In 1782 had Cowpox when she was attended by Jenner. In 1795 she, and seven other pauper women of Tortsworth, who also had had Cowpox, were inoculated with Smallpox by Henry Jenner without effect. “This state of security proved a fortunate circumstance,” observed Jenner, “as many of the poor women were at the same time in a state of pregnancy.” Why then, it might have been asked, did Henry Jenner try to variolate them? * * * * * These Twelve Cases illustrate Jenner’s procedure; and those familiar with scientific methods, and the scrutiny and caution requisite to arrive at trustworthy physiological data, will view with some astonishment his free and easy induction. In the majority of the Cases he was without proof that his subjects had suffered Cowpox; and the absence of this certainty was the more remarkable as he knew that the dairy-folk described as Cowpox several varieties of eruption. The same rural observers who held that Cowpox averted Smallpox, also held that Smallpox averted Cowpox; and yet Jenner had to show in Rodway’s Case No. vii., that they were mistaken; although, granting the thesis that Smallpox and Cowpox were equivalents and mutually preventive, the rural faith ought to have stood justified, and Smallpox shown to be good against Cowpox. Again Jenner allowed that an attack of Cowpox did not prevent a subsequent attack of Cowpox, saying-- It is singular to observe that the Cowpox virus, although it renders the constitution insusceptible of the variolous, should nevertheless leave it unchanged with respect to its own action. Singular indeed! The observation in presence of the principle to be established was nothing short of imbecile. If Smallpox prevented Smallpox, and Cowpox was one with Smallpox, and Cowpox did not avert Cowpox, how was Cowpox to avert Smallpox? The insusceptibility of Jenner’s subjects to variolous inoculation was, as observed, of little account. Resistance to inoculated Smallpox was of common occurrence, and inoculators practised various dodges to overcome it. To have made such experiments approximately conclusive would have required the inoculation with Smallpox of subjects of corresponding ages and temperaments who had not passed through Cowpox; and the probability is that the results would not have been dissimilar. We must not, however, proceed farther until Cowpox is described; and for that purpose I cannot do better than cite Jenner verbatim. JENNER’S DESCRIPTION OF COWPOX. Cowpox appears on the nipples of the Cows in the form of irregular pustules. At their first appearance they are commonly a palish blue, or rather of a colour somewhat approaching to livid, and are surrounded by an inflammation. These pustules, unless a timely remedy be applied,[98] frequently degenerate into phagedenic [spreading] ulcers, which prove extremely troublesome. The animals become indisposed, and the secretion of milk is much lessened.