Nicol belonged to the mulatto Settler class that exerted great influence in Freetown during the 19th century.
After returning from school in England, Nicol entered the government service in 1829 and served in the Mixed Court until 1841.
The Colonial Treasury increased his pension to 396 pounds for serving in the harsh climate of Sierra Leone which was at that time known as the 'White Man's Grave'.
Possibly because he was an 'octoroon' Nicol was given special consideration in regard to pension as the Treasury evidently thought him to be an Englishman and did not realize that Sierra Leone had been his birthplace.
Nicol sold his valuable Freetown property to Charles Heddle, a mixed race Senegalese 'merchant prince' who had amassed a fortune in the groundnut trade.