1000000030

,bl, it immerli1tdl' noll's : the ("Irh"r

a~in~

as a nux

tu it. !\11\'"r tltu, "uitt¡\ lI'ith (ulphur (orms

ma(s tI,.t

""'Y be rm, i, h

¡\f

m.llt ;¡I.I~,

an,1 h"th u"Mly tlt" eo-

1,)ul a",1n.nlil!. """ ,.f

k;¡tI,

If this fulrhu,ated

lilv~r

~l'

k.1"

a 10uC tlln" In fuli"u, aud

a creat degrec o(

1\(',11 , ,h" li,ll'ltur 1I,,,s nlT aod

I~al'es

thelilrer purc, Jlut

ir the fulphur he el',lpOr,lteJ by a violeot heat, it carries

011'

IVith it pm of the lilver.

Sil.er

'lOiles anu

mix~s

I'erfdlly with gold in fufioo.

The 111'0 met.t1s thus mixeu form

eompound IVith pro–

perites r.trt:tkJo!: of both.

~I etallurglll~

h,lI'e hithmo fought in vain fOr a per–

fe~lI)'

guo.l dr..1 e,lry method of kp.lratiog thefe til'O

01:–

Jals by the ':')

'lO")

only: (T his term is ufcJ tO fignily

.11

ul'~r.t!"'::-

pel

fUllncd

by fUlioo :) but they Me eonve–

niend, eoou·' I pmeJ by the

II/újl

'lila).

that IS, by aeid

C"lvents, This method IS foundeu on the above·men·

t1nn~d

rrorenies of gn!'1and lilm

~'ith

refpeél

acids.

h.th

betn Ihell'o, tI,"t

oq""

I'<,~j¡

ollly

ill u;Ir.,lve

t t,ld; that fi lver, on the e"nmry, is nut fol ubk by

/J–

q '/"

r,:~Í1,

ard that its pl urer

f~ll'ent

is the,aeid of nitre:

C"nfe~uentl\',

II hen gold ,\nd I,h er are nll xed tngether,

ir thc ellnlpoünd m ..fs be put into

(/q""¡orlil,

this aeiu

will

t"k~

up all the fil\'er, ",ithom dlll'ohing a p' lIidc uf

the

~,,¡'I. ~,t.i( h

will thereforc rem.,in rure ; . nd

tft"

nI~l"S th~

ddi,ed

I;'p" r~tio"

dr~lIed.

This O1Clhod,

'hieh is en Hmnn!y made ufe of by goldfmiths and in

O1,nI' , is " Iietl Ihe

parling

~lfa) .

p\.un, that If

oql/fl

"gil

w~re

employed inlle,ld of

07"" ¡',rIÍJ ,

t h~

fep.tration \Vould be equally elTeéled;

an.!

Ihat the only lhfi'crenee

bet\ve~n

thil procefs

~nd

Ihe

f.¡: nl:r 1I0uld elllllifl in this, thal oow the gol" would he

olnol"d, anc! the fil\'er remain pureo But theoperatlon

"q'" ¡"Iil

is preferablc; beeaufe

"qu" "gil

does

t"ke up a liltle,filrer, whereas

"qua [orlÍJ

hath nOt the

le,11I dLél on go!d.

mufl b: ,oliCemd, tIlat when gold and film are

mixed together in equal pam, they eannot be poned by

the rolear" of

a7uo¡mi!.

1'0

eoable the

"qll" /" Ii.

aél duly on the fi

l.er

, tbis met.1O1ull be, al leafl. in a

triple prcpol tioo 'o Ihe

g~ld.

If it be in a lefs propar,

tion, you mufl eitber employ

"qua rtgÍJ

to make the fe–

p"ration, or, if you prefer the ufe of

oqua ¡ _rlÍ!,

mell

themmlline mals, and add as much fi l,er as is necefr. ry

make up the proponionabOIe·meotioned: And benee

this ploeefs is e"lIed

qu"rlalion,

TIIlS eff:él, whie!. i, pretty fingular, probablyarifes

from heoce. thal whenthe gnld cxeecdl, or el'cn equals

the film in quantity, the pans of both bting intimm ly

uniccd, the former

~rc

cap"bleof coating OVlr the lantr,

. od

cov=rill~

thcm fo

tOdtftnd ,hem from the

~élion

uf the

oqua¡orlll;

",llIeh is not thc cafe when there is

Ihnee as OIuch fil'tr

~'gn:J.

