Crookes
SIR WILLIAM, an Engof Chemistry under Hofmann, and after don in 1832; studied at the Royal College 1851 devoted himself to original researches in science.
He invented the radiometer in 1875, and in 1877, and announced in 1879 his dis- radiometer in 1875, and the otheoscope covery of the fourth or ultra-gaseous in 1877, and announced in 1879 his disstate of matter.
In 1880 the French Académie des Sciences bestowed on him and a gold medal in recognition of his an extraordinary prize of 3,000 francs discoveries in molecular physics and ra- SIR WILLIAM CROOKES diant matter. In 1881 he acted as juror at the International Exhibition of Electricwas not entitled to a medal, but in the ity in Paris. In this official position he official report his fellow jurors, after of four systems of incandescent lamps, declared-"None of 14-Vol . III-Cyc CROQUET them would have succeeded had it not been for these extreme vacua which Mr.
Crookes has taught us to manage." It is stated that he was the first to apply photography to the investigation of the solar spectrum. He is the author of "Select Methods in Chemical Analysis," "Manufacture of Beet-root Sugar in England," "Handbook of Dyeing and Calico-Printing," "Manual of Dyeing and Tissue-Printing," etc. He is also joint author of the English adaptation of Kerl's "Treatise on Metallurgy." He has edited the last three editions of Mitchell's "Manual of Practical Assaying," and has translated into English and edited Reimann's "Aniline and its Derivatives," Wagner's "Chemical Technology," Auerbach's "Anthracen and its Derivatives," and Ville's "Artificial Manures." He is an authority on sanitary questions, especially the disposal of town-sewage. In 1907 he shared the Nobel prize for Chemistry with E. Buchner, and in 1910 was awarded the Order of Merit. He died on April 4, 1919.