384- Royal Geological Society of Cornwall. 



the same rocks for the purpose of exchanges. Simple cry- 

 stalline minerals cannot be obtained to any great extent, but 

 at prices very far exceeding our funds, and indeed such 

 Cornish minerals may be found in the collections of all exten- 

 sive mineral dealers. Rock specimens, however, are not to 

 be met with in such places, but they can be collected with 

 comparatively little expense ; and a series of granite, slate, 

 and serpentine rocks would be the most valuable return the 

 Society could make in their exchanges with scientific institu- 

 tions. Moreover such intercourse cannot fail of being highly 

 advantageous to both parties, and may be instrumental in the 

 advancement of the science of geology. 



(By order) H. S. Boase, Secretary. 



Oct. 13, 1826. 



The following Papers have been read since the last report : 

 — On the granite of the west of Cornwall. By Joseph Carne, 

 Esq. F.R.S.- — On the sand banks of the northern shores of 

 Mount's Bay. By H. S. Boase, M.D. — Some account of 

 certain ancient circles and barrows on the summit of Botrea 

 Hill, in the parish of Sancreed. By T. F. Barham, M.D. — 

 On the changes which appear to have taken place in the pri- 

 mitive form of the Cornish peninsula. By John Hawkins, 

 Esq., F.R.S. — On the temperature of mines. By Henry 

 Boase, Esq. — An account of some circumstances connected 

 with the heave of a copper lode by a flucan vein in the Con- 

 solidated mines, in the parish of Gwenap. By Mr. W. J. Hen- 

 wood. — On the geology of the coast from Sennen Cove to the 

 Land's End. By Joseph Carne, Esq. F.R.S. — On a singular 

 exudation of gas in the Union mines, in the parish of Gwenap. 

 By Mr. W. J. Henwood. — Observations on the suspension of 

 the stannary courts. By Henry Boase, Esq. — On the impor- 

 tance of a deep adit from the northern coast. By R. Ed- 

 monds, Esq. — A notice relative to a new fusee for the blasting 

 of rocks. By R. Collins, Esq. — An account of the quantity 

 of tin produced in Cornwall in the year ending with the 

 Midsummer quarter, 1826. By Joseph Carne, Esq., F.R.S. 

 j — An account of the produce of the copper mines of Corn- 

 wall, in ore, copper and money, in the year ending the 30th 

 June, 1826. By Mr. Alfred Jenkyns. 



Donations of Minerals, since the last Anniversary. 

 Various modifications of serpentine, augite, maclurite, 

 frankiinite, red oxide of zinc, &c. from the United States of 

 America. By Wm. Maclure, Esq. of Philadelphia. — Colopho- 

 nite, garnets, beryl in the matrix, coccolite, sulphate of ba- 

 rytes, red oxide of zinc, hornblende, rose-quartz, &c. By Jer. 



Van 



