Arthur Cayley (1821-1895), British mathematician. Cayley was instrumental in establishing the British school of pure mathematics. He published 250 mathematical papers in the 14 years he spent working as a lawyer, and hundreds more thereafter when holding a professorship at the University of Cambridge. Among his achievements was the development of matrix multiplication. He was elected president of the Royal Astronomical Society in 1872, and in 1883 he became president of the British Association for the Advancement of Science.