1000000030

of getting 3n aeid from it, we obuin only a volatile alkali.

We fl\all not here

Cpe~k

of the manner of feparating

and depurating the principies obtained by this proeeCs;

but referve it for the analyfis of animals, which is :tUfo–

lutely the Came. We O\all content ourCelves IVith obfer–

ving, that the fir/! ,olatile alb li, IVhieh rifes at the be–

ginning of the operation together with the phlegn\, in a

degree of

h~at

below thatof boiling water, differs from

tbat which do\h not COme over till tOIVards the end of the

dirlillation, when the Jarl thick oil aCeeods. The differ–

ent times, and difFerent negrees of heat, in whieh thefe

two a!kalis riCe, !hew that the former exirls aélually and

perfeélly in the plant; but that the

lilter

is generated

during the dirlillation, and is the produél of the 6re, whieh

combines togetber the materials whereof it is compoCed.

Vegetables. that thus yield a volatile alkali with a

heat leCs

th~n

that of boiling water, irritate the organ of

fmelling, affeéling it witb a CenCation of acrimony; and

.th~

dHuvia, which riCe from tbem IVhen bruiCed, make

tbe eyes fman fo as tO draw

te~rs

from tltem in abun–

dance. Several of tbeCe malters. being only bruifed,

effervefee with acids: e[,éls producible only by a very

volatile ¡Ikaline priociple.

This is that alkali, the lighte/! of all the principies

that can be extraéled from bodies, IVhicl) rifes 6r11 in our

dillillation along IllÍth tite phlegm, and with a degree of

heat much inferior to that of boiling water. As tbe

phlegm with whieh it riCes is very eopious, it is di!fol–

ved thereby; which is the reaCon it doth not appear in

a concrete formo To tltis water it gives a flight yellolV–

ilb tinge, becauCe it is impure aod oily. The falioe al·

Italine properties of this liquor Itave proeured it the title

of a volatile fpirit. This volatile alkali, whieh exirls

naturally and perfeélly formed in murlard.feed, onioo!,

garliek, ere!fes, and other Cueh vegetable!, eonrlitutes a

differenee betVoleeo tbem and animal fubrlance!, whieh

contain ooly the materials requifi te

form a "olotile al–

kali, but nooe ready formed, unlefs they have undergone

the putrid fermentation.

Tite feeond volatile alkali, which rifes in onr dirlilla–

tion, but not without avery IIrong degree of fire, and al

the Came time IVith tbe larl thick oil, feeon to be a pro–

duélioo ofthe fire; for, if it were already formed in the

mixt¡ as the other is, it IVould rife with the fame heat,

¡¡nd at the fame time,. being equally

vol~tile.

o¡

tbe Subjlnnw obtnined ¡rom VegelablcJ

·by

COlllbuJiíon.

'l.

procure

fixed Caujl;c Alüline 8a/1 ¡r.m a Ve–

getnóle 8ubjlance, by b.rning

¡he

.pw Air.

AK2

aoy vegetable matter wbatever; Cet it

fire,

and lel it burn in the

op~o

ai r till it be wholly reduced

lOalhes.

theCe a!hes pour a quantity of boiling wa–

Culficient to nrench them thoroughly. Fiher tite li–

quor, in

ord~r

f<p1ra:e the eartlty pam;

~nn

evaporate

your Iye to drynefs, Oirriog it iOleírantly; and you will

have a ycllolVilh.white C. lt.

Put this falt in

crucible;

Cet

it io a meltiog furRace,

and make a moder.<le fire, fo as nOI to fufe the fal t.

VOL .

