ZINC, BISMUTH, AND NICKEL. 425 



Mr. J. D. Kendall urges that the veinstones of all the veins in 

 Cumberland are part of the original rock in- which the metallic matter 

 has been deposited 1 from chemical solutions, which removed the 

 /soluble rock-substance along a joint, and filled the spaces with ores. 



In the Isle of Man there are eleven lead mines, the most famous 

 of which is the Great Laxey. Galena yields from 60 to 75 per cent, 

 of metallic lead. The quantity of silver in the lead varies at different 

 times in the same mine; 12 ounces to the ton is common, and 35 

 ounces of silver to the ton of galena is exceptional. 



In Scotland the Leadhill mines in Lanarkshire were formerly 

 among the most important ; and in Ireland an important lead mine 

 occurs at Luganure, in County Wicklow. 



Zinc is obtained from lodes, some of which occur in the older 

 Cambrian rocks, others in the Carboniferous limestone. The mines 

 which yield the largest quantity of zinc, also yield ores of lead. 

 Thus the West Chiverton in Cornwall, the Van mines of Montgomery- 

 shire, and the Great Laxey of the Isle of Man, are among the most 

 important ; but the Minera in Denbighshire, the Talargoch in Flint- 

 shire, the Woodend mine near Threlkeld, and Force Crag mine, Cum- 

 berland, and other mines in Shropshire, Devonshire, Cardiganshire, 

 Caernarvonshire, and Eadnorshire, all have local importance. The 

 chief ores are sulphide termed blende, carbonate termed calamine, 

 and silicate of zinc. The production is decreasing. Blende yields 40 

 to 47 per cent, of metallic zinc. 



Bismuth. Native bismuth is found near Redruth in Cornwall, at 

 Carrack Fell in Cumberland, and at Alloa near Stirling. The 

 sulphide of bismuth is also met with in Cumberland and Cornwall; 

 and the oxide and carbonate are found at St. Agnes in Cornwall ; 

 but the supply of bismuth in our own country is too small for it to 

 have any importance as an ore. 



Of Mercury there is no British ore. Mr. J. A. Phillips remarks 

 that the ores are found in the most ancient as well as in the most 

 modern rocks. Some of the principal veins are in the Silurian 

 strata, while the deposits of New Almaden, in California, are of 

 Cretaceous age. 



Arsenic is obtained from the ores of tin in Cornwall and 

 Devon. 



Antimony. A little sulphide of antimony is found in Cornwall, 

 but the chief supply is from Borneo. 



Nickel occurs in small quantity in this country, chiefly in the 

 Pengelley and St. Austell Consol's mines in Cornwall, and at the 

 Bathgate silver mine in Scotland. Nickel is found associated with 

 iron at Voel Hiradig, Cwm in Flintshire, to the amount of about 2 -3 

 per cent. 



Cobalt, in the form of cobalt glance, is found in the Botallack 

 mine ; and smaltine and cobalt bloom are also found in Corn- 

 wall. 



1 Manch. Geol. Soc., April 1884. 



