36 



CHILI. 



which is kept full of water by a constant small 

 stream ; and when the machine is put in motion, 

 the stone goes rapidly round, crushing and grind- 

 ing the ore under the water. As soon as the 

 whole is reduced, by this process of trituration, to 

 a fine mud, quicksiher is added, and by its union 

 with the detached particles of gold, an amalgam 

 is soon formed. This process is said to be quick- 

 ened by the agitation of the water, and the fric- 

 tion of the millstone. The water is allowed to 

 trickle off* by a nick cut in the edge of the 

 trough, and is received in long wooden channels, 

 covered with coarse cloths, the folds and irregu- 

 lar parts of which catch any stray portions of 

 gold, or of the amalgam, which the agitation of 

 the water may have thrown out of the trough. 

 When all the gold is supposed to be combined with 

 the quicksilver, the water is removed, and the 

 amalgam being exposed to heat in vessels adapt- 

 ed to the purpose, the quicksilver is distilled off*, 

 and the gold remains behind in a pure state. 



After passing a considerable time at the gold 

 mill, we strolled along the face of the hills, which 

 are indented in many places by copper mines, or 



