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chief propenie's wJlieh c:lmphor

polfcrr~s

in comlnon Wilh

rer.os

: bUl in Olher refpeéls il dilfers 10lally from them ;

efpecially in the fullowing particulars,

Camphor rakes fire and flames with vallly more eafe

'than aoy other refio.

is fo very volatile, that it ,a·

Ilifhes entirely io the air, without any other heat than

that of the atmofphere. In diflillatioo il riCes eotire,

WilhoUl aoy deeompofilioo, or,even the leafl alreralion.

dilfolves in eooeentraled mioeral aeids; bUl Wilh cir·

cumflanees very differenl from thofe lhal atteod orher

oily or refioous Cubflanees. The dilfolulion is aeeompa–

'oied wirh no elfmeCeenee,

fenfible heat; and eonfe–

quently can produce no innammation, Acids do no!

buro, blaeken, or thieken it, as they do other oily mal–

ters; on the contrary, it beeomes fluid, and runs with

them into a liquor rhat looks like oil.

Camphor dOlh not, like other oily matters, acquire a

diCpofition 10 dilfolve in water by the union it cootraas

wirh acids; though ils union wirh them Ceems 10 be more

inrimate than lhar

many oily matters with lhe fame a–

cids , On the contrary,

acombioatioo

camphor aod

sn acid be diluted with water, thefe two fubflanees io–

Haotly feparare from each orher: the acid unites with

¡he waler, and the camphor, beiog eotirely diCengaged

from it, Cwims on the Curfaee of the liquor.

N~irher

volarile alkalis, nor the moti cauflie r.xed slkalis, can

be brought into union with ir'; for il always eludes th:ir

power.

NOlwithtlanding thefe wide differences between cam–

phor aod all orher oily and refinous fubflances, the rule,

thac acids thicken oils, Ceems to be fo univerCal, and fo

cooflaotly obCerved by nature, thac we eannOl help rhink–

ing Ihis

Cubflan~e,

like al! lhe refl, is an oil rhiekened

by an acid.

BlIl

whal oill what acid

aod how are

they uoiled

This is a {ubjea for very curious ioqui–

ries.

Wirh a yellow oil drawn from wine, and an acid vi·

nous Cpirir, Mr Hellol made a kind of artificial cam–

phor; a fubfl,oce haviog lhe odour, Cavóur, aod ioSam–

mabilily of camphor; an imperfea camphor. True

camphor h.llh rhe levity, lhe volatility, and the inHAm–

mabilily of :Ether. Can il be a fubflance of the Carne

nature with :lther, a kind of Colid :lrher, ao :lther io a

concrete form

The

An.Ij

¡iJ

Di/limen¡:

i~nnn(ed

Amhe,. '!he

Volatile S.I/ ahd Oil

Amó!,.

Ino a glafs rerorl pur

Come

Cmall bits of amber,

as to fill bUl tWO thirds of che velfel. Ser your retort in

a furoace covered wirh il! dome; fil on a large glaCs re:

ceiver; and beginoing with a vcry gentle heat, diflill

with degrm of fire. Sorne phlegOl will firfl come olf,

which will gradually grow more aeid, and be Cucceeded

by a volarile falr, figured like fine needles, lhat \ViII flick

tOthe fides of the receiver.

Keep the fire up to lhis degree; in order 10 drive over

all rhe Callo

When you perceive rhar linte or oone

riCe!, change the receiver, and increafe your fire a little.

A lighr, clear, limpid oilwill afcend, As the diflilla–

.tioo advanm, this oil wil! grow higher coloured, leCs

limpid, and rhicker; lill at lan il will be .opaque,

bh.ck¡

ano have the confiflence of turpentine.

Whenyou perceive rhar, though tfie retort be red·hot,

nothing more comes off, let the fire go OUl. You will

have in the retorl a black, light, Cpuogy eoal. If yoo

have taken care to n,ift the receiver, from lime to time,

dllring rhe dinillation of your oil, you ",ill have Cundry

Ceparate portions thereof, each of which will have a dif–

ferenl degree of tenuiry or thickneCs, according as it

carne over al the beginning, or towards the eod of the

di·

fliJlatioo.

TH ECubflance of which we have here given the ana>

Iyfis, logether with aJl others of lhe Carne, lhal is, of the

biruminouskiod, is, by mofl chemifls and naturalifls, c1alfed

\Virh minerals: aod fo far they are righr, that we aaual.

Iy get theCe mixts, like other minerals, out 01 lhe bowela

of the emh, and never procure them immediarely Crom

any vegetable or animal compound. Yel we have our

reaCons for aéliog olherwife, aod for lhinking rhat

could nor, io this work, place lhem beuér, thao imme–

diately aflcr thoCe vegetable Cubflanees which we eaU '(–

}in/o

Several motives determine us 10 proceed io lhis mao–

ner. The analyfis of birumens demontlrates, thal, witll

regard 10 lhe principies of which they confifl, lhey are

lotally difl'erent from every other kind of mineral; aod

thar, on lhe contrary, rhey gready reCemble

veg~lable

refins in almotl every reCpea. In !hOrt, though they

are not imolediately procured from vegetables, lhere is

the greatefl reaCon for believiog that they were originaJly

of the vegerable kingdom, aod thar !hey are 00 other

than refinous and oilv parts. of trees or plant!, which by

Iying long in the earth, and tbere conrraaing ao union

\Virh the mineral acids, have acquired rhe qualities that

diflinguifh them from refins.

Mioeralogifls know very well thar we find, every

\Vhere in the ea!lh, many vegetable Cubflaoces, lhat have

Iain very long buried

Ond~r

it, and frequeotly al a con–

fiderable deplh.

is 001 uncommon 10 find, under

ground, vafl beds of

folf.Je

trees, whieh feem 10 be the

remains of immenCe forefls : and bitumens, panicularly

amber, are often found amoog this fubterraoeous wood.

Thefe confiderarions, joined 10 prooFs drawn from their

analyfis, make this opinior< more Iban probable: oor are

we fingular in maintaining il, as il is adopted by many

able modero ehemiJls.

The

aoalyfi~

of amber, above deCcribed, may ferve

a geoeral fpecimen of the decompofition of orher bitu·

mens: witb rhis fingle difference, thar amber is the only

one among them which yields the volarile Calr aforefaid;

and this dctermined us tO examine il preferably tO any o·

cher. As for lhe rell, lhey aJl yicld a phlegm, an acid

liquor, and an oil; which is thin at firfl, but growl

thicker and thicker as the diflillation draws.rowards an

end.

mufl be underllood, however, that lheCe a.ids .

and rheCe oils may dilfer, according to lhe nature of the

birumens from which lhey are dral' n; jufl as lhe phlegm,

the aeid, and the oil, reCulring from the decomrofitioD

of reGns, diffcr

quantity and quality, aceording tO rhe

oarure of lhe refios from whieh lhey are proeured.

Tbe