394 Scientific Intelligence » [May, 



the difference observable in the hues of the precipitate made at differ- 

 ent times is to be ascribed to the different ])roportions in which the 

 oxides of the two metals have combined together, and, perhaps, also 

 to their different degrees of oxidation. — (Transactions of the Cambridge 

 Philosophical Society.) 



II. Qiiantitif of Copper raised in Corntvall. 



In Six Months ending June 1819. 

 The produce of 58 mines, 3327 tons ; of which, 1736 tons were pro- 

 duced by six mines as under : 



Ore* Copper. 



United mines .... 5005 tons 4194- tons 



W. Abraham, &c 5496 395 



Dolcoath 4704 345-i. 



Treskerby 2313 197 



Wheal Squire 2353 195^ 



Crennis 2407 183-i- 



22278 1736 



Produce of the ore about 74 per cent. 

 Price of copper, 131/. per ion. 



In Six Months ending Dec, 1819. 



The produce of 74 mines, 3477 tons; of which, 1768 tons were pro- 

 duced by six mines as under: 



Ore. Copper. 



United mines 5817 tons 482 tons 



W. Abraham 5655 395 



Dolcoath 5305 375 



Wheal Squire 2053 188 



Treskerby 2170 185 



Wheal Unity, &c 1873 143 



22873 1768 



Produce of the ore about 7-i per cent. 

 Price of copper 124/. per ton. 



In Six Months ending June 1820. 



The produce of 65 mines, 3545 tons; of which, 1760 tons were pro- 

 duced by six mines as under : 



Ore. Copper. 



United mines 5798 tons 511 tons 



Dolcoath 5438 .... 406 



W. Abraham, &c 5298 364 



Treskerby. 2206 223 



Wheal Unity, &c 1693 1 30 



Wheal Squire 1415 126 



21848 1760 



Produce of the ore about 8 per cent, 

 Price of copper, 114/. per ton. 



