STUDIES ON WINE. 113 



moment when he had just been proving that there 

 was nothing spontaneous either in the phenomena of 

 fermentation or in animal and vegetable infusions. 



Pasteur tried first of all to show that wine does 

 not ' work ' as much as it was supposed to do. Wine 

 being a mixture of different substances, among which 

 are acids and alcohol, particular ethers are no doubt 

 formed in it in course of time, and similar reactions 

 perhaps take place between the other constituents of 

 the liquid. But if the exactitude of such facts cannot 

 be denied, based as they are upon general laws, con- 

 firmed and extended by recent inquiries, Pasteur 

 thought that a false application was made of them 

 when they were employed to explain the maladies of 

 wine, the changes which occur in it through age in 

 a word, the alterations, whether good or bad, which 

 wines are subject to. The 'ageing' of wine soon 

 appeared to him to consist essentially in the phe- 

 nomena of oxidation, due to the oxygen of the air 

 which dissolves and is diffused in the wine. He 

 gave manifest proofs of this. I will only mention 

 one of them. New wine inclosed in a glass vessel 

 hermetically sealed keeps its freshness ; it does not 

 * work,' it does not ' age.' Pasteur demonstrated 

 besides, that all the processes of wine-making are 

 explained by the double necessity of oxygenising the 

 wine to a suitable degree, and of preventing its dete- 

 rioration. In seeking for the actual causes of in- 



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