Jenner’s design in the foregoing statement was manifest. It was to minimise the faith of the country folk, and to represent that by his own perspicacity he had discovered the virtue of Cowpox through his failures to inoculate with Smallpox. The inquiries of Pearson and others, however, showed conclusively that in many parts of the south of England, in Ireland, and on the Continent it was believed that to have suffered from Cowpox was to be secure from Smallpox; and the belief was entertained altogether independently of failures to inoculate with Smallpox; just as a similar belief prevailed among farriers as to the prophylaxy of Horsegrease. The faith in Cowpox was neither vague, nor new, nor confined to Jenner’s neighbourhood; and his assertion to the contrary showed with what hardihood he had undertaken to construct a case in his own favour.
In opposition to the rural faith, medical men maintained that it was possible to have Smallpox after Cowpox; and surgeons averred that they had successfully inoculated many who had suffered Cowpox. Indeed it was indubitable professional testimony to this effect that compelled Jenner to forsake his first fancy for Cowpox, and to report the true specific as Horsegrease Cowpox. Having, however, to sacrifice that discovery, and revert to the Cowpox he had discredited, a fresh manœuvre was requisite; and thus was it performed—
In the course of the investigation I found that some of those who seemed to have undergone the Cowpox, nevertheless, on inoculation with the Smallpox, felt its influence just the same as if no disease had been communicated to them by the Cow. This occurrence led me to inquire among the medical practitioners in the country around me, who all agreed in this sentiment, that the Cowpox was not to be relied upon as a certain preventive of the Smallpox. This for a while damped, but did not extinguish my ardour; for as I proceeded I had the satisfaction to learn that the Cow was subject to some varieties of spontaneous eruptions upon her teats, that were all capable of communicating sores to the hands of the milkers, and that whatever sore was derived from the animal was called in the dairy the Cowpox. Thus I surmounted a great obstacle, and, in consequence, was led to form a distinction between these diseases, one of which only I have denominated the true, the others the spurious Cowpox, as they possess no specific power over the constitution.
Here we have the trick before us at the very point of transformation. He consulted with medical practitioners, “who all agreed that Cowpox was not to be relied upon as a certain preventive of Smallpox.” True. What did he do next? He discovered that what Cowpox did not prevent, the variety derived from Horsegrease did. Such was the original revelation of 1798. In 1801 we have a different story, and his quest a different issue. Not a word about the discovery of the sure preventive in Horsegrease Cowpox—not one word! Although his ardour was damped by the medical evidence against Cowpox, he yet prosecuted his inquiry; and to his satisfaction ascertained that what the milkers called Cowpox was not always Cowpox, but that any sores whatever derived from the Cow were so designated. He therefore was led to form a distinction between the diseases, and to denominate one as true and the others as spurious Cowpox.
Thus the Horse, the obnoxious Horse, was got rid of, and the Cow represented as of herself yielding pox, which pox was the Cowpox that Pearson and Woodville (in contempt of Jenner’s 1798 revelation) had brought into fashion; and which it had become all essential for Jenner to claim as his own in order to realise his “fond hope of enjoying independence.”
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]