ia) p Wie WN, i) Me a OF oe f Ml ‘ i pe ne 0 i) a a i i o sie i i ii LG ce Me oS A a aN nl ve OS ey a i : 4 ne ‘ Ml) BNL) i y an ss : mM i My ve My i iy ' . ae fi a she ; KG a eee i eh enV IY i ve th Nia Ve tiie ti a na Hai mi a BaD i HH a} i ) Mi My i De i i < ic ue i ee i te shine! CORNELL UNIVERSITY. THE Roswell P. Flower Library THE GIFT OF ROSWELL P. FLOWER FOR THE USE OF THE N. Y. STATE VETERINARY COLLEGE. 1897 Oi > se ae | eam | heees| eee | re ae. a eee x = z a n 9 2 c Gl > CHEMICAL PHYSIOLOGY. BY THE SAME AUTHOR. BLANCHARD & LEA, PHILADELPHIA, HAVE JUST ISSUED PHYSIOLOGICAL CHEMISTRY, BY PROFESSOR OC. G. LEHMANN. TRANSLATED FROM THE SECOND EDITION, BY GEORGE EH. DAY, M.D., F.B.S., &o. Epitep sy R. E. ROGERS, M.D., Professor of Chemistry in the Medical Department of the University of Pennsylvania. WITH ILLUSTRATIONS SELECTED FROM FUNKE’S ATLAS OF PHYSIOLOGICAL CHEMISTRY, AND AN APPENDIX OF PLATES, Complete in two large and handsome octavo volumes, extra cloth, containing 1200 pages, With nearly thoo Hundred Lustrations. This great work, universally acknowledged as the most complete and authoritative exposition of the principles and details of Zoochemistry, in its passage through the press, has received from Professor Rogers such care as was necessary to present it in a correct and reliable form. To such a work additions were decmed superfluous, but several years having elapsed between the appearance in Germany of the first and last volume, the latter contained a supplement, embodying numerous correc- tions and additions,resulting from the advance of the science. These have all been incorporated in the text in their appropriate placcs, while the subjects have been still further elucidated by the insertion of illustrations from the Atlas of Dr. Otto Funke. With the view of supplying the student with the means of convenient comparison, a large number of wood-cuts, from works on kindred subjects, have also been added in the form of an Appendix of Plates. The work is, therefore, pre- sented as in every way worthy the attention of all who desire to be familiar with the modern facts and doctrines of Physiological Science. The most important contribution as yet made to Physiological Chemistry.—Am. Journal Med. Sciences, Jan. 1856. The present volumes belong to the small class of medical literature which comprises elaborate works of the highest order of merit.—Montreal Med. Chronicle, Jan. 1856. Already well known and appreciated by the scientific world, Professor Lehmann’s great work requires no laudatory sentences, as, under a new garb, it is now presented to us. The little space at our command would ill suffice to set forth even a small portion of its excellences. To all whose studies or professional duties render the revela- tions ‘of Physiological Chemistry at once interest- ing and essential, these volumes will be indis- pensable. Highly complimented by European reviewers, sought for with avidity by scholars of every nation, and admirably written throughout, it is sure to win a welcome and to be thoroughly studied.— Boston Med. and Surg. Journal, Dec. 1855. All teachers must possess it, and every intelli- gent physician ought to do likewise.—Southern Med. and Surg. Journal, Dec. 1855. Zoochemistry is now deservedly taking a high rank in Physiological research, and these volumes will be eagerly sought by all medical students who are aiming at a high standard of professional attainments, and for the reason that they consti- tute a standard authority in Europe and America. The multiplied illustrations and superior engrav- ings which abound in both volumes, will be found to be invaluable to medical microscopists, who are everywhere increasing in numbers and zeal. Professor Rogers has performed good service in his editorial revision of Professor Lehmann’s books, for which the profession will be greatly indebted.--. Y. Med. Gazette, Dec. 1855. The progress of research- in this department is. so rapid, that Prof. Lehmann’s treatise must be regarded as having completely superseded that of Simon; and all who desire to possess a sys- tematie work on Physiological Chemistry by a man who is thoroughly qualified, both by his physiological and chemical acquirements, by his own eminence as an experimentalist, and by the philosophic impartiality of his habits of thought, to afford a comprehensive and exact view of its present aspect, should lose no time in attaching themselves to tho Society by which it is in course of publication.—British and Foreign Medico- Chirurgical Review. The work of Lehmann stands unrivalled as the most comprehensive book of reference and infor. mation extant on every branch of the subject on which it treats.—Hdinburgh Monthly Journal of Medical Science. MANUAL OF CHEMICAL PHYSIOLOG FROM THE GERMAN or Pror. €. G. LEHMANN, M.D. TRANSLATED WITH NOTES AND ADDITIONS BY J. CHESTON MORRIS, M.D. WITH AN INTRODUCTORY ESSAY ON VITAL FORCE, BY SAMUEL JACKSON, M.D., PROFESSOR OF INSTITUTES OF MEDICINE IN THE UNIVERSITY OF PENNSYLVANIA, ETC. ILLUSTRATED WITH FORTY WOOD-CUTS. PHILADELPHIA: BLANCHARD AND LEA. 1856. Entered according to.the BLANCHARD AND LEA, in the office of the Clerk of the District Court of the United States in and for the Eastern District of Pennsylvania. Ho 890 cr oIt Leime of Congress, in the year 1856, by PHILADELPHIA: y. K. AND P. G. COLLINS, PRINTERS. TRANSLATOR’S PREFACE. No apology is necessary in presenting to the American medical public the work of one so widely known and universally acknow- ledged as an authority as Professor Lehmann. In so doing, how- ever, I am surrounded with more than ordinary difficulties. A correct English translation of a German work is no easy task; but when the original is not a full discussion of the subject considered, but as compressed a statement of facts as is compatible with clear- ness, the difficulty of avoiding idiomatic expressions is greatly in- creased. : From Dr. Lehmann’s views of the forces operative in living organisms, I must express my dissent. Dr. Jackson has been kind enough, at my request, to prepare an article on these views, stating the doctrines which he has so ably advocated for many years. To adapt the work for the use of students of physiology, I have incorporated in the text additional matter (derived mainly from notes on Dr. Jackson’s Lectures, Carpenter’s Human Physiology, Todd and Bowman’s Physiological Anatomy, Kolliker’s Microscopic Anatomy, &c.), of a more purely physiological nature, which will be found included in brackets, thus [—]. Short notes have also been added, in the shape of an Appendix, on kindred subjects not treated of by the author; and illustrations selected from various sources have been introduced, instead of referring, as the author has done, to the “ Atlas of Physiological Chemistry, by Otto Funke.” These alterations have so changed the character of the work as to render the title of “Chemical Physiology” more applicable than vi TRANSLATOR’S PREFACE. that originally given to it of ‘Handbook of Physiological Chemis- try,” which has, however, been retained for Dr. Lehmann’s portion of it. I can only hope that, in its present shape, the work may prove of use to those who wish to ascertain what may be considered. as established in Physiological Chemistry, and who yet have not time to wade through detail and controversy, and my aim will be ac- complished if I have succeeded in aiding those who desire a more intimate acquaintance with the phenomena presented by organized beings. Paiwapetrata, March, 1858. AUTHOR’S PREFACE. ‘WE have made the attempt, in the present little work, to place together, in as compressed a form as possible, the positive facts which can now be looked on as the certain possessions of physio- logical chemistry, and to bring to bear only those conclusions which carry upon them, according to our present physical views, the stamp of relative truth. Notwithstanding the very active zeal with which physiological chemistry is cultivated on all sides in so satisfactory a manner, and in spite of the many extended works and treatises on some of the most important heads of this science, we are unfortunately forced to confess that, until now, but few undisputed facts, but few un- doubted propositions, are established. Hence we cannot ourselves decide whether the attempt to present the department of physio- logical chemistry in a short epitome, where the fixed marks are so few, and the deficiencies so innumerable, has succeeded. If one wishes not to enter the domain of debates and discussions, a number of weighty questions must remain, if not unnoticed, yet unanswered. Yet we have just attained a position in physiological chemistry where we can ask:important questions, whose answers, even in part, the near future does not as yet promise. If it is in itself more difficult to represent a subject briefly, than to enlarge on it discursively, the deficiency of our physiologico- chemical knowledge just alluded to, has increased the difficulty ot presenting this science in its outlines. We hope, therefore, for indulgence where we shall have done too much or too little. vii AUTHOR’S PREFACE. We have throughout avoided introducing the names of investi- gators and authorities, as such introductions would have prejudiced the compressed brevity which we have had in view, and the purely objective treatment of the individual subjects. On this account, also, we have nowhere brought forward our own researches, or referred to our larger work (Teaxt-Book of Physiological Chemistry, 3 vols. Leipsic, 1853, W. Engleman), but throughout have cited, where it seemed proper, the excellent Atlas of Physiological Chemis- try, by O. Funke, Leipsic, 1883, W. Engleman. C. G. LEHMANN, Lerpsic, May, 1854. ' This work has been recently presented to the American public, complete in two volumes, under the auspices of Dr. Rogers, of the University of Pennsylvania. CONTENTS. INTRODUCTORY ESSAY ON THE HUMAN ORGANISM AND ITS FORCES. 5 2 : é : ‘ ; 17 GENERAL RELATIONS 7 ‘ A ‘ ‘ i. ‘ 19 CuemicaL RELATIONS y “ : ‘ 21 StaTIcaAL RELATIONS - i 3 ‘ 7 - A 24 Forces, ok DYNAMICAL RELATIONS . 7 3 é ‘ 27 Orq@anic Forces . ‘ i j . a : . 82 Organic, Formative, or Vital Force . ‘ j . 82 Organic, or Vital Action 7 : : : 2 : 33 Nervous, or Mechanical Force : . 5 F 85 Excitor Force . ‘ s 4 ‘ : 36 Motor Force * ‘ " : i 387 REMARKS ON DR. LEHMANN’S DOCTRINE OF VITAL FORCES . 41 HanpzBoox oF PHysioLoGicAL CHEMISTRY ‘ ‘ é Fi 49 General Observations i i é ‘ 5 49 ZOOCHEMISTRY 3 4 r 7 : 5 ‘ ¥ 55 OrGaAnic SUBSTRATA OF THE ANIMAL ORGANISM . F e 53 Oraanic Non-NITROGENISED ACIDS ‘ ‘ ‘ ‘ 62 Fat Acids : ei é ; Z : ¥ 62 Volatile Fat Acid - 7 ‘ : . 7 63 Fixed Fat Acids ‘ ; : ‘ x 68 Succinic Acid Group = 4 : ‘ : 3 72 Oily Fat Acids ‘ % : q di . 7 73 Benzoic Acid Group . ‘ : 5 : : : 74 Lactic Acid Group. : ‘ 7 : : 5 76 Non-nitrogenised Conjugate Acids. . - : 7 78 NirroceniseD Basic anD NeuTRAL Bop1es 7 F é * 79 NirroGENISED PAIRED ACIDS : i - . . . 87 Non-Nrrrogenisep Bases, Hatoip Bases 6 : 7 ‘i 92 Lipoips . . < f 8 . 5 . a 95 Non-Nirrogenisep Nevrrat Bopres, CARBOHYDRATES . Z 5 97 ANIMAL CoLoring MATTERS : . . . 3 . 99 HistoGENEetic SUBSTANCES ‘ ‘ . . . . 102 1 =. 2 CONTENTS. PAGE Protein Bodies . " 7 3 3 105 Proximate Derivatives of the Protein Bodies 7 i ‘ 113 MINERAL SUBSTANCES OF THE ANIMAL Bopy : i. . . 115 Mechanically useful, . 5 2 : . ‘ a 116 Chemically operating j : , . : : 118 Accidental . * - 2 ‘ i ‘ 7 121 PHLEGMATO-CHEMISTRY . ; = : ‘ . F 122 Screncz or roe ANIMAL FivuIps . : ‘ - é : 122 The Blood . 7 is % : é , 3 124 The Chyle . : : 3 5 : . Fi 148 The Lymph . ‘ ‘ : ; : ‘ : 150 Transudations ? - ‘ i : ; ; 151 The Milk j s : ‘ r ‘ : 2 155 The Semen . Fi : é ‘ . . 158 The Fluids of the ‘ican . : F : < 3 159 Mucus ri . F A ‘ . ‘ : 161 Saliva 7 rs ‘ : . . . : 168 The Gastric Fluid. , : ‘ id ‘ Q 167 The Bile 5 2 ‘ i 5 i 169 The Pancreatic Fluid . ‘ c " . y s 174 The Intestinal Fluid . " ‘ ‘i ; 175 Contents of the Intestines . ‘ ; ‘ Z . 176 The Sebaceous Secretions . : : : ‘ - 182 The Sweat . J . ‘ f . F A 183 The Urine . 3 ‘4 ‘ ’ . ‘ A 185 HISTO-CHEMISTRY. : 3 - ‘ ‘ , - 201 ScrENcE or Tae ANIMAL TISSUES . ‘ , - : 3 201 Osseous Tissue z a 7% ‘i : é . 202 Dental Tissue F % ‘ 5 ‘ F Z 206 Cartilaginous Tissue . z i . ; 4 x 207 Connective Tissue . : z ‘ ‘ ‘ 3 209 Elastic Tissue i é : ; ‘ , é 210 Horny Tissue ‘ 2 ‘ ‘ “ é ‘ 211 Hair Tissue . , s é 5 Fi ‘ 212 Contractile Fibre-Cells ‘ 5 ‘ é : 214 Transversely Striated Muscular Fibres ‘ ; ‘ ‘ 215 Nerve Tissue %, * Z ‘ . . ; 218 Exudations . Z 7 ; A é * 223 ZOOCHEMICAL PROCESSES ‘3 3 is 3 ; 229 Forcss anp Laws oF THE ORGANIC MovEMENTS . 229 Tissuz METAMORPHOSIS IN. GENERAL ‘ ‘ 2 2 : 234 DicEstion ‘ . A . ‘ : < “ 246 REsPIRATION ‘ . 3 : - 3 . 5 258 Nourririon i - 3 7 . : . , 274 APPENDIX CrrcuLation Repropuction . . Lire PHEenomMena . y Muscular Contraction Volition Voice Hearing 3 Vision . Smell Be a Taste Touch GENERAL INDEX CONTENTS. PAGE 289 291 297 804 806 808 808 3809 818 819 819 820 321 INTRODUCTORY ESSAY ON THE HUMAN ORGANISM AND ITS FORCES. WITH REMARKS ON DR. LEHMANN’S DOCTRINE OF VITAL FORCES, BY SAMUEL JACKSON, M.D., PROFESSOR OF THE INSTITUTES OF MEDICINE IN THE UNIVERSITY OF PENNSYLVANIA. OF THE HUMAN ORGANISM. GENERAL RELATIONS. THE organism of man, in its physiological, pathological, and therapeutical relations, is the subject and object of medical science. A comprehensive view of its general nature, and of its varied phenomena, will facilitate the investigations indispensable for a perfect understanding of them, by which alone medicine can be constituted a science. Without this knowledge, it cannot rank above an art or empiricism. Regarded in its completeness, it is an organic mechanism, the last and the most marvellous of the works of God; the fulfilment of the Creative thought in this world. In its structure, it is in the highest degree complicated ; in its nature, it is compound: it com- prehends within itself all organic nature. As-in every mechanism, its phenomena are divisible into statical and dynamical. The first embraces its material structure and forms: the second, its varied movements and its forces, or causes of its actions. It includes three distinct natures, or spheres of existences— vegetable, animal, and spiritual, or psychological. They form three separate classes of phenomena, or branches of science; vegetability, animality, spirituality, or psychology. The first is characterized by growth, development, nutrition, and secretion: the second, by sensibility, general and special; contractility or irritability; spontaneous and voluntary movements and locomotion: the third, by consciousness, perception, ideality, causality, moral sentiments, and instincts. The actions belonging to the first, are vital, chemical, and physi- cal; to the second, mechanical, physical, and dynamical; to the last, psychological and metaphysical. 20 OF THE HUMAN ORGANISM. The special or organic instruments of the first are germs, cells—epithelial, mucous, and glandular—fibres, and the gan- glionic or sympathetic nervous system: of the second, muscular fibres, muscles, and the spinal nervous system, and nervous organs of the special senses; of the third, the cerebral lobes, hemispheres, or brain. The above phenomena blend together, are interdependent, closely associated; and are the most intricate that exist in nature. They can be understood only when subjected to an accurate analysis, by which each component of a complex phenomenon may be sepa- rately demonstrated. This indispensable process for the acquiring a reliable knowledge‘of organic phenomena, necessitates a compe- tent acquaintance with each science of which the elementary phe- nomena are subjects. A deficiency of this requisite has been, and continues to be, a source of error in observation, and of fallacy in interpretation. Properly to comprehend a complex phenomenon, it must be recognized as such; it must be viewed in each of its aspects, in each of its separate attributes; the action and influence of each component part must be appreciated in the production of the gene- ral result, the object of research. A partial view, however complete it may be; the determination of a single property, or of a single component, however accurate, cannot explain the attributes, actions, or nature of the compound. Errors of this kind have abounded in medicine. It is only within a few years that the means of correctly analyzing the phenomena of living beings was possible. The unstableness of all former theories and doctrines in medicine arose from this defect. ‘They were based on a partial view, or on a single fact of life, mostly dynamical, as vital force, and irritability, or sensorial power; or on chemical views. Most of the organic chemists of the present day neglect all other components of a phenomenon except the chemical; and the inferences are conse- quently incorrect, although the shemical fact they establish may be of great value when taken in conjunction with others. The chemi- cal view presented of the blood in most works of organic chemistry, gives no adequate idea of that fluid as circulating in the vessels, and of its relations to vital phenomena. The pure physiologists who discard chemistry and physics as the leading characteristics of organic or vegetative functions, are nearly as remote from the truth as are the chemists. A just appreciation of the complex phenomena \ OF THE HUMAN ORGANISM. 21 of the human organism can be obtained in no other mode than by viewing and treating them by the lights of the collateral, physical, chemical, and other sciencts, to which their elementary phenomena belong. The material substance, the basis of the structure of the organism, is plastic, or organizable matter. The elementary plastic matter is albumen, which becomes transformed into various proximate plas- mata, of which the different solid elementary tissues and organs are formed. CHEMICAL RELATIONS. Organic matter has for its constituents the common chemical elements of inorganic bodies. Four of these, carbon, nitrogen, hydrogen, and oxygen, may be regarded as the special chemical elements of organic matter. They alone, of all the chemical ele- ments, possess the power of forming almost unlimited series of com- binations with each other, and those series again are endowed with similar powers of combination. This attribute adapts them to the purposes of organic nature: without it, organic matter and organic bodies could have no exist- ence. The chemical elements that constitute organic matter, are not divested of their special nature, properties, or relations, when they enter into its composition: they do not cease to be chemical substances any more than when they form inorganic compounds. The older physiologists were firmly convinced that chemical actions and vitality were essentially incompatible; and many physicians of the present day adhere to the same opinion. From the imperfection of chemistry, the chemical actions of living beings could not be recognized or understood, and were denied. So far are these opinions from the truth, that’ vital actions and organization are impossible without chemical action. Organic matter is not, like inorganic, an originally created, self-existing, and indestructible substance, as it was supposed to be by Buffon. The vegetable kingdom is the great chemical laboratory of nature, in which are effected the decompositions of carbonic acid, water, and ammonia, in order to obtain the four essential chemical elements of organic matter, and to combine them along with sulphur, phosphorus, &c., into an infinite number of organic matters, vegetable and animal. These are the materials for the organization and development of the 22 OF THE HUMAN ORGANISM. plants themselves, and animal organic substances, for the construc- tion of animals. The albuminoid organic substances, named by Liebig vegetable albumen, vegetable fibrin, and vegetable casein, are the primary or crude organic substances, elaborated by chemical action in vegetable cells, destined to the production of animal albu- men, fibrin, and casein, the crude organic plasmata, or substances from which are formed the immediate organizable or plasmatic matters of the different animal tissues. These last organic sub- stances are produced in the formative act of nutrition or assimila- tion, at the moment the organic form of the special animal structure is generated. ‘Thus, musculin,-a chemical modification of albumen, does not exist in the blood. It is known only as forming the or- ganic material composing the solid portion of the muscular fibril : the transformation of the albumen must take place in the muscular fibrilla simultaneously with the production of its form. The or- ganic matter of animal tissues is not permanent. From the great number of its chemical equivalents, or atoms, it is highly mutable. This character is most striking in some structures, as in mucous, glandular, muscular, and nervous tissues. The functional actions of organs cause waste and destruction of organic material propor- tioned to their activity. This is a result of chemical action, indis- solubly connected with vital action. In vegetables, the predominant chemical action consists in the deoxidation of organic substances, the oxygen being chiefly discharged into the atmosphere, while new organic substances are produced, as wax, oils, acids, &c., from the deoxidation of starch. Oxidation is the predominant chemical process in animals. The oxygen introduced into the blood by the function or act of respiration, combines with the carbon and hydrogen of the organic matters of the blood and the tissues. The whole chemical arrangement is broken up, and a reduction. of the complex plastic substance into simpler bodies takes place, from successive processes of oxidation. They are creatin, creatinin, inosin, inosic acid, uric acid, urea, and, in addition, lactic, sulphuric, and phosphoric acids, and other unknown substances that lie con- cealed in the extractive matters enumerated by the chemists as existing in the blood and urine. Independent of these normal chemical actions, consisting in the molecular changes and transformations of the plastic organic matter, there are other chemical changes, some therapeutic, some abnormal or pathological, belonging to the relations of the plastic OF THE HUMAN ORGANISM. 23 or organizable substances with other bodies. Albumen, fibrin, and other proximate organic bodies, unite chemically with many of the chemical elements, as with additional quantities of oxygen, or with acids, metallic oxides, and earthy, alkaline, and metallic salts. Through this combination some of these substances are absorbed into the blood. Doubtless many other bodies possess chemical relations with the plastic organic substances of the blood and tissues, some entering into combination with them, others exciting molecular action and evolving new compounds, or transforming them into new matters, by causing new molecular arrangements and production of new organic matters. In this mode, abnormal contagious animal poisons are generated in the organism, when in- troduced into it by inoculation or otherwise. A minute quantity of smallpox matter inserted in the skin, or an invisible miasm of it inhaled from the atmosphere, acting as a kind of ferment, will give rise to the production of some ounces of an identical matter, in a case of confluent smallpox. The inoculation of a small quantity of putrid organic matter by a slight wound or scratch in dissection, will so destroy the crasis of the blood as to cause death. Absorption of sanious discharges from the uterus, it is probable, gives rise to some of the fatal forms of what is called puerperal fever. And again, the normal chemical changes attending the organic actions are accelerated by some bodies, as acetate and nitrate of potash, iodide of potassium, and the mercurial preparations. It is this that con- stitutes an alterative action. Those substances are organic altera- tives. Other substances retard those changes and diminish the waste of the tissues; such are alcoholic liquors, caffein, thein, and the narcotics. To acertain extent, it may be the action of some vegetable tonics. The whole history of organic matter, it is apparent, is essentially chemical. Itself a chemical product, it is incomprehensible in its infinite, endless forms, and incessant changes, without a knowledge of chemistry. It is the elaborated product of the chemical labora- tories of nature—vegetable organic cells. But the immediate plastic: material of each tissue of an organized being, always a special organic material, is generated or assimilated from a crude plasma of the nutritive fluid, in the tissue itself, by the organizing or germ force of the tissue. The formation of organizable plastic matter, necessitates a living organism, independent of which it can have no existence. In this necessity, we have the scientific demonstration 24 OF THE HUMAN ORGANISM. of a creation, and the direct primary agency of a Creator, the first cause of the organized world. Organic chemistry is identified with physiology and medicine. No absolute progress can be made by either without it. The future progress of both those departments must depend, to a great extent, on the development of its principles and higher perfection of its methods of investigation. The present work, principally a translation of Lehmann’s Handbook of Physiological Chemistry, is believed to be the best adapted to initiate the student in a know- ledge of physiological or organic chemistry, indispensable to a scientific medical education. STATICAL RELATIONS. The animal is an organism, a complicated living mechanism. In carrying on its numerous and diversified’ operations, it presents a great variety of phenomena, and possesses numerous subordinate instruments, each appropriated to a special office. They are termed organs and apparatuses of organs. ach organ and apparatus possesses a special organization, is endowed with a special vital activity and properties, performs a special function, and manifests special phenomena. To be thoroughly known, they must be sub- jected to exact analysis, be investigated by experiment, as are inorganic bodies, and be assigned to the natural class to which their actions and phenomena show them to belong. A chemical, physical, mechanical or dynamic fact does not lose its proper nature and attributes, or cease to be subject to its proper laws, because it occurs in a living organism, and is associated with special vital facts or phenomena, or controlled and directed by vital force. In the living organism of man are found to concentre all the actions and phenomena, chemical, physical, and mechanical, that exist in the exterior inorganic world, combined with those peculiar to organized or living beings. This may be expressed in the formula: inorganic phenomena, plus organic and psychical phenomena. The chemistry, physics, and mechanics of the human organism are transcendental; they are each the development of the highest possible conception in each branch of knowledge; the instruments that execute them are inimitable by any of man’s invention, for the purpose of exemplifying the phenomena and principles of the natural sciences. Such, for example, is the eye as an optical instru- OF THE HUMAN ORGANISM. 25 ment, the ear as an acoustic instrument, the larynx as a phonetic and musical instrument, the vascular system as a hydrostatic appa- ratus, and the muscular system as a mechanical mechanism. The organism .of man in action is a locomotive engine, in the perfection of its machinery and adaptation to its purposes, infinitely beyond any similar engine that man ever can devise. It is com- posed of a number of distinct mechanisms, or machines and instru- ments, by which it is self-formative; by which it procures and prepares the materials for its repair and renovation, conveys them to every part of its structure where they are required, generates its own temperature and the forces that work its machinery, and brings its mechanical powers into action. The intelligence for whose use this engine exists, whose will it obeys, whose work it performs, that rules and controls it for the purpose of accomplishing the objects of life, resides in and is a com- ponent part of the machine itself. The intellect is to the human locomotive, what the engineer is to the steam locomotive. It em- ploys the extraordinary powers of this wonderful and magnificent mechanism to mould exterior material nature, after the ideal crea- tions of its own interior and spiritual nature, evolved in ideas and thought. The state of society of any country, its institutions, its works, its science, its arts, the meliorating features impressed on the rude face of nature by its industry and labors, are the reflec- tion and manifestation of the intelligence, knowledge, and moral character of its people. By his locomotive machinery, aided by his inventions, that ren- der it more efficient, that augment his powers, man overcomes all the barriers and obstacles of nature. No mountain is so lofty as to be inaccessible to his footsteps, no valley into whose depths he cannot penetrate; he mounts into the upper regions of the air to gratify his curiosity; he perforates the earth and descends into its bowels thousands of feet below its surface, to bring forth its buried treasures; the wide expanse of ocean he has made his highway; and he circumnavigates the earth in the pursuit of pleasure, science, or wealth. These extraordinary powers he owes to his inventive faculties and the knowledge acquired by his intelligence. With their aid he devises the required means that enable him to seize on the forces and appliances of nature, to turn them to his purposes, and, through their agency, to triumph over nature herself. The amount of mechanical force and power, produced, and 26 OF THE HUMAN ORGANISM. expended in the daily working of the animal machinery, is far beyond what can be conceived by those who have not investigated this subject. I will here merely state that, for the organic functions of respiration and circulation, the daily amount expended is not less than some thousands of pounds; and a considerable sum is required for the daily operations of the ingestion and digestion of food and expulsion of the excretions; while the aggregate result during labor and locomotion of various kinds, is often enormous, exceeding, frequently, two millions of pounds aday. The immediate mechanic force by which the mechanic power of the muscular system is brought into action, is generated in the spinal system, the anterior nervous ganglia of the spinal cord or axis, and appears to be either derived from a transmutation of heat into the nervous motor or excitor force; or that force and heat are correlative. A direct relation certainly exists between the two. MM. Jules, Serres, and other physicists, have demonstrated the identity of heat and me- chanic force: they are mutually correlative and equivalent to each other. This fact is expressed by M. Jules in the following for- mula :— One degree of heat is equivalent to 750 pound-feet. Or, One degree of heat is the equivalent of a mechanic force that will raise 750 pounds one foot. The same principle is equally true and applicable to animal me- chanics. Tn the animal mechanism, the heat, the equivalent of its mechanic nervous force, is evolved by the oxidation or slow combustion, chiefly of carbon and hydrogen, in the blood: The oxygen is introduced into the blood by the process of respiration, and the hydro-carbons and carbo-hydrates, by the food—as oils, sugar, starch, &c., digested and prepared by the functions of the alimentary canal, so’as to be absorbed, and introduced into the circulatory apparatus. The amount of pure carbon that must be introduced into the blood, by the food, and oxidized, to furnish the heat cor- relative of the nervous mechanic force each day, in labor, is not less than from 10 to 12 ounces. In this exhibition of facts is de- monstrated the close, immediate connection between different func- tions and actions, as respiration, digestion, absorption, circulation, oxidation, animal heat, nervous force, and mechanical actions. The working power of man is a product of the food on his dish; it comes OF THE HUMAN ORGANISM. 27 from his meals: and so also is it with his blood, and flesh, his limbs, organs, and viscera. They are constructed of the nitrogen- ized organic matters of food digested in the stomach, absorbed and assimilated. Food or aliment is the commencement of organization; it may be said, of life; for the first vital action of the germ is to absorb and assimilate nutritive matter, for the augmentation of germ material, and the formation of the germ mass, the first stage in the develop- ment of the organism; and the whole of organic or nutritive life is the repetition of its first commencing act. FORCES, OR DYNAMICAL RELATIONS. This word dynamics is derived from the Greek dvvaues, power, force, rule. It was confined for a long period to the science of mechanics, to designate the laws and actions of mechanical machines and movements of bodies. It has acquired, with the progress of science, a much more extended application. It is now the equivalent or synonym of forces, and is employed to express the science of acting and moving causes, not only of solids or mechanical bodies, but of all actions and move- ments whose cause is unknown. In this sense it is introduced into medicine; and in physiology, is applied to designate the forces of the living organism, or causes of its actions; and in therapeutics, is used by some to express the causes of medical action as dis- tinct from the medical substance itself. In the mechanics of the muscular system, the term is of as legitimate application as in common mechanics. The spinal nervous apparatus is a dynamical system, generating forces that excite and control muscular actions, that perform the mechanical functions of the economy. The direct meaning of the word force, synonymous with dyna- mics, derived from the Latin fortis, is strength, power, energy. It is used for want of a more fitting word in science to express an abstract idea, a result of a mental process of reasoning. The common experience of our senses teaches us that inorganic bodies, at rest, never move unless set in motion by an impulse derived from some other body, agent, or matter. It does not move of itself, Whatever produces the motion, is regarded as the cause of the motion, and the mind infers it exerts an action indicating a force as the cause of the motion or action. 28 OF THE HUMAN ORGANISM. But movements and actions are observed to occur often without any known tangible or perceptible cause of the movement or ac- tion. Of this es cause of action and movements, the mind forms an abstract idea by a process of reasoning, as a force or unknown cause, producing actions, movements, or, in other words, phenomena. Phenomena, actions or movements, of the same na- tures and characters, are constantly reproduced under the same conditions. The mind infers from this circumstance the existence of gonstant, persistent, and special forces. The term force has no other meaning—expresses no more than an unknown cause for known or observable phenomena. Phenomena, yecognizable by our senses, and comprehensible by the intellectual faculties, are numerous, various, and different. From their resemblances, coincidences, and differences, always permanent and consistent, they are capable of being arranged into divisions, classes, orders, genera, &c.: that is, the mind arranges and classifies phenomena according to the above circumstances of agreements and dissimilarities which are observed to exist in nature. : The forces to whose action the special phenomena observed in nature are to be attributed, are divisible into two classes: the physical or general, and the organic or vital forces. The first are classed and named by physicists, as gravity, light, electricity, mag- netism, and chemical affinity. These terms in reality express no more fin constant modes of actions, or phenomena: characterized by Mr. Grove as “ affections of matter.” They are the only forces recognized by physicists. Tio which, it appears to me, are to be added the second class, or vital forces. They are, 1st, organic, or formative force ; 2d, the spinal nervous excitor, and motor forces; ‘and 8d, muscular contractility, or irritability. Before proceeding further in this discussion, it will be necessary to make a short digression for the better understanding of this subject. It is a remarkable feature of intellectual operations, that from the earliest period of knowledge, of science, and philosophy, down to our day, two distinct modes of viewing this subject, two oppo- site sides of this question have occupied, and been presented by, thinking and observing minds. The ideas arising from these views have lain, and yet lie, at the root of scientific principles and philosophic thought, forming two antagonist schools. They generally date from two of the eminent intellects of Grecian OF THE HUMAN ORGANISM. 