1000000030

fix da)'s in digcnion. and nieeed from time tO tÍme. A

lixivium of pure alk.lii, nOt acuateJ by lime, Il)"y alfo be

\lfed to make (oap: but it is ob(erved, that the combina·

lion (ucceeds bcttcr, aod thRt lhe alkali unites (ooner

and more perfcélly with Ihe oil, when il is Olarpencd by

lime.

The oil is 6rn mixed with a welkee and moee aqueous

Iye, to Ihe end \hat the combinalion mal'

001

take place

100

haOlly, bUI that all the particles of lhe IWO (ub–

/lances

be compounded together mal' unile equally.

But as foon as the alkali begins

dill'olve the oil gra–

dually and quietly, the dill'nlution mal' Ihen be aceele–

rated ; and that is done by adding the remaining Iye,

which is Ilronger and le(s diluted than lhe other.

Soap made with olive oil is while, hard, and hath nOI

a veey di(ageeeable (mell: but as lhat oi! is deae, others,

e'en lhe fal and oils

animals, are (ometimes fubOi–

tuted (or it. The (oaps made Wilh moO of the(e olhee

malters are neilher (o hard, nor fo while, as Ihal made

of olive oil: lhey are called

foll/anpt.

Oíls Ihus all'ocimd with fixeJ alkalis are by Ihat

means eendered folubfe in water; becaufe the alkaline

falls, having a great a/linity with waler, communicale

part thmo( to the oils Wilh which lhey are now incoe–

porated. Yet the oil is nol

foe

all that ee.ldercd tho·

rooghly mi(cible with water, or perfeélly (oluble thmin ;

foe

the watee in whieh (oap is dill'olved hath always a

milky can : now there is no olhee criterion of a perfeét

folution but tran(parency.

Alkalis.al(

o lo(e part of their a/linity with water, by

lhe union Ihey thus contraét Wilh oils: for, when the

combination is properly made, Ihey no longer attraét lhe

rnnilluee of lhe air, nor doth water dill'olve Ihem in (uch

quamities as before. Thecnmpofition of (oap is plainly

• (alumion of an alkali with an oil; and, in order to

make perfeét (oap, \Ve are forced, as was (aid in tbe pro–

ee(s, tO geope, in a manner, by repeated trials, for this

point of (aluration; juO

when we prepare a neutral

falt by (aturating an alkali with an acid: The union

which lhe oil contraéts with the alkali makes it lo(e, io

part, the readine(s with which it naturaJly takes fire;

becaufe the (alt js not inflammable: the water al(o,

which enters, in prmy confideeable quantities, inlo the

compofition of (oap. contribules a good dcal

hindee

.he accenfioD of theoil.

Soap mal' be decompounded either by diOiJling it, or

by mixing il with fome (ubllance that hath a grcater a/li–

l ity than oi! with alkalis.

we decompouod it by dilliJlation, a phlegm, or

uan(parent (piri t, of a (omewhat yellowi/h colour, 6rO

(omes overo Thisliquor is the aqueoos part of the foap,

'luickcned by a little of its alkali, which gives it an acrid

talle.

is foJlowed by a red oil, which at (¡rn is prctly

Ibin and limpid, but thickens as the diOilration advances,

~rows

black, and has a very difagreeable empyrellmatic

fmell. Thi! oil is (oluble in f'pirit of \Vine.

When the dillillation is fini/hed, that is, when the

rcton being kept red·hot for (ome lime \ViII difcharge no

more, there is lefl in it a (aline mars; which is the al–

kali of Ihe (oap, cruHcd over Wilh (ome of the moO 6xed

"ml

t.bc

oíl, tilat are chamd

a coal.. This fall

'Y.

mal' be renored to the (ame degeee of purity it had before

itl combinatioo with lhe oil, by calcining it in a crucible

with a naked 6re, that may con(ume this burot pan of

the oil, and reduce it to a/hes.

is plain, Ihat the oiJ contained in foa p is affeéted by

dinillation, much in lhe (ame manner as that which we:

mixcd with lime and

diflill~d.

Mr Geoffroy, by analyfing (oap with care, difcovmd

that two ounces lhereof conlain ninety-fix grains of (alt

of kclp, freed from all oi! and moiHure; Or two dram,

and forty-eight grains of that falt, as it is u(ed in manu–

faéturing (oap; lhat is, containing water enough to make

it cryHalli(e

one ounce three drams twenly grains of

o–

li'e oil

and about two drams foue grains of water.

As acids have a greater a/linity titan any other (ub–

llanee with alkalis, they may be very effeétually employed

to decompound (oap.

If you propo(e to decompound (oap by means thereof.

yau muO 6rH dill'olve it in a (ullicient quantity of water.

Mr Geoffroy, who made this experiment likewi(e, diC.

(olved t\Vo ounces thereof in about three gallons of warm

water, and tO the folution added oil of vitriul, which he

let faJl into it drop by drop. Every time a drop of acid

falls into it, a

cong"l"m

form~d

in the liquor. The

.ell'el in which the (olution is contained muH then be

/haken,

~hat

the acid may equaJly attack all the alkali

diffu(ed in il. When no new coagulation is produ.ced

by a drop of the acid, it is a fign you have added e–

nough. The liquor then begins tO gro\V clear: and if

another quart of water be

ad~ed,

in order tOfacilitate

the fepantion of the oily particles, you will fee them rife

and unite together on the furface of tbe liquor.

This is apure, clear, true olive oil, hath its talle,

jts fmell, and, like it, is fluid in wum weather, and be–

comes 6xed by cold. Yet it diffm in fome re(peéts

from that which never hath been uniled "ith an alkali io

order to form a (oap; for it burns more vi,'idly ana

more rapidly, and is (oluble in (piril of wine. \Ve (hall

account for Ihe(e di[erences when we come to trm of

ardent (pirits.

Not only the ,itriolic acid, but all othm, even thore

obtained from vegelables, ale capable of decompounding

foap, and (epaming the oi! from the alkali. In the li–

quor wherein (oap is lhus decompounded, isJound a neu–

tral (alt, confilling of the acid made u(e of, united with

the alkali of the (oap. If the .iteiolic acid be u(ed, you.

will have a Glauber's falt

a quadrangular nitee, if the

nitTOus acid be ufed; and (o of the reO.

11le facility with which acids decompound (oap is the

rearon that no water, but what is very pure, will

dill'ol.~

it, or is fil to be ufed in wa/hing Wilh ir.

Water that doth not dill'olve foap well is u(ually eaJlea

hard water. Such walers contain a cemin qtr.lntity oF

faline rnatters. wa/hed out of the earths through' which.

rhey par,o The hardnefs of water is geDerally occa–

fioned by (elenitic parlicles.

The h'ardners oF mon wen·waters is owing to a conli–

d:rable quantity of (elenitic gyp(um with which lhe foi l

abounds. 11le (elcnites are neutral fallS confining of the

vitriolic acid united Wilh an earthy bafis. If, thcrefore.

foap be pUL iUlO Wale[

whicll a

r~11

of Ibis kind is dir.:

ral~ed.