Edmund Victor Flack was employed in the civil service of the Cape Colony on 4 April 1898 as a clerk in the Government Analytical Laboratory, Department of Agriculture, Cape Town. He gradually took on the work of a chemical assistant and on 1 September 1906 was appointed as analyst. Following the formation of the Union of South Africa in 1910 he was appointed in April 1912 as second grade chemical assistant in the Government Analytical Laboratory in Grahamstown. By 1918 he had moved to Southern Rhodesia (now Zimbabwe), where he continued to work in agricultural chemistry.
Flack's scientific publications included the following articles: "Some factors influencing the solubility of phosphoric acid in mixed fertilizers containing superphosphates" (South African Journal of Science, 1916, Vol. 13, pp. 201-211), with a follow-up paper on the same topic a few years later (ibid, 1920, Vol. 17, pp. 268-274); "Bat guano deposits of Rhodesia" (ibid, 1920, Vol. 17, pp. 158-170); "Manure supplies under present conditions" (Rhodesian Agricultural Journal, 1918, Vol. 15(6), pp. 516-528); and "Rhodesian soils and their treatment" (ibid, 1926, Vol. 23, pp. 591-595).