John Reid (sometimes Reed), attorney and "collector of curiosities" in Cape Town, held the position of clerk to the attorney-general of the Cape Colony in 1831. By 1845 he was an attorney practising before the Supreme Court and in December that year was one of a group of attornies who submitted a petition to the governor and Legislative Council relating to proposed changes in the administration of justice.
Reid became a member of the South African Institution - the first scientific society of note in the Cape Colony, founded in June 1829 - in November 1829. The previous month he had presented the Institution with a large piece of "transparent calcareous spar" (i.e., calcite), via Dr James Adamson*. Reid delivered two chemical papers before the Institution, both of which were published in the South African Quarterly Journal: "Experiments on candle-wicks and on the effects of chlorine upon the combustible properties of the wax of the Candleberry Myrtle" (1830, No. 2, pp. 121-128), and "On some of the combinations of mercury" (1831, No. 5, pp. 48-). By 1831 he was a member of the council of the Institution, and continued as a member when it amalgamated with the South African Literary Society in 1832 to form the South African Literary and Scientific Institution. From 1835 to 1838 he was a member of the Institution's Statistical Committee, and again served on its council from 1839 to 1841.
Reid supported the movement to establish a botanic garden in Cape Town during 1845, and in April 1849 subscribed £1 per year to its development. On 19 September 1848 the Cape of Good Hope Agricultural Society held its plowing contest on the farm of "Mr Attorney Reid", near the Royal Observatory. Eight teams took part and Reid's own team won the competition.