Deceased Members — Professor Esmark. 535 



President from its formation in 1827 until his death; and a collec- 

 tion of Duplicates to the museum of Saffron Walden, near which 

 place he then resided. He was an active member of the Geological 

 Society of Cornwall, and of many scientific institutions in London ; 

 had a knowledge of Chemistry, Conchology, and Botany ; and was 

 a patron of the fine arts and a collector during his whole life. 



In Brigadier Charles Silvertop the Society has lost the au- 

 thor of many interesting communications to our Evening Meetings 

 on the Geology of Spain, the mineral structure of which, notwith- 

 standing its proximity to France and England, and the long-con- 

 tinued military operations of both these nations upon its territory, 

 is less known than that of any other portion of civilized Europe. 



The unhappy circumstances of the country have long abstracted 

 the attention of the Spaniard from researches of science, and the dif- 

 ficulties of travelling in the midst of civil commotions have deterred 

 even the enterprising spirit of neighbouring geologists from endea- 

 vouring to fill up the lamentable blank which Spain still presents 

 upon the scientific map of Europe. 



Brigadier Silvertop, though occupied in the professional engage- 

 ment of arms, was not forgetful of the pursuits of science. He pub- 

 lished the substance of his communications to this Society in a small 

 volume, 1836, wherein he gives a sketch of the widely-disseminated 

 deposits of tertiary beds in the provinces of Granada and Murcia, 

 accompanied by a general view of the volcanic and other rocks of the 

 same district, illustrated by sections, which represent the configura- 

 tion of the ground, the relative height of the ridges, and the super- 

 position of the strata. He died at Rennes, in June last, on his way 

 to the Pyrenees and Italy. 



Mr. Louis Hunton was the author of a paper printed in our 

 Transactions on the Upper Lias and Marl-stone of Yorkshire, 

 showing the limited vertical range of the species of Ammonites and 

 other Testacea, and 'illustrating their value as geological tests. His 

 observations are founded on the details of the section of Easington 

 height, near Whitby. 



Jens Esmark, Professor of Mineralogy in the University of 

 Christiania, was one of the many disciples of the school of Frey- 

 berg, who imbibed from their master an enthusiastic devotion to his 

 theories, which largely contributed to stimulate into activity that ge- 

 neral spirit of geological inquiry, the expansion of which, during the 

 present century, has produced such unexpected and extensive dis- 

 coveries in the development of the structure of the earth. 



In 1794, deeply imbued with the doctrines of Werner, he went 

 to Vienna to prepare himself for a tour through Hungary ; after 

 this he remained some months at Chemnitz, and visited the other 

 chief mining districts of Hungary, Transylvania, and the Bannat, 

 and crossing the Carpathians to Wielitzka and Cracow, returned 

 to Saxony by the mines of Tarnovitz in Silesia. 



In 1 798 he published, at Freyberg, the result of his observations, 

 in a small octavo volume, giving descriptions of the mines he visited, 

 and -their respective productions, and expressing his conviction of 



