One of the most distinguished members of the Academy of Medicine, M. Davainne, who was the first to give his attention to rigorous experiments on the influence that organic ferments exercise on the production and propagation of infectious diseases, declares that the idea of his researches on _splenic fever_ and _malignant pustule_ was suggested to him by his perusal of our work on butyric fermentation, published in 1861. In 1850 this gentleman and M. Rayer discovered in the blood of animals attacked by these diseases minute filiform bodies, to which they paid little attention, and which M. Davainne recollected, when he came across our Memoir. He had the foresight to conjecture—a conjecture that was soon confirmed most decisively by his researches—that the former disease, known under the name of _sang de rate_, might be the production of a fermentation analogous to the butyric, in which the minute filiform bodies observed by Rayer and himself, in 1850, played the part which vibrios fill in butyric fermentation. Within two years of this the first works of Messrs. Coze and Feltz appeared. These clever and courageous experimentalists avowed that their beautiful researches had been suggested to them by the perusal of my work on putrefaction, published in 1863. We might also quote the striking and admirably conceived experiments of Dr. Chauveau, on castration.[26] We cannot, however, refrain from reproducing here a letter addressed to us in 1874 by the celebrated Edinburgh surgeon, Mr. Lister:— “Edinburgh, Feb. 10, 1874. “DEAR SIR,—Will you permit me to beg your acceptance of a pamphlet which I forward to you by this post, and which describes certain inquiries into a subject upon which you have thrown so much light—the theory of germs and fermentation? It gives me pleasure to think that you will peruse with some interest what I have written about an organism that you were the first to study in your Memoir on lactic fermentation. I do not know if you ever see the records of British surgery. If you have perused them you may have observed from time to time notices of the antiseptic system which I have been endeavouring for the last nine years to bring to perfection. Permit me to take this opportunity of offering you my most hearty thanks for having demonstrated by your brilliant researches the truth of the theory of putrefactive germs, and for having afforded me in this manner the sole means of perfecting the antiseptic system. “Should you ever come to Edinburgh I am sure that you will be truly gratified to see in our hospital the extent to which the human race has profited by your work. I need hardly add, that I should have great satisfaction in showing you how greatly surgery is indebted to you.