbon and hydrogen were present in any 
 other form in the starch (or in the compound from 
 which the fat was produced) 4 it is obvious that a change 
 in the arrangement of the atoms must have occurred, in 
 consequence of which the atoms of the carbon and of 
 the hydrogen have united with those of the oxygen, to 
 form carbonic acid and water. 
 
 Now, so far as chemical researches have gone, our 
 knowledge of the constitution of starch, and of the va- 
 rieties of sugar, will justify no other conclusion than 
 this, that these substancfes contain no ready formed car- 
 bonic acid. 
 
 We are acquainted with a large number of processes 
 
88 THE FORMATION OF FAT IS 
 
 of metamorphosis of a similar kind, in which the ele- 
 ments of carbonic acid and water are separated from 
 certain preexisting compounds ; and we know with 
 certainty that all these processes are accompanied by a 
 disengagement of heat, exactly as if the carbon and 
 hydrogen 'combined directly with oxygen. 
 
 Such a disengagement of carbonic acid, for example, 
 occurs in all processes of fermentation or putrefaction, 
 which are, without exception, accompanied with the 
 generation of heat. 
 
 In the fermentation of a saccharine solution, in con- 
 sequence of a new arrangement of the elements of the 
 sugar, a certain part of its carbon and oxygen unite to 
 form carbonic acid, which separates as gas ; and as an- 
 other result of this decomposition, we obtain a volatile 
 combustible liquid, containing little oxygen, namely, 
 alcohol. 
 
 If we add to 2 equivalents of sugar the elements of 
 12 equivalents of water, and subtract from the sum of 
 the atoms 24 equivalents. of oxygen, there remain 6 
 equivalents of alcohol. 
 
 (C 24 H 24 24 -J- H 12 12 ) - 24 = C 24 H 36 12 = 6 eq. alcohol. 
 These 24 equivalents of oxygen suffice to oxidize 
 completely a third equivalent of sugar, that is, to 
 convert its carbon into carbonic acid and its hydrogen 
 into water, and by this oxidation we recover the 12 
 equivalents of water supposed to be added in the former 
 part of the process, exactly as if this water had taken 
 no share in it. 
 
 Ci 2 H 12 O 12 + O 24 = 12CO 2 -f 12HO. 
 
A SOURCE OF ANIMAL HEAT. 89 
 
 According to the ordinary view, 12 equivalents of 
 carbonic acid separate from 3 of sugar, yielding 6 of 
 alcohol, that is, exactly the same amount of these pro- 
 ducts as if two thirds of the sugar had yielded oxygen 
 to the remaining third, so as completely to oxidize its 
 elements. 
 
 C 36 H 36 36 = C 24 H 36 12 + 12C0 2 . 
 
 By a comparison of these two methods of represent- 
 ing the same change, it will easily be seen, that the 
 division or splitting of a compound like sugar into car- 
 bonic acid, on the one hand, and a compound containing 
 little oxygen, on the other, is, in its results, perfectly 
 equivalent to a separation of oxygen from a certain por- 
 tion of the compound and the oxidation or combustion 
 of another portion of it at the expense of this oxygen. 
 
 It is well known that the temperature of a fermenting 
 liquid rises ; and if we assume that a hogshead of wort, 
 holding 1,200 litres =2,400 Ibs., French weight, con- 
 tains 16 per cent, of sugar, in all 384 Ibs., then, during 
 the fermentation of this sugar, an amount of heat must 
 be generated equal to that which would be produced 
 by the combustion of 51 Ibs. of carbon. 
 
 This is equal to a quantity of heat, by which every 
 pound of the liquid might be heated by 297-9 ; that is, 
 supposing the decomposition of the sugar to occur in a 
 period of time too short to be measured. This is well 
 known not to be the case ; the fermentation lasts five or 
 six days, and each pound of liquid receives the 297-9 
 
 * For an explanation of the formulae and equations employed, see 
 the Introduction to the Appendix. 
 
90 FORMATION OF FAT. 
 
 degrees of heat during a period of 120 hours. In each 
 hour there is, therefore, set free an amount of heat ca- 
 pable of raising the temperature of each pound of 
 liquid 2-4 degree ; a rise of temperature which is very 
 powerfully counteracted by external cooling and by the 
 vaporization of alcohol and water. 
 
 The formation of fat, like other analogous phenom- 
 ena, in which oxygen is separated in the form of car- 
 bonic acid, is consequently accompanied by a disen- 
 gagement of heat. This change supplies to the animal 
 body a certain proportion of the oxygen indispensable to 
 the vital processes ; and this especially in those cases in 
 which the oxygen absorbed by the skin and lungs is not 
 sufficient to convert into carbonic acid the whole of the 
 carbon adapted for this combination. 
 
 This excess of carbon, as it cannot be employed to 
 form a part of any organ, is deposited in the cellular 
 tissue in the form of tallow or oil ; and the production 
 of this fat, explains the fact, that the oxygen given out 
 in the shape of carbonic acid and water is more than 
 equal to that directly absorbed in respiration. 
 
 At every period of animal life, when there occurs a 
 disproportion between the carbon of the food and the 
 inspired oxygen, the latter being deficient, fat must be 
 formed. Oxygen separates from existing compounds, 
 and this oxygen is given out as carbonic acid or water. 
 The heat generated in the formation of these two pro- 
 ducts contributes to keep up the temperature of the 
 body. Every pound of carbon which obtains the oxygen 
 necessary to convert it into carbonic acid from sub- 
 
FORMATION OF FAT. 91 
 
 stances which thereby pass into fat, must disengage as 
 much heat- as would raise the temperature of 200 Ibs. 
 of water by 70, that is, from 32 to 102. 
 
 Thus, in the formation of fat, the vital force pos- 
 sesses a means of counteracting a deficiency in the sup- 
 ply of oxygen, and consequently in that of the heat 
 indispensable for the vital process. 
 
 Experience teaches us that in poultry, the maximum 
 of fat is obtained by tying the feet, and by a medium 
 temperature. These animals, in such circumstances, 
 may be compared to a plant possessing in the highest 
 degree the power of converting all food into parts of its 
 own structure. The excess of the constituents of blood 
 forms flesh and other organized tissues, while that of 
 starch, sugar, &c., is converted into fat. When ani- 
 mals are fattened on food destitute of nitrogen, only 
 certain parts of their structure increase in size. Thus, 
 in a goose, fattened in the method above alluded to, the 
 liver becomes three or four times larger than in the 
 same animal when well fed with free motion, while we 
 cannot say that the organized structure of the liver is 
 thereby increased. The liver of a goose fed in the 
 ordinary way is firm and elastic ; that of the imprisoned 
 animal is soft and spongy. The difference consists in 
 a greater or less expansion of its cells, which are filled 
 with fat. 
 
 In some diseases, the starch, sugar, &c., of the food 
 obviously do not undergo the changes which enable 
 them to assist in respiration, and consequently to be 
 converted into fat. Thus, in diabetes mellitus, the 
 
92 CONSTITUENTS OF FOOD. 
 
 starch is only converted into grape sugar, which is ex- 
 pelled from the body without further change/ 
 
 In other diseases, as for example, in inflammation of 
 the liver, we find the blood loaded with fat and oil ; and 
 in the composition of the bile there is nothing at all 
 inconsistent with the supposition, that some of its con- 
 stituents may be transformed into fat. 
 
 XVIII. According to what has been laid down in the 
 preceding pages, the substances of which the food of 
 man is composed may be divided into two classes ; into 
 nitrogenized and non-nitrogenized. The former are 
 capable of conversion into blood ; the latter incapable 
 of this transformation. 
 
 Out of those substances which are adapted to the 
 formation of blood are formed all the organized tissues. 
 The other class of substances, in the normal state of 
 health, serve to support the process of respiration. 
 The former may be called the plastic elements of nutri- 
 tion j the latter, elements of respiration. 
 
 Among the former we reckon 
 
 Vegetable fibrine. 
 > Vegetable albumen. 
 Vegetable caseine. 
 Animal flesh. 
 Animal blood. 
 
 Among the elements of respiration in our food, are 
 
 Fat. Pectine. 
 
 Starch. Bassorine. 
 
 Gum. Wine. 
 
 Cane sugar. Beer. 
 
 Grape sugar. Spirits. 
 Sugar of milk. 
 
CONSTITUENTS OF FOOD. 93 
 
 XIX. The most recent and exact researches have 
 established as a universal 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. 
 
 No nitrogenized compound, the composition of which 
 differs from that of fibrine, albumen, and caseine, is 
 capable of supporting the vital process in animals. 
 
 The animal organism unquestionably possesses the 
 power of forming, from the constituents of its blood, 
 the substance of its membranes and cellular tissue, of 
 the nerves and brain, of the organic part of cartilages 
 and bones. But the blood must be supplied to it ready 
 formed in every thing but its form, that is, in its 
 chemical composition. If this be not done, a period is 
 rapidly put to the formation of blood, and consequently 
 to life. 
 
 This consideration enables us easily to explain how 
 it happens, that the tissues yielding gelatine or chon- 
 drine, as, for example, the gelatine of skin or of bones, 
 are not adapted for the support of the vital process ; 
 for their composition is different from that of fibrine or 
 albumen. It is obvious, that this means nothing more 
 than that those parts of the animal organism which form 
 the blood, do not possess the power of effecting a trans- 
 formation in the arrangement of the elements of gelatine, 
 or of those tissues which contain it. The gelatinous 
 tissues, the gelatine of the bones, the membranes, the 
 cells, and the skin, suffer, in the animal body, under the 
 influence of oxygen and moisture, a progressive altera- 
 
94 GELATINE 
 
 tion ; a part of these -tissues is separated, and must be 
 restored from the blood ; but this alteration and restora- 
 tion is obviously confined within very narrow limits.* 
 
 While, in the body of a starving or sick individual, 
 the fat disappears, and the muscular tissue takes once 
 more the form of blood, we find that the tendons and 
 membranes retain their natural condition ; the limbs of 
 
 * It is probably known to the reader, that a controversy has for 
 some time been carried on on this subject. D'Arcet first proposed 
 the use of gelatine as an article of hospital diet, and introduced it in 
 Paris with the greatest success. 
 
 But experiments made with pure gelatine used exclusively as food, 
 showed that animals, thus fed, soon died with the symptoms of starva- 
 tion ; and it was found that men fed for a day or two on gelatine ex- 
 clusively, acquired an absolute disgust at it. It was hence concluded, 
 that the use of gelatine in any shape was hurtful, and ought not to 
 be permitted. 
 
 Now that we know, as the author has proved, that gelatine, al- 
 though formed from proteine, is no longer a compound of proteine, 
 and cannot yield blood, we can easily see how it is incapable, alone, 
 of supporting life and health. But on the other hand, when we con- 
 sider, how great a part of the body (membranes and bones, for 
 example) is formed of gelatine, when we see the dog digesting per- 
 fectly the gelatine of bones, and man that of soup or jelly j we must 
 admit the great probability of the author's most ingenious supposition, 
 namely, that gelatine is dissolved in the stomach, and enters the 
 blood, where it serves as a means of restoring the waste of the gela- 
 tinous tissues ; while the weak digestive powers of a convalescent or 
 patient are not taxed to convert albumen, fibrine, or caseine into gela- 
 tine ; and thus its use, as apart only of the diet of hospitals, becomes 
 at once obvious. 
 
 We can no longer reject the facts proved by D'Arcet, (although 
 peremptorily denied by some,) namely, that the period of the stay of 
 patients in the hospital, is, on the average, much shortened where 
 gelatine has been employed, while, when mixed with other food, the 
 patients relish it highly. At least, we cannot reject them without 
 examination. On the other hand, we can now clearly perceive the 
 error of those, who, because the composition of gelatine approaches 
 to that of fibrine, &c., maintained it to be equally nutritious. For 
 our knowledge on this subject we are indebted, first, to the discovery 
 of proteine by Mulder ; secondly, to the discovery, that gelatine is 
 
MAY SERVE TO NOURISH. 95 
 
 the dead body retain their connexions, which depend 
 on the gelatinous tissues. 
 
 On the other hand, we see that the gelatine of bones 
 devoured by a dog entirely disappears, while only the 
 bone earth is found in his excrements. The same is 
 true of man, when fed on food rich in gelatine, as, for 
 example, strong soup. The gelatine is not to be found 
 either in the urine or in the faeces, and consequently 
 must have undergone a change, and must have served 
 some purpose in the animal economy. 
 
 It is clear, that the gelatine must be expelled from 
 the body in a form different from that in which it was 
 introduced as food. 
 
 When we consider the transformation of the albumen 
 of the blood into a part of an organ composed of fibrine, 
 the identity in composition of the two substances ren- 
 ders the change easily conceivable. Indeed, we find 
 the change of a dissolved substance into an insoluble 
 organ of vitality, chemically speaking, natural and easily 
 explained, on account of this very identity of compo- 
 sition. Hence, the opinion is not unworthy of a closer 
 investigation, that gelatine, when taken in the dissolved 
 state, is again converted, in the body, into cellular 
 tissue, membrane, and cartilage ; that it may serve for 
 the reproduction of such parts of these tissues as have 
 been wasted, and for their growth. 
 
 And when the powers of nutrition in the whole body 
 
 not a compound of proteine; and, thirdly, to the sagacity of Liebig, 
 in first drawing the conclusions now so obvious to all who attend to 
 the subject. 
 
96 GELATINE. 
 
 are affected by a change of the health, then, even should 
 the power of forming blood remain the same, the organic 
 force by which the constituents of the blood are trans- 
 formed into cellular tissue and membranes must neces- 
 sarily be enfeebled by sickness. In the sick man, the 
 intensity of the vital force, its power to produce meta- 
 morphoses, must be diminished as well in the stomach 
 as in all other parts of the body. In this condition, the 
 uniform experience of practical physicians shows, that 
 gelatinous matters in a dissolved state, exercise a most 
 decided influence on the state of the health. Given in a 
 form adapted for assimilation, they serve to husband the 
 vital force, just as may be done, in the case of the stom- 
 ach, by due preparation of the food in general. Brittle- 
 ness in the bones of graminivorous animals is clearly 
 owing to a weakness in those parts of the organism, whose 
 function it is to convert the constituents of the blood 
 into cellular tissue and membrane ; and, if we can trust 
 to the reports of physicians who have resided in the 
 East, the Turkish women, in their diet of rice, and in 
 the frequent use of enemata of strong soup, have united 
 the conditions necessary for the formation both of cel- 
 lular tissue and of fat. 
 
PART II. 
 
 THE 
 
 METAMORPHOSIS OF TISSUES. 
 
THE 
 
 METAMORPHOSIS OF TISSUES. 
 
 1. THE absolute identity of composition in the chief 
 constituents of blood and the nitrogenized compounds 
 in vegetable food would, some years ago, have furnished 
 a plausible reason for denying the accuracy of the 
 chemical analyses leading to such a result. At that 
 period, experiment had not as yet demonstrated the 
 existence of numerous compounds, both containing ni- 
 trogen and devoid of that element, which, with the 
 greatest diversity in external characters, yet possess the 
 very same composition in 100 parts ; nay, many of 
 which even contain the same absolute amount of equiv- 
 alents of each element. Such examples are now very 
 frequent, and are known by the names of isomeric and 
 polymeric compounds. 
 
 2. Cyanuric acid, for example, is a nitrogenized 
 compound, which crystallizes in beautiful transparent 
 octahedrons, easily soluble in water and in acids, and 
 very permanent. Cyamelide is a second body, abso- 
 lutely insoluble in water and acids, white and opaque 
 like porcelain or magnesia. Hydrated cyanic acid is a 
 third compound, which is a liquid, more volatile than 
 pure acetic acid, which blisters the skin, and cannot be 
 
100 ISOMERIC BODIES. 
 
 brought in contact with water without being instantane- 
 ously resolved into new products. These three sub- 
 stances not only yield, on analysis, absolutely the same 
 relative weights of the same elements, but they may be 
 converted and reconverted into one another, even in 
 hermetically closed vessels, that is, without the aid 
 of any foreign matter. (See Appendix, 21.) Again, 
 among those substances which contain no nitrogen, we 
 have aldehyde, a combustible liquid miscible with water, 
 which boils at the temperature of the hand, attracts 
 oxygen from the atmosphere with avidity, and is there- 
 by changed into acetic acid. This compound cannot 
 be preserved, even in close vessels ; for after some 
 hours or days, its consistence, its volatility, and its 
 power of absorbing oxygen, all are changed. It de- 
 posits long, hard, needle-shaped crystals, which at 212 
 are not volatilized, and the supernatant liquid is no long- 
 er aldehyde. It now boils at 140, cannot be mixed 
 with water, and when cooled to a moderate degree crys- 
 tallizes in a form like ice. Nevertheless, analysis has 
 proved, that these three bodies, so different in their 
 characters, are identical in composition. (21) 
 
 3. A similar group of three occurs in the case of 
 albumen, fibrine, and caseine. They differ in external 
 character, but contain exactly the same proportions of 
 organic elements. 
 
 When animal albumen, fibrine, and caseine are dis- 
 solved in a moderately strong solution of caustic pot- 
 ash, and the solution is exposed for some time to a 
 high temperature, these substances are decomposed. 
 
DISCOVERY OF PROTEINE. 101 
 
 The addition of acetic acid to the solution causes, in all 
 three, the separation of a gelatinous translucent precipi- 
 tate, which has exactly the same characters and com- 
 position, from whichever of the three substances above 
 mentioned it has been obtained. 
 
 MULDER, to whom we owe the discovery of this 
 compound, found, by exact and careful analysis, that it 
 contains the same organic elements, and exactly in the 
 same proportion, as the animal matters from which it 
 is prepared ; insomuch, that if we chednct from* the 
 analysis of albumen, fibrine, and caseine, <he 'ashes they 
 yield, when incinerated, as well a$ the" sniper arid' 
 phosphorus they contain, and then calculate the re- 
 mainder for 100 parts, we obtain the same result as in 
 the analysis of the precipitate above described, pre- 
 pared by potash, which is free from inorganic matter, (as) 
 
 Viewed in this light, the chief constituents of the 
 blood and the caseine of milk may be regarded as com- 
 pounds of phosphates and other salts, and of sulphur 
 and phosphorus, with a compound of carbon, nitrogen, 
 hydrogen, and oxygen, in which the relative proportion 
 of these elements is invariable ; and this compound may 
 be considered as the commencement and starting-point 
 of all other animal tissues, because these are all pro- 
 duced from the blood. 
 
 These considerations induced Mulder to give to this 
 product of the decomposition of albumen, &c. by pot- 
 ash, the name of proteine (from TT^WTSWO, "I take the 
 first rank"). The blood, or the constituents of the 
 9* 
 
102 PROTEINS EXISTS IN FIBRINE, 
 
 blood, are consequently compounds of this proteine 
 with variable proportions of inorganic substances. 
 
 Mulder further ascertained, that the insoluble nitro- 
 genized constituent of wheat flour (vegetable fibrine), 
 when treated with potash, yields the very same product, 
 proteine ; and it has recently been proved that vegeta- 
 ble albumen and caseine are acted on by potash pre- 
 cisely as animal albumen and caseine are. 
 
 4. As far, therefore, as our researches have gone, it 
 , . may be laid down as a law, founded on experience, that 
 vegetables produce, in their organism, compounds of 
 . vprotcioe;.; a;nd ,tha^ out of these compounds of proteine 
 the various tissues and parts of the animal body are de- 
 veloped 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 these vegetable and animal pro- 
 ducts, and although the difference in their properties 
 seems to indicate that their elements are not arranged in 
 the same manner, yet the hypothesis of the preexistence 
 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 
 
 * The experiment of Tiedemann and Gmelin, who found it impos- 
 sible to sustain the life of geese by means of boiled white of egg, may 
 be easily explained, when we reflect that a graminivorous animal, 
 especially when deprived of free motion, cannot obtain, from the 
 transformation or waste of the tissues alone, enough of carbon for the 
 respiratory process. 2 Ibs. of albumen contain only 3 oz. of carbon, 
 of which, among the last products of transformation, a fourth part is 
 given off in the form of uric acid. L. 
 
ALBUMEN, AND CASEINE. 103 
 
 compounds assume the same arrangement when acted on 
 by potash at a high temperature. 
 
 All the organic nitrogenized constituents of the body, 
 how different soever they may be in composition, are 
 derived from proteine. They are formed from it, by 
 the addition or subtraction of the elements of water or 
 of oxygen, and by resolution into two or more com- 
 pounds. 
 
 5. This proposition must be received as an undeniable 
 truth, when we reflect on the development of the young 
 animal in the egg of a fowl. The egg can be shown to 
 contain no other nitrogenized compound except albu- 
 men. The albumen of the yolk is identical with that 
 of the white ; (23) the yolk contains, besides, only a 
 yellow fat, in which cholesterine and iron may be de- 
 tected. Yet we see, in the process of incubation, 
 during which no food and no foreign matter, except the 
 oxygen of the air, is introduced, or can take part in the 
 development of the animal, that out of the albumen, 
 feathers, claws, globules of the blood, fibrine, mem- 
 brane and cellular tissue, arteries, and veins, are pro- 
 duced. The fat of the yolk may have contributed, to a 
 certain extent, to the formation of the nerves and brain ; 
 but the carbon of this fat cannot have been employed to 
 produce the organized tissues in which vitality resides, 
 because the albumen of the white and of the yolk al- 
 ready contains, for the quantity of nitrogen present, ex- 
 actly the proportion of carbon required for the forma- 
 tion of these tissues. 
 
 6. The true starting-point for all the tissues is, con- 
 
104 DIGESTION COMPARED 
 
 sequently, albumen ; all nitrogenized articles of food 
 whether derived from the animal or from the vegetabL 
 kingdom, are converted into albumen before they cai 
 take part in the process of nutrition. 
 
 All the food consumed by an animal becomes in thi 
 stomach soluble, and capable of entering into the circu 
 lation. In the process by which this solution is effected 
 only one fluid, besides the oxygen of the air, takes j 
 part ; it is that which is secreted by the lining membran< 
 of the stomach. 
 
 The most decisive experiments of physiologists have 
 shown, that the process of chymification is independen 
 of the vital force ; that it takes place in virtue of a pure 
 Jy chemical action, exactly similar to those processes of 
 decomposition or transformation which are known a: 
 putrefaction, fermentation, or decay (eremacausis). 
 
 7. When expressed in the simplest form, fermenta- 
 tion, or putrefaction, may be described as a process of 
 transformation, that is, a new arrangement of the ele- 
 mentary particles, or atoms, of a compound, yielding 
 two or more new groups or compounds, and caused bj 
 contact with other substances, the elementary particles 
 of which are themselves in a state of transformation 01 
 decomposition. It is a communication, or an imparting 
 of a state of motion, which the atoms of a body in a 
 state of motion are capable of producing in other bodies, 
 whose elementary particles are held together only by a 
 feeble attraction. 
 
 8. Thus the clear gastric juice contains a substance 
 in a state of transformation, by the contact of which 
 
TO FERMENTATION. 105 
 
 with those constituents of the food which, by themselves, 
 are insoluble in water, the latter acquire, in virtue of a 
 new grouping of their atoms, the property of dissolving 
 in that fluid. During digestion, the gastric juice, when 
 separated, is found to contain a free mineral acid, the 
 presence of which checks all further change. That the 
 food is rendered soluble quite independently of the vi- 
 tality of the digestive organs has been proved by a num- 
 ber of the most beautiful experiments. Food, enclosed 
 in perforated metallic tubes, so that it could not come 
 into contact with the stomach, was found to disappear as 
 rapidly, and td be as perfectly digested, as if the cover- 
 ing had been absent ; and fresh gastric juice, out of the 
 body, when boiled white of egg, or muscular fibre, were 
 kept in contact with it for a time at the temperature of 
 the body, caused these substances to lose the solid form 
 and to dissolve in the liquid. 
 
 9. It can hardly be doubted, that the substance which 
 is present in the gastric juice in a state of change is a 
 product of the transformation of the stomach itself. 
 No substances possess, in so high a degree as those 
 arising from the progressive decomposition of the tis- 
 sues containing gelatine or chondrine, the property of 
 exciting a change in the arrangement of the elements of 
 other compounds. When the lining membrane of the 
 stomach of any animal, as, for example, that of the 
 calf, is cleaned by continued washing with water,. it pro- 
 duces no effect whatever, if brought into contact with 
 a solution of sugar, with milk, or other substances. 
 But if the same membrane be exposed for some time to 
 
106 POWER OF ANIMAL MEMBRANE. 
 
 the air, or dried, and then placed in contact with such 
 substances, the sugar is changed, according to the state 
 of decomposition of the animal matter, either into lactic 
 acid, into mannite and mucilage, or into alcohol and 
 carbonic acid ; while milk is instantly coagulated. An 
 ordinary animal bladder retains, when dry, all its prop- 
 erties unchanged ; but when exposed to air and moist- 
 ure, it undergoes a change not indicated by any obvious 
 external signs. If, in this state, it be placed in a solu- 
 tion of sugar of milk, that substance is quickly changed 
 into lactic acid. 
 
 10. The fresh lining membrane of the stomach of 
 a calf, digested with weak muriatic acid, gives to this 
 fluid no power of dissolving boiled flesh or coagulated 
 white of egg. But if previously allowed to dry, or if 
 left for a time in water, it then yields, to water acidulated 
 with muriatic acid, a substance in minute quantity, the 
 decomposition of which is already commenced, and is 
 completed in the solution. If coagulated albumen be 
 placed in this solution, the state of decomposition is 
 communicated to it, first at the edges, which become 
 translucent, pass into a mucilage, and finally dissolve. 
 The same change gradually affects the whole mass, and 
 at last it is entirely dissolved, with the exception of fatty 
 particles, which render the solution turbid. Oxygen is 
 conveyed to every part of the body by the arterial 
 blood ; moisture is everywhere present ; and thus we 
 have united the chief conditions of all transformations 
 in the animal body. 
 
 Thus, as in the germination of seeds, the presence 
 
LACTIC ACID. 107 
 
 of a body in a state of decomposition or transformation, 
 which has been called diastase, effects the solution of 
 the starch, that is, its conversion into sugar; so, a 
 product of the metamorphosis of the substance of the 
 stomach, being itself in a state of metamorphosis which 
 s completed in the stomach, effects the dissolution of 
 all such parts of the food as are capable of assuming a 
 soluble form. In certain diseases, there are produced 
 from the starch, sugar, &c., of the food, lactic acid 
 and mucilage. (24) These are the very same products 
 which we can produce out of sugar by means of mem- 
 brane in a state of decomposition out of the body ; but 
 in a normal state of health, no lactic acid is formed in 
 the stomach. \ 
 
 11. The property possessed by many substances, 
 such as starch and the varieties of sugar, by contact 
 with animal substances in a state of decomposition, to 
 pass into lactic acid, has induced physiologists, without 
 further inquiry, to assume the fact of the production of 
 lactic acid during digestion ; and the power which this 
 acid has of dissolving phosphate of lime has led them 
 to ascribe to it the character of a general solvent. But 
 neither Prout nor Braconnot could detect lactic acid in 
 the gastric juice ; and even Lehmann (see his " Lehr- 
 buch der Physiologischen Chemie," Tom. L p. 285) 
 obtained from the gastric juice of a cat only microscopic 
 crystals, which he took for lactate of zinc, although 
 their chemical character could not be ascertained. The 
 presence of free muriatic acid in the gastric juice, first 
 observed by Prout, has been confirmed by all those 
 
108 GASTRIC JUICE. 
 
 chemists who have examined that fluid since. This 
 muriatic acid is obviously derived from common salt, 
 the soda of which plays a very decided part in the con- 
 version of fibrine and caseine into blood. 
 
 Muriatic acid yields to no other acid in the power of 
 dissolving bone earth, and even acetic acid, in this re- 
 spect, is equal to lactic acid. There is consequently 
 no proof of the necessity of lactic acid in the digestive 
 process ; and we know with certainty, that in artificial 
 digestion it is not formed. Berzelius, indeed, has found 
 lactic acid in the blood and flesh of animals ; but when 
 his experiments were made, chemists were ignorant of 
 the extraordinary facility and rapidity with which this 
 acid is formed from a number of substances containing 
 its elements, when in contact with animal matter. 
 
 In the gastric juice of a dog, Braconnot found, along 
 with free muriatic acid, distinct traces of a salt of iron, 
 which he at first held to be an accidental admixture. 
 But in the gastric juice of a second dog, collected with 
 the utmost care, the iron was again found. (Ann. de 
 Ch. et de Ph. lix. p. 249.) This occurrence of iron 
 is full of significance in regard to the formation of the 
 blood. 
 
 12. In the action of the gastric juice on the food, no 
 other element takes a share, except the oxygen of the 
 atmosphere and the elements of water. This oxygen 
 is introduced directly into the stomach. During the 
 mastication of the food, there is secreted into the mouth 
 from organs specially destined to this function, a fluid, 
 the saliva, which possesses the remarkable property of 
 
NITROGEN GIVEN OUT. 109 
 
 enclosing air in the shape of froth, in a far higher degree 
 than even soap suds. This air, by means of the saliva, 
 reaches the stomach with the food, and there its oxygen 
 enters into combination, while its nitrogen is given out 
 through the skin and lungs. The longer digestion con- 
 tinues, that is, the greater the resistance offered to the 
 solvent action by the food, the more saliva, and conse- 
 quently the more air enters the stomach. Rumination, 
 in certain graminivorous animals, has plainly for one 
 object a renewed and repeated introduction of oxygen ; 
 for a more minute mechanical division of the food, only 
 shortens the time required for solution. 
 
 The unequal quantities of air which reach the stom- 
 ach with the saliva in different classes of animals, ex- 
 plain the accurate observations made by physiologists, 
 who have established beyond all doubt, the fact, that 
 animals give out pure nitrogen through the skin and 
 lungs, in variable quantity. This fact is so much the 
 more important, as it furnishes the most decisive proof, 
 that the nitrogen of the air is applied to no use in the 
 animal economy. 
 
 The fact, that nitrogen is given out by the skin 
 and lungs, is explained by the property which animal 
 membranes possess of allowing all gases to permeate 
 them, a property which can be shown to exist by the 
 most simple experiments. A bladder, filled with car- 
 bonic acid, nitrogen, or hydrogen gas, if tightly closed 
 and suspended in the air, loses in twenty-four hours the 
 whole of the enclosed gas ; by a kind of exchange, it 
 passes outwards into the atmosphere, while its place is 
 10 
 
HO USE OF THE SALIVA. 
 
 occupied by atmospherical air. A portion of intestine, 
 a stomach, or a piece of skin or membrane, acts pre- 
 cisely as the bladder, if filled with any gas. This per- 
 meability to gases is a mechanical property, common to 
 all animal tissues ; and it is found in the same degree in 
 the living as in the dead tissue. 
 
 It is known that in cases of wounds of the lungs a 
 peculiar condition is produced, in which, by the act of 
 inspiration, not only oxygen but atmospherical air, with 
 its whole amount (|ths) of nitrogen, penetrates into 
 the cells of the lungs. This air is carried by the 
 circulation 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. 
 There can be no doubt that the oxygen of the air, thus 
 accumulated in the cellular tissue, enters into combina- 
 tion, while its nitrogen is expired through the skin and 
 lungs. 
 
 Moreover, it is well known that in many graminivo- 
 rous animals, when the digestive organs have been over- 
 loaded with fresh juicy vegetables, these substances 
 undergo in the stomach the same decomposition as they 
 would at the same temperature out of the body. They 
 pass into fermentation and putrefaction, whereby so 
 great a quantity of carbonic acid gas and of inflamma- 
 ble gas is generated, that these organs are enormously 
 distended, sometimes even to bursting. From the struc- 
 ture of their stomach or stomachs, these gases cannot 
 escape through the oasophagus ; but in the course of a 
 
GASES PERMEATE MEMBRANES. 1 1 1 
 
 few hours, the distended body of the animal becomes 
 less swollen, and at the end of twenty-four hours no 
 trace of the gases is left. (25) 
 
 Finally, if we consider the fatal accidents which so 
 frequently occur in wine countries from the drinking 
 of what is called feather-white wine (der federweisse 
 Wein), we can no longer doubt that gases of every 
 kind, whether soluble or insoluble in water, possess the 
 property of permeating animal tissues, as water pene- 
 trates unsized paper. This poisonous wine is wine still 
 in a state of fermentation, which is increased by the 
 heat of the stomach. The carbonic acid gas, which 
 is disengaged, penetrates through the parietes of the 
 stomach, through the diaphragm, and through all the 
 intervening membranes, into the air-cells of the lungs, 
 out of which it displaces the atmospherical air. The 
 patient dies with all the symptoms of- asphyxia caused 
 by an irrespirable gas ; and the surest proof of the 
 presence of the carbonic acid in the lungs is the fact, 
 that the inhalation of ammonia (which combines with it) 
 is recognised as the best antidote against this kind of 
 poisoning. 
 
 The carbonic acid of effervescing wines and of soda- 
 water, when taken into the stomach, or of water satur- 
 ated with this gas, administered in the form of enema, 
 is given out again through the skin and lungs ; and this 
 is equally true of the nitrogen which is introduced into 
 the stomach with the food in the saliva. 
 
 No doubt a part of these gases may enter the venous 
 circulation through the absorbent and lymphatic vessels, 
 
112 SOURCES OF THE NITROGEN 
 
 and thus reach the lungs, where they are exhaled ; but 
 the presence of membranes offers not the slightest .ob- 
 stacle to their passing directly into the cavity of the 
 chest. It is, in fact, difficult to suppose that the absor- 
 bents and lymphatics have any peculiar tendency to 
 absorb air, nitrogen, or hydrogen, and convey these 
 gases into the circulation, since the intestines, the stom- 
 ach, and all spaces in the body not filled with solid or 
 liquid matters, contain gases, which only quit their po- 
 sition when their volume exceeds a certain point, and 
 which, consequently, are not absorbed. More especial- 
 ly in reference to nitrogen, we must suppose that it is 
 removed from the stomach by some more direct means, 
 and not by the blood, which fluid must already, in pass- 
 ing through the lungs, have become saturated with that 
 gas, that is, must have absorbed a quantity of it, propor- 
 tioned to its solvent power, like any other liquid. By 
 the respiratory motions all the gases which fill the other- 
 wise empty spaces of the body are urged towards the 
 chest ; for by the motion of the diaphragm and the ex- 
 pansion of the chest a partial vacuum is produced, in 
 consequence of which air is forced into the chest from 
 all sides by the atmospheric pressure. The equilibrium 
 is, no doubt, restored, for the most part, through the 
 windpipe, but all the gases in the body must, neverthe- 
 less, receive an impulse towards the chest. In birds 
 and tortoises these arrangements are reversed. If we 
 assume that a man introduces into the stomach in each 
 minute only |th of a cubic inch of air with the saliva, 
 this makes in eighteen hours 135 cubic inches; and if 
 
EXHALED FROM THE LUNGS. 113 
 
 ^th be deducted as oxygen, there will still remain 108 
 cubic inches of nitrogen, which occupy the space of 
 3 Ibs. of water. Now, whatever may be the actual 
 amount of the nitrogen thus swallowed, it is certain that 
 the whole of it is given out again by the mouth, nose, 
 and skin ; and when we consider the very large quanti- 
 ty of nitrogen found in the intestines of executed crim- 
 inals by Magendie, as well as the entire absence ot 
 oxygen in these organs (26), we must assume that air, 
 and consequently nitrogen, enters the stomach by re- 
 sorption through the skin, and is afterwards exhaled by 
 the lungs. 
 
 When animals are made to respire in gases contain- 
 ing no nitrogen, more of that gas is exhaled, because in 
 this case the nitrogen within the body acts towards the 
 external space as if the latter were a vacuum. (See 
 Graham, " On the Diffusion of Gases.") 
 
 The differences in the amount of expired nitrogen in 
 different classes of animals are thus easily explained ; 
 the herbivora swallow with the saliva more air than the 
 carnivora ; they expire more nitrogen than the latter, 
 less when fasting than immediately after taking food. 
 
 13. In the same way as muscular fibre, when sep- 
 arated from the body, communicates the state of de- 
 composition existing in its elements to the peroxide of 
 nydrogen, so a certain product, arising by means of the 
 vital process, and in consequence of the transposition 
 of the elements of parts of the stomach and of the 
 other digestive organs, while its own metamorphosis is 
 10* 
 
114 DIGESTIVE PROCESS. 
 
 accomplished in the stomach, acts on the food. The 
 insoluble matters become soluble, they are digested. 
 
 It is certainly remarkable, that hard-boiled white 
 of egg or fibrine, when rendered soluble by certain 
 liquids, by organic acids, or weak alkaline solutions, 
 retain all their properties except the solid form (cohe- 
 sion) without the slightest change. Their elementary 
 molecules, without doubt, assume a new arrangement ; 
 they do not, however, separate into two or more groups, 
 but remain united together. 
 
 The very same thing occurs in the digestive process ; 
 in the normal state, the food only undergoes a change 
 in its state of cohesion, becoming fluid without any 
 other change of properties. 
 
 The greatest obstacle to forming a clear conception 
 of the nature of the digestive process, which is here 
 reckoned among those chemical metamorphoses which 
 have been called fermentation and putrefaction, consists 
 in our involuntary recollection of the phenomena which 
 accompany the fermentation of sugar and of animal sub- 
 stances (putrefaction), which phenomena we naturally 
 associate with any similar change ; but there are num- 
 berless cases in which a complete chemical metamor- 
 phosis of the elements of a compound occurs without 
 the smallest disengagement of gas, and it is chiefly these 
 which must be borne in mind, if we would acquire a 
 clear and accurate idea of the chemical notion or con- 
 ception of the digestive process. 
 
 All substances which can arrest the phenomena of 
 fermentation and putrefaction in liquids, also arrest di- 
 
NATURE OF FERMENT. 115 
 
 gestion when taken into the stomach. The action of 
 the empyreumatic matters in coffee and tobacco-smoke, 
 of creosote, of mercurials, &c., &c., is, on this ac- 
 count, worthy of peculiar attention with reference to 
 dietetics. 
 
 The identity in composition of the chief constituents 
 of blood, and of the nitrogenized constituents of vege- 
 table food, has certainly furnished, in an unexpected 
 manner, an explanation of the fact, that putrefying 
 blood, white of egg, flesh, and cheese produce the 
 same effects in a solution of sugar as yeast or ferment ; 
 that sugar, in contact with these substances, according 
 to the particular stage of decomposition in which the 
 putrefying matters may be, yields, at one time, alcohol 
 and carbonic acid ; at another, lactic acid, mannite, and 
 mucilage. The explanation is simply this, that ferment, 
 or yeast, is nothing but vegetable fibrine, albumen, or 
 caseine, in a state of decomposition, these substances 
 having the same composition with the constituents of 
 flesh, blood, or cheese. The putrefaction of these 
 animal matters is a process identical with the metamor- 
 phosis of the vegetable matters identical with them ; it 
 is a separation or splitting up into new and less complex 
 compounds. And if we consider the transformation of 
 the elements of the animal body (the waste of matter 
 in animals) as a chemical process, which goes on under 
 the influence of the vital force, then the putrefaction of 
 animal matters out of the body is a division into simpler 
 compounds, in which the vital force takes no share. 
 The action in both cases is the same, only the products 
 
116 COMPOSITION OF PROTEINE. 
 
 differ. The practice of medicine has furnished the most 
 beautiful and interesting observations on the action of 
 empyreumatic substances, such as wood, vinegar, creo- 
 sote, &c., on malignant wounds and ulcers. In such mor- 
 bid phenomena two actions are going on together ; one 
 metamorphosis, which strives to complete itself under the 
 influence of the vital force, and another, independent of 
 that force. The latter is a chemical process, which is 
 entirely suppressed or arrested by empyreumatic sub- 
 stances ; and this effect is precisely opposed to the 
 poisonous influence exercised on the organism by pu- 
 trefying blood when introduced into a fresh wound. 
 
 14. The formula C 48 H 36 N 6 O 14 * is that which most 
 accurately expresses the composition of proteine, or 
 the relative proportions of the organic elements in the 
 blood, as ascertained by analysis. Albumen, fibrine, 
 and caseine contain proteine ; caseine contains, besides, 
 sulphur, but no phosphorus ; albumen and fibrine con- 
 tain both these substances chemically combined, the 
 former more sulphur than the latter. We cannot directly 
 ascertain in what form the phosphorus exists, but we 
 have decided proof that the sulphur cannot be in the 
 oxidized state. All these substances, when heated 
 with a moderately strong solution of potash, yield the 
 sulphur which we find in the solution as sulphuret of 
 potassium ; and, on the addition of an acid, it is given 
 off as sulphuretted hydrogen. When pure fibrine, or 
 ordinary albumen is dissolved in a weak solution of 
 
 * For the method of converting this and other formulee into pro- 
 portions per cent, see Appendix. 
 
FIBRINE. 117 
 
 potash, and acetate of lead is added to the solution, in 
 such proportion that the whole of the oxide of lead 
 remains dissolved in the potash, the mixture, if heated 
 to the boiling point, becomes black like ink, and sul- 
 phuret of lead is deposited as a fine black powder. 
 
 It is extremely probable, that by the action of the 
 alkali the sulphur is removed as sulphuretted hydrogen, 
 the phosphorus as phosphoric or phosphorous acid. 
 Since, in this case, sulphur and phosphorus are elimina- 
 ted on the one hand, and oxygen and hydrogen on the 
 other, it might be concluded, that fibrine and albumen, 
 when analyzed with their sulphur and phosphorus, would 
 yield a larger proportion of oxygen and hydrogen than 
 is found in proteine. But this cannot be shown in the 
 analysis ; for fibrine, for example, has been found to 
 contain 0-36 per cent, of sulphur. Assuming, then, 
 that this sulphur is eliminated by the alkali in combina- 
 tion with hydrogen, proteine would yield 0'0225 per 
 cent, less hydrogen than fibrine ; instead of the mean 
 amount of 7*062 per cent, of hydrogen, the proteine 
 should yield 7'04 per cent. In like manner, by the 
 elimination of the phosphorus in combination with oxy- 
 gen, the amount of oxygen in fibrine would be reduced 
 from 22-715 22-00 per cent, to 22-5 21-8 per 
 cent, in proteine. But the limits of error in our analy- 
 ses are, on an average, beyond ^th per cent, in hydro- 
 gen, and beyond T 4 ths per cent, in the oxygen ; while 
 in the supposed case the difference in the hydrogen 
 would not be greater than ^th per cent. 
 
 Finally, if we reflect, that the elimination of oxygen 
 
118 COMPOSITION OF FIBRINE. 
 
 and hydrogen with the sulphur and phosphorus does 
 not exclude the addition of the elements of water, and 
 if we assume that fibrine and albumen, in passing into 
 proteine, do combine with a certain quantity of water, 
 an occurrence which is highly probable, we shall see, 
 that there is no probability, that the ultimate analysis 
 of these compounds will ever enable us to decide such 
 questions, or to fix the chemical view of the relation 
 of proteine to albumen, fibrine, or caseine, farther than 
 has been done above. 
 
 Some have endeavoured to prove the existence of 
 unoxidized phosphorus in albumen and fibrine from the 
 formation of sulphuret of potassium when they are 
 acted on by potash, supposing the oxygen of the pot- 
 ash to have formed phosphoric acid with the phospho- 
 rus ; but caseine, which contains no phosphorus, yields 
 sulphuret of potassium, just like the other substances ; 
 and here its formation cannot be accounted 1 for, unless 
 we admit the previous production of sulphuretted hy- 
 drogen. In the mere boiling of flesh, for the purpose 
 of making soup, sulphuretted hydrogen, as Chevreul 
 has shown, is disengaged. 
 
 Moreover, the proportion of sulphur, for the same 
 amount of phosphorus, is not the same in fibrine and 
 albumen, from which no other conclusion can be drawn, 
 but that the formation of sulphuret of potassium has no 
 relation to the presence of phosphorus. Sulphuret of 
 potassium is formed from caseine, which is not sup- 
 posed to contain any uncombined phosphorus ; and it 
 
COMPOSITION OF TISSUES. 119 
 
 is formed, also, from albumen, which contains only 
 half as much phosphorus as fibrine. 
 
 Every attempt to give the true absolute amount of 
 the atoms in fibrine and albumen in a rational formula, 
 in which the sulphur and phosphorus are taken, not in 
 fractions, but in entire equivalents, must be fruitless, 
 because we are absolutely unable to determine with 
 perfect accuracy the exceedingly minute quantities of 
 sulphur and phosphorus in such compounds ; and be- 
 cause a variation in the sulphur or phosphorus, smaller 
 in extent than the usual limit of errors of observation, 
 will affect the number of atoms of carbon, hydrogen, 
 or oxygen to the extent of 10 atoms or more. 
 
 We must be careful not to deceive ourselves in our 
 expectations of what chemical analysis can do. We 
 know, with certainty, that the numbers representing 
 the relative proportions of the organic elements are the 
 same in albumen and fibrine, and hence we conclude 
 that they have the same composition. This conclusion 
 is not affected by the fact, that we do not know the 
 absolute number of the atoms of their elements, which 
 have united to form the compound atom. 
 
 15. A formula for proteine is nothing more than 
 the nearest and most exact expression in equivalents, 
 of the result of the best analyses ; it is a fact estab- 
 lished so far, free from doubt, and this alone is, for 
 the present, valuable to us. 
 
 If we reflect, that from the albumen and fibrine of 
 the body all the other tissues are derived, it is perfectly 
 clear, that this can only occur in two ways. Either 
 
120 DIFFERENCES IN COMPOSITION 
 
 certain elements have been added to, or removed from, 
 their constituent parts. 
 
 If we now, for example, look for an analytical ex- 
 pression of the composition of cellular tissue, of the 
 tissues yielding gelatine, of tendons, of hair, of horn, 
 &c., in which the number of atoms of carbon is made 
 invariably the same as in albumen and fibrine, we can 
 then see, at the first glance, in what way the proportion 
 of the other elements has been altered ; but this in- 
 cludes all that physiology requires in order to obtain 
 an insight into the true nature of the formative and 
 nutritive processes in the animal body. 
 
 From the researches of Mulder and Scherer we ob- 
 tain the following empirical formula : 
 
 Composition of organic tissues. 
 
 Albumen C 48 N 6 H 36 O 14 -f- P + S* 
 
 Fibrine C 48 N 6 H 36 O 14 + P + 2S 
 
 Caseine C 48 N 6 H 36 O 14 -f S 
 
 Gelatinous tissues, tendons . . 
 
 Hair, horn C 48 N 7 H 39 O 17 
 
 Arterial membrane C 48 N 6 H 38 O 16 
 
 The composition of these formulae shows, that when 
 proteine passes into chondrine (the substance of the 
 cartilages of the ribs), the elements of water, with 
 oxygen, have been added to it ; while in the formation 
 of the serous membranes, nitrogen also has entered into 
 combination. 
 
 If we represent the formula of proteine, C 48 N 6 H 3(! O 14 
 
 * The quantities of sulphur and phosphorus here expressed by 
 S and P are not equivalents, but only give the relative proportions 
 of these two elements to each other, as found by analysis. 
 
OF ORGANIC TISSUES. 121 
 
 by Pr, then nitrogen, hydrogen, and oxygen have been 
 added to it in the form of known compounds, and in 
 the following proportions, in forming the gelatinous tis- 
 sues, hair, horn, arterial membrane, &c. 
 
 Proteine. Ammonia. Water. Oxygen. 
 Fibrine, Albumen .... Pr 
 Arterial membrane ... Pr . . . . -f- 2HO 
 
 Chondrine Pr . . . . + 4HO + 2O - 
 
 Hair, horn Pr -}- NH 3 ... -f 3O. 
 
 Gelatinous tissues . . . 2Pr 4. 3NH 3 -f- HO -f 7O.* 
 
 16. From this general statement it appears, that all 
 the tissues of the body contain, for the same amount 
 of carbon, more oxygen than the constituents of blood. 
 During their formation, oxygen, either from the atmo- 
 sphere or from the elements of water, has been added 
 to the elements of proteine. In hair and gelatinous mem- 
 brane we observe, further, an excess of nitrogen and hy- 
 drogen, and that in the proportions to form ammonia. 
 
 Chemists are not yet agreed on the question, in what 
 manner the elements of sulphate of potash are arranged ; 
 it would therefore be going too far, were they to pro- 
 nounce arterial membrane a hydrate of proteine, chon- 
 drine a hydrated oxide of proteine, and hair and mem- 
 branes compounds of ammonia with oxides of proteine. 
 
 The above formulae express with precision the differ- 
 ences of composition in the chief constituents of the 
 animal body ; they show, that for the same amount of 
 carbon the proportion of the other elements varies, and 
 how much more oxygen or nitrogen one compound con- 
 tains than another. 
 
 * See Note XXVII. 
 11 
 
122 GELATINE CONTAINS NO PROTEINK 
 
 17. By means of these formulae we can trace the 
 production of the different compounds from the constit- 
 uents of blood ; but the explanation of their production 
 may take two forms, and we have to decide which of 
 these comes nearest to the truth. 
 
 For the same amount of carbon, membranes and the 
 tissues which yield gelatine contain more nitrogen, oxy- 
 gen, and hydrogen, than proteine. It is conceivable, that 
 they are formed from albumen by the addition of oxygen, 
 of the elements of water, and of those of ammonia, 
 accompanied by the separation of sulphur and phos- 
 phorus ; at all events, their composition is entirely dif- 
 ferent from that of the chief constituents of blood. 
 
 The action of caustic alkalies on the tissues yielding 
 gelatine shows, distinctly, that they no longer contain 
 proteine ; that substance cannot in any way be obtained 
 from them ; and all the products formed by the action 
 of alkalies on them differ entirely from those produced 
 by the compounds of proteine in the same circumstances. 
 Whether proteine exist, ready formed, in fibrine, albu- 
 men, and caseine, or not, it is certain that their elements, 
 under the influence of the alkali, arrange themselves so 
 as to form proteine ; but this property is wanting in the 
 elements of the tissues which yield gelatine. 
 
 The other, and perhaps the more probable explana- 
 tion of the production of these tissues from proteine, 
 is that which makes it dependent on a separation of 
 carbon. 
 
 If we assume the nitrogen of proteine to remain en- 
 tire in the gelatinous tissue,' then the composition of the 
 
4 ORIGIN OF GELATINE. 123 
 
 latter, calculated on 6 equivalents of nitrogen, might be 
 represented by the formula, C 38 N 6 H 32 O 14 . This formula 
 approaches most closely to the analysis of Scherer, al- 
 though it is not an exact expression of his results. A 
 formula corresponding more perfectly to the analyses, is 
 C 32 N S H 27 O 12 ; or, calculated according to Mulder's 
 analysis, C M N,H 42 O 20 . * 
 
 According to the first formula, carbon and hydrogen 
 have been separated ; according to the two last, a cer- 
 tain proportion of all the elements has been removed. 
 
 18. We must admit, as the most important result of 
 the study of the composition of gelatinous tissue, and as 
 a point undeniably established, that, although formed 
 from compounds of proteine, it no longer belongs to the 
 series of the compounds of proteine. Its chemical 
 characters and composition justify this conclusion. 
 
 No fact is as yet opposed to the law, deduced from 
 observation, that nature has exclusively destined com- 
 pounds of proteine for the production of blood. 
 
 No substance analogous to the tissues yielding gelatine 
 is found in vegetables. The gelatinous substance is not 
 a compound of proteine ; it contains no sulphur, no 
 phosphorus, and it contains more nitrogen or less car- 
 bon than proteine. The compounds of proteine, under 
 the influence of the vital energy of the organs which 
 form the blood, assume a new form, but are not altered 
 in composition ; while these organs, as far as our expe- 
 
 * The formula C 52 N 8 H 40 O 20 , adopted by Mulder, gives, when re- 
 duced to 100 parts, too little nitrogen to be considered an exact ex- 
 pression of his analyses. 
 
124 ORIGIN OF GELATINE. , 
 
 rience reaches, do not possess the power of producing 
 compounds of proteine, by virtue of any influence, out 
 of substances which contain no proteine. Animals 
 which were fed exclusively with gelatine, the most high- 
 ly nitrogenized element of the food of carnivora, died 
 with the symptoms of starvation ; in short, the gelatin- 
 ous tissues are incapable of conversion into blood. 
 
 But there is no doubt that these tissues are formed 
 from the constituents of the blood ; and we can hardly 
 avoid entertaining the supposition, that the fibrine of 
 venous blood, in becoming arterial fibrine, passes through 
 the first stage of conversion into gelatinous tissue. We 
 cannot, with much probability, ascribe to membranes 
 and tendons the power of forming themselves out of 
 matters brought by the blood ; for how could any matter 
 become a portion of cellular tissue, for example, by 
 virtue of a force which has as yet no organ ? An al- 
 ready existing cell may possess the power of reproduc- 
 ing or of multiplying itself, but in both cases the pres- 
 ence of a substance identical in composition with cellu- 
 lar tissue is essential. Such 'matters are formed in the 
 organism, and nothing can be better fitted for their pro- 
 duction than the substance of the cells and membranes 
 which exist in animal food, and become soluble in the 
 stomach during digestion, or which are taken by man in 
 a soluble form. 
 
 19. In the following pages I offer to the reader an 
 attempt to develope analytically the principal metamor- 
 phoses which occur in the animal body ; and, to pre- 
 clude all misapprehension, I do this with a distinct pro- 
 
METAMORPHOSIS OF TISSUES. 125 
 
 test against all conclusions and deductions which 
 now or at any subsequent period be derived from it in 
 opposition to the views developed in the preceding part 
 of this work, with which it has no manner of connexion. 
 The results here to be described have surprised me no 
 less than they will others, and have excited in my mind 
 the same doubts as others will conceive ; but they are 
 not the creations of fancy, and I give them because I 
 entertain the deep conviction, that the method which has 
 led to them is the only one by which we can hope to 
 acquire insight into the nature of the organic processes. 
 
