YEAST OR FERMENT. 251 



monia, and, in addition to it, there are tnree new 

 products, formed from the component parts of 

 the juice. One of these is lactate acid, the slightly 

 volatile compound found in the animal organism ; 

 the other is the crystalline body which forms the 

 principal constituent of manna ; and the third is a 

 mass resembling gum-arabic, which forms a thick 

 viscous solution with water. These three products 

 weigh more than the sugar contained in the juice, 

 even without calculating the weight of the gaseous 

 products. Hence they are not produced from the 

 elements of the sugar alone. None of these three 

 substances could be detected in the juice before 

 fermentation. They must, therefore, have been 

 formed by the interchange of the elements of the 

 sugar with those of the foreign substances also 

 present. It is this mixed transformation of two or 

 more compounds which receives the special name 

 of putrefaction. 



ON YEAST OR FERMENT. 



When attention is directed to the condition of 

 those substances which possess the power of induc- 

 ing fermentation and putrefaction in other bodies, 

 evidences are found in their general characters, and 

 in the manner in which they combine, that they all 

 are bodies, the atoms of which are in the act of 

 transposition. 



The characters of the remarkable matter which 

 is deposited in an insoluble state during the fer- 



