1()8 Dr. Berg ER on the physical Si met are 



Of the mines of copper and tin, there are four in each of the 

 parishes of Redruth and Gwennap, three in St. Agnes, and two in 

 St. Neot. 



The two mines of lead marked in the above-mentioned map, 

 occur in the parish of Sithney, in a situation which is nearly of 

 the same elevation, as the lead mines of Beer-alston in Devonshire. 



The mine of lead and silver is found in the parish of Wendron, 

 and that of silver in the parish of Cubert. 



The mine of copper and silver is in the parish of Gwinear ; the 

 antimony at St. Austle and Endellyon ; copper and cobalt in Cam- 

 borne ; tin and cobalt in Madron ; manganese near Launceston 

 and the Indian Queen. 



If we examine these localities it will appear, that the copper and 

 tin vv^hich either singly or combined form four-fifths at least of the 

 mines in Cornwall, are met ivlth near the junction of the granite and 

 grauwacke : * but it also appears, that tin may, contrary to the 

 opinion of Werner,f be sometimes found in secondary stratified 

 mountains. It is true that at Kithill, and in the islands of Scilly,:}: it 

 is found in the true granite. 



When the tin is not combined with copper, it usually forms a 

 constituent part of the granite, and in this case it is often accom- 

 panied by wolfram in the matrix of the vein.§ 



* Baron Born and Fcrbcr have made the same obscrvaiions, the former in the 

 Bannat, the latter in the mountains of the Veronese and of the Vicentine. Fcrber's 

 Letters on Italy, to Baron Born, p. 36. 



+ Journal des Mines, No. xvlli. p. 90. 



J " The vestigia of any tin lodes, mines or worlfings, in the islands of Scilly, arc 

 " scarcely discernible; for there is but one place that exhibits even an imperfect ap- 

 " pearancc of a mine." Pryce's Miner. Coriuib. 



§ At Kithill near Callington. 



