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THE ENEEGY 
 
 OF 
 
 LIVING PROTOPLASM, 
 
 BY 
 
 OscAK LoBW, Ph. D., 
 
 Professor in the Imperial University, Japan. 
 
 LONDON 
 
 KECAN PAUL, TRENCH, TRUBNER & CO. Ltd. 
 
 PATEKN03TEB HOUSE, CHARING CnoSS EOAD. 
 1896. 
 
If there is one thing clear about the pre 
 of modern science, it is the tendency to reduce 
 all scientific problems, except those which are 
 pui'ely mathematical , to questions of molecular 
 physics — that is to say, to the atti'actions, 
 repulsions, motions, and co-ordination of the 
 ultimate particles of matter. 
 
 T. H. Huxley, The Scieniific Aspects of 
 PosiTivissr. 
 
PREFACE. 
 
 The interest which I have taken in the chemistry of 
 proteids and in the chemical nature of protoplasm ever 
 since I devoted myself to chemistry awakened the desire 
 «ome years ago to frame some conception of the mode of 
 origin of these substances in plants. Setting out from 
 certain observations which bear upon the subject I became 
 convinced that there must exift an unstable modification 
 of albumin witli which alone we have to do in living 
 protoplasm and differing from that of dead protoplasm 
 or from ordinary albumin, though easily passing into 
 it. On this assumption I ultimately found m.yself able 
 in great measure to account for the production of 
 albumin itself as well as to enunciate laws of toxic actions 
 which not only covered the facts already known but 
 also others revealed by observations carried out to test 
 their validity. Moreover, that hypothesis led Dr. Bdkorny 
 and myself to the actual discovery of a very easily 
 changeable albumin contained as reserve material in 
 various plants and remarkable for its properties. 
 
 The theory having thus proved its value as a guide to 
 the discovery of new truth, I believe it will be useful to 
 
IV PREFACE. 
 
 give a survey of it and the facts on which, it i"ests, 
 descriptions of which now lie scattered through various 
 publications. I trust that scientific readers will treat the 
 question with unbiassed mind ; all I ask for is impartial 
 consideration and positive criticism. 
 
 Some of the chapters of this treatise have, in more or less 
 abridged form., been communications to the Bulletin of the 
 Agricultural College of the Imperial University , Japan, 
 and in part have made the substance of lectures to 
 scientific Societies in Tokyo. 
 
 My special thanks are due to Dr. Edward Divers, 
 F. R. S., Professor in the Imperial Universitj-, for valuable 
 
 Tokyo, May, i8g6. 
 
 OSCAK LOEW. 
 
CHAPTEE ]. 
 
 VIEWS ON THE CAUSE OF VITAL PHENOiMEKA. 
 
 The change from life to death has always been con- 
 sidered as an insoluble mystery. The sudden stop of all 
 manifestations of life, the irrecoverable loss of motion and 
 sensation, appeared as melancholy as it was inconceivable. 
 Even the gradual arrest of movement in infusoria or 
 diatoms killed under the cover-glass while viewed with 
 powerful microscopes, or the contraction of the protoplasm 
 of the dying cells of 8pirogyra when a deadly pressure 
 upon the cover-glass is exerted, cannot fail to awake 
 emotion and I confess (his has made a more lasting 
 impression upon my mind than the killing of an animal 
 for culinary purposes. In what, now, consists the power, 
 that produces the actions of life ? In what consists this 
 change to the rest of death ? Before we enter upon our 
 reply let us first review the opinions of the old philosophers 
 and the modern physiologists. 
 
 Anaxagoras defined an animal as an automatic machine, 
 but left undecided how it moved. Socrates ridiculed this 
 idea, even on his death-bed.* According to Aristotle animal 
 motions and animal heat are intimately connected, and 
 the latter is produced by the food. The heart is the centre 
 of motion and sensation, has a life of its own, and is the 
 hottest part of the body.^ Platu considered the red colour 
 
 (Ij Flato, Phaedon 97, 98. 
 
 (2) Aristotle (Edifcio BekUeri) de part. anim. II, 1; III. IV, 4 7; V. 
 2. — Hist. anim. I. XVII. — De respiratiorc VI. 
 
2 VIEWS ON THE CAUSE OF VITAL PHENOMENA. 
 
 of tlie blood to be an effect of the living fire, and the blood 
 itself, as the bearer of the vital power, to be the Stat of 
 the soul.' The Pythagoreans defined animal life as the 
 result of tlie entrance of the " life-spirit " into the body* 
 by the respiration- process, and declared the brain to be 
 the seat of sensation. 
 
 After the development of science was brought to a 
 stand-still by various causes, biological questions took a 
 new start in the seventeenth century. It was Descartes, 
 who, in the year 1P37, declared all powers of nature to be 
 molecular motions; animals were in his opinion caloric 
 automatic machines, in which the motions of the blood 
 and of the organs were the effects of chemical heat- 
 producing processes.^ 
 
 With the observation of Galvani, in the year 1780, of 
 the convulsions of a frog's leg brought in contact with 
 two metals, indicating an electrical current, the view of 
 Gal rani found numerous followers, and men like Eumholdt 
 were among the admirers of the new vital theory. However, 
 VoUa's experiments on contact-electricity soon eclipsed 
 Galvani s results and when the latter succeeded, in the year 
 1793, in adducing irrefragable proof of the presence of an 
 electrical current in the animal, electrical contraction 
 without metals, it did not find grace with the scientific 
 
 (1) Plato, Tim. 493 etc. 
 
 (2) Democritus, in Aristotle, De respiratione, IV. 
 
 {Z) Rene Descartes works, edited by H.Kirchmann, II. Soon after- 
 wards (1687) Mayow, a now celebrated English savant, showed ( Opera 
 omnia) that life and fire are sustained by one and the same principle con- 
 tained in the aii', and that this principle is mixed with another indifferent 
 substance. He can be considered not only as a forerunner of Lavoisier, 
 but also as tlie first propounder of the doctrine of the conservation of 
 energy. 
 
VIEWS ON THE CAUSE OF VITAL PHENOMENA. 3 
 
 public ; the doubts and distrusts crer.ted bj' Volta were 
 miglitier than the language of the new experiments ; 
 Galvani got no satisfaction and died with the value of his 
 work unrecognised. Nor when Du Bois lieymond pi'oved, 
 in the year 1843, the correctness of Galvani' s views of 
 the presence of electrical currents in animals, was one 
 voice raised in support of the theory that electricity is 
 the primum movens of all vital phenomena. Indeed, 
 the electrical phenomena observed are, just like animal 
 beat, but secondary actions, and not the first cause of life. 
 Another view gained much foothold also, one that was 
 even defended by Liebig, the theory that organisms 
 are ruled by a specific power quite different from any 
 other, inscrutable to men, and supernatural : it was 
 ■called vital force} Justus Liebig said: ''the cause 
 of vital force is not chemical force, not electricity, not 
 magnetism ; it is a power that possesses the most general 
 properties of all causes of motion, of variation of form and 
 qualities of matter, and is a specific one, because it pro- 
 duces effects like those of no other power." " The laws 
 of life, and every thing disturbing, promoting, or varying 
 them, can doubtless be investigated, but without ever 
 knowing what life really is."^ Even in tlie third edition 
 of his work, published in 1846, we find upon the fii-st 
 
 (1) Attempts to define the limits of scientific inqiiii'y iu tliis directioa 
 have often been made in former and in recent years. 
 
 (2) Die organ. Chemie in ihrer Anwendung auf Physiologie und Patlio- 
 logie, Braunschweig 1842, pp. 7 and 237. These few quotiitions will, 
 suffice to rorrect the erroneous statement, made sometimes, that Liebig was 
 the first who combated the hypothesis of a specific vital power. Chap. 23 
 of Liehig's " Chemische Briefe " (1858) will be found especially instructive 
 in this regard, as it exhibits Liebig as. a most energetic defender of that 
 hypothesis. The term force was formerly used in a more general sense than 
 now. 
 
4 VIEWS ON THE CAUSE OF VITAL PHENOMENA. 
 
 page : " in the animal egg, in the plant-seed, is recognis- 
 able a remarkable activity, a cause of increase in sub- 
 stance, a compensation of loss, a power in the state of 
 
 rest this power we call vital force." From page 225 
 
 the following characteristic passage may be quoted : " an- 
 other fundamental error entertained by physiologists is^ 
 that physical or chemical forces alone or in combination 
 with anatomy can suf3fice to explain vital phenomena." 
 
 lAebig did not share all the expectations created by the 
 first synthesis of an organic compound, that of urea by 
 Woehler in the year 1828. Previous to this discovery it 
 was often asserted that organic compounds could only be- 
 produced by " vital powers " and even Berzelius, but one 
 year before, had expressed this opinion. This author, even 
 in 1847, still declared his conviction that life is something; 
 inscirutable : " once connected with matter it produces de- 
 velopment and growth, but how this proceeds is an 
 insoluble mystery.' That life is something independent of 
 matter but merely working through it, is even to-day a 
 very general opinion.^ 
 
 Mulder^ believed that the specific vital power is intimate- 
 ly connected with the four elements found principally 
 in organic compounds: carbon, hydrogen, nitrogen, and 
 oxygen. Hanstein assumed the existence of a special 
 psychic principle acting in union with physical and 
 chemical power*; and Biitschli the presence of a vital 
 ferment, localised in the nucleoli.^ 
 
 (1) Text-book of Chemistry, 1827, III, p. 1. I.ehrb. d. Clieui., 5th, 
 ed. vol. 4 p. 5. 
 
 (2) Cf. Science, March, 1893. 
 
 (3) Versuoh einer allgein. physiolog, Cheiii. (1843). 
 
 (4) Das Protoplasmn, p. 293 (1880). 
 
 (5) Z'xjlog. Anzeiger, 1882, p. 66. 
 
VIEWS ON THE CAUSE OF VITAL PHENOMENA. 5 
 
 View3 very different from those of Liehig and Benelius 
 were entertained even a century ago by the Germaia physio- 
 logist, Eeil^ who wrote : " the so called vital force has fooled 
 us long enough, and has led us into sterile deserts. Matter 
 itself and not a specific new force is the cause of vital pheno- 
 mena." In still stronger terms Schleiden^ wrote : " Only 
 ignorance and indolence of spirit are the defenders of the 
 vital force in the present state of development of the natural 
 sciences ; of a power that can acoamplish everything and 
 of which nobody can tell how it acts or what laws it obeys. 
 The savage, who takes a locomotive for a wild animal, is 
 not more ignorant than the natural philosopher who talks 
 about vital force in organisms." 
 
 lu a similar sense, Matteucci declared that : " parlare di 
 forze vitale, dame la definizione, interpretare fenomeni col 
 loro soccorso, e intanto ignorare le leggi di quests forze 
 suppnste, & dir nulla o ^ peggio che dir nulla, S appagare 
 lo spirito, cessare dalla ricerca della veritd." ' 
 
 TJie opinion, expressed by the physiologist Lehmann, 
 (1853) are of the same tendency ; " though many vital 
 phenomena are for the present inexplicable, we do not feel 
 the necessity of assuming such a ruler as vital force."* Less 
 hopeful of our ability to dispense with the aid of some 
 such agency Gorup-Besanez (1874) said : " All the 
 physical and chemical laws known to us at the present 
 day are insufficient to explain the formation of a 
 plant-cell, the process of generation, or the conduction 
 of sense-impressions to the brain." ^ 
 
 (1) Jieih Aichiv, III, 434 (1798). 
 
 (2) Grimdzuge der wissenschiiftliohen Botanik I, 60 (1844). 
 
 (3) Lezioiii sui fenomeni fiaco-chiraici dei coi-pi viventi., 2d. ed., p. 10 
 (1846). 
 
 (4) Lelirbuoh der phjsiolog. Cliem., 2d. od., vol. Ill, p. 15 1. 
 
 (5) Lehrbuch der orgvn. Cliera., 3d. ed., p. 6. 
 
6 VIEWS ON THE CAUSE OF VITAL PHENOMENA. 
 
 HaecUel^ however, finds the formation of a cell as simple 
 as that of a crystal. He asfumos a kind of " soul " in 
 every atom and a progressive development of it in the 
 organism. 
 
 Moleschott' defined life " not as the result of a specific 
 force but as a certain condition of matter caused by 
 peculiar motions produced by heat and light, water and 
 air, electricity and mechanical actions," and Beidenhain? 
 as a "peculiar connection of physical and chemical 
 energies," which is essentially also the opinion of NencJci,* 
 Pfiiiger, Huppe,^ Halliburton,^ B. Meyur, Helmholtz and 
 Huxley.'' The last mentioned asks in a significant 
 manner : " is the matter of life composed of ordinary 
 matter dififering from it only in the manner in whioli its 
 atoms are aggregated?" Gohn^ infers that the energy of 
 the living organism must be of a mechanical order 
 though as yet undecomposable into other known energies, 
 while Balfour Stewart^ vsrites : " In fine, we have not 
 succeeded in solving the problem as to the true nature of 
 
 (1) Generelle Morphologie der Orgauisnicn, I, pp. 143 u. 148. — Cf. also 
 Tageblatt der Naturforscliei'versammlung zu Milnchen, 1877, p. --. 
 
 (2) Kraft und Stoff, 3id ed., p. 256 (1856). 
 
 (3) Handbuoh di-.r Physiologie, V, p. II. 
 
 (4) Areli. f. exp. Path. u. Pliarmacol., 20, 343. 
 
 (5) On the Cause of Fermentations, etc. , BerUn, 1893, p. 14. 
 (6J Chemical I'hysiclogy, Chapt. 14(1890). 
 
 (7) Lessons on Klfiuientary Physiology (1870), lossou VXI, ai.d in 
 " The physical basis of life." 
 
 (8) LebeusfragMi, Bot. Centralbl., 1886. 
 
 (9) Conservation of Energy, Chap. V (1875). In full accoidance 
 wi^ Balfour Stewart, another piominent English savant, S.E. Armstrong, 
 declared (Anniversary Address ; Chemical Society, London, 1895) : " Wiiat- 
 ever the nature ,of the protoplasmic molecules they must be of extreme 
 complexity and, consequently they must present very many nc/iie regions 
 to which other groups may become attached and within which therefore 
 circuits can be established ; hence the marvellous power of protoplasm of 
 conditioning a great variety of changes ; and it is doubtless the maricllous 
 complexity of the albuminoids which renders such divei'sity of type possible 
 in both the animal and vegetable Isingdonis." 
 
Views on the cause of vital phenomena. 7 
 
 life, but have only driven the diflficulty into a borderland 
 of thick darkness, into wliich tlie light of knowledge 
 has not yet been able to penetrate." " We have now 
 to remark that the particular force which, is thus used 
 by living beings is clieir.ieal affinity. Our bodies are, in 
 truth, examples of an unstable ai'rangement of chemical 
 forces, and the materials which compose them, if not 
 liable to sudden explosion, like fulminating powder, are 
 yet pre-eminently the subjects of decay." 
 
 Also Tyndall (1874) confessed' that he discerned in 
 matter " the promise and potency of every form and 
 quality of life." In doing so, as has been so acutely pointed 
 out by Stallo,^ he only then re-worded an old thought of 
 Francis Bacon : " And matter, whatever it is, must be held 
 to be so adorned, furnished, aiid formed, that all virtue, 
 essence, action, and motion may be the natural consequence 
 and emanation thereof."^ The conviction that chemical 
 science will principally be concerned in the solution of 
 vital problems is emphatically expressed by Erlenmeyer's 
 appeal : " if physiologists like 0. Lu&wig identify the pro- 
 gress of physiology with the progress of chemistry, then 
 the chemists must feel anew instigated to devote themselves 
 to physiological problems."* And not less decided is the 
 opinion of Bmthelot on this point, when he declared his 
 object to be ' ramener la chimie tout entiere . . . au memes 
 principes m^caniques qui regissent d^ja les diverses 
 branches de la physique.' 
 
 The collection of views, hypotheses, and declarations we 
 
 (1) Inaugural Address to tlie British Association at its Belfast Meeting. 
 
 (2) Concepts and Theories of Modern Pliysics, Neio XorJc, 1884. 
 
 (3) Ue Prine. atque Origg., 0pp. ed. Bohn., 2, 691. 
 
 (4) Zeitschr. f. Chem., 1859. 
 
8 VIEWS ON THE CAUSE OF VITAL PHENOMENA. 
 
 have ventured to present to the reader will certainly prove 
 of some interest. One author merely denies current ideas ; 
 another presumes, or asks questions ; a third makes 
 positive statements without any proof whatsoever. No- 
 where do we find the least attempt to attack the questions 
 at i.=isue by experiment j everywhere it becomes evident, that 
 in using the word life the authors have not distinguished 
 properly between the Energy of living matter and vital 
 Functions which stand to each other about in the same 
 relation as the pressure of the steam to the working of an 
 engine. It is one question what energy is the 2>^imum 
 movens, but there are others much more complicated 
 as to how this energy is utilised to perform various, 
 functions and how the machinery is constructed. Just as 
 steam can be used for the most different performances, 
 so vital energy serves for a variety of vital functions. 
 And the comprel tension of these functions, again, can be 
 attained only by commencing with the simplest forms 
 of life, as Claude Bernard} has justly pointed out : 
 " Pour comprendre les fonctions de Vorganisme, il faut 
 connaitre celle de la cellule." 
 
 (1) Lefons sur les phenomines de la vie commuiis aux animaux et 
 aux veffetaux, pag. 458. 
 
CHAPTER 11. 
 
 CHAKACTERISTICS OF PROTOI'LASBI. 
 
 The discovery of the morphological units of complex 
 organisms are of comparatively recent date. But although 
 manA- investigators have contributed their share towards 
 creating a stock of anatomical and physiological knowledge 
 and a great number of phenomena have been described 
 with minute exactness, final satisfactory explanations have 
 not been readied. 
 
 After Eobort Hojke, in the middle of the seventeenth 
 century, had discovered the cellular nature of plants, 
 Malpighi and Gr^w had closely investigated their an- 
 atomical structure, and Gorti, in the year 1772, had 
 observed the circulatory movements in plant cells, a 
 long time elapsed before Schwann, promulgated his cell 
 theory in 1839. Schleiden had recognised about two years 
 previously that each cell is the product of another and is 
 never spontaneously formed in the fluids of the organism, 
 fie declared : omnia cellida e cellula. The cellular nucleus 
 was first described by li. Brown in tlae year 1833, while 
 the animal cytoplasm was discovered by Dujardin, who 
 called it sarcode. Mohl observed later, in the year 1844, 
 a similar substance in plant cells which he designated as 
 protoplasm, whereupon ilfa.i! Hchulze demonstrated the 
 close chemical analogy between the living matter of 
 animals and plants. A cell was defined as nucleated 
 protoplasm with or without a cell wall, the nucleun as a 
 
10 CHARACTERISTICS OF PROTOPLASM. 
 
 network of filaments containing the nuclear fluid and 
 covered by the nuclear membrane ; the surrounding 
 protoplasm, again, as a mixture of solid and liquid 
 materia], forming a tenaceous transparent mass of neutral or 
 weak alkaline reaction, which was later designated as 
 cytoplasm in contradistinction to the protoplasm of the 
 nucleus and of the chlorophyll bodies.' Further micros- 
 copical investigations revealed the important role of the 
 nucleus and of the centrospheres with the centrosomes in 
 the multiplication of cells and in the sexual propagation 
 of organisms.^ 
 
 Gradually it became clear that protoplasm was an in- 
 strument of great complexity, especially in a germ cell, 
 which ai-e, to speak witli Maxwell, " representative bodies 
 containing members collected from every rank of the long 
 drawn ramification of the ancestral tree, the numbers of 
 these members being amply sufficient to furnish charac- 
 teristics of -every ojgan." Our microscopes, however, do 
 not reveal the systematic arrangements of the smaller par- 
 ticles, and even the coarser structures, alveolar or reticular, 
 are, as F, Klemm has shown, not fixed but changeable and 
 often merely appearing at the moment of death ; only the 
 iibrillar structure of the nucleus in its living state seems 
 to be fully establislied. At any rate it may be convenient 
 to distinguish by ' tectonic ' the invisible molecular 
 arrangement in protoplasm, from the visible differentiation 
 
 (1) The fwrtlier distinctions of polioplnsm, filarplasni, hyaloplasm, 
 archoplasm, kinoplasm, ti-ophoplasm, and idioplasm may here be passed 
 over. 
 
 (2) Many authors participated in the di.-covei-ies, I need mention only 
 Flemming, Utrassburger , H. Zaccharias, Camay, Van Seneden, Hoveri, 
 Ouignard, 
 
CHARACTERISTICS OF PROTOPLASM. 11 
 
 within cells aud multicellular organisms wliich is ' orga- 
 nisation.' 
 
 Innumerable cells of various- fot-ms and functions com- 
 pose the organs of motion, secretion, sensation, and 
 generation, and many sacrifice their individual existence 
 in support of the whole. The multifarious actions and 
 the combined efforts of various cell systems in a 
 multicellular organism secure the proper condition for its 
 existence. One of the most important properties of 
 protoplasm coming here into play is irritability, which 
 no organism can dispense with. In virtue of it even 
 the lowest forma of life are capable of responding to 
 (^xternal influences of exceedingly subtle nature.' With 
 the highest development the processes known as sensa- 
 tions are connected with specialised organs, the nerves, 
 in which accumulation, conduction, transformation, and 
 translation of energy is carried on {Eosenhach}.'^ Part of 
 this remarkable system is the brain with myriads of 
 connecting and ramifying threads and those cephalic 
 ganglia denominated by Huxley ' registering apparatus.' 
 Huxley defined a nerve as a ' linear tract of specially 
 modified protoplasm between two points of an organism, 
 one of whi(jh is able to affect the other by means of 
 the communication so established,' and thought it con- 
 ceivable that the lowest animals and even plants might 
 have a kind of nervous system.' 
 
 (1) Tims tlse infusorium, Paramecium, is seiisi;ive for differences of 
 temperature as snmll as O'l" C. {Mendelsohn, 1895). 
 
 (2) Tlie muscles also are highly in-itablo so that grazing with the tip 
 of a piu will produce a coutraoLion wliereby an increased amount of oxygen 
 is absorbed with liberatiin of hoat aud electricity {FJlilger). 
 
 (3) Lecture at the lioyal Institution, London, 1876. Cf. also the in- 
 teresting deductions of F. Miippe, Naturwisspnschaftliche Kinfiilirung in 
 die iiacteriologie, pag. 136. 
 
12 CHARACTERISTICS OF PROTOPI.ASM. 
 
 Mos< extraordinary appear the functions of the nerves 
 of the higher animals; not only the finest diEEerences in 
 the waves of light and sound are perceived with great 
 precision but also surprisingly small quantities of certain 
 compounds can be noticed by the olfactory and gustatory 
 organ.' As little as 0"0006 thousandths of a milligram of 
 vanillin can, e.g., still be noticed by the smell (Passy). 
 Similar wonders, however, are presented by the vegetal pro- 
 toplasm ; of diammonium phosphate 00000033 milligram 
 suffices to cause the inflexion of the tentacles of Drosera 
 {Darwin). Pfeffer has noticed that a solution of 0*01 % of 
 sodium malate can attract spermatozoids of ferns^ and that 
 movements of bacteria are detemined by the attraction or 
 repulsion they experience in contact with certain substances 
 (chemiotaxis). Again, the direction of the growth of the 
 mycelium of fungi is guided by the presence of nutritive 
 compounds [Miyoshi), and most minute quantities of 
 certain still unknown substances (enzymes ?) can produce 
 various galls on leaves or start an abnormal growth in 
 branches (hexenbesen). 
 
 Sensitiveness to sunlight is in plants not only manifested 
 by helioti-opism but also in various other waysj thus 
 Merulius lacrimans as well as Rydrodictyon are induced 
 
 (1) It may, however, be mentioned here that compounds of the widely 
 di£Eerent chemical constitution can produce sometimes very similar im- 
 pressions upon the olfactory or gustatflry nei-ve. Thus, several nitro-com- 
 pounds (nitroflavoline and trinitroisobutyltolyl ketone) possess the odour of 
 musk J alkaloids as well as non-nitrogenous compounds may have nearly 
 the same bitter taste and certain benzene dei-ivatives (Remsen's sacchai-in ; 
 diilcin ; amidocamphor) and dimethylurea taste as sweet as sugai-s. 
 
 (2) Maleic acid also attracts them, fumaric acid does not {Pfeffer). Of 
 peculiar interest is also the difference between the behaviour of malic and 
 that of the closely i-ehited tartaric acid upon the tentacles of Drosera ; the 
 former causes inflection, the latter does not {Darwin.) 
 
CHARACTERISTICS OF PROTOPLASM. IS 
 
 to fonri spores (B. Harlig ; Klebs). Irritability to molar 
 energy is not only noticed in geotropism but also in the 
 inflection of tlie tentacles of Drosera by a hair of 0-00082 
 milligram in weight (Darwin), or in the influence by a 
 thread of 0-00025 milligr. upon the direction of a tendril 
 of Sicyos angulatuK (Pfeffer)} 
 
 Truly, problems of most intricate nature are involved 
 in the dii3Eerentiations of irritability and tectonic. One 
 thing, however, is certain : before the first step towards 
 solving the moi'e difficult problems can be made it is 
 absolutely necessary to answer the fundamental question.: 
 What is the cause of the never-ceasing cell-activity ? What 
 is the nature of the energy governing the living cell ? 
 
 (1) Hydrotropism imd aerotropism are but special cases of cheniio- 
 tropism. Also the stimulation of certain chemical activities by very smalt 
 quantities of poisons belongs to this class of phenomena. — A case of thenno- 
 tropis\ii with a bacteri\;ni was observed by ISeyerinh and a case of negative- 
 electrotropism with Fhycomyces by Hegler. 
 
CHAPTER ILL 
 
 PROTKIDS AND PROTOPLASM. 
 
 The fact thiit witli the differentiation of the pi-otoplastn 
 distinct classes o£ cells are produced, that do continually 
 a specific kind of work as long as tiiey live, can only 
 be attributed to a special and fixed system of tectonic, 
 or structure, for each separate case. A change of con- 
 struction, an alteration in the system, must interfere with 
 the normal working and produce an entirely different 
 result. A comparison with the inultitude of machines 
 used in industries, all built of the same material and 
 moved by the same energy but doing very different 
 work according to their construction, will here suggest 
 itself to the mind. Any injury to an important connection 
 will at once stop the normal working. 
 
 If we now consider protoplasm from the chemical point 
 of view, the constant presence oiproteids^ must strike us as 
 the most important fe.'iture. In a cell we can discern 
 principally albumin and nuclein ; ^ the former, along with 
 some nucleo-albumin, in the cytoplasm, the latter as con- 
 stituent of the nucleus and containing as chief component, 
 
 (1) The iiaiiie proieid is used here in the general sense, not in the 
 restricted meaning of some German authors. 
 
 (2) We leave out of cousi.leration here the many kinds of reserve 
 proteids. Osborne and Vorhees (7th Ann. Eep. of Connect. Agr. Exp. 
 Stat. , 1893) have shown the presence of six different reserve proteids in 
 whont-grain alone j Osborne also four in cotton seed, three in oats and flax 
 seed. Cf. also the investigations of Ritthausen and others. 
 
