Thus far we have traced the rise of inoculation as an idea. It was one way of procuring the smallpox, which had gradually arisen out of other fanciful or real modes of infection. The populace for long retained a preference for giving their children the smallpox by exposing them to the contagion of it; in the last quarter of the 18th century, Haygarth found the common people of Chester still following the earlier practice of inviting the smallpox in the natural way[896]. It is even more remarkable that Huxham, the ablest epidemiologist in England during the first period of inoculation, preferred that children should take the disease naturally, believing that they might be so “prepared” to receive the seeds of it by the breath as to have always a sufficiently mild but effective dose of it. Still, the insertion of smallpox matter at a puncture or wound of the arm appeared to many to have advantages over the natural way. In London it was taken up by the Court, by the Court doctors, and by the Royal Society, the leading physicians in favour of it having been Sloane, Mead, Arbuthnot and Jurin. It appears that Freind, a more learned physician than any of these, was adverse to it. It was to him that Wagstaffe, physician to St Bartholomew’s Hospital, dedicated a hostile essay on inoculation when it was new; and Freind himself brought into his History of Physic, published in 1725-26, the following sarcastic passage upon John of Gaddesden, whom he regarded as a high-placed charlatan:
“He had an infallible plaster and caustick for a rupture; could cure a cancer from an outward cause with red dock. And if he had lived in our day, he would, I don’t question, have been at the head of the Inoculators; and in this case the position he lays down, contrary to the experience of the best physicians, that one may have the smallpox twice, might have served him in good stead for salvo’s upon many occasions.”
—which means that, in Freind’s opinion, the inoculated smallpox was no security against a subsequent attack in the natural way[897].
Wagstaffe, in his printed letter to Freind, sums up the objections to inoculated smallpox as follows:
“Some have had the distemper not at all, others to a small degree, others the worst sort, and some have died of it. I have given instances of those who have had it after inoculation in the common way; and consequently as it is hazardous, so ’twill neither answer the main design of preventing the distemper for the future. I have considered what the effects may be of inoculating on an ill habit of body, and how destructive it may prove to spread a distemper that is contagious: and how widely at length the authors in this subject disagree among themselves, and how little they have seen of the practice:—all which seem to me to be just and necessary consequences of these new-fangled notions, as well as convincing reasons for the disuse of the practice[898].”
These objections were shared by several, including Blackmore, Clinch, and Massey, the apothecary to Christ’s Hospital.
On the other hand Jurin, who took the lead in defending inoculation, reduced the issues to two[899]:
1. Whether the distemper given by inoculation be an effectual security to the patient against his having the smallpox afterwards in the natural way?
2. Whether the hazard of inoculation be considerably less than that of the natural smallpox?
These questions, thus put forward as of equal moment, did not receive equally full handling. Jurin dismissed the former question in a brief sentence: “Our experience, so far as it goes, has hitherto strongly favoured the affirmative side”—a conditional assent which became an absolute affirmative after a short time. Having thus disposed of the question which has all the scientific or pathological interest, he turned with his whole energy to give a precise arithmetical demonstration of what no one could doubt, namely, that inoculated smallpox was many times less fatal than smallpox in the natural way,—having got the idea of such a comparison from Nettleton as well as a large part of the statistics necessary for it. Jurin’s statement of the questions at issue, and his manner of answering them, became the received mode, so much so that even towards the end of the eighteenth century one finds capable medical men contrasting the almost infinitesimal mortality from inoculation, as then practised, with the high mortality from the natural smallpox, as if that were the question at issue. The permanent impression in favour of inoculation made by Jurin’s arithmetic was shown a generation later, when Dr George Baker pronounced an eulogy upon him in the Harveian Oration before the College of Physicians in 1761[900]. “It was his special glory,” said the orator, to have “confirmed the practice of inoculation by his experiments and his authority.” There was only one experiment, and it was a remarkable one. The Princess of Wales had begged George I. to pardon six Newgate criminals under sentence of death on condition that they would submit to be inoculated. It was assumed that those six had not had smallpox in infancy or childhood, and Sloane, relating the facts in a letter to Ranby some years after, does in fact call them “six condemned criminals who had not had the smallpox[901].” The concurrence of six persons belonging to the criminal classes and about to be hanged together in Newgate, of whom none had already gone through the common infantile trouble of London and other large towns, was singular. They were inoculated, and it was found that they had escaped the death penalty on very easy terms: John Alcock, aged twenty, had most smallpox, but even he had “not more than sixty pustules”; Richard Evans, aged nineteen, had none, but his antecedents were inquired into, and then it was found that he had had smallpox in gaol only six months before. One of the others, a woman named Elizabeth, was chosen for the grand crucial experiment. Sir Hans Sloane and Dr Steigerthal clubbed together to pay her expenses to Hertford where smallpox was then very prevalent; thither Elizabeth went and ministered among the sick; she lay in bed with one in the smallpox, or she lay in bed with various in the smallpox; at all events she exposed herself to contagion and did not catch it, according to certificates from the woman she lodged with and from another person, which certificates were published with much formality and lawyer-like precision[902]. This was the single experiment in which Jurin had any part. What were the chances of her having had smallpox in childhood? What were the chances of her knowing anything about it, or telling the truth about it if she knew? (One of her fellows in the experiment upon the pardoned convicts had smallpox only six months before, but the fact was not discovered until it was wanted.) What were the chances of her taking smallpox at Hertford, supposing that she had hitherto escaped it? These questions do not appear to have been debated[903].