1000000030

129 / 1042

e H M
' :Is itfdf to be dilfoll'cd only by the liver of fulphur,
",hich is known ,O be a compofation of fulphur and fixed
alb li.
At the head of the tcnth column ~ppears mercury, and
bcneath it f(vml mculline in the order of
lheir ~Ainities Wlth it. 1'hofc mmlline fubllanccs are
Eold, fall'er, lead, copper, zin~, and reRulus of anti·
mony.
1'he c1cl'enth column nle\V! that lead has a greater affi·
oity y'ith falv"r than with copper.
The tlVrJfth, that copper has a greatcr a/linity with
mercury thdn with "lamine.
The Ihirlecoth, that filver has a greater affinity with
lead than with copper.
11le founeenth contains the a/linities of iron. Re·
gulus of anumony Il,nds immedi~tely underneath it, 'as
being the mctallic fubllance which has the gremll alli·
nity with it. Silver, copper, and lead, are plaCA!d tOo
gethrr in the next fquate below, becanfe the degrees of
allinity which thore m<!uls have with iron are n~t exaélly
determincd.
l 11e is to be faid of the fifteenth column : Re·
~nlus of antimnnyIh nds at its head; iron is immediatdy
below it ; and bclo\\' the iron the fame Ihree mmls oc·
cupy one fqnoreas befMe.
Lallly, The fixteenth column indicates that water has
a ~reatcr aflinity with fpirit of wine than with fahs. By
tI,is geoenl expreflion muJl not be nnderOood any f. lioe
(nbll,nce whmver; bUI only the neutral fahs, which
fpirit of ",ine frees fromthe water Ihat kepl them in fo·
lution. t'lxed .Ikalis, on the contwy, as wdl as the
mineral acids, have a gte.tcr affinity than fpirit of wine
with water; fo that falioe fubllances, being \Vell
dephlecmatcd and mixed with fpirit of wine, imblbe Ihe
wate'r it cootaios and reélify it.
f he rbeory ~r COlljlruflil/g the Veje/¡ moji
cQ/III/lol/ly l/red i/l Chc1l1ijlr)'.
CHHttSTS cannot perform the operatioos of thd(art
"~thout the hcIp of a confidmble number of velfels, in·
Ilruments, and farnates, adapted 10 contain the bodies
on which they ioteo~ 10 work, aod to apply tO themthe
{¡'vml d~grees of hm required by di[ferent procelfes.
Velfels intended for chemical operatioos ntOuld be able
10 bear, without breaking, the fudden applicalion of
grM hm and greal cold; he imp~nmable to every
thing, and unalterable by any foh'ent; uovitrifiablc, and
rapable of endoring the moll violen! fire wilhout melt·
ing: Bu huheno no vetTels hare beeo found wi!h all
t1,& qualitlcs unlted.
Theyare made of rundry materials, namcly, of me·
tal, of gl.1fs, and of earth. Mmlline v,lfels, efptcially
Ibufe madeof iron or copper, are apt tO be corroded by
alOloll erery f.llnc, Dily, or even aqueous fubOance.
)' or this reafon , in order 10 renderthe ufe of thema Itl'
t!: Olore eXlcnfi"e, they are tinned on the infide. BUI,
nOt\VlthJl.nding Ihts precaution, Ihey are on many occa·
finos not tObe Hulled ; and Chould ncver be employed in
aoy mce opeminns which require grw accumy; they
al'-, OIoreo,''', tncapable of refilliog the forceof fire.
s T R Y.
Earchen velfcls are of feveral fort!. Some, Ihat are
made of a refrdélory emh, are capable or being fudden·
Iy expofed to a IIrong fire wilhout breaking, and even of
fuJlaining a great degree of heat for a conlidcrable time:
!lUI they generally fulfer the v~pt,urs of the mallm which
l/tey contain, as well as vitrificd metab, to par. through
Ihem; erpecially the glafs of lead, which cafily pene.
Irales Ihem, and ruO! Ihrough their pores, as through a
a ficve. There are mhers made of an eanh , Ihat, wheo
well baked, looks as ir it were h;t1f vitrified : l'hefe be.
ing much lefs porous are capable of retaining the vapour~
of the OlattCr! which they contain. and even glafs of
lead in fulion i which is one of the feveren trials a vrtrcl
can be pUt 10: Hut then tbey are mOfe brittle than the
other fon.
Good glafs.vetrels Chould confiMtIy be employed in
preference 10 all others. whenmr Ihey can poflibly be
ufed: And Ihat not only becaufe they are no way inju.
r<d hy the moll allive foh'ents, nor fuffer any pan of
whal l/tey conlaio to pafs through, but allo becaule their
tranfpmncy allows the ChCOHII to obfen'e wbat palf"
within Ihem; which is always both curious and uftfuJ.
Rut it is pily, that velfcIs of Ihis fon {hQuld no! b~ a·
ble t'o endure a licree fire "'ithout Olehiog.
Dillill.ltion, as halh becn already faid, i, an opera·
tion by whieh we feparm (rom a body, by !he help
01' a gfddual /tw, the feveral principies of whieh it
confills.
There are time methods of difiilling. The firfi is
perl'ormed by applying the heat om the body whofe
principies are 10 be eXlralled. In this cafe, as the li·
quors when hcated and converled into "apours conllantly
endeavour 10 fiy (rom the c!nlre of heat, Ihey are foro
ced 10 re·unite in the lower par! of the velfel that con·
tains the maller in dilltllation, and fo pafling through
tbe pores or holes of that velfel, Ihey fall imo another
cold veO(1 applied undernealh tO reccive them. This
way of diOdItng is, on this accounl, call.d dilliJling ptr
titfttnJum. lt requires no OthH apparatus than two
vell'ds figured like fegmenu of hollow fpheres, whereof
that which is pierced Wilh little holes, ~nd inlended 10
co~tain the maller to be dirIlJleJ, oughl 10 be much Icfs
than the other which is tO conlaio the fire, and clole ils
apenure exaflly; the whole logether, beiog fupportcd
venicallyupon a third velfel, whichis 10 ferve thepurrol.
of a reClplent, admitttng into its mouth the convex bot–
tomof Ihe velfél conlaining the matter 10 be diOilled,
which murI accuralely fill it. Thil melhod o( dillilling
is but !ittle ured.
The fecond method of ditiilling il performed by ap'
plying !he he.n underneath thi"n.¡ter 10 be decompofed.
00 Ihis occafion the liquors being hem d, rmfied, and
cODverted iOlo vapours, rife, and are condenfeJ in a vef·
fel contrived for thal purpofe, which \Ve {haJl prefentIy
defcribe: This lI'~y of difiilling is callcd dillilling ptr
aft'"!u,", ~nd is much ufed. .
Thc .elfel iD whieh tite diOillation ptr ,fa nfutn is
performed, w eaJl ~n alemble Plale LXIV. 6g. ' .
TIlere Me fe'eral forlS thereof JIIf<nng (rom one ano
olher oolh in the mmer uf wlúch, aod Ibe mno, r iD
whiell, Ihey are malle.
ofe