PROTEiDs And protoplasm. 15 
 
 besides metaphosphoric acid, also albumin. Another pro- 
 teid called plastin, less easily attacked bj acids and alkalies 
 than nuclein but related to it, was f;bservcd in plant cells 
 by lleinlie and by Zaccliarias. Other compounds pre- 
 sent may vary in quality and quantity, according to the 
 species and state of nutrition or development of the 
 organism ; they may be eitlier required for respiration 
 and other useful purposes or they may be mere by-pro- 
 ducts ; but they cannot possibly be essential to the causation 
 of the vital properties of protoplasm. Besides the occasion- 
 al absence of these compounds as an objection to their being 
 essential in causing vital action, it has to be pointed out 
 that there exist organoids of the vegetal cells, as, e.g. 
 the tonoplast, that contain absolutely notliing else but 
 proteids, watei', and mineral rriatter. In the cytoplasm 
 itself, however, are often found lecithin and cholesterin, fat 
 globules and carbohydrates. But even though the quantity 
 of these be sometimes larger than that of the proteids, that 
 cannot possibly tell against the leading role of the latter. 
 Earlier autlioi-s defined as protoplasm the entire mixture 
 of various compounds present' ; others, led by Pfluger and 
 Hanstein, reserved that name for the organised proteids 
 only. How, however, in view of the constancy and 
 uniformity of the work of a given protoplasm, the former 
 view, that by the co-operation of all the compounds 
 present the vital properties are produced, can still find 
 defenders at the present day, remains incomprehensible to 
 a logical mind. We are left by that view to wonder why 
 in the dead cells that mixtum compositum which is still 
 present does not ever, by some instigation or other begin 
 to co-operate again and exhibit the activities of life once 
 (1) Compare, e. g., Beinke's definition ; Botan., Zeitg. 1883 p. 66. 
 
16 PROTEIDS AND PROTOPLASM. 
 
 more. Some one who found 27 per cent calcium carbonate 
 in a fungus (^thalium) even concludes that this belongs 
 to the molecular system of the protoplasm of this organism ! 
 Eut if all the substances found in protoplasm were to 
 be essential for its constitution, then all secretions, 
 numerous organic acids, tannins, alkaloids, hydocarbons, 
 esters, and wax, urea and uric acid in animals, etc. would 
 all be parts of various kinds of protoplasm. All these 
 substances are formed in the protoplasm of different cells 
 and must exist there, even if only for a short time. This 
 older view of declaring everything found in protoplasm to 
 be an essential part of it and attributing to it even vital 
 actions, mu'^.t therefore lead simply to absurdities. 
 
 But a new definition, a new conception, will always be 
 considered as a sort of challenge by those who cling to 
 the old notions ; no wonder then that in the attempts to 
 defend the impossible very odd ideas are often expressed. 
 Thus, we find in ati attack upon the new proposition, 
 among all sorts of objections and declarations that do not 
 hit the points in question, the following passage : " Is it 
 thinkable that the vital properties are connected with only 
 one class of compounds ? Why not ascribe them to water 
 which in quantity exceeds that of the proteids, or why not 
 to the lecithin or to the potassium salts which are of general 
 occurrence in the cells ?" . This will suffice as an example 
 of the conceptions still prevalent in the year 1882. 
 Eeflection must lead us logically to consider the proteids 
 to be pabulum of the protophism. Indeed a protoplasm 
 without proteids would be a non-entity, while it might 
 contrariwise be asserted that one without any other, 
 organic compound but proteids could very well exist, in 
 case reserve-proteids are stored up in it as food. 
 
PROTEIDS AND PROTOPLASM. 17 
 
 If, tlicii, we must look upon the proteids as yielding 
 the vital phenomena and observe that the chemical pro- 
 perties of dead and living cells are totally different, there 
 remains no other conclusion but that the proteids of 
 the Vicing protoplasm undergo a chemical change at ike 
 moment of death. The fact that in tbe living cells a 
 continuous combustion is going on, in the dead ones 
 not, led Pfliiger, even in the year 1875, to infer that 
 the chemical nature of the proteids is altered.' Other 
 chemical facts, however, lead to the same conclusion, 
 such as that there are many poisons having no action 
 wliatever on common proteids, which act upon the pi'o- 
 teids of the living protoplasm (cf. Chap. VI). 
 
 PJlvger also pointed out that the decomposition of 
 albuminous matter in the living animal organism yields 
 other products than the decompositions artificially accom- 
 plished in the laboratory, and concluded tliat the nitrogen 
 
 (1) rfliig. Arch., 10, 320. We may quote as illustration of the uu- 
 !>en able position of the opponents of this view the following passages = 
 
 * Why s-hould just the proteids and not the wafer undergo a chemical change 
 when the cell dies ?" was objected by one who evidently had forgotten 
 the existence of isomerism. "That in living cells chemical processes go 
 on which are no longer observed in dead cells, is an old observation, 
 hence the assertion that the living cells are chemically different from the 
 dead is nothing new," was objected by another adversary, who thus 
 proved that he did not di>tinguisli between a fact in itself and an ex- 
 planation of the causation of the fact. Such have been the a'tempts to 
 discredit the new doctrine. 
 
 As to the function of the water, nobody would deny its great importance. 
 We see on the one hand org'niisms die that lose a certain amount of water 
 and on the other hand thu embryo of seeds awake to life when water has 
 entered. But it is evident that water cannot he the " primum movens." The 
 vital energy in a seed is a suppressed kinetic energy. The force of cohesion 
 is here opposed to plasmic enei'gy, but as the state of cohesion is changed 
 
 by the entering vater, the energy can be displayed, the solicitation is n 
 
18 PROTEIUS AND PROTOPIASM. 
 
 of the " living albumin " is linked to the other atoms 
 in a different manner.' He supposed tliat it is linked as in 
 the cyanogen-group, and that this group becomes changed 
 by fixation of the elements of water when the cell dies : 
 
 .c]sr-f-ii20=.co.isrH2 
 
 'J'liis hypothesis, however, is not supported by chemical 
 facts. Certain cyanogen compounds are, it is true, very 
 unstable, being very easily converted into polymeric 
 forms, and isocyanic acid is quickly decomposed by water 
 into carbon dioxide and ammonia, but such cases cannot 
 serve here for comparison j neither can the transformation 
 of ammonium isocyanate into urea serve as an example ; 
 nor the transformation of nitriles into amides. And just as 
 little probability exists for the hypothesis of Latham who 
 assumes the existence of a series of cyanhydrins attached 
 to benzene derivatives^ and a chemical change of these 
 groups at tlie moment of death. Nevertheless, it was 
 evident that some chemical change, whatever it miglit be, 
 must certainly take place in the proteids, although the 
 physiologists were few who openly admitted this. 
 
 Among them stood conspicuous M. Nenclci, who de- 
 clared : I have repeatedly expressed my opinion, that 
 investigation into the albuminous bodies must take a new 
 direction, if we want to undertake with success the closer 
 investigation of those actions we call ''life;" the pro- 
 longer prevented from taking effect, and the first sign of life makes its 
 appearance in form of respiration. The dormant life of certain seeds can 
 be presert-ed for over fifty years {A. Peter). 
 
 (1) This conclnsion however he was not justified in drawing, for the 
 same albuminous matter can yield under different conditions very different 
 products. Besides, certain nitrogenous compounds of the animal are 
 formed by stinthelical operations, as uric acid or uvea. 
 
 (2) British Med. Journ., I., 626 (1886). 
 
PKOTEIDS AND PROTOPLASM. 19 
 
 teids of the living cells must have another chemical con- 
 •stitulion than those of the dead cells." ' And, again, " It 
 is of essential significance, that albuminous substances, 
 isolated at very low temperatures from living atiimals, 
 are of a very changeable character, as, e.g., blood- 
 plasm, oxyh'i^nioglobin, and myosin." " The most im- 
 portant function, nay even the most characteristic feature 
 ■of lite itself, is the formation of labile albumin molecules. "' 
 
 lioaenhach? and Detrner* may also be cited, tlie former 
 having declared that " Death is the upset of the unstable 
 •equilibrium of atoms in the living matter," while the latter 
 ■assumed that all the atoms of the "living albumin 
 TOolccules " are in such a lively motion that a dissociation 
 can easily take place forming thereby, on the one hand, 
 dion-nitrogenous compounds such as glucose and, on the 
 ■other, am.ides. By this disuncAation respiration M'oiild be 
 induced and other vital phenomena made possible. Such 
 a hypothesis, howevci', is incompatible with the great 
 sensitiveness of tlie protoplasm towards every disturbing 
 influence. The continuous regeneration supposed by 
 Delmer would be wholly impossible, as dissociation would 
 Jead to death. 
 
 Now, if the view is correct that some chemical cliange 
 does take place, it must further bo recognised that when 
 the dead matter of our food is convei"ted into the living 
 matter of our nerves, muscles, and glands, a considerable 
 
 (1) Arch. f. exper. Pnthol. und Pharmacol., 20, p. 343 and Journ. f. 
 pralcfc. Chera., vol. 26. 
 
 (2) Pfltig. Areh., 31, 336 ; Ber. D. Cliom. Ges., 18, 385. 
 
 (3) Aufg.iben der Therapie, Chap. 14 (1891). 
 
 (4) Vergleichende Physiologic des Keimungsprocesses. Jen-!. 1S80. 
 Ber. D. Bot. Ges., 1S93 ; cf. also the views of Henle. 
 
20 PKO'l'EIDS AND PROTOPLASM. 
 
 chemical clifinge must a]so take place and just in th& 
 opposite direction lo that counected with the loss of life. 
 Pfiiiger {I. c.) exprepsed liis conviction in llie following, 
 •words: "An albumin-molecide, which in tlie brain, 
 concurs in the production of thought, which in the 
 spinal column mediates senFation, which in the nniFclcs 
 performs mechanical work, or in the glands starts- 
 chemical activity, is doubtless derived from the same 
 dead albumin of the blood, but it is changed in chemical 
 character as soon as it enters the living cell.' From the- 
 moment it forms a part of the living protoplasm, it com- 
 mences to respire, to live. Only the cells have the pro- 
 perty of life ; such albumin, which has not become- 
 prctoplasm, is dead albumin, even in the living body."^ 
 
 As living cells are so easily killed by chemical treat- 
 ment and an investigation as to the chemical state of 
 the living protoplasm, carried on in the usual way, must 
 be excluded, other means have to be resorted to (cf. 
 Chap. VI). 
 
 Theordwfi?-2/proteids,however,have ofleii been the object 
 of chemical investigation but the manifold observations 
 
 (1) This production of living matter from dend was declared by Pfiiiger 
 to be one of the greatest enigmas of nature (Die nllgemcinen l.eben- 
 sercbeinnngen, Bonn 1889). FJiilger's supposition, tluit Liebig entertained 
 the belief in a chemical diffcicnco between albuminous matter in living and 
 dead cells, is an error. Nowhere in Lietig's writings can a decisive opinion, 
 be found. 
 
 (2) Later investigations however, have shown that the dissolved 
 protcids of the animal body are by no means ordinary inactive proteids.. 
 Sndolf Emmerich was the first win obrervcd, in 1887, that bacteriii are 
 killed by the blood of a living animal. The scrum of dog's blood quickly 
 kills leucocytes of man and rabbits. H. Btuhneriamv\ (hut these properties 
 of the dissolved albumin are lost at 55° C. 
 
PROTEIDS AND PROTOPLASM. 21 
 
 relating to their decomposition under different conditions 
 are partly not suitable and partly still too imp^rteot to 
 lead to a correct view as to the clioinioal structure of the 
 proteids. However, a brief survey as to the principal 
 ■cliemical characteristics may here be in order. 
 
 Numerous analysss of albumin led Lieherlcuhn to the 
 formula t!72Hj,2N,8S022 which expresses in the present state 
 ■of science as nearly as possible tlie relation between the 
 iimmbers of atoms but not yet the molecular magnitude, 
 ■which in all probability is a multiple of this expression.' 
 ■Certain proteids, e.g., hsemoglobin, have a still higher 
 molecular weight tlian albumin. While crude albumin is 
 ■easily soluble, pure albumin, free of any trace of inorganic 
 matter, is insoluble in water, but easily soluble in very 
 dilute hydrochloric acid. Acid solutions are easily precipi- 
 tated by neutral salts, while alkaline ones are unaffected by 
 them. The general chemical character is that of amido- 
 acids, i.e., the proteids can play the part of weak acids 
 as well as that of weak bases. Moreover, they are 
 capable of passing into widely differing products, ao jording 
 to the nature of the chemical attacks made upon them, a 
 bshaviour which in all probability is due to a special 
 facility of atomiG migration, in consequ:;nGeof the presence 
 
 (1) While Liehei'Jcilhn's formula mi^ht perl^ips correspond tj) tint oE 
 propepiimo proper, tlio moleouliir weight of deiitero »lburaoso was found by 
 Sahanajejf and Afex<indroiv, by tho cryoscopic method, to be about 3200, 
 or neirly d)uble thit which Lieherlctl\ns formula would lead to, and that 
 of albiimln to ba 14-270, i.e.; nearly nine times as lii^h, while Sioquisl 
 recently calculated from different oxperimejits 800 only. On the othei- hand, 
 the molecular weight of peptone was found by Patl and by Ciamician to 
 lie much iower tliau s'lpposod, ».e. , ti be bss tlrm ■lOD, and that of 
 antipeptone or earnie acid by Siegfried to be 257. Peptone is, according 
 to Foal's view, a mixture of severiil compounds. 
 
2'2 prOteids and protoplasm. 
 
 of many hydroxy! groups, wliereby ftfRnities arc loosened',, 
 as in tlib sugars. The sugars yield upon boding witli 
 strong mineral acids products' which no chemist would' 
 dare to assume present as sucli in the molecules. An- 
 analogous case is exhibited by the proteids, wliicli yield 
 upon such decomposition amido-acids and bases.^ The 
 older view assumed the existence o£ these complexes in 
 the proteids, supposed to be complicated ureas or guani- 
 dines in which the hydrogen atoms were replaced by the- 
 radicals of those amido-acids and bases.' Such a com- 
 pound, however, would not be capable of yielding so great 
 a variety of decomposition products, under different 
 ciiemical or physiological influences. Thus, we observe- 
 the formation of pyrrol, indol, skatol, and methyl- 
 mercaptan {.^ieher), by fusion with caustic pota-ssa; the- 
 formation of skatolacet'c acid by certain microbes'; that 
 of kynurenio acid, an oxyquinoline carboxylic acid, in the 
 liver of the dog; that of glucose, glycogen, and milk- 
 sugar in the body of carnivorous animals^ ; while probably 
 
 (1) lluniic acid, furfural, lajvuliiiic acid, L niiic acid, and carbonic acid. 
 
 (2) Leuciue, tyrosine, plieiiylaniido-piopioiiio acid, aspartic acid and 
 glutamic acid, lysine, lysatine {Vrev&eel) and argiuiuc {Hedin). 
 
 (3) We can conclude with a hish degree of probability tliat the 
 leucine radical does not e.^ist as such in the proteids, not only from the 
 bchavio'ir towards potassium permangiinate but also towards osmium 
 tetroxide, uhicli is reducj'd to metal by every componnd containing the 
 group — C'Hg — CHj— and therefore by leucine, but not by albumin in the- 
 dark. It is true, many compounds show other reactions when liberated 
 from complex moloci.lcs, but this is only the case when a reacting group 
 becomes generated Ijy that liberation, as, <-. g., in the hydrolysis of cane- 
 sugar, whereby nldchydo groups are generated. Such oljjections have no- 
 weight in onr case. 
 
 (")•) Neitcki, Wien. Akad. Her., 1889. 
 
 (5) Some authors deny that any carbohydrate can he obtijinoil from 
 albumin ; others, like Favy, assert that it is possible by treatment with 
 
PROTEIDS AND PROTOPLASM. 23 
 
 also guanine, xanthine, and related bases are first produced 
 from albumin before tliey become constitnentsof the nucleus. 
 Moderate oxidation cif albumin by potassium per- 
 mangante yields oxyproteosiilphonic and then peroxy- 
 proteic acids,' while further oxidation leads to diKruption 
 of the molecule and formation of benzoic, succinic^ acetic, 
 formic, oxalic, hydrocyanic, and carbonic acids, besides 
 ammonia and sulphuric acid.''' Tliere exist— to judge by 
 tho amount of bromine taken up by dry albumin — only 
 two pairs of doubly linked carbon atoms' of the ordinary 
 kind in the molecule, if LieberMhn'e formula is taken as 
 foundation, while the existence of several benzene rings is 
 highly probable and generally assumed.* As to the smaller 
 atomic groups there are neitlier ketonic, and probably 
 neither nitrile nor carboxylic groups present in the 
 ordinary albumin ;° nitrogen is in all probability partly 
 present as amidb-groups,^ partly as imido-gi'oups ; and sul- 
 
 bascs to get sugar. Sehiitzenberger ir.eiitioned long ago that a dextrin-like 
 bcdy can be obtained by (heir decomposition with barium hydroxide. 
 
 (1) Maly, Jahresber. f. Thierchem., vol. 15. This author found 
 among the decomposition products of peroxyproteic acid by barium hydroxide 
 a large amount of oxalic and glutamic acids. 
 
 (2) Loeio, Jonm. f. prakt. Chcm., 31, 153. 
 
 (3) Loeto, ibid, pag. 139. 
 
 (4) Nencki, I.e., assumes the exiatence ol an ox.vpheny!, a phenyl, and 
 a skatol radical. 
 
 (5) On the behaviour iif nitri'.es to liydroNylamine, cf. Tiemann, Her. 
 I). Chem. Ges., 1884, p. 128. If my hypothesis is correct (cf. the following 
 chapter) then the carbon is present essentially in the form of CH , CH2 , and 
 CHOH groups. Lorenz showed that the groups O.CH3 orO.C2H6 are 
 not present in albumin but are apparently so in small quautity in uucleins. 
 
 (6) Some difference as to the relative number of the amidc-gi'oups may 
 exist in propcptone and albumin, since the former yields at once an insoluble 
 compound upon addition of form aldehyde, the latter only after some time or 
 on addition of acids. 
 
24: PROTEIDS AND PKOTOPI-ASM. 
 
 pilur as hydi-osulpliyl. Ordinary albumin, although easily 
 yielding to the attack of strougei- chemical agents, does 
 not belong to the labile compounds in the proper sense 
 of the word, which implies a mucli more subtle nature.' 
 
 It appeared to me tlia,t more insight into the chemical 
 nature of the proteids could be obtained by the study 
 of the formation of proteids in plant cells. Starting 
 from a series of observations 1 reached a hypothesis, 
 which led me to infer the existence of a labile and a stable 
 modification of albumin, as explaining in a more satis- 
 factory manner than the views of Pfiiiger and of Latham 
 (see above) the diflierence between the proteids of the 
 living protoplasm and those of the dead (cf. Chap. IV, V, 
 and VI). 
 
 (1) 'I he eft'oi'ts made by soma iiutliors to rjach proteids by synthesis 
 would — leaving all otlier objections aside — never lead to sucli protrids as 
 compose living protoplasm , since the mctlioils emplovi'd would be wholly 
 unsuitable for the purpose. 
 
GLIAPTER IV. 
 
 THKORY OF THE POKMATION OF ALBUMIN IN 
 PLANT-CKLLS. 
 
 The formation of iilbmniiions matter in plant-cells is 
 certainly one of the most importiint processes in tiie 
 domain of general physiology, for upon it depends the 
 growth of protoplasm, the multiplication of cells, the 
 development of plants, and, through plants, the possibility 
 of animal life. 
 
 This process, however, is not less interesting from a 
 chemical point of view, as relatively simple substances are 
 with astonishing facility converted by it into the most 
 complex compounds known. Ijct us see whether certain 
 principles of the nutrition of tlie lower fungi and of the 
 phtenogams will not furnish some clue to tiiis extraordinary 
 process.' 
 
 A. Nutrition of Microbeii ani Mould funji. 
 
 Among fungi tlie microbes arc especially rem.irkable f(ir 
 tlie intensity of their chemic.il activity. Oxidations and 
 decompositions are accomplislied in them on an extensive 
 scale. Numerous compounds are easily split up and, 
 aided by atomic migrations, otlicrs of a more solid structure 
 
 (1) From the dawn of exact knowleiige to the present day, observation, 
 experiment, and speculation have gone hand in hand. 'J'he invention of 
 verifiable hypotheses is not only permissible but is one of the conditions of 
 progress {Uuxley). Jj'hypoth^se ct le raisonnemcnt ont anssi un r61e in- 
 dispensable ; il faut le repeter, puisqne certains esprits persistent & vouloir 
 que Ton s'en tienne exelusivement aux fails {Leo Errera), 
 
26 FORMATION OF ALBUMIN. 
 
 n-e formed: the prodvicts of fermentations. Amid tins 
 destructive activity proteids are built up within tlie cells 
 and become organised into living protoplasm, what under 
 favourable conditions is done witli such rapidity that one 
 cell yields by multiplication in 24 hours more than trillion 
 of new cells. 
 
 The degradation of complex substances must precede the 
 synthetic work in order that not only energy but also the 
 requisite atomic groups may be obtained. 
 
 Although organic compounds of very different chemical 
 constitution may serve for nourishment and development, 
 there can be hardly any doubt but that in all cases the 
 same proteids result in one and the same species, otherwise 
 the structure and the functions of the protoplasm formed 
 would show variations and thus new species would spring 
 into existence with ease under the influence of the food. 
 We iind, however, the species of bacteiium or of mould- 
 fungus preserved, whether it is nourished on glycerol, 
 glucose, or galactose, acetic or quinic acid ; whether we 
 offer leucine or betaine, asparaginc or kreatine as the 
 source of nitrogen.' 
 
 This experience teaches us that the formation of proteids 
 must commence with atomic groups simple enough to be 
 derived from substances widely different. 
 
 The nutritive properties depend, other things being 
 equal, upon the chemical constitution. The more easily a 
 compound is attacked by the cells tlie quicker is the 
 development of new cells. Slight chemical changes may 
 
 (1) The characters of certnin bacteria may, however, be modified bj 
 changing otlier conditions of cuHitation ; but v hethcr such modifications 
 would lead in course of time to new species, a point Hhich would be of liiyh 
 
FORMATION OF ALBUMIN. 27 
 
 convert an indifferent compound into a nulritive oua 
 and this again into a poison, a fact, illustrated by the 
 following series : CHij CliiiOlI; CII2O. Besides, whether 
 a substance proves to be nutrient or poisonous will depend 
 often upon tlie degree of conL-eritration of its solution. 
 Good nutrients, such as glucose, can be utilised in higher 
 concentration than poorer ones, such as sodium acetate.' It 
 is further a noticeable fact that maleic acid is very unfavour- 
 able compared with the isomeric fumaric acid, and that in 
 certain cases the accumulation of methyl-groups in a com- 
 pound diminishes the nutritive value, as we observe in 
 comparing tetramethylglycol (pinacone) "with glycol, or 
 trirnelhylamine with methylamine.^ Sources of carbon are : 
 alcohols, aldehydes, ketones, acids, esters, bases ; sources 
 of nitrogen are: nitrates, ammonium-salts, amido-acids, 
 amides, amines, ammonium- bases, nitrilts; sources of 
 sulphur are not only sulphates but also certain organic 
 sulphur compounds. 
 
 In regard to the relative value as sources of carbon for 
 aerohic bacteria, the following conclusions may be drawn 
 from numerous experiments : 
 
 importance iu connection with the prohleni of evolution, remains to bo 
 investigated. 
 
 (1) Some very sniiill differences excit an inflnence here upon certain 
 species, as Fasleur and otliers liuve shown, with dextro, and lajvo-rotatory 
 modifications of varions compounds. Further, the introduction of an 
 amido-sroup into a molecule will in many cases increase nutritive value, 
 while in some it has the opposito effect; thus, e.g, , acetone is a good nutrient 
 while diacotoucaminn i-! a very poor one (O. Loew, Centrbl. f. Uact., 12, 362\ 
 
 (2) O. Loew, Centralbl. f. Bact., 12, 46o; SoJcorn^, Cliem. Ztg., 1896, 
 Nr. 9. That chemical stability is iiioreased by the aecuumlatiou of methyl- 
 groups iu a compound has been repeatedly observed. The most interesting 
 case of the kind has recently been described by I elrenko, Chem. Ztg., 
 1895, pag. 1880. 
 
28 FORMATION OF ALBUMIN'. 
 
 1) The nutritive value of acids is enhanced by the 
 presence of alcoholic hydroxyl-groups, and that of alcohols 
 increases with the number of iiydroxyl-gronps ; thus, lactic 
 acid is sup-jrior to propionic acid, and glycerol to propyl- 
 alcoliol. 
 
 2) The presence also of aldehyde or kctone-groups in- 
 creases nutritive qualities, so that glucose is bettor than 
 mannitol.' 
 
 3) Lower alcohols, such as methyl-alcohol, may bo used 
 in higher concentration than the higher ones, e.g., amyl 
 alcohol. 
 
 4) The lower membei's of tlie fatty series are more 
 easily assimilated than the higher members; sodium 
 acetate being far more so than sodium valerate. 
 
 5) Unsaturated cyclic compounds are generally not 
 favourable ; thus pyridine, antipyrine, and dimethyl- 
 oxypyrimidine appear to be wholly unsuitable, and 
 benzoic and salicylic acid.-^ arc very poor sources of c.irbon, 
 while phenyl-acetic acid, as containing a CII^ group, is far 
 better, and quinic acid, containing a xatiiraled benzene- 
 ring with 4 CJIOII group.s, is a very good sourc?.^ 
 
 Tiie question wIkcIi is the comp )und that sji-vcs as a 
 starting point for protcid fonnation , can onl}' bu answered 
 by taking intoconsiderntion the lowest compounds utili.°iable 
 
 (1) If «e compare, e.ff., ethyl acctoaeetate with ethyl acetate, both in 
 O'l per cent, solutions, we observe a nmie rapiil development of baetciia in 
 the former than in th.> latter. O. Loeiv, Bi )1. Centralbl., 10, 533. 
 
 (2) In carrying out such experiments, mineral solutions slnnUl he 
 prepared, containing 0-02% ningnesiuni sulphite, 0-2% potassimn nitrate 
 or neutral ammonium pli isphato and 0- 1-0-2% neutral potassium phosphate. 
 After addition of the organic nutrient to be tested the liijuids aie sterilised 
 by heat or filtration through Clw mberland' s filter and inoculated. Organic 
 bases are best neutrnlisod with plnsphoric acid ; acids are bc-t employed as 
 sodium salts. 
 
FORMATION OK ALBUMIN'. ^W 
 
 fis niitvicnts, and, as metliyl-alooliol, nietliylamine and 
 methyl- sulpliuric acid' serve the pui-pose, the darting group 
 must contain only o?ie atom of carbon in the molecule. And, 
 further, since methyl-alcohol or methylamine, as such, do 
 not serve for synthetic operations, tranpformation into a 
 compound capable of condensation must take place,- and this 
 can only be form-aldehyde, the same substance that forms 
 by condensation various kinds of sugars. Neither acetic, 
 glycolio, nor amidoacetic acid can be utilised as such, but 
 by oxidation may load to the one compound that can be 
 utilised, viz., to form-aldehyde; no other unsaturated 
 atomic group could here result, suitable for synthesis. 
 This oxidation in the cells may be expressed by the 
 following equation in the case of acttic acid : 
 
 cH3.coon+02=ciro-i-co,+ii,o 
 
 We can thus understand why polyhydric alcohols and 
 acids are so favourabb, and why such substances ai-e 
 capable of nourishing certain bacteria endowed with 
 ferm,entatiue propei-tiesi, even in the absence of air, while 
 compounds without the CHOlI-groups can be used as 
 food ouly ill the presence of air, oxidation being then 
 necessary to produce this ClIOH-group or the isomeric 
 form-aldehyde.^ But cun that conclusion be admitted if 
 form-aldehyde is a poison ? No doubt tlii-i seems a weighty 
 objection, but if we consider how easily form-aldehyde is 
 changed under condensation influences and how indifferent 
 
 (1) In this case, for obvious reasons, au alknline reaction is necessary. 
 
