1811–82, American scientist, philosopher, and historian, b. near Liverpool, England, M.D. Univ. of Pennsylvania, 1836. In 1839 he became professor of chemistry at the Univ. of the City of New York. He helped organize the medical school of the university, became its professor of chemistry and physiology, and in 1850 succeeded as its president.
Draper's chief contribution to abstract science was research in radiant energy. His work on the spectra of incandescent substances foreshadowed the development of spectrum analysis, in which his son Henry Draper became a pioneer. Draper's research in the effect of light upon chemicals led him to take up photography. He was said to be the first in New York to use Daguerre's process, announced in 1839, improving it so much that by December of that year he made his first satisfactory photographic portrait. A picture he took (1840) of his sister is the oldest surviving photographic portrait. Draper also made (1839–40) the first photographs of the moon.
Most of his papers on radiant energy were republished in his Scientific Memoirs (1878). His Human Physiology (1856) was the leading textbook of the period in its field, and it contained his own admirable micro-photographs, the first ever published. In 1863 his History of the Intellectual Development of Europe was published, and in 1874 his History of the Conflict between Religion and Science, a rationalistic classic that aroused great controversy. His other works include History of the American Civil War (3 vol., 1867–70) and Thoughts on the Future Civil Policy of America (1865).
His son, Henry Draper, 1837–82, was a physician by vocation, but he made major contributions in the field of astronomical photography and spectroscopy. He was the first to photograph stellar spectral lines.