John Armstrong, an English physician and author, born at Bishop-Wearmouth, May 8, 1784, died in London, Dec. 12, 1829. He graduated at Edinburgh university, and practised at Sunderland, where he wrote a work on "Typhus" (1816), which had a rapid sale throughout the kingdom. In 1818 he removed to London, where he failed to pass his examination before the college of physicians; but as that institution was exceedingly unpopular in the profession, his rejection was ascribed to jealousy, and he was soon afterward elected physician to the fever hospital. In 1821 he united with Mr. Grainger in founding the Webb street school of medicine, where his lectures were exceedingly popular. His chief defect was immoderate egotism. He regarded himself as a great reformer in the healing art, and ridiculed almost all medical learning except his own. His lectures, edited by Joseph Rix, were published in 1834.