 (2) Thus, e.g., acetates or leucine can nourish facultative anaerobs, Only 
 if air has access, whi'e tartaric acid can do so also in absence of air ; the 
 oxygen of nitrates cannot replace fiee oxygen, prcbably because oxidation 
 then takes a course d^fferei.t from that raquiied to form the starting group 
 for proteid formation. 
 
30 FORMATION OF ALBUMIN. 
 
 certain compounds of this aldehyde are, the objection no 
 longer appears so serious ; -we have only to adopt the view 
 that the form-aldehjde undergoes rapid transformations and 
 that no molecule remains unchanged for a second.' 
 
 If we are correct in our inference we may express the 
 general rule thus : — 
 
 Compounds that are easily oxidiaed or decomposed hy 
 hacteria and thereby yield form-aldehyde are good nutrients 
 for them. 
 
 In this connection also it is an interesting fact that there 
 exists a microbe species,^ which can develop in nourishing 
 solutions containing as sole organic substance the com- 
 bination of form -aldehyde with sodium acid sulphite, 
 CHjOH.SOgNa ; or the compound which form-aldeh3rde 
 yields with ammonia, the so-called hexaraethylenamine. 
 This microbe is also capable of utilising formates,' in which 
 cnse a synthetic operation has to be assumed to occur, 
 form-aldehyde being probably reached by an intermediate 
 foi'mation of glyoxylic acid : * — 
 
 2HC00H=HC0.C00n-hlL0 
 
 nco.coon=H,co+co, 
 
 A still farther reaching synthesis has to be accomplished 
 when ammonium carboniite serves as nutrient for the 
 nitrifying microbe, a highly interesting case, first observed 
 by P. Hiippe and Herdns and studied also by Munro, 
 
 (1) Cf. O. Zoem, Ber. d. Deutscli. Cliem. Cos., 22, 481. Synthetic 
 processes require substances of a oerbain labiiitj ; very active substances, 
 however, are more or less poisonous, 
 
 (2) I described it as Bacilltis metJii/licus in Centr.ilbl. f. Bact., 12, 463. 
 
 (3) O. Loew, ibid., p. 463. 
 
 (4) Cf. Koen!gs, Bjr. D. Chem. Ge5., 25, 801. BoJcorny {I. c.) has 
 observed that glyoxylic acid can be utilised by bacteria. 
 
FORMATION OF ALBUMIN. 81 
 
 Warington Franlcland, and IVinoyradski. Here, very 
 probably, a part of the liyiirogcn of the a mmonia serves 
 for the production of form-aklehyde from carbonic acid.' 
 
 Some additional remarks may be made on the nutrition 
 of mould-fungi {Penicillinm, Aspergillus, Mucor). Sub- 
 stances supporting the life of aerobic bacteria, generally 
 also serve as food for mould-fungi, tliough there exist 
 exceptions : methylamino, methyl alcohol and sodium 
 valerate are better utilised by bacteria, glyoxal better by 
 mould-fungi. A neutral reaction is best suited for most 
 kinds of fungi; in alkaline liquids, however, bacteria thrive 
 better than mould-fungi, while in an acid one the contrary 
 is observed (with some exceptions). 
 
 To those . compounds which cannot be utilised by 
 mould-fungi belong maleic,^ citraconic, mesaconio, 
 dibenzylmalonic, and diethylsuocinic acids. Benzyl- 
 succinic, di-substituted glutaric and oxyisobutyric acids 
 are very poor sources, while malonio, succinic, mono- 
 methylsuccinic, and monoethylsuccinic acids are good 
 ones.' 
 
 But it is not only in regard to the sources of carhon that 
 great variety exists ; it does so also in regard to the 
 sources of nitrogen. Of the great number of the latter 
 compounds I will mention, as examples : glycocoll, aspa- 
 ragine, kreatine, allantoine, methylamine, acetaraide, me- 
 thyl-cyanide, betaine, strychnine. Nitrites are, in a certain 
 concentration, less favourable than nitrates, and are in acid 
 solutions poisonous. Hydroxy lamine and diamide being 
 
 (1) Cf. F, mippe, Naturw. Einfiilining in di« Baoteriologie, Wies- 
 baden, 1896, pp. 63-66. 
 
 (2) E. Stichner, R. d. Deutsch. Chem. Ges., 1892, p. 1163. 
 
 (3) S. Mei/er, Ibid., 1891, p. 1071. 
 
32 FORMATION OF ALBUMIN. 
 
 Strong poisons, canEot be utilised at all, and Ljdrogcn azide 
 only in Ligh dilution?.' For the rer.sons that bold good 
 in tbe case of carbon, nitrogen compounds must be 
 transformed first into ore and tbe pame atomic group, be- 
 fore synthetic work can start; tbis group is evidently 
 ammonia which, in iorm of its salts, is not only very suit- 
 able for mould-fungi and bacteria, but is also the simplest 
 nitrogen compound that can be directly utilised.^ 
 
 The liberation of the niti-ogen of oj'ganic compounds 
 as ammonia may be accomplished by hydrolysis, as with 
 amides ; by oxidation, as pi'obably in the case of amines 
 and amido-acids ; or by reduction, a means applied by 
 ana'erolic microbes. Compounds easily decomposed, as 
 kreatine, will also, of course, be of more value than such 
 as offer considerable resistance, as strychnine.' 
 
 Finally, in regard to the sulphur of the proteids,* the 
 
 (1) O. Loew, Biol. Centralbl., 10, 588 nrd Ber. Deutsili. Cheiu. Ges., 
 vol. 24, p. 2947. Certain fungi, as Saccharomyces M),roderma prefer 
 animcnja as somen of nitrogen to amido-acicls and peptone [Bei/erinc/r), 
 The common beci-jeast however, can at low temperature, make bettor 
 use of the latter than of the former; further it cannot utilise nitrates 
 {A. lUayer). Lament has shown that this is due to the conversion of these 
 into the poisonous nitrites. 
 
 (2) Kilrates have to be reduced first to ammonia. Tbe supposition 
 that hydroorylamine is the lowest nitrogen compound from wliicb proteid- 
 sjntliesis takes its start, is not admissible; for, leaving other objections 
 aside, anaeii bs would certainly find it impossible, to produce this compound 
 from ammonia in absence of air. 
 
 (3) A very lemarkable case is that of the assimilation of free nitrogen 
 by certain lactcria of the soil, recognised years ago by Berthelot and 
 recently confirmed by WinogradzJci. The free nitrogen is here probably 
 first converted into ammonium nitrite, and the nitrous acid then so rapidly 
 reduced to ammonia, that it cannot accumulate or bo set free. 
 
 (4) The protcids of mould-fungi and yeasts contain sulphur, but 
 thn^c of ECMiiil kinds of bacteria were found free from sulphur by Nencki, 
 
FORMATION OF ALBUMIN. 33 
 
 beliavioiir leaves no doubt that tliis is present in a 
 reduced state, and hence the next conclusion is that 
 all sulphur-compounds have to be reduced to hydrogen 
 sulphide in the process of proteid formation. Thus, then, 
 ihe experimental evidence leads us to the inference that 
 the atomic groups for the production of proteids are : — 
 form-aldehyde, ammonia and hydrogen sidpMde} 
 
 B. Nutrition of Phcenogams. 
 
 As chlorophyll-bearing plants produce by assimilation 
 carbohydrates, it is natural that such well-suited com- 
 pounds should form, here also, the main source of carbon 
 for the proteids. Nitrates or ammonium salts furnish the 
 nitrogen ; sulphates the sulphur. If all conditions are 
 otherwise favourable, then the synthetic work proceeds so 
 rapidly that the intermediate steps cannot be directly 
 traced. From numerous observations, however, the con- 
 clusion appears justified that it is asparagine to which an 
 important r61e must be attributed in this connection.^ 
 
 On the one hand, this substance appears as a final 
 product of metabolism, on the other, as a step in the 
 formation of proteids. We find it not only in shoots and 
 buds and in plants kept in darkness but also in roots of 
 
 (1) These three substances are either formed only in the quantities 
 required for proteid-forniation ; or, if an excess of one or the other should 
 have resulted, are transformed into innocuous compounds. But certain 
 species of bacteria produce ammonia, from amido-compounds or nitrates, and 
 hydrogen sulphide, from sulphates, in excess of the needs for the production 
 of proteids. Further, it may be assumed as highly probable that even the 
 smallest excess of form-aldehyde is at once transformed into carbohydrates 
 (mucilage, glycogen, etc.). 
 
 (2) Ti. Harfig first recognised the importance of asparagine for 
 proteid production. Borodin, Pfeffer, and Kellner ieolsLwA asparagine to be 
 
34 FORMATION OF ALBUMIN. 
 
 fully developsd plants under normal circumstances. In 
 shoots, the more of it is produced, the smaller is the 
 amount of carbohydrates in the seeds' and, when these 
 young plants have formed enough chlorophyll for the 
 production of a larger amount of sugar by assimilation it 
 disappears gradually again. 
 
 Moreover, before the assimilation process has set in with 
 sufficient intensity, a gradual increase of asparagine is 
 observed in proportion as the other amido-compounds, 
 formed by the action of a trypsin- like enzyme upon the 
 reserve proteids, decrease.^ That the proteids, as such, are 
 oxidised dircetly to asparagine, as BoussingauU first 
 supposed, has not been proved. 
 
 In tliose cases, however, in which roots and stems rich 
 in sugar contain much asparagine, this cannot be derived 
 from proteids by metabolism, and its origin; has to be look- 
 ed for from another source. It was surmised by various 
 authors, Kellner, Schuhe, and others, that nitrates or 
 ammonium salts may give rise to its formation, but 
 it has only recently been proved that it is essentially 
 
 the form in which proteids are translocated in plants. The most extensive 
 investigations in this direction, however, we owe to E. Sehulze and his 
 school; cf. Landw. Jahrb., vol. 12j 17; 21. Landw. Vers. St., 1880-96. 
 
 (1) The degree of protcid decomposition in shoots depends largely also 
 upon the time, at which the reserve-carhohydrates become soluble ; only 
 dissolved carbohydrates afford protection to proteids ; in this way, certain 
 anomalies observed in germinating peas as compared with beans may be 
 explained. 
 
 (2) This way of generation of asparagine from proteids offers a certain 
 analogy to that of urea in aiiimals ; in both cases amido-acids are the 
 Intermediate products which lead upon further oxidation to nniuionia. 
 In animals this again leads to carbamic acid (DreeAsel and Abel), and 
 thence to carbamide, whilst iu jihaenogams it leads to asparagine. The 
 investigations of TSencki and his collaborators have thrown a flood of light 
 upon the production of urea in animals. 
 
FORMATION OF ALBUMIN. 35 
 
 •tlie latter wliicli do so.' Nitrates can be stored up as sncli, 
 if more has been absorbed than is immediately needed 
 for proteid production, but ammonium salts cannot, being 
 noxious in a certain concentration, and , therefore, have to 
 be transformed into an innocuous compound ; this proved 
 to be asparagine. 
 
 Let us turn now to the question of the conversion of 
 asparagine into proteids. The relative amount of sugar, 
 Ihe temperature, the intensity of respiration and of growth, 
 the supply of the required mineral salts, all influence tliis 
 process. We cannot, therefore, be surprised to see in cases 
 where one of these conditions is wanting or imperfect, that 
 asparagine may be present along with a considerable 
 amount of sugar, without proteid production being ac- 
 complished. The lower temperature of the soil at a 
 certain depth^ as well as the weaker degree of respiration 
 {due, partly, to this lower temperature, partly, to the less 
 favourable anatomical structure), brings out the result that 
 in roots this process is much slower than in leaves.^ 
 This circumstance gave rise to misconceptions and even to 
 the assertion that the transformation of asparagine into 
 proteids would be possible only by the " nascent carbohy- 
 ■drates " in the chlorophyll bodies during the assimilation 
 process, a hypothesis which would encounter more than 
 one physiological objection that the thoughtful reader 
 
 (1) This question was examiued into in the College of Agriculture of the 
 Imperial Univerity, Tokyo, by Mr. KinosMta and Mr. Suzuki, who 
 undertook its solution at my instigation. Under certain conditions, nitrates 
 «re quickly reduced to ammonia and will yield then, of course, also largo 
 quantities of asparagine. 
 
 (2) Only the superficial layers acquire a higher temperature hy direct 
 insolation. 
 
 (3) Stems anil roots may serve also as rcsei-voirs and for this reason also 
 •contain generally more asparagine than leaves. 
 
36 FORMATION OF ALBUMIN. 
 
 will easily divine. Eesides, recent experiments have 
 proved beyond a doubt, that shoots can, even in complete 
 darkness,' foim proteids from asparagine when a suitable 
 ron-nitrogenous nutrient, es glycerol, is present in the 
 nourishing solution. Thus, shoots of soya beans, deprived 
 of their cotyledons, reduced their amount of asparagine 
 from 21 to 13 per cent, within 27 days, when kept in 
 solutions containing 1 percent of glycerol and exhibited a 
 much better development than the shoots in water, which 
 showed, moreover, an increase of asparagine from 21 to 
 28 per cent.^ 
 
 How, then, are M'e to explain the transformation of 
 asparagine into albumin ? If we reflect that aspai-agine is 
 of a low order of chemical compounds, while proteids are 
 the most complex of all ; if we take into consideration that 
 there are encountered neither nitrogenous by-products nc r 
 any other intermediate sub.stances; and, finally, if we 
 observe the great rapidity of proteid formation' under 
 favourable circumstances, we cannot but draw the inference 
 that this remarkable transformation must consist in a 
 so-called cundensation-jprocesn. That is to say, aspai-agine 
 being incapable of serving as such, has to be transformed; 
 into a suitable derivative exhibiting the same pioportion 
 between carbon and nitrrgen atoms as albumin, viz.,4: : ]» 
 This looked-for product cf n hardly be any other than the 
 
 (1) It is an eld obscrvatinn also that fungi can prepare in complete 
 darkness their prcteids from various sources. 
 
 (2) iSr/«c.«/i(Ya, Bulletin of the Agricultural College of the Imperii 1 
 University, Japan, vol. II., no. 4. 
 
 (3) A bamboc-shcot will grow in suh-trojiioal regions one centimeter per 
 hour, in tro] ical regions much more; which signifies the production of 
 millions of mcleci.les (f albumin in a Fiigle cell, every minute. 
 
FORMATION OF ALBUMIN. 37 
 
 aldehyle of aspctrtic acid, a still unknown product, whose 
 exceedingly cliangeable nature can bs foretold.' 
 
 Eeferring to what I have pointed out above, that form- 
 aldehyde and ammonia, besides hydrogen sulphide, are the 
 groups serving to build up proteids, aspartio aldehyda 
 would consequently represent the following step, a transi- 
 tion which thus far lias not been acoomplished. Supposing, 
 however, the living cells, to bring this on, it could be 
 represented by the following equation : — 
 I. 40 li 4- NH3 = GOH CO H 
 
 I I +2B.S). 
 
 CH., - CH.NH2 
 
 Aspartio aldohydeZ 
 
 The subsequent condensations may be represented by 
 the following equations : — 
 II. SC.HjNO, = 0,2 11,7^3 0,. + 211,0; 
 
 Aspartio aldehyde IntenneJiate product 
 
 III. 60,2E„N3O, + 12H + H2S = 0,2 H„2 N,8 SO22 -J- 2H2 O. 
 
 JOieherhlikn' s albnmin-formula^ 
 
 (1) I first drew tliis inference in the year IS80 {PJliicf. Aroh., 22, 303), 
 iu opposition to the gener.iUy adopted opinion that proteids are complex 
 nreas or guanidines, containing the radicals of tlnse amido-compounds that 
 result from the decorapoition of proteids by acids. Those who uphold this 
 view have to assume that all those amido compounds have to be prepared 
 first in the proper quantity, whereupon they are forced at the proper moment 
 and in the proper order into the urea or guanidiue-type (cf. Chapt. Ill), 
 oertaiiily a most complicated sort of work. 
 
 (2) Sohiit'eriberger has met with a body of this empirical composition 
 among the decomposition products of proteids by caustic baryta; Siegfried 
 with a similar one, to which he assigned the formula, (Ci Hg NO2 )a . 
 
 (3) It is certainly no accident that the number of carbon atoms for the 
 lowest possible expression of albumin stands in a simple ratio to those in the 
 molecule of glycerol, sugar, stearic acid, and oleic acid. We have Cj in 
 glycerol, Ce in glucose, Cjg in stearic and oleic acids, and C72 in the simplest 
 expression for albumin. This circumstance points also to the principle of 
 condensation after simple ratios. 
 
38 FORMATION OF ALBUMIN. 
 
 For the process repreKented by equation IT., the as- 
 sumption has to be made that the amido-groups are 
 protected, and that the condensation proceeds between the 
 aldehyde and methylene groups, while for that in equation 
 III., condensation by reduction after the type of 
 pinacone-formation is assumed. In this way, a highly 
 unstable substance would result containing 12 aldehyde 
 and 18 amido-groups, and possessed, therefore, of much 
 kinetic energy in the form of motions of the labile atoms ; 
 ■while, by atomic migration, it would with the loss of the 
 aldehyde character lead to a relatively stable product, the 
 ordinary albumin. 
 
 Let us now, guided by our hypothesis, revi. w the 
 observations in regai-d to the occurrence of asparagine in 
 ].ilants. The accumulation of it in developing shoots and 
 buds is intimately comic cted with the gradual consumption 
 of the amido-products {leucine, tj-rosine, phcnylamido- 
 propionic acid, glutamic acid, aspartic acid, lysine, 
 arginine), which result from the action of an enzyme upon 
 ±he reserve proteids. These amido-products, either on 
 their way to the young growing parts or, after their 
 transportation thereto, are gradually disappearing, while 
 proteids are formed for the protoplasm of the growing and 
 multiplying cells. All tliese different products, however, 
 have to be either transformed into form-aldehyde and am- 
 monia or more directly into aspartic aldehyde,' before proteid 
 formation can take place, as this process, caii hardly go on 
 here differently from what it does in the fungi ; cf. p. 33. 
 
 Thus the decomposition of leucine by oxidation may be 
 expressed by the following equation : — 
 
 (I) Aspai-tio acid and gltituniic acid probably are ti-ansfonncd dii-cctly 
 into aspartic aldehyde. 
 
FORMATION OF ALBUMIN. 39 
 
 CeHisNO^ + 70 = 2CO2 + ^hO + 4CII^0 + NIT,. 
 Tims, not only are the starting groups obtained, but 
 respii'ation is supported in the combustion of a part 
 of the carbon and hydrogen of leucine. Jf, now, less 
 carbohydrate is present than is required for the trans- 
 formation of all the ammonia, thus formed, into proteids, 
 then asparagine' will result : — 
 
 4CH2O + 2N H3 + 02 = CiHgN.Oa + 3 U^O 
 
 Asparagine 
 
 If, however, glucose or other suitable material is brought 
 in sufficient quantities from the reserve stores, or from the 
 green leaves, then an adequate amount of this asparagine is 
 transformed into proteids by way of aspartic aldehyde, 
 which we may express by the general equation : 
 
 0,118^203 + C6n,A+ 02 = 20, II,N02+ 2CO2 + BHjO 
 
 Asparagine Aspartic aldeliydo 
 
 Jfurther, in those cases, in which, as in the seeds of 
 Gramineae, there is a considerable excess of carbohydrate 
 present as reserve material, an intermediate production of 
 asparagine will take place only to a very small extent, as 
 tlie proteids can be formed more directly in the shoots. 
 
 finally, in the instances, in which asparagine is not 
 the result of metabolism but of a product due to an excess 
 of ammonia taken up by the roots, the necessary carbon 
 in the form of form-iddehyde is in all probability derived 
 from glucose, and thus the formation of asparagine by 
 synthesis appears exactly the same process as when formed 
 By the destruction of proteids, although the original 
 material is vastly diflr'erent. 
 
 (1) Thus, two noxious compounds are transformed into an indifferent 
 one. 
 
40 FORMATION OF ALBUMIN. 
 
 To the inferences to whicli I have been led by contemp- 
 latioa of the facts, further belongs the cbnolusion that the 
 definition of Pfeffer, Borodin, and others, of asparagine as 
 the form in which -proteids are transported, does not hit the 
 point, since the plant cells produce their proteids also from 
 other amido-compounds. But as the various amido-pro- 
 ducts formed by the action of enzymes upon proteids, leu- 
 cine, tyrosine, etc. are, on the way to their destination, 
 part;ly oxidised, whereby their nitrogen accumulates in the 
 form of asparagine, it gives the impression that the trans- 
 portation of proteids talces place in tliis form. The facts, 
 however, are better covered by the definition of asparagine 
 as the form into which ammonia is transforined when it 
 is present in excess of the immediate needs of proteid pro- 
 duction ; it appears also as the form into which aspartic al- 
 dehyde is converted when an excess of ammonia is present, 
 and thus a step in the proteid production is preserved m 
 the form of a derivative.' Tlie relations between arparagine 
 and albumin will appear now more simple than they did 
 from the former views, which evidently disregard the prin- 
 ciple of economy of work.^ The important part too, which 
 gliKosG plays is easily intelligible. It is, in the first place, an 
 excellent source of carbon and hydrogen, secondly, a ready 
 means of reduction, and, thirdly, the best supporter of 
 respiration by which an increased amount of energy for 
 chemical work is procured. Finally, it protects proteids, to 
 a certain extent, against disruption. It is therefore clear that 
 the leaves are so well suited for the process of proteid produc- 
 
 (1) Asparagine, however, is not only an excellent nutrient for pliEcnogams 
 but also for fungi. 
 
 (2) Critical comments upon other viavvs are contained in E. Schulze's 
 publications, Landw. Jahrb., vol. 9; 12j 17; 21. 
 
FORMATION OF ALBUMIN. 41 
 
 tion, although the assimilation proo3ss, as such, i.e. a direct 
 influence of the sun's I'ays, is not requisite. 
 
 From a series of well established facts and guided by 
 simple chemical laws, I have framed a hypothesis as to 
 the formation of albumin, and as to the existence of a 
 labile and a stable modification of it. The labile form 
 which would lead to living mitter, was designated by 
 myself as active albumin, in contradistinction to the stable, 
 ordinary, pissive albumin stored up in seeds and eggs. 
 The name 'living albumin' used by SDme authors can- 
 not signify any thing but living protoplasm and had 
 - better be discarded altogether to avoid misconceptions. 
 Still more objectionable for the molecules in the living 
 protoplasm is the expression ' living molecules ' and 
 ' units of life.' The name ' active albumin ' on the other 
 hand, does not necessarily imply organisation, and is a 
 mere chemical conception.' Indeed there exists a highly 
 labile proteid in plants which is not yet organised into 
 living matter; the nature of tliis is the. subject of the 
 following chapter. 
 
 (1) Since there must exist energetic ntomio oscillations in labile 
 substances this designation will bo found justified (cf. Cliap. VI). 
 
CHAPTER V. 
 
 ACTIVE ALBUMIN AS RKSERVE-MATEHIAL IN PLANTS. 
 
 The hypothesis developed in the foregoing chapter 
 indaced Br. Th. Bokorny and myself to make a series of 
 experiments on vegetable life' whose final results may be 
 summed up as follows : — 
 
 1. There exists in plants a peculiar albumin that 
 undergoes a chemical change by the same influences 
 as those by which protoplasm is killed. 
 
 2. This albumin plays the part of a reserve material. 
 
 3. It can occur in higher as well as in lower forms of 
 chlorophyllous plants, is to be found in various 
 parts and some oi-gans at all times, and again may 
 be restricted to certain states of development. 
 
 4. It is by its labile nature strikingly distinguished 
 from the ordinary pi'oteids. 
 
 This peculiar, easily changeable proteid is met with m 
 certain groups of plants very frequently, as in JiiUflorce, 
 Gisliflorw.yMnculinece, Saxifraginecv,Myrt'!JlorcB, Rosiflorw, 
 .IHcornes. It has not yet been found in Poa, Hordeum, 
 Avena, Pisum, Vicia, Solannm, In fungi'' and most 
 algae it has also not been detected, but certain alg», 
 especially Spirogyra, are capable of storing up large 
 quantities of it. Its wide-spread occurrence in the vegetal 
 
 (l; Cf. Botaii. Ceiitralllatt, 1889 and 1893; Flora, 1892 mid 1895 
 Tringslieim's Jahrb., Vol. 19 and 20; Pfiug. Arcli., vol. 45 and 50. 
 
 (2) Slight indications of it in certain cases requiic fiii'tlier e.'iaininatlon. 
 
ACTIVE AI.BU.MIiSr AS RESERVE-MATl-RIAI,. 43 
 
 kingdom may be estimated by the fact that, of 230 species 
 examined by Th. BoJcomy, O. Daikuhara, and myself 120 
 were found to contain it in one part or other of their 
 structure. 
 
 Of special objects rich in this proteid may be enu- 
 merated : young leaves of Prunus, liosa, Quercus, Alnus, 
 Mimosa, Pceonia, Saxifraga, Sedum, and Gephalotus; the 
 bark of Prunus, Quercus, and Fagiis; petals of Gentmna, 
 Primula, Sorbus, Cyclamen, Hotteia, and Gornus; stamens 
 of Eugenia, Drosera, and Melaleuca; pistils of Orocus, 
 Salix, Euphorbia, and Rhododendron; ncctaria of Pas- 
 siflora; roots (epidermis) of Saxifraga, CEnothera, Thesium 
 decurrens, and Xanthoceylon piperitum ; fruits (epidermis) 
 of Punica and Camellia. 
 
 This proteid can be present in the different tissues of 
 the leaves, but cells of epidermis and of the fibro-vascular 
 tissue are in certain cases preferred by it. Young leaves 
 contain generally more of it tlian older ones, but even 
 when leaves have turned yellow in autuma it may yet be 
 thero, provided the cells are still alive. In roots and fruits 
 it seems to occur less frequently than in leaves and flowers. 
 Leaves in the shade contain less than those in the light, 
 while leaves with partial" albinism may contain in the 
 white paits nearly as much as in the green. In plants 
 exposed to starvation by being kept in darkness, it is 
 gradually consumed, with production of amido compounds.' 
 Of parts that contain it only at one stage of development, 
 may be mentioned : the unripe fruits of Symphoriearpiis 
 racemosus, the cotyledons of Helianthus, the epidermis of 
 the seeds of Triticum, the larger cells in the leaves of 
 Vallisneria. Especially noticeable is the large amount 
 
 (1) Cf. O. Loem, Flora, 1895. p. 85; Daikuliura, ibid. 
 
44 ACTIVE ALBUMIN AS RESERVE-MATERIAL. 
 
 present in the insectivorous plants, Utricularia alone being 
 devoid of it. Brosexp, sliows it not only in the leaves and 
 their tentacles, but also in stem and flower. 
 
 Active albumin is stored up generally in the vacuole, 
 but in some cases also in the cytoplasm, and is separable 
 from its apparent solution by organic bases. If the bases 
 applied are weak enough not to injure the life of the cells 
 in too short a time, the small liquid particles of the 
 separated albumin will preserve for some time tbeir 
 chemical properties and coalesce gradually to larger, bright 
 droplets, whose changes by various reagents can easily be 
 followed under the microscope. Caffeine and antipja'ine 
 in 0'5 per cent, solution answer the purpose very well.' 
 
