246 EESOUKCES OF CALIFOKNIA. 



The sluice-boxes having been made, and set up with th 

 proper grade, the water is turned in. The boxes are made ot 

 the rough boards as they come from the saw, and the joints are 

 not waterproof, but the leaks are soon stopped by the swelling 

 of the wood, or by the dirt. The stream of water in the sluici 

 is at least two inches deep over the bottom. The height of 

 the sides of the boxes is from eight inches to two feet. The 

 sluice usually runs through the claim, and the auriferous dirt 

 is thrown in with shovels, of which from four to twenty are 

 constantly at work. A man will throw in from two to five 

 cubic yards of dirt in one day. The water rushing over the 

 dirt as it lies in the box, rapidly dissolves the clay and loam, 

 and then sweeps the sand, gravel, and stones down. The first 

 dirt in the box goes to fill the spaces between the rifiie-bars. 

 After the sluicing has been in progress a couple of hours, some 

 quicksilver is put in at the head of the sluice, and it gradually 

 finds its way downward, most of it stopping, however, near 

 where it is put in. 



§ 180. Atnalgamatio7i. — There are a few metals, including 

 gold, silver, copper, and tin, which, with quicksilver, form a 

 peculiar chemical union called amalgamation, a process of great 

 importance to the gold miner. When a piece of gold or silver 

 is placed in mercury, the latter metal gradually penetrates 

 through it, destroys the coherence of its particles, and forms 

 with it a mass like dough. A lump of gold as large as a bean 

 will be soaked through in three or four days ; with silver and 

 copper the process is slower, but they are affected in the same 

 manner. Amalgamation, though a union of a sohd with a 

 liquid, differs much from a solution. In the latter the union is 

 mechanical ; in the former it its chemical. In the latter the 

 solid is reduced to particles of impalpable fineness ; in the 

 former it is not. An ounce of salt will be dissolved in, and 

 nearly equally diffused through, a pint of water ; but if an ounce 

 of gold be thrown into a pint of quicksilver, it will, after forming 

 an amalgam with the quicksilver, remain at the bottom. We 

 have no texture so fine that it wiU strain salt out of water ; but 



