Ch. X. SOUTH AMERICA. 451. 



The gold min€S in thefe parts are not Caxa mines, 

 as thofe of filver and many of gold are-, that is, they 

 are not contained and confined as it were betwixt two 

 natural walls-, but the gold is found difperfed and 

 mixed with the earth and gravel as fands are found 

 mingled with earths of different fpecies. Thus the 

 whole difficulty confifls in feparating the grains of gold 

 from the earth ; and this is very eafily done, though 

 . otherwife it would be impradicable, by running con- 

 duits of water. This method is alfo equally neceffary 

 in the Caxa mines, where the filver and gold are inti- 

 mately united with other bodies, as, after having gone 

 through the operation of the quickfilver, which their 

 quality renders indifpenfable, it is wafhed in order to 

 feparate the remaining filth. After the laft operation 

 the amalgama is pure, confifting entirely of quickfil- 

 ver, and gold or filver, according to the fpecies which 

 has been worked. 



The manner, throughout the whole jurifdi6lion 

 of Popayan, for extrading the gold, is, to dig the ore 

 out of the earth, and lay it in a large cocha, or re- 

 fervoir, made for that purpofe ; and when this is fil- 

 led, water is conveyed into it through a conduit : they 

 then vigoroufly flir the whole, which foon turns to 

 a mud, and the lighted parts are conveyed away 

 through another conduit, which ferves as a drain ; and 

 this work is continued till only the moil ponderous 

 parts, as little Ifones, fand, and the gold, remain at 

 the bottom. The next part of the progrefs is, to go 

 into the cocha with wooden buckets miade for this 

 purpofe, in which they take up the fediment -, then 

 moving them circularly and uniformly, at the fame 

 time changing the waters, the lefs ponderous parts 

 are feparated and at lafl the gold remains at the 

 bottom of the bucket, clear from all mixture. It isr 

 generally found in grains as fmall as thofe of fand ; ^-^ 

 and for that reafon called oro en polvo-, though fome- 



G g 2 tim.es 



