Leo Yaffe, educator, nuclear scientist, university administrator (b at Devil's Lake, N Dak 6 July 1916). In 1952 Yaffe established a productive nuclear chemistry research laboratory at McGill. He has contributed richly to measurements of beta radiation, neutron- and proton-induced reactions, nuclear isomer ratios, and analysis of archaeological artifacts, all described in over 150 publications. He was director of Research and Laboratories (1963-65) of the International Atomic Energy Agency, Vienna; chairman, Dept of Chemistry (1965-72) and vice-principal, administration (1974-81) of McGill; and president (1981-82) of the Chemical Inst of Canada. He has been the recipient of many honours. In 1984 he was made professor emeritus at McGill.