John Hamilton Barclay was born on 19 January 1887 in Newcastle-upon-Tyne, the son of John Cairns Barclay and his wife Janet, née Hamilton. He started his career in 1906 at the newly-opened Royal Victoria Infirmary, graduating MB BS with honours in 1911 and obtaining the MRCS LRCP in the same year. After a resident appointment at the Royal Victoria Infirmary he entered a well-known Newcastle general practice as an assistant. He took his FRCS in 1914 just before the outbreak of war and immediately joined the RAMC in the field ambulance of the 50th (Northumbrian) Division. During the first world war Barclay served in France and Belgium where he gained valuable experience in the treatment of chest injuries, which was then a new field in surgery. His interest in the subject was reflected by his choice of subject for his thesis, haemothorax. While, like many other surgeons, he found the medical services unprepared to cope with battle casualties on a hitherto unknown scale, he was remarkably successful in reducing the number of cases of sepsis in compound fractures after adopting the technique of debridement, pioneered by his old chief, Rutherford Morison. Using BIPP paste, a mixture of bismuth, iodoform and paraffin, under the dressing, Barclay was able to reduce the incidence of sepsis even further. He obtained his MS with honours in 1915 and his MD in 1919. When he was demobilised Barclay worked for a time at the Hospital for Sick Children in Newcastle. In 1920 he was appointed to the honorary medical staff of the Royal Victoria Infirmary as an assistant surgeon and became full surgeon in 1929. Other appointments included visiting consultant to the Ingham Infirmary, South Shields, and Durham County Hospital. He also attended Morpeth Asylum and Alnwick Cottage Hospital. He was a member of the Newcastle and Northern Counties Medical Society and a founder member of the North of England Surgical Society, and served as President of both. In a wider sphere he was an active member of the Association of Surgeons of Great Britain and Ireland. In 1944 Barclay succeeded F C Pybus as Professor of Surgery, the last of Rutherford Morison's pupils to occupy this position, which he held until his retirement in 1947. This was only a part-time chair and during his tenure an additional full-time chair of surgery was established. Barclay retained the clinical work while the new professor, F H Bentley, was responsible for scientific research. In 1916 Barclay married Ella Davidson Allan, by whom he had a daughter and a son who entered medicine. Ella Barclay died in 1956; thereafter his sister, Janet, kept house for him. For several years Barclay signed on as ship's doctor on liners making winter voyages to Australia and New Zealand as this enabled him to visit his son, Cairns, although these ceased with his son's death in Australia. Barclay died peacefully on 3 February 1975, aged 88 years. He had been in failing health for several years and had been blind for some time.