Revival of Inoculation in 1740: a New Method.
As early as the Boston inoculations of 1721, the matter had now and again been taken, not from a case of the natural smallpox, but from the pustules of a previous inoculation[921]. But at Charleston in 1738 there really began, doubtless in the way of empirical trial, a systematic attenuation of virus, which has had great scientific developments in our time and has come to be considered as of the essence of the inoculation principle. Describing the South Carolina practice, Kilpatrick says[922]:
“Some persons were of opinion that the pock of the inoculated would be too mild to convey the disease; or, at least, that it must become effete by a second or third transplantation. Experience manifested the contrary. I have inoculated from those who were infected by the matter taken from others of the inoculated, and found no defect. Mr Mowbray, who inoculated many more than any other practitioner, assured me he had infused matter in the fifth or sixth succession from the natural pock, and observed no difference.... The smallest violation of the surface, if it was stained with blood, was a sufficient entrance for the matter, and the least matter was sufficient.”
The last point was a return to the Greek practice, and an abandonment of the more severe method of Nettleton and Boylston.
The Charleston smallpox of 1738, imported by slave-ships from Africa, became extensively epidemic and mortal. It had been last in Charleston fourteen or fifteen years before, but only one or two died on that occasion, and hardly more than ten were attacked. But for that small outbreak, it had not been known in the South Carolina port for a generation previous to 1738. The number of victims in that year is not known precisely. As at Boston in 1721, the epidemic dragged through the spring months, and became very extensive and mortal in the hot weather of June and July. It was then that Mowbray began inoculating, most of the Charleston faculty being opposed to it. He was soon followed by Kilpatrick, who had lost one of his children in the epidemic, and was moved thereby to inoculate the other two. No exact account was kept of the inoculations, nor, we may be sure, of the protective effects; some said a thousand were inoculated, Kilpatrick says eight hundred, but the total of four hundred is also given. Eight died after inoculation, six whites and two negresses. One child of ten months died in convulsions on the ninth day after inoculation, with few signs of smallpox; a minister, aged 40, sickened on the third or fourth day, which was too soon for the artificial disease, and was almost certainly the effects of the inhaled virus; two other adult whites died in such circumstances as to make it doubtful whether they died of inoculation or of coexistent natural smallpox; one negress died of confluent smallpox, having treated herself unwisely; while two other children and a negress died after inoculation, of whom no particulars are known. Besides the fatal cases after inoculation, some “had an eruption that might be called a moderate confluence”; but in these cases also it is not clear that infection was not taken in the natural way: as regards one gentlewoman who had confluent smallpox, it was not certain in what manner she received the infection, whilst “Miss Mary Rhett’s eruption did not appear until the 14th day, yet was supposed to be effected by art.” To meet such cases Kilpatrick adopted the doctrine that there was “no precise term for the artificial eruption.” Among those “hardly dealt with” by the disease, supposed to have been given by art, were two ladies who had their eyes permanently injured. “With regard to a second infection of the inoculated who took, this was asserted by some who wished for it, but were as soon refuted.” Nineteen in twenty of the inoculated had an exceedingly slight eruption, so slight indeed that they thought the confinement indoors irksome and unnecessary. As to the negroes, who had all been born in Africa (and commonly have smallpox there or in the voyage across), it was not easy, he admits, to find out whether they had had smallpox before or not, the pits on their faces being less obvious than in whites, and the marks of other distempers easily mistaken for them. On the whole Kilpatrick was confident that inoculation in this epidemic had saved many lives; and it was the rumour of its success, together with corresponding reports from the plantations in the West Indies relating the valuable lives of negroes saved, that gave a fresh impulse to the practice in England. In 1743 Kilpatrick came to London, where he republished his Charleston essay, with an historical appendix, and soon got into the leading practice as an inoculator, having proceeded to the degree of M.D. and changed the spelling of his name to Kirkpatrick. Woodville says “he was esteemed the most scientific inoculator in London.” During the eleven years from his setting up in practice there until the publication of his Analysis of Inoculation (1754), he had almost certainly been applying the arm-to-arm method which he learned from Mowbray in Charleston, having briefly indicated it in his first essay and avowed it more explicitly in his second. The establishment of Kirkpatrick in London, to practise the Charleston method of inoculation, corresponds, as nearly as one can trace it, with the revival of the practice in the south of England, to the extent of some two thousand cases in the counties of Kent, Surrey, Sussex, Hampshire and Dorset. We have a glimpse of that practice in the essay on inoculation published in 1749 by Dr Frewen, of Rye in Sussex[923], a physician of considerable learning (of the school of Boerhaave), whose theories of the effects of inoculation