Thomas Lewis, whose father, Henry Lewis, J.P, was a Cardiff colliery-owner, was educated at home and at Clifton. He did his pre-clinical training at University College, Cardiff, taking the B.Sc. degree with first-class honours in both anatomy and physiology in 1902. His career at University College, London, where he qualified in 1904, was equally distinguished, his prizes including the Atchison scholarship. In 1906 he was elected to the staff of the City of London Hospital for Diseases of the Chest, but an invitation by Leonard Hill to write an article on the pulse drew him into the field of research. His first important discovery was made in 1909 when he identified auricular fibrillation as the cause of a heart irregularity observed by James Mackenzie, with whom he was associated. Appointment to a Beit memorial fellowship followed in 1910, to a lectureship in cardiac pathology at University College in 1911, and to the staff of University College Hospital in 1913. He then engaged in research on the mechanism of the heart-beat, and in 1914, after visiting the United States, made a study of heart affections in warfare for the Medical Research Committee and became consulting physician on heart diseases to Eastern Command. In 1916 he gave up his practice and entered the Committee’s full-time service. His department, after the War, became known as the Department of Clinical Research, and he himself, now consulting physician to the Ministry of Pensions, turned from electrocardiography to research on blood vessels. From this he moved on eventually to the study of the origin of pain.

In addition to editing Heart from its foundation in 1908 and its successor Clinical Science till 1944, Lewis was the author of numerous articles and textbooks. His most important publications all achieved a number of editions, Clinical Disorders of the Heart Beat (1912) (seven editions), Clinical Electrocardiography (1913) (six), The Soldier's Heart and the Effort Syndrome (1918) (two), Mechanism and Graphic Registration of the Heart Beat (1920) (three). His work received widespread recognition. The Royal Society, having awarded him the Royal Medal in 1927, paid him its supreme tribute — the Copley Medal — in 1941, and three years later, jointly with the Royal College of Physicians, presented him with the Conway Evans Prize. At the College he was Oliver-Sharpey Lecturer in 1921, Croonian Lecturer in 1926 and Harveian Orator in 1933. He was created C.B.E. in 1920 and knighted in 1921.

Lewis’s achievement lay not so much in his individual researches, notable though they were, as in bringing scientific methods and standards to the examination of disease in man at the bedside. The requisite qualities of vision, single-mindedness and courage were his in full measure. He would pursue a course of action on which he had decided with the utmost energy, letting nothing distract or deter him. His work, moreover, gave evidence of meticulous preparation and faultless precision. His teaching, if on occasions too erudite for the average student, bore the same traits. Both mentally and physically, he gave an impression of ceaseless activity, which was heightened by the penetrating gaze of his deep blue eyes. Watching and photographing birds were the recreations of his holidays, and in later years he took to fishing and gardening. Lewis married in 1916 Lorna Treharne-James of Merthyr Tydfil, and had one son and two daughters. He died at Rickmansworth.

G H Brown

[Lancet, 1945; B.M.J., 1945; Presidential Address to R.C.P., 1945, 14]