Sutton made it known that the effects of this method were exceedingly mild—no keeping of bed, no trouble at all: “if any patient has twenty or thirty pustules, he is said to have the smallpox very heavy.” Being put on his trial at Chelmsford for spreading abroad the contagious particles of smallpox by the number of his inoculations, his defence was to have been (if the bill had not been thrown out by the grand jury), that he “never brought into Chelmsford a patient who was capable of infecting a bystander.” The mildness of his artificial smallpox was acknowledged with satisfaction by some, with dissatisfaction by others. Dr Giles Watts, an inoculator in Kent, says it was “a most extraordinary improvement. The art of inoculation is enabled to reduce the distemper to almost as low a degree as we could wish.... There is now an opportunity of seeing what a very small number of the multitude of persons of all ages, habits and constitutions, who have been inoculated in these parts, have been ill after it.” Comparing it with the method which he had practised before, he says that he never knew ten or twelve inoculated together “in the old way” but one or more had the distemper in a pretty severe manner; on the other hand, he had inoculated four of his children in the new way and all of them together had not so many as eighty pustules. He adds that sometimes the inoculated had not even a single pustule (besides the one at the point of insertion) or at other times not more than two or three[936].
The Suttonian practice was objected to by Bromfeild in an essay dedicated to Queen Charlotte. Tracing it to Gatti, whose manifesto had been published in England two years before, he said that it was mere credulity “to have given credit to a man who should assert, that he would give them a disease which should not produce one single symptom that could characterize it from their usual state of health.... Inoculation, though hitherto a great blessing to our island, will in a very short time be brought into disgrace,” if it were assumed “that health and security from the disease can be equally obtained by reducing the patients so low as only to produce five to fifteen pimples[937].”
Bromfeild was not openly supported except by Dr Langton, of Salisbury, who contended that “the matter communicated is not the smallpox, because numbers have been inoculated a second, third and fourth time, that therefore it is no security against a future infection.” He cites Gatti’s case of the Duchess de Boufflers, and declares, as to the English inoculations, that not above one in ten have so many variolous symptoms as may be remarked in her case. “The old method of inoculating,” he says, “was to take the infection from a good subject where the pustules were well maturated, whereby the operation was sure of succeeding; but the present practice is to take the matter from the incision the fourth day after the incision is made [this was Sutton’s avowed practice]. By this means you have a contagious caustic water instead of laudable pus, and a slight ferment in the lymph is raised, producing a few watery blotches in the place of a perfect extrusion of the variolous matter[938].”
There was no difference of opinion as to the exact purport and upshot of the new method; it was to reduce the eruption to the lowest point or to a vanishing point. Nothing can be more emphatic than Gatti’s profession of belief that a single pustule, at the place of insertion, was as effectual as ten thousand; and it is not only likely, on the face of it, that such a mitigation as Reid’s to the thirtieth remove from natural smallpox, would produce merely the local pustule, but it is clear that Gatti saw no way of ensuring more by his method, supposing he were to gratify the prejudices of the laity in favour of more, than by puncturing the skin at twenty, thirty, or fifty separate points. It is not to be supposed, however, that the minimum result was obtained in all cases, or that all inoculators were equally adroit in procuring it; even Sutton had to admit that some of his thirteen thousand patients had more pustules on the skin than he desired.
Perhaps the most exact record of the number of pustules produced in a comparative trial of various methods is that of Sir William Watson at the Foundling Hospital in 1768[939]. Of 74 children inoculated in October and November, twelve had no eruption at all, but yet were held to have been protected by the operation. The remaining sixty-two had a very small average of pustules in addition to the local pustules, which average, small as it was, came mostly from two or three severer cases (e.g. one with 440 pustules, one with 260, and one with near 200), the most having three or four or a dozen or perhaps two dozen (e.g. three had only 7 pustules among them, or, in another batch of ten done with crude or ichorous matter, “the most that any boy had was 25, the least 4, the most that any girl had was 6, the least 3,” or, in another batch of ten, also with crude lymph, two had no eruption, seven had 35 pustules among them, and one had 30). Of the amount of smallpox upon the whole sixty-two cases which had some eruption Watson says: “Physicians daily see in one limb only of an adult person labouring under the coherent, not to say confluent smallpox, a greater quantity of variolous matter than was found in all these persons put together.”
