BERNARD, CLAUDE (1813-1878), French physiologist, was born on July 12, 1813, in the village of Saint-Julien near Villefranche. He received his early education in the Jesuit school of that town, and then proceeded to the college at Lyons, which, however, he soon left to become assistant in a druggist's shop. His leisure hours were devoted to the composition of a vaudeville comedy La Rose du Rhone, and the success it achieved moved him to attempt a prose drama in five acts, Arthur de Bretagne. At the age of 21 he went to Paris, armed with this play and an introduction to Saint-Marc Girardin, but the critic urged him to take up the study of medicine, and in due course he became interne at the Hotel-Dieu. He worked under the great physi ologist, F. Magendie, who was physician to the hospital, became his deputy in 1848, and in 1855 succeeded him as full professor. Some time previously he had been chosen the first occupant of the newly-instituted chair of physiology at the Sorbonne. There no laboratory was provided for his use, but Louis Napoleon, after an interview with him in 1864, remedied the deficiency, at the same time building a laboratory at the natural history museum in the Jardin des Plantes, and establishing a professorship, which Ber nard left the Sorbonne to accept in 1868—the year in which he was admitted a member of the Institute. He died in Paris on Feb. Io, 1878, and was accorded a public funeral—an honour never before bestowed by France on a man of science.
Claude Bernard's first important work was on the functions of the pancreas gland, the juice of which he proved to be of great significance in the process of digestion. A second investigation (perhaps his most famous) was on the glycogenic function of the liver; in the course of this he was led to the conclusion, which throws light on the causation of diabetes, that the liver, in addition to secreting bile, is the seat of an "internal secre tion," by which it prepares sugar at the expense of the elements of the blood passing through it. A third research resulted in the discovery of the vaso-motor system. While engaged, about 1851, in examining the effects produced in the temperature of various parts of the body by section of the nerve or nerves belonging to them, he noticed that division of the cervical sympathetic gave rise to more active circulation and more forcible pulsation of the arteries in certain parts of the head, and a few months after wards he observed that electrical excitation of the upper por tion of the divided nerve had the contrary effect. In this way he established the existence of vaso-motor nerves—both vaso-dilata tor and vasoconstrictor. The study of the physiological action of poisons was also a favourite one with him, his attention being devoted in particular to curare and carbon monoxide gas. The full exposition of his views, and even the statement of some of the original facts, can only be found in the 17 vols. of his pub lished lectures. He also published Introduction a la medecine experimentale (1865) and Physiologie generate (1872).
An English Life of Bernard, by Sir Michael Foster, was published in London in 1899.