John Williamson Legge, known as Jack Legge, was a biochemist also interested in the problem of evolution. He was educated at Geelong College and the University of Melbourne. After completing his science course in 1935(?) he spent five years with Dr Max Rudolph Lemberg at the Kolling Institute of Medical Research (Sydney) with grants from the National Health and Medical Research Council to carry out investigations into blood pigment metabolism and allied problems.

From 1942 to 1946 Jack Legge was engaged in research with the Australian Chemical Warfare Research and Experimental section of the Services and Munitions Department, carrying out physiological research in the field of chemical warfare. Legge was involved in mustard gas trial tests at Townsville, North Brook Island, Proserpine and Mission Beach, for which he and fellow biochemist Hugh Ennor designed a one hundred cubic metre, air-conditioned gas chamber. Colleague Dr David Sinclair, when writing of his own involvement in the trials, recalled Jack Legge as "a slight, mild mannered man, subtle in argument and persuasive in direction" (Sinclair, 1989, p. 107).

Journalist Bridget Goodwin conducted interviews with Jack Legge regarding his experiences working on mustard gas tests, and his recollections featured in her documentary Keen As Mustard (1989), and her subsequent book of the same name (St. Lucia, Queensland: University of Queensland Press, 1998).

A fellowship (details unknown) enabled Legge to spend two years in England, which he did after the war, working at the Molteno Institute, Cambridge University with Professor David Keilin. On returning to Melbourne Legge took up a laboratory in the Old Chemical School at the University of Melbourne and lectured on biochemistry.

He worked at the University until c.1981. After retirement Legge continued pursuing his scientific interests. In the mid 1980s he ran the radio program "CR Science", familiarising his audience with scientific achievements in the world.

The correspondence contained in this archive reflects that in later life Jack Legge supported the soldiers and volunteers seeking compensation for health problems associated with mustard gas trials. To this end he lobbied the Prime Minister and other members of parliament to request their claims be addressed.