1000000030

nnitin¡; ",ith the "itriolie acid. with whieh it forms

o Olct.dlic falt (jr "itriol ealleJ

whit( vitriol,

"itliol

=.1;(.

Nitre ",i xed with

zin~,

ano proje,qed ioto a

r~o

hot

crueible, detOo"t<:s with"i"lenee : aod duriog the detona·

tioo there arilCs a gre.t quaotit

of ",hite Ilowers, hke

tbo(e ",hieh appear ",hen it is c. lcioed hy i!Cel!'.

Sulphur has 00 po\\,er ol'er zinc. Ereo I:rer of fui

phur, which ¿irr" h'l's all othl r o,c!aJlie fubil.nces, con·

trJ~ts

00 unioo with this feOli·metal.

R' CULUS

A RHN'c,

RE CULU S

of arfeoie is the mol! I'ol"tile of aJl the

femi·mmls . .'\ vcry moderate hm

mak~s

it wholly

"'aporate, aod fi y off in fUOle$: on whieh aC!'CIuOt ,t

eaooot be brou;;ht tOfuGoo, oor cao aoy conriJeral,le

marres thertof be obtaincd. It has a mer.dlic eolour,

fomewh.,t refembling lead ; but (000 lo(es its

!illen~or

wheo expofed tOthe ai ro

uoites reacli:y eoough with metallic

(ubrboce~,

hariog the (ame aHinities with tht m as regulus of ami·

mooy hath. It makes

th~m

britlle, ar.d uomalleable.

1t I'a'h .1(0 the property o( reoderiog themvolatlle, .lId

greatly facilitares their reorincatioo.

[t very eaGly pans ",ith its phologil!oo and metallie

fOfln. \Vheo expofed tO the fire it rifes io a kiod of

Ihioiog eryl!aJlioe ealx, \\'hieh 00 that aeeour.! looks

more like a falioe ma!t<r thao a O1erallie

e~l x.

To this

ealx

01'

thefe flowers are given the oames of

wl,it, arfe·

tlic, cr;JlalliM a,¡,nie,

aod moJI eom01only pl.lin

IIrfwic.

Arfenie differs from every other metallioe ealx, firfi ,

io be:og volotile; whereas the e.lxes of . 1I otha metal·

lie (u[¡lIaoees, Mt exeepting tho(e of the me!l volatile

femi·metals, fu eh as regolus of aotimony aod zioe, are

exeeediogly nxed; aod feeoodly, io haviog a f, lioe eha·

raéler, whieh is oot fouod io any other mmllioe ellx.

T he fal ioe eharaDcr of arfeoic

appe.rs,

lirll, from its

beiog (I,luble io \Vat" ; recoodly, from its eorroGve qua·

Jiry, whieh makes it Lloe of the mol! violeot poifoos:

a quality (rom \\'hich the other metallie fubfi,nees are

frtt, wheo they are OOt eOO1bioed \Vith

me (aline m:lt·

ter. Regulus of antimooy mull however be exeepted :

but theo the befi chemills agrec, that this (emi.melal is

.ilher oearlv oí the f:lme natU re wirh arfeoie,

01'

cuo·

tains a por;ioo thereof in its eompofirioo: bcGdes. itt

noxIIlus ql,alities never difcove r

th~mfdvcs

fo plaioly as

Vlhen ir is eombioed \Vi,h fOllle

a~id.

L. fily, arfeoie

. éls jun like the ritriolie aeid upoo oi!Ce; thdt is, it

¿ccompotlnds that oelltral fah, byexpd linr, its . eid

from ilS .11t:,Jioe bafis, of whi.:h it ta!;e' po([,dlioll, and

thcctwirh forms a oew (alioe eompound.

T h;s

eOO1hio~tion

is a fpecies

01'

(,h tha t is perf,·a ly

O"I't'al.

Wheo the ope,atino is pcrforOled io a

c10re

"cntl , the f, lt (hOOts ioto cr)'fl. ls io tI'e

fO~1Il

of righr·

aqlcrl qu.rlraogul:lr prifms, termiooteo at

e.eh

etrc'llIty

pyromids thJt are alfo qu.draobulu and ri¡o,ht·aogle.!;

lome of whieh, howel'er, iollead of codiog io a poiot,

. 'e ob'u(e as if truoeMcd. T he cllofequence ISd.rftreot

>I:..

the 0ilt,,:ioo is p: rfo' llled in ao open ,dkl

f~r

theo oothiog is ob" ioed bU l l n alltalioe f::h impre&oated

\\'ith "feoie.

hieh e.IOIlOr be

eryllalli7.cd

The c.!tlfe of this dinereot clflét is tI,is : Wheo

th~

arfenle is ollce eogag"d io the "Ikalioe baGs of the oltre,

it eao oel'er be 1·' p.'l'ared fl'om it by the u'lIIon force of

fi re, (o loog as it is kept io " c10fe ve(['eI ; wbereas, if

youCXpll!c

tn the lire withoutthat preeaution, it readi·

Iy (q'"r,ltcs from it.

