Some Academicians discoursed on these notes as on simple suggestions and advised Pasteur to continue his studies without allowing himself to be delayed by mere control experiments. Others considered these notes as the expression of Claude Bernard’s thought. “That opinion,” said Pasteur--man of sentiment as he was--“that opinion, however, does not explain the enigma of his silence towards me. But why should I look for that explanation elsewhere than in my intimate knowledge of his fine character? Was not his silence a new proof of his kindness, and one of the effects of our mutual esteem? Since he thought that he held in his hands a proof that the interpretation I had given to my experiments was fallacious, did he not simply wish to wait to inform me of it until the time when he thought himself ready for a definite statement? I prefer to attribute high motives to my friend’s actions, and, in my opinion, the surprise caused in me by his reserve towards the one colleague whom his work most interested should give way in my heart to feelings of pious gratitude. However, Bernard would have been the first to remind me that scientific truth soars above the proprieties of friendship, and that my duty lies in discussing views and opinions in my turn with full liberty.” Pasteur having made this communication to the Academy on July 22, hastily ordered three glass houses, which he intended to take with him into the Jura, “where I possess,” he told his colleagues, “a vineyard occupying some thirty or forty square yards.” Two observations expounded in a chapter of his _Studies on Beer_ tend to establish that yeast can only appear about the time when grapes ripen, and that it disappears in the winter only to show itself again at the end of the summer. Therefore “germs of yeast do not yet exist on green grapes.” “We are,” he added, “at an epoch in the year when, by reason of the lateness of vegetation due to a cold and rainy season, grapes are still in the green stage in the vineyards of Arbois. If I choose this moment to enclose some vines in almost hermetically closed glass houses, I shall have in October during the vintage some vines bearing ripe grapes without the exterior germs of wine yeast. Those grapes, crushed with precautions which will not allow of the introduction of yeast germs, will neither ferment nor produce wine. I shall give myself the pleasure of bringing some back to Paris, to present them to the Academy and to offer a few bunches to those of our colleagues who are still able to believe in the spontaneous generation of yeast.” In the midst of the agitation caused by that posthumous work some said, or only insinuated, that if Pasteur was announcing new researches on the subject, it was because he felt that his work was threatened.