M. Roux had seen Pasteur try to “extract the soluble alcoholic ferment from yeast cells by crushing them in a mortar, by freezing them until they burst, or by putting them into concentrated saline solutions, in order to force by osmose the succus to leave its envelope.” Pasteur confessed that his efforts were vain. In a communication to the Académie des Sciences on December 30, 1878, he said-- “It ever is an enigma to me that it should be believed that the discovery of soluble ferments in fermentations properly so called, or of the formation of alcohol by means of sugar, independently of cells would hamper me. It is true--I own it without hesitation, and I am ready to explain myself more lengthily if desired--that at present I neither see the necessity for the existence of those ferments, nor the usefulness of their action in this order of fermentations. Why should actions of _diastase_, which are but phenomena of hydration, be confused with those of organized ferments, or vice versâ? But I do not see that the presence of those soluble substances, if it were ascertained, could change in any way the conclusions drawn from my labours, and even less so if alcohol were formed by electrolysis. “They agree with me who admit: “Firstly. That fermentations, properly so called, offer as an essential condition the presence of microscopic organisms. “Secondly. That those organisms have not a spontaneous origin. “Thirdly. That the life of every organism which can exist away from free oxygen is suddenly concomitant with acts of fermentation; and that it is so with every cell which continues to produce chemical action without the contact of oxygen.” When Pasteur related this discussion, and formed of it an appendix to his book, _Critical Examination of a Posthumous Work of Claude Bernard on Fermentations_, his painful feelings in opposing a friend who was no more were so clearly evidenced that Sainte Claire Deville wrote to him (June 9, 1879): “My dear Pasteur, I read a few passages of your new book yesterday to a small party of professors and _savants_. We all were much moved by the expressions with which you praise our dear Bernard, and by your feelings of friendship and pure fraternity.” Sainte Claire Deville often spoke of his admiration for Pasteur’s precision of thought, his forcible speech, the clearness of his writings. As for J. B. Dumas, he called the attention of his colleagues at the Académie Française to certain pages of that _Critical Examination_. Though unaccustomed to those particular subjects, they could not but be struck by the sagacity and ingenuity of Pasteur’s researches, and by the eloquence inspired by his genius. A propos of those ferment germs, which turn grape juice into wine, and from which he had preserved his swathed bunches, Pasteur wrote--