•

Tllls rilt

pC)r1~ni:s

maoy fi ngular properties, the chief

of wllleh

111',·

th, fe : FifÍl, it eaouor be Jecompnuodcrl

by the ,nterveotino of aoy aciJ, eveo the IIroogdl . cid

01'

"itriol ; and thi$, joioetl to its proptrty of

e~pdliog

the 0ltr0US .cid from its bafis, nte"l5 that it has a vcry

great alJinity with fi xcd alkalis.

Sceoodly, rhis very (. It, 00 which pure aeids have 110

elfe,~,

isdeeompouoded with the grcate!l ,,[e by acios

tlnit ed with metallie f"brLlom. The re,'(lIo of this phe·

nomeooo is curious, aou fumirhes tlSwith ao iollance of

IVhat IVe advaoc('d cOlleeroing double a!Ti,tities.

If to a (olutioo of ally metalhc J'ublJ.lllee whatever,

made by aoy acid IIhatevcr, (exccpt that of mereury

by the marioe aeid, aod that of gold by

aq/la rrgiJ,)

cenaio quootity of this (ah dilfolveu io watCl' be added ,

the m t. llie (ubllaoee is iollaotaoeouny feparatecl froOl

the acid io whieh it was dilfol"cd, and f.lIs tO thebotloO!

of the liql\or.

AII

metallic precipitatcs obtaioed io this maoner are

fouod tO be. comhioatioo o( the metal wirh ar(coie;

whence it neee["ily foll olVs that the oeutral falt is by

this mean, decompouoded, its arfeoical pan uoitiog with

the 1Uet:tllic (ubflaoce, aod its . Ika!ine bafis with the a·

cid io which tbat (ubllooee IVas di(['olved.

The anioitits of the(e (,,'er.1 bodies mun be coofider·

en as upel'.tiog 00 this ocealioo io the (ollowiog maooer ,

The aeids IVhieh teod

deeompoul\d the oeutral (alr

of adeoie, by rinue of their a!Tinity with its alk,:l ine

hafis, are oot ablc to aceomplinl it, beeau(e this arfioity

is pOlVerfully eouoteraéted by that which the .,feoie has

IVith the fame alkalioe bafis, aod whieh is equal

0 1'

eveo fupcrior tO thms. Hut if thefe aeios happeo

be ul\itetl with a (ubllaoee whieh oaturall y has a very

grea! a!Tioity IVith the ar(, oical pm of the oeutral [.dt,

theo, the tlVO palts

\\'h;ch this falt cooGns, beiog

drawo d,¡rerent ways hy tl'lO(e\'eral , /lioiti" , teodiog

fcparat(· them rrom caeh orh,'r, the (,.lt ",ill uod<ego a

cler.ompofilioo, which could uot have b" n cffeétcd with.

out the hclp of this (e('onn :,¡liolty. Now, as

OIetall i~

(ubllaores have a·gro't :¡{lioit}

ith arfenie, it is oot

(urrrifiog 'h:u the ocut"" f:dt o( ar(eoic, which eaonO!

be decompolloJed by a purc aeid, Ihllulrl nevenhcle(;

yidd to . 0 acid eomhi,led IVith a 0""1.

T he rleeompr.·

rillon of ,his f. lt, thcrd ore, aon the precil'itatioo whieh

of collr(e it p,odue,s io met.\lIie folmiuos, are bronght

about by the IIle""s of a

do"bJc

aflioity

oarncly, that

of the . rid with tllc , Ikalioe ba!is of the oell tr:"

(,I!,

allcl thar of the metal wi th the arieoical pan of that

fah.

At(~oic

has OOt the fame e(['ca 00 fea· (.h as 00

nitr~,

ood eaooot

exl'cI

itS aeid: a vcry fioglll. r' pllCoomeollll,

[or II'hich il is hard

,/libo a reafoll

for the oitrons

aeí.!