113 / 1042
94
e
H
M
contain. For this purpofe, therefore, recourfe mun he
ha'! tOfire: a gende heat, r'ut
exce~ding
that of boiling
\Vmr, will exrr,1i ,di the eAcntial oils of a vcgn hlt ;
.nd this is the moti ufual and
01011
convenieot way of pro·
curing them .
1
he fat oils caonOt be
ohtain~d
by the fame method :
Ihefe beiog mueh lefs vol.!ile thao the &eotial oils, re·
quire • much greater dcgree of heat tO raife them;
which, oeverthelefs, they caonot bear without beiog
much fpoile ; .nd entirely ch. ngcd io their nature, as A ..
II
pr&ntly be Ihewn.
AII
oils, thercfore, whlCh rife with
the heat of boilillg water, aod fueh alooe, Ihould be call·
'ed elfeoti.1oils.
Elreoti.1 oils, io a looger or AlOrter time, according to
Ihe oature of each, lofe the fragraot fmell they had IVheo
Dewly dillilled, aod acquire aoother which is lI",og,
,aoCld, aod much lels agree,ble : They
dio
lo(e their te·
'DU:'
y,
oeconllog thiek ..,d vifcid ; and io this Itate they
greddy rdrmule thofe fu bílance<ab.ouodiog io oil which
tlow from cem in trees, .nd which
are
called
h"'fll/IJ
or
,tji>:I,
aecdr¿ing .s they are Icfs or more coofilleo!.
Balfams aod r('fios are out· folublc ' io wnr. But
there are other
o¡¡y
compouods wbteh likcwife run frcm
Irees ; and o though oot uolike relio,. are
howev~r
lo·
luble io water. l hefe are called
,el/lIf' ;
aod thci r pro·
per:y of dilfulviog in water arifes (rom their contaioing
more water aoel mOre fal t than refios hal'e; o¡ at
1 ..
(1
their fal"le pans are lefs c1or,ged and more dileogaged
Bal(.ms and refins diOilled with the hm uf builing
wm r j'lclo great qu.ntities of • limpid, fubrile odori·
ferous, and, in ooe IVord. elfeoti. l oil. In the nill there
remains a (ubOance t1l1cker ano more confilleot than the
bal(l.mor relin wa, hefore dillrllatioo The (ame thiog
hap~ens
tO elfeoti,l oils.IVhich by len&tI¡ of time hm ac
quired . confillence, .od are gro..n
rcfi~ous.
If they
be
IedillilleJ, they rec ,ver their former teouity, leaving
be·
hiod th,,",.• remaioder thrcker aod more refinous than
Ihey rhemfelves IVere. This (ecood diOillatioo is called
¡he
,,{lítica/í,n
of ao oil.
lt
muO be ooferved, that aD elfential oil , combined
with ao .cid IIroog eoongh
10
dllfoll'e it, immediately
bec·,m,s as thick aod refioous, in coofequeoee of this
uoion, as ir it h3d heen long expa(ed
10
the air: which
p,om the confiíl',nee an oil acquires hy loog keeping to
be owing to this, th.t its lightell . nd It(s aeid partS be·
ing e" ' poroteo, the proporrion of its aeid tOthe rem,io·
der is (u iocre>.led that it produces therein the (ame
ehange as dn arlditiooal .cid mixed with the oil would
hal'e wrought before the evapom ion.
'1
'his alfo O,ewsus, that l"l(ams and refios are ooly
e(·
fenti,1oils «,mhioed wilh a great proportioo
of
" id, aod
the"by Ihickencd
If vegetable fub(laoces, from which 00 more elfeoti,l
cil t'an be draIVo by Ihe heat of builiog water, be ex·
po{.:d to a nronger heat, they yield an addiri00al qu.o
tity uf oil: but it i, thilker aod he,lvicr than the elfLo·
tialoil. T' ef oils are black, and
h~ve
a Vt rydlf.lgrce
ahl,; burn! ¡",e11 which halh m de them
be
eallcd
¡'lid,
vr
" 1/'
"
,¡III I( t(
011( .
