220 THE HISTORY OF SCIENCE 



organisms which live in the absence of oxygen, while 

 vinegar is produced from wine through the agency 

 of bacteria freely supplied with the oxygen of the 

 air. Pasteur was seeing ever more clearly the part 

 played by the infinitesimally small in the economy 

 of nature. Without these microscopic beings life 

 would become impossible, because death would be 

 incomplete. On the basis of Pasteur's study of fer- 

 mentation, his demonstration that decomposition is 

 owing to living organisms and that minute forms of 

 life spring from parents like themselves, his disciple 

 Joseph Lister began in 1864 to develop antiseptic 

 surgery. 



Pasteur's attention was next directed to the wine 

 industry, which then had an annual value to France 

 of 500,000,000 francs. Might not the acidity, bit- 

 terness, defective flavor, which were threatening the 

 foreign sale of French wines, be owing to ferments ? 

 He discovered that this was, indeed, the case, and 

 that the diseases of wine could be cured by the sim- 

 ple expedient of heating the liquor for a few mo- 

 ments to a temperature of 50 to 60 C. Tests on a 

 considerable scale were made by order of the naval 

 authorities. The ship Jean Bart before starting on 

 a voyage took on board five hundred liters of wine, 

 half of which had been heated under Pasteur's direc- 

 tions. At the end of ten months the pasteurized 

 wine was mellow and of good color, while the wine 

 which had not been heated had an astringent, almost 

 bitter, taste. A more extensive test seven hundred 

 hectoliters, of which six hundred and fifty had been 

 pasteurized was carried out on the frigate la 

 Sibylle with satisfactory results. Previously wines 



