This article was published in Australian Dictionary of Biography, Volume 9, (MUP), 1983
Thomas Harvey Johnston (1881-1951), biologist and parasitologist, was born on 9 December 1881 at Balmain, Sydney, son of Thomas Johnston, Irish-born foreman mason, and his Australian-born wife Mary, née McLeod. After schooling Johnston joined the education department, won the Jones memorial medal and went to the University of Sydney (B.A., 1906; B.Sc., M.A., 1907; D.Sc., 1911). On 1 January 1907 at Petersham he married Alice Maude Pearce.
Johnston taught at Fort Street Public School in 1903-06, lectured in zoology and physiology at Sydney Technical College in 1907-08 and became assistant director of the Bathurst Technical College in 1908. He was appointed assistant microbiologist at the newly established Bureau of Microbiology of the New South Wales Health Department in 1909. Lecturer in charge of the department of biology in the new University of Queensland from 1911, he was appointed professor in 1919.
Johnston was chairman of a committee formed in 1912 to investigate control measures for the introduced pest, prickly pear, and worked overseas in 1912-14 with Henry Tryon. The two men, known as 'the prickly pair', succeeded in introducing Dactylopius ceylonicus, the cochineal insect which controlled one species of the pear Opuntia monacantha. In 1920 Johnston was appointed controller of the Commonwealth prickly pear laboratories and went overseas again in 1920-22. He had twice collected and introduced unsuccessfully the insect Cactoblastis cactorum in 1914, when it did feed on the pear but died out in 1921. The eventual devastation of the prickly pear by it followed a later introduction in 1924.
Johnston was keenly interested in the marine ecology of Caloundra and the southern Barrier Reef islands. He was president of the Royal Society of Queensland (1915-16) and of the Queensland Field Naturalists' Club (1916-17). He was a foundation member of the Great Barrier Reef Committee and a member of the Australian National Research Council until his death.
Johnston was appointed professor of zoology at the University of Adelaide in 1922, creating a new department, and acted also as professor of botany in 1928-34. Specializing in descriptive parasitology, he was also a world authority on helminthology; he added much new material to the extensive collection of the South Australian Museum. At the invitation of Sir Douglas Mawson he served as chief zoologist with the British, Australian and New Zealand Antarctic Research Expedition of 1929, went on two cruises of the Discovery in 1929-31 and was editor of the zoological and botanical reports. In 1929-37 he participated with (Sir) John Cleland in many expeditions to Central Australia.
Active in many scientific and cultural institutions and societies, Johnston won numerous honours including the David Syme prize in 1913, the first Walter and Eliza Hall fellowship in economic biology in the University of Queensland, the Sir Joseph Verco medal and, in 1939, the Mueller medal of the Australian and New Zealand Association for the Advancement of Science. He wrote or co-authored 299 papers.
Affectionately known as 'T.H.J.', Johnston was gentle, kindly, hard working, clear thinking and sensitive, with a slow, quiet sense of humour. He lived up to a high ethical code and was in the sense of the Greek philosophers 'a complete man'. He died in Adelaide of coronary thrombosis on 30 August 1951, survived by his wife and daughter; his son predeceased him. He was cremated.
Dorothea F. Sandars, 'Johnston, Thomas Harvey (1881–1951)', Australian Dictionary of Biography, National Centre of Biography, Australian National University, http://adb.anu.edu.au/biography/johnston-thomas-harvey-6862/text11887, accessed 25 May 2013.
This article was first published in hardcopy in Australian Dictionary of Biography, Volume 9, (MUP), 1983