On his entering the Académie des Sciences, Balard and Dumas advised Pasteur to let alone his wooden crystals and to continue his studies on ferments. He undertook to demonstrate that “the hypothesis of a phenomenon of mere contact is not more admissible than the opinion which placed the ferment character exclusively in dead albuminoid matter.” Whilst continuing his researches on beings which could live without air, he tried, as he went along, à propos of spontaneous generation, to find some weak point in his work. Until now the liquids he had used, however alterable they were, had been brought up to boiling point. Was there not some new and decisive experiment to make? Could he not study organic matter as constituted by life and expose to the contact of air deprived of its germs some fresh liquids, highly putrescible, such as blood and urine? Claude Bernard, joining in these experiments of Pasteur’s, himself took some blood from a dog. This blood was sealed up in a glass phial, with every condition of purity, and the phial remained in a stove constantly heated up to 30°C. from March 3 until April 20, 1862, when Pasteur laid it on the Académie table. The blood had suffered no sort of putrefaction; neither had some urine treated in the same way. “The conclusions to which I have been led by my first series of experiments,” said Pasteur before the Académie, “are therefore applicable in all cases to organic substances.” While studying putrefaction, which is itself but a fermentation applied to animal materia, while showing the marvellous power of the infinitesimally small, he foresaw the immensity of the domain he had conquered, as will be proved by the following incident. Some time after the Académie election, in March, 1863, the Emperor, who took an interest in all that took place in the small laboratory of the Rue d’Ulm, desired to speak with Pasteur. J. B. Dumas claimed the privilege of presenting his former pupil, and the interview took place at the Tuileries. Napoleon questioned Pasteur with a gentle, slightly dreamy insistence. Pasteur wrote the next day: “I assured the Emperor that all my ambition was to arrive at the knowledge of the causes of putrid and contagious diseases.” In the meanwhile, the chapter on ferments was not yet closed; Pasteur was attracted by studies on wine. At the beginning of the 1863 holidays, just before starting for Arbois, he drew up this programme with one of his pupils: “From the 20th to the 30th (August) preparation in Paris of all the vessels, apparatus, products, that we must take. September 1, departure for the Jura; installation; purchase of the products of a vineyard. Immediate beginning of tests of all kinds. We shall have to hurry; grapes do not keep long.”