About Jean Becquerel
Jean Becquerel (5 February 1878 – 4 July 1953) was a French physicist, and son of Antoine-Henri Becquerel. He worked on the optical and magnetic properties of crystals, discovering the rotation of the plane of polarisation by a magnetic field. He also published a textbook on relativity. In 1909 he became the fourth in his family to occupy the physics chair at the Muséum National d'Histoire Naturelle following in the footsteps of A. E. Becquerel and Antoine César Becquerel. .