The practice of the ancients in giving mandragora and Indian hemp has no connection with the recent discovery for preventing the pain of operations, which may be briefly related as follows:—Sir Humphrey Davy made the suggestion that nitrous oxide gas might be employed for this purpose, and, at the end of forty-four years, Mr. Horace Wells carried this suggestion into practice, but failed to bring the nitrous oxide into general use, and gave the matter up. Two years later, Dr. Morton, who was well acquainted with the efforts of Mr. Wells, applied the vapour of ether, which was already known to resemble nitrous oxide in its action. He succeeded completely in preventing the pain of operations, and in bringing his discovery into general use throughout the civilized world. In a short time the inhalation of ether was found to be so safe and certain in its action, and to prevent the pain of operations so entirely, that the most ardent imagination could scarcely conceive that anything further could be desired in this direction. Dr. Morton withheld at first the name of the agent he was employing, but its strong and peculiar odour revealed it so plainly that concealment was impossible. Dr. Bigelow, of Boston, having tried sulphuric ether, and found it to produce all the effects of the so-called letheon, he made the subject known, not only to his own countrymen, but also by letter to Dr. Boot of London. The first operation under the influence of ether on this side of the Atlantic, was the extraction of a tooth, at the house of Dr. Boot, on Dec. 19th, 1846. Mr. Robinson, of Gower Street, administered the ether and performed the operation. The patient was a lady, named Miss Lonsdale. The ether was quite successful in preventing the pain in this case, as well as in two operations performed at University College two days afterwards, by the late Mr. Liston. These operations were amputation of the thigh, and evulsion on both sides of the great toe-nail. The ether was given by Mr. Squire, of Oxford Street, with an apparatus which he contrived for the occasion. Considerable opposition was made to the inhalation of ether in America, soon after its introduction, and it seemed likely to fall into disuse, when the news of its successful employment in the operations of Mr. Liston, and others in London, caused the practice of etherization to revive. Mr. Robinson, dentist, gave much time and attention to the exhibition of ether in London on its first introduction, and was on the whole very successful. This was not generally the case, however, with other operators during the first six weeks of the new practice. Owing to imperfections in the inhalers employed and in the method of using them, the ether often either failed altogether or only made the patient partly insensible; and Mr. Liston, and some other surgeons, were inclined to discountenance the use of it, in consequence of the struggles and cries of patients to whom it had been administered.