Modern surgery has been greatly facilitated by the employment of numerous anesthetics, chemicals which possess the power of inducing local or general insensibility. Soporific drugs have been used in surgical operations since the remotest antiquity, but modern practices in the employment of anesthetics followed the discoveries of Faraday in 1818. He described the properties of nitrous oxide, or ether and other gases in that year and suggested their use in medicine. John Godman (1822), James Jackson (1833), and Drs. Wood and Bache (1834) were among American medical men who made use of Faraday's suggestions. Dr. Horace Wells, a dentist at Hartford, Connecticut, used ether in 1844. Two years later W. T. Morton, a dentist in Boston, employed it successfully. Chloroform was described as a useful anesthetic by Dr. Flourens, of Paris, in 1847, the year in which Sir James Simpson introduced ether as an anesthetic in obstetric practice. Mesmer introduced hypnosis into medical practice about 1777, and in 1784 Benjamin Franklin reported favorably on the medical value of what he called magnetic sleep. Alexandre Bertrand, about 1831, described the nature of hypnosis and in 1841 James Braid employed it in his English medical practice. The employment of hypnosis has not become general, although it is recognized that in certain nervous troubles there is a field for it. Among other American medical men who advanced their science in the past were James Marion Sims (1813-1883) and Thomas Emmet, who acquired wide fame for successful methods of operating in obstetric diseases. William Beaumont (1785-1853) investigated the offices of the gastric juice and devised treatment for digestive troubles. John Shaw Billings served his profession by compiling, with the assistance of Robert Fletcher, an Index Catalogue of the Surgeon General's library, Washington. Pharmacology is as old as medicine. The medicinal qualities of herbs, roots, and gums were known to primitive man. There have been herbalists and druggists in all important communities at all times. Scientific pharmacology, however, is just as new as modern medicine. Cordus published a pharmacopœia, which listed drugs in use in 1535. Since that time many such works have appeared. The second of the Monros of Edinburgh University Medical School, Magendie, and Claude Bernard placed pharmacy upon a scientific basis. They followed scientific methods used by Fontana in Florence in 1765 in studying the effects of snake poisons. Pareira's "Elements of Materia Medica" was the leading textbook in 1842. This work gave very brief accounts of the physiological effects of drugs. The physiological values were not properly appreciated until about twenty years later.