Biot, Jean Baptiste

Biot, Jean Baptiste (zhäN bätēst` byō), 1774–1862, French physicist, grad. École Polytechnique (1797). He taught mathematics at Beauvais before becoming (1800) professor of mathematical physics at the Collège de France and later (1809–49) of astronomy at the Sorbonne. With French physicist François Arago, Biot measured properties of gases, and with French physicist Felix Savart, he formulated a law for the magnetic force near a wire carrying an electric current. He discovered that when light passes through some substances, including sugar solutions, the plane of polarization of the light is rotated by an amount that depends on the color of the light.