IH4 7. J On the Refinage of under standard Silver, 559 



quently known Sycec silver at 16£ Br. alloyed with 2 \ copper, to yield 

 bars as brittle as slate or cast iron ; and these when assayed to prove 2 

 or even 3 dwts. better than standard. This proceeds from the presence 

 of lead or sulphur in the Sycee silver, part of which burning off leaves 

 the resulting mass richer in silver than before, but brittle from the small 

 portion of lead which remains. On the other hand I have still more 

 frequently seen alloys of silver and copper, 50 to 80 worse than stand" 

 aid, affording with the due proportion of richer silver, a perfectly malle- 

 able and standard metal. 



The object of refinages for the mint is therefore usually to re- 

 move the lead, tin, zinc or sulphur and to leave the silver and copper 

 or occasionally, when pure or rich silver is not available, to bring up 

 inferior alloys to standard or even superior fineness. 



The process followed by the native refiners in the bazar is that of 

 cupellation, and is performed by them with great success and economy. 

 They use for the cupel a mixture of one part by weight of recently burned 

 lime, sifted but unslaked, and two parts by weight of chaff ashes. With 

 this they make a basin like mass, usually eighteen inches in diameter be- 

 low and 4 to 6 inches deep. This they moisten well with water and beat 

 with the hands into firm consistence. Pieces of brick are placed round 

 the sloping sides to give support, and two pairs of bellows are arranged 

 so that by their alternate use a constant blast of air is kept up during 

 the process. 



While still wet the basin is charged with charcoal and an active fire 

 kindled, the silver is then introduced and lead added till all is melted 

 and red hot. Two large logs of firewood are then placed over the 

 charcoal so as to form a dome to the heap, and at the interstices torch - 

 like pieces of wood are continually introduced, so that a powerful flame 

 is reverberated from the blazing dome above. 



By this manipulation the lead is oxidized, and the oxyde of lead 

 (litharge) formed is absorbed with the oxides of copper, and other base 

 metals usually present, by the porous mixture of lime and ashes. None 

 of the litharge is removed by skimming. In refining 2500 tola wt.* from 

 16 " worse" they use 1200 tolas of lead, and the operation is completed in 

 less than 3 hours, yielding a cake of silver 16 to 17 dwt. "better" than 

 standard. The bazar refiners contract to return all the silver according 

 * The tolu is 180 Troy grains. 32 tolas = od<j Troy pound. 



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