JENKS, JOSEPIL d. 1683; b. England; a metalworker, supposed to have been the first founder and inventor in America, having settled in Lynn, Mass., in 1645. He worked in brass and iron, but experimented in mechanics in different directions, and is recorded as having received a patent in 1646 for an application of water-power to mills. also invented a saw-mill and a fire-engine. He is said to have made the dies for the pine-tree money issued in Massachusetts in 1652; Jenks had. his foundry on the Saugus river at Lynn, and in 1667 was there engaged in wire-drawing, and appears on the records as an applicant to the general court for aid in his business.
JEN11111/, EDWAltD, the discoverer of vaccination, was b. at Berkeley, iu Gloucester shire, on May 17, 1749, and was the third son of the rev. Stephen Jenner, vicar of the parish, and rector of liockhampton. His scholastic education being finished, he was removed to Sodbury, near Bristol, in order to be instructed in the elements of surgery and pharmacy by Mr. Ludlow, an eminent surgeon there; and on the expiration of his term with this gentleman, he went to London, in the 21st year of his age, to prosecute his professional studies under the direction and instruction of the celebrated John Hunter (q.v.), in whose family he resided for two years. Under Hunter's superintendence, he became an expert anatomist., a sound pathologist, a careful experimenter, and a good naturalist. The influence of the master exerted a lasting effect on the pupil; and Hun ter's letters, which Jenner carefully preserved, evince the affectionate feeling and com munity of tastes which subsisted between them. On leaving London Jenner settled at Berkeley, where his sound professional knowledge and kindly disposition soma acquired for him a large amount of practice. In 1788 his well-known memoir, On the Natural Ilistou tf the Cuckoo, appeared in the Transactions of the royal society, con taining the results of investigations begun at th€ request of Hunter. A few years after wards, the fatigues of general. practice having become irksome to him, be resolved ta. confine himself to medicine, and with that view lie obtained the degree of '1.7). from the university of St. Andrews.
The discovery of the prophylactic power of vaccination, by which the name of Jenner has become immortalized, was the result of a prolonged series of observations and experiments. His attention, whilst he WaS yet a youth, was forcibly attracted to the nature of cow-pox in the following manner: He was pursuing his professional edu cation in the house of his master at Sodbury, when a young country-woman came to seek advice. The subject of small-pox being mentioned in her presence, she observed:
I cannot take that disease, for I have bad cow-pox." This was before the year 1770. It was not till 1775 that, after his return to Gloucestershire, he had an opportunity of examining into the truth of the traditions respecting cow-pox; and it was five years later before he began clearly to his way to the great discovery that was in store for him. In the month of May, 1780, while riding with his friend Edward Gardner, on the road between Gloucester and Bristol, " he went over the natural history of cow-pox; stated his opinion as to the origin of this affection from the heel of the horse [when suffering from the grease]; specified the different sorts of disease which attacked the milkers when they handled infected cows; dwelt upon that variety which afforded protection against small-pox; and with deep and anxious emotion, mentioned his hope of being able to propagate that variety from one human being to another, till he had disseminated the practice all over the globe, to the total extinction of small-pox."—Baron's Life of Jenner, p. 128. Many investigations regarding the different varieties of cow-pox, etc., delayed the actual discovery for DO less than 16 years, when at length the crowning experiment on James Phipps (see INOCULATION) was made on May 14, 1796, and Jen ner's task was virtually accomplished. This experimnet was followed by many of Bit same kind; and in 1798 he published his first memoir, entitled An Inquiry into tin Causes and Erects of the Varialce Although the evidence accumulated by Jenner seemed conclusive, yet the practice met with violent opposition until a year had passed, when upwards of 70 of the principal physicians and surgeons in London signed a declaration of their entire confidence in it. His discovery was soon promulgated throughout the civilized world. Honors were conferred upon him foreign courts, and he was elected an honorary member of nearly all the learned societies of Europe. Parliament voted him, in 1802, a grant of £10.000, and in 1807 a second grant of 20,000; and in the year 1858 a public statue in his honor was erected in the metropolis. His latter clays were passed chiefly at Berkeley and.Cheltenham, and were occupied in the dissemination and elucidation of his great discovery. He died of apoplexy at Berkeley in Feb., 1823.