returned home, however, Henry Cline, surgeon of St Thomas's Hospital, inoculated some vaccine matter obtained from him over the diseased hip-joint of a child, thinking the counter-irritation might be useful, and found the patient afterwards incapable of acquiring small-pox. In the autumn of the same year, Jenner met with the first opposition to vaccination; and this was the more formidable because it proceeded from J. Ingenhousz, a celebrated physician and man of science. But meanwhile Cline's advocacy of vaccination brought it much more decidedly before the medical profession, of whom the majority were prudent enough to suspend their judgment until they had more ample information. But besides these there were two noisy and troublesome factions, one of which opposed vaccination as a useless and dangerous practice, while the other endangered its success much more by rash and self-seeking advocacy. At the head of the latter was George Pearson, who in November 1798 published a pamphlet speculating upon the subject, before even seeing a case of cow-pox, and afterwards endeavoured, by lecturing on the subject and supplying the virus, to put himself forward as the chief agent in the cause. The matter which he distributed, which had been derived from cows that were found to be infected in London, was found frequently to produce, not the slight disease described by Jenner, but more or less severe eruptions resembling small-pox. Jenner concluded at once that this was due to an accidental contamination of the vaccine with variolous matter, and a visit to London in the spring of 1799 convinced him that this was the case. In the course of this year the practice of vaccination spread over England, being urged principally by non-professional persons of position; and towards its close attempts were made to found institutions for gratuitous vaccination and for supplying lymph to all who might apply for it. Pearson proposed to establish one of these in London, without Jenner's knowledge, in which he offered him the post of honorary corresponding physician! On learning of this scheme to supplant him, and to carry on an institution for public vaccination on principles which he knew to be partly erroneous, Jenner once more visited London early in 1800, when he had influence enough to secure the abandonment of the project. He was afterwards presented to the king, the queen and the prince of Wales, whose encouragement materially aided the spread of vaccination in England. Meanwhile it had made rapid progress in the United States, where it was introduced by Benjamin Waterhouse, then professor of physic at Harvard, and on the continent of Europe, where it was at first diffused by De Carro of Vienna. In consequence of the war between England and France, the discovery was later in reaching Paris; but, its importance once realized, it spread rapidly over France, Spain and Italy.