SIR HENRY ROSCOE. 92S 



Petrology was the branch of geology in which von Richthofen was 

 first interested, and in his work on melaphyre he endeavored to 

 systematize the science by adapting a classification of rock-species in 

 a scheme similar to that used in systematic zoology. His complete 

 classification was published in his "Natural System of Volcanic 

 Rocks." The faults of his plan to separate similar rocks because of 

 different ages reflect on the conceptions of geology in Germany at the 

 time rather than on his appreciation of the facts. 



Two other works deserve mention: his "Fiihrer fiir Foischungs- 

 reisende" (1886), and his " Geognostische Beschreibung von Pre- 

 dazzo" (1860). In the former he emphasized the desirability of pre- 

 cision in geographical description; in the latter he maintained that 

 the dolomites of the South Tyrol were coial reef deposits and that the 

 associated beds were contemporary deep-sea or coral-sand deposits. 

 He re-asserted his conclusions in 1874, after a study of living Malay- 

 sian reefs. 



Sidney Powers, at the request of R. A. Daly. 



SIR HENRY ROSCOE (1833-1915) 



Foreign Honorary Member in Class I, Section 3, 1890. 



The Rt. Hon. Sir Henry Enfield Roscoe died suddenly at his resi- 

 dence near London December 18th, 1915. Born January 7th, 1833, 

 he had nearly completed his 83rd year. Up to within an hour of his 

 death he was in good health and spirits. Then "heart failure" put 

 an end to his interesting and useful life. 



He was sent to University College, London, in 1848. Graham was 

 then the professor of chemistry there, and he was succeeded by Wil- 

 liamson during Roscoe's student years. After receiving the degree 

 of B. A. from the University of London he went to Heidelberg to 

 continue his studies under Bunsen. Here he took part in the well- 

 known researches on the chemical action of light. He continued work 

 in this field for some years after receiving the degree of Doctor of 

 Philosophy from Heidelberg in 1854, returning to Heidelberg in the 

 summer vacations for this purpose. In Ostwald's reprint in his 

 Collection of Scientific Classics, he says: "The Photochemical Re- 



