Born on 4 July 1905 son of William Aird and Jean Elizabeth Binnie, he was educated at George Watson's College and the University of Edinburgh where he obtained the Thomson Scholarship, Wightman Prize and Annandale Gold Medal. Postgraduate studies followed in Paris, Vienna and St Louis, Missouri. In 1935 he was appointed surgeon to the Royal Hospital for Sick Children in Edinburgh and assistant surgeon to the Royal Infirmary. During the period between these appointments and the beginning of the war in 1939 he acquired a great reputation as a teacher of surgery in Edinburgh and as a coach for higher surgical examinations. On the outbreak of war he joined the RAMC rising to the rank of Lieutenant-Colonel and being twice mentioned in dispatches. Most of his service was in the North African campaign as one of the pioneers of a mobile surgical unit. For a brief period he became a prisoner of war in the ebb and flow of the campaign and received praise from both Germans and Italians for his treatment of their wounded. When he returned to Scotland in 1944 he was appointed assistant surgeon to the professorial unit in Edinburgh and deputy director of the Wilkie Surgical Laboratories. In 1946 he was appointed Professor of Surgery in the Postgraduate Medical School at Hammersmith in succession to Professor Grey Turner. A man of outstanding academic achievement and phenomenal industry he was an ideal director of a research unit and an inspiration to men working with him. In 1953 he achieved notoriety for an operation to separate Siamese Twins from Kano, Nigeria. This publicity tended to obscure his much more solid and important surgical achievements, such as the development of the heart-lung machine and of organ transplantation. He served on the Court of Examiners and the Council of the College and examined in London, Edinburgh, Birmingham, Singapore, Colombo, Kampala, Khartoum and Cairo. He travelled extensively as an invited guest to surgical centres: in 1949 in the US at New York, Philadelphia and New Orleans; in 1952 in Malaya; in 1953 in the Union of South Africa; in 1955 in the US again, at Minneapolis, Houston and Rochester; in 1956 in Canada and Poland; in 1957 at Chicago and Minneapolis; in 1958 at Stockholm; in 1959 at Chicago, Indianapolis, Philadelphia and Los Angeles; in 1960 at Athens, Beirut, Pakistan, East Africa and Oslo; and in 1961 at Khartoum, Ceylon, British Guiana, Montreal, Windsor, Toronto, Cleveland, Toledo, New York, Prague, Lyons, and Brussels. This involved the most strenuous professional duties and no less strenuous social obligations. As a writer his outstanding achievement was his *Companion to Surgical Studies*, a large book deriving from his notes as a postgraduate teacher, a tour-de-force coming from a single pen, published in 1949. All this intense activity in an individual with an innately sensitive temperament, although apparently supremely extroverted, inevitably took its toll, and on 17 September 1962 he was found dead in bed at Hammersmith Hospital, from barbiturate poisoning taken while suffering from depression. He married in 1936 Margaret, daughter of William Goodman Cowes of Buenos Aires, who survived him with a son and a daughter. A memorial service attended by the President and Council of the College was held in St Columba's Church, Pont Street on 11 October 1962. Publications *A companion to surgical studies* Livingstone 1949. *The making of a surgeon* Butterworth 1961. Military surgery in geographical perspective. *Edinb med J* 1944, 51, 166-183. Surgery of peripheral nerve injury. *Postgrad med J* 1946, 22, 225-254. Surgery of biliary system. *Ann Roy Coll Surg Engl* 1948, 2, 194-209. Genesis of peptic ulceration. *Edinb med J* 1949, 56, 89-98. Surgical aspects of interhepatic biliary obstruction. *Ann Surg* 1952, 136, 27-38. Conjoined Twins of Kano. *Brit med J* 1954, 1, 831-837. Blood groups in reaction to peptic ulceration and carcinoma (et al). *Brit med J* 1954, 2, 315-321. Primary aldosteronism. *Quart J Med* 1957, 26, 317-333.