Adair, a physician distinguished by his researches in chemical physiology, was born in Ireland about the year 1748. His father, the Rev. Thomas Crawford, was the Presbyterian minister of Crumlin, near Belfast, in the county of Antrim. The family were originally from Scotland; a remote ancestor, who was a clergyman, having fled from that country to Ireland during the reign of Charles II., in order to escape the fury of religious persecution directed against all who like himself had refused to conform. The zeal which had stood so severe a test appears to have been cherished and perpetuated as an honourable inheritance in the family, which exhibited for six generations the clerical profession descending from father to son. Adair Crawford was, from his early youth, remarkable for the sweetness of his temper, the excellence of his heart, and the strength of his understanding; qualities which were so happily united, as at once to engage the affections and to command the respect of all who knew him. To his nearest relatives he was an object of extraordinary interest, from the delicacy of his constitution, which required that he should be brought up with peculiar care; but so amiable was his disposition, that no shade of jealousy was ever excited among his brothers and sisters by the greater attention that was paid to him. He received his classical education from his father; and at the age of fourteen was sent to Glasgow for the prosecution of his studies. Distinguished from a child by a thirst for knowledge, his progress at the university was rapid, and corresponded with the warmest hopes of his parents. They had intended him for the vocation of Presbyterian clergyman, which was also the destination of his eldest brother; and he at one time bestowed much pains on the composition of sermons with that view, but he afterwards relinquished the plan on account of the weakness of his voice. It was then proposed to him to pursue the profession of the law, for succeeding in which he was eminently qualified by the excellence of his memory, and the acuteness of his reasoning powers; though the same physical incapacity as to exertions in public speaking might, in a great measure, confine his practice to that of a chamber lawyer. He accordingly turned his attention to this new course of study, which he pursued under the guidance of the celebrated Dr Millar of Glasgow. At this period his younger brother, Alexander, was a student of medicine in the college of Edinburgh; and was sufficiently advanced in the knowledge of his profession to discover the immensity of the field which this science lays open to an ardent mind, and the scope which it affords for the exertion of industry and genius, such as he knew his brother possessed. Convinced that extraordinary success would be the result of this new application of his powers, he persuaded him once more to change his views; and whilst they were together at their father's house he one day left him, on setting out on a journey, a skull and a few other dry bones, together with Monro's book on Osteology. On his return he found, as he had expected, that Adair had already outstripped his preceptor in accurate knowledge of the subject. It was then decided that he should return to Glasgow on the ensuing winter, for the purpose of attending the medical classes. This plan he carried into execution with great steadiness; and as early as the following spring had begun to direct his inquiries to the connection between respiration and animal heat, a subject which for a long time engaged a principal share of his attention. In the next winter he went to Edinburgh, still pursuing the same objects of study at that university. His views of the theory of animal heat were favourably received by the professors, and were long taught by Dr Monro in his anatomical lectures. In the ensuing spring, 1779, he went to London, where he then published the first edition of the work which has gained him so much celebrity. In the beginning of the same winter, a degree, probably an honorary one, of Doctor of Physic, was conferred upon him by the university of Glasgow. He was held in much respect by the professors of that university, his long residence among whom had given them the means of appreciating his worth and talents. It was observed by the celebrated Dr Reid, on his quitting them, that he had left no man behind him better qualified for the professorships of Greek and of Natural Philosophy than Adair Crawford. The facility with which he acquired knowledge of every kind was, indeed, extraordinary, and appeared to be the result of the singular faculty he possessed of concentrating the whole force of his mind upon any subject to which he chose to direct his attention. He now determined upon settling in London, and soon after offered himself as candidate for one of the dispensaries, to which, after a severe contest, he succeeded in being elected physician. His talents speedily brought him forward in the philosophical world, as well as in his own profession. He was elected a member of the Royal Society, and shortly afterwards he obtained the appointment of physician to St Thomas's Hospital. In the year 1788 he published a second edition of his work, greatly corrected and improved, under the title of 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. His reputation as a philosopher was now established, and procured him the notice of all the scientific noblemen of the kingdom, and the appointment of lectur- Dr Crawford was now rising into great eminence as a medical practitioner; but his incessant application to the laborious duties of his profession, as well as to his philosophical pursuits, was beginning to undermine a constitution naturally weak. He was invited by the first Marquis of Lansdowne to his seat of Hardwell Cliff, near Lymington, in hopes that the change of air might have a beneficial effect upon his health. But the foundations of his disorder were too deeply laid; he gradually declined, and shortly after died at Lymington, on the 29th of July 1795. He was buried in the church at Hardwell. It was the intention of his noble patron to have erected a monument to his memory, and, at his lordship's solicitation, two very appropriate and elegant compositions were written, the one by Dr Denman, who was among his early friends; and the other by the well-known Gilbert Wakefield. Lord Lansdowne, however, did not live to see his design carried into execution.

During the year 1785, he married Miss Stone, a lady from Devonshire, by whom he left four children, two sons and two daughters; the eldest son being a clergyman, the other in the medical profession. The daughters, who were infants at his death, were principally educated under the immediate superintendence of the celebrated Miss Elizabeth Hamilton, who was first cousin to their father, and who adopted them as her own children.

His eldest brother, the Reverend William Crawford, and the father of Dr Stewart Crawford of Bath, was a man of considerable literary attainments; he published Remarks on Lord Chesterfield's Letters, which met with success, and also Translations from Turcetine, and a short History of Ireland. His second brother, John, was for many years a surgeon in the service of the East India Company, and published, many years ago, a pamphlet showing, from a number of cases, the efficacy of calomel, conjoined with other purgatives, in the treatment of those morbid affections of the liver to which the inhabitants of India are so prone; a work which probably laid the first foundation of the practice which has since been so generally adopted. His brother Alexander, whom we have already had occasion to mention, was a physician at Lisburn in Ireland, and obligingly furnished most of the particulars above given, relative to his brother, who was endeared to him by the strongest ties of affection, and of whose moral worth he spoke in terms of the highest veneration.

The published works of Dr Crawford, besides that on Animal Heat, above noticed, were, a paper in the Philosophical Transactions, On the power inherent in the Human Constitution of resisting high degrees of Temperature; and another On the effect of Muriate of Barytes in the Cure of certain Diseases. A posthumous work of his On the effect of Tonics on the Animal Fibre, was edited by his brother, Dr Alexander Crawford.

He had a taste for poetry, which, however, he indulged but sparingly. An elegy which he wrote On the death of Lady Sarah Stewart, the mother of Lord Castlereagh, afterwards Marquis of Londonderry, was supposed to have considerable merit, but he could never be prevailed on to publish it.