Crawford, Adair (1748–96), doctor and chemist, was born in Ballytromery, near Crumlin, Co. Antrim, third son among four sons and two daughters of Thomas Crawford, presbyterian minister in Crumlin 1724–82, and Anne Crawford (née Mackay). His brothers were Thomas Crawford, Alexander Crawford (qv), and John Crawford (qv). He was educated at home by his father, and graduated MA from Glasgow University in 1770. He at first intended to become a minister, but his voice was weak, and he studied medicine instead. In March 1778 William Drennan (qv) wrote to his sister: ‘That awkward-looking lout Adair Crawford who is at present pursuing and will soon overtake the profession of physic is universally esteemed the most ingenious student of medicine at present in the university.’ He graduated MD in January 1780, and practised in London, where he became a physician to the general dispensary, and then to St Thomas's Hospital. He was a licentiate of the Royal College of Physicians in 1784, was one of the original members of the RIA in 1785, and became FRS in 1786; he was enthusiastic about the study of science, and was selected to become professor of chemistry in the Military Academy, Woolwich.
Even before he graduated from Glasgow, Crawford had begun detailed and painstaking experiments on physiology, and in 1779 he published Experiments and observations on animal heat, and the inflammation of combustible bodies; being an attempt to resolve these phenomena into a general law of nature. This volume, in which Crawford examined the work of many earlier scientists, attracted a good deal of attention, was well received and translated into German and Italian, and was republished in a second, corrected edition in 1788. Crawford's attempt to explain the generation of heat in living organisms in terms of combustion processes was in some ways prescient and ingenious, but ultimately vitiated by his acceptance of the erroneous theory which postulated that a substance called phlogiston was a product of combustion. Crawford noted his difficulties with the theory, which was still accepted by authorities such as Joseph Priestley and Richard Kirwan (qv), who both endorsed his findings. Crawford published other works on the action of tonics and on cancer, but is best known for his experiments on a substance found near Strontian in Argyllshire, which enabled him and his assistant William Cruikshank to state in Medical Communications of 1790 that they had discovered that the new mineral, later named ‘strontianite’, was distinct from similar minerals derived from the element barium. In 1808 Humphrey Davy discovered the element from which Crawford's mineral (which was strontium carbonate), was derived, and called it ‘strontium’.
Crawford injured his health by overwork in his enthusiasm for science and medicine, and in July 1795 went to Lymington, Hampshire, to stay with his friend John Petty-Fitzmaurice (qv), 2nd marquess of Lansdowne, hoping to recover his strength, but he died there on 19 or 29 July 1796. Lansdowne wanted to erect a monument to Crawford, and William Drennan and the famous writer Gilbert Wakefield both composed inscriptions in memory of their friend, but the monument was not erected.
Crawford married (22 May 1786) Eleanor Stone of Tiverton, Devon, who survived him; they had two sons and two daughters. One son, Thomas Crawford (1788–1870), educated at TCD, became rector of Drumcliffe, Sligo; the other, Stewart Crawford, became a successful doctor in Bath, and married Caroline, sister of William A'Court (qv), marquess of Heytesbury and lord lieutenant of Ireland.