Jean Baptiste Biot, a French savant, born in Paris, April 21, 1774, died Feb. 2, 1862. He served for some time in the artillery, entered the polytechnic school in 1794, became a professor in the central school of Beauvais, and in 1800 professor of physics in the college de France. In 1803 he was elected a member of the academy of sciences, and the following year entered the observatory of Paris. In conjunction with Arago he continued the researches into the refracting power of gases, already begun by Borda. In 1806 he was associated with Arago, in Spain, in measuring an arc of the meridian. He was next appointed professor of physical astronomy in the faculty of sciences, and in 1817 he made a journey to the Orcades for the purpose of correcting the observations relating to the measure of the meridian. In 1856 he became a member of the French academy. His fame rests chiefly upon his astronomical, mathematical, and physical writings. His Traite de physique experimental et mathematique (4 vols., Paris, 1816) is regarded as his masterwork.

A third edition of his Traite elementaire d'astronomiephysique was completed in 5 vols, in 1857. In 1858 he collected three volumes of his Melanges scien-tifiques et litteraires.