626 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 102 



shorter time, to grind the ore. The Tarapaya range is the shorter; 

 the mills there grind with the water of a stream on which they 

 are built. 



1655. After grinding and sifting the ore they dump it into con- 

 tainers for the furnaces and saturate it with brine, using for every 

 50 quintals of ore, 5 of salt, more or less, according to the quality 

 of the ore, for it to eat and consume it, or part of it, and scour it. 

 Then they put the mercury in, so that by this arrangement it may 

 better embrace and combine with the silver, and shorten the process, 

 and bring about a union of the mercury with the silver, having thrown 

 salt in with it ; they knead it twice a day with their feet, just as they 

 do clay in the making of tile or brick, and they remix with mercury 

 twice a day ; then they put the containers on furnaces and start the 

 fires underneath in small ovens, so that the heat may cause the mercury 

 to amalgamate more quickly with the silver. 



Although the ore all comes from one range, the mines and the ore 

 are usually of different grade, and so different materials are necessary 

 for their treatment ; for some they put in salt and lime, and iron or 

 copper ground up in water, for which processing they have some 

 small mills ; in others, they put lead and tin ; other ore — the negrillo 

 (stephanite) — is first roasted in ovens for its grinding in the mills. 

 Thus in some cases they use all these materials, in some, many, and 

 in some, fewer, according to the need and to the grade of the ore ; 

 if low, the quicksilver is hampered in its union and amalgamation 

 with the silver. With all this preparation and solicitude, in one case 

 it may come to 20, in others more or less ; with the fire or heat they 

 apply, and these materials mentioned, the quicksilver absorbs the 

 silver within 8 days. 



1656. At the moment which seems right to them, according to the 

 ore and the treatment given it, the mercury having already absorbed 

 the silver, they dump this ore into large tubs with water running 

 into them. These have a device with paddles or wheels in continual 

 motion inside the tubs, so that the ore dust is carried off by the 

 running water, and the combined mercury and silver, being heavier, 

 goes to the bottom and settles there in the tubs. The rest of the 

 ore, which was not well washed in these tubs or other puddling 

 operations, they finish refining, until the silver and mercury alone 

 are left, without any dust. This lump, which is soft as dough, is 

 put in a linen cloth and squeezed hard until they press out and 

 separate all the mercury they can from the silver. Then they put 

 the lumps of silver which have had the mercury squeezed out, into 

 clay forms or pots shaped like sugar loaves, with an aperture at the 