 The numberless qualitative investigations of animal 
 matters which are made are equally worthless for phys- 
 iology and for chemistry, so long as they are not insti- 
 tuted with a well-defined object, or to answer a ques- 
 tion clearly put. 
 
 If we take the letters of a sentence which we wish 
 to decipher, and place them in a line, we advance not 
 a step towards tl^ discovery of their meaning. To 
 resolve an enigma, we must have a perfectly clear con- 
 ception of the problem. There are many ways to the 
 highest pinnacle of a mountain ; but those only can 
 hope to reach it who keep the summit constantly in 
 view. All our labor and all our efforts, if we strive to 
 attain it through a morass, only serve to cover us more 
 completely with mud ; our progress is impeded by dif- 
 ficulties of our own creation, and at last even the great- 
 est strength must give way when so absurdly wasted. 
 
 20. If it be true, that all parts of the body are form- 
 ed and developed from the blood or the constituents of 
 11 * 
 
126 THE SECRETIONS CONTAIN 
 
 the blood, that the existing organs at every moment of 
 life are transformed into new compounds under the in- 
 fluence of the oxygen introduced in the blood, then the 
 animal secretions must of necessity contain the products 
 of the metamorphosis of the tissues. 
 
 21. If it be further true, that the urine contains those 
 products of metamorphosis which contain the most ni- 
 trogen, and the bile those which are richest in carbon, 
 from all the tissues which in the vital process have been 
 transformed into unorganized compounds, it is clear that 
 the elements of the bile and of the urine, added togeth- 
 er, must be equal, in the relative proportion of these 
 elements to the composition of the blood. 
 
 22. The organs are formed from the blood, and con- 
 tain the elements of the blood ; they become trans- 
 formed into new compounds, with the addition only of 
 oxygen and of water. Hence, the relative proportion 
 of carbon and nitrogen must be the same as in the 
 blood. * 
 
 If then we subtract from the composition of blood 
 the elements of the urine, then the remainder, deduct- 
 ing the oxygen and water which have been added, must 
 give the composition of the bile. 
 
 Or if from the elements of the blood, we subtract 
 the elements of the bile, the remainder must give the 
 composition of urate of ammonia, or of urea and car- 
 bonic acid. 
 
 It will surely appear remarkable, that this manner of 
 viewing the subject has led to the true formula of bile, 
 or, to speak more accurately, to the most correct em- 
 
ALL THE ELEMENTS OF THE BLOOD. 127 
 
 pirical expression of its composition ; and has furnished 
 the key to its metamorphosis, under the influence of 
 acids and alkalies, which had previously been sought for 
 in vain. 
 
 23. When fresh drawn blood is made to trickle over 
 a plate of silver, heated to 140, it dries to a red, 
 varnish-like matter, easily reduced to powder. Muscu- 
 lar flesh, free from fat, if dried first in a gentle heat, 
 and then at 212, yields a brown, pulverizable mass. 
 
 The analyses of PLAYFAIR and BOECKMANN (se) 
 give for flesh (fibrine, albumen, cellular tissue, and 
 nerves) and for blood, as the most exact expression of 
 their numerical results, one and the same formula, 
 namely, C 48 N 6 H 39 O 16 . This may be called the empir- 
 ical formula of blood. 
 
 24. The chief constituent of bile, according to the 
 researches of DEMARCAY, is a compound, analogous 
 to soaps, of soda with a peculiar substance, which has 
 been named choleic acid. This acid is obtained in 
 combination with oxide of lead, when bile, purified by 
 means of alcohol from all matters insoluble in that men- 
 struum, is mixed with acetate of lead. 
 
 Choleic acid is resolved, by the action of muriatic 
 acid, into ammonia, taurine, and a new acid, choloidic 
 acid, which contains no nitrogen. 
 
 When boiled with caustic potash, choleic acid is re- 
 solved into carbonic acid, ammonia, and another new 
 acid, cholic acid (distinct from the cholic acid of 
 Gmelin). 
 
 Now it is clear, that the true formula of choleic acid 
 
128 METAMORPHOSES OF BILE. 
 
 must include the analytical expression of these modes 
 of decomposition ; in other words, that it must enable 
 us to show that the composition of the products derived 
 from it is related, in a clear and simple manner, to the 
 composition of the acid itself. This is the only satis- 
 factory test of a formula ; and the analytical expression 
 thus obtained, loses nothing of its truth or value, if it 
 should appear, as the researches of BERZELIUS seem 
 to show, that choleic and choloidic acids are mixtures 
 of different compounds ; for the relative proportions of 
 the elements cannot in any way be altered by this cir- 
 cumstance. 
 
 25. In order to develope the metamorphoses which 
 choleic acid suffers under the influence of acids and 
 alkalies, the following formula alone can be adopted as 
 the empirical expression of the results of its analysis. 
 Formula of choleic acid : C 76 N 2 H 66 O 22 . (29) 
 
 J repeat, that this formula may express the composi- 
 tion of one, or of two or more compounds ; no matter 
 of how many compounds the so-called choleic acid 
 may be made up, the above formula represents the rela- 
 tive proportions of all their elements taken together. 
 
 If now we subtract from the elements of choleic acid, 
 the products formed by the action of muriatic acid, 
 namely, ammonia and taurine, we obtain the empirical 
 formula of choloidic acid. Thus ; from the 
 
 Formula of choleic acid C 76 N 2 H 66 O 22 
 
 subtract 
 1 atom taurine . . . C 4 NH 7 O 10 > r N H O 
 
 1 -VTTT / == ^4 -^2** 10^10 
 
 1 eq. ammonia . . . NH 3 $ 
 There remains the formula of cho- 
 loidic acid = C 72 H S6 O 12 (30) 
 
METAMORPHOSES OF BILE. 129 
 
 26. Again, if from the formula of choleic acid we 
 subtract the elements of urea and 2 atoms of water, 
 (=2 eq. carbonic acid and 2 eq. ammonia,) there will 
 remain the formula and composition of cholic acid. 
 Thus ; from the 
 
 Formula of choleic acid = C 76 N 2 H 66 O 22 
 
 subtract 
 
 2 eq. carbonic acid = C 2 O 4 > r- ivr u r 
 2 eq. ammonia = N 2 H 6 j = C N " 
 
 Remains the formula of cholic 
 acid = C 74 H 60 18 (31) 
 
 When we consider the very close coincidence be- 
 tween these formulae and the actual results of analysis 
 (see Appendix, 29, 30, 31), it is scarcely possible to 
 doubt, that the formula above adopted for choleic acid 
 expresses, as accurately as is to be expected in the 
 analysis of such compounds, the relative proportion of 
 its elements, no matter in how many different forms 
 they may be united to produce that acid. 
 
 27. Let us now add the half of the numbers which 
 represent the formula of choleic acid, to the elements 
 of the urine of serpents, that is, to neutral urate of 
 ammonia, as follows : 
 
 the formula of choleic acid . . . . = C 38 N H 33 O U 
 
 Add to this 
 
 1 eq. uric acid . . . = C 10 N 4 H 4 O 6 > p, N H n 
 
 1 eq. ammonia . . . = N H 3 5 ~ 
 
 The sum is = C 48 N 6 H 40 O 17 
 
 28. But this last formula expresses the composition 
 of blood, with the addition of 1 eq. oxygen and 1 eq. 
 water. 
 
130 RELATION OF BILE TO FIBRINE. 
 
 8 N 6H 39 O 1 
 HO 
 
 Formula of blood 
 
 1 eq. water ....... = HO ) 
 
 1 eq. oxygen ...... = O \ 
 
 The sum is = C 48 N 6 H 40 O 17 
 
 29. If, moreover, we add to the elements of pro- 
 teine those of 3 eq. water, we obtain, with the excep- 
 tion of 1 eq. hydrogen, exactly the same formula. 
 
 Formula of proteine = C 48 N 6 H 36 O 14 
 
 Add 3 eq. of water . . == H 3 O 3 
 
 The sum is C 48 N 6 H 39 O 17 
 
 differing only by 1 eq. of hydrogen from the formula 
 above obtained by adding together choleic acid and 
 urate of ammonia. 
 
 30. If, then, we consider choleic acid and urate 
 of ammonia the products of the transformation of mus- 
 cular fibre, since no other tissue in the body con- 
 tains proteine (for albumen passes into tissues, without 
 our being able to say, that in the vital process it is di- 
 rectly resolved into choleic acid, and urate of ammonia), 
 there exist in fibrine, with the addition of the elements 
 of water, all the elements essential to this metamor- 
 phosis ; and, except the sulphur and phosphorus, both 
 of which are probably oxidized, no element is separated. 
 
 This form of metamorphosis is applicable to the vital 
 transformations in the lower classes of amphibia, and 
 perhaps in worms and insects. In the higher classes 
 of animals the uric acid disappears in the urine, and is 
 replaced by urea. 
 
 The disappearance of uric acid and the production 
 of urea plainly stand in a very close relation to the 
 amount of oxygen absorbed in respiration, and to the 
 
OXIDATION OF URIC ACID. 131 
 
 quantity of water consumed by different animals in a 
 given time. 
 
 When uric acid is subjected to the action of oxygen, 
 it is first resolved, as is well known, into alloxan and 
 urea. (32) A new supply of oxygen acting on the 
 alloxan causes it to resolve itself either into oxalic acid 
 and urea, into oxaluric and parabanic acids, (33) or into 
 carbonic acid and urea. 
 
 31. In the so-called mulberry calculi we find oxa- 
 late of lime, in other calculi urate of ammonia, and 
 always in persons, in whom, from want of exercise 
 and labor, or from other causes, the supply of oxy- 
 gen has been diminished. Calculi containing uric 
 acid or oxalic acid are never found in phthisical 
 patients ; and it is a common occurrence in France, 
 among patients suffering from calculous complaints, 
 that when they go to the country, where they take 
 more exercise, the compounds of uric acid, which 
 were deposited in the bladder during their residence in 
 town, are succeeded by oxalates (mulberry calculus), 
 in consequence of the increased supply of oxygen. 
 With a still greater supply of oxygen they would have 
 yielded, in healthy subjects, only the last product of 
 the oxidation of uric acid, namely, carbonic acid and 
 urea. 
 
 An erroneous interpretation of the undeniable fact, 
 that all substances incapable of further use in the or- 
 ganism, are separated by the kidneys and expelled from 
 the body in the urine, altered or unaltered, has led 
 practical medical men to the idea, that the food, and 
 
132 UKIC ACID AND UREA DERIVED 
 
 especially nitrogenized food, may have a direct influence 
 on the formation of urinary calculi. There are no 
 reasons which support this opinion, while those opposed 
 to it are innumerable. It is possible that there may be 
 taken, in the food, a number of matters changed by the 
 culinary art, which, as being no longer adapted to the 
 formation of blood, are expelled in the urine, more or 
 less altered by the respiratory process. But roasting 
 and boiling alter in no way the composition of animal 
 food. (34) 
 
 Boiled and roasted flesh is converted at once into 
 blood ; while the uric acid and urea are derived from 
 the metamorphosed tissues. The quantity of these 
 products increases with the rapidity of transformation 
 in a given time, but bears no proportion to the amount 
 of food taken in the same period. In a starving man, 
 who is any way compelled to undergo severe and con- 
 tinued exertion, more urea is secreted than in the most 
 highly fed individual, if in a state of rest.. In fevers 
 and during rapid emaciation the urine contains more 
 urea than in the state of health. (PR OUT.) 
 
 32. In the same way, therefore, as the hippuric acid, 
 present in the urine of the horse when at rest, is con- 
 verted into benzoate of ammonia and carbonic acid as 
 soon as the animal is compelled to labor, so the uric 
 acid disappears in the urine of man, when he receives, 
 through the skin and lungs, a quantity of oxygen suffi- 
 cient to oxidize the products of the transformation of 
 the tissues. The use of wine and fat, which are only 
 
RELATION OF BLOOD TO URINE. 133 
 
 so far altered in the organism that they combine with 
 oxygen, has a marked influence on the formation of 
 uric acid. The urine, after fat food has been taken, 
 is turbid, and deposits minute crystals of uric acid. 
 (PROUT.) The same thing is observed after the use 
 of wines in which the alkali necessary to retain the uric 
 acid in solution is wanting, but never from the use of 
 Rhenish wines, which contain so much tartar. 
 
 In animals which drink much water, by means of 
 which the sparingly soluble uric acid is kept dissolved, 
 so that the inspired oxygen can act on it, no uric acid 
 is found in the urine, but only urea. In birds, which 
 seldom drink, uric acid predominates. 
 
 If to 1 atom of uric acid we add 6 atoms of oxygen 
 and 4 atoms of water, it resolves itself into urea and 
 carbonic acid : 
 
 1 at. uric acid C 10 N 4 H 4 O 6 1 
 
 4 at. water > }>= J 2 ' urea C 4 N 4 H 8 O 4 , 
 
 6 at. oxygen $ H 4 O 10 j t 6 at. carbonic acid C 6 Oi 2 
 
 C 10 N 4 H 8 16 C 10 N 4 H 8 16 
 
 33. The urine of the herbivora contains no uric acid, 
 but ammonia, urea, and hippuric or benzoic acid. By 
 the addition of 9 atoms of oxygen to the empirical for- 
 mula of their blood multiplied by 5, we obtain the ele- 
 ments of 6 at. of hippuric acid, 9 at. of urea, 3 at. of 
 choleic acid, 3 at. of water, and 3 at. of ammonia ; or, 
 if we suppose 45 atoms of oxygen to be added to the 
 blood during its metamorphosis, then we obtain 6 at. of 
 benzoic acid, 13| at. of urea, 3 at. of choleic acid, 15 
 at. of carbonic acid, and 12 at. of water. 
 
134 RELATION OF PROTEINE TO ALLANTOINE. 
 
 5 (G 48 N 6 H 39 15 ) + 3 = C 240 N 30 H 196 84 
 f 6 at. hippuric acid, 6 (C 18 N H 8 O 6 ) = C 108 N 6 H 48 O 30 
 
 9 at. urea, 9 (C 2 N 2 H 4 O 2 ) = C 18 N 18 H 36 O 18 
 
 = <( 3 at. choleic acid, 3 (C 38 N H 33 O n ) = C 114 N 3 H 99 O 33 
 
 3 at. ammonia, . . 3 ( N H 3 ) = N 3 H 9 
 t'$ at. water, .... 3 ( H O ) = H 3 O 3 
 
 The sum is C 240 N 30 H 196 O 84 
 
 or, 
 
 5 (C 48 N C H 39 1S ) + 46 = C 240 N 30 H 195 120 
 f 6 at. benzoic acid, 6 (C 14 H 5 O 3 ) = C 84 H 30 O 18 
 
 I 27 at. urea, 27 (C NH 2 O ) = C 27 N 27 H M O 27 
 
 = J 3 at. choleic acid, 3 (C 38 NH 33 O U ) = C 114 N 3 H 99 O 33 
 
 15 at. carbonic acid, 15 (C O 2 ) = C 15 O 30 
 
 L12 at. water, ... 12 ( H O )= H 12 O 12 
 
 34. Lastly, let us follow the metamorphosis of the 
 tissues in the foetal calf, considering the proteine furnish- 
 ed in the blood of the mother as the substance which 
 undergoes or has undergone a transformation ; it will 
 appear that 2 at. of proteine, without the addition of 
 oxygen or any other foreign element, except 2 at. of 
 water, contain the elements of 6 at. of allantoine and 1 
 at. of choloidic acid, (meconium ?) 
 
 2. at proteine=2 (C 48 N 6 H 36 O 14 )+2 at. water= 2 HO == C 96 N 12 H 74 O 30 
 _J 6 at. allantoine, 6 (C 4 N 2 H 3 O 3 ) = C 24 N 12 H 18 O 18 
 " \\ at. choloidic acid ( = C 72 H 56 O 12 
 
 C 96 N 12 H 74 30 
 
 35. But the elements of the six atoms of allantoine 
 in the last equation correspond exactly to the elements 
 of 2 at. of uric acid, 2 at. of urea, and 2 at. of water. 
 
 !2 at. uric acid C 20 N 8 H 8 O 12 
 2 at. urea .C 4 N 4 H 8 O 4 
 2 at. water H 2 O 2 
 
 C 24 N 12 H 18 O 18 
 The relations of allantoine, which is found in the 
 
RELATION OF PROTEINE TO GELATINE. 135 
 
 urine of the foetal calf, to the nitrogenized constituents 
 of the urine in animals which respire, are, as may be 
 seen by comparing the above formulae, such as cannot 
 be overlooked or doubted. Allantoine contains the 
 elements of uric acid and urea, that is, of the nitro- 
 genized products of the transformation of the com- 
 pounds of proteine. 
 
 36. Further, if to the formula of proteine, multiplied 
 by 3, we add the elements of 4 at. of water, and if we 
 deduct from the sum of all the elements half of the ele- 
 ments of choloidic acid, there remains a formula which 
 expresses very nearly the composition of gelatine. 
 From 
 
 3 (C 48 N 6 H 36 14 ) + 4 HO . . . = C 144 N 18 H 112 46 
 Subtract at. choloidic acid = C 36 H 28 O 6 
 
 There remain C 108 N 18 H 84 O 40 (35) 
 
 37. Subtracting from this formula of gelatine the 
 elements of 2 at. of proteine, there remain the elements 
 of urea, uric acid, and water, or of 3 at. of allantoine 
 and 3 at. of water. Thus, 
 
 Formula of gelatine (Mulder) C 108 N 18 H 84 O4o 
 Subtract 2 at. proteine .... C 96 N 12 H 72 O 28 
 There remain C 12 N 6 H 12 O 12 = 
 
 3 at. allantoine C 12 N 6 H 9 O 9 
 3 at. water . . H 3 O 3 
 
 !1 at. uric acid C 10 N 4 H 4 O 6 J f 
 1 at. urea . . C 2 N 2 H 4 O 2 > = < 
 4 at. water H 4 O 4 ) ( 
 
 C 12 N 6 H 12 12 C 12 N 6 H 12 12 
 
 38. The numerical proportions calculated from the 
 
 above formula differ from those actually obtained in the 
 
 analyses of MULDER and SCHERER in this, that the 
 
 latter indicate somewhat less of nitrogen in gelatine ; 
 
1 36 ORIGIN OF GELATINE. 
 
 but if we assume the formula to be correct, it then ap- 
 pears, from the statement just given, that the elements 
 of two atoms of proteine, plus the nitrogenized products 
 of the transformation of a third atom of proteine (uric 
 acid and urea) and water ; or three atoms of proteine, 
 minus the elements of a compound containing no nitro- 
 gen, which actually occurs as one of the products of 
 the transformation of choleic acid, yield in both cases a 
 formula closely approaching to the composition of gela- 
 tinous tissues. We must, however, attach to such for- 
 mulae, and to the considerations arising from them, no 
 more importance than justly belongs to them. I would 
 constantly remind the reader, that their use is to serve 
 as points of connexion, which may enable us to acquire 
 more accurate views as to the production and decompo- 
 sition of those compounds which form the animal tissues. 
 They are the first attempts to discover the path which 
 we must follow in order to attain the object of our re- 
 searches ; and this object, the goal we strive to reach, 
 is, and must be, attainable. 
 
 The experience of all those, who have occupied 
 themselves with researches into natural phenomena leads 
 to this general result, that these phenomena are caused, 
 or produced, by means far more simple than was previ- 
 ously supposed, or than we even now imagine ; and it is 
 precisely their simplicity, which should most powerfully 
 excite our wonder and admiration. 
 
 Gelatinous tissue is formed from blood, from com- 
 pounds of proteine. It may be produced by the addi- 
 tion, to the elements of proteine, of allantoine and 
 
ORIGIN OF THE BILE. 137 
 
 water, or of water, urea, and uric acid ; or by the sep- 
 aration from the elements of proteine of a compound 
 containing no nitrogen. The solution of such problems 
 becomes less difficult, when the problem to be solved, 
 the question to be answered, is matured and clearly put. 
 Every experimental decision of any such question in the 
 negative forms the starting-point of a new question, the 
 solution of which, when obtained, is the necessary con- 
 sequence of our having put the first question. 
 
 39. In the foregoing sections, no other constituent of 
 the bile, besides choleic acid, has been brought into the 
 calculation ; because it alone is known with certainty to 
 contain nitrogen. Now, if it be admitted that its nitro- 
 gen is derived from the metamorphosed tissues, it is not 
 improbable that the carbon, and other elements which 
 it contains, are derived from the same source. 
 
 There cannot be the smallest doubt, that in the carni- 
 vora, the constituents of the urine and the bile are de- 
 rived from the transformation of compounds of proteine ; 
 for, except fat, they consume no food but such as con- 
 tains proteine, or has been formed from that substance. 
 Their food is identical with their blood ; and it is a mat- 
 ter of indifference which of the two we select as the 
 starting-point of the chemical development of the vital 
 metamorphoses. 
 
 There can be no greater contradiction, with regard 
 to the nutritive process, than to suppose that the nitro- 
 gen of the food can pass into the urine as urea, without 
 having previously become part of an organized tissue ; 
 for albumen, the only constituent of blood, which, from 
 12* 
 
138 ORIGIN OF THE BILE. 
 
 its amount, ought to be taken into consideration, suffers 
 not the slightest change in passing through the liver or 
 kidneys ; we find it in every part of the body with the 
 same appearance and the same properties. These or- 
 gans cannot be adapted for the alteration or decomposi- 
 tion of the substance from which all the other organs of 
 the body are to be formed. 
 
 40. From the characters of chyle and lymph, it ap- 
 pears with certainty, that the soluble parts of the food or 
 of the chyme acquire the form of. albumen. Hard- 
 boiled white of egg, boiled or coagulated fibrine, which 
 have again become soluble in the stomach, but have lost 
 their coagulability by the action of air or heat, recover 
 these properties by degrees. In the chyle, the acid re- 
 action of the chyme has already passed into the weak 
 alkaline reaction of the blood ; and the chyle, when, 
 after passing through the mesenteric glands, it has 
 reached the thoracic duct, contains albumen coagulable 
 by heat ; and, when left to itself, deposits fibrine. All 
 the compounds of proteine, absorbed during the passage 
 of the chyme through the intestinal canal, take the form 
 of albumen, which, as the results of incubation in the 
 fowl's egg testify, contains the fundamental elements of 
 all organized tissues, with the exception of iron, which 
 is obtained from other sources. 
 
 Practical medicine has long ago answered the ques- 
 tion, what becomes in man of the compounds of prote- 
 ine taken in excess, what change is undergone by the 
 superabundant nitrogenized food ? The blood-vessels 
 are distended with excess of blood, the other vessels 
 
ORIGIN OF THE BILE. 139 
 
 with excess of their fluids, and if the too great supply 
 of food be kept up, and the blood, or other fluids 
 adapted for forming blood, be not applied to their natu- 
 ral purposes, if the soluble matters be not taken up by 
 the proper organs, various gases are disengaged, as in 
 processes of putrefaction, the excrements assume an al- 
 tered quality in color, smell, &c. Should the fluids in 
 the absorbent and lymphatic vessels undergo a similar 
 decomposition, this is immediately visible in the blood, 
 and the nutritive process then assumes new forms. 
 
 41. No one of all these appearances should occur, 
 if the liver and kidneys were capable of effecting the 
 resolution of the superabundant compounds of proteine 
 into urea, uric acid, and bile. All the observations 
 which have been made in reference to the influence of 
 nitrogenized food on the composition of the urine, have 
 failed entirely to demonstrate the existence of any direct 
 influence of the kind ; for the phenomena are suscepti- 
 ble of another and a far more simple interpretation, if, 
 along with the food, we consider the mode of life and 
 habits of the individuals who have been the subjects of 
 investigation. Gravel and calculus occur in persons 
 who use very little animal food. Concretions of uric 
 acid have never yet been observed in carnivorous mam- 
 malia, living in the wild state,* and among nations 
 which live entirely on flesh, deposits of uric acid con- 
 
 * The occurrence of urate of ammonia in a concretion found in a 
 dog, which was examined by Lassaigne, is to be doubted, unless 
 Lassaigne extracted it himself from the bladder of the animal. L. 
 
140 ORIGIN OF BILE 
 
 cretions in the limbs or in the bladder are utterly un- 
 known. 4 
 
 42. That which must be viewed as an undeniable 
 truth in regard to the origin of the bile, or, more ac- 
 curately speaking, of choleic acid in the carnivora, 
 cannot hold in regard to all the constituents of the bile 
 secreted by the liver in the herbivora, for with the 
 enormous quantity of bile produced, for example, by 
 the liver of an ox, it is absolutely impossible to sup- 
 pose, that all its carbon is derived from the metamor- 
 phosed tissues. 
 
 Assuming the 59 oz. of dry bile (from 37 Ibs. of 
 fresh bile secreted by an ox) to contain the same per- 
 centage of nitrogen as choleic acid (3-85 per cent.), 
 this would amount to nearly 2 oz. of nitrogen ; and 
 if this nitrogen proceed from metamorphosed tissues, 
 then, if all the carbon of these tissues passed into the 
 bile, it would yield, at the utmost, a quantity of bile 
 corresponding to 7'15oz. of carbon. This is, how- 
 ever, far below the quantity which, according to obser- 
 vation, is secreted in this class of animals. 
 
 43. Other substances, besides compounds of pro- 
 teine, must inevitably take part in the formation of bile 
 in the organism of the herbivora ; and these substances 
 can only be the non-nitrogenized constituents of their 
 food. 
 
 44. The sugar of bile of Gmelin (picromel or biline 
 of Berzelius), which Berzelius considers as the chief 
 constituent of bile, while Demargay assigns that place 
 essentially to choleic acid, burns, when heated in the 
 
IN THE HERBIVORA. 141 
 
 air, like resin, yields ammoniacal products, and, when 
 treated with acids, yields taurine and the products of 
 the decomposition of choleic acid ; when acted on by 
 alkalies, it yields ammonia and cholic acid. At all 
 events, the sugar of bile contains nitrogen, and much 
 less oxygen than starch or sugar, but more oxygen than 
 the oily acids. When, in the metamorphosis of sugar 
 of bile or choleic acid by alkalies, we cause the separ- 
 ation of the nitrogen, we obtain a crystallized acid, 
 very similar to the oily acids (cholic acid), and capa- 
 ble of forming with bases salts, which have the general 
 characters of soaps. Nay, we may even consider the 
 chief constituents of the bile, sugar of bile and choleic 
 acid, as compounds of oily acids with organic oxides, 
 like the fat oils, and only differing from these in con- 
 taining no oxide of glycerule. Choleic acid, for ex- 
 ample, may be viewed as a compound of choloidic acid 
 with allantoine and water : 
 
 Choloidic acid. Allantoine. Water. Choleic acid. 
 C 72 H 66 12 + C 4 N 2 H 3 3 + H 7 7 = C 76 N 2 H 66 22 
 
 Or, as a compound of cholic acid, urea, and water : 
 
 Cholic acid. Urea. Water. Choleic acid. 
 
 C 74 H 60 18 -f C 2 N 2 H 4 2 4- Ho0 2 = C 76 N 2 H 66 22 
 
 45. If, in point of fact, as can hardly be doubted, 
 the elements of such substances as starch, sugar, &c., 
 take part in the production of bile in the organism 
 of the herbivora, there is nothing opposed to such a 
 view in the composition of the chief constituents of bile, 
 as far as our knowledge at present extends. 
 
 If starch be the chief agent in this process, it can 
 
142 FORMATION OF BILE IN HERBIVORA. 
 
 happen in no other way but this, that, as when it 
 passes into fat, a certain quantity of oxygen is separated 
 from the elements of the starch, which, for the same 
 amount of carbon (for 72 atoms), contains five times 
 as much oxygen as choloidic acid. 
 
 Without the separation of oxygen from the elements 
 of starch, it is impossible to conceive its conversion 
 into bile ; and this separation being admitted, its con- 
 version into a compound, intermediate in composition 
 between starch and fat, offers no difficulty. 
 
 46. Not to render^ these considerations a mere idle 
 play with formulae, and not to lose sight of our chief 
 object, we observe, therefore, that the consideration of 
 the quantitative proportion of the bile secreted in the 
 herbivora leads to the following conclusions : 
 
 The chief constituents of the bile of the herbivora 
 contain nitrogen, and this nitrogen is derived from com- 
 pounds of proteine. 
 
 The bile of this class of animals contains more car- 
 bon than corresponds to the quantity of nitrogenized 
 food taken, or to the portion of tissue, that has under- 
 gone metamorphosis in the vital process. 
 
 A part of this carbon must, therefore, be derived 
 from the non-nitrogenized parts of the food (starch, 
 sugar, &c.) ; and in order to be converted into a ni- 
 trogenized constituent of bile, a part of the elements 
 of these bodies must necessarily have combined with 
 a nitrogenized compound derived from a compound of 
 proteine. 
 
 In reference to this conclusion, it is quite indifferent 
 
PRODUCTION OF HIPPURIC ACID. 143 
 
 whether that compound of proteine be derived from 
 the food or from the tissues of the body. 
 
 47. It has very lately been stated by A. Ure, that 
 benzoic acid, when administered internally, appears in 
 the urine in the form of hippuric acid. 
 
 Should this observation be confirmed,* it will ac- 
 quire great physiological significance, since it would 
 plainly prove, that the act of transformation of the tis- 
 sues in the animal body, under the influence of certain 
 matters taken in the food, assumes a new form with re- 
 spect to the products which are its result ; for hippuric 
 acid contains the elements of lactate of urea, with the 
 addition of those of benzoic acid : 
 
 1 at. urea . . . . C 2 N 2 H 4 O 2 \ ( 
 
 \ 2 at crystallized hippuric acid 
 
 1 at. lactic acid . C 6 H 4 O v = } 
 
 2 at. benzoic acid COR H 1A ( 
 
 C 36 N 2 H 18 O 12 
 
 48. If we consider the act of transformation of the 
 tissues in the herbivora, as we have done in the car- 
 nivora, then the blood of the former must yield, as 
 the last products of the metamorphosis, from all the 
 organs taken together, choleic acid, uric acid, and am- 
 monia (see p. 129) ; and, if we ascribe to the uric acid 
 an action similar to that of the benzoic acid in Ure's 
 observation, such, namely, that the further transfor- 
 mation, owing to the presence of this acid, assumes 
 another form, the elements of the uric acid being incor- 
 
 * The analysis of the crystals deposited from the urine on the ad- 
 dition of muriatic acid has not been performed. Besides, the state- 
 ment of A. Ure, that hippuric acid, dissolved in nitric acid, is red- 
 dened by ammonia, is erroneous, and shows, that the crystals he ob- 
 tained must have contained uric acid. L. 
 
144 HIPPURIC ACID. 
 
 porated in the final products, it will appear, for exam- 
 ple, that 2 at. of proteine, with the addition of the ele- 
 ments of 3 at. of uric acid and 2 at. of oxygen, might 
 give rise to the production of hippuric acid and urea. 
 
 2 at. proteine, 2 (C 48 N 6 H 36 O 14 ) = C 96 N 12 H 72 O 28 
 
 3 at. uric acid, 3 (C 10 N 4 H 4 O 6 ) = C 30 N 13 H 12 O 18 
 2 at. oxygen = O 2 
 
 The sum is = C 126 N 24 H 84 O 48 = 
 
 _ C 6 at. hippuric acid, 6 (C 18 N H 8 O 6 ) = C 108 N 6 H 48 O 30 
 ~\ 9 at. urea 9 (C 2 N 2 H 4 O 2 ) = C 18 N 18 H 36 O 18 
 
 The sum is C 126 N 24 H 84 O 48 
 
 49. Finally, if we bear in mind, that, in the herbi- 
 vora, the non-nitrogenized constituents of their food 
 (starch, &c.) must, as we have shown, play an essential 
 part in the formation of the bile ; that to their elements 
 must of necessity be added those of a nitrogenized 
 compound, in order to produce the nitrogenized constit- 
 uents of the bile, the most striking result of the combi- 
 nations thus suggested is this, that the elements of starch 
 added to those of hippuric acid are equal to the ele- 
 ments of choleic acid, plus a certain quantity of car- 
 bonic acid : 
 
 2 at. hippuric acid, 2 (C 18 NH 8 O 6 ) = C 36 N 2 H 16 O 10 
 5 at. starch, . . . 5 (C 12 H 10 O 10 ) = C 60 H 60 O 60 
 2 at. oxygen, ... = O 2 
 
 The sum is = C 96 N 2 H 66 O 62 
 
 _J 2 at. choleic acid, 2 (C 38 NH 33 O n ) = C 76 N 2 H 66 O 22 
 ~~ \ 20 at. carbonic acid, 20 ( C O 2 ) = C 20 O 40 
 
 The sum is = C 96 N 2 H 66 O 62 
 
 50. Now, since hippuric acid may be derived, along 
 with urea, from the compounds of proteine, when to the 
 elements of the latter are added those of uric acid 
 (see above) ; since, further, uric acid, choleic acid, 
 
CHOLEIC ACID, AMMONIA, &c. 145 
 
 and ammonia contain the elements of proteine in a pro- 
 portion almost identical with that of proteine itself, (see 
 p. 129) ; it is obvious that, if from 5 at. of proteine, 
 with the addition of oxygen and of the elements of 
 water, there be removed the elements of choleic acid and 
 ammonia, the remainder will represent the elements of 
 hippuric acid and of urea ; and that if, when this separa- 
 tion occurs, and during the further transformation, the 
 elements of starch be present and enter into the new 
 products, we shall obtain an additional quantity of choleic 
 acid, as well as a certain amount of carbonic acid gas. 
 
 That is to say, that if the elements of proteine and 
 starch, oxygen and water being also present, undergo 
 transformation together and mutually affect each other, 
 we obtain, as the products of this metamorphosis, urea, 
 choleic acid, ammonia, and carbonic acid, and besides 
 these, no other product whatever. 
 
 The elements of 
 
 5 at. proteine ") f 9 at. choleic acid 
 15 at. starch II 9 at. urea 
 12 at. water i j 3 at. ammonia 
 
 5 at. oxygen J 1.60 at. carbonic acid 
 In detail, 
 
 5 at. proteine, 5 (C 48 N 6 H 36 O 14 ) = C 240 N 30 H 180 O 70 
 
 15 at. starch, 15 (C 12 H 10 O 10 ) = C 180 H 150 O 150 
 
 12 at. water, 12 ( HO ) = H 12 O 12 
 
 5 at. oxygen, = O 6 
 
 The sum is ......... = C 4 2oN 30 H 3 4 2 O23 7 
 
 and, 
 
 9 at. choleic acid, 9 (C 38 N H 33 O n ) = C 342 N 9 H 29r O 99 
 9 at. urea, . . . . 9 (C 2 N 2 H 4 O 2 ) = C 18 N 18 H 36 O 18 
 
 3 at ammonia, . . 3 ( N H 3 ) = N 3 H 9 
 60 at carbonic acid, 60 (C O 2 ) = C 60 O 120 
 
 The sum is 
 
 13 
 
146 SODA ESSENTIAL TO THE 
 
 The transformation of the compounds of proteine 
 present in the body is effected by means of the oxygen 
 conveyed by the arterial blood, and if the elements of 
 starch, rendered soluble in the stomach, and thus carried 
 to every part, enter into the newly formed compounds, 
 we have the chief constituents of the animal secretions 
 and excretions ; carbonic acid, the excretion of the 
 lungs, urea and carbonate of ammonia, excreted by the 
 kidneys, and choleic acid, secreted by the liver. 
 
 Nothing, therefore, in the chemical composition of 
 those matters, which may be supposed to take a share in 
 these metamorphoses, is opposed to the supposition, that 
 a part of the carbon of the non-azotized food enters into 
 the composition of the bile. 
 
 51. Fat, in the animal body, disappears when the 
 supply of oxygen is abundant. When that supply is 
 deficient, choleic acid may be converted into hippuric 
 acid, lithofellic acid, (37) and water. Lithofellic acid is 
 known to be the chief constituent of the bezoar stones, 
 which occur in certain herbivorous animals : 
 
 2 at. choleic acid CN.,HO ) ( 2 at hi P- acid C 36 N 2H 16 O 10 
 
 2 at. choleic acid C 76 N.,H 66 O 22 ) _ ( 2 at hi P- acid 
 
 10 at. oxygen . O lrt S ) l at lith ' acid C 
 
 _ _ ( 14 at. water . . 
 
 C 76 N 2 H 66 32 C 76 N 2 H 66 32 
 
 52. For the production of bile in the animal body a 
 certain quantity of soda is, in all circumstances, neces- 
 sary ; without the presence of a compound of sodium 
 no bile can be formed. In the absence of soda, the 
 metamorphosis of the tissues composed of proteine can 
 yield only fat and urea. If we suppose fat to be com- 
 
FORMATION OF THE BILE. 147 
 
 posed according to the empirical formula C n H 10 O, 
 then, by the addition of oxygen and the elements of 
 water to the elements of proteine, we have the elements 
 of fat, urea, and carbonic acid. 
 
 Proteine. Water. Oxygen. 
 
 2 (C 48 N 6 H 36 14 ) + 12 HO + 14 O = C 96 N 12 H M O M = 
 t 6 at. urea ....== C 12 N 12 H 24 O 12 
 
 = < Fat = C 66 H 60 6 
 
 ( 18 at. carbonic acid = C 18 O 36 
 
 C 96 N 12 H 84 O 64 
 
 The composition of all fats lies between the empirical 
 formulae C U H 10 O and C 12 H 10 O. If we adopt the lat- 
 ter, then the elements of 2 at. proteine, with the ad- 
 dition of 2 at. oxygen and 12 at. water, will yield 6 at. 
 urea, fat (C 72 H 60 O 6 ), and 12 at. carbonic acid. 
 
 It is worthy of observation, in reference to the pro- 
 duction of fat, that the absence of common salt (a 
 compound of sodium, which furnishes soda to the ani- 
 mal organism) is favorable to the formation of fat ; 
 that the fattening of an animal is rendered impossible, 
 when we add to its food an excess of salt, although 
 short of the quantity required to produce a purgative 
 effect. 
 
 53. As a kind of general view of the metamorphoses 
 of the nitrogenized animal secretions, attention may 
 here be very properly directed to the fact, that the 
 nitrogenized products of the transformation of the bile 
 are identical in ultimate composition with the constitu- 
 ents of the urine, if to the latter be added a certain 
 proportion of the elements of water. 
 
148 RELATION OF URINE TO BILE. 
 
 1 at. uric acid . C 10 N 4 H 4 O 6 j taurine 
 
 1 at. urea . . . C 2 N 2 H 4 O 2 = \ ^^ ' 
 22 at. water . . . H, 2 O 22 ) 
 
 C 12 N 6 H 30 30 C 12 N 6 H 30 30 
 
 1 at. allantoine C 4 N 2 H 3 O 3 > C 1 at. taurine C 4 N H 7 O 10 
 
 7 at. water . H 7 O 7 $ (1 at. ammonia N H 3 
 
 C 4 N 2 H 10 10 C 4 N 2 H 10 10 
 
 54. In reference to the metamorphoses of uric acid 
 and of the products of the transformation of the bile, 
 it is not less significant, and worthy of remark, that the 
 addition of oxygen and the elements of water to the 
 elements of uric acid may yield either taurine and urea, 
 or taurine, carbonic acid, and ammonia. 
 
 1 at. uric acid C 10 N 4 H 4 O 6 ) 
 
 i \ ^ at. taurine . . O 8 1> 2 H 14 U 20 
 
 14 at. water . . li 4 U 14 > \ ., _. ., TT _. 
 
 * ( ( 1 at. urea . . . C 2 N 2 H 4 O 2 
 
 2 at. oxygen . O 2 ) 
 
 C 10 N 4 H 18 22 - C 10 N 4 H 18 22 
 
 J 2 at. taurine . . C 8 N 2 H 14 O 20 
 \ 2 at. carbon, acid C 2 O 4 
 
 Add 2 at. water H 2 O 2 J '2 at. ammonia . N 2 H 6 
 
 C 10 N 4 H 20 O 24 C 10 N 4 H 20 O 24 
 
 55. Alloxan, plus a certain amount of water, is iden- 
 tical in the proportion of elements with taurine ; and, 
 finally, taurine contains the elements of superoxalate 
 of ammonia. 
 
 H 4 O 10 1 ^ 
 
 H 10 O 10 5 : = 2 (C 4 NH 7 O 10 ) 
 
 1 at. alloxan* C 8 N 2 H 4 O 10 
 10 at. water ... 
 
 !2 at. oxalic acid C 4 O 6 
 1 at. ammonia NH 3 
 4 at. water . . H 4 O 4 
 
 C 4 NH 7 10 
 
 * It would be most interesting to investigate the action of alloxan 
 
RELATION OF STARCH TO BILE. 149 
 
 56. The comparison of the amount of carbon in the 
 bile secreted by an herbivorous animal, with the quan- 
 tity of carbon of its tissues, or of the nitrogenized con- 
 stituents of its food, which, in consequence of the con- 
 stant transformations, may pass into bile, indicates, as 
 we have just seen, a great difference. 
 
 The carbon of the bile secreted amounts, at least, 
 to more than five times the quantity of that which could 
 reach the liver in consequence of the change of matter 
 in the body, either from the metamorphosed tissues or 
 from the nitrogenized constituents of the food ; and we 
 may regard as well founded the supposition, that the 
 non-azotized constituents of the food take a decided 
 share in the production of bile in the herbivora ; for 
 neither experience nor observation contradicts this 
 opinion. 
 
 57. We have given, in the foregoing paragraphs, 
 the analytical proof, that the nitrogenized products of 
 the transformation of bile, namely, taurine and ammo- 
 nia, may be formed from all the constituents of the 
 urine, with the exception of urea, that is, from hip- 
 puric acid, uric acid, and allantoine ; and when we 
 bear in mind that, by the mere separation of oxygen 
 and the elements of water, choloidic acid may be 
 formed from starch ; 
 
 on the human body. Two or three drachms, in crystals, had no 
 injurious action on rabbits to which it was given. In man, a large 
 dose appeared to act only on the kidneys. In certain diseases 
 of the liver, alloxan would very probably be found a most powerful 
 remedy. J. L. 
 
150 RELATION OF STARCH, &c. TO BILK 
 
 From 6 at. starch = 6 (C 12 H 10 O 10 ) = C 72 U K) O 60 
 Subtract 44 at. oxygen i _ HO 
 
 4 at. water \ 
 
 Remains choloidic acid = C 72 H 66 O 12 ; 
 
 that, finally, choloidic acid, ammonia, and taurine, if 
 added together, contain the elements of choleic acid ; 
 
 ] at. choloidic acid = C 72 H S6 O 12 
 1 at. taurine . . -. = C 4 N H 7 O 10 
 1 at. ammonia . . = N H 3 
 
 1 at. choleic acid . = C 76 N 2 H 66 O 22 ; 
 
 if all this be considered, every doubt as to the possi- 
 bility of these changes is removed. 
 
 58. Chemical analysis and the study of the living 
 animal body mutually support each other ; and both 
 lead to the conclusion, that a certain portion of the 
 carbon of the non-azotized constituents of food (of 
 starch, &c., the elements of respiration) is secreted by 
 the liver in the form of bile ; and further, that the 
 nitrogenized products of the transformation of tissues in 
 the herbivora do not, as in the carnivora, reach the 
 kidneys immediately or directly, but that, before their 
 expulsion from the body in the form of urine, they take 
 a share in certain other processes, especially in the 
 formation of the bile. 
 
 They are conveyed to the liver with the non-azotized 
 constituents of the food ; they are returned to the cir- 
 culation in the form of bile, and are not expelled by the 
 kidneys till they have thus served for the production 
 of the most important of the substances employed in 
 respiration. 
 
 59. When the urine is left to itself, the urea which 
 
ORIGIN OF THE BILE. 151 
 
 it contains is converted into carbonate of ammonia ; 
 the elements of urea are in such proportion, that by the 
 addition of the elements of water, all its carbon is con- 
 verted into carbonic acid, and all its nitrogen into am- 
 monia. 
 
 1 at. urea C 2 N 2 H 4 O 2 > _ J 2 at. carbonic acid C 2 O 4 
 
 2 at. water H 2 O 3 $ ~~ \ 2 at. ammonia . . . N 2 H 6 
 
 C 2 N. t H 6 O 4 C 2 N 2 H 6 O 4 
 
 60. Were we able directly to produce taurine and 
 ammonia out of uric acid or allantoine, this might per- 
 haps 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, we 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- 
 existence.of taurine and ammonia in the bile ; nay, that 
 it is not even probable, that these compounds, which 
 are only known to us as 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 reagent ; and when, instead of the acid, we use 
 potash, we obtain the same elements, although arranged 
 in another, and quite a different manner. If taurine were 
 present, ready formed, in bile, we should obtain the 
 
152 ORIGIN OF THE BILE. 
 
 same products by the action of acids and of alkalies. 
 This, however, is contrary to experience. 
 
 Thus, even if we could convert allantoine, or uric 
 acid and urea, into taurine and ammonia, out of the 
 body, we should acquire no additional insight into the 
 true theory of the formation of bile, just because the 
 preexistence of ammonia and taurine in the bile must 
 be doubted, and because we have no reason to believe 
 that urea or allantoine, as such, are employed by the 
 organism in the production of bile. We can prove that 
 their elements serve this purpose, but we are utterly 
 ignorant how these elements enter into these combina- 
 tions, or what is the chemical character of the nitro- 
 genized compound which unites with the elements of 
 starch to form bile, or rather choleic acid. 
 
 61. Choleic acid may be formed from the elements 
 of starch with those of uric acid and urea, or of allan- 
 toine, or of uric acid, or of alloxan, or of oxalic acid 
 and ammonia, or of hippuric acid. The possibility of 
 its being produced from so great a variety of nitrogen- 
 ized compounds is sufficient to show, that all the nitro- 
 genized products of the metamorphosis of the tissues 
 may be employed in the formation of bile, while we 
 cannot tell in what precise way they are so employed. 
 
 By the action of caustic alkalies allantoine may 
 be resolved into oxalic acid and ammonia ; the same 
 products are obtained when oxamide is acted on by the 
 same reagents. Yet we cannot, from the similarity of 
 the products, conclude that these two compounds have 
 a similar constitution. In like manner the nature of 
 
VITAL METAMORPHOSES. 153 
 
 the products formed by the action of acids on choleic 
 acid does not entitle us to draw any conclusion as to 
 the form in which its elements are united together. 
 
 62. 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 a third ; but we 
 cannot expect from it the synthetic proof of the accuracy 
 of the views entertained, because every thing in the 
 organism goes on under the influence of the vital force, 
 an immaterial agency, which the chemist cannot employ 
 
 at will. 
 
 The study of the phenomena which accompany the 
 metamorphoses of the food in the organism, the dis- 
 covery of the share which the atmosphere or the ele- 
 ments of water take in these changes, lead at once to 
 the conditions which must be united in order to the 
 production of a secretion or of an organized part. 
 
 63. The presence of free muriatic acid in the stom- 
 ach, and that of soda in- the blood, prove beyond all 
 doubt the necessity of common salt for the organic pro- 
 cesses ; but the quantities of soda required by animals 
 of different classes, to support the vital processes, are 
 singularly unequal. 
 
 If we suppose, that a given amount of blood, con- 
 sidered as a compound of soda, passes, in the body of 
 a carnivorous animal, in consequence of the change of 
 
154 USES OF COMMON SALT. 
 
 matter, into a new compound of soda, namely, the 
 bile, we must assume, that in the normal condition of 
 health, the proportion of soda in the blood is amply 
 sufficient to form bile with the products of transforma- 
 tion. The soda which has been used in the vital pro- 
 cesses, and any excess of soda, must be expelled in 
 the form of a salt, after being separated from the blood 
 by the kidneys. 
 
 Now, if it be true, that, in the body of an herbivo- 
 rous animal, a much larger quantity of bile is produced 
 than corresponds to the amount of blood formed or 
 transformed in the vital processes ; if the greater part 
 of the bile, in this case, proceeds from the non-azotized 
 constituents of the food, then the soda of the blood 
 which has been formed into organized tissue (assimilated 
 or metamorphosed) cannot possibly suffice for the sup- 
 ply of the daily secretion of bile. The soda, therefore, 
 of the bile of the herbivora must be supplied directly 
 in the food ; their organism must possess the power of 
 applying directly to the formation of bile all the com- 
 pounds of soda present in the food, and decomposable 
 by the organic process. All the soda of the animal 
 body obviously proceeds from the food ; but the food 
 of the carnivora contains, at most, only the amount of 
 soda necessary to the formation of blood ; and in most 
 cases, among animals of this class, we may assume that 
 only as much soda as corresponds to the proportion 
 employed to form the blood, is expelled in the urine. 
 
 When the carnivora obtain in their food as much 
 soda as suffices for the production of their blood, an 
 
USES OF SALT. 155 
 
 equal amount is excreted in the urine ; when the food 
 contains less, a part of that which would otherwise be 
 excreted, is retained by the organism. 
 
 All these statements are most unequivocally confirmed 
 by the composition of the urine in these different classes 
 of animals. 
 
 64. As the ultimate product of the changes of all 
 compounds of soda in the animal body, we find in the 
 urine the soda in the form of a salt, and the nitrogen in 
 that of ammonia or urea. 
 
 The soda in the urine of the carnivora is found in 
 combination with sulphuric and phosphoric acids ; and 
 along with the sulphate and phosphate of soda we never 
 fail to find a certain quantity of a salt of ammonia, either 
 muriate or phosphate of ammonia. There can be no 
 more decisive evidence in favor of the opinion, that the 
 soda of their bile, or of the metamorphosed constituents 
 of their blood is very far from sufficing to neutralize the 
 acids which are separated, than the presence of am- 
 monia in their urine. This urine, moreover, has an 
 acid reaction. 
 
 In contradistinction to this, we find, in the urine of 
 the herbivora, soda in predominating quantity ; and that 
 not combined with sulphuric or phosphoric acids, but 
 with carbonic, benzoic, or hippuric acids. 
 
 65. These well-established facts demonstrate, that 
 the herbivora consume a far larger quantity of soda than 
 is required merely for the supply of the daily consump- 
 tion of blood. In their food are united all the condi- 
 tions for the production of a second compound of soda, 
 
156 LAKGE AMOUNT OF ALKALIES 
 
 destined for the support of the respiratory process ; and 
 it can only be a very limited knowledge of the vast 
 wisdom displayed in the arrangements of organized 
 nature, which can look on the presence of so much 
 soda in the food and in the urine of the herbivora as 
 accidental. 
 
 It cannot be accidental, that the life, the develop- 
 ment of a plant is dependent on the presence of the 
 alkalies which it extracts from the soil. This plant 
 serves as food to an extensive class of animals, and in 
 these animals the vital process is again most closely 
 connected with the presence of these alkalies. We 
 find the alkalies in the bile, and their presence in the 
 animal body is the indispensable condition for the pro- 
 duction of the first food of the young animal ; for with- 
 out an abundant supply of potash, the production of 
 milk becomes impossible. 
 
 66. All observation leads, as appears from the pre- 
 ceding exposition, to the opinion, that certain non- 
 azotized constituents of the food of the herbivora 
 (starch, sugar, gum, &c.) acquire the form of a com- 
 pound of soda, which, in their bodies, serves for the 
 same purpose as that which we know certainly to be 
 served by the bile (the most highly carbonized product 
 of the transformation of their tissues) in the bodies of 
 the carnivora. These substances are employed to sup- 
 port certain vital actions, and are finally consumed in 
 the generation of animal heat, and in furnishing means 
 of resistance to the action of the atmosphere. In the 
 carnivora, the rapid transformation of their tissues is a 
 
REQUIRED BY HERBIVORA. 157 
 
 condition of their existence, because it is only as the 
 result of the change of matter in the body, that those 
 substances can be formed, which are destined to enter 
 into combination with the oxygen of the air ; and in 
 this sense we may say, that the non-azotized constituents 
 of the food of the herbivora impede the change of mat- 
 ter, or retard it, and render unnecessary, at all events, 
 so rapid a process as occurs in the carnivora. 
 
 67. The quantity of azotized matter, 'proportionally 
 so small, which the herbivora require to support their 
 vital functions, is closely connected with the power 
 possessed by the non-azotized parts of their food to act 
 as means of supporting the respiratory process ; and 
 this consideration seems to render it not improbable, 
 that the necessity for more complex organs of digestion 
 in the herbivora is rather owing to the difficulty of ren- 
 dering soluble and available for the vital processes cer- 
 tain non-azotized compounds (gum ? amylaceous fibre ?)' 
 than to any thing in the change or transformation of 
 vegetable fibrine, albumen, and caseine into blood ; 
 since, for this latter purpose, the less complex digestive 
 apparatus of the carnivora is amply sufficient. 
 
 68. If, in man, when fed on a mixed diet, starch 
 perform a similar part to that which it plays in the body 
 of the herbivora ; if it be assumed, that the elements of 
 starch are equally necessary to the formation of the bile 
 in man as in these animals ; then it follows, that a part 
 of the azotized products of the transformation of the 
 tissues in the human body, before they are expelled 
 through the bladder, returns into the circulation from 
 
 14 
 
158 STARCH, &c., ASSIST IN FORMING 
 
 the liver in the shape of bile, and is separated by the 
 kidneys from the blood, as the ultimate product of the 
 respiratory process. 
 
