3/38 VINOUS FERMENTATION. 



there are few ferruginous earths which do not evolve 

 ammoniacal products when heated to redness, and 

 ammonia is the cause of the peculiar smell perceived 

 upon moistening aluminous minerals. Thus, ammo- 

 nia, by being a constituent of the atmosphere, is a 

 very widely diffused cause of nitrification, which 

 will come into play whenever the different conditions 

 necessary for the oxidation of ammonia are com- 

 bined. It is probable, that other organic bodies in 

 the state of eremacausis are the means of causing 

 the combustion of ammonia ; at all events, the cases 

 are very rare, in w^hich nitric acid is generated from 

 ammonia, in the absence of all matter capable of 

 eremacausis. 



From the preceding observations on the causes of 

 fermentation, putrefaction, and decay, we may now 

 draw several conclusions calculated to correct the 

 views generally entertained respecting the fermenta- 

 tion of wine and beer, and several other important 

 processes of decomposition which occur in nature. 



CHAPTER IX. 



ON VINOUS FERMENTATION: — WINE AND BEER. 



It has already been mentioned, that fermentation 

 is excited in the juice of grapes by the access of air ; 

 alcohol and carbonic acid being formed by the de- 

 composition of the sugar contained in the fluid. But 

 it was also stated, that the process once commenced, 

 continues until all the sugar is completely decom- 

 posed, quite independently of any further influence 

 of the air. 



In addition to the alcohol and carbonic acid formed 

 by the fermentation of the juice, there is also pro- 

 duced a yellow or gray insoluble substance, contain- 

 ing a large quantity of nitrogen. It is this body 

 which possesses the power of inducing fermentation 



