Vol. 69.] ANNIVERSARY ADDRESS OF THE PRESIDENT. lxi 



sophical treatment of these fossils. After becoming Professor in 

 Tubingen, he studied industriously the geology of Wiirtemberg, 

 while still continuing his palseontological work ; and a visit to the 

 Salt Range in India in 1902 led him to take a special interest in 

 Permo-Triassic problems. He contributed a remarkable, though 

 somewhat speculative paper on the Permian ice-age to the centenary 

 volume of the ' Neues Jahrbuch' in 1007. A complete list of. his 

 writings is published in the ' JNeues Jahrbuch' for 1912, vol. ii, 

 pt. 3. 



While occupied with these numerous researches and his ordinary 

 professorial duties, Koken was an editor of the ' Neues Jahrbuch ' 

 and the ' Geologische & Pakeontologische Abhandlungen ' from 

 1899, as also of the ' Palaeontographica' from 1904, until his death. 

 He planned and arranged the fine new Geological Institute of the 

 University of Tubingen which was completed in 1902, and made 

 extensive additions to the collection by his own field-work both at 

 home and abroad. He. was beloved by his students and all his 

 associates, who deplore his untimely loss. Ho was elected a 

 Foreign Correspondent of the Geological Society in 1900. 



[A. S. W.] 



Konstantin Dmitrievich Khrt/shchov (C. de Chrcstschofe), 

 who was elected a Foreign Correspondent of this Society in 1895, 

 died on April 19th, 1912. His work on the artificial reproduction 

 of minerals, by which he is best known, extended over a quarter 

 of a century (1870-1895). It was commenced in Ereslau, con- 

 tinued for a time in 1872 at the School of Mines in New York, 

 and again in Breslau until 1890. He had studied also at Leipzig 

 and Heidelberg, but he took his degree of doctor at Breslau. On 

 his return to Russia in 1890 he was attached to the Chemical 

 Laboratory, and afterwards to the Mineralogical Museum of the 

 Imperial Academy of Sciences of St. Petersburg. From 1S95 

 onwards he was Professor of Geology & Mineralogy in the Military 

 Medical Academy at St. Petersburg. 



His first paper ' On Silicic Acid & the Silicifi cation of 'Woods,' 

 in which he gave a preliminary account of his work on the artificial 

 formation of crystallized silica, was published in 1872 in the 

 i American Chemist.' Then followed a pamphlet (Wiirzburg, 1878) 

 giving the results, mainly petrographical, of a visit of several months' 

 duration in 1873 to the Cerro del Mercado (or Iron Mountain), near 

 Durango in Mexico. In succeeding years a series of mineralogical 



