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often with the surface studded with the pyramidal ends of the 

 separate crystals; while in other cases the surface is nearly as smooth 

 as that of a cannon ball. Almost as commonly Witherite occurs as 

 encrusting masses like stalagmite, with a fibrous radiate structure. 

 In each and every one of these cases the surface of the mineral is 

 coated over with a chalky crust. Beautiful pearly crystals are 

 found at Bleagill, Alston. 



Witherite has a high commercial value, being employed in the 

 manufacture of plate-glass, and of beet-sugar, besides being used 

 also in the manufacture of certain pigments. Our fell-side 

 folk employ it as a rat-bane ; and it is said to be so noxious 

 that even the small quantity carried down in suspension in the 

 water of streams draining areas where this mineral is worked, is 

 sufficient to cause death in the smaller animals, and to give rise to 

 serious disturbances of health in the case of the larger, even at a 

 distance of three or four miles from the point where the poisonous 

 detritus first enters the stream. 



Strontianite, Strontium Carbonate, is said to have been ob- 

 tained from the Alston district, but I have been unable to discover 

 on what evidence its existence as a separate mineral has been 

 claimed for Cumberland. 



Cerussite, Plumbic Carbonate, the " White Ore " of miners, is 

 of general occurrence in connection with Galena. It seems, as a rule, 

 to occur chiefly in those parts of mineral veins that are most exposed 

 to the influence of surface-waters, just as might be expected in the 

 case of a mineral that is almost certainly a decomposition-product 

 of other ores of lead. In the Caldbeck Fells, and, to a smaller 

 extent, also in other mines, large masses of what were evidently at 

 one time solid crystals of Galena, may be found with the inner 

 parts of the crystal eaten almost entirely away, and the corroded 

 surface of the interior irregularly lined with Cerussite. Some of 

 these groups of crystals, especially at Brandy Giil, are in the form 

 of stellate macles, like six-rayed stars. Others, especially the 

 Cerussites from Braithwaite Mine, Force Crag Mine, Newlands, 

 Goldscope, Thornthwaite, and other places in the Keswick 

 district, occur in the form of tuft-like groups of slendef prisms, 



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