 69. When there is a deficiency of non-azotized mat- 
 ter in the food of man, this form of the production of 
 bile is rendered impossible. In that case, the secre- 
 tions must possess a different composition ; and the 
 appearance of uric acid in the urine, the deposition of 
 uric acid in the joints and in the bladder, as well as 
 the influence which an excess of animal food (which 
 must be considered equivalent to a deficiency of starch, 
 &c.) exercises on the separation of uric acid in certain 
 individuals, may be explained on this principle. If 
 starch, sugar, &c., be deficient, then a part of the azo- 
 tized compounds, formed during the change of matter, 
 will either remain in the situation where they have been 
 formed, in which case they will not be sent from the 
 liver into the circulation, and therefore will not undergo 
 the final changes dependent on the action of oxygen ; 
 or they will be separated by the kidneys in some form 
 different from the normal one. 
 
 70. In the preceding paragraphs I have endeavored 
 to prove, that the non-azotized constituents of food ex- 
 ercise a most decided influence on the nature and quality 
 of the animal secretions. Whether this occurs directly ; 
 whether, that is to say, their elements take an immedi- 
 ate share in the act of transformation of tissues ; or 
 whether their share in that process be an indirect one, is 
 a question probably capable of being resolved by care- 
 ful and cautious experiment and observation. It is 
 
BILE IN THE HUMAN BODY. 159 
 
 possible, that the non-azotized constituents of food, 
 after undergoing some change, are carried from the in- 
 testinal canal directly to the liver, and that they are 
 converted into bile in this organ, where they meet with 
 the products of the metamorphosed tissues, and subse- 
 quently complete their course ^through the circulation. 
 
 This opinion appears more probable, when we reflect, 
 that as yet no trace of starch or sugar has been detected 
 in arterial blood, not even in animals which had been 
 fed exclusively with these substances. We cannot as- 
 cribe to these substances, since they are wanting in 
 arterial blood, any share in the nutritive process ; and 
 the occurrence of sugar in the urine of those affected 
 with diabetes mellitus, (which sugar, according to the 
 best observations, is derived from the food,) coupled 
 with its total absence in the blood of the same patients, 
 obviously proves that starch and sugar are not, as such, 
 taken into the circulation. 
 
 71. The writings of physiologists contain many 
 proofs of the presence of certain constituents of the 
 bile in the blood of man in a state of health, although 
 their quantity can hardly be determined. Indeed, if we 
 suppose 8|lbs. (58,000 grs.) of blood to pass through 
 the liver every minute, and if from this quantity of blood 
 2 drops of bile (3 grains to the drop) are secreted, this 
 would amount to ^th part of the weight of the blood, 
 a proportion far too small to be quantitatively ascer- 
 tained by analysis. 
 
 72. The greater part of the bile in the body of the 
 herbivora, and in that of man fed on mixed food, ap- 
 
160 ORIGIN OF THE NITROGEN. 
 
 pears from the preceding considerations to be derived 
 from the elements of the non-azotized food. But its 
 formation is impossible without the addition of an azo- 
 tized body, for the bile is a compound of nitrogen. All 
 varieties of bile yet examined yield, when subjected to 
 dry distillation, ammonia and other nitrogenized pro- 
 ducts. Taurine and ammonia may easily be extracted 
 from ox bile ; and the only reason why we cannot posi- 
 tively prove that the same products may be obtained 
 from the bile of other animals is this, that it is not easy 
 to procure, in the case of many of these animals, a 
 sufficient quantity of bile for the experiment. 
 
 Now, whether the nitrogenized compound which 
 unites with the elements of starch to form bile be de- 
 rived from the food, or from the substance of the meta- 
 morphosed tissues, the conclusion, that its presence is 
 an essential condition for the secretion of bile, cannot 
 be considered doubtful. 
 
 Since the herbivora obtain in their food only such 
 nitrogenized compounds as are identical in composition 
 with the constituents of their blood, it is at all events 
 clear, that the nitrogenized compound which enters into 
 the composition of the bile, is derived from a compound 
 of proteine. It is either formed in consequence of a 
 change which the compounds of proteine in the food 
 have undergone, or it is produced from the blood, or 
 from the substance of the tissues, by the act of their 
 metamorphosis. 
 
 73. If the conclusion be accurate, that nitrogenized 
 compounds, whether derived from the blood or from 
 
MEDICINAL AND POISONOUS SUBSTANCES. 161 
 
 the food, take a decided share in the formation of the 
 secretions, and particularly of the bile, then it is plain, 
 that the organism must possess the power of causing 
 foreign matters, which are neither parts nor constituents 
 of the organs in which vital activity resides, to serve 
 for certain vital processes. All nitrogenized substances 
 capable of being rendered soluble, without exception, 
 when introduced into the organs of circulation or of di- 
 gestion, must, if their composition be adapted for such 
 purposes, be employed by the organism in the same 
 manner as the nitrogenized products which are formed 
 in the act of metamorphosis of tissues. 
 
 We are acquainted with a multitude of substances, 
 which exercise a most marked influence on the act of 
 transformation, as well as on the nutritive process, 
 while their elements take no share in the resulting 
 changes. These are uniformly substances, the particles 
 of which are in a certain state of motion or of decompo- 
 sition, which state is communicated to all such parts of 
 the organism as are capable of undergoing a similar 
 transformation. 
 
 74. Medicinal and poisonous substances form a sec- 
 ond and most extensive class of compounds, the ele- 
 ments of which are capable of taking a direct or an 
 indirect share in the processes of secretion and of 
 transformation. These may be subdivided into three 
 great orders ; the first (which includes the metallic 
 poisons) consists of substances which enter into chemi- 
 cal combination with certain parts or constituents of 
 the body, while the vital force is insufficient to destroy 
 14* 
 
162 JMEDICINAL AND POISONOUS SUBSTANCES. 
 
 the compounds thus formed. The second division, 
 consisting of the essential oils, camphor, empyreumatic 
 substances, and antiseptics, &c., possesses the property 
 of impeding or retarding those kinds of transformation 
 to which certain very complex organic molecules are 
 liable ; transformations which, when they take place 
 out of the body, are usually designated by the names 
 of fermentation and putrefaction. 
 
 The third division of medicinal substances is composed 
 of bodies, the elements of which take a direct share in 
 the changes going on in the animal body. When intro- 
 duced into the system, they augment the energy of the 
 vital activity of one or more organs ; they excite mor- 
 bid phenomena in the healthy body. All of them pro- 
 duce a marked effect in a comparatively small dose, and 
 many are poisonous when administered in larger quan- 
 tity. None of the substances in this class can be said to 
 take a decided share in the nutritive process, or to be 
 employed by the organism in the production of blood ; 
 partly, because their composition is different from that 
 of blood, and, partly, because the proportion in which 
 they must be given, to exert their influence, is as noth- 
 ing, compared with the mass of the blood. 
 
 These substances, when taken into the circulation, 
 alter, as is commonly said, the quality of the blood, and 
 in order that they may pass from the stomach into the 
 circulation with their entire efficacy, we must assume 
 that their composition is not affected by the organic in- 
 fluence of the stomach. If insoluble when given, they 
 are rendered soluble in that organ, but they are not de- 
 
ACTION OF ARTERIAL BLOOD. 163 
 
 composed ; otherwise, they would be incapable of ex- 
 erting any influence on the blood. 
 
 , 75. The blood, in its normal state, possesses two 
 qualities closely related to each other, although we may 
 conceive one of them to be quite independent of the 
 other. 
 
 The blood contains, in the form of the globules, the 
 carriers, as it were, of the oxygen which serves for the 
 production of certain tissues, as well as for the genera- 
 tion of animal heat. The globules of the blood, by 
 means of the property they possess of giving off the 
 oxygen they have taken up in the lungs, without losing 
 their peculiar character, determine generally the change 
 of matter in the body. 
 
 The second quality of the blood, namely, the prop- 
 erty which it possesses of becoming part of an organ- 
 ized tissue, and its consequent adaptation to promote the 
 formation and the growth of organs, as well as to the 
 reproduction or supply of waste in the tissues, is owing, 
 chiefly, to the presence of dissolved fibrine and albu- 
 men. These two chief constituents, which serve for 
 nutrition and reproduction of matter, in passing through 
 the lungs are saturated with oxygen, or, at all events, 
 absorb so much from the atmosphere as entirely to lose 
 the power of extracting oxygen from the other substan- 
 ces present in the blood. 
 
 76. We know for certain that the globules of the 
 venous blood, when they come in contact with air in the 
 lungs, change their color, and that this change of color 
 is accompanied by an absorption of oxygen ; and that 
 
164 ACTION OF ARTERIAL BLOOD. 
 
 all those constituents of the blood, which possess in any 
 degree the power of combining with oxygen, absorb it 
 in the lungs, and become saturated with it. Although 
 in contact with these other compounds, the globules, 
 when arterialized, retain their florid, red color in the 
 most minute ramifications of the arteries ; and we ob- 
 serve them to change their color, and to assume the 
 dark red color which characterizes venous blood, only 
 during their passage through the capillaries. From these 
 facts we must conclude, that the constituents of arterial 
 blood are altogether destitute* of the power to deprive 
 the arterialized globules of the oxygen which they have 
 absorbed from the air ; and we can draw no other con- 
 clusion from the change of color which occurs in the 
 capillaries, than that the arterialized globules, during 
 their passage through the capillaries, return to the con- 
 dition which characterizes them in venous blood ; that, 
 consequently, they give up the oxygen absorbed in the 
 lungs, and thus acquire the power of combining with 
 that element afresh. 
 
 77. We find, therefore, in arterial blood, albumen, 
 which, like all the other constituents of that fluid, has 
 become saturated with oxygen in its passage through 
 the lungs, and oxygen gas, which is conveyed to every 
 particle iri the body in chemical combination with the 
 globules of the blood. As far as our observations ex- 
 tend (in the development of the chick during incuba- 
 tion), all the conditions seem to be here united which 
 are necessary to the formation of every kind of tissue ; 
 while that portion of oxygen which is not consumed in 
 
ACTION OF MEDICINAL AGENTS. 165 
 
 the growth or reproduction of organs, combines with the 
 substance of the living parts, and produces, by its union 
 with their elements, the act of transformation which we 
 have called the change of matter. 
 
 78. It is obvious, that all compounds, of whatever 
 kind, which are present in the capillaries, whether sepa- 
 rated there, or introduced by endosmosis (A) or imbibi- 
 tion, if not altogether incapable of uniting with oxygen, 
 must, when in contact with the arterialized globules, the 
 carriers of oxygen, be affected exactly in the same way 
 as the solids forming part of living organs. These com- 
 pounds, or their elements, will enter into combination 
 with oxygen, and in this case there will either be no 
 change of matter, or that change will exhibit itself in 
 another form, yielding products of a different kind. 
 
 79. The conception, then, of a change in the two 
 qualities of the blood above alluded to, by means of a 
 foreign body contained in the blood or introduced into 
 the circulation (a medicinal agent), presupposes two 
 kinds of operation. 
 
 Assuming, that the remedy cannot enter into any such 
 chemical union with the constituents of the blood as puts 
 an end to the vital activity ; assuming, further, that it is 
 not in a condition of transformation capable of being 
 communicated to the constituents of the blood or of the 
 organs, and of continuing in them ; assuming, lastly, 
 that it is incapable, by its contact with the living parts, 
 of putting a stop to the change of matter, the trans- 
 formation of their elements ; then, in order to discover 
 the modus operandi of this class of medicinal agents, 
 
166 ORGANIC REMEDIAL AGENTS. 
 
 nothing is left but to conclude that their elements take 
 a share in the formation of certain constituents of the 
 living body, or in the production of certain secretions. 
 
 80. The vital process of secretion, in so far as it is 
 related to the chemical forces, has been subjected to 
 examination in the preceding pages. In the carnivora 
 we have reason to believe, that, without the addition of 
 any foreign matter in the food, the bile and the constit- 
 uents of the urine are formed in those parts where the 
 change of matter takes place. In other classes of ani- 
 mals, on the other hand, we may suppose that in the 
 organ of secretion itself, the secreted fluid is produced 
 from certain matters conveyed to it ; in the herbivora, 
 for example, the bile is formed from the elements of 
 starch along with those of a nitrogenized product of the 
 metamorphosis of the tissues. But this supposition by 
 no means excludes the opinion, that in the carnivora the 
 products of the metamorphosed tissues are resolved into 
 bile, uric acid, or urea, only after reaching the secreting 
 organ ; nor the opinion, that the elements of the non- 
 azotized food, conveyed, directly by the circulation to 
 every part of the body, where change of matter is going 
 on, may there unite with the elements of the metamor- 
 phosed tissues, to form the constituents of the bile and 
 of the urine. 
 
 81. If we now assume, that certain medicinal agents 
 may become constituents of secretions, this can only 
 occur in two ways. Either they enter the circulation, 
 and take a direct share in the change of matter, in so 
 far as their elements enter into the composition of the 
 
NITROGENIZED ORGANIC REMEDIES. 167 
 
 new products ; or they are conveyed to the organs of 
 secretion, where they exert an influence on the forma- 
 tion or on the quality of a secretion by the addition of 
 their elements.* 
 
 In either case, they must lose in the organism their 
 chemical character ; and we know with sufficient cer- 
 tainty, that this class of medicinal bodies disappears in 
 the body without leaving a trace. In fact, if we as- 
 cribe to them any effect, they cannot lose their peculiar 
 character by the action of the stomach ; their disap- 
 pearance, therefore, presupposes that they have been 
 applied to certain purposes, which cannot be imagined 
 to occur without a change in their composition. 
 
 82. Now, however limited may be our knowledge 
 of the composition of the different secretions, with the 
 exception of the bile, this much is certain, that all the 
 secretions contain nitrogen chemically combined. They 
 pass into fetid putrefaction, and yield either in this 
 change, or in the dry distillation, amrnoniacal products. 
 Even the saliva, when acted on by caustic potash, dis- 
 engages ammonia freely. 
 
 83. Medicinal or remedial agents may be divided into 
 two classes, the nitrogenized and the non-nitrogenized. 
 The nitrogenized vegetable principles, whose composi- 
 tion differs from that of the proper nitrogenized ele- 
 ments of nutrition, also produced by a vegetable or- 
 ganism, are distinguished, beyond all others, for their 
 powerful action on the animal economy. 
 
 * See note XLIII. on the conversion of benzole acid into hippuric 
 acid. 
 
168 VEGETABLE ALKALIES, &c. 
 
 The effects of these substances are singularly varied ; 
 from the mildest form of the action of aloes, to the 
 most terrible poison, strychnia, we observe an endless 
 variety of different actions. 
 
 With the exception of three, all these substances 
 produce diseased conditions in the healthy organism, 
 and are poisonous in certain doses. Most of them are, 
 chemically speaking, basic or alkaline. 
 
 No remedy, devoid of nitrogen, possesses a poison- 
 ous action in a similar dose.* 
 
 84. The medicinal or poisonous action of the nitro- 
 genized vegetable principles has a fixed relation to their 
 composition ; it cannot be supposed to be independent 
 of the nitrogen they contain, but is certainly not in di- 
 rect proportion to the quantity of nitrogen. 
 
 Solanine (as), and picrotoxine (39), which contain 
 least nitrogen, are powerful poisons. Quinine (40) con- 
 tains more nitrogen than morphia (41). Caffeine (42), 
 and theobromine, the most highly nitrogenized of all 
 vegetable principles, are not poisonous. 
 
 85. A nitrogenized body, which exerts, by means of 
 its elements, an influence on the formation or on the 
 quality of a secretion, must, in regard to its chemical 
 character, be capable of taking the same share as the 
 nitrogenized products of the animal body do in the for- 
 mation of the bile ; that is, it must play the same part 
 
 * This consideration or comparative view has led lately to a more 
 accurate investigation of the composition of picrotoxine, the poison- 
 ous principle of cocculus indicus; and M. Francis has discovered the 
 existence of nitrogen in it, hitherto overlooked, and has also deter- 
 mined its amount. L. 
 
NITROGENIZED COMPOUNDS. 169 
 
 as a product of the vital process. On the other hand, 
 a non-azotized medicinal agent, in so far as its action 
 affects the secretions, must be capable of performing in 
 the animal body the same part as that which we have 
 ascribed, in the formation of the bile, to the non-azotized 
 elements of food. 
 
 Thus, if we suppose that the elements of hippuric or 
 uric acids are derived from the substance of the organs 
 in which vitality resides ; that, as products of the trans- 
 formation of these organs, they lose the vital character, 
 without losing the capacity of undergoing changes under 
 the influence of the inspired oxygen, or of the appara- 
 tus of secretion ; we can hardly doubt that similar ni- 
 trogenized compounds, products of the vital process in 
 plants, when introduced into the animal body, may be 
 employed by the organism exactly in the same way as 
 the nitrogenized products of the metamorphosis of the 
 animal tissues themselves. If hippuric and uric acids, 
 or any of their elements, can take a share, for example, 
 in the formation and supply of bile, we must allow the 
 same power to other analogous nitrogenized compounds. 
 
 We shall never, certainly, be able to discover how 
 men were led to the use of the hot infusion of the leaves 
 of a certain shrub (tea), or of a decoction of certain 
 roasted seeds (coffee). Some cause there must be, 
 which would explain how the practice has become a 
 necessary of life to whole nations. But it is surely 
 still more remarkable, that the beneficial effects of both 
 plants on the health must be ascribed to one and the 
 same substance, the presence of which in two vegeta- 
 15 
 
170 VEGETABLE PRODUCTS: CAFFEINE. 
 
 bles, belonging to different natural families, and the 
 produce of different quarters of the globe, could hardly 
 have presented itself to the boldest imagination. Yet 
 recent researches have shown, in such a manner as to 
 exclude all doubt, that caffeine, the peculiar principle 
 of coffee, and theine, that of tea, are, in all respects, 
 identical. 
 
 It is not less worthy of notice, that the American 
 Indian, living entirely on flesh, discovered for himself, 
 in tobacco smoke, a means of retarding the change of 
 matter in the tissues of his body, and thereby of mak- 
 ing hunger more endurable ; and that he cannot with- 
 stand the action of brandy, which, acting as an element 
 of respiration, puts a stop to the change of matter by 
 performing the function, which properly belongs to the 
 products of the metamorphosed tissues. Tea and cof- 
 fee were originally met with among nations whose diet 
 is chiefly vegetable. 
 
 86. Without entering minutely into the medicinal 
 action of caffeine (theine) , it will surely appear a most 
 striking fact, even if we were to deny its influence on 
 the process of secretion, that this substance, with the 
 addition of oxygen and the elements of water, can yield 
 taurine, the nitrogenized compound peculiar to bile : 
 
 1 at. caffeine or theine = C 8 N 2 H S O 2 
 
 9 at. water = H 9 O 9 
 
 9 at. oxygen = O 9 
 
 C 8 N 2 H 14 20 = 
 == 2 at. taurine = 2 (C 4 NH 7 O 10 ) 
 
 A similar relation exists in the case of the peculiar 
 principle of asparagus and of althaea, asparagine ; which 
 
RELATION OF CAFFEINE AND ASPARAGINE. 171 
 
 also, by the addition of oxygen and the elements of 
 water, yields the elements of taurine : 
 
 1 at. asparagine = C 8 N 2 H 8 O 6 
 6 at. water . . = H 6 O 6 
 
 8 at. oxygen . = O 8 
 
 C 8 N 2 H 14 20 
 = 2 at. taurine . = 2 (C 4 NH 7 O 10 ) 
 
 The addition of the elements of water and of a cer- 
 tain quantity of oxygen to the elements of theobromine, 
 the characteristic principle of the cacao bean (theo- 
 broma cacao), yields the elements of taurine and urea, 
 of taurine, carbonic acid, and ammonia, or of taurine 
 and uric acid : 
 
 1 at. theobromine C 18 N 6 H 10 O 4 \ ... 
 
 10 4 ( J 4 at. taurine . . C 16 N 4 H 28 O 40 
 
 && at. Water . . . Xl 2 oV/22 / == I i r^ in n r\ 
 
 1 < 1 at. urea . . . C 2 N 2 H 4 O 2 
 16 at. oxygen . . O 16 ) 
 
 C 18 N 6 H 32 42 &tf#t/fo 
 
 or, 
 
 1 at. theobromine C 18 N 6 H 10 O 4 \ t 4 at. taurine . . C I6 N 4 H 28 O 40 
 24 at. water . . . H 24 O 24 > = < 2 at. carbon, acid C 2 O 4 
 
 16 at. oxygen . . O 16 ) ( 2 at. ammonia . N 2 H 6 
 
 8 at. water ... H 8 O 8 > = 
 
 C 18 N 6 H 34 O 44 
 
 or, 
 1 at. theobromine C 18 N 6 H IO O 4 
 
 ~~ ^ 1 at. uric acid . C 10 N 4 H 4 O 6 
 
 14 at. oxygen 
 
 C 18 N 6 H 18 26 C 18 N 6 H 18 26 
 
 87. To see how the action of caffeine, asparagine, 
 theobromine, &c., may be explained, we must call to 
 mind, that the chief constituent of the bile contains only 
 3-8 per cent, of nitrogen, of which only the half, or 1*9 
 per cent., belongs to the taurine. 
 
 Bile contains, in its natural state, water and solid 
 
172 RELATION OF THEOBROMINE TO BILE AND URINE. 
 
 matter, in the proportion of 90 parts by weight of the 
 former to 10 of the latter. If we suppose these 10 
 parts by weight of solid matter to be choleic acid, with 
 3-87 per cent, of nitrogen, then 100 parts of fresh bile 
 will contain 0'171 parts of nitrogen in the shape of 
 taurine. Now this quantity is contained in 0'6 parts 
 of caffeine ; or S^ths grains of caffeine can give to 
 an ounce of bile the nitrogen it contains in the form 
 of taurine. If an infusion of tea contain no more than 
 the ^th of a grain of caffeine, still, if it contribute in 
 point of fact to the formation of bile, the action, even 
 of such a quantity, cannot be looked upon as a nullity. 
 Neither can it be denied, that, in the case of an excess 
 of non-azotized food and a deficiency of motion, which 
 is required to cause the change of matter in the tis- 
 sues, and thus to yield the nitrogenized product which 
 enters into the composition of the bile ; that in such 
 a condition, the health may be benefited by the use 
 of compounds which are capable of supplying the place 
 of the nitrogenized product produced in the healthy 
 state of the body, and essential to the production of an 
 important element of respiration. In a chemical sense, 
 and it is this alone which the preceding remarks are 
 intended to show, caffeine or theine, asparagine, and 
 theobromine, are, in virtue of their composition, better 
 adapted to this purpose, than all other nitrogenized 
 vegetable principles. The action of these substances, 
 in ordinary circumstances, is not obvious, but it un- 
 questionably exists. 
 
 88. With respect to the action of the other nitro- 
 
ACTION OF ALKALIES ON THE NERVOUS SYSTEM. 173 
 
 genized vegetable principles, such as quinine, or the 
 alkaloids of opium, &c., which manifests itself, not in 
 the processes of secretion, but in phenomena of an- 
 other kind, physiologists and pathologists entertain no 
 doubt, that it is exerted chiefly on the brain and nerves. 
 This action is commonly said to be dynamic, that 
 is, it accelerates, or retards, or alters in some way the 
 phenomena of motion in animal life. If we reflect, 
 that this action is exerted by substances which are 
 material, tangible, and ponderable ; that they disappear 
 in the organism ; that a double dose acts more power- 
 fully than a single one ; that, after a time, a fresh dose 
 must be given, if we wish to produce the action a 
 second time ; all these considerations, viewed chemi- 
 cally, permit only one form of explanation ; the sup- 
 position, 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. 
 
 However strange the idea may, at first sight, appear, 
 that the alkaloids of opium or of cinchona bark, the 
 elements of codeine, morphia, quinine, &c., may be 
 converted into constituents of brain and nervous matter, 
 into organs of vital energy, from which the organic mo- 
 tions of the body derive their origin ; that these sub- 
 stances form a constituent of that matter, by the re- 
 moval of which the seat of intellectual life, of sensation, 
 and of consciousness, is annihilated : it is, nevertheless, 
 certain, that all these forms of power and activity are 
 most closely dependent, not only on the existence, but 
 
174 COMPOSITION AND ORIGIN 
 
 also on a certain quality of the substance of the brain, 
 spinal marrow, and nerves ; insomuch, that all the mani- 
 festations of the life or vital energy of these modifica- 
 tions of nervous matter, which are recognised as the 
 phenomena of motion, sensation, or feeling, assume an- 
 other form as soon as their composition is altered. The 
 animal organism has produced the brain and nerves out 
 of compounds furnished to it by vegetables ; it is the 
 constituents of the food of the animal, which, in conse- 
 quence of a series of changes, have assumed the prop- 
 erties and the structure which we find in the brain and 
 nerves. 
 
 89. If it must be admitted as an undeniable truth, 
 that the substance of the brain and nerves is produced 
 from the elements of vegetable albumen, fibrine, and 
 caseine, either alone, or with the aid of the elements of 
 non-azotized food, or of the fat formed from the latter, 
 there is nothing absurd in the opinion, that other con- 
 stituents of vegetables, intermediate in composition be- 
 tween the fats and the compounds of proteine, may be 
 applied in the organism to the same purpose. 
 
 90. According to the researches of Fremy, the chief 
 constituent, of the fat found in the brain is a compound 
 of soda with a peculiar acid, the cerebric acid, which 
 contains, in 100 parts, 
 
 Carbon, . . . $%- 66-7 
 
 Hydrogen, .. . . ''*'. 1() ' 6 
 
 Nitrogen, . .' ^\ . 2-3 
 
 Phosphorus, . . . . 0-9 
 
 Oxygen, . . ,, f ^. . 19-5 
 
 It is easy to see that the composition of cerebric acid 
 
OF THE NERVOUS MATTER. 175 
 
 differs entirely, both from that of ordinary fats and of 
 the compounds of proteine. Common fats contain no 
 nitrogen, while the compounds of proteine contain nearly 
 17 per cent. Leaving the phosphorus out of view, the 
 composition of this acid approaches most nearly to .that 
 of choleic acid, although these two compounds are quite 
 distinct. 
 
 91. Brain and nervous matter is, at all events, formed 
 in a manner similar to that in which bile is produced ; 
 either by the separation of a highly nitrogenized com- 
 pound from the elements of blood, or by the combina- 
 tion of a nitrogenized product of the vital process with a 
 non-azotized compound (probably, a fatty body). All 
 that has been said in the preceding pages on the various 
 possible ways by which the bile might be supposed to be 
 formed, all the conclusions which we attained in regard 
 to the cooperation of azotized and non-azotized ele- 
 ments of food, may be applied with equal justice and 
 equal probability to the formation and production of the 
 nervous substance. 
 
 We must not forget, that, in whatever light we may 
 view the vital operations, the production of nervous 
 matter from blood presupposes a change in the compo- 
 sition and qualities of the constituents of blood. That 
 such a change occurs is as certain as that the existence 
 of the nervous matter cannot be denied. In this sense, 
 we must assume, that from a compound of proteine may 
 be formed a first, second, third, &c., product, before a 
 certain number of its elements can become constituents 
 of the nervous matter ; and it must be considered as 
 
176 RELATION OF VEGETABLE ALKALIES. 
 
 quite certain, that a product of the vital process in a 
 plant, introduced into the blood, will, if its composition 
 be adapted to this purpose, supply the place of the first, 
 second, or third product of the alteration of the com- 
 pound of proteine. Indeed, it cannot be considered 
 merely accidental, that the composition of the most ac- 
 tive remedies, namely, the vegetable alkaloids, cannot 
 be shown to be related to that of any constituent of the 
 body, except only the substance of the nerves and brain. 
 All of these contain a certain quantity of nitrogen, and, 
 in regard to their composition, they are intermediate be- 
 tween the compounds of proteine and the fats. 
 
 92. In contradistinction to the chemical character, 
 we find that the substance of the brain exhibits the char- 
 acters of an acid. It contains far more oxygen than 
 the organic bases or alkaloids. We observe, that quin- 
 ine and cinchonine, morphia and codeine, strychnia and 
 brucia, which are, respectively, so nearly alike in com- 
 position, if they do not produce absolutely the same 
 effect, yet resemble each other in their action more than 
 those which differ more widely in composition. We 
 find, that their energy of action diminishes, as the 
 amount of oxygen they contain increases (as in the case 
 of narcotine), and that, strictly speaking, no one of 
 them can be entirely replaced by another. There can- 
 not be a more decisive proof of the nature of their ac- 
 tion than this last fact ; it must stand in the closest rela- 
 tion to their composition. If these compounds, in point 
 of fact, are capable of taking a share in the formation or 
 in the alteration of the qualities of brain and nervous 
 
RELATION OF VEGETABLE ALKALIES. 177 
 
 matter, their action on the healthy as well as the dis- 
 eased organism admits of a surprisingly simple explana- 
 tion. If we are not tempted to deny, that the chief 
 constituent of soup may be applied to a purpose corre- 
 sponding to its composition in the human body, or that 
 the organic constituent of bones may be so employed in 
 the body of the dog, although that substance (gelatine in 
 both cases) is absolutely incapable of yielding blood ; if, 
 therefore, nitrogenized compounds, totally different from 
 the compounds of proteine, may be employed for pur- 
 poses corresponding to their composition ; we may 
 thence conclude that a product of vegetable life, also 
 different from proteine, but similar to a constituent of 
 the animal body, may be employed by the organism in 
 the same way and for the same purpose as the natural 
 product, originally formed by the vital energy of the 
 animal organs, and that, indeed, from a vegetable sub- 
 stance. 
 
 The time is not long gone by, when we had not the 
 very slightest conception of the cause of the various 
 effects of opium, and when the action of cinchona bark 
 was shrouded in incomprehensible obscurity. Now 
 that we know that these effects are caused by crystalli- 
 zable compounds, which differ as much in composition 
 as in their action on the system ; now that we know the 
 substances to which the medicinal or poisonous energy 
 must be ascribed, it would argue only want of sense to 
 consider the action of these substances inexplicable ; 
 and to do so, as many have done, because they act in 
 
178 ACTION OF NITROGENIZED PRODUCTS. 
 
 very minute doses, is as unreasonable as it would be to 
 judge of the sharpness of a razor by its weight. 
 
 93. It would serve no purpose to give these con- 
 siderations a greater extension at present. However 
 hypothetical they may appear, they only deserve atten- 
 tion in so far as they point out the way which chemistry 
 pursues, and which she ought not to quit, if she would 
 really be of service to physiology and pathology. The 
 combinations of the chemist relate to the change of 
 matter, forwards and backwards, to the conversion of 
 food into the various tissues and secretions, and to their 
 metamorphosis into lifeless compounds ; his investigations 
 ought to tell us what has taken place and what can take 
 place in the body. It is singular that we find medicinal 
 agencies all dependent on certain matters, which differ 
 in composition ; and if, by the introduction of a sub- 
 stance, certain abnormal conditions are rendered normal, 
 it will be impossible to reject the opinion, that this phe- 
 nomenon depends on a change in the composition of the 
 constituents of the diseased organism, a change in which 
 the elements of the remedy take a share ; a share simi- 
 lar to that which the vegetable elements of food have 
 taken in the formation of fat, of membranes, of the 
 saliva, of the seminal fluid, &c. Their carbon, hydro- 
 gen, or nitrogen, or whatever else belongs to their com- 
 position, are derived from the vegetable organism ; and, 
 after all, the action and effects of quinine, morphia, 
 and the vegetable poisons in general, are no hypotheses. 
 
 94. Thus, as we may say, in a certain sense, of 
 caffeine, or theine and asparagine, &c., as well as of 
 
NITROGENIZED VEGETABLE PRODUCTS. 179 
 
 the non-azotized elements of food, that they are food 
 for the liver, since they contain the elements, by the 
 presence of which that organ is enabled to perform its 
 functions, so we may consider these nitrogenized com- 
 pounds, so remarkable for their action on the brain and 
 on the substance of the organs of motion, as elements 
 of food for the organs as yet unknown, which are des- 
 tined for the metamorphosis of the constituents of the 
 blood into nervous substance and brain. Such organs 
 there must be in the animal body, and if, in the diseased 
 state, an abnormal process of production or transforma- 
 tion of the constituents of cerebral and nervous matter 
 has been established ; if, in the organs intended for this 
 purpose, the power of forming that matter out of the 
 constituents of blood, or the power of resisting an 
 abnormal degree of activity in its decomposition or 
 transformation, has been diminished ; then, in a chemi- 
 cal sense, there is no objection to the opinion, that 
 substances of a composition analogous to that of ner- 
 vous and cerebral matter, and, consequently, adapted 
 to form that matter, may be employed, instead of the 
 substances produced from the blood, either to furnish 
 the necessary resistance, or to restore the normal con- 
 dition. 
 
 95. Some physiologists and chemists have expressed 
 doubts of the peculiar and distinct character of cerebric 
 acid, a substance which, from its amount of carbon and 
 hydrogen, and from its external characters, resembles a 
 nitrogenized fatty acid. But a nitrogenized fat, having 
 an acid character, is, in fact, no anomaly. Hippuric 
 
180 PHOSPHORUS SEEMS ESSENTIAL 
 
 acid is in many of its characters very similar to the 
 fatty acids, but is essentially distinguished from them by 
 containing nitrogen. The organic constituents of bile 
 resemble the acid resins in physical characters, and yet 
 contain nitrogen. The organic alkalies are intermediate 
 in their physical characters between the fats and resins, 
 and they all contain nitrogen. A nitrogenized fatty acid 
 is as little improbable as the existence of a nitrogenized 
 resin with the characters of a base. 
 
 96. An accurate investigation would probably dis- 
 cover differences in the composition of the brain, spinal 
 marrow, and nerves. According to the observations 
 of Valentin, the quality of the cerebral and nervous 
 substance is very rapidly altered from the period of 
 death, and very uncommon precautions would be re- 
 quired for the separation of foreign matters, not prop- 
 erly belonging to the substance of the spinal marrow or 
 brain. But, however difficult it may appear, the inves- 
 tigation seems yet to be practicable. We know, in the 
 mean time, that all experience is against the notion of 
 a large amount of carbon and hydrogen in the substance 
 of the brain. The absence of nitrogen as an element 
 of the cerebral and nervous matter, appears, at all 
 events, improbable. This substance, moreover, can- 
 not be classed with ordinary fats, because we find the 
 cerebric acid combined with soda, whereas, all fats are 
 compounds of fatty acids with oxide of glycerule. In 
 regard to the phosphorus of the brain, we can only 
 guess as to the form in which the phosphorus exists. 
 Walchner observed recently, that bubbles of spontane- 
 
TO THE NERVOUS MATTER. 181 
 
 ously inflammable phosphuretted hydrogen were disen- 
 gaged from the trough of a spring in Carlsruhe, on 
 the bottom of which fish had putrefied ; and gases 
 containing phosphorus have also been observed among 
 the products of the putrefaction of tjie brain.* 
 
 * The curator of the museum at Geneva gave to M. Leroyer, 
 apothecary, a large quantity of spirit of wine, which had been used 
 for the preservation of fishes, and which he undertook to purify. He 
 distilled it from a mixture of chloride of calcium and quicklime, and 
 evaporated the residue in the air, over a fire. As soon as the mass 
 had acquired a certain consistence, and a higher temperature, a pro- 
 digious quantity of spontaneously inflammable phosphuretted hydro- 
 gen was disengaged. (Dumas, V. 867.) 
 
 16 
 
PART III. 
 
 THE 
 
 PHENOMENA OF MOTION 
 
 IN THE 
 
 
 
 ANIMAL ORGANISM. 
 
THE 
 
 PHENOMENA OF MOTION 
 
 IN THE 
 
 ANIMAL ORGANISM. 
 
 I. 
 
 IT might appear an unprofitable task to add one more 
 to the innumerable forms under which the human intel- 
 lect has viewed the nature and essence of that peculiar 
 cause, which must be considered as the ultimate source 
 of the phenomena which characterize vegetable and 
 animal life, were it not that certain conceptions present 
 themselves as necessary deductions from the views on 
 this subject developed in the introduction to the first 
 part of this work. The following pages will be devoted 
 to a more detailed examination of these deductions. It 
 must be admitted here, that all these conclusions will 
 lose their force and significance, if it can be proved that 
 the cause of vital activity has, in its manifestations, 
 nothing in common with other known causes which 
 produce motion or change of form and structure in 
 matter. 
 
 But a comparison of its peculiarities with the modus 
 operandi of these other causes, cannot, at all events, 
 fail to be advantageous, inasmuch as the nature and 
 16* 
 
186 THE PHENOMENA OF MOTION 
 
 essence of natural phenomena are recognisable, not by 
 abstraction, but only by comparative observations. 
 
 If the vital phenomena be considered as manifesta- 
 tions of a peculiar force, then the effects of this force 
 must be regulated by certain laws, which laws may be 
 investigated ; and these laws must be in harmony with 
 the universal laws of resistance and motion, which pre- 
 serve in their courses the worlds of our own and other 
 systems, and which also determine changes of form and 
 structure in material bodies ; altogether independent 
 of the matter in which vital activity appears to reside, 
 or of the form in which vitality is manifested. 
 
 The vital force in a living animal tissue appears as a 
 cause of growth in the mass, and of resistance to those 
 external agencies which tend to alter the form, struc- 
 ture, and composition of the substance of the tissue in 
 which the vital energy resides. 
 
 This force further manifests itself as a cause of mo- 
 tion and of change in the form and structure of material 
 substances, by the disturbance and abolition of the state 
 of rest in which those chemical forces exist, by which 
 the elements of the compounds conveyed to the living 
 tissues, in the form of food, are held together. 
 
 The vital force causes a decomposition of the con- 
 stituents of food, and destroys the force of attraction 
 which is continually exerted between their molecules ; 
 it alters the direction of the chemical forces in such 
 wise, that the elements of the constituents of food ar- 
 range themselves in another form, and combine to pro- 
 duce new compounds, either identical in composition 
 
IN THE ANIMAL ORGANISM. 187 
 
 with the living tissues, or differing from them ; it further 
 changes the direction and force of the attraction of co- 
 hesion, destroys the cohesion of the nutritious com- 
 pounds, and forces the new compounds to assume forms 
 altogether different from those which are the result of 
 the attraction of cohesion when acting freely, that is, 
 without resistance. 
 
 The vital force is also manifested as a force of at- 
 traction, inasmuch as* the new compound produced by 
 the change of form and structure in the food, when it 
 has a composition identical with that of the living tissue, 
 becomes a part of that tissue. 
 
 Those newly-formed compounds, whose composition 
 differs from that of the living tissue, are removed from 
 the situation in which they are formed, and, in the shape 
 of certain secretions, being carried to other parts of 
 the body, undergo in contact with these a series of anal- 
 ogous changes. 
 
 The vital force is manifested in the form of resis- 
 tance, inasmuch 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 agencies tend to produce ; a power 
 which, simply as chemical compounds, they do not 
 possess. 
 
 As in the case of other forces, the conception of an 
 unequal intensity of the vital force comprehends not 
 only an unequal capacity for growth in the mass, and an 
 unequal power of overcoming chemical resistance, but 
 also an inequality in the amount of that resistance which 
 
188 THE PHENOMENA OF MOTION 
 
 the parts or constituents of the living tissue oppose to 
 a change in their form and composition, from the action 
 of new external active causes of change ; just as the 
 force of cohesion or of affinity is in direct proportion to 
 the resistance which these forces oppose to any external 
 cause, mechanical or chemical, tending to separate the 
 molecules, or the elements of an existing compound. 
 
 The manifestations of the vital force are dependent 
 on a certain form of the tissue in which it resides, as 
 well as on a fixed composition in the substance of the 
 living tissue. 
 
 The capacity of growth in a living tissue is deter- 
 mined by the immediate contact with matters adapted 
 to a certain decomposition, or the elements of which 
 are capable of becoming component parts of the tissue 
 in which vitality resides. 
 
 The phenomenon of growth, or increase in the mass, 
 presupposes that the acting vital force is more powerful 
 than the resistance which the chemical force opposes to 
 the decomposition or transformation of the elements of 
 the food. 
 
 The manifestations of the vital force are dependent 
 on a certain temperature. Neither in a plant nor in an 
 animal do vital phenomena occur when the temperature 
 is lowered to a certain extent. 
 
 The phenomena of vitality in a living organism di- 
 minish in intensity when heat is abstracted, provided the 
 lost heat be not restored by other causes. 
 
 Deprivation of food soon puts a stop to all manifes- 
 tations of vitality. 
 
IN THE ANIMAL ORGANISM. 189 
 
 The contact of the living tissues with the elements of 
 nutrition is determined in the animal body by a me- 
 chanical force produced within the body, which gives to 
 certain organs the power of causing change of place, 
 of producing motion, and of overcoming mechanical 
 resistance. 
 
 We may communicate motion to a body at rest by 
 means of a number of forces, very different in their 
 manifestations. Thus, a time-piece may be set in 
 motion by a falling weight (gravitation), or by a bent 
 spring (elasticity) . Every kind of motion may be pro- 
 duced by the electric or magnetic force, as well as by 
 chemical attraction ; while we cannot say, as long as 
 we only consider the manifestation of these forces in the 
 phenomenon or result produced, which of these various 
 causes of change of place has set the body in motion. 
 
 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 external agencies ; it is the 
 vital force. 
 
 In order to attain a clear conception of these mani- 
 festations of the vital force, so different in form, we 
 must bear in mind, that every known force is recognised 
 by two conditions of activity, entirely different in the 
 phenomena they offer to the attention of the observer. 
 
 The force of gravitation inherent in the particles of a 
 stone, gives to them a continual tendency to move 
 towards the centre of the earth. 
 
 This effect of gravitation becomes inappreciable to 
 
190 THE PHENOMENA OF MOTION 
 
 the senses when the stone, for example, rests upon a 
 table, the particles of which oppose a resistance to the 
 manifestation of its gravitation. The force of gravity, 
 however, is constantly present, and manifests itself as a 
 pressure on the supporting body ; but the stone remains 
 at rest ; it has no motion. The manifestation of its 
 gravity in the state of rest, we call its weight. 
 
 That which prevents the stone from falling is a re- 
 sistance produced by the force of attraction, by which 
 the particles of the wood cohere together ; a mass of 
 water would not prevent the fall of the stone. 
 
 If the force which impelled the mass of the stone 
 towards the centre of the earth were greater than the 
 force of cohesion in the particles of the wood, the latter 
 would be overcome ; it would be unable to prevent the 
 fall of the stone. 
 
 When we remove the support, and with it the force 
 which has prevented the manifestation of the force 
 of gravity, the latter at once appears as the cause of 
 change of place in the stone, which acquires motion, or 
 falls. Resistance is invariably the result of a force in 
 action. 
 
 According as the stone is allowed to fall during a 
 longer or shorter time, it acquires properties which it had 
 not while at rest ; it acquires, for example, the power 
 of overcoming more feeble or more powerful obstacles, 
 or that of communicating motion to bodies in a state 
 of rest. 
 
 If it fall from a certain height it makes a permanent 
 impression on the spot on which it falls ; if it fall from a 
 
IN THE ANIMAL ORGANISM. 191 
 
 still greater height (during a longer time) it perforates 
 the table ; its own motion is communicated to a certain 
 number of the particles of the wood which now fall 
 along with the stone itself. The stone, while at rest, 
 possessed none of these properties. 
 
 The velocity of the falling body is always the effect 
 of the moving force, and is, ceteris paribus, propor- 
 tional to the force of gravitation. 
 
 A body, falling freely, acquires at the end of one 
 second a velocity of 30 feet. The same body, if fall- 
 ing on the moon, would acquire in one second only a 
 velocity of s 3 B ths of a foot = 1 inch, because, in the 
 moon, the intensity of gravitation (the pressure acting 
 on the body, the moving power) is 360 times smaller. 
 
 If the pressure continue uniform, the velocity is di- 
 rectly proportional to it ; so that, for example, the 
 body falling 360 times slower, will, after 360 seconds, 
 have the same velocity as the other body after one 
 second. 
 
 Consequently the effect is proportional, not to the 
 moving force alone, nor to the time alone, but to the 
 pressure multiplied into the time, which is called the 
 momentum of force. 
 
 In two equal masses the velocity expresses the mo- 
 mentum of force. But under the same pressure a body 
 moves more slowly as its mass is greater ; a mass twice 
 as great requires, in order to attain in the same time an 
 equal velocity, twice the pressure ; or, under the single 
 pressure, it must continue in motion twice as long. 
 
 In order, therefore, to have an expression for the 
 
192 THE PHENOMENA OF MOTION 
 
 whole effect produced, we must multiply the mass into 
 the velocity. This product is called the amount of 
 motion. 
 
 The amount of motion in a given body must in all 
 cases correspond exactly to the momentum of force. 
 
 These two, the amount of motion and the momentum 
 of force, are also called simply force; because we sup- 
 pose that a less pressure acting, for example, during 10 
 seconds, is equal to a pressure ten times greater, acting 
 only during one second. 
 
 The momentum of motion, in mechanics, signifies the 
 effect of a moving force, without reference to the time 
 (velocity) in which it was manifested. If one man, for 
 example, raises 30 Ibs. to a height of 100 feet, and a 
 second one 30 Ibs. to a height of 200 feet, then the lat- 
 ter has expended twice as much force as the former. 
 A third who raises 60 Ibs. to a height of 50 feet, ex- 
 pends no more force than the first did in raising 30 Ibs. 
 to the height of 100 feet. The momentum of motion 
 of the first (30X100) is equal to that of the third 
 (60X50), while that of the second (30X200) is twice 
 as great. 
 
 Momentum of force and momentum of motion, in 
 mechanics, are therefore expressions or measures for 
 effects of force, having reference to the velocity attained 
 in a given time, or to a given space ; and in this sense 
 they may be applied to the effects of all other causes of 
 motion, or of change in form and structure, howevei 
 great or however small may be the space or the time in 
 which their effects are displayed to the senses. 
 
IN THE ANIMAL ORGANISM. 193 
 
 Every force, therefore, exhibits itself in matter either 
 in the form of resistance to external causes of motion, 
 or of change in form and structure ; or as a moving 
 force when no resistance is opposed to it ; or, finally, 
 in overcoming resistance. 
 
 One and the same force communicates motion and 
 destroys motion ; the former, when its manifestations 
 are opposed by no resistance ; the latter, when it puts 
 a stop to the manifestation of some other cause of mo- 
 tion, or of change in form and structure. Equilibrium 
 or rest is that state of activity in which one force or 
 momentum of motion is destroyed by an opposite force 
 or momentum of motion. 
 
 We observe both these manifestations of activity in 
 that force which gives to the living tissues their pecu- 
 liar properties. 
 
 The vital force appears as a moving force or cause 
 of motion when it overcomes the chemical forces (co- 
 hesion and affinity) which act between the constituents 
 of food, and when it changes the position or place in 
 which their elements occur ; it is manifested as a cause 
 of motion in overcoming the chemical attraction of the 
 constituents of food, and is, further, the cause which 
 compels them to combine in a new arrangement, and to 
 assume new forms. 
 
 It is plain, that a part of the animal body possessed 
 of vitality, which has therefore the power of over- 
 coming resistance, and of giving motion to the elemen- 
 tary particles of the food, by means of the vital force 
 17 
 
194 THE PHENOMENA OF MOTION 
 
 manifested in itself, must have a momentum of motion, 
 which is nothing else than the measure of the resulting 
 motion or change in form and structure. 
 
 We know that this momentum of motion in the vital 
 force, residing in a living part, may be employed in 
 giving motion to bodies at rest (that is, in causing de- 
 composition, or overcoming resistance), and if the vital 
 force is analogous in its manifestations to other forces, 
 this momentum of motion must be capable of being 
 conveyed or communicated by matters, which in them- 
 selves do not destroy its effect by an opposite manifes- 
 tation of force. 
 
 Motion, by whatever cause produced, cannot in it- 
 self be annihilated ; it may, indeed, become inappre- 
 ciable to the senses, but even when arrested by resist- 
 ance (by the manifestation of an opposite force) its 
 effect is not annihilated. The falling stone, by means 
 of the amount of motion acquired in its descent, pro- 
 duces an effect when it reaches the table. The im- 
 pression made on the wood, the velocity communicated 
 by its parts to those of the wood, all this is its 
 effect. 
 
 If we transfer the conceptions of motion, equili- 
 brium, and resistance, to the chemical forces, which, 
 in their modus operandi, approach to the vital force 
 infinitely nearer than gravitation does, we know with 
 the utmost certainty, that they are active only in the 
 case of immediate contact. We know, also, that the 
 unequal capacity of chemical compounds to offer re- 
 
IN THE ANIMAL ORGANISM. 195 
 
 sistance to external, disturbing influences, to those of 
 heat, or of electricity, which tend to separate their 
 particles, as well as their power of overcoming resist- 
 ance in other compounds (of causing decomposition) ; 
 that, in a word, the active force in a compound de- 
 pends on a certain order or arrangement, in which its 
 elementary particles touch each other. 
 
 The same elements, united in a different order, when 
 in contact with other compounds, exert a most unequal 
 power of offering or overcoming resistance. In one 
 form the force manifested is available (the body is ac- 
 tive, an acid, for example) ; in another not (the body 
 is indifferent, neutral) ; in a third form, the momentum 
 of force is opposed to that of the first (the body is 
 active, but a base). 
 
 If we alter the arrangement of the elements, we are 
 able to separate the constituents of a compound by 
 means of another active body ; while the same ele- 
 ments, united in their original order, would have op- 
 posed an invincible resistance to the action of the 
 decomposing agent. 
 
 In the same way as two equal inelastic masses, im- 
 pelled with equal velocity from opposite points, on 
 coming into contact are brought to rest ; in the same 
 way, therefore, as two equal and opposite momenta 
 of motion mutually destroy each other ; so may the 
 momentum of force in a chemical compound be de- 
 stroyed in whole or in part by an equal or unequal, 
 and opposite momentum of force in a second com- 
 
196 THE PHENOMENA OF MOTION 
 
 pound. But it cannot be annihilated as long as the 
 arrangement of the elementary particles, by which its 
 inherent force was manifested, is not changed. 
 
 The chemical force of sulphuric acid is present in 
 sulphate of lime as entire as in oil of vitriol. It is 
 not appreciable by the senses ; but if the cause be 
 removed which prevented its manifestation, it appears 
 in its full force in the compound in which it properly 
 resides. 
 
 Thus the force of cohesion in a solid may disappear, 
 to the senses, from the action of a chemical force (in 
 solution), or of heat (in fusion), without being in re- 
 ality annihilated or even weakened. If we remove the 
 opposing force or resistance, the force of cohesion ap- 
 pears unchanged in crystallization. 
 
 By means of the electrical force, or that of heat, 
 we can give the most varied directions to the manifes- 
 tations of chemical force. By these means we can 
 fix, as it were, the order in which the elementary 
 particles shall unite. Let us remove the cause (heat 
 or electricity) which has turned the balance in favor 
 of the weaker attraction in one direction, and the 
 stronger attraction will show itself continually active in 
 another direction ; and if this stronger attraction can 
 overcome the vis inertiae of the elementary particles, 
 they will unite in a new form, and a new compound of 
 different properties must be the result. 
 
 In compounds of this kind, in which, therefore, 
 the free manifestation of the chemical force has been 
 
IN THE ANIMAL ORGANISM. 197 
 
 impeded by other forces, a blow, or mechanical fric- 
 tion, or the contact of a substance, the particles of 
 which are in a state of motion (decomposition, trans- 
 formation), or any external cause, whose activity is 
 added to the stronger attraction of the elementary par- 
 ticles in another direction, may suffice to give the pre- 
 ponderance to this stronger attraction, to overcome the 
 vis inertia?, to alter the form and structure of the com- 
 pound, which are the result of foreign causes, and to 
 produce the resolution of the compound into one or 
 more new compounds with altered properties. 
 
 Transformations, or, as they may be called, phe- 
 nomena of motion, in compounds of this class, may 
 be effected by means of the free and available chemi- 
 cal force of another chemical compound, and that with- 
 out its manifestation being enfeebled or arrested by 
 resistance. Thus the equilibrium in the attraction be- 
 tween the elements of cane-sugar*is destroyed by con- 
 tact with a very small quantity of sulphuric acid, and 
 it is converted into grape-sugar. In the same way 
 we see the elements of starch, under the same influ- 
 ence, arrange themselves with those of water in a new 
 form, while the sulphuric acid, which has served to 
 produce these transformations, loses nothing of its 
 chemical character. In regard to other substances on 
 which it acts, it remains as active as before, exactly 
 as if it had exerted no sort of influence on the cane- 
 sugar or starch. 
 
 In contradistinction to the manifestations of the so- 
 17* 
 
198 THE PHENOMENA OF MOTION 
 
 called mechanical forces, we have recognised in the 
 chemical forces causes of motion and of change in form 
 and structure, without any observable exhaustion of 
 the force by which these phenomena are produced ; 
 but the origin of the continued manifestation of activity 
 remains still the same ; it is the absence of an opposite 
 force (a resistance) capable of neutralizing it or bring- 
 ing it into the state of equilibrium. 
 
 As the manifestations of chemical forces (the mo- 
 mentum of force in a chemical compound) seem to 
 depend on a certain order in which the elementary par- 
 ticles are united together, so experience tells us, that 
 the vital phenomena are inseparable from matter ; that 
 the manifestations of the vital force in a living part are 
 determined by a certain form of that part, and by a 
 certain arrangement of its elementary particles. If we 
 destroy the form, or alter the composition of the organ, 
 all manifestations of vitality disappear. 
 
 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 there- 
 fore be considered as a resting point, from which an 
 investigation into these phenomena, and the laws which 
 regulate them, may be commenced ; exactly as we 
 consider the properties and laws of light to be depend- 
 
IN THE ANIMAL ORGANISM. 199 
 
 ent on a certain luminiferous matter, or ether, which 
 has no further connexion with the laws ascertained by 
 investigation. 
 
 Considered under this form, the vital force unites in 
 its manifestations all the peculiarities of chemical forces, 
 and of the not less wonderful cause, which we regard 
 as the ultimate origin of electrical phenomena. 
 
