The contagion which Pasteur showed, appearing clearly in the disorders visible in the carcases of inoculated guinea-pigs, was counted as nothing. As to the assimilation of a laboratory experiment on rabbits and guinea-pigs to what occurred in human pathology, it may be guessed that it was quite out of the question for men who did not even admit the possibility of a comparison between veterinary medicine and the other. It would be interesting to reconstitute these hostile surroundings in order to appreciate the efforts of will required of Pasteur to enable him to triumph over all the obstacles raised before him in the medical and the veterinary world. The Professor of Alfort School, Colin, who had, he said, made 500 experiments on anthrax within the last twelve years, stated, in a paper of seventeen pages, read at the Academy of Medicine on July 31, that the results of Pasteur’s experiments had not the importance which Pasteur attributed to them. Among many other objections, one was considered by Colin as a fatal one--the existence of a virulent agent situated in the blood, besides the bacteridia. Bouley, who had just communicated to the Academy of Sciences some notes by M. Toussaint, professor at the Toulouse veterinary school, whose experiments agreed with those of Pasteur, was nevertheless a little moved by Colin’s reading. He wrote in that sense to Pasteur, who was then spending his holidays in the Jura. Pasteur addressed to him an answer as vigorous as any of his replies at the Academy. “Arbois, August 18, 1877.--My dear colleague ... I hasten to answer your letter. I should like to accept literally the honour which you confer upon me by calling me ‘your master,’ and to give you a severe reprimand, you faithless man, who would seem to have been shaken by M. Colin’s reading at the Académie des Sciences, since you are still holding forth on the possibility of a virulent agent, and since your uncertainties seem to be appeased by a new notice, read by yourself, last Monday, at the Académie des Sciences. “Let me tell you frankly that you have not sufficiently imbibed the teaching contained in the papers I have read, in my own name and in that of M. Joubert, at the Académie des Sciences and at the Academy of Medicine. Can you believe that I should have read those papers if they had wanted the confirmation you mention, or if M. Colin’s contradictions could have touched them? You know what my situation is, in these grave controversies; you know that, ignorant as I am of medical and veterinary knowledge, I should immediately be taxed with presumption if I had the boldness to speak without being armed for struggle and for victory! All of you, physicians and veterinary surgeons, would quite reasonably fall upon me if I brought into your debates a mere semblance of proof.