29 origin, Pythagoras, born 584 B.C. and Thales, 640 B.C. The first taught that matter was incapable of any action or movements from its innate powers. God was the power whence all natural phenomena proceeded through subordinate agents. This is the origin of the spiritual philosophy and the modern dynamic theories. The abuses and perversions of this doctrine by the ignorant, and those incapable of enlightened and broad intellectual views, have produced ontology in science, and superstition in religion. Thales, on the other side, regarded matter as possessed of inherent or innate forces and properties, from which all natural phenomena, and all objects, animate and inanimate, have proceeded, and con- tinue to be produced. This is the material school, and, pushed to its extreme results, leads to atheism. In our time, the first of these primary conflicting opinions is represented by the doctrine that matter is devoid of active forces, and that phenomena are dependent on imponderable forces acting on ponderable matter, changing, modifying its states, conditions, and forces; and are the sole causes of action or phenomena. The second is embodied in the doctrine that matter is endowed with active forces as properties, by and through which, all the phe- nomena of nature, its forms, actions, motions, molecular or in masses, are accomplished. This doctrine escapes from the inevitakle con- clusion to which it leads—atheism—in attributing, as is done by some, the possession of these properties by matter, as endowments conferred on it by the Supreme Creator. Modern researches have shown that the forces of nature, pre- viously enumerated, are correlative, cannot exist independent of, and are convertible into, each other. The conclusion from the above facts and views, is that what are termed natural or physical forces, are no more than modes of mani- festation of one force, one agent. In 1836-7, I advanced this opinion, and, in addition, that the phenomena of living beings were to so great an extent identical with the ordinary phenomena of physics, that “Physiology might very properly be designated as organic physics.” In 1848, Mayer, of Heilbron, promulgated the same opinion. But it was Mr. Grove, of London, who first, ina complete treatise, undertook to prove the truth of this proposition. In a 2d edition, 1850, he throws out the conjecture that the doctrine of correlation will apply in physiology; and cites muscular action and animal heat as probable instances. This very application of the 30 OF THE HUMAN ORGANISM. doctrine I had made the year previous, 1849, to animal mechanic force as correlative of heat, in a paper read at the meeting of the American Medical Association, held in Boston. This doctrine was announced by me as early as 1837, in a pub- lished lecture. This proposition was then laid down, “that the same causes and actions which in inorganic bodies constitute physics, in organic bodies constitute physiology, or, as it may be more aptly termed, organic physics.” The idea then broached, subsequently ripened into a complete development; and my lectures were arranged on a plan in con- formity to it. Dr. Carpenter, in the preface to the third edition of his General and Comparative Physiology, claims “ as more particularly his own,” the doctrine of the “mutual connection of the vital forces and their relation to the physical.” I indulge the hope that this statement of similar views promulgated by myself eighteen years since, annually repeated and so extended as to form a full section of my course, will not be considered out of place on this occasion, or subject me to the imputation of egotism. The doctrine of the correlation of the physical forces has been generally adopted; and consequently, if a clear insight has been obtained of the nature of any one or more of them, that of all the others must be similar or identical. Whatever theory is adopted to explain the phenomena of one must be applicable to the others. Now, as respects two of the forces, light and heat, physicists have, without an exception at this time, embraced the dynamical or undulation hypothesis. According to this doctrine, the phenomena of light and heat are due to motion or undulatory vibrations excited in an aerial fluid existing throughout the universe, occupying the interplanetary spaces, and penetrating and existing in the interstices, and surrounding the molecules of the densest bodies, whether inorganic or organic. This fluid is named the Ether. It is mentioned by Aristotle; Newton advocated the hypothesis, and employed it in solving some of his philosophical problems;. he estimated its specific gravity as 750 times less than the difference between the atmosphere and granite rock. Euler assumed that the ether is 36,000,000 times thinner, and 1,278 times more elastic than atmospheric air. The grounds of this hypothesis are by no means vague. It is clear, without any doubt, that in vision or seeing there must exist OF THE HUMAN ORGANISM, 81 some agent or body between the retina of the eye, the nervous sensitive tissue or membrane, and the exterior visual object. The retinal membrane is the portion of the eye that receives the direct impressions proceeding from the external body. In this impres- sion, in reality, consist light and color. It is not a single and simple membrane, but a complex one; it is composed of thousands of minute, independent and distinct sensitive spaces, or, as they may be regarded, associated retinas. Each one of these receives a separate, distinct impression, coming from each separate distinct point of the exterior body seen, a perfect miniature mosaic picture of which is thus represented on the retina, or is, it may be said, pricked into it by the rays of light; or, more properly, the undulations of the molecules of the ether. This body, this agent intermediate between external bodies and the retina, exists in the interior of the eye, diffused through all its tissues and interior media. It is the sole normal or physiological excitor of the special nervous sensibility of the retina, and the - nervous central optical organs, provided in the order of nature, shat animals may possess the function of vision. This is effected by the immediate relation this agent possesses with the nervous sensibility of the retina of the optic nerve and the optic lobes. The two must be closely related, and analogous or identical in their nature or innate constitutions. This accumulation of scientific probabilities almost amounts to a demonstration that a body or most tenuous fluid is present between all external bodies and the retina in the eye of animals. It is not the atmosphere, for it cannot penetrate the cornea, the lens, or the humors of the eye. Its presence would be injurious to vision by disturbing the course of the rays of light. Vision is not limited to the surface of our globe; it extends to the infinitely remote regions of space, and consequently the ether, whose systems of undulations or waves traverse those immeasurable dis- tances, and, impinging on the retina, cause light, or vision, must fill all space. . . The present philosophical hypothesis of physical or natural forces, presented in the preceding summary, in the present state of our knowledge must be accepted as the truest exposition of the causes of natural phenomena. Having it before us, we are better prepared to examine the relation in which they stand to the forces 32 OF THE HUMAN ORGANISM. that, in the living organism of man, are the causes of its special actions and phenomena. These forces are manifested in the organic actions of which they are the causes, and must be studied and interpreted through them. In this manner alone can their identity or diversity, their correla- tion or irrelevancy with the physical forces be correctly appreciated and determined. ORGANIC FORCES. The only forces and phenomena that can properly be named organic or vital, are such as are exclusively found in organized and living beings. Two series of phenomena alone possess this charac- ter. They are, for the first series, the production of a formless plastic matter, and the development of typical organic forms—tis- sues, organs, organisms—from this formless material, and their maintenance by growth and nutrition. For the second series, they are.the nervous excito-motor forces, and muscular contractility. Sensibility and intelligence, or the psychological actions, are nervous phenomena, to which the term force, and the actions of force, are not applicable. ‘The first series is common to all organic, or living beings—vege- table and animal: the last exists exclusively in animals. As the causes of the above phenomena present special characters that distinguish them as much from the physical forces as they are themselves distinguished from each other, I can perceive no valid reason why they should not be placed in a separate class, named organic forces, as they are most clearly the antecedents, or causes of especial organic phenomena, or actions. Guided by the light of our present philosophy, the organic or vital forces are regarded by many physiologists, among them Dr. Lehmann, the author of this work, as correlative of the common forces of the inorganic world. I now proceed to an investigation of the phenomena character- istic and distinctive from all others, that are specially organic, that are exclusive to living beings and to animal life. The first is— ORGANIC, FORMATIVE, OR VITAL FORCE. This force presides over all organic beings-vegetable and animal. No organic form or action, or any phenomena of life, can have OF THE HUMAN ORGANISM. 33 existence in its absence. It is as perfect in the lowest and simplest as in the most complex and elevated of organic beings; in the monad as in man; in the cell vegetable as the oak; in the lowest form of tissues as in the most complex and developed. Organic force is the first cause of organic forms. Modality, or the production of organic forms from a formless, plastic fluid, or organic matter, is its distinctive characteristic. It is embodied in the germ. No living, no organic form, endowed with vital activity, ever had existence, or can exist, independent of germs. Every organic form is the realization, in an appropriate and special or- ganic material, of an ideal model, or type, of that form. This force is not self-acting. It is dormant like electricity, caloric, light, until excited into action. A definite temperature is an indis- pensable condition. In warm-blooded animals, 100° F. to 102° F. in the blood, is the normal temperature. Below this, say 96° to 97° F., germ development is imperfect, and arrested in its first stage. ORGANIC, OR VITAL ACTION. The result of the activity of organic force, excited by caloric, or heat, is the production of an organic action, life or formative action, summed up in the term nutrition, The nature and constituent factors of this action are now to be analyzed. It is a compound action, composed, Ist, of the production of an immediate, or special plastic organic matter, from a crude or proto- plasm ; 2d, of the creation, or production of special organic forms from the organic plastic matter ; 3d, of the death, or chemical dis- integration of the organized substance of the interior structures, and its transformation into simpler and lower combinations, form- ing the matters and substances of the excretions; 4th, the moulting, desquamation, or casting off the dead and recremental material of the organic structure of the internal and external surfaces, in com- munication with the exterior world. At the same time, new or- ganic forms, and organized structure are being produced. The organic plastic matter is special for each tissue—musculin is the material for muscular tissues, neurin for nerve tissue, the vari- ous gelatiniform materials for areolar, serous, fibrous tissues, &c. Organic forms are equally various. Lach tissue and each organ has its speciality of form, and arrangement of its component parts. These component parts, each having a special plasm and a distinct organization, are interwoven with the utmost intricacy, necessitating 3 34 OF THE HUMAN ORGANISM. different and complicated chemical and constructive processes simul- taneously occurring in the same place and same moment of time, which are utterly inexplicable and impossible as the operations of the physical forces. The organic form produced is maintained amidst the incessant decomposition of the organic substance in which the type of form is expressed. This is the most significant and characteristic fact, of the organic or life action. It individualizes and separates it from every other kind of action. All inorganic forms are maintained: by the absolute repose, or equilibrium of molecular actions. The form is destroyed utterly, when molecular actions are excited. Incessant molecular activity, and persistence of form, are the essentialities of organic, or life action. The cessation of the special molecular activity of living structure, is productive of the cessation of organic, or life action: it is death. The organic force disap- pears; chemical affinity, that was forced by it to effect special com- binations of chemical elements, to form special plasmata, is now set free, to exert its natural tendencies, and the result is putrefac- tion, if the temperature be such as to excite it into a certain degree -of activity. An organic action analyzed, reduced to its component phenomena, presents evidences of the combination of the following series of actions and phenomena :— 1. Organic, or formative force, producing, creating it may be said, organic forms, or manifesting modality, stamping the form after an ideal type of tissue, or organ. 2. Chemical affinity, chained, con- trolled, and forced into, the formation of special chemical combina- tions and formation of plasmata. 3. ‘Chemical disintegration, retro- grade chemical products to be eliminated, or the dead organic material desquamated, and thrown off from exterior surfaces. This series and union of forces and actions, entering into an or- ganic, or life action, can occur and exist only under absolute special conditions. These are, 1st, the presence of organic force embodied in a germ; 2d, a crude organic plasm; albumen in animals of the higher classes, capable of transformation into special plasmata; 3d, a definite temperature of 100° to 102° F.; 4th, oxygen, to effect, by its direct action, the chemical decompositions of the organized mate- rials wasted in the organic actions, and indirectly accomplishing the same result by the thousand acts of oxidation occurring in the organism, generating its temperature, and maintaining the endless OF THE HUMAN ORGANISM, 35 chemical actions required for the production of the secretions, ex- cretions, and numerous other products of the economy. The preservation of the above conditions of organic, or life actions, is the object of dietetics and regimen, or art of preserving health; and the investigation of those conditions, in all their varied rela- tions, constitutes the science of hygiene. Their restoration, when in an imperfect state, or in any mode disordered so as to con- stitute disease, is the object of therapeutics and the practice of medicine. NERVOUS, OR MECHANIC FORCE. This force is wholly dissimilar, in every respect, to organic force. The character and object of this force, is to work the machinery of the organism so as to bring into operation the mechanical power of the organism required for various objects indispensable to its existence, to maintain the conditions of the organic actions, and for the pur- poses of animal existence in the creation. Its most perfect mani- festations are in animals of the higher classes. This nerve force is generated in the spinal cord, or axis, and the cerebral axis, medulla oblongata, crura cerebri, thalami, and corpora striata. These organs constitute the dynamic, or force generating apparatus. Mechanic nerve force is to the animal organism what steam is to the locomotive. The dynamic apparatus, or cerebro- spinal axis, is in the organism what the boiler is in the steam engine. This statement exhibits, in strong relief, the difference between organic and nervous force. The first exhibits no mechanic power in the organism, produces no direct mechanic effect. It is limited to the molecular actions required for the production of plastic matter and organic forms. ‘The spinal nerve force is exclusively manifested in the mechanical movements of masses, as of the circulation of the blood, the expan- sion of the chest in respiration, in movements of the limbs and body in locomotion, and in the production of other mechanical effects, Notwithstanding these wide and strongly marked differences between them, the two have been, and continue to be, confounded together as one—as identical. This error, regarding nerve force as an organizing force, as the cause of all organic phenomena, was committed by Oken, by Carus, by Klencke, by Unger, by Lamarck, Legallois, and Dutrochet, and is yet entertained by many French 86 OF THE HUMAN ORGANISM: and German physiologists. It is advocated by a distinguished teacher in this city, who bases many of his pathological views on this hypothesis. This error arises from not analyzing the complex phenomenon of an organic action, and of not studying it in its first inception in the formation of germ matter, and development of the multiplication of the germ into the embryonic germ mass, the first stage of the animal organization; and further, the ignoring of the process of development in the seeds of plants, and of their organ- ization. To find the truth, it is not to be sought in complicated phenomena, but in the simplest; in which its expression is clear and distinct. Nerve force has been shown to be limited to an apparatus. Actions or phenomena requiring an organ or apparatus are, and must be, functional. Nerve force is, consequently,.a function or office of the organs and apparatus on which it depends—the spinal dynamic apparatus. The apparatus itself is constructed by the formative organic actions directed and maintained by organic or vital force. : Spinal nerve force is restricted to two series of phenomena—ex- citation 6f muscular mechanical actions and of general sensibility. Organic or vital force is universal in the organism; it requires no apparatus. It is present in every act of life, in every tissue, in the simplest as in the most complex: if is active in every living organic molecule. Spinal nerve force is composed of two distinct forees—an excitor force and a motor force. Hach has a separate nervous apparatus or combination of organs for its manifestation. Excitor Nerve Force. The first, or excitor force, has a close affinity with sensibility; they are constantly-confounded. Itis an excitor of general sensibility, as well as of motor force. It is somewhat difficult to distinguish, between them. Sensibility may, possibly, be no more than the mental perception and consciousness of the excited state of the excitor force, or of the afferent nerves. The excitor force, like special sensibility, is in contact with the exterior world. Impres- sions on the skin or mucous membranes excite it into action, as cold air, or water sprinkled on the face, recalling respiration in fainting, and worms or indigestible food in the alimentary canal, causing convulsions or spasms. OF THE HUMAN ORGANISM. 37 Certain irritations and impressions also of which we have no consciowpness, excite its action normally, as in respiration, main- tained by the unconscious presence of carbonic acid or black blood in the lungs, and abnormally by splinters lodged in fascias, causing no sensation, yet producing tetanus after the wound has healed. It is independent of the brain or cerebrum. This is shown in complete palsy of sensation and motion, caused by injuries to the spine. The lower extremities will be drawn up violently, from tickling the soles of the feet, though the patient is unconscious either of the sensation or the movement of the limb. The apparatus of the excitor force are the posterior ganglia of the spinal marrow or axis, of the medulla oblongata, and nerves commu- nicating between those nerve centres and exterior and interior sur- faces. These nerves have ganglia on their roots, which is a distin- guishing character, though their office yet remains unknown. All impressions on, or states or conditions of surfaces are transmitted to the excitor ganglia or the posterior nerve centres of the spinal cord and medulla oblongata, Motor Force. The second or especial relation of motor force is with muscular contractility, and its function is to excite muscular contractions from which result mechanical effects. The apparatus to which it belongs, and through which it acts, are the anterior ganglia or nerve centres of the spinal marrow or axis and medulla oblongata, and the nerves that place them in connection with the muscular system. These nerves have no ganglia at their roots. This force is the direct physiological excitor of muscular contractility ; and, in the normal state, is the only proximate cause of muscular action. Excitor and motor force are, in the organism, constantly asso- ciated in action. The continuous play of the respiratory muscles, of the heart, of the muscular coats of the stomach and intestines, is maintained in this manner. They are involuntary machine or automatic actions. The two forces are not identical, and often act independent of each other. Irritation, or any excited state of excitor nerves and surfaces, will cause pain without producing muscular actions or influencing motor force, as in some pure neuralgias. Sen- gations and muscular actions sometimes occur simultaneously, are 88 OF THE HUMAN ORGANISM. connected, but more frequently sensations are unattended with muscular actions. 9 The nervous force exhibits in some of the inferior animals remarkable varieties of susceptibility to the impressions of external bodies. The Batrachians, when placed in water of the temperature of 100° to 110° F., are immediately thrown into a state of spasmodic rigidity ; a tetanic state is developed, which in a short time would prove fatal. If in this state they are thrown into water of the ordinary temperature of spring water, 45° to 48° F., the spasm immediately ceases, and they resume their usual activity. In the Ophiura, or Luidia, a species of the starfish, the very reverse of what occurs in the frog is observed. If taken from sea water, and plunged into fresh water of the same temperature, they die instantly in a state of the strongest tetanic extension and rigidity. Motor force, associated with and excited by excitor force, pro- duces what are called reflex actions. This name, though generally employed, is objectionable, as it involves a hypothesis which has not been verified. Excito-motor actions and automatic actions are preferable, as they indicate positive phenomena. Motor force is also excited into action by other causes, the whole forming four classes of actions. The first is the excito-motor or automatic actions as above de- scribed, constituting involuntary actions. The second are the excitements of the motor force by the emo- tions, constituting emotional actions. The third are the excitements of the motor force by acts of the mind, attended with a consciousness of the mental action, and are called voluntary actions. By these actions is carried out some determination, or is accomplished some desire or purpose, or is fulfilled some idea. The fourth is a new class, unknown to metaphysicians, but recognized by physiologists. Motor muscular force is often ex- cited by a fixed, strongly impressed and vivid idea, without that active participation of the consciousness that is called volition. Hence the individual is unaware of the cause of the muscular action, and in some instances is unconscious of its occurrence. The nervous excito-motor or mechanic force is not constant; it varies incessantly. The apparatus generating itis exhausted by prolonged muscular exertions. This state is expressed by a sense of weariness, lassitude, or fatigue, according to the degree of ex- OF THE HUMAN ORGANISM. 89 haustion induced. It is renovated by repose, from which proceed feelings of vigor and activity. The following are the conditions indispensable to its generation and normal action :— 1. Gray neurine vesicles grouped into centres or species of ganglia in the posterior and anterior cornua of the spinal axis and in the medulla oblongata. 2. Nerves communicating between interior and exterior surfaces and the posterior ganglia of the spinal axis—afferent or excitor nerves; and nerves communicating between the anterior ganglia of the spinal axis and muscles—efferent or motor nerves. 8. Red blood corpuscles, in the proportion of 1380 to 140 to 1000 of dry bload, or 510 to 520 of liquid blood. 4, A temperature of 100° F. in the blood. The identity of electricity and nervous force is a favorite suppo- sition with many writers at this time. The facts relied on are far from being positive. Those of Matteucci and Du Bois Raymond possess the largest amount of probability, but are not absolutely demonstrative. Molecular action is always attended with electrical phenomena. This kind of action is a constant characteristic of vital activity : and in those tissues and organs in which molecular action is ener-. getic, electric phenomena are the most clearly manifested. Every living organism, as a whole, and in its several structures, is an electro-genetic apparatus. During life, the muscles, and the mucous membranes and skin, exhibit, with the galvanoscope, the most marked and highest evi- dences of free electricity. The nervous structure fails to affect this instrument in a decided manner, though the more delicate sensitive- ness of “the prepared frog’s leg” proves its existence. This fact tends rather to show a less degree of electrical development in nerve structure, corresponding with slower molecular changes of organic substance, than in muscles and mucous membranes. Du Bois Raymond has demonstrated, by the peculiar apparatus he has constructed, and by his manipulations, that dead nerve struc- ture exhibits a feeble electric current. This can scarcely be con- strued as an evidence that the nerve force of the living apparatus is electricity. There is also a source of fallacy in the experiment that has not been noticed. Spallanzani had observed the fact that organized structure, when dead, until putrefaction has commenced, 40 OF THE HUMAN ORGANISM. continues to exhibit the constant phenomena of living structures, the absorption of oxygen and elimination of carbonic acid. Robin and Verdeil assert that they have verified the correctness of this obser- vation, This chemical action must of course generate electric currents. Although the proofs of the identity of nervous force and elec- tricity remain as yet inconclusive, there is every reason to regard as probable a correlation between them; and that nervous force belongs to the same class; that it is, in fact, a special modification of the physical forces manifested in living organisms, and adapted to the special class of mechanical actions in them. It is ether transformed into nerve force, or this last is itself a modifieation of ether. REMARKS ON DR. LEHMANN’S DOCTRINE OF VITAL FORCES. BY 8S. JACKSON, M.D., —~ PROFESSOR OF THE INSTITUTES OF MEDICINE IN THE UNIVERSITY OF PENNSYLVANIA. THE foregoing views respecting the forces of the organism are at variance with the doctrine of the author of this work, Dr. Leh- mann. They are the opinions I formed early in my professional studies, and have been since entertained by me. The conviction of their general truth has strengthened with time and increased knowledge. The facts and arguments of Dr. Lehmann have been carefully considered and weighed, but have failed to convince me of their correctness, or to weaken confidence in my previous con- clusions. It is a fault not unfrequent with those absorbed in the pursuit of the positive sciences, and accustomed to find the objects of their researches subject to the application of fixed laws, and their diffi- culties solved by experimental demonstration, to expect that simi- lar means and processes are available and applicable to all other sciences. Habituated to reach certain results in the investigations of their limited range of phenomena, they demand the same con- ditions in those infinitely more complicated and widely different. The confidence with which they are inspired, leads them to assume that man’s intellect is the measure of the universe, and that no truth can have a depth outreaching its capacity, or is placed beyond the grasp of its logic and comprehension. The unknowable is not acknowledged, and any hypothesis is preferred to a concession of a mystery. 42 REMARKS ON Yet, a moment's reflection must show, that the causes of the laws whose unerring certainty they boast, are unknown, are mysteries, and must forever remain as such. It is the error of Dr. Lehmann, and it is common to most physicists, more particularly chemists, that he views the complex phenomena of life in one aspect—in their chemical relations. The physiological, or especial organic phenomena, are entirely neglected or overruled, though the settle- ment of the question in discussion must depend almost exclusively on a thorough investigation, not of the mere organic substance and its nature, but of the sole material fact to be determined—the proximate cause, or origin of specialized individual organic forms— of the different organs and organisms of living beings. The principal arguments of Dr. Lehmann are battlings with shadows. The former physiologists were generally ignorant of chemistry, and could not recognize chemical facts in the living organism. They were denied, and the matter of the animal eco- nomy was believed to be exempt from the laws of chemical affinity. All its actions were imputed to vital forces, exclusively existing in the organism. ‘These opinions are attacked and refuted, though no longer advocated by modern physiologists. The identity of the chemical actions of living beings and of in- organic bodies is now generally admitted. It is granted “ that the same chemical laws preside over the constitution and transforma- tions of different compounds, whether organic or inorganic.” Ad- mitting the accuracy of this proposition, it does not authorize the assertion, that “all the differences observed between these two different classes of bodies are accidental, relative, and have nothing essential.” Will it be affirmed that when an unfecundated egg is placed in the conditions for incubation, and the result is its putre- faction, while, in a fecundated egg, the albuminoid contents are transformed into blood, muscles, viscera, nerves, brain, heart, ves- sels, and organs of sense, and it is endowed with special sensibilities, with consciousness and voluntary movements, that these two classes of phenomena are only accidental, relative, and non-essential ? It is certainly true, that chemical affinities and molecular actions are indispensable to produce the varied special proximate organic materials of the fluids, tissues, organs, and the living organism of the chick. But, without the presence of the germ, a fact neglected by Dr. Lehmann, this extraordinary play of specific chemical affini- ties, and specialities of chemical actions, and the development of some DR. LEHMANN’S DOCTRINE OF VITAL FORCES. 43 hundred organic forms, included in the living being, from the form- less organic matter, could not have occurred. Certainly, here are displayed, in the two classes of bodies—inorganic and organic— differences that are not accidental, or relative, and that are essential. The same general facts are observed in the germination of seeds. If the germ cell at the hilum of a seed be artificially ruptured, and it be placed in the same circumstances of germination with a per- fect seed, the first will rot, while, in the other, are formed dextrin, grape sugar, cellulose, and albuminoid compounds; and these or- ganic matters are developed into the tissues and organs of a perfect plant. In these, which are but single series of organic phenomena, the most absolutely marked and undeniable differences are to be ob- served between the two classes of bodies: it is impossible to regard them as “accidental, relative, and non-essential.” These phenomena have occurred in living beings with absolute constancy, in all generations of animals and vegetables, and are so completely under the control of positive law, that any one, or all of them, can be predicated and foretold with as much certainty as any chemical or physical action. Another argument urged as conclusive is the following: “ We should not lay down a new force, a general specific cause, until we have eliminated all other possibly operative forces from the group of phenomena in question. A proof of the existence of a purely yital force is hence only to be obtained by an exclusion of every physical force.” A full assent is given to the conditions of the argument; and it is affirmed most positively that the only phe- nomena—the exclusive attributes of a vital or organic force—the creation from a liquid formless plasm of typical organic forms, and organic instruments to execute physical, chemical, mechanical, and dynamical actions, in the living organism, which are operative only during life, cannot be explained by any one, or all of the physical forces combined. They are absolutely excluded. Let the subject be expressed in special terms, and it is affirmed that neither heat, nor light, nor electricity, nor magnetism, nor gravity, can construct an eye, can form a retina, heterogeneous in its organic materials; complicated in the distinct organized anatomical elements of ‘its structure, and endowed with a special sensibility—light and colors— manifested normally only when excited by a special external agent, 44, REMARKS ON the luminiferous ether. Nor can they generate the black pigment cells of the choroid coat, for the express purpose of suppressing the luminous rays, which have accomplished their impression, with- out which there can be no distinct vision; nor cause the formation anterior to the retina of the vitreous humor and the crystalline lens, admirably adapted in form, shape, and density, to refract the rays of light into a focus, the distance from the retina calculated so truly, as to subtend on it a visual focus, in which is a perfect repre- sentation of external bodies. The formation of this organic optical apparatus, constructed in the foetus included in the ovum or uterus, excluded from the direct operations of the physical forces except heat, it is affirmed, is absolutely inexplicable by the physical forcés, or by any known physical process or actions. The insuperable difficulties presented by these facts, it is sought to evade by assuming that, as the causes of physical actions are unknown, and that new physical phenomena may be discovered, a resort to a new force is useless and unscientific. But it will not be pretended that the causes of physical actions will ever be better known than they are at present; and, whatever new physical actions may be discovered, they cannot differ in their nature from those of the present known physical actions. They will be unable to furnish any new light to solve the nature and origin of phenomena that reach far beyond the range of the physical forces; to which physical forces and actions are accessories, but cannot hold the relation of productive causes. From the admission by Dr. Lehmann, in his argument “that a new force may be assumed in science, whenever groups of pheno- mena are inexplicable by any known forces,” the assumption of an organic or vital force, as distinct from physical forces, and as presiding over the developments of the organic forms of living beings, is an authorized and legitimate deduction. ‘A third argument, and the last that will be noticed as having a bearing on the question is, “that the idea of a vital force is illogical; for a force is merely the abbreviated expression of a law from which the causal connection of certain phenomena may be deduced; and that a vital force corresponds to no law.” This statement proves that Dr. Lehmann has not investigated the physiological facts of embryology or organic development, or he could not have so broadly asserted that the vital or organic force DR. LEHMANN’S DOCTRINE OF VITAL FORCES, 45 corresponds to no law, and is not a necessary cause of multitudi- nous consequent phenomena. So far is this statement from being correct, it may confidently be asserted that the evidences of law, of causal connection and depend- ence are as strong, as palpable, in the phenomena, the direct results of organic or vital foree—those of organization—as are to be found in any of the physical forces. A few facts will prove this position: Prevent the spermatozoon from reaching the egg, no monadiform germ cell, the primary form of all animals, is produced. Let this germ cell be artificially broken or injured, and no blastoderm will. be formed; injure the blastoderm, and either no embryon and chick will be developed, or this last will be imperfect. Here are law and causal dependence and connection. Professor Owen, in his Hunterian Lectures (ed. 1855), has demonstrated that “every animal, in the course of its development, represents some of the permanent forms of animals inferior to itself, but it does not successively repeat them all, nor acquire the organization of any of the inferior forms which it transitorily typifies. One organic form, the microscopic infusorial monad, is either permanently or transito- rily represented throughout the animal kingdom. Other forms are represented less exclusively in the development of the animal king- dom, and may be regarded as secondary forms. These are the polype, the worm, the tunicary, and the lamprey. They are second- ary in relation to the animal kingdom at large, but are primary in respect to the primary divisions or provinces.” In the above statement is demonstrated the subordination to a law, to a great overruling force in the organic world, on the pre- sence and action of which depend the type of organic forms, and the order of development of animal organisms. In the immutable harmony of organic nature, in the unchangeable characters that mark the distinétion of species, genera, families, orders, and classes, are displayed unmistakable signs of the opera- tion of laws, of causal connections and dependency. Cuvier demonstrated the persistence, as he believed the permanency of species, and certainly the permanency of genera and families, by his anatomical researches. Gcethe, as it were by a philosophical inspira- tion, had previously conceived and evolved the idea of the “Unity of Organization.” In 1790, he enunciated the generalization, that “all the parts of an animal, taken together or separately, ought to be found in all animals.” This deep-reaching thought of the 46 REMARKS ON philosopher anteceded the empirical demonstration of the anato- mist. Oken and Geoffroy St. Hilaire struck on the same vein of thought, and by their researches and investigations established its truth, and made it the crowning fact of organic science. This widest and boldest generalization in natural science is, in the organic world, what Newton’s law of gravity is in the universe. In the infinitude of the phenomena and forms and beings that compose the organic world, the universality and dependence of causal connections and, special law, and in the evidences of its ever-during beauty, order, and harmony that pervade organic nature, is demonstrated the supremacy of a dominant force, far transcend- ing the physical forces in the higher nature of its productions, and more exalted character of its powers, influences, and relations. In its operations it appears as a ray emanating from the divine intelli- gence, stamping on each created living being types of organic structures, a revelation in material forms of the creative ideas of the Eternal Artificer of the universe. That force cannot be more appropriately expressed, than as the Organic or Vital force. This conclusion will no doubt be condemned as unscientific by physicists generally. In the present state of knowledge, the inexplicable and inconceivable in the physical, and still more in the physiological sciences, constantly cross our path, and arrest our investigations. Knowledge, science, philosophy, have their ultima thule, beyond which lie the vague and dreamy realms of conjecture. The sciences are the facts or phenomena discovered in the order of their connection, and interpreted by man’s intelligence, such as they exist in the world exterior to itself. Indissolubly connected, they form the circumference of a vast circle, each advancing as it progresses, and is developed like radii, and meet in one common centre. That centre is the incomprehensible, the infinite; it. is the first Eternal Cause—the creative God! It is always to me an assurance that the line of inquiry pursued is the true one, when its direction tends obviously to this termina- tion. Whenever investigation is turned from this course, it is invariably lost in misty and groundless hypotheses. In dissenting from the author's views of organic or life force, there has been no purpose of disrespect, or intention to undervalue his knowledge and the authority of his opinions on the special branch he has cultivated. It has been rendered necessary by the manner in which the subject has been treated. Almost exclusively DR. LEHMANN’S DOCTRINE OF VITAL FORCES. AT physiological, it has been handled as a chemical question. All that has been urged by the author as to the extent, variety, and import- ance of the chemical actions and influences of chemical laws in the living organism is perfectly just; but to force chemical affinity and its laws from their appointed ordinances in nature, is not correctly scientific, and leads to serious errors and misconceptions. Yet such a perversion, it strikes us, takes place when physics and chemistry are summoned to explain the origin and the permanent constitution of the typical forms of organization, differing so widely from the molecular processes and actions, exclusively the results of their special activity and energies in the plan of creation. In adopting the handbook of Dr. Lehmann as a manual of organic chemistry for the use of the students of the University, and in recommending his original work of PHYSIOLOGICAL CHEMISTRY for their more mature studies, the high value of his researches and the great weight of his authority, in that important department of medical science, are fully recognized. Buse ‘ eh i B KS ee: ‘ é ‘ i , a: is : HANDBOOK OF PHYSIOLOGICAL CHEMISTRY. f GENERAL OBSERVATIONS. By Physiological Chemistry we understand the science of the chemical processes in the living organism: this science will hence have to deal not only with the chemical principles of living organ- isms, but mainly with the mutual reaction of the chemical elements and the influence of the external world on the same in the course of the individual life processes. We consider so-called Pathological Chemistry, not as a separate science, but as an integral part of Physiological Chemistry, because no sharp boundary can be drawn between the two, and because, further, the laws which find their application in the illustration of life-phenomena are the same in physiological and pathological cir- cumstances, and the difference of the phenomena depends entirely on the difference of the external conditions. Physiological Animal Chemistry and Physiological Vegetable Chemistry must, on the contrary, be strictly separated from each other, although both sciences have many points of contact with each other: as the objects, so also the most essential chemical pro- cesses whose exploration is the subject of inquiry, are different throughout. The closer relations, in which Animal Life stands to Vegetable, form a separate chapter of Chemical Zoophysiology. Physiological Animal Chemistry divides itself into three sec- tions: the science of the chemical substrata, the science of the ani- mal fluids and tissues, and the science of the zoochemical processes, This is no arbitrary systematic division : it follows of necessity from the nature of the subject. 