List of sources:
Cape of Good Hope Government Gazette, 16 September 1862, Government Notice No. 284, List of the apothecaries, chemists and druggists, licensed in the Cape Colony; Ibid, 9 January 1885, pp. 41-45, List of licensed medical practitioners in the Cape Colony.
Eastern Province Year Book and Annual Register for 1862 (p. 102). Grahamstown: Godlonton & Richards.
Grahamstown Journal, 19 May 1869, p. 2, Natural History Society; 22 September 1887, p. 3, Illuminated Hydro-speculum.
Kaapsche Grensblad, 19 February 1859, p. 4, advertissement: H. Knowles, Apothecary in Grahamstown.
Medical and Pharmacy Register for the Colony of the Cape of Good Hope. Cape Town: W.A. Richards, 1893.
National Automated Archival Information Retrieval System (NAAIRS). http://www.national.archives.gov.za/naairs.htm Documents relating to Henry Knowles / H. Knowles.
South African Medical Directory for 1897. Cape Town: Cape Times, 1897.