Darling born at Stow, near Galashiels, was educated at the university of Edinburgh, and, having made two or three voyages as surgeon in the East India Company's service, settled in London in general practice.

He had a considerable intimacy with artists, David Wilkie, Benjamin Haydon, Thomas Lawrence, and Francis Leggatt Chantrey being both his patients and his friends.

In 1814 he published anonymously ‘An Essay on Medical Economy,’ which he dedicated to his friend and fellow-countryman Sir James Mackintosh.

Darling was of a singularly retiring disposition, and published this essay anonymously.

At a later period he interested himself about the making of bread by the disengagement of carbonic acid by chemical means, and printed a pamphlet on the subject, ‘Instructions for Making Unfermented Bread.’ This, like the book just mentioned, was anonymously published.