ORIGIN OF THE YEASTS OF WINE 219 



and so new, known for a year through the publication 

 of the Etudes sur la biere, had been forgotten in 1877 by 

 Claude Bernard. One of his principal experiments at 

 St. Julien, which he had repeated at various times 

 because he had never been content with the results, had 

 consisted in crushing ripe grapes, sound or decayed, to 

 express and filter therefrom the juice until it was per- 

 fectly clear, then to compare in an approximate manner 

 the quantity of alcohol in the liquids after their filtration, 

 and in the same liquids after standing about 48 hours. 

 Bernard found that in this interval the amount of alcohol 

 increased, although the liquid remained clear, and he did 

 not hesitate to draw from this fact conclusions favorable 

 to the existence of the diastase of which we have al- 

 ready spoken. 



The experiment of Bernard allowed various sources 

 of error which Pasteur pointed out in the discussion 

 which he made of it. He cites in opposition the results 

 described in the Etudes sur la biere, but he goes farther: 

 he proposes to repeat the same experiments on a much 

 larger scale, in such a way as not to allow any of those 

 conditions of time and place of the experiments of Ber- 

 nard, which one could invoke in their favor, to come 

 into play. Here, we can let him speak, for he has him- 

 self given an account quite at length of this episode, 

 wherein he has painted a very exact portrait of himself, 

 with his ardor in returning to already conquered posi- 

 tions when they were menaced, and that suddenness 

 which he always brought into his decisions when a 

 great question was under consideration. 



The day following the posthumous publication of the 

 manuscript of Bernard, Pasteur's plan and program were 

 made: "Without too much care for expense," 1 he said, "I 



1 Examen critique d'un ecrit posthume de Cl. Bernard sur la fermenta- 

 tion, p. 66. 



