The Placer herald., 1859-07-02
NUMBER N 49,: !:
Mining with Quicksilver.

1t has always been desideratum, says the
San Juan Press, with our miners who en-.
ploy quicksilver in their operations, to en-
poy some plan by which continuous sur
face of the amalgamator could be presented.
and over which all the dirt washed would
surely pass and come in contact BY the
old process this was not accomplished. The
subtle metal would retire to crevices, Law
against rifles, or sn water worn hollows, and
thus elude contact with the finer particle of
gold; amagamating with such particles only
as found it by their own gravity, and would,
perhaps, have been saved without its aid,
Hence the object sought to be accomplished
by the use Of quicksilver was not attained,
and the great waste CT the precious metal
only slightly, if at all decreased. Even in
this vicinity, where mining is more system
atically and intelligently pursued than at,
at any other locality of equal extent within
our knowledge. there has ever been a large
loss of gold, in spite of hundreds Of feet Of
sluice boxes and the use of enormous quaint;
ties Of quicksilver.
Some claims extend sluices for ten or.
twelve hundred feet, and have in these as
much as three or four hundred pounds of
quicksilver, which loses at the rate Of about.
seyenty-fve pounds per month. Beyond
these main sluices others are laid for much
greater distance, for the purpose of catching
and rewashing the earth as it goes down to
the river. The sluces of one company on
San Juan Hill reach the enormous length Of
nearly, or quite six thousand feet. Yet be-
yond all these the washed dirt is found to
contain gold, and men are preparing to work
tha koJ 10 ohto;c - of
ners believe they loose fully one.fourth, it.
not one half of all the gold their claims
contain. 1t is now known that much of It
is in the form of an impalpable powder,
which is visible only when gathered in i
quantities. Doubtless the most of this au-
rferous dust, literally speaking, has not here:
tofore been saved. Suspended in the dis
solved earth, without sufficient gravity to i,
preciptate and come in saving contact with
quicksilver, it floated away and was lost.
There is a reason now. to hope that some
of the loss described above may hereafter
be prevented, and the productiveness Of our.
deep diggings much increased. Some weeks
ago, we described the following invention Of
Mr.. S. Briggs, of Michigan Bluffs, Placer
county, whereby wooden blocks, such as mi
ners use in the bottom of their sluices, are
charged with quicksilver, and made to pre-,
sent continuous surface Of that metal suff,
ciently thick to amalgamate readily and rs-
tard the gold. This valuable invention may
be briefly described as round iron cup, or
bowl made of any desired size, the sharp
rim of which is stuck into the block. The
quicksilver is then placed in it, and, by
bv means of lever and valves, atmospher-
ic pressure is brought to bear upon the met.
al until it is forced into the pores Of the
wood the required depth--say two, four or.
six inches, the block being completely s;l7
vered.
About three of these blocks placed in the
sluice at intervals Of from twelve to fifteen
feet, and the friction of dirt and water wears
them sufficiently to keep always exposed a.
surface Of quicksilver. AS the gold catches
on this it is urged along more slow y until
it is partly amalgamated and drops into the !,
crevices between the blocks, or at their sides.
Within the last week these charged blocks
have been introduced iuto the San Juan dig
gings by Messrs Moore & Readshaw, who,
have very high opinion of them, and ex--
pect to save by their use both gold and quick
silver. Mr.. Readshaw has purchased from,
the paten:ee the right to the invention on this
hill, and, we believe, is ready to charge
blocks to order, at reasonable price If
the quicksilver blocks accomplish all that is
predicted and expected of them, they will
not only enrich their originator, but save to-
the mining community Of our State many,
millions Of money.