Sir William Drummond Macdonald Paton CBE FRS (5 May 1917 – 17 October 1993)[1] was a British pharmacologist and vivisection activist.

Paton was born in Hendon and educated at Repton School and New College, Oxford, where he was awarded a BA in animal physiology.

In 1939 he entered University College Hospital (UCH) to study clinical medicine and was appointed house physician to the medical unit.

[2] Unfit for military service he took the post of pathologist in a tuberculosis sanatorium, later moving to the National Institute for Medical Research, then in Hampstead, London.

[2] In 1952 he returned to UCH as reader in applied pharmacology, and spent the next two years studying submarine physiology, developing the blend of oxygen, helium and nitrogen (Tri-mix) which enables divers to work at deeper depths.