STUDIES ON WINE. 121 



liquid, Pasteur shook the bottle, and then examined 

 with the microscope the residue of each bottle. He 

 perceived in each case distinct filaments of ferment. 

 The wines, however, were not in the least bitter to 

 the taste, but the germs of a possible evil were there 

 an evil which would have been first detected by the 

 palate when the little fungus had fully developed. 



Without uncorking it, Pasteur then heated a 

 bottle of each of these wines. The heating was carried 

 to a temperature of sixty degrees (140 Fahr.). After 

 the cooling of the bottles he laid them by the side of 

 other unheated bottles of the same wines in a cellar, 

 the temperature of which varied in summer between 

 thirteen and seventeen degrees. Every fifteen days 

 Pasteur inspected them. Without uncorking the 

 bottles, he held them up against the light, so that he 

 could see the sediment at the bottom of each bottle, 

 and thus detect the least formation of deposit. In less 

 than six weeks, particularly in the wine of 1863, a 

 very perceptible floating deposit began to form in all the 

 unheated bottles. These deposits gradually augmented, 

 and on examining them with the microscope they were 

 seen to be formed of organised filaments, mixed some- 

 times with a little colouring matter which had become 

 insoluble. No deposit appeared in the heated bottles. 



The idea of heating wines does not belong to 

 Pasteur. Those who love to search into questions of 



