He was born in Ayr on 18 July 1877, the son of Margaret Miller, from a family of rivet and bolt manufacturers, and Edward Moore Cathcart, a merchant in the town. His father died when Cathcart was only nine, leaving his mother to raise him and his younger brother and sister. He was educated at Ayr Academy, then attended the University of Glasgow, graduating in 1900. He then travelled to Germany, both Munich and Berlin,[3] to complete further studies in bacteriology and chemical pathology. At this time he was heavily influenced by the work of Carl von Voit. From 1902 to 1905 he worked at the Lister Institute of Preventive Medicine in London.
From 1905 to 1915 he served as the Grieve Lecturer in Physiological Chemistry at the University of Glasgow. During World War I he served with the Royal Army Medical Corps. He was then attached to the Anti-Gas Services section, rising to be Depute Director of that service. In 1917 he was transferred to the same role in relation to the Home Services. He rose to the level of Lt Col Director on the General Staff (Army Medical Services).
After the war he returned to the University of Glasgow as Professor of Physiological Chemistry. He served as Regius Professor of Physiology at the University from 1928 until his retiral in 1947.[4]
He was elected a Fellow of the Royal Society in 1920 and a Fellow of the Royal Society of Edinburgh in 1932. The University of St Andrews awarded him an honorary doctorate (LLD) in 1928 and the University of Glasgow the same in 1947.[5]
He died at home, 80 Oakfield Avenue in Glasgow, on 18 February 1954.[6]
