Ch. X. SOUTH AMERICA. 451 



' Th e gold mines in these parts are not Caxa mines, 

 as those of silver and many of gold are; that is, they 

 are not contained and confined as it werehetwixt two 

 natural walls; but the gold is found dispersed and 

 nnxed with the earth and gravel ; as sands are found 

 iningled with earths of different species. Thus the 

 whole difficulty consists in separating the grains of 

 gold from the earth ; and this is very easily done, 

 though otherwise it would be impracticable, by run- 

 ning conduits of water. This method is also equally 

 necessary in the Caxamines, where the silver and gold 

 are intimately united with other bodies, as, after 

 having gone througli the operation of the quicksilver, 

 which their quality renders indispensable, it is washed 

 in order to separate the remaining filth. After the 

 last operation the amalgama is pure, consisting en- 

 tirely of quicksilver, and gold or silver, according to 

 the species which has been worked. 



The manner, throughout the whole jurisdiction 

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

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

 servoir made for that purpose ; and when this is fill- 

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

 then vigorously stir the whole, which soon turns to 

 a mud, and the lightest parts are conveyed away 

 through another conduit, which serves as a drain ; and 

 this work is continued till only the most ponderous 

 parts, as little stones, sand, and the gold, remain at 

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

 into the cocha with wooden buckets made for this 

 purpose, in which they take up the sediment ; then 

 moving them circularly and uniformly, at the same 

 time changing the waters, the less ponderous parts 

 are separated ; and at last the gold remains at the 

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

 generally found in grains as small as those of sand; 

 and for that reason called oro en polvo; though some- 



G g 2 times 



