EXTRACTION OF SILVER. 



55 



brown sugar,) soap, baize, cotton, and coarse linen cloths, woollen 

 cloths, silk handkerchiefs, foreign ponchos, ribbons, silk, sashes, <fcc, &c, 

 which are supplied to the Indians at about one hundred per cent, 

 advance on their cost at Lima, and charged against his wages, which 

 amount to half a dollar a day, with half a dollar more if he work at 

 night. 



The manner of getting the silver from the ore, or beneficiating it, as 

 it is called in Peru, is this : The ore, after it is dug from the mine and 

 brought to the surface, is broken into pieces about the size of a Madeira 

 nut or English walnut, and sent to the hacienda, in hide-bags, on the 

 backs of llamas or mules. (The hacienda is always situated on the 

 nearest stream to the mine, for the advantages of the water-power in 

 turning the mill.) There it is reduced, by several grindings and siftings, 

 to an impalpable powder. The mill consists of a horizontal water- 

 wheel, carrying a vertical axis, which comes up through the floor of 

 the mill, the wheel being below. To the top of this axis is bolted a 

 large cross-beam, and to the ends of the beam are slung, by chains, 

 heavy, rough stones, each about a ton weight. These stones, by the 

 turning of the axis, are carried around nearly in contact with a 

 concave bed of smoother and harder rock, built upon the floor of the 

 mill, and through which the axis comes up. The ore is poured by 

 the basket-full upon the bed, and the large hanging rocks grind it to 

 powder, which pours out of holes made in the periphery of the bed. 

 This is sifted through fine wire sieves, and the coarser parts are put in 

 the mill again for re-grinding. The ground ore, or harina, is then 

 mixed with salt (at the rate of fifty pounds of salt to every six hundred 

 pounds of harina) and taken to the ovens (which are of earth) and 

 toasted. I could not learn the quantity of heat necessary" to be applied ; 

 it is judged of by experiment. 



The fuel used in these ovens is the dung of cattle, called taquia ; it 

 costs three cents for twenty-five pounds. The ovens here burn one 

 million five hundred thousand pounds yearly. After the harina is 

 toasted, it is carried in hide-bags to the square enclosed in the 

 buildings of the hacienda, and laid in piles of about six hundred 

 pounds each upon the floor. This floor is of flat stones, but should be 

 of flags cemented together ; because the stones have often to be taken 

 up to collect the quicksilver, many pounds of which run down between 

 the interstices. Ten of these piles are laid in a row, making a caxon 

 of six thousand two hundred and fifty pounds. The piles are then 

 moistened with water, and quicksilver is sprinkled on them through a 

 woollen cloth. (The quantity of mercury, which depends upon the 



