FEEMENTATION. 69 



from nitrogen in the form of ammonia, it follows that 

 one-eighth of the contents of the cells underwent com- 

 plete decomposition. "We cannot, however, consider 

 it as certain that during fermentation the albuminous 

 matter was completely resolved into ammonia, carbonic 

 acid, and water. By the putrifying of caseine, leucine 

 is formed, and the progress of the same process in 

 other bodies gives rise to other nitrogenous substances. 



An investigation which should follow out the re- 

 sults of the decomposition of ferment during the fer- 

 mentation of sugar would be of the greatest value, 

 especially with regard to wine, for as far as these 

 matters are concerned, we are almost entirely ignorant. 



I may here just notice one observation of Schmidt's. 

 During fermentation, he found the ferment (considered 

 to be dry) increased in weight, which can only be 

 accounted for by the conversion of sugar into cel- 

 lulose. 



5 c. c. of beer ferment, washed with water and 

 dried, gave a dry residue of O410 (6'3 grains) ; the 

 same quantity of ferment, after fermenting during 

 eight days with 3 grammes (46'3 grains) of sugar, 

 gave a dry residue of O628 (9'7 grains) . This last had 

 yielded O012 (O1S grains) nitrogen in the form of am- 

 monia ; it had lost in albuminous contents, and yet had 

 gained in weight. The ferment remaining after fermen- 

 tation is cellulose, into which sugar has been converted. 



That which is gained as cellulose by the ferment 

 cells is lost to the sugar (out of which it is formed) as 



