152 Mr. H. L. PattinsoK on Smelting Lead Ore, fyc. 



No. III. — An Account of the Method of Smelting Lead Ore and Refining 

 Lead, practised in the Mining Districts of Northumberland, Cumber- 

 land, and Durham, in the year 1831. By Mr. H. L. Pattinson. 



Read, Oct. 17, 1831. 



1 he total quantity of Lead ore, produced in the northern mining 

 districts annually, is about 70,000 bings, of 8cwt. avoirdupois each, 

 or 28,000 avoirdupois tons. Nearly the whole of this quantity is Ga- 

 lena, which, on reduction, yields Lead containing from two to twenty- 

 four ounces of silver per fodder of 21cwt. or 2352lbs. The other 

 varieties of Lead ore which occur, are Carbonate and Phosphate of 

 Lead, but they are always found in situations near the surface, and in 

 comparatively small quantities. 



The Galena is principally cubical, but some veins produce steel- 

 grained, compact, and antimoniated Galena. Cubical and steel-grained 

 Galena are often variously blended together, and every variety is, in 

 most cases, intimately mixed with Spar and Vein Stone, or Rider, as it is 

 provincially called, when brought out of the mines. Each vein con- 

 tains generally a peculiar, and frequently a distinguishing, species of 

 Spar and Rider. The Spars are Fluate and Carbonate of Lime, Pearl 

 Spar, Sulphate of Barytes, Baryto-calcite, and among them may be in- 

 cluded Blende and Iron Pyrites. The Riders differ nearly as much.. 

 In some veins they consist of fragments of the adjacent strata, appa- 

 rently cemented together by interposed spar or ore ; and in others, 

 the Rider is a hard and (as the miners term it) burnt, or soft and friable 

 stone, strongly impregnated with iron. 



However these substances are intermingled with the ore, they ought 

 to be removed as much as possible in the process of washing, for, ex- 

 cept this is done entirely, the residual portion affects the ore, and gives 

 it a peculiar character in the subsequent operation of smelting. The 



