OILY AND ETHEREAL PRODUCTS. 341 



by which ferment is generated. Thus yeast is de- 

 stroyed 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 deoxidation 

 of the sugar, new compounds containing a large pro- 

 portion 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 vol- 

 atile and highly combustible acid ; the ether is of an 

 oily nature, and has received the name (Enanthic 

 ether. It is also ascertained, that the smell and 

 taste of brandy from corn and potato are owing to a 

 peculiar oil, the oil of potatoes. This oil is more 

 closely allied to alcohol in its properties, than to 

 any other organic substance. 



These bodies are products of the deoxidation of 

 the substances dissolved in the fermenting liquids ; 

 they contain less oxygen than sugar or gluten, but 

 are remarkable for the large quantity of hydrogen 

 which enters into their composition. 



(Enanthic acid contains an equal number of equiv- 

 alents of carbon and hydrogen, exactly the same 

 proportions of these elements, therefore, as sugar, 

 but by no means the same proportion of oxygen. 

 The oil of potatoes contains much more hydrogen. 



Although it cannot be doubted, that these volatile 

 liquids are formed by a mutual interchange of the 



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