KLESZCZYNSKY SILVER AND LEAD FROM BOHEMIA. 1/ 



The lignites above referred to are known at Vienna under the 

 name of "Traunthal coal," and are at present worked over a surface 

 of 6977 joch (17,240 acres). They yield from IQ to 22 jper cent, of 

 water at a temperature of 100° C. : heated in closed ovens, they give 

 40 to 4.5 -per cent, of coke ; and, when burnt in the open air, they 

 leave 5 jier cent, of ash. In a well-constrticted heating-apparatus, 

 15-16 zentners (185 1-1 974*4 pounds avoirdup.) are equivalent to 

 100*401 English cubic feet of fir-wood. The ashes of the lignite 

 have been successfully used for manuring moist meadow-land. 



The total mass of this fossil fuel, as at present known from mining- 

 operations, may be estimated, at a moderate rate, as about 6 millions 

 of cubic feet, or 4 millions 800,000 zentners. [Count M.] 



On the Extraction of the Silver and Lead from the 

 Argentiferous Galena of Pribram, Bohemia. By 

 M. Kleszczynsky. 



[Proceedings of the Imp. Geol. Institute of Vienna, January 22, 1856.] 



The ores of Pribram * are argentiferous galena, copiously mixed with 

 zinc-blende, carbonate of lime, and sulphate of barytes, together with 

 quartz, carbonate of iron, iron-pyrites, and grey copper in less pro- 

 portions. The separation of the blende from the galena is the chief 

 difficulty, as it cannot be brought about by a merely mechanical 

 means. The ores and "Schlichs" produced, during 1852, contained 

 an average of ^^ of silver and y^^ of lead. 



The operation for the extraction of the silver and lead begins with 

 submitting the ores to three consecutive roastings in the open air. 

 Recently the experiment was made of effecting the roasting in furnaces 

 by means of coal, and it succeeded in diminishing the expense. The 

 roasted ores are mixed with 5-8 per cent, of cast iron, 10-12 ^er 

 cent, of plumbiferous residuum from former smeltings, and 36-48 per 

 ^ent. of soft-iron-slags, for the purpose of facilitating the fusion and 

 to remove the superfluous sulphur, and are melted down in furnaces. 

 Each smelting requires about eighteen days, and is followed by a 

 cleansing and repairing of the furnace. The substances obtained by 

 the operation are argentiferous lead, cast into iron moulds (with 

 about -| per cent, of silver, slags, furnace-dust, and concretions 

 [Gekraetz]). The lead-cakes are melted down on a flat circular 

 bellows-furnace, with an artificial marl-sole, on which, as a final re- 

 sult of the operation, is left a cake of pure silver, the oxidated lead 

 running out of the furnace or being imbibed into the marl-sole. The 

 silver, after having been completely purified from all trace of hetero- 

 geneous substances by undergoing fusion in crucibles, with a mixture 

 of wood-ashes and burnt bones, together with some borax and salt- 

 petre, is finally cast into the form of bars. 



* See Quart. Joum. Geol. Soc. vol. xi; part 2, Miseell, p. 40. 





