Antoine Cesar Becquerel, French physicist and chemist and one of the founders of electrochemistry. He made a special study of magnetism and the voltaic cell, and invented a number of instruments, including an electromagnetic balance and a differential galvanometer. His experiments led to the synthesis of mineral substances and his name is linked to the discovery of piezoelectricity. He was interested in metereology, climate and agriculture. He was the father of the physicist A. E. Becquerel and grandfather of Henri Becquerel, also a physicist.