 Generally, it will sufHce to place small chips of the 
 vegetable tissue in a few drops of caffeine solution and 
 then tear them up into finer fragments by the help of dis- 
 section needles. Microscopical examination will then 
 reveal either at once or, in case of thicker cell-walls being 
 present, after some time, numerous globules uniting 
 gradually to larger ones, which may occupy one fourth 
 and more of the entire volume of a cell. 
 
 "i'hese globular formations were designated by Th. 
 Bolwrny and myself as proteosomes} 
 
 If the objects ai'e taken from these solutions and replaced 
 in pure water, the droplets will gradually disappear again 
 
 (1) Caffeine acts in much higher dilutions than nntipyrine, iind is In 
 many cases preferablo, because it does not interfere with certain chemical 
 reagents to be applied for identification, such as iodine solution, which would 
 yield with antipyrine a dark brown coloration. 
 
 (2) Some remarks may here be made as to the ag<»regation, observed 
 first by Ch. Darwin in the leaves of Drosera, in which the livuig pro- 
 toplasm itself , as well as the stored upaciive albumin, is involved. De Vries, 
 Pringsh, Jahrb., 16, has recognised that here, as in other cases, the division 
 
ACTIVE ALBUMIN AS RESERVE-MATERIAL. 45 
 
 in proportion as tlie bases mentioned lea\e tlie cells by 
 osmosis. The cells then continue their life as before 
 the treatment. This dissolving process is accelerated by 
 higher temperatures ; at 30°0. ib requires but a few 
 minutes. A return of the objects to a solution of one of 
 these bases makes the droplets reappear. If, however, the 
 cells die by the prolonged influence of caffeine or an- 
 tipyrine, or if they are hilled by iodine solution, or acids, or 
 by form- aldehyde, hydroxy lamine, diamide, prussic acid, 
 free cyanogen, or salts of copper, or by vapours of ether, 
 then these dropltts change their properties, becoming turbid 
 from numerous and minute vacuoles, formed by a sudden 
 loss of absorbed water, and losing their solubility in water'. 
 In some cases the small vacuoles unite into one large one, 
 a hollow sphei'c thus resulting, in other cases the spherical 
 form is lost entirely, leaving an irregular shaped mass. 
 In others, again, the vatuoles disappear by further contrac- 
 
 of the contracting tonoplast (the inner wall of the cytoplasm) can produce 
 globular formations, what he called anomalous plasmolysis. SoTcorny 
 declared {Pringsh. Jahrb., 20. 465, and Biol. Centr., 13,231) that the 
 production of proteosomes has the principle in common with ordinary and 
 anomalous plasmolysis that some of the water of imbibition is expelled, and 
 it is an interesting fact that he could produce all three phenomena with 
 even very dilute caffeine solution, and sometimes two of them in one and the 
 same object. I'lasn-.olysis, by caffeine can, e,ff.,he observed in thepetalsof 
 Ipomaa hedracea, the leaves of Camellia iheijera, the leaf -veins of Fyrus 
 Toringo, and sometimes in Spirogyra, after it has been cidlivatod in 
 solutions containing at least 5 p. mille mineral salts. By treatment with 
 dilute ammonia (0"2%) or iodine solution, plasmolysed formations can, easily 
 be distinguished from proteosomes. — Another closely related phenomenon is 
 the enlargement of vacuoles under the influence of caffeine in amajbae and 
 infusoria, whereby the protoplasm increases in density and refractive power, 
 as observed by BoJcorn;/, Pfliig. Arch., 59, 557. 
 
 (1) It is but rarely the case that the proteosomes are altered before the 
 death of the cells is caused by the prolonged action of caffeine. 
 
46 ACTIVE ALBUMIN AS RESERVE-MATERIAL. 
 
 tion, and the solidified but now insoluble globules retain a 
 certain brightness. In one case, viz., thatof the proteosomes 
 produced in the petals of Hotteia japonica, still another 
 phenomenon has been observed, consisting in the formation 
 of numerous radiating fissures by treatment with a dilute 
 solution of iodine in potassium iodide. It offers consider- 
 able interest to watch these changes under the microscope, 
 as e. g. that caused by alcohol of 10-20 per cent., or by 
 hydrochloric acid of 10 per cent., form-aldehyde of 10 per 
 cent., prussic acid of 1-2 per cent. Acetic acid of O'l per 
 cent, will, although more slowly, also produce coagulation.' 
 
 Still more striking is the effect of ether vapour. If 
 Spirogyra, which is an excellent object, containing freshly 
 ■produced droplets, is exposed in a flask at the ordinaiy 
 temperature to the vapours of ether, the cells are found 
 killed in a short time, and soon afterwards all the globules 
 change their aspect, losing their brightness and their 
 solubility. 
 
 The coagulation by heat is easily observed if the objects 
 are dipped in boiling water containing 5 per cent, of 
 sodium chloride, all droplets then exhibiting a turbid ap- 
 pearance ; neither boiling water nor absolute alcohol will 
 change them any further. In a saturated caffeine solution 
 
 (1) If, instead of diluted alcohol, ffiso/a/ealcolioT is applied, the caffeine 
 is Sf) rapidly extracted that the smaller globules dissolve before they are 
 coagulated, while the larger ones shrink to irregulai^shaped, thin films. 
 Here, the exosmose of oafPoVne proceeds more quioldy than the endosmose of 
 a sufficient quantity of alcohol. All these experiments are best made with 
 the larger globules ; the changes cannot be well observed if the globules are 
 too minute; for then they may be dissolved before the proper action can take 
 place, especially in the case of dilute acids. Therefore, the caffeine solution 
 should be permitted to act until the smaller globules have united to 
 droplets. 
 
ACTIVE ALBUMIN AS RESERVE-MATERIAL. 47 
 
 containing 5 per cent, potassium sulphate, a gradual 
 coagulation is observed at 50°. 
 
 Of much interest to chemists is the behaviour to 
 ammonia.* While freshly produced proteosomes are 
 dissolved by concentrated ammonia, they will turn in- 
 soluhle, if exposed for 12-15 hours to the action of am- 
 monia in the high dilution of 0'l-0-5 per mille. This 
 change, however, is different from that produced by heat 
 or acids, as tlie chemical behaviour clearly indicates.^ A 
 dilute hydrochloric acid (0-5 per cent.) will at 40°C. 
 gradually attack the coagulated proteosomes, but not those 
 solidified by ammonia. Even a 10 per cent, hydrochloric 
 acid dissolves the latter at 80° with much difficulty. 
 
 Active albumin also changes quickly in the dissolved 
 state with the death of the cells ; in dead cells caffeine 
 never produces any globules.^ If we treat Spirogyra 
 Webeii for one minute with a dilute solution of iodine in 
 potassium iodide the globules may be still produced im- 
 mediately afterwards, but not after ten minutes action. 
 
 (1) This behaviour to ammonia may serve in certain cases to distinguish 
 small and indistinct proteosomes from tannates of caffeine or antipyrine, 
 which will be readily dissolved by dilute ammonia ; when proteosomes are 
 very rich in tannin the behaviour to ammonia may be altered. 
 
 (2) All these reactions are so characteristic that confounding pro- 
 teosomes with fat globnles is not possible. The simplest ways to distinguish 
 them are, firstly, the application of dilute solution of iodine in potassium 
 iodide whereby a vacuolisation of the proteosomes readily sets in; secondly, 
 treatment with alcohol of 20 per cent, for one hour, with subsequent 
 application of a mixture of ether and alcohol, which does not affect the 
 coagulated proteosomes. 
 
 (3) The opinion that the change of the active albumin in the vacuole is 
 brought on by certain compounds that pass from the cytoplasm into the 
 vacuole at the moment of death, is erroneous, since the same labile proteid 
 is contained also in the cytoplasm in the case of Spiroffi/ra. 
 
48 ACTIVE ALBUMIN AS RESERVE-MATEKIAL. 
 
 That the substance has not left tbe dead cell by osmosis 
 can be easily proved by caffeine. 
 
 It is then an undeniable fact that the albumin here 
 described is strikingly distinguished from ordinary albumin, 
 although otherwise it gives (in the coagidated *?tate) all the 
 reactions of it.' 
 
 Treated with phosphotungstic acid the proteosomes 
 remain insoluble even after weeks, while hydrochloric acid 
 of 10 per cent, changes them gradually and dissolves them 
 in some days at the ordinary temperature. — A solution of 
 caustic soda or potash of moderate strength soon dissolves 
 the proteosomes, but if they have been treated with a 
 neutral solution of form-aldehyde they have lost their easy 
 solubility in caustic lyes, — in this recalling that behaviour 
 of ordinary proteids, I observed some time ago.^ — Millon's 
 reaction is obtained by leaving the objects for 8-10 hours 
 in a solution of mercuric nitrate containing some potassium 
 nitrite, and then heating for a short time to the boiling 
 point. — The ' biuretreaction ' is obtained on treating the 
 proteoscmes, first, for twelve hours with diluted ammonia 
 (G'1%), then, for 12 hours with a dilute solution of copper 
 acetate, and, finally, with dilute caustic potash. 
 
 (1) Instructive slides for demonstration may be produced by treating 
 olijccts (filan-.ents of Spircgira) for sevcial hours with 0'£% eaffeii e- 
 solution, then, for 12 hours with a solution of 0-01% ammonia, and lastly 
 after extraction of the chlovopliyll by ether-alcohol, with a highly dilute 
 solution of methyl gi'een in acetic acid. Jtieniarkable is the great brittleness. 
 of these solidifitd proteoscmes, for slight pressure will break them into 
 numerous fragments. This recalls the sti'iking brittleness of blocd crystals 
 {Preyer, 1871) and of the rr.\ stallised pliycocyan, a pioteid recently studied 
 by MoUsch (Bot. Ztg., 1895, p. 133). 
 
 (2) Cf. 0. loeio, Jalircsbcricht f. Thierchemie, 1892, p. 29 and 1888, 
 p. 273. 
 
ACTIVE ALBUMIN AS RESERVE-MATP:RIAL. 49 
 
 The proteosomes give also an intense yellow colour 
 ■with hot nitric iicicl, are coloured yellow by iodine, and 
 have the property of being easily stained by aniline 
 dyes, in even very high dilution. In short, their proteic 
 nature is proved. 
 
 That this labile proteid corresponds in essential points to 
 my theory cannot be doubted, since it can be demonstrated - 
 (1) that it serves for building up new protoplasm, and (2) 
 that it lias an aldehyde character. That it serves for build- 
 ing up protoplasm can easily be verified by cultivating 
 Spirogyra, rich in this labile reserve proteid, in solutions 
 devoid of any assimilable nitrogen compound, but other- 
 wise well suited to promote multiplication of cells. Any 
 formation of proteid is then impossible, and the growing 
 filaments have to draw upon the store of labile proteid in 
 the cells j that they do do so can be shown by the caifeine 
 reaction.^ The increase of living matter is here most 
 probably accomplished by direct 'organisation' of the 
 labile reserve proteid. A previous coagulation, decom- 
 position into am.ido acids, and transformation of these into 
 living matter would be an unnecessary, time-absorbing 
 operation, contradicting the principle of economy of work; 
 the transportation through various cell strata required by 
 
 (1) Growth of the filaments, connected with total consumption of tlie labile 
 loserve proteid, can, e.g., be observed oii Spirogyra Weheri, cultivated for 
 several « ecks in the following solution : — 
 
 0'5 per mille calcium sulphate. 
 
 0'2 ,, ,, calcium carbon.<ite (as bicarbonate). 
 
 0°2 ,, ,, magnesium sulphate. 
 
 0"05 ,) ,, monopotassium phosphate. 
 
 Trace of ferrous sulphate. 
 As soon as parasites [Pseudospora, Chytridia, etc.) make their ap- 
 dearance, the filaments have to be washed and the solution renewed. 
 
50 ACTIVE ALBUMIN AS RESERVE-MATERIAL. 
 
 a gi-owing shoot, is not at all necassaiy here, where each 
 growing cell is provided with a certain amount of labile 
 reserve albumin. 
 
 If, however, we change the conditions, reducing the 
 amount of magnesia, and offering a large proportion of 
 nitrates/ we can observe again, after a few weeks, an 
 intense formation of proteosomes by the caffeine treatment. 
 
 Changes of temperature have also great influence. Hot 
 weather favours multiplication of cells, and then the active 
 albumin is consumed as rapidly as it is produced. If, now, 
 cold weather follows, growth will be more retarded than 
 the production of proteids, and that leads again to an accu- 
 mulation of the active albumin in the unorganised form.^ 
 
 As to the question whether the labile albumin has also 
 the aldehydic character, required by my hypothesis, the 
 following observations may serve to answer it. We know 
 that, of compounds not of an acid character,' only aldehydes 
 
 (1) I made use of the following composition : — 
 
 0'5 per niille potassium nitrate. 
 0*3 ,, ,, calcinm nitrate. 
 O'OS „ ,, magnesium sulphate. 
 O'OS ,, ,, monopotassium phosphate, 
 Slight trace of ferrous snlphate. i) 
 
 Spirogyra majuscula forms in this solution, after several weeks, such 
 large quantities of active albumin, that it commences, in some cells, to 
 separate in globules, even viithout the caffeine treatment, 
 
 (2) The state of copulation does not depend upon the amount of stored 
 up active albumin j I have observed, in some instances, much of the latter, 
 in others, none at all. 
 
 (3) The contents of living cells of Spirogyra have not an acid reaction ; 
 otherwise, diluted solutions of potassium iodide or nitrite would prove 
 poisonous, as is the case with all plants that have an acid cell sap. 
 However, by the change from life to death, caused by heat or by mechanical 
 action, the weak alkaline reaction of the protoplasm becomes still weaker, 
 or even slightly acid. 
 
ACTIVE ALBUMIN AS RESERVE-MATERIAL, 51 
 
 and ketones can readily combine with ammonia ; and that, 
 in certain cases, ammonia can react in such a way with these 
 bodies as that it cannot again be liberated.' I have pointed 
 out above that, by the action of ammonia, the proteosomes 
 undergo a change quite different from that produced by acids 
 or heat and that we must infer that it enters into most in- 
 timate combination witli them, since, otherwise, treatment 
 with hydrochloric acid should suffice to extract it again 
 and yield thereby the same coagulated product tliat is 
 obtained by the direct action of hydrochloric acid upon the 
 caffeine proteosomes. The ammonia must, therefore, have 
 converted the labile proteid (at least partially) into a 
 product different in character fi'om those which result when 
 it acts upon mono aldehydes. 
 
 While caffeine or antipyrine forms evidently a very 
 loose kind of combination with the labile -reserve proteid, 
 or leads to a loose kind of polymerisation, (with partial 
 loss of water of imbibition), that allows the separated 
 labile proteid to preserve the liquid form ; stronger 
 bases, though at first also producing granulations, 
 change these so quickly that no coalescence into 
 droplets can take place, and besides, soon kill the 
 cells. Ammonia acts thus if highly dilute, say 0'2-0'5 
 per mille, while in a concentrated state it fails to 
 produce a trace of granulation because the dissolved 
 labile proteid is too rapidly altered. Amines, ammonium 
 bases, piperidine, and quinine act nearly like ammonia, 
 while quinoline, pyridine, and morphine operate less 
 energetically. Certain bases, as quinine, act also when in 
 the form of vaiious salts ; others, as ammonia or guanidine. 
 
 (1) This is, e.g., tlie case wlien ammonia, acting upon 1.4. diketones, 
 produces pyrrols. 
 
52 ACTIVE ALBUMIN AS RESERVE-MATERIAL. 
 
 also in form of carbonates, while potassa or soda acts only 
 •when free. A decidedly basic character is essential ; thus, 
 e.g., trimethylamine or amarine can produce protcosomes ; 
 betaine, kreatine, urea, or hydrobenzamide cannot. While 
 this behaviour is quite in accordance with the supposed 
 aldehyde nature of the labile proteid, such a constitution 
 is rendered still more probable by the fact that the proteid 
 reduces the metal from even highly dilute alkaline 
 silver solutions. 
 
 This reaction requires objects free of tannin, which has 
 itself reducing properties, although very small traces of it 
 will not essentially interfere with the result. We observe 
 in both cases an intense blackening of all the proteosomes 
 by a prolonged action of a highly dilute alkaline silver 
 solution, while after coagulation of the proteosomes this 
 reaction is not obtained ; but if a trace of tannin is present,. 
 a yellmv coloration of the coagulated proteosomes will make 
 its appearance under the action of the silver solution. 
 
 It is well known that various kinds of tannins are of 
 wide-spread occurrence' in the vegetable kingdom ; there 
 still exists, however, a great difference of opinion as to 
 their physiological relations.^ In different species of algae 
 it is also present, but the amount of it, e.g., in Spirogyra 
 may vary considerably, as from several per cent, of the 
 dry matter to none at all. 
 
 The fact that the tannins easily enter into combination 
 with proteids, implies that, when proteosomes are pro- 
 duced by the action of bases, all the tannin present is 
 drawn into the proteosomes. 
 
 (1) Cf. Benri/ Tnm6le,The Tannins, 1894, 2 vol. 
 
 (2) Cf . Eeinitxer, Ber. D. Bot. Ges. , 1889; vol. 7, 187. 
 
ACTIVE ALBUMIN AS RESERVE-MATERIAL. 53 
 
 Furtlier, it has to be noted that, although the tannin is 
 produced in the living matter itself, it accumulates in the 
 vacuole, into which it is secreted. Often there are mere 
 traces of tannin in the cytoplasm and even these will easily 
 disappear altogether by keeping the algse for some time in 
 soft well-water in darkness, while t!ie tannin in the vacuole 
 will not thus completely disappear, not even when death 
 by stai'vation has set in. In such a case, it is easy to 
 observe that the proteosomes produced in the cytoplasm 
 reduce alkaline silver solution just as well as those pro- 
 duced in the vacuole.^ b'or these obssrvations Spirogyra 
 oiitida, a larger species is best adapted. 
 
 The decrease of tannin can be accomplished in full 
 daylight under vaa-ious conditions, which either depress 
 its production or increase its c'.msumption. The tanuin of 
 the cytoplasm then disappsara always long before that of 
 the vacuole. 
 
 Various circumstances, such as difference of species, 
 degree of temperature, the amount of tannin originally 
 present, etc., will exert some influence upon the time 
 required to free the cells from tannin. Smaller kinds of 
 Spirogyra containing only one chlorophyll spiral are 
 sooner obtained free of tannin than the larger kinds. 
 Thus, a sample of Spirogyra gracilis containing so much 
 tannin that the decoction made with relatively little water 
 
 (1) The two kinds of proteosomes can easily be distinguislied by placing 
 threads of Spirogyra nitida in a narrow tube in » vertical position while 
 the caffeine acts ; for, then most of the proteosomes formed in the vacuole 
 will settle to the bottom of the cells, whilst those of the cytoplasm will 
 remain in situ. 
 
 Sometimes there is in smaller kinds of Spirogyra so much of the 
 labile proteid stored up in the cytoplasm that the production of proteo- 
 somes will lead to serious disorder and therefore an early death. 
 
54 ACTIVE ALBUMIN AS RESERVE-MATERIAL. 
 
 yielded a dark blue colour with ferrous sulphate, could 
 by five days cultivation be so far deprived of tannin 
 that not the slightest trace of colour could be obtained 
 by that reagent.' The last remnant of tnnnin , which could 
 not be extracted by boiling water, because it was retained 
 by proteids, disappeared within the following three days.^ 
 The solution used in this case was prepared by dis- 
 solving in the purest distilled water* 
 
 0'20 per iijille nionopotassiuni phosphate, 
 0*02 „ ,, inonopotassium carbonate, 
 O'lO ,, ,, calduin sulphate, 
 0'05 ,, ,, calcium nitrate, 
 slight traces of magnesium and ferrous sulphates. 
 
 The amount of the labile reserve proleid gra- 
 dually decreased but a moderate portion was still 
 there when the last ti-ace of tannin had disappeared.* 
 
 (1) Ferrous snlphate which is here a much better reagent than ferric 
 chloride, will indicate tannin even in a dilution of 1 in 100 000. 
 
 (2) The last traces of tannin aie best discovered by first producing pro- 
 teosomes, then moistening the object with a solution of ferious sulphate, 
 and permitting the water to evaporate slowly. The dried objects are 
 moistened again and, after exposure to the air for some time, examined 
 with a high magnifying power. A trace of tannin will thus load to a blue 
 coloration of the proteosomes. In those cases in which the objects have 
 been treated with acids to coagulate the proteosomes, a washing with highly 
 diluted ammonia is recommended before the application of ferrous sulphate. 
 
 (3) As the common distilled water often acts noxiously because o£ the 
 presence of traces of copper, it has cither to be redistilled from glass 
 vessels or left standing with some iron filings for 15-20 hours before it 
 can serve for preparing the nutrient solutions. 
 
 (4) Tliere exist also other objects free of tannin, yielding proteosomes j 
 among which may be mentioned the roots of Thesium decurrens, young 
 iairs of many Crucifers, and the unripe berries of Si/mphorioarpus 
 racemosus. 
 
ACTIVE ALBUMIN AS KESERVE-MATERIAI.. 55 
 
 These cells yielded no trace of any reduction, either in 
 cytoplasm or nucleus, or in the cell sap, upon being 
 placed for 24 hours in the dark in a 1 per cent. 
 neutral solution of silver nitrate ; only the chlorophyll- 
 bodies showed, along their rim especially, a yellowish 
 colour. A 0"5 per cent solution of osmium tetroxide 
 produced in all cells a weak blackening ; and in many cells 
 :; very fine granulation could be distinguished exhibiting 
 a deeper blackening than the other parts. This osmium 
 reaction can only be due to traces of lecithin or perhaps 
 more properly lecith-albumin. The chlorophyll bodies had 
 preserved their green colour and could in this (perhaps 
 exceptional) case not have contained any fatty matter. 
 
 Some filaments of this culture boiled with a few drops 
 of water yielded a decoction which i-emained colourless 
 upon addition of a 0.1 per cent, solution of silv-er nitrate 
 supersaturated with ammonia ; neither did the boiled 
 filaments themselves show any reaction with this solution. 
 Hence, neither a silver reducing body was present in the 
 extract nor an insoluble reducing body wiihin tlie hoiled 
 cells. Nevertheless, the proteosornerf, produced witli caf- 
 feine in the living cells, exhibited an intenne llaclcening if 
 kept in a highly dilute ali^aline solution of silver nitrate' 
 
 (1) This solution was iirepiired just before use. A 1 per cent, solution of 
 silver nitrate and u mixture of 13 cc, potasli ley of 1'33 sp. griiv, with 
 10 cc. of aqueons ammonia of 0'96 sp. grav. were kept in stock. One 
 cc, of each solution was taken, the two quantities were mixed and the 
 mixture was diluted to one liter. About one fourth of a liter of this 
 reagent served for the test with a few filaments. This high dilution was 
 preferred in order to avoid the objection that the reducing atomic groups 
 could be other than aldehydic ones. In the present case, only oxyketonio 
 ones could also come into consideration, which are, moreover, closely related 
 to the former. This reaction is of course quite different from the ordinary 
 staining method with silver nitrate under the influence of light. 
 
56 ACTIVE ALBUMIN AS RESERVE-MATERIAL. 
 
 for 12-15 hours in complete darkness. When, however, 
 these proteosomes had been changed by coagulation, the 
 reducing power had vanished. My theory (cf. Chap. IV) 
 explains this chemical change by an atomic migration, 
 leading to the loss of the aldehyde group : 
 
 -CI-I-NIl^ -GTI-NH 
 
 = - of =0 - CHOH 
 
 An active group.' A passive group. 
 
 That the entire ' active ' group has exactly the constitu- 
 tion ascribed to it by my theory, is not indeed yet proved, 
 but I refer to it, because this assumption it is which has 
 given the inducement for the entire investigation.^ 
 
 In order to demonstrate that by coagulation the pro- 
 teosomes lose the property of reducing alkaline silver- 
 
 (1) Twelve of such groups are — according to my hypothesis of the 
 formation of active albumin — contained in one molecule of the latter, if the 
 simplest expression, i.e., Lieherkiihn's formula, for albumin be taken as a 
 foundation. 
 
 (2) A few words may suffice hero to cliaracterise tlie objections raised 
 againsttho explanation given by Bokorui/ and myself of this silver reduction. 
 It has been asserted that the reducing substance is free tannin, tannate of 
 albumin, tannate of caffeine, or hydrogen peroxide. It has been asserted 
 that the reaction indicates merely certain reducing processes going on in 
 living cells, and that the reducing groups cannot be with any degree of 
 certainty defined as aldehyde groups because also hydrosjianiine, alloxan, 
 and morphine have reducing properties. The thoughtful reader will, I 
 surmise, not insist upon a reiteration of the refutations, which we were 
 moved to make ; those who desire to control our arguments may be referred 
 to Pfiiiger'a Arohiv, 30, 357 ; Ber. Deutsch. Chnm. 6es., (1888) 21, 1818 ; 
 Botan. Centralblatt, 1889. Nr. 18, 19, 39, 45j ibid., 1893. Nr. 6. Flora, 
 1895, p. 68. It will suffice to state, that not a sin°;le one of the objections 
 was proved, but a liberal use was made of violent language and derision. In 
 order to give apparent strength to feeble argumentation. 
 
ACTIVE ALBUMIN AS RESERVE-MATERIAL. 57 
 
 solution the following expei'iments with Spirogyra, in 
 which proteosomes were pi'oduced bj the action of caffeine, 
 may serve : 
 
 1. The filaments are formed into a small heap and 
 thus allowed to dry up very slowly. Hereby, all the small 
 proteosomes unite gradually to a few droplets which finally, 
 upon the death of the cells, turn into hollow splieres. 
 These remain either colourless after 8-]0 hours treatment 
 with the silver solution in the dark, or become merely 
 slightly yellow. If, however, the filaments are diied up 
 rapidly, the numerous small globules do not unite, but 
 shrink to bright particles, which still retain the reducing 
 power, like those treated with ammonia (see below), thus 
 indicating that the caffeine has entered now into chemical 
 combination, whereby the aldehyde character has been but 
 little altered ; 
 
 2. The filaments taken from the caffeine solution are 
 placed in a cold saturated caffeine solution to which 20 
 per cent, alcohol has been added. After 10 hours, or 
 even less, all the proteosomes are coagulated (vacuolised) 
 and 'have completely lost every trace of reducing power. 
 Ether vapoura also may be applied for one hour with the 
 same result ; 
 
 3. Tlie filaments are pressed between two object- 
 carriers, and left there, protected against drying up, for 10 
 hours.' Microscopical examination will then reveal dead 
 Cells with coagulated proteosomes,^ and living cells with 
 unchanged ones. 
 
 (1) While the chlorophyll here preserves its colour, it turns yellow by 
 the treatment with alcohol of 20 per cent. 
 
 (2) Here merely the contact with the dezd protoplasm produces tlie 
 coagulation of the proteosomes. In those cases in which small 
 
58 ACTIVE ALBUMIN AS RESERVE-MATERIAL. 
 
 Accordingly, we find, after the treatment with the silver 
 reagent, that those coagulated remain colourless while 
 those that have not been coagulated become intensely black. 
 
 The noticeable behaviour of the iDVoteosomes to ammonia, 
 pointed out above, has also considerable interest in regard 
 to the silver reduction. By the fixation of ammonia the 
 reducing power is not onl}' retained for a longer time, but 
 its destruction requires now also more energetic means. 
 A slow drying up or treatment with a ] per cent, acetic 
 acid for twelve hours now proves insufficient to destroy it., 
 Boiling water destroys it in about two minutes (a few; 
 seconds are not sufficient), acetic acid of 80 per cent, or 
 hydrochlor'c acid of 10 per cent, in one to two minutes.' 
 
