The discoverer of the electron, Joseph John Thomson, revolutionised knowledge of atomic structure and won the Nobel Prize for Physics - yet his degree was in mathematics. He was born on December 18, 1856, son of a bookseller in a Manchester suburb. Lucky enough to attend a college that provided experimental physics courses at the age of 14, he won a scholarship to Trinity College, Cambridge in 1876 - and remained there for the rest of his life. He joined the Cavendish Laboratory and began to develop the theory of electromagnetism, but his biggest achievement was in concluding that all matter contains particles of the same kind that are much smaller than the atoms of which they form a part. He called them 'corpuscles' - we call them electrons. In 1896 argument was raging between German physicists who reckoned cathode rays, produced in a vacuum tube to which a current is applied, were something in the 'ether' thought to pervade all space, and British and French who thought they were particles. Thomson showed they were particles by refining the vacuum technique and using different metals to provide the current and different gases in the tube. Winner of the Nobel Prize in 1906 and knighted in 1908, he was also an outstanding leader of Cavendish, gathering great scientists to it. Seven of Thomson's appointees won Nobel Prizes. He was also greatly interested in rare plants, politics, fiction, drama and sports. The Encyclopedia Britannica says that in the 1880s physics was seen as coming to an end after the great 19th century discoveries in magnetism, electricity and thermodynamics. By 1914 a new physics was 'wildly exciting to those who, lucky enough to be engaged in it, saw its boundless possibilities' and that this was thanks to a half dozen great physicists, one of them Thomson 'who made atomic physics a modern science'. Thomson died in 1940 in Cambridge.