In this connection the question occurs, Why should “some varieties of spontaneous eruptions” have been designated _spurious_ Cowpox? Such eruptions were not Cowpox in any sense. Why then spurious? That Cows communicated a variety of sores to their milkers, described by them in common as Cowpox, was an assertion for which Jenner never adduced any evidence; which, too, (as we shall see) at a later date he disowned as a misapprehension. Nevertheless spurious Cowpox got the New Inoculation over many difficulties. When Smallpox, or any notable mischief, followed Cowpox it was said, “Ah! the Cowpox must have been spurious; for Smallpox, or any harm, is impossible after true Cowpox.” People did not stay to inquire whether spurious Cowpox (that was to say, matter “from a variety of sores on the Cow,” according to Jenner’s second version) could be propagated from arm-to-arm, even if taken from the Cow by mistake. The illusory Variolous Test and the Spurious Cowpox Dodge worked marvellously for the public deception. Another point Jenner tried to score at the cost of Pearson and Woodville. When they began to inoculate they found they had to ascertain at what period the virus should be taken from the Cow, and from the arms of the inoculated. Jenner afforded them no guidance. Writing to John Ring, 1st July, 1801, he confessed-- In the early part of my inoculations I had not learned to discriminate between the efficacy of the virus taken at an early and at a late period of the pustule.[125] Where Jenner had not learned to discriminate, the line became clear in the course of general practice; and Pearson was especially explicit as to the right time for taking virus; but to make good his claim to national consideration, Jenner fancied it necessary to exhibit himself as complete master of the art of Cowpox Inoculation, owing nothing to others; and he therefore proceeded to appropriate the fruit of the common medical experience, assigning it to a season when he alone was in the field. Referring to his separation of true from spurious Cowpox, he thus prosecuted his raid--