TRANSACTIONS OF SECTION B. 633 



led him to the conclusion that the fibrin on which it is made to actcomhines in the 

 first instance with the ferment itself, the latter after the hydration of the fibrin is 

 completed being again set at liberty, and then able to act on fresh quantities of 

 fibrin. Thus, according to AVurtz, the action is found to be the same as that of 

 chemical agents, properly so called, such as sulphuric acid, of which minute quanti- 

 ties may exert a hydrating action in consequence of the transitory formation of 

 compounds which are constantly being produced and again decomposed. 



There is another question referring to these soluble ferments to which in the 

 present state of our knowledge it is impossible to frame a probable answer, -viz., 

 why does it so frequently happen that each ferment exerts a specific action, an 

 action peculiar to itself, this affording in fact, in the absence of any marked chemical 

 characters, the only means by which they can be distinguished one from the other? 

 Why does one ferment act on starch only, while the function of another consists 

 in the hydration of fibrin, that of another in the decomposition of a glucoside, and 

 so on? In accordance with the explanation of Wurtz, we should say that a 

 specific ferment is one capable of combining only with the body on which it is 

 to act, and with no other. I was led to ask this question when engaged in the 

 examination of the colouring matters of Rubin tinctoi'um. The root of this plant, 

 the madder of commerce, contains glucosides, which, though coloured, are quite 

 devoid of tinctorial power. Nature has at the same time placed in the root a 

 peculiar ferment, which, coming into contact with these glucosides at a certain 

 temperature, eflecis their decomposition, splitting them up into glucose and true 

 colouring matters. Now this ferment is a body sui generis and cannot be replaced 

 by any other ferment that I have tried ; its action is specific. Why Nature should 

 have deposited this body in the recesses of the plant for the express purpose of acting 

 on certain glucosides and forming colouring matters, the object of which, so far as 

 the economy of the pla:it is concerned, can only be guessed at, is difficult to under- 

 stand. One is inclined in such a cas3 to revert to the old-fashioned doctrine that 

 some natural processes were devised for the use and delectation of man. It is 

 quite certain in the case of madder that had it not been for its peculiar ferment 

 erythrozjTn, the valuable tinctorial properties of the root, which liave for centuries 

 been applied in the Production of that splendid dye Turkey red, would have 

 remained iRiknown perhaps to the present day, since the only efficient substitute 

 for the natural fermfnt is a strong mineral acid, and such acids and their uses 

 were unknown in former days. 



I am inclined to think that some of the younger chemists and physiologists of 

 to-day may live to see the time when all the at present mysterious and unaccount- 

 able processes going on in the organisms of plants and animals, including those of 

 fermentation, will be found to obey purely physical and chemical laws. To the 

 biologist it may seem derogatory to the dignity of his science to haA'e tlie principle 

 of vitality, which has so long reigned supreme, dethroned and replaced by hard, un- 

 bending law. Such, however, is not the opinion of that distinguished botanist 

 Sachs, who says, referring to this ver}' point : — ' Der Organismus selbst ist nur die 

 aus verschiedenenTheilen bestehende Ma3chine,die durchweitere EingriHe iiusserer 

 Krafte in Bewegung gesetzt werden muss : von ihrer Struktur liangt es alj, welchen 

 Effekt diese ausseren Krafte an ihr bewirken. Es wiirde einen sehr niedrigen 

 Horizont wissenschaftlicher Bildung verrathen, in diesem Vergleich eine Herabset- 

 zung des Organismus sehen zu wollen, denn in einer Maschine, wenn audi nur von 

 Menschenhanden gemacht, liegtdasResultat tiefsten und sorgfaltigsten Nachdenkena 

 und hoher Intelligenz, soweit es ihre Struktur betrifift, und wirksam sind in ihr 

 schliesslich dieselben Naturkrafte, welche in anderer Combination die Lebenskrafte 

 eines Organs darstellen. Die Vergleichung des organischen Lebens mit unorganischen 

 Processen kann nur dann als eine Erniedrigung des ersteren gelten, wenn man so 

 thoricht gewesen ist, die letzteren als etwas Niedriges und Gemeines aufzufassen, 

 wahrend die unbegreifliche Grosse und Durcbgeistigung der Natur in beiden Fallen 

 sich gleichartig offenbart.' ' The time may be far distant when these views of the 

 great botanist shall be universally accepted ; but they will, I think, sooner or later 

 prevail, 



' VorJesungen iiher Pflanzeniihysiologie. 



