The daily union. [volume] (Washington [D.C.]) 1845-1857, 1853-08-30

sa,isfy general curiosity as to the process OF assay
ing we will give in detail The method prsctised in this
country 90 far relates 10 consge Science has g. is
perfected this method 10 bring 10 comparative unorm
~ the modes pracsed in different coanes-the NAN d
fernee being only in the quantity oil metal used of these
trials As the reduced value OF bullion is exactly pro-
porionae TO The degree OF adxiare with sEser metals
numerous methods had previously 10 the one now IN
use) be devsed for ascertaoing ssch admxure but
he uncertainty tedousness and expense attending these
have found happy alternative and succedaneum in the
ART of assaying as now prac,ised which unes the nds-
pensbe requisites of precsion DESPATCH and chespness
In any certain weight Of the subject OF trial The question
before the assayer How much ne gold hns silver,
or OF BOTH does il contain! To ascertain this fact he
weighs small portion with suitable exsc,ness, submits
II to the usual process OF separating the alloy, re~eEhs
II when the operation is completed, and makes his report
accordingly This operation is performed in The assay
furnace which contains kind of esTiben muf
fe within which placed several small vessels made
o bone ashes known by the name OF coppes, Or llle
eups, which. when sufficiently heated BY The charcoal
are with which The furnace is FLIED, and which eucioses
the muf. on all sde. each assay. wrapped in
proper quantity Of thin lead These melting Immediately
together the lead becomes gradually and in ram converted
TO glass. Serving As Gensuuum IN Toe vncaifon oil
the other base metals aeo. these sink together into the
porous substance Of The coppe leaving the precious met,
ais the ,rface thoroughly rekne, which hn-hrs The
process of silver assay II gold The subject OF trial,
the Assay piece beat thin. made soft in The FIRE. and
when rolled lightly together, put into glass vessel
containing aquaforus. previously heated over gentle
hIe which the silver gradually dissolved, and the
gold left in state OF purity. retaining The form il pos
ceased previous the soutoa Of slver To The
Perfection OF this process the proportion OF silver gold
n The asesy piece should be az TO 1, which ad-
diton, when Necessary, is made before The gold
say il pr, on the eoppei. When mixture OF gold and
silver the sohject OF us, and The quantity of the lsner
exceeds tina, oil The former called rtr ariag. and,
II eoniIawise, geld poyng With The former The assay
er proceeds in all respects he would with silver
say, making his repo, all the fine metal he find,
but gold parting he weighs two assay pieces OF equal
weight, OF which he treats exactly silver a,ssy
and The obet ne gold assay. When this is Gone, By
weighing tie assay pieces against each other, the
10 The forper which still the silver. be-
cones tie rror, Of foe silver the pound. When The
subject OF al contains than moe,y OF alloy,
denoupaled msiai for gold and sduer. and The alb
solu,e quantity Of each is reported The larger the guam
,y OF weal used IN these ia, the less win any casual
snor in'he process bear TO the whole o,hsr~i.e
the qoany quite indifferent for whatever the assayer
takes for bis unit greatest weight he divides pro,or
ionab'y TO real Troy weigh,s