The son of a Scottish clergyman, John Armstrong took his medical degree at Edinburgh in 1732. He is remembered as the friend of James Thomson (who drew his portrait in Castle of Indolence) and seems to have been on good terms with most of literary London, though he famously quarreled with John Wilkes. Armstrong's once-high reputation as a poet and essayist did not survive the eighteenth century. There is a portrait by Joshua Reynolds.
Dissertatio medica inauguralis de tabe purulenta. 1732.
An essay for abridging the study of physick. 1735.
The economy of love: a poetical essay. 1736.
A synopsis of the history and cure of venereal diseases [Luisini, trans. Armstrong]. 1737.
The art of preserving health: a poem. 1744.
The muncher's and guzzler's diary. 1749.
Of benevolence: an epistle to Eumenes. 1751.
Taste: an epistle to a young critic. 1753.
Sketches; or, essays on various subjects. 1758.
A day: an epistle to John Wilkes. 1761.
Miscellanies. 2 vols, 1770.
A short ramble through some parts of France and Italy. 1771.
Medical essays. 1773.
Poems of Armstrong and Johnson. 1882.