 The vital force does not act, like the force of gravi- 
 tation or the magnetic force, at infinite distances, but, 
 like chemical forces, it is active only in the case of im- 
 mediate contact. It becomes sensible by means of an 
 aggregation of material particles. 
 
 A living part acquires, on the above supposition, the 
 capacity of offering and of overcoming resistance, by 
 the combination of its elementary particles in a certain 
 form ; and as long as its form and composition are not 
 destroyed by opposing forces, it must retain its energy 
 uninterrupted and unimpaired. 
 
 When, by the act of manifestation of this energy in 
 a living part, the elements of the food are made to 
 unite in the same form and structure as the living organ 
 possesses, then these elements acquire the same powers. 
 By this combination, the vital force inherent in them is 
 enabled to manifest itself freely, and may be applied in 
 the same way as that of the previously existing tissue. 
 
 If, now, we bear in mind, that all matters which 
 serve as food to living organisms are compounds of two 
 or more elements, which are kept together by certain 
 chemical forces ; if we reflect that in the act of mani- 
 
200 THE PHENOMENA OF MOTION 
 
 festation of force in a living tissue, the elements of the 
 food are made to combine in a new order ; it is quite 
 certain that the momentum of force or of motion in the 
 vital force was more powerful than the chemical attrac- 
 tion existing between the elements of the food.* 
 
 The chemical force which >kept the elements together 
 acted as a resistance, which was overcome by the ac- 
 tive vital force. 
 
 Had both forces been equal, no kind of sensible 
 effect would have ensued. Had the chemical force 
 been the stronger, the living part would have undergone 
 a change. 
 
 If we now suppose that a certain amount of vital 
 force must have been expended in bringing to an equi- 
 librium the chemical force, there must still remain an 
 excess of force, by which the decomposition was ef- 
 fected. This excess constitutes the momentum of 
 force in the living part, by means of which the change 
 was produced ; by means of this excess the part ac- 
 quires a permanent power of causing further decompo- 
 sitions, and of retaining its condition, form, and struc- 
 ture, in opposition to external agencies. 
 
 We may imagine this excess to be removed, and 
 employed in some other form. This would not of it- 
 
 * The hands of a man, who raises with a rope and simple pulley, 
 30 Ibs. to the height of 100 feet, pass over a space of 100 feet, while 
 his muscular energy furnishes the equilibrium to a pressure of 30 Ibs. 
 Were the force which the man could exert not greater than would 
 suffice to keep in equilibrium a pressure of 30 Ibs., he would be una- 
 ble to i-aise the weight to the height mentioned. 
 
IN THE ANIMAL ORGANISM. 201 
 
 self endanger the existence of the living part, because 
 the opposing forces would be left in equilibrio ; but, by 
 the removal of the excess of force, the part would lose 
 its capacity of growth, its power to cause further de- 
 compositions, and its ability to resist external causes of 
 change. If, in this state of equilibrium, oxygen (a 
 chemical agent) should be brought in contact with it, 
 then there would be no resistance to the tendency of 
 the oxygen to combine with some element of the living 
 part, because its power of resistance has been taken 
 away by some other application of its excess of vital 
 force. According to the amount of oxygen brought to 
 it, a certain proportion of the living part would lose its 
 condition of vitality, and take the form of a chemical 
 combination, having a composition different from that 
 of the living tissue. In a word, there would occur a 
 change in the properties of the living compound, or 
 what we have called a change of matter. 
 
 If we reflect that the capacity of growth or increase 
 of mass in plants is almost unlimited ; that a hundred 
 twigs from a willow tree, if placed in the soil, become 
 a hundred trees ; we can hardly entertain a doubt, that 
 with the combination of the elements of the food of 
 the plant so as to form a part of it, a fresh momentum 
 of force is added in the newly formed part to the pre- 
 viously existing momentum in the plant ; insomuch, that 
 with the increase of mass, the sum of vital force is 
 augmented. 
 
 According to the amount of available vital force, the 
 
202 THE PHENOMENA OF MOTION 
 
 products formed by its activity from the food are va- 
 ried. The composition of the buds, of the radical 
 fibres, of the leaf, of the flower, and of the fruit, are 
 very different one from the other ; and the chemical 
 force by which their elements are held together is very 
 different in each of these cases. 
 
 Of the non-azotized constituents of plants we may 
 assert, that no part of the momentum of force is ex- 
 pended in maintaining their form and structure, when 
 their elements have once combined in that order in 
 which they become parts of organs endued with vitality. 
 
 Very different is the character of the azotized vege- 
 table principles ; for, when separated from the plant, 
 they pass, as is commonly said, spontaneously, into 
 fermentation and putrefaction. The cause of this de- 
 composition or transformation of their elements is the 
 chemical action which the oxygen of the atmosphere 
 exercises on one of their constituents. Now we know, 
 that, as long as the plant exhibits the phenomena of 
 life, oxygen gas is given off from its surface ; that this 
 oxygen is altogether without action on the constituents 
 of the living plant, for which, in other circumstances, it 
 has the strongest attraction. It is obvious, therefore, 
 that a certain amount of vital force must be expended, 
 partly to retain the elements of the complex azotized 
 principles in the form, order, and structure which be- 
 long to them ; and partly as a means of resistance 
 against the incessant tendency of the oxygen of the 
 atmosphere to act on their elements, as well as against 
 
IN THE ANIMAL ORGANISM. 203 
 
 that of the oxygen separated in the organism of the 
 plant by the vital process. 
 
 With the increase of these easily altered compounds, 
 in the flower and in the fruit, for example, the sum of 
 chemical force (the free manifestation of which, coun- 
 teracted by an equal measure of vital force, is employed 
 to furnish resistance) also increases. 
 
 The plant increases in mass until the vital force in- 
 herent in it comes into equilibrium with all the other 
 causes opposed to its manifestation. From this period, 
 every new cause of disturbance, added to those pre- 
 viously existing, (a change of temperature, for example,) 
 deprives it of the power of offering resistance, and it 
 dies down. 
 
 In perennial plants, (in trees, for example,) the mass 
 of the easily decomposable (azotized) compounds, 
 compared with that of the non-azotized, is so small, 
 that of the whole sum of force, only a minimum is 
 expended as resistance. In animals, this proportion is 
 reversed. 
 
 During every period of the life of a plant, the avail- 
 able vital force (that which is not neutralized by 
 resistance) is expended only in one form of vital mani- 
 festation, that of growth or increase of mass, or the 
 overcoming of resistance. No part of this force is 
 applied to other purposes. 
 
 In the animal organism, the vital force exhibits itself, 
 as in the plant, in the form of the capacity of growth, 
 and as the means of resistance to external agencies ; 
 
204 THE PHENOMENA OF MOTION 
 
 but both of these manifestations are confined within 
 certain limits. 
 
 We observe in animals, that the conversion of food 
 into blood, and the contact of the blood with the living 
 tissues, are determined by a mechanical force, whose 
 manifestation proceeds from distinct organs, and is 
 effected by a distinct system of organs, possessing the 
 property of communicating and extending the motion 
 which they receive. We find the power of the animal 
 to change its place, and to produce mechanical effects 
 by means of its limbs, dependent on a second similar 
 system of organs or apparatus. Both of these systems 
 of apparatus, as well as the phenomena of motion pro- 
 ceeding from them, are wanting in plants. 
 
 In order to form a clear conception of the origin and 
 source of the mechanical motions in the animal body, 
 it may be advantageous to reflect on the modus operandi 
 of other forces, which in their manifestations are most 
 closely allied to the vital force. 
 
 When a number of plates of zinc and copper, ar- 
 ranged in a certain order, are brought into contact with 
 an acid, and when the extremities of the apparatus are 
 joined by means of a metallic wire, a chemical action 
 begins at the surface of the plates of zinc, and the wire, 
 in consequence of this action, acquires the most singular 
 and wonderful properties. 
 
 The wire appears as the carrier or conductor of a 
 force, which may be conducted and communicated 
 through it in every direction with amazing velocity. 
 
IN THE ANIMAL ORGANISM. 2Q5 
 
 It is the conductor or propagator of an uninterrupted 
 series of manifestations of activity. 
 
 Such a propagation of motion is inconceivable, if in 
 the wire there were a resistance to be overcome ; for 
 every resistance would convert a part of the moving 
 force into a force at rest. 
 
 When the wire is divided in the middle, and its con- 
 tinuity interrupted, the propagation of force ceases, and 
 we observe, that in this case the action between the 
 zinc and the acid is immediately stopped. 
 
 If the communication be restored, the action which 
 had disappeared, reappears with all its original energy. 
 
 By means of the force present in the wire, we can 
 produce the most varied effects ; we can overcome all 
 kinds of resistance, raise weights, set ships in motion, 
 &c. And, what is still more remarkable, the wire acts 
 as a hollow tube, in which a current of chemical force 
 circulates freely and without hinderance. 
 
 Those properties which, when firmly attached to 
 certain bodies, we call the strongest and most energetic 
 affinities, we find, to all appearance, free and uncombin- 
 ed in the wire. We can transport them from the wire 
 to other bodies, and thereby give to them an affinity 
 (a power of entering into combination) which in them- 
 selves they do not possess. According to the amount 
 of force circulating in the wire, we are able by means 
 of it to decompose compounds, the elements of which 
 have the strongest attraction for each other. Yet the 
 substance of the wire takes not the smallest share in 
 18 
 
206 THE PHENOMENA OF MOTION 
 
 all these manifestations of force ; it is merely the con- 
 ductor of force. 
 
 We observe, further, in this wire, phenomena of at- 
 traction and repulsion, which we must ascribe to the 
 disturbance of the equilibrium in the electric or mag- 
 netic force ; and when this equilibrium is restored, the 
 restoration is accompanied by the development of light 
 and heat, its never-failing companions. 
 
 All these remarkable phenomena are produced by 
 the chemical action which the zinc and the acid exert 
 on each other ; they are accompanied by a change in 
 form and structure, which both undergo. 
 
 The acid loses its chemical character ; the zinc en- 
 ters into combination with it. The manifestations of 
 force produced in the wire are the immediate conse- 
 quence of the change in the properties of the acid and 
 the metal. 
 
 One particle of acid after another loses its peculiar 
 chemical character ; and we perceive that in the same 
 proportion the wire acquires a chemical, mechanical, 
 galvanic, or magnetic force, whatever name be given to 
 it. According to the number of acid particles which 
 in a given time undergo this change, that is, according 
 to the surface of the zinc, the wire receives a greater 
 or less amount of these forces. 
 
 The continuance of the current of force depends on 
 the duration of the chemical action ; and the duration 
 of the latter is most closely connected with the carry- 
 ing away, by conduction, of the force. 
 
IN THE ANIMAL ORGANISM. 207 
 
 If we check the propagation of the current of force, 
 the acid retains its chemical character. If we employ 
 it to overcome chemical or mechanical resistance, to 
 decompose chemical compounds, or to produce motion, 
 the chemical action continues ; that is to say, one par- 
 ticle of acid after another changes its properties. 
 
 In the preceding paragraphs we have considered 
 these remarkable phenomena in a form which is inde- 
 pendent of the explanations of the schools. Is the 
 force which circulates in the wire the electrical force ? 
 Is it chemical affinity ? Is it propagated in the conduc- 
 tor like a fluid set in motion, or in the form of a series 
 of momenta of motion, like light and sound, from one 
 particle of the conductor to another ? All this we 
 know not, and we shall never know. All the supposi- 
 tions which may be employed as explanations of the 
 phenomena have not the slightest influence on the truth 
 of these phenomena ; for they refer merely to the form 
 in which they are ma ilfested. 
 
 On some points, however, there is no doubt ; name- 
 ly, that all the effects which may be produced by the 
 wire are determined by the change of properties in the 
 zinc and in the acid ; for the term " chemical action " 
 signifies neither more nor less than the act of change in 
 them ; that these effects depend on the presence of a 
 conductor, of a substance which propagates in all direc- 
 tions, where it is not neutralized by resistance, the 
 force or momentum produced ; that this force becomes 
 a momentum of motion, by means of which we can 
 
208 THE PHENOMENA OF MOTION 
 
 produce mechanical effects, and which, when trans- 
 ferred to other bodies, communicates to them all those 
 properties, the ultimate cause of which is the chemical 
 force itself; for these bodies acquire the power of caus- 
 ing decompositions and combinations, such as, without 
 a supply of force through the conductor, they could not 
 effect. 
 
 If we employ these well-known facts as means to 
 assist us in investigating the ultimate cause of the me- 
 chanical effects in the animal organism, observation 
 teaches us, that the motion of the blood and of the 
 other animal fluids proceeds from distinct organs, which, 
 as in the case of the heart and intestines, do not gener- 
 ate the moving power in themselves, but receive it from 
 other quarters. 
 
 We know with certainty that the nerves are the con- 
 ductors and propagators of mechanical effects ; we 
 know, that by means of them motion is propagated in 
 all directions. For each motion we recognise a sep- 
 arate nerve, a peculiar conductor, with the conducting 
 power of which, or with its interruption, the propaga- 
 tion of motion is affected or destroyed. 
 
 By means of the nerves all the parts of the body, all 
 the limbs, receive the moving force which is indispen- 
 sable to their functions, to change of place, to the pro- 
 duction of mechanical effects. Where nerves are not 
 found, motion does not occur. The excess of force 
 generated in one place is conducted to other parts by 
 the nerves. The force which one organ cannot pro- 
 
JN THE ANIMAL ORGANISM. 209 
 
 duce in itself is conveyed to it from other quarters ; 
 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. 
 
 We observe further, that the voluntary and involun- 
 tary motions, in other words, all mechanical effects in 
 the animal organism, are accompanied by, nay, are de- 
 pendent on, a peculiar change of form and structure in 
 the substance of certain living parts, the increase or 
 diminution of which change stands in the very closest 
 relation to the measure of motion, or the amount of 
 force consumed in the motions performed. 
 
 As an immediate effect of the manifestation of me- 
 chanical force, we see, that a part of the muscular sub- 
 stance loses its vital properties, its character of life ; 
 that this portion separates from the living part, and loses 
 its capacity of growth and its power of resistance. 
 We find that this change of properties is accompanied 
 by the entrance of a foreign body (oxygen) into the 
 composition of the muscular fibre (just as the acid lost 
 its chemical character by combining with zinc) ; and all 
 experience proves, that this conversion of living mus- 
 cular fibre into compounds destitute of vitality is accel- 
 erated or retarded according to the amount of force 
 employed to produce motion. Nay, it may safely be 
 affirmed, that they are mutually proportional ; that a 
 rapid transformation of muscular fibre, or, as it may be 
 called, a rapid change of matter, determines a greater 
 18* 
 
210 THE PHENOMENA OF MOTION 
 
 amount of mechanical force ; and conversely, that a 
 greater amount of mechanical motion (of mechanical 
 force expended in motion) determines a more rapid 
 change of matter. 
 
 From this decided relation between the change of 
 matter in the animal body and the force consumed in 
 mechanical motion, no other conclusion can be drawn 
 but this, that the active or available vital force in certain 
 living parts is the cause of the mechanical phenomena in 
 the animal organism. 
 
 The moving force certainly proceeds from living 
 parts ; these parts possessed a momentum of force or 
 of motion, which they lost in proportion as other parts 
 acquired a momentum of force or of motion ; they lose 
 their capacity of growth, and their power to resist ex- 
 ternal causes of change. It is obvious that the ultimate 
 cause, the vital force, from which they acquired those 
 properties, has served for the production of mechanical 
 force, that is, has been expended in the shape of 
 motion. 
 
 How, indeed, could we conceive, that a living part 
 should lose the condition of life, should become inca- 
 pable of resisting the action of the oxygen conveyed to 
 it by the arterial blood, and should be deprived of the 
 power to overcome chemical resistance, unless the mo- 
 mentum of the vital force, which had given to it all 
 these properties, had been expended for other pur- 
 poses ? 
 
 By the power of the conductors, the nerves, to 
 
IN THE ANIMAL ORGANISM. 211 
 
 propagate the momentum of force in a living part, or 
 the effect which the active vital force inherent in the 
 part produces on all the surrounding parts, in all direc- 
 tions where- the force, or rather its momentum of mo- 
 tion, is consumed without resistance (for without motion 
 no change of matter occurs, and when motion has 
 begun, there is no longer resistance), an equilibrium is 
 obviously established in the* living part, between the 
 chemical forces and the remaining vital force ; which 
 equilibrium would not have occurred had not vital force 
 been expended in producing mechanical motion. 
 
 In this state, any external cause capable of exerting 
 an influence on the form, structure, and composition of 
 the organ meets with no further resistance. If oxygen 
 were not conveyed to it, the organ would maintain its 
 condition, but without any manifestation of vitality. It 
 is only with the commencement of chemical action that 
 the change of matter, that is, the separation of a part 
 of the organ in the form of lifeless compounds, begins. 
 
 The change of matter, the manifestation of mechani- 
 cal force, and the absorption of oxygen, are, in the 
 animal body, so closely connected with each, other, that 
 we may consider the amount of motion, and the quantity 
 of living tissue transformed, as proportional to the 
 quantity of oxygen inspired and consumed in a given 
 time by the animal. For a certain amount of motion, 
 for a certain proportion of vital force consumed as me- 
 chanical force, an equivalent of chemical force is mani- 
 fested ; that is, an equivalent of oxygen enters into 
 
212 THE PHENOMENA OF MOTION 
 
 combination with the substance of the organ which has 
 lost the vital force ; and a corresponding proportion of 
 the substance of the organ is separated from the living 
 tissue in the shape of an oxidized compound. 
 
 All those parts of the body which nature has des- 
 tined to effect the change of matter, that is, to the pro- 
 duction of mechanical force, are penetrated in all direc- 
 tions by a multitude of the most minute tubes or vessels, 
 in which a current of oxygen continually circulates, in 
 the form of arterial blood. To the above-mentioned 
 separation of part of the elements of these parts, in 
 other words, to the disturbance of their equilibrium, this 
 oxygen is absolutely essential. 
 
 As long as the vital force of these parts is not con- 
 ducted away and applied to other purposes, the oxygen 
 of the arterial blood has not the slightest effect on the 
 substance of the organized parts ; and in all cases, only 
 so much oxygen is taken up as corresponds to the con- 
 ducting power, and, consequently, to the mechanical 
 effects produced. 
 
 The oxygen of the atmosphere is the proper, active, 
 external cause of the waste of matter in the animal 
 body ; it acts like a force which disturbs and tends to 
 destroy the manifestation of the vital force at every 
 moment. But its effect as a chemical agent, the dis- 
 turbance proceeding from it, is held in equilibrium by 
 the vital force, which is free and available in the living 
 tissue, or is annihilated by a chemical agency opposed 
 
IN THE AN[MAL ORGANISM. 213 
 
 to that of oxygen, the manifestation of which must be 
 considered as dependent on the vital force. 
 
 In chemical language, to annihilate the chemical ac- 
 tion of oxygen, means, to present to it substances, or 
 parts of organs, which are capable of combining with it. 
 
 The action of oxygen (affinity) is either neutralized 
 by means of the elements of organized parts, which 
 combine with it (after the free vital force has been con- 
 ducted away), or else the organ presents to it the pro- 
 ducts of other organs, or certain matters formed from 
 the elements of the food, by the vital activity of certain 
 systems of apparatus. 
 
 It is only the muscular system which, in this sense, 
 produces in itself a resistance to the chemical action 
 of oxygen, and neutralizes it completely. 
 
 The substance of cellular tissue, of membranes, and 
 of the skin, the minutest particles of which are not in 
 immediate contact with arterial blood (with oxygen), 
 are not destined to undergo this change of matter. 
 Whatever changes they may undergo in the vital pro- 
 cess, affect, in all cases, only their surface. 
 
 The gelatinous tissues, mucous membranes, tendons, 
 &c., are not designed to produce mechanical force ; 
 they contain in their substance no conductors of me- 
 chanical effects. But the muscular system is inter- 
 woven with innumerable nerves. The substance of the 
 uterus is in no respect different in chemical composition 
 from the other muscles ; but it is not adapted to the 
 change of matter, to the production of force, and con- 
 
214 THE PHENOMENA OF MOTION 
 
 tains no organs for conducting away the moving power. 
 Cellular tissue, gelatinous membranes, and mucous 
 membranes, are far from being destitute of the power 
 of combinin ; with oxygen, when moisture is present ; 
 we know that, when moist, they cannot be brought in 
 contact with oxygen without undergoing a progressive 
 alteration. But one surface of the intestines and the 
 cells of the lungs is constantly in contact with oxy- 
 gen ; and it is obvious, that they must be as rapidly 
 altered by the chemical action of the oxygen in the 
 body as out of it, were it not that there exists in the 
 organism itself a source of resistance, which completely 
 neutralizes the action of the oxygen. Among the 
 means by which this resistance is furnished we may 
 include all substances which are capable of combining 
 with oxygen, or acquire that property under the influ- 
 ence of the vital force, and which surpass the tissues 
 above-mentioned in their power of neutralizing its 
 chemical action. 
 
 All those constituents of the body which, in them- 
 selves, do not possess, in the form of vital force, the 
 power of resisting the action of oxygen, must be far 
 better adapted for the purpose of combining with, and 
 neutralizing it, than those tissues which are under the 
 influence of the vital force, although only through the 
 nerves. In this point of view, we cannot fail to per- 
 ceive the importance of the bile in regard to the sub- 
 stance of the intestines, and that of the pulmonary cells, 
 as well as that of fat, of mucus, and of the secretions 
 generally. 
 
IN THE ANIMAL ORGANISM. 215 
 
 When the membranes are compelled from their own 
 substance to furnish resistance to the action of the 
 oxygen, that is, when there is a deficiency of the sub- 
 stances destined by nature for their protection, they 
 must, since their renewal is confined within narrow 
 limits, yield to the chemical action. The lungs and 
 intestines will always simultaneously suffer abnormal 
 changes. 
 
 From the change of matter itself, from the meta- 
 morphosis of the living muscular tissue, these organs 
 receive the means of resistance to the action of oxygen 
 which are indispensable to their preservation. Ac- 
 cording to .the rapidity of this process, the quantity of 
 bile secreted increases ; while that of the fat present in 
 the body diminishes in the same proportion. 
 
 For carrying on the involuntary motions in the ani- 
 mal body, a certain amount of vital force is expended 
 at every moment of its existence ; and, consequently, 
 an incessant change of matter goes on ; but the amount 
 of living tissue, which, in consequence of this form of 
 consumption of vital force, loses its condition of life 
 and its capacity of growth, is confined within narrow 
 limits. It is directly proportional to the force required 
 for these involuntary motions. 
 
 Now, although we may suppose that the living mus- 
 cular tissue, with a sufficient supply of food, never 
 loses its capacity of growth ; that this form of vital 
 manifestation is continually effective ; this cannot apply 
 to those parts of the body whose available vital force 
 
216 THE PHENOMENA OF MOTION 
 
 has been expended in producing mechanical effects. 
 For the waste of matter, in consequence of motion and 
 laborious exertion, is extremely various in different 
 individuals. 
 
 If we reflect, that the slightest motion of a finger 
 consumes force ; that in consequence of the force ex- 
 pended, a corresponding portion of muscle diminishes 
 in volume ; it is obvious, that an equilibrium between 
 supply and waste of matter (in living tissues) can only 
 occur when the portion separated or expelled in a life- 
 less form is, at the same instant in which it loses its 
 vital condition, restored in another part. 
 
 The capacity of growth or increase in mass depends 
 on the momentum of force belonging to each part ; 
 and must be capable of continued manifestation (if 
 there be a sufficient supply of nourishment), as long 
 as it does not lose this momentum, by expending it, 
 for example, in producing motion. 
 
 In all circumstances, the growth itself is restricted 
 to the time ; that is to say, it cannot be unlimited in 
 a limited time. 
 
 A living part cannot increase in volume at the same 
 moment in which a portion of it loses the vital con- 
 dition, and is expelled from the organ in the form of 
 a lifeless compound ; on the contrary, its volume must 
 diminish. 
 
 The continued application of the momentum of force 
 in living tissues to mechanical effects determines, there- 
 fore, a continued separation of matter ; and only from 
 
IN THE ANIMAL ORGANISM. 217 
 
 the period at which the cause of waste ceases to oper- 
 ate, can the capacity of growth be manifested. 
 
 Now, since, in different individuals, according to the 
 amount of force consumed in producing voluntary me- 
 chanical effects, unequal quantities of living tissue are 
 wasted, there must occur, in every individual, unless 
 the phenomena of motion are to cease entirely, a con- 
 dition in which all voluntary motions are completely 
 checked, in which, therefore, these occasion no waste. 
 This condition is called sleep. 
 
 The growth of one part, which is not deprived of 
 its vital force, cannot be in the slightest degree affected 
 by the consumption of the vital force of another part 
 in producing motion. The one may increase in vol- 
 ume, while the other diminishes , and the waste in 
 one can neither increase nor diminish the supply in the 
 other. 
 
 Now, since the consumption of force for the in- 
 voluntary motions continues in sleep, it is plain, that 
 a waste of matter also continues in that state ; and 
 if the original equilibrium is to be restored, we must 
 suppose that, during sleep, an amount of force is accu- 
 mulated in the form of living tissue, exactly equal to 
 that which was consumed in voluntary and involuntary 
 motion during the preceding waking period. 
 
 If the equilibrium between waste and supply of mat- 
 ter be in the least degree disturbed, this is instantly seen, 
 in the different amount of force available for mechanical 
 purposes. 
 
 19 
 
218 THE PHENOMENA OF MOTION 
 
 It is further obvious, that if there should occur a dis- 
 proportion between the conducting power of the nerves of 
 voluntary and involuntary motion, a difference in the 
 phenomena of motion themselves will be perceptible, in 
 the same proportion as the one or the other is capable 
 of propagating the momentum of force, generated by 
 the change of matter. As the motions of the circulat- 
 ing system and of the intestines increase, the power of 
 producing mechanical effects in the limbs must diminish 
 in the same proportion (as in wasting fevers) ; and if, in 
 a given time, more vital force has been consumed for 
 mechanical purposes (labor, running, dancing, &c.) 
 than is properly available for the voluntary and involun- 
 tary motions ; if force be expended more rapidly than 
 the change of matter can be effected in the same time ; 
 then a part of that force which is necessary for the in- 
 voluntary motions must be expended in restoring the 
 excess of force consumed in voluntary motion. The 
 motions of the heart and of the intestines, in this case, 
 will be retarded, or will entirely cease. 
 
 From the unequal degree of conducting power in the 
 nerves, we must deduce those conditions which are 
 termed paralysis, syncope, and spasm. Paralysis of 
 the nerves of voluntary motion may exist without ema- 
 ciation ; but frequently recurring attacks of epilepsy (in 
 which vital force is rapidly wasted in producing me- 
 chanical effects) are always accompanied by remarkably 
 rapid emaciation. 
 
 It ought to excite the highest admiration when we 
 
IN THE ANIMAL ORGANISM. 21 9 
 
 consider with what infinite wisdom the Creator has di- 
 vided the means by which animals and plants are quali- 
 fied for their functions, for their peculiar vital manifes- 
 tations. 
 
 The living part of a plant acquires the whole force 
 and direction of its vital energy from the absence of all 
 conductors of force. By this means the leaf is enabled 
 to overcome the strongest chemical attractions, to de- 
 compose carbonic acid, and to assimilate the elements 
 of its nourishment. 
 
 In the flower alone does a process similar to the 
 change of matter in the animal body occur. There, 
 phenomena of motion appear ; but the mechanical ef- 
 fects are not propagated to a distance, owing to the ab- 
 sence of conductors of force. 
 
 The same vital force which we recognise in the plant 
 as an almost unlimited capacity of growth, is converted 
 in the animal body into moving power (into a current of 
 vital force) ; and a most wonderful and wise economy 
 has destined for the nourishment of the animal only 
 such compounds as have a composition identical with 
 that of the organs which generate force, that is, with the 
 muscular tissue. The expenditure of force which the 
 living parts of animals require, in order to reproduce 
 themselves from the blood ; the resistance of the chem- 
 ical force which has to be overcome in the azotized 
 constituents of food by the vital agency of the organs 
 destined to convert them into blood ; these are as noth- 
 ing compared to the force with which the elements of 
 
220 THE PHENOMENA OF MOTION 
 
 carbonic acid are held together. A certain amount of 
 force would necessarily be prevented from assuming the 
 form of moving power, if it were to be expended in 
 overcoming chemical resistance ; for the momentum of 
 motion of the vital force is diminished by all obstacles. 
 But the conversion of the constituents of blood into 
 muscular fibre (into an organ which generates force) is 
 only a change of form. Both have the same composi- 
 tion ; blood is fluid, muscular fibre is solid blood. We 
 may even suppose that this change takes place without 
 any expenditure of vital force ; for the mere passage 
 of a fluid body into the solid state requires no manifes- 
 tation of force, but only the removal of obstacles, which 
 oppose that force (cohesion), which determines the 
 form of matter, in its manifestations. 
 
 In what form or in what manner the vital force pro- 
 duces mechanical effects in the animal body is altogeth- 
 er unknown, and is as little to be ascertained by experi- 
 ment as the connexion of chemical action with the phe- 
 nomena of motion which we can produce with the galvan- 
 ic battery. All the explanations which have been attempt- 
 ed are only representations of the phenomenon ; they 
 are, more or less, exact descriptions and comparisons 
 of known phenomena with these, whose cause is un- 
 known. In this respect we are like an ignorant man, 
 to whom the rise and fall of an iron rod in a cylinder, 
 in which the eye can perceive nothing, and its connex- 
 ion with the turning and motion of a thousand wheels at 
 a distance from the piston-rod, appear incomprehensible. 
 
IN THE ANIMAL ORGANISM. 221 
 
 We know not how a certain something, invisible and 
 imponderable in itself (heat), gives to certain bodies 
 the power of exerting an enormous pressure on sur- 
 rounding objects ; we know not even how this some- 
 thing itself is produced when we burn wood or coals. 
 
 So is it with the vital force, and with the phenomena 
 exhibited by living bodies. The cause of these phe- 
 nomena is not chemical force ; it is not electricity, nor 
 magnetism ; it is a force which has certain properties in 
 common with all causes of motion and of change in form 
 and structure in material substances. It is a peculiar 
 force, because it exhibits manifestations which are found 
 in no other known force. 
 
 .'.;-.: ii. , 
 
 In the living plant, the intensity of the vital force far 
 exceeds that of the chemical action of oxygen. 
 
 We know, with the utmost certainty, that, by the 
 influence of the vital force, oxygen is separated from 
 elements to which it has the strongest affinity ; that it 
 is given out in the gaseous form, without exerting the 
 slightest action on the juices of the plant. 
 
 How powerful, indeed, must the resistance appear, 
 which the vital force supplies to leaves charged with 
 oil of turpentine or tannic acid, when we consider the 
 affinity of oxygen for these compounds ! 
 19* 
 
222 THE PHENOMENA OF MOTION 
 
 This intensity of action or of resistance the plant 
 obtains by means of the sun's light ; the effect of which 
 in chemical actions may be, and is, compared to that 
 of a very high temperature (a moderate red heat). 
 
 During the night an opposite process goes on in the 
 plant ; we see then that the constituents of the leaves 
 and green parts combine with the oxygen of the air, 
 a property which in daylight they did not possess. 
 
 From these facts we can draw no other conclusion 
 but this ; that the intensity of the vital force diminishes 
 with the abstraction of light ; that with the approach 
 of night a state of equilibrium is established, and that 
 in complete darkness all those constituents of plants 
 which, during the day, possessed the power of separat- 
 ing oxygen from chemical combinations, and of resisting 
 its action, lose this power completely. 
 
 A precisely similar phenomenon is observed in ani- 
 mals. 
 
 The living animal body exhibits its peculiar manifes- 
 tations of vitality only at certain temperatures. When 
 exposed to a certain degree of cold, these vital phe- 
 nomena entirely cease. 
 
 The abstraction of heat must, therefore, be viewed 
 as quite equivalent to a diminution of the vital energy ; 
 the resistance opposed by the vital force to external 
 causes of disturbance must diminish, in certain tempera- 
 tures, in the same ratio in which the tendency of the 
 elements of the body to combine with the oxygen of 
 the air increases. 
 
IN THE ANIMAL ORGANISM. 223 
 
 By the combination of oxygen with the constituents 
 of the metamorphosed tissues, the temperature ne- 
 cessary to the manifestations of vitality, is produced 
 in the carnivora. In the herbivora, again, a certain 
 amount of heat is developed by means of those ele- 
 ments of their non-azotized food, which have the prop- 
 erty of combining with oxygen. 
 
 It is obvious, that the temperature of an animal body 
 cannot change, if the amount of inspired oxygen in- 
 creases in the same ratio as the loss of heat by external 
 cooling. 
 
 Two individuals, carnivora, of equal weight, ex- 
 posed to unequal degrees of cold, lose, in a given time, 
 by external cooling, unequal quantities of heat. Ex- 
 perience teaches, that if their peculiar temperature and 
 their original weight are to remain unaltered, they re- 
 quire unequal quantities of food ; more in the lower 
 temperature than in the higher. 
 
 The circumstance, that the original weight remains 
 the same, with unequal quantities of food, obviously 
 presupposes, that in the same time a quantity of oxygen 
 proportional to the temperature has been absorbed ; 
 more in the lower than in the higher temperature. 
 
 We find that the weight of both individuals, at the 
 end of 24 hours, is equal to the original weight. But 
 we have assumed that their food is converted into blood ; 
 that the blood has served for nutrition ; and it is plain, 
 that when the original weight has been restored, a quan- 
 tity of the constituents of the body, equal in weight to 
 
224 THE PHENOMENA OF MOTION 
 
 those of the food, has lost its condition of life, and has 
 been expelled in combination with oxygen. 
 
 The one individual, which, being exposed to the 
 lower temperature, consumed more food, has also ab- 
 sorbed more oxygen ; a greater quantity of the con- 
 stituents of its body has been separated in combination 
 with oxygen ; and, in consequence of this combination 
 with oxygen, a greater amount of heat has been lib- 
 erated, by which means the heat abstracted has been 
 restored, and the proper temperature of the body kept 
 up. 
 
 Consequently, by the abstraction of heat, provided 
 there be a full supply of food and free access of oxy- 
 gen, the change of matter must be accelerated ; and, 
 along with the augmented transformation, in a given 
 time, of living tissues, a greater amount of vital force 
 must be rendered available for mechanical purposes. 
 
 With the external cooling, the respiratory motions 
 become stronger ; in a lower temperature more oxygen 
 is conveyed to the blood ; the waste of matter increases, 
 and if the supply be not kept in equilibrium with this 
 waste, by means of food, the temperature of the body 
 gradually sinks. 
 
 But, in a given time, an unlimited supply of oxygen 
 cannot be introduced into the body ; only a certain 
 amount of living tissue can lose the state of life, and 
 only a limited amount of vital force can be manifested 
 in mechanical phenomena. It is only, therefore, when 
 the cooling, the generation of force, and the absorption 
 
IN THE ANIMAL ORGANISM. 225 
 
 of oxygen are in equilibrium together, that the tem- 
 perature of the body can remain unchanged. If the 
 loss of heat by cooling go beyond a certain point, the 
 vital phenomena diminish in the same ratio ; for the 
 temperature falls, and the temperature must be consid- 
 ered as a uniform condition of their manifestation. 
 
 Now experience teaches, that when the temperature 
 of the body sinks, the power of the limbs to produce 
 mechanical effects (or the force necessary to the vol- 
 untary motions) is also diminished. The condition of 
 sleep ensues, and at last even the involuntary motions 
 (those of the heart and intestines, for example) cease, 
 and apparent death or syncope supervenes. 
 
 It is obvious that the cause of the generation of force, 
 namely, the change of matter, is diminished, because, 
 with the abstraction of heat, as in the plant by abstrac- 
 tion of light, the intensity of the vital force diminishes. 
 It is obvious, that the momentum of force in a living 
 part depends on its proper temperature ; exactly as the 
 effect of a falling body stands in a fixed relation to cer- 
 tain other conditions ; for example, to the velocity at- 
 tained in falling. 
 
 When the temperature sinks, the vital energy dimin- 
 ishes ; when it again rises, the momentum of force in 
 the living parts appears once more in all its original in- 
 tensity. 
 
 The production of force for mechanical purposes, 
 and the temperature of the body must, consequently, 
 
226 THE PHENOMENA OF MOTION 
 
 bear a fixed relation to the amount of oxygen which 
 can be absorbed in a given time by the animal body. 
 
 The quantities of oxygen which a whale and a carri- 
 er's horse can inspire in a given time are very unequal. 
 The temperature, as well as the quantity of oxygen, 
 is much greater in the horse. 
 
 The force exerted by a whale, when struck with the 
 harpoon, his body being supported by the surrounding 
 medium, and the force exerted by a carrier's horse, 
 which carries its own weight and a heavy burden for 
 eight or ten hours, must both bear the same ratio to the 
 oxygen consumed. If we take into consideration the 
 time during which the force is manifested, it is obvious 
 that the amount of force developed by the horse is far 
 greater than in the case of the whale. 
 
 In climbing high mountains, where, in consequence 
 of the respiration of a highly rarefied atmosphere, much 
 less oxygen is conveyed to the blood, in equal times, 
 than in valleys or at the level of the sea, the change of 
 matter diminishes in the same ratio, and with it the 
 amount of force available for mechanical purposes. 
 For the most part, drowsiness and want of force for 
 mechanical exertions come on ; after twenty or thirty 
 steps, fatigue compels us to a fresh accumulation of 
 force by means of rest (absorption of oxygen without 
 waste of force in voluntary motions) . 
 
 By the absorption of oxygen into the substance of 
 living tissues, these lose their condition of life, and are 
 separated as lifeless, unorganized compounds ; but the 
 
IN THE ANIMAL ORGANISM. 227 
 
 whole of the inspired oxygen is not applied to these 
 transformations ; the greater part serves to convert into 
 gas and vapor all matters which no longer belong to the 
 organism ; and, as formerly mentioned, the combination 
 of the elements of such compounds with the oxygen 
 produces the temperature proper to the animal organism. 
 
 The production of heat and the change of matter are 
 closely related to each other ; but although heat can be 
 produced in the body without any change of matter in 
 living tissues, yet the change of matter cannot be 
 supposed to take place without the cooperation of 
 oxygen. 
 
 According to all the observations hitherto made, 
 neither the expired air, nor the perspiration, nor the 
 urine contains any trace of alcohol, after indulgence in 
 spirituous liquors ; and there can be no doubt that the 
 elements of alcohol combine with oxygen in the body ; 
 that its carbon and hydrogen are given off as carbonic 
 acid and water. 
 
 The oxygen which has accomplished this change 
 must have been taken from the arterial blood ; for we 
 know of no channel, save the circulation of the blood, 
 by which oxygen can penetrate into the interior of the 
 body. 
 
 Owing to its volatility and the ease with which its 
 vapor permeates animal membranes and tissues, alcohol 
 can spread throughout the body in all directions. 
 
 If the power of the elements of alcohol to combine 
 with oxygen were not greater than that of the com- 
 
228 THE PHENOMENA OF MOTION 
 
 pounds formed by the change of matter, or that of the 
 substance of living tissues, they (the elements of alco- 
 hol) could not combine with oxygen in the body. 
 
 It is, consequently, obvious, that by the use of alco- 
 hol a limit must rapidly be put to the change of matter 
 in certain parts of the body. The oxygen of the arte- 
 rial blood, which, in the absence of alcohol, would have 
 combined with the matter of the tissues, or with that 
 formed by the metamorphosis of these tissues, now 
 combines with the elements of alcohol. The arterial 
 blood becomes venous, without the substance of the 
 muscles having taken any share in the transformation. 
 
 Now, we observe, that the development of heat in 
 the body, after the use of wine, increases rather than 
 diminishes, without the manifestation of a correspond- 
 ing amount of mechanical force. 
 
 A moderate quantity of wine, in women and children 
 unaccustomed to its use, produces, on the contrary, a 
 diminution of the force necessary for voluntary motions. 
 Weariness, feebleness in the limbs, and drowsiness, 
 plainly show that the force available for mechanical pur- 
 poses, in other words, the change of matter, has been 
 diminished. 
 
 A diminution of the conducting power of the nerves 
 of voluntary motion may doubtless take a certain share 
 in producing these symptoms ; but this must be al- 
 together without influence on the sum of available force. 
 
 What the conductors of voluntary motion cannot 
 carry away for effects of force, must be taken up by the 
 
IN THE ANIMAL ORGANISM. 229 
 
 nerves of involuntary motion, and conveyed to the 
 heart, lungs, and intestines. In this case, the circula- 
 tion will appear accelerated at the expense of the force 
 available for voluntary motion ; but, as was before re- 
 marked, without the production of a greater amount of 
 mechanical force by the process of oxidation of the 
 alcohol. 
 
 Finally, we observe, in hybernating animals, that, 
 during their winter sleep, the capacity of increase in 
 mass (one of the chief manifestations of the vital 
 force), owing to the absence of food, is entirely sup- 
 pressed. In several, apparent death occurs in conse- 
 quence of the low temperature and of the diminution of 
 vital energy thus produced ; in others, the involuntary 
 motions continue, and the animal preserves a tempera- 
 ture independent of the surrounding temperature. The 
 respirations go on ; oxygen, the condition which deter- 
 mines the production of heat and force, is absorbed 
 now as well as in the former state of the animal ; and 
 previous to the winter sleep, we find all those parts 
 of their body, which in themselves are unable to furnish 
 resistance to the action of the oxygen, and which, like 
 the intestines and membranes, are not destined for 
 the change of matter, covered with fat ; that is, sur- 
 rounded by a substance which supplies the want of re- 
 sistance. 
 
 If we now suppose, that the oxygen absorbed during 
 the winter sleep combines, not with the elements of 
 living tissues, but with those of the fat, then the living 
 20 
 
230 THE PHENOMENA OF MOTION 
 
 part, although a certain momentum of motion be ex- 
 pended in keeping up the circulation, will not be sep- 
 arated and expelled from the body. 
 
 With the return of the higher temperature, the ca- 
 pacity of growth increases in the same ratio, and the 
 motion of the blood increases with the absorption of 
 oxygen. Many of these animals become emaciated 
 during the winter sleep, others not till after awaking 
 from it. 
 
 In hybernating animals the active force of the living 
 parts is exclusively devoted, during hybernation, to the 
 support of the involuntary motions. The expenditure 
 of force in voluntary motion is entirely suppressed. 
 
 In contradistinction to these phenomena, we know 
 that, in the case of excess of motion and exertion, the 
 active force in living parts may be exclusively and 
 entirely consumed in producing voluntary mechanical 
 effects ; in suchwise that no force shall remain avail- 
 able for the involuntary motions. A stag may be 
 hunted to death ; but this cannot occur without the 
 metamorphosis of all the living parts of its muscular 
 system, and its flesh becomes uneatable. The con- 
 dition of metamorphosis into which it has been brought 
 by an enormous consumption both of force and of 
 oxygen, continues when all phenomena of motion have 
 ceased. In the living tissues, all the resistance offered 
 by the vital force to external agencies of change is 
 entirely destroyed. 
 
 But however closely the conditions of the produc- 
 
IN THE ANIMAL ORGANISM. 231 
 
 tion of heat and of force may seem to be connected 
 together, with reference to mechanical effects, yet the 
 disengagement of heat can in no way be considered as 
 in itself the only cause of these effects. 
 
 All experience proves, that there is, in the organism, 
 only one source of mechanical power ; and this source 
 is the conversion of living parts into lifeless, amor- 
 phous compounds. 
 
 Proceeding from this truth, which is independent of 
 all theory, animal life may be viewed as determined by 
 the mutual action of opposed forces ; of which one 
 class must be considered as causes of increase (of sup- 
 ply of matter), and the other as causes of diminution 
 (of waste of matter) . 
 
 The increase of mass is effected in living parts by 
 the vital force ; the manifestation of this power is de- 
 pendent on heat ; that is, on a certain temperature 
 peculiar to each specific organism. 
 
 The cause of waste of matter is the chemical action 
 of oxygen ; and its manifestation is dependent on the 
 abstraction of heat as well as on the expenditure of the 
 vital force for mechanical purposes. 
 
 The act of waste of matter is called the change of 
 matter ; it occurs in consequence of the absorption of 
 oxygen into the substance of living parts. This absorp- 
 tion of oxygen occurs only when the resistance which 
 the vital force of living parts opposes to the chemical 
 action of the oxygen is weaker than that chemical ac- 
 tion ; and this weaker resistance is determined by the 
 
232 THE PHENOMENA OF MOTION 
 
 abstraction of heat, or by the expenditure in mechanical 
 motions of the available force of living parts. 
 
 By the combination of the oxygen introduced in the 
 arterial blood with such constituents of the body as 
 offer no resistance to its action, the temperature neces- 
 sary for the manifestation of vital activity is produced. 
 
 From the relations between the consumption of oxy- 
 gen on the one hand, and the change of matter and 
 development on the other, the following general rules 
 may be deduced. 
 
 For every proportion of oxygen which enters into 
 combination in the body, a corresponding proportion 
 of heat must be generated. 
 
 The sum of force available for mechanical purposes 
 must be equal to the sum of the vital forces of all tis- 
 sues adapted to the change of matter. 
 
 If, in equal times, unequal quantities of oxygen are 
 consumed, the result is obvious, in an unequal amount 
 of heat liberated, and of mechanical force. 
 
 When unequal amounts of mechanical force are ex- 
 pended, this determines the absorption of corresponding 
 and unequal quantities of oxygen. 
 
 For the conversion of living tissues into lifeless com- 
 pounds, and for the combination of oxygen with such 
 constituents of the body as have an affinity for it, time 
 is required. 
 
 In a given time, only a limited amount of mechani- 
 cal force can be manifested, and only a limited amount 
 of heat can be liberated. 
 
IN THE ANIMAL ORGANISM. 233 
 
 That which is expended, in mechanical effects, in 
 the shape of velocity, is lost in time ; that is to say, 
 the more rapid the motions are, the sooner or the more 
 quickly is the force exhausted. 
 
 The sum of the mechanical force produced in a 
 given time is equal to the sum of force necessary, 
 during the same time, to produce the voluntary and 
 involuntary motions ; that is, all the force which the 
 heart, intestines, &c., require for their motions is lost 
 to the voluntary motions. 
 
 The amount of azotized food necessary to restore 
 the equilibrium between waste and supply is directly 
 proportional to the amount of tissues metamorphosed. 
 
 The amount of living matter, which in the body 
 loses the condition of life, is, in equal temperatures, 
 directly proportional to the mechanical effects produced 
 in a given time. 
 
 The amount of tissue metamorphosed in a given time 
 may be measured by the quantity of nitrogen in the 
 urine. 
 
 The sum of the mechanical effects produced in two 
 individuals, in the same temperature, is proportional to 
 the amount of nitrogen in their urine ; whether the me- 
 chanical force has been employed in voluntary or invol- 
 untary motions, whether it has been consumed by the 
 limbs or by the heart and other viscera. 
 
 That condition of the body which is called health in- 
 cludes the conception of an equilibrium among all the 
 causes of waste and of supply ; and thus animal life is 
 20* 
 
234 THE PHENOMENA OF MOTION 
 
 recognised as the mutual action of both ; and appears 
 as an alternating destruction and restoration of the state 
 of equilibrium. 
 
 In regard to its absolute amount, the waste and supply 
 of matter is, in the different periods of life, unequal ; 
 but, in the state of health, the available vital force must 
 always be considered as a constant quantity, correspond- 
 ing to the sum of living particles. 
 
 Growth, or the increase of mass, stands, at every 
 age, in a fixed relation to the amount of vital force con- 
 sumed as moving power. 
 
 The vital force, which is expended for mechanical 
 purposes, is subtracted from the sum of the force avail- 
 able for the purpose of increase of mass. 
 
 The active force, which is consumed in the body in 
 overcoming resistance (in causing increase of mass), 
 cannot, at the same time, be employed to produce me- 
 chanical effects. 
 
 Hence it follows necessarily, that when, as in child- 
 hood, the supply exceeds the waste of matter, the me- 
 chanical effects produced must be less in the same 
 proportion. 
 
 With the increase of mechanical effects produced, 
 the capacity of increase of mass or of the supply of 
 waste in living tissues must diminish in the same pro- 
 portion. 
 
 A perfect balance between the consumption of vital 
 force for supply of matter and that for mechanical ef- 
 fects occurs, therefore, only in the adult state. It is 
 
IN THE ANIMAL ORGANISM. 235 
 
 at once recognised in the complete supply of the matter 
 consumed. In old age more is wasted ; in childhood 
 more is supplied than wasted. 
 
 The force available for mechanical purposes in an 
 adult man is reckoned, in mechanics, equal to |th of his 
 own weight, which he can move during eight hours, 
 with a velocity of five feet in two seconds. 
 
 If the weight of a man be 150 Ibs., his force is 
 equal to a weight of 30 Ibs. carried by him to a dis- 
 tance of 72,000 feet. For every second his momen- 
 tum offeree is= 30X2-5 =75 Ibs.; and for the 
 whole day's work, his momentum of motion is = 30 X 
 72,000 = 2,160,000. 
 
 By the restoration of the original weight of his body, 
 the man collects again a sum of force which allows him, 
 next day, to produce, without exhaustion, the same 
 amount of mechanical effects. 
 
 This supply of force is furnished in a seven hours 1 
 sleep. 
 
 In manufactories of rolled iron it frequently happens, 
 that the pressure of the engine, going at its ordinary 
 rate, is not sufficient to force a rod of iron of a certain 
 thickness to pass below the cylinders. The workman, 
 in this case, allows the whole force of the steam to act 
 on the revolving wheel, and not until this has acquired 
 a great velocity does he bring the rod under the rollers ; 
 when it is instantly flattened with great ease into a 
 plate, while the wheel gradually loses the velocity it 
 had acquired. What the wheel gained in velocity, the 
 
236 THE PHENOMENA OF MOTION 
 
 roller gained in force ; by this process force was ob- 
 viously collected, accumulated in the velocity ; but in 
 this sense force does not accumulate in the living or- 
 ganism. 
 
 The restoration of force is effected, in the animal 
 body, by the transformation of the separated parts, des- 
 tined for the production of force, and by the expendi- 
 ture of the active vital force in causing formation of 
 new parts ; and, with the restoration of the separated or 
 effete parts, the organism recovers a force equal to that 
 which has been expended. 
 
 It is plain, that the vital force manifested, during 
 sleep, in the formation of new parts 'must be equal to 
 the whole sum of the moving power expended in the 
 waking state in all mechanical effects whatever, plus a 
 certain amount of force, which is required for carrying 
 on those involuntary motions which continue during 
 sleep. 
 
 From day to day, the laboring man, with sufficient 
 food, recovers, in seven hours' sleep, the whole sum 
 of force ; and without reckoning the force necessary 
 for the involuntary motions which may be considered 
 equal in all men, we may assume, that the mechanical 
 force available for work is directly proportional to the 
 number of hours of sleep. 
 
 The adult man sleeps 7 hours, and wakes 17 hours ; 
 consequently, if the equilibrium be restored in 24 hours, 
 the mechanical effects produced in 17 hours must be 
 
IN THE ANIMAL ORGANISM. 237 
 
 equal to the effects produced during 7 hours in the 
 shape of formation of new parts. 
 
 An old man sleeps only 3| hours ; and if every thing 
 else be supposed the same as in the case of the adult, 
 he will be able, at all events, to produce half of the 
 mechanical effects produced by an adult of equal 
 weight; that is, he will be able to carry only 15 Ibs. 
 instead of 30 to the same distance. 
 
 The infant at the breast sleeps 20 hours and wakes 
 only 4 ; the active force consumed in formation of 
 new parts is, in this case, to that consumed in mechani- 
 cal effects, (in motion of the limbs,) as 20 to 4 ; but 
 his limbs possess no momentum of force, for he cannot 
 yet support his own body. If we assume, that the aged 
 man and infant consume in mechanical effects a quantity 
 of force corresponding to the proportion available in 
 the adult, then the mechanical effects are proportional 
 to the number of waking hours, the formation of new 
 parts to the number of hours of sleep, and we shall 
 have : 
 
 Force expended Force expended in 
 
 in mechanical effects. formation of new parts. 
 
 In the adult 17 : 7 
 
 In the infant 4 : 20 
 
 In the old man .... 20 : 4 
 
 In the adult, a perfect equilibrium takes place be- 
 tween waste and supply ; in the old man and in the 
 infant, waste and supply are not in equilibrium. If we 
 make the consumption of force in the 17 waking hours 
 equal to that required for the restoration of the equili- 
 
238 THE PHENOMENA OF MOTION 
 
 brium during sleep = 100 = 17 waking hours, = 7 
 hours of sleep, we obtain the following proportions. 
 The mechanical effects are to those in the shape of 
 formation of new parts : 
 
 In the adult man = 100 : 100 
 
 In the infant . . = 25 : 250 (24 : 286) 
 
 In the old man . = 125 : 50 (118 : 43) 
 
 Or the increase of mass to the diminution of waste : 
 
 In the adult man == 100 : 100 
 
 In the infant . . = 100 : 10 (9) 
 
 In the old man . = 100 : 250 (274) 
 
 It is consequently clear, that if the old man performs 
 an amount of work proportional to the sleeping hours 
 of the adult, the waste will be greater than the supply ; 
 that is, his body will rapidly decrease in weight, if he 
 carry 15 Ibs. to the distance of 72,000 feet with a ve- 
 locity of 2j feet in the second ; but he will be able, 
 without injury, to carry 6 Ibs. to the same distance. 
 
 In the infant the increase is to the decrease as 10 to 
 1, and consequently, if we in his case increase the ex- 
 penditure of force in mechanical effects to ten times its 
 proper amount, there will thus be established only an 
 equilibrium between waste and supply. The child, 
 indeed, will not grow ; but neither will it lose weight. 
 
