The next epoch-making event in the history of anæsthesia was the discovery of the anæsthetic properties of chloroform. The substance itself had been known for over a quarter of a century. Thomson, in his “System of Chemistry,” 1820, describes a liquid which is formed by the union of chlorine and olefiant gas, called “Dutch liquid,” or chloric ether. Early in the year 1831, Samuel Guthrie of Brimfield, Massachusetts, who was then residing in Sackett’s Harbour, New York State, in consequence of a statement that he had read that the alcoholic solution of this chloric ether was useful in medicine as a diffusible stimulant, devised an easy method of preparing it. This being done, he wrote an article which he entitled “A Spirituous Solution of Chloric Ether,” and forwarded it to the editor of the “American Journal of Science and Art,” in which it was published in October of the same year. In this article he fully describes his method of preparation. A few months later, in January, 1832, Soubeiran published a paper in a French journal, stating that he had discovered this method in 1831, and to the distilled fluid he produced he had given the name of “bichloric ether,” the formula being CHCl. Still a third claimant to the discovery came forward in the person of Liebig, who published his account in November, 1831, six months after Guthrie’s manuscript was in the publisher’s hands, and one month after its publication. The formula which Liebig deducted from his analysis was C_{4}Cl_{5}, and he called his product “chloride of carbon.” Although there may be some doubt as to which of these claimants was actually the first to manufacture the liquid, it is clear that Guthrie was the first to publish the account of the discovery. He was born in 1782, was a surgeon in the United States Army in 1812, and died in 1848. From an account given by D. B. Smith, of Philadelphia, in the “Journal of the College of Pharmacy”[2] in 1832, there can be little doubt that the liquid first made by Guthrie was a fairly pure chloroform. He describes it in the following words: “The action of this ether on the living system is interesting, and may hereafter render it an object of importance in commerce. Its flavour is delicious, and its intoxicating properties equal to or surpassing those of alcohol.” In 1834, Dumas examined the liquid as prepared by Soubeiran, and declared that he had not obtained it pure, and further, that Liebig had made an error in its composition. On further research, Dumas gave the liquid the name of “chloroform,” and first worked out the real formula, C_{2}HCl_{3} (or, using the present system of atomic weights, CHCl_{3}). [2] Now the “American Journal of Pharmacy” [Sidenote: Previous use of chloroform in medical practice]