 Guided by my theory, this phenomenon finds a simple 
 explanation, since aldehydes retain their reducing power 
 after the fixation of ammonia.^ 
 
 Moreover, this behaviour admits of a simple expl.'mation 
 of the apparently anomalous fact that while cells killed by 
 heat, pressure, alcohol, or acids have lost the silver 
 reducing property, those killed by diluted ammonia have 
 not.^ It explains, further, why cells brought, in a living 
 condition, into an alkaline silver solution continue to reduce 
 silver even after they have died in it. For, this solution con- 
 tains ammonia (cf. above, p. 55, footnote) which, before the 
 
 proteosomes cannot be easily distinguished from snuill starcli-graimles 
 (disorder having occurred by the pressing), it will be sufficient to keep the 
 filaments for several hours in highly diluted solution of an aniline colour. 
 
 (1) It is hardly nccessnry to remark, that the granulations directly 
 produced in living cells by Lit,My diluie ammonia represent the same 
 product, as that of the ca£feii:e proteosomes treated with ammonia, 
 
 (2) A part of the absorbed animcnia, however, must have entered into 
 still nioie intimate combination (cf . above, pp. 47 and 51.) 
 
 (3) The attempt, therefore, to find in tills difference an argument against 
 us, is a failure. 
 
ACTIVE ALBUMIN AS RESERVE-MATERIAL. 59 
 
 cells have died, causes a copious production of granulations 
 which represent the ammoniacal derivative of tlie active 
 albumin.' 
 
 We see, then, on the one hand, a close similarity in 
 chemical behaviour between the living matter and the 
 labile reserve proteid, and, on the other, the notable dif- 
 ference that tbe latter can combine with ammonia and 
 reduce alkaline silver solutions, while the former cannot.^ 
 If we, however, admit, that the lability is considerably 
 increased by the ' organisation ' of active albumin into 
 living matter, and that the most minute cliemical attack 
 upon living protoplasm can bring on death long before 
 every molecule of it has had a chance to enter into pro]-ier 
 reaction with the attacking substance, we can understand 
 why certain reactions succeed with the non-organised 
 albumin that do not succeed with the organised albumin. 
 
 It will be conceded that the evidence which the nature 
 
 (1) The fact that by absnrption of ammonia the silver lednoing pi-operty 
 of the labile albumin is preserved can be made use of in such cases as that of 
 the snoHbeiry {Si/mphoriearpus racemoiM) where the presence of reducing 
 sugar would be an obstacle to making the sUver test. If the fleshy tissue 
 of uni'ipe snowberries is treated, first with caffnlne, tljen with O-l % am- 
 monia, and then washed with tepid water to remove every trace of sugar, 
 we can get, here also, an intense blackening of the proteosomcs by alkaline 
 silver solution. 
 
 (2) Bokorni) and myself in the beginning of our studies declared this 
 silver reduction, observed first in Spiroyi/ra, to be caused by the living 
 protoplasm itself, because we tlien only paid attention to the silver reduction 
 going on in living protoplasm, and not to that in the vacuole, and, like those 
 authors who rejected the definition of living protoplasm as a varying mixtum 
 eompositmn, entertained the opinion that all albuminous matter present in 
 the cytoplasm is also an essential part of it. Hence, our declaration was 
 justified at that stage of development of knowledge. Later on, however, 
 we ourselves recognised that it is a new kind of reserve proteid, which 
 causes the silver reduction, a proteid that cau occur in the cytoplasm as 
 well as in the cell sap. 
 
60 ACTIVE ALBUMIN AS RESERVE- MATE RIAL. 
 
 of the case admits of is in favour of the assumption that 
 the labile reserve albumin, discovered by Th. Bukorny and 
 myself, corresponds closely to the active albumin foreseen 
 by my theory. All reserve proteida that were known before 
 that discovery, were what T designate as passive protsids. 
 These compounds, whether they compose aleurone grains 
 or proteid crystals,' or are merely dissolved albuminous 
 matter, are in all probability various derivatives of the 
 originally formed active albumin which has lost its labile 
 groups in becoming them. An accumulation of acids or 
 other compounds in the vacuole may contribute to the 
 transformation from the labile to the stable modification 
 of the reserve proteid in cells that are still alive. 
 
 To sum up, it may be convenient for the reader to have 
 pointed out the most striking diflferences between active 
 and passive albumin. 
 
 1 . The capacity for water of imbibition is greater in 
 the active than in the passive albumin, as is clearly in- 
 dicated by the vacuolisation of the proteosomes during 
 their coagulation. 
 
 2. Many of the stronger bases have the property of 
 yielding insoluble combinations with the active but not 
 with the passive albumin, 
 
 3. Weak organic bases, as caffeine or antipyrine, 
 separate the active albumin in the original labile con- 
 dition from its solution, yielding it as bright droplets 
 (proteosomes), a behaviour not observed with passive 
 albumin. 
 
 (I) A plienomonou reported by Peters (Bot. Centrbl., 48, 181) is, in this 
 connection, worthy of recording. This author observed in cells of Carex 
 and Sparganium that the formation of proteid crystals commences in the 
 interior of a drop-like acoumnlation of albuminous mailer. 
 
ACTIVE ALBUMIN AS RESERVE-MATERIAL. 61 
 
 4. Alcohol of 10 per cent, ether vapour, and dilute priis- 
 sic acid, coagulate the active, but not the passive albumin. 
 
 5. Active albumin reduces highly diluted alkaline 
 silver solutions, the passive does not. 
 
 A few. remarks may here he added in regard to 
 enzymes, which we have to consider as bodies related, to a 
 certain extent, to the proteids of the living protoplasm." 
 Both are changed by heat, acids, alkalies; but enzymes 
 not so easily as protoplasm. Certain compounds, however, 
 which kill the latter, as alcohols, will (in a short time) 
 not change the former. Chloroform merely retards enzyme 
 action [Salkowsjci). But, on the other hand, a consider- 
 able difference in resistance is found among the enzymes 
 themselves. Diastase, e.g., is killed by highly dilute 
 hydrochloric acid, while pepsin is not. Prussic acid of 
 25 % will destroy in 12 hours the diastatic but not the 
 proteolytic enzyme of the pancreas.^ Certain bacterial 
 enzymes are rendered inactive by hydrogen sulphide.' 
 
 That enzymes owe their activity* to certain labile 
 atomic groups, has been surmised by a few authors, and 
 
 (1) That enzymes belong to the class of albuminoid bodies has often 
 been asserted and, again, often denied. I can draw, however, absolutely no 
 other conclusi'in than that the enzyme? of the pancreas which I have 
 investigated {Pfliig. Arch. , 27, 20S) belong to the pvoteidsj Wurtz proved 
 this for papain; Oshorne for the diastase of malt (18th Ann. Kep. Agr, 
 Exp. Stat, of Conn.); Seegen and Kratschmer for the diastase of the liver 
 (Jahvosher. f. Thiercheuiie, 1877). 
 
 (2) 0. Loew, ?.c., pag. 208; cf. also Schdr, Jahresb. f . Thierchem., 1875, 
 p. 269. 
 
 (3) Fermi and Sernossi, Arch. Hyg., 1894. 
 
 (4) The fact that different carbohydrates require different enzymes for 
 theii' hydrolysis had Irng ago awakened the interest of physiologists, and I 
 had again called attention to it, in Pfliig. Arch., 27, 210; the conclusion of 
 X!, Fischer that the configuration of the carboyhdrate must in a certain way 
 
02 ACTIVE ALKUMIN AS RESERVE-MATEKIAL. 
 
 was recently again pointed but by Ferdinand Huppe,^ but 
 the question as to the nature of the labile atomic groups 
 is not yet satisfactorily settled. Aldehyde groups can, 
 at least in the most common enzymes, only be present in 
 a less reactive polymeric form, if at all ; but the presence 
 of highly labile amido-groups seems to be indicated by the 
 noxious action of form-aldehyde upon them.^ In general, 
 the enzymes, although belonging to the labile proteids show 
 a behaviour diiTlerent from that of the 'active albumin' 
 which Bohorny and I have found in plant cells, as they 
 neither enter into reaction with organic bases, nor have 
 action upon alkaline silver solution.' 
 
 correspond to the configuration of the enzyme was therefore close at hand. 
 It is the same principle as that I applied, nearly two years before Fischer, 
 to explain the specific action of cortKin alkaloids npon the protoplasm of 
 different cells and organisms. Cf. Ein Natiirliches System der Giftwirk- 
 ungen, p. 85, (1893). 
 
 (1) tJoher die Ursachen der Garungun efc, p. 35. 
 
 ^''''Bass die labilen Kineisskorper, gleichgiiltig oh sie von der Zelle 
 tionnbar sind oder nicht, aber ganz ausserordentliche Bewe- 
 gungen ausfuhren und dadurch auch ausloscn kOnnen, ist 
 gerade dureh die bacteriologisohen Untersuchungen der letzten Jahre 
 slohergestellt. VTclche geringen. Mengen Enzyme vernii-gen als Permente 
 hydrolytischo Spaltungen oder Gerinnungen herbeizufiihreu ! Wie geringe 
 Giftmengen ciweissartiger Natur, Toxalbumine, geniigen, um die Ver- 
 giftungen von Tetanns und Diphtherie herbeizufiihreu ! tJnd wie 
 energisch schiitzen die aetiven Kiweisskorper des Blutsernms, natiirlich 
 Jmmuher oder immunisirter Thiere das 'J'hier gegen die eindringendeu 
 Parasifcen und deren Gifte ! " 
 
 (2) O. Zoew, Naturl. System der Giftwirkungen, p. 71. The poison 
 rtf the bacilli of tetanus ( £7ioAt»«%) and that of the micrococci of diphtheria 
 {Bnrckhurd) are also destroyed by dilute formaldehyde. 
 
 (3) Nenchi and Macfadyen observed with one enzyme only, viz. , one 
 of the cholera bacillus, reduction of an alkaline silver solution (1891), while 
 Brieger obtained a phenylhydrazoue with a proteid contained in a culture of 
 the micrococci of diphtheria. 
 
CHAPTER VI. 
 
 LIVING PROTOPLASM AND CHEMICAL LABILITY. 
 
 I liave in Chapt. Ill drawn tlio inference that the 
 proteids of living protoplasm are different from those of 
 dead protoplasm ; a new hypothesis as to the production 
 of proteids, described in Chap. IV, led me further to a 
 highly probable conception of the nature of that difference, 
 while in the last chapter facts have been described, which 
 prove the existence of a labile form of albumin. Let us 
 now examine whether and in what degree the proteids 
 composing the living protoplasm itself resemble the labile 
 organic compounds of chemistry, and whether my view 
 as to the nature of that lability can be suppoi-ted by 
 facts} '' •» 
 
 A lahile position exists if in a molecule one atom is 
 influenced simultaneously by the affinities of two neigh- 
 bouring atoms and thus becomes subject to an oscillatory 
 movement and possessed, therefore, of kinetic energy in the 
 form of continuous atomic motion.^ 
 
 (1) There is some difference between the conception of lability and that 
 of instahility. Unstable componnds may merely contain much potential 
 energy capable of being suddenly liberated and leading to explosion, as 
 nitroglycerol, diazo-compounds, or fulminating silver. The other kind of 
 instability, which is what we here have in view, consists in the presence of 
 kinetic energy and leads not to explosion but merely to an atomic migra- 
 tion within the molecule, whereby molecular motion, i.e., heat, is generated. 
 A labile position of atoms bears to chemical affinity a relation similar to that 
 of a mechanically unstable system to gravity. 
 
 (2) A remark of Grant Allen in his famous publication : " Force and 
 Energy" is in this connection of interest: "Atomic motion may be 
 
64 I.IVING PROTOPLASM AND CHEMICAL LABILITY. 
 
 Such labile atoms, compared with all other atoms in the 
 same molecule, occupy an exceptional • position in this 
 regard. We know that the atoms with their sphere of 
 action occupy in diEferent compounds different volumes ; 
 thus oxygen in the aldehyde group occupies a larger 
 volume than in the hydroxyl group, the ratio being ] : 0-6. 
 I'he atomic volume of nitrogen in the cyanogen group is 
 larger than in the nitro-group, and in this, again, larger than 
 in the amido-group, the ratios being 1 : 0-50 : 0*13. And 
 if the atomic volume of hydrogen were determined carefully 
 in different compounds, we should very probably find, 
 that it occupies, in an aldehydic and in an amido-group a 
 larger volume than in a methyl and in a hydroxyl group. 
 
 Very justly, F. Siohrnann, who has earned such great 
 credit by his extensive calorimetric investigations, remarks : 
 " The total energy of organic compounds consists of two 
 parts ; one part, thelarger one, is determined by the number 
 and kind of the atoms, the other, smaller, part is determined 
 by the constitution and is therefore variable in isomeric 
 compounds. This second part stands in close relation to 
 the molecular volume, specific gi-avity, melting and boiling 
 point, refractive power, and the degree of stability of the 
 body." We may be justified in adding: the former and 
 laiger amount is potential, the latter and smaller part 
 is, in many cases at least, Idnetic energy. 
 
 Indeed, the greater the molecular volume of a compound 
 compared with its isomers, the more kinetic energy it must 
 
 separative as in deTOmpositi( ii, or aggregative as in the act of combining. 
 The continuous or neutral s'tige is not at present known, though there is 
 reason to think tliat it exibts." Indeed , physicists have thus far paid but 
 little attention to tl:e donsidcrahle amount of encigy pi-esent in labile 
 compounds. 
 
LIVING PROTOPLASM AND CHEMICAL LABILITY. 65 
 
 possess in form of atomic motion ;' the more easily its trans- 
 formation into a stable isomeric or polymeric compound 
 ■will take place ; and the larger will also be the amount of 
 its contraction. Such transformations can bring on a very 
 considerable change in the chemical character. I may men- 
 tion, as examples ; the transformation of ammonium isooya- 
 nate into urea, of hydrazobenzene into benzidine, of hydro- 
 benzamide into amarine, of ketoximes into amides, of 
 pinacone into pinacolin, and of malei'c acid into f umaric acid. 
 One of the most interesting labile atomic groups is tlie 
 aldehyde group, —C^jj, in which the oxygen exerts an 
 attracting influence upon the hydrogen connected with 
 the carbon atom, this being generally tetravalent, but 
 sometimes only bivalent. The hydrogen atom is tlius ever 
 oscillating, between the carbon and the oxygen^ as may be 
 indicated by the following formulce : — 
 
 (1) Wc observe, e.g., tlint ethylaldeliyde has a larger specific volume than 
 the less labile ethylene oxide, the ratio being 56"4 : 50"6. Unsaturated carbon 
 compounds occupy a larger molecular volume than that calculated from the 
 data obtained from -saturated ones. Further, the saturated hydrociirbons, 
 alcohols, and acids of the methane series are , in comparison with the aldehydes , 
 very stable compounds ; so also are the saturated hydrocarbons of the benzene 
 series. The stability, however, decreases with the number of entering 
 hydroxyl groups. The stability of acids decreases also by the entrance of 
 an amido-gronp, e.g., amidomalonic acid gives off carbon dioxide at a much 
 lower temperature than malonic acid. Besides, the relatire position has 
 an influence; j3-amido-acids are moi-e easily decomposed than a-araido- 
 acids. Further, in fatty acids the hydrogen atoms in the a-position are more 
 labile than the others and more readily replaced. — Certain labile com- 
 pounds, again, show very great affinity for molecular oxygen, as zinc 
 ethyl, dimethyl-arsine, monobrom-acetylene and the sodium compounds of 
 ketones and aldehydes, all of which burst into flame in contact with air. 
 
 (2) I defined, as early as 1882, the lability of the aldehyde group as 
 kinetic energy iu form of atomic motion (Die chemische Kraftquelle im 
 lebenden Protoplasma, p. 22). 
 
66 LIVING PROTOPLASM AND CHEMICAL LABILITY. 
 (1) (2) C3) % (4) 
 
 These motions are accelerated by rise of temperature ; 
 in the same measure the inclination to chemical reactions 
 increases. Ammonia, diamidogen, hydroxy lamine, hydro- 
 cyanic acid, hydi'ogen sulphide, and primary sulphites, act 
 with great facility upon aldehydes, and even molecular 
 oxygen is taken up easily by many aldehydes. Certain 
 substances bring on a rapid change : thus a little sulphuric 
 acid will transform ethaldehyde into paraldehyde, whereby 
 a contraction and development of heat takes place. Caustic 
 potash converts this aldehyde into a resin.' 
 
 Another labile group is represented by the following 
 position : — 
 
 -C==0 -C-OH 
 
 I , easily passing into : — || 
 
 -CHj -CH 
 
 In short, the lability of aldehydes and ketones can be 
 considerably modified by the entrance of other groups. 
 It can be increased lay an amido-group and lessessed by a 
 nitro-group, as the comparison of amidobenzaldehydes with 
 nitrobenzaldehydes shows. Much depends, however, upon 
 the relative position which the entering group occupies . 
 further, alternating keto-groups bring on a greater lability 
 than when they are immediately connected. 
 
 (1) The lower aldehydes in the methane series have more chemical energy 
 than the higher members ; the tendency to condensation and polymerisation, 
 the action upon amines, efo,, decrease with the rise in the series. Aldehydes 
 are, moreover, more energetic than the corresponding ketones; while, e.ff., 
 ethaldehyde decomposes ammonium carbonate with lively effervescence, 
 acetone has no such action, 
 
 (2) A certain degree of lability is, however, still observable in the ketone 
 acids; thus, pyruvic acid is even more easily acted upon by hydrogen 
 sulphide than acetone. 
 
LIVING PROTOPLASM AND CHEMICAL LABILITY. 67 
 
 Let us now compare the principal cliaracteristics of labile 
 compounds witli the behaviour of living protoplasm : — • 
 
 1. Labile compounds are easily changed by heat, acids, 
 ■or alkalies into stable, isomeric or polymeric products, 
 whereby contraction takes place} 
 
 Living protoplasm is also changed under such influences; 
 it loses its chemical activity entirely and betrays its changed 
 chemical character by being now very easily stained by 
 even highly diluted solutions of aniline colours. Farther, 
 the physical characters of protoplasm are altered, the 
 peculiarity of the osmotic membrane of the cytoplasm has 
 given place to the properties of a filter, a change which can 
 ■orAj be explained by a disruption of the organisation, in 
 consequence of the contraction of the molecules of the 
 plasma-proteids themselves, followed, in many cases (when 
 death is not instantaneous), by a visible contraction of the 
 entire cytoplasm.^ 
 
 2. Labile compounds develop heat in their transfurma- 
 
 (1) In certiiin instances the labile modification can be easily got back 
 from the stable one. Thus WisUcenus prepared two isomeric modifications 
 ■of foniiyl-phenylacetio ether, tha one solid and acid, the other liquid and 
 neutral. The liquid modification passes into the solid one at very low 
 temperatures, while the reverse takes place at the ordinary temperature. 
 ■Caustic soda, also, transforms the liquid into the solid modification (Cliem. 
 Ztg., 1895. Nr. 78). 
 
 (2) Peculiar molecular motions, also, such as are exerted by alcohols, 
 •esters, chloroform, etc., even when largely diluted, can change living 
 into dead protoplasm. Here the toxical action of the alcohols of the 
 methane series increases with the moleonlar weight. Unsaturated alcohols, 
 however, have other, secondary, and more poisonous properties. Cf. 
 the publications of Meissner, Dogiel, Oibbs and Meichert, Mering, 
 Tsukamoto, and others. 
 
 The phenomena of disorganisation in protoplasm exposed to various 
 noxious influences have recently been more minutely studied by P. Klemm 
 (Jahrb. f. wiss. Bot,, 28, 674). 
 
68 LIVING PROTOPLASM AND CHEMICAL LABILITY. 
 
 tion into stable ones. Atoms, in such a state of con- 
 tinuous movement as prevents them from aggregating with 
 neighbouring atoms, r.re in equilibrium mobile. If, now, 
 this aggregation is accomplished by external influences, 
 a stable position is established, the energy of atomic motion 
 has passed into energy of molecular motion, i.e., heat. 
 Now, in regard to living protoplai'm the measuring of 
 small changes of temperature is only possible in higher 
 animal organisms, for obvious reasons, and here, indeed^ 
 we observe a rise of temperature, when, soon after the 
 death of the nervous system (which dies first), the muscular 
 tissue also succumbs, being no longer nourished by 
 currents of oxygenated blood. The long-known, so- 
 called, post mortem rise of temperature finds thus a simple 
 explanation. This phenomenon is accompanied by an 
 increase of acid reaction and the setting in of stifiEness 
 (' rigor Trior tis '). 
 
 3. Labile compounds can, by means of their containing 
 Mnetic energy, bring on chemical changes in other com- 
 pounds, [cf. Chap. VII.) 
 
 4. Compounds containing labile hydrogen atoms are 
 jparlicularly inclined to attract the molecular oxygen of the 
 air and in this respect present great analogy to living- 
 protoplasm, {cf. Chap. VIII. p. 108-110.) . 
 
 6. Laiile compounds enter readily into reaction with 
 many other substances. 
 
 The potency of the vibrations of the labile atom-^^ 
 facilitates chemical reactions. Must we not recognise- 
 analogy to the behaviour of living protoplasm when we 
 see that numerous substances, even highly diluted 
 £i.d neutral, can attack protoplasm and kill it ? A 
 
LIVING PROTOPLASM AND CHEMICAL LABILITY. 69 
 
 minute sppoific attack, so insignificant that it is impossible 
 to trace it chemically, can suffice to lead gradually to the 
 •collapse of the entire protoplasm of a coll, and if this cell 
 happens to occupy an important position in a nerve centre, 
 ■death may spread along the nerves like an irritation, and, 
 since the action of the heart is then soon brought to an endr 
 death of the muscles must follow. In this way, a 
 minute quantity of a strychnine salt, or of prussic acid, or 
 abrin can, as it is not retained by the blood or lymph, 
 reach the nerve centres and bring on the death of myriads 
 of cells that have not themselves absorbed a trace of it. 
 
 Living protoplasm behaves, indeed, like a most delicate 
 indicator of the chemical character of a substance. Merely ^ 
 by the introduction of a carboxylic or of a salpho group, 
 NencJci c inverted strong poisons into innocuous com- 
 pounds. On the other hand, a harmless body may be- 
 come a poison, if an imido-group is formed by the 
 migration of a hydrogen atom from carbon to nitrogen, as 
 is the case with the non-poisonous hydrobenzamide, -when 
 it is converted into the isomeric amarine. It is obvious 
 that a subtle reaction must have been made possible by 
 tlie changed chemical character. The more labile com- 
 pounds are, the quicker will thej' act upon each other, 
 and the more can they remain active under high dilution. 
 Convinced of the logical necessity of the presence of labile 
 atomic groups in the living protoplasm, I could not help 
 seeing in the great proximity of aldehyde and amido-groups 
 to each other, as indicated by my hypothesis of albumin, 
 formation, the very condition I had, long ago, endeavoured 
 to malce out} 
 
 (1) I had prediotpd in 1881 {Pfliig. Arch., 23, 152) that amido-aldehydes, 
 then an unknown class of bodies, would he prepared In the near future, and 
 
70 LIVING PROTOPLASM AND CHEMICAL LABILITY.' 
 
 Amido-aldehydes are of very great lability. Oriho- 
 amido-benzaldehyde can exist in combination witli hydro- 
 chloric acid in concentrated solution, while diluted acid 
 changes it rapidly (Friedlcender). Those of the fatty acids, 
 prepared by Wolffenslein, can reduce the metal, not only 
 from gold, silver, and mercury salts, but also from copper 
 solutions.' Amido-ethaldchyde is converted, soon after 
 being set free from its combination with hydrochlorie acid, 
 into a gelatinous mass, and loses thereby its aldehyde 
 character {E. Fincher). Diamido-acetone shows the same 
 behaviour, passing into an amorphous compound of totally 
 different properties.^ Compared with amido-aldehydes^ 
 many oxy-aldehydes, such as the aldose-sugars, appear 
 as relatively stable compounds. 
 
 The question now arises : can it be proved, directly or in- 
 directly, that aldehydic and amido-groups are really present 
 in the proteids of the living protoplasm ? — Jf our hypothe- 
 sis is correct, that vital motion emanates from these 
 groups, it follows, that every substance, acting in 
 great dilution upon them, must prove a poison for 
 every living vegetal or animal organism, because the 
 chemical character of living matter is thereby changed. 
 Observation confirms this inference. Aldehydes are very 
 easily acted upon by hydroxylamine, prussic acid, hydrogen 
 sulphide, sulphurous acid (acid sulphites), diamidogen, 
 
 would prove to be much more easily chaiigeiible than ordinary aldehydes. 
 Soon afterwards, Faul Friedlcender made us acquainted with ortho-amido- 
 benzaldeliyde and, later on, Wolffenstein with the first amido-aldehyde of the 
 fatty series, thus proving the correctness of my predictions. The latter 
 obtained [such aldehydes by careful oxidation of piperidlne, ooniine, and 
 ^-pipccolme with peroxide of hydrogen. 
 
 (!) Ber. D. Chem. Ges., 25, 2777 and 28, 1461. 
 
 (2) Siigheimer and Mieschel, ibid., 35, 1563. 
 
LIVING PROTOPLASM AND CHEMICAL LABILITY. 71 
 
 phenylhydrazine, and aniidophenol, while labile amido- 
 groups enter very easily into reaction with free cyanogen, 
 nitrous acid, and foi'm-aldehyde. Noio all these compounds 
 are also strong poinons. 
 
 What an enormous change in poisonous properties 
 is observed, when one hydrogen atom of the ammonia- 
 molecule is replaced by the hydroxyl, or by the amido- 
 group ! While ammonia in form of neutral salts 
 is only a weak poison for animals, the substitution- 
 products thus obtained, viz., hydroxylamine anddianiid- 
 ogen are, in the same dilution and in neutral solutions, 
 very strong poisons. Bacteria and mould fungi, that are 
 not poisoned by concentrated solutions of neutral am- 
 monium salts, ai'e easily attacked by hydroxylamine, even 
 at a dilution of 1 : 10,000.' Marpmann observed, later, its 
 poisonous effect also upon pathogenic microbes. 1 have 
 found, that diatoms are killed within 24 hours by hy- 
 droxylamine in a dilution of 1 : 100,000, and phasnogams 
 in a dilution of 1 : 15,000, in a few days. 
 
 Willie ammonia is, next to nitrates, the most important 
 source of nitrogen for the nutrition of plants, hydroxyl- 
 amine never can be used for this purpose, being a deadly 
 poison ! 
 
 In a dilution of 1 : 20,000 it is a stronger poison for 
 infusoria than strychnine ; in 1: 10,000 it kills crustaceans 
 within three hours ; in ] : 20,000 various aquatic animals 
 within 36 hours {Loew) ; 0*05 g of the hydrochloride kills 
 a pigeon in three minutes ; 0-1 g pro kilo of a warm- 
 blooded animal will produce convulsions {Eaimundi and 
 Bertoni • Binz ; Lewin). 
 
 (1) O. Lorn, Paag. Arch., vol. 35, p. 515 (1885). 
 
