human subject, but this eruption seems to have had rather the character of a modified variola than that of a true vaccinia; and, as its transmission by inoculation through a succession of human subjects did not produce what the best judges considered a genuine cow-pock, it was allowed to die out. The case was very different, however, with another set of experiments made a few years afterward (in ignorance of Mr. Ceely's) by Mr. Badcock, a druggist at Brighton, who was led to institute them through having himself suffered an attack of small-pox, though vaccinated in early life, and having been thus led to suspect that the protective power of vaccination had undergone deterioration. From the account he gave of his work in a small pamphlet published in 1845 (for a sight of which I am indebted to his son), it appears—1. That he inoculated his cows with small-pox virus furnished to him from an unquestionable source; 2. That this inoculation produced vesicles which were pronounced by some of the best practitioners of Brighton to have the characters of genuine vaccinia; 3. That lymph drawn from these vesicles, and introduced by inoculation into the arms of children, produced in them vaccine vesicles of the true Jennerian type; 4. That free exposure of some of these children to small-pox infection showed them to have acquired a complete protection; and, 5. That this new stock of "vaccine" had been extensively diffused through the country, and had been fully approved by the best judges of true vaccinia, both in London and the provinces.
Mr. Simon, writing in 1857, stated that, from the new stock thus obtained by Mr. Badcock (not once only, but repeatedly), more than 14,000 persons had been vaccinated by Mr. Badcock himself, and that he had furnished supplies of his lymph to more than 4,000 medical practitioners. And I learn from Mr. Badcock, junior, who is now a public vaccinator at Brighton, that this stock is still in use in that town and neighborhood.
Against these positive results are to be set the negative results of attempts made in the same direction by many other able experimenters, such as Professor Chauveau and his coadjutors, the recent Belgian Commission, and Professor Burdon-Sanderson, as well as the unsatisfactory results obtained by Ceely. But I can not see that their non-successes are in any way contradictory of the absolute and complete successes which, if testimony is to be trusted, were obtained by Thiele and Badcock. The lesson taught by the failures appears to me to be the careful imitation of the conditions under which the successes were obtained; and, as Mr. Badcock, senior, is still living, and is said to be both able and willing to give all needful information, it is the inten-
- The only possible fallacy in these experiments, as it seems to me, might lie in his medical friend, Mr. (afterward Sir J.) Cordy Burrows, having supplied him with vaccine lymph, instead of with variolous virus. But, though this might have been the case once or twice, it could scarcely have happened several times, except by design, which is scarcely to be thought of.