Year: 1867

For some years past many of the mines
in this as well as neighboring States,


which for years had afforded a rich and
regular yield, have failed to produce like
results, and in consequence their stock
fell in market. The direct cause of this
failure was attributed, and still is by
many, to deterioration in the rock. This
was the cause of the failure of the work
ings of the Mariposa estate, which in
volved a large outlay and damage, to a
greater extent than can be estimated in
dollars and cents, the mining interests
of the Pacific coast. For several years
past, experiments have been made in an
entirely new mode of extracting the pre-
cious metals, and six or seven years ar
duous labor have brought the same to
perfection that will, we think, lend great
zeal to mining operations. 1t has been
well known that the rock of the Jose
phine and Pine Tree mines of the Mari
posa estate did not yield under the well
crushing process and the workings of
ordinary quartz mills over SO per ton,
although the assays thereof gave much
larger results. A few months since it
was determined to experiment in the
new process, the inventor of which had
persisted in maintaining it's superiority.


accordingly the necessary works were
erected ana the same IUIIy UesUeu. ne
result of working fifteen tons of the ordi-
nary rock of the Pine Tree mine-quartz
full of the finest gold of which tons and
tons have been tioated off into the Mer-
ced river, from the inability of the pro


cess in vogue to retain--was submitted
to the new method. Under ordinary


workings the yield was scarcely over an
average of SO. The result of the pres
ent new system made a return of $32
TON no =, ,ia1ti


an excess of over $40 per ton in favor of
the new process. This result is of great
Importance, as it may lead to an entire
revolution in quartz working, and as
such deserves the calm consideration of
every one interested in the future pros
perity of our State. The proof of the
pudding is the eating" we all know.
The result of the workings of the tail
ings of the Pine Tree, Josephine, Prince
ton, and other mines of the Mariposa es-
tate, fully demonstrated that the system
of wet crushing, amalgalnating in the


batteries, ETC., the usual method of quartz
crushing, was losing business; to make
the mines pay, some other system or
method of working the quartz was re-
quisite. After much solicitation the new
method was assayed, with the result as
stated. As it has demonstrated itself TO
be of great value-perfect in its work
ings-so much so that an assay of the
tailings exhibits but a trace of metallic
matter, we will endeavor to explain the
process. The rock is dry crushed, and
afterwards submitted to- the action of
balls in drum to insure full pulveriza-
ton, it being desirable that the powder
should approach as near wheat flour as
possible. A charge of this powdered
quartz is taken, placed in an air tight
cylinder, the interior of which is fur
nished with q worm of pipes TO convey
superheated steam therein. This fine
pulverized ore is then submitted to the
superheated steam for about twenty min
utes. The superheated steam is then
cut off, and certain quantity of quick
silver put In and common steam turned
on, and the whole seethed or boiled for
an allotted period. On the top of this
cylinder a water bath is placed, and as
the mercurial vapors rise they become
condensed. Thus the system of thor
Oughly impregnating the crushed rock
with quicksilver is carried out with effi-
cheney. After thus cooking, the cylinder
door is opened, and the whole mass dis
charged upon a novel shaking table,
which is worked by the power of the
steam employed III the previous opera
ton. This table is built of copper, on
wooden frame with rollers and rifles of
peculiar construction, which, when il is
in motion, give the water, amalgam and
dust the same action of the ocean SUR
an undertow. AS the mass descends the
amalgam from its metallic weight gradu-
ally clears itself from the quartz dust,
and the result is that it is all collected
in the troughs of the rifles, containing
every particle of metal, be it precious or
base, the quartz holds. The mode of ap-
plying superheated steam to the crushed
rock desu,phurizes it, freeing the metals,
and all that is to retort the amalgam TO
obtain the result of the yield. We learn
that this process iE not as expensive as
the ordinary method of working, and the
public will look with considerable inter
est TO the future experiments with the