DEAFER, HENRY. 



DRAPER, JOHN W. 



219 



about a year and a half, on the medical staff 

 of Bellevue Hospital. He was then elected to 

 the chair of Physiology in the University of 

 the City of New York, and six years later 

 (1866) was placed in the chair of Physiology 

 in the medical department of the same institu- 

 tion. As managing officer in that department 

 he was active and energetic, and was also very 

 successful in arousing interest in the institu- 

 tion after the severe loss of property it met 

 with by fire. At this time he married a daugh- 

 ter of Oourtland Palmer, of New York, who 

 not only brought to him wealth and abundant 

 means to carry forward to any extent his 

 scientific pursuits, but also entered warmly 

 into her husband's studies and purposes. His 

 attention had been directed, when he was quite 

 a youth, to the possibilities of microscopical 

 photography, of which he made valuable use 

 in mecjical science ; he also incidentally discov- 

 ered the use of protochloride of palladium in 

 darkening collodion negatives. Soon after re- 

 turning from Europe he constructed a fifteen- 

 and-a-half-inch reflecting telescope, and, with 

 the aid of this instrument, took a photograph 

 of the moon, fifty inches in diameter. Pro- 

 fessor Draper was the first to obtain a photo- 

 graph of the fixed lines in the spectra of stars, 

 an experiment which has been repeated only 

 once or twice since. He was incessantly de- 

 voted to his work, and is said to have obtained 

 photographs of more than one hundred of the 

 spectra of different stars. In 1874 he was 

 appointed, by Congress, to the commission 

 created to observe the transit of Venus across 

 the disk of the sun. As superintendent of the 

 photographic department of the commission 

 he was so successful in his work that a special 

 gold medal was struck in his honor, by order 

 of Congress, in the mint at Philadelphia. In 



1877 he published a paper entitled "Discovery 

 of Oxygen in the Sun, and a New Theory of 

 the Solar Spectrum." The theory has been 

 doubted and disputed, but it is reported that 

 further studies in science tend to vindicate 

 Draper's conclusions. At this date he visited 

 the high ground between the Rocky Mountains 

 and the Sierra Nevada, to test the question 

 whether a great elevation was of special ad- 

 vantage for locating an observatory. As be- 

 tween lofty elevations inland or near the sea, 

 he gave his judgment in favor of the latter as 

 the most favorable site for an observatory. In 



1878 he went to the Rocky Mountains again 

 to photograph an eclipse of the sun, and for 

 two years subsequent he labored to obtain pho- 

 tographs of the nebula of Orion. His observa- 

 tory at Hastings-on-the-Hudson, and his lab- 

 oratory at his residence in New York, were 

 admirably equipped with everything which a 

 scientist could desire, and he was one among 

 the very few who could carry on any course 

 of study or experiment without regard to cost 

 or expenditure. Professor Draper died child- 

 less, and left no immediate descendant to carry 

 forward his favorite studies. 



DRAPER, JOHN WILLIAM, M. D.,LL.D;, born 

 at St. Helen's, near Liverpool, England, May 5, 

 1811 ; died at Hastings-on-the-Hudson, Janu- 

 ary 4, 1882. His early education was at the 

 Wesleyan School, Woodhouse Grove, where his 

 scientific tastes were early developed. He pur- 

 sued the study of physics, chemistry, and higher 

 mathematics, under private instructors, and in 

 1829 went to the University of London, where 

 he devoted himself to investigations into chem- 

 istry, specially, and the science of medicine in 

 general. Most of his family having emigrated 

 to the United States, John William followed, 

 in 1833 entered the University of Pennsylva- 

 nia, and graduated in medicine in 1836. His 

 thesis on the crystallization of camphor under 

 the influence of light, and kindred subjects, was 

 regarded as of such superior merit that it was 

 selected by the faculty for publication. This 

 was the first of a long series of experimental 

 researches on radiant energy. It led to his 

 appointment to the chair of Chemistry and 

 Physiology in Hampden Sidney College, Vir- 

 ginia, where he prosecuted these and other in- 

 vestigations in the same line. In 1839 he was 

 invited to assume charge of his favorite depart- 

 ment in the University of the City of New 

 York, a position which he held during the 

 remainder of his life. In 1841 he was active 

 in establishing the University Medical College, 

 of which he was presiding officer for nearly 

 forty years. Dr. Draper's later years were 

 spent at Hastings-on-the-Hudson, near the as- 

 tronomical observatory of his son, Dr. Henry 

 Draper. His wife died many years before him, 

 leaving three sons and three daughters. His 

 sons followed in their father's footsteps, and 

 have maintained the family reputation. 



Dr. Draper was a man of more than ordina- 

 ry note in science ; he was also a student and 

 earnest thinker in the department of the phi- 

 losophy of history and human progress. For 

 more than forty years he was occupied in mak- 

 ing experimental researches in physiology and 

 molecular chemistry, and gave to the world the 

 results of his work in the pages of " The New 

 York Medical Journal," "The Journal of the 

 Franklin Institute," "The American Journal 

 of Science," and "The London Philosophical 

 Magazine." These researches cover a very 

 large range of subjects, but were chiefly de- 

 voted to a study of the chemical phenomena of 

 light, in both the organic and inorganic world. 

 In 1878 Dr. Draper collected and condensed 

 these researches, and published them in a vol- 

 ume, entitled " Scientific Memoirs, being Ex- 

 perimental Contributions to a Knowledge of 

 Radiant Energy " (8vo, pp. 473). This volume 

 is pronounced by competent judges to be a no- 

 ble monument to his memory, being the results 

 of labors which have greatly advanced the sum 

 of human knowledge. In it he claims to have 

 been the first in America to give attention to 

 the spectroscope and its importance in astro- 

 nomical science. " The first photographic por- 

 trait from the life was made by me " (he says). 



