Antoine César Becquerel (7.03.1788-18.1.1878) was a French physicist and a member of the Paris Academy of Sciences (1829), its president in 1838. He was born in Châtillon-Coligny. He graduated from the École Polytechnique. He was an officer in the engineer corps. From 1815 he took up science, and from 1838 he was head of the chair of physics at the Paris Museum of Natural History.
His work was on the study of minerals, piezoelectricity, thermoelectricity, and magnetic and electrical phenomena. He showed that the electrification of crystals under pressure is a general phenomenon. He studied the properties of tourmaline. In 1829 he invented a weakly polarising galvanic cell (the first constant galvanic cell) and used it to obtain crystals of various sulfides. He proposed (1838) using electrolysis to obtain metals (copper, silver, gold). In 1837 he constructed an “electromagnetic balance”, and in 1826 a differential galvanometer with a double winding. He introduced the “null” method of measurement. In 1827 he observed magnetic repulsion (diamagnetism).
The Copley Medal (1837)