David Keys was born in Toronto on November 4th, 1890. He graduated from the University of Toronto with his B.A. in 1915 and his M.A. in 1916. He pursued graduate studies at Harvard (M.A. 1917, Ph.D. 1920) and Cambridge (Ph.D. 1922) before coming to McGill as Assistant Professor of physics. He later rose to become Associate Professor (1927), Professor (1929) and Macdonald Professor of Physics (1942). During the Second World War, he directed training programs at McGill for R.C.A.F. radio technicians, and in 1945 he became director of Special Courses for Veterans. As Vice-President of the National Research Council, Keys was appointed director of the Chalk River nuclear research project in 1947. Although his major research interest lay in geophysics, he also published a number of papers on ionization. Keys retired in 1961, dedicating his time to writing his memoirs, which remain unpublished. He passed away in 1977.