OILY AND ETHEREAL PRODUCTS. 285 



In the former case, the yeast disappears during the 

 decomposition of the sugar; but in the latter, a 

 transformation of gluten is effected at the same 

 time, by which ferment is generated. Thus yeast 

 is destroyed in the one case, but is formed in the 

 other. 



Now since no free hydrogen gas can be detected 

 during the fermentation of beer and wine, it is evi- 

 dent that the oxidation of the gluten, that is, its 

 conversion into ferment, must take place at the 

 cost either of the oxygen of the water, or of that of 

 the sugar ; whilst the hydrogen which is set free 

 must enter into new combinations, or by the deoxi- 

 dation of the sugar, new compounds containing a 

 large proportion of hydrogen, and small quantity 

 of oxygen, together with the carbon of the sugar, 

 must be formed. 



It is well known that wine and fermented liquors 

 generally contain, in addition to the alcohol, other 

 substances which could not be detected before their 

 fermentation, and which must have been formed, 

 therefore, during that process in a manner similar to 

 the production of mannite. The smell and taste 

 which distinguish wine from all other fermented 

 liquids are known to depend upon an ether of a vola- 

 tile and highly combustible acid, which is of an oily 

 nature, and to which the name of (Enanthic ether 

 has been given. It is also ascertained that the smell 

 and taste of brandy from corn and potatoes is owing 

 to a peculiar oil, the oil of potatoes. This oil is 



