from
gold, the latter must be melted with three times its weight of silver,
and then hammered or rolled out thin before it is exposed to the nitric
acid, which dissolves the silver and leaves the pure gold behind.
In
powdering the quartz, the process is rendered quicker by making the
quartz red hot, and then plunging it in cold water. If the quartz, as
is sometimes the case, contain magnetic iron, dry the powdered mass
thoroughly, and apply a good magnet, which will take out all the iron,
and thus save an immense trouble in getting the gold pure.
Gold Washing.
From
our previous extracts it will be seen, that so abundant is gold in some
parts of Australia, that it has repeatedly been obtained by a kick of
the foot, and by boys and men with a tin dish. These modes are,
however, too primitive to be profitable, except accidentally so. A tin
dish is no bad test of the soil when " prospecting." Wash the soil,
pouring carefully away the mud, leaving the heavier portion at the
hinder angle of the pan. Then amalgamate the residue with a little
quicksilver. If there is gold, the quicksilver on kneading it will
become solid, and form a pasty mass. If the quicksilver remain liquid,
and in globules, there is no gold—try again.
The
Hungarian method of separating gold would answer well in Australia,
where for the most part the gold is coarse and heavy. Get a long broad
board, grooved longitudinally, and nail a thin strip of wood all round
it, except at one end. Nail also a few strips of wood across the inside
of the trough) to stop the gold, whilst the soil washes over. Give the
trough a slight incline against a bank, and put your gold earth at the
upper end. Pour water over this, and if there is gold it will all
remain from its weight in the upper grooves, whilst the soil being
light, will be washed away. Where people work independently, as in
Australia, and gold is coarse, and water plentiful, this method, simple
as it is, would be a very efficient one.
The
following is just as simple and efficacious. Carry with you a large
wooden bowl, and put into this, or dig out of the bed of the stream
with the bowl, a quantity of earth; stir this well in the water, and
let it rest a minute or so; then throw away the water, and repeat the
operation six or seven times. The gold, with care, will remain at the
bottom. A bowl with five or six pounds' weight of stuff may be washed
in a few minutes, and this method will be quite as productive as the "
cradle," in which, by the testimony of all parties, half the gold is
wasted. The sediment may be treated with quicksilver as before, if
required, and the superfluous quicksilver may be wrung out through a
piece of wash-leather, leaving the gold amalgam behind. We shall
by-and-by show how to recover the quicksilver.
We
are here supposing the absence of mechanical contrivances, many of
which are more ingenious than useful, and that the Australian miner has
chiefly to depend on his wits and his arms. To such, the following easy
method, well known in South America, is worth more than the "radle,"
and is attended with none of its inconveniences. Make a wooden gutter,
the longer the better; very slightly incline it, so as to allow the
water to run off; put your soil at up'per end; and if the gutter is
long enough, all the soil may be washed away, leaving the gold at the
top, or at most, not half way down. The running water thrown on will
carry off all the light soil, and the stones may be picked out by hand.
The gutter, to be efficacious, should be wide, and pretty deep, and if
long enough, there would be no fear of losing any gold. Such a
contrivance where a party is working, would, in point of producing,
beat a dozen cradles.
A
shallow tub or pail makes a first-rate washing machine. The manner of
using it is this:—Place the tub in the water, an inch or two under the
surface, then stir up the sediment,—the running stream will carry all
the light soil away, and by-and-by you will have a respectable tubfull
of gold ; the stones may be picked out as before, and the remainder
either separated by hand or with quicksilver.
