DISEASES OF WINE AND VINEGAR 119 



a general summary of his investigations. He told 

 his audience of the work of the minute organisms 

 that are responsible for fermentation, the condi- 

 tions necessary for their life, the real reasons for 

 the procedures followed in vinegar-making, the 

 sources of failure so frequently encountered in this 

 industry, and the means by which these failures 

 may be avoided. "Nothing," he said in concluding 

 his lecture, "is more agreeable to men devoted to 

 a scientific career, than to increase the number of 

 discoveries, but when the practical utility of their 

 observations is demonstrated by practical utility 

 their joy is complete." To Pasteur it was a great 

 satisfaction to grapple with a troublesome problem 

 and after mastering it, to set forth his discoveries 

 before his grateful hearers. 



Pasteur's studies on vinegar afforded a natural 

 introduction to his investigations of the maladies 

 of wines. Wine-making has always been one of 

 the important industries of France, and French 

 wines enjoyed a reputation which caused them to 

 be sought after all over the world. But the wine 

 industry had come to suffer from several diseases 

 which occasioned much financial loss. Even the 

 best of wines sometimes went bad, and wine- 

 makers were quite in the dark as to the causes of 



