SUBSTANCES FOUND TO POSSESS 





be added, which removes the hydrogen as it becomes 

 free and combines with it. 



Butyric acid is not, however, the fatty acid first 

 formed in wine; it is usually originated at a later 

 period, and forms one of the odoriferous ingredients 

 of old wine ; and hence in turning our attention to 

 butyric acid, I have considered it not as a primary but 

 as a secondary substance in wine. The well-ascertained 

 fact must, however, be stated that butyric acid is formed 

 out of cellulose and sugar, thereby establishing that 

 the fatty acids of wine are not necessarily derived from 

 the fatty substances of the stones and skins or of 

 the grape-juice, but may come from a source which 

 depends entirely on the decomposition of the sugar. 



The .first fatty acid found with oxide of ethyl imme- 

 diately after its formation in wine, is cenanthic acid. 

 Since oenanthic acid appears to be the source of the 

 butyric, caproic, and other acids formed at a later 

 period, we must devote some attention to it. It has 

 been asserted that oenanthic acid cannot be a product 

 of fermentation, because none is obtained if ferment 

 be added to sugar to induce fermentation. The real 

 state of the case is this : during fermentation, under 

 the influence of the ferment which is undergoing 

 change, no oenanthic acid is obtained; but this does not 

 prove that this acid is not produced when ferment is 

 forming. I consider this point of sufficient importance 

 to merit special consideration. 

 When potato syrup is fermented (to make spirit), 



