was born, to whom John Hunter was godfather.
Jenner's general practice soon became so large that he decided to give up midwifery and surgery, and in 1792 obtained the degree of M.D. from the university of St. Andrews. In 1793 he published ‘A Process for Preparing Pure Emetic Tartar by Recrystallisation’ in the ‘Transactions’ of a ‘Society for the Improvement of Medical and Chirurgical Knowledge.’ In 1794 he had typhus fever severely.
After his recovery he continued those investigations as to the protective power of cow-pox against small-pox which he had begun in earlier years. There was a local belief, of which he had known in boyhood, that dairymaids who had had cow-pox did not take small-pox, then almost the commonest epidemic disorder in all ranks of society. He had mentioned this to Hunter, and always kept the subject in mind, observing and often talking to others of his observations. He came to the conclusion, since shown to be erroneous, that grease, a disease of the feet in horses, and cow-pox were the same disease, and to the now well-established conclusion that cow-pox is protective against small-pox. On 14 May 1796 he vaccinated in the arms James Phipps, a boy of eight, with lymph taken from vesicles of cow-pox on the hand of Sarah Nelmes. The boy had cow-pox. On 1 July the same boy was inoculated from a case of small-pox. This was not an unjustifiable experiment, as inoculation of children when well was then thought a safe way of getting them through the almost inevitable epidemic disease. The boy did not have small-pox. This completed Jenner's argument. The first summary of his observations exists in a holograph manuscript at the Royal College of Surgeons, and is endorsed in his own hand ‘On the Cow-pox, the original paper.’ That it was his intention to send it to some society, possibly the Royal Society, as the first account of inoculation had been read there in 1714, is indicated by the fact that on fol. 35 the words ‘on the minds of this society’ are altered to ‘on the minds of my readers.’ No evidence exists to show that it was ever sent to any society. It ends with the words: ‘I shall endeavour still further to prosecute this inquiry, an inquiry I trust not merely speculative, but of sufficient moment to inspire the pleasing hope of its becoming essentially beneficial to mankind.’ The paper was never printed. In June 1798 he published in London a fuller account of his observations and conclusions in a short treatise, which will always be respected as one of the classics among medical books, ‘An Inquiry into the Cause and Effects of the Variolæ Vaccinæ, a Disease discovered in some of the Western Counties of England, particularly Gloucestershire, and known by the name of the Cow-pox.’ The book is a quarto of seventy-five pages, and is dedicated to Dr. C. H. Parry of Bath. There are some coloured plates, of which one is of the hand of Sarah Nelmes showing the vaccine pustules upon it. Twenty-three cases are described, and the most important conclusion is ‘that the cow-pox protects the human constitution from the infection of small-pox.’ The experience of nearly a hundred years has led to the acceptance of this conclusion throughout the civilised world; and by the whole body of the medical profession, and of the very few men who have declined to regard it as an invaluable addition to the practice of medicine, a majority do so on grounds which have no relation to scientific observation. A minor conclusion, that the disorder began in the horse and must pass through the cow to man in order to be protective, was erroneous, but in no way affects the main thesis.
Jenner stayed in London from 27 April to 14 July 1798 making known his discovery to the medical world. He was much disappointed because he could get no one to allow himself to be vaccinated in London. About a month later Mr. Cline, surgeon to St. Thomas's Hospital, vaccinated some patients with lymph given him by Jenner. Cline advised Jenner to come to London, and assured him of a large income in practice, but the discoverer wrote in answer that he had enough and was content.
Dr. Ingenhousz was staying with Lord Lansdowne in 1798, and wrote a courteous letter of dissent from the conclusions of the ‘Inquiry’ (Crookshank, History and Pathology of Vaccination, i. 143), mentioning observations of his own which were opposed to them. Jenner replied frankly that his own observations had been few, and no doubt needed the confirmation of other observers. Further opposition soon arose, and on 5 April 1799 Jenner published ‘Further Observations on the Variolæ Vaccinæ or Cow-pox,’ which is chiefly a reply to objectors. He continued to work at his subject at Berkeley and at Cheltenham, and in 1800 published ‘A Continuation of Facts and Observations relative to the Variolæ Vaccinæ or Cow-pox,’ and ‘A Complete Statement of Facts and Observations relative to the Cow-pock.’ He added two continuations of the same subject: (1) ‘On the Origin of Vaccine Inoculation,’ 1801, and (2) ‘On the Varieties of the Vaccine Pustule occasioned by an herpetic state of the Skin.’ He returned to
