Gold Hill daily news. [volume] (Gold Hill, N.T. [Nev.]) 1863-1882, 1865-12-04

covering the surface with charcoal dust.
Silver may be welded when IN the pulver-
ulent states, by the samo process as that
adopted for welding platinum, and like wa
ter, il possesses the property of expanding
as it solidifes, which may be observed by n
piece of solid silver floating on the sur
face of the melted metal. While in the
melted state it possesses the property OF alb
lsorbing oxygen in the same loose wnyas
water takes up various gases. This takes
place when silver is fused in the air, or un;
der a small quantity Of nitre. The absorbed
oxygen TO the amount OF % times the vol
ume Of the metaD escapes as the metal So
lidifes, and may be collected over water; If,
in consequence Of rapid cooling, the surface
Of the silver solidifes before the oxygen has
escaped from the interior, the gas bursts the
superficial crust, and drives out part Of the
melted silver in globules and excrescences;
this effect is called the splitting OF silver, and
is frequently q source Of trouble and error IN
the hands Of amateur and inexperienced or
careless assayers. --'". .'.,
In the form Of fused nitrate, silver is used
in surgery as a cautery. 1t is also used in
t~ernally in certain forms Of epilepsy, but it
is a dangerous remedy, and should be admin
istered with great prudence. Persons who
have taken this medicine, should avoid expo
sure to the light Of day until the salt Of sill
yer which is distributed t%hroughot the whole
organism has been carried of. Without this
prccaution, all the parts Of the body exposed
to light :urn blue, in consequence OF the de.
composition Of the salt Of silver in the SUBJ
cutaneous tissue.
With oxygen silver forms three compounds,
namely the suboxide, the protoxide, and the
binoxide. The protoxidc IS the only oxide
OF silver possessing any interest, as being
| the base Of all the ordinary salts Of silver.
As n base it is exceedingly powerful, COM
bining with even the weakest acids, and per-
fectly neutralizing powerful acids, as regards
their action on colOred reagents.
The soluble salts Of silver are obtained by
dissolying the carbonate Of silver in acids,
while those that are insoluble are precipitated
from the nitrate by double decomposition, as
illustrated by the following experiments
l-Protoxidc prepared by potash;
2-Sulphide pp'd BY sulphidc ofammonia;
3-Chloridc pp'd by salt;
4-Iodidc pp'd BY iodide Of potassium;
5-Chromate pp'd by chromatc Of potash
6-Phosphatc pp'd BY phosphate Of soda.
Dried portions OF these insoluble com
pounds of silver are on the table before me
and may be examined at the close Of the
lecture.
Inc ores from WulCu tue hilNCI VI COll'
mercc is obtained are very numerous, and
often so intcrmixcd with each other, and with
ores Of other metals, as to cause much trouble
and pe~rplexity in their metallurgical treat
ment. To this intcrmixture may be attributed
the loss in the reduction Of silver
from its ores, 80 per cent. being the average
loss in Nevada by the most improved mode Of
working, while in Peru, by the Patio system,
it frequently exceeds so per cent.
The ores mostly worked are those Of native
silver, antimonial silver, arsenal silver, anti
monial sulphide, or ruby silver, the gray, red
and black sulphides, and the chloride or horn
silver. In addition to these, considerable
quantities Of silver are obtained from galena
and copper ores, indeed the galenas Of Eng
and have never been found altogether free
from silver.
Native silver is found in almost all silver
mines, in larger or smaller proportions, as
ISOLATED with the mineralized metal. Il
sometimes occurs crystalized in wedge form
octohcdrons, in cubes, and cube octohcdrons.
At other times it is found in dendritic or mr.
borescent shapes, resulting from minute
crystals implanted upon each other. But
more usually it presents itself in small grains
without determinable form, or in amorphcus
masses Of various magnitude. At present il
is found in the greatest abundance in the
mines OF Charnacillo, near Copiapo, in Chile,
and at Kingsberg, in Norway. In this coun-
try, very elegant specimens are associated
with the native copper Of Lake Superior.
The silver generally penetratcs the copper i'll
masses and strings, and is nearly pure, not
outstanding the copper in which 1t is en-
closed. Antimonial silver is Of Il ycllowish
blue color, aud is very brittle, with u high
specific gravity 9.5, it is known by its lamel-
Ter fracture, aud when pure contains 81 per
cent. Of silver and lG Of anthony. The
mixed antimonial and arsenical orc Of silver
is much more abundant than the pure anti
monial, its constituents are silver lG, iron Al,
arsenic 80, and anthony ). Ruby silver is
remarkable for its l~ustre, color, and variety
Of forms. 1t is friable. easily cut with 4
knife, and affords q powder Of a lively rimson
red. Its color in mass is brilliant red, dark
red, or even metallic reddish black. 1t crys-
talizes in a variety Of forms. Its constit-
uents are-silvcr from Sc to 81 anthony
from lG to 20; sulphur from II to IL and
oxygen s to 10. The antimony being in the
state Of n purple oxide in this ore is consid-
cred to be its coloring principles. Like native
silver il is found more or less in almost all
silver mines, but is mel with in the greatest
abundance ut Freiberg, in Chile, Peru and
Mexico. Only a few isolated specimens of it
have been found in the Comstock lead, one
Of which, from the Potosi mine, is on the
table before me.
The sulphidc of silver is Of a dark gray or
leadcn hue slightly mallcable, and easily
cut with n knife, when it betrays II metallic
lustrc ; it consists Of Is per cent. sulphur and
81 per cent. of silver. 1t occurs crystalizcd
in most silver mines, but is especially album
dant in those Of Friebcrg, Bohemia, Hun
gary, Mexico and Nevada. This, with the
black sulphide being the chief ore in the
Comstock lead. Do ..... ...
The black sulphidc is Of u sooty blackness
-soiling the fingers-brittlc and cellular. It
is found abundantly in Peru and Mexico, and
is called negriRo by the Spaniards.
The red sulphidc is a somewhat rare ore;
its composition closely resembles the black
and gray variety-containing from 81 to Sc
per cent. of silver. 1t is Of a light scarlet or
ccrece color, and is sometimes denominated
the Eight red silver ore to distinguish it from
the dark red antimonial sulphide Of silver.
The chloride Of horn silver is scmi.trans-
parent, and OF n yellowish or greenish aspect,
giving of u peculiar odor, resembling decaycd
cheese, when freshly taken from the mine.
Il is so soft that it may be cut with the
nail, and may be easily recognized by its Pc
c%uliarly horny or waXy aspect. 1t mclts in
fame Of Il candle, and is reduced to the me
tallic state easier than any other mineralized
| ore Of silver-simple fusion with metallic
iron or an alkaline carbonate being sufficient
to reduce it. II also amalgamates with mer-
curry with great facility, and gives up its
| silver within u very small per centage Of its
assay value. II is abundant in Chilli and
Peru-most Of the CHILEAN silver being OBJ
tanned from this ore. 1t has lately been
found in the Kearsarge and San Antonio Dis