156 Dr. Berger on the physical Structure 



the upper part this rock is compact. From this eminence there Is 

 a very extensive view of the coast, which presents a very irregu- 

 lar broken Hne. 



In going from Redruth to Truro, by Carnon which is at the 

 farthest extremity of Restronget Creek, we follow for some time the 

 road to Falmouth, and for the first three miles at least there is only 

 granite ; a little before coming to the road from Penryn to Truro, 

 and just before leaving the parish of Gwennap, the grauwacke 

 formation begins and continues without interruption as far as Truro, 

 its positions to the east of which town I have already described. 



General Observations on the Mines of Cornwall. 



I passed too short a time in Cornwall, and I am not sufficiently 

 familiar with the practical part of mining to enable me to treat of 

 this interesting subject in detail ; I must leave it to those who are 

 more capable. I shall confine myself to a few geological obeerva- 

 tions alone, and I shall, as may be expected, follow with most other 

 mineralogists the opinions of Werner on the formation of veins. 



All mineral beds or deposits whatsoever may, I believe, be referred 

 to one of the three following divisions. 



A. Mineral beds. 



B. Mineral veins. 



C. Alluvial depositions.* 



* This denomination, which conveys a very good idea of what is meant here, was 

 suggested by two friends, instead of the less correct French word " minerais dc lavage," 

 (stream-works). 



