INOCULATION (Lat. inoculalio, from Lat. inoc•ulurc, to graft, from in, in + oculus, eye; connected with OChurch Slay. oleo, OPruss. G fills, Litli. aI is, Goth. uugd, 0kW. ouyc, tier. Auge, As. ?aye, Eng. eye). Intentional infection of an individual with a disease by introducing its virus into the tissues or fluids of the body. Inoculation of the lower animals is used in the study of bacte riology, for it is possible by this means to repro duce in animals, with some organisms, time patho logical condition presented in the natural disease. Cultures are made of the micro-organionIs of the disease, or tissues, secretions, or excretions are obtained from the diseased body, to constitute the material for use. (See DISEASE, GERM '1'IIEORY OF.I The inoculation is either sabcutoncoas, in Iruscrous, iulrarascular, or in Ira cerebra!, accord ing as (lie injection is made respectively into the tissue under the skin, into a serous cavity like the pleura, into a vein, or directly into the sub stance of the brain.
Criminals have been inoculated with disease for experimental purposes, as well as volunteers for science' sake. Preventive inoculation is prae ticecl in the ease of several diseases, as rabies, plague, diphtheria, ate. Virus of disease which has become weakened (attenuated) by being passed through several animals is injected into Human beings who have been or are to be exposed to the disease, and the desirable blood change, to gether with the development of antitoxin, is obtained. (See ANTIToxu ; IMMUNITY; SERUM TnEIIAI'Y.) The first use of inoculation in human beings was probably the intentional transference of smallpox. From very ancient tines the Ilia• dus, amp from as early as time sixth century the Chinese, inoculated persons with smallpox and then cared for then, with the result of a smaller mortality than if they had caught the disease during an epidemic. in 1717 Lady Mary \\ort Icy Montague, wife of the English Amhascador in 'L'nrkey, became convinced of the advantages of inoculation with smallpox, as practiced by the Greeks and Armenians there. In 17°_I she caused
her son to be inoculated in London. Six con• dcnmned criminals at were the next experimental cases; and, after the two children of Caroline, Prineess of were also inoeu• lated, the fashion became cstablishcd among the wealthy and high-born. The mortality from smallpox in England at that time was one in five, while tlne mortality of the inoculated was lint one in 3000. The Chinese used crusts, placed in the nostrils, or caused the children to wear the clothes of a smallpox patient. Following the method, time English made incisions in the arms, into which the pus from a pustule was introduced. In general. a milder course was taken by the disease resulting from inoculation, about fifty pocks appearing, it is said : lint in some eases itdense invasion followed with a fatal result. The disadvantage of the method appears from the fact that every inoculated person he eanne a focus for the spread of the disoasc, and isolation was expemicive. Besides, tine percentage of deaths from smallpox, in spite of (or possibly because of) inoculation, increased till, at the end of the eighteenth century, one-tenth of the popular tion of England died of the disease. After becom ing very fashionable and spreading over the civi lized world, inoculation fell into disrepute short ly after Jemter's introduction, in 1796, of vaccina tion, w•hieli be had discovered in 1775, to be a preventive of smallpox. 'l'he entire eflicieney of Vaccination and its safety and case caused its rapid supplanting of inoculation. Prussia in 1835 prohibited inoculation for smallpox, aml l:rcat Britain enacted laws against it in I510.
It is he still in vogue in China and iu Algiers. nsult: Moor, The IIistory of tSmull po.I (London, 1815) ; Collinsom, Nmiallpox and I accinalion llislorically and Medically l'onsid c•retl (London, 1560). Sec JEN NER.