'111~re

is one thingmure 'o

taken no ice of with re·

gHd

tllI! procef,; "hid, ", that perfdlly pure

"q""

¡"til

is wdy

be met wi,h, fOI two re..fon':

FIlIt,

's dillieuh in matinn it ... holly

plevenl thenfingof the

Oled'umcmployed tO difengaJc the nllrOUSaeid

,hat is,

hule o'f the vitrio!ic aCOlI "'111

mi~

with the vapours of

th,

"qua forlh :

econdly, unlefs the fahpetre be . er)'

,"ell pJli5 d, it \ViII

a1"",p

huId fome fmall ponion of

fed.h, Ihe aeid of w!.ieh, we knnw, is very reacfily ret

luofe by the l'itrioli, ncid, and

c~nf~ql1cntly

riftl

to~':Iher with the ".lpOUr! of the

aq/l" [ortÍ!,

It is ea(y 10

ree, that

"q"(/ ¡"rlÍ!,

nlixcd either ",itn Ihe one or the

other, is not proper fur the paning procefs; heeallfe, as

has jull becn f.1id, Ihe vi triolic and the m.rrtnc ,Icid e–

qllally prccipitate fi lm diflolved in the nitrOIlS acid; by

which OIedns, whclI they are unitetl IVitlt that

aci~,

they

wcaken its

~l1i"n

"l'0n the li lver, and I"nder the ,!t¡folll–

tion. Add, that

"quII ¡.rlil

adultera,ell wllh a miXtlll'C

of fpi, it of I, h beetlnlc' an

"qll '

TtglJ ,

aod eoofeqllently

is rendered "pahle "f Ihlr.,h'lnA guld, In proponiun :Il

its aélion upon film is diminilh.,1,

lo order

rcm~dy

this inconvenienee, and f,ee

aqlla

¡o"ÍJ

f,tlm the !'II, ioli

marinc .cid with ",hich it i!

tainted, filve, mul! be dinol" ed therein : By degrccs, a,

the mml difrolve<, thore hetcrogeneons acids I. y hold

of il.

~nJ

preeipiwe "ilh it m the ft" mof a nhlle pow–

der,

IVe obfen'e" bdo,e. Thls preeipiwe

bein~

IVhl/lly fallen, the liqllor grows citar

aftcr IVhieh, if it

tilllod elpable or ditrolving morc fill'er, without tllrn–

ing mill:y,

nlay be depended on as a perfeétly pure

a·

q//II

¡_rlÍ!.

Then filtre

11,

dilloh'c more tilver In it. as

IlIng .IS il \ViII t"ke up any, nnd you will hal'e a fulution

01"

lil,er in a very purc

aqlla [ouÍ!.

l1y OIe,lOS of thiJ

folution otay other

eqlla ¡"Iil

be punfild : for, pour

((W drops the,eof 1010 a \'ery iOlpure

"V/laflrlÍ!,

anJ

iOlOlediatdy Ihe "i,riolic

marineacid. with \Vhieh tha¡

"qlla ¡orlÍ!

is eontaminated, IV,II join the fi lm and f, 1I

therewith

the boltom. Whcn Ihe fulution of filver

prepa,ed as abol'e dacs nut in the leall afr,'él ,he mnfra–

renel'

01"

the

' V"O [orlil ,

it is then rery pure, and nt

for the purpores or quartalion.

T his opcwioo of pUlifylOg

0v"a¡orlil

by a folution

of filver is ealled the

pm ipilll/" n

.¡

nqllo [orlll ;

and

"V/lOj'rtil

thus punlicJ i, called

pffCipi/ald aqua

[ol'lil.

\Vhco film is difrol\'ed in

"VU1

(orlil

it mal' be fepa–

rateJ therefrom. as ha, been fllCWD, by abforbeot

ean~

and 6xeJ ,Ikalts.

o¡

E l.

all the imperfell mcral!, eopper comes the nearrll

to gol.! anu r.lveL lts na'ur.11colour is a deep.red

ti·

10IV.

refins a very violent degree of 6re (or a con(¡–

derable ,iOle ; but loling

liS

phloglnon at lan, it chang.s

itl menll,ne fOrol (ur thal of

"Ix, or apure rcdd,O,

m,h. Tltis e,lx is hardly, if at al1, redUCIble to glaf"

",ithout the addilion 01' fOOleth,ng

promote '" rufion ;

a11 that the fi<rcdl hcat can do berng only tOrender

roft. Corp' r,

even

",hile it retains in meta/hne form,

and il I·ery pure, requtrcs a confiderable degree of fire tO

meh it, and does not begin to nliw till lung after it il

red·ho\. When io fufion, It communiuteJ a grcentlh

eolour tOthe flame of thc coals.

TI.is

metal is toferror 10 filfe r in poin of ltmity ;

nor is in du8illly fo grw. ,houel, it be pr ry confider–

able: Hut, on the othrr hand, it

e~ctft"

that mml in

Iwdnefs.

unites read,ly ..lrh gold and filver: nor

docs it ereatly lerren thm beauty ..ben added tO themin

fmall quantity: ay, '1nen procures th:m fum: . d-

vaDt~gel

;