11. No. 36.

157

will tum filrl of

blue.grey colour, aClerlVar.!s

a hllle–

grecn, and'at la{\ reddilh. Put on the dome of the

(u~nace; fill it IVith coals; makc yOllr fi re /lroog enough

to md t the C:tlt, and kecp it io fufioo for ao hour, ur

Jo.

hour and

h.lr

. Theo pour it ioto a heatd

'3ml

mu,–

tar ; pouo,1it while it is red-hot ; put it as fooo as poC–

fibl e into a

gl~fs

bOllle, firll mane very hot

~nd

dry,

and !hut it up doCc IVith a slaCs Ilopple ruLbed IVid\ eme–

ry. By this meaos you will have the pure 6xcu alkali of

the vegetable Cuhllanee you burO!.

. )juroiog a veget.ble fubllanec in theopen

~ir

is a kind

of violent

~od

rapid aoalyfis

m~de

by fire, which fepa–

rates, refolves, aod dceompofes

le.er

of its prmciples.

When any \'Iood or plant is laid on a quick lire, thae

afceods from it immediately an aqueous Cmoke, IVhiel\

coofirls of liltle

mor~

than phlegm; but this fmoke Coon

becomes thicker

~oJ

blaeker; it is then punlleot, draw9

tears from one's eyes, aod excites a cough if JraIVo ioto

the lungs with the breath. TheCe, eff'eéls a, ifz from il$

beiog replete with the aeid, and fume of the oil, of the

vegetable cunverted into

v~pours.

Soon after this the.

fmoke grows exeeeding black and th:Ck; it is now rl iJl

more acrid,

~od

the plant turos

bl~ck.

Its

IIron~ell

a–

cid and la/! thiek oi! are nolV difcharged IVith impctuJ-'

lity.

This rare6ed oil being heaten red-hot Cuddeoly takes.

6re and 8ames. The vegttable burns aod defla 'rateg

rapidly, till all its oil is coofu med.

Th~o

the

8ame

eeafes; and nothiog remains but a coal, like that found

in a reton

~fter

all the principies of a plant have been ex–

traéled by the force

tre. But this coal haviog a free

communic"ioo wilh the air, whie b is . bColutelyoece!fary

to keep a'eomburlibleborning,eontinues tObered, Cparkl:s,

and wafles till all its phlogirlon is diflipared and deflro}'ed.

After this nothiog remaios but the emh aod Iixed C.h of

Ihe vegetable; IVhieh, mixed together, Corm IVhal \Ve'

eall rhe a!hes. Water, IVhieh is the

n~tur.1

folvent of

fahs, takes up every thing of that kind that is

cont~ineJ

io the a!hcs; fo that by lixiviating them, as di,eéld,

311 the :Calt is extraéled,

~nd

oothing lerl bUI the pu re

e3rth of the mixI whieh is thus decompoCed.

The phenomeoa obCcrved·io Ihe burning ofa vegetahle

fubrlance, and

th~

produélion thereby of a fixed

~Ikali,

feem to prove that this Calt is the .work of the fire; tbal

it did not exil! io the plant befure it IVas burnt; that the

plant .nnly coolained materials

.~dapted

to form tltis

C.lt

;

and thal litis Cal! is no other than

combio:ltion of fome

of the aeid, uoited with a portion of earth, by means of

Ihe igneous motioo.

The .Ikali obtaioed from the

~lhes

of burn! plaolS is

nOI perfeélly pure : it is

cont~mlnaten

with a fm all mix–

ture of fatt y matters, which IVere probahly defended

thereby

ag~inlllhe

Rélion of the fire, and urhiel. render

it {omewhat

C~ponaceolls.

In order tOfree it from this

extraneous maner, and to render it fCry caul!ic, it mul!

be calcinen a lons time in

erucible, hUI wilhout melt–

iogitat firn;

beeau C~

it is IVith tltis r.llt as wilh mol!

m~tallic

m~tters,

whirh are fOllner and more cafily dcrl'il'ltl

of Iheir phlogiflon by b,ing calcinco wilhuut

mdlio~,

providen they be eomminute" iOlo (,n,,1I particles, thao

when they are in fufioD

all meltcJ m.lttell h,¡,iog but