Henry Peter [George] Bayon (originally Enrico Pietro Bayon)l, Italian British physician and researcher, studied engineering at the University of Genoa and then studied medicine at the University of Würzburg and the University of Genoa to qualify as Doctor of Medicine (MD) in 1905. That same year he went to London and completed a course at the London School of Tropical Medicine. He then became a ship's surgeon and went on voyages to South America, South Africa and the Black Sea. In 1907 he joined the Sleeping Sickness Commission and went to Uganda where he conducted research on sleeping sickness and other tropical diseases. Returning to London he held various positions as pathologist and by 1911 held an appointment as Craggs Investigator at the London School of Tropical Medicine. There he investigated the cause and nature of leprosy. Among others he published "Demonstration of specimens relating to the culture of the leprosy bacillus" (1911) and "Organisms cultivated from the lesions of human leprosy" (1912) in The British Medical Journal, "The culture and identification of the germ of leprosy and the relationship of the human disease to rat leprosy" (Transactions of the Royal Society of Tropical Medicine and Hygiene, 1912), and "The leprosy problem in the British Empire" (The Lancet, 1913).
In April 1912 Bayon was appointed as bacteriologist for leprosy research in the Department of the Interior of the Union of South Africa. That same year the University of the Cape of Good Hope honoured him by admitting him to the MD degree ad eundem. He was stationed on Robben Island for some time, as he appears on a staff photo taken on the island in 1913, including staff of the leper colony and mental hospital. During his stay the government sent him to Russia for six months to study leprosy there. His investigations and recommendations were written up in the following Parliamentary Report: South Africa, Department of the Interior. Report by the Government Research Bacteriologist (leprosy) on the necessity or advisability of segregation in relation to the conditions and spread of leprosy in South Africa at the present time; the measures to be provided for the prevention and cure of leprosy; and the suitability of Robben Island as a place of detention for lepers (Cape Town, 1913, 9 pp). On 7 March 1913 he attended a meeting of the Durban Medical Society and presented a well-received lecture on leprosy. Later he published a paper on a harmless group of parasites found in arthropods, "Herpetomonidae found in Scatophaga hottentota and Chamaeleon pumulus" in the Transactions of the Royal Society of South Africa (1915-1916, Vol. 5, pp. 61-65), though he had left the country by then.
Other publications by Bayon included the following: "The cultivation of Trypanosoma rhodesiense, Stephens and Fantham" (Royal Society of London Proceedings, Series B, 1912), "A new species of Treponema found in the genital sores of rabbits" (British Medical Journal, 1913), and "Racial and sexual differences in the appendix vermiformis" (The Anatomical Record, 1920). During World War I (1914-1918) he served with the British Red Cross. Later he obtained a position at the Molteno Institute for Research in Parasitology of the University of Cambridge. Among others he studied diseases of poultry and published various papers on the history of medicine. He was fluent in several languages and during his travels collected zoological specimens.
