The quicksilver cradle is a more complicated and expensive machine, requiring six men instead of three to work it. It is understood, however, to save at least 20 per cent. of the metal, and indeed to be indispensable in some places in California, where the gold is in too fine particles to be detected by the common rocker. Quicksilver has so strong an affinity for gold, that the minutest particle of the latter having once touched, it is deprived of the possibility of escape; and when the process of washing has been completely gone through, the whole mass of gold particles will be found bound together by the quicksilver into a compact lump, in size and shape often resembling an egg. The gold is thus obtained in the form of an amalgam; but the quicksilver is easily evaporated, if its loss be of no consequence, or separated without loss by a more scientific process.
We have more than once used the word prospecting, which, we believe, is peculiar to this kind of mining. The deposits of gold are so capricious, that the adventurers, in order to lose as little time as possible in removing from place to place, detach one of their number on the hunt for a mine—and this is called prospecting. He sets out with a few provisions, a rifle, a pick and shovel, at all events, with a pan and large knife; and on reaching some hopeful-looking locality, he makes experiments on the soil by washing. The considerations that determine his calling the company to the spot are of course influenced by the circumstance of their having a common or a quicksilver cradle. He calculates the average value of the gold he finds in several panfuls of the soil at different depths; and he takes into account the distance it has to be carried for washing, the means of transit there exist, and how far off is the nearest store. The prospector, therefore, is a very important member of the concern, and in many cases the success of the adventure depends upon his experience and sagacity.