On his return from Europe he prepared for publication his first work, "The Evolution of Life," 193 pages, issued in 1872. Joseph Leidy, and the naturalist, Timothy Abbott Conrad, were his warm friends, and sponsors for his election to the Academy of Natural Sciences, to the proceedings of which he often contributed. He became a director of the Zoological Society of Philadelphia in 1881, was its secretary in 1884 and corresponding secretary 1890–1904.
From 1873 to 1876 he was Leidy's assistant in the University of Pennsylvania and lectured on anatomy and physiology. The next year he was a curator of the Academy, succeeding George W. Tryon, Jr., and served again in 1891, to fill the vacancy caused by the death of Leidy.
From 1877 to 1880 he was demonstrator of physiology in association with James Aiken Meigs (q. v.), in Jefferson Medical College, and 1879–1880 was curator of the museum; in 1878 the college gave him his second degree in medicine, when his thesis was the "Persistence of Forces in Biology." Meigs died in the autumn of 1879, soon after starting his lectures for the term, and the course was continued by Chapman who, in 1880, was appointed to the vacant chair of institutes of medicine and medical jurisprudence. From 1878 to 1885 he served as professor of physiology in the Pennsylvania College of Dental Surgery. The University of Pennsylvania gave him the degree of Doctor of Science in 1908.
Chapman wrote much on the anatomy of the apes and was fortunate in securing a gorilla (1878) and a chimpanzee (1899) for dissection; practically all the valuable material coming out of the Philadelphia Zoological Garden passed through his hands. He records in a report that his experience as prosector showed "that the principal causes of deaths during the first six months of the existence of the Garden were improper food, badly regulated temperature and ill constructed cages."
His articles on the placenta of an elephant and on the placentation of the kangaroo "are his most important contributions to original research" (Nolan). For nearly thirty years he spent his summers at Bar Harbor, Maine, where he devoted himself to its flora and fauna.
Nolan, his biographer, states that Chapman's "History of the Discovery of the Circulation of the Blood" (56 pages, 1884) is, "from a literary point of view, the author's most satisfactory work."
In 1902 he examined the collections in Florence under the guidance of Giglioli, director of the Museum, and those of the Zoological Station of Naples, where Professor Dohrn helped him secure for the Academy of Natural Sciences a collection of the invertebrates of the Bay of Naples. In 1905 he went to Egypt where he studied hieroglyphics and Egyptian antiquities.
While devoting himself to science he gave time, also, to social diversions; some of us younger men watching Chapman at the Academy thought that his scientific work suffered from overdevotion to "Philadelphia Society."
Dr. Chapman married Hannah Naglee, daughter of Samuel Megargee.
He died at his home at Bar Harbor, from hemorrhage, probably resulting from gastric ulcer, September 7, 1909. He was survived by his widow.
Chapman, Nathaniel (1780–1853)
The Chapmans were old settlers in Virginia on the Pamunkey River, and Nathaniel was born in Fairfax County on the Potomac, May 28, 1780, and is to be remembered because of his conception of medical journalism and the impulse he gave it through many long laborious years. As a boy he went to the Alexandria Academy and when seventeen began to study medicine in the Pennsylvania School. Other than an excellent education in the classics and two years' desultory medical reading he had no advantages. Yet, although a stranger, poor, without acquaintance or introduction, he had capital in a delightful personality, making powerful friends by his graciousness and holding them by his sterling qualities. The popular young fellow graduated in 1801 with a thesis on "Hydrophobia" in which he defended certain propositions of his preceptor Rush. Then he went abroad for three years and seems to have been a social lion in Edinburgh, where he was taken by Lords Buchan, Dugald Stewart and Brougham.
In 1804 he settled down to practise in Philadelphia and had success for a period of fifty years, commanding whatever he could attend of practice; also that same year he married Rebecca, daughter of Col. Clement Biddle. The personality of the man made a great impression on the Philadelphia of our grandfathers. He was always gay, jovial and witty, and as he grew older his habit of punning increased. His easy graceful way of treating everything appeared even in his writing when he became