 If, in the adult man, the consumption of force for 
 mechanical purposes in 24 hours be augmented beyond 
 the amount restorable in seven hours of sleep, then, if 
 the equilibrium is to be restored, less force, in the same 
 proportion, must be expended in mechanical effects in 
 
IN THE ANIMAL ORGANISM. 239 
 
 the next 24 hours. If this be not done, the mass of 
 the body decreases, and the state characteristic of old 
 age more or less decidedly supervenes. 
 
 With every hour of sleep the sum of available force 
 increases in the old man, or approaches the state of 
 equilibrium between waste and supply which exists in 
 the adult. 
 
 It is further evident, that if a part of the force which 
 is available for mechanical purposes, without disturbing 
 the equilibrium, should not be consumed in moving the 
 limbs, in raising weights, or in other labor, it will be 
 available for involuntary motions. If the motion of the 
 heart, of the fluids, and of the intestines, (the circula- 
 tion of the blood and digestion,) are accelerated in 
 proportion to the amount of force not consumed in 
 voluntary motions, the weight of the body will neither 
 increase nor diminish in 24 hours. The body, there- 
 fore, can only increase in mass, if the force accumulated 
 during sleep, and available for mechanical purposes, is 
 employed neither for voluntary nor for involuntary mo- 
 tions. 
 
 The numerical values above given for the expen- 
 diture of force in the human body refer, as has been 
 expressly stated, only to a given, uniform temperature. 
 In a different temperature, and with deficient nourish- 
 ment, all these proportions must be changed. 
 
 If we surround a part of the body with ice or snow, 
 while other parts are left in the natural state, there oc- 
 curs, more or less quickly, in consequence of the loss 
 
240 THE PHENOMENA OF MOTION 
 
 of heat, an accelerated change of matter in the cooled 
 part. 
 
 The resistance of the living tissues to the action of 
 oxygen is weaker at the cooled part than in the other 
 parts ; and this, in its effects, is equivalent to an in- 
 crease of resistance in these other parts. 
 
 The momentum of force of the vitality in the parts 
 which are not cooled is expended, as before, in me- 
 chanical motion ; but the whole action of the inspired 
 oxygen is exerted on the cooled part. 
 
 If we imagine an iron cylinder, into which we admit 
 steam under a certain pressure, then if the force with 
 which the particles of the iron cohere be equal to the 
 force which tends to separate them, an equilibrium will 
 result ; that is, the whole effect of the steam will be 
 neutralized by the resistance. But if one of the sides 
 of the cylinder be movable, a piston-rod, for example, 
 and offer to the pressure of the steam a less resistance 
 than other parts, the whole force will be expended in 
 moving this one side, that is, in raising the piston- 
 rod. If we do not introduce fresh steam (fresh force), 
 an equilibrium will soon be established. The piston- 
 rod resists a certain force without moving, but is raised 
 by an increased pressure. When this excess of force 
 has been consumed in motion, it cannot be raised high- 
 er ; but if new vapor be continually admitted, the rod 
 will continue to move. 
 
 In the cooled part of the body, the living tissues 
 offer a less resistance to the chemical action of the 
 
IN THE .ANIMAL ORGANISM. 24 I 
 
 inspired oxygen ; the power of the oxygen to unite 
 with the elements of the tissues is, at this part, ex- 
 alted. When the part has once lost its condition of 
 life, resistance entirely ceases ; and in consequence of 
 the combination of the oxygen with the elements of 
 the metamorphosed tissues, a greater amount of heat 
 is liberated. 
 
 For a given amount of oxygen, the heat produced 
 is, in all cases, exactly the same. In the cooled part, 
 the change of matter, and with it the disengagement 
 of heat, increases ; while in the other parts the change 
 of matter and liberation of heat decrease. But when 
 the cooled part, by the union of oxygen with the ele- 
 ments of the metamorphosed tissues, has recovered its 
 original temperature, the resistance of its living parti- 
 cles to the oxygen conveyed to them again increases, 
 and, as the resistance of other parts is now diminished, 
 a more rapid change of matter now occurs in them, 
 their temperature rises, and along with this, if the cause 
 of the change of matter continue to operate, a larger 
 amount of vital force becomes available for mechanical 
 purposes. 
 
 Let us now suppose that heat is abstracted from the 
 whole surface of the body ; in this case the whole ac- 
 tion of the oxygen will be directed to the skin, and 
 in a short time the change of matter must increase 
 throughout the body. Fat, and all such matters as 
 are capable of combining with the oxygen which is 
 21 
 
242 THEORY OF DISEASE. 
 
 brought to them in larger quantity than usual, will be 
 expelled from the body in the form of oxidized com- 
 pounds. 
 
 III. 
 
 THEORY OF DISEASE. 
 
 Every substance or matter, every chemical or me- 
 chanical agency, which changes or disturbs the restora- 
 tion 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 disease. Disease occurs when the sum of vital 
 force, which tends to neutralize all causes of disturb- 
 ance (in other words, when the resistance offered by 
 the vital force), is weaker than the acting cause of 
 disturbance. 
 
 Death is that 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. 
 
 To the observer, the action of a cause of disease 
 exhibits itself in the disturbance of the proportion be- 
 tween 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 bcdy, is called disease. 
 
THEORY OF DISEASE. 243 
 
 It is evident that one and the same cause of disease 
 will produce in the organism very different effects, 
 according to the period of life ; and that a certain 
 amount of disturbance, which produces disease in the 
 adult state, may be without influence in childhood or 
 in old age. A cause of disease may, when it is added 
 to the cause of waste in old age, produce death (anni- 
 hilate all resistance on the part- of the vital force) ; 
 while in the adult state it may produce only a dispro- 
 portion between supply and waste ; and in infancy, only 
 an equilibrium between supply and waste (the abstract 
 state of health). 
 
 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. 
 
 A child, lightly clothed, can bear cooling by a low 
 external temperature without injury to health ; the 
 force available for mechanical purposes and the tem- 
 perature of its body increase with the change of matter 
 which follows the cooling ; while a high temperature, 
 which impedes the change of matter, is followed by 
 disease. 
 
 On the other hand, we see, in hospitals and chari- 
 table institutions (in Brussels, for example) in which 
 old people spend the last years of life, when the tem- 
 perature of the dormitory, in winter, sinks 2 or 3 de- 
 
244 THEORY OF DISEASE. 
 
 grees below the usual point, that by this slight degree 
 of cdoling the death of the oldest and weakest, males 
 as well as females, is brought about. They are found 
 lying tranquilly in bed, without the slightest symptoms 
 of disease, or of the usual recognisable causes of death. 
 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 of the atmosphere. 
 
 When, from any cause whatever, this resistance di- 
 minishes in a living part, the change of matter increases 
 in an equal degree. 
 
 Now, since the phenomena of motion in the animal 
 body are dependent on the change of matter, the in- 
 crease of the change of matter in any part is followed 
 by an increase of all motions. According to the con- 
 ducting power of the nerves, the available force is car- 
 ried away by the nerves of involuntary motion alone, 
 or by all the nerves together. 
 
 Consequently, if, in consequence of a diseased trans- 
 formation of living tissues, a greater amount of force 
 be generated than is required for the production of the 
 normal motions, it is seen in an acceleration of all or 
 some of the involuntary motions, as well as in a higher 
 temperature of the diseased part. 
 This condition is called fever. 
 
 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. 
 
THEORY OF DISEASE. 245 
 
 This state is called a febrile paroxysm. 
 
 In consequence of the acceleration of the circulation 
 in the state of fever, a greater amount of arterial blood, 
 and, consequently, of oxygen, is conveyed to the dis- 
 eased 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 diseased part alone. 
 
 According as a single organ, or a system of organs 
 is affected, the change of matter extends to one part 
 alone, or to the whole affected system. 
 
 Should there be formed, in the diseased parts, in 
 consequence of the change of matter, from the ele- 
 ments 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 undergo transformation, then 
 these new products will suffer, at the place where they 
 have been formed, a process of decomposition analo- 
 gous to fermentation or putrefaction. 
 
 In certain cases, medicine removes these diseased 
 conditions, by exciting in the vicinity of the diseased 
 part, or in any convenient situation, an artificial dis- 
 eased state (as by blisters, sinapisms, or setons) ; thus 
 diminishing, by means of artificial disturbance, the re- 
 sistance offered to the external causes of change in 
 these parts by the vital force. The physician succeeds 
 in putting an end to the original diseased condition, 
 21 * 
 
246 THEORY OF DISEASE. 
 
 when the disturbance, artificially excited, (or the dim- 
 inution of resistance in another part,) exceeds in amount 
 the diseased state to be overcome. 
 
 The accelerated change of matter, and the elevated 
 temperature in the diseased part show, that the resis- 
 tance offered by the vital force to the action of oxygen, 
 is feebler than in the healthy state. But this resistance 
 only ceases entirely when death takes place. By the 
 artificial diminution of resistance in another part, the 
 resistance in the diseased organ is not indeed directly 
 strengthened ; but the chemical action (the cause of the 
 change of matter) is diminished in the diseased part, 
 being directed 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). 
 
 A complete cure of the original disease occurs, when 
 external action and resistance, in the diseased part, are 
 brought into equilibrium. Health and the restoration of 
 the diseased tissue to its original condition follow, when 
 we are able so far to weaken the disturbing action of 
 oxygen, by any means, that it becomes inferior to the 
 resistance 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 ne- 
 cessary condition of increase of mass in the living or- 
 ganism. 
 
 In cases of a different kind, where artificial exter- 
 nal disturbance produces no effect, physicians adopt 
 other* indirect methods to exalt the resistance offered 
 
THEORY OF DISEASE. 247 
 
 by the vital force. These methods, the result of ages 
 of experience, are such, that the most perfect theory 
 could hardly have pointed them out more acutely or 
 more justly than has been done by the observation 
 of sagacious practitioners. They diminish, by blood- 
 letting, the number of the carriers of oxygen (the 
 globules), and by this- means the conditions of change 
 of matter ; they exclude from the food all such matters 
 as are capable of conversion into blood ; they give 
 chiefly or entirely non-azotized food, which supports 
 the respiratory process, as well as fruit and vegetables, 
 which contain the alkalies necessary for the secretions. 
 
 If they succeed, by these means, in diminishing the 
 action of the oxygen in the blood, on the diseased part, 
 so far that the vital force of the latter, its resistance, in 
 the smallest degree overcomes the chemical action ; and 
 if they accomplish this, without arresting the functions 
 of the other organs, then restoration to health is certain. 
 
 To the method of cure adopted in such cases, if 
 employed with sagacity and acute observation, there 
 is added, as we may call it, an ally on the side of the 
 diseased organ, and this is the vital force of the healthy 
 parts. For, when blood is abstracted, the external 
 causes of change are diminished also in them, and their 
 vital force, formerly neutralized by these causes, now 
 obtains the preponderance. The change of matter, 
 indeed, is diminished throughout the body, and with it 
 the phenomena of motion ; but the sum of all resisting 
 powers, taken together, increases in proportion as the 
 
THEORY OF DISEASE. 
 
 amount of oxygen acting on them in the blood is di- 
 minished. In the sensation of hunger, this resistance, 
 in a certain sense, makes itself known ; and the pre- 
 ponderating vital force exhibits itself, in many patients, 
 when hunger is felt, in the form of an abnormal growth, 
 or an abnormal metamorphosis of certain parts of organs. 
 Sympathy is the transference of diminished resistance 
 from one part, not exactly to the next, but to more 
 distant organs, when the functions of both mutually 
 influence each other. When the action of the diseased 
 organ is connected with that of another ; when, for 
 example, the one no longer produces the matters ne- 
 cessary to the performance of the functions of the other, 
 then the diseased condition is transferred, but only 
 apparently, to the latter. 
 
 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 action of a blister. 
 
 The nerves, which accomplish the voluntary and in- 
 voluntary motions in the body, are, according to the 
 preceding exposition, not the producers, but only the 
 conductors of the vital force ; they propagate motion, 
 and behave towards other causes of motion, which in 
 their manifestations are analogous to the vital force, 
 towards a current of electricity, for example, in a pre- 
 cisely analogous manner. They permit the current to 
 traverse them, and present, as conductors of electricity, 
 
THEORY OF DISEASE. 249 
 
 all the phenomena which they exhibit as conductors of 
 the vital force. 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 ; but still, the medicinal action of electricity, 
 as well as that of a magnet, which, when placed in con- 
 tact with the body, produces a current of electricity, 
 cannot be denied. For to the existing force of motion 
 or of disturbance there is added, in the electrical current, 
 a new cause of motion and of change in form and 
 structure, which cannot be considered as altogether in- 
 efficient. 
 
 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 change of 
 matter. This occurs especially in certain morbid con- 
 ditions in the substance of the centre of the apparatus 
 of motion ; when a glowing heat and a rapid current of 
 blood towards the head point out an abnormal metamor- 
 phosis of the brain. When this condition continues 
 beyond a certain time, experience teaches that all mo- 
 tions 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. 
 By surrounding the head with ice, the temperature is 
 lowered, but the cause of the liberation of heat contin- 
 ues ; the metamorphosis, which decides the issue of the 
 disease, is limited to a short period. We must not for- 
 get, that the ice melts and absorbs heat from the dis- 
 
250 THEORY OF DISEASE. 
 
 eased part ; that if the ice be removed before the com- 
 pletion of the metamorphosis, the temperature again 
 rises ; that far more heat is removed by means of ice 
 than if we were to surround the head with a bad con- 
 ductor of heat. There has obviously been liberated in 
 an equal time a far larger amount of heat than in the 
 state of health ; and this is only rendered possible by 
 an increased supply of oxygen, which must have deter- 
 mined a more rapid change of matter. 
 
 The self-regulating steam-engines, in which, to pro- 
 duce 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 arrange- 
 ment connected with the regulating wheel, this stop- 
 cock opens when the wheel moves slower, and closes 
 more or less completely 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 of the 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 the change of matter, by the combustion 
 of coals in the fire-place. The force increases (the 
 
THEORY OF DISEASE. 251 
 
 amount of steam generated, and its tension increase) 
 with the temperature in the fire-place, which depends 
 on the supply of coals and of air. 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 retarded, the supply of 
 force (of steam) is diminished. When the engine goes 
 slower, more steam is admitted to the cylinder, its ten- 
 sion diminishes, the air passages are opened, and the 
 cause of disengagement of heat (or production of force) 
 increases. Another arrangement 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, the tension within is diminished ; this is immedi- 
 ately seen in the regulators of force, which act precise- 
 ly as if we had removed from the boiler a certain quan- 
 tity of steam (force). The regulator and the air pas- 
 sages open, and the machine supplies itself with more 
 coals. 
 
 The body, in regard to the production of heat and 
 of force, acts just like one of these machines. With 
 the lowering of the external temperature, the respira- 
 tions 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 temperature of the body is to remain 
 unchanged. 
 
252 THEORY OF DISEASE. 
 
 It is hardly necessary to mention, that in the body, 
 the tension of vapor cannot, any more than an electri- 
 cal current, be considered the cause of the production 
 of force. 
 
 From the theory of disease developed in the preced- 
 ing pages, it follows obviously, that a diseased condition 
 once established, in any part of the body, cannot be 
 made to disappear by the chemical action of a remedy. 
 A limit may be put by a remedy to an abnormal process 
 of transformation ; that process may be accelerated or 
 retarded ; but this alone does not restore the normal 
 (healthy) condition. 
 
 The art of the physician consists in the knowledge of 
 the means which enable him to exercise an influence on 
 the duration of the disease ; and in the removal of all 
 disturbing causes, the action of which strengthens or 
 increases that of the actual cause of disease. 
 
 It is only by a just application of its principles that 
 any theory can produce really beneficial results. The 
 very same method of cure may restore health in one 
 individual, which, if applied to another, rnay prove fatal 
 in its effects. Thus, in certain inflammatory diseases, 
 and in highly muscular subjects, the antiphlogistic 
 treatment has a very high value ; while in other cases 
 blood-letting produces unfavorable results. The vivify- 
 ing agency of the blood must ever continue to be the 
 most important condition in the restoration of a dis- 
 turbed equilibrium, which result is always dependent on 
 the saving of time ; and the blood must, therefore, be 
 
THEORY OF RESPIRATION. 253 
 
 considered and constantly kept in view, as the ultimate 
 and most powerful cause of a lasting vital resistance, as 
 well in the diseased as in the unaffected parts of the 
 body. 
 
 It is obvious, moreover, that in all diseases where 
 the formation of contagious matter and of exanthemata 
 is accompanied by fever, two diseased conditions simul- 
 taneously exist, and two processes are simultaneously 
 completed ; and that the blood, as it were by reaction 
 (that is, fever), becomes a means of cure, as being the 
 carrier of that substance (oxygen) without the aid of 
 which the diseased products cannot be rendered harm- 
 less, destroyed, or expelled from the body ; a means of 
 cure by which, in short, neutralization or equilibrium is 
 effected. 
 
 IV. 
 
 THEORY OF RESPIRATION. 
 
 During the passage of the venous blood through the 
 lungs, the globules change their color; and with this 
 change of color, oxygen is absorbed from the atmos- 
 phere. Further, for every volume of oxygen absorbed, 
 an equal volume of carbonic acid is, in most cases, 
 given out. 
 
 The red globules contain a compound of iron ; and 
 no other constituent of the body contains iron. 
 22 
 
254 THEORY OF RESPIRATION. 
 
 Whatever change the other constituents of the blood 
 undergo in the lungs, thus much is certain, that the 
 globules of venous blood experience a change of color, 
 and that this change depends on the action of oxygen. 
 
 Now we observe that the globules of arterial blood 
 retain their color in the larger vessels, and lose it only 
 during their passage through the capillaries. All those 
 constituents of venous blood, which are capable of 
 combining with oxygen, take up a corresponding quan- 
 tity of it in the lungs. Experiments made with arterial 
 serum have shown, that when in contact with oxygen it 
 does not diminish the volume of that gas. Venous 
 blood, in contact with oxygen, is reddened, while oxy- 
 gen is absorbed ; and a corresponding quantity of car- 
 bonic acid is formed. 
 
 It is evident that the change of color in the venous 
 globules depends on the combination of some one of 
 their elements with oxygen ; and that this absorption of 
 oxygen is attended with the separation of a certain 
 quantity of carbonic acid gas. 
 
 This carbonic acid is not separated from the serum ; 
 for the serum does not possess the property, when in 
 contact with oxygen, of giving off carbonic acid. On 
 the contrary, when separated from the globules, it ab- 
 sorbs from half its volume to an equal volume of car- 
 bonic acid, and, at ordinary temperatures, is not satu- 
 rated with that gas. (See the article " Blut " in the 
 u Handworterbuch der Chemie von Poggendorff, Woh- 
 ler, und Liebig," p. 877.) 
 
THEORY OF RESPIRATION. 255 
 
 Arterial blood, when drawn from the body, is soon 
 altered ; its florid color becomes dark red. The florid 
 blood, which owes its color to the globules, becomes 
 dark by the action of carbonic acid, and this change of 
 color affects the globules, for florid blood absorbs a 
 number of gases which do not dissolve in the fluid part 
 of the blood when separated from the globules. It is 
 evident, therefore, that the globules have the power of 
 combining with gases. 
 
 The globules of the blood change their color in dif- 
 ferent gases : and this change may be owing either to a 
 combination or to a decomposition. 
 
 Sulphuretted hydrogen turns them blackish green and 
 finally black ; and the original red color cannot, in this 
 case, be restored by contact with oxygen. Here a 
 decomposition has obviously taken place. 
 
 The globules darkened by carbonic acid become 
 again florid in oxygen, with disengagement of carbonic 
 acid. The same thing takes place in nitrous oxide. It 
 is clear that they have here undergone no decomposi- 
 tion, and, consequently, they possess the power of 
 combining with gases, while the compound they form 
 with carbonic acid is destroyed by oxygen. When left 
 to themselves, out of the body, the compound formed 
 with oxygen again becomes dark, but does not recover 
 its florid color a second time by the action of oxygen. 
 
 The globules of the blood contain a compound of 
 iron. From the never-failing presence of iron in red 
 blood, we must conclude, that it is unquestionably neces- 
 
256 THEORY OF RESPIRATION. 
 
 sary to animal life ; and, since physiology has proved, 
 that the globules take no share in the process of nutri- 
 tion, it cannot be doubted that they play a part in the 
 process of respiration. 
 
 The compound of iron in the globules has the char- 
 acters of an oxidized compound ; for it is decomposed 
 by sulphuretted hydrogen, exactly in the same way as 
 the oxides or other analogous compounds of iron. By 
 means of diluted mineral acids, peroxide (sesquioxide) 
 of iron may be extracted, at the ordinary temperature, 
 from the fresh or dried red coloring matter of the blood. 
 
 The characters of the compounds of iron may, per- 
 haps, assist us to explain the share which that metal 
 takes in the respiratory process. No other metal can 
 be compared with iron, for the remarkable properties of 
 its compounds. 
 
 The compounds of protoxide of iron .possess the 
 property of depriving other oxidized compounds of 
 oxygen ; while the compounds of peroxide of iron, 
 under other circumstances, give up oxygen with the 
 utmost facility. 
 
 Hydrated peroxide of iron, in contact with organic 
 matters destitute of sulphur, is converted into carbonate 
 of the protoxide. 
 
 Carbonate of protoxide of iron, in contact with wa- 
 ter and oxygen, is decomposed ; all the carbonic acid 
 is given off, and, by absorption of oxygen, it passes in- 
 to the hydrated peroxide, which may again be convert- 
 ed into a compound of the protoxide. 
 
THEORY OF RESPIRATION. 257 
 
 Not only the oxides of iron, but also the cyanides 
 of that metal, exhibit similar properties. Prussian blue 
 contains iron in combination with all the organic ele- 
 ments of the body ; hydrogen and oxygen (water), 
 carbon and nitrogen (cyanogen). 
 
 When it is exposed to light, cyanogen is given off, 
 and it becomes white ; in the dark it attracts oxygen, 
 and recovers its blue color. 
 
 All these observations, taken together, lead to the 
 opinion that the globules of arterial blood contain a 
 compound of iron saturated with oxygen, which, in the 
 living blood, loses its oxygen during its passage through 
 the capillaries. The same thing occurs when it is 
 separated from the body, and begins to undergo de- 
 composition (to putrefy). The compound, rich in 
 oxygen, passes, therefore, by the loss of oxygen (re- 
 duction), into one far less charged with that element. 
 One of the products of oxidation formed in this pro- 
 cess is carbonic acid. The compound of iron in the 
 venous blood possesses the property of combining with 
 carbonic acid ; and it is obvious, that the globules of 
 the arterial blood, after losing a part of their oxygen, 
 will, if they meet with carbonic acid, combine with 
 that substance. 
 
 When the globules reach the lungs, they will again 
 take up the oxygen they have lost ; for every volume of 
 oxygen absorbed, a corresponding volume of carbonic 
 acid will be separated ; they will return to their former 
 
 22* 
 
253 THEORY OF RESPIRATION. 
 
 state ; that is, they will again acquire the power of giv- 
 ing off oxygen. 
 
 For every volume of oxygen which the globules can 
 give off, there will be formed (as carbonic acid con- 
 tains its own volume of oxygen, without condensation) 
 neither more nor less than an equal volume of carbonic 
 acid. For every volume of oxygen which the globules 
 are capable of absorbing, no more carbonic acid can 
 possibly be separated than that volume of oxygen can 
 produce. 
 
 When carbonate of protoxide of iron, by the ab- 
 sorption of oxygen, passes into the hydrated peroxide, 
 there are given off, for every volume of oxygen neces- 
 sary to the change from protoxide to peroxide, four 
 volumes of carbonic acid gas. 
 
 But from one volume of oxygen only one volume of 
 carbonic acid can be produced ; and the absorption of 
 one volume of oxygen can only cause, directly, the 
 separation of an equal volume of carbonic acid. Con- 
 sequently, the substance or compound which has lost 
 its oxygen, during the passage of arterial into venous 
 blood, must have been capable of absorbing or com- 
 bining with carbonic acid ; and we find, in point of 
 fact, that the living blood is never, in any state, satu- 
 rated with carbonic acid ; that it is capable of taking 
 up an additional quantity, without any apparent disturb- 
 ance of the function of the globules. Thus, for ex- 
 ample, after drinking effervescing wines, beer, or min- 
 eral waters, more carbonic acid must necessarily be 
 
THEORY OF RESPIRATION. 259 
 
 expired than at other times. In all cases, where the 
 oxygen of the arterial globules has been partly ex- 
 pended, otherwise than in the formation of carbonic 
 acid, the amount of this latter gas expired will corre- 
 spond exactly with that which has been formed ; less, 
 however, will be given out after the use of fat and of 
 still wines, than after champagne. 
 
 According to the views now developed, the globules 
 of arterial blood, in their passage through the capilla- 
 ries, yield oxygen to certain constituents of the body. 
 A small portion of this oxygen serves to produce the 
 change of matter, and determines the separation of 
 living parts and their conversion into lifeless com- 
 pounds, as well as the formation of the secretions and 
 excretions. The greater part, however, of the oxy- 
 gen is employed in converting into oxidized compounds 
 the newly formed substances, which no longer form 
 part of the living tissues. 
 
 In their return towards the heart, the globules which 
 have lost their oxygen combine with carbonic acid, 
 producing venous blood ; and, when they reach the 
 lungs, an exchange takes place between this carbonic 
 acid and the oxygen of the atmosphere. 
 
 The organic compound of iron, which exists in ven- 
 ous blood, recovers in the lungs the oxygen it has lost, 
 and, in consequence of this absorption of oxygen, the 
 carbonic acid in combination with it is separated. 
 
 All the compounds present in venous blood, which 
 have an attraction for oxygen, are converted, in the 
 
2(50 THEORY OF RESPIRATION. 
 
 lungs, like the globules, into more highly oxidized com- 
 pounds ; a certain amount of carbonic acid is formed, 
 of which a part always remains dissolved in the serum 
 of the blood. 
 
 The quantity of carbonic acid dissolved, or of that 
 combined with soda, must be equal in venous and 
 arterial blood, since both have the same temperature ; 
 but arterial blood, when drawn, must, after a short 
 time, contain a larger quantity of carbonic acid than 
 venous blood, because the oxygen of the globules is 
 expended in producing that compound. 
 
 Hence, in the animal organism, two processes of 
 oxidation are going on ; one in the lungs, the other in 
 the capillaries. 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. 
 
 A man, who expires daily 13-9 oz. of carbon in the 
 form of carbonic acid, consumes, in 24 hours, 37 oz. 
 of oxygen, which occupy a space equal to 807 litres 
 = 51,648 cubic inches (Hessian). 
 
 If we reckon 18 respirations to a minute, we have, 
 in 24 hours, 25,&20 respirations ; and, consequently, 
 in each respiration, there are taken into the blood 
 f'j?|8 1 -99 cubic inch of oxygen. 
 
 In one minute, therefore, there are added to the 
 constituents of the blood 18 X 1*99 = 35'8 cubic 
 
THEORY OF RESPIRATION. 261 
 
 inches of oxygen, which, at the ordinary temperature, 
 weigh rather less than 12 grains (12-2 Eng.). 
 
 If we now assume, that in one minute 10 Ibs. of 
 blood pass through the lungs (Miiller, Physiologic, vol. i., 
 p. 345), and that this quantity of blood measures 320 
 cubic inches, then 1 cubic inch of oxygen unites with 
 9 inches of blood, very nearly. 
 
 According to the researches of Denis, Richardson, 
 and Nasse (Handworterbuch der Physiologic, vol. i., 
 p. 138), 10,000 parts of blood contain 8 parts of per- 
 oxide of iron. Consequently, 76,800 grains (10 Ibs. 
 Hessian) of blood contain 61-44 grains of peroxide of 
 iron, in arterial blood, = 55-30 of protoxide in venous 
 blood. 
 
 Let us now assume, that the iron of the globules of 
 venous blood is in the state of protoxide. It follows, 
 that 55'30 grains of protoxide of iron, in passing 
 through the lungs, take up, in one minute, 6-14 grains of 
 oxygen (the quantity necessary to convert it into perox- 
 ide). But since, in the same time, the 10 Ibs. of blood 
 have taken up 12 grains of oxygen, there remains 5-86 
 grains of oxygen, which combine with the other constit- 
 uents of the blood. 
 
 Now, 55-30 grains of protoxide of iron combine 
 with 34-8 grains of carbonic acid, which occupy the 
 volume of 73 cubic inches. It is obvious, therefore, 
 that the amount of iron present in the blood, if in the 
 state of protoxide, is sufficient to furnish the means of 
 carrying or transporting twice as much carbonic acid as 
 
262 THEORY OF RESPIRATION. 
 
 can possibly be formed by the oxygen absorbed in the 
 lungs. 
 
 The hypothesis just developed rests on well-known 
 observations, and, indeed, explains completely the pro- 
 cess of respiration, as far as it depends on the globules 
 of the blood. It does not exclude the opinion, that 
 carbonic acid may reach the lungs in other ways ; that 
 . certain other constituents of the blood may give rise to 
 the formation of carbonic acid in the lungs. But all 
 this has no connexion with that vital process by which 
 the heat necessary for the support of life is generated 
 in every part of the body. Now it is this alone which, 
 for the present, can be considered as the object truly 
 worthy of investigation. It is not, indeed, uninterest- 
 ing to inquire, why dark blood becomes florid by the 
 action of nitre, common salt, &c. ; but this question has 
 no relation to the natural respiratory process. 
 
 The frightful effects of sulphuretted hydrogen, and 
 of prussic acid, which, when inspired, put a stop to all 
 the phenomena of motion in a few seconds, are ex- 
 plained in a natural manner by the well-known action of 
 these compounds on those of iron, when alkalies are 
 present ; and free alkali is never absent in the blood. 
 
 Let us suppose that the globules lose their property 
 of absorbing oxygen, and of afterwards giving up this 
 oxygen and carrying off the resulting carbonic acid ; 
 such a hypothetical state of disease must instantly be- 
 come perceptible in the temperature and other vital 
 phenomena of the body. The change of matter will 
 
THEORY OP RESPIRATION. 263 
 
 be arrested, while the vital motions will not be instantly 
 stopped. 
 
 The conductors of force, the nerves, will convey, 
 as before, to the heart and intestines the power necessa- 
 ry for their functions. This power they will receive 
 from the muscular system, while, as no change of matter 
 takes place in the latter, the supply must soon fail. As 
 no change of matter occurs, no lifeless compounds are 
 separated, neither bile nor urine can be formed ; and 
 the temperature of the body must sink. 
 
 This state of matters soon puts a stop to the process 
 of nutrition, and, sooner or later, death must follow, but 
 unaccompanied by febrile symptoms, which, in this 
 case, is a very important fact. 
 
 This example has been selected in order to show the 
 importance and probable advantage of an examination of 
 the blood in analogous diseased conditions. It cannot 
 be, in the slightest degree, doubtful, that the function as- 
 cribed to the blood-globules may be considered as fully 
 explained and cleared up, if, in such morbid conditions, 
 we shall discover a change in their form, structure, or 
 chemical characters, a change which must be recog- 
 nisable by the use of appropriate reagents. 
 
 If we consider the force which determines the vital 
 phenomena as a property of certain substances, this 
 view leads of itself to a new and more rigorous consid- 
 eration of certain puzzling phenomena, which these very 
 substances exhibit, in circumstances in which they no 
 longer make a part of living organisms. 
 
APPENDIX; 
 
 CONTAINING 
 
 THE ANALYTICAL EVIDENCE 
 
 REFERRED TO IN THE SECTIONS IN WHICH ARE DESCRIBED THE 
 
 CHEMICAL PROCESSES OF RESPIRATION, 
 
 OF 
 
 NUTRITION, 
 
 AND OF THE 
 
 METAMORPHOSIS OF TISSUES. 
 
 23 
 
[The Notes correspond with the numbers in parentheses in the 
 text. All the Analyses quoted, which have the mark* attached, 
 have been made in the chemical laboratory of the University of 
 Giessen.] 
 
APPENDIX. 
 
 INTRODUCTION TO THE ANALYSES. 
 
 THE method formerly employed to exhibit the differ- 
 ences in composition of different substances, that, namely, 
 of giving the proportions of the various elements in 100 
 parts, has been long abandoned by chemists ; because it 
 affords no insight into the relations which exist between 
 two or more compounds. In order to give some proofs 
 of this statement, we shall here state, in that form, the 
 composition of aldehyde and acetic acid, of oil of bitter 
 almonds and benzoic acid. 
 
 Oil of 
 
 Carbon 
 
 Acetic acid. 
 40-00 
 
 Aldehyde. 
 55-024 
 
 Benzoic acid. 
 69-25 
 
 bitter almc 
 79-56 
 
 Hydrogen 
 Oxygen 
 
 6-67 
 53-33 
 
 8-983 
 35-993 
 
 4-86 
 25-89 
 
 5-56 
 
 14-88 
 
 Now aldehyde is converted into acetic acid, and oil of 
 bitter almonds into benzoic acid, simply by the addition 
 of oxygen, without any change in regard to the other 
 elements. This important relation cannot be traced in 
 the mere numerical results of analysis as above given ; 
 but if the composition of the related compounds be ex- 
 pressed in formulae, according to equivalents, the con- 
 
268 APPENDIX. 
 
 nexion in each case becomes obvious, even to him who 
 knows no more of chemistry than that C represents an 
 equivalent or combining proportion of carbon, H an 
 equivalent of hydrogen, and O an equivalent of oxygen. 
 
 Formula Formula 
 
 of acetic acid. of aldehyde. of benzoic acid. of oil of bitter almonds. 
 
 C 4 H 4 4 C 4 H 4 2 C 14 H 6 4 C 14 H 6 2 . 
 
 These formulae are exact expressions of the results of 
 analysis, which, in each of the two cases quoted, refer to 
 a fixed quantity of carbon ; in one to 4 equivalents, in the 
 other to 14. They show, that acetic acid differs from 
 aldehyde, and benzoic acid from oil of bitter almonds, 
 only in the proportion of oxygen. 
 
 Nor is it more difficult to understand the signification 
 of the following formulae. 
 
 Cyamelide. 1 eq. cyanuric acid. 3 eq. hydrated cyanic acid. 
 
 C 6 N 3 H 3 6 = Cy 3 ( = C 6 N 3 )0 3 + 3HO = 3(CyO + HO) = 
 =C 6 N 3 H 3 6 =C 6 N 3 H 3 6 . 
 
 (In these formulae, N represents an equivalent of nitro- 
 gen, and Cy an equivalent of cyanogen. This latter sub- 
 stance being composed of 2 equivalents of carbon and 1 
 equivalent of nitrogen, Cy = C 2 N.) 
 
 The first formula (that of cyamelide) is what is called 
 an empirical formula, in which the relative proportions of 
 the elements are, indeed, exactly known, but where we 
 have not even a theory, far less any actual knowledge, of 
 the order in which they are arranged. The second for- 
 mula is intended to express the opinion, that 3 eq. of 
 cyanogen (=6 eq. of carbon -(-3 eq. of nitrogen) having 
 united to form a compound atom or molecule, have com- 
 bined with 3 eq. of oxygen and 3 eq. of water, to form 
 
 
ANALYTICAL EVIDENCE. 269 
 
 1 eq. of hydrated cyanuric acid. The third expresses the 
 order in which the elements are supposed to be arranged 
 in hydrated cyanic acid, the whole multiplied by 3. Each 
 equivalent of cyanic acid is formed of 1 eq. of cyanogen, 
 1 eq. of oxygen, and 1 eq. of water ; and hence the same 
 number of atoms of each element, which together formed 
 1 eq. of cyanuric acid, is here so divided as to yield 3 eq. 
 of cyanic acid. 
 
 We have here, therefore, the same absolute and rela- 
 tive amount of atoms of each element, arranged in three 
 different ways ; yet in each of these the proportions of 
 the elements, calculated for 100 parts, must of course be 
 the same. It is easy, therefore, to see the advantage we 
 possess by the use of formulae ; that, namely, of exhibit- 
 ing the relations existing between compounds of different 
 composition ; and that also of expressing the actual, 
 probable, or possible differences between substances, 
 whose composition, in 100 parts, is the same, while their 
 properties, as in the case above quoted, are perfectly 
 distinct. 
 
 It does not come within our province here to explain 
 the method or rule by which the composition of a sub- 
 stance, in 100 parts (as it is always obtained in analysis), 
 is expressed in a formula ; we shall only describe the rule 
 for calculating, from a given formula, the composition in 
 100 parts. For this purpose it must be noted, that C, in 
 a chemical formula, signifies a weight of carbon expressed 
 by the number 76-437 (according to the most recent de- 
 terminations 75-8 or 75-0, a variation which has no effect 
 whatever on the formulae here adduced, all of which are 
 calculated on the number 76-437) ; that H signifies a 
 23* 
 
270 APPENDIX. 
 
 weight of_ hydrogen = 12-478 ; N a weight of nitrogen 
 = 177-04 ; and lastly, O a weight of oxygen = 100. 
 
 The formula of proteine, C 48 N 6 H 36 O 14 , expresses, there- 
 fore, 
 
 48 times 76-437 = 3668-98 carbon, 
 6 times 177-040 1062-24 nitrogen, 
 36 times 12-478= 449-21 hydrogen, 
 14 times 100-000 = 1400-00 oxygen. 
 
 The sum gives a weight of 6580-43 proteine. 
 Therefore, 
 
 In 100 parts. 
 
 In 6580.43 parts of proteine are contained 3668-98 carbon 55 756 
 In 6580-43 ditto 1062 24 nitrogen 16-142 
 
 In 6580-43 ditto 449-21 hydrogen 6-827 
 
 In 6580-43 ditto 1400-00 oxygen 21-275 
 
 100-000 
 
 The actual results of analysis, reduced to 100 parts, 
 when compared with the above numbers, will show how 
 far the assumed formula is correct ; or, supposing the for- 
 mula ascertained, they will show the degree of accuracy 
 displayed by the experimenter. Thus the proportions in 
 100 parts, calculated from the formula, furnish an impor- 
 tant check to the operator, and, conversely, the formula 
 calculated from his results, when compared with other 
 known formulae, supplies a test of his accuracy, or of the 
 purity of the substance analyzed. 
 
ANALYTICAL EVIDENCE. 271 
 
 NOTE I. P. 12. 
 
 CONSUMPTION OF OXYGEN BY AN ADULT, a 
 JLn Mull Man 
 
 ~ * v Carbon contained 
 
 consumes of oxygen produces of carbonic in the 
 
 According to in 24 hours acid in 24 hours carbonic acid. 
 
 cubic in. grains, cubic in. grains, grains. 
 
 Lavoisier and Seguin 46,037 15,661 14,930 8,584 2,820 French. 
 Menzies .... 51,480 17,625 English. 
 
 Davy .... 45,504 15,751 31,680 17,811 4,853 do. 
 
 Allen and Pepys . 39,600 13,464 39,600 18,612 5,148 do. 
 a Gmelin, Brande's Manuel, p. 1198. 
 
 NOTE II. P. 13. 
 COMPOSITION OF DRY BLOOD (SEE NOTE 28). 
 
 In 100 parts. In 4'8.1bs. Hessian = 36,864 grains. 
 
 Carbon . . . 51-96 .... 19154-5 
 
 Hydrogen . . 7-25 2672-7 
 
 Nitrogen . . . 15-07 .... 5555-4 
 
 Oxygen ... 21-30 7852-0 
 
 Ashes . . , 4-42 , 1629-4 
 
 100-00 36864-0 
 
 Grains. Grains. 
 
 19154-5 carbon form, with 50539-5 oxygen, carbonic acid. 
 2672-7 hydrogen do. 21415-8 do. water. 
 
 Sum = 71955-3 do. 
 Deduct oxygen present ) _ 
 in blood . . . . / 
 
 Remain 64103-3 grains of oxygen, required 
 for the complete combustion of 4-8 Ibs. of dry blood.f 
 
 It is assumed, in this calculation, that 24 Ibs. of blood 
 yield 4-8 Ibs. (20 per cent.) of dry residue. The remain- 
 der, 80 per cent., is water. 
 
 t Or 63685-6, H = 12-478 and C = 76-437. 
 
272 APPENDIX. 
 
 NOTE III. P. 14. 
 
 DETERMINATION OF THE AMOUNT OF CARBON 
 EXPIRED. 
 
 1. ANALYSIS or 
 
 Faces. 
 
 2-356 dry faeces left 0-320 ashes (13-58 per cent). 
 
 0-352 dry fseces yielded 0-576 carbonic acid, and 0-218 water. 
 
 Lentils. 
 
 0-566 lentils, dried at 212, yielded 0-910 carbonic acid and 
 0-366 water. 
 
 Pease. 
 
 1-060 pease, dried at 212, left 0-037 ashes. 
 0-416 do. do. yielded 0-642 carbonic acid, and 
 
 0-241 water. 
 
 Potatoes. 
 
 0-443 dried potatoes yielded 0-704 carbonic acid and 0-248 
 water. 
 
 Black Bread (Schwarzbrod). 
 
 302 dried black bread yielded 0-496 carbonic acid and 0-175 
 water. 
 
 0-241 do. 0-393 do. 0-142 
 
 water. 
 
 From the above, which are the direct results of experi- 
 ment, the composition in 100 parts is calculated as in the 
 following table. 
 
ANALYTICAL EVIDENCE. 
 
 273 
 
 2. COMPOSITION 
 
 Of Faces. Black Bread. Potatoes. Flesh. 
 
 Playfair.* Boeckmann.* Boussingault. Boeckmann.* 
 
 See note 
 28.) 
 
 Carbon 
 
 45-24 
 
 45-09 
 
 45-41 
 
 44-1 
 
 43-944 
 
 Hydrogen 
 
 6-88 
 
 6-54 
 
 6-45 
 
 5-8 
 
 6-222 
 
 Nitrogen ) 
 
 34-73 
 
 45-12 
 
 44-89 
 
 45-1 
 
 44-919 
 
 Oxygen ) 
 
 
 
 
 
 
 Ashes 
 
 13-15 
 
 3-25 
 
 3-25 
 
 5-0 
 
 4-915 
 
 10000 100-00 100-00 100-0 100-000 
 Water 300-00 
 
 400-00 
 
 
 
 Of Pease. 
 
 Lentils. 
 
 Beans. 
 
 
 
 Playfair.* 
 
 Playfair.* 
 
 Playfair.* 
 
 
 Carbon * ' \ 
 
 . . 35-743 
 
 37-38 
 
 38-24 
 
 
 Hydrogen . 
 
 . . 5-401 
 
 5-54 
 
 5-84 
 
 
 Nitrogen ) 
 
 . . 39-366 
 
 37-98 
 
 38-10 
 
 
 Oxygen $ 
 
 
 
 
 
 Ashes . . 
 
 ,/:" 3-490 
 
 3-20 
 
 3-71 
 
 
 Water n . 
 
 . . 16-000 
 
 15-90 
 
 14-11 
 
 
 
 100-000 
 
 100-00 
 
 100-00 
 
 Of Fresh Meat. 
 
 Potatoes. 
 
 Black Bread. 
 
 Boeckmann.* 
 
 __A. ~ 
 
 Boussingault. 
 
 Boeckmann.* 
 
 Water 75 
 
 \ 
 74-8 
 
 72-2 73-2 
 
 33 31-418 
 
 Dry 
 
 Matter 25 
 
 25-2 
 
 27-8 26-8 
 
 67 68-592 
 
 
 100 
 
 100-0 100-0 100-0 
 
 100 100-000 
 
 3. CALCULATION, 
 
 with the help of the preceding data, of the amount of 
 carbon expired by ail adult man. The following results 
 are deduced from observations made (see table) on the 
 average daily consumption of food, by from 27 to 30 sol- 
 
274 APPENDIX. 
 
 diers in barracks for a month, or by 855 men for one day. 
 The food, consisting of bread, potatoes, meat, lentils, 
 pease, beans, &c., was weighed, with the utmost exact- 
 ness, every day during a month (including even pepper, 
 salt, and butter) ; and each article of food was separately 
 subjected to ultimate analysis. The only exceptions, 
 among the men, to the uniform allowance of food, were 
 three soldiers of the guard, who, in addition to the daily 
 allowance of 2 Ibs. of bread, received, during each of the 
 periods allotted for the pay of the troops, 2| Ibs. extra ; 
 and one drummer, who, in the same period left 2| Ibs. un- 
 consumed. According to an approximative report by the 
 sergeant-major, each soldier consumes daily, on an aver- 
 age, out of barracks, 3 oz. of sausage, | oz. of butter, 
 | pint of beer, and ^ pint of brandy ; the carbon of which 
 articles amounts to more than double that of the faeces 
 and urine taken together. In the soldier, the faeces 
 amount daily, on an average, to 5\ oz. ; they contain 75 
 per cent, of water, and the dry residue contains 45*24 per 
 cent, of carbon, and 13*15 per cent, of ashes. 100 parts of 
 fresh faeces consequently contain 11 '31 per cent, of car- 
 bon, very nearly the same proportion as in fresh meat. In 
 the calculation, the carbon of the faeces and of the urine 
 has been assumed as equal to that of the green vegetables 
 and of the food (sausages, butter, beer, &.c.) consumed in 
 the alehouse. 
 
 From the observations, as recorded in the table, the 
 following conclusions are deduced. 
 
 Flesh. Meat devoid of fat, if reckoned at 74 per cent, 
 water, and 26 per cent, dry matter, contains in 100 parts 
 very nearly 13 6 parts of carbon. Ordinary meat con- 
 
ANALYTICAL EVIDENCE. 275 
 
 tains both fat and cellular tissue, which together amount to 
 fth of the weight of the meat as bought from the butcher. 
 The number of ounces consumed (by 855 men) was 4,448, 
 consisting, therefore, of 
 
 3812-5 oz. of flesh, free from fat, containing 1 of carbon 518*5 oz. 
 635-5 oz. of fat and cellular tissue, ditto 449-0 oz. 
 
 4448-0 oz. In all, carbon 967-5 oz. 
 
 With the bones, the meat, as purchased, contains 29 
 per cent, of fixed matter, including bones ; 4,448 oz. of 
 flesh, therefore, contain 448 oz. of dry bones. These have 
 not been included in the calculation, although, when 
 boiled, they yield from 8 to 10 per cent, of gelatine, which 
 is taken as food in the soup. 
 
 Fat. The amount of fat consumed was 56 oz. ; which, 
 the carbon being calculated at 80 per cent., contain in all 
 44'8 oz. of carbon. 
 
 Lentils, pease, and beans. There were consumed 53 '5 
 oz. of lentils, 185'5 oz. of pease, and 218 oz.f of beans. 
 Assuming the average amount of carbon in these vegeta- 
 bles to be 37 per cent., the total quantity of carbon con- 
 sumed in this form was 169-1 oz. 
 
 Potatoes. 100 parts of fresh potatoes contain 12'2 
 parts of carbon. In the 15,876 oz. of potatoes consumed, 
 therefore, the amount of carbon was 1936-87 oz. 
 
 Bread. 855 men eat daily 855 times 32 oz., besides 
 36 Ibs. of bread in the soup, which in all amounts to 
 27,936 oz. 100 oz. of fresh bread contain, on an average, 
 30-15 oz. of carbon ; consequently, the carbon consumed 
 in the bread amounts to 8771-5 oz. 
 
 t According to the table, 222 oz. 
 
276 APPENDIX. 
 
 The total consumption, therefore, was 
 
 In the meat .... 967-50 oz. of carbon. 
 In the fat . . 44-80 ditto 
 
 In the lentils, pease, and beans 169*10 ditto 
 
 In the potatoes . . . 1936-87 ditto 
 
 In the bread . . . 8771-50 ditto 
 
 Consumed by 855 men 11889-77 ditto 
 Consumed by 1 man . . 13-9 ditto f 
 
 The faeces of a soldier weigh 5-5 oz., and contain, in 
 the fresh state, 1 1 per cent, of carbon. For 86 kreutzers 
 (about 2s. 5d. sterling) there may be bought, on an aver- 
 age, 172 Ibs. of vegetables, such as cabbages, greens, 
 turnips, &.c. : 25 maas of sour krout weigh 100 Ibs. ; and 
 for 48| kreutzers (Is. 5d, sterling) there are bought, on an 
 average, 24| Ibs. of onions, leeks, celery, &c.J 855 men 
 consumed 
 
 Of green vegetables .... 2,802 oz. 
 Of sour krout ..... 1,600 
 Of onions, &c 388 
 
 In all , 4,790 
 
 And one man .... 5.6 oz. 
 
 For this reason, the carbon of the last mentioned arti- 
 cles of food has been assumed as equal to that of the 
 
 t Taking the composition of bread as given on page 273, 100 oz. 
 contain 30-68, which would give 8570-76, reducing each man's con- 
 sumption -23. 8771-50 disagrees even with the percentage 30-15. 
 W. 
 
 \ In the original table, the quantities of these vegetables are en- 
 tered according to their value in kreutzers, but they are here calcu- 
 lated by weight from the above data, as this appeared better adapted 
 for comparison in this country than the prices would have been. G 
 
 According to the table, 2752. 
 
ANALYTICAL EVIDENCE. 277 
 
 faeces and urine. Sausages, brandy, beer, in short, the 
 small quantity of food taken irregularly in the alehouse, 
 has not been included in the calculation. 
 
 The daily allowance of bread, being uniformly 2 Ibs. 
 per man, with the exceptions formerly mentioned, has not 
 been inserted in the table, which includes only those 
 matters of which, from the daily allowance being variable, 
 an average was required. The small quantity of bread in 
 the table is that given in the soup, which is over and 
 above the daily supply. 
 
 24 
 
If 
 
 ;=; -^ co co TJ< 
 
 10 to 
 
 no Oi W 
 i i-(l> TS- ,-H 
 
 1O CO 
 CO tO 
 
 w 5? 
 
 ;> 5^ 
 
 H 
 
 * 
 
 JSK 
 
 
 
 J 05 Si 05 05 53 
 
 lr. 
 
 ol< 
 
 ill 
 ;il 
 
 :So|S|j 
 2233 
 
 -G -*J J 
 
 33 
 
 if* 
 
 sr 
 
 w 
 
 ?Sfii7 
 
 e 2.tS-S|s 
 
 5s M'S 
 
 "^ t .2 ? fee 
 
 ID 
 
 h. 3 i . 
 
 l|2l ! 
 
 llll 
 
 it 
 
ANALYTICAL EVIDENCE. 
 
 279 
 
 TABLE II. Note IV., page 14. a. f 
 
 FOOD CONSUMED BY A HORSE IN TWENTY-FOUR HOURS. 
 
 
 Weight 
 
 Weight 
 
 
 
 
 
 Salts 
 
 Articles 
 
 in the 
 
 in the 
 
 Carbon. 
 
 Hydro- 
 
 Oxy- 
 
 Nitro- 
 
 and 
 
 of food. 
 
 fresh 
 
 dry 
 
 
 gen. 
 
 gen. 
 
 gen. 
 
 earthy 
 
 
 state. 
 
 state. 
 
 
 
 
 
 matters. 
 
 Hay 
 
 7500 
 
 6465 
 
 2961-0 
 
 323-2 
 
 2502-0 
 
 97-0 
 
 581-8 
 
 Oats 
 
 2270 
 
 1927 
 
 977-0 
 
 123-3 
 
 707-2 
 
 42-4 
 
 77-1 
 
 Water 
 
 16000 
 
 
 
 
 
 
 
 
 
 
 
 13-3 
 
 Total 
 
 25770 
 
 8392 
 
 3938-0 
 
 446-5 
 
 3209-2 
 
 139-4 
 
 672-2 
 
 EXCRETIONS OF A HORSE IN TWENTY-FOUR HOURS. 
 
 Excretions. 
 
 Weight 
 in the 
 fresh 
 state. 
 
 Weight 
 in the 
 dry 
 
 state. 
 
 Carbon. 
 
 Hydro- 
 gen. 
 
 Oxy- 
 gen. 
 
 Nitro- 
 gen. 
 
 Salts 
 and 
 earthy 
 mat- 
 ters. 
 
 Urine 
 Excrements 
 
 1330 
 14250 
 
 302 
 3525 
 
 108-7 
 1364-4 
 
 11-5 
 
 179-8 
 
 34-1 
 1328-9 
 
 37-8 
 77-6 
 
 109-9 
 574-6 
 
 Total 
 
 15580 
 
 3627 
 
 1473-1 
 
 191-3 
 
 1363-0 
 
 115-4 
 
 684-5 
 
 Total from 
 the previous 
 part of this 
 Table. 
 
 25770 
 
 8392 
 
 3938-0 
 
 446-5 
 
 3209-2 
 
 139-4 
 
 672-2 
 
 Difference 
 
 10190 
 
 4565 
 
 2464-9 
 
 255-2 
 
 1846-2 
 
 24-0 
 
 12-3 
 
 -for- 
 
 
 
 
 
 
 
 
 
 
 
 
 
 + 
 
 a Boussingault, Ann. de Ch. et de Phys., LXX. 136. The weights 
 in this table are given in grammes. 1 gramme = 15-44 grains Troy, 
 very nearly. 
 
 t The discrepancy between the results of Table II. and those given 
 
280 
 
 APPENDIX. 
 
 TABLE II. Note IV., page 14 (concluded}. 
 
 FOOD CONSUMED BY A COW IN TWENTY-FOUR HOURS. 
 
 
 
 
 
 
 
 
 Salts 
 
 Articles 
 
 Weight 
 in the 
 
 Weight 
 in tne 
 
 Carbon. 
 
 Hydro- 
 
 Oxy- 
 
 Nitro- 
 
 and 
 earthy 
 
 of food. 
 
 fresh 
 
 dry 
 
 
 gen. 
 
 gen. 
 
 gen. 
 
 mat- 
 
 
 state. 
 
 state. 
 
