STLDIES ON FERMENTATION. 317 



tlist time we felt sure that the celebrated chemist of Munich 

 had adopted our conclusions, from the fact that he remained 

 silent on this question for a long time, although it had been 

 until then the constant subject of his study, as is shown by all 

 his works. Suddenly there appeared in the Annales de Chimie 

 ct ch Physique a long essay, reproduced from a lecture delivered 

 by him before the Academy of Bavaria in 1868 and 18C9. In 

 this Liebig again maintained, not, however, without certain, 

 modifications, the views which he had expressed in his former 

 publications, and disputed the correctness of the principal facts 

 enunciated in our Memoir of 1860, on which were based the 

 arguments against his theory. 



" I had admitted/' he says, " that the resolution of ferment- 

 able matter into compounds of a simpler kind must be traced 

 to some process of decomposition taking place in the ferment, 

 and that the action of this same ferment on the fermentable 

 matter must continue or cease according to the prolongation or 

 cessation of the alteration produced in the ferment. The mole- 

 cular change in the sugar would, consequently, be brought 

 about by the destruction or modification of one or more of the 

 component parts of the ferment, and could only take place 

 through the contact of the two substances. M. Pasteur regards 

 fermentation in the following light : — The chemical action of 

 fermentation is essentially a phenomenon correlative with a vital 

 action, beginning and ending with it. He believes that alco- 

 holic fermentation can never occur without the simultaneous 

 occurrence of organization, development, and multiplication of 

 globules, or continuous life, carried on from globules already 

 formed. But the idea that the decomposition of sugar during 

 fermentation is due to the development of the cellules of the 

 ferment, is in contradiction with the fact that the ferment is 

 able to bring about the fermentation of a pure solution of sugar. 

 The greater part of the ferment is composed of a substance that 

 is rich in nitrogen and contains suljDhur. It contains, moreover, 

 an appreciable quantity of phosphates, hence it is difficult to 

 conceive how, in the absence of these elements in a pure solution 



