"At a meeting of the Société de Pédiatrie (Paris), held June 1901, a resolution was adopted affirming that preventive inoculations present no serious dangers, and confer immunity in the great majority of cases for some weeks, and recommending their employment in children's institutions and in families in which scientific surveillance cannot be exercised. Netter stated that he had collected 32,484 observations (cases) of prophylactic injections, and after eliminating cases in which the disease developed in less than twenty-four hours after injection, or more than thirty days after, there were 6 per cent. of failures. On the other hand, the author stated that he had recently made ninety preventive injections with but 2.17 per cent. of failures. Potter reports a series of twenty-four families in which preventive injections were used. Only one case of diphtheria occurred. In another series of cases, in which no prophylactic injections were given, the disease occurred secondarily in one-third of the houses, and one-sixth of the inmates contracted the disease, in spite of the fact that a large number of the primary cases were removed to the hospital. Blake reports a series of thirty-five prophylactic injections. The treatment was instituted after three cases of diphtheria had developed in a children's home. No secondary cases developed. Voisin and Guinon describe an epidemic of diphtheria in the Salpetrière Hospital among idiots and epileptics. Prophylactic injections were given to all those exposed to the contagion. After that, but four cases appeared, all mild in character. One severe case developed, however, two weeks later, ending fatally in twenty-four hours, showing that the prophylactic action of the antitoxin, while efficacious, is not of very long duration." It would be easy to prolong _ad infinitum_ the proofs of the curative and preventive efficacy of the antitoxin: it would be impossible to find any evidence to be weighed for one moment against these proofs. There are three early records that ought to be quoted more fully: the 1894 report from the Hospital for Sick Children, Paris; the 1896 report of the American Pædiatric Society; and the 1898 report of the Clinical Society of London. I