Born at Gloucester in 1863, son of William Washbourn, a descendant of Sir Roger Washbourn, of Knight's Washbourn (*temp* 1370), went to King's College, Gloucester, then studied at Guy's Hospital, winning the Entrance Scholarship in 1881 and greatly distinguishing himself as well by taking prizes at the Hospital as by the scholarships and medals he won at the University. After his resident appointment he worked under von Baumgarten at Königsberg and Grüber in Vienna on bacteriology and bacteriotherapy. On his return in 1889 he was appointed Assistant Physician at Guy's Hospital, where he initiated the Department of Bacteriology. In 1891 he became Joint Lecturer on Physiology, and Lecturer on Bacteriology in 1892, Physician to the London Fever Hospital in 1897, and Physician to Guy's Hospital. Commenced in Germany, Washbourn carried on up to the time of his death researches on the pneumnococcus in relation to pneumonia, the varieties and life history of the Diplococcus pneumoniae, with an estimation of the virulence of the various strains. He sought to obtain from horses an antipneumonic serum, potent enough to influence cases of acute pneumonia, and he recorded his results in the *British Medical Journal* (1897, i, 510; ii, 1849). He studied the clinical applications of antidiphtheritic serum and published his observations in conjunction with Drs E W Goodall and J H Card. In 1897 he investigated the Maidstone typhoid epidemic and found the source of contamination in the water from the Tutsham-in-Field spring. With G Bellingham Smith he investigated the infective sarcomata of dogs in 1898. In February, 1900, Washbourn went out as Consulting Physician to the Imperial Yeomanry Hospital in South Africa, and served for sixteen months, first at Deelfontein, then in Pretoria. He organized the medical work of the Hospital with great success, was gazetted Consulting Physician to the Forces and made a CMG. Soon after his return, when President of the Section of Pathology and Bacteriology at the Annual Meeting of the British Medical Association, he took as the subject of his opening address "Some Pathological Notes from South Africa" and related "Observations on Infective Diseases Prevalent in the South African Army" (*Brit Med Jour*, 1901, ii, 699). He had acted as Examiner in Physiology for the Royal College of Physicians, and he was appointed Croonian Lecturer for 1902. He devoted the winter of 1901-1902 to the preparation of the subject of his lectures, "The Natural History and Pathology of Pneumonia". The lectures were delivered from his notes by Sir William Hale-White after Washbourn's death, and included a survey of the subject, the varieties and virulence of the coccus, the modes of its growth, and the preparation of an antipneumonic serum. He had carried out with Dr M S Pembrey a series of experiments on the channels taken by dust inhaled into the lungs. Washbourn had an infinite capacity for taking pains, a keenly critical appreciation of the relative value of his results, tempered with a scepticism which refused to accept the apparently obvious until after an accumulation of confirmatory evidence. As a teacher he was luminous, and at Guy's Hospital made his mark in the physiological and bacteriological departments and generally by his powers of organization. He was popular alike with his colleagues and with students, interested in sports and amusements, himself a good tennis player and skater. He combined a fair controversialist in a staunch friend and a strong partisan. At the time of his death he was Hon Secretary of the Epidemiological Society and of the Metropolitan Counties Branch of the British Medical Association. He had suffered in South Africa from dysentery complicated by thrombosis. After the winter's work, including the preparation of his Croonian Lectures, he had an attack of influenza. After partial recovery he again fell into ill health, and was removed for a change of air to Tunbridge Wells. There miliary fever was diagnosed, and he died on June 20th, 1902. He married in April, 1893, Nellie Florence, daughter of William Freeland Card, of Greenwich Hospital School; she died after giving birth to a daughter, who survived her father. Good portraits accompany his obituary in the *British Medical Journal* (1902, i, 1627; 85). A portrait is also included in Wale's *List of Books by Guy's Men* (1913, 65). Eulogies were pronounced by many, including one by Alfred Willett, President of the Royal Medico-Chirurgical Society (*Trans Med-Chir Soc*, 1903, lxxxvi, p. cxvii), and by Dr E W Goodall (*Trans Epidemiol Soc*, 1901-2, xxi, 151). Publication: *A Manual of Infectious Diseases* (with E W Gooneys), 8vo, London, 1896; 2nd ed, 1908.