FERMENTATION. 63 



mical change in their constituents to the constituents 

 of the sugar. There is a fixed relation between the 

 quantity of alcohol produced (a sufficiency of sugar 

 being pre-supposed), and the quantity of albuminous 

 matters capable of undergoing change which sets up 

 fermentation. According to Thenard, 100 parts of 

 sugar require 1 parts ferment, reckoned in a dry 

 state. The analysis of ferment teaches us that about 

 half of it consists more or less of albuminous mat- 

 ters, and therefore f parts albumen are required in 

 order to convert 100 parts sugar into alcohol and 

 carbonic acid. 



"We must address ourselves more particularly to the 

 examination of ferment, not only on account of its 

 connexion with the preparation of wine, but also with 

 regard to the constituents of wine.* 



I may here observe, in few words, that some years 

 since an examination of ferment and fermentation en- 

 abled me to obtain some general results,f which agree 

 with those given by Dumas, J Mitscherlich, and 

 Schlossberger,|| in so far as they relate to this matter. 



Ferment consists of cells, the substance of which 



* Fabroni, Bertholon, Le Gentil, Mourgues,Cbaptal, Dandale, Par- 

 mentia, Gervais, Aster, Herpin, Colier, Fontenelle, and others, have 

 written upon fermentation, and especially upon the fermentation of 

 wine. The treatises of the two last named appear in the Ann. de 

 Ch. et de Phys. torn. xxv. p. 133, and torn, xxviii. p. 128, and in the 

 Journ. de Pharm. Sept. 1823, p. 437. 



+ Scheik. Onderz. deel. ii. p. 409. 



J Versuch einer Chemischen Statistik, s. 88. 



Lehrbuch der Chemie, 4 Aufl. s. 370. 



|| Liebig's Annalen, Bd. 51, s. 193. 



