Alexander L. McDonald resided in Grahamstown, where he played an active role in the advancement of science for several years. He may have been Alexander Lowrie McDonald, who died in the Cape Colony in 1879. He may also be the same person as A.L. McDonald, assistant purveyor in the Purveyor's Department, Military Headquarters, Grahamstown (Campbell's Grahamstown annual, 1867, p. 31) and as Alexander L. McDonald (c. 1821-1880), who was associated with the paymaster's office in Cape Town and elsewhere. The latter's biography, in the form of a manuscript written by Eric A. McDonald in 1937, is in the National Library, Cape Town.
Mr Alexander L. McDonald was the only non-medical person present at the founding of the Medico-Chirurgical Society of Grahamstown on 3 July 1855, in which Dr G.A. Hutton* played a leading role. McDonald was elected as the society's honorary secretary and treasurer at the first meeting. Towards the end of the year the society's name was changed to the Literary, Scientific and Medical Society, and their collection of specimens became the Albany Museum (Natural History). He was re-elected as secretary in June 1856 and eventually resigned his post in January 1859, but continued to serve on the society's management committee. He served also on the subcommittee responsible for the management of the Albany Museum and in 1858 was responsible for naming and arranging the collection of rocks and minerals.
McDonald, like several of his contemporaries in Grahamstown, frequently lectured on scientific topics. Some of his presentations were in the form of papers read before the Literary, Scientific and Medical Society on topics such as "The polarization of light" (November 1855) and "Meteorology" (July 1857). Others were lectures, usually delivered under the auspices of the society, aimed at educating the youth or general public. For example, he and Mr Francis Tudhope planned to present a bi-weekly class on natural philosopy during 1856. That same year he began to use the museum's collection of rocks and minerals as a basis for lectures and demonstrations to pupils. He appears to have enjoyed a good general education, for he also presented classes on English literature (June 1857) and lectured on Longfellow's poems (July 1859).