58 FEKMEtfTATION. 



that he, by the use of the same means, had obtained 

 very unfavourable results ; Liebig defended himself, 

 and maintained that the experiments had been badly 

 tried. Not having any practical experience in this 

 matter, I cannot enter more particularly upon it. 

 But something appears to me to have been overlooked. 



The admission of a large quantity of air is not 

 only unnecessary but injurious, if the object desired 

 be to increase the quantity of alcohol. If wine of 

 another quality is wished, this may be obtained by 

 regulating the quantity of air admitted during fer- 

 mentation. Every kind of grape juice cannot bear 

 the admission of air in large quantities, or at least 

 circumstances may occur, which may render it pos- 

 sible to obtain good wine, if the air be excluded. 



These three conclusions are, if I do not mistake, 

 generally admitted. 



The last observation is so completely the result of 

 large experience, that it appears unnecessary to dwell 

 upon it longer. If any one should still maintain that 

 every kind of grape juice can bear the admission of 

 air in large quantities, we would only ask, Why, 

 then, did experiments tried with grape juice in open 

 vats fail, while the very same grape juice, placed in 

 closed vessels, yielded good wine ? 



The two former results are deduced principally 

 from experiments by which De Saussure * tried, and 

 proved that a large admission of air is unnecessary 



* Bibl. Univ. t. xxxii. p. 168. 



