McLennan, Sir John Cunningham

Sir John Cunningham McLennan, physicist (b at Ingersoll, Ont 14 Apr 1867; d at Paris, France 9 Oct 1935). After graduating in physics from the University of Toronto in 1892, McLennan worked as a demonstrator and in 1898 went to the Cavendish Laboratory in Cambridge, Eng. In 1900 he received the first doctorate in physics from U of T. He spent his career at that university, bringing his physics laboratory to the forefront of research in radioactivity, spectroscopy and low-temperature physics.

During WWI McLennan was scientific adviser to the British Admiralty. In 1915 he was elected to the Royal Society of London (receiving its gold medal in 1928) and in 1917 received the Order of the British Empire. After the war he returned to U of T but spent each summer in Britain, becoming president of the scientific section of the British Association for the Advancement of Science in 1923.

President of the Royal Canadian Institute in 1916, he helped found the NATIONAL RESEARCH COUNCIL and was a member of the ONTARIO RESEARCH FOUNDATION (est 1928). He resigned from U of T in 1932 and moved to England where he continued his pioneering research in the use of radium to treat cancer. He was knighted in 1935.