As evidence of how completely Jenner’s prescription of horsegrease cowpox was put out of sight, I may refer to the treatise of Dr. Willan _On Vaccine Inoculation_, published in 1806, wherein all that was thought important concerning the new practice was set forth; and although Jenner was freely cited, yet neither horsegrease nor horsegrease cowpox was referred to from the first page to the last. Instead, cowpox, after the fancy of the dairymaids, was exalted as the true prophylactic, apparently without a suspicion of its questionable character. As I have said, Jenner not only offered no resistance to this amazing transformation, but conformed to it, and assumed the issue as his own. Since the public preferred cowpox to horsegrease cowpox, he saw no reason why he should object, especially as the same foolish public lusted after some one to worship for their deliverance from the plague of variolation. The world resounded with praises of the immortal Jenner, the saviour of mankind from smallpox. Enveloped in the smoke of such incense, it is scarcely surprising that the idol came to believe that his worshippers knew him better than he did himself. SPURIOUS COWPOX. The promise of vaccination, its absolute security and harmlessness, was speedily belied. The vaccinated caught smallpox; they fell sick after the operation; they were afflicted with eruptions and swellings; they died. These mishaps were at first denied--stoutly denied; and when denial was no longer possible, it was attempted to explain them away. The cowpox used could not have been genuine cowpox, but spurious; and for awhile spurious cowpox did yeoman’s service in the way of apology; but by-and-by the excuse began to work more harm than good. Mishaps were so numerous that people became afraid of this omnipresent spurious cowpox, and to ask what it was, and how it could be avoided. How can there be spurious pox? Whoever heard of spurious disease? Milkmen vend spurious milk, grocers spurious sugar, smashers spurious coin; but surely cows are not to be numbered with such malefactors as producers of spurious pox! The thing was absurd on its face, and absurd it proved. When Jenner was under examination by a committee of the College of Physicians in 1806, he was pressed hard for a definition of spurious cowpox, when he “owned up.” He knew nothing of spurious cowpox. The words had been employed, not to describe any irregularity on the part of the cow, but certain irregularities in the action of cowpox on the part of the vaccinated: which was to say that when the vaccinated recovered creditably and did not catch smallpox, the cowpox was genuine; but when the sequences were otherwise, why then it was spurious! Ingenious and convenient, was it not? HORSE VIRUS VINDICATED.