 
 
 
 
 ters. 
 
 Potatoes 
 
 15000 
 
 4170 
 
 1839-0 
 
 241-9 
 
 1830-6 
 
 50-0 
 
 208-5 
 
 After Grass 
 
 7500 
 
 6315 
 
 29744 
 
 353-6 
 
 2204-0 
 
 151-5 
 
 631-5 
 
 Water 
 
 60000 
 
 
 
 
 
 
 
 
 
 
 
 50-0 
 
 Total 
 
 82500 
 
 10485 
 
 4813-4 
 
 595-5 
 
 4034-6 
 
 201-5 
 
 890-0 
 
 EXCRETIONS OF A COW IN TWENTY-FOUR HOURS. 
 
 Excretions. 
 
 Weight 
 in the 
 fresh 
 state. 
 
 Weight 
 in the 
 dry 
 state. 
 
 Carbon. 
 
 Hydro- 
 gen. 
 
 Oxy- 
 
 gen. 
 
 Nitro- 
 gen. 
 
 Salts 
 and 
 earthy 
 mat- 
 ters. 
 
 Excrements 
 Urine 
 Milk 
 
 28413 
 8200 
 8539 
 
 4000-0 
 960-8 
 1150-6 
 
 1712.0 
 261-4 
 
 62S-2 
 
 208-0 
 250 
 99-0 
 
 1508-0 
 253-7 
 321-0 
 
 92-0 
 36-5 
 46-0 
 
 480-0 
 384-2 
 56-4 
 
 Total 
 
 45152 
 
 6111-4 
 
 2601-6 
 
 332-0 
 
 2082-7 
 
 174-5 
 
 920-6 
 
 Total of 
 first part of 
 this Table. 
 
 82500 
 
 10485-0 
 
 4813-4 
 
 595-5 
 
 4034-6 
 
 201-5 
 
 890-0 
 
 Difference 
 
 37348 
 
 4373-6 
 
 2211-8 
 
 263-5 
 
 1951-9 
 
 27-0 
 
 31-6 
 
 + or~ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 + 
 
 in the Agricultural Chemistry, page 176, arises from their being cal- 
 culated on 2-02 per cent, of nitrogen in hay, and 0-33 per cent, in 
 excrements. W. 
 
ANALYTICAL EVIDENCE. 
 
 281 
 
 NOTE V. P. 18. 
 
 TEMPERATURE OF THE BLOOD AND FREQUENCY OF 
 THE PULSE. 
 
 According to Prevost and Dumas. 
 
 The mean 
 tcmpero-luro is 
 
 The frequency 
 
 
 of the pulse 
 
 of the respiration 
 
 
 F. 
 
 in the minute. 
 
 in the minute. 
 
 In the Pigeon 
 
 107-6 
 
 136 
 
 34 
 
 Common Fowl . 
 
 106-7 
 
 140 
 
 30 
 
 Duck .... 
 
 108-5 
 
 170 
 
 21 
 
 Raven . . ' / 
 
 108-5 
 
 110 
 
 21 
 
 Lark . . ;> .'-.. 
 
 117-2 
 
 200 
 
 22 
 
 Simia Callitriche 
 
 95-9 
 
 90 
 
 30 
 
 Guinea Pig . . 
 
 100-4 
 
 140 
 
 36 
 
 Dog . . . J 5 V 
 
 99-3 
 
 90 
 
 28 
 
 Cat . . > V V 
 
 101-3 
 
 100 
 
 24 
 
 Goat .... 
 
 102-5 
 
 84 
 
 24 
 
 Hare .... 
 
 100-4 
 
 120 
 
 36 
 
 Horse .... 
 
 98-2 
 
 56 
 
 16 
 
 Man .... 
 
 98-6 
 
 72 
 
 18 
 
 Man (Liebig) . . 
 
 97-7 
 
 65 
 
 17 
 
 Woman (Liebig) 
 
 98-2 
 
 60 
 
 15 
 
 The temperature of a child is 102-2. 
 
 The temperature of the human body, in the mouth or 
 in the rectum, for example, is from 97-7 to 98-6. That 
 of the blood (Magendie) is from 100-6 to 101-6. As a 
 mean temperature, 99-5 has been adopted in this work, 
 page 18. 
 
 24* 
 
282 
 
 APPENDIX. 
 
 NOTE VI. P. 34. 
 
 The prisoners in the house of arrest at Giessen receive 
 daily 1J lb. of bread (24 oz.), which contain 7J oz. of 
 carbon. They receive, besides, 1 lb. of soup daily, and 
 on each alternate day, 1 lb. of potatoes. 
 
 ] lb. of bread contains . . 7-25 oz. of carbon. 
 1 lb. of soup contains . . 0-75 ditto. 
 lb. of potatoes contains . . 1-00 ditto. 
 
 Total . . 9-00 ditto.f 
 
 NOTE VII. P. 42. 
 
 COMPOSITION OF THE FIBRINE AND ALBUMEN OF 
 BLOOD, a 
 
 Albumen from Serum of Blood. 
 Scherer.* 
 
 Fibrine. 
 Scherer.* Mulder. 
 
 I. 
 
 53850 
 
 6983 
 
 15-673 
 
 ii. 
 
 55-461 
 
 7-201 
 
 15-673 
 
 in. 
 56-097 
 
 6880 
 15-681 
 
 i. 
 
 53-67J 
 6-878 
 15-763 
 
 ii. HI. 
 
 54-454 54-56 
 
 7-069 6-90 
 
 15-762 15-72 
 
 23-494 21-655 22-342 23-688 22-715 22-82 
 
 Carbon . 
 Hydrogen 
 Nitrogen 
 Oxygen 
 Sulphur 
 Phosphorus ) 
 a Annalen der Chem. und Pharm., XXVIII., 74, and XL., 33, 36. 
 
 For additional analyses of animal fibrine and albumen, 
 see Note XXVII., which also contains analyses of the 
 various animal tissues. 
 
 t At page 34 the carbon contained in the daily food of these pris- 
 oners is calculated at 8 oz., and the Appendix in the original makes 
 the number also 8-5, apparently by an error in adding up the above 
 numbers, which yield the sum of 9 oz. Possibly there may be an 
 error in excess in the proportion of carbon calculated for the soup, 
 which, in that case, ought to be 25 oz. G. 
 
ANALYTICAL EVIDENCE. 
 
 NOTE VIII. P. 47. 
 
 COMPOSITION OF VEGETABLE FIBRINE, VEGETABLE 
 ALBUMEN, VEGETABLE CASEINE, AND VEGETABLE 
 GLUTEN. 
 
 VEGETABLE FIBRINE. 
 
 GLUTEN. 
 
 Scherer.*a 
 
 I. H. ill. 
 
 Carbon . . 53-064 546.03 54-617 
 
 Hydrogen . 7-132 7-302 7-491 
 
 Nitrogen . 15-359 15-809 15-809 
 Oxygen -\ 
 
 Sulphur V 24-445 22-285 22 083 
 Phosphorus J 
 
 a Ann. der Chem. und Pharm., XL., 
 
 b Ibid., XL., 65. 
 
 c L. Gmelin's Theor. Chemie., II., 1092. 
 
 As obtained from 
 wheat flour. 
 
 Jones. *& Marcet.c. Bouisin- 
 
 gault. 
 IV. I. II. 
 
 53-83 55-7 53.5 
 
 7-02 14-5 15-0 
 
 15-58 7-8 7-0 
 
 2356 22-0 24-5 
 
 7. 
 
 VEGETABLE ALBUMEN, a 
 
 From Rye. From Wheat. From Gluten. From Almonds. 
 
 Carbon . . 
 
 Hydrogen 
 
 Nitrogen 
 
 Oxygen 
 
 Sulphur 
 
 Phosphorus 
 
 Jones.* 
 
 54-74 
 
 7-77 
 15-85 
 
 21-64 
 
 Carbon 
 Hydrogen 
 Nitrogen 
 Oxygen, &c. 
 
 Jones.* Varrentrapp & Will* Jones*. 
 
 55-01 54-85 57-03 
 
 7-23 6-98 7-53 
 
 15-92 15-88 13-48 
 
 21-84 
 
 Boussingault. 
 
 52-7 
 . 69 
 
 18-4 
 , 22-0 
 
 22-39 
 
 21-96 
 
 Varrentrapp and Will.* 
 
 15-70 
 
 a Ann. der Chem. und Pharm., XL., 66, and XXXIX., 291. 
 
284 APPENDIX. 
 
 VEGETABLE CASEINE. a 
 
 Sulphate of Caseine 
 
 and Potash. 
 Scherer.* Jones.* Varrentrapp and Will. 
 
 Carbon .... 54-138 55-05 51-41 51-24 
 
 Hydrogen .... 7-156 7-59 7-83 6-77 
 
 Nitrogen . . . 15-672 15-89 14-48 13-23 
 Oxygen, &c. . . . 23-034 21-47 
 
 a Ann. der Chem. und Pharra., XXXIX., 291, and XL., 8 and 67. 
 
 VEGETABLE GLUTEN. 
 
 Jones. *a Boussingault. 
 
 Carbon . . 
 
 . . . 55-22 
 
 54-2 
 
 52-3 
 
 Hydrogen 
 
 . . . 7-42 
 
 7-5 
 
 6-5 
 
 Nitrogen 
 
 . . . 1598 
 
 13-9 
 
 18-9 
 
 Oxygen, &c. 
 
 . . . 21-38 
 
 24-4 
 
 22-3 
 
 a Ann. der Chem. und Pharra., XL., 66. 
 
 The pure gluten, analyzed by Jones, was that portion 
 of the raw gluten from wheat flour, which is soluble in hot 
 alcohol. The insoluble portion is vegetable fibrine, the 
 analysis of which has been already given. 
 
 NOTE IX. P. 51. 
 COMPOSITION OF ANIMAL CASEINE. a 
 
 Scherer.* 
 
 Carbon 
 Hydrogen 
 Nitrogen 
 Oxygen > 
 Sulphur ) 
 
 a Ann. der Chem. und Pharm., XL., 40 et seq. 
 
 b This substance, called, in German, zieger, is contained in the 
 whey of milk after coagulation by an acid. It is coagulated by heat, 
 and very much resembles albumen. 
 
 From fresh 
 milk. 
 
 From sour From milk by 
 milk. acetic acid. 
 
 Albuminous 
 substance 
 
 
 , 
 
 .*, v 
 
 
 in milk, b 
 
 I. 
 
 II. 
 
 in. 
 
 IV. 
 
 V. ' 
 
 54-825 
 
 54-721 
 
 54665 
 
 54-580 
 
 54-507 
 
 7-153 
 
 7-239 
 
 7-465 
 
 7-352 
 
 6-913 
 
 15-628 
 
 15-724 
 
 15-724 
 
 15-696 
 
 15-670 
 
 22394 
 
 22-316 
 
 22-146 
 
 22-372 
 
 22-910 
 
ANALYTICAL EVIDENCE. 285 
 
 Mulder, a 
 
 Carbon 54-96 
 
 Hydrogen v 7'15 
 
 Nitrogen 1580 
 
 Oxygen . . . . . 2173 
 
 Sulphur 0-36 
 
 a, For the analysis of vegetable caseine, see the preceding note. 
 
 NOTE X. P. 63. 
 
 AMOUNT OF MATTER SOLUBLE IN ALCOHOL IN THE 
 SOLID EXCREMENTS OF THE HORSE AND COW. 
 
 (WILL.*) 
 
 18*3 grammes of dried horse-dung lost, by the action 
 of alcohol, 0-995 gramme. The residue, when dry, had 
 the appearance of saw-dust, after it has been deprived, by 
 boiling, of all soluble matter. 
 
 14-98 grammes of dry cow-dung lost, by the same 
 treatment, 0-625 gramme. 
 
 NOTE XL P. 68. 
 COMPOSITION OF STARCH, a 
 
 Strecker.* 
 
 Calculated 
 
 < 
 
 From 
 
 From 
 
 From 
 
 From 
 
 Cis Hio Oio. 
 
 Peas. 
 
 Lentils. 
 
 Bean*. 
 
 Buckwheat. 
 
 Carbon 44-91 
 
 44-33 
 
 44-46 
 
 44-16 
 
 44-23 
 
 Hydrogen 6-11 
 
 6-57 
 
 6-54 
 
 6-69 
 
 6-40 
 
 Oxygen 48-98 
 
 49-09 
 
 49-00 
 
 49-15 
 
 49-37 
 
286 
 
 APPENDIX. 
 
 Strecfcer.* 
 
 r 
 
 From maize. From horse-chestnuts. From wheat. 
 
 Carbon 44-27 44-44 44-26 
 
 i 
 
 From rye. 
 
 44-16 
 
 Hydrogen 
 Oxygen 
 
 6-67 
 49-06 
 
 6-47 
 49-08 
 
 6-70 
 49-04 
 
 6-64 
 49-20 
 
 Strecker.* 
 
 Carbon 
 
 From rice. 
 
 44-69 
 
 From 
 dahlia roots. 
 
 44-13 
 
 From 
 unripe apples. 
 
 44-10 
 
 From 
 unripe pears. 
 
 44-14 
 
 Hydrogen 
 Oxygen 
 
 6-36 
 
 48-95 
 
 6-56 
 49-31 
 
 6-57 
 49-33 
 
 6-75 
 49-11 
 
 From potatoes. 
 
 From arrow-root. From yams, a 
 
 Berzelius. 
 
 Carbon 44-250 
 Hydrogen 6-674 
 Oxygen 49-076 
 
 Gay Lussac & Thenard. Prout. Ortigosa. 
 
 43-55 44-40 44-2 
 
 6-77 6-18 6-5 
 
 49-68 49-42 49-3 
 
 a The starch employed for the analyses, made by Strecker and Or- 
 tigosa, was prepared from the chemical laboratory at Giessen, from the 
 respective seeds, bulbs, and fruits. 
 
 NOTE XII. P. 69. 
 
 COMPOSITION OF GRAPE SUGAR (STARCH SUGAR). 
 
 Carbon 
 
 Hydrogen 
 
 Oxygen 
 
 From grapes. a From starch.6 
 De Saussure. 
 
 36-71 
 
 6-78 
 
 56-51 
 
 37-29 
 
 6-84 
 
 55-87 
 
 From honey, c 
 Prout. 
 
 36-36 
 
 7-09 
 
 5655 
 
 a Ann/de Chimie, XI., 381. 
 b Ann. of Philosophy, VI., 426. 
 c Philosoph. Trans. 1827, 373. 
 
 Calculated 
 Ci 2 H 14 14 . 
 
 36-80 
 
 7-01 
 
 56-19 
 
ANALYTICAL EVIDENCE. 
 
 NOTE XIII. P. 70. 
 COMPOSITION OF SUGAR OF MILK. 
 
 287 
 
 Gay Luasac 
 
 and ThSnard. Front. 
 
 Carbon 38825 40-00 
 
 Hydrogen 7-341 6-66 
 
 Oxygen 53-834 53-34 
 
 Calculated 
 
 Brunn. Berzelius. Liebig.* Ci2Hi2Oi2. 
 40437 39474 40-00 40-46 
 6-711 7-167 6-73 660 
 52-852 53359 53-27 52-94 
 
 NOTE XIV. P. 70. 
 COMPOSITION OF GUM. 
 
 Calculated 
 
 Gay Lussac 
 and Thenard. 
 
 Carbon 42-23 
 
 Hydrogen 6-93 
 Oxygen 50-84 
 
 NOTE XV. P. 72. 
 
 ANALYSIS OF OATS (BOUSSINGAULT). a 
 100 parts of oats contain of dry matter . . 84-9 
 
 Gocbel. 
 
 Berzelius. 
 
 C 12 H n Oi 
 
 42-2 
 
 42-682 
 
 42-58 
 
 6-6 
 
 6-374 
 
 6-37 
 
 51-2 
 
 50-944 
 
 51-05 
 
 Ditto 
 
 water 
 
 100 parts of oats dried at 212 = 117-7 parts dried at 
 the ordinary temperature, contain 
 
 Carbon '-> . 
 Hydrogen 
 Oxygen . . 
 Nitrogen s.V; . 
 Ashes *, **,.'" ->? 
 
 Water . . . . 
 
 Oats dried in the air . . 117-7 contain, in 100 parts, 
 
 1-867 of nitrogen. 
 
 a Ann. de Chirnie et de Phys., LXXI., 130. 
 
288 APPENDIX. 
 
 ANALYSIS OF HAT. 
 
 100 parts of hay dried in the air contain 86 of dry matter, 
 
 14 of water. 
 
 100 
 
 100 parts of hay dried at 212 = 116-2 parts dried in 
 air, contain 
 
 Carbon 45-8 
 
 Hydrogen .... 5-0 
 Oxygen .... 38-7 
 Nitrogen .... 1*5 
 Ashes 9-0 
 
 100-0 
 16-2 water, 
 
 116-2 hay dried in the air. 
 
 100-0 of hay dried at the ordinary temperature contain 1-29 
 of nitrogen. 
 
 240 oz. of such hay = 15 Ibs. contain 3-095 oz. of nitrogen. 
 72 oz. of oats = 4 Ibs. contain 1-34 ditto. 
 
 Total 4435 
 
 NOTE XVI. (a.) P. 74. 
 
 AMOUNT OF CARBON IN FLESH AND IN STARCH. 
 
 100 parts of starch contain 44 of carbon ; therefore, 64 
 oz. (4 Ibs.) contain 28*16 oz. of carbon. 
 
 100 parts of fresh meat contain 13-6 of carbon (see 
 Note III.) ; hence 240 oz. (15 Ibs.) contain 32'64 oz. of 
 carbon. f 
 
 t By an error in calculation in the original, the amount of carbon in 
 15 Ibs. of meat Is stated to be 27-64 oz. It follows, that the carbon of 
 4 Ibs. of starch is not equal, as stated in the text, to that of 15 Ibs. of 
 flesh, but to that of 13 Ibs. This difference, however, is not sufficient 
 to affect the argument at p. 81. G. 
 
ANALYTICAL EVIDENCE. 
 
 289 
 
 NOTE XVI. (b.) P. 81. 
 COMPOSITION OF 
 
 Hog's lard. 
 
 Mutton fat. 
 Chevreul. a 
 
 Human fa 
 
 Carbon .... 
 Hydrogen . . . 
 Oxygen .... 
 
 79-098 
 11-146 
 9-756 
 
 78-996 
 11-700 
 9-304 
 
 79-000 
 11-416 
 9-584 
 
 a Recherches Chim., sur les corps gras. Paris. 1823. 
 
 NOTE XVII. P. 81. 
 COMPOSITION OF CANE SUGAR. 
 
 Berzelius. 
 
 42-225 
 
 6600 
 
 5M75 
 
 According to 
 
 Gay Lussac Calculated 
 Prout. W. Crum. Liebig.* &Th6nard. Ci 2 H u On. 
 
 42-86 4214 42-301 42-47 42-8 
 6-384 6-90 6-37 
 51-315 50-63 51-05 
 
 6-35 
 5079 
 
 6-42 
 51-44 
 
 Carbon 
 
 Hydrogen 
 
 Oxygen 
 
 For the composition of gum and of starch, see Notes 
 (14) and (11). 
 
 NOTE XVIII. P. 82. 
 COMPOSITION OF CHOLESTERINE. 
 
 According to 
 Chevreul. a Couerbe.J Marchand. 
 
 Carbon 85-095 84-895 84-90 
 
 Hydrogen 11-880 12-099 12-00 
 
 Oxygen 3-025 3-006 3-10 
 
 a Recherches sur les corps gras, p. 185. 
 b Ann. de Ch. et de Phys., LVL, p. 164. 
 
 25 
 
 Calculated 
 C 36 H 32 0. 
 
 84-641 
 
 12-282 
 
 3-077 
 
290 APPENDIX. 
 
 NOTE XIX. P. 84. 
 THE PRODUCTION OF WAX FROM SUGAR, a 
 
 As soon as the bees have filled their stomach, or what 
 is called the honey bladder, with honey, and cannot de- 
 posit it for want of cells, the honey passes gradually in 
 large quantity into the intestinal canal, where it is digest- 
 ed. The greater part is expelled as excrement ; the rest 
 enters the fluids of the bee. In consequence of this great 
 flow of juices, a fatty substance is produced, which oozes 
 out on the eight spots formerly mentioned, which occur 
 on the four lower scales of the abdominal rings, and soon 
 hardens into laminae of wax. On the other hand, when 
 the bees can deposit their honey, only so much enters 
 the intestinal canal as is necessary for their support. 
 The honey bladder need not be filled with honey longer 
 than forty hours in order to bring to maturity, on the eight 
 spots, eight laminae of wax, so that the latter fall off. I 
 made the experiment of giving to bees, which I had 
 enclosed in a box with their queen about the end of Sep- 
 tember, dissolved sugar candy instead of honey. Out of 
 this foo laminae of wax were formed ; but these would 
 not separate and fall off readily, so that the mass, which 
 continued to ooze out, remained, in most of the bees, 
 hanging to the upper lamina ; and the laminae of wax 
 became as thick as four under ordinary circumstances. 
 
 a From F. W. Gundlach's Natural History of Bees, p. 115. Cassel, 
 1842. We are acquainted with no more beautiful or convincing proof 
 of the formation of fatty matter from sugar, than the following process 
 of the manufacture of wax by the bee, as taken from observation. 
 
ANALYTICAL EVIDENCE. 29 1 
 
 The abdominal scales of the bees were, by means of the 
 wax, distinctly raised, so that the waxen laminae pro- 
 jected between them. On examination, I found that these 
 thick laminae, which under the microscope exhibited sev- 
 eral lamellae, had a sloping surface downwards near the 
 head, and upwards in the vicinity of the tail. The first 
 waxen lamina, therefore, must have been pushed down- 
 wards by the second, because, where the abdominal 
 scales are attached to the skin, there is no space for two 
 laminae, the second by the third, and thus the inclined sur- 
 faces on the sides of the thick laminae had been produced. 
 I saw distinctly from this, that the first-formed laminae are 
 detached by those which follow. The sugar had been 
 converted into wax by the bees, but it would seem that 
 there was some imperfection in the process, as the laminae 
 did not fall off, but adhered to the succeeding ones. 
 
 In order to produce wax in the manner described, the 
 bees require no pollen, but only honey. I have placed, 
 even in October, bees in an empty hive, and fed them 
 with honey; they soon formed comb, although the weather 
 was such that they could not leave the hive. I cannot, 
 therefore, believe that pollen furnishes food for the bees, 
 but I think they only swallow it in order, by mixing it 
 with honey and water, to prepare the liquid food for the 
 grubs. Besides, bees often starve in April, when their 
 stock of honey is consumed, and when they can obtain in 
 the fields abundance of pollen, but no honey. When 
 pressed by hunger, they tear the nymphae out of the cells, 
 and gnaw them in order to support life by the sweet juice 
 which they contain. But, if in this condition they are 
 not artificially fed, or if the fields do not soon yield their 
 
292 APPENDIX. 
 
 proper food, they die in the course of a few days. Now, 
 if the pollen were really nourishment for bees, they ought 
 to be able to support life on it, mixed with water. 
 
 Bees never build honeycomb unless they have a queen, 
 or are provided with young out of which they can educate 
 a queen. But if bees be shut up in a hive without a 
 queen, and fed with honey, we can perceive in forty-eight 
 hours that they have laminae of wax on their scales, and 
 that some have even separated. The building of cells is, 
 therefore, voluntary, and dependent on certain conditions, 
 but the oozing out of wax is involuntary. 
 
 One might suppose, that a large proportion of these 
 laminae must be lost, since the bees may allow them to 
 fall off, out of the hive as well as in it ; but the Creator 
 has wisely provided against such a loss. If we give to 
 bees engaged in building cells honey in a flat dish, and 
 cover the dish with perforated paper, that the bees may 
 not be entangled in the honey, we shall find, after a day, 
 that the honey has disappeared, and that a large number 
 of laminae are lying on the paper. It would appear as if 
 the bees which have carried off the honey, had let fall the 
 scales ; but it is not so. For, if above the paper we lay 
 two small rods, and on these a board, overhanging the 
 dish on every side, so that the bees can creep under the 
 board and obtain the honey, we shall find next day the 
 honey gone, but no lamina on the paper ; while laminae 
 will be found in abundance on the board above. The 
 bees, therefore, which go for and bring the honey, do 
 not let fall the laminae of wax, but only those bees which 
 remain hanging to the top of the hive. Repeated experi- 
 ments of this kind, have convinced me that the bees, as 
 
ANALYTICAL EVIDENCE. 293 
 
 soon as their laminae of wax are mature, return to the 
 hive and remain at rest, just as caterpillars do, when 
 about to change. In a swarm that is actively employed in 
 building, we may see thousands of bees hanging idly at 
 the top of the hive. These are all bees whose laminae of 
 wax are about to separate. When they have fallen off, 
 the activity of the bee revives, and its place is occupied 
 for the same purpose by another. 
 
 [From page 28 of the same work.] In order to ascer- 
 tain how much honey bees require to form wax, and how 
 often, in a swarm engaged in building, the lamina? attain 
 maturity and fall off, I made the following experiment, 
 which appears to me not uninteresting. 
 
 On the 29th of August, of this year (1841), at a time 
 when the bees could obtain in this district no further sup- 
 ply of honey from the fields, I emptied a small hive, placed 
 the bees in a small wooden hive, having first selected the 
 queen bee, and shut her up in a box, furnished with wires, 
 which I placed in the only door of the hive, so that no 
 embryos could enter the cells. I then placed the hive in 
 a window, that I might be able to watch it. 
 
 At 6 P. M. I gave the bees 6 oz. of honey run from the 
 closed cells, which had thus the exact consistence of 
 freshly made honey. This had disappeared next morning. 
 In the evening of the 30th, I gave the bees 6 oz. more, 
 which, in like manner was removed by the next morning ; 
 but already some laminae of wax were seen lying on the 
 paper with which the honey was covered. On the 31st 
 August and the 1st September, the bees had in the even- 
 ing 10 oz., and on the 3d of September in the evening 
 7 oz. ; in all, therefore, 1 Ib. 13 oz. of honey, which had 
 25* 
 
294 APPENDIX. 
 
 run cold out of cells which the bees had already closed. 
 On the 5th of September I stupefied the bees, by means 
 of puff-ball, and counted them. Their number was 2,765, 
 and they weighed 10 oz. I next weighed the hive, the 
 combs of which were well filled with honey, but the cells 
 not yet closed ; noted the weight, and then allowed the 
 honey to be carried off by a strong swarm of bees. This 
 was completely effected in a few hours. I now weighed 
 it a second time, and found it 12oz. lighter ; consequently 
 the bees still had in the hive 12 oz. of the 29 oz. of honey 
 given to them. I next extracted the combs, and found 
 that their weight was | of an ounce. I then placed the 
 bees in another box, provided with empty combs, and 
 fed them with the same honey as before. In the first few 
 days they lost daily rather more than 1 oz. in weight, and 
 afterwards half an ounce daily, which was owing to the 
 circumstance, that from the digestion of so much honey, 
 their intestinal canal was loaded with excrements ; for 
 1,170 bees, in autumn, when they have been but a short 
 time confined to the hive, weigh 4 oz. ; consequently 
 2,765 bees should weigh 9 oz. But they actually weigh- 
 ed 10 oz., and therefore had within them 1 oz. of excre- 
 ment, for their honey bladders were empty. During the 
 night the weight of the box did not diminish at all, be- 
 cause the small quantity of honey the bees had deposited 
 in the cells, having already the proper consistence, could 
 not lose weight by evaporation, and because the bees 
 could not then get rid of their excrements. For this 
 reason, the loss of weight occurred always during the 
 day. 
 
 If, then, the bees, in seven days, required 3J oz. of 
 
ANALYTICAL EVIDENCE. 295 
 
 honey to support and nourish their bodies, they must have 
 consumed 13| oz. of honey in forming % of an ounce of 
 wax ; and consequently, to form 1 Ib. of wax, 20 Ibs. of 
 honey are required. This is the reason why the strongest 
 swarrns in the best honey seasons, when other hives, that 
 have no occasion to build, often gain in one day 3 or 
 4 Ibs. in weight, hardly become heavier, although their 
 activity is boundless. All that they gain is expended* in 
 making wax. This is a hint for those who keep bees, to 
 limit the building of comb. Cnauf has already recom- 
 mended this, although he was not acquainted with the 
 true relations of the subject. From 1 oz. of wax, bees 
 can build cells enough to contain 1 Ib. of honey. 
 
 100 laminae of wax weigh 0-024 gramme (rather more 
 than 3 of a grain), consequently, 1 kilogramme (= 15,360 
 grains) will contain 4,166,666 laminae. Hence, j- of an 
 ounce will contain 81,367 laminae. Now this quantity 
 was produced by 2,765 bees in six days ; so that the bee 
 requires for the formation of its 8 laminae (one crop) 
 about thirty-eight hours, which agrees very well with my 
 observations. 
 
 The laminae, when formed, are as white as bleached 
 wax. The cells also, at first, are quite white, but they 
 are colored yellow by the honey, and still more by the 
 pollen. When the cold weather comes on, the bees re- 
 tire to the hive under the honey, and live on the stock 
 they have accumulated. 
 
 P. 54. Many believe that bees are hybernating ani- 
 mals ; but this opinion is quite erroneous. They are 
 lively throughout the winter ; and the hive is always 
 warm in consequence of the heat which they generate. 
 
296 APPENDIX. 
 
 The more numerous the bees in a hive, the more heat is 
 developed ; and hence strong hives can resist the most 
 intense cold. It once happened that I forgot to remove 
 from the door, which was unusually large, of a hive in 
 winter, a perforated plate of tinned iron, which I had 
 fastened over the opening to diminish the heat in July ; 
 and yet this hive came well through the winter, although 
 th cold was very severe, having been for several days 
 so low as 0. But I had added to this hive the bees of 
 two other hives ! When the cold is very intense, the 
 bees begin to hum. By this means respiration is accele- 
 rated and the development of heat increased. If, in 
 summer, bees without a queen are shut up in a glass box, 
 they become uneasy and begin to hum. So much heat is 
 by this means developed, that the plates of glass become 
 quite hot. If the door be not opened in this case, or if 
 air be not admitted, and if the glass be not cooled by the 
 aid of water, the bees are soon suffocated. 
 
 XX. COMPOSITION OF BEES' WAX. 
 
 Guy Lussac De Saus- Calculated 
 
 and Th6nard.a sure.6 Oppermann.c Killing. d Hess.e ConHonO. 
 
 Carbon 81-784 81-607 81-291 81-15 81-52 81-39 
 
 Hydrogen 12-672 13 859 14-073 13-75 13 23 13 29 
 
 Oxygen 5-544 4-534* 4-636 5-09 5-25 5-32 
 
 a Traite de Chimie, par Thenard, 6me. e d., IV., 477. 
 
 b Ann. de Ch. et de Phys , XIII., 310. 
 
 c Ibid., XLIX., 224. 
 
 d Annal. der Pharm., II., 267. 
 
 e Ibid., XXVII., 6. 
 
ANALYTICAL EVIDENCE. 297 
 
 NOTE XXI. (a.) P. 100. 
 
 COMPOSITION OF HYDRATED CYANURIC ACID, OF 
 HYDRATED CYANIC ACID, AND OF CYAMELIDE, IN 
 100 PARTS, ACCORDING TO THE ANALYSIS OF 
 
 Wohlcrand Liebig*a 
 
 Cyanuric acid, cyanic 
 
 acid, cyamelide. 
 
 Carbon ..... 28-19 
 
 Hydrogen 2-30 
 
 Nitrogen 32-63 
 
 Oxygen 36-87 
 
 a PoggendorfFs Annalen, XX., 375 et seq. 
 
 NOTE XXI. (b.) P. 100. 
 
 COMPOSITION OF ALDEHYDE, METALDEHYDE, AND 
 ELALDEHYDE a 
 
 Aldehyde. Metaldehyde. Elaldehyde. Calculated 
 
 Liebig.* Fehling.* C4 H* Oz. 
 
 Carbon 55-024 54511 54-620 54.467 55-024 
 Hydrogen 8-983 9-054 9-248 9-075 8-983 
 Oxygen 35-993 36-435 36-132 36-458 35-993 
 
 a Ann. der Pharm., XIV., 142, and XXVII., 319. 
 
 NOTE XXII. P. 101. 
 COMPOSITION OF PROTEINE. 
 
 From the From albumen. From fibrine. 
 crystalline lens. 
 
 Scherer.*a 
 
 Carbon . . 
 
 . 55-300 
 
 55-160 
 
 54-848 
 
 Hydrogen . 
 
 . 6-940 
 
 7055 
 
 6-959 
 
 Nitrogen 
 
 . 16-216 
 
 15-966 
 
 15-847 
 
 Oxygen 
 
 . 21-544 
 
 21-819 
 
 22-346 
 
298 
 
 APPENDIX. 
 
 Scherer.*a 
 
 From hair. From horn. C 48 H 36 N 6 O 14 . 
 
 Carbon 
 
 54-746 55-150 55408 54-291 
 
 55-756 
 
 Hydrogen 
 
 7-129 7-197 7-238 7-082 
 
 6-826 
 
 Nitrogen 
 
 15-727 15-727 15-593 15-593 
 
 16-142 
 
 Oxygen 
 
 22-398 21-926 21-761 23-034 
 
 21-276 
 
 
 a Ann. der Chem. und Pharm., XL., 43. 
 
 
 
 From vegetable From From 
 
 From 
 
 
 albumen. fibrine. albumen. 
 
 cheese. 
 
 
 Mulder.a 
 
 
 Carbon 
 
 . . 54-99 55-44 55-30 
 
 55.159 
 
 Hydrogen 
 
 . . 6-87 6-95 6-94 
 
 7-176 
 
 Nitrogen 
 
 . . 15-66 16-05 1602 
 
 15-857 
 
 Oxygen 
 
 . . 22-48 21-56 21-74 
 
 21-808 
 
 a Ann. der Pharm., XXVIII., 75. 
 
 NOTE XXIII. P. 103. 
 
 COMPOSITION OF THE ALBUMEN OF THE YOLK AND 
 OF THE WHITE OF THE EGG. a 
 
 From the yolk. 
 Jones.* 
 
 From the white. 
 Scherer * 
 
 55000 
 
 53-72 53-45 
 
 7-55 7-66 
 
 7-073 
 
 1360 13-34 
 
 15-920 
 
 Carbon . 
 
 Hydrogen 
 
 Nitrogen 
 
 Oxygen -\ 
 
 Sulphur ( 25-13 25-55 
 
 Phosphorus ) 
 
 a Ann. der Chem. und Pharm., XL., 36, ibid. 67. 
 
 22007 
 
 NOTE XXIV. P. 107. 
 
 COMPOSITION OF LACTIC ACID. 
 
 C 6 H s 
 
 Carbon 44-92 
 
 Hydrogen 6-11 
 
 Oxygen . . -. \' . 48-97 
 
ANALYTICAL EVIDENCE. 299 
 
 NOTE XXV. P. 111. 
 
 GAS FROM THE ABDOMEN OF COWS AFTER EATING 
 CLOVER TO EXCESS, OBTAINED BY PUNCTURE. 
 
 a Examined by Lameyran and Fremy. b By Vogel. 
 c By Pfluger. 
 
 Air. 
 
 a 5 
 
 Carbonic acid. 
 
 5 
 
 Inflammable gas 
 
 15 
 
 Sulphuretted hydrogen. 
 
 80 Vol. in 100 Vol. 
 
 625 
 
 2? 
 
 48 
 
 
 
 c 
 
 60 
 
 40 
 
 
 
 c 
 
 20 
 
 80 
 
 
 
 NOTE XXVI. P. 113. 
 
 MAGENDIE FOUND IN THE STOMACH AND INTESTINES 
 OF EXECUTED CRIMINALS : 
 
 a In the case of an individual who had taken food in 
 moderation one hour previous to death ; 6, in the case of 
 one who had done so two hours previously ; and c, in the 
 case of a third, who had done so four hours previous to 
 execution : 
 
 100 volumes of the gas contained 
 Oxygen. Nitrogen. Carbonic Inflam- 
 
 acid. mable gai. 
 
 ( From the stomach 11-00 Vol. 71-45 14-00 3-55 
 
 a < small intestines 00 00 20-03 24-39 55-53 
 
 ( large intestines 00-00 51-03 43-50 5-47 
 
 C From the stomach 00-00 00 00 00-00 00-00 
 
 b < small intestines OO'OO 8-85 40.00 51-15 
 
 f _ large intestines 0000 18-40 70-00 11-60 
 
 C From the stomach 00-00 0000 0000 0000 
 
 c < small intestines 00-00 66-60 25-00 8-40 
 
 ( large intestines 00 00 45-96 42-86 11-18 
 
300 
 
 APPENDIX. 
 
 NOTE XXVII. (referred to in NOTE VIL, P. 43 and 121.) 
 
 COMPOSITION OF ANIMAL ALBUMEN AND FIBRINE, 
 AND OF THE DIFFERENT TISSUES OF THE BODY. 
 
 1. ALBUMEN. 
 
 From the serum of blood. 
 
 From eggs. 
 
 From yolk of egg. 
 
 Scherer.*a 
 
 Jones.*6 
 
 ,. 
 
 n. 
 
 in. 
 
 IV. 
 
 V. 
 
 VI. 
 
 Carbon 53-850 
 
 55-461 
 
 55-097 
 
 55-000 
 
 53-72 
 
 53-45 
 
 Hydrogen 6-983 
 
 7-201 
 
 6-880 
 
 7-073 
 
 7-55 
 
 7-66 
 
 Nitrogen 15-673 
 
 15-673 
 
 15-681 
 
 15-920 
 
 13-60 
 
 13-34 
 
 Oxygen "\ 
 
 
 
 
 
 
 Sulphur V 23-494 
 
 21-655 
 
 22342 
 
 22-007 
 
 25-13 
 
 2555 
 
 Phosphorus ) 
 
 
 
 
 
 
 a Ann. 
 
 der Chem. 
 
 und Pharm., XL., 
 
 36. 
 
 
 6 Ibid., 
 
 67. 
 
 
 
 
 
 Jones.* 
 
 
 
 Scherer.* 
 
 
 
 From 
 
 From 
 
 From 
 
 
 
 From 
 
 albumen 
 
 hydrocele. 
 
 congestive. From pus. 
 
 fluid of 
 
 of braia. 
 
 
 abscess. 
 
 
 
 dropsy. 
 
 VII. 
 
 VIII. 
 
 IS. 
 
 X. 
 
 XI. 
 
 XII. 
 
 Carbon 55-50 
 
 54-921 
 
 54757 
 
 . 54-663 
 
 54101 
 
 54-302 
 
 Hydrogen 7-19 
 
 7-077 
 
 7-171 
 
 7-022 
 
 6-947 
 
 7-176 
 
 Nitrogen 16-31 
 
 15-465 
 
 15-848 
 
 15-839 
 
 15-660 
 
 15-717 
 
 Oxygen ^ 
 
 
 
 
 
 
 Sulphur V 21-00 
 
 22-537 
 
 22224 
 
 22-476 
 
 23-292 
 
 22-805 
 
 Phosphorus J 
 
 
 
 
 
 
 Mulder.a 
 
 Carbon 
 
 
 
 
 54-84 
 
 
 Hydrogen 
 
 
 
 
 7O9 
 
 
 Nitrogen 
 
 , , 
 
 . . 
 
 . . 
 
 15-83 
 
 
 Oxygen 
 
 . 
 
 . . 
 
 . 
 
 . 21-23 
 
 
 Sulphur 
 
 . 
 
 . 
 
 . 
 
 0-68 
 
 
 Phosphorus 
 
 
 
 
 0-33 
 
 
 a Ann. der Pharm., XXVIIL, 74. 
 
ANALYTICAL EVIDENCE. 
 
 301 
 
 2. FlBRINE. 
 
 Carbon 
 
 Hydrogen 
 
 Nitrogen 
 
 Oxygen 
 
 Sulphur 
 
 Phosphorus 
 
 Scherer.* a 
 
 I. II. III. IV. V. VI. VII. 
 
 53-671 54-454 55002 54-967 53-571 54-686 54-844 
 
 6878 7-069 7216 6867 6895 6-835 7*219 
 
 15-763 15-762 15-817 15913 15-720 15-720 16065 
 
 23688 22-715 21-965 22244 23814 22-759 21-872 
 a Ann. der Chem. und Pharm., XL., 33. 
 
 Carbon ...... 
 
 Hydrogen 
 
 Nitrogen ...... 
 
 Oxygen 
 
 Sulphur 
 
 Phosphorus . . . 
 
 a Ann. der Pharm., XXVIII., 74. 
 
 Mulder, a 
 
 54-56 
 
 6-90 
 
 15*72 
 
 22-13 
 
 0-33 
 
 0-36 
 
 Isinglass. 
 
 3. GELATINOUS TISSUES. 
 
 Scherer.* a 
 
 Tendons of the 
 calf's foot. 
 
 Tunica 
 sclerotica. 
 
 Carbon 50-557 49-563 50-960 50774 50-995 
 Hydrogen 6903 7-148 7-188 7-152 7-075 
 Nitrogen 18-790 18470 18-320 18-320 18-723 
 Oxygen 23750 24-819 23-532 23-754 23-207 
 a Ann. der Chem. und Pharm., XL., 46. 
 
 Calculated 
 
 50-203 
 
 7-000 
 
 18-168 
 
 24-629 
 
 Mulder. 
 
 Carbon . 
 Hydrogen 
 Nitrogen 
 Oxygen 
 
 50.048 50-048 
 
 6-477 6-643 
 
 18-350 18-388 
 
 25-125 24-921 
 
 26 
 
302 APPENDIX. 
 
 4. TISSUES CONTAINING CfiONDRINE. 
 
 Calculated 
 
 Scherer.*a 
 
 50-745 
 6-904 
 14-692 
 27-659 
 
 a Ann. der Chem. und Pharm., XL., 49. 
 
 Cartilages of the 
 ribs of the calf. 
 
 Cornea. 
 
 49522 
 7097 
 14399 
 
 28-982 
 
 Carbon 
 Hydrogen 
 Nitrogen 
 Oxygen 
 
 49496 
 7-133 
 
 14-908 
 28-463 
 
 50-895 
 6962 
 14-908 
 27-235 
 
 Mulder. 
 
 50-607 
 
 6578 
 
 14-437 
 
 28-378 
 
 5. COMPOSITION OF THE MIDDLE MEMBRANE OF ARTERIES. 
 
 Scherer.*o 
 
 Carbon 
 Hydrogen 
 Nitrogen 
 Oxygen 
 
 I. 
 
 53-750 
 
 7-079 
 
 15-360 
 
 23-811 
 
 n. 
 
 53-393 
 
 6-973 
 
 15-360 
 
 24-274 
 
 a Ann. der Chem. und Pharm., XL., 51. 
 
 Calculated 
 
 54-10 
 
 6-64 
 
 15.67 
 
 23.59 
 
 6. COMPOSITION OF HORNY TISSUES. 
 
 Scherer.*a 
 
 External skin Hair of 
 
 of the sole of the foot, the beard. 
 
 Carbon 51-036 50 752 
 
 Hydrogen 6-801 6-761 
 
 Nitrogen 17-225 17-225 
 Oxygen > 
 
 Sulphur I 24 ' 938 25 ' 262 
 
 51-529 
 
 6-687 
 
 17-936 
 
 Hair of the head. 
 Fair. Brown. Black. 
 
 50^652 49-345 "^50-622 49-935 
 
 6-769 6576 6613 6631 
 
 17-936 17936 17-936 17-936 
 
 23 ' 848 24>643 26 ' 143 24 ' 829 25 ' 498 
 
 Scherer.* 
 
 Buffalo IK 
 
 Nails. Wool. Calculated 
 
 Carbon 51-990 51-102 51-620 51540 51-089 50-653 51.890 
 Hydrogen 6-717 6597 6754 6-779 6-824 7-029 6542 
 Nitrogen 17-284 17-284 17-284 17284 16901 17-710 17-525 
 
 Oxygen 
 Sulphur 
 
 24-009 24-957 24342 24-397 25-186 24-608 24-043 
 
 a Ann. der Chem. und Pharm., XL , 53. 
 
ANALYTICAL EVIDENCE. 303 
 
 The composition of the membrane lining the interior of 
 the shell of the egg, approaches closely to that of horn. 
 According to Scherer, it contains 
 
 Scherer.* a 
 
 Carbon . . . .' . . . 50-674 
 
 Hydrogen ...... 6-608 
 
 Nitrogen ...... 16761 
 
 25-957 
 
 Sulphur 
 
 a Ann. der Chem. und Pharm., XL., 60. 
 
 The composition of feathers is also nearly the same as 
 that of horn. 
 
 Scherer.* a 
 
 
 Beard of the 
 
 Quill of the Calculated 
 
 
 feather. 
 
 feather. C 48 H 39 N 7 Oie 
 
 Carbon . 
 
 . 50-434 
 
 52-427 52633 
 
 Hydrogen . 
 
 7-110 
 
 7-213 6-637 
 
 Nitrogen 
 
 . 17-682 
 
 17-893 17-778 
 
 Oxygen 
 
 24-774 
 
 22-467 22-953 
 
 The analysis here given of the beard of feathers agrees 
 closely with that of horn, while that of the quill is more 
 accurately represented by the attached formula, which 
 differs from that of horn by 1 eq. of oxygen only. 
 a Ann. der Chem. und Pharm., XL., 61. 
 
 7. COMPOSITION OF THE PIGMENTUM NIGRUM OCULI. 
 
 Scherer.* a 
 
 Carbon . . . 58-273 58-672 57-908 
 Hydrogen . . 5-973 5-962 5-817 
 Nitrogen . . 13-768 13-768 13-768 
 Oxygen . . 21-986 21-598 22-507 
 a Ann. der Chem. und Pharm., XL., 63. 
 
304 
 
 APPENDIX. 
 
 NOTE XXVIII. P. 127. 
 
 According to the analyses of Playfair and Boeckmann, 
 
 0-452 parts of dry muscular flesh gave 0-836 of carbonic acid. 
 
 0-407 0-279 of water. [of water. 
 
 0-242 0-450 of carbonic acid and 0-164 
 
 0-191 0-360 . . . 0-130 
 
 0-305 of dried blood gave 0-575 carbonic acid and 0-202 of water. 
 
 0-214 . . . 0-402 . . . 0138 
 
 1-471 of dried blood, when calcined, left 0-065 of ashes = 4 42 per cent. 
 
 The dried flesh was found to contain of ashes 4 23 per cent. 
 
 The nitrogen was found to be to the carbon as 1 to 8 in equivalents. 
 
 Hence 
 
 Flesh (beef). Ox-blood. 
 
 Blood. 
 
 
 
 
 
 
 Mean of 2 
 
 
 Playfair. 
 
 Boeckmann. 
 
 Playfair. 
 
 Boeckmann. 
 
 analyses. 
 
 Carbon 
 
 51-83 
 
 51-89 
 
 51-95 
 
 51-96 
 
 51-96 
 
 Hydrogen 
 
 7'57 
 
 7-59 
 
 7-17 
 
 7-33 
 
 7-25 
 
 Nitrogen 
 
 15-01 
 
 15-05 
 
 15-07 
 
 15-08 
 
 15-07 
 
 Oxygen 
 
 21-37 
 
 21-24 
 
 21-39 
 
 21-21 
 
 21-30 
 
 Ashes 
 
 4-23 
 
 4-23 
 
 4.42 
 
 4-42 
 
 4-42 
 
 Deducting the ashes, or inorganic matter, the compo- 
 sition of the organic part is, 
 
 Carbon . . 5412 54-18 54-19 54-20 
 
 Hydrogen . 7-89 7-93 7-48 7-65 
 
 Nitrogen . . 15-67 15-71 1572 15-73 
 
 Oxygen . . 22-32 22-18 22-3! 22-12 
 
 This corresponds to the formula 
 
 C 48 V ' . 54-81 
 
 H 39 , r 691 
 
 N 6 . 15-87 
 
 19 . . . . 22-41 
 
ANALYTICAL EVIDENCE. 
 
 305 
 
 NOTE XXIX. p. 128. 
 COMPOSITION OF CHOLEIC ACID, a 
 
 Calculated 
 
 Carbon 
 
 Demarcay. Dumas. C 76 H C6 N 2 O 22 . 
 
 63707 63-5 63-25 
 
 Hydrogen 
 Nitrogen . 
 Oxygen 
 
 . 8-821 9-3 
 3255 33 
 . 24-217 23-9 
 
 8-95 
 3-85 
 2395 
 
 
 a Ann. der Pharm., XXVII., 284 and 293. 
 
 
 NOTE XXX. P. 128. 
 
 COMPOSITION OF TAURINE AND OF CHOLO1DIC ACID. 
 
 
 1. TAURIINE. a 
 
 
 Carbon 
 
 Demarcay.* Dumas. 
 
 . . 19-24 1926 
 
 Calculated 
 C4H 7 N0 10 . 
 
 19-47 
 
 Hydrogen 
 Nitrogen 
 Oxygen 
 
 5-78 5-66 '. 
 . 11-29 11-19 
 63-69 63-89 
 
 5-56 
 11-28 
 63-69 
 
 
 a Ann. der Pharm., XXVII., 287 and 292. 
 
 
 
 2. CHOLOIDIC ACID, a 
 
 
 
 Demarcay.* 
 I. 11. 
 
 Calculated 
 
 Carbon 
 
 . 73-301 73522 73-3 
 
 74-4 
 
 Hydrogen 
 Oxygen . 
 
 3*.^ 9-511 9-577 9.7 
 . 17-188 16-901 17-0 
 
 9-4 
 16-2 
 
 a Ann. der Pharm., XXVII., 289 and 293. 
 
 In reference to the researches of Demar^ay on the bile 
 I would make the following observations. 
 
 The matter to which I have given the name of choleic 
 acid is the bile itself separated from the inorganic con- 
 stituents (salts, soda, &c.) which it contains. By the 
 action of subacetate of lead aided by ammonia, all the 
 26* 
 
306 APPENDIX. 
 
 organic constituents of the bile are made to unite with 
 oxide of lead, with which they form an insoluble, resinous 
 precipitate. The substance here combined with oxide of 
 lead contains all the carbon and nitrogen of the bile. 
 The substance which I have named choloidic acid is that 
 which is obtained, when the bile, purified by alcohol from 
 the substances insoluble in that fluid, is boiled for some 
 time with an excess of muriatic acid. It contains all the 
 carbon and hydrogen of the bile, except those portions 
 which have separated in the form of taurine and ammonia. 
 The cholic acid contains the elements of bile, minus those 
 of carbonate of ammonia. 
 
 These three compounds, therefore, contain the products 
 of the metamorphosis of the entire bile ; their formulae 
 express the amount of the elements of the constituents of 
 the bile. No one of them exists ready formed in the bile 
 in the shape in which we obtai? it ; their elements are 
 combined in a different way from that in which they were 
 united in the bile ; but the way in which these elements 
 are arranged has not the slightest influence on the deter- 
 mination by analysis of the relative proportions of the 
 elements. In the formulas themselves, therefore, is in- 
 volved no hypothesis ; they are simply expressions of the 
 results of analysis. It signifies nothing that the choleic 
 or choloidic acids may be composed of several compounds 
 united together. No matter .how many such they may 
 contain, the relative proportions of all the elements taken 
 together is expressed by the formula which is derived 
 from the analysis. 
 
 The study of the products which are produced from the 
 bile by the action of the atmosphere, or of chemical re- 
 
ANALYTICAL EVIDENCE. 307 
 
 agents, may be of importance in reference to certain pa- 
 thological conditions ; but except as concerns the general 
 character of the bile, the knowledge of these products 
 is of no value to the physiologist ; it is only a burden 
 which impedes his progress. It cannot be maintained of 
 any one of the 38 or 40 substances, into which the bile 
 has been divided or split up, that it exists ready formed 
 in the healthy secretion ; on the contrary, we know with 
 certainty that most of them are mere products of the ac- 
 tion of the reagents which are made to act on the bile. 
 
 The bile contains soda ; but it is a most remarkable 
 and singular compound of soda. When we cause that 
 part of the bile which dissolves in alcohol (which contains 
 nearly all the organic part) to combine with oxide of lead, 
 thus separating the soda, and then remove the oxide of 
 jead, we obtain a substance, choleic acid, which, when 
 placed in contact with soda, forms a compound similar to 
 bile in its taste ; but it is no longer bile ; for bile may be 
 mixed with organic acids, nay, even with dilute mineral 
 acids, without becoming turbid or yielding a precipitate ; 
 while the new compound, choleate of soda, is decomposed 
 by the feeblest acids, the whole of the choleic acid being 
 separated. Hence, bile cannot be considered, in any 
 sense, as choleate of soda. Further, it may be asked, in 
 what form are the cholesterine, and stearic, and margaric 
 acids, which are found in bile, contained in that fluid ? 
 Cholesterine is insoluble in water, and not saponifiable by 
 alkalies ; and if the two fatty acids just named were 
 really present in the bile as soaps of soda, they would be 
 instantly separated by other acids. Yet diluted acids 
 cause no such separation of stearic and margaric acids 
 in bile. 
 
308 APPENDIX. 
 
 It is possible that, in the course of new and repeated 
 investigations, the composition of substances obtained 
 from bile may be found different from that which has been 
 given in our analytical development of this subject. 
 But this, if it should happen, can have but little effect on 
 our formulas ; if the relative proportions of carbon and 
 nitrogen be not changed, the differences will be confined 
 to the proportions of oxygen and hydrogen. In that case 
 it will be necessary for the development of our views in 
 formulas, only to assume that more water and oxygen, or 
 less water and oxygen, have taken a share in the meta- 
 morphosis of the tissues ; but the truth of the develop- 
 ment of the process itself will not be by this means 
 affected. 
 
