John Beresford Leathes was born in London, the second son of the Rev. Stanley Leathes, professor of Hebrew at King’s College, London, and prebendary of St. Paul’s. His mother, Matilda Butt, was descended from a collateral branch of the family which produced Sir William Butts, physician to Henry VIII. The‘s’ was dropped from the name in the seventeenth century. She was also distantly connected on the maternal side with the family of Charles Darwin. Leathes was educated at Winchester College, where he first gained a knowledge of the classics in which he had a life-long interest. From Winchester he went to New College, Oxford. His decision to study medicine instead of pathology was unwelcome to his father who practically withdrew his support, so that he lived with an aunt in Highgate while studying at Guy’s Hospital. Even then he had become a friend of E. H. Starling, to whom he was to be demonstrator in physiology.
After some years of study in Germany he returned to England to the appointment of lecturer in physiology at St. Thomas’s Hospital, with a part-time appointment at the Lister Institute where he worked with C. J. Martin and others. In 1909 he went to Toronto to a new chair of pathological chemistry and it was here that he did some of the work which led to his election to the fellowship of the Royal Society. In 1914 he accepted an invitation to become professor of physiology in the University of Sheffield, where he helped Arthur Hall and others to build up the reputation of its Medical School as an advanced centre of education. He was a pioneer in breaking down the barrier between pre-clinical and clinical studies, with the result that students continued physiological studies into their final year: an ‘innovation’ which forty years later was being considered in other medical schools.
Some of his earlier work was on purine metabolism, but he soon turned to the fats as his main interest and published a classical monograph on this subject in 1910, and with Raper wrote a second edition in 1925. At the College he gave the Croonian lectures, ‘The Role of fats in vital phenomena,’ in 1923, and in 1930 the Harveian oration, ‘The Birth of chemical biology’; he was a Councillor, 1930-32.
Unquestionably J. B. Leathes was a great physiologist and a pioneer in chemical physiology, held in very high esteem by the great generation of British physiologists that included Bayliss, Starling, and J. S. Haldane. Outside the reading of the classics his other recreations were walking, music and art. He was a skilled artist himself, mostly in pastel, which added to his enjoyment of the countryside. Although sometimes frightening to younger colleagues, he was essentially a friendly and tolerant man. In 1896 he married Sonia Marie Natanson, a Russian by birth. Their only child, Margaret, married Lionel Penrose, F.R.C.P., F.R.S.
Richard R Trail
* He was elected under the special bye-law which provides for the election to the fellowship of "Persons holding a medical qualification, but not Members of the College, who have distinguished themselves in the practice of medicine, or in the pursuit of Medical or General Science or Literature..."
[Biogr.Mem.Roy.Soc., 1958, 4, 185-91 (p), bibl.; Brit.med.J., 1956, 2, 770-71 (p), 1436; Lancet, 1956, 2, 686-7 (p); Nature (Lond.), 1956, 178, 833-4; Times, 18, 25 Sept. 1956.]