Telegram-herald., 1890-06-05
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eoss1lns 80 ast@i ~ ss S.sG ~ltk $40 81
- hznA. Or VIZ A. sz-A-saza 4 ga saa
nsrsary. al r1@a vg-zzll-zlzsg lae L2--az
r..saL. Aad tie saEns process NAs ca ngllgsd
- s.lgerLsg Ia - bEzsGasslli s2ccsE@s4
u - zlnS I2< b@ssT Elefzls - raSzz@ y
zalY2n-c e1rrs2t, oat TIE drss % aazke he
uspoosS : surcess was TIE caes1ls1 De Il
Rve. and II has sinos beeB gEs~t.y III
pro gsd 0y later .2res--s sacQxS
Ike proosss ceFsz1s upoa tie pocu-lsr
power whica ths yolCslc carreuG possess
q sepzxztlEg osrtaia eo2poznd bodles 1870
their eousrilaeat prs.
kor instance, Il = cg-rrs-g from & scirsl2
battery : psssed by n4saaa u PlSisuuna
electrodes t1rougA water 20 vLsch sal-
Dhuric aid hSs aeen a.tded, ts.i5 cl-ea-.cSl
separation, which = lAlled e-ecIrolysls,
VIII take gi1ce, TIE water belug resoiFed
into is Constituent saSss. ozy sen al
hydroeen.
Nov. II some sulphete of copper Is
throgsn into the liquid e.ecErslysls ~ -. sail
20 on viii a doCble resalg--the water All
ke seu2rzte1 tlto It's elsInsn -, snd tie by
crogen, ty is stronger 4-1aity, AL forn
a uew compound with tie suiphgr IA the
sulphete, setting the copper free, and tie
liberated copper, being electro positive n
character. viii be deposited on the plat
iaum eiecuode. which y negative.
On this general principle the process Of
eleetroplatins or e!sStrctypl-g depends
and its AT consists ia applying TIE metals
thus released from their solutions - arts
tic ard useful purposes. The solutions
generally employed IS electrotypes from
which 70 separate gold and silver respect
lively are thoss Of the a-gsnto cyanide and
the auro cyanide OF potassium.
These compounds ere what are knOWn 20
chemists as double salts, that Is, while cy-
enide II potassium Il simply a compound
of potassium and oyanOgen, argentO oya-
nide OF potassium Is cyanide % silver com
bined with cyanide OF potassium. When
solution OF this double salt is subjected 20
the action Of electricity, silver appears az
one elcctrode and cyanOcen at the other,
while the cyanide OF potassium, from
which the other salt had been thus separGt-
ed. reappears Ia tic solution.
II is the negative elect rode which takes
the silver, and II. therefore, the positive
electrOde Is made Of silver, tie ADera III
cyanOgen combines with il, forming cyan
ide OF silver which, by uniting with the
liberated cyanide Of potassium. keeps he
strength Of the solution 10 the proper ie-
gree. The apparatus used is an outer ycs-
sci Of glass or earthenware, in which Ia
smaller vessel OF biscuit ware or other pr
ous material
In the smaller vessel is placed the sal
phur.c acid. with "a plate Of amslgamatd
zinc The cyanide solution is in the outsr
vessel. aud n il i suspended the object o
lie silyered or gilded, which is connected "
wire with the zine in the cell to convey
the galvanic current. The strength Of this
current must be regUlated if the acid
very powerful the electricity developed vii
be more than sufficient 10 release the meta,
and hydrogen viii be evolved. which vii
interfere with tie plating process. To carry
on electroplating on q large scale oblons
watts are used, which may hold 200 gallons
OF solution.
Silver plates connected with a powerful.
voltaic battery are placed at intervals in
the vats; they form the positive electrodes,
and correspond in extent OF surface with
the articles TO be coated, and face them on
/ both sides
These articles-knives, forks, spoons,
cTUet frames, teapots, urns, etc.--act as
the negative electrodes. are suspended by
copper wires from brass rods laid length
wise over the vats and connected with tho
battery
The articles arc prepared for plating by
being first boiled in strong lye, TO free them
from all grease; they are then quickly dip
ped in muriatic acid TO remove any oxide
that may have formed on the surface, and
after this are well washed in water to re-
move every trace Of the acid
They are then dipped into a solution OF
mercury, and then washed in water again.
The effect of the latter operation is 10 make
the film OF silver adhere more readily. The
articles are then weighed and suspended in
! the solution and are left there until a suf-
/ lcient amount of silver has been deposited
/ upon them.
This amount is tested by weight II the
additional weight is not gained in the ex-
I pected time the article IS put in the solu-
/ ton again.
1 When finally taken out the articles are
I brushed with brushes OF fins wire and
/ clearsed with fine sand; they are then pol
I ished on revolving brushes with rotten
/ stone, then with chamois leather and rouge.
( and lastly with the naked hand.
/ The process of electrogilding is essential
/ II the same Is that given above for silver
4 ing, substituting gold toT silver.-Go.dea
/ Days