W.J.R. Simpson, British physician and specialist in tropical medicine, qualified as Bachelor of Medicine (MB) and Master of Surgery (CM) at the University of Aberdeen, Scotland, in 1876. In 1880 he was awarded the degree Doctor of Medicine (MD) by the University of Aberdeen, as well as the Diploma in Public Health by the University of Cambridge. The next year he started work as the first full-time medical officer of health of Aberdeen, while also lecturing at the university. In 1886 he was appointed as the first medical officer of health of Calcutta (now Kolkata), India. However, two years later he returned to Britain to take up an appointment as professor of hygiene at King's College, London, a position he held to 1923. Continuing his work in India he edited the Indian Medical Gazette from 1889 to 1896, and the Journal of Tropical Medicine from its inception. Returning to England around 1898 he became a co-founder of the London School of Tropical Medicine the next year and lectured there on tropical hygiene. He married Isabella M.J. Jamieson in 1888 and they eventually had two children.
Simpson did research on epidemic diseases such as cholera, small-pox and bubonic plague. He investigated health conditions, and particularly outbreaks of plague, in many British colonies. In 1900, during the Anglo-Boer War (1899-1902), he came to South Africa as member of the Commission on dysentery and enteric fever in South Africa, to inquire into these diseases among British troops. The findings were written up in his Report of the Commission on the nature, pathology, causation and prevention of dysentery and its relationship to enteric fever (London, 1903). He had hardly finished his field work when bubonic plague broke out among the war refugees that had settled around an overcrowded Cape Town. Upon travelling to the city he advised the local government on keeping the disease in check. On 31 May 1901 he delivered a "Lecture on plague" before the Cape Town Branch of the British Medical Association. The lecture was published in the Cape Times and reprinted as a pamphlet (1901). Part of it dealt with the plague in Cape Town. While in South Africa he published (or re-published) a Memorandum on the influence of rats in the dissemination of plague (London?, 1900; Cape Town, 1901, 13p). It dealt with measures to be taken to combat an epidemic of plague, with reference to outbreaks of the disease in the East.
Simpson was next appointed as a commissioner to investigate plague in Hong Kong (1902); sanitation in Singapore (1906); plague on the Gold Coast (now Ghana); public health on the Gold Coast, in Sierra Leone and Nigeria (1908); plague and public health in East Africa (1913); etc. His last visit to the tropics was to the copper mines of Northern Rhodesia (now Zambia) in 1929. Meanwhile he had been honoured as a Companion of the Order of St Michael and St George (CMG) in 1909 and as a Knight Commander of that order (KCMG) in 1923. Three years later he became a co-founder of the Ross Institute and Hospital for Tropical Diseases at Putney, London, and was appointed as its first director of tropical hygiene, a position he held to his death in 1931. He was a quiet and courteous man. His books included A treatise on plague dealing with the historical, epidemiological, clinical, therapeutic and preventing aspects of the disease (1905), The maintenance of health in the tropics (1905) and The principles of hygiene in relation to tropical and sub-tropical climates... (1908). Various reports by him dealt with the health history of Aberdeen (1883), cholera and its prevention in India (Calcutta, 1894, 1896), plague prevention in Hong Kong (1902), sanitation in the West African colonies (1909), and other similar topics. He also published papers on cholera and its prevention in India (Practitioner, 1894; Indian Medical Gazette, 1895), the production of a small-pox vaccine (ibid, 1897-1898), and plague in India (Journal of Tropical Medicine, 1898-1899).