Born 12 January 1862 at Westport, Connecticut, the eldest son of Horace Bradley Coley, farmer, and Clarine Bradley Wakeman, his wife. He was educated at Westport School, at Yale University (1880) and at the Harvard Medical School (1886-88). He acted as instructor in surgery at the New York Postgraduate School and Hospital from 1890 to 1897; was clinical lecturer in surgery at the Columbia University College of Physicians and Surgeons 1898-1908 and was associate professor 1908-09. He was professor of clinical surgery at Cornell University Medical College, New York; chief surgeon to the Mary McClelland Hospital, Cambridge, Massachusetts; consulting surgeon to the Physicians Hospital, Plattsburg, to the Fifth Avenue Hospital and the Memorial Hospital for the treatment of Cancer and Allied Diseases, New York, and to the Sharon, Connecticut, Hospital. At the time of his death he was emeritus surgeon in-chief to the New York Society for the Relief of the Ruptured and Crippled. He early made his name in the operative treatment of hernia, and shortly before his death told the story of the radical cure of hernia in the *American Journal of Surgery* 1936, ns31, 397. Instigated by Sir James Paget's observation that malignant tumours occasionally diminish or disappear after an attack of erysipelas, he worked assiduously on the action of living streptococci upon sarcoma. He published a series of cases of inoperable sarcoma which appeared to have received benefit from the injection of a fluid containing Bacillus prodigiosus and Streptococcus erysipelatis. Other surgeons had a similar experience with "Coley's fluid" in from 2 to 4 per cent of similar cases. "Coley's fluid" was, in 1910, included in the list of non-official remedies compiled by the American Council on pharmacy and chemistry. The story was completed by Coley and his son B L Coley in 1926. Coley's work was done under great physical difficulties. He was a life-long sufferer from acromegaly, and he was "short circuited" for a duodenal ulcer. He died in a New York hospital of an acute intestinal affection on 16 April 1936, leaving a widow *née* Alice Lancaster of Newton, Mass, whom he had married on 4 June 1891, and two children. Publications:- Contribution to the knowledge of sarcoma. *Ann Surg* 1891, 14, 199; with bibliography, *ibid*, 1906, 43, 610. Primary malignant tumours of the long bones; end results in 170 operable cases, with Bradley L Coley, MD, *Arch Surg*, Chicago, 1926, 13, 779 and 1927, 14, 63. A special lecture delivered at the Royal College of Surgeons of England on 10 October 1935 on "The treatment of inoperable malignant tumours with the toxins of erysipelas and *Bacillus prodigiosus*, based on a study of end results from 1893 to 1934" was never published.