4 50 PHYSIOLOGICAL CHEMISTRY. The first part, in some measure the basis of the whole of Physi- ological Chemistry, the science of the chemical substrata of the animal frame, is called, in the narrower sense of the term, Zooche- mistry. We cannot understand the chemistry of the metamorpho- sis of animal tissue in all its forms, if we do not know exactly the substances which play their parts in the animal body, «. e. both its actual constituents, and those substances which, adduced from without, come into reciprocal action with the former. For a successful treatment of zoochemistry two points of obser- vation must be maintained, viz: the chemical and the physiological. Without the most exact knowledge of all the chemical relations of - a substance, a judgment of its physiological importance is impos- sible: but the bare announcement of all the facts derived. from pure chemistry, which the individual substances accidentally present in animal bodies exhibit, is still not zoochemistry; for the most important point of observation, the physiological, is wanting. Zoochemistry should not be a compendium of facts and theories amassed from pure chemistry ; these must be taken, on the contrary, as fully known beforehand, when the question should be as to their physiological relation. We therefore, in what follows, pass over entirely that part of zoochemistry which would be nothing more than a limited excerpt from Organic Chemistry; for not only those substances must be known which are accidentally constituents of the animal organism for the study of zoochemistry, ‘but it de- mands, at the same time, a thorough acquaintance with the whole of theoretical chemistry. The physiological point of observation, which we must main- tain in zoochemistry, consists only in the relations in which each individual substratum stands to the other constituents of the animal organism during life: according to these we are to determine the value of the individual to the whole, that is, its physiological func- tion. Our judgment is to be guided in this respect by the investi- gation of the mode of occurrence, origin, and destruction of each individual zoochemical substance. By the second section of Physiological Chemistry, 7. e. by the science of the Animal Fluids and Tissues (Phlegmatochemistry and Histochemistry), we obtain already data which afford us a deeper insight into the movements of animal matter: for we see physiolo- gical processes taking their course immediately in the animal fluids and tissues. Both of these, tissues and fluids, are as well factors as Re Sa S- TE SEe GENERAL OBSERVATIONS, 51 products of the changes of animal matter. Their investigation is, however, accompanied with much greater difficulties than that of the zoochemical substrata. One of the most important difficulties is, that here we generally have to do with complicated mechanical mixtures whose separation lies often beyond the limits of possibility. In the tissues, different organic elements are stored up together: hence nowhere more than here is there necessity for a microscopico- mechanical analysis; but in the fluids, and especially in the most important of them, the blood, we find morphotic constituents, not mechanically separable, the microscopical investigation of which must precede all further research. The determination of the chemi- cal substances which belong to these morphotic elements, and of those which are only dissolved in the fluid surrounding them, is among the most difficult tasks of zoochemical analysis: and yet this circumstance is of the greatest importance in the physiological determination of the results of chemical research. Without a knowledge of the morphotic constitution of the blood, without an insight into the division of its chemical constituents into cells and liquor sanguinis, we would have only very partial grounds for the construction of a physiology of the blood. When we have investigated on all sides the physiological and chemical relations of the fluids and tissues in the same manner as in the simpler substrata of the animal body, a point must next occu- py us which is of the highest importance for physiology. This point consists in the quantitative relations of the formation and secretion of the objects in question. It is a maxim which holds good in all natural sciences, that only through the establishment of certain numerical relations, can a theory attain its full scientific worth, and authorize more general views. It is self-evident that we must have investigated the amount of the individual factors of animal tissue- metamorphosis, before we could allow ourselves a decided opinion on their activity, and the part performed by them in the general life-functions. While chemical and physiological facts give us so many conclusions on the function of this or that animal fluid or tis- sue, it is by ascertaining these amounts that we obtain not only a measure, but also the most secure position for judging, of the phy- siological importance of the object in question. The physiological function of an animal fluid or tissue ts, however, exactly equal to tts chemical constitution, just as the physiological im- portance of each individual chemical element is entirely dependent 52 PHYSIOLOGICAL CHEMISTRY. on its chemical quality. On this account, the immediate relations which exist between chemistry and physiological function must be more closely considered in the physiologico-chemical science of the fluids and tissues; while there must remain for chemical physi- ology proper (the third part of Physiological Chemistry) to pursue the movements of animal matters as a whole as well as in all their closer and more distant relations to each other and to the general life-functions. By the consideration of the physiological value of each fluid and tissue, which rests entirely on its chemical qualifica- tion, we are then only collecting the stones for founding the physi- ology of the animal tissue-metamorphosis. The third division of Physiological Chemistry embraces the sci- ence of the Zoochemical Processes, i. e. the chemistry of metamor- phosis of tissue, of nutrition and secretion. In the establishment of these relations consists the highest task of our science; here the causative connection of all the chemical manifestations accompanying life is investigated, and the necessity of the consequences presented in the. combination of all the chemical phenomena of life. On this field of our science we dare not content ourselves, for the attainment of this object, with parallelizing chemical character and function as in the science of the fluids; it is necessary here to take into account general physiological relations. When we cannot observe the inner mechanism of a great organic whole, we are accustomed, by establishing certain numerical rela- tions, to make for ourselves a safer basis for further investigations ; hence it is the earliest and still the safest way which has been devised to establish a physiology of the animal tissue-metamorphosis, by in- vestigating the matters taken in and given out by the organism, the quantities of the individual secretions and their relations to each other, the quantitative partition of each of the separate elements, and their distribution in certain proportions in different fluids, to establish exact numerical values, which form in a manner the solid framework within which the results of further investigations prose- cuted in other ways may be registered. These are the statistics of the metamorphosis of animal tissue. They afford us absolute proofs of many physiological propositions, by showing their necessity ; but since they lead only to absolute assertions, we only learn by them that' the facts are so, and not otherwise, but not why they are so— z. e. we obtain by the statistical method no deeper insight into the closer connection of the facts established by it. GENERAL OBSERVATIONS. 53 Another way to the same end is the comparative analytical or chemico-experimental method; this consists in an imitation of animal chemistry out of the organism, in a comparison of certain organico- chemical processes with apparently analogous zoochemical processes. The idea of comparing the processes of fermentation and putrefac- tion with the phenomena of life, has always guided the researches of physiologists. Later times have comprehended this idea to a greater extent. In the degree that the views of those chemical phenomena have been generalized, have we succeeded in attempting a more useful application of them to the vital processes. Certain chemical processes, which form a great series of consecutive pheno- mena, show undeniable resemblances to the course of certain chemi- cal processes in the living body, so that we may hold ourselves justified in assuming the same chain of causes in the corresponding life-processes. It follows, hence, that the conclusions to which this method leads are founded upon analogy. Owing to the imperfection of the argument from analogy, it be- comes us here especially to avoid the errors into which Physiology has already often fallen in some of its departments by the misuse of this logical form; so much the more care is necessary, as this method has hitherto been the most productive for Physiological Chemistry, and as, on the other hand, it has led to many crude chemical and entirely erroneaus views. The third method of investigation accessible to us is the physio- logico-experimental. The theatre of actual physiological experi- ments is the living body itself; it is of great use to make its vital actions appreciable by our senses under circumstances which at the same time allow of an opinion as to their causative connection. However decisive conclusions this experience of the most direct observation promises to science, and in part really performs, it has as yet done least among the modes of investigation adduced. The great pliancy which life phenomena are capable of, prevents in many cases the communication of a categorical answer by nature, to whom in physiological experiments we prefer to propose a disjunct- ive case for decision, a “whether—or” as a question. Physiological Chemistry is generally confined to those processes in the living body which belong to the so called vegetative sphere, and in fact those parts especially of Physiology demand elucidation from it which concern the processes of nutrition and secretion; but its realm is far more extensive; for in all the processes of life; in 54 PHYSIOLOGICAL CHEMISTRY. all animal actions, chemical affinity participates simultaneously with other forces. That, parallel to the activity of the muscles, chemical processes take their course, no one doubts; that the nervous system could display its activity without simultaneous chemical action, is not to be believed; in short, no function, no process, no phenomenon occurs in living bodies without chemical force as the cause or means ; hence, e. g. every disease must be accompanied by certain chemical alterations. As in the living organism no force exclusive of this, z. e. no so- called vital force is to be proved, all animal phenomena must be referred to fixed physical and chemical laws; the investigator of nature will recognize in these only the explanations of life phe- nomena. The time will come, and is no longer distant, when the entire physiology of animal life will be resolved into Physiological Physics and Physiological Chemistry. ZOOCHEMISTRY. ORGANIC SUBSTRATA OF THE ANIMAL ORGANISM. Ir is a proposition fully confirmed by the later investigations of theoretical chemistry, that no actual difference exists between organic and inorganic bodies, and that all the differences which were for- merly presented as actual between the two classes of bodies, are only accidental peculiarities, limited by no other laws than such as have their force in inorganic chemistry. Those differences which in fact crowd upon us in comparing organic with inorganic bodies in no small number and very decided manner, are then not based upon forces different in principle, or (as many philosophers believed) in a peculiar element, a so-called organo-genium, but arise from the multiplicity of forms often passing into each other, aud correspond to the more prominent extremes of series of quali- ties frequently intersecting each other. In considering the differences of chemical substances, the unalter- able law must be remembered that the peculiar qualities of substan- ces are not irrelative aggregates of characteristics, but that these latter stand in the most intimate relations to each other, as do the angles and edges of a crystal. So, e.g.,no one doubts that the numerous tourmalines, which show so great resemblance not only in their crystalline forms but in their hardness, &c., notwithstanding the difference of their components, are yet associated by a common bond which gives rise to their integrating properties. By ascer- taining the mutual relations of the actual qualities of a substance, we obtain as the idea of it an exact index, which is not the sum of loosely connected characteristics, but rather the product of its closest related properties. We must certainly, in pure chemistry, as yet con- tent ourselves with the description of radicals by simply recounting their characteristics: for unfortunately we are still far from know- 56 ZOOCHEMISTRY. ing the relations of the individual qualities of a body to each other, so that we can deduce one property from all the rest. Later chemis- try has put it in evidence, however, that the properties of chemical radicals do stand in such intimate relations to each other, and that we shall soon no longer have to satisfy ourselves with barely. re- counting their characteristics, but shall reach, instead, clear, distinct conceptions of the world of chemical bodies. Of how many radi- ‘cals, which have been hardly seen or formed once, can the pro- perties and their intimate composition be described? How many otherwise isolated chemical facts can now be held together by a simple leading idea: thus the introduction of the idea of homo- logy has opened at once a general survey of the relations which exist in a very striking manner between a certain mode of compo- sition and particular characteristic properties of a large series of chemical substances. We need only refer to the volatile organic acids, to the varieties of ethers, or to the ammoniacal alkaloids to prove that a logical index has already been obtained for many sub- stances, — It is this intimate and peculiar connection of all their properties which imparts to the different elements forming the substrata of the animal frame their physiological as well as their chemical character. It is the unity of the material relations which occasions the entire behavior of a substance towards all heterogeneous substances and physical influences, as well as the manner of its participation in the chemical processes of life. Since pure chemistry has shown us that the laws which govern the combination of different atoms in stones and rocks are no other than those through which the exist- ence of the complex atoms of animal and vegetable substances are governed, the forces also (to which they are subject in the animal organism) should lead under similar conditions to analogous con- sequences corresponding to the chemical compounds. The essen- tial character of a substance remains then the same whether it be subjected to the influences of atmospheric forces, or the different chemical operations of our laboratories, or the peculiar conditions of life-emovements. No element is enchanted in the animal frame: its relation in the sphere of life remains ever coincident with its chemical quality. The whole of Zoochemistry affords empirical proof of the justice of this proposition ; for we never find that sub- stances chemically entirely different have similar physiological func- tions, or, on the other hand, that substances of similar physiological ORGANIC SUBSTRATA OF THE ANIMAL ORGANISM. 57 value, are widely separated according to chemical principles. Hence it is an established proposition that the physiological importance of a body ws dependent entirely on its chemical constitution, Hence we can follow in zoochemistry no other system or mode of division than a chemical one; for the latter must at the same time take account of physiology, and hence will always be a physiological one also. But, unfortunately, we possess no system in pure chemistry which corresponds with all the demands of science; for although the recent brilliant progress of chemistry has succeeded in presenting certain groups or series of bodies which possess certain concordant tenden: cies, certain common characters, certain fixed definitions, yet there are a great number of substances, more or less closely investigated, which cannot be classed in any of the systems yet formed, and hence escape a general view. Unhappily, here belong many of the sub- stances most important in zoochemistry—we need only name the so-called protein bodies. Our inability to embody these and similar substances in a scientific, systematic classification, depends less on the deficiency of the present system than on our still very unsatisfactory knowledge of such substances. We must, hence, content ourselves with arranging them according to their more palpable physical and chemical properties, without possessing a fixed scientific basis there- for. Where, then, the chemical basis fails us, the analogous physio- logical importance of such substances may sometimes guide us. In choosing among the systems now used in theoretical chemistry one which deserves to be adopted for a zoochemistry, that will be the best by which, with least violence, a general view can be ob- tained of the numerous substances which play a more or less import- ant part in the animal organism. There are four hypotheses which have obtained great importance in modern chemistry, and have been used as principles of classifica- tion; these are the hypotheses of radicals, substitution, pairing and homology. In the endeavor to discover proximate elements in organic bodies, the scarce expected result was reached that, in organic substances, compound bodies exist, which, like inorganic elements, form integral constituents of certain series of combinations, partly with inorganic elements, partly with similar organic compounds. These were called organic radicals; they are composite elements which are capable of uniting with inorganic or other organic elements, and take the place of true elements in many combinations, Like the elements of inor-. 58 ZOOCHEMISTRY. @ ganic chemistry, the compound radicals may be divided into such as correspond to hydrogen or the metals, and such as more resemble the non-metallic elements; but as no well defined boundary can be drawn between these, so also the easiest transition takes place from one to the other class of radicals. The organic metals are almost entirely carbo-hydrogens, of which many are multiples of each other; like the true metals, these unite with oxygen to form basic bodies; like them, they enter into neutral combinations with chlorine, bro- mine, iodine, &.; and lastly, some of them can combine, as it is known the metals do, with hydrogen to form hydrurets; ¢. g. marsh gas = C, H, is reduitlell as the hydruret of methyl = C, H,. H; for more sian one fact proves that the fourth atom of hydrogen stands in that gas in a different relation to the whole compound from that of the other three atoms of hydrogen. Such oxidated carbo-hydrogens as benzoyl (C,, H,; O,), acetyl (C, H, O,), salicyl (C,, H, O,), &., are commonly regarded as the radicals corresponding to the non-metallic elements; here also we may safely place cyanogen, which confessedly presents the most decided analogies with the chlorine group. These radicals form with oxygen those numerous organic acids with 3 and 5 atoms of oxygen; they also unite with hydrogen, like sulphur, chlorine, &c.; for instance, hydrurets of benzoyl and salicyl; aldehyde (C, H, O,) is ‘prahably the hydruret of acetyl = C,H, O,. H. Another theory, which has been established by numerous re- searches in modern chemistry, viz: that of substetution, has given us a deeper insight into the intimate constitution of many bodies, The unexpected fact has presented itself that, in very many organic bodies, certain atoms of hydrogen may be replaced by chlorine, bromine, iodine, or peroxide of nitrogen, without destroying the original compound atom, or altering materially the. physical and chemical properties of the substance. Thus, e. g., in the organic bases, certain atoms of hydrogen may be substituted by those elements, or by peroxide of nitrogen, without their wholly losing their power to unite with acids. By this, as a general rule, we can judge of the influence which a certain number of the atoms have on the quality of the type of some compound atoms. Not less fruitful has been a third mode of observing the consti- tution of organic substances, viz: the so-called pairing, or conjugation of radicals, by virtue of which many substances, contrary to the ordi- nary theory of binary combination, can so unite with each other that the one substance, be it acid or base, loses nothing of its capa- ORGANIC SUBSTRATA OF THE ANIMAL ORGANISM. 659 city for saturation, while the other body, called the pairling, or copula, attached to it in a certain manner, accompanies it in all its combinations with acids or bases. The pairlings are hence not to be separated from the acids or bases belonging to them, by single or double affinity. At first only those compound atoms were con- sidered as paired, in which an organic acid was combined with an organic aggregate molecule, such as sugar, glycin, &c. But latterly the theory of pairing [or of conjugate radicals] has been extended in favor of a theory of the organic acids with three atoms of oxygen ; so that an element, as for instance carbon, may pair itself with an organic radical, a carbohydrogen, a view for which there are several weighty reasons. That elements can actually unite with carbohydrogens to form bodies which have great affinity for oxygen, and, combined with it, form acids, was proved by the long-known kakodyl (C, H,),~As, stibethyl (C, H,),~Sb, &c. It was then not inappropriate to regard bodies as paired of methyl, ethyl, phenyl, &c., and a double atom of carbon, which then would form the well-known acids, acetic acid = (C, H,)~C,.0,, metacetonic acid = (C, H,)~C,.0,, benzoic acid = (C,, H,)~C,.0, Then it was found that the combinations of such radicals with cyano- gen, by treatment with alkalies and with the decomposition of water, yielded those acids and ammonia, e. g. cyanide of ethyl gave, on being boiled with potash ley, ammonia and metacetonic acid (C, H,.C, N + 8HO = H,N+C,H,.~C,. O,): according to this, the 2 atoms of carbon appear not to belong to the radicals of the acids, and hence the hypothesis of a pairing of the radicals with 2 atoms of carbon is not inapposite. This theory affords at least the great practical advantage, that in most organic bodies, whether basic, neutral, or acid, we can recognize these carbohydrogens as elements, and thus obtain a readier survey of a great realm of organic chemistry. Probably the recognition of the so-called homology of substances has had the most powerful influence in placing organic chemistry on a philosophical basis, and establishing a rational system for it. By homologous bodies are understood such as resemble each other closely in composition and properties, and differ from each other by (2CH)n. If some of these homologous bodies were early classed together on account of the similarity of their properties, yet others are thus recognized as belonging together, which previously no one would have ventured so to arrange. Who would previously 60 ZOOCHEMISTRY. have .believed, ¢. g., that formic acid = C, H O,. HO, and margaric acid = C,, H,, O, . HO, were different members of the same series? And yet no one now doubts that these acids, with their numerous intermediate members, belong together ; for it is not only this simi- larity in their composition which causes us to regard them as members of a class, but their products of decomposition, analogous throughout, their modes of combination, their similar .relations to certain basic oxides of carbohydrogens (the so-called ethers), almost force us to look upon them as one family. We obtain an advan- tage by forming series of such homologous bodies, not only as regards system, but also in the theoretical consideration of such substances: for we thus approach closely our object, to present definite ideas of these substances, to establish certain formulas, from which the majority of their physical and chemical properties may be calculated, as any number of given cases from a mathematical formula. Thus, we can say that in substances of the composi- tion (C, H,),.O, or C,, H,,,.O3; . HO, their consistency, their boiling point, the density of their vapor, increases with the number of carbohydrogen atoms, while their solubility, their reaction on vegetable colors, their fluidity, stand in inverse ratio to their atomic weight. Under similar circumstances, these bodies form products of decomposition, which are again mutually homologous. In organic acids we have been able to establish thus far five series of such homologous substances, viz: besides the formic acid series, the succinic acid series = O,, H,,_,.O,. HO, the oleic acid series = C,, H,,,.0,.HO, that of benzoic acid = C,, H,,_,. O,. HO, and that of lactic acid = C,, H,,_,.0O,. HO. We have lately arrived at a view of the intimate constitution of many bodies, principally in consequence of the more exact investi- gation of the organic nitrogenised bases, the so-called alkaloids—a view which is in general based upon the four chemical hypotheses above explained, but which does not coincide with their further de- velopment into theories. It has been established beyond a ques- tion by the most direct observations, that in certain bodies, and es- pecially in ammonia (H, N) and oxide of ammonium (H, N. 0), not only one, but several, indeed all the atoms of hydrogen may be replaced by the carbohydrogens, which we have regarded as the metallic elements of organic chemistry. For the sake of illustration, anilin may be adduced as an example; this is ammonia in which 1 atom of hydrogen is replaced by phenyl = (C,, H,).H.H.N; a ORGANIC SUBSTRATA OF THE ANIMAL ORGANISM. 61 second atom of hydrogen of the ammonia may be replaced by methyl, ethyl, &c.—ethylanilin = (C,, H,).(C,H,). H.N; still a third may be replaced by methyl, amy], &c., e. g. methyl-ethyl-anilin = (C,, H,) .(C, H,). (C, H,).N. In the oxide of ammonium all the four atoms of hydrogen may be replaced by four atoms of the same or different radicals, as in the oxide of methyl-ethyl-amylo-pheny]l- ammonium = C,H,.C,H,.C,,H,,.C,,H,;.N.O. By theestablish- ment of this fact, all previous theories underwent essential modifica- tions; the radicals do something more here than form with oxygen and other elements acids and bases, and then exhibit salt-like com- binations with each other. Substitution takes place here to the fullest extent, but not in the former sense, when hydrogen atoms were replaced only by negative elements or radicals, and when sub- stitution could not be carried back to such simple substances as ammonia and water. Especially the idea of pairing (unless it be taken in a very wide sense) finds no application in these circum- stances, for those alkaloids, e. g., arise not by a pairing of ammonia with those radicals, but the latter serve rather for the completion of the single atoms of hydrogen in the ammonia. All the volatile alkaloids, then, are to be regarded as ammonias, in which one or more atoms of hydrogen are replaced by carbo- hydrogens; in most of the alkaloids containing oxygen, as also in the so-called amides, one or more atoms of hydrogen are replaced by radicals containing oxygen; and thus we possess a principle of classification for the great majority of nitrogenised bodies, according to which a number of homologous series may be established. While, according to this view, many nitrogenised bodies, and indeed those best known, are formed after the type of ammonia, two other great classes of organic bodies may in like manner be conceived as formed after the type of water; for if we consider the hydrogen in water to be replaced by the organic elements, methyl, amyl, phenyl, &c., we obtain the non-nitrogenised bases of organic chemistry, the so-called ethers, e. g., HO corresponding to (C, H,) . O. If, on the other hand, the hydrogen be displaced by radicals containing oxygen, organic acids arise, ¢. 9. HO, corresponding to (C,, H; O,). 0, According to this mode of observation, the idea of pairing, which we made use of above to unfold the inner constitu- tion of the acids, must be laid aside—the internal constitution of the oxygen-containing radicals would then remain to be further deve- loped. 62 ZOOCHEMISTRY. These are the most important points of observation from which theoretical chemistry has hitherto been investigated, and which afford the only starting points for a rational classification of organic bodies, and especially of zoochemical substances. Although zoo- chemistry neither can, nor dare get rid of the views which are of force in theoretical chemistry, it does not belong to its province to enter into a closer discussion of clashing opinions; it has in general to hold to the actual and to receive the theoretical so far as it con- forms closely to established facts. The simplest and safest way to classify zoochemical bodies, with reference at the same time to. their physiological importance, will be to consider certain series of bodies together, whether they be really homologous or only generally very similar. But in zoochemistry, a number of bodies press upon us which cannot readily be grouped from one or other point of view; these can only be placed together according to accidental resem- blances; yet the time is perhaps no longer distant when even the protein bodies shall be classed in a scientifically arranged group. ORGANIC NON-NITROGENISED ACIDS. FAT ACIDS = C,, H,,_, O, . HO. Formic acid =(C, H O,.HO. Acetic acid = ©, H, O,. HO. Metacetonic acid = ©, H, O,. HO. Butyric acid = C0, H, O,. HO. Valerianic acid. = ©, H, O,. HO. Caproic acid = C,, H,, O,. HO. Oenanthic acid. = C,, H,, 0, HO, Caprylic acid . = C,, H,, O, . HO. Pelargonic acid = ©,, H,, O, . HO. Capric acid = ©, H,, O, . HO. Magaritic acid . = C,, H,, O, . HO. Laurostearic acid = C,, H,, O, . HO. Cocinic acid = (FH, 0... W0. Myristic acid = C,, H,, O, . HO. Cetic acid. = CU, H., 0,0, ORGANIC NON-NITROGENISED ACIDS. 63 Palmiticacid. . . . =O, H,,0,. HO. Margaric acid . = CU, H., O, . HO. Stearic acid. ‘ ; . =O, H,, 0, . HO. Cerotic acid . = O,,H,, 0, . HO. Melissic acid . ‘ ‘ . =O, H, O, . HO. The two extremes of this group of acids show in many respects such striking physical and chemical differences that their physiolo- gical value should, accordingly, be very different; hence we divide this series in zoochemistry, as in general chemistry, into two groups; we limit the first somewhat arbitrarily at capric acid, and call those previously mentioned, volatile fat acids; they are fluid, or melt, at least, below 86° F., have a strong odor, can be distilled without change, are more or less soluble in water, of strongly acid reaction; while the members of the other group are solid or buttery, melt. above 86°, are with difficulty distilled (im an atmosphere of carbonic acid), entirely insoluble in water, and act but slightly on vegetable colors. Volatile Fat Acids. The combinations and products of decomposition of the volatile fat acids have generally been very carefully investigated; we here adduce only the following, in regard to these relations, from pure chemistry ; the salts of the volatile fat acids are fur the greater part soluble in water; they are harder of solution, as the atomic weight of the acid in question rises; and hence the salts of capric acid are the least soluble. The boiling point of these acids rises in an as- cending series, about 34.2° F. for each acid; 7. e. for each C, H,. Of many of the acids there are lower stages of oxidation, which have been called aldehyds; thus, the ordinary aldehyd of acetic acid = C, H, O. HO, that of metacetonic acid = C, H,O.HO,&c. An intermediate stage of oxidation between the acid and the aldehyd, is only known of acetic acid, the so-called acetous acid = (C,H, 0,. HO). The aldehyds are liquid, volatile, and easily oxidized. Bodies isomeric with the aldehyds are formed by dry distillation of the salts, especially the barytic salts, of these acids, e.g. butyral = CO, H, 0,, valeral = C,, H,, O,, oily, volatile fluids, of very penetrat- ing odor, less easily oxidized than the aldehyds. Another species of very volatile, colorless, highly inflammable fluids (the cetones), is formed by dry distillation of the alkaline salts 64 ZOOCHEMISTRY. of these acids; e. g. butyrone = C, H, O. (KO, C, H, 0, = KO, CO, +C, H, 0). As in most organic bodies, one or more atoms of hydrogen may be replaced in these acids by chlorine, bromine, or iodine, e. g. in butyric acid, C, (H, Cl,) O, and C, (H, Cl,) O,, &c. All the acids of this group are capable of forming so-called amides; these result from treating the salts of these acids and the oxide of ethyl, with ammonia, e. g., acetamid = O, H, O.C, H, O, +H,N=C,H,0,.H;N+C,H,O.HO. The amides of these acids are crystallizable, colorless, soluble in water and alcohol, distil over unchanged, and are without reaction on vegetable colors. Like all amides, they are decomposed, on being treated with strong acids or alkalies, by combination with water into ammonia and the cor- responding acid: by means of nitrous acid, the corresponding acid is again obtained, with the development of water and nitrogen, e.g. C, H, NO, + NO, = 2N + 2HO+ C,H, 0, Only the amides of this group of acids yield, on treatment with potassium, cyanide of potassium and a carbohydrogen., When, lastly, the amides of these acids are treated with anhydrous phosphoric acid, the so-called nitrils are formed from them by the loss of two atoms of water; these are, however, nothing more than the cyanogen compounds of certain ethers corresponding to the acids. They are oily, very volatile fluids, less soluble in water than in alcohol or ether, and without action on vegetable colors: by strong acids, or alkalies, they are resolved, with the reception of three atoms of water, into ammonia, and the corresponding acid, e.g. C,, H, N + 8HO=H,N+0,,H, 0, Treated with potassium, they afford cyanide of potassium and carbohydrogens. They are so much the more to be regarded as cyanogen compounds, as the artificially prepared cyanide of ethyl has all the properties of a nitril; it decomposes, for instance, by treatment with strong alka- lies, into metacetonic acid and ammonia, C, H,N = C, H,.C,N + 3HO = H,N + C0,H,0,. Hydrocyanic acid would be the nitril of formic acid; for it readily passes, as is known, into formic acid and ammonia. On this circumstance, the theory above alluded to (p. 59) was founded, according to which the acids of this group were considered as oxalic acids, paired with carbohydrogens = C,, H,.4;,- [According to this theory, for instance, the formula of metacetonic acid = C, H;0,.HO should be written (C, H,) .~0, O,.HO.] Hence we rank oxalic acid with these acids. ORGANIC NON-NITROGENISED ACIDS. 65 The acids of this group are found principally in the excretions, or appear in the prima vie as products of fermentation : they are met with especially in the sweat, where they are free, and hence are easily recognized by their fluidity and odor: in the urine and solid excrements, on the other hand, they are commonly combined with the alkalies, or with lime. OXALIC ACID, on account of its great affinity for lime, or rather on account of the insolubility of this salt, we find, in the animal organism, always combined with lime. In the solid excrements it is seldom Fig. 1. OXALATE oF Line.—1, 2, and 3. Octohedra of oxalate of lime in different positions. 4, This form arises from the juxtaposition of two octohedra, and when slightly altered produces the ovals 5 and 6. 7%. A rare form, also derived from the octohedron. 8, 9,10 aud 11. “Dumb- bells:” these are probably carbonate of lime; they never appear in recent urine, but are formed subsequently to the octohedra of oxalate of lime. found ; in fact, only after partaking of vegetables containing oxalic acid: it is often observed, on the other hand, in the urine, of which it even appears to form a normal constituent. Its quantity in the urine may be increased by the use of vegetable food, even when this contains no oxalic acid: this appears, at least, from the appreciable quantity of oxalate of lime always present in the urine of herbivo- rous animals, e.g. the horse, ox, &c. An increase of this salt is moreover observed after very abundant partaking of food, even of animal origin, and very often after slight debauches. An increase of oxalate of lime in the urine is commonly observed after drinks rich in carbonic acid, after the use of bicarbonated alkalies, of salts 5 66 ZOOCHEMISTRY. of organic acids, &c.; in short, after all food and drinks which over- load the blood with carbonic acid. Corresponding with this, an increase of oxalate of lime in the urine occurs in disturbances of respiration, accumulation of carbonic acid in the blood, and espe- cially in disordered metamorphosis of tissue; hence we have it in emphysema of the lungs, diseases of the tieart, after epileptic con-. vulsions, in the convalesence from typhus, &c, In estimating the presence of oxalate of lime in the urine, it must not be forgotten that, in the so-called acid fermentation of urine, in’ connection with another acid, oxalic acid is formed, and immediately combines with the lime of other salts. In fresh urine, often no trace is to be found of oxalate of lime: it occurs after the acid fermenta- tion has gone so far that crystals of free uric acid have separated. The urine occasionally undergoes the acid fermentation within the bladder, and thus gives occasion to the formation of mulberry calculi, which consist mainly of oxalate of lime; the origin of such con- cretions may often be deduced less from onal acid separated by the kidneys than from this fermentation. [The appearance of oxalate of lime in the urine is esteemed very differently by different authorities. Some regard it as indicative always of serious disease of the system, demanding active medica- tion; while others view it as a result of imperfect digestion, or of deficient oxygenation in the blood. The mode of its occurrence renders the latter the more probable view: hence the cases of oxa- luria generally present. symptoms of dyspepsia, or of exhausted nervous forces, as in spermatorrhcea, &c. The form in which oxalate of lime presents itself under the microscope, is generally that of the octohedron, or some of its derivatives—J. C. M.] Formic AcID is one of the most important constituents of the sweat; among the fluid constituents, it is far the largest. In the blood, it has been found only after the prolonged use of sugar. In the fluids of muscles, as also in those of the spleen, it is found in small quantity. ACETIC ACID is also a constant constituent of the sweat. It may be found in the blood, especially after the use of brandy, as also in the disease called leuchzemia (which is associated with enlargement of the spleen). Small quantities of this acid have also been found in the juices expressed from the muscles and from the spleen. In imperfect digestion, the contents of the stomach sometimes undergo an acid fermentation: we then find acetic acid in the matters vomited. ORGANIC NON-NITROGENISED ACIDS. 67 It is not improbable that small quantities of METACETONIC ACID exist in the animal frame wherever acetic or butyric acids are present, while it has never been detected with certainty. Burtyric Acrp is found only in relatively small quantity in the sweat, although this often smells strongly of it. Butyrates have never been detected in the blood, although their presence there is very probable. In the fluids of transversely striated and smooth muscles, as also in that of the spleen, it is found in small quantity. It seldom presents itself in the urine. In the contents of the sto- mach, it is only an abnormal constituent, arising from carbohydratés which have passed into fermentation; on the contrary, it exists pretty constantly in the contents of the large intestine, as the carbo- hydrates reaching there are generally disposed to the butyric acid fermentation by the fluid of the large intestine. Whether Caproic ACID exists in the sweat, which often develops an odor similar to it, is yet undecided; the same remark is appli- cable to caprylce and capric acids. It is not unlikely that the pecu- liar odors which are developed by treating the blood of different animals with sulphuric acid, depend upon these acids, and hence they may be contained ready formed in the blood in some combina- tion. That, in connection with margarin and olein, butyrate, caproate, caprylate, and caprate of glycerin or oxide of lipyle, are contained in milk, has long been placed beyond doubt, and hence their presence in the blood is not improbable. Cinanruic and PeLarGonic acids have never been found ready formed in the animal body; they present themselves at most as products of the decomposition of nitrogenised substances. From the mode of occurrence of all the acids of this group, the. conclusion may at once be drawn that they do not play an import- ant part in the animal organism ; they are either, as in the stomach and alimentary canal, accidentally present, resulting from ferment- ations, or they are characterized as true excretory products, and hence appear mainly in the sweat and urine. AAs the sweat-glands serve principally for the separation of the more volatile matters, we find almost the whole series of acids of this group in the sweat, while oxalic acid is mainly present in the urine, as it is not volatile and unites so actively with lime. All these substances, therefore, are products of the retrograde metamorphosis of tissues, 1. ¢., they arise from those changes which the tissues and organs undergo in performing their physiological functions. In the perfectly healthy 68 ZOOCHEMISTRY. state, the animal organism secretes less of these substances, as they are then for the most part further oxidised and excreted in the. form of carbonic acid and water. We see them occurring in increased quantities in the excretions when in consequence of any pathological processes the process of oxidation in the blood is inter- fered with. That circumstances which prevent the separation of these substances from the blood must give rise to a perverted metamorphosis of tissue, and pathological phenomena, is self-evi- dent: but of what sort these pathological phenomena are, and whether they coincide with what is called rheumatism, must remain undecided. Fixed Fat Acids. These acids, which, as already remarked, differ from those above: described in only a few of their properties, enter very probably into the same relative combinations as the acids of less atomic weights; in but few, as cetylic acid, is the homology in this respect with the previous group ascertained by direct experiment. But as several chemical properties of these acids are entirely different from those just considered, in consequence of their higher atomic weight, 2. ¢., from the radicals, containing more numerous atoms of carbobydrogen, so their physiological relations, their importance in the metamorphosis of animal tissues, etc., through their richness in carbohydrogen, differs from what we have learned respecting the volatile fat acids. . Of the fixed fat acids referred to above, CocInic, MYRISTIC, CETIC, and PALMITIC ACIDS occur in small quantities in animal fat, while MARGARIC AND STEARIC ACIDS occur as its principal constituents. These acids are but seldom met with uncombined in the animal fluids, in fact only in such as have already undergone, either within or without the body, a certain degree of alteration, thus, e. g., in pus which has either become acid in the air, or has been discharged - from so-called cold abscesses. The spindle-shaped and grass-like tufts of margaric acid crystals are then especially to be seen. They are also occasionally found in the fluids of encysted dropsies, and also free in the solid excrements. More commonly these acids are combined with the alkalies with which they exist as salts in the blood, chyle, saliva, and SeEronenE, particularly in the bile, and in pus. Their physiological importance, however, rests upon the presence. ORGANIC NON-NITROGENISED ACIDS, 69 of these acids in the shape of so-called neutral fats, in which they are combined with the non-nitrogenised, glycerin-yielding base, the oxide of lipyle. Always mingled with more or less oleate of the oxide of lipyle, or olein, they form the common fat of animals, which is partly Fig. 2. stored up in special cells, particularly e in the subcutaneous areolar tissue, and partly is suspended in most of the ani- mal fluids, especially in milk. Anatomists distinguish, as is well ‘// known, a peculiar tissue, the adipose, 2, é. cellular tissue, in which the above mentioned oval, or polyhedral cells are imbedded. Adipose tissue is an integral . : é 5 Fat cells imbedded in a fibrous part of many organs, from which it never stroma.