72 LIVING PROTOPLASM AND CHEMICAL LABILITY. 
 
 When diamidogen was discovered by Th. Gurdus, in the 
 year 1887, and its remarkable affinities for aldehydes 
 became known,* I predicted at once, that it would 
 prove a to be a universal poison, a poison for all kinds of 
 living cells. In fact I have observed that the neutralised 
 sulphate in a dilution of 1 : 10,000 kills algse in from one 
 to two days ; farther, in less than a day at 1 : 5000, bacteria ; 
 and at 1 : 2000, infusoria, Crustacea, mollusca, and aquatic 
 lai'vas of insects, while neutral ammonium sulphate in this 
 dilution produces not the slightest effect whatever. I liave 
 found, further, that young sun-flower plants die within 
 4 days, and barley within 2 days, when placed in a solution 
 containing 0'2 per inille of neutralised sulphate of diamido- 
 gen while the same plants treated with equal quantities of 
 ammonium sulphate developed normally."'' 0'5 g. of 
 diamidogen sulphate will kill a rabbit in less than two 
 hours {Buchner). 
 
 How is it that liydroxylamine and diamidogen are such 
 strong poisons compared with ammonia ? 'Vhe answer 
 can only be found in their marked difference of behaviour 
 to aldehydes. It has been demonstrated by recent inves- 
 tigations, that salts of liydroxylamine f«nd of diamidogen 
 act even in high dilutions upon aldehydes, while ammonia 
 axjts only either in the free state or as carbonate and with 
 less energy. This difference is due to the greater lability 
 of the hydrogen atoms in the former enabling them to 
 attaclc more easily the labile oxygen of aldeliydes.' 
 
 (1) Acooi-ding to Curtius, diamidogen attacks aldehydes even In strong 
 acid solutions, wliilo it combines with ketones only when in the free 
 state. 
 ■ (2) O. Loew, Berichte d. D. Chem. Ges., vol. 23, p. 3201. 
 
 (3) The reaction upon ketones is much less energetic. 
 
LIVING PROTOPLASM AND CHEMICAL tABILITV. 73 
 
 H H H 
 
 N— H N— n N— H 
 
 Ammoiiia. Hydroxylamino DUmidogen. 
 
 In further perfect acQordanoe witli the aldehyde theory, 
 I have found aniline to be a weaker poison than phenylhy- 
 drazine or ainidophenol ; phenol to be a weaker poison than 
 amido-phenol; and pyridine a weaker poison than piperidine. 
 
 It is of considerable interest, that certain derivatives of 
 hydroxylamine also react easily with aldehydes and exhibit 
 accordingly a poisonous character ; these derivatives ai-e 
 the ' amidoximes,' prepared by Tiemann by the action 
 of concentrated hydroxylamine upon nitriles at higher 
 
 temperatures. Of benzenyl-amidoxime, CjHj C<^ , 
 
 ^NOH, 
 O'l gr. suffices to kill a rabbit.' 
 
 Again, prussic acid is a poison tor all kinds of living 
 organisms, but it attacks lower organisms less energetically 
 than the higher ones. 
 
 In a dilution of 1 : 2000, it kills the lower aquatic 
 animals within a few hours, and, in dilution of 1 : 1000, 
 •phsenogams, alg.-i3, and the lower fungi, after about 15 
 hours. 
 
 "While prussic acid acts easily upon the aldehyde 
 groups, free cyanogen attacks readily labile amido groups. 
 Accoi'dingly, the latter forms just as general a poison as 
 the former and, for the lower organisms, even a more 
 violent one. In dilution of 1 : 5000, it kills bacteria and 
 
 (I) Mering, Bsr. D. Chem. Ges., 1885, p. 1045. An exceedingly 
 poisonous compound is also phenyl-hydroxylamine, discovered by E, Bam- 
 berger; cf. Berl. Klin. Wochcnsclirift, 1895, 41-42. 
 
74 LIVING PROTOPLASM AND CHEMICAL LABILITY. 
 
 yeast cells, of 1 : 10,000, algse, phsenogams, and lower 
 aquatic animals' ; 0'02 gr. suffices to kill a cat {Bimge), for 
 which only 0'004 gr. of prussic acid is enough. 
 
 Of special interest in connection with the present 
 subject is the highly poisonous character of nitrous 
 acid, compared with other mineral acids, a fact, again 
 easily accounted for by my theory, since it acts as 
 an energetic oxidising agent upon amido-gvow^B. Free 
 nitrous acid in a dilution of 1 : 100,000 kills algse 
 within 48 hours.^ Nitrites are poisonous in all those 
 cases, where nitrous acid is set free from them by the 
 organism ; therefore, for plants containing free acids or 
 acid salts. To the higher animals also nitrites are very 
 noxious, as the observations of Binz, Emmerich and 
 Tsuboi, and others have shown. 
 
 Then, too, the poisonous action of form-aldehyde only 
 becomes intelligible by taking into consideration its 
 readiness in affecting amido-gi-ouTps of a certain lability : in 
 a dilution of 1 : ] 0,000 it kills microbes and algse ; while 
 in solution of 1 : 2000 it kills, in 2 hours, crustaceans, 
 worms and mollusca.' liabbits are killed by 0-24 gr. pro 
 kilo. (Zuntz). Phsenogams, watered with a 1 p. m. solution, 
 die ill from two to six days (BoTcorny). 
 
 On contemplating these numerous toxicological facts, 
 it will be admitted that there exists perfect accordance 
 between the anticipated phenomena and the actual ones, 
 i.e. the proteids of living protoplasm have an aldehyde 
 character, while those of dead protoplasm have no 
 
 (1) O. Loeui and M, Tsukamoto, liullotin of the Agricultural College of 
 tlie Imperial University, Japan. II. No. 1. 
 
 (2) O. Loew and Th. Bohorni/, Botan. Ztg., Di'c. 1887. 
 (8) 0. Loeto, Jaliresb. f . Thiercliemie, 1888. 
 
LIVING PROTOrLASM AND CHEMICAL LABILITY. 75 
 
 such character ; the former have afRinity for hj/droxyl- 
 amine, diamidogen, 'or prussic acid, the latter have 
 not. The views of Pfliiger and of Latham, where it 
 is assumed that the labile groups are cyanogen groups, 
 indicate a different behaviour.' Moreover, according to 
 the view of PJluger, the change connected with loss? 
 of life consists in the chemical fixation of the dements 
 of water; according to my view, it consists in a 
 migration of atoms from labile to stable positions, 
 without water being taken up. 
 
 As my deduction is verified by facts, the further 
 inference may be drawn that "the more labile the 
 aldehydic or amido-groups contained in a compound, 
 the stronger is its poisonous property." But as labile 
 amido-groups act readily upon labile aldehyde groups, 
 there constantly exists the danger to the living cells 
 themselves of an inter-molecular poisoning taking place ; 
 indeed one needs only heat the living organisms to 50° 
 for death to result, with rare exceptions ; the threatened 
 danger has become a reality. 
 
 The easy change from the living to t[ie dead state must, 
 however, on the other hand, lead, to the inference that 
 energy has to be spent by living cells in transforming 
 passive proteids into living protoplasm, a conclusion, 
 Pfliiger arrived at in the year 1875.''' Hei-e kinetic 
 energy, as such, is taken up into the molecule. The 
 regeneration of the labile groups in the transition from 
 
 (1) Hydvoxylamiue will aiit upon ct/anides (iiitriles) in concentrated 
 solutions and at Iiiglier temperatures ; upon aldeht/des, even in the cold 
 and in high dilution. Frussic acid is without action upon nitriles. 
 
 (2) Pfiug. Arch., 10, 308. " Bei del- Gewebebildmig wird eine Arbeit 
 geleistet, wodurcli die Colisesion des Eiweissmoleculs ausserordentlich 
 gelockert erscheiut." 
 
76 LIVING PROTOPLASM AND CHEMICAL LABILITV. 
 
 passive into active albumin' could, in the sense of the 
 theory developed in Chap. IV, be represented in the 
 following manner, water being taken up and yielded 
 again : 
 
 -CH-NH -OH-NI-I2 
 
 =C - C< + ^ — =C - CIT< 
 
 A passive group 
 
 -CH-NH2 
 
 = 1 + H,,0 
 
 =C - CHO 
 
 An aciive group 
 
 111 scrutinising the general behaviour of protoplasm, 
 we have to take one step farther, and to infer that not 
 only is the chemical structure of the proteids a labile one, 
 but also the morphological structure of the protoj)lasm that 
 is, the tectonic, the invisible arrangement of the molecules 
 of active albumin into small particles of protoplasm. 
 Not only slight disturbances of a chemical nature, but 
 those also of a mechanical nature in some minute portion of a 
 living cell, may cause the collapse of the entire protoplasm. 
 Morphological structure and chemical nature are evidently 
 most intimately connected ; an injury to one will also 
 damage the other : TAving protoplasm is a labile structure 
 huilt up of labile mMerial. 
 
 Naturally, there exist various degrees of labilitjr in 
 different kinds of protoplasm. The power of resistance 
 to noxious influences varies not only with the lower or 
 
 (1) In plants tliis transformation, when connected witli transportation, 
 of proteid, takes a more indirect way, via amido-compounds j cf. Chap. IV. 
 
LIVING PROTOPLASM AND CHEMICAL LABILITY. 77 
 
 higher development of different organisms, but also with 
 the nature of the different cell-groups of one and the same 
 organism ; it varies even with the organoids of a cell, for 
 the nucleus and chloroplasts of plant-cells are much more 
 sensitive to many noxious influences than the cytoplasm. 
 
 Those cells or organs which have the most delicate 
 office to perform are the very firat to perish. The more 
 labile the tectonic of a protoplasm the greater its efficiency 
 will be and the more dingerous a slight injury will prove 
 to it. 
 
 Further, the labile character of protoplasm is the 
 essential condition for its irritajbility. Only labile com- 
 pounds exhibit properties which have a resemblance — 
 although a remote one — to the phenomenon of irritability, 
 for these only may, by seemingly slight influences, be chang- 
 ed into isomeric or polymeric stable compounds. Thus, 
 e.g., rubbing with a glass rod can transform the labile benzo- 
 phenone (melting point 27°C) into its stable isomer 
 (melting point 49 °C). A trace of triethyl-phospMne will 
 transform methyl-isocyanate into a polymeric form, with 
 liberation of heat (Hofmann)} 
 
 Now, when any irritation of the living protoplasm takes 
 place, chemical change of the living matter is excluded, 
 for that would mean death ; protoplasm can supply the 
 energy required merely by retardation of its usual atomic 
 motions. The heat of respiration can quickly cover the loss 
 
 (1) A still more remote example of quick change by an apparently in- 
 significant influence is exlubUed by Glauber's salt, in supersatuiated solution. 
 In this, a trace of dust on a glass rod, with which it is touched, may bring 
 on crystallisation with development of heat, after which the stable condition 
 may easily be reconverted to the unstable one by applying heat. I here 
 avoid, for good reasons, citing such cases as examples as lead to a perfect 
 desti'uction of the compound. 
 
78 LIVING PROTOPLASM AND CHEMICAL LABILITY. 
 
 incurred, by passing into atomic motion. I cannot accept 
 the opinion of Haechel, when he speaks of • souls ' in 
 atoms, and the perfection of these souls in the living 
 protoplasm ;' and cannot agree with Ndgeli's inference 
 that " because sensibility is a property of albumin 
 molecules, we must ascribe it also to other compounds."^ 
 Clearly, it is a erroneous supposition that ordinary 
 albumin molecules have sensibility ; this property stands 
 and falls with lability and proper organisation (tectonic). 
 Not with matter itself, but with lability of matter, irri- 
 tability is possible ; not in the atoms themselves but in 
 the labile position of atoms in proteids does the first trace of 
 vital energy manifest itself. 
 
 (1) Tageblatt der Naturforscherversammlung zn Miinchen, 1877. p. 22. 
 
 (2) Ibid, p. 39. 
 
CHAPTEE VI r. 
 THE CHEMICAL ACTIVITY OF LIVIKG CELLS. 
 
 The great chemical activity of living cells astonishes the 
 pondering mind. Constructive, as well as destructive 
 metabolism, betrays the presence of a power admirably 
 adapted to do chemical work. The synthesis of carbo- 
 hydrates, the transformation of starch into cellulose and 
 fat, the production of the highly complicated proteids, are 
 executed with great readiness by plant-bells. Animal 
 protoplasm, also — although, in extent and power of chemical 
 synthesis, far excelled by vegetal protoplasm — is capable 
 of many highly interesting chemical operations, such as 
 the construction of living protoplasm out of inert album- 
 inous matter, the formation of haemoglobin, mucin, elastin, 
 keratin, and coUagene from the proteids of the food, the 
 production of enzymes, or the transformation of sugar into 
 fat. Not less remarkable than the synthetic work is 
 the energetic oxidation exhibited by the respiration 
 process.' 
 
 The character of the chemical work in plant-cells is 
 many-sided : polymerisation, condensation, esterification, 
 formation of amido-compounds, generation of the cyclic 
 constitution, reductions, and oxidations are included in it. 
 We find acids and bases, aldehydes and ketones, ethers, 
 alcohols, and sulphides in the vegetal kingdom j but 
 
 (1) See the following chapter. 
 
80 THE CHEMICAL ACTIVITY OF LIVING CELLS. 
 
 neither aldoximes, nor ketoximes,' neither sulpho-acids, 
 nor nitre-, nor azo-compounds. Thus, the chemical 
 activity, varied as it is, seems, nevertheless, not to leave 
 certain channels.^ A number of chemical operations can 
 be caiTied out by every plant-cell ; others only by specifi- 
 cally endowed ones ; and, -while certain compounds are 
 found in all cells, such as carbohydrates, fats, and proteids, 
 others are not of universal occurrence, though still very 
 frequent, such as tartrates, succinates, glucosides, resins, 
 tannins. Others, again, are very rare, being either restrict- 
 ed to one family, as quinine or stiychnine, or to a few 
 families, as caffeine. 
 
 In scrutinising the chemical activity of a plant-cell, we 
 have at first to pay attention to the differentiation of the 
 plasmic contents. The cortical layer of the cytoplasm has 
 not the same function as the inner layer or tonoplast ; the 
 former produces the cellulose-wall from starch or sugar 
 while the latter restrains noxious substances accumulated 
 in the vacuole from rtturning into the organoids. The 
 letiTiojilasis foim starch from sugar, thereby preventing a 
 higher concenti'ation of the sugar-.=o]ution, which would, 
 to some extent, check plasmic activity. The chloroplasts, 
 again, with the aid of ethereal oscillations of a determined 
 
 (1) No derivative of hjdroxjlaniine lias, as yet, been discovered in 
 ovganismf?. 
 
 (2) It is a notable fact, for which explajiation has, hitherto, not been given, 
 that especially such benzene derivatives as have a lateral group of three 
 carton atoms frequently occur in plants, some in the form of glucosides. 
 I may mention : hesperidin, cufpeic acid, cumarin,umbelliferone, daphnetin, 
 conif cryl-alcohol , eugenol, nncthol, safrol, cinnamic alcohol and aldehyde, 
 cinnaniic acid, thymol, scopoletin, asarone, syringin, sesculetin, absinthol, 
 camphor, the terpencs. Also, tyrosine and phenylamido-propionic acid, as 
 decomposition-products of proteids, have to be mentioned. 
 
THE CIIKMICAI, ACTIVITY OF LIVING CELLS. 81 
 
 wave-length, tr;insforrn carbonic acid into sugar.' The 
 nucleus, finally, is charged, among other things, with the 
 duty of producing enzymes. 
 
 A plant cell deprived of the nucleus is incapable of 
 forming cellulose {Klebu) ; very probably on account of 
 suspension of the production of diastase necessary for 
 a sufficient saccharification of starch for that process. For 
 the lowest animal forms, an analogous case was proved 
 by B. Hofer ; amoebaj can no longer digest albuminous 
 particles when deprived of their nucleus.^ 
 
 That the vegetal nucleus seems to be the manufacturer 
 of the proteids, was first siggested by Slrasshurger and 
 Schmitz ; proteid-crystalloids are frequently found in the 
 nuclei of plant-cells, especially in the orders, Oleaceoe, 
 Scrophidarineoe, Bignnniacece, and in the Pteridophytes 
 (Zivimermann). It does not seem probable tiiat this 
 proteid has its source in the cytoplasm and is tlien trans- 
 ported into the nucleus for crystallisation. Again, in 
 germinating seeds, where proteid formation from fragments 
 of decomposed reserve-proteids proceeds witli considerable 
 activity, the nuclei (and also the nucleoli) increase in size.^ 
 
 (1) In the assimilation of ciirbonic add it is generally assumed that form- 
 aldehyde is the first prodnct. 'J'liis yiplJs, hovverer, upon condensation in 
 solution, as I have shown, not dextrose but other sugars; moreover, it is 
 poisonous. Therefore, I have added the hypothesis that the formaldehyde 
 combines at once witli cortniu hydroxyl-groups in the proti)plasni of the 
 chloroplasts, the amido-groups being prolected. The concieiisatinn taking 
 place afterwai-ds must thus lead always to one and the same configuration 
 of tlie resulting sugar, sincj the molecules of form-aldehyde have lost their 
 fi-eedom of motion. Cf. O. Zoeiv, Ber. D. Cheni. Ges., 1889, pp. 484 
 and 473. 
 
 (2) Further observations in this regard were made by KorscheH and by 
 Verworn {Pflug. Arch., 51). 
 
 (3) Feiers, Botan. Centralbl., 48, 181. Also in the cells of glands 
 relatively large nnclei are often present. It is also a reuiaikable 
 observation that plant-cells deprived of their nucleus do not produce 
 
82 THE CHEMICAL ACTIVITY OF LIVING CELLS. 
 
 The nucleus plays also a certain part in the organisation 
 of the cytoplasm. In cases of mutilation, only such cells 
 can be regenerated as still contain the nucleus (Nussbaum, 
 Gruher). Since the growth of vegetal cells bears a certain 
 relation to the nucleus, as was observed by Klebs and 
 Haherlandt,^ it is probable that the nucleus prepares the 
 proteids suitable for the purpose of organisation. The 
 vegetal nucleus performs this by far-reaching synthesis, 
 the animal nucleus by transforming dissolved proteid^ 
 
 The most impoi-tant function of the nucleus, liowever, 
 is connected with the division and multiplieytion of cells 
 and with sexual propagation in plants and animals. The 
 nuclein known to chemists, extracted with alkaline liquids 
 
 any more starch by assimilation. Only certain algae, containing 
 pyrenoids {Zt/ffiiemaceie) have thus far been observed to be excep- 
 tions in regard to starch-production under this condition {Klehs), — 
 Simpler organisms, like amoebaa and alga;, are especially well suited for 
 experiments with isolated cytopliisni. K!ebs Inis, by plasiuolysis, and 
 Oerasimoff, by low temperature during the process of karyokiuesis of algie, 
 obtained living cytoplasm M>i7AoM< a nucleus. The life of such cytoplasm, 
 however, did not last longer than about six weeks. On the other hand 
 the nuclei of radiolaria can remain alive, if deprived of the ci/toplasm, 
 only 10-15 hours. Nucleus and cytoplasm influence each other by certain 
 of their products (^Verworn, Ffliig. Arch., 51, 113). 
 
 (1) Biol. Centralbl., 8, 133. 
 
 (2) I consider the process of organisation as a sort of polymerisation, in 
 which only molecules of Me same configuration can participate, and in which 
 isomeric molecules would be hurtful, as the mutual reaction between their 
 labile groups would be facilitated (Cf. O. ioeto, Natural System of Poisonous 
 Actions, Chap. V. On the poisonous proteids, 82). This, again, would 
 imply a specific tectonic for the nuclei of different species as the necessary 
 condition for yielding one and the same kind of active albumin for the 
 organisation of each cytoplasm. I'he possible isomers and especially stereo- 
 isomers of a proteid reach evidently to an immense number, even if we start 
 from one and the same active pesptono. Differences have been observed 
 between the oxyhaemoglobins, fibrins and alexins of different animals. 
 
THE CHEMICAL ACTIVITY OF LIVING CELLS. S3 
 
 and precipitated with acids, is a relatively stable com- 
 pound,' which would be entirely incapable of serving the 
 physiological phenomena of kai-yokinesis. These clearly 
 point to a higlilv labile state of the albumin contained in 
 nuclein^. 
 
 Division of chemical labour, still of restricted compass 
 in a single plant-cell, keeps growing in importance and 
 extent with the development of multicellular organisms, 
 both, in plants and animals. 
 
 The glands, (chemical factories in the service of an 
 organism), — of simple structure in plants, but forming 
 complicated organs in the higher animals, — betray again 
 a far-reaching differentiation. They may secrete enzymes, 
 carbohydrate."', acids, fat, or wax. Products secreted by 
 vegetal glands alone are terpenes and resins.^ Glands se- 
 creting poisonous compounds (toxalbumins, etc.) occur in 
 the mouth of snakes, in the skin of the toad, on the feet 
 of scolopendras. Crustaceans and beetles produce chitin ; 
 8pidci-s and caterpillars, iibroin; cars;bidte, butyric acid; bees 
 and ants, formic acid. How different again the products 
 
 (1) Ziebermirnn showed that nuclein contains metaphosphoric acid, and 
 Kossel, that bases of the xanthine series and nndeic acid are contained in 
 it. My onn ohsevvations make it highly probable that the nnelein of plants 
 ('.he lowest algae and fungi excepted) is present as a lime c.mipound. 
 Cf. 0. Loew, On the fnnetions of calcium and magnesium salts in plants. 
 Flora, 1892, 368; Landw. Versuchs-Stat., 11, 467 ; Bot. Centrbl., 1S95, 
 Nr. 52. Also Molisch, ibid. Nr. 4. 
 
 (2) Differences have been shown to exist between the nuclei of nerves, 
 glands, and muscles; further, between those of the male and female sexual 
 cells, the foi-mer being richer in nuclein (£. Zaccharias). SUll greater 
 must be the differences between the nuclei of the germ-cells and tliose of the 
 somatic cells, especially in animals. 
 
 (3) An elaborate treatise on the resin-producing glands of the conifers 
 was recently published by JS. 31ayr, formerly professor in T6ky5. 
 
84 THE CHEMICAL ACTIVITY OF LIVING CELLS. 
 
 of the anal glands of the skunk, musk deer, beaver, and 
 civet. Finally, the chemical labour of the liver varies 
 ■with the dififerent classes of animals. Dogs can produce 
 ethyl sulphide {Abel) and Icynurjuic acid ; birds, ornithuric 
 acid ;' the bile of geese contains chenotaurocliolic nc'.d ; that 
 of swine, hyotaurocholic acid. Birds and snakes produce 
 more uric acid than urea, while the reverse is the case 
 of mammalia^. 
 
 This very brief survey bears sufficient testimony to the 
 extraordinary ability of living cells to do a great variety of 
 chemical work ; such admirable chemical transmutations 
 could not fail to arouse the lively interest of chemists and 
 to instigate them to ayntlictio operations. Indeed, many 
 organic substances Iiavc been artificially prepared, since 
 the start was made by Woehler in the year 1828. Carbon 
 and hydrogen were united in the electric arc by Berthelot ; 
 acetylene, thus formed, leads, among other things, to 
 ethylene, ethyl alcohol, acetic acid, aldehyde, acetone, and 
 glyoxal. Acetylene yields at low red heat benzene, from 
 which, again, numerous derivatives can be obtained. 
 Acetone, further, may easily be converted into trimethyl- 
 benzene, aldehyde into trimetliyl-pyridine ; from pyridine, 
 again, con line may be reached (Ladenburg). Glyoxal 
 leads, by way of its cyanhydrin, to tartaric acid. 
 
 Carbon can be united with metals and some of such 
 products can yield on decomposition gaseous, liquid- 
 and solid hydrocarbons. Methane, again, yields, 
 methyl alcohol and form-aldehyde, while the latter yields 
 
 (1) This acid, a dibenzoyl-oniithine, is secreted after ingestion of 
 benzoic acid; ornithine again is probably a diamido-valerio acid (Jaffe.) 
 
 (2) Also, pathologic processes vary in animals; thus, pliloridzia will 
 produce diabetes in dogs, bnt not in rabbits or frogs. 
 
THE CHEMICAL ACTIVITY OF LIVING CELLS. 85 
 
 by condensation several kinds of sugars (0. Loew). Formic 
 acid can be obtained by the action of sodium upon moist 
 carbon dioxide (IT. Kolbe), or by the action of iron filings 
 upon carbon bisulphide in presence of water in sealed 
 tubes at 100° (0. Loew). Oxalic acid results on pass.ng dry 
 carbon dioxide over hot sodium amalgam (J?. Drechael), 
 or on treating the jiroduct of reduction of carbon 
 bisulphide by sodium amalgam with fusing potash or boiling 
 baryta-water [0. Loew). From a mixture of oxalic ether 
 and acetic ether, aconitic acid can bs obtained [L. Glaisen 
 and B. Eori) ; from acetone and oxalic ether, oxytoluic 
 acid, and from this, an anthracene derivative, (dimethyl- 
 anthrai'ufin) has been obtained {Glaisen). From malonic 
 ether phloroglucin can be reached {A. Baeyer), and also caf- 
 feine (E. Fischer); from succinic ether, hydroquinol; from 
 malic acid, oxynicotinic acid and daphnetin [Peckmann). 
 
 These, and similar synthetic processes, are, however, for 
 the most pai-t only possible by the application of powerful 
 agents, such as strong bases or acids, sodium ethoxide, 
 sodium amalgam, zinc cliloride, etc., and partly by the. 
 aid of high temperatures ; while no light, is thrown upon 
 the .•'pec'ial method followed by the living protoplasm of 
 plant-cells, a material consisting of pi'oteids of neutral 
 reaction, or nearly so, and of a very subtle nature 
 forbidding a simple analogy with the ordinary chemical 
 proeessts. "We are led to assume an energy differing to 
 some extent from the common chemical energy and 
 consisting in wave motions of a specific character 
 Attempts to explain the chemical actions of protoplasm 
 by a kind of motion were first made, years ago, e.g. by 
 ^dgeli, in defining the fei-mentative activity of yeast. 
 Mc. Laugldin went still fartlier, applying the laws of 
 
86 THE CHEMICAL ACTIVITY OF LIVING CELLS. 
 
 oscillations established by physicists to the action of 
 bacteria in infectious diseases.' But neitber Nageli nor 
 Mc. Laughlin touched the question, why such energetic 
 motions stop at once on the death of a cell, although the 
 conclusion that the living protoplasm must consist of 
 easily changeable, labile proteids was close enough at 
 hand. Mc. Laughlin expresses bis views upon the fer- 
 mentative action of bacteria and yeast-cells in the following 
 words : " The distinctive energy or waves of a cell, say a 
 yeast-cell, can influence those substances only, whose 
 waves bear a certain relationship to those of a yeast-cell ; 
 and they must be equal in their periods, direction, and, 
 perhaps, in other characterisues, before those on one side 
 can influence those on the other. I'he nature of this 
 influence will again depend on whether the two sets of 
 waves coincide in trough and crest. If they do, the waves 
 will supplement each other and their amplitude will be 
 enlarged ; if they do not, they will antagonise each other, 
 and their amplitude will be diminished ; or, it may bo, the 
 waves will be destroyed by mutual antagonism ; it will be 
 remembered that all tin's occurs in waves of sound, of 
 light, and of water, and, if analogy has any merit, it can 
 occur in waves of molecular energy." 
 
 This deduction, however, notwithstanding its scientific 
 appearance, is not justified, as such molecular motions ought 
 to be present also in dead cells. There exist evidently 
 motions in the living protoplasm, but they are much more 
 powerful than the atomic or molecular motions that may 
 be connected with nutrients. 
 
 We are acquainted with chemical actions caused by 
 
 (1) Fermentation, Infection, and Immupity ; 1892. 
 
