In his passion for truth and his desire to be convincing Pasteur threw out this challenge: “Would M. Frémy confess his error if I were to demonstrate to him that the natural juice of the grape, exposed to the contact of air, deprived of its germs, can neither ferment nor give birth to organized yeasts?” This interpellation was perhaps more violent than was usual in the meetings of the solemn Academy, but scientific truth was in question. And Pasteur, recognizing the old arguments under M. Frémy’s hemiorganism and M. Trécul’s transformations, referred his two contradictors to the experiments by which he had proved that alterable liquids, such as blood or urine, could be exposed to the contact of air deprived of its germs without undergoing the least fermentation or putrefaction. Had not this fact been the basis on which Lister had founded “his marvellous surgical method”? And in the bitterness given to his speech by his irritation against error, the epithet “marvellous” burst out with a visible delight in rendering homage to Lister. Pasteur, then in full possession of all the qualities of his genius, was feeling the sort of fever known to great scientists, great artists, great writers: the ardent desire of finding, of discovering something he could leave to posterity. Interrupted by these belated contradictors when he wanted to be going forward, he only restrained his impatience with difficulty. His old master, Balard, appealed to him in the Académie itself (January 22, 1872), in the name of their old friendship, to disregard the attacks of his adversaries, instead of wasting his time and his strength in trying to convince them. He reminded him of all he had achieved, of the benefits he had brought to the industries of wine, beer, vinegar, silkworms, etc., and alluded to the possibility foreseen by Pasteur himself of preserving mankind from some of the mysterious diseases which were perhaps due to germs in atmospheric air. He ended by urging him to continue his studies peacefully in the laboratory built for him, and to continue the scientific education of young pupils who might one day become worthy successors of Van Tieghem, Duclaux, Gernez, Raulin, etc.... thus forming a whole generation of young scientists instructed in Pasteur’s school. M. Duclaux wrote to him in the same sense: “I see very well what you may lose in that fruitless struggle--your rest, your time and your health; I try in vain to see any possible advantage.”