—a. Isolated cells showing vanishes entirely, even in sickness, e. g., *Pindle-shaped tufts of margarie from the orbit, from between the muscular fasciculi of the heart, and between the muscles of the face. Very variable quantities are found, on the other hand, in the areolar tissue under the cutis, and in that surrounding the muscles, especially be- tween the glutei, under the skin of the sole of the foot, and the palm of the hand. The tendons are often surrounded by fatty cysts, which sometimes extend to the joints (glands of Havers). Large collec- tions of fat cells are also found between the folds of the great omentum, around the kidneys, and in the female breasts. The marrow of bones consists mainly of fat rich in olein. The lungs, the glans penis, the clitoris, and the brain, have but little fat, and are destitute of fat cells. In the animal fluids, also, fat occurs partly free in minute drops, partly in special cell-membranes and in no small quantities, as for example in milk, in which each particle is surrounded by a delicate membrane; in the yelk of the egg the fat is partly inclosed in mem- ‘branes, partly suspended in minute drops; the same holds good of the chyle, especially after food rich in.fat, and also in part of the lymph. In the blood, on the contrary, more saponified and dissolved, than free suspended fats, are contained. Only under peculiar circumstances does suspended unsaponified fat increase in the blood, as, a short time after the use of fatty nourishment, often in pregnant women, but most frequently in drunkards, when granular degeneration of the liver has commenced. The solid excrements contain much 70 ZOOCHEMISTRY. free fat partly after over-abundant partaking of fat, especially when diarrhoea has simultaneously set in, or when the influx of the bile into the intestines is either prevented or interfered with, whether the cause be a mechanical stoppage of the gall-duct (by colic, gall- stones, or duodenitis), or a deficient secretion of bile. Several organs,.as the liver, spleen, and even the kidneys, contain normally more or less fat inclosed in, or exterior to their proper cells; but in pathological conditions, especially after parenchyma- tous inflammation of these organs, fine fat granules accumulate partly within, and partly outside of the cells in large quantities; this condition has been called fatty degeneration, and regarded as a result of inflammation. Fat is collected abnormally in tumors, and so-called lipomata ; cancerous tumors, also, are often very fatty. When cavities are formed in the body by loss of substance, too active absorption, &c., in the place of the destroyed tissue fat is often deposited, as in para- lyzed muscles or in bone rendered less dense by any pathological process. ; In observing the quantity of fat in the animal body in general, we find that it varies very much with the age; while the organism is almost destitute of fat in the early periods of foetal life, we find it collected in great quantity in new-born infants; this abundance of fat decreases sensibly at the approach of puberty, increases during matu- rity, and vanishes remarkably in old age. The body of the female is, on the average, richer in fat, and more inclined to fatty deposits than that of the male. That sexual excitement, excessive muscular action, modes of living, temperament, and mental conditions have much influence upon fatty deposits in the body, is taught by daily experience. Beyond doubt, the source of the fats of the animal body is prin- cipally to be sought for in the fatty matters contained in the food; nevertheless, the most careful chemical statistical experiments, partly on lactiferous animals, partly on those living on mast, partly on bees fed only on sugar, prove that the animal organism, as well as the vegetable, possesses the power of forming fat. The animal economy must, according to these observations, which show a far greater increase of fat than could be referred to that derived from the food, be able to develop fat either from the carbo- hydrates afforded to it, or from the nitrogenised protein bodies. We shall hereafter, when we come to consider the metamorphosis of ORGANIC NON-NITROGENISED ACIDS. 71 animal tissues in general, enter more closely into the consideration of the grounds which indicate the one or the other mode of fat for- mation in the animal body; but we must here make the confession that we do not know in what way, by what process, or according to what chemical equation fat can be formed from a carbohydrate, or protein substance; we know, hence, as little the parts of the or- ganism where fat formation takes place, as we know whether the organism, when abundantly supplied with fat, still makes use of its powers of fat formation. Fats are of great physiological importance in the animal organism; so that we shall return to them in considering the general metamor- phosis of tissues at greater length. Thus much must here suffice for the determination of the physiological functions of the fats; we see fat accumulated, in the first place, in those parts which are ex- posed to heavy blows or pressure from without; they serve here as cushions or pads, to neutralize, as far as. possible, the force of such external impressions; we find it stored up for this purpose, not only in the sole of the foot, the palm of the hand, and on the tuberosity of the ischium, but also in special sacs inclosed in the joints between the bones. Fat fills up also the vacant spaces between muscles and other organs, so as to afford these more freedom of motion; hence its accumulation in the omentum, in the orbit, and among the mus- cular fibres of the heart. That organs, such as the bones, especially when their tissue is rendered less dense, are made less brittle and in a measure more pliable by the presence of fat, scarcely needs to be mentioned. Fat is, besides, a bad conductor of heat ; hence we see it deposited, in greater or less quantity, in the subcutaneous areolar tissue, in order to lessen, as far as possible, the loss of the free heat of the body by radiation. The great changes of the external temperature would operate much more readily and disadvantageously on animal life, if the body were not, in some degree, protected against them, by the panniculus adiposus cutis ; thus, also, the fatty greater omen- tum serves as a protecting, warmth-preserving coat, to promote the processes of digestion. The fats are useful more than all other substances in exciting and maintaining animal temperature; it is a physical necessity that a great amount of heat must be set free by the gradual or rapid oxida- tion of fats in the animal organism; they contain but little oxygen 72, ZOOCHEMISTRY. combined in them; hence the gaseous oxygen taken up-in respira- tion must be applied principally to the oxidation of these substances, which are seldom excreted as such, but generally, after perfect com- bustion, in the shape of carbonic acid and water. The fats are, moreover, very important agents in the metamorphosis of animal substances. As small quantities of fat are necessary, at least to the rapid induction of the lactic acid fermentation, so, accord- ing to some experiments, the fats appear not to be without influence on digestion. The presence of fat in the egg, in pus, in all plastic exudations, in all organs abounding in cells, indicates clearly that it plays an important part in cell formation ; as yet no animal cell, no cell-forming plasma has been observed, in which appreciable quantities of fat were not contained. Whether fat, as has been main- tained, in the form of granules or vesicles presents the first step toward cell-development, must yet remain undecided. Finally we must not omit to mention here, that a part of the fat introduced into the body assists in forming the resinous acid of the bile, cholic acid; exact comparative analyses of the blood of the portal vein and hepatic veins, and comparative experiments instituted in animals with fistula of the gall-bladder, and on healthy animals, or on such as were kept fasting in order to determine the quantities of carbonic acid excreted, have, in connection with certain pathological facts, given great probability to the hypothesis that the formation of bile is impossible without fat; the chemical constitution and pro- ducts of decomposition of cholic acid favor this hypothesis rather than oppose it. SUCCINIC ACID GrouP=O,H,_, O,. HO. The acids of this group— Succinic acid C, H, O,. HO Lipinic “ C, H, O,. HO Adipic “ C, H, O,. HO Pimelic “ C,H; 0)... HO Suberic “ CO, H, O,. HO Pyroleic “ C,,H, O, . HO are observed only as artificial products of animal substances, espe- cially the fats; they are principally obtained by oxidation of the latter by means of nitric acid. In constitution they may be re- garded either as a radical paired with a double atom of carbon = (C, H,)~C,, or as a radical containing oxygen = OC, H,_, O,. ORGANIC NON-NITROGENISED ACIDS. 73 These acids are all easily crystallized, without odor, do not melt below 212° F., sublime unchanged, are soluble in water, alcohol, and ether (the solubility stands here in inverse ratio to the atomic weight of the acid), redden litmus, and yield oxalic acid and volatile products when fused with hydrate of potassa. Of these only Succinic AcrD has as yet been found in the animal body, and that but once in the fluid contents of hydatids; it may perhaps occur more commonly in small quantity. PYROLEIC ACID, or sebacic acid, is only deserving of notice in that it has hitherto been obtained from no substance except oleic acid or olein, and then by dry distillation. OILY FAT ACIDS=O, H, , O,. HO. The following acids belong to this class:— Acrylic acid : . . . ©, H, O,. HO Damaluricacid . « . «» ,H,0,. HO Damolic acid C,, H,,O,. HO Oleic acid : : ¥ . C,,H,,0,. HO Doeglic acid : : , . OC, H,,O,. HO Erucic acid . C,, H,,0,. HO The first three of these acids are oily, volatile liquids, somewhat soluble in water, more so in alcohol and ether, and redden litmus; they stand in the same relation, perhaps, to the other three as the volatile fat acids do to the fixed. The three last named acids, properly oily acids, are of an oily consistence at moderate and crystallize at lower temperatures, gen- erally above 32°, are entirely insoluble in water, easily soluble in hot alcohol, and ether, redden litmus slightly, are decomposed by heat, and in most other respects have properties in common with the fixed fat acids. DAMALURIC AND DAMOLIC acids have hitherto been found only among the volatile constituents of the urine of cows, and hence have not attained much physiological interest. . Dozexic actD has yet been found only once, viz: in the train- oil of the Balena rostrata. OLEIC ACID, on the contrary, we find wherever margaric and stearic acids exist; thus, combined with alkalies in the blood and bile, free in acid pus, and combined with oxide of lipyle as olein in the fat of cellular tissue, and avberever else free fat presents itself in the body. 74 ZOOCHEMISTRY. The fat of animals contains, on the average, far less olein than that of vegetables. Whether a part of the oleic acid taken up in vegetable fat is transformed into margaric acid, or whether the oleic acid is consumed more rapidly in the metamorphosis of tissue in the animal than margaric acid, cannot as yet be decided. Margarin and olein are likewise not equally distributed in the ani- mal body: in one place the fat-mass is richer in olein, in another in margarin; the panniculus adiposus renum contains more margarin and stearin, the marrow of the bones an excess of olein, &c.—In general the function of olein corresponds closely with that of the other free fats. BENZOIC ACID GROUP=O, H,,0,;.HO. To this group belong— Benzoic acid. C,, H, O, . HO. Myroxylic acid Cig ty Oy - HO. Toluylic “ C,, H, O, . HO. Cumic acid . : . : . ©, H,, O,. HO. Copaivic “ . ‘ C,, H,, O, . HO. Although cinnamic acid, 4.0, H, O,. HO, differs in composition by 2 equiv. of hydrogen from the set of this group, its chemical properties and physiological relations are so similar that it deserves to be classed with them. All these acids are fixed, crystallizable in needles or plates, des- titute of odor, fusible, sublime without change, are scarcely soluble in cold water, easily in hot, as also in alcobol, less so in ether, and redden litmus. Their salts are also analogous. We should not omit here to mention that another group of acids exists, closely approximated to these, resembling them in their pro- perties, in which the same carbohydrogen atoms are united with five atoms of oxygen, viz:— Salicylic acid, C,, H, O,. HO, corresponding with benzoic acid. Anisic “ OC, H, O,.HO, i “ toluylic “ Cumaric “ C,H, O,. HO, " “ cinnamic “ Copalic “ CO, H,, O,.HO, iF “ copaivic “ In close relation to these acids stand certain oily volatile sub- stances existing in the vegetable kingdom, some acid, some basic, some indifferent, which contain one atom more of hydrogen and one less of oxygen than the corresponding acids‘: — ORGANIC NON-NITROGENISED ACIDS. 75 Hydruret of benzole, C,, H, O,, corresponding to benzoic acid, “ “ salicyl, C,, TH, 0, “ “ salicylic “ i “ cinnamyl, C,, H, O,, “ cinnamic * Cumarin ‘ . OC, H, O,, Me “.cumaric “ Cumin . : . ©, H,,0,, i “cumic “ As the atom of hydrogen in these combinations can be easily displaced by chlorine, bromine, iodine, sulphur, or cyanogen, the atom of oxygen in the corresponding acids has been assumed to have been substituted for hydrogen; hence they have been regarded as simply oxides of a radical containing oxygen, viz: C, H,_, O, = (0, H_, O,) O. The existence of the amides of these acids favors this mode of viewing their composition, inasmuch as these may be regarded as ammonias in which one equiv. of hydrogen is replaced by the oxygen-containing radical of the acid, e. g., benzamid = (C,, H, O,) H.H.N. On the other hand, two other groups of bodies, which are connected with these acids, favor the hypothesis, according to which there exists in these bodies a radical, paired of two atoms of carbon and a carbohydrogen = OC, H,_, In the first place are the nitrils, bodies free from oxygen, which, like the nitrils spoken of before, are volatile inflammable liquids of the composition C,H,,N. As these yield cyanogen with potassium, one would be inclined to regard the two atoms of carbon going over to the cyanogen as form- ‘ing not the carbohydrogen (C, H,_,), but rather = (C, H,_,)C,. The existence of certain carbohydrogens, which are obtained by heating the acids with an excess of alkalies, favors the latter view; e. g., benzole from benzoic acid = C,, H, O, . HO—2CO, = C,, H,; thus cumole (C,, H,,) arises from cumic acid, and toluole (C,, H,) from toluylic acid. Asin these carbohydrogens, one atom of hydro- gen may be substituted by chlorine, bromine, iodine, or peroxide of nitrogen, we are justified in regarding them as combinations of hydrogen with the radicals, C,, H,, C,, H,,, and C,, H,; these are exactly the radicals which the above hypothesis considers as paired with a double atom of carbon. Of the acids of this group,only BENZOIC and SALICYLIC AcIDs de- serve a short notice, from their relation to physiology ; the first oc- curs only paired in the animal fluids, in the shape of an amide, as hippuric acid. It is only found in the urine after vegetable food, x 76 ZOOCHEMISTRY. in consequence of the decomposition of the last-named acid ; recent urine never contains benzoic acid. After the use of benzoic acid, large quantities of hippuric acid are always found in the urine; it also passes into the sweat, and is found there as such, never in any nitrogenised combination. SALICYLIC ACID is found in the urine, together with hydruret of salicyl, after the use of salicin. As it exists in castoreum (in con- sequence of the abundant use of willow bark by the beaver), it probably is contained as a normal element in the urine of this animal, together with hydruret of salicyl. S LACTIC ACID GROUP = OC, H,_, O,. HO. n—1 Here belong— ! Glycic acid. ‘ ; : C, H, O,. HO. Lactic acid ‘ : : C, H, O;. HO. Leucic acid . . . f Cy Hy Op. HO,. These acids form, when most free from water, oleaginous fluids of strongly acid: taste, without odor, soluble in water, alcohol, and ether almost in all proportions, redden litmus strongly, decompose by heat, form with bases soluble salts, some of which are-readily erystallizable. According to the above empirical formul, we arrive easily at the idea of regarding these acids as only higher stages of oxidation of the same carbohydrogens which we recognized in the volatile fat acids. According to this, glycic acid would correspond to acetic acid, lactic to metacetonic, and leucic to valerianic; but a different hypothesis has attained a high probability in consequence of certain facts. According to this, they are to be regarded as formic acid paired with aldehydes— Glycic acid . ‘ » = 0, H, 0,0; BO,.H0, Lactic acid . ‘ C0, H, O,.C, H O, . HO. Leucic acid . . =O, H,O,.C,HO,. HO. We have an analogy for this composition in amygdalic acid, which has long been viewed as paired of hydruret of benzoyle and formic acid (C,,H, O,.C, H.O,. HO=C,,H, O,. HO). Several salts of lactic cif actually degdlon the alichyd of acetic acid by dry distillation; but the artificial formation of lactic acid from alanin (C, H, N O,) favors this hypothesis still more. Alanin itself is ORGANIC NON-NITROGENISED ACIDS. 77 formed from aldehyd-ammonia and hydrocyanic acid by digestion with hydrochloric acid (C, H,0,+C, HN+2H0 = C, H,N O)). If alanin is treated with nitrous acid, nitrogen, water, anil lactic acid are formed; it may hence be supposed that the aldehyd has remained unchanged in alanin, and formic acid has been formed from the tipilteovawin: as happens easily elsewhere. GLycic AND LeEuctc actps have never as yet been found pre- formed in the animal organism; the first forms with benzoic acid a conjugate or paired acid, of which hippuric acid, so constantly present in the urine of the herbivora, is the amid. Lactic ActD is very frequently, but by no means always, con- tained in the gastric juice, together with hydrochloric acid; in the saliva, it is only recognized with certainty in diabetes. The acid reaction, which the contents of the duodenum and jejunum exhibit, especially after vegetable diet, depends in a great measure on lactic acid; lactate of lime is often found in the duodenum of herbivorous animals. The contents of the large intestine also, which exhibit so ‘strong an acid reaction after amylaceous and saccharine food, owe this to the lactic acid developed by fermentation, and accompanied, as remarked above, by butyric acid. This acid may be detected in the chyle of the thoracic duct of the horse, especially after feeding on oats and starch; it is probable, according to some observations, that it also exists in the lymph. _ Lactic acid is not to be detected in the blood in normal circum- stances, as it is there quickly oxidized and entirely consumed, whether introduced from the intestines or other organs; lactates of the alkalies injected into it disappear rapidly, and show themselves in the urine as carbonates. In pathological blood, however, especially in puerperal fever and leuchzmia, it is detected beyond doubt. Occasionally, it exists in puriform exudations, which have remained long in abscess-cavities. This acid is not contained in healthy milk ; it is soon formed in it from lactin by fermentation. © Lactic acid is further found’ in the juice both of striated and smooth muscles in tolerably large quantities. In the acid juice of the spleen, also, lactic acid and lactates of the alkalies are found. In the wrine it is occasionally, but not constantly found; it only passes into this when it is not all consumed in the blood; hence we find it in the urine of animals after feeding them on amylaceous food, and confining them constantly in stalls, also in disturbances 78 ZOOCHEMISTRY. of respiration by emphysema of the lungs or tuberculous deposits. Very often it is formed in urine during the acid fermentation. (See “Urine.”) It is obvious, from the circumstances in which lactic acid is found, that it has a double origin in the animal economy; it arises in the prime vie by the fermentation of the amylacea; but as it exists in the muscles in proportion to the previous energy of their action, it may be regarded as a product of the metamorphosis of the muscular fibre. The physiological importance of lactic acid must not be too lightly esteemed ; for in the first place, it is the cause, actually, with hydro- chloric acid, of the digestive power of the gastric juice; no other mineral or organic acids can take the place of these two in the gas- tric juice; secondly, lactic acid assists, as free acid, in the absorption or transudation of the digested food from the prime vie into the alkaline blood or lymph; thirdly, by the ready combustibility of its salts in the blood, it becomes an important assistant in maintaining the animal temperature; and finally it excites an electric tension in the muscles as opposed to the “alkaline blood, which possibly is not without influence on the muscular function. NON-NITROGENISED CONJUGATE ACIDS. The bodies'which we place together under this title, do not form a well-defined group, and by no means possess common character- istics; it is only the impossibility of classifying them, at present, more rationally, and the circumstance that, if the theory of pairing be admitted, substances with.more than three atoms of oxygen may safely be regarded as paired, which induces us here to institute such a group. In zoochemistry there are only three of these acids, viz:— Benzoglycic acid. . . «. O,H, O,. HO. Lithofellic “ . , » « GL HO, HO, Cholic Be ee ae oe gd Os BO, BENZOGLYCIC ACID, which, then, is regarded as paired of benzoic and glycic acids = C,, H, O,. C, H, O,, as it is resolved into them so easily by digestion with dilute acids, has never been found pre- formed in the animal organism; it possesses interest in zoochemistry only inasmuch as it is formed from hippuric acid by treatment with NITROGENISED BASIC AND NEUTRAL BODIES. 79 nitric oxide, on which account that acid is usually regarded as the amid compound of benzoglycic acid. LITHOFELLIC ACID, a crystalline, resinous acid, is only found in certain rare intestinal concretions of several species of goats, in so- called bezoars; it is not known, however, whether it is derived from the food of the animals, or is a product of the secretion of the liver, or of some other excretion, into the intestinal canal. CHOoLIc ActD, which passes so readily, by the action of acids, into choloidic acid, isomeric with it, and, after longer action, into dyslysin, is found in the bile paired with taurin or glycin, and in these com- binations passes also, in’abnormal conditions, into the blood and other fluids; in the alimentary canal, however, it is soon separated from its nitrogenised pairlings and changed partly into choloidic acid and dyslysin. It is found in very small quantity in normal excrement; only in diarrhoea does it occur in larger quantities. That cholic acid is formed in the liver, has been placed nearly beyond doubt; but it is uncertain from what materials or substances in the liver this resinous acid is elaborated. Since fats are especially applied to the formation of the bile, as is proved, partly from exact comparative analyses of the blood flowing to and from the liver, and partly from careful statistical experiments on living animals, the hypothesis is not at all absurd, that this acid is a combination, prin- cipally, of oleic acid and a carbohydrate (C,, H,, O,+C, H, O, = C,, H, O,); at the same time, a carbohydrate, sugar, is proved to be formed in the liver. The products of its chemical decomposition are at least not against this hypothesis; for cholic acid yields, on treatment with concentrated nitric acid, the same products of decom- position as oleic acid, and, together with these, another carbohydrate, cholesteric acid = C, H, O,. NITROGENISED BASIC AND NEUTRAL BODIES. We embrace here only the simpler nitrogenised substances which were formerly regarded as organic bases, or as alkaloids; but so easy is the transition from strongly basic to perfectly neutral bodies that no fixed boundary can be drawn between them. Such more com- 80 ZOOCHEMISTRY. plex radicals as the protein bodies, the gelatinous substances, we are the less disposed to consider in this class, as we are not yet in condition to make the remotest guess at their theoretical con- stitutions, while on the other hand, according to the principles before alluded to and now acknowledged in chemistry, we are able to form an idea of the theoretical constitution of the substances belonging to this class. We have already remarked ia the introduction, that. ammonia may be taken as the type of a great number of nitrogenised organic bodies, one or all of whose atoms of hydrogen may be re- placed by compound elements, the so-called radicals. Strongly basic and indeed volatile sobstannes arise when carbohydrogens take the place of one or more atoms of the hydrogen of ammonia; thus are formed the so-called volatile non-oxygenated alkaloids, of which, ac- cording to the composition of the carbohydrogens, several homolo- gous series may be defined; thus we have a methylamin series = (, Hy).H.H,N,a phenylaniin series = (C, H,,).H.H. N, &e. This method of regarding them, so simple in itself, does not extend far enough to indicate the theoretical constitution ofall the bodies (some of them strongly basic) belonging here. Thus lactamid, alanin and sarcosin are perfectly isomeric = C, H, N O,; if in all these 1 atom of the hydrogen of ammonia were replaced by the aggregate C, H, 0, these bodies could not possibly exhibit the differences which we recognize in them. There are also alkaloids which con- tain more than one atom of nitrogen, so that the nitrogen must be contained in them in another form than that of ammonia. As alkaloids have been artificially prepared which contain cyanogen (C, N) as a pairling, the idea is not improbable, that in the alkaloids which contain more than one atom of nitrogen, either cyanogen or one of its compounds is coupled with the ammonia base. If cyano- gen itself be taken as the type of an especial class of bodies, seve- ral of the neutral bodies belonging here, must rather be regarded as analogues of the cyanogen type than of the ammonia type. But, as the group of bodies belonging to the former is not suficiently defined, and as this separation is very difficult, or quite impossible, especially in reference to individual substances, we embrace all these bodies in one group. ‘ Of the volatile alkaloids, none have yet been found preformed in the animal organism: as artificial or spontaneous products of de- composition, TRIMETHYLAMIN (OC, H,. C, H,. C, H, . N == C, H, N) NITROGENISED BASIC AND NEUTRAL BODIES. 81 was' found in herring pickle, in putrid urine, and in alcoholic prepa- rations of animal objects. BUTYLAMIN or PETININ, C, H,, N, PyRI-: DIN, C,, H, N, PHENYLAMIN or ANILIN, and its isomeric PICOLIN, C,, H, N, and turrpiy, C,, H, N, are formed only by the dry distil- lation of animal substances. Among the oxygen-containing bodies, we first mention a group of crystallizable homologous bases = C, H,4, N O, viz:— Glycin. : : . : 5 Ry Ey NO, Sarcosiny. « « » «= w»« OG BNO, Leucin .. ‘ . 4 ; » GH NG. These are changed by nitrous acid into acids of the lactic acid group, so that glycin yields the above-mentioned glycic acid (C, H, NO,+ NO, = 2N+ 2HO+C,H,0,); on the other hand, by means of strong alkalies, they develop hydrogen, ammonia, carbonic acid, and one of the volatile fat acids: glycin thus yields formic, sarcosin acetic, and leucin valerianic acids, e.g.,C,,H,, N O, + 83KO + 3HO = 2KO.00, + H,N+ 4H + KO.C,,H, 0,. No one of these three has been found isolated in animal fluids. Guycrn,' which often appears as a product of decomposition of animal substances, by means of strong acids or alkalies, has attained a higher interest from its occurring in certain animal acids as a nitrogenised pairling or conjugate: thus, e.g., in the bile, it is con- tained paired with cholic acid as glycocholic acid ; hippuric acid also yields glycin when treated with strong acids, on which account it was long regarded as glycobenzoic acid. SARcOSIN is known only as a product of decomposition of creatin by means of caustic baryta. LEUCIN arises very frequently in the putrefaction of animal sub- stances, or by fusing them with hydrate of potash, or when they are disintegrated by sulphuric acid. Next to the above-named bodies is ranked TyRos1n, C,, H,, N O,, a nearly neutral substance, which is formed by the decomposition of nitrogenised animal matter, by means of concentrated acids or alkalies. The following nitrogenised, crystallizable substances are all found ready formed in the animal body, but are characterized as products 1 This substance is also known as glycochol, or gelatin sugar. 6 82 ZOOCHEMISTRY. of decomposition resulting from the metamorphoses of nitrogenised tissues and fluids. We here consider :— Creatin . . . ; » O HN, 0; Creatinin C, HN, 0, Urea OC, H,N, O, Allantoin O. HN, OQ; Guanin . C,H ay Os Lienin ? Cystin . . C, HN 5, 0, Taurin . -«- «»« « « « @ H,N&,0, These immediate élements of animal fluids are not properly to be reckoned among the alkaloids; for it is very improbable that they are constituted according to the ammonia type, not only because they mostly (except creatinin) have so slightly basic, or quite neutral properties, but also because their large content of nitrogen corre- sponds‘ but little with that hypothesis. The cyanogen type is rather to be suspected in them. CREATIN forms a constant element of the juices of voluntary and involuntary mus¢les. ‘In different animals, and in different muscles Fig. 8. Creatin. of the same -animal, it is found in very different, but always very small quantities, 2.¢., 0.07 to 0.82 per cent. of flesh. Lean meat contains always rather more creatin than fat meat. In the flesh of fowls has been found the largest proportion of creatin ; then, in a descending series, in the horse, fox, doe, stag, hare, ox, sheep, calf, NITROGENISED BASIC AND NEUTRAL BODIES. 88 and fish. The flesh of man contains about 0.067 per cent. of creatin. Creatin has also been found in the blood, and, more decidedly 3 in the urine, though always in very small quantities. [It has been suggested that the substances in the urine, frequently taken for lactates, were in reality creatin and creatinin. The ready solubility (one part in 70 of water) of creatin prevents its being often presented in urinary deposits, as its proportion in health can- not be more than one part in 1000; but, recently, attention has been called by Dr. Miltenberger, Professor of Pathology in the University of Maryland, to crystals of creatin formed by spon- taueous evaporation of urine containing oxalate of lime. Some doubt was thrown upon this at first, and it was suggested that they might be irregular forms of chloride of sodium: but I have suc- ceeded in finding them in two cases of oxalurja. The application of a drop of the solution of nitrate of silver removes all suspicion of their being chloride of sodium ; the latter is instantly transformed, under the microscope, into a dark, granular mass, while creatin is unaffected, or slightly browned.—J. C. M.] It is formed by the action of the muscles in life, and therefore is a product of their retrogressive metamorphosis. Its ready decom- position into different excretory elements, such as creatinin, sarcosin, and urea, as also the fact of its being secerned in the urine, are in favor of its excrementitious nature. CREATININ, which may be artificially prepared from creatin, and distinguishes itself from the rest of these bodies by its strong alka- line reaction, is found likewise in the fauids of muscles ; it has been detected, also, in the bigod, the liquor amnit, and particularly i in the urine. In the latter, it occurs in relatively greater, in the muscles in relatively smaller, quantities than creatin. That it also results in the animal economy from creatin, is then highly probable, not only from the mode of obtaining it artificially, but also from its mode of occurrence; hence it is to be regarded, even more than creatin, as an excretory substance. UREA is the most important constituent of the urine; in that of man, it forms 77 to 82 per cent. of the solid constituents, in that of the carnivora often more. In human urine, whose very varying quantity of water causes the proportions of its solid constituents to appear very different, from 1.5 to 3.8 per cent. of urea are contained, averaging 2.5 per cent., under ordinary circumstances. 84 ZOOCHEMISTRY. [In order to ascertain, approximately, the quantity of urea ina specimen of urine, a small portion of the urine is evaporated to half its bulk, and an equal quantity of nitric acid is added ; on standing, a crystalline deposit, the nitrate of urea, separates, which should be collected on a filter, redissolved in alcohol, and recrystallized. This method is sufficiently accurate for practical purposes—J. C. M.] A healthy man excretes, in 24 hours, from 340 to 679 grains (on the average about 494 grains); but the quantity depends very much on the external and internal conditions of the organism: thus, by men whose weight is over 238 pounds, 570 to 617 grains are dis- charged daily ; by those, on the other hand, whose weight is only 132 pounds, 432 to 494 grains. Under exclusively animal diet, as much as 895 grains, under food containing little nitrogen, less than 232 grains, are excreted in 24 hours. Under non-nitrogenised diet, urea does not entirely disappear from the urine, any more than by prolonged abstinence from all food; the quantity excreted is only notably lessened. Hence, in diseases in which a spare diet is ob- served, the quantity excreted is much diminished, although the con- centrated urine discharged at one time appears rich in this substance. Violent bodily exercise causes an increased excretion of urea. Men discharge in an equal time more of this substance than women and children; but, in proportion to their weight, children often dis- charge twice as much as adults. It is worthy of remark that the quantity of urea secreted daily increases with that of the water (without any determinate numeri- NITROGENISED BASIC AND NEUTRAL BODIES. 85 cal ratio being observable). If much water, then, is discharged in the urine, more urea is also secreted. In healthy blood, only very small quantities of urea are found, as it is separated from it so quickly by the kidneys. An abnormal increase appears only to occur in cases of deficient function of the kidney, which are usually combined with a degeneration of that organ. When urea is secreted in but small quantity, or not at all, by the kidneys, it is found in most of the animal fluids, especially in the sweat; sometimes in such quantities that the latter, by spontaneous evaporation, forms a bluish-white crust, consisting mainly of urea, on the skin (especially the face). Under these circumstances it is met with not only in all serous transudations, but also in the salva, in the bile, and especially in the fluids vomited. Urea is also found normally in the aqueous humor and in the liquor amni. The opinion that urea is formed in the kidneys has long been abandoned, as it was proved that it accumulated in the blood and other fluids, upon their extirpation or entire degeneration. That it arises out of the nitrogenised constituents of the organism, scarcely needs proof; we know from theoretical chemistry how readily it occurs as a product of decomposition or change of other nitrogen- ised substances; its artificial preparation is well known. As the metamorphosis of tissue in the muscles is the most active in the organism, it is generally regarded as for the most part the product of the effete muscular tissue; but doubtless it is also formed by the metamorphosis of other organs: hence it is found in the urine after non-nitrogenised diet or prolonged abstinence. Whether it is formed in those places at which the metamorphosis is progressing, or in the blood, cannot be decided with certainty; while there is much reason for supposing that it is formed by preference in the blood, from other nitrogenised substances, which are to be regarded as the debris of the organs, as products of the metamorphosis of tissues. Thus, out of the organism, creatin and uric acid, as we know, separate readily into urea and other substances; these, as well as glycin, alloxantin, thein, &c., when taken by the mouth, are decomposed into urea and other substances, of which the former is found in increased quantity in the urine. In the muscles them- selves, creatin has been detected, but not urea. Finally, it is not very probable that the increase of urea in the urine would take 86 ZOOCHEMISTRY. place so soon after partaking abundantly of gelatin-yielding sub- stances, unless the nitrogenised materials are immediately consumed in the blood, and their nitrogen united with certain other elements to form urea. Its formation, then, takes place principally in the blood, and its origin, according to the last-mentioned phenomenon, is to be sought not only in the destruction of nitrogenous parts of organs, but also partly in thé species of food taken. . ALLANTGIN is found in the fluid of the allantois of the cow, and in the urine of calves while they are suckled; as soon as they par- take of vegetable food it disappears, and hippuric acid, which pre- viously was wanting, takes its place. GUANIN is found in the excrement of certain sea-birds (in guano) and spiders, as also in the green organ of river crawfish, and the organ of Bojanus of the Anodonta cygnea. Cystin has been found, though rarely, in urinary calculi, and as a sediment in the urine. As neither its internal constitution has been investigated, nor the pathological conditions ascertained under which it is formed in the body, we are still wholly in the dark as to its origin. This substance contains a large proportion of sulphur. TAURIN is found in the bile of most animals, coupled with cholic acid. As taurocholic acid is soon decomposed: in the small intes- tines, we find small quantities of taurin in the contents of the small and large intestines, and in the solid excrements. 'That it is formed in NITROGENISED PAIRED ACIDS. 