Millheim Journal. [volume] (Millheim, Pa.) 1876-1984, 1882-03-23

CHiOrldC Of GOtd The mode OF prOce-
dure is TO dissolve the gold, throw it down
to obtain pure gold, wash the precIpitate,
and redissOve. A solution Of the salt is
then obtained To dissolve the gold, a
mixture Of pure nitric and hydrochloric
acids in the proportion of one 10 three is
used. The usual manufacturers use an
ounce of gold to four ounces Of the mixture
though in our own practice we usually find
double that quantity needed, as consider
able loss of chlorine takes place during the
prolonged digestion. A porcelain or glass
vessel should be employed, on account Of
the value of the contents. The kind We
have found most useful IS one that can be
obtained from any dealer in chemical appa-
ratus; in shape it may be likened TO an egg
with one end widencd out. A useful
glass vessel IS made specially for such pur-
poses, though we prefer the porcelain, par
ticularly when the operations may not all
be carried on by principal himself This
glass vessel is bulb blown at the end of a
long tube, and is so constructed with the
object of avoiding waste through spashing.
We place the gold in tile porcelain vessel,
pour over it the mixed acid, and put the
whole IN bathr u tin canister almost filled
with sand will answer ali purposes. The
whole is then put III place wh:Ie the
fumes will not do any harm. The hob of
al open fireplace is very good for the pur-
pose, as the draught from the fire take up
the fumes, and the heat facilitates the dis
solution of the metal. If such place be
chosen, care mnst be taken that no oflicous
houscmaid knocks the vessel and its valr =
able contents over. In few hours the
gold will be dissolved. Should 1t not be,
however, the liquid must be poured off
and fresh supply of acid put upon it, and
gentle heat again applied, When all Is
dissolved the liquid is next to be transferr-
ed TO an evaporating dish, which should
again be placed upon sand bath and heat
ed till the bulk of the liquid is driven
away. Ii mIst not be made dry, or there
will be loss of gold by the production of
an lnsoluble salt and, further, for the af-
ter operations it is desirable to have some
quantity of acid present. The solution be-
ing thus brought TO a small bulk it must be
transferred TO precipltatIng glass, water
added TO reduce It's strength, and filt.r-
ed solution of sulphate OF iron poured in.
For safety two ounces OF sulphate may be
added for each sovereign piece. A deep
brown preclpitate, sometimes appearing
green when looking through the vessel, Is
then produced; it is pure metallic silver
This must be allowed to settle till the su-
pernatant liquid if quite clear, and when
this happens il may be poured or siphoDed
off, fresh pure water added, the precipitate
stirred and allowed to settle, the fluid
again poured of, and water added, ETC.,
till all the iron is washed away. The pre-
cipitate then may be transferred to the
porcelain holder again, and either heated
to drive off the water or allowed to stand
till the precipitate occupies a small space,
when almost all the water may be rcmov =
ed. All that is now required is to redis-
solve this precipItate in the smallest possl-
bic quantity of acids aud slightly to evap-
crate, when solution of acid terchloride
of gold, or chloride OF gold and hydrogen.
is at hand, and it may be kept, with a
little water added. with far more conve-
nience than if it were In the solid state.