Alexander Melvin, Doctor of Medicine (MD), entered the Army Medical Department in Britain in 1810. He came to the Cape of Good Hope in 1851, having been appointed deputy inspector of colonial hospitals on 24 September that year. He served also as president of the Colonial Medical Committee from 1851 to 1855. As the principal medical officer of the military establishment in the colony he was furthermore in charge of the military hospital in Cape Town. In June 1854, when it was feared that cholera would be introduced at the Cape from Mauritius, he published a memorandum setting out the sanitary and dietetic precautions necessary to prevent infection, and stated that the disease was comparatively harmless if treated in time. He was promoted to inspector-general of hospitals on 5 June 1855 and stationed at Military Headquarters in Grahamstown.
When the Grahamstown Medico-Chirurgical Society was formed in July 1855 by Drs W.G. Atherstone*, W. Edmunds*, R.M. Armstrong*, G.A. Hutton* and D.D.M. McDonald, they decided at their first meeting to ask Dr Melvin to become its president. Melvin accepted the nomination, presiding over the rapid initial growth of the society, its name change to the Literary, Scientific and Medical Society of Grahamstown towards the end of that year, and the establishment of its museum, which became the Albany Museum.
At a meeting of the society on 25 September 1855 Melvin read a paper on the effects of poisonous snake bites. He described experiments by an unnamed colleague who caused full-grown cobras to bite several dogs. The bites proved fatal, also in a dog treated with infusions and pulp of the snake root - a popular local remedy widely believed to be effective. However, a dog in which the tissue around the bite was excised survived. Melvin recommended excision as the most effective treatment for snake bites, but after discussion it was decided that local suction and the immediate application of a ligature above the affected part was the best approach.
Melvin retired as president of the society early in July 1856. He also retired from the army that year and left Grahamstown to settle in England. Upon his death he was described in the local press as a man who "endeared himself to all by his unobtrusive, courteous and Christian character, and his unostentatious and cheerful benevolence" (Burrows, 1958, p. 175). A medallion depicting him, made by Mr C. Essex and presented to the society, is in the Albany Museum.