The career of M. Pasteur is one of those which rank among the greatest in the value of the results which he has obtained. Starting as a great chemist, he went on, step by step, making great discoveries in the line of his work, till he finally proved absolutely the germ theory of disease, which, prior to his investigations and experiments, had been merely an hypothesis. The great crowning work of his life, however, has been the establishment of the fact that vaccination, as discovered by Jenner is not an isolated truth, but one of a class of similar truths, which could be utilized to the incalculable blessing of the world; in other words, that it is possible in the case of a great many diseases to make the system proof against contagion by inoculation with an attenuated virus of the same nature. He has been splendidly successful in the cases of splenic fever and of hydrophobia, and all the analogies indicate that this is only the beginning of a much wider extension of the same principle. Pasteur’s conclusions are now accepted by the whole scientific, and a host of ardent and ingenious disciples are working along the same line of experiment and investigation. The beneficent results are likely to be of such a character as to revolutionize the whole treatment of disease. Before Pasteur had reached the culmination of his great career, he had saved millions of francs per annum to France by his discovery of the means to cure diseases in vines, and the method of saving silk-worms from the parasitic ailment which threatened the whole silk culture of France. But in absolutely demonstrating, starting from the germ theory of disease as a basis, that disease could be guarded against, at least in certain cases, by inoculation with attenuated virus, he has opened the way probably for results the greatness of which we do not yet appreciate. Like Dr. Robert Koch, of Berlin, he has been experimenting with cholera, but, unlike Dr. Koch, he denies that the cholera germ, or _bacillus_, has yet been found. Investigators are, however, on the road to the truth, and we confidently anticipate that the goal will be reached not only in cholera, but many other diseases. If so Pasteur’s name will shine _primus inter pares_ among those who most contributed to such a beneficent revolution in the methods, of grappling with the most fatal forms of disease and death. The story of Pasteur’s life, of his methods of work, of his progress from discovery to discovery, is told by his admiring disciple and son-in-law in a very fresh and attractive style, unencumbered by technical terms and with a peculiarly French vivacity and grace of touch. There is a very interesting summary of the results of Pasteur’s work written by no less an authority than Professor John Tyndall, who does ample justice to the genius and ability of his great French contemporary. Pasteur is now only sixty-two years of age, and as his health has lately been re-established, the world may expect still