 NOTE XXXI. P. 129. 
 COMPOSITION OF CHOLIC ACID, a 
 
 Dumas. Calculated C 7 4H6oOi 8 . 
 
 Carbon 68-5 68-9 
 
 Hydrogen .... 97 9-2 
 
 Oxygen 21-8 21-9 
 
 a Ann. der Pharm., XXVII., 295. 
 
 NOTE XXXII. P. 131. 
 
 COMPOSITION OF THE CHIEF CONSTITUENTS OF THE 
 URINE OF MEN AND ANIMALS. 
 
 1. URIC ACID. 
 
 Liobig.*o Mitscherlich. b Calculated CioH^Oe. 
 
 Carbon . . 36-0&3 35-82 36-01 
 
 Hydrogen . 2441 2.38 2-35 
 
 Nitrogen. . 33-361 34-60 33-37 
 
 Oxygen . 28126 27-20 28-27 
 
 a Ann. der Pharm., X., 47. 
 
 b Poggendorff's Ann., XXXIII., 335. 
 
ANALYTICAL EVIDENCE. 
 
 309 
 
 2. ALLOXAN. a 
 A PRODUCT OF THE OXIDATION OF URIC ACID. 
 
 Wohler and Liebig.* Calculated C 8 H 4 Na ' 
 
 . 30-38 ~~30-18 30-34 
 
 2-57 2-48 2-47 
 
 . 17-96 17-96 ]7-55 
 
 49-09 49-38 49-64 
 a Ann. der Pharm., XXVI., 260. 
 
 a UREA. 
 
 Carbon 
 Hydrogen 
 Nitrogen 
 Oxygen 
 
 
 
 Calculated 
 
 Prout. a 
 
 Wohler and Liebig. b 
 
 C 2 H 4 N 2 2 . 
 
 19-99 
 
 20-02 
 
 20-J92 
 
 6-65 
 
 6-71 
 
 6-595 
 
 46-65 
 
 46-73 
 
 46-782 
 
 26-63 
 
 26-54 
 
 26-425 
 
 a Thomson's Annals, XL, 352. 
 b Poggend. Ann., XX., 375. 
 
 4. CRYSTALLIZED HIPPURIC ACID. 
 
 Liebig.* a Dumas, b 
 
 Carbon 60-742 60-5 
 
 Hydrogen 4-959 4-9 
 
 Nitrogen 7-816 7-7 
 
 Oxygen 26483 26-9 
 
 Calculated 
 Mitscherlich. c C 18 H 8 NO 5 -f HO. 
 
 60-63 60-73 
 
 4-98 4-96 
 
 7-90 7-82 
 
 26-49 26-49 
 
 a Ann. der Pharm., XII., 20. 
 
 b Ann. de Ch. et de Phys., LVIL, 327. 
 
 c Poggend. Ann., XXXIII., 335. 
 
 Carbon 
 Hydrogen 
 Nitrogen 
 Oxygen , 
 
 5. ALLANTOIXE. a 
 
 Wohler and Liebig.* 
 
 . 30-60 
 
 3-83 
 
 . 35-45 
 
 30-12 
 
 Calculated C 8 H 6 N 4 O 6 . 
 
 30-66 
 
 3-75 
 
 35-50 
 
 30-09 
 
 a Ann. der Pharm., XXVL, 215. 
 
310 
 
 APPENDIX. 
 
 6. URIC OR XANTHIC OXIDE, a 
 
 Carbon 
 Hydrogen 
 Nitrogen 
 Oxygen , 
 
 Wbhler and Licbig.* 
 
 . 39-28 
 
 2-95 
 
 . 36-35 
 
 21-24 
 
 Calculated C s H 2 N 2 O 2 . 
 
 39-76 
 
 260 
 
 36-84 
 
 20-80 
 
 a Ann. der Pharm., XXVI., 344. 
 
 Carbon 
 Hydrogen 
 Nitrogen 
 Oxygen . 
 Sulphur 
 
 7. CYSTIC OXIDE, a 
 
 Thaulow.* 
 
 . 30-01 
 5-10 
 
 . 11-00 
 
 28-38 
 
 , 25-51 
 
 Calculated C 6 H 6 NO4 S 2 . 
 
 30-31 
 4-94 
 11-70 
 26-47 
 26-58 
 
 a Ann. der Pharm., XXVII., 200. 
 
 The cystic oxide is distinguished from all the other 
 concretions occurring in the urinary bladder by the sul- 
 phur it contains. It can be shown with certainty, that 
 the sulphur is present neither in the oxidized state, nor in 
 combination with cyanogen ; and in regard to its origin 
 the remark is not without interest, that four atoms of 
 cystic oxide contain the elements of uric acid, benzoic 
 acid, sulphuretted hydrogen and water ; all of which are 
 substances, the occurrence of which in the body is be- 
 yond all doubt. 
 
 1 atom uric acid . . 
 1 atom benzoic acid 
 8 atoms sulphuret- ) 
 ted hydrogen ) 
 7 atoms water . 
 
 H 8 S, 
 H 7 7 
 
 4 atoms cystic oxide =C 24 N 4 H 24 O I6 S 8 = 4 (C 6 NH 6 O 4 S 2 ). 
 
ANALYTICAL EVIDENCE. 
 
 311 
 
 An excellent method of detecting the presence of cystic 
 oxide in calculi or gravel is the following : 
 
 The calculus is dissolved in a strong solution of caustic 
 potash, and to the solution is added so much of a solution 
 of acetate of lead, that all the oxide of lead is retained in 
 solution. When this mixture is boiled there is formed a 
 black precipitate of sulphuret of lead, which gives to the 
 liquid the aspect of ink. Abundance of ammonia is also 
 disengaged ; and the alkaline fluid is found to contain, 
 among other products, oxalic acid. 
 
 NOTE XXXIII. P. 131. 
 
 COMPOSITION OF OXALIC, OXALURIC, AND PARABA- 
 NIC ACIDS. 
 
 1. OXALIC ACID (hydrated). 
 
 Gay Lussac & Th6nard. Berthollet. 
 
 Carbon . . 26566 25-13 
 
 Hydrogen . 2-715 3-09 
 
 Oxygen . . 70-689 71-78 
 
 Calculated 
 C 2 3 + HO. 
 
 27-04 
 
 2-21 
 
 70-75 
 
 Carbon 
 
 Wbhler and 
 
 . 27-600 
 
 Liebig.* 
 
 27-318 
 
 Calculated 
 C 6 H 4 N 2 8 . 
 
 27-59 
 
 Hydrogen 
 Nitrogen . 
 Oxygen . 
 
 . 3.122 
 
 . 21.218 
 . 48-060 
 
 3-072 
 21-218 
 
 48-392 
 
 3-00 
 21-29 
 48-12 
 
 a Ann. der Pharm., XXVI., 289. 
 3. PARABANIC ACID, a 
 
 Wohler and Liebig.* 
 
 Carbon . . . 31-95 
 
 31-940 
 
 31-91 
 
 Hydrogen . . 2-09 
 Nitrogen . . 2466 
 Oxygen . . 41-30 
 
 1-876 
 24-650 
 41-534 
 
 1-73 
 24-62 
 41-74 f 
 
 Ann. der Pharm., XXVI., 286. 
 
 t Calculated C- 
 
 H! NI O 3 . 
 
312 APPENDIX. 
 
 NOTE XXXIV. P. 132. 
 COMPOSITION OF ROASTED FLESH. 
 
 (1.) 0.307 of flesh gave 0-584 of carbonic acid and 0-206 of water. 
 (2.) 0-255 do. 0-485 do. 0-181 do. 
 
 (3.) 0-179 do. 0-340 do. 0-125 do. 
 
 Hence 
 
 Flesh of roedeer (1). Flesh of beef (2). Flesh of veal (3). 
 
 Carbon . 
 Hydrogen 
 Nitrogen 
 Oxygen ? 
 Ashes S 
 
 NOTE XXXV. P. 135. 
 
 The formula C 108 H 84 N 18 O^, or C 54 H 42 N 9 O 20 , gives, 
 
 when reduced to 100 parts, 
 
 C 64 50-07 
 
 H^ . . . . . 6-35 
 
 N 9 19-32 
 
 020 24-26 
 
 Compare this with the composition of gelatine, as given 
 
 in Note (27). 
 
 Boeckmann.* 
 
 
 Playfair.* 
 
 52-60 
 
 52-590 
 
 52-52 
 
 7-45 
 
 7-886 
 
 7-87 
 
 15-23 
 
 15-214 
 
 14-70 
 
 24-72 
 
 24-310 
 
 24-91 
 
 NOTE XXXVII. P. 146. 
 
 COMPOSITION OF LITHOFELLIC ACID, a 
 
 Calculated 
 Ettling and Will.* Wohler. 40 H 36 O 8 . 
 
 Carbon . . 71-19 70-80 . 70-23 70-83 70-99 
 Hydrogen . 10-85 10-78 10-95 10-60 10-44 
 Oxygen . . 17-96 18-42 18-92 18-57 18-57 
 
 a Ann. der Chem. und Pharm., XXXIX., 242., XLL, 154. 
 
ANALYTICAL EVIDENCE. 313 
 
 NOTE XXXVIII. P. 168. 
 
 COMPOSITION OF SOLANINE FROM THE BUDS OF 
 GERMINATING POTATOES, a 
 
 Blancbet. 
 
 Carbon .... 62-11 
 Hydrogen . . . 8-92 
 Nitrogen .^ . . . 1-64 
 Oxygen .... 27-33 
 a Ann. der Pharm., VII., 150. 
 
 NOTE XXXIX. P. 168. 
 
 COMPOSITION OF PICROTOX1NE. a 
 
 Francis.* 
 
 Carbon . 60-26 
 
 Hydrogen . . . 5-70 
 Nitrogen .... 1-30 
 Oxygen . . . 32-74 
 
 a In another analysis, M. Francis obtained 0-75 per cent, of nitro- 
 gen. The picrotoxine employed for these analyses was partly ob- 
 tained from the manufactory of M. Merck, in Darmstadt, and was 
 partly prepared by M. Francis himself; it was perfectly white, and 
 >eautifully crystallized. Regnault, as is well known, found no nitro- 
 gen in this compound. 
 
 NOTE XL. P. 168. 
 COMPOSITION OF QUININE. 
 
 Liebig.* Calculated 
 
 CM H 12 N0 2 . 
 
 Carbon . . . 75-76 74-39 
 
 Hydrogen . . 7-52 7-25 
 
 Nitrogen . . .8-11 8-62 
 
 Oxygen . . 8-62 9-74 
 27 
 
314 
 
 APPENDIX. 
 
 NOTE XLI. P. 168. 
 
 COMPOSITION OF MORPHIA. a 
 Liebig.* Regnault. 
 
 Carbon . . 72-340 72-87 
 
 Hydrogen . 6-366 6-86 
 
 Nitrogen . 4-995 5-01 
 
 Oxygen . . 16-299 15-26 
 
 Calculated 
 
 , C 35 H 20 NOe 
 
 72-41 7227 
 
 6-84 6-73 
 
 5-01 4-78 
 
 15-74 16-22 
 
 a Ann. der Pharm., XXVI., 23. 
 
 NOTE XLII. P. 168. 
 
 COMPOSITION OF CAFFEINE, THEINE, GUARANINE, 
 THEOBROMINE, AND ASPARAGINE. 
 
 Caffeine.a Theine.J Guaranine.c Calculated 
 
 Pfaff and Liebig.* Jobst. Martiua. 
 
 Carbon . . 49-77 50-101 49679 
 
 Hydrogen . 5-33 5-214 5-139 
 
 Nitrogen . . 28-78 29-009 29-180 
 
 Oxygen . . 16-12 15-676 16-002 
 
 C 8 H 6 N 2 2 
 
 49-798 
 
 5-082 
 
 28-832 
 
 16-288 
 
 a Ann. der Pharm., I., 17. 
 
 b Do. XXV., 63. 
 
 c Do. XXVI., 95. 
 
 Guaranine is the name given to the crystallized prin- 
 ciple of the guarana officinalis, till it was shown to be 
 identical with caffeine and theine, as the above analyses 
 demonstrate. 
 
 COMPOSITION OF THEOBROMINE. a 
 
 Woskroseusky. Calculated C 9 H 6 N 3 O 2 
 
 46-44 
 4-20 
 35-85 
 13-50 
 a Ann. der Chem. und Pharm., XLI., 125. 
 
 Carbon 
 
 . 47-21 
 
 46-97 
 
 46-71 
 
 Hydrogen 
 
 . 4-53 
 
 4-61 
 
 4-52 
 
 Nitrogen . 
 
 . 35-38 
 
 35-38 
 
 35-38 
 
 Oxygen . 
 
 . 12-88 
 
 13.04 
 
 13-39 
 
ANALYTICAL EVIDENCE. 315 
 
 COMPOSITION OF ASPARAGINE. a 
 
 Liebig.* Calculated C8 Hs N 2 O 6 + 2 HO. 
 
 Carbon . . 32-351 32-35 
 
 Hydrogen . . 6-844 6-60 
 
 Nitrogen . . 18-734 18-73 
 
 Oxygen . . 42-021 42-32 
 
 a Ann. der Pharm., VII., 146. 
 
 NOTE XLIII. P. 143, 167. 
 
 ON THE CONVERSION OF BENZOIC ACID INTO 
 HIPPURIC ACID.* 
 
 By WILHELM KELLER. 
 (From the Annalen der Chemie und Pharmacie.) 
 
 So early as in the edition of Berzelius's "Lehrbuch der 
 Chemie," published in 1831, Professor Wohler had ex- 
 pressed the opinion, that benzoic acid, during digestion, 
 was probably converted into hippuric acid. This opinion 
 was founded on an experiment which he had made on the 
 passage of benzoic acid into the urine. He found in the 
 urine of a dog, which had eaten half a drachm of benzoic 
 
 *To the evidence produced by A. Ure, of the conversion of benzoic 
 acid into hippuric acid in the human body, M. Keller has added some 
 very decisive proofs, which 1 append to this work on account of their 
 physiological importance. The experiments of M. Keller were, made 
 in the laboratory of Professor Wohler, at Gottingen ; and they place 
 beyond all doubt the fact that a non-azotized substance taken in the 
 food can take a share, by means of its elements, in the act of trans- 
 formation of the animal tissues, and in the formation of a secretion. 
 This fact throws a clear light on the mode of action of the greater 
 number of remedies; and if the influence of caffeine on the formation 
 of urea or uric acid should admit of being demonstrated in a similar 
 way, we shall then possess the key to the action of quinine and of the 
 other vegetable alkalies. /. L. 
 
316 APPENDIX. 
 
 acid with his food, an acid crystallizing in needle-shaped 
 prisms, which had the general properties of benzoic acid, 
 and which he then took for benzoic acid. (Tiedemann's 
 Zeitschrift fur Physiologic, i., 142.) These crystals were 
 obviously hippuric acid, as plainly appears from the state- 
 ments, that they had the aspect of nitre, and, when sub- 
 limed, left a residue of carbon. But at that time hippuric 
 acid was not yet discovered ; and it is well known, that 
 till 1829, when these acids were first distinguished from 
 each other by Liebig, it was uniformly confounded with 
 benzoic acid. 
 
 The recently published statement of A. Ure, that he 
 actually found hippuric acid in the urine of a patient who 
 had taken benzoic acid, recalled this relation, so remark- 
 able in a physiological point of view, and induced me to 
 undertake the following experiments, which, at the sug- 
 gestion of Professor Wohler, I made on myself. The 
 supposed conversion of benzoic acid into hippuric acid, 
 has, by these experiments, been unequivocally established. 
 
 I took, in the evening before bedtime, about thirty-two 
 grains of pure benzoic acid in syrup. During the night I 
 perspired strongly, which was probably an effect of the 
 acid, as in general I am with great difficulty made to 
 transpire profusely. I could perceive no other effect, even 
 when, next day, I took the same dose three times ; in- 
 deed, even the perspiration did not again occur. 
 
 The urine passed in the morning had an uncommonly 
 strong acid reaction, even after it had been evaporated, 
 and had stood for twelve hours. It deposited only the 
 usual sediment of earthy salts. But when it was mixed 
 with muriatic acid, and allowed to stand, there were 
 
ANALYTICAL EVIDENCE. 317 
 
 formed in it long, prismatic, brownish crystals, in great 
 quantity, which, even in this state, could not be taken for 
 benzoic acid. Another portion, evaporated to the con- 
 sistence of syrup, formed, when mixed with muriatic acid, 
 a magma of crystalline scales. The crystalline mass was 
 pressed, dissolved in hot water, treated with animal char- 
 coal, and recrystallized. By this means the acid was 
 obtained in colorless prisms, an inch in length. 
 
 These crystals were pure hippuric acid. When heated, 
 they melted easily ; and wh^n exposed to a still stronger 
 heat, the mass was carbonized, with a smell of oil of bitter 
 almonds, while benzoic acid sublimed. To remove all 
 doubts, I determined the proportion of carbon in the 
 crystals, which I found to be 60 - 4 per cent. Crystallized 
 hippuric acid, according to the formula C 18 H B NO 5 -f~ HO, 
 contains 60-73 per cent, of carbon ; crystallized benzoic 
 acid, on the other hand, contains 69* 10 per cent, of carbon. 
 
 As long as I continued to take benzoic acid, I was able 
 easily to obtain hippuric acid in large quantity from the 
 urine ; and since the benzoic acid seems so devoid of any 
 injurious effect on the health, it would be easy in this way 
 to supply one's self with large quantities of hippuric acid. 
 It would only be necessary to engage a person to continue 
 for some weeks this new species of manufacture. 
 
 It was of importance to examine the urine which con- 
 tained hippuric acid, in reference to the two normal chief 
 constituents, urea and uric acid. Both were contained in 
 it, and apparently in the same proportion as in the normal 
 urine. 
 
 The inspissated urine, after the hippuric acid had been 
 separated by muriatic acid, yielded, on the addition of 
 27* 
 
318 APPENDIX. 
 
 nitric acid, a large quantity of nitrate of urea. It had 
 previously deposited a powder, the solution of which in 
 nitric acid gave, when evaporated to dryness, the well- 
 known purple color characteristic of uric acid. This ob- 
 servation is opposed to the statement of Ure ; and he is 
 certainly too hasty in recommending benzoic acid as a 
 remedy for the gouty and calculous concretions of uric 
 acid. He seems to suppose that the uric acid has been 
 employed in the conversion of benzoic acid into hippuric 
 acid ; but as his observation^ were made on a gouty pa- 
 tient, it may be supposed that the urine, even without the 
 internal use of benzoic acid, would have been found to 
 contain no uric acid. Finally, it is clear that the hippuric 
 acid existed in the urine in combination with a base, be- 
 cause it only separated after the addition of an acid. 
 
 In the London, Edinburgh, and Dublin Philosophical 
 Magazine, for June, 1842, is a paper by Mr. Garrod, con- 
 firming Dr. Ure's fundamental observation. When from 
 a scruple to half a drachm of benzoic acid was swallowed, 
 a copious crop of crystals of hippuric acid was obtained, 
 amounting to from fifteen to twenty-nine grains, by the 
 addition of hydrochloric acid to the urine passed three or 
 four hours afterwards. Mr. Garrod states, that he was 
 always able to obtain a distinct trace of uric acid from a 
 drop or two of the urine. 
 
ANALYTICAL EVIDENCE. 319 
 
 NOTE (A.) P. 165. 
 ENDOSMOSE AND EXOSMOSE. 
 
 If we place the lower end of an open tube which has 
 been covered with a thin membrane, such as a piece of 
 moistened bladder, in a vessel of water, and pour a solu- 
 tion of sugar into the tube, the water from the vessel will 
 shortly be found to pass into the tube, and the column of 
 liquid will increase in height. At the same time, the 
 water in the vessel will become slightly sweet ; a small 
 quantity of syrup having passed through the pores of the 
 bladder into the water without, while a much larger por- 
 tion of water has entered the tube. The water will con- 
 tinue to enter the tube, and the syrup to leave it, until the 
 two liquids are nearly of the same density. A solution of 
 gum, salt, or other substances may be employed instead 
 of sugar. If two solutions be employed, as, for instance, 
 sugar or gum within the tube, and potash or soda without, 
 a circulation will in like manner take place. Instead of 
 animal membrane, any vegetable matter with fine pores, 
 such as a thin piece of wood, or any porous mineral sub- 
 stance, may be substituted without affecting the result. 
 Dutrochet, the discoverer of these phenomena, gave the 
 name of Endosmose to the inward, and that of Exosmose to 
 the outward movement. He supposed them to be due to 
 two opposite currents of electricity. Dutrochet's hypo- 
 thesis has not been confirmed. It does not constantly 
 happen, that the denser fluid attracts more of the thinner 
 than the latter does of the former ; in the case of gases, 
 especially, the contrary is seen to be sometimes the case. 
 
320 APPENDIX. 
 
 But the chemical constitution of the fluid, and its physical 
 and chemical relation to the animal membrane which it 
 permeates, seem to have an important influence on the 
 phenomenon. The phenomenon of the endosmosis of 
 gases, on which M. Faust (Amer. Med. Jour. Vol. VII. 
 Froriep's Not. N. 646,) has instituted experiments, are 
 very remarkable. A bladder half filled with atmospheric 
 air being placed under a jar containing carbonic acid, 
 becomes more distended ; and if the bladder which is 
 placed in the carbonic acid gas contained hydrogen, it 
 becomes distended to bursting. If, on the contrary, the 
 jar contains the lighter, and the bladder the denser gas, 
 the bladder becomes collapsed. (Muller's Elements of 
 Physiology, p. 245.) Gases also permeate moist animal 
 textures, and will be absorbed by fluids within them. 
 This explains how gaseous matters can enter into the 
 blood without the globules of the blood escaping. 
 
 ACTION OF THE HEART. SEE PAGE 56. 
 
 The contraction (systole) only of the heart is an active 
 state ; the dilatation (diastole) is the moment of repose, in 
 which the fibres are relaxed, and ,in which the blood is 
 poured from the contiguous veins into the cavities of the 
 heart, to Jill the vacuum consequent on the relaxation of its 
 fibres ; the valves of the heart being so arranged as to 
 allow the influx of the blood from the veins. (Muller's 
 Physiology, Vol. I. p. 173.) See also the experiments of 
 
ANALYTICAL EVIDENCE. 321 
 
 Sir David Barry, ibid. 234, and those of Poiseuille, ibid. 
 Miiller, although not admitting to their full extent the in- 
 ferences of Barry, admits that by the sucking of the heart, 
 and by the action of the valves, a part of the resistance 
 which opposes the course of the venous blood is overcome. 
 
 EXCRETION OF CARBON. 
 
 Berzelius considers the quantity of carbonic acid in all 
 the calculations, as given p. 271, to be too great, for the 
 solid food taken into the body contains fths of its weight of 
 water, and of the other |th, seldom more than | is carbon ; 
 consequently 6| Ibs. of solid food would be necessary to 
 supply the quantity of carbon which, according to these 
 estimates, is excreted from the body by the lungs in 24 
 hours, independent of what is got rid of in other ways. 
 Mulder, 1-308. 
 
INDEX. 
 
 
INDEX 
 
 A. 
 
 ACID. 
 
 Acetic. Composition; and relation to that of aldehyde, 267, 268. 
 
 Benzole. Composition, and relation to that of oil of bitter almonds, 
 
 267, 268. Converted into hippuric acid in the human body, 143, 
 315. 
 
 Carbonic. Is the form in which the inspired oxygen and the car- 
 
 bon of the food are given out, 12. Its formation in the body the 
 chief source of animal heat, 11-21. Occurs, combined with pot- 
 ash and soda, in the serum of the blood, 39. Formed by the action 
 of oxygen on the products of the metamorphosis of the tissues, 59. 
 Its formation may also be connected with the production of fat 
 from starch, 82 - 87. Generated by putrefaction of food in the 
 stomach of animals, 110. Also by the fermentation of bad wine 
 in man, when it causes death by penetrating into the lungs, 111. 
 Escapes through both skin and lungs, ib. Produced, along with 
 urea, by the oxidation of uric acid, 133. Produced, with several 
 other compounds, by the oxidation of blood, ib. May be formed, 
 along with choleic acid, from hippuric acid, starch, and oxygen, 
 145. Also, along with choleic acid, urea, and ammonia, by the 
 action of water and oxygen on starch and proteine, ib. Produced, 
 along with fat and urea, from proteine, by the action of water and 
 oxygen, in the absence of soda, 146. Combines with the com- 
 pound of iron present in venous blood, and is given off when 
 oxygen is absorbed, 257. Is absorbed by the serum of blood in 
 all states, 258. 
 
 Cerelric. Its composition, 174. Its properties, 176. 
 
 28 
 
326 INDEX. 
 
 > 
 ACID. 
 
 Choleic. Represents the organic portion of the bile, 127. Its for- 
 
 mula, 128. Its transformations, ib. Half its formula, added to 
 that of urate of ammonia, is equal to the formula of blood -f- a 
 little oxygen and water, 129. Produced in the oxidation of blood, 
 133. Views which may be taken of its composition, 141. May 
 be formed by the action of oxygen and water on proteine and 
 starch, 144. Products of its oxidation, 146. Various ways in 
 which it may be supposed to be formed in the body, 152. Its 
 composition, 305. Cannot be said to exist ready formed in the 
 bile, 307. 
 
 Cholic. Its composition, 308. Derived from choleic acid, 127, 129. 
 
 Possible relation to choleic acid, 141. 
 
 Choloidic. Its composition, 305. Derived from choleic acid, 128. 
 
 Possible relation to choleic acid, 141. Possible relation to starch, 
 150. Possible relation to proteine, 134. 
 
 Cyanic. Its formula, 268. 
 
 Cyanuric. Its formula, 268. 
 
 Hippuric. Its composition, 309. Appears in the urine of stall-fed 
 
 animals, 80. Is destroyed by exercise, 80, 132. Is probably 
 formed in the oxidation of blood, 133. Is found in the human 
 urine after benzoic acid has been administered, 143, 315. May 
 be derived from proteine when acted on by oxygen and uric 
 acid, 144. With starch and oxygen, it may produce choleic and 
 carbonic acids, ib. May be derived from the oxidation of choleic 
 acid, 146. 
 
 Hydrocyanic or Prussic. Its poisonous action explained, 262. 
 
 Lithqfellic. Its composition, 312. Probably derived from the ox- 
 
 idation of choleic acid; is the chief constituent of bezoar stones, 
 146. 
 
 Lactic. . Its composition, 298. Its origin, 107. Does not exist in 
 
 the healthy gastric juice, ib. 
 
 Margaric. Exists in bile, 307. 
 
 Muriatic. Exists in the free state in the gastric juice, 107, 108. 
 
 Is derived from common salt, 108, 153. 
 
 Oxaluric. Analysis of, 311. 
 
 Parabanic. Analysis of, 31 1. 
 
 Phosphoric. Exists in the urine of the carnivora in considerable 
 
 quantity, 76, 155. Its proportion very small in that of the gra- 
 minivora, 76. Derived from the phosphorus of the tissues, ib. 
 It is retained in the body to form bones and nervous matter, 77. 
 
INDEX. 327 
 
 ACID. 
 
 Sulphuric. Exists in the urine of the carnivora, 76, 155. Derived 
 
 from the sulphur of the tissues, 76. 
 
 Uric. Its composition, 308. Products of its oxidation, alloxan, 
 
 oxalic acid, carbonic acid, urea, &c., 131, 133. Is probably de- 
 rived, along with choleic acid, by the action of oxygen and water 
 on blood or muscle, 130. Disappears almost entirely in the sys- 
 tem of men and of the higher animals, 54, 130. Appears as cal- 
 culus, when there is a deficiency of oxygen, 131. Never occurs 
 in pthisical cases, ib. Yields mulberry calculus when the quan- 
 tity of oxygen is somewhat increased, but only urea and carbonic 
 acid with a full supply of oxygen, ib. Uric acid calculus pro- 
 moted by the use of fat and of certain wines, 133 Unknown on 
 the Rhine, ib. Uric acid and urea, how related to allantoine, 
 134 ; to gelatine, 135. Forms the greater part of the urine of 
 serpents, 53. Yields, with the elements of proteine and oxygen, 
 hippuric acid and urea, 144. How related to taurine, 148, 149. 
 Calculi of it never occur in wild carnivora, but often in men who 
 use little animal food, 139. 
 ACTION. Of the heart, 120. 
 
 AFFINITY, Chemical. Is the ultimate cause of the vital phenomena, 
 10. Is active only in the case of contact, and depends much on the 
 order in which the particles are arranged, 194. Its equilibrium 
 renders a compound liable to transformations, 196. In producing 
 the vital phenomena, it is modified by other forces, 198. It is not 
 alone the vital force or vitality, but is exerted in subordination to 
 that force, 221. 
 
 Am. Introduced into the stomach during digestion with the saliva, 
 109. Effects of its temperature and density, dryness, &c., in respi- 
 ration, 15, 16. 
 
 ALBUMEN. Animal and vegetable albumen identical, 47^48. Their 
 composition, 283, 284, 21)7, 298. Vegetable albumen, how obtained, 
 45. Is a compound of proteine, and in organic composition iden- 
 tical with fibrine and caseine, 47, 100, 102. Exists in the yolk as 
 well as the white of eggs, 103. Also in the serum of the blood, 39. 
 Is the true starting point of all the animal tissues, 102, 103. 
 ALCOHOL. Is hurtful to carnivorous savages, 170. Its mode of action ; 
 checks the change of matter, 228. In cold climates serves as an 
 element of respiration, 21. 
 ALDEHYDE. Its composition ; how related to that of acetic acid, 2(37, 
 
 268. 
 
 ALKALIES. Mineral alkalies essential both to vegetable and animal 
 life, 156. Vegetable alkalies all contain nitrogen, all act on the 
 
328 INDEX. 
 
 nervous system, and are all poisonous in a moderate dose, 172. 
 Theory of their action ; they take a share in the transformation or 
 production of nervous matter, for which they are adapted by their 
 composition, 173-179. Action of caustic alkalies on bile, or cho- 
 leic acid, 127. 
 
 ALLANTOINE. Is found in the urine of the fetal calf. How derived 
 from proteine. How related to uric acid and urea, 134. How re- 
 lated to choleic acid, 141. Its composition, 309. 
 
 ALLEN and PEPVS. Their calculation of the amount of inspired 
 oxygen, 271. 
 
 ALLOXAN. Formed by the oxidation of uric acid, 129. Converted by 
 oxidation into oxalic acid and urea, oxaluric and parabanic acids, 
 or carbonic acid and urea, 131. How related to taurine, 148. 
 Seems to act as a diuretic, 149. Recommended for experiment in 
 hepatic diseases, ib. (note.) 
 
 ALMONDS, BITTER. Oil of. Its composition ; how related to benzoic 
 acid, 268. 
 
 AMMONIA.. Combined with uric acid it forms the urine of serpents, 
 birds, &c., 53. Its relation to choleic, choloidic, and cholic acids, 
 128. Is one of the products which may be formed by the oxidation 
 of blood, 133; or of proteine, 145. Its relation to uric acid, urea, 
 and taurine, 147. To allantoine and taurine, 148. To alloxan and 
 taurine, 148. To choleic and choloidic acid and taurine, 150. To 
 urea, water, and carbonic acid, 151. Is found in combination with 
 acids in the urine of the carnivora, 155. 
 
 ANALYSIS. Of dry blood, 271, 304. Of dried flesh, 304. Of faeces, 
 273. Of black bread, ib. Of potatoes, ib. Of peas, ib. Of beans, 
 ib. Of lentils, ib. Of fresh meat, ib. Of moist bread, ib. Of 
 moist potatoes, ib. Of the fibrine and albumen of blood, 282, 300, 
 301. Of vegetable fibrine and albumen, vegetable caseine and 
 gluten, 2JJ3, 284. Of animal caseine, 284. Of starch, 285, 286. 
 Of grape or starch sugar, ib. Of sugar of milk, 287. Of gum, ib. 
 Of oats, ib. Of hay, 288. Of fat, 289. Of cane-sugar, ib. Of 
 cholesterine, ib. Of wax, 296. Of cyanic acid, cyanuric acid, and 
 cyamelide, 297. Of aldehyde, metaldehyde, and elaldehyde, ib. 
 Of proteine, ib. Of albumen from the yolk and white of egg, 298. 
 Of lactic acid, ib. Of gas from the stomach of cows after eating 
 to excess, 299. Of gas from stomach and intestines of executed 
 criminals, ib. Of gelatinous tissues, 301 . Of tissues containing 
 chondrine, 302. Of arterial membrane, ib. Of horny tissues, ib. 
 Of the lining membrane of the egg, 303. Of feathers, ib. Of the 
 pigmentum nigrum, ib. Of choleic acid, 305. Of taurine, ib. Of 
 
INDEX. 329 
 
 choloidic acid, ib. Ofcholic acid, 308. Of uric acid, ib. Of al- 
 loxan, 309. Of urea, ib. Of hippuric acid, ib. Of allantoine, ib. 
 Of xanthic oxide, 310. Of cystic oxide, ib. Of oxalic acid, 311. 
 Of oxaluric acid, ib. Of parabanic acid, ib. Of roasted flesh, 312. 
 Of lithofellic acid, ib. Of solanine, 323. Of picrotoxine, ib. Of 
 quinine, ib. Of morphia, 314. Of caffeine, theine, or guaranine, 
 ib. Of theobromine, ib. Of asparagine, ib. 
 
 ANIMAL HEAT. Derived from the combination of oxygen with the 
 carbon and hydrogen of the metamorphosed tissues, which proceed 
 ultimately from the food, 16, 17. Is highest in those animals whose 
 respiration is most active, 18. Is the same in man in all climates, 
 18, 19. Is kept up by the food in proportion to amount of external 
 cooling, 21. Is not produced either by any direct influence of the 
 nerves, or by muscular contractions, 28-32. Its amount in man, 
 32. Chemical action the sole source of it, 36. The formation of 
 fat from starch or sugar must produce heat, 88 -90. The elements 
 of the bile, by combining with oxygen, serve chiefly to produce 
 it, 59. 
 
 ANIMAL LIFE. Distinguished from vegetable life by the absorption 
 of oxygen, and the production of carbonic acid, 2. Must not be 
 confounded with consciousness, 6, 7. Conditions necessary to an- 
 imal life, 9,11. Depends on an equilibrium between waste and 
 supply, 233 - 242. 
 
 ANTISEPTICS. They act by putting a stop to fermentation, putrefac- 
 tion, or other forms of metamorphosis, 162. Their action on 
 wounds and ulcers, 116. 
 
 ARTERIES. Composition of their tunica media, 312. How derived 
 from proteine, 121. 
 
 ARTERIAL BLOOD. Conveys oxygen to every part of the body, 59, 
 257. Contains a compound of iron, most probably peroxide, 257. 
 Yields oxygen in passing through the capillaries, 59, '259. Contains 
 carbonic acid dissolved or combined with soda, 260. 
 
 ASPARAGINE. Its composition, 315. Its relation to taurine and bile, 
 170. Theory of its action on the bile, 171. 
 
 ASSIMILATION. In animals it is independent of external influences, 
 3. Depends on the presence in the blood of compounds of pro- 
 teine, such as fibrine, albumen, or caseine, 38-103. Is more en- 
 ergetic in the young than in the aduH animal, 65. Is also more 
 energetic in the herbivora than in the carnivora, 78. 
 
 ATMOSPHERE. See AIR. 
 
 AZOTIZED PRODUCTS. Of vegetable life, 44, 167, 173. Of the meta- 
 morphosis of tissues. Necessary for the formation of bile in the 
 28* 
 
330 INDEX. 
 
 herbivora, 150. In man, 157-160. May be replaced by azotized 
 vegetable compounds, 161. Theory of this, 168-172. Of the 
 transformation of the bile, or of choleic acid ; how related to the 
 constituents of urine, 147. 
 
 B. 
 
 BEANS. Composition of, 273. 
 
 BEER. Forms part of the diet of soldiers in Germany, 274-277. 
 
 BEES. Their power of forming wax from honey, 290, 295. 
 
 BENZOIC ACID. See Acid, Benzoic. 
 
 BERTHOLLET. His analysis of oxalic acid, 311. 
 
 BERZELIUS. His analysis of potato starch, 286; of sugar of milk, 
 287 ; of gum, ib. ; of cane-sugar, 289. On excretion of carbon, 321. 
 
 BEZOAR STONES. See Acid, Lithofellic. 
 
 BLANCHET. His analysis of solanine, 313. 
 
 BILE. In the carnivora is a product of the metamorphosis of the 
 tissues, along with urate of ammonia, 130. May be represented by 
 choleate of soda, with which, however, it is not identical, 307. 
 Products of its transformation, 129, 306. Remarks on these, 305- 
 308. Origin of bile, 60, 137. Starch, &c., contribute to its for- 
 mation in the herbivora, 141, 148, 150, 152, 157. Soda essential to 
 it, 146, 153, 155. Relation of bile to urine, 148. To starch, 150. 
 To fibrine, 130. To caffeine, &c., asparagine, and theobromine, 
 271. For the acid substances derived from bile, choleic, choloidic, 
 and cholic acids, see Acid, choleic, &c. Yields taurine, 128. 
 Contains cholesterine, 82, 307. Also stearic and margaric acids, 
 ib. Its function : to support respiration and produce animal heat 
 by presenting carbon and hydrogen in a very soluble form to the 
 oxygen of the arterial blood, 59 - 63. Amount secreted by the dog, 
 the horse, and man, 62. It returns entirely into the circulation, 
 and disappears completely, 59-61. 
 
 BLOOD. The fluid from which every part of the body is formed, 8. 
 Its chief constituents, 38. How formed from vegetable food, 44. 
 Can only be formed from compounds of proteine, 47. Is therefore 
 entirely derived from vegetable products in the herbivora. and indi- 
 rectly also by the carnivora, which feed on the flesh of the former, 
 48. Its composition identical with that of flesh, 127. Analysis of 
 both, 304. The secretions contain all the elements of the blood, 
 126. Its relation to bile and urine, 129. Products of the oxidation 
 of blood, 133. Excess of azotized food produces fulness of blood 
 and disease, 139. Soda is present in the blood, 153-155. Impor- 
 
INDEX. 331 
 
 tant properties of the blood, 163-166. Venous blood contains 
 iron, probably as protoxide ; arterial blood, probably as peroxide, 
 259-261. Theory of the poisonous action of sulphuretted hydro- 
 gen and Prussic acid ; they decompose the compound of iron in 
 the blood, 262. The blood, in analogous morbid states, ought to be 
 chemically examined, 263. 
 
 BLOOD LETTING. Theory of its mode of action, 247. It may pro- 
 duce opposite effects in different cases, 252. 
 
 BOECKMANN. His analysis of black bread, 273; of potatoes, ib. ; of 
 dry beef, 304 ; of dry blood, ib. ; of roasted flesh, 312. 
 
 BONES. Phosphoric acid of the food retained to assist in forming 
 them, 77. Gelatine of bones digested by dogs, 93. See, further, 
 Gelatine. Cause of brittleness in bones, 96. 
 
 BOUSSINGAULT. His analysis of potatoes, 273. His comparison of the 
 food and excretions in the horse and cow, Table, 289. His analy- 
 sis of gluten, 283: of vegetable albumen, ib. ; of vegetable case- 
 ine, 283 ; of oats, 287 j of hay, 288. 
 
 BRACONNOT. On the presence of lactic acid in gastric juice, 107; of 
 iron in the gastric juice of the dog, 108. 
 
 BRAIN. See Acid, Cerebric, and Nervous Matter. 
 
 BREAD. Analysis of, 273. 
 
 BRUNN. His analysis of sugar of milk, 287. 
 
 BUCKWHEAT. Analysis of starch from, 285. 
 
 BURDACH. His statement of the amount of bile secreted by animals, 
 62. 
 
 BUTTER. Forms a part of the food of soldiers in Germany, 274. 
 
 BUZZARD. Its excrements consists of urate of ammonia, 53. 
 
 c. 
 
 CAFFEINE. Identical with theine, 170. Its relation to taurine and 
 bile, 171. Theory of its mode of action, 171. Its composition, 
 314. 
 
 CANE SUGAR. Its composition, 289. 
 
 CARBON. Is accumulated in the bile, 59. Is given off as carbonic 
 acid, 12. Excess of carbon causes hepatic diseases, 23. By com- 
 bining with oxygen, it yields the greater part of the animal heat. 
 See Animal Heat, Bile, and Acid, Carbonic. Amount of carbon 
 oxidized daily in the body of a man, 14. Calculations on which 
 this statement is founded, 272-291. Amount consumed by the 
 horse and cow, 14. Different proportions of carbon in different 
 kinds of food, 16. Carbon of flesh compared with that of starch, 
 
332 INDEX. 
 
 showing the advantage of a mixed diet, 73. Calculation on which 
 this statement is founded, 272. Amount of carbon in dry blood cal- 
 culated, 271. Amount in the food of prisoners calculated, 282. 
 Excretion of carbon, 321. 
 
 CARBONIC ACID. See Acid, Carbonic. 
 
 CARBONATES. They occur in the blood, 39. 
 
 CALCULUS, Mulberry. Derived from the imperfect oxidation of uric 
 acid, 131. Uric acid calculus is formed in consequence of de- 
 ficiency of inspired oxygen, or excess of carbon in the food, 131. 
 See Acid, Uric. Bezoar stones composed of lithofellic acid, 146. 
 
 CARNIVORA. Their nutrition the most simple, 43. It is ultimately 
 derived from vegetables, 47, 48. Their young, like graminivora, 
 require non-azotized compounds in their food, 49. Their bile is 
 formed from the metamorphosis of their tissues, 57, 59. The pro- 
 cess of assimilation in adult and young carnivora compared, 65. 
 Their urine, 76. The assimilative process in adult carnivora less 
 energetic than in graminivora, 78. They are destitute of fat, 80. 
 They swallow less air with their food than graminivora, 113. Con- 
 cretions of uric acid are never found in them, 139. Both soda and 
 ammonia found in their urine, 155. 
 
 CA SEINE. One of the azotized nutritious products of vegetable life, 
 46. Abundant in leguminous plants, 46. Identical in organic 
 composition with fibrine and albumen, 47. Animal caseine found 
 in milk and cheese j identical with vegetable caseine, 50. Fur- 
 nishes blood to the young animal, 51. Is one of the plastic ele- 
 ments of nutrition, 92. Yields proteine, 101, 102. Its relation to 
 proteine, 120. It contains sulphur, ib. Potash essential to its pro- 
 duction, 156. Contains more of the earth of bones than blood does, 
 51. Its analysis, 284. 
 
 CEREBRIC ACID. See Acid, Cerebric. 
 
 CHANGE OF MATTER. See Metamorphosis of Tissues. 
 
 CHEMICAL ATTRACTION. See Affinity. 
 
 CHEVREUL. His researches on fat, 81. His analysis of fat, 289. Of 
 cholesterine, ib. 
 
 CHLORIDE OF SODIUM. See Common Salt. 
 
 CHOLEIC ACID. See Acid, Choleic. 
 
 CHOLESTERINE. See Bile. 
 
 CHOLIC ACID. See Acid, Cholic. 
 
 CHOLOIDIC ACID. See Acid, Choloidic. 
 
 CHONDRINE. Its relation to proteine, 120. Analysis of tissues con- 
 taining it, 302. 
 
 CHRONIC DISEASES. The action of inspired oxygen is the cause of 
 death in them, 26, 27. 
 
INDEX. 333 
 
 CHYLE. When it has reached the thoracic duct, it is alkaline, and 
 contains albumen coagulable by heat, 138. 
 
 CHYME. It is formed independently of the vital force, by a chemical 
 transformation, 105. The substance which causes this transforma- 
 tion is derived from the living membrane of the stomach, 105. 
 Chyme is acid, 138. 
 
 CLOTHING. Warm clothing is a substitute for food to a certain ex- 
 tent, 21. Want of clothing accelerates the rate of cooling, and the 
 respirations, and thus increases the appetite, ib. 
 
 COLD. Increases the appetite by accelerating the respiration, 21. Is 
 most judiciously employed as a remedy in cerebral inflammation, 
 249. 
 
 CONCRETIONS. See Calculus, and Acid, Uric; also, Acid, Lithofellic. 
 
 CONSTITUENTS, Jlzotized. Of blood : see Fibrine and Albumen. Of 
 vegetables: see Fibrine, Vegetable ; Albumen, Vegetable; Caseine, 
 Vegetable; Alkalies, Vegetable; and Caffeine. Of bile: see Acid, 
 Choleic, Cholic, and Choloidic. Of urine : see Acid, Uric ; Urea, 
 and Allantoine. 
 
 COOLING. See Cold, and Clothing. 
 
 COUERBE. His analysis of cholesterine, 289. 
 
 Cow. Amount of carbon expired by the, 14. Comparison of the 
 food with the excretions of the cow, 280. 
 
 CRUM. His analysis of cane-sugar, 289. 
 
 CULTIVATION. Is the economy of force, 75. 
 
 CYAMELIDE. Its formula, 268. 
 
 CYANIC ACID. See Acid, Cyanic. 
 
 CYANIDE OF IRON. Its remarkable properties, 257. 
 
 CYANURIC ACID. See Acid, Cyanuric. 
 
 D. 
 
 DAVY. Oxygen consumed by an adult man, 271. 
 
 DEATH. Cause of, in chronic diseases, 26. Caused in old people by 
 
 a slight depression of temperature, 243. Definition of it, 242. 
 DEMAR<JAY. His analysis of choleic acid, choloidic acid, and taurine, 
 
 305. Remarks on his Researches on Bile, 305. 
 DENIS. His experiments on the conversion of fibrine into albumen, 
 
 39, 40. 
 DESPRETZ. His calculation of the heat developed in the combustion 
 
 of carbon, 32. 
 DIABETES MELLITUS. The sugar found in the urine in this disease 
 
 is grape sugar, and is derived from the starch of the food, 92. 
 
334 INDEX. 
 
 DIASTASE. Analogy between its solvent action on starch, and that of 
 the gastric juice on coagulated albumen, 106. 
 
 DIFFUSION OF GASES. Explains the fact that nitrogen is given out 
 through the skin of animals, 113; and the poisonous action of 
 feather- white wine, 111. 
 
 DIGESTION. Is effected without the aid of the vital force, by a meta- 
 morphosis derived from the transformation of a substance proceed- 
 ing from the lining membrane of the stomach, 105. The oxygen 
 introduced with the saliva assists in the process, 109. Lactic acid 
 has no share in it, 107. 
 
 DISEASE. Theory of, 242 et seq. Cause of death in chronic disease, 
 25. Disease of liver caused by excess of carbon or deficiency of 
 oxygen, 22. Prevails in hot weather, 23. 
 
 DOG. Amount of bile secreted by, 62. Digests the gelatine of the 
 bones, 94. His excrements contain only bone earth, 95. Concre- 
 tion of urate of ammonia said to have been found by Lassaigne in a 
 dog, doubtful, 139 (note.) 
 
 DUMAS. His analysis of choleic acid, 305 ; of choloidic acid, ib. ; of 
 taurine, i&. ; of cholic acid, 308 j of hippuric acid, 309. His views 
 borrowed from Liebig, 41. 
 
 E. 
 
 EGGS. Albumen of the white and of the yolk identical, 103. Analy- 
 sis of both, 298; of lining membrane, 303. The fat of the yolk 
 may contribute to the formation of nervous matter, 103. This fat 
 contains iron, ib. 
 
 ELALDEHYDE. See Aldehyde. 
 
 ELEMENTS. Of nutrition. 92. Of respiration, ib. 
 
 EMPYREUMATICS. They check transformations, 162. Their action 
 on ulcers, 116. 
 
 EQUILIBRIUM. Between waste and supply of matter is the abstract 
 state of health, 233, 246. Transformations occur in compounds in 
 which the chemical forces are in unstable equilibrium, 104. 
 
 ETTLING. His analysis of wax, 296. 
 
 ETTLING and WILL. Their analysis of lithofellic acid, 312. 
 
 EXCREMENTS. Contain little or no bile in man and in the herbivora, 
 none at all in the dog and other carnivora, 62. Those of the dog 
 are phosphate of lime, 95. Those of serpents are urate of ammo- 
 nia, 53. Those of birds also contain that salt, 54. Those of the 
 horse and cow compared with their food, 279, 280. 
 
 EXCRETION. Of carbon, 321. 
 
INDEX. 335 
 
 EXCRETIONS. Contain, with the secretions, the elements of the blood 
 or of the tissues, 126, 130. Those of the horse and cow compared 
 with their food, 279, 280. Bile is not an excretion, 62. 
 
 F. 
 
 FAECES. Analysis of, 273. 
 
 FAT. Theory of its production from starch, when oxygen is deficient, 
 80 et seq. ; from other substances, 83. The formation of fat supplies 
 a new source of oxygen, 86 ; and produces heat, 86 et seq. Maxi- 
 mum of fat, how obtained, 91. Carnivora have no fat, 80. Fat in 
 stall-fed animals, 86. Occurs in some diseases in the blood, 92, 
 Fat in the women of the East, 96. Composition compared with that 
 of sugar, 81 , 82. Analysis of fat, 289. Disappears in starvation, 24. 
 Is an element of respiration, 92. 
 
 FATTENING OF ANIMALS. See Fat. 
 
 FEATHERWHITE WINE. Its poisonous action, 111. 
 
 FEBRILE PAROXYSM. Definition of, 244. 
 
 FEHLING. His analysis of met.aldeb.yde and elaldehye, 307. 
 
 FERMENTATION. May be produced by any azolized matter in a state 
 of decomposition, 115. Is arrested by empyreumatics, ib. Is anal- 
 ogous to digestion, 114. 
 
 FEVER. Theory and definition of, 244. 
 
 FIBRE. Muscular. See Flesh. 
 
 FIBRINE. Is an element of nutrition, 92. Animal and vegetable 
 fibrine are identical, 47. Is a compound of proteine, 102. Its rela- 
 tion to proteine, 121. Convertible into albumen, 40. Is derived 
 from albumen during incubation, 103. Its analysis, 282, 283, 301. 
 Vegetable fibrine, how obtained, 45. 
 
 FISHES. Yield phosphuretted hydrogen, 18 (note}. 
 
 FLESH. Consists chiefly of fibrine, but from the mixture of fat and 
 membrane, has the same formula as blood, J27. Analysis of flesh, 
 304. Amount of carbon in flesh compared with that of starch, 74, 
 288. 
 
 FOOD. Must contain both elements of nutrition and elements of res- 
 piration, 92. Nutritious food, strictly speaking, is that alone which 
 is capable of forming blood, 38. Whether derived from animals or 
 from vegetables, nutritious food contains proteine, 38, 101 et seq. 
 Changes which the food undergoes in the organism of the carniv- 
 ora, 52 et seq. The food of the herbivora always contains starch, 
 sugar, &c., 68. Food, how dissolved, 104 et seq. Azotized food 
 has no direct influence on the formation of uric acid calculus, 131. 
 
336 INDEX. 
 
 Effects of superabundant azotized food, 138, 139. Non-azolized 
 food contributes to the formation of bile, and thus to respiration, 
 140 et seq. Salt must be added to the food of herbivora, in order 
 lo yield soda for the bile, 154. Caffeine, &c., serve as food for the 
 liver, 178. The vegetable alkalies may be viewed as food for the 
 organs which form the nervous matter, 179. Amount of food con- 
 sumed by soldiers in Germany, 275. Its analysis, 272 Food of 
 the horse and cow compared with their excretions, 279, 280. 
 
 FORMULAE. Explanation of their use, 268. How reduced to 100 
 parts, 269. Formulae of albumen, fibrine, caseine, and animal tis- 
 sues, 120. Formula of proteine, 116 ; of blood and flesh, 127; of 
 fat, 82; of cholesterine, 82; of aldehyde, acetic acid, oil of bitter 
 almonds, and benzoic acid, 268; of cyamelide, cyanic acid, and 
 cyanuric acid, 268; of choleic acid, 128; of choloidic acid and 
 cholic acid, 128; of gelatine, 135; of hippuric acid, 143; of litho- 
 fellic acid, 146 ; of taurine, 148; of alloxan, 148. See Analysis. 
 
 FRANCIS. His analysis of picrotoxine, 313. 
 
 FREMY. Lameyran and Fremy. Their analysis of gas from the ab- 
 domen of cows after excess in fresh food, 299. His researches on 
 the brain, 43, 174. 
 
 FREQUENCY of the pulse and respiration in different animals, 18, 281. 
 
 FRUITS. Contain very little carbon, and hence are adapted for food 
 in hot climates, 16. 
 
 G. 
 
 GAS. Analysis of gas from abdomen of cows after excess in fresh 
 food, 110, 299. Analysis of gas from the stomach and intestines of 
 executed criminals, 111, 299. 
 
 GASTRIC JUICE. Contains no solvent but a substance in a state of 
 metamorphosis, by the presence of which the food is dissolved, 104. 
 Contains free acid, 105. Contains no lactic acid, 107. In the dog 
 has been found to contain iron, 108. See Digestion, Chyme, Food. 
 
 GAY-LUSSAC and THENARD. Their analysis of starch, 286 ; of sugar 
 of milk, and of gum, 287; of cane-sugar, 289; of wax, 296; of 
 oxalic acid, 311. 
 
 GELATINE. Is derived from proteine, but is no longer a compound 
 of proteine, and cannot form blood, 122 ct seq. May serve as food 
 for the gelatinous tissues, and thus spare the stomach of convales- 
 cents, 95, 124. In starvation the gelatinous tissues remain intact, 
 93. Its relation to proteine, 125. Its formula, 135. Its analysis, 301, 
 302. 
 
 GOEBEL. His analysis of gum, 287. 
 
