Gold Hill daily news. [volume] (Gold Hill, N.T. [Nev.]) 1863-1882, 1864-11-30
THE EVENING NEWS.

Yesterday, lnLOuSH -AN
senior member of this firm, We visited the
entire establishment, and for the benefit Of
our readers, will tell something OF what
we SAW. After the crude bullion is re-
ce;ved at the office, it is placed in pair
of very large, but finely graduated scales
manufactured by Ladd 4 Oertling, Lon
don, and weighed with care. Thence we
descend one story to the basement, where
are arranged six large furnaces for melt
inc the bullion, which is placed in large
ron mortar and cut to requisite size; It
is then placed in large crucibles and COW
cred with charcoal, and subjected to an
intense hea,-say about 1850 deg. Fab
renheit-which reduces it to liquid state,
the quicksilver passing of, leaving the
metal, which is poured into large IRON
moulds, and left to cool. These moulds
are made of cast-iron, and polished so as
TO be perfectly smooth. The time required
TO reduce 1000 ounces to bars is generally
about two hours, although this firm have
in one dav assayed -, 900 ounces Of crude
bullion. After the bars become cool, a
small piece is Clipped " from each, and
the operator proceeds to find out the value
Of the same in gold, silver and base met
ais. The following is the process: A
stated quantity of grains Of the sample IS
carefully weighed on scales Of so nice ad-
iustment that the one-rhousandth part OF
a grain will turn the beam when loaded.
The scales are from the aforementioned
manufacturers, and are Of the very finest
mechanism, costing about $3.50, delivered
here. After the precise weight of the
sample is ascertained and noted, the same
is placed in nitric acid (well known TO be
Z solvent of silver, and not Of gold. The
silver becomes dissolved, but the gold re-
mains in its normal state in the bottom of
the glass vessel, which is technically de-
nominated "a matrass." The acid IS
then poured of. the gold collected,
dried and carefully weighed. The weight
of the gold being then deducted from the
weight Of the sample placed in the acid
denotes with tolerable accuracy the
amount of silver which the sample con-
tanned; but in order TO ascertain the
amount of base metal (Which in the ores
Of this district averages about five thou
sandthsl, the process of cupellation "
NAV be had. and which is hereinafter de-
scribed. As the first process is not pre-
cjsely accurate. and as by cupellation En-
rors are liable to occur, careful assayers
have generally adopted the Humid Pro
cess" which was discovered by Guy Lus-
sac, and has come into general use. The
process is based on the affinity of chlor-
inc for silver, and is substantially as fol-
lows: As before, the sample is dissolved
in nitric acid, and the "matrass" con-
tanning the solution is placed beneath a
large copper tank. supplied with gradu.
ated pipets Quilt ike proof-glaSses - OF
course you know what of-slasses are),
marked in lines and showing accurately
the number of drops each contains. In
the tank solution of chloride of sodium
common salt is placed, Of such strength
that exactly 1000 drops thereof will pre-
cipitate the amount of the sample taken
for ASSAY. Now if the whole thousand
drops are required to precipitate the sam
pie, it shows it to be pure silver, whereas
il but 900 drops OF the chloride IS required,
It shows that, beside the silver, there was
100 parts Of other metals. Now, then,
what constitutes "precipitation:" The
bottle, or matrasS of glass, containing the
soluble silver, is placed beneath the tank,
and the chloride of sodium is dropped
drop by drop into the same, which is per-
fectly clear before; Immediately the mix
ture assumes 4 muddy or cloudy hue,
something like milk. The dropping of
the chloride is continued until the whole
again assumes perfectly clear appearance,
which denotes that the silver has been
precipitated, and the assayer knows his
work is done, and the number of drops
required to produce the above result Is
shown on the sides Of the graduated
"pipets," giving the exact fineness of the
sample subjected TO tire process. To Illus
trate-if thirty grains Of gold is contained
in the assay, as shown by the acid, it
should require go drops of the chloride
of sodium to precipitate the silver.
If but $50 drops are required, it shows
that there must be 20 parts or thousandths
of base metals, as lead, tin, ETC., etc. The
preparation of this chloride of sodium re-
quires great care, and to procure proper
article the water used is distilled, an ap-
paratus being had for that purpose. To
determine the amount Of gold and silver
contained in quartz, an ounce thereof IS
reduced to an impalpable powder, and
mixed with solvents for the slick and
gangues" which is any active alkali, such
as carbonate of soda, potash, etc., etc.,
oxide of lead is added, and the whole sub
jected to an intense heat, the oxide OF
lead and the balance of the mixture be-
comes liquid, the metal settling to the
bottom of the crucible, forming q little
button containing all the metallic sub
stance of the ore. This button is then
subjected to the process of "cuPellatlon
TO ascertain the amount Of gold and silver
therein contained, which is as follows:
the " button" is placed in q small crucible
manufactured of bone dust, and again
subjected to the heat of the furnace, when
the lead either passes off in Yapor, or be-
comes absorbed by the porous crucible,
leaving AACtoA 49, eAAS -
a minute globule at the bottom, this glo-
bule IS then weighed, and subjected to
nitric acid, the gold remaining shows the
amount of silver, as before, and the assay
Is finished. After the value of gold and
silver in the sample from the bars has
been ascertained, the proportion is made,
and the bars stamped with the assayers
name, the 6neness of the bar in gold and
silver, the weight and value. The whole
process employed we have endeavored to
describe as accurately as our space per-
mits, although did we impart the half that
the chief assayer of the establishment,
friedrich Listee, told US, it would fill a
moderate sized book. The whole estab-
lishment is model one, and your reporter
is indebted for the urbanity with which ne
was treated.
VIOLATION OF CITY ORDINANcE.-Ies-
rerday the irrepressible Tyrell came into
Virginia, and finding the roads in bad
condition essayed a ride on the sidewalk.
p;r3ael1 Dromntly arrested the offender,