DRAPER, JOHN WILLIAM (1811-1882), American scientist, was born at St Helen's, near Liverpool, on the 5th of May 1811. He studied at Woodhouse Grove, at the University of London, and, after removing to America in 1832, at the medical school of the University of Pennsylvania in 1835-1836. In 1837 he was elected professor of chemistry in the University of the City of New York, and was a professor in its school of medicine in 1840-1850, president of that school in 1850-1873, and professor of chemistry until 1881. He died at Hastings, New York, on the 4th of January 1882. He made important researches in photo-chemistry, made portrait photography possible by his improvements (1839) on Daguerre's process, and published a _Text-book on Chemistry_ (1846), _Text-book on Natural Philosophy_ (1847), _Text-book on Physiology_ (1866), and _Scientific Memoirs_ (1878) on radiant energy. He is well known also as the author of _The History of the Intellectual Development of Europe_ (1862), applying the methods of physical science to history, a _History of the American Civil War_ (3 vols., 1867-1870), and a _History of the Conflict between Religion and Science_ (1874). His son, HENRY DRAPER (1837-1882), graduated at the University of New York in 1858, became professor of natural science there in 1860, and was professor of physiology (in the medical school) and dean of the faculty in 1866-1873. He succeeded his father as professor of chemistry, but only for a year, dying in New York on the 20th of November 1882. Henry Draper's most important contributions to science were made in spectroscopy; he ruled metal gratings in 1869-1870, made valuable spectrum photographs after 1871, and proved the presence of oxygen in the sun in a monograph of 1877. Edward C. Pickering carried on his study of stellar spectra with the funds of the Henry Draper Memorial at Harvard, endowed by his widow (_née_ Mary Anna Palmer). See accounts by George F. Barker in _Biographical Memoirs of the National Academy of Science_, vols. 2 and 3 (Washington, 1886, 1888).