126 LOUIS PASTEUR. 



if they existed, and that the imagination added the 

 report was not without considerable influence in the 

 tasting, since the members of the commission had 

 themselves fallen into a little experimental snare. 



Thus Pasteur, after having revealed the causes 

 which determine the alterations of wines, had found 

 the means of practically neutralising them. By the 

 application of heat, and without producing any change 

 in the colour or flavour of the wines, he had been able to 

 insure their limpidity, and to render them capable of 

 being indefinitely preserved in well-closed vessels. If 

 these wines, being afterwards exposed too long to the 

 air, were again threatened with alteration, it was be- 

 cause the air brought to them new living germs of 

 those ferments which had been destroyed by the heat. 

 But germs from this source are so trifling compared 

 with those contained in the wine itself, that one may 

 almost say the heating process renders the wine un- 

 alterable even after it has been rebottled in contact 

 with the air. Thus, by a series of experiments which 

 left nothing to chance, one of the greatest economic 

 questions of the day was solved. Wines could be 

 kept or transported into all countries without losing 

 their flavour or their perfume. These experiments of 

 the laboratory were destined to have an extensive 

 application ; for very soon arrangements were made 

 for heating wine in barrels, the inquiry thereby as- 

 suming the proportions of a public benefit. 



