Notices and Extracts from the Mmutes of the Geological Society/. 495 



relation of metalliferous veins to primary, unstratified formations ; and thus to 

 lead to the inference, that the metals were deposited in the former by subli- 

 mation from the latter: and he adds, that Baron Humboldt^ accounts for the 

 association of the mines of the Oural and Altai mountains with granite, por- 

 phyry, and syenite, by supposing- all of them to be the effect of volcanic agency, 

 taken in its most extended signification. 



The doctrine of the sublimation of the metalliferous contents of veins from 

 igneous matter, occurred to the author twelve years ago, from observing the 

 deposition of specular iron on the cooled, lateral edges of a stream of lava 

 flowing down the side of Vesuvius ; and he was induced from that circum- 

 stance to institute a series of inquiries, in further prosecution of which, he 

 proposes, in the memoir, the following questions : 



1st. Is there near each of the known metalliferous deposits any unstratified 

 rock ? 



2ndly. If none is to be found in the immediate vicinity of such deposits, is 

 there no evidence, derived from the geological constitution of the district, 

 which would lead to the belief that an unstratified rock may extend under the 

 metalliferous district, and at no great distance from the surface of the country f* 



3rdly. Do metalliferous deposits exist entirely disconnected from unstrati- 

 fied rocks ? 



With respect to the first of these questions, the author shows, by copious 

 references to works on England 2, Scotland'^, Ireland"*, Norway^, France^, 



' Essai de Geologic et dc Climatologie Asiatique. 



* Berger, on the Physical Structure of Devonshire and Cornwall, Geol. Trans., First Series, 

 vol. i. p. 93, 1811. Richard Thomas, Topographical Map and Sections of the country between 

 Redruth and Camborne, 1819. Conybeare and Phillips, Outlines of the Geology of England and 

 Wales, 1822 ; Ibid., for Cornwall, Map and Sections; and for Derbyshire, p. 448 ; Greenougli's 

 Geological Map, for Northumberland. Henslow, Geological Description of Anglesea, Trans. 

 Camb. Phil. Soc, vol. i. 1822. Berger, Mineralogical Accoiuit of the Isle of Man, Geol. Trans., 

 First Series, vol. ii. pp. 8 & 22, 1814. Macculloch, Description of the Western Islands of Scotland, 

 &c., vol. ii. pp. 530 & 574, 1819. 



' Edinburgh Review, No. 103, p. 54. ^one, Essai Geol. sur I'Ecosse, -p]), 27, \Q2,8i.c. Maccul- 

 loch, Geol. Trans., Second Series, vol. i. p. 65, and Description of the Western Isles of Scotland, 

 vol. i. p. 68. 



^ Boue, Essai Geol. sur I'Ecosse, p. 374 — 376. Weaver, Geol. Trans., First Series, vol. v. 

 p. 135, et seq. 



^ Von Buch, Voyage en Norvcge (French translation), tome i. p. 112. 



** De Bonnard, Geologic de quelques parties de la Bourgogne, Annales dcs Mines, lere Serie, 

 tome X. p. 193, et seq. Charbaut, Memoires sur la Jura, Annales des Mines, lere Serie, tome iv. 

 p. 579, et tome xiii. p. 177. Cox(\\ex, Amiales des Mines, lere Serie, tome iv. p. 16. Lucas, 

 Tableau Methodique des Mineraux, Partie II. p. 480. Thierria, Notice Geologique sur les Envirom 



3 s 2 