are reflected in Kirkpatrick’s Analysis of 1754. In 350 cases, Frewen had only one fatality, the death of a child, aged four, from worm fever on the eighth day of a discrete eruption. He still used the incision on the arm, but less deep than Nettleton’s, keeping the pledget of lint, moistened with matter, bound upon it for twenty-four hours; also he encouraged the rendering from the incision for some weeks, giving the same reason as before, that “Nature by means of a continual drain is greatly aided in her attempts to throw off the matter of the disease.” In his general account of the effects of inoculation, we seem to be reading of as real symptoms and as many pocks as Nettleton described—the eruption, always of the simple distinct kind, beginning on the 9th day, all out in three or four days after, the pocks filling and turning yellow for the next four or five days, then scabbing and falling, leaving temporary shallow marks. But it is clear that he had other results than these from trying new ways of procuring matter. “Experience,” he says, “has convinced me that it is in reality of no consequence from what kind of smallpox it [the matter] is procured.” If taken from the natural smallpox, it should be taken from ripe pustules: “yet I have sometimes applied it sooner, while only a limpid water.” Oftentimes it happened that an inoculation produced too “slight” pustules to furnish matter for the succeeding operations. The question then arose whether the matter rendering from the incisions on the arms in these cases was merely common pus or whether it had the property of “variolosity.” This abstract quality, as it were the essence or quiddity of the pustular exanthem, was assumed to be present if the pus of the rendering incision could be made to raise a pustule on another arm, and if the person so infected could stand exposure to natural smallpox with impunity. One person so inoculated did have an attack of smallpox by contagion, so that Frewen concluded that the matter used for his protection had “run off all its variolosity.” But others inoculated with the same, “in whom the symptoms were remarkably light, and in some few no pustules at all,” were equally exposed to contagion without catching it, so that they were “judged to be secure from ever taking the smallpox again.” Frewen’s general conclusion, if it be not very logical, is at least modest:
“However, it may be worth the attention to reflect seriously whether it be not highly probable, from the success attending the numbers I have been concerned for, that inoculation has been often times a security against taking the most dangerous kinds of the natural smallpox.”
Whether Frewen got the ideas of these novelties of method from Kirkpatrick’s first account of the South Carolina practice, or struck them out for himself, it is clear that Kirkpatrick, in his next essay of 1754, has adopted variolosity as an abstract doctrine to surmount certain difficulties in the concrete reason. Many of his inoculated cases had only a few bastard pustules of smallpox, some had none. Was their disease smallpox? Did it warrant their future security?
“As many of the inoculated have very few pustules, and they are sometimes disposed to scab and wither away with very little suppuration, it might be of service to discover that the matter from the incisions would infect. But it would be certainly satisfactory to find it would where there was no eruption from inoculation, as its variolosity would greatly warrant the future security of the person it was taken from. That it is variolous is now evinced by the fact that it infected others to the like slight degree[924].”
The movement towards attenuating the virus used for inoculation was general in Europe. One of the mild methods, invented by Tronchin, of Amsterdam and afterwards of Paris, was to raise a small blister on the arm and to pass through the fluid a thread moistened with smallpox matter. This became one of the most common continental methods and was in use until the beginning of the 19th century. Kirkpatrick, who went to see the practice of Tronchin, found the method by blister to produce as slight effects in the way of eruption as he describes for his own method:
“I attended and infected five poor children:—three, about seven years old, by incision; and two, about five years old, by vesication. Of the first three, one, a girl, had a pretty moderate but very kindly sprinkling; the two boys very few. The two by blisters, a boy and a girl, had rather less,—the boy Dudin, a very fair delicate little child, not having above three or four, all which had not matter enough to infect one patient[925].”
Everywhere after the middle of the eighteenth century inoculation was coming into fashion again. In France it was lauded by the philosophes, while it was scouted by the medical faculty. La Condamine, a mathematician who had acquired fame by his journey to the Amazon to measure the three first degrees of the meridian, became interested in the subject by hearing from a credulous Carmelite missionary at Para how he had saved half of his Indian converts by inoculation after the other half had been destroyed by the natural smallpox. The mathematical philosopher on his return became an enthusiast for inoculation, and twice harangued the Académie des Sciences thereon. “The practice of inoculation,” he said, “was improved during the time of its disgrace.” What this improvement consisted in he also explained: “Neither the eruption is essential to the natural nor the pustules to the artificial smallpox: and perhaps art will one day come to effect what one hopes for and what Boerhaave and Lobb have even tried—I mean a change in the external form of this malady without any increase of its danger[926].”