VAUGHAN, John, physician, born in Uchland, Chester County, Pennsylvania, 25 June, 1775; died in Wilmington, Delaware, 25 March, 1807. His father, John, was a Baptist minister. The son was educated at Old Chester, studied medicine in Philadelphia under Dr. William Currie, and at the University of Pennsylvania in 1793-'4, and in 1795-'9 practised in Christiana Bridge, Delaware, after which time he resided in Wilmington. He attained note in his profession, and numbered among his intimate friends and familiar correspondents Thomas Jefferson, Aaron Burr, John Dickerson, Caesar A. Rodney, and Dr. Benjamin Rush. He was a member of many scientific bodies, and in 1799-1800 delivered a course of lectures on chemistry and natural philosophy at Wilmington. After 1806 he officiated occasionally as a Baptist. preacher. Besides numerous articles in periodicals, Dr. Vaughan published an edition of Dr. Smith's "Letters," a "Chemical Syllabus," and "Observations on Animal Electricity in Explanation of the Metallic Operation of Dr. Perkins," a defence of Dr. Elisha Perkins's "metallic tractors," of which he was a zealous advocate.