Watson’s sole measure of “success” in inoculating was the slightness of the effect produced; and as he found that crude or watery matter from the punctured spot of a previous inoculation had the least effect, he decided to use that kind of matter always in future at the Foundling Hospital. On the other hand, Mudge, of Plymouth, raised a different issue and put it to the test of experiment on a large scale. Did crude matter infect the constitution? Did it make the patient insusceptible of the effects of a second inoculation with purulent matter? The experiment came out thus:
At Plympton, in Devonshire, in the year 1776, thirty persons were inoculated with crude or watery matter from the arm of a woman who had been inoculated five days before, and ten persons were at the same time inoculated with purulent matter from the pustules of a case of natural smallpox. The thirty done with crude matter had each “a large prominent pustule” at the place of puncture, “but not one of them had any eruptive fever or subsequent eruption on any part of the body.” Matter taken from their local pustules produced exactly the same result in the next remove, namely, a local pustule, but no eruptive fever nor eruptive pustules. The thirty were inoculated again, this time with purulent matter (five from natural smallpox, twenty-five from inoculated smallpox), and all of them had, besides the local pustule, an eruptive fever and an eruption “in the usual way of inoculated patients.” The ten who were originally inoculated with purulent matter had that result at first[940].
In the subsequent history of inoculation it would appear that the method known by the name of Sutton, of using crude or watery matter from a previous inoculated case, was the one commonly preferred. But it was not always preferred. One of the medical neighbours of the afterwards celebrated Dr Jenner took matter from the pustules and kept it in a phial; his patients inoculated therewith had somewhat active effects, even “sometimes eruptions.” But “many of them unfortunately fell victims to the contagion of smallpox, as if they had never been under the influence of this artificial disease,” so that Jenner, who had probably not heard of Mudge’s experiment, was confirmed in his preference for the crude matter (before the eruptive fever) from a previous inoculation. It was of great importance, he said, to attend to that point, as it would “prevent much subsequent mischief and confusion[941].” Of course there were many more chances of getting matter from natural smallpox than from inoculated; but it would appear that in the former also it was taken in the ichorous or unripe stage of the eruption, according to the practice of Sutton, and despite the experimental proof that Mudge gave of its merely superficial or formal effects.
Mudge’s experiment was on a large scale, and designed to test a general or scientific issue. The testing experiment usually made was merely for the sake of the particular case; the patient was inoculated a second time, shortly after the first, with the same matter as before, or a third time, or even a fourth time. Whatever the significance of this for the doctrine of inoculation in general (as in the issue raised by Mudge), the individual was both reassured and fortified so far as concerned his own safety. The experiment of the former generation that was usually cited was that of the Hon. John Yorke. On his leaving the university at the age of one and twenty it was thought prudent that he should be inoculated for smallpox before entering on the great world. He was inoculated by serjeant surgeon Hawkins, and had the local suppuration, some fever, but little or no eruption. The inoculator was satisfied, but not so the youth: he insisted upon a second inoculation, which had no effect. This was considered a leading case. When the Suttonian method came in, and the absence of eruption (barring a few pimples or bastard pustules) became the usual thing, the occasions for a second inoculation became more common, owing to the prejudice, as Gatti said, of the laity in favour of something tangible although not excessive[942].
Dimsdale inoculated many of his patients a second time, and produced the local pustule again, as at first. Of the 74 foundlings in Watson’s experiment of Oct.-Nov. 1767, there were twelve who had no eruption, of whom four were re-inoculated with no better result or with no result. Of the whole twelve he says: “Although they had no eruption, I consider them as having in all probability gone through the disease, as the punctures of almost all of them were inflamed and turgid many days.” It was so unusual for a second inoculation, in a doubtful case, to produce more than the first, that Kite, of Gravesend, communicated to the Medical Society of London two cases where that had happened, as being “anomalous.” He had never before been able to communicate the smallpox, on a second attempt, “to any patient whose arm had inflamed, and who had even a much less degree of fever” than Case 1, who had only the local pustule and “on the eighth day was quite well:” and he cites Dimsdale to the same effect[943].