They
are mureover vtry itcrid .
lt
nlurt
lo,
,i;Lrved, th. t if a vegctable liloOance
be
txpAcd
la
a
degree of heat greater thao that of boiJing
s
T
n.
Y.
IVater, be(orethe f,lt or the elfeoti,ll oil is extra<'\ed 'rom
it, an empyreumat!c uil
~nly
will thln be ob aillcd; be.
c,lufe bOllr the fat aod ('lfemi:rI oils, IVheoexpofed
!O
the
forc~
of fire, are thereby hurnt, rendered acrid, acquire
a
finell of lhe fire, aod, io
a
wurd, become truly empy·
reumatic. T here is groulld tOthink, thal aoempyreurna·
tic oil i! nothiog
el
fe but ao elfential or fH oil bllrnt aod
(poileo by rhe fire, .otl th'rt 00 other oil befides thefe two
exifis naturall y io vegetablcs.
Empyreumatie orls,
el
1Ir1led and reélrfied (everal times
by a geode
h.al, ae'luire by every dinlllatioo a gleater
degree of tenuity, lightnc(s, and limpidity By Ihis
means al(o they lofe (omething of their difagrwble o–
dour; (o that they gradually come nearer and oearLr tO
the oaturl of elfential oils : antl if the reélificatiuns be
often enough lepcatcd. teo or tIVelve times for ioll.nce,
they recome perfelilv
Irk~
thu(e oils : exc, pt that tl'eir
Imell
11
rll oever
be
(o agreeabk. oor like that of the (ub·
O~ofes
fromwhieh they were obtaioed.
Fat oils may , Ifo be brought by the f.,nte mc.tos
10
re.
femble
tn~otd
oils; but ocither elfeotial oor (mpyreu–
matic uils are capable of acquinng the propenies of fat
oili.
~
o¡
A
N
r
M
A
L
O
J
L
s,
DI
sTr
LLA
TI os procures ns eoofidrrable qnantiti<s
of
oil fromall the
r
IrIS of animal bodies, aoo e(pecially
from their fa!. This oil at firO is oot very fluid, aod
is
extnmcly fetid; but by
m.nyn élifi cations it gradually
aequires a great degree of c1earn,(s ano tenuity, and at
the (ame time lo[es mueh of its di(agreeable odour.
qr
F E R M E NT A T ION
in general.
,By fermentntion is meant ' o inteOine motioo, which,
arifing fpontao<ollOy.mong. the iof, nfible parlS of a body,
proouces a o_w<difpofitioll aod a dilfereot combinatioo of
lho(e parlS .
To excite a fermeotation io a mixt body, it is oecef·
fary, firO, that there be io lhe compofition of that mixt a
cer'aio proportion of ",atery, f.rlioe, oily, 3nd eallhy
pans ; but thi! proportioo is OOt yet (ullicieotlyafeer.
taioed. Secondly,
i~
is reqll,fit ethat the body tu be fer·
mented be placeo in a cmaio
dewee
of tempmte heat ;
fo r much cold obllrulls ferment<tloo, aod 100 mueh heat
decompo(es bodirs. LaOl)'. the cuoeurreoce of the
air
is alfu oecelfary to fermeot. liun.
AII
vegetable .rnd animal fubO. oees are (ufeeptible of
fermeotatioo, becollf· all of them contain in a du. pro·
portioo the priociples aboye fpecified. However. oMny
of them
\V,O(
the pruper quantity of water, and cannot
ferment IVhile thcy remain io (uchaOateof drincfs. Bot
it is rafy tO(upply th.•t dcfell.
With re(peél tu mioerals properly (o calleo, lhey are
OO! (ubjell to any felmentatioo, at leal!
tira!
our hlts
can perccive.
There are three (ortS of fermentalioo, diOiogniOrrd
fromone allother bv their fel'era) proJnélioos The firn
proouces wines alld fpirilOus liquors; for whieh re,I00
it is eallcd th,
0',..""
ur
'tifí/"'''J
(mll,n/o/t.. :
Tire
r fult of ¡he lecuad is
an
acid llquor
i
{tnd
thm(~rt
it is
uJled