The Black range. (Robinson, Socorro County, N.M.) 1882-1897, 1883-05-11
Determination of Silver.
WET TEST.

WET TEST.
PulveriZe the ore supposed to con-
tain SiFe 4 1Iis take a small nj
snficiehl ny At (experiencs teaeil
thte1n atesl lube pour in water. so Is
Hpofethan cover The p~ulver,zes ore.
aid al A. sheors Nas much nitric
aeIj an Eater used. The operator
uSust then place the tube over the fame
OF the spirit lamp aud hold it there for
The space of about five minutes. At
the close of this time pour in water in
the proportion of one-third the capa-
city OF the tube. In cast lead is pres
ent in the miaeral, %sulphuric acid must
he added until the deposition Of that
metal in the form of white flakes has
stopped, when the operator must pro-
coed to decant or filter the clean solu
tlpn into another tube. When this is
affected, muriatic acid or a clear solu-
ton of common salt must be added
until the precipitation of chloride CT
silver in the form of a white deposit
ceases.
FIRE TEST.
Take one-half ounce of pulveri zed
ore, one and one-half ounces of bi-car.
Donate Of soda, one-fourth to one-halt
ounce, of pure silica or pulveIized glass,
orle-half ounce litharge, and as much
charcoal as can be held on the point of
the large blade of a pen-knite. Mix the
whole thoroughly, place in a crucible
Of suitable size and pack firmly. Cover
with one-fouTth inch of common salt
AID place in a common blacksmith
forge and fuse. Care must be taken
that in fu5ing the mass ii Goes riot boil
| over. The heat must be continued until
the mass assumes an oily appearance in
the crucible, when it must he withdrawn
from the fire and the contents poured
into "a mould to cool. The Stag and
glass is broked and carefully removed
with a small brush. When this is done,
place the button upon a clean anvil,
and with a bright hammer fatten the
button into the form of a PARALLEL
gram and place it in a dry cupel. AT
this stage of the operation, as the ex-
perimenter is supposed to posses neither
mufle nor accessories, it will be nee
cessary for him to place a piece of fiat
iron, or, still better, friedrich in the
forge and upon this fiat surface deposit
the cupel when the blast must be put
on and continued until the lead is alb
sobed by the cupel, which fact is dis.
covered by the Spluttering and uneasy
movement of the remaining silver glo-
bule. 1t, is better for a novice, TO with
draw the cupel when the metal has as
sumed the spherical form, and when 1t
has lost that changing and iridescent
hue which indicates that the lead has
been removed. At this stage remove
he cupel from the fire. allow the but.
ton to cool and weigh the silver button
which remains.
BLOW PIPE TEST.
Put as much of the ore as will be
held OF the point of Il pocket knife
blade into a recess in the charcoal, mix
with an equal quantity ~bicarbonate of
soda and place under the influence of
the inner or reducing flame. When
fused separate the button from the Stag,
clean carefully and cupel. this time
using the outer, Or oxydizing flame.
When lead is not present, in the ore, ii
must be added before subjectlng the
pulveriZed ore to fusion. When this is
the case, add as much lead by weight
as of ore used In the experiment. The
color which indicates the presence OF
silver iii ore or mineral is a light brown
yellow which remains upon the coal
For a small sum a complete blow pipe
outfit can be secured, including a meter
or scale by which the button can be
measured and an approximation of its
value obtained.