87 the liver is highly probable, according to what we shall learn of its origin under “Bile.” Fig. 6. LiENIN has hitherto been found only in the fluid of the spleen, and has not been very closely investigated. As most of the pecu- liar components of the splenic juice are characterized as products of retrogressive metamorphoses, lienin probably belongs also to them. NITROGENISED PAIRED ACIDS, We embrace in this group the following nitrogenised bodies, whether a determinate nitrogenised pairling has been detected in them or not:— Hippuric acid . ‘ ‘ C,, H, NO, . HO. Glycocholic acid : . C,H, NO,,.HO. Hyocholie acid . i ‘ C,, H,, N O,,. HO. Taurocholic acid i , C,, H,, NS, 0,,. HO. These four acids are characterized especially as conjugated, or paired, since, on being treated with concentrated acids, or even alka- lies, they are resolved into a nitrogenised body, which is usually re- garded as the pairling, and a non-nitrogenised acid. Hippuric acid has hitherto been commonly regarded as benzoic acid paired with glycin, as it is resolved into glycin and that acid 88. ZOOCHEMISTRY. by digestion with concentrated mineral acids (C,, H, NO, + 2HO = 0,H,N0O,+C,,H,0,); but, as it yields with nitrous acid the before-mentioned benzoglycic acid (C,, H, NO, + NO, = 2N + 2HO + C,,H,0,), the opinion has become more probable that it is a true amid of benzoglycic acid (H, N.C,, H, O,), which, like aspa- ragic acid (the amid of malic acid), still possesses acid properties. It is uncertain whether a similar relation obtains in regard to gly- cocholic and hyocholic acids, which also yield glycin by treatment with acids or alkalies; hitherto they have been viewed as acids paired with glycin, according to the theoretical formula for glyco- cholic acid = C,H, NO, .C,, Hy, O,, and for hyocholic acid = C, H, NO,.C,,H,,0,. Taurocholic acid is resolved into taurin and cho- loidic acid by treatment with acids; hence it is regarded as cholic acid paired with taurin = C,H, NS, O,. C,, Hy, O,. The two acids— Inosic acid . : . ‘i C, H, N, O,,. HO, ‘ ? and Pneumic acid have been as yet too little investigated to enable us to indicate their pairling, and the acid paired with it. One of the most important acids belonging to this class stands in composition, and even in some of its properties, in very close rela- tions to two neutral animal substances, hypoxanthin and xanthin, as is seen by the following formule :— Hypoxanthin i C,, H, N, O,. Xanthin ; ‘ & : CG, HN, O,. Uneatd « «» » «= ws G38, 0. i These combinations resemble different stages of oxidation of the same radical = C,,H,N,. It is also worthy of note that xanthin forms a homologous series with two vegetable nitrogenised bodies, which, according to this, differ from each other by a certain number of carbohydrogen atoms, viz:—- Xanthin S @ 2° = «= ie Oo. Theobromin . ; > oe i C, H, N,O, 2a. law ON That, moreover, the homology of these three bodies is no acci- dental freak of nature, results trom other investigations as tothe mode of disintegration of thein and theobromin; for, according to these observations, these vegetable substances afford, under analo- NITROGENISED PAIRED ACIDS, 89 gous conditions, products of decomposition which are perfectly homologous with those of the animal substance. HIPPURIC AcID is found in great quantity in the wrine of herbi- vorous mammalia; it also exists in that of some of the amphibia, e.g. of Testudo graeca ; it is also a constant element of human urine Fig. 7. Hippuric Actp.—1, 2. Irregular crystalline masses of hippuric acid. 3, 4, 5, 6. Acicular crystals in different positions, sometimes also crossing each other at right angles. after the use of mixed or vegetable food. Our observations are not yet sufficiently numerous to enable us to decide how far the amount of hippuric acid is increased or diminished in disease. It has been detected in the blood in very small quantities, though with cer- tainty. From what substances especially, and in what places, hip- puric acid is formed, cannot be determined with certainty; for neither its theoretical constitution, nor the well-known change of benzoic acid in the organism into hippuric acid, nor the appearance of unaltered benzoic acid in the sweat, is sufficient for forming an opinion as to its mode of production. 7 GLYCOCHOLIC AcID is found principally in ox-gall, and exists also in the bile of several other animals, although mostly in rela- tively small quantities. It is speedily decomposed in the alimentary canal. It is probable that this acid is formed in the liver. Its func- tion in the alimentary canal may correspond with that of the bile in general, viz: the absorption of fat. 90 ZOOCHEMISTRY. Hyocuoic Actp is found in the bile of swine, taking the place of glycocholic acid in the organism of other animals. TAUROCHOLIC ACID is found in the bile of man and the ox, and probably in the sulphuretted bile of the fox, bear, sheep, dog, wolf, goat, of several birds, and fresh-water fishes; in the bile of the boa anaconda it appears to exist alone, z.e. without any non-sulphuretted resinous bile acid. In the blood, in transudations, and in’ the urine, -taurocholic acid may be detected in all cases where the excretion of bile is repressed or interfered with. In the alimentary canal this acid is also soon decomposed, so that we find there free taurin and choloidic acid, &c. It is scarcely to be doubted that this acid is formed in the liver. Its function, as a means of promoting the absorption of fat, will be more fully discussed under “The Bile.” Inosic ActD, which has as yet been found only in the fluids of flesh, and PNEuMIC ACID, which appears to exist only in those of the lungs, are too little known for the formation of an opinion con- cerning their origin and function. HYPoXANTHIN was found, in the first instance, in the juice of the spleen, and afterwards in the fluids of the cardiac muscle of the ox. It also exists in the blood, in small proportions, which increase notably in that disease of the spleen called Leuchemia. The close relation in which this substarfce stands to xanthin and to uric acid indicates significantly enough that it is to be regarded as a product of change, and an excretory substance. XANTHIN has been found, though rarely, in urinary calculi. Under what conditions this substance is formed in the body, and gives rise to the formation of such concretions, is entirely unknown. URIc ACID is a constant constituent. of human urine, which con- tains, on an average, about 0.1 per cent. of it. It is found in smaller quantities in the urine of carnivorous mammalia, but not at all in that of omnivora or herbivora (it is only found in that of calves while sucking). The urine of birds and serpents consists almost entirely of urates. Uric acid has, finally, been found also in the urine of tortoises, and in the red excrements of ‘butterflies, as also in those of beetles and caterpillars, in the biliary ducts of which, especially, it is accumulated. . The proportion of uric acid in human urine varies, of course, with its concentration; hence the highly concentrated morning urine contains often 0.8 per cent., without any absolute increase of the acid. The absolute quantity of uric acid in human urine varies NITROGENISED PAIRED ACIDS. 91 but little, according to the kind of diet; an absolute increase of the quantity daily excreted is found in disordered digestion, especially Fig. 8. Crystals of uric acid. after the use of indigestible food and alcoholic drinks, and in all diseases accompanied by violent fever. In these cases, uric acid is deposited from the urine as it cools, generally combined with soda Urate of soda. as an amorphous granular sediment, which may be recognized by its ready solubility on the application of heat. We observe, espe- cially, an increase of uric acid with the formation of this sediment (which, however, does not always indicate an absolute increase of uric acid, but only a greater concentration of the urine), in all cases 92 ZOOCHEMISTRY. which are connected with a disturbance of the respiratory functions or of the circulation, as e.g. in emphysema of the lungs, diseases of the heart, liver, &. In acute arthritis, the uric acid in the urine is augmented before the occurrence of the paroxysm; during it, how- ever, and in chronic gout, it is diminished. ree wric acid is very seldom found in recently passed urine; but the urine of fever has this peculiarity, that it becomes acid in the air sooner than normal urine, and deposits crystals of uric acid. Urate of ammonia is like- wise a product of fermentation of urine, but of the alkaline, which generally occurs out of the body; but in obstinate vesical catarrh (especially in paralysis of the bladder) the urine becomes alkaline in the bladder, and contains then, when recently discharged, this salt in the shape of dark-brown granules surrounded with delicate needles. Uric acid is found in the dlood only in very small] quantities, slightly increased in arthritis and in Bright’s disease. It is detected as a constant element of the fluid expressed from the spleen. Urate of soda, crystallized, is contained in most of the so-called chalk-stones. It is thought also to have been found in the sweat of those suffering under gout. Uric acid is, like urea, an excretory product. It stands in very close relation to the latter, inasmuch as a great part of the urea in the organism, and even in the blood, seems to be formed from it; at least this is indicated by the circumstance that, after the ingestion of uric acid, this appears again in the urine, not as acid, but as urea (exactly as uric acid yields urea on being treated with peroxide of lead). On the other hand, in urine which contains much uric acid, relatively little urea is usually found. We also find uric acid occurring in increased quantities in the urine in cases of interruption of the respiratory functions and of the circulation of the blood. NON-NITROGENISED BASES. HALOID BASES. We have seen, in the introduction to Zoochemistry, that there are many carbohydrogens, in part polymeric, which comport them- selves like elements, and resemble in many respects the metals. These carbohydrogens form, with one atom of oxygen, basic bodies NON-NITROGENISED BASES.—HALOID BASES. 93 which unite with water, as also with acids, forming with the latter both neutral and acid salts. It is well known that the study of these bodies has greatly ad- vanced theoretical chemistry; but, unfortunately, these studies have as yet exercised no very important direct influence on zoochemistry, as in the latter these substances are as yet only of secondary im- portance. Hence we recall to remembrance, in regard to them, only the following :— All these oxides form combinations with water, the so-called alcohols, which present in some respects very important differences from the anhydrous oxides, the so-called ethers. The alcohols are generally regarded as hydrates of the ethers, but later discoveries, viz: those of the compound species of ethers, have rendered this view somewhat doubtful. If potassio-alcohol [C,H,O.K O] is treated with iodide of methyl, or the bisulphate of the oxide of methyl and pot- ash, we should expect the simultaneous formation of oxide of methyl (C, H, O) and oxide of ethyl (C,H, 0); but, instead of this, a new ether is formed, of the composition C,H,O. It has, hence, been concluded that ordinary alcohol contains but one atom of oxygen, and thus is not C,H,0O,, but C,H,O. It has then been further con- ceived, in conformity with the atomic theory, that water contains two atoms of hydrogen to one of oxygen, and that in alcohol only ‘one, in ether both, atoms of hydrogen are replaced by ethyl; that in the above-mentioned compound ether, one atom of the hydrogen of water is replaced by ethyl, the other by methyl. This mode of viewing them, which has much in its favor, makes the alcohols appear in a light very different from that of hydrates. The better known non-nitrogenised organic bases, and their so- called hydrates, are generally fluid and very volatile bodies; but here, as with the fat acids, they become less volatile as the atomic weight increases, z.e. the more carbohydrogen atoms they contain, and present themselves as soft, and finally as solid bodies. The alcohols are, as a rule, less volatile than the corresponding ethers. The combinations of these bodies with acids, whether organic or inorganic, have many peculiarities by which they differ from other salts. We may mention that they are not as easily resolved into their proximate components by single or double elective affinity, and that when decomposed they absorb water, so that both acid and base become hydrates; for it is worthy of remark that these neutral salts never contain water, and hence never form hydrates, as inor- 94 ZOOCHEMISTRY. ganic salts often do. It is also remarkable that the neutral salts of most of these bases volatilize unchanged, while their acid salts all decompose on heating. The acid salts all redden litmus, but none of the neutral. Several homologous series of these bodies also may be arranged, whose individual members differ by C,H,; the best known of them is the ethyl series = C, H,,,O. Of these the following have some interest in zoochemistry :— Doeglic oxide ; eos . ©, H,, 0 Oxide of cetyl . . : : . OC, H,, O Oxide of cerotyl 3 ‘ : A C,, H,, O Oxide of melissyl . : : ‘ C,, H,, O The existence of DOEGLIC OXIDE has been as yet determined only from the analysis of the unsaponified train-oil (fat of the Balena rostrata), and the absence of glycerin. The hydrate of OxIDE OF CETYL, ethal, is found combined with cetylic acid only in spermaceti, the fat of the sperm-whale. The OXIDE OF CEROTYL, cerotin, is contained principally in China wax combined with cerotic acid. The OXIDE OF MELISSYL, myricin, exists in wax. A second homologous series of non-nitrogenised bases corresponds with the formula C,H, _,O. Among these the hypothetical oxipz OF LIPYLE, C, H, O, alone possesses any physiological interest: from this base, it is supposed, GLYCERIN == C, H, O,. HO, results in the decomposition of neutral fats. Of the combinations of this body with the fat acids, and their entire relations in the animal organism, we have spoken above (pp. 68-72). It is only necessary to mention here GLYCERO-PHOSPHORIC ACID = C, H,O,+2HO + PO,, which has been ascertained to be probably a constituent of the yolk of the eggs of birds and fishes, and also of the brain. The origin of glycerin in the animal body, from the neutral fats, is undoubted; the circum- stance, however, that neutral fats, in glycerin- wielding substances, almost exclusively are introduced into the animal body, while many free fat acids exist in the organism, in connection with the small quantity of glycerin combined with phosphoric acid, indicates its application to a far different purpose. It is possible that it passes into metacetonic acid (as in fermentation with yeast), which is im- mediately consumed in the blood. , LIPOIDS. 95 A third group of these bodies has scarcely any basic properties, As yet only two members of it are known, viz:— Hydrated oxide of phenyl. C,, H, O. HO. Hydrated oxide of tauryl . C,,H, 0. HO, HYDRATED OXIDE OF PHENYL, also called phenylic or carbolic acid, has been found with certainty only in castoreum. Whether it oc- curs, together with salicylous and salicylic acid, after the use of salicin, is yet doubtful, inasmuch as, even in very small quantities, it acts poisonously on animal life. HYDRATED OXIDE OF TAURYL, taurylic acid, has been found only in the urine of cows, in very small quantity. LIPOIDS. ~ These bodies, often called also unsaponifiable fats, are neutral, resembling the fats in many of their physical properties, but corre- sponding with them neither in composition nor in modes of decom- position. Among these bodies are reckoned— Cholesterin ee ee ee ee ee ee Castorin . em . > &£ i Ambra 5 = ww 8 * % ? Serolin . . é at ? CHOLESTERIN exists very abundantly in the animal organism, partly dissolved by soaps or taurocholate of soda, partly suspended or deposited in rhombic plates, the obtuse angle of which measures 100° 80’. Its presence in the bile is well known, where it is almost, always in solution. Suspended cholesterin has very seldom been found in diseased bile; but biliary calculi are very common, the most of which consist of it almost wholly. This body is also a normal constituent of the blood, but in very varying proportions (from 0.0025 to 0.0200 per cent.); it increases in that of old per- sons, and on the occurrence of diseases accompanied with fever. Cholesterin is likewise a constant constituent of the brain. In pus it is seldom wanting. It is often found in dropsical transudations, viz: in great quantities occasionally in the fluid of hydrocele; also in exudations, especially in softening tubercles, old sacs of echino- 96 ZOOCHEMISTRY. cocci, degenerated ovaries, and testicles; also on the inner coat of atheromatous arteries, in.tumors, particularly encysted tumors (me- Fig. 10. Crystals of cholesterin, with mucous corpuscles and blood-discs. licera), cholesteatomata, and carcinomata. From the bile, choles. terin passes into the solid excrements, and thus is found in meconium. We are wholly in the dark as to the source of cholesterin. It is never found in the vegetable kingdom. Its theoretical chemical constitution is so little ascertained, that no hypothesis of its mode of origin can be grounded thereupon; but its mode of occurrence in the animal body indicates that it is to be regarded rather as a product of metamorphosis and an excretory substance. It scarcely appears to subserve any important purpose in the animal body pre- vious to its excretion. - The two easily crystallizable lipoids, cAstoRIN, which is found only in castor, and AMBRIN, found in amber, have been too slightly investigated, chemically, to possess as yet any physiological interest, even on account of their rarity. ; SEROLIN, so called, is nothing more than a mixture of the crys- tallizable fats contained in the serum of the blood. NON-NITROGENISED NEUTRAL BODIES, ETC, 97 NON-NITROGENISED NEUTRAL BODIES. CARBOHYDRATES. The substances belonging to this class have been called carbo- hydrates, because in them, together with carbon, hydrogen and oxygen exist in the same proportions as in water; it is also worthy of remark that, according to the determinations of their atomic weights, the number of atoms of carbon is always divisible by 6. In spite of the numerous investigations which have been made with several, at least, of these substances, it is still impossible to form an exact conception of their theoretical constitution. However differ- ent the physiological properties of these bodies may be, even when perfectly isomeric, they have many resemblances in their products of decomposition. They are all so indifferent as to unite with diffi- culty with other bodies, and generally in several proportions. They are all decomposed by heat, forming acid products of distillation, and inflammable gases together with watery vapor. By digestion with dilute acids, they pass generally into grape sugar. By con- centrated nitric acid, they are changed into oxalic, or mucic and saccharic acids; other concentrated mineral acids produce from them humus-like substances. As is known, these bodies are separated into four groups—sugars, gums, starches, and vegetable fibrin. The following individual members only of these groups stand in rela- tion to animal chemistry :— Grape sugar » « «@ Gy H.O. + 2B0. Lactin ‘ ‘ ‘ ‘ C,, Hy, Or. : Tnosit ; F : C,, H,, O,, + 4HO. Paramylons « «ws ww Sei, Oi. Cellulose . ‘ ‘ : C,, Hyg Oro GRAPE SUGAR, or mucous sugar (so called), glucose, is always found in the prime vie after the enjoyment of saccharine and amylaceous food, especially in the small intestine; the quantity is generally small, since the sugar is immediately absorbed as fast as formed from the starch. In the chyle, only traces of it are found after amylaceous diet. Sugar is a constant constituent of the blood; that of the hepatic veins is especially rich in it, while in that of the portal vein (although so much sugar is developed in the intestinal canal, and necessarily absorbed by the veins) only traces of it are accidentally found. Sugar passes into the urine, in normal con- 7 98 ZOOCHEMISTRY. ditions, only when very large quantities are partaken of at once, or in a short space of time; and then not commonly, as it is rapidly decomposed in the bladder. It passes readily into the urine when it has been injected into the veins in sufficient quantity. Direct experiments on rabbits have taught us that when the proportion of sugar in the blood rises above 0.4 per cent. it appears in the urine; if there is less than this in the blood, it is decomposed within the circulation. In that very obscure disease, diabetes mellitus, notable quantities of sugar are daily excreted with the urine. In other dis- eases, sugar has seldom been seen to pass into the urine; the circum- -stances and conditions under which this happens abnormally are as yet by no means satisfactorily established. The discovery that the injury of the base of the fourth ventricle of the brain—that is, of the medulla oblongata at a certain point—is followed, for several: hours, by the presence of sugar in the urine, has been confirmed, though no satisfactory explanation of the fact has been presented. In the fluids of the amnion and allantois, sugar has occasionally been found. In the white and in the yolk of the egg a little sugar is constantly present; during incubation, its proportion appears to increase. In the parenchymatous fluid of the liver, sugar is also found, when neither amylaceous nor saccharine food has been introduced into the organism. In the liver of man, mammalia, and birds, the proportion of sugar is much more important than in that of rep- tiles; in the recent liver of man, mammals, and birds, we find, on an average, 2 per cent. of sugar; in that of reptiles, at most, 1 per cent. It is remarkable that sugar appears not to be contained in the liver of fishes. In disease, it frequently vanishes from the liver. In diabetes, sugar is found in all the serous fluids, in the saliva, in the matters vomited, in the solid excrements, and occasionally even in the sweat; not, however, in the brain, spinal marrow, pancreas, or spleen. Two sources of sugar in the organism are apparent: the saliva, the pancreatic and intestinal fluids, change the starch of the food into sugar. It is, however, also developed in the liver, probably from nitrogenised matters; this is rendered probable not only by the abundance of sugar in the liver, but also by the circum- stance that the blood flowing to the liver (that of the portal vein) is So poor in sugar, while that flowing from it (that of the hepatic vein) is richer therein than the blood of any other vessel. Under 1 See note on the blood of the hepatic veins. ANIMAL COLORING MATTERS. 99 “Metamorphosis of Tissue” we will treat more at large of the high physiological importance of sugar. LAcTIN appears to be an integral constituent of the milk of all the mammalia; it is found, however, in far less proportions in that of carnivorous than in that of herbivorous animals. (As to the quan- tities of sugar contained in the milk of different animals, see “Milk.”) Lactin has not been hitherto detected with certainty in other animal fluids. As only the fermentable grape sugar is found in the blood, it is more than probable that lactin is first developed in the mam- mary glands, and from the former. The object of this sugar for the nourishment of the suckling will be discussed under “Metamor- phosis of Tissue.” Ivosit, a sugar incapable of the vinous fermentation, is found, singularly enough, only in the juice of the cardiac muscle, PARAMYLON, a substance closely resembling starch, has been found in the body of an infusorial animal, Huglena viridis. CELLULOSE, which forms, as is known, the basis of all vegetable cells, is found only in some of the lower animals, e.g. in the mantle of Phallusia mammillaris, in the cartilaginous covering. of the simple Ascidiz, in the leathery mantle of the Cynthic, and in the external tube of the Salpz. Whether cellulose, or a similar substance, exists in certain parts of the brain of higher animals, as also in certain pathological deposits, is still very doubtful. [The existence of cellulose in the human economy is now gene- rally acknowledged by physiologists. It has been found normally in the ependyma of the brain, and pathologically in that form of degeneration of the spleen known as the “waxy spleen.” Its occur- rence in other organs is still doubtful—ZJ. C. M.] ANIMAL COLORING MATTERS. The coloring matters, especially those which are animal, belong to the substances whose theoretical composition is but imperfectly known. To animal chemistry belong— Heematin j i 2 , C,, H, N, O, Fe. Bile-pigment . ; ; ? Urine-pigment : <> ? Melanin. . «© «© - ? 100 ZOOCHEMISTRY. Hatin is found only in the colored blood-cells of the higher animals, intimately mingled with their hemato-crystallin; but whe- ther the hematin, as separated artificially, is identical with that dissolved in the blood-cells, and whether it differs from the latter somewhat, as coagulated albumen does from uncoagulated, or whe- ther it is wholly a product of transformation, has not yet been posi- tively decided, as all attempts to separate soluble hematin from heemato-crystallin have hitherto failed. It is scarcely to be expected but that the proportion of the hematin to the blood, as a whole, should alter with the number of the blood-corpuscles; but it is also at least probable that the proportion of this pigment to the blood- corpuscles, or to the hemato-crystallin, is variable; for, on the one hand, we find the intensity of color of the individual blood-cor- puscles very different, as well as the colored hemato-crystallin arti- ficially prepared from them; and, on the other hand, if we may judge of the proportion of hematin from the quantity of iron in the blood-corpuscles, direct analyses have proved a difference in the proportion of this substance in them. We are entirely in the dark as to the origin of hematin in the blood. That it must perform a particular function in the blood-corpuscles, is hardly to be doubted; ‘but what this is has not yet been ascertained, for it is only an hy- pothesis, founded upon the changes of color which it undergoes under the influence of certain gases, that the interchange of gases ‘in the blood is affected by its agency. Hzematin appears to be dis- ‘integrated, like the blood-corpuscles, principally in the spleen; at least, a modification of it has been found in the fluid expressed from ‘the latter. When blood is extravasated in the body (escapes from © a vessel), and stagnates for some time in the cellular tissue or pa- renchyma of an organ, it is transformed into a crystalline body, generally of a pomegranate-red color, hematoidin. BILE-PIGMENT is found, as its name indicates, in the bile, usually in solution; though it also forms either entire concretions, or their nuclei. Chemically, this pigment has been so little investigated, that we have no exact idea of the essential difference of its modi- fications; we only know that the original pigment, especially in man and the carnivora, is brown, cholepyrrhin, and that it becomes green even in the gall-bladder, by gradual oxidation, or when exposed to oxygen itself. In the bile of most birds, fishes, and amphibia, green bile-pigment, bilverdin, alone appears to exist. In the v6 dilaanihe ** human milk =10: 40 ** lentils =10: 21 *¢ horse-beans =10 : 22 “ peas = 10 : 28 ‘ flesh of sheep (fattened) = 10 : 27 = 11.25 fat. “do swine (do) =10 : 30=125 « : “do ox =10 : 17= 7.08 « “ do hare =10 : 2= 0.88 « “ do calf =10 : l= 041 « ‘¢ wheat flour =10: 46 * oatmeal = 10: 50 “ rye flour = 10: 57 “ barley =10: 57 “« white potatoes =10 : 86 “ blue do =10 : 115 “« rice = 10 : 123 *s buckwheat meal = 10 : 180 A more modern physiology of nutrition cannot be satisfied with these data; although we may thus obtain an approximate view of the value of an article of food as a plastic substance, and as a mate- rial for respiration, yet we know that the fats and carbohydrates have, besides, specific functions to perform; in fact, direct experi- ments show that the carbohydrates cannot be substituted entirely for the fats in an article of food. We, therefore, are at present un- able to give the proportion of these four nutritive elements, which is most favorable for the purposes of life, in an article of food; numerous and circumstantial experiments are still wanting for this. We can only, therefore, in order to form a tolerable idea of the mixture of these four groups of bodies which agrees best with the prosperity of the human organism as to its growth, recur to the composition NUTRITION, 277 of the food afforded by nature herself to the child, woman’s milk; according to this, the most favorable proportion between the four nutritive elements would be the following: to 10 parts of plastic substance belong 10 parts of fat, 20 parts of sugar, and 0.6 of a part of salts. We are in possession of some, though not very nu- merous facts, from which it appears that, in the food of an animal, no one of these four factors of nourishment can be wanting, and yet the animal be maintained alive; thus, e. g,, turtledoves, when fed with protein-substances and sugar, perished with the same phe- nomena as if they had received no solid food. Even when all the factors of nutrition are presented to an animal in its food, but one of them preponderates much over the others, nutrition takes place very imperfectly ; thus, e.g. potatoes and beets have been found alone very insufficient to nourish a cow. When, however, we seek to ascertain the most favorable mixture of the nutritive elements, we must not think that this will remain one and the same for all condi- tions ; the proportions of the nutritive elements must, on the con- trary, change, according to the state in which the organism to be nourished is; its necessities will as little demand always the same proportions of this mixture, as the necessity for food remains con- stant in regard to the absolute quantity. We have seen under “Milk,” how the milk of the mother alters in certain portions with the growth of the child. The proportions of the constituents of this nutritive fluid which is presented to the new-born infant, are entirely different (although the same to it) from those which we find in the fluid flowing for the animal which has longer breathed the air. How different, further, is the proportion of these consti- tuents in the milk of different animals! Although this depends partly upon the kind of food of the parent animal, yet here also the same proportion holds good for similar conditions of the suckling. There can, therefore, be no doubt that the proportions in which the four categories of nutritive elements are mingled, exercise a most decided influence upon the welfare of the organism, and that the mutual action of the different factors of nourishment is highly im- portant for the metamorphosis of animal tissue. However great variations nature institutes in the proportions, an unconditional preponderance of any one of the factors operates injuriously upon the proper course of the process of nutrition; hence a diminution of any one of them cannot occur without the concurrence of all; 278 ZOOCHEMICAL PROCESSES. thus, e. g., all the experiments instituted upon fattening, show that the carbohydrates alone will not suffice for the formation of fat in the animal body; in order that fat may be formed, protein bodies as well as salts must participate in the metamorphosis; a develop- ment of fat is only possible by the mutual action of these sub- stances; in fact, a small quantity of fat, introduced from without, seems, according to the experiments, to be, if not necessary, at least of great assistance to this process. We are better informed as to the absolute quantities of food re- quired for the maintenance of life and for the energetic perform- ance of all its functions, than as to the most favorable propor- tion in the mixture of the nutritive elements. We cannot assert, however, in regard to this question, that it has found a complete answer in all respects in the numerous investigations which have been made. In order to determine the quantities of food neces- sary to the animal organism, its secretions and exeretions have been quantitatively ascertained and compared with the quantities of food taken. This was done from the view that the need for food is regulated by the amount of waste; but, however simple and just this idea appears at first sight, many difficulties present themselves to its carrying out. The excretions, namely, depend far more upon the quantity of food taken, than the need for food upon the amount of the excretions ; for we have seen in the consideration both of the urinary excretion and of respiration, that far more nutritive elements may be taken up than are necessary for the maintenance of the animal functions, and that then the excreta are formed ina proportion nearly corresponding to the quantity of food received. Hence investigations upon inanition, so-called, were instituted, ¢. e., animals were deprived of all food, and their excreta, in the state of hunger, quantitatively determined. In this manner, the minimum quantities of nutritive elements required by the organism for the con- tinuance of life were ascertained; but experiments of this kind afford no test of the quantities of food which are necessary to main- tain an animal in perfect health, and in the full use of its externally active powers. Ifan animal were furnished only with such quan- tities of food as would correspond to the quantities of excreta found in the experiments upon inanition, it would have a worse than miserable existence, and could never arrive at a full use of its powers. If, on the other hand, as much food were given to an NUTRITION, 279 animal as it would consume, the case just alluded to would occur; far more food would be ingested, digested and absorbed, than would be necessary for the most energetic performance of its functions. A so-called superfluous consumption (Luxus consumtion) would then take place, in consequence of which a very large part of the food absorbed would either be again excreted, or at least not be ap- plied to the formation of cells, fibres, and tissues. In this way we might at furthest ascertain the maximum quantities of nutritive ele- ments which can enter into the metamorphosis of animal tissue. The ascertaining of the maximum quantities has, meanwhile, its value, as well as that of the minimum quantities. In these experi- ments, however, two circumstances must not be overlooked if they are to lead to practical results; viz: Ist, the animal subjected to them should not be taken during growth; and 2d, that condition should not occur which is usually denominated fattening. In both cases, through the detention of assimilated food in the body, this measure for the determination of the amount of the proper tissue- metamorphosisis lost. It is self-evident that during a greater energy of all the life-functions, during a considerable or continued exercise of the powers, a greater consumption takes place than in the state of rest or passive vegetation; the necessity of food then increases with the increase of the external activity. We might call this case that of consumption of labor. From all this, it is evident that the need for food is subject to excessive variations, and that it is, there- fore, extremely difficult to fix definite numerical values, which shall indicate the quantities of food that are necessary. Such experi- ments, conducted in this manner, according to the statistical method, would have led to far more exact and conclusive results as to the nutrition of the animal organism if two other factors, of the greatest consequence for the knowledge of the nutritive process, could have been taken more closely into consideration; namely, firstly, the knowledge of the quantities of the individual articles of food which can be absorbed in the intestines ; and, secondly, that of the alterations which the blood undergoes in consequence of the ingestion of certain quantities of differently mixed food. Experiments as laborious as careful have been instituted with reference to both of these ques- tions; but they do not possess such a degree of accuracy and agree- ment as to render them satisfactorily available for the explanation of the process of nutrition. According to experiments conducted 280 ZOOCHEMICAL PROCESSES. upon ducks, it may be calculated that in the intestines of an animal articles of food may be absorbed in about the following proportions:— -Protein-substance . 4 j ; : . 100. Gelatin . : Se % : i : . 836 Fat . : ; ; . i ‘ ; . 65 ‘Starch =. ; : ; ; ‘ ; . AOL Sugar. é Z : . 429 From other exes Gateway instituted on different mammalia), it may be calculated that for every 1000 grs. weight of animal there may be taken up from the intestinal canal in one hour only the following quantities of nutritive elements :— Protein-substance . : . 0.710 of a grain. Fat . ‘ ; ; ’ . 0465 « & & Sugar. ‘ ‘ . 4500 “" # Still less have numerical values been obtaited with reference to the influence of food upon the chemical constitution of the blood, as is shown by the following results of the investigations as to this point: After animal food, the “tendency to sink” of the blood-corpuscles increases, the color of the blood becomes somewhat darker, and its coagulation slightly hastened; the amount of fibrin is slightly aug- mented, as also its content of phosphates and salts generally — Fatty food oceasions, in the course of one hour, an increase of fat in the blood ; this, however, soon diminishes again. By the prolonged use of fatty food, the average amount of fat in the blood is not increased.— Vegetable diet renders the blood somewhat brighter ; the proportion of fibrin in it is not altered, while those of the fat and the salts, especially the phosphates, are somewhat lessened.— After ‘the last meal, the quantity of the solid constituents of the blood increases up to the ninth hour; it then begins again to diminish._— We are, therefore, not in a condition to follow in this manner the transformations of the elements of food in their individual phases, and hence must recur to the following statistical investigations for the determination of the quantitative metamorphosis of animal tissue. One of. the first questions which it was sought to answer by means of quantitative researches into the recepta and final excreta of an organism was the following: How are the products of disinte- gration, into which the nutritive elements fall during their service in the body, divided in the excretions? .A short and comprehensive answer to this question is not possible as yet, as the experiments concern- ing it have been made upon very different animals, with different NUTRITION, 281 quantities of various kinds of food, and under otherwise differing circumstances ; hence, we dare not at present fix certain numerical values, e. g., for man, for the reception of solid and fluid articles of food, and the division of the final products of transformation in the excreta. Although the cause of such differences is often easily explicable, yet they prevent almost all comparison. If, for instance, the elements of food are sought in the excretions, it appears that in carnivora far more of the food taken passes into the urine and the _ transpiration than in herbivora; this difference does not depend so much upon any actual difference in the tissue-metamorphosis of the animals of the two categories, but is to be referred to the fact that a large amount of indigestible material, or at least such as is inac- cessible to the digestive fluids, is afforded to the herbivora in their. food, which, therefore, reappears unaltered in the solid excrements, But, disregarding this circumstance, there are presented, according to the researches thus far instituted, several differences in quantitative tussue-metamorphosis between herbivora and carnivora. In the former, far less water is absorbed from the intestine than in carnivora. The difference is very great; thus, in horses and cows only one-half of the water introduced into the intestine is absorbed, while in dogs and cats, on the other hand, seventeen-twentieths are absorbed. Further, in herbivora, only fifteen to twenty per cent. of the water which is absorbed and that developed from the elements pass off by the kidneys, while in carnivora about eighty per cent. passes off in the urine. That the carbon absorbed is excerned through the lungs in much greater quantities by the herbivora than by the car- nivora (the ratio of the carbon in the urine to that in the air expired is in the former = 1 : 19, in the latter = 1 : 9.5) can arise only from the nitrogenised food of the carnivora, since the product of its trans- formation, urea, carries off a quantity of unoxidized carbon, while the carbohydrates are perfectly consumed, giving as their product carbonic acid and water, of which the former leaves the body almost solely by means of respiration; peculiar relations of organization can hardly be the cause of this phenomenon. We find a similar ratio with reference to the hydrogen in the animals of the different dietetic categories. The ratio of the hydrogen excreted by the urine to that excreted by the lungsis in herbivora = 1 : 23.0, in carnivora = 1: 8.8; the reason of this difference is the same as that which occasions the difference in the quantities of carbon excreted. ‘In regard, also, to the ratios of the excretion of nitrogen, a striking 282 ZOOCHEMICAL PROCESSES. difference is found with respect to the different categories of animals: herbivora excrete often of 100 parts of nitrogen absorbed in the pro- tein-bodies nearly 40 per cent., by means of respiration and perspira- tion, carnivora, on the contrary, scarcely one per cent. The cause of this difference is not quite clear; it may be supposed that, in the or- ganism of herbivora, the process of oxidation is so active, that a great part of the urea, which in carnivora is excreted as such in the urine, is further disintegrated ; this view is supported, in some degree, by the total absence of uric acid in the urine of herbivorous mam- malia. That the desquamation of the skin, or the growth and fall- ing out of the hairs, which consume a great deal of nitrogen, is greater in the herbivora than in the carnivora, and thus causes this remarkable difference, we are not justified in supposing, at least according to other observations.