The greatest triumph achieved in any department of medicine, and worthy, perhaps, to be described as almost, if not quite, the most beneficent discovery in the world’s history, is that of the successful employment of anæsthetics. This great glory belongs to the nineteenth century. Indian hemp had been employed for centuries in the East, mandragora had a classical reputation, and from time to time the possibilities of hypnotism had been expounded by one or another of its professors. But it is only within the past sixty years that the terrible anxiety and suffering associated with surgical operations have been so far mitigated as largely to increase the prospects of success, and to annihilate the pain. To Sir Humphry Davy is due the credit of first suggesting the line of advance towards this precious goal by describing his experiences of the inhalation of nitrous oxide gas which he found had the effect of relieving toothache and other pains; “uneasiness swallowed up for a few minutes by pleasure,” were his own words; and he foresaw the possibility of this agent being employed as an inhalation “in such surgical operations as involved no great effusion of blood.” That was in the year 1800. About 1830 Faraday observed and noted the effect of ether on the nervous system, which he stated was similar to that of nitrous oxide gas. [Illustration: HORACE WELLS.] The possibility of painless operations began to be imagined about this time, but not much serious experimental work seems to have been attempted. In 1842, Dr. Long, of Athens, Georgia, U.S.A., claimed to have removed a tumour from a patient under the influence of ether, and about the same time Dr. Jackson, of Boston, U.S.A., also professed to have carried out successfully a similar operation. These experiments have not been rigorously established, but there is no question about the authenticity of the next. Horace Wells, a dentist of Hartford, Connecticut, U.S.A., suffering from toothache, resolved to experiment on himself. He induced a colleague named Rigg to draw a molar while he was under the influence of nitrous oxide gas, and did not feel the pain of the extraction. This was in 1844. Wells then, in association with another dentist, named William Thomas Green Morton, started to demonstrate the discovery publicly. The first exhibition was an ignominious failure, and the two pioneers were derided as impostors. Wells suffered so severely from his disappointment on this occasion that he died insane a few years later. Morton, however, continued his investigations, and he and the Dr. Jackson already mentioned worked together on ether, and assured themselves of its anæsthetic powers by experiments on animals. Morton then inhaled it himself on September 30, 1846, and awoke from deep unconsciousness a few minutes later, convinced of the reality of his discovery. Just then a patient rang the bell. It was towards evening, but the visitor was shown into the surgery.