Dr. Tarnier, a student residing at the Maternité during that disastrous time, related afterwards how the ignorance of the causes of puerperal fever was such that he was sometimes called away, by one of his chiefs, from some post-mortem business, to assist in the maternity wards; nobody being struck by the thought of the infection which might thus be carried from the theatre to the bed of the patient. The discussion which arose in 1858 at the Académie de Médecine lasted four months, and hypotheses of all kinds were brought forward. Trousseau alone showed some prescience of the future by noticing an analogy between infectious surgical accidents and infectious puerperal accidents; the idea of a ferment even occurred to him. Years passed; women of the lower classes looked upon the Maternité as the vestibule of death. In 1864, 310 deaths occurred out of 1,350 confinement cases; in 1865, the hospital had to be closed. Works of cleansing and improvements gave rise to a hope that the “epidemic genius” might be driven away. “But, at the very beginning of 1866,” wrote Dr. Trélat, then surgeon-in-chief at the Maternité, “the sanitary condition seemed perturbed, the mortality rose in January, and in February we were overwhelmed.” Twenty-eight deaths had occurred out of 103 cases. Trélat enumerated various causes, bad ventilation, neighbouring wards, etc., but where was the origin of the evil? “Under the influence of causes which escape us,” wrote M. Léon Le Fort about that time, “puerperal fever develops in a recently delivered woman; she becomes a centre of infection, and, if that infection is freely exercised, the epidemic is constituted.” Tarnier, who took Trélat’s place at the Maternité, in 1867, had been for eleven years so convinced of the infectious nature of puerperal fever that he thought but of arresting the evil by every possible means of defence, the first of which seemed to him isolation of the patients. In 1874, Dr. Budin, then walking the hospitals, had noted in Edinburgh the improvement due to antisepsis, thanks to Lister. Three or four years later, in 1877 and 1878, after having seen that, in the various maternity hospitals of Holland, Germany, Austria, Russia and Denmark, antisepsis was practised with success, he brought his impressions with him to Paris. Tarnier hastened to employ carbolic acid at the Maternité with excellent results, and his assistant, M. Bar, tried sublimate. While that new period of victory over fatal cases was beginning, Pasteur came to the Académie de Médecine, having found, in certain puerperal infections, a microbe in the shape of a chain or chaplet, which lent itself very well to culture.