—If it is thought to be a necessary consequence of the researches to be afterwards mentioned, that, in the carnivora, all the nitrogen taken up with the food is excreted in the urine in the shape of urea, yet other researches (compare p. 189) have shown that, especially upon a scanty diet of flesh, a great part of the nitrogen thus taken up does not appear in the urine as urea. Hence, we cannot directly infer the amount of the metamorphosis of tissue as regards the nitrogenised materials, from the quantity of urea contained in the urine. Tn inanition, ¢.e.,, when the tissue-metamorphosis takes its course in the organism without the supply of fresh material from without, the proportions of the elements of the urine to those of the perspiration are almost the same as in nutrition by means of fatty flesh; for the . simple reason that the organism, when starving, lives, in a measure, upon its own flesh.—_An interesting relation of the excretion of the elements presents itself when the bile is discharged externally (by means of a fistula of the gall-bladder), instead of being poured into the intestine. Whether the quantity of animal food taken be great or small, 10 to 12 per cent. of the carbon absorbed, and 11 to 18 per cent. of the hydrogen absorbed, are excreted by the bile; in the urine, carbon and hydrogen are excerned in the same proportions as when the bile is poured into the intestine, and there resorbed; the loss of carbon and hydrogen, arising from the abduction of the bile, is wanting in the products of respiration; thus proving that the se- creted bile, after its reabsorption in the intestine, contributes to the process of respiration. Of the nitrogen taken up, only 3.0 to 3.2 per cent. pass into the bile, and this is found to be wanting, in the urine, when the bile is conducted off. NUTRITION, 9838 From experiments upon cats, it results that the minimum of food for the carnivora in the 24 hours is about 23, and the oxygen necessary for its consumption about ,, of the bodily weight. In starvation, on the other hand, the body of a carnivore loses (be- tween the third and ninth day of inanition), in 24 hours, only about 35 of its weight. Many carnivora (e. g. cats) are able to take so much animal food into their tissue-metamorphosis as to amount to 4 of their bodily weight, the oxygen necessary being zzth. These figures must, however, be regarded only as uncertain Tules, as in other experiments ratios differing considerably from these have been presented—On comparing the excretory products during scanty, with those during abundant, feeding upon meat, it appears, in the first place, that the quantities of the excretions stand nearly in direct proportion to the quantities of food taken; and, therefore, that the augmentation or diminution of animal food is without influence upon the proportions of the individual excretions, or upon their quality ; in all cases, the ratio of the oxygen absorbed in respiration to that exhaled in the carbonic acid = 100:79.3. In excessive use of animal food, however, the proportion between the carbonic acid and the water which are expired is altered; under scanty meat diet, more water is expired, relatively to the carbonic acid, than under abundant meat diet: in the latter case, relatively more water passes off by the urine and feces; under scanty meat diet, and total abstinence from drink, the proportion between the carbonic acid and the water is so altered, that, in this case, relatively to the carbonic acid, far more passes off through the skin and lungs. The following tabular arrangement of the figures obtained from direct observations, will afford the best view of the relations here pointed out. TI. has reference to the transformation of substances with the reception of the minimum of food, and water ad liitum ; II. Greatest amount of food with unrestricted access to water; IIT. Normal animal diet while deprived of water. Recepta and egesta. I. II. Ill. Meat (calculated asdry) . . . 100.0 100.0 100.0 Oxygen absorbed . . . ‘ . 167.0 166.0 167.3 Solid residue of the urine . i . 31.3 80.4 80.6 Solid residue of the feces . . - 1.7 2.5 17 Carbonic acid expired . 7 s 182.0 181.4 182.6 Watery vapor expired . : , : 187.6 76.4 | 152 6 Under these different conditions, therefore, the meat eaten is sub- 284 ZOOCHEMICAL PROCESSES. jected in the organism to one and the same process of combustion, similar to an elementary analysis, 7. e., 1 part of dry flesh-substance is in one case exactly as in the others, decomposed with the aid of 1.67 parts of oxygen into 0.81 of a part of urine substances, 0.02 of a part of fecal matter, and 1.82 parts of carbonic acid. As the lean flesh applied in such experiments contains 19.56 per cent. of albuminous. and gelatin-yielding substances, 4.74 per cent. of fat, 1.00 per cent. of inorganic matters, and 74.70 per cent. of water, and as there are contained on the average in the solid urine- residue after the ingestion of such flesh, 85.5 per cent. of urea, and 14.5 per cent. of salts (including 2.8 per cent. of sulphuric acid), and in the dried solid excrements about 63 per cent. of bile residue, there results the following balance for 1,000 grains of a carni- vore, supposing that it will consume in 24 hours 50 grains of lean flesh. 1000 grains of eit consume, Water. watauga Fat. Salts. during 24 hours— ing substances, 60.000 grains of flesh 87.350 9.780 2.370 0.510 21.125 es oxygen 71.125 grains in all. Intestinal Bile. 1000 grains of animal excrete, Ww: Carbonic ater. excrements. during 24 hours— acid, Urea..| Salts. 39.468 grains of perspiration 16.445 | 23.0238 30.761. “ urine 26.839 |... | 8.58 | 0.569 ee. ac 0.806 “ — feces 0.681 | ... | .. |0.041| 0.039 | 0.135 71.125 grains in all 43.965 se eee | 0.610 |- That the excess of water = 6.615 in the egesta denotes the water formed in respiration, scarcely need be mentioned; the increase to the amount of 0.100 of a grain is caused by the oxidation of the sulphur in the albuminates. According to these experiments, all the nitrogen of the food is excreted in the shape of urea, which is, however, incorrect, as we see from the previously mentioned ex- periments: as in them a deficit always presented itself. We do not know whither this nitrogen, which does not appear in the urine as urea, goes. We are therefore confined to the simple announce- ment of the facts relating to this deficit; it was relatively ahd abso- lutely greatest during insufficient meat- diet (3 of the nitrogen re- NUTRITION, 285 ceived); less (j of that received) during exactly sufficient meat-diet ; during very abundant meat-diet, it was relatively and absolutely diminished. When fat was devoured together with the flesh, this deficit was far less, so that then almost all the nitrogen actually appeared in the urine as urea. This deficit is also diminished, finally, by the free use of water (compare p. 189). The metamorphosis of the nitrogenised materials in the animal body is also considerably modified by the simultaneous ingestion of non- nitrogenised articles of food. The ingestion of fat, e. g., under all cir- cumstances, restricts the transformation of the nitrogenised materials of the body; thus, for instance, during perfect starvation, more urea is excreted than when non-nitrogenised food only is eaten. Ordi- narily, far less urea is excreted under a diet of fatty meat than corresponds to the quantity of protein-bodies received; but occa- sionally more urea is excreted than under a pure meat diet, as this deficit of nitrogen is lessened by the fat. Hence, especially, the quantities of urea excreted cannot be taken alone as the measure of the metamorphoses of the nitrogenised material ingested, since even in fully grown and old animals, sometimes more, some- times less nitrogenised material is stored away as tissue, and thus Yemains in the body. For it must not be forgotten that in excess of fatty food, nitrogenised material is applied to the formation of fat-cells, and on the other hand, in excess of meat-food, the fat in- troduced into the body, or formed there, is applied to the growth or renewal of the nitrogenised tissues.—It is such considerations, which render so exceedingly difficult an exact determination of the amount of the tissue-metamorphosis, even with the most exact sta- tistical researches of the kind described. Hence a number of highly important questions with regard to the metamorphosis of animal tissue must remain unanswered, and be left open for further in- vestigations: thus, ¢. g., the simple question, whether all the protein- bodies taken in the food must first be transformed into tessue-elements, before they form urea, or whether they may be immediately disintegrated in the blood into urea, carbonic acid, and water, cannot as yet be de- cided with certainty. The positive results of the researches hitherto made allow of so many interpretations, that we cannot, even with all the aid of our reasoning faculties, arrive at a degree of even relative truth. The observations which have been made upon animals deprived of all solid nutriment, can serve only for the confirmation of several 286 ZOOCHEMICAL PROCESSES, of the above stated propositions. The results of the best and most reliable of these experiments are as follows: The total loss of weight, which a starving animal undergoes previous to its death, varies according to the species; the animals perish when they have lost from 81 to 52 per cent. of their bodily weight. Carnivorous mam- mals (¢. g. cats) lose, before death, 51.7 per cent. of their weight; as they can live about 18 days after the withdrawal of all food, the daily loss of weight would amount to 2.87 per cent. Other animals lose during starvation on an average 4.2 per cent. of their weight in 24 hours; thus, within this period, ,4; of the mass of the body is lost, which corresponds with the above-adduced results of experi- ments with exactly sufficient nutriment. From the first to the eighth day, the bodily weight diminishes (in cats) regularly, corre- sponding with the quantity of carbonic acid expired ; afterwards the excretion of carbonic acid diminishes less than the bodily weight; and only during the last two days of life does the carbonic acid excre- tion sink more considerably as compared with the loss of bodily weight. The kidney excretion diminishes very considerably as com- pared with the loss of weight of the animal, and then remains almost exactly proportional to it until the 16th day; it sinks materially, like the carbonic acid excretion, during the last two days. The urine becomes richer in phosphoric and sulphuric acids, as also in extractive matters; the chlorine compounds disappear from the urine after the first "fow days. The proportion between the phosphoric and sulphuric acids remains constant during the whole period of inanition. As the carnivora (cats) subjected to inanition, perspire in every 24 hours, 2.16 per cent. of their bodily weight of carbonic acid, and 1.6 per cent. of watery vapor, and excrete 0.20 per cent. of uréa, 0.008 per cent. of sulphuric acid, 0.011 per cent. of phosphoric acid, and also 0,080 per cent. of dry feces (including 0.020 per cent. of bile-residue), and 2.24 per cent. of liquid water by the kidneys and rectum; it may be calculated that on the average in the period named 0.611 per cent. of the bodily weight of muscular substance, and 0.422 per cent. of fat are subjected to disintegration during inanition. From the determina- tions of the loss of weight which each individual organ undergoes during starvation, it results that the total loss of the body is caused mainly by the destruction of the substance of the muscles, the blood and the fat. According to particular calculations of the diminution of the bodily weight, one-half comes upon the muscular tissue, one- NUTRITION, 287 fourth upon the fat, and one-fourth upon all the other organs, Thus it was found, e.g. that in cats during an inanition period of 18 days, the blood had suffered the loss of 98.7 per cent. of its original weight, the fatty tissue, 80.7 per cent. and the muscles, 66.9 per cent. The observations upon animals which were deprived of all fluid nourishment have thus far led to the following results: the ani- mals always take less solid food, and hence the excretions are considerably diminished. During a 12 days’ period of thirst, a dog discharged, on the first day, 926 grains of urine, on the seventh, 870 grains, and on the twelfth, only 108 grains; the skin peels off, and the hairs (in birds, the feathers) fall out; the excrements become brittle or hard. The quantity of the egesta exceeds far that of the ingesta; hence the considerable diminution of the bodily weight. Pigeons lost daily, during deprivation of water, 3.7 per cent. of their weight, and after 12 to 13 days’ thirst, 4.6 per cent. The greatest part of the decrease of weight fell here also upon the muscles, the skin, and the fat; while the brain, eyes, and spleen presented no material change. One of the most important questions in relation to the conditions of nutrition of the animal organism, has reference to the ascertaining of the relations of food to the metamorphosis of tissue, as with it is con- nected the increase of the weight of the body, and hence growth, and that kind of increase of bodily weight which is denominated the becoming fat. Unfortunately, we must yet wait for the answer to this inquiry. Several series of experiments have indeed been presented which are concerned with this condition; but they are not sufficient to direct us to any general conclusions, on account of the continual variations to which the bodily weight is subject, even under per- fectly normal circumstances, as the consequence of the deposition and destruction of the tissues. Even the researches into the tissue- metamorphosis in the egg during incubation, are still too few or not accurate enough to authorize the attempt to draw general con- clusions from them.—It needs only to mention here, that certain substances introduced into the body with the food, diminish the transformation of the nitrogenised matters, and hence possibly con- duce to the more abundant deposition of nitrogenised tissue- material; while others, such as chloride of sodium, or abundant ingestion of water, appear to hasten their transformation, and inter- fere with this deposition. , 288 ZOOCHEMICAL PROCESSES. As the science of the process of nutrition is the culminating point, ‘or final object of all physiologico-chemical investigations, it is not surprising that this chapter has afforded relatively the least scientific profit; for all the chemico- physiological investi- gations hitherto made, have only tended to establish first a firm basis for the review and examination of this process at large and in general. We are still, however, so far behind in the theory of nutrition, that we must content ourselves with investigating the balances between the recepta and excreta, in order to form even the outlines of a representation of the tissue-metamorphosis in general. We must look to the future for an investigation of the internal exchange of elements in the process of nutrition, of its in- dividual members and stages, of the so-called intermediate tissue- metamorphosis, in order to obtain an exact scientific comprehen- sion of the chemical phenomena of life. APPENDIX. 19 oF CIRCULATION. By this term we understand the distribution of the blood throughout the organism during life, connected as this is with the various functions taking place in the system which have been already, in great measure, described in the previous part of this work—such as secretion, nutrition, digestion, respiration, and ex- cretion. For the maintenance of the circulation, we find an apparatus provided which may safely be characterized as the most perfect hydraulic apparatus in existence. Nearly all the phenomena - which pertain to the circulation may be readily explained on the ordinary principles of hydrostatics and hydrodynamics; our object, however, in this chapter, is not so much to illustrate the truth of this proposition as to call attention to the adaptation of the me- chanisms here found to the execution of the life-functions. We shall therefore consider the subject under the following divisions— the Heart, and Arteries; the Veins, and the Capillaries, We might also divide it with reference to the so-called greater and lesser cir- culations, or the circulation through the system generally, and that through the lungs, but we hardly consider this as warranted by the difference in these two great branches of the circulatory system. THE HEART AND ARTERIES. From all parts of the system the blood is brought to the heart by means of the veins, and thence is driven onward through the arteries to supply again the various parts with that fluid which is necessary for their vital activity. In man, and in all the upper classes of animals, the heart is double, and two sorts of blood are brought to it, each of which is forwarded by that organ in its pro- _per course. Oxygenated, and, in a great measure, depurated blood, is brought from the lung-capillaries through the pulmonary vems 292 ‘ APPENDIX. to the left side of the heart, to be sent thence through the general arterial system in order to subserve the general tissue metamor- phosis, and to the kidneys and skin, there to lose other effete matters which are not discharged by the lungs; while, from the right side of the heart, the blood which has accumulated from the system at large, bringing with it the products of the tissues disin- tegrated in the life-processes, and also the results of digestion, is propelled through the pulmonary artery to the lungs, there to undergo such changes as shall fit it again for the general purposes of nutrition, and which have been fully treated of under “ Respira- tion.” As the blood enters the heart, it is dilated, from the base to the apex, gradually at first, then toward the last it is suddenly distended, and immediately contracts in the same direction, 7. e, from the base downwards. The dilatation of the heart is called the diastole, and is divided into two stages—the passive (during which the blood flows quietly through the auricle into the ventricle), and the active (in which there is apparently an active dilatation of the heart in order that it may be filled to its entire extent); this is then followed by the systole or contraction, which takes place first in the auricles (they thus emptying themselves into the ventricles), and next in the ventricles, the tricuspid and mitral valves being closed partly by the current of blood thrown against them and partly by the action of the columnee carnez attached by the chords tendinexe to their edges; the blood contained in them is thus forced into the aorta and pulmonary artery. Its return into the ventricles upon the relaxation which follows is prevented by means of the semilunar valves placed at the orifices of these arteries, which are closed by the pressure of the returning column of blood. This period of* activity of the heart is then followed by one of comparative repose, nearly equal in length, when the same phenomena are again ex- hibited. They may be observed readily in the frog after the removal of the sternum, or in the sheep, the animal having pre- viously been rendered insensible by means of a blow upon the cranium, and respiration being artificially maintained. The rapidity with which the blood passes through the heart may be conceived of by recalling to mind the experiments performed by injecting ferrocyanide of potassium into one of the jugular veins of a horse, and noting the time which elapsed before its appearance in the other; in twenty seconds it had traversed the lung-capillaries, the heart, the carotid artery and its capillaries, and reappeared in THE HEART AND ARTERIES. 293 the jugular vein of the opposite side.” Allowing three fluidounces to be the quantity propelled by each contraction of the left ventri- cle, each particle of blood in the body would pass through the heart in a little more than one minute. Here we find an apparent discrepancy in the results of these two modes of investigation; we are not at present able to decide which of them is the most reliable. The force with which the blood is sent from the heart through the system is more accurately determined; this is done by means of the so-called hamadynamometer, which, in an improved form, consists of a glass tube, provided with a stopcock, and terminating in a U-shaped tube; the U is partly filled with mercury, and a small quantity of a strong solution of bicarbonate of soda is placed upon the mercury (to prevent the coagulation of the blood from interfering with the experiment), the straight portion of the tube being then attached to the artery, the stopcock is turned, and the depression ensuing in one leg of the U, and the corresponding ele- vation in the other, are noted; we thus have a measure of the pressure exerted by the heart upon the blood in the artery experi- mented upon. This has been found to be equal, in the aorta, to four pounds three ounces. Both the frequency and force of the current of the blood, as was to be expected, are found to diminish as we recede from the heart to the extremities. 5 When blood is forced into the aorta, the elasticity of its walls: causes it to be lengthened and increased in diameter at the first impulse, and then to contract again, propelling the blood onward through its branches, in which the same process is repeated. A great advantage is attained by the elasticity of the arteries (which is due principally to their middle coat) in the equalization of the current of the blood. By this means the blood which is propelled in jets in the larger arteries is made to flow more regularly as it approaches the capillaries. A loss of power is, however, expe- rienced, which is compensated in some measure by the introduction into the middle coat of the smaller arteries of contractile fibre-cells. These promote the current of the blood through the smaller arte- ries; they are, in great measure, under the influence of the sympa- thetic nervous system (as may be proved in the rabbit by section of the sympathetic, which produces a dilatation of the minute arte- ries on the side injured), and give rise, probably by their degree of contraction, to the tonicity of the pulse: thus, when they are stimulated to excessive action, we will find the pulse at the wrist 294 APPENDIX. corded and small; when, on the contrary, they are relaxed, the pulse will be full, soft, and compressible. THE CAPILLARIES. There is every reason to believe that in connection with these vessels, nearly all the phenomena which characterize life take place; the importance of their functions is hence readily perceptible. They receive from the arteries (in the systemic circulation), blood which is oxygenated and loaded with materials destined for the nutrition of the various tissues, or for the formation by the organs of their secretions and excretions; the changes accompanying these processes take place either within or around them; they receive from these tissues and organs their debris, the various products, such as carbonic acid, water, &c., which result from their vital activity, and consign them in their turn to the veins. The various pheno- mena here occurring can be but partially explained as yet, owing to the fact that only their results, generally speaking, are accessible to direct observation. We may refer for a view of some of these to p. 197, where, in treating of the formation of the urine, the mechanical arrangements for its excretion are fully explained. The same principles are applicable elsewhere ; but one phenomenon remains open for discussion, the movement of the blood through the capillaries. The area of the capillary rete is enormously increased as compared with that of the arterial system: and the diminished force of the heart’s action is in all probability wholly insufficient to drive the blood over this vastly increased extent of surface (some authors compute it as 400 times as great). We also frequently see in disease a great disproportion between the heart’s action and the capillary circulation; and in inflammation, for instance, of one hand, the amount of blood passing in a given time through an in- flamed part is greater than that passing through the corresponding healthy part, although the heart propelling the blood must obviously act equally on both. These facts suffice to show that the capillary circulation is maintained by some power besides the action of the heart, and that the metamorphosis of tissue must take place in connection with their function. Two factors cf this movement may be recognized: 1st, the chemical attraction of the tissues beyond the capillaries, and in which they are imbedded jor their contents ; and 2d, the capillary attraction of the capillary walls themselves. The THE CAPILLARIES, 295 capability of chemical affinity to produce molecular motion need not be here discussed; it must be evident that the tissues and organs will attract to themselves the arterial blood so rich in the oxygen which they need for their transformations, while the venous blood, loaded with carbonic acid, water, and their other products of vital action, is forced on into the veins. The same takes place in the capillaries of the lungs; the blood which is rich in carbonic acid presses forward to exchange its excess for the oxygen which abounds in the air-cells; this done, it becomes indifferent, and is moved onward by the vis d tergo of other portions pressing forward to make the same exchange. Direct experiments prove the cor- rectness of this reasoning ; if access of air be limited, the blood is found to accumulate in the arterial system; the pressure in the arteries Increases as long as the heart’s action is maintained, as shown by the hemadynamometer. Venous blood is also found to have accumulated in the arteries of the lungs, giving rise to their congestion. The importance of the second coefficient of this capil- lary movement is proved by the experiments performed with the view of determining the relative rapidity of passage of fluids of different densities through capillary tubes; e.g. alcohol passes much more slowly than water, &c. The distribution of the capillaries in the tissues and organs is well worthy of notice, each tissue having a mode of capillary arrangement peculiar to itself. The description of these modes, however, belongs rather to minute anatomy than to physiology ; we therefore merely remark, in this place, that as the physiological function of a substance stands in close relation to its chemical nature, so also the mechanical arrangements, by means of which a part is supplied with nutritive matter, will be of the greatest moment in determining its mode of nutrition, ¢.e. the substances which it will abstract from that complex pabulum, the blood, its subsequent action upon these substances, and the materials which it will return into the blood. We are not yet able to follow the steps of this process, on account of our ignorance of the intermediate stages between albumen, &c., and the principles of organized tissues. But the proposition which we are seeking to establish is evidently a corollary of the great physiological truth that form always corresponds to function; that is, where the functions are similar, we have similar forms or apparatus for their performance ; and where they are different or special, we have different or special 296 APPENDIX. apparatus for their performance. Hence we need not have recourse to the supposition that there exists in any parts or tissues of the body a so-called selective affinity, or sort of intelligent attraction, for the substances appropriate for their nutrition ; the arrangement of their capillaries necessitates the transudation of the materials required as much as the laws of chemical affinity control their com- binations. - THE VEINS. The functions of the venous system seem to be much more simple than those of the capillaries; they may be summed up in great measure as follows: They receive the blood which, having subserved the purposes of nutrition, secretion, or excretion, is to be conveyed back to the heart in order that it may be sent thence, in the case of the systemic blood, to the lungs, to be freed from part of its water, carbonic acid, &c., or in that of the aerated blood, from the lungs, to be distributed throughout the organism. To this it may be added that absorption seems to’ take place through the veins more readily than through any other part of the circulatory system; the capillaries also possess this power to a great extent, but it is the venous capillaries and radicles which principally perform this function. The rapidity of the blood-current through the veins is less than that through the arteries, as their surface is much greater; it is maintained principally by the vis @ tergo of the blood in the capillaries, with the aid probably of the respiratory movements, and the onward current of the blood in the arteries as a wis a fronie, while the contraction of the muscular tissues surrounding many of them would propel the blood contained in them, the valves pre- venting its regurgitation. REPRODUCTION. UNDER this head are included all the phenomena which have for their object the formation of new individuals resembling in all respects the parent individuals. Throughout all organized nature, the law prevails that every living organism has proceeded or been derived from a pre-existing organism, i. e., is not merely the result of the unaided action of the ordinary forces of nature, occurring or not by chance, but is the direct result or effect of a vital force operative in accordance with certain laws. In the lowest orders of existence, the individuals of which are composed of cells, or aggregations of cells, the production of new individuals often takes place by the process of gemmation or subdivision; this process we shall also notice as the first step towards organization in the fecundated ovum. Advancing in the scale of existence, we find individuals composed, not as before, of similar cells, all performing the same functions, but an adaptation of certain cells to the performance of certain functions, &. The organism is now more complex, and often passes through several stages of development before it is per- fected ; still we find often that it is propagated by gemme originat- ing from the parent being. In these beings, on the borders of existence, we notice another phenomenon which is not observed among higher beings, at least to any extent, viz: when a portion of an individual is removed a similar portion is soon developed; indeed, the whole animal may be divided into small pieces, each of which will then grow and complete itself, so as to resemble the original animal. ; But, when any degree of development is attained, we find special organs set apart for the formation of new beings and the perpetua- tion of the species; so universal is this proposition that it has been said “omne vivum ab ovo’—a law to which at present we know of no exception; the apparent one of gemmation ceases to be such if 298 APPENDIX. we regard the gemmated offspring as part of the original individual. Another proposition of universal applicability is, that for the forma- tion of a new individual, it is necessary that the two opposite sexual elements should be united. These may be contained in the same individual, as in hermaphrodites, or may be formed in different indi- viduals, the union being accomplished in various ways in the dif- ferent classes of beings. These sexual elements have been desig- nated the germ-cell and the sperm-cell. The former, which is supplied by the female, is imbedded in a mass of plastic matter, the yolk, which is capable of being assimilated by the germ-cell and trans- formed (when the latter has been fertilized by means of the sperm- cell or male element) into a mass of germs, from which the future organism is to be developed. For this development, as stated by Dr. Jackson in his introduction, there are necessary a due supply of oxygen, a certain temperature (differing in different classes of beings, but fixed, within certain limits, for each), a supply of proper plasma, and the presence of organic force, which is produced by this union of the contents of the sperm-cell and the germ-cell. The only apparent exception to this law is that of so-called parthenogenesis, or the production of one or more series of individuals without sexual intercourse. This takes place especially among the aphides, whose mode of propagation may be described as follows: in the autumn, sexual intercourse having taken place, ova are formed and deposited so as to be hatched in the spring; these, after passing through the larva state, are developed into perfect aphides, all of which are females; they, however, give birth to successive progenies of female aphides; the latter also possessing the same power; this continues until autumn, when males are also produced, sexual intercourse takes place, and ova are deposited as before. But this apparent exception is easily explained on the hypothesis that a quantity of superfluous germ-mass is inclosed in the body of each aphis, from which the successive individuals are developed. That superfluous germ-mass is often stored up in the organisms of the lower orders of animal life, we see demonstrated by the renewal of whole limbs, &c., after their loss, as in crabs, lobsters, &c. Passing, then, at once to the consideration of the process of repro- duction in the human species, we shall take up the phenomena which are exhibited in the development of the foetus. The nature, appearance, &c., of the human sperm-cell, or spermatozoon, has already been sufficiently described; it only remains to state that in REPRODUCTION. 299 this microscopic molecule resides all the influence which the father exerts over the organization of his offspring. On the other hand, the mother contributes not only the essential female element, the germ-cell, but also the nutrient material for the development of the footus. This germ-cell, or germinal-vesicle, as it is generally termed, with its nucleus or germinal spot, occupies originally the centre of the vitellus, or yolk (true yolk, or germ-yolk, as distinguished from. the food-yolk of the eggs of birds); but, when the ovum is mature, it approaches as nearly as possible the peritoneal covering of the ovary. The vitellus is surrounded by a membrane called the zona pellucida, and floats in the cavity of the Graafian vesicle, the interior of which is lined by a layer of epithelial cells constituting the discus proligerus. The ovum, then, consisting of the zona pellucida and its contents, having been matured in the Graafian vesicles of the ovary, escapes into the Fallopian tube on the rupture of the Graafian vesicle, and is thence discharged through the womb into the vagina; or being fecundated by the contact of the male element, the spermatozoon, a series of phenomena, the most wonderful in all nature ensues. As it passes through the Fallopian tubes, it receives an additional layer of a fibrino-albuminous nature, the chorion. This is organized primarily into fibrils and nucleate cells, the latter sub- sequently passing into connective tissue and bloodvessels; it is villous or shaggy on the external surface, and insinuates its villosi- ties or tufts into the interstices of the decidua; after the develop- ment of the foetus has reached such a point that sufficient nutriment for it can no longer be derived from the fluids thus absorbed from the matters secreted by the uterus, the vascular element of the cho- rion becomes excessively developed at one spot, a corresponding vascular growth taking place on the walls of the uterus. Between the foetal and maternal blood thus brought into close approxima- tion, intercurrents are established, carrying from the foetal to the maternal blood the products of the tissue metamorphosis of the embryo, and from the maternal to the foetal fresh supplies of oxygen and plasma, for the maintenance of the life-functions of the latter. In the uterus itself certain changes take place upon the occurrence of conception. The mucous lining of the uterus secretes a tough viscid mass, called the membrana decidua. As the ovum enters the uterus from the Fallopian tubes it pushes before it, according to the older authorities, a layer of this deciduous membrane, constituting the decidua refleca ; while that which covers the uterus is called the 300 APPENDIX. decidua vera: according, however, to more recent researches, the ovum is lodged upon the internal surface of the decidua, which then grows over and around it. We next come to consider the changes which take place in the fecundated ovum itself. The spermatozoids have been traced clearly in the zona pellucida, but their further progress into the germinal vesicle has not been observed; so that we must remain contented for the present with the knowledge that, in some manner (probably by endos- mose), the contents ‘of the two cells are mingled. The germinal vesicle then disappears, and in its place we have a granular mass called the yolk-mass, containing a nucleus; a fission of this mass and its nucleus into two similar masses then occurs, and this pro- cess is repeated until we have the whole of the yolk-mass (occupy- ing the place of the original germinal vesicle) subdivided into cell- like bodies, which become true cells by the development of an investing-membrane around each of them, and then constitute a mulberry-like mass. Gradually, this agglomeration of cells is seen to separate itself so as to form two layers, differing considerably from each other in appearance; the external or serous layer is that from which are to be developed the tissues and organs of animal life; while the mucous er internal layer is devoted to the formation of the tissues and ergans of vegetative or organic life. One spot in these layers is next noticed to be darker than the surrounding; this is called the area germinativa; at first of a rounded shape, it gradually becomes ovoid, and clearer near the centre; the name of area pellucida is applied to this part, and that of area vasculosa to the outer part of the area germinativa. A‘dark line is then observed in the middle of the area pellucida, the primitive trace, formed by a groove in the serous layer; this is gradually deepened by the growth of the adjacent sides of the serous layer so as to form the lamine dorsales ; these gradually approach at their summits so as to convert the primitive trace into a tube. We thus have formed the rudiment of the cra- nio-vertebral system. At the same time, a layer of cells is being developed between the serous and mucous layers, termed the vas- cular layer ; the walls of these cells are developed into capillary “bloodvessels, while their nuclei probably serve to originate the blood-dises; a distinct vascular rete is now seen to extend itself over the périning? area, and thence over the whole of the vitelline membrane, serving thus as a means for carrying the unassimilated REPRODUCTION. 