INDEX. 337 
 
 GLOBULES of the blood are the carriers of oxygen to all parts of the 
 
 body, 163 - 166. They contain iron, 253 et seq. 
 GLUTEN. Contains vegetable fibrine, 45. Analysis of it, 233. 
 GMELIN. On the sugar of bile, 140. 
 GOOSE. How fattened to the utmost, 91. 
 GRAMINIVORA. See Herbivora. 
 GRAPE-SUGAR. An element of respiration, 92. Is identical with 
 
 starch sugar and diabetic sugar, 72. Its composition, 73. Its anal- 
 ysis, 286. 
 GROWTH, or increase of mass, greater in graminivora than in carniv- 
 
 ora, 77. Depends on the blood, 38 ; and on compounds of pro- 
 
 teine, 102. See Nutrition. 
 GUM. An element of respiration, 92. Its composition, 71. Is related 
 
 to sugar of milk, ib. Its analysis, 287. 
 GUNDLACH. His researches on the formation cf wax from honey of 
 
 the bee, 291. 
 
 H. 
 
 HAIR. Analysis of, 302. Its relation to proteine, 120. Analysis of 
 proteine from hair, 298. 
 
 HAY. Analysis of, 288. 
 
 HEART. Action of the, 320. 
 
 HEPATIC DISEASES. Cause of, 22. 
 
 HERBIVORA. Their blood derived from compounds of proteine in 
 their food, 47. But they require also for their support non-azotized 
 substances, 68. These last assist in the formation of their bile, 140 
 et seq. They retain the phosphoric acid of their food to form brain 
 and nervous matter, 77. Their urine contains very little phospho- 
 ric acid, 76. The energy of vegetative life in them is very great, 
 78. They become fat when stall-fed, 79. 
 
 HESS. His analysis of wax, 296. 
 
 HYBERNATING ANIMALS. Their fat disappears during the winter 
 sleep, 24. They secrete bile and urine during the same period, 60. 
 
 HIPPURIC ACID. See Acid, Hippuric. 
 
 HORN. Analysis of, 302. Contains proteine ; its relation to proteine, 
 120. Analysis of proteine from horn, 298. 
 
 HORSE. Amount of carbon expired by, 14. Comparison of his food 
 with his excretions, 279. Force exerted by a horse in mechanical 
 motion compared to that exerted by a whale, 226. 
 
 HYDROCYANIC ACID. See Acid, Hydrocyanic. 
 29 
 
338 INDEX. 
 
 HYDROGEN. By combining with oxygen contributes to produce the 
 animal heat, 23. 
 
 I. 
 
 ICE. Is judiciously employed as a remedy in cerebral inflammation, 
 249. 
 
 INORGANIC constituents of albumen, fibrine, and caseine, 39, 116, 120. 
 
 JOBST. His analysis of theine, 314. 
 
 JONES, Dr. Bence. His analysis of vegetable fibrine, 283 ; of vegeta- 
 ble albumen, ib. ; of vegetable caseine, 284; of gluten, ib.; of the 
 albumen of yolk of egg, 289, 300 j of the albumen of brain, 300. 
 
 IRON. Is an essential constituent of the globules of the blood, 253 el 
 seq. Is found in the fat of yolk of egg, 103. Also in the gastric 
 juice of the dog, 108. Singular properties of its compounds, 256. 
 
 ISOMERIC BODIES. 99, 268. 
 
 K. 
 
 KELLER. His researches on the conversion of benzole acid into hip- 
 
 puric acid in the human body, 315. 
 KIDNEYS. They separate from the arterial blood the nitrogenized 
 
 compounds destined for excretion, 76. 
 
 L. 
 
 LACTIC ACID. See Acid, Lactic. 
 
 LAVOISIER. His calculation of the amount of inspired oxygen, 12, 
 271. 
 
 LEHMANN. On the presence of lactic acid in gastric juice, 107. 
 
 LIEBIG. His analysis of sugar of milk, 287 ; of cane sugar, 289; of 
 aldehyde, 297 ; of uric acid, 308 ; of hippuric acid, 309 ; of qui- 
 nine, 313 ; of morphia, 314 ; of asparagine, 315. His calculation of 
 the carbon daily expired as carbonic acid, 13, 272. Table, 278. 
 His remarks on Demar<jay's researches on bile, 305-308. 
 
 LIEBIG and PFAFF. Their analysis of caffeine, 314. 
 
 LIEBIG and WOHLER. Their analysis of alloxan, 309 ; of urea, ib. ; 
 of allantoine, ib.\ of xanthic oxide, 310 ; of oxaluric acid, 311 ; of 
 parabanic acid, ib. 
 
 LENTILS. Contain vegetable caseine, 46. Analysis of,' 272, 273. 
 Form part of the diet of soldiers in Germany, 275. Table, 278. 
 
 LIGHT. Its influence on vegetable life analogous to that of heat on 
 animal life, 222. 
 
INDEX. 339 
 
 LIME. Phosphate of. See Bones. 
 
 LIVER. It separates from the venous blood the carbonized constitu- 
 ents destined for respiration, 57. Diseases of the liver, how pro- 
 duced, 22. Accumulation of fat in the liver of the goose, 91. 
 
 M. 
 
 MAIZE. Analysis of starch from, 286. 
 
 MARC HAND. On the amount of urea in the urine of the dog when 
 fed on sugar, 60. His analysis of cholesterine, 289. 
 
 MARCET. His analysis of gluten, 283. 
 
 MARTIUS. His analysis of guaranine, 314. 
 
 MECHANICAL EFFECTS. See Motion. 
 
 MEDICINE. Definition of the objects of, 245 et seq. Action of medi- 
 cinal agents, 161 et seq. 
 
 MENZIES. His calculation of the amount of inspired oxygen, 12, 271. 
 
 METALDEHYDE. See Aldehyde. 
 
 METAMORPHOSIS OF TISSUES, 99 et seq. In other parts of the vol- 
 ume, passim. 
 
 MILK. Is the only natural product perfectly fitted to sustain life, 50. 
 Contains caseine, ib. Fat (butter), ib. Sugar of milk, ib. Earth 
 of bones, 51. And potash, 156. 
 
 MITSCHERLICH. His analysis of uric acid, 308 ; of hippuric acid, 309. 
 
 MOMENTUM. Offeree, 191. Of motion, 192. 
 
 MORPHIA. Contains less nitrogen than quinine, 168. Its analysis, 
 314. 
 
 MOTION. Phenomena of motion in the animal body, 186 et seq. 
 Different sources of motion, 189. Momentum of motion, 191. Mo- 
 tion propagated by nerves, 208. Voluntary and involuntary mo- 
 tions accompanied by a change of form and structure in living 
 parts, 209. Motion derived from change of matter, 210 et seq. The 
 cause of motion in the animal body is a peculiar force, 220. The 
 sum of the effects of motion in the body proportional to the amount 
 of nitrogen in the urine, 233. 
 
 MULBERRY CALCULUS. See Calculus. 
 
 MULDER. Discovered proteine, 101. His analysis of fibrine of blood, 
 282. Of animal caseine, 285. Of proteine, 298. Of fibrine, 301. 
 Of gelatine, ib. Of chondrine, 302. 
 
 MUSCLE. See Flesh. 
 
 MUSCULAR FIBRE. Its transformation depends on the amount of 
 force expended in producing motion, 209. 
 
340 INDEX. 
 
 N. 
 
 NERVES. Are the conductors of the vital force, and of mechanical 
 effects, 208. Effects of the disturbance of their conducting power, 
 218. They are not the source of animal heat, 28. 
 
 NERVODS LIFE. Distinguished from vegetative, 36. 
 
 NERVOUS MATTER. Contains albumen, and fatty matter of a pecu- 
 liar kind, 43. Vegetables cannot produce it, 49. The fat of yolk 
 of egg probably contributes to its formation, 103. The phosphoric 
 acid and phosphates, formed in the metamorphosis of the tissues of 
 the herbivora, are retained to assist in the formation of nervous mat- 
 ter, 77. The vegetable alkalies affect the nervous system, 172-174. 
 Composition of cerebric acid, 174. Theory of the action of the veg- 
 etable alkalies, 175. 
 
 NITROGEN. Essential to all organized structures, 42, 43. Substances 
 in the body which are destitute of it not organized, 43. Abounds 
 in nutritious vegetables, 45. Nutritious forms in which it occurs, 
 ib. et seq. Occurs in all vegetable poisons, 167 j also in a few sub- 
 stances which are neither nutritious nor poisonous, but have a pecu- 
 liar effect on the system, such as caffeine, 167 et seq. 
 
 NITROGENIZED. See Azotized. 
 
 NoN-AzoTizED. Constituents of food. See Starch. 
 
 NUTRITION. Depends on the blood, 38. On albumen, fibrine, or 
 caseine, 38 et seq. Elements of nutrition, 92. Compounds of pro- 
 teine alone are nutritious, 101. Occurs when the vital force is 
 more powerful than the opposing chemical forces, 188. Theory of 
 it, 199. Is almost unlimited in plants from the absence of nerves, 
 201. Depends on the momentum of force in each part, 216. De- 
 pends also on heat, 231. 
 
 o. 
 
 OATS. Amount required to keep a horse in good condition, 72. An- 
 alysis of, 287. 
 
 OIL OF BITTER ALMONDS. Its composition. How related to benzoic 
 acid, 267, 268. 
 
 OLD AGE. Characteristics of, 236 et seq. 
 
 OPPERMANN. His analysis of wax, 296. 
 
 ORGANIZED TISSUES. All contain nitrogen, 42, 43. All such as are 
 destined for affecting the change of matter are full of small vessels, 
 212. Their composition, 120. The gelatinous and cellular tissues, 
 
INDEX. 341 
 
 and the uterus, not being destined for that purpose, are differently 
 constructed, 213. Waste of organized tissues rapid in carnivora, 73- 
 
 ORGANS. The food of animals always consists of parts of organisms, 
 2. All organs in the body contain nitrogen, 42, 43. There must 
 exist organs for the production of nervous matter, 179 ; and the 
 vegetable alkalies may be viewed as food for these organs, ib. 
 
 ORIGIN. Of animal heat, 16, 29. Of fat, 78 et seq. Of the nitrogen 
 exhaled from the lungs, 109 et seq. Of gelatine, 121 et seq. Of 
 uric acid and urea, 129 et seq. Of bile, 128, 136, 139 et seq. 150. 
 Of hippuric acid, 143, 315. Of the chief secretions and excretions, 
 145. Of the soda of the bile, 153 et seq. Of the nitrogen in bile, 
 1 60. Of nervous matter, 1 73 et seq. 
 
 ORTIGOSA. His analysis of starch, 286. 
 
 OXALIC ACID. A product, along with urea, of the partial oxidation 
 of uric acid, occurring in the form of mulberry calculus, 131. Its 
 analysis, 311. 
 
 OXYGEN. Amount consumed by man daily, 12, 271. Amount con- 
 sumed daily in oxidizing carbon by the horse and cow, 14. The 
 absorption of oxygen characterizes animal life, 2. The action of 
 oxygen is the cause of death in starvation and in chronic diseases, 
 24 - 26. The amount of oxygen inspired varies with the tempera- 
 ture, dryness, and density of the air, 16. Is carried by arterial 
 blood to all parts of the body, 163. Fat differs from sugar and 
 starch only in the amount of oxygen, 81. It also contains less oxy- 
 gen than albumen, fibrine, &c., 83. The formation of fat de- 
 pends on a deficiency of oxygen 85 et seq.; and helps to sup- 
 ply this deficiency, 86. Oxygen essential to digestion, 108. Re- 
 lation of oxygen to some of the tissues formed from proteine, 120. 
 Oxygen and water, added to blood or to flesh, yield the elements 
 of bile and of urine, 128. Action of oxygen on uric acid, 129, 
 132; on hippuric acid, 79, 133; on blood, ib. ; on proteine, with 
 uric acid, 144 ; on proteine and starch, with water, ib. ; on 
 choleic acid, 146 ; on proteine, with water, 147. By depriving 
 starch of oxygen and water, choloidic acid may be formed, 
 150. Oxygen is essential to the change, of matter, 164. Its action 
 on the azotized constituents of plants when separated, 202. Its 
 action on the muscular fibre essential to the production of force, 
 209-215. Oxygen is absorbed by hybernating animals, 229. Is 
 the cause of the waste of matter, 231 ; and of animal heat, 232. 
 Blood-letting acts by diminishing the amount of oxygen which acts 
 on the body, 247. Its absorption is the cause of the change of color 
 from venous to arterial blood, 253. The globules probably contain 
 29* 
 
342 INDEX. 
 
 oxide of iron, protoxide in venous blood, peroxide in arterial, 255 et 
 seq. All parts of the arterial blood contain oxygen, 164, 165, 254, 
 259. 
 
 P. 
 
 PEARS. Analysis of starch from unripe, 286. 
 
 PEASE. Form part of the diet of soldiers in Germany, 272, 276. 
 Abound in vegetable caseine, 46. Analysis of pease, 277 ; of starch 
 from pease, 285. 
 
 PEPYS and ALLEN. Their calculation of the amount of inspired oxy- 
 gen, 271. 
 
 PEROXIDE or IRON. Probably exists in arterial blood, 255 et seq. 
 
 PFLUGER. His analysis of the gas obtained by puncture from the ab- 
 domen of cattle after excess in green food, 299. 
 
 PHENOMENA of motion in the animal body, 185 et seq. 
 
 PHOSPHATES. See Bones. 
 
 PHOSPHORIC ACID. See Acid, Phosphoric. 
 
 PHOSPHORUS. Exists in albumen and fibrine, 39, 43, 120. It is not 
 known in what form, 116 et seq. Is an essential constituent of 
 nervous matter, 174, 180. 
 
 PHOSPHURETTED HYDROGEN. Occurs among the products of the pu- 
 trefaction of fishes, 180, 181. 
 
 PICROTOXINE. Contains nitrogen, 168 (note). Its analysis, 313. 
 
 PLANTS. Distinguished from animals by fixing carbon and giving out 
 oxygen, 2, 202; by the want of nerves and of locomotive powers, 3. 
 Their capacity of growth almost unlimited, 219. Cause of death in 
 plants, 203. 
 
 PLAYFAIR, DR. L. His formula for blood, 127. His analysis of 
 faeces, of pease, of lentils, of beans, 273; of flesh and of blood, 304 ; 
 of roasted flesh, 312. 
 
 POISONS, VEGETABLE. Always contain nitrogen, 167 et seq. Differ- 
 ent kinds of poisons, 161. Theory of the action of Prussic acid and 
 of sulphuretted hydrogen, 262. 
 
 POLYMERIC BODIES, 99. 
 
 POTASH. Essential to the production of caseine or milk, 156. 
 
 POTATOES. Amount of carbon in, 275. They form part of the diet 
 of soldiers in Germany, ib. Analysis of, 275 ; of starch from, 286; 
 of solanine from the buds of germinating potatoes, 313. 
 PREVOST and DUMAS. On the frequency of the pulse and respira- 
 tions, 281. 
 
 PRODUCTS. Of the metamorphosis of tissues found in the bile and 
 
INDEX. 343 
 
 urine, 126. Of the action of muriatic acid on bile, 127. Of the 
 action of potash on bile, ib. Of the action of water and oxygen on 
 blood or fibre, 129. Of the oxidation of uric acid, 130. Of the ox- 
 idation of blood, 133. Of the action of water on proteine, 135. Of 
 the action of urea on lactic and benzoic acids, 143. Of oxygen and 
 uric acid on proteine, 144. Of oxygen on starch and hippuric acid, 
 ib. Of oxygen and water on proteine and starch, 145. Of oxygen 
 and water on proteine, when soda is absent, 146. Of the separation 
 of oxygen from starch, 149. Of the action of water on urea, 151. 
 Of the action of water and oxygen on caffeine or theine, asparagine, 
 and theobromine, 170. 
 
 PROTEINE. Discovered by Mulder, 101. Its composition, 102. Pro- 
 duced alone by vegetables, ib. Is the source of all the organic 
 azotized constituents of the body, 103. Its formula, 1 16. Its rela- 
 tion to fibrine, albumen, caseine, and all the animal tissues, 120. 
 Gelatine no longer yields it, although formed from it, 123. Its re- 
 lation to bile and urine, 130. Its relation to allantoine and cho- 
 loidic acid, 134; to gelatine, 135; to hippuric acid, 143; to the 
 chief secretions and excretions, 144, 145 ; to fat, 146. Analysis of 
 proteine from the crystalline lens, from albumen, from fibrine, from 
 hair, from horn, from vegetable albumen and fibrine, from cheese, 
 297 et seq. 
 
 PROUT. His analysis of starch, 286 ; of grape sugar from honey, ib. ; 
 of sugar of milk, 287 ; of cane sugar, 289 ; of urea, 309. His dis- 
 covery of free muriatic acid in the gastric juice, 107. On the effect 
 of fat food on the urine, 132. 
 
 PRTJSSIC ACID. See Acid, Hydrocyanic. 
 
 PULMONARY DISEASES. Arise from excess of oxygen, 22. Prevail in 
 winter, 23. 
 
 PULSE. Its frequency in different animals, 281. 
 
 PUTREFACTION. Is a process of transformation, 104. Membranes 
 very liable to it, 105. Effects of the putrefaction of green food in 
 the stomach of animals, 110. Is analogous to digestion, 114. Pu- 
 trefying animal matters cause the fermentation of sugar, 115. Is 
 checked by empyreumatics, 116, 162. 
 
 Q. 
 
 QUININE. Contains nitrogen, 168. Its analysis, 313. 
 
344 INDEX. 
 
 R. 
 
 REGNAULT. His analysis of morphia, 314. 
 
 REPRODUCTION OF TISSUES. See Nutrition. 
 
 REPRODUCTION OF THE SPECIES, 37. 
 
 RESPIRATION. Theory of, 263 et seq. Its connexion with the food 
 
 and with animal heat, 11 et seq. 
 RHENISH WINES. Contain so much tartar, that their use prevents 
 
 the formation of uric acid calculus, 133. 
 
 S. 
 
 SALT, Common. Essential to the formation of bile in the herbivora, 
 and to that of gastric juice, 153 et seq. 
 
 SAUSSURE, DE. His analysis of grape sugar and of starch sugar, 
 286 ; of wax, 296. 
 
 SCHERER, DR. Jos. His analysis of albumen from serum of blood, 
 282 ; of fibrine of blood, ib. ; of vegetable fibrine, 283 ; of vegeta- 
 ble caseine, 284 ; of animal caseine, ib. j of proteine from different 
 sources, 297 ; of albumen from white of egg, 298 ; of albumen from 
 different sources, 300 ; of fibrine, 301 ; of gelatine from different 
 sources, ib. ; of tissues containing chondrine, 302 ; of the tunica 
 media of arteries, ib. ; of horny tissues, ib.; of the lining mem- 
 brane of the egg, 303 ; of feathers, ib. ; of the pigmentum nigrum 
 oculi, ib. Results of his researches, 120, 121. 
 
 SECRETIONS. See Bile and Urine. 
 
 SEGUIN. His calculation of the amount of inspired oxygen, 271. 
 
 SERPENTS. Their excrements consist of urate of ammonia, 53. The 
 process of digestion in them, 53. 
 
 SLEEP. Theory of, 217. Amount of sleep necessary for the adult, the 
 infant, and the old man, 236 et seq. Induced by alcohol or wine, 
 228. 
 
 SODA. Essential to blood and bile, and derived from common salt, 
 153 et seq. 
 
 SODIUM, Chloride of. See SALT. 
 
 SOLANINE. Contains nitrogen, 168. Its analysis, 313. 
 
 STARCH. Exists in the food of the herbivora, 68. Is convertible 
 into sugar, 69. Its relation to gum and sugar, 71. Its function in 
 food, ib. et seq. Amount of carbon in starch compared with that in 
 flesh, 73, 74. Its composition compared with that of fat, 81, 86. 
 Is the source of diabetic sugar, 91. Is an element of respiration, 
 
INDEX. 345 
 
 92. Dissolved by diastase, 107. Its relation to choleic acid, 144. 
 Its relation to the principal secretions and excretions, 145; to cho- 
 loidic acid, 149; to bile, 150, 153, 155, 157. Its analysis from fif- 
 teen different plants, 285 et seq. 
 
 STARVATION. Process of, 24. Cause of death in, 26. 
 
 STRECKER. His analysis of starch from 12 different plants, 286. 
 
 SUGAR. Analysis of grape-sugar, 286 ; of sugar of milk, 287 ; of 
 cane-sugar, 289. Is an element of respiration, 92. 
 
 SULPHUR. Exists in albumen, and caseine, 39, 120. 
 
 SULPHURETTED HYDROGEN. Theory of its poisonous action, 262. 
 
 SULPHURIC ACID. See Acid, Sulphuric. 
 
 SUPPLY of matter. See Nutrition. 
 
 SUPPLY and WASTE. Equilibrium between them constitutes the 
 abstract state of health, 242, 243. Effects of its disturbance, ib. et 
 seq. Means for restoring the equilibrium, 236, 245, et seq. 
 
 T. 
 
 TABLES of the food consumed by soldiers in Germany, 278. Of the 
 food and excretions of the horse and cow, 279, 280. 
 
 TAURINE. How produced from bile, 127. Its relation to choleic 
 acid, 128. Its relation to uric acid and urea, and to allantoine, 147; 
 to uric acid , 148 ; to alloxan, z7>. ; to choloidic and choleic acids, 
 and ammonia, 150 ; to caffeine, or theine, 170 ; to asparagine, ib. ; 
 to theobromine, il. t 171. 
 
 TEMPERATURE. Its effects on the amount of inspired oxygen, 16, 
 and on the appetite, 17 et seq. A slight depression of temperature 
 causes death in aged people, 255. Temperature of the blood in 
 different animals, 281. Temperature of the body constantly kept 
 up by internal causes, 18-22. 
 
 TENDONS. Analysis of, 301. 
 
 THAULOW. His analysis of cystic oxide, 310. 
 
 THEINE. Identical with caffeine, 169. And with guaranine, 314. 
 Theory of its action, 171 et seq. Its relation to bile, 170. Its 
 analysis, 314. 
 
 THEOBROMINE. Analogous to theine, 169. Theory of its action, 
 
 171 et seq. Its relation to bile, 170, 171. Its analysis, 314. 
 THEORY. Of animal heat, 16 et seq. Of digestion, 104 ct seq. Of 
 
 respiration, 253 et seq. Of the motions in the animal organism, 
 185 et seq. Of disease, 242 et seq. Of the action of caffeine, &c., 
 
 172 et seq. Of the action of the vegetable alkalies, ib. Of health, 
 242, 243. 
 
346 INDEX. 
 
 TIEDEMANN and GMELIN. Their attempt to support a goose upon al- 
 bumen alone, unsuccessful, 102. 
 
 TISSUES, METAMORPHOSIS OF. See Metamorphosis. Analysis of the 
 animal tissues, 300. Formula of, 120. 
 
 TOBACCO. Arrests or retards the change of matter, 170. 
 
 TRANSFORMATION. See Metamorphosis. 
 
 TURNIPS. Juice of, contains vegetable fibrine and albumen, 46. 
 
 u. 
 
 UREA. Derived from uric acid, 130, 133. Also from the oxidation 
 of blood, 133; from allantoine, 134. Its relation to choleic acid, 
 141: to hippuric acid, 143 ; to proteine, ib. ; to proteine and 
 starch, 145 ; to proteine and fat, 146 ; to taurine, 147 ; to carbon- 
 ate of ammonia, 151 ; to theobromine, 171. Its analysis, 309. 
 Occurs in the urine of those who have taken benzoic acid along 
 with hippuric acid, 317. 
 
 URINARY CALCULI. See Calculus. 
 
 URIC ACID. See acid, Uric. 
 
 V. 
 
 VARRENTRAPP and WILL. Their analysis of vegetable albumen, 283. 
 Of sulphate of potash and caseine, 284. 
 
 VEGETABLES. Alone produce compounds of proteine, 102. Azotized 
 constituents of, nutritious, 44 ; rnedical or poisonous, 167. Analy- 
 sis of those vegetables which are used for food, 273 et seq. 
 
 VEGETABLE LIFE. Distinguished from nervous life, 36. Predomi- 
 nates in the early stages of life, ib. Also in the female, 37. 
 
 VENOUS BLOOD. See Blood. 
 
 VITAL FORCE, or vitality. Definition of, 1 et seq. Theory of, 185 et 
 seq. 
 
 VOGEL. His analysis of gas from the abdomen of cattle after excess 
 in green food, 299. 
 
 w. 
 
 WATER. Is one of the two constituents of the body which contain 
 no nitrogen, 43. Its use as a solvent, ib. Contributes to the great- 
 er part of the transformations in the body, 130, 133, 134, 135, 141, 
 145, 146, 147, 148, 149, 151, 170, 171. 
 
INDEX. 347 
 
 WAX. On its production from honey by the bee, 290-296 Its 
 analysis, 296. 
 
 WHEAT. Contains vegetable fibrine, 45. Analysis of fibrine, albu- 
 men, and gluten, from wheat, 283. 
 
 WILL and ETTLING. Their analysis of lithofellic acid, 312. 
 
 WINE. The wines of the south promote the formation of calculus, 
 133. But not Rhenish wines, ib. Theory of its action, 228. 
 
 WosKRESENSKy. His analysis of theobromine, 314. 
 
 Y. 
 
 YAMS. Analysis of starch from, 286. 
 
PROFESSOR LIEBIG'S 
 REPORT ON ORGANIC CHEMISTRY. 
 
 NOTICES OF PART I. 
 AGRICULTURAL CHEMISTRY. 
 
 THIS work has already acquired great reputation in Great 
 Britain, and several notices and reviews of it have appeared 
 in the foreign journals, all of which unite in expressing their 
 high estimation of its contents. Three lectures have been 
 recently delivered on Agriculture at Oxford by Dr. Daubeny, 
 the distinguished Professor of Chemistry and Botany, in which 
 he has illustrated and adopted Professor Liebig's views. 
 
 " Every page contains a mass of information. I would 
 earnestly advise all practical men, and all interested in culti- 
 vation, to have recourse to the book itself. The subject is 
 vastly important, and we cannot estimate how much may be 
 added to the produce of our fields by proceeding on correct 
 principles." LOUDON'S Gardener's Magazine for March, 
 1841. 
 
 In alluding to this work, before the British Association for 
 the Advancement of Science, Dr. Gregory remarked ; 
 
 "Every thing was simply and clearly explained. It was 
 the first attempt to apply the newly created science of 
 Organic Chemistry to Agriculture. In his opinion, from 
 this day might be dated a new era in the art, from the prin- 
 ciples established by Professor Liebig. He was of opinion, 
 that the British Association had just reason to be proud of 
 such a work, as originating in their recommendation." 
 
 The following is from the address at the Anniversary 
 Meeting of the Royal Society, November 30, 1840, when 
 one of the Copley medals was awarded to Professor Liebig, 
 in presenting which, the President, the Marquis of Northamp- 
 ton, thus addressed Professor Daniell, who, in the absence 
 of Professor Liebig, received for him the medal ; 
 
" I hold in my band and deliver to you one of the Copley 
 medals, which has been awarded by us to Professor Liebig. 
 My principal difficulty, in the present exercise of this, the 
 most agreeable part of rny official duty, is to know, whether 
 to consider M. Liebig's inquiries as most important in a 
 chemical or in a physiological light ; however that may be, 
 he has a double claim on the scientific world, enhanced by 
 the practical and useful ends to which he has turned his 
 discoveries." 
 
 "It is the best book," writes Mr. Nuttall, "ever pub- 
 lished on Vegetable Chemistry as applied to Agriculture, 
 and calculated undoubtedly to produce a new era in the 
 science." 
 
 Extract from a letter from Mr. Colman, Commissioner for 
 the Agricultural Survey of Massachusetts, dated February 
 15th, 1841 ; 
 
 "It is the most valuable contribution to Agricultural sci- 
 ence, which has come within my knowledge. It takes new 
 views on many subjects, which have been long discussed 
 without any progress towards determinate conclusions ; and 
 reveals principles, which are of the highest importance. 
 Some of these principles require further elucidation and 
 proof; but, in general, they are so well established by facts 
 within my own observation, that in my opinion the truth, if 
 not already reached, is not far distant." 
 
 From Silliman's Journal, January, 1841 ; 
 " It is not too much to say, that the publication of Profes- 
 sor Liebig's Organic Chemistry of Agriculture, constitutes 
 an era of great importance in the history of Agricultural 
 science. Its acceptance as a standard is unavoidable, for , fol- 
 lowing closely in the straight path of inductive philosophy, the 
 conclusions which are drawn from its data are incontrovertible." 
 "To some, the style of this work may seem somewhat 
 obscure ; but it will be found, on a re-perusal, that great 
 condensation, brevity, and terseness, have been mistaken 
 for obscurity." "We can truly say, that we have never 
 risen from the perusal of a book with a more thorough con- 
 viction of the profound knowledge, extensive reading, and 
 practical research of its author, and of the invincible power 
 and importance of its reasonings and conclusions, than we 
 have gained from the present volume." 
 
In the notice from which the foregoing is extracted, the 
 learned editors enumerate among the most important chap- 
 ters, those on manure, the composition of animal manure, 
 the essential elements of manure, bone manure, the supply 
 of nitrogen by animal matter, mode of applying urine, value 
 of human excrements, &c. 
 
 The Second Part of the work is a masterpiece of con- 
 densed reasoning on chemical transformations, fermentation, 
 decay, and putrefaction, and on contagion, poisons, and 
 miasms. 
 
 From the Farmer's Register, Petersburg, Va., August, 
 1841 ; 
 
 "This work of Professor Liebig has received more re- 
 spectful attention and applause, than any on Agriculture that 
 has issued from the press." "No work have we yet seen 
 that furnished to Agriculturists a more abundant store of 
 scientific facts." " We earnestly recommend to scientific 
 Agriculturists and to Chemists to study Liebig." 
 
 " By the perusal of such works as this, the farmer need no 
 longer be groping in the dark, and liable to mistakes ; nor 
 would the not unnatural odium of farming by the book, be 
 longer existent. 
 
 " In conclusion, we recommend the work to the Agricul- 
 turist and to the Horticulturist, to the amateur florist, and to 
 the curious student into the mysteries of organic life, as- 
 sured that they will find matter of interest and of profit in 
 their several tastes and pursuits." HOVEY'S Magazine of 
 Horticulture , &c., September, 1841. 
 
 " We regard the work of Liebig as a work of extraordinary 
 philosophical acumen, and conferring upon him the highest 
 honor. The more it is examined, the deeper will be the inter- 
 est which it will create, and the stronger the admiration of the 
 ability with which it is written. It is not a work to be read, 
 but studied ; and if further inquiries and experiments should 
 demonstrate, as seems to us from many facts within our own 
 knowledge in the highest degree probable, the soundness of 
 his views, his work, not merely as a matter of the most inter- 
 esting philosophical inquiry, but of the highest practical utili- 
 ty, will be invaluable." North American Review, July, 1841. 
 
" Dr. Webster has rendered an important service to the agricul 
 tural community, by presenting 1 an edition of this now well known 
 and highly esteemed work. Professor Liebig has for some time 
 been known as one of the most eminent chemists of Europe, and th< 
 publication of this work in England has excited general and unqual 
 ified approbation. Almost all the scientific and literary periodicals 
 have been loud in its praise, and all concur in the opinion, that a 
 new era in agriculture must date from its appearance. The presen 
 edition has been greatly increased in value and utility by the addi 
 tions which it has received from the American editor. The Notes 
 and Appendix contain much important information for the agricul 
 turist, and the explanations which have been added of chemica 
 terms, render it intelligible to all. It should be in the hands of every 
 fanner. The typography and general appearance of the volume is 
 such as might be expected from the University Press." Christian 
 Examiner, July, 1841. 
 
 " In the present work, Dr. L. has pointed out the path to 
 be pursued, and has amply vindicated the claim of science to 
 be considered the best guide, by correcting the erroneous 
 views hitherto prevailing, of the sources whence plants derive 
 their nourishment, by developing the true causes of fertility 
 in soils, and finally, by establishing, on a firm basis, the true 
 doctrine of manures." Quarterly Review, March, 1842. 
 
 NOTICE OF PART II. 
 ANIMAL CHEMISTRY. 
 
 "While we have given but a very imperfect sketch of this origi- 
 nal and profound work, we have endeavored to convey to the read- 
 er some notion of the rich store of interesting matter which it con- 
 tains. The chemist, the physiologist, the medical man, and the 
 agriculturist, will all find in this volume many new ideas and many 
 useful practical remarks. It is the first specimen of what modern 
 organic chemistry is capable of doing for physiology; and we have 
 no doubt that, from its appearance, physiology will date a new era 
 in her advance. We have reason to know that the work, when in 
 progress, at all events the more important parts of it, were submit- 
 ted to Mtiller of Berlin, Tiedernann of Heidelberg, and Wagner of 
 Gottingen, the most distinguished physiologists of Germany ; and 
 without inferring that these gentlemen are in any way pledged to 
 the author's opinions, we may confidently state that there is but one 
 feeling among them as to the vast importance of Chemistry to Phys- 
 iology at the present period ; and that they are much gratified to 
 see the subject in such able hands." Quarterly Review. 
 
THE 
 
 HISTORY OF HARVARD UNIVERSITY. 
 
 BY JOSTAH QUINCY, LL. D., 
 
 PRESIDENT OF THE UNIVERSITY. 
 
 CAMBRIDGE: 
 PUBLISHED BY JOHN OWEN. 
 
 [Royal 8vo. Vols. I. and II. pp. 612 and 728.] 
 21 ENGRAVINGS. 
 
 " This History is a monument of patient and unwearied 
 investigation, of rigid impartiality and discrimination in 
 deductions from time-worn records. It embraces the events 
 of two centuries, and historical and biographical notices of 
 nearly every individual whose name is found connected with 
 any important incident in the annals of the University." 
 Boston Courier. 
 
 "There is no hazard in saying, that this work is rich in 
 materials, many of which have escaped the notice of even 
 extensive readers, and that it bears marks of thorough re- 
 search, and great care in the collection and verification of 
 facts, and judgment and skill in the arrangement and devel- 
 opement of the narrative." Daily Advertiser. 
 
 (( The American press has rarely, if ever before, sent 
 forth two such beautiful volumes in typographical execution, 
 as these, containing an admirable and interesting history of 
 the venerable University of Cambridge. To the numerous 
 Alumni of Harvard, these volumes will be precious indeed." 
 Neiv York American. 
 
 ."The history of the University is now written; and it 
 needs no prophetic sagacity or boldness to assert, that it will 
 
6 
 
 endure. For the indefatigable diligence and learned re- 
 search with which the materials have been assembled ; for 
 the fullness, candor, and impartiality, with which they are 
 now exhibited ; for the light reflected thus on the history, 
 not only of the College, but of the times ; in fine, for what 
 he has here done to establish the claims of Harvard College, 
 in the successive periods of its history, to the gratitude and 
 veneration of her sons in all coming time, we offer him, 
 in their name, nor will they deem it presumptuous, our cor- 
 dial thanks." Christian Examiner. 
 
 "We expected to find in these volumes the authentic re- 
 sults of diligent research, and accordingly, a valuable con- 
 tribution to the completeness of existing aids to an acquaint- 
 ance with the men and doings of the ancient times. But we 
 confess we did not expect to find them so fruitful in enter- 
 tainment, and in materials for engaging and profitable, as 
 well as. (to a patriot) complacent reflection. We did not 
 expect to see a record of the fortunes of a single institution 
 of learning, taking the place, which this seems to us des- 
 tined to take, among works of historical literature. 
 
 "This is not a book to be welcomed and enjoyed by the 
 friends of Harvard College alone, nor by either of the small 
 classes of New England, or of academical antiquaries, but 
 one which will sustain permanent claims on the attention of 
 the general student of history." North American Review. 
 
 This work is, in fact, not simply the history of one of our 
 most ancient literary institutions, but a history of the prog- 
 ress of letters in New England from the earliest days of the 
 Puritan colonists ; the history of the most illustrious minds, 
 for heroism and genius, which have adorned the annals of 
 Massachusetts for the last two centuries. 
 
 The whole net proceeds of the sale of these volumes will 
 be devoted to assist indigent students. 
 
WORKS RECENTLY PUBLISHED BY 
 
 J. OWEN, CAMBRIDGE. 
 
 THE HISTORY OF HARVARD UNIVERSITY, by JOSIAH 
 QUINCY, LL. D., President of the University. With 21 Engrav- 
 ings. 2 vols. royal 8vo. cloth. 
 
 VOICES OF THE NIGHT, by HENRY WADSWORTH LONG- 
 FELLOW. 6th edition. JGmo. boards. 
 
 THE SAME, royal 8vo. fine paper, boards. 
 
 THE CLOUDS OF ARISTOPHANES. With Notes by C. C. 
 FELTON, Professor of Greek Literature in Harvard University. 
 12mo. cloth. 
 
 LECTURES ON MODERN HISTORY, from the Irruption of 
 the Northern Nations to the close of the American Revolution. 
 By WILLIAM SMYTH, Professor of Modern History in the Univer- 
 sity of Cambridge. From the Second London Edition, with a 
 Preface, List of Books on American History, &c., by JARED 
 SPARKS, LL. D., Professor of Ancient and Modern History in 
 Harvard University. 2 vols. 8vo. cloth. 
 
 BALLADS AND OTHER POEMS, by HENRY WADSWORTH 
 LONGFELLOW. 4th edition. 16rno. boards. 
 
 THE SAME, royal 8vo. fine paper, boards. 
 
 A NARRATIVE OF VOYAGES and Commercial Enterprises' 
 by R. J. CLEVELAND. 2 vols. I2mo. cloth. 
 
 AN INQUIRY into the Foundation, Evidences, and Truths of 
 Religion. By HENRY WARE, D. D., late Hollis Professor of 
 Divinity in Harvard College. 2 vols. 12mo. cloth. 
 
 HENRY OF OFTERDINGEN : A Romance. From the Ger- 
 man of Novalis (Friedrich von Hardenberg). J2mo. cloth. 
 
 PROF. LIEBIG'S REPORT ON ORGANIC CHEMISTRY. 
 
 PART I. 
 
 AGRICULTURAL CHEMISTRY. 
 
 CHEMISTRY in its Application to Agriculture and Physiology 
 By JUSTUS LIEBIG, M. D., Ph. D., F. R. S., M. R. I. A., Professor of 
 Chemistry in the University of Giessen, &c. Edited from the 
 Manuscript of the Author, by LYON PLAYFAIR, Ph. D. With 
 numerous Additions, and a New Chapter on Soils. Third Ameri- 
 can from the Second English Edition, with Notes and Appendix, 
 by JOHN W. WEBSTER, M. D., Erving Professor of Chemistry in 
 Harvard University. 12mo. 
 
8 
 
 PART II. 
 ANIMAL CHEMISTRY. 
 
 ANIMAL CHEMISTRY, or Organic Chemistry in its Application 
 to Physiology and Pathology. By JUSTUS LIEBIG, M. D., PH. D., 
 F. R. S., M. R. I. A., Professor of Chemistry in the University of 
 Giessen, &c. Edited from the Author's Manuscript, by WILLIAM 
 GREGORY, M. D., F. R. S. E., M. R. I. A., Professor of Medicine 
 and Chemistry in the University and King's College, Aberdeen. 
 With Additions, Notes, and Corrections, by Dr. GREGORY, and 
 others by JOHN W. WEBSTER, M.D., Erving Professor of Chem 
 istry in Harvard University. 1 vol. 
 
 IN PRESS, 
 
 A TREATISE ON MINERALOGY, on the Basis of Thomson's 
 Outlines, with Numerous Additions : comprising the Description 
 of all the new American and Foreign Minerals, their Localities, 
 &c. Designed as a Text-Book for Students, Travellers, and 
 Persons attending Lectures on the Science. By J. W. WEB- 
 STER, M. D., Professor of Chemistry and Mineralogy in Harvard 
 University. 8vo. 
 
 THE EVIDENCES OF THE GENUINENESS OF THE GOS- 
 PELS. By ANDREWS NORTON. Vols. II. and III. (being the 
 completion of the work). 8vo. 
 
Reply to a " NOTICE " of Messrs. WILEY & PUTNAM, publishers 
 of the unauthorized reprint of the Second Part of Professor 
 Liebig's Report on Organic Chemistry, published in the " Bos- 
 ton Daily Advertiser," of August 16, and in other newspapers. 
 
 THE First Part of Professor Liebig's Report on Organic 
 Chemistry, drawn up at the request of the British Association, 
 has passed to a third edition in this country, having been pub- 
 lished by Mr. John Owen, of Cambridge. That the publisher 
 of the First Part of this Report would make arrangements for 
 publishing the Second, namely, the Animal Chemistry, was to 
 be expected, both by the " trade " and the public. 
 
 From the care bestowed upon the republication of the First 
 Part, the author and translator were desirous that the Second 
 should appear from the same press, under the supervision of the 
 editor of the first, and arrangements were accordingly made. 
 
 The arrangements, and the wishes of the translator and author 
 were duly announced! in the " Boston Medical Journal," in the 
 newspapers, and by a circular of the editor. 
 
 In April, Messrs. Carey and Hart, of Philadelphia, announced 
 their intention of republishing the new work of Professor Liebig. 
 On being informed of the wishes of the author and translator, 
 they, at once, courteously relinquished their undertaking. 
 
 Regardless of the usages of the trade, and of the published 
 wishes of the author and translator, Messrs. Wiley and Putnam, 
 of New York, with all possible despatch, republished the work, 
 from a London copy, with all the errors of the London press, 
 and others in addition. 
 
 The editor, to whom the care of the republication in this 
 country had been committed by Dr. Gregory, deemed it his duty 
 to make known the fact, that the New York reprint was in- 
 correct. 
 
As was to be expected, the public were disinclined to pur- 
 chase the New York edition, and as more than one of the trade 
 disapproved of the interference, Messrs. Wiley and Putnam 
 issued their " Notice," or, what would be more correctly termed, 
 an apology to the trade. 
 
 Tn this " Notice," assertions are made, which are entirely 
 without foundation. This would have been proved to the sat- 
 isfaction of all, before this, had the editor not preferred to wait 
 for evidence. It has now come to hand, and has, moreover, 
 been confirmed by a gentleman, who has long been intimately 
 connected with the British Association, and who is thoroughly 
 familiar with all its rules and customs. But upon the pub- 
 lished evidence alone, contained in the annual volumes of the 
 Association, the assertions of Messrs. Wiley and Putnam will be 
 seen to have no foundation. 
 
 Messrs. Wiley and Putnam published their edition, with a 
 notice attached to it, that it was "faithfully copied from the Lon- 
 don edition." This is freely admitted, and a more certain meth- 
 od of diminishing its value could hardly have been found, than 
 that of pasting in each copy this certificate by themselves, that 
 their book contains all the errors of the London press, a 
 press from which, scientific works, especially where figures are 
 concerned, are so often admitted by the authors themselves to 
 be incorrect. We have an example in Turner's Chemistry, a 
 book in the hands of every Chemist in this country ; it was not 
 until after the many and laborious corrections of the accom- 
 plished editor of the American edition, that it could be relied 
 upon. 
 
 In their "Notice," Messrs. Wiley and Putnam say, "the work 
 being prepared at the request of, and paid for by, the British 
 Association, &c., could not be, and was not published, until pre- 
 sented to, and read before the Association, which was done on 
 the 24th of June. (See Athenaeum, 1 July 2d.)" 
 
 There is not the slightest foundation for this positive asser- 
 tion, the book was not read, nor was it paid for, by the Asso- 
 ciation. On referring to the " Athenaeum" of July 2d, what do 
 we read in the account of the proceedings of the Association? 
 
Why, that Dr. Lyon Playfair read an Abstract of Professor 
 Liebig's Report ! An abstract, merely, not the book ; not a 
 volume of more than three hundred pages ! but an abstract, 
 
 which is given in the " Athenseum," of which it occupies two 
 
 pages. The Association, undoubtedly, had time to listen to this 
 abstract, but not to an octavo volume, with all its figures and 
 calculations. Indeed, Dr. Playfair expressly says, that of parts, 
 and important parts, of the Report he " dared not venture to 
 make an abstract." (Vide London " Athenaeum," July 2d.) So 
 much foundation is there for this unfortunately positive assertion 
 of Messrs. Wiley and Putnam. 
 
 Again, Messrs. Wiley and Putnam assert, with equal positive- 
 ness, that the Report of Professor Liebig " was- purchased by 
 the Association." They had less, if possible, of foundation for 
 this assertion. In the first place, all who are conversant with 
 the proceedings, rules, and customs of the Association, know 
 that this cannot be true. The Association appropriate funds 
 for the prosecution of some scientific researches, for necessary 
 apparatus, &c. In the Annual Reports, all such appropria- 
 tions are particularly designated, and in the Treasurer's An- 
 nual Statement, all sums so employed and paid, are noted. 
 From the examination of these documents, from the time 
 Professor Liebig was requested to draw up this Report, name- 
 ly, in 1838, not a shilling appears to have been appropriated 
 for defraying the expense- or to have been paid to Professor 
 Liebig. These documents are accessible to all. 
 
 On this point, too, evidence, has been obtained from the dis- 
 tinguished member of the Association already alluded to, who 
 has held the office of Vice President in the Association, and been 
 a member of its Council. Not only has he confirmed the infer- 
 ences previously drawn from the volumes of the Association, 
 but supplied additional evidence, that payment could not have 
 been made, or the Report published, at the cost of the Associa- 
 tion. The only Reports published at the cost of the Association 
 are those contained in the annual volume. Up to the latest 
 date, nothing appears from which Messrs. Wiley and Putnam 
 could, in the slightest degree, be authorized to say, that pay- 
 
ment was made to Professor Liebig, or the translator ; but all 
 the evidence is wholly the other way. 
 
 So much for the foundation of the assertion that Professor 
 Liebig " was paid " for his Report, and that it was " generously 
 given," by the British Association, "to the world." 
 
 To return to the Abstract of Dr. Playfair. It was, no doubt, 
 prepared from the German original ; not from Dr. Gregory's 
 translation. Of this abstract, the editor of the Cambridge edi- 
 tion had been already informed by Dr. Gregory, in one of his 
 letters. The abstract was read on the 24th of June. Messrs. 
 Wiley and Putnam positively assert, that the book (that is, 
 Dr. Gregory's translation), was not, and could not be published, 
 until the 24th of June. This it is not necessary now to dispute ; 
 it may, however, be worth while to state, that a medical friend, 
 being in London, actually purchased a copy " at open sale " on 
 the 23d ! But, even admitting that what Messrs. Wiley and 
 Putnam say is correct, how could Dr. Playfair have found time 
 to read, much less to study, the book in its English dress, to 
 write his abstract and to read it on the very day of publication ? 
 He had obviously made use of the German original. Further- 
 more, on the 30th of June, Dr. Gregory writes : " The new 
 work has been received in Germany with enthusiasm." The 
 work, then, must have been published in Germany, before the 
 time, when only (according to Messrs. Wiley and Putnam), it 
 could have been published, not in London alone, but in the world, 
 namely, June 24th. But it seems it had been published on the 
 continent, had been read and admired, and sufficient time had 
 elapsed for Dr. Gregory to learn that it had created a sensation 
 in Germany. 
 
 Messrs. Wiley and Putnam undertake to decide, that Professor 
 Liebig had " no power to authorize the republication of his work 
 any where." This they infer from their previous assertion, that 
 it had been " purchased from him by the Association." Having 
 shown, that there could have been no purchase, this inference 
 has no foundation. Besides, by a standing Rule of the Associ- 
 ation, even had the work been purchased by the Association, the 
 author might have retained his right of property in it, and his 
 
power to authorize the publication of it, when and where he 
 chose. The Rule is as follows ; " The author of any paper or 
 communication shall be at liberty to reserve his right of prop- 
 erty therein." (Vide any of the volumes of the Reports of the 
 British Association.) 
 
 That the author had this right, and that he exercised it, is ap- 
 parent from the work having been published in Germany. And 
 the translator had the same right over his translation. The as- 
 sertion, that the author had no power to authorize the republica- 
 tion, is but a feeble apology for interference with the wishes of 
 the author, and, like the other assertions, has no foundation in 
 fact. 
 
 It seems hardly worth while to attend to the insinuations in 
 Messrs. Wiley and Putnam's " Notice," since any effect they 
 were designed to produce, has been so completely dissipated by 
 the pithy reply of Mr. Owen, and the statement of the printers, 
 which was published in the newspapers, and is given below.* 
 
 Messrs. Wiley and Putnam endeavor in their " notice " to 
 convey an impression, that the Cambridge edition was printed, 
 
 * As I understand from the Booksellers, that the public are disposed 
 to wait for the appearance of the Cambridge edition of Liebig's new 
 Work on Animal Chemistry, I should have no motive again to call at- 
 tention to the subject, except to reply to the insinuation of the pub- 
 lishers of the New York edition, that theirs will be used in revising 
 mine. The following statement of the printers may serve to show 
 from what source the revision of my edition will be made. 
 
 J. OWEN. 
 
 Cambridge, August 17, 1842. 
 
 More than one half the pages of Liebig's Animal Chemistry, now 
 printing at our press, was in type before the publication of the New 
 York edition. The printing was commenced and has been entirely 
 done from manuscript, and the corrected sheets sent out by the trans- 
 lator, Dr. Gregory. In no instance has the New York edition been 
 used as copy or to " revise " the proofs. 
 
 METCALF, KEITH, & NICHOLS, 
 
 Printers to the University. 
 Cambridge, August 17, 1842. 
 
at least in part, from " early proofs," and that the delay in the 
 arrival of the other sheets, and with corrections, rendered that 
 edition the only incorrect one. Whence they got the notion is 
 unknown, the term " early proofs " was not used in any an- 
 nouncement of the Cambridge edition ; if, in any notice of that 
 edition from other hands, the term has been used, it is unknown 
 to the editor. So far from " early proofs " having been sent out 
 by Dr. Gregory, he expressly says, in his letter of May 14th, 
 " he does not send such, being obliged to keep them in order 
 to introduce some essential alterations expected daily from 
 Professor Liebig." With the sheets sent on the 17th of June, 
 he writes, "I send the sheets," (not early proofs) " before publi- 
 cation" And in another place he writes, " you will see that 
 up to page 224, the sheets are printed off, the rest being last 
 proofs" He then speaks of the cancelled sheets, which he also 
 sends. Not only were the printed sheets, but also the cancels, 
 the last proofs, and the manuscript matter received, but receiv- 
 ed before any copy of the work, or of any part of it, reached 
 New York. Mr. Owen, too, was in possession of a copy of the 
 London edition, the first received in this country. It was in his 
 hands, and in those of several other persons here, before Wiley 
 and Putnam could have received their copy. It was purchased 
 in London at " open sale " no fewer than nine days prior to the 
 purchase of Wiley and Putnam's copy. So far, then, as the 
 usages of the trade are to be taken into account, Mr. Owen had 
 still another claim to become the publisher, in addition to that 
 arising from his publication of the First Part of the Report. 
 
 Messrs. Wiley and Putnam say, that no announcement was 
 made in London, as late as July 19th, of any other edition, nor 
 was there any intimation, that the edition was incorrect. Hence, 
 they say, our reprint must be correct, for it is faithfully copied 
 from the London edition. No one doubts that it is a faithful 
 copy, not an error has been corrected. 
 
 Another assertion, we will not call it designed misrepresen- 
 tation, of Wiley and Putnam is, that the editor of the Cam- 
 bridge edition, " wishes us to believe, that the corrections were 
 withheld from the English edition for the express purpose of 
 
making his the only perfect copy, not only in America, but in 
 the world." In refutation of this misrepresentation it will only 
 be necessary to quote the words of the circular announcing the 
 fact, that corrections, &c. would be furnished by the translator ; 
 the words are, " The American edition will comprise all the 
 corrections and additions, which are most important:" <; the 
 author and editor have committed the corrected sheets to the 
 care of the subscriber." " The only correct edition will be that 
 now printing at Cambridge." This, taken in connexion with 
 what is stated on the first page of the circular, and the whole 
 relating to the Cambridge edition, or to an American edition, 
 renders the meaning sufficiently apparent. Nothing is said or 
 implied in relation to any other edition " in the world." The 
 impression intended was, most obviously, that the Cambridge 
 edition would be more correct than the London edition, or any 
 other edition printing at the time in this country. It would 
 have been no perversion of language, however, to have said, 
 that the New York reprint is the most incorrect " not only in 
 America, but" (as far as we yet know) " in the world." 
 
 It appears that Mr. Owen had the earliest copy of the work, 
 and he had more than one half of it in type before the New York 
 publication appeared ; he had corrections, and matter not con- 
 tained in the London copies ; he had the sheets, the cancels, 
 corrected last proofs, and manuscript, and the Cambridge edi- 
 tion had been announced by circular and in the newspapers. 
 The fact had also been made known that the Cambridge edition 
 was printing in compliance with the wishes of those to whom 
 both the original and the translation belonged, and who had an 
 undoubted right to authorize the republication. 
 
 Messrs. Wiley and Putnam would have the public and the 
 trade believe, that they were not aware that the republication 
 had been undertaken by any other publisher. It was long 
 known to the trade, had been sufficiently announced, and one 
 of the firm was at Boston and Cambridge after the printing had 
 been commenced at. Cambridge. Is it to be supposed, that in 
 his interviews with the booksellers in Boston, and elsewhere in 
 the vicinity, nothing was seen or heard of the republication ? 
 
8 
 
 ft Until some protection is extended by the law to the literary, 
 as it is to the personal property, of foreign authors, they can 
 expect but little regard to their wishes and arrangements for 
 the republication of their works, and even the usages of the 
 trade will not always shield the publisher from interference. 
 
 J. W. W. 
 Cambridge, August 29, 1842. 
 
 
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