James B Aiken was a partner in the Durban firm Palmer & Aiken, accountants and agents, and served on the Durban town council during 1881-1883. From 1879 he was honorary secretary of the Natal Agricultural and Horticultural Society (1848-1883). By Law 21 of 1883 (Colony of Natal), the members of this society were constituted a corporation under the name "The Durban Botanic Society", with the object of maintaining the Natal Botanic Gardens "for the introduction, cultivation, propagation, and distribution of plants of every climate". As honorary secretary of this new society (to 1884 only), Aiken forwarded its first annual report to the Colonial Secretary in 1884, outlining the developments leading up to the name change.
By 1890 Aiken was listed as residing at Ruthville estate in Lower uMzimkhulu (Transkei). In 1893 J B Aiken and D C Aiken published an 11 page pamphlet on The marbles, lime and cement of lower Umzimkulu, Natal in Pietermaritzburg. It was also published in the Natal Almanac for 1894 (pp. 593-599). A few years later, in 1898, their collection of marbles and vein calcite from Lower uMzimkhulu was donated to the South African Museum.
Aiken was married to Emily Ruth Aiken (born Ridge).