301 yolk to the embryo until it is exhausted. From the lamine dor- sales, prolongations next take place outwards and downwards, to form the transverse processes of the vertebra: and the ribs, thus inclosing the abdominal cavity. A portion of the yolk is thus included in the embryo, communicating with the rest (now known as the umbilical vesicle) by the vitelline duct. The mucous layer aids in this process by rising on each side of the embryo, and arch- ing over so as to meet and unite in the median line, thus forming the rudiment of the intestinal canal. The serous lamina beyond the area germinativa is meanwhile seen to rise up all around the embryo in a double fold until it meets, and forms thus a double investment of the embryo; this membrane is called the amnion. Its external layer covers the internal surface of the chorion, while the inner constitutes a distinct membranous covering of the foetus, and contains a peculiar fluid, the liquor amnii. From the caudal extremity of the digestive tube, a mass of cells is next observed to be developed ; in the centre of these a cavity is formed, and the whole vesicle, the allantois, is then developed until it reaches the part of the chorion which is in closest vascular connection with the decidua; the capillaries of the embryo are extended through its walls, and come thus into connection with the villous tufts of the chorion, which soon become converted into capillary loops, dipping into the substance of the membrana decidua. In the latter, bloodvessels and sinuses communicating with the circulatory system of the mother have been developed, and the foetal blood is thus brought into close connection with that of the mother; its effete matters are absorbed, and it returns to the foetus duly oxygenated. When the allantois has performed (in the human embryo) the office of carrying the bloodvessels to the chorion, and aided in the depurat- ing process by its communication with a large surface of the cho- rion until a more direct mode of exchange is formed by the growth of the placenta in the same manner as just described, it shrivels up, and remains only as a minute vesicle upon the umbilical cord. The same take place with regard to the umbilical vesicle, the con- tents of which have now been exhausted. The circulation of the fluid in the capillaries of the embryo, and the gradual formation of the heart, arteries, and veins, are phenomena of great interest. After the formation of the vascular layer and the area vasculosa, the fluid contained in the vessels is seen first to move to the em- bryo; then a pulsatile movement is observed in the part of the 802 APPENDIX. bloodvessel walls which is to constitute the heart; this motion becomes stronger, the wall of the tube is thickened, and muscular tissue is developed in it; it is soon divided into three cavities, the auricle or receiving cavity, the ventricle or propelling cavity, and the bulbus arteriosus, or commencement of the aorta; it is also doubled on itself. The blood passing into the aorta is propelled mainly toward the head and upper portions of the embryo, causing them to be developed more rapidly than the inferior portions. It is also distributed, as mentioned, over the umbilical vesicle, to absorb the nutriment stored up in it, and over the allantois for the purpose of depuration and renovation by the fluids absorbed by the chorion from the decidua. After some time, however, the ven- tricle is divided by a septum, and the auricle also to a certain degree; the umbilical vesicle being exhausted, and the placenta being substituted for the allantois, the embryo derives its nourish- ment from the circulatory fluid of the mother; the three or five arches to which the bulbus aorticus gave rise are transformed into the bloodvessel distribution of the adult; the blood returned from the placenta is sent nearly unmixed by the foramen ovale to the left auricle, left ventricle, and thence to the head; while the sys- temic blood is directed into the right ventricle, ductus arteriosus, and descending aorta, thence to be distributed to the system, and to the placenta. For a description of the foetal circulation, we must refer to General Anatomy. It only remains to notice the. forma- tion of the liver and other great organs of the body. The simple digestive tube already described is soon transformed and marked out so as to indicate the future stomach, small and large intestines. At one spot on the small intestine a mass of cells is seen to be formed, with a central cavity or cecum communicating with the digestive tube; this is gradually elongated and developed so as to form the biliary duct, while the same process is continually re- peated in it, and bloodvessels distributed through the mass, until the liver is formed. The pancreas, salivary glands, and lungs are developed by a repetition of the same process. The kidneys are preceded by two peculiar bodies, known as the corpora Wolffiana ; these commence as prolonged tubes lying on each side of the ver- tebral column, being gradually furnished with numerous ccecal appendages, and secreting a fluid which they discharge into the uro-genital sinus which communicates with the allantois by means of the urachus. Behind them, the kidneys are developed from a REPRODUCTION. 8038 mass of blastema; at first distinctly lobulated, they gradually attain the character which they have in after life; as they are developed the Wolffian bodies are atrophied, leaving finally only the rudi- ment which descends with the testis into the scrotum, the excretory duct of each constituting the vas deferens. For all further account of the development we must refer to General Anatomy; our object here is not so much to give a detailed account of the development of the foetus, as to illustrate the action of organic or formative force in bringing almost shapeless matter into the likeness of the human form divine. In the deficiency of any one of the conditions already named as essential for vital action we have corresponding deviation in the resulting foetus; and here, as also in the arrest of development, are we to look for the explanation of the anomalies and monstrosi- ties so often presented. In fact, no more convincing proof could be adduced of the regular action of the laws of vitality, and of repro- duction in particular, than the recent classification and reduction to system of these very monstrosities. As, too, an imperfect being can only produce an imperfect plasma, we have explained the fact of hereditary transmission of disease, a fact inexplicable on the hypothesis that our organisms are the results of the action merely of the ordinary imponderable agents. LIFE-PHENOMENA. HiTHERTO we have considered the constituents of the animal organism, the proximate principles which are found therein, their products of decomposition, and the modes of their entrance into, and exit from the economy. We have studied the arrangements of the organs, and the results of their actions. We have not, how- ever, hereby studied Physiology; we have only learned the appa- ratus, the tools, the mechanism by means of which, and in which, nature guides the series of processes which we call Life. We must look further, and seek to investigate the forces which control and act through this mechanism. In this effort, however, we are met by the difficulty that the source of these forces, as well as the evi- dences of their subsequent action, is to be sought in the organism itself; so that in the living body we have presented the phenomenon of a machine which organizes itself from materials furnished to it, produces the forces necessary for its action, repairs its own waste, and provides for the creation of similar machines; finally ceasing to act, and restoring the material appropriated by it when the original cause of the action is exhausted, or when it is checked by some countervailing force. Are the ordinary forces of nature ade- quate to this task? Wecan observe their action in organic bodies, and have seen that it is precisely analogous to their action in the inorganic world, allowance being made for the difference in the substances acted upon; but in all the phenomena of life there is a difference, real and essential, which shows itself even in the term vital, as applied to distinguish them from the ordinary results of natural forces. Can the latter form an organic cell, endowed with the properties of nutrition, development, secretion, excretion, and reproduction? No one pretends ever to have seen a single instance in which this has occurred. And yet we are told that it is unphi- losophical to suppose that when all known causes are insufficient LIFE-PHENOMENA, 805 to account for a series of phenomena, there must be some other cause still unknown which produces them. If none but the ordi- nary forces of nature are concerned in the production of life-pheno- mena, why do we find that, suddenly or slowly, without the appre- ciable diminution of any one of these forces, the whole of these phenomena cease, and, instead of them, the ordinary results of the action of these forces take place? When we find a certain series of phenomena taking place in a fixed sequence, and capable of being formularized into certain laws, we infer that there must be a certain force which produces them; this is pre-eminently the case with life-phenomena. It would have been less irrational and unphilo- sophical to have maintained, in the days of the alchemists, that no such force as chemical affinity could exist, because its laws were very imperfectly known, than to insist, at the present day, that . vital force is an unnecessary assumption because we cannot fully unravel all the mysteries of its action. The common object which all life-phenomena tend to accomplish is, the maintenance of form with the change of material, Whenever deviations occur from this, they are the consequences of external influences; and death is no- thing more than the cessation of this process. Other general laws of life might be adduced, as the one previously referred to, that the structure of organs corresponds closely with their function—or the one, that each individual seeks to repeat the type of the parent; but the dis- cussion of these points is foreign to the object of this work, and we think that sufficient has been said to convince any thinking man that the supposition of a wital force is not unnecessary; and that it acts uniformly in accordance with definite laws. It is not the sole cause of the operations of the organism, but acts in it with the ‘other forces which act everywhere throughout nature, and con- trolling them in the same sense as magnetism may be said to control the gravity of a piece of iron suspended to a magnet, The phenomena of life presented for our consideration in the human organism may be arranged in three classes, viz: those of vegetativity, animality, and spirituality. Those of the first are common to all organic nature, vegetable as well as animal ; those of the second are peculiar to animals; while the consideration of the third class belongs to metaphysics. 7 7 The phenomena of organic life, or vegetativity, are nutrition, secretion, excretion, reproduction, and irritability. These take place by the agency of the organic cell, under the conditions men- 20: 806 APPENDIX. tioned in the Introductory Essay of Dr. Jackson, viz: when there are present a sufficient supply of germ force, heat, oxygen, and the proper plasma or organizable material. The deficiency or absence of any one of these four conditions is accompanied by other pheno- mena, but not by those of vegetativity. The property of irrita- bility belongs to all organized beings, and may be defined as that property which causes them to contract on the application of appro- priate stimuli; it must-be distinguished from muscular contract- ility, and from sensibility, which imply the action of special organs, and are properties only of animal tissues. The remaining phe- nomena of vegetativity are fully discussed by Dr. Lehmann. The phenomena of animality occur only in the animal kingdom, and may be divided into general and special. The first class con- sists of the phenomena of sensibility, which depend upon an irrita- tion communicated to the nerves supplying the tissues which then . cause them to contract; this property of the tissues gives rise to their tonicity. It is probable that we are to seek in the sympathetic system for the source of this property as well as (in some measure) for that of the chemical actions which take place in the animal body. That the sympathetic system influences materially the che- mical processes seems to be indicated by the results of numerous vivisectional experiments. The special phenomena of animality may be arranged under the heads of Muscular Contraction, Volition, Voice, Hearing, Vision, Smell, Taste, and Touch. For each of these a special apparatus is required, the structure of which is learned from General Anatomy; we now enter upon the considera- tion of them individually. Muscular Contraction. The muscles of animals are divided into two classes, the voluntary or muscles of animal life, and involuntary, or muscles of organic life. These differ in their structure as well as in their function: thus cor- responding ‘with the general law already alluded to. The nervous system may be divided into the cerebral, cerebro-spinal, and gan- glionic systems, each of which has its special functions: the cere- bral system, consisting of the cerebral hemispheres, seems to be the instrument of the intellectual faculties; the cerebro-spinal, consisting of the cerebellum, medulla oblongata, and spinal marrow, regulates muscular action ; and the sympathetic (closely connected, however, with the cerebro-spinal), presides over the various organic move- MUSCULAR CONTRACTION, 307 ments. From this it will be seen that muscular contraction seems to depend, in the living body, upon the action of the cerebro-spinal axis. When an impression is made upon a surface, intelligence of it (so to speak) is conveyed to the nerve centres corresponding with the surface, by means of the nervous communication, when an influence is immediately sent to the muscles of the part, deter- mining their action. Supposing a nerve to be destined for each of these functions, the one performing the first would-be called the afferent or excitor nerve; the other, the efferent or motor nerve. The existence of this circuit (so to speak) is clearly proved by vivisections, and the muscular contractions are more striking when the influence of the will is removed. The seat of the sensation seems to be in the posterior columns of the spinal marrow, and that of the motor force in the anterior columns. In all cases, the ganglia, composed of gray neurine, seem to be the originators of nerve-force, the tubules, composed of white neurine, acting merely as its conductors, and as commissures to the ganglia, promoting their consentaneous action. The performance of the functions necessary to life depends upon the conveyance to the different organs of the force necessary to direct and control their actions. If anything prevents this conveyance from the proper centre, as the interruption of the communication, or of the generation of the requisite force, death results. Thus, injury of the respiratory tract of the medulla oblongata, or section of the pneumogastric nerves on both sides, destroys life by putting a stop to respiration. The apparatus is perfect, but the force is wanting to set it in motion. Puncture of the medulla oblongata at the point of the calamus scriptorius, is also followed by instantaneous death. The division of muscles into voluntary and involuntary, cannot be strictly maintained : for the will is not without influence over the con- traction of involuntary muscles, and further, the voluntary muscles often act independently of the will. A marked difference occurs in their mode of contraction : in voluntary muscles parallel bundles of fasciculi contract alternately, while in involuntary, the contraction occurs consecutively, as in the peristaltic contraction of the mus- cular coat of the intestine. The phenomena of muscular contrac- tion on the application of galvanic stimuli are still too little inves- tigated to allow of our giving here any account of them. Much light has recently been thrown upon them, but much still remains to be cleared up. The amount of muscular force expended daily . ww 308 APPENDIX. in maintaining the various functions of the economy has been already alluded to by Dr. Jackson; and the structure of muscular tissue, the chemical changes occurring in connection with its activ- ity, are fully discussed by Dr. Lehmann. Volition. The phenomena connected with this subject are too complicated, and too closely associated with the phenomena of intellect, to per- mit our entering upon them in this connection: they lie beyond the aim of the present work. Suffice it to say that they embrace the reception of the impressions made by the outer world upon our senses, the action of the mind upon these impressions, and the con- sequent determination of the individual. Voice. The voice is produced in the larynx by means of the vibration of the vocal chords. For a description of the mechanism of the Fig. 34. Brrp’s-EYE VIEW OF LARYNX FROM ABOVE :—G, E, H. The thyroid cartilage, embracing the ring of the cricoid r, u, xX, w, and turning upon the axis 2 2, which passes through the lower horns, not visible from above. N, F, N, F. The arytenoid cartilages, connected by the arytenoideus transversus. 1, V, T, V. The vocal ligaments. n, x. The right crico-arytenoideus lateralis (the left being removed). v, k, f. The left thyro-aryténoideus (the right being re- moved). wn,,N, 7. The crico-arytenei postici. B, B. The crico-arytenoid ligaments. larynx we must refer the reader to descriptive anatomy : suffice it to say, that experiments have clearly demonstrated the fact that sounds may be produced by instruments resembling the larynx in construction: 7. e, with chords or membranes so extended that a VOICE. 309 current of air shall be made to pass between them, the tone pro- duced depending upon the tension and elasticity of the chords, as well as their length and thickness. The vocal chords are com- posed of yellow elastic tissue, and as we possess no substance of equal elastic properties, we cannot construct an artificial larynx with a scale equal to the human larynx: an approximation has however been obtained by Mr. Willis, as follows:— Fig. 85. Artificial glottis. “A wooden pipe of the form a should be prepared, having a foot C, like that of an organ pipe, and an upper opening, long and nar- row, as at B, with a point A, rising at one end of it. If a piece of: leather, or, still better, of sheet India rubber, be doubled round this point and secured by being bound round the pipe at D, with strong thread, as in 6, it will give us an artificial glottis with its upper edges G, H, which may be made to vibrate or not at pleasure, by inclining the planes of the edges: a couple of pieces of cork, #, F, may be glued to the corners to make them more manageable, From this machine various notes may be obtained by stretching the edges in their length G, H: the notes rising in pitch through the length of the vibrating edges is increased.”— Articulation is the result of the modification of the sounds produced in the larynx by means of the different parts of the oral cavity. Hearing. This may be defined to be the cognizance taken by a peculiar nerve-structure of the vibrations or undulations constituting sound, 310 APPENDIX. For the performance of this function, a special apparatus is neces- sary, varying in its structure and complexity with the degree of perfection required. The anatomy of the human ear may be de- scribed as follows: The organ of hearing is composed of three parts, the external, middle, and internal ear. The external ear Fig. 36. GENERAL VIEW OF THE EXTERNAL, MIDDLE, AND INTERNAL Ear, as seen in a prepared section through a, the auditory canal. 6. The tympanum, or middle ear. ec. Eustachian tube, leading’ to the pharynx. d. Cochlea; and e. Semicircular canals and vestibule, seen on their exterior, as brought into view by dissecting away the surrounding petrous bone. The styloid process projects below ; and the inner surface of the carotid canal is seen above the Eustachian tube. : consists of a cartilaginous and fibrous tube, widely spread exter- nally and thrown into various curves and converging into the meatus auditorius internus in such a manner as to collect and con- vey the sonorous vibrations towards the membrana tympani which separates the external from the middle ear. The latter is comprised- in the tympanic cavity, and is contained (as also the internal ear) in the petrous portion of the temporal bone. It is limited by the membrana tympani, the walls of the tympanum, and the fenestra rotunda and the fenestra ovalis—these being covered by a membrane; the cavity communicates with the fauces by means. of the Eustachian tube. It contains the ossicula of the ear—a chain « . of small bones articulated together, and so attached by means of muscles and ligaments to the membrana tympani and fenestra ovalis, that the membrana tympani may be rendered more or less HEARING, 811 tense by their motion, which is of the highest importance in render- ing the membrane susceptible to graver or acuter vibrations. The internal ear is affected by the undulations of the air in the tym- Fig. 37. InTERIOR OF THE OssEous LAByRINTH.—V. Vestibule. a, v. Aqueduct of the vestibule. o. Fovea semi-elliptica. +r. Fovea hemispherica. §. Semicircular canals. «. Superior. Pp. Posterior. i. Inferior. a,a,a. The ampullar extremity of each. C. Cochlea. a,c. Aque- duct of the cochlea. «, v. Osseous zone of the lamina spiralis, above which is the scala vestibuli, communicating with the vestibule. et. Scala tympani below the spiral lamina. panum (communicated to it by the membrana tympani), only through the fenestra rotunda and fenestra ovalis. The internal ear consists of the osseous and membranous labyrinth (the latter lining Fig. 38. HE ORIGIN AND DISTRIBUTION OF THE PortTio Mouuts or THE SEVENTH Patr, coe eae The medulla oblongata. 2. The pons Varolii. 3, 4. The crura cerebelli of the right side. 5. The eighth pair of nerves. 6. The ninth pair. 7. The auditory nerve distributed to the cochlea and labyrinth. 8. The sixth pair of nerves. 9. The portio dura of the seventh pair. 10. The fourth pair. 11. The fifth pair. 312 APPENDIX. the former and corresponding exactly to it) which is composed of three parts: the cochlea, a double spiral communicating at the top and opening at the bottom into the vestibule, and having spread: upon the lamina which separates the spirals, the fibrils of the auditory nerve; the vestibule, a triangular cavity communicating with the semicircular canals, which, three in number, are placed posteriorly ; the direction of the latter is somewhat fancifully de- scribed as being in three planes perpendicular to each other. Be- tween the osseous and membranous labyrinth (except in the cochlea), there is contained a fluid called the perilymph, and within the membranous labyrinth another fluid, the endolymph. It has been recently demonstrated that ganglionic cells form a Iarge part of the nervous tissue distributed over the cochlea, vestibule and ampullz (or openings into the semicircular canals); these are supposed to be capable of receiving impressions from sonorous vibrations, and transmitting them to the nervous centres by the portio mollis. In fact, the hypothesis is now generally received, that for the occur- rence of nerve phenomena, whether of sensation or motion, gan- glionic cells must exist, both in the sentient part and in the nerve- centre, whence corresponding action proceeds; this we shall see exemplified also in the senses of vision and touch. The following. extract from Dr. Jackson’s lecture on this subject, as published in a note to Carpenter’s Human Physiology, last edition, p. 699, explains more satisfactorily than any other hypothesis which has been ad- vanced, the functions of the different portions of the internal ear. He says:— 7 “The semicircular canals have no direct agency in the produc- tion of sound or hearing. They contain no nervous structure: no portion of the acoustic nerve reaches them. They are small appendages to the vestibule, opening into it and the ampulla. The membranous: canals, like the membranous vestibule, are floated in a fluid, the perilymph, and are filled with a similar fluid, the endolymph. The membranous structure constitutes the essential solid portion of the organ of hearing. It is nowhere in direct contact with the osseous walls of the corresponding cavities excavated in the temporal bone. The perilymph is interposed between the membranous vestibule, the semicircular canals, and the surrounding osseous walls. In the Petromyzon, this membranous structure (vestibule and semicircular canals) is contained in a com- mon cavity, uninclosed in corresponding excavations in bone sub- HEARING. 813 stance.' As Miiller observes, this is “a fact of great physiological. importance.” It proves the membranous portion of the apparatus. of hearing and its fluid to be independent of the bony structure in the excitation of the sense of sound or hearing. “The semicircular canals are evidently intended to perfect the sense of hearing or sound, as executed in its most complete mani- festations, in the higher development of this apparatus of sense in man and the superior animals. “The hypothesis of Scarpa has been adopted as the most plausi- ble in this point of view. He supposed the semicircular canals to be intended to increase the intensity of the sonorous impressions on the acoustic nerve, and thus to make hearing more distinct. They effect this operation by receiving and collecting the vibrations of the solid parietes of the cranium transmitted to the lymph-fluid, and through it to the nervous expansion of the acoustic nerve. “This hypothesis cannot be entertained. ‘In the first place, it is very doubtful whether the aerial vibrations, in ordinary hearing, can or do communicate vibrations to the hard parts of the cranium. When a light carriage passes rapidly over the rough pavement with a sharp, rattling noise, if the ears be completely closed, not a sound is heard; nor is a single note of a large orchestra to be dis- tinguished when the ears are pressed with the fingers) When sound is attended with concussion, a noise may then be distin- guished, but this differs from the ordinary sense of hearing, If vibrations are excited in the solid parts of the cranium by sonorous vibrations of the air, they are obviously too feeble to make an impression on the nerves of sense, and incapable of reinforcing the vibrations transmitted through the stapes. “Tn the second place, vibrations, if excited in the lymph-fluid of the semicircular canals, would move in a direction the reverse of the molecular vibrations of the lymph-fluid of the vestibule and ampullw, the real excitors of the sense of hearing or sound. These vibrations are transmitted through the fenestra ovalis by the stapes, and radiate from that point in expanding waves through the vesti- bular lymph-fluid into the ampulle and semicircular canals, Vibra- tions proceeding from the solid walls of the semicircular canals, to reach the nerve expansions, would come in conflict with those proceeding from the stapes, and either interference, and consequent 1 « Miller’s Physiology,” Baly’s translation, vol. ii. p. 1288. 314 APPENDIX. suppression and silence would ensue, or the effect of an echo, or noise, or simple sound be the result. The hypothesis of Scarpa, it appears to me, cannot be sustained, though ably advocated by Miiller. “The hypothesis that assigns to the semicircular canals the per- ception of the direction of sound does not merit an investigation. The notion of the direction of sound, like that of distance, is a men- tal action; a conclusion to which the mind arrives, from certain phenomena or facts acquired by experience. “ As to the manner in which the semicircular canals perfect the sense of hearing, my conclusion is the opposite to that of Scarpa. Instead of increasing the sonorous undulations or vibrations of the lymph of the vestibule, the immediate excitants of the sense of hear- ing, they serve to suppress them. They arrest the waves of reflexion which would necessarily occur in a simple cavity, wholly limited by plane surfaces, as the vestibule would be without these append- ages. Such is the rudimentary vestibule or internal ear of the invertebrata. The consequence of reflected undulating vibrations, maintained in the labyrinthic fluid, would be the production of ‘mere sound or noise of different intensities. The perception of the immense number of fine and delicate tones, and other qualities of sound of which the ear has cognizance, would be utterly impossible in the confusion of sonorous vibrations in the fluid of the labyrinth continuously reflected to and fro, unless some provision is made for their suppression. The molecules of a fluid contained in a closed vessel continue in undulatory vibration until the impetus exciting their motion is expended or suppressed. The semicircular canals accomplish this purpose. They are, in the apparatus of hearing, what the pigmentum nigrum of the choroid coat is in that of vision. : “The two senses and their apparatus are homologous. The essen- tial phenomena and laws of each are identical. The knowledge of those of the one sense demonstrates those of the other. The condi- tions of perfect vision and perfect hearing are the same. They are, for vision: 1st. The existence of separate, independent, sensitive spaces or sections of the retina for distinct images and perceptions of visual impressions. Volkmann estimates these to be 0™™0005;1 and others at 0°000005 of an inch. 2d. A single distinct impres- ' « Annual Report of the Progress of Chemistry and Allied Sciences,” by Liebig and Kopp, vol. fil. p. 98. 2 «Vardner’s Handbook of Optics,” p. 155. HEARING, 315 sion made by the molecular vibration of the Ether—the excitor of the sense of sight. “The above conditions are obtained, a, by the special anatomical arrangement of the retina: 2, by the refracting apparatus of the globe of the eye that concentrates the undulatory rays of the Ether proceeding from every point of a visual object on the distinct sen- sitive points or spaces of the retina: ¢, by the suppression of the undulatory vibrations immediately they have excited an impres- sion in the retina, by the black pigment of the choroid coat. Their reflection from the exterior surface of the sclerotic coat, and reite- rated excitement of the retinal surface, is in this way prevented. In Albinos the pigment of the choroid is either deficient or absent, and the consequence is indistinct vision in daylight, from the general excitement of the retina by the reflected undulations of the Ether occupying the globe of the eye. “Similar conditions are obtained in hearing: Ist. By the auditive nerve being decomposed into its separate filaments and gangli- onic vesicles, amounting to some thousands, and spread out in a manner to receive single, individual impressions, in the membra- nous vestibule, ampulle, and on the lamina spiralis of the cochlea. 2d. By the molecular undulations or vibrations excited ‘in the fluids—peri- and endo-lymph—by the sonorous undulations com- municated by the stapes, occupying the fenestra ovalis. From this point they radiate in expanding waves of undulations, strike on and pass through the membranous vestibule and ampullz, on which the filaments of the vestibular branch of the auditive nerve are arranged, producing a single,-distinct impression, reinforced by the resonance of the superimposed otoconiz, acting like the sound- ing board of the piano, and exciting a single and distinct impulse, and perception of sound. The sonorous vibration having thus com- pleted its office, the specific excitation of the sense of hearing must, like that of the visual vibration, cease or be suppressed. This oc- curs in part in the ampulla, but mostly in the semicircular canals. “The vibrations of the endolymph reaching the ampulle are partially broken and weakened at their openings ; those entering the ampulle again expand, losing thereby their impetus, and either die away against the membranous walls, or come in conflict with the vibrations of the perilymph on their exterior. The two can scarcely be in perfect consonance of expansion or condensation, and interference ensues by which they are suppressed. In this 316, APPENDIX. mode all the feebler vibrations are terminated. Those of greater force enter simultaneously the two opposite openings of the semi- circular canals. The orifices and the commencement of each canal differ as to size and form, and consequently each entering wave of undulatory vibrations is modified, thus losing their consonance of expansion, and when they meet interference and suppression result. Reflexion of sonorous vibrations is completely provided against. “ Parallel conditions exist in the cochlea. Its two canals—the. superior scala vestibuli, and the inferior scala tympani—are filled with lymph-fluid continuous and identical with that of the vesti- bule. The first, the scala vestibuli, according to the latest investi-. gations of Kolliker,' is the principal seat of hearing. On its lamina. spiralis is expanded a sentient, nervous structure, the recipient of the sonorous vibrations excitative of the sense of hearing. It is the homotype of the retina of the eye. The scala tympani furnishes space for spreading out the filaments of the nerve, but the terminal extremities pass through the membranous spiral lamina, to be incorporated with the sentient organ of hearing in the superior. canal or scala vestibuli. The filaments of the inferior canal or scala tympani are mere conductors of the nervous excitement of the audi-. tive sentient membrane. The scala tympani, similar to the semi- circular canals, has no direct connection with the production of hearing. It is the homotype of the semicircular canals, and per- forms the same office. “The sonorous vibrations, starting from the stapes and fenestra ovalis, rushing into the adjacent opening of the scala vestibuli, ex- cite, by their impulse, the auditory membrane or retina, spread over its lamina spiralis, and reach its termination where it opens into the scala tympani. Feeble vibrations may subside sponta- neously by exhaustion from their extension, The stronger pass. on into the scala tympani, where they fade away, or are suppressed. by the interference of vibrations entering the inferior canal by the. fenestra rotunda from the tympanum. The condition for perfect hearing, for the distinct perception and appreciation of the finest tones and notes, so that each vibration shall make but gne, single, distinct impression, and then be suppressed, is thus amply fulfilled. “ Analogous provisions are perceived to exist in the tympanum, to preserve in that cavity perfect wave-systems of undulations, ! «Human Microscopical Anatomy,” Da-Costa’s translation. Note, p. 175. HEARING. 317 indispensable to the perfection of the sense of hearing. Vibrations existing in air contained in a cavity with plane walls, would con- tinue to be reflected from side to side, producing confused sounds or noise. The air in the tympanum is thrown into vibrations by impulses of the membrana tympani. They are communicated pure and in perfect accord to the membrane of the fenestra rotunda, This curious and beautiful result is effected in the following man- ner: on one side the tympanum communicates by numerous open- ings with the mastoid cells communicating with one another. All the vibrations impinging on this side are suppressed in the mastoid cells. Those that reach the opposite side are swallowed up and lost in the Eustachian tube. All resonance and reflexion of vibra- tions are suppressed, and the wave-systems of sonorous vibrations traverse the tympanum undisturbed, enter with augmented force the lymph-fluid of the scala tympani, and meet the corresponding undulations coming from the scala vestibuli, from which both sys- tems are suppressed by interference. “Tn the ‘Annual Report’ by Justus Liebig and H. Kopp, vol. iii. p. 58, is the following observation: ‘It is certain that the ear is capable of receiving and distinguishing many notes, the vibrations of which reach it simultaneously. As the atmospheric particles which convey the various wave-systems to the ear can never receive from them more than one resulting motion, it follows necessarily that the ear possesses the power of distinguishing in this resulting motion, the periods of the component wave-trains. For the present we are, however, unable to explain upon what this power depends.’ “The preceding theory furnishes an explanation of the above problem, considered as inexplicable by Liebig and Kopp, in 1852. Tt demonstrates the manner in which the wave-systems of sonorous vibrations pass through the fluid of the labyrinth undisturbed, pre- serving their relations to each other and their special qualities of sound. Each separate vibration of the molecules of the lymph- fluid are shown to produce a special, distinct impression on the nerve structure, and excite a corresponding perception of sound. “The small space through which the vibrations pass, and the rapidity of their movements in fluids, cause the impressions they make on the nervous sentient organ, and the perceptions they ex- cite, to appear as an instantaneous act. The mind has cognizance of them, however diversified they may be, as a unity of sounds simultaneously instant in action: whence it forms the compound idea of a perfect harmony, 818 APPENDIX. “ An analogous phenomenon occurs in vision. When a body composed of different forms and colors is presented to the eye, as a bouquet of flowers, a landscape, or picture, each different form, color, tint and shading, are perceived blended, but perfect and dis- tinct, forming the image of a single object. Yet thousands of Kther vibrations are traversing the eye, and are exciting each a separate, distinct impression, without confusion, on the retina, and as many distinct and separate perceptions, from which a corresponding com- pound idea of a single object is formed by the mind.” Vision. This may be defined to be the impression made upon the retina by rays of light, or undulatory luminous vibrations excited in the all-pervading wether. The mechanism of the eye is so constantly presented in all works upon Optics and Anato- my, that we think it unnecessary to introduce it here, but will enter at once upon the consideration of the ‘function of the retina. Here, as in the ear, we find a special nervous appara- tus provided for the performance of a special function, 7. e, recognition of luminous impressions. We find the fibrils. of the optic nerve, after its en- trance into the globe of the eye, forming a plexus over the interior surface of the choroid coat; between this plexus and the choroid coat there exists a layer of ganglionic cells similar to those of the encephalon, and upon these again a granular and fibrous layer; while finally upon the latter are found the Cee econ Batt lye, “vods” and “cones” of the membrana 2. Outer layer, granular. 3. Interme- Jacobi. These are in connection with diate, fibrous layer. 4. Inner granu- i layer. 5.’ Finely grenaias gray the granular cells by means of pro- ayer. 6. Layer of nerve-cells. 7. < . , < Layer ae ahree ak optic nerve. 8, longations or fibrils, which again ex- ahaa anemibrane, tend as far as the ganglionic cells. The “rods” and “cones” are so placed that the rays of light reaching the retina strike vertically upon SMELL. 819 them in the direction of their long axis, and a close correspondence is said to exist between their diameter and that of the smallest ob- ject perceptible by the eye. Be this as it may, their absence from that point of the retina where the optic nerve enters the eye which is comparatively insensate to light, together with their abundance in the “yellow spot of Scemmering” (yellow from the deficiency of the granular layer which allows the choroid partially to appear), where vision is most intense, renders it probable that they are the immediate agents of the perception of light. As in the ear we have provision made for the suppression of the sonorous undulations when the effect has been produced upon the acoustic nerve, so also in the eye, the choroid coat, with its black pigment-cells, absorbs the luminous undulations as soon as they have acted upon the optic nerve. The iris acts as a diaphragm, allowing only a certain quan- tity of luminous rays to pass through it; it is essentially a sphinc- ter muscle, containing two sets of contractile fibre-cells, an internal circular and external radiating layer. The adaptation of the eye to the perception of objects at different distances is effected by the movement of the lens; actual experiments have proved that the extent of motion required hardly exceeds one line. Smell. This is the perception of odors by means of the olfactory nerve. The im- mediate nerve structure instrumental in this perception has not been so thoroughly investigated as that of the other sensory organs; the only difference clearly esta- blished is, that the nerve-fibres resemble more the gelatiniform nerve-fibres than the ordinary fibres. The portions of the nasal cavity upon which they are distri- buted are lined with a peculiar sepia-brown tessellated epithelium. Fibres of ultimate ramifica- tions of Olfactory Nerve of Dog. Taste. This is the function of certain nervous structures distributed principally upon the surface of the tongue; their construction has not been clearly made out, but is probably closely allied to that of 820 APPENDIX. the tactile corpuscles, as the papille in which they are contained closely resemble those of the skin. This special sense seems to stand in an intermediate position between smell and touch; but many phenomena prove that it is not to be confounded with them, such as the obliteration of one, while the other is maintained, &c. Touch. _ The structure which has for its object our acquaintance with the form, resistance, &c., of external bodies, is not confined to a small portion of the body, but is dis- tributed over its whole surface, more or less closely. In those parts which possess. this sense in a higher degree, as the palms of the hands, the lips, &c., we find papille, which, in addition to bloodvessels, con- tain. nervous loops, and also peculiar ovoid bodies, called “axile corpuscles,” which pos- Verticar Section or Skin or Frveer (palmar Eee (according mS some) gray surface), treated with caustic soda.