I not only very much doubt that the Cowpox is a permanent preventive of Smallpox, but I am confirmed in this opinion by occurrences in my own practice, by conversing with many medical men on the subject, and by Dr. Beddoes, who writes, “I have a case where the Smallpox was taken after the Cowpox had been twice gone through.”[116] Yet in presence of such testimonies, which were neither examined nor exploded, Jenner prophesied in this strain-- Some there are who suppose the security from the Smallpox obtained through the Cowpox will be of a temporary nature. This supposition is refuted, not only by analogy with respect to diseases of a similar nature, but by incontrovertible facts, which appear in great numbers against it. A person had the Cowpox 53 years before the Smallpox was tried upon him, and as he completely resisted it, I conceive every reasonable mind must be satisfied that he was secure from the disease during the intervening time. Such was the evidence that he thought should satisfy every reasonable mind! How did he know that the said person had cowpox 53 years before, or had the right sort of cowpox, and in the right way? Inoculation with smallpox was continually unsuccessful (without reference to cowpox as cause of failure) and especially among elderly folk. When, however, there is a disposition to believe, the most indifferent reasons serve for conviction. Cowpox and Smallpox, said Jenner, were modifications of the same disease; and Smallpox, whether contracted or inoculated, was a well-known excitant of scrofula; and Jenner was inclined to consider it probable that “the general introduction of the Smallpox into Europe had been among the most conducive means in exciting that formidable foe to health.” Then, it might be said, Cowpox as a modification of Smallpox must be liable to the like objection. “Not at all!” protested the smooth-spoken adventurer. “The diseases are the same, but unlike in the excitation of scrofula”-- Having attentively watched the effects of the Cowpox in this respect, I am happy in being able to declare, that the disease does not appear to have the least tendency to produce this destructive malady. Considering his limited experience, the asseveration as to the non-excitation of scrofula was sheer quackery, and of a piece with the wilder assurance that follows. In 1798 he had set forth cowpox as a useful alternative to smallpox for inoculation; but in 1800 the claim was thus magnified-- When scrutiny has taken place, not only among ourselves, but in the first professional circles in Europe, and when it has been uniformly found in such abundant instances-- _That the Human Frame when once it has felt the influence of the genuine Cowpox is never afterwards, at any period of its existence, assailable by the Smallpox_,