Jean Baptiste Perrin

Jean Baptiste Perrin FRS (30 September 1870 – 17 April 1942) was a French physicist and Nobel laureate. Born in Lille, France, Perrin attended the École Normale Supérieure, the elite grande école in Paris. He became an assistant at the school during the period of 1894-97 when he began the study of cathode rays and X-rays. He was awarded the degree of docteur ès sciences (PhD) in 1897. In the same year he was appointed as a lecturer in physical chemistry at the Sorbonne, Paris. He became a professor at the University in 1910, holding this post until the German occupation of France during World War II. In 1895, Jean Perrin showed that cathode rays were made of corpuscles with negative electric charge. He computed Avogadro's number through...