THE CHEMICAL ACTIVITY OF LIVING CELLS. 87 
 
 waves of heat, light/ electricity,^ and even of sound 
 (explosion of nitrogen iodide), but concerning tlie 
 related phenomenon oE chemical action set up by 
 oscillating motion of labile atoms, our knowledge is 
 but very scanty. Such processes are of the kind termed 
 Icatalytic actions.^ This expression was first used by 
 Berzelius to designate chemical phenomena apparently 
 caused by mere contact with a certain substance. The 
 unsatisfactory definition of Berzelius, and the denomina- 
 tion of certain processes £is katalytic whicli in reality were 
 not such at all, implied a misunderstanding, and after 
 Liebig had lidiculed the idea of Berzelius, tliis interesting 
 group of phenomena was ignored for many years.'' 
 
 Katalj^tic actions exist, however, but they are not tlie 
 result of a mere contact, as Berzelius believed, but of a 
 
 (1) The action of h'gkt may consist inbiinging about («) combinations, as 
 tliat between clilorinc anil hyilvogpn, or (A) disruptionn ; bisn'.pliide of 
 carbon is split i:;to sulphur and <i, lower sulphide (0. Loew); aqueous 
 sulphurous acid is split into sulphur and s"ulphuric acid (O. Loew); nitric 
 acid into oxygen and nitrons acid; silver salts are reduced to metal; 
 [e) reductions of organic compounds: in alcoholic solution qninone is changed 
 into hydroquinol, nitrobenzene into aniline (Ci'ami'crara and SUber), benzd 
 into benzil-benzoin, ;i portion of the alcohol present behig converted into 
 aldehyde; (d) polymerisation and condensation; thymoquinone, anetliol, 
 phenyl-mphthoquinono aie polymerised ; mono-bromacetvlene is converted 
 into tribrombcnzene ; propar^ylic acid into trin-.esic acid (Ber. D. Chem. 
 Ges. 27,958). 
 
 12) Highly intci'Osting synthases have been accomplished by means of 
 electricity by Crum Brown and by H'. v. Miller. 
 
 (3) The great resemblance of the chemical netivity of living cells to 
 Icatalytic actions was recognised more than thirty years ago by the great 
 physiologist, C. Ludwig. Also C ieimonn in his " Lehrb. d. physiolog. 
 Chem,," and, later on, Traube und Stolimann expressed themselves in the 
 same sense. 
 
 (4) Even now-artiays voices are raised in the sense of Liebig. See S. 
 Macleod's lecture at the meeting of the JBritish Assoc, in Edinburgh, 1892. 
 
88 TH1-: CHEMICAL ACTIVITY OF LIVING CELLS. 
 
 certain amount of energy being conveyed, whereby the 
 Jcatahjser remains chemically intact.^ If, however, the 
 appariintly katalytically acting substance undergoes inter- 
 mediary chemical changes with final regeneration, the 
 process is not a katalytic one. Such pseudo-lcatalytiii 
 actions are, for example, the part nitric oxide plays in the 
 manufacture of sulphuric acid, that of cobaltic oxide in 
 the development of oxygen from chloride of lime, tlie 
 action of aluminium chloride in the synthesis of hydro- 
 carbons, tliat of zinc chloride in the transformation of 
 glycol into aldehyde, and the accelerating action of iron 
 and copper salts upon the oxidation of phenol by peroxide 
 of hydrogen.^ 
 
 The genuine katalytic actions' may be divided into 
 three groups : 
 
 1. Katalysis by labile organic compounds ; 
 
 2. Katalysis by mineral acids, alkalis, and certain 
 salts ; 
 
 3. Katalj'sis by finely divided metals. 
 
 As examples of the first group may be mentioned the 
 
 (1) I cannot agree with Ostwald, when he says (Anla, 1895) : 
 " Worauf die Wirkung der katalytischen Stoffe beruht, ist zur Zeit noch 
 cin Ratsel, dessen Losung urn so schwieriger ist; als sie nur auf Grund 
 neuer JPrlnzipieny wclche iiber das ^nergiegesetz hinausgehen, gcftinden 
 wei'den konnte." 
 
 (?) Chem. Ccuti'iilbl. 1885, p. 224. In certain cases the apparently 
 katalytically acting substance is mainly a suitable medium to bring two 
 compounds into more intimate contact with each other, or by combining 
 with one of two compounds present to loosen somewhat certain affinities 
 in the molecule, and thereby bring about combination with the second 
 compound, 
 
 (3) StoJimann (Zeitschr. Biol. 1895 p. 389) defines katalysis as a 
 " mode of atomic motion in molecules of labile structure which is brouglit 
 on by an eiiergy exerted from another body, and leads witli loss of 
 energy to tiie formation of more stable compounds." 
 
THE. CHEMICAI, ACTIVITY OF LIVING CEI.I.S. 89 
 
 conversion of free cyanogen into oxaraide by a dilute 
 solution of ethyl aldehyde, a reaction observed by Lielig ; 
 the transformation of thio-urea into the isomeric am- 
 monium thiocyanate by an alcoholic solution of ethyl 
 nitrite [Glaus) ; the facilitating action of acetic ether upon 
 the combination of hydrocyanic with hydrochloric acid 
 {Glaisen and Mathews). Maleic acid transforms ketazines 
 into the isomeric pyrazolines with liberation of heat,' 
 whilst fumaric acid can only accomplish this at a tem- 
 perature of ] 00°. 
 
 • No doubt, the action of the enzymes also belongs to 
 this group (of. Chap. VI). 
 
 In the second group of katalytic actions may be counted 
 the transformation of maleic into tl'.e isomeric fnmario acid 
 by mineral acids ; of maleic ether into fumaric ether by 
 ■contact with hydrochloric acid at the ordinary temperature 
 (Skraup) and of citraconic into mesaconic acid {Delisle, 
 Franz) ; of hydromellitic into isohydromellitic acid by 
 hydrochloric acid (Baeyer) ; of dihydroterephtalic into an 
 isomeric acid by a solution of caustic soda ; the formation 
 of para-amidophenol from phenyl-hydroxylamine {E. Bam- 
 berger) and that of paranitroso- com pounds from aromatic 
 nitrosamines. Also, the transformation of oleic into elaidic 
 acid by nitrous acid deserves mentioning. 
 
 In connection with the third group the following actions 
 deserve attention : platinum black brings about an 
 oxidation of hydrogen, of ammonia, of alcohols, and of 
 various other compounds ; it unites sulphur dioxide with 
 dry oxygen to form sulphur trioxide ; it co mbines hydro- 
 
 (1) CurlUs and Foersterlir^g , Ber. D. Cl.em. Ges., 27, 770. Maleic 
 acid yields 326-3 units of heat, fumaric acid only 319-7 pro gram- 
 jnolooule {Slohm,7,ni). Cr. p. 61. 
 
90 THE CHEMICAL ACTIVITY OF LIVING CELLS. 
 
 gen with hydrocyanic acid into methylamine at 110 
 (Dehus); it transforms a mixture of nitric oxide and 
 hydrogen into ammonia and water ; it accelerates the 
 decomposition of hydroxylamine in presence of caustic 
 potash ; it decomposes peroxide of hydrogen energetically; 
 it transforms ozone into common oxj'gen {Mulder); it 
 decomposes azoimide and water into ammonia and nitrous 
 oxide (0. Loew), and nitrososulphate ' into sulphates and 
 nitrous oxide {Fdouze). 
 
 Finely divided iridium or rhodium decomposes formic 
 acid into carbon dioxide and hydrogen {Deville and 
 Debray) ; palladium powder effects the oxidation of hypo- 
 phosphorous acid with liberation of hydrogen ;' finely 
 divided copper incites a rapid decomposition of form- 
 aldehyde by caustic potash with liberation of hydrogen,''' 
 it also decomposes diazobenzene chloride into nitrogen 
 and chlorbenzene at low temperatures.' Zinc filings at 
 100° condense acet-aldehyde to aldol and croton-aldehyde. 
 
 All these actions of finely divided metals can be best 
 explained by the assumption that a modification of heat 
 uaves takes place in such a manner that this energy can 
 now pass more easily into chemical energy. With platinum 
 black this modification is carried still farther by the dense 
 layer of oxygen surrounding the metallic particles.* 
 
 {l)2Sngely Coinpt. rend., 110, 786. Tlic chemical expluniitiou given 
 by this author is certainly incorrect. 
 
 (2) O. l.oeio, Ber. D. Cliem. Ges., 20, 145. 
 
 (3) GaUermann, ibid. 23, 1218 and 25, 1091, footnote. 
 
 (4) Platinum-black can absorb 800 times its own volume of oxygen 
 {Doebereiner) 1 Mond, Ramsat/, and Shields calculate much less; the kind 
 of preparation may have some influence. But this alone would not suffice 
 to explain its oxidising power, compressed oxygen possessing no in- 
 creased energy at the ordinary temperature. Of. also Ber. D. Oh em. 
 Ges. 23, 290 and 677, where I fiist gave the above explanation of the 
 katalytic action of platinum black. 
 
THE CHEMICAL ACTIVITY OF LIVING CELLS. 91 
 
 The katalytic powers of platinum-black are clearly o£ a 
 very inferior character, compared with the faculties of 
 living protoplasm, — but iu regard to simpler reactions a 
 parallelism can nevertheless be shown to exist, of which I 
 here adduce some further proof. One of tlie most general 
 synthetic processes is the formation of fat from glucose 
 in living cells, a. process consisting in condensation and 
 reduction : 
 
 (stearic acid) 
 CdUis06 + 4H = 2G3H803 
 
 (glycerol) 
 
 The remarkable transformatio.n of sugar into the higher 
 fatty acids has thus far not yet been imitated by katalysis, 
 but we can at least obtain lower fatty acids of rancid 
 odour if we mix a diluted glucose solution with, about half 
 its weight of very actiAc platinum-black ; the odour will 
 be perceptible after several hours and increase gradually. 
 The main action, of course, is a direct oxidation, but 
 simultaneously a reduction is going on in other molecules 
 which yield up a part of their oxygen also to glucose.' 
 Platinum-black deprived of its absorbed oxygen in one 
 way or other, is less active in this regard.^ The rancid 
 smell is not noticed if we boil the mixture of sugar solution 
 and platinum black in presence of some sodium or calcium 
 carbonate, and acidulate afterwards. 
 
 Another process, hitherto unexplained, is the easy 
 
 (1) O. Loeio, Bev. Dentsdi. Chem. Ges., 23, 863. 
 
 (2) Also presence of chlorides interferes very mucli with its activity. 
 'Xliis miiy be restored by treatment with alkalis and exposure to air 
 after wasliing. 
 
92 THE CHEMICAL ACTIVITY OF LIVING CELLS. 
 
 reduction of nitrates to ammonia in the formation of 
 proteids. As there exists no na=cent hydrogen in the 
 living cells, I have long entertained the view that glucose 
 under tlie Icatalytic influence of the living protoplasm 
 would be the reducing agent, and have now succeeded in 
 imitating that reduction bj' means of platinum-black, even 
 at the ordinary temperature. If 50 cc. of a mixture of a 
 five to ten per cent, glucose solution with two per cent, 
 calcium nitrate and 10 g. platinum-black is left to stand 
 for five days in a closed flask, wc observe upon super- 
 saturation with potassa a strong ammoniacal odour, 
 while in a control experiment without the platinum no 
 trace is observable.' If we modify'- the experiment by 
 increasing the amount of the nitrate to three times that of 
 the sugar, we find on heating that the acid reaction 
 generated at first, soon diminishes and finally gives way 
 to an alkaline one, and then the ammonia previously 
 formed becomes very perceptible by its odour.^ The 
 platinum-black imparts to the hydrogen atoms of the 
 glucose molecules motion, thereby loosening the existing 
 affinities, and awakening others ; this leads to an exchange 
 of oxygen and hydrogen between the nitrate and the 
 sugar. 
 
 Jn a similar way, chlorates can be reduced to chlorides 
 katalytically; sulphates however resist and evidently require 
 more energy ; but at least with a certain sulpho-acid, the 
 combination of form-aldehyde with acid sodium sulphite, 
 
 (1) other experhmeuts lu-ovo beyond doiibt that only the phitinum- 
 black itself and not any oxidation product or bacterial action is the cause of 
 the formation of amniouia. 
 
 (2) If the mixture is rendered .ilkaline hefore the platinum-black is 
 added, no ammonia will he produced, n result Hliieh finds its explanation 
 in what has been nientiuncd above. 
 
THE CHEMIC.Vr. ACTIVITV OF IJVIN'G -CliCJ.S. $3 
 
 I succeeded iu effecting I'eduction ; for this, in presence 
 of some sodium carbonate, yields bj moderately heating 
 with platinum-black, small quantities of sodium sulphide,' 
 while the odour of moth}-! mercaptan becomes per- 
 ceptible. 
 
 The katalytic action of platinum- black is manifested 
 in still another cose of physiological interest. If moisten- 
 ed witli pure potassa and exposed to air it forms 
 from nitrogen and water nitrous acid and ammonia to a 
 small extent.^ Such a process may take place when 
 nitrogen is assanilated by leguminous plants whose roots 
 have entered into symbiosis with certain bacteria. The 
 reverse process can also be katalytically accomplished ;' 
 for a neutral solution of ammonium nitrite, which is only 
 decomposed by application of heat, will in presence of 
 platinum-black show a continuous development of nitrogen 
 at the ordinary temperature. A mixture of 6 g. am- 
 monium sulphate with its equivalent quantity of potassium 
 nitrite dissolved in 130 cc. water developed after addition 
 of 20 g. platinum-black in 24 hours ] 91 co. nitrogen, and 
 in 5 days as much as 768 cc, at 15° and 723 mm. 
 barometric pressure. A similar process takes place in 
 cases of putrefaction when nitrates are present, where the 
 protoplasm of the bacteria acts upon the ammonium 
 nitrite formed and liberates nitrogen. 
 
 To repeat : in all katalytic actions the platinum-hlack 
 remains exactly what it was ; it does not act by virtue of 
 any chemical affinities, but only by a specific mode of 
 
 (1) We might express this result by tlie following equntion: 
 2CHjOH.S03Na + 4Na2C03=Nn2S + S03Na2 + HCOONa + 5NaHC03 
 
 Cf. O. Zoew, Ber. Ueutsoli. Chera. Ges., 2a, 3125. 
 
 (2) O. Zoew, ibid., 23, 1413. 
 
 (3) O. Loeui, ibid., 3019. 
 
94 THE CHEMICAL ACTIVITY OF LIVING CELLS. 
 
 motion. Analogous to this is the action of living pro^ 
 ioplasm ; it remains what it is while it produces various 
 chemical transformations. If it acted hy virtue of chemical 
 affiniiies, it would itself undergo a change, and that would 
 mean death, when that change amotintod to more than 
 slight traces in the unit of time. 
 
 Affinities in the protoplasm, however, come into con- 
 sideration, when certain compounds become attached 
 which thus must yield easily to the katalytic influence, 
 i.e •, to the impacts of th,e protoplasm. 
 
 The ])eculiar energy, then, so well adapted to do 
 chemical work must be a function of the chemical lability 
 of the living matter. "We have, in the foregoing chapter, 
 explained this lability as due to a specifio atomic motion. 
 This is perpetually being communicated to atoms of those 
 substances that enter into the protoplasm changing thereby 
 the existing affinities in them. The result depends upon 
 different conditions : 
 
 1. The intensity which the oscillations of the labile 
 atoms in the living matter have assumed under the in- 
 fluence of the heat of respiration ■ 
 
 2. Tlae specific tectonic of the protoplasm ; 
 
 3. The degree of chemical resistance offered by the 
 entering compound, and the presence of certain other 
 substances which may readily enter into action under the 
 influence of the living protoplasm. 
 
 The power connected with the chemical constitution of 
 the plasma proteids not only plays the part of a liberating 
 energy but also may, supported by heat energy, or by 
 radiant energy, lead to accumulation of potential energy ; 
 in other words : the liatalytic actions of living cells may 
 be either exothermic or endothermic. Stohmann {I.e.), 
 
THE CHEMICAL ACTIVITY OF LIVING CELLS. 95 
 
 however, distinguishes between katalytic and synthetic 
 processes. In the former energy is liberated, in the latter 
 it is absorbed, and passes from the kinetio into the 
 potential mode. According to this definition the produc- 
 tion of protoplasm from the proteids of the food, or the 
 production of fat, starch, or glycogen from sugar, or that 
 of carbohydrates from carbonic acid in the green plants 
 would not be hatalytic processes proper. But, I think, 
 this distinction would only complicate the understanding, 
 without any real advantage being gained. Besides, the 
 explanation I have given, is not in contradiction with the 
 laws of Energy. 
 
CHAPTER VII r. 
 
 THEORY OF RKSPIRATION. 
 
 The living organism has frequently been compared with 
 a machine using coal ; in both cases a liberation of energy 
 by oxidation and its application for various useful per- 
 formances are accomplished. This comparison, however, is 
 only admissible within a very narrow compass, since the 
 diflferenco becomes great with an increased supply of 
 oxygen. Then, the coal will burn with much greater 
 vigour, whilst respiration will not be intensified, because 
 the amount of oxygen needed is regulated by the living 
 cell {PiJiiger). 
 
 The respiratory intensity not only exhibits great 
 differences in various species of organisms'; but also 
 in different organs of one and the same organism. 
 
 The intensity is greater in flowers tliaa in leaves and 
 roots,^ greater in leaves than in stem and fruits {Saussure), 
 
 (l)_ To-day it seems hardly ci'edible that Liehig still iiiMiiitaiiied that 
 chlorophyll-bearing plants will not carry on respiration, althongli Saussure 
 had positively proved to the contrary as early as 1805 ! Anotlier 
 erroneous conception, vi7. , tliat the blood is the principal seat of 
 respiratory oxidation in animals was corrected in tlie year 1868 by Pfliiger, 
 who has recently told ns what enormous labour for years it took him to 
 convince iiliysiolngists of the truth that 0'.idations iu animals are 
 accomplisiit'd by the cells of tlie various organs. 
 
 (2) Tlie root-ends of young ]>lants of Vicia Faha consume in 24 hours 5 
 per cent, of Iheir dry matter {Palladin). Young rootlets and especially 
 root-liairs have an energetic respii-ation , while the interior of large roots 
 respires certainly much less than leaves. Not only the restricted access 
 of air but also the lower temperature to which usually roots are exposed 
 at some depth in the soil, will under ordinai-y conditions lower the intensity 
 of respiration. 
 
THEORY OF RESPIRATION. 97 
 
 greater in light-plants than in shade-plants (Adolf Mayer), 
 greater in shoots of oil-seeds than in those of starch-seeds 
 {Godlewsld), greater in air-plants than in hydrophytes 
 (Bcehm), double in the cat what it is in the sheep 
 [Mitnck), 
 
 AVhile increase of pressure of oxygen will not influence 
 the intensity of respiration, the effect of rising temperature 
 is, on the other hand, very considerable, the activity of 
 the protoplasm being thereby greatly enhanced. At 0° 
 the respiration of plants is very slight, at 17-20° it is 
 already twenty times more intense (Kreusler), and still 
 gradually increases with the temperature nearly up to 
 that of death. Cold-blooded aTiimals respire less than 
 warm-blooded,' while animals in hybernation exhil'it a 
 lower temperature and respire less than those in activity. 
 
 Heat, visible motion, chemical action, and, in certain 
 cases, electrical phenomena and liglit are the forms of 
 energy resulting. 
 
 Even the finest currents in tlie protoplasm depend upon 
 the presence of oxygen, as Kiihne has shown, and tlie 
 increased work connected with a rapid development of 
 shoots and embiyos, or with tlie transportation of starcli in 
 plants, requires also an increase of respiration. This 
 holds good also foi- every increase of muscular exertion. 
 The work done by a muscle corresponds to about 33 
 
 (I) The intensity in frogs and earthworms is only about one tenth that 
 in the dogj that of higher plants is generally found loss than that of 
 warm-blooded animals, in many cases also less than that of cold-blooded, 
 if equal weights of dr^ matter are considered. It is in sprouting peas 
 about one half that of the frog, while in well nourished mould fungi it 
 much surpasses even that of mammalia. — Increase of ninrogeuous 
 manure intensifies the respiration of plants (//. Miiller). Infection with 
 Feronospora increases it in the potato plnnt {Boehw). 
 
98 THEOKY OF RESPIRATIOX. 
 
 per cent, of tlie energy yielded by respiration {Zuntz), 
 while in a steam-engine only 10 per cent, of the caloric 
 value is secured in the form of work.' 
 
 The function of respiration, however, consists not mei'ely 
 in yielding kinetic energy ; it serves also to prepare 
 useful oxidation products, as carbohydrates fi-om fats in 
 plants,^ and it. helps to prepare from different materials 
 the necessary starting groups for proteid formation (cf. 
 Chapter IV). 
 
 Besides, not all organisms produce their physiological 
 energy by respiration ; the fermentative organisms gain it 
 without the aid of oxygen, by decomposition of organic 
 matter.' Bacteria can utilise various hydroxy-acids, 
 
 (1) Bumford remarked, long since, that a ton of Iiay wonlil be administer- 
 ed more economically by feeding a horse with it, and then getting work out 
 of the liorso, than by burning it as fuel in an engine. 
 
 (2) The |onnatiou of organic acids is also dne to respiration, viz., to an 
 imperfect oxidation of sugar in most cases. An interesting example is 
 finnished by the flowers of Ipomcea triloba, which aie hltie in the morning 
 and remain so during cold, frggy, and rainy days, but turn red on warm 
 bright diys. Since this change from blue to red can also be easily accom- 
 plished by organic acids, wo must assume that the increased respiration on 
 warm days onuses the production of such acids. 
 
 (3) The fact that bacteria can bo d';privcd of their formenlaiice faculties, 
 without their life being impaired and thus be turned from anaerobs into 
 obligate aerobs, has led me to the view, that thei-e exists a special organoid 
 in those organisms endowed with the function of fernientati in. This 
 would, to a oertaii degree, be analogous to the chloroplast of gi-eeii plants ; 
 the latter prepares suitable material for growth from carbonic acid, while 
 the former prepares it by decomposing various organic matters. A small 
 fraction of these fermenting compounds does not appear in the form of 
 fermentation products, but in parts of new cells of the fermenting organism. 
 We see, therefore, here also, as in respiration of plant cells, a double parj 
 played, viz., that of liberating energy nnd that of preparing the necessary 
 groups for proteid formation. Cf. O. Loeio, Oentralbl. f. Baeteriol.,9,Nr. 22. 
 
THEORY OF RESPIKATJON. 99 
 
 proteids, sugars, and i)olyvalent alcohols, while the yeasts 
 utilise certain kinds of sugar only. This so-called 
 intramolecular renpiration yields, ceteris paribus, less energy 
 than the normal. Certain animals can, for a limited time, 
 also subsist on intramolecular respiration, as Pfliiger has 
 obsei'ved in frogs, and Bimge in worms.' 
 
 The views propounded by various authors as to the 
 cause of respii'ation exiiibit considerable discrepancy. 
 The oldest hj^pothesis, that of Schonbein, assumjng the 
 formation of ozone, had soon to be discarded.' But 
 nevertheless, the idea that common oxygen had to be 
 changed into an active form or modification before it could 
 unite with the compounds in the cell, prevailed also in the 
 other theories. The supposed activifying process con- 
 sisted in the splitting of the oxj'gen molecule into its two 
 atoms with free affinities. Hoppe-Seyler supposed that 
 tlie living cells jDroduce hydrogen, which in its nascent 
 state accomplishes the ' activifying ' process by com- 
 bining with one of, the atoms and setting the other 
 free. But it was objected that hvdrogen ought to make 
 its ajipearance at the moment oxygen is being withdrawn. 
 Now, germinating seeds can remain one day, certain 
 worms {Ascaris) even 5-7 days, alive in absence of 
 oxygen, but no trace of hydrogen is evolved by these 
 oi'ganisms during that time.' 
 
 (1) With insufficiency of oxygen, animals will show albumin, glucose, 
 and lactic acid in the uvine {Araki), also an increase of oxalic acid 
 {JReale and Soeri). 
 
 (2) Xiebig never discussed tlio singular fact that cai boh jdrates and 
 fats are oxidised so easily in the living orgnnisni, while they are so 
 indifferent to the common oxygon outside of it. 
 
 (3) if. Traiibe contends, moreover, that nascent hydrogen can 
 not activify oxygen; it can merely produce hydrogen peroside. 
 
100 THEORY OF RESPIRATION. 
 
 Reinlee holds that there exist in the living cells easily 
 oxidisable organic matters, ' autoxidisers,' which are capable 
 of sutEering oxidation in contact with molecular oxjgen, 
 so as to produfio hydrogen peroxide, which under the 
 inflaonco of enzymes brings about powerful oxida- 
 tions.' But Reinke omitted to prove that the supposed 
 ' autoxidisers ' arc really capable of inducing oxi- 
 dations of sugar or fat, while, as regards the peroxide, its 
 absence in plant-cells has been proved by Th. Bokorny^ and 
 by W. Pfeffer? Neither couid it be discovered in animal 
 cells. Reinke s view, moreover, could not explain how 
 respiration, throughout such a wide range, is independent 
 of the amount of oxygen present, an objection already 
 raised by Pfefer. But that there exist in many plants 
 easily oxidisable compounds is correct, since many plant- 
 juices acquire soon a reddish or brown coloration, if 
 exposed to air. As the ' autoxidisers ' of lieinke, however, 
 are neither present in all plants, nor in animals, this 
 theo]-y cannot be admissible. 
 
 The theory of I'raiibe* assumes the existence of oxidising 
 enxymes, wjiich would act as transporters of oxygen, 
 somewhat like nitric oxide in the manufacture of sulphuric 
 ac!d.^ The occurrence of such enzymes was not proved 
 
 (1) Botan. Zeitg., 1883. Kr. Sand 6. 
 
 (2) Ber. Deutscli. Cliem. Ge*., 21, 1100 and 184*. Prhigsli. Jahib., 
 17, 317. 
 
 (3) Ber. Saclis. Akad. (!. Wiss., 1889. The recent assertion of Bach was 
 shown by Cho, to bo again crroneons. 
 
 (4) Theoris der I'ermentwirkungen, Berhn, 1858. Tirch. Arch., 21 
 386. Ber. 1). Clicm. Ges., 10, 984. 
 
 (5) Analogous processes are the oxidation'of aniline by a slight trace of 
 ammonium vanadate (Bull. see. chini., 45, 309), or the oxidation of nitro- 
 genous compounds when added to a solution of oxide of copper in ammoiiia 
 exposed to air {Loew, Z. Bii-l., 1S78; Journ. f. prakt. Chem., 1878). 
 
THEORY OF RESPIRATION. 101 
 
 by Tranhe, but lias recently been demonstrated by llerlrand 
 and others.' Tliese enzymes are the cause of the colouring 
 of ihe juices of many plants when easily oxidisable 
 matters are present, as in potatoes, in the roots of Dmicus, 
 Beta, Lactuca, and Taraxacum. Among the algae Zygnema 
 may be mentioned, whose fresh juice turns black, and 
 among the fungi Boletus luridus, whose freshly cut surface 
 turns blue in contact with air.' ]f, however, oxidising 
 enzymes ai'e present ■mhore easily oxidisable compounds 
 are n-anting, then the existence of the former can be 
 shown by adding guaiacum solution or liydroquinol, ca- 
 techol, or pyrogallol. Guaiacum will yield a blue colour, 
 the latter a brown or black one. Schonbein observed this 
 blue reaction in various seeds, and especially well in those 
 of Gunara f Molisch in the secretions of various roots, as 
 those of Pisum, Brassica, Gucurhita, Lepidlum, Scorzonera 
 and Neottia.* 
 
 (1) A year before Serirand published his observations, tliteir existence 
 was positively proved by Toyanaga in the laboratory of the College of 
 Agi-icultnre of the Imp. Univereity in 'J'okyo. 
 