—a, 6. Cuta- ganglionic vesicles or cells; neous nerves, forming a terminal plexus, and ae Oe : finally passing into the papille ec, e, ¢. this 18, indeed, denied by some eminent microscopists, who consider the axile corpuscles as nothing more than a thickened neurilemma,; at all events a peculiar development of nerve-tissue is found here, which, probably, gives rise to the sensations com- municated by the nerves to the nerve-centres; thus showing an analogy with the facts found relatively to the transmission of lumi- nous and sonorous vibrations. INDEX. A Absorption, see Digestion, 247; laws of, of gases, with reference to respiration, 272; by the bloodvessels, 247; by the lymphatics, 248. Acetamid, 64. Acetic acid, 62, 66; in fluid of muscles, 218; in leuchzmic blood, 148; in the sweat, 184. Acetone, see Cetones, 63. Acid, free, importance of, in tissue meta- morphosis, 241; in the gastric fluid, 167; in the urine, 192. Acids, organic, non-nitrogenised, 62. - paired, conjugate, nitrogenised, 87; non-nitrogenised, 78. Acrylic acid, 73. Adipic acid, 72. Adipocire, 239. Alanin, 76. Albumen, white of egg, sce Fluids of ovum, 161. Albumen, 105, 107: adsorption of, in the intestines, 255: coagulation of, 106, 107: constitution of, theoretical, unknown, 102: digestibility of, see Digestion, 257: importance of, physiological, 108; in tis- sue metamorphosis, 235: mode of occur- rence of, 108; in the bile, 171; blood, 139; chyle, 149; excrements, 182; fluids of muscles, 218 ; fluids of ovum, 160, 161; intestines, 177; lymph, 150; milk, 157; mucus, 163; pus, 227; saliva, 165; se- rum, 139; transudations, 152; urine, 194: physiological relations of, 108, 235; products of decomposition of, 108: proper- ties of, 102, 107: source of, 108; transu- dation of, conditions of, 152. Albuminates, see Histogenetic Substances, 102. Albuminuria, 194. Alcohols, 93. ; Aldehyds, 63; of the benzoic acid group, 75; of the butyric acid group, 63. Alkali, action of, in the blood, sce Tissue metamorphosis, 243. Alkalies, carbonates of the, 119; in the bile, 170; blood, 142; fluids of ovum, 21 161: lymph, 150; milk, 157; transuda- tions, 154; urine, 198: lactates of the, in the chyle, 194; lymph, 150; transu- dations, 154: phosphates of the, 118; origin of, 118; mode of occurrence of, 119; in the blood, 126, 188; chyle, 149; “ lymph, 150; milk, 157; saliva, 164; transudations, 154; urine, 191: sul- phates of the, 121; in the blood, 142; bones of fishes and reptiles, 205 ; lymph, 150; urine, 191. , Alkaloids, volatile, 80; theoretical com- position of, 60. Allantoin, 82, 86. Allantois, the, 301; use of the, 301. Ambrin, 96. Amides, 64; of the benzoic acid group, 75. Ammonia, bases of the type of, 60, 80. Ammonia, salts of, 121, 122; in the blood, 142; exudations, 120; gastric fluid, 168; lymph, 150; sweat, 184; transudations,. 154; urine, 187, 195: urate of, 92. Amnion, fluid of the, see Transudations, 151. Anemia, blood of, 146, 147; urine of, 199. Anilin, 60, 81. Animal heat, see Temperature. Anisic acid, 74. Areolar tissue, see Connective tissue. Arsenic, 121. Arthritis, blood in, 141, 148; chalk-stones of, 92. Ashes, analyses of, 115. B Bases, non-nitrogenised, 92; nitrogenised, 79 Benzoglycic acid, 78. Benzoic acid, 74, 75; group, 74; reap- pearance of, as hippuric acid, in the urine, 1938; in the sweat, 185. Benzole, hydruret of, 74. Bezoars, 182. Bile, the, 169: amount secreted, 171; de- pendent upon disease, 172; the kind and quantity of food, 172; medicines, 172; 322 INDEX. coloring matters of, 170: composition of, quantitative, 170; normal, 169; abnor- mal, 171: concretions, 171: formation of, in the liver, 178: function of, 172; acting on the chyme, 172; dntacid, 172; anti- septic, 172; furthering fat-absorption, 173: mode of obtaining, 169: properties of, 169; pathological, 171. Bile-acids, see Glycocholic acid. Bile-pigment, 100, 170; in the blood, 141; in the intestines, 178, 181; in transu- dations, 153; in the urine, 195; in vomit, 180. Biliary concretions, 171. Bilifulvin, 101, 171. Bilin, see Taurocholic acid, 87, 90. Biliverdin, 100. Blood, the, 124: alkali in, 243; action of, on the carbohydrates, 243; fats, 244; organic acids, 248; protein bodies, 244: analysis of, 126, 142; determination of the dried corpuscles, 148; of the moist, 144; of the other constituents, 145: capacity for heat of, 124: clot, coagulum, 136; form and consistence, 124, 137: coagulation of the, 124, 185; circum- stances influencing, 124, 186: color of the, depending upon chemical condi- tions, 180; shape of the corpuscles, 128; thickness of cell-membranes, 129; suspended molecules, 180: composition, ‘quantitative, of the, 126; under different circumstances, 145; age, 145; during digestion, 146; in different classes of animals, 146; in different vessels, 146 ; in disease, 147; anemia, 146, 147; arthritis, 148; Bright’s disease, 147; carcinoma, 148; chlorosis, 147; cholera, 147; diabetes, 148; dysentery, 147; ex- anthemata, 147; inflammation, 147; leuchemia, 148; plethora, 147; puer- peral fever, 147; pysemia, 148; rheu- matism, scorbutus, tuberculosis, 148; typhus, uremia, 147; yellow fever, 147; pregnancy, 145; sex, 145; starva- tion and loss of blood, 145: constituents of the, chemical, 126, 188; mechanic- ally separable, 125, 1381; morphotic, 125; corpuscles, colorless, 125, 135: red, 125; cell-membranes of, 181; constitu- ents of, chemical, 126, 132; fats, 133; gases, 134; hematin, 183; hemato- erystallin, 182; iron, 134; mineral—of, 133; mode of combination of gases of, 134; physical properties of, 127; pro- portion of, to blood, 132, 143; shape and changes of, 125, 127; specific gra- vity of, 127; ‘‘tendency to sink” of, 127; depending partly on spec. gray. of, 127; partly upon the “rolling,” 127; different in different kinds of blood, 128; proportion of, to intercellular fluids, 182: definition of, 124: dichroism of ’ venous, 180: fibrin of, 126, 185; pro- portion in blood, 126, 138: fibrinous Jiakes, 135: intercellular fluid, liquor san- guinis, 125: inflammatory crust, buffy coat, 187: nutrition, influence of, upon composition of the, 280: odor of, 142: properties of, 124: serum of, 124, 126, 188; constituents of, 139; acetic acid, 141; albumen, 1389; alkali salts, 142; bile acids, 141; bile pigment, 141; car- bonate of ammonia, 142; casein, 139; coloring matter, 141; creatin, creatinin, 141; fats, 139; formic acid, 141; glutin, 141; hippuric acid, 141; hypoxanthin, 141; salts, 142; silicic acid, 142; sugar, 140; suspended molecules, 138; urea, 141; uric acid, 141; water, 188: spe- ‘cific gravity of, 124. Bone, see Osseous tissue, 202. Bone glue,, see Glutin, 118. Brain, see Nerve tissue, 217. Bright’s disease, blood in, 147; transuda- tions in, 158; urine in, 194. Buffy coat of the blood, 137. Butter, 156. Butylamin, 81. Butyral, 63. Butyric acid, 62, 67; in the sweat, 184; in the intestines, 177; in the urine, 195. Butyrone, 64. Cc Calcium, chloride of, see Chlorides; fluo- ride of, 116, 118. Calculi, biliary, 171; intestinal, 182; sali- vary, 165; urinary, 200. Capric acid, 62, 67. Caproic acid, 62, 67. Caprylic acid, 62, 67. Carbohydrates, 97; digestion of, 250; importance of, in tissue metamorphosis, 240; nutritive value of, 275. aaa acid, hydrated oxide of phenyl, Carbonic acid, see Respiration. Cartilage, 207. Cartilagin, see Chondrin. - Cartilaginous tissue, 207; chemical con- stituents of, 207; histology of, 207; quantitative relations of, 209. Carbohydrogens, analogy of, with the metals, 58; uses, &c. of, see Fats. Casein, 105, 111: mode of occurrence of, 111; in the blood, 189; in the fluids of muscles, elastic tissue, thymus gland, connective tissue, 111; in milk, 156; in the urine, 194; in the yolk, 160; origin of, 111: physiological importance of, 111: properties of, 111. INDEX. Castoreum, 183. Castorin, 95, 96, 183. Cellular tissue, see Connective tissue, 209. Cellulose, 97, 99;- digestibility of, 254. i in nerve tissue, 228 ; in the yolk, Cerotic acid, 62. Cerotin, 94. Cerotyl, oxide of, 94. Cetic acid, 62, 68. Cetones, 63. Cetyl, oxide of, 94. Cetylic acid, 94. Chalk-stones, of arthritis, 92. Chemistry, physiological, definition of, 49; division of, 49; pathological, relation of, to physiological, 49. Chitin, 113, 114. Chloride of ammonium, in the gastric fluid, 168. Chloride of calcium, in the gastric fluid, 168. Chloride of potassium, in the gastric fluid, 168; in the blood-serum, 142; in the chyle, 149; in saliva, 164; in the urine, 191. Chloride of sodium, 118; importance of, in tissue metamorphosis, 244; mode of occurrence of, 118; in the bile, 170; blood, 142; chyle, 149; exudations, 228; gastric fluid, 168; fluid of mus- cles, 218; pancreatic fluid, 174; fluids of ovum, 161; lymph, 150; milk, 157; mucus, 163; saliva, 164; sweat, 184; transudations, 154; urine, 191; phy- siological importance of, 118, 244; with grape sugar, 245; with urea, 245. Chlorohydric acid, 118. Chlorosis, blood in, 147; respiration in, 269. Cholepyrrhin, 100; with lime, see Biliary concretions. Cholera, bile in, 171; blood in, 147; vomit in, 180; excrements in, 182; respira- tion in, 269; transudations in, 154. Cholesterin, 95; mode of occurrence, 95; in the bile, 170; biliary calculi, 171; blood, 139; intestines, 178; nerve tis- sue, 222; smegma preputii, 183; trans- udations, 153. Cholic acid, 78, 79; formation of, 79; mode of occurrence of, 79. Choloidic acid, 79. Chondrin, 118, 114; in intercellular sub- stance of cartilage, 208. Chyle, the, 148; constituents of, chemical, 149; morphotic, 148: influence of food upon, 149: mode of obtaining, 148: pro- pertics of, 148; quantity of, 150. ; Cinnamic acid, 74; passing into the urine as hippuric acid, 193 ; in the sweat, 185. Cinnamyl, hydruret of, 75. 323° Circulation, the, 291, Cocinic acid, 62, 68. Colla, see Glutin, 113. Coloring matters, 99; of the bile, 99, 100; blood-corpuscles, see Heematin, 99, 100; blood-serum, 141; choroid, sce Melanin, 99, 101; urine, 99, 101. Colostrum, see Milk. Conjugate radicals, see Pairing. Connective tissue, 209; chemical relations of, 209; of the embryo, see Mucous tis- sue, 210; histological characters of, 209. Contractile fibre-cells, 214. Copalic acid, 74, Copaivic acid, 74. Copper, 121. Copula, see Pairing. Corpuscles, blood, see under Blood, 125; cytoid, 226; in mucus, 162; pus, 225; transudations, 151, Creatin and creatinin, 82, 83; in the blood, 141; in the fluids of muscles, 218; in transudations, 154; in the urine, 83, 190. Crystalline substance of the blood, see Heematocrystallin, 112. Cumaric acid, 74, Cumarin, 75. Cumic acid, 74. Cumin, 75. Cynuric acid, in urine of dogs, 190. Cystic oxide, and cystin, 82, 86; in the urine, 188; in urinary calculi, 200. Cytoid corpuscles, see Exudations, 226. D Damaluric acid, 73. Damolic acid, 73. Degeneration, fatty, 70, 239. Dental tissue, 206; cementum, 207; den- tine, 206; enamel, 207; teeth of dif- ferent animals, 207. Deoxidation, process of, visible in acci- dental constituents of urine, 193. Derivations, proximate, of the protein bodies, 104, 113. Dextrin, absorption of, 253; importance of, in tissue metamorphosis, 240. Diabetes, 98; bile in, 171; blood in, 148; excrements in, 182; respiration in, 269; urine in, 195; vomit in, 180. Diastase, see Saliva, 160. Diffusion, currents of, between the blood and parenchymatous fluids, 242; be- tween the gases of the blood and of the air-passages, 270. Digestion, 246: absorption of cane sugar, 252; cellulose, 254; chondrin, 255; curarin, 255; dextrin, 253; emulsin, 255; fats, 254; gluten, 254; glutin, 255; grape sugar, 250; laws of absorp- 324 tion of, 251: quantity absorbed corre- sponding with laws of endosmose, 251; in direct ratio to concentration of solu- tion, 251; independent of amount of sutface of intestine, 251; gum, 253; inulin, 253; lactin, 252; protein bodies, 255; transformation of, into peptones, 255; reappearance of albumen, &c., in chyle, 256; starch, 253; gradual trans- formation of, into sugar by the intesti- nal fluids, 176 ; hy the bloodvessels, 249, 251, 254, 256; by the lacteals, 248, 254, 256 ; modes of ascertaining, 249: capa- bility of, depending upon physical and chemical properties of the substances, 246: definition of, 246: difficulty of ab- sorption of some substances, 248: diges- tibility of articles of food, 257: division of objects of, 247, 250: explanation of process, 246: extent of process, 279: laws of absorption (of sugar), 251: me- chanical conditions of, 246, 247; influ- ence of blood-current upon, 247; of concentration of solution, 247; of op- posite reaction (acid and alkaline), 247: quantities of articles of food absorbed, 257: quantities of the digestive fluids, 256: relations of absorbability of substance and the digestive fluids, 247. Doeglic acid, 73. Doeglic oxide, 94. Dumb-bell crystals, 65. aa blood in, 147; excrements in, 182. Dyslysin, 79. E Ear, cartilage of, 209; function of, 312; structure of, 310; sebaceous secretion of, 182. Egg, albumen of, see Fluids of the ovum, 161 Elastic tissue, 210; chemical behavior of, 210; histology of, 210; mode of occur- rence of, 210; substance of, elasticin, 118, 114. Elasticin, 114. Ellagic acid in intestinal concretions, 182. Embryo, connective tissue of, 210. Emulsin, see Digestion, 255. Entomaderm, see Chitin, 114. Epidermis, see Horny tissue, 211. Erucic acid, 73. Ethal, 94. Ethers, 93. Ethy] series, 94. Excitor nerve-force, 36. Excrements, the solid, 181: amount of, 181: containing albumen, 182; blood, 182; epithelium, 182; fat, 182; fibrin, & INDEX. 182; mucus, 182; sugar, 182; triple phosphate, 181: of the foetus, meconium, 179: yellow, of sucklings, 181. Extractive matters, in the blood, 183; in the chyle, 149; in the lymph, 150; in urine, 190; in transudations, 153. Exudations, 228: character (general) of, 223: ecytoid corpuscles, 226: difference between, and transudations, 224: modi- fication of, 225: pus, 225; constituents of, accidental, 228; chemical, normal, 227; abnormal (casein, pyin, muco- sin), 227; morphotic, 225; pus-cor- puscles, 225; microchemical reactions of, 227; modes of decomposition, acid fermentation of, 226; alkaline fermen- tation of, 226; quantitative relations of, 228; serum of, 227. Eye, fluids of the, see Transudations, 151: choroid, function of, 819: iris, function of, 819; structure of, 319: retina, func- tion of, 318; structure of, 319. F Faces, see Solid excrements, 181. Fat acids: fixed, 68; oily, 73; volatile, 63. Fats, neutral, 69: digestion of, 178, 254: formation of, from nitrogenised, sub- stances, 239: importance of, chemical, 71; physical, 71;. physiological, 72; in tis- sue metamorphosis, 237 : mode of occur- rence of, in the bile, 170; blood-corpus- eles, 183; blood-serum, 139; bones, 204; cartilage, 209; chyle, 149; excre- ments, 182; fluids of ovum, 160; hairs, 213; intestines, 178; lymph, 150; milk, 156; mucus, 162; muscles, 217, 218; nerve-tissue, 238; pus, 227; sebaceous secretions, 183; sweat, 184; transuda- tions, 153; urine, 194: source of, 70. Feathers, 214. Ree ation of urine, acid, 185; alkaline, 186. : Fever, the urine in, 198. Fibre-cells, contractile, 214; cell sub- stance of, 215; histology of, 204; inter- stial fluid of, 215; microchemical reac- tions of, 214; nuclear substance, of, 214. Fibrin, 105, 109: coagulation of, 109; mode of occurrence of, 109; in the blood, 185; chyle, 149; exudations, 224; lymph, 150; transudations, 152; urine, 187: origin of, 110: physiological importance of, 110; properties of, 109. Fibrinous flakes, see the Blood, 135. Fibro-cartilage, 208. Fibroin, 113, 114. Fluids, animal, see Phlegmato-chemistry, 128. INDEX. Fluoride of calcium, 116, 118; in bones, 206; in teeth, 207. Food, articles of, see Digestion, 257, and Nutrition, 275: plastic, 285, 255, 257: respiratory, 237, 240, 265. Force, definition of, 27, 229. Force, organic, vital, formative, 32; nerv- ous, mechanic, 85; excitor, 36; motor, 87; conditions requisite for develop- ment of, 39; connection of, with electri- city, 39. Force, vital, 229; remarks on Dr. Leh- mann’s doctrine of, 41. mura and laws of organic movements, Forces, correlation of, 29. Forces or dynamical relations of the or- ganism, 27. Formic acid, 62, 66; in the blood in leu- chemia, 141,148; in the fluids of mus- cles, 218; in the sweat, 184; in the urine, 190. Fungus in the urine, 187. G Gall-stones, biliary calculi, 171. Gallic acid as an accidental constituent of urine, 193. Gases, of the blood, 134; intestines, 173; urine, 192: exchange of, in the lungs, laws regulating, 272. Gastric fluid, the, 167; amount secreted, 168: artificial, 168: constituents, chemi- eal, 167; free acid, 167; pepsin, 167; mineral, 168; solid residue, 167: func- tion of, 168: mode of obtaining, 167: properties of, 167; peptones, 167, 168. Gelatin, animal, see Glutin, 113. Gelatin, sugar of, see Glycin, 61. General observations, 49. Globulin, 105, 111: mode of occurrence of, 112: physiological importance of, 112: properties of, 111. f Glucose, see Grape sugar. ; Glutin, 113; in the blood in leuchwmia, 141, 148; in bone cartilage, 204; in connective tissue, 209. Glycerin, 94. ; Glycero-phosphorie acid, 94; in the yolk, 160. Glycin, 81. Glycic acid, 76, 77. : Glycocholic acid, 87, 89; in the blood, 141; excrements, 181; intestines, 177; trans- udations, 153; urine, 195; vomit, 180. Grape sugar, 97: conditions of absorption of, 251: digestion of, 250; importance of, in the economy, see Tissue metamor- phosis, 240: mode of occurrence of, 97; in blood-serum, 140; chyle, 149; ex- 825 crements, 182; fluids of amnion and allantois, 98, 153; intestines, 177; ovum, 161; pus, 226; saliva, 165; sweat, 185; transudations, 153; urine, 194; vomit, 180: nutritive value of, 275; origin of, in the liver, 98, 140; food, 98: transformation of, in the blood, 248. Guanin, 82, 86. H Heematin, 99, 100; in the blood-corpus- cles, 182, 183. Heemato-crystallin, 105, 112: mode of oc- currence of, in the blood cells, 182: pro- perties of, 112. Hematoidin, 100. Hair-tissue, 212: constituents of, chemical, 218; histological, 212; fibrous substance, 218; medulla, 218; cuticle, 212; micro- chemical behavior of, 218. Haloid bases, 92; salts of the, 93. Hearing, sense of, 309. Heat, Animal, see Temperature. Hippuric acid, 87, 89; in the blood, 141; in the urine, 190; in the sebaceous se- cretions, 183. Histochemistry, 50, 201; difficulties of in- vestigation in, 201; influence of micro- chemistry upon, 201; necessity of study- ing the interstitial fluids, 202; physio- logical importance of, 201. Histogenetic substances, 102; division of, 108; products of decomposition of, 103; properties of, 102; ready putrefaction of, 103; theoretical composition of, un- known, 102. Homology, 59. Hoofs and Horns, see Horny tissue, 211; chemical constituents of the, 212; general properties of, 211; relations of, microchemical, 211; mor- phological, 211; substance of the, 211. Hydrochloric acid, 118; in the gastric fluid, 167. Hyocholic acid, 87, 90. Hypoxanthin, 88, 90; in blood of leuchz- mia, 141. I Jnanition-experiments, see Nutrition. Inflammation, globules of, see Mucus, 162: blood in, 147; respiration in, 269; urine in, 198. Inflammatory crust, buffy coat, 137. Infusoria, in milk, 156; pus, 226; urine, 187. Inosic acid, 88, 90; in fluid of muscles, 218, 21% 326 Inosit, 97, 99; muscles, 99. Intestinal concretions, 182. Intestinal fluid, the, 175; amount of, 176; constituents of, 175; function of, 176; mode of obtaining, 176; properties of, 175. Intestines, contents of the, 175; composi- tion of the, general, 176; constituents of the, insoluble, 178; soluble, 177; gases of the, 178; in the foetus, 179; reaction of the, 176; causes of latter, 177; sarcina ventriculi, 180; vomit, 179. Iodide of potassium, passing into the milk, ‘157; into the saliva, 165. — Tron, 118, 120: mode of occurrence of, 120; in the bile, 170; blood, 1383; gastric fluid, 168; hematin, 100; hair, 213; melanin, 101; sweat, 184; urine, 101, 192; physiological importance of, 120. in the fluid of the cardiac K Keratin, 211. Kyestein, see the Urine, 198. L Lactic acid, 76, 77: mode of occurrence of, 77; in the chyle, 149; fluids of muscles, 218; gastric fluid, 167; intestines, 177; lymph, 150; milk, 157; sweat, 184; transudations, 154; urine, 190: origin of, 78: physiological importance of, 78. Lactic acid group, 76. Lactin, 97, 99; digestion of, 252; mode of occurrence of, 99, 157; nutritive value of, 276; origin of, 99. Laurostearic acid, 62. Lead, 121, 122. Lecithin, nerve-tissue, 223; 160. Leuchemia, blood of, 141, 148. Leucic acid, 76, 77. Leucin, 81. Lienin, 82, 87. Life-pheuomena, 306. Lime, carbonate of, 116, 117: mode of oc- currence of, 117; in the bones, 204; in concretions, 117; saliva, 165; sebaceous secretions, 183: oxalate: of, 65; as a urinary sediment, 188: phosphate of, 116; in the bones, 204; in the urine, 192; cretions, 183. Lipinic acid, 72. Lipoids, 95. Lipyle, oxide of, 94; salts of, 69, 73. Liquor amnii, sce Transudations, 161. Liquor sanguinis, see Blood, 125, 135. in the yolk, sulphate of, in the sebaceous se-| INDEX. ‘Lithofellic acid, 78, 79 ; in contents of the intestines, 182. Lungs, exhalation from the, see Respira- tion, 260. Lutidin, 81. Lymph, 150: constituents of the, chemical, 150; morphotic, 150: mode of coagula tion of, 150; properties of, 150. M Magnesia, carbonate of, 121 :. phosphate of, 116, 117; in the bones, 204; in the urine, 192: and ammonia, in the excre- ments, 181; in intestinal concretions, 182; in urinary sediments, 188, 200. Manganese, 121. Margaric acid, 63. Margarin, 68; in the ovum, 160, 161. Margaritic acid, 62, 68. Mechanic force, correlation of heat and, 26. : ‘ Meconium, see Contents of the intestines, 179. Molen 99, 101; origin and importance of, 1 Melissic acid, 63. Melissyl, oxide of, 94. Mercury in saliva, 165. Metacetonic acid, 62, 67. Methods (of investigation), chemico-ex- perimental, 53; plysjologico-experi- mental, 53; statistical, 52. Methyl- -oxalic acid, see Acetic acid, 59, 66. Milk, the, 155: ‘amount secreted, 158: analysis of, 157: animals, milk of dif- ferent, 155, 156: coagulation of, 155: colostrum of, 156: constituents of, chemi- cal, 156; abnormal and accidental, al- bumen, 157; iodide of pétassium, 157; urea, 157; normal, casein, 156; fats, 156; lactin, 157; salts, 157: morphotic, 155; abnormal, blood-corpuscle, 156; epithelial cells, 156; fibrinous coagula, 156; infusoria, 156; mucous corpuscles, 156 ; normal, colostrum-corpuscles, 156; milk globules, 155: cream, 155: pro- perties of, 155: reaction of, 155. Mineral substances of the animal body, 115; division of, 115; accidental, 121; chemically operative, 118; mechanically useful, 116. Molecular forces, relation of, to life, 229; difference of their action upon organic substances, 230. Monads in the urine, 187. Motor force, 87. Mucin, Mucosin, 162. Mucous corpuscles, 162; chemical compo- sition of, see Cytoid corpuscles, 226; mode of occurrence of, in bile, 169; ex~ INDEX. 327 crements, 182; mucus, 162; saliva, 163; urine, 186; vomit, 180. Mucous sugar, see Grape sugar. Mucous tissue, gelatinous tissue of Whar- ton, 210. Mucus, 161 ; constituents of, chemical, 162; albumen, 163; fat, 168; mucosin, 162; mineral substances, 168; morphotic, blood-corpuscles, 162; coagula of fibrin, 162; epithelial cells, 161; fat-globules, 162; granular cells, 162; granular masses, 162; molecular granules, 162; inflammation globules, 162; mucous corpuscles, 162: properties of, 161: re- action of, 161, 163. Muriatic acid, see Hydrochloric acid. Muscular action, amount of force expended in, 26. Muscular fibres, smooth, see Contractile: fibre-cells, 214. Muscular fibres, striated, 215; constituents of, chemical, 217; acetic acid, 218; albumen, 218; casein, 218; creatin and creatinin, 218; fats, 218; formic acid, 218; inosit, 218; lactic acid, 218; nu- clear substance, 217; salts, 218; syn- tonin, musculin, or fibrin of muscles, 110, 217; water, 218; histological, 215 ; fat-granules, 217; primitive bundles, 215; sarcolemma, 216: fluid of muscles, 218: ‘microchemical reactions of, 216; quantitative composition of, 208. Muscular contraction, 306. Musculin, see Syntonin, 110. Myricin, 94. Mpristic acid, 62, 68. Myroxylic acid, 74. N Nails, see Horny tissue, 212. Nerve tissue, 218: constituents of, chemi- cal, 222; cerebrin, 223; cholesterin, 222; fats, 222; lecithin, 223; mineral |: substances, 223; protein substance, neurin, 222; water, 223; histological, 218; nerve-fibres, cerebro-spinal, 218; sympathetic, 219; axis-cylinder of, 219; cortical substance of, 219; investing membrane of neurilemma, 219; nerve- cells, 219; investing membrane of, 219: nuclei of, 219; nucleoli, 219; chemical composition of the individual morphotic constituents of the nerve-fibres, 221; axis-cylinder, 221 ; investing membrane, 221; medulla, 222; of the nerve cells, 222: of the contents, 222; investing membrane, 222; nuclei, 222: micro- chemical reactions of, 220: quantitative relations of, 223. Nervous force, mechanic force, 85. Neutral bodies, non-nitrogenised, carbohy- drates, 97. Nitrils, 64; of the benzoic acid group, 75; of the volatile fat acids, 64. Nitric acid, in the urine, 195. Nitrogenised bodies, basic and neutral, 79; of the ammonia type, 61, 80; of the cy- anogen type, 80. Nitrogenised paired acids, 87. Nuclear fibres, see Elastic tissue, 210, and connective tissue, 209. Nutrition, 274: amount of food absorbed in the intestines, 280: animal food, pro- ducts of disintegration of, 285: articles of food, most favorable proportions of, qualitatively, 274; quantitatively, 276; depending upon the necessity for food, 277; and the internal states of the or- ganism, 278; consumption of labor, 279; superfluous consumption (Luxus con- sumtion), 279; maximum quantities, 279; minimum quantities, 283: the blood after the reception of food, 145, 280: excreta of the organism, 281; carbonic acid, 281; hydrogen, 281; nitrogen, 281; differ- ence between carnivora and herbivora, 281; in inanition experiments, 282; when the bile is conducted externally, 282: inanition experiments, 285; excre- tion of elements in, 286; of carbonic acid, 286; of the kidneys, 286; general results of, 285; loss of weight of the whole body, 286; of different organs, 286: necessity for food, and its amount, 278: nutritiousness, and nutritive value of articles of food, 277; depending upon amount of plastic materials, 275; of non-nitrogenised substances, 275; tissue metamorphosis, in carnivora, with maxi- mum of food, 283; with minimum, 283; amount of, difficult to determine, 278 ; during development, 279, 287; during mast-feeding, 279; during thirst, 287 ; influence of non-nitrogenised food upon in nitrogenised tissues, 285; nitrogen which does not pass into the urine, 282, 284; urea not a sure index of, 282. Nutritive value of articles of food, 275. 0 Observations, general, 49. Odor of the blood, 142. Odoriferous substances, as accidental con- stituents of the urine, 194. (Enanthic acid, 62, 67. Oleic acid, 73. Olein, 738. Omichmyle, oxide of, see the Urine, 191. Organic action, vital action, 33. Organic force, formative force, 32. 828 Organism, the human, 19: relations of, chemical, 21; dynamical, 27; general, 19; statical, 24: organic forces of, 32. Osseous tissue, 202: chemical relations of, 204; general, 204; as affected by age and sex, 205; in different bones of same individual, 205; in disease, 205; of fossil bones, 206; of the different mor- photic constituents, 203 : histological re- lations of, 202; bone-cartilage, 203 ; bone-corpuscles, 202; bone-granules, 208; bone-medulla, 202; lamella, 203; medullary canals, Haversian canals, 202; medullary cavities, 202. Ovum, fiuids of the, 159: constituents of the, chemical, 160, 161; morphotic, 159, 161; white, 161; yolk, 159. Oxalic acid, 65; salt of, with lime, 65; as a urinary sediment, 188, 200. Oxidation, process of, in the animal body, 237; evinced by accidental constituents of the urine, 193 ; furthered by alkalies, 248; limits of, 244. Oxygen, proportion of in arterial and in venous blood, 134. P. Pairing, hypothesis of, 58; importance of in tissue-metamorphosis, 248. Palmitic acid, 638, 68. Pancreatic fluid, the, 174: amount secreted, 174: chemical constituents of, 174; but- tery fat, 174; mineral substances, 174; protein-body, pancreatin, 174: function of, 175: mode of obtaining, 174: proper- ties of, 174. Pancreatin, 174. Paramylon, 97, 99. Parotid, secretion of the, see Saliva, 164. Pelargonic acid, 62, 67. Pepsin, 167. Peptones, 167, 168. Perspiration, 185; relation of, to respira- tion, 269. Petinin, 81. Phenyl, hydrated oxide of, phenylic acid, 95; in castor, 183. Phenylamin, 81. Phlegmato-chemistry, 50, 123; basis for the study of tissue-metamorphosis, 52, 128; requisites for a proper investiga- tion of, 128; difficulties of latter, 123. Phosphates, 116, 118, 119: importance of in tissue-metamorphosis, 243: mode of occurrence of, 116, 119; in the blood, 133; exudations, 224; fluids of muscles, 218; semen, 159; transudations, 154; urine, 191; yolk, 160. Picolin, 81. Pimelic acid, 72. INDEX. Plasma, see Blood, 125. Plastic articles of food, 235, 255, 257, 276. Plethora, the blood in, 147. Pneumic acid, 88, 90. Potassa, salts of, preponderating in the blood-cells, 133; in smooth muscles, 215; in striated’ muscles, 218; in the yolk, 160. Potassium, iodide of, passing into milk, 157; saliva, 165; urine, 193. Processes, zoochemical, 52. Protein-bodies, 104, 105; constitution of the, 107: coagulation of the, mode of, 106: derivatives of the, 104,113: diges- tibility of the, 257: digestion of the, 255: homology of the, 107; importance of in tissue metamorphosis, 235: mode of co- agulation of the, 106: modifications of the, 104: nutritive value of the, 275: properties of the, 105; soluble, 106 ; in- soluble, 107. Ptyalin, salivin, see Saliva, 164. Pus, see Exudations, 225. Pyzmia, the blood in, 148. Pyin, see Pus, 227. Pyridin, 81. Pyroleic acid, 72, 78. R. Radicals, hypothesis of, 57; negative, 58; positive, 58. Reproduction, 297. Respiration, 258: agents of, 237, 240, 265, 276: in animals, 268; amphibia, 268 ; birds, 268; eggs of birds, 268; earth- worms, 268; fishes, 268; insects, 268 ; mammalia, 268; animals breathing by the skin, 268: animal temperature, a8 & consequence of, 273, and tissue metamor- phosis, 273: in artificial atmospheres, 262; rich in carbonic acid, 262; in oxy- gen, 262; in nitrogen, 262 ; in nitrous oxide, 263; composed of hydrogen and oxygen, 263: carbonic acid, amount of in air expired, 260, 262; depending upon the depth of the respirations, 262; their frequency, 260; holding the breath, 262; in air of air-vesicles, 262: characteristics of, general, 258: composition of air ex- pired, 260: conditions of, 258, 272: in diseases, 269: gases, quantities of, con- sumed and produced in a given time, 260: influences of external world upon, 268; atmospheric pressure, 263 ; moist- ure of atmosphere, 263 ; period of day, 264; of year, 264; temperature, 263: influence of internal states of the. organ- ism, 264; abstinence from food, 264; age, 267; alcoholic drinks, 267; diges- tion, 264; bodily exercise, 267; food, INDEX. articles of, 264; chemical nature of, 264; quantity of, 267; hibernation of animals, 267; sex, 267; waking, 267: methods of investigation, 259: relations of, to perspiration, 269: respiratory equiva- lenis, 265; value of in determining amount of tissue-metamorphosis (for- mule), 266: theory of, 269; absorption, laws of, 272; mechanical conditions of, 269; carbonic acid, formation of, 270; in the blood itself, 274; in the contact of blood in capillaries with the organs, 271; in the parenchymata of organs, 270; condition of the gases in the blood, 272; diffusion the cause of the exchange of gases in the air-passages, 270; per- meability of membranes, relatively to the exchange of gases, 272. Rheumatism, the blood in, 148. 8 Salicin, transformation of in the organism, see the Urine, 194. Salicyl, hydruret of, 75. Salicylic acid, 74; with salicylous acid in urine after ingestion of salicin, 75. Salavin, sce Saliva, 164. Saliva, mixed, 163 - amount secreted, 165: concretions, calculi, 165: constituents of, abnormal, 165; normal, 164: diastase, animal, 166: functions of 165; chemical, 166 ; dynamical, 166; mechanical, 165; passive, 166: mode of obtaining, 163: properties of, 168: secretion of the oral mucus membrane, 164; of the parotid, 164; constituents of, 164; mineral sub- stances, 164; potash-salt of a volatile fat acid, 164; ptyalin, 164; sulphocya- nide of sodium, 164; reaction of, 164; of submazillary glands, 164. Salivary calculi, 165. Salts, inorganic, 115; importance of in tissue-metamorphosis, 242. Sarcina, in the gastric contents, 180; in the urine, 187. Sarcolemma, of striated muscles, 216. Sarcosin, 81. Scorbutus, the blood in, 148. Scrofulosis, the blood in, 148. Sebaceous Secretions, the, 182. Semen, seminal fluid, the sperma, 158: constituents of, chemical, 158; fluid, 158; salts, 159; spermatin, 159; morphotic, 158; seminal granules, 158, spermato- zoids, 158; mode of obtaining, 158: mode of recognition, 159: properties of, 158. 4 Series, homologous, 60. Serolin, 95, 96, 139. Serum, sce Blood. 329 Serum casein, 111, 189. Silicic acid, 116, 118: mode of occurrence of, 118; in the blood, 142; bones, 206 ; hair-tissue, 218; ovum, 161; urine, 192. Skin, the, evaporation from, 188: sebace- ous secretion of, 182; constituents | of, 188; ammonia-soap, 183; cells, 183; epithelium, 188; fats, 183; mineral sub- stances, 183; protein-substance, 183; where secreted, 182. Smegma, preputii, 188. Smell, sense of, 319. ‘ Soda, carbonate of, 118, 119: phosphate of, 118, 119: urate of, 91, 187. Sodium, chloride of, see Chlorides ; sulpho- cyanide of, 121, 122; in the saliva, 164; in the urine, 191. Spermatic filaments, spermatozoa, see Se- men, in the urine, 187. Spermatin, see Semen. Starch, transformation of into sugar, by the intestinal fluid, 176; by the saliva, 166; granules of, in intestines, 178. Stearic acid, 63, 68. Suberic acid, 72. Substitution, hypothesis of, 58. Substrata, organic, of the organism, 55, Succinic acid, 72, 73: group, 72. Sugar, cane, digestion of, 252: grape, see Grape sugar. Sulphates, sce Aikalies ; in the urine, 191. Sulphocyanide of sodium, see Sodium. Sweat, the 183: amount secreted, 185: constituents of, accidental, 185; benzoic acid, 185; cinnamic acid, 185; coloring matters, 185; urea, 185; chemical, 184; ammonia-salts (products of decomposi- tion), 184; chlorides of alkalies, 184; fats, 184; fat-acids, volatile, 184; gases, 185; oxide of iron, 184; phosphates of alkalies, 184; of earths, 184; morphotic, 184: mode of obtaining, 183; properties of, 183, Syntonin, 105, 110: mode of occurrence of, 110; in contractile fibre-cells, 215; in transversely striated muscles, 217. Systems of theoretical chemistry, 57; va- lue of, for physiological chemistry, 62. T Tannic acid, appearing in the urine as gallic acid, 193. Taste, sense of, 319. Taurin, 82, 86. Taurocholic acid, 87, 90. Tauryl, hydrated oxide of taurylic acid, 95 ‘ Teeth, see Dental tissue. Temperature, animal, 273. Thein, 88. 330 INDEX. Theobromin, 88. Tissue-metamorphosis, during deprivation of water, 287. Tissue-metamorphosis, during develop- ment, 287, Tissue-metamorphosis, during fattening, 287. ; Tissue-metamorphosis, in general, 284: amount of, 285: application of the free acids, 241; acid phosphates formed by, 242; diffusive currents excited by, 242; muscular function connected with, 241; paired phosphoric acids, 243: of the al- kalies in the blood, 248; action of on albumen, 244; gelatin, 244; sugar, 248; as a means of oxidation, 243; of chlo- ride of sodium, 244; action of on pro- tein-bodies, 245; sugar, 245; urea, 245; formation by, of chloride of potas- sium, 245 ; hydrochloric acid, 245; im- portance of in cell-formation, 245; in mechanical tissue-metamorphosis, 245; of the fats, 237 ; as agents of respiration, 237; bile acids formed from, 79, 238; constituents of nerve-tissue, 288; de- position of in peculiar cells, 237; forma- tion of, in the body, 239; from nitro- genised substances free from fat, 239; oxidation of, 237 ; of grape sugar, 240; as an agent of respiration, 240; formation of acids from, 240; of fats from, 241; mode of occurrence, 240; solvent action of, on fat, 241; of the potash salts, 242 ; opposition of acids and alkalies, 242; phosphates, 248; of the protein-bodies, 285; action of oxygen upon, 236; as bases of tissues of greatest vital activity, 235; as plastic materials for all ‘hitro- genised tissues, 235: oxidation, process of, furthered by alkalies, 243; limits of, 244; seen in accidental urinary consti- tuents, 244: partition, division, or allot- ment of acids and alkalies, 241: rela- tions of individual factors of, to ‘each other, 234: temperature, animal, as a consequence of, 237, 273; intermediate, 288. Toluylic acid, 74. : Tortoise-shell, see Horny tissues, 212. Touch, sense of, 820. Transudations, 151: abnormal, contents of blisters, 151; in cavities or in paren- chymata of organs, 151; secretion of wounds when free from blood-cells, 151: conditions under which formed, 151; re- gulating the proportion of albumen, 152; constituents of, chemical, 151; albumen, 152; ammonia-salts (products of decom- position), 154; constituents, 153; cho- lesterin, 153; extractive matters, 153; fats, 153; fibrin, 152; gases, 154; salts, 164; sugar, 153; urea, 152; morphotic, 151: definition of, 151: normal, 151; aqueous humor, 151; liquor amnii, 151; secretions of serous membranes, 151; properties of, 151. Trimethylamin, 80. Tuberculosis, bile in, 171; blood in, 148 ; respiration in, 269. Typhus, bile in, 171; blood in, 147; ex- crements in, 181; respiration in, 269. Tyrosin, 81." | U Urate of soda, 91, 187; of ammonia, 92, 187. Urea, 82, 83: amount of, 88, 189; depend- ing upon the circulation, 189; upon the food, 84, 189: mode of occurrence of, 85; in the bile, 171; the blood, 141; fluids of eye, 158; lymph, 150; milk, 157; pus, 227; sweat, 185; transudations, 153; urine, 188; vomit, 180: origin of, 85 Urie acid, 88, 90: mode of occurrence of, 92; in the blood, 141; in the urine, 90, 187, 190: origin of, 92: physiological importance of, 92. Uric oxide, see Xanthin, 90. Urinary sediments, 91, 187, 200. Urine, the, 185: amount excreted, 197; of animals, 199: calculi, formation of in, 200: conditions of excretion of, 195: con- stituents of, accidental, 198; chemical, 188; abnormal, albumen, 194; ammo- nia-salts, 195; bile-acids, 195; bile- pigment, 195; butyric acid, 195; casein, 194; fats, 194; nitric acid, 195; sugar, 194; normal, chlorides of alkalies, 191; coloring matters, 101, 191; creatin and creatinin, 190; cynuric acid, 190; ex- tractive matters, 190; formic acid, 190; free acid, 192, gases, 192; hippuric acid, 190; iron, 192; lactic acid, 190; oxide of omichmyle, 191; phosphates, 191; silicic acid, 192; sulphates, 191 ; urea, 188; quantity of latter, 189; de- pending upon the circulation, 189; and upon the diet, 189; uric acid, 190; water, 192; morphotic, 186; blood-cor- puscles, 187; casts of tubuli, 186; cys- tin, 188; fibrinous clots, 187; fungus, 187; monads, 187; mucous corpuscles, 186 ; sarcina, 187; sediments of cystin, 188; of oxalate of lime, 188; of phos- phate of magnesia and ammonia, 188; of urate of ammonia, 187; of urate of soda, 187 ; of uric acid, 187; spermato- zoids, 187; vibriones, 187: fermentation of, alkaline, 186; acid, 185: influences upon, pathological, 198; physiological, 198: mechanism of, excretion of, 195: INDEX. properties of, 185: sediments, formation of, in, 185, 187, 200. Urine-pigments, uroerythrin and urosacin, 101, v Valeral, 63. Valerianic acid, 62. Valyl-oxalic acid, see Valerianic acid, 62. Vernix caseosa, see Sebaceous secretions, 182. Vibriones, in milk, 156; in mucus, 162; in urine, 187. Vision, sense of, 318. Vitellin, see Casein, 111, 160. Vital force, 82, 41, 229. Voice, mechanism of the, 308. Volition, 308. Vomit, 179; containing ammonia, 180; bile, blood, 180; fat, 180; salt, 180; sarcina ventriculi, 180; sugar, 180; re- sembling rice-water, 180; watery, 180. 331 WwW Whalebone, see Horny tissues, 212. Water, bases of the type of, 61; acids, of the type of, 61. Water, amount of in the body, 120; im- portance of, 120; origin of in the econo- my, 120; quantity in urine, 192. Wharton, gelatinous tissue of, 210. Wool, see Hair tissue, 213, x Xanthic oxide, and Xanthin, 88, 90; in the urine, 200. Y Yolk-fluid, see Fluids of the ovum, 159. Yolk-globules, 159. Z Zoochemical processes, 52, 229. Zoochemistry, 50, 55. ERRATA. Page 62, for ‘‘magaritic,” read ‘margaritic.” «69, 9th line from bottom, for ‘‘yelk,” read ‘yolk.” «© 193, 11th <« ae “« quinine,” read ‘‘quinone.” «161, 4th = « top ‘ 15.2 grammes,” read “234.5 grains.” « 161, 4th «“ gs s¢ 23,9 grammes,” read ‘¢368.8 grains.” WATERED rae Nf nN AGH rior } aN SM i rh Ly rb) i Hy Nera i Mah ie i‘ } i oy Rati Aa ost , Morse Sah Hist oo ie ey i SUI Nese Gn Bait i A a A Se ee i Se en i vi i) i AHH ak es an PARAS ; ae ea - Hoi 55 Dy . Sees 2 Sora ay Sates ane Se iH fs eH iif ie ; Ha sf