246 RESOURCES OF CALIFORNIA. 
The sluice-boxes having been made, and set up with the 
proper grade, the water is turned iu. The boxes are made of 
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 sluice 
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 riffle-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. Amalgamation—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 largeas 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 solid 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 will strain salt out of water; but 
