Shenandoah herald. [volume] (Woodstock, Va.) 1865-1974, 1892-10-14
A GOLD BRICK.
HOW INGOT METAL Is TURNED
INTO COIN GOLD.
The Various Interesting Processes
at the United States Assay OF
fice-Scales of Marvellous
Delicacy.

in his hand bundle the size OF a thin
brick, wrapped in paper. He laid it
down on the counter in the Office and
Ilowly unwrapped the bundle. 1t was
gold brick. The clerk took the bullion,
and stepping across the floor placed it in
one of the pans of large pair OF scales.
Then he closed the office windows and
placed some weights in the other When
it balanced nicely he went to his desk,
took out blank form, and wrote to the
effect that 400 ounces of gold bullion
had been received from the st. Louis
Smelling and Refining Works at the
United States Assay Office, to be assayed.
This was signed by Z. c. Jewett, the
assayer in charge, aud the men went
away. This is the first step the Govern
ment takes toward obtaining precious
metal for coming purposes.
1t is extremely interesting to follow
this process of assaying through all the
steps until the value of the gold is de-
termined and the Cover nment's check
given for it.
While Clerk Rex was filling out the
receipt Mr.. Jewett explained the mar
velous delicacy Of the scales. Their
weighing capacity is 5000 ounces, and it
is possible to indicate by them the diff
ference in weight of one grain. To il.
lustrate, so that this may be easily
grasped, two heavy men could be placed
in one of the pans, and by moving pin
from the coat of one of them the balance
would be changed. Still, it would be
difficult to obtain the exact weight Of
the men owing to the constant change
in the mems bodies by perspiration aud
other causes.
After the bullions weight was de.
termined on by these scales, it was ,akcn
to the furnace room and placed in
black-le lead crucble. This was set on a
fire brick resting on crate aud a fire
built around it. The fuel used is \ mix
ture OF anthracite coal and charcoal.
After an hours melting, during which
time it was frequently stirred with a
plumbago poker, to which gold does not
cling, sample of the metal was dipped
out with an ordinary clay pipe and
poured into a small mold. The ASSAY is
made from this, as it takes so much
longer for the larger quantity to cool.
A piece of the sample was cut of,
pounded, and then rolled through a
roller of tool steel, looking something
like a clothes wringer. to make it thin.
When this was done, Herman, the Ger
man who aids tie assayer in his work,
handed the thin golden strip to him,
and then went back to the furnace room
to pour out the molten thousands into
the big mold.
Mr.. Jewett cut the strip into small
pieces, aud then, forming little lead
cornucopias of uniform weight, dropped
into two of them 500 milligrams lone
sixteenth of an ounce OF accurately
weighed gold to be assayed. Into two
Others he puts the same quantity Of alb.
solutely pure gold. Enough silver was
then added to make the proportion OF
silver to gold two to Que, as this propor-
tion is necessary in order that the gold
should separate from the silver when
boiled in nitric acid.
There is in all gold certain amount
of silver, and it is owing to its presence
and certain other foreign substances that
the color of gold varies. The idea that
gold found in California or Australia is
of such a color because found there is a
mistaken one.
After the silver had been added the
leaden cornucopias were squeezed up aud
each one placed in what is called a
cupel. A cupel is a little cup made of
sheep bones burned to ashes, ground 6ne,
moistened and nodded into a mold an
inch long, an inch in diameter, with
cup-shaped depression at one end. The
cupels we're placed in a small furnace
with a temperature of about LOO de-
grees centigrade, and when heated to
white heat the little metal chunks were
laid by the aid Of tougs, one in each
cupeI. They melted, sputtered apd
dubbed, and theu began to grow smaller.
In about ten minutes they were taken
out and all the lead aud foreign
substances had been absorbed by the
cupel, leaving only the noble metals in
little round balls. When these were
boiled in nitric acid the silver passed
into nitrate of silver and the gold was
left in its pure state. BY this was found
the ratio of pure gold in the bullion.
The weigbings Of pure gold are used
as a check to any peculiar conditions OF
heat, etc. The assayer knows the con-
stitutioD, weight, and specific gravity Of
the pure gold used. When it is weighed
after the heating process, II it has changed
its weight it is fair to suppose that it is
owing to the conditions OF heat or strength
Of acid, and that the same influences
have been at work on the assay gold
By allowing for this in the assay gold
rue result is reached.