CHAPMAN, Nathaniel, physician, born in Summer Hill, Fairfax County, Virginia, 28 May, 1780; died in Philadelphia, Pennsylvania, 1 July, 1853. After receiving an excellent classical education at the academy in Alexandria, Virginia, he went to Philadelphia, and was graduated at the medical department of the University of Pennsylvania in 1800. While a student, he attracted the notice of Dr. Benjamin Rush, and became one of his private pupils. At his suggestion Chapman presented an inaugural thesis on hydrophobia in answer to an attack on Dr. Rush's favorite theory on the pathology of theft disease. Subsequently he went abroad, studying for a year in London under Dr. Abernethy, and then for two years in the University of Edinburgh. He returned to the United States in 1804 and began practice in Philadelphia, where he soon became eminent. In 1810 he assisted Dr. Thomas C. James, then professor of midwifery, and three years later he became professor of materia medica in the University of Pennsylvania. In 1816 he was elected to the chair of theory and practice of medicine, which he held until 1850. He founded the medical institute in 1817, and for more than twenty years delivered a summer course of lectures in that institution, also for many years gave clinical lectures in the hospital of the Philadelphia ahnshouse. For some time he was president of the Philadelphia medical society, president of the American philosophical society (1846-'8), and the first president of the American medical association. In 1820 he began the publication of "The Philadelphia Journal of the Medical and Physical Sciences," which he edited for several years. Many of his lectures appeared in the "Medical Examiner" of Philadelphia during 1838-'40, and afterward were issued in book form. His published works include "Select Speeches, Forensic and Parliamentary" (Philadelphia, 1808); " Elements of Therapeutics and Materia Medica" (1828); "Lectures on Eruptive Fevers, Hemorrhages, and Dropsies, and on Gout and Rheumatism" (1844); and "Lectures on the Thoracic Viscera." A compendium of his lectures was published by Dr. N. died Benedict. His grandson, Henry Cadffalader, physician, born in Philadelphia, Pennsylvania, 17 August, 1845. He was graduated at the University of Pennsylvania in 1863, and at the medical department in 1867, after which he spent three years in Europe. He then settled in Philadelphia, was for some time lecturer on anatomy and physiology in the University of Pennsylvania, and in 1877 became lecturer on the physiology of the nervous system in Jefferson medical College. He is curator of the Philadelphia academy of natural sciences, and a member of the American philosophical society. To the proceedings of these organizations he is a frequent contributor, and has also published papers in the "Medical Times," and also "Evolution of Life" (Philadelphia, 1873), and " History of the Discovery of the Circulation of the Blood" (1884).