 (2) Also the Ciimbial sap of the conifers turns gradually brown in 
 contact with air. The turning brown of blossoms and green leaves 
 which sets in after death, belongs to the same group of phenomena. 
 
 (3) Journ. prakt. Cheni., 88 and 105; Gme^iii-KraiU, I. 2. p. 456. 
 Schonbein had also observed that these oxidising effects of plant-juices 
 are not met with in presence of ferrous salts or prussie acid. Pfsffer had 
 surmised that oxidising enzymes are contained in the cytoplasm, while 
 the oxidisable compounds that give rise to various colorations after death , 
 lire accumulated in the vacuole, which explains why these colorations are 
 not noticed as long as the cells are alive. 
 
 (4) E. SclnSne (Z. analyt. Chem., 33, 159) obseived that old guaiacum 
 tincture yields a greenish blue coloration with diastase alone; fresJi 
 tinctnre, however, wants the addition of hydrogen pei'oxide. The sub- 
 stance yielding the bine product is guaiaconic acid, C20 ^^24 Oj (Ijiiclicr).^ 
 Sencii observed u blue coloration of guaiacum tincture upon addition of 
 benzaldeliyde (Journ. prakt. Chom., 26, 25). 
 
102 THEORY OF RESPIRATION. 
 
 I observed, many years ago, that an enzyme-like 
 compound of proteid nature can be precipitated from 
 potato juice by alcohol, which loses its property of 
 blackening hydroquinol upon drying in the exsiccator. 
 
 Toyanaga determined the temperature at which the 
 potato lost its ))eouliar action upon hydroquinol, pyi"o- 
 gallol, aad catechol, and found it to be 73°, Mercuric 
 chloride destroyed that property at 55° in one hour, formic 
 aldehyde (5%) after two days standing, almost completely; 
 dilute sulphuric acid and caustic potash acted in the 
 same way, so that there can be hardly any doubt that the 
 active principle is an enzyme. 
 
 Oxidising enzymes appear to be present also in the 
 animal body. Saliva produces a blue colour with Wurs- 
 ter's reagent (tetrametbyl-paraphenylene-diamine), a fact 
 erroneously taken to be a proof of the presence of 
 hydi-ogen peroxide ; it produces further a brown colora- 
 tion with hydroquinol. K Salhowsld found in the 
 blood, Schmiedeberg, Jaquet, and also Yamagiwa in 
 the lungs, kidneys, and mi^sJes, enzyme-like agencies, 
 capable of producing small quantities of benzoic acid 
 from benzyl alcohol and of salicylic acid from its 
 aldehyde.' That the juice of fresh liver, also pus and 
 milk, colour guaiacum tincture blue and that milk heated 
 to 80° has lost this property, are old observations. 
 
 Such oxidations by enzymes are always of a very narrow 
 compass and appear to be limited to certain benzene 
 derivatives; nobody has ever observed that they could 
 attack sugar or fat, to say nothing of bringing on a 
 complete combustion. The theory of Trnube has therefore 
 
 (1) Jahresl). f. Tluerohem., 22, 387. Also Rohmann and Spitzer, 
 lier. Oheni. Ges., 28, 567. 
 
THEORY OK RESPIRATION-. 108 
 
 also to be rejected as being quite insufficient to account for 
 most of the great and varied changes which constitute the 
 phenomena of repiration. 
 
 Most of the phj Biologists of the present day still cling 
 to the idea that oxygen is activificd in one way or other. 
 But such a modification of oxygen as would he capable to 
 completely burn up sugar or fat would certainly kill the 
 protoplasm instead of serving the office of respiration. We 
 know that the protoplasm is an exceedingly subtle body 
 which is very easily killed by oxidising agencies as e.g., 
 bv hydrogen peroxide or potassium permanganate. 
 
 It appears singular that just the most important con- 
 dition for respiration, i.e., the living state of the protoplasm 
 has been ignored. Taking a plain chemical start and leaving 
 physiology aside, these physiologists have endeavoured to 
 reach a satisfactory explanation, biased by the idea that the 
 albuminous compounds the chemist studies in his vials are 
 the same as those composing living matter. , This er- 
 roneous conception still governs the minds of many, and 
 b}- tliem respiration will never be comprehended. Pfliiger 
 was the first who dissented from the general opinion, and 
 declared that " not the oxygen is activified but the pro- 
 teids of the living protoplasm have tl)e activitj'." 
 
 Eespiration exhibits, like the oxidations by various 
 agents,' its own specific oxidising action. An animal 
 capable of oxidising in 24 hours several hundred grams of 
 stai'ch (sugar) completely to cai'bon dioxide and water,' is 
 
 (\) Potassium permangaQate, nitrons acid, hypoclilorites, hyilrogen per- 
 oxide, leiul peroxide, silver oxide, Imve all a spnoific oxidising action. Tlie 
 results nmy be modified by relatively small changes in the mi.lecides to be 
 oxidised, as by the introduction of an acidic or alkylic radical. 
 
 (2) The question as to the intermediary products is of relatively small 
 importance. The foi-matioii of glucuronic acid in animals shows that to a 
 very small extent acids are produced, but formic and oxalic acids are 
 eertalidy only formed in insignificant qnantitie?. 
 
lO-i THEORY OF RESPIRATION. 
 
 unable to burn up a few grams of oxalic or formic acid.' 
 It is even unable to oxidise 1 g. of benzene completely to 
 phenol. And while it destroys tyrosine, quinaldine, and 
 pyrrol, it attacks with difficulty hydroquinol, phe- 
 jiylacetic acid, or naphthoic acid. 
 
 A series of investigations by Nenclci, Mering, Baumann, 
 Salkou-sld, and othei's, led to the recognition that certain 
 compounds reappear in the urine unchanged, such ns 
 benzidine ; others in combination with sulphuric acid, as 
 phenol ; others again (partially oxidised or not) as deriva- 
 tives of glycocoll, like piooline or benzoic acid ; or of 
 glucuronic acid, as tertiary alcohols and thymol ; they 
 may also be transformed into uramido-compounds like 
 sulplianilic acid, or taurine. The Literal chains of aromatic 
 ketones are oxidised to carboxyl, if the benzene ring does 
 not contain a hydroxyl-gronp, otherwise the entire com- 
 pound will reappear in combination with sulphuric or 
 glucurooic acid in the urine, with the lateral chain pre- 
 served (Nenclci). Some sulphur compounds will yield 
 sulphuric acid, while others will not.^ 
 
 It is, further, of great interest that the oxidation of 
 benzene to phenol and to small quantities of catechol 
 and hydroquinol in . the animal body [Nenclci and 
 Giacosa) is diminished by the introduction of certain 
 poisons.^ 
 
 (1) Soiliuni oxiJate in i:oii-k'tliiil doses reappears in the urine vvith a 
 loss of only 7 per cent (Gff^/)'o). Sodium formate reappears to the extent 
 of 50 to 70 per cent, of the dose-in the urine [Grehant and Quinquaud), 
 
 (2) Ooniponnds of the genend formula NHg — CO — S— It easily yield 
 sulpliuric acid ; tliiopliene or snlplional do not (Siiiiti). 
 
 (3) Nenci:!. umi Sieber [PJlUg. Arch., 31, 319J. found e.g., that while in 
 the body of a healthy man 0"82 g. plienol was formed from 2 g. benzene, 
 under normal conditions, oidy 0'33 g. was formed if 2 g. ethyl alcohol per 
 kilo of body-weight were administered at the snme time. By various 
 conditions the pliysiological oxid ition in anim:ds m.iy also be increased, 
 as Tfiilger, Foehl, Jacksc'i and others have shown. 
 
THKORY OF RESPIKATIOy. 105 
 
 Tlie difficulty in completely oxidising benzene deriva- 
 tives of a certain constitution is not only encountered in 
 the animal but also in the vegetal organism. Many 
 phsenogams accumulate tannins without utilising theni 
 again under ordinary ccmditions; neither do certain 
 alkaloids undergo further metamorphosis.' It is, further, 
 very characteristic of the oxidising faculties of plant-cells 
 that certain compotmds are left unchanged, which, even by 
 such a comparatively weak oxidising agent as hydrogen 
 peroxide, are attacked readily. Thus, it was observed by 
 Pfeffer that cyanine (a quinoliue derivative), introduced 
 into plantcells, is not altered, while it is easily bleached 
 by the peroxide. Also certain compounds in the roots 
 of Vida and of Trianea Bogotensis are easily converted 
 into brown oxidation products by it, while they remain 
 colourless during their stay in normal cells.^ 
 
 How weak tiie oxidising power of the cells appears to 
 be here, and then how energetic when sugar conjes under 
 action ! AVe search the entire domain of chemistry in 
 vain for a single case of complete combustion of an organic 
 compound in aqneoits solution by the oxygen of the air. 
 However, there exist cases where partial oxidations by 
 molecular oxygen can easily take place. I may mention the 
 transform;ition of aldehydes into acids, of hydrazo-benzene 
 to azobenzene, of indigo-white into indigo-blue. Also llie 
 behaviour of bibrom-ethylene, anthrahydroquinol, oxindol, 
 and paramidophenol to common oxygen may be cited. Cer- 
 tain compounds become active upon molecular oxygen 
 
 (1) Cf. the investigations of I-ea Errera, Maistriav, and Clautriau, 
 especially tlioso of the latter in the Bulletin Beige de Microscopie, 189-1. 
 
 (2) Ber. Sachs. Akad. d. Wiss., 1889, p. 493. nie-se observations 
 likewise proved the absence of H2O2 in plant-cells. 
 
106 THEORY OF RESPIRATION. 
 
 through the presence of an alkali, as pyrogallol, pyrogal- 
 loquinol, cbrysarobin, fnroin,' while benzene does so in 
 the presence of aluminium chloride. In all these cases 
 it is a state of lability^ that leads to oxidation, a condition 
 that can be either directly connected with the constitution 
 of the compound or can be imparted. The latter case 
 has evidently to be assumed when we observe that such 
 relatively stable compounds' as sugar, fatty acids, and 
 amido-acids easily undergo combustion in contact with 
 living protoplasm. 
 
 It is* the CLIj-group in the fatty, acids and amido-acids 
 and the CH Oli-group in ketoses, aldoses, and hydroxylat- 
 ed acids that are most easily attacked in tlie living cells. 
 The oarboxyl-grojp renders the ClIOH-group in a 
 molecule much more easily attackable than does the 
 alcoholic group CH2 Oil. Thus, we see tliat glycerol and 
 mannitol are (at least in the animalj by no means easily 
 oxidised^ while, e.g., tartaric acid is. The influence of 
 the carboxyl-group also becomes evident when we com- 
 pare the bibasic phthalic acid with the monobasic benzoic 
 acid ; the latter resists while the former is for the greater 
 part burned up. 
 
 (1) A preliminary ' activifying ' of oxjgoii takes place here just ai 
 little as in living protoplasm . 
 
 (2) Lability o£ hylrogen linked to carbon may be of two kinds: one 
 wliich detei-mines its easy exchange by certain metals, as in acetylene; the 
 other which causes its increased affinity for oxygen , as in aldehydes. In 
 regard to the first kind, it may be mentioned that throe nitro-groups have (in 
 trinitromethane) tlie same effect as two carboxylgronps (in malonic ether), 
 (Ctaisen). — A high degree of lability is connected with the hydrogen in 
 diamidogen, which absorbs moleculiir oxygen with liberation of nitroyen 
 {Lohry de IBruyn). 
 
 (3) Nenchi and Sieber have tried to determine the extent of oxidation 
 which sugar and albumin can undergo, when exposed at 36° in alkaline 
 solution to air, and have found it to be very slight. 
 
THEORY OF RESPIRATION. 107 
 
 That in the animal the amido-acids (leucine, glycocoll, 
 tyrosine) undergo combustion witli especial facility,' yield- 
 ing thereby urea, was demonstrated by Nencki and 
 SchuUzen, as early as 1872. Nenclci declared, therefore, 
 the amido-compounds to he the forerunners of urea. Tliis 
 view, which does not assume a direct oxidation of dissolved 
 proteids, but a previous splitting into a group of well 
 known amido-acids, is very well supported by observations 
 of Hofmeider, which prove with what difficulty peptone, 
 as such, is oxidised in the living animal.^ A rabbit of 
 1'75 kilo, discliarged, after intravenous injection of 0"318g. 
 peptone, over 80 per cent, of it again in the urine, and 
 after subcutaneous injection about 66 per cent. 
 
 The oxidation caused by living protoplasm exhibits 
 evidently great analogy to that instigated by platinum 
 black, which renders alcohol molecules so labile that 
 oxygen is readily taken up with production of aldehyde 
 and acid. This property of platinum black cannot be 
 due to a special chemical activity of the absorbed oxygen, 
 
 (1) The ainido-acids from proteids are even more quickly oxidised in tlie 
 cells than the carbohydrates, as must be concluded from investigations 
 by Kumagmoa, wlio nourished dogs with an excess of lean meat and 
 observed that under this condition the glycogen of the meat was 
 deposited as fat in the animal (Mittheilungen der medic. Facultat 
 Tokyo. 189J). It is, moreover, of great interest to obsei-ve how the 
 production of nrea is influenced by chemical constitution : negative 
 groups connected with the nitrogen will prevent the formation of urea, 
 lis Nenciii has shown with acetamide, recallinj!: the resistance of hippuric 
 acid, ^^lt taurine and s;irkosine are also oxidised with difficulty, reuppear- 
 ing as uraraido-componnds iu the urine (^Salliowsii). 
 
 (2) It may be mentioned that while hydrogen peroxide or platinum 
 black has hardly any oxidising action upon peptone, this is very easily 
 attacked if its solution in amnioniacal solution of copper hydroxide is 
 exposed to air. A moderate amount of oxalic acid is hereby produced 
 (ioejo, Z. Kiol., 1878, p. 29 tj. 
 
108 THEORY OF RESPIKATION. 
 
 since moder.itely comprexsei oxygen has, at tlie ordinary 
 temperature, no special chemical action. Nor can the 
 assumption be sustained tlmt platinum black can transform 
 oxygen into an fictive modification, for we know how 
 easily it transforms, on the cpntraiy, ozone into indifferent 
 oxygen. Oxidations by protoplasm,' as well as by 
 platinum-black, have to be looked upon as hatalytic 
 oxidations^ i.e., as oxidations caused hy imptuting a .ipecific 
 energy. 
 
 1'he view here taken as to the cause of respiration, 
 corresponds in its principal feature to the definition Ndgeli 
 gives of oxidising fermentation.' This author says :. " the 
 specific state of motion in living protoplasm of the 
 bactei'ia is extended simultaneously to the alcohol and to 
 the oxygen molecules. If, thus, the equilibrium is 
 disturbed to a certain extent, chemical change takes place 
 by aid of chemical affinities." This theory, however, is 
 still imperfect, as it does not show, how the ' specific state 
 of motion ' in the protoplasm is caused, and does not 
 define, whether it consists of a molecular or of an atomic mo- 
 tion.' It is the chemical difference between the proteid:= of 
 
 (1) How little the protoplasm itself in presence of much sugar undergoes 
 the oxidsitiim process may be illustrated by the fact that in special cases 
 95 per cent, of the mater osidised m.ty be sugar and only 5 per cent, proteids; 
 in bees the percentage of the latter oxidised is still less. 
 
 (2) The old supposition of TAeblg that the proteids of the fond are 
 transformed first into living matter and as such decomposed and yield 
 urea has beon revived of late, but it cau only to a certain extent be correct. 
 
 (3) Theorie der Garimg, p. ^3. 
 
 (4) NcigeH published his " Tliorie der Giirung" in the year 1879. 
 After that time I often had discussions with him concerning the difference 
 between living and dcnd protoplasm, which ho had taken for a physical 
 and anatomical one. Later on, however, he agreed that there must exist a 
 chemical difference. \ageli's fermentation theory differs considerably from 
 that of Liebig. Cf. his " Theorie der Garnng" p. 26. 
 
THEORY OF KESPIKATIOX. 109 
 
 living and those of dead protoplasm which furnishes the key 
 to the ' specific state of motion ' which is caused by atoms 
 in labile positions. 
 
 As the force of cohesion is counteracted by heat 
 energy, so the atomic cohesion, i.e., the affinities in a 
 molecule, are overcome by plasrnic energy. Increased 
 molecular motion (heat) can, at a certain temperature, 
 partially pass into atomic motion, leading thereby to 
 combustion ; ' plasmic enei-gy however, accomplishes 
 the same result at a much lower temperature, b}- 
 by driving the atoms asunder against the force of affinity. 
 In otlier words, the chemical affinities existing between 
 the atoms in molecules of sugar, or fatty acids,^ or 
 amido-acids constitute a resistance that tlie charge of 
 kinetic energy derived from living particles can easily 
 over^jome, thus inducing the union with oxygen, normal 
 respiration . 
 
 But if molecular oxygen is absent, then such ' activifi- 
 ed ' sugar molecules will undergo other changes, with the 
 production of fat, lactic acid, or alcohol ; these processes 
 are accompanied by a development of carbon dioxide, and 
 have received tire name, intramolecular respiration.^ 
 
 (1) A previous activifying of thu oxygen is here never noticed, for 
 tlie small amount of ozone formed by rapid eonib'.istion under certain 
 ciremnstances is only a by-product. The oxygen-niclecul is split in the 
 moHieut of combining. 
 
 (2) Fats, as such, ran hardly serve for respiration, not being soluble in 
 aqueous fluids. It was thei'efore supposed that a previous saponification 
 is necessai'y. It is, however, much more probable that a conversion of the 
 neutral fats into lecithin takes pLice, which swells up easily in water and 
 is even a little soluble in it. Cf. O. Loew, Ou the physiological functions 
 of phosphoric acid, Biol. 0., 11, 270. 
 
 (3) The view of several authors that the so-called intramolecular 
 respiration is the primary cause of nonv.al respiration has been refuted 
 as erroneous by Sachs, Viaionow, GodUivski, and others. 
 
110 THEORY OF KESPIRATION. 
 
 If the amount of respiratory fuel decreases, the intensity 
 of respiration will diminish also, and, finally, the active 
 proteids of the living protoplasm will, on account of their 
 lability, themselves take up oxygen. And if in a cell a 
 small amount of protoplasm has thus been changed, the 
 equilibrium of the entire tectonic will be disturbed and a 
 rapid chemical change will follow : death by starvation. 
 The protoplasm, however, as if endowed with intelligence, 
 understands how to avoid this dangerous result. It 
 absorbs food and instead of itself taking up oxygen, 
 throws it upon the ' activified ' molecules of food and 
 thus derives the greatest profit to itself, the liberated 
 energy being utilised for various vital functions. A great 
 part assumes the form of heat and is dissipated, another 
 serves to increase the original plasmic energy and leads 
 thus to mechanical and chemical performances.' 
 
 But the increased state of lability will lead in turn to 
 an increased respiration, and this, again, to an increased 
 lability. Thus the temperature would continuously rise 
 also, and another dangerous point would be reached : 
 death hy heat, at 45-50°C. The increased motions of the 
 labile atoms would facilitate re-nggregation into stable 
 position, and passage into pasxive proteids by the action of 
 the labile groups upon each other; we may define this death, 
 therefore, as caused by an intramolecular self-poisoning. 
 However, there exist, again, conditions to prevent this 
 result, heat being lost by conduction, by radiation, and, 
 
 (I) It is but natural that all attempts to explain the amoeboid move- 
 ment, or the locomotion of diatoms and swarm-spores on purely mechanical 
 principles, have thus far, proved failures, since the chemical character 
 of the living pi'otoplasm , the energy of lability in tlie proteids composing 
 it, that forms the fundamental condition of contractility, has been entirely 
 disregarded. 
 
THEORY OF RESPIRATION. ~ HI 
 
 further, by evaporation of Avater. Higher animals also 
 enjoy the benefit of regulating contrivances in the nervous 
 system. It is, nevertheless, admirable to see how close 
 the temperature of birds is kept to that dangerous degree 
 ■which, like an abyss, separates life from death. And still 
 more remarkable are tlie few exceptions to the general 
 rule, as observed in cei-tain algae and bacteria, which can 
 remain alive even at temperatures above 90°C.' 
 
 If we now consider again the general teaching that 
 " the potential energy of the food yields the kinetic 
 energies of the organism," we must keep in mind that 
 there is originally present kinetic energy in the living 
 matter, which liberates that potential energy by com- 
 bustion, and that it is the original energy being thus 
 intensified that leads to the vital functions in the various 
 organs and orga)iisms.- 
 
 Orant Allen, in his admirable treatise ' Force and 
 Energy ' gives the following ' Table of kinetic enel'gies" : 
 
 (1) Cf. the interesting iittempt of Davenport and Castle to explain 
 these anomalies. Arch. il. Kntw.-Meclianik, II, 2. (1895). 
 
 (2) There still prevail erroneo;is conceptions on this point among phy- 
 siologists, as may be illustrated by a passage of Ffliiger in his ' Archiv 
 fiir die gesamnito Physiologie,' vol. 10, p. 327; " Die Warms isi also die 
 Vrsache des Lehens und nicht wie man die Sache geipUhnlich nnsieht nur 
 die Folge'' No donbt, the molar, molecular, and chemical activities of the 
 protoplasm are to be accounted for by the transformation of potential 
 energy of the food, but this is not sufficient to justify that sentence of 
 Ffluger, as there must exist a special means — (1) for aocoraplishing the 
 combustion, and (2) for turning the heat to account. Tkis means, as 
 explained above, must also le the first cause of vital activity. 
 
112 
 
 THEORY OF RESPIRATIOX. 
 
 Separative, 
 
 Separative 
 
 molar motion. 
 
 (In a body raised 
 
 from the earth's 
 
 surface). 
 
 Separative 
 
 molecular 
 
 motion. 
 
 (In a body torn 
 
 apart). 
 
 Separative 
 
 atomic motion. 
 
 (In chemical 
 
 decomposition). 
 
 Separative 
 
 electrical 
 
 motion. 
 
 (In an electrical 
 
 machine). 
 
 Aggregative. 
 
 Aggregative 
 
 molar motion, 
 
 (In a falling 
 
 body). 
 
 Aggregative 
 molecnlar 
 motion. 
 (In a body cool- 
 ing), 
 
 Aggregative 
 atcm'.c motion. 
 
 fXn chemical 
 combination). 
 
 Aggregative 
 electrical 
 
 motion, 
 (In lightning). 
 
 Continuous. 
 
 Continuous 
 
 molar motion. 
 
 (In a top or in 
 
 a planet). 
 
 Continuous 
 
 molecular 
 
 motion. 
 
 (Motion in 
 
 heat). 
 
 Continuoits 
 
 atomic motion. 
 U7j'known. 
 
 Continuous 
 electrical 
 motion. 
 
 (In magnet;. 
 
 Now, the energy consisting in continuous atomic motion, 
 
 for which Allen could not cite an example, must be 
 
 identical with that displayed by atoms in labile position. 
 
 The foremost example of such energy is represented by 
 
 PLASMIC ENERGY. 
 
CONCLUSION. 
 
 It may be convenient to the reader to have the leading 
 facts and inferences recapitulated. Our point of departure 
 has been a theory of proteid-formation in plants, which led 
 to a new conception of the chemical character of the pro- 
 teids composing living protoplasm, and thence to inferences 
 that proved to be in perfect accordance with observed 
 facts. Waiving all speculation, I can express these facts 
 in the following sentences : 
 
 1. The transition of living protoplasm into dead pro- 
 toplasm exhibits a far-reaching i-esemblance to the transi- 
 tion of a labile substance into an isomeric stable form by 
 atomic migration. 
 
 2. Compounds that enter easily into reaction with 
 aldehydes are poisonous for all kinds of organisms. Such 
 compounds have no action upon dead protoplasm or upon 
 common proteids. 
 
 3. Compounds that enter easily into reaction with 
 labile amido-groupgave poisonous for all kinds of organisms, 
 but these compounds have an action upon ordinary 
 proteids also, and, therefore, also upon dead protoplasm 
 (cf. Chap. VI). 
 
 4. There exists, widespread in the vegetal kingdom, a 
 highly labile proteid serving as reserve material, which 
 undergoes chemical change by the same influences as those 
 which cause the death of tlie cells (cf. Ch;,p. V). 
 
114 CONCLUSION. 
 
 The evidence to be drawn from the information supplied 
 by nature leads to the very same conclusions as those 
 I had already reached by deduction. They are (1) that a 
 great activity, iii the form of oscillations of certain ato^^ 
 in labile position, exists in the proteids of living protopla^p 
 and (2) that this ever active chemical energy, leading to 
 respiration and in turn intensified by it, is especially well 
 adapted to do chemical work, since atoms can be set in 
 motion by others already in motion, just as molecular 
 motion (heat) can be imparted to other molecules, i.e., 
 conveyed by impact. As I fully agree with Huxley^ 
 wlien he says : " it is a favourite popular delusion that the 
 scientific inquirer is under a sort of moral obligation to 
 abstain from going beyond the generalisation of observed 
 facts," I venture to offend against that popular delusion 
 and conclude that the peculiar mode of motion in the 
 lalile proteids is also the source of vital activity. This 
 Energy is the necessary link in the chain of constructive 
 and destructive metabolism. It must, on tlie one hand, 
 help radiant energy to construct carbohydrates from 
 ■carbonic acid in green plants and, on the other, lend its aid 
 ■to burn up carbohydrates, fats, and amido-acids in the 
 respii-ation process. 
 
 However, not only the potential energy of the thermo- 
 genes, but also the hinetic enei'gy of the labile proteids 
 composing the living protoplasm, is, in the long run, but 
 6ne of the vicissitudes of Solar Energy. 
 
 I have not failed to point out that the expression ' living 
 molecules,' used by some authors, is not justified, since 
 every life-action is the result of the working of a complex 
 inachinery. Even the simplest function of a living cell 
 
 (1) The advance of science in tlie lust lialf-ccntury. 
 
co^-CI.usION. 115 
 
 depends upon the proper working of an apparatus, which, 
 in some cases, may be represented by a mere fibre, but 
 which must, even then, be built up of an immense number 
 of molecules. Living particles exist, living molecules do 
 not. To avoid any misunderstanding, I have proposed the 
 name active molecules to designate the condition of the 
 molecules in living matter, and to indicate a distinction 
 between them and other labile proteids, such as enzymes 
 and toxalbumins. 
 
 What I have attempted has not been an explanation of 
 complicated vital ftmctions, but merely that of the nature 
 of the Energy emanating from the proteids of living pro- 
 toplasm. The reader will judge whether the evidence 
 wliich has been adduced suffices to substantiate the- main 
 proposition with which I set out. 
 
CONTENTS. 
 
 Cliapter. I'age. 
 
 I. Views on the Cause of Vital Phenomena i 
 
 II. Characteristics of Protoplasm 9 
 
 III. Proteids and Protoplasm 14 
 
 IV. Theory of the Formation of Albumin in Plant- 
 
 Cells 25 
 
 V. Active Albumin as Reserve-Material in Plants.. 42 
 
 VI. Living Protoplasm and Chemical Lability ... 63 
 
 VII. The Chemical Activity of Living Cells 79 
 
 VIII. Theory of Respiration 96 
 
 Conclusion 113 
 
 — " ^^^^^sSa^.Jfi'''^'^^ 
 
 Printed by Kokubunsha, 
 TOKIO.