42 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 



in 1862, and an Englisli translation by Mr. P. H. Lawrence, with 

 additions by the author, in 1866. This is interesting as being the 

 last systematic work on the subject that appeared before the 

 general application of microscopic mineralogy to the study of rocks. 

 The treatise on mineral deposits was issued as a text-book for his 

 Preiberg class in 1854, the author having commenced, in 1817, a 

 miscellany under the title of ' Gangstudien ' (Lode studies), con- 

 taining monographs on mineral veins in different countries, con- 

 tributed by himself and others, which was continued at irregular 

 intervals up to a fourth volume in 1862. In 1859 the text-book 

 was reprinted in an extended form in two volumes ; and in 1861 it 

 was rearranged under the title of the ' Mineral Deposits of Europe.' 

 An English translation, under the title of 'A Treatise on Ore 

 Deposits,' by Mr. E. Prime, was published in America in 1870. 



Subsequently to 1845 mineral veins formed a chief object of 

 his study, his attention being principally devoted to the mining- 

 districts of the Eastern Alps, Hungary, the Banat, and the Buko- 

 wina, special memoirs upon which were published from time to 

 time. In 1868, on the invitation of the Emperor of Pussia, he 

 made a summer trip to the Altai, the result of his observations 

 being published in a large octavo volume in 1871. 



Cotta's popular and general geological works have attained a 

 circulation in Germany comparable with those of Sir Charles Lyell 

 in this country. The more important among these are : — 1. * Geo- 

 logical Letters upon Humboldt's Kosmos,' 1848, with a third edition 

 in 1855 ; 2. ' Geological Pictures,' a collection of articles originally 

 contributed to the Illustrirte Zeitung of Leipzig, of which six 

 editions appeared between 1852 and 1876, and a Pussian trans- 

 lation in 1859 ; and 3. ' Modern Geology ' (Geologic der Gegenwart), 

 in which he sought to establish the principle of development applied 

 by Darwin to the origin of species as the general law of terrestrial 

 development, published in 1866, and, in a fourth edition, in 1874, 

 besides translations into Magyar and Eussian. The same idea 

 of continuous development as a factor in geology appears in an 

 earlier work, ' Deutschlands Boden,' in which the influence of soil 

 and geological structure upon the population of Germany is treated 

 at length. This appeared in 1854, and, in a second edition, in 

 1858. 



In 1857-58 he revised and supplied a preface to a translation of 

 the 5th edition of Sir Charles Lyell's ' Geology.' 



His latest work was a commencement of a general history of 

 Geology ; the first volume (under the title of ' Geologisches Eeperto- 

 rium'), containing the titles of the principal works on Geology pub- 

 lished between 1546 and 1876, appeared in 1877. 



He was elected a Eoreign Correspondent of this Society in 1867, 

 and a Eoreign Member only last year. After his retirement he re- 

 sided at Ereiberg until his death on September 15, 1879. 



Among the Eoreign Members of which our Society has to deplore 

 the loss, one of the most distinguished is 



