that the intimacy which sprung up between the master and pupil, and which continued until Hunter's death, exercised a powerful influence on Jenner's subsequent career. The love of natural science, which we have seen to have been with him almost an instinct, was fostered and quickened into the highest degree of life and energy by the example and teachings of Hunter. The latter, at the time of Jenner's introduction, had held for two years the post of surgeon to St. George's hospital; he had collected a menagerie at Brompton, where he carried on constant observations and experiments in biological science; and he had already commenced the formation of that magnificent museum which forms the lasting monument to his fame. It was in such a field that Jenner's powers were cultivated. He became an expert practical anatomist, a careful and observant experimenter, a sound pathologist, and a finished naturalist. The influence of Hunter followed his pupil long after he had quitted his roof; throughout the life of the former they continued to correspond; and Hunter's letters, which Jenner carefully preserved, evince the affectionate feeling and the community of tastes which subsisted between them. They are principally occupied by directions for experiments and observations intended to solve various questions in animal and vegetable physiology, and present a lively picture of the active inquiring character of the writer's mind. Many of them relate to the phenomena connected with animal torpidity; and a series of experiments performed by Jenner for the purpose of determining the diminution of heat in various parts of the body of the hedgehog during torpidity, were published by Mr. Hunter in his paper on the power of producing heat in animals. During the time of Jenner's residence with Hunter, in the year 1771, Captain Cook returned from his first voyage, and Jenner was recommended by Hunter for the service of arranging and preparing the specimens of natural history, which had been collected by Sir Joseph Banks. The manner in which the task was accomplished showed so much skill and knowledge, that Jenner was offered the post of naturalist to the next expedition, which sailed in 1772. He declined, however, the appointment, and decided to return to Gloucestershire and fix his residence in the place of his birth. Affection for the elder brother who had been the guardian of his childhood, was partly the motive which weighed with him in forming this determination; partly, also, he was influenced by a love of rural life, and a strong attachment to the scenes of his childhood. On his return to Berkeley he took up his residence with his brother, and commenced the practice of his profession. The reputation he had brought with him from London, the great professional knowledge he evinced, his kindly disposition and manners, rapidly brought him practice. He possessed an extraordinary power of interesting those with whom he came in contact; the charms of his conversation were so great, that his friends used frequently to accompany him for many miles in his rounds on horseback, for the pleasure of listening to his glowing descriptions of surrounding scenery, or for the purpose of being instructed by his explanations of the structure and economy of the various living forms which attracted his observation. His appearance at this time is thus graphically described by Edward Gardner, one of his early friends:—"His height was rather under the middle size; his person was robust, but active and well formed. In his dress he was peculiarly neat, and everything about him showed the man intent and serious, and well prepared to meet the duties of his calling. When I first saw him, it was on Frampton Green. I was somewhat his junior in years, and had heard so much of Mr. Jenner of Berkeley, that I had no small curiosity to see him. He was dressed in a blue coat and yellow buttons, buckskins, well polished jockey boots, with handsome silver spurs, and he carried a smart whip with a silver handle. His hair, after the fashion of the times, was done up in a club, and he wore a broad-brimmed hat. We were introduced on that occasion, and I was delighted and astonished. I was prepared to find an accomplished man, and all the country spoke of him as a skilful surgeon and a great naturalist, but I did not expect to find him so much at home on other matters. I, who had been spending my time in cultivating my judgment by abstract study, and smit from my boyhood with the love of song, had sought my amusement in the rosy fields of imagination, was not less surprised than gratified to find that the ancient affinity between Apollo and Æsculapius was so well maintained in his person," The latter sentence refers to Jenner's poetical tastes, which he cultivated as a recreation from severer studies. Some of the fugitive pieces he has left evince considerable poetical feeling, with an observant eye for the beauties of nature; and not a few are characterized by a quaint humour, which we are told frequently sparkled in his conversation. Not long after his settlement at Berkeley, he refused an offer of a lucrative appointment in India, made him by a gentleman whom he had casually met at a dinner party, and who had been much impressed by Jenner's intelligence and sagacity. He subsequently declined a still more flattering proposal from John Hunter, to join him in teaching natural history in London. In March, 1788, he married Miss Catherine Kingscote, a lady of elegant manners, accomplished mind, and vigorous understanding, in whose counsel and sympathy he ever found a sure solace amid the anxieties of his after life. About this period he presented the Royal Society with his curious paper on the habits of the cuckoo, which at the time attracted considerable attention, and the observations in which have been generally adopted by succeeding ornithologists. It is well known that the cuckoo does not herself hatch the eggs which she lays in the spring, but deposits them in succession in the nests of other birds, as the hedge-sparrow, water-wagtail, &c. The facts connected with this vicarious incubation are reported with Jenner's characteristic accuracy, and an ingenious reasoning is applied to the elucidation of this natural anomaly. In the year 1792 Jenner retired from the more onerous duties of a country practitioner's life, and obtained the degree of M.D. from the university of St. Andrews. In the following year John Hunter died; this event had been foreseen by Jenner as early as 1778, when he had noticed in Hunter symptoms of the affection known as angina pectoris, a disease to the pathology of which Jenner had paid particular attention, ascribing its origin to ossification of the coronary arteries of the heart; an opinion which he communicated to Dr. Parry of Bath, who afterwards adopted it in his work on the subject. To the last day of Jenner's life he continued to entertain the highest love and veneration for his former teacher; he always spoke of Hunter as "the dear man,"' and acknowledged the debt of obligation he owed to the example of his indefatigable industry and scientific ardour.
It is now time that we turn to the history of the great discovery, which may be said to have eclipsed every other discovery of modern science in the amount of benefit it has conferred on the human race, and which has enwreathed the memory of Jenner with honours that time can never wither. The first incident in the story dates back to the time when Jenner, as the surgeon's apprentice, was pursuing his professional education at Sodbury. One day a young countrywoman applied at the surgery of his master for advice. The small-pox was casually mentioned in her hearing; she immediately observed, "I cannot take that disease, for I have had cow-pox." This assertion made a deep impression on Jenner's mind; it was the first time he had heard of what had been for many years a tradition amongst the peasantry in the dairy districts of Gloucestershire and other counties; he continued to think of it, and when, some time after, he was domiciled in London with Hunter, he mentioned the subject of cow-pox to him. It does not, however, appear that Hunter was impressed with the importance of the consequences which were involved in the popular observation. A pustular eruption occurring on the teats of cows had been long known under the name of cow-pox in various country districts. The disease was infectious, and was generally communicated to the hands of persons employed in milking, and it had become an established opinion amongst the peasantry, that persons so inoculated were proof against the small-pox. Hunter mentioned the Gloucestershire tradition in his lectures on Jenner's authority. He likewise spoke of it to some professional friends, and it was noticed in other lectures of the time; but he never pursued the matter further. Jenner, however, never lost sight of it; he found the subject loaded with many obscurities and contradictions which he set himself to unravel, and he never failed to stimulate all his professional friends and acquaintances to apply themselves to its investigation. In this latter object he met with but little success. "We have all heard," his brother practitioners would observe, "of what you mention, and we have even seen examples which certainly do give some sort of countenance to the notion to which you allude; but we have also known cases of a perfectly different nature—many who were reported to have the cow-pox, having subsequently caught the small-pox. The supposed prophylactic powers probably, therefore, depend upon some peculiarity in the constitution of the individual who
