Alec was educated at Glasgow University, where he graduated M.B. and C.M. in 1892. He then filled the posts of medical superintendent at Paisley Infirmary and Fever Hospital; at the Gockston Small-pox Hospital; and at the Croydon Borough Hospital, before going into practice at Chislehurst, Kent. He joined the R.A.M.C. as a temporary lieutenant on 15th July 1915, and was promoted to temporary captain after a year’s service. Alec was the son of Charles Smith of Paisley; and the husband of Margaret Flora Robb Smith (nee Aitken) of "Heatherbank" Chislehurst, Kent.