OIL. 
The alkalies have wan lefs — yee the Ser oils 
than upon the fixed o y are more fufceptible of 
combining sr thefe bodies in proportion as they Laan 
the ftate of r ommon turpentine ere with pot- 
afh, while oil of turpentine is but with difficulty made to 
unite with it. This has been called Starkey’s foap. 
Weare in poffeffion of fome faéts relative to the aCtion of 
acids upon the oils. 
ulphuric acid diffolves them, and mutual decom- 
pofition takes place. The colour becomes dark, and char- 
coal is at length depofited. When water is poured upon 
the folution, a refinous mafs becomes feparated. Hence it 
the fulphuric — paces a 
he effential 
great violence, leaving 
olour. The acid fhould 
It may eafily be eeeed. ‘dit many of the metallic 
oxyds “ail produce the fame changes upon the volatile oils 
which are produced by the acids, and the oxygen of the 
atmofphere. The facility with which lead, mercury, and 
manganefe give up their ark ian? offers a ready method for 
an accurate analyfis of thefe bodies. 
he volatile oils are ufed in merlin, and are confidered 
ftimulants. They perfumes; and in the 
compofition of varnifhe 
Fixed, Vegetable, or ce Oils —The fixed oils have 
the following charater: 
1. They are greafy o , the to 
2. They are moftly liquid, or notes in the ftate of a mo- 
ns thick, but not vifcid, fluid, at the common tem- 
perature of the atmofphere, ‘but become folid at certain 
degrees below 
5: They do not boil at lefs than 600 
« They re certain ae and burn 
with different es of brillian 
Py 
they congeal : 
{pherical temperature, as palm 
vegetable “ butters,’’ as they are called from this circum- 
{tance ; others require being cooled down to the freezing 
point of water; and others, again, are capable of ee 
a much greater degree of cold without becoming folid. 
hey are infoluble in water and alcoho 
7. They =~ a {tain on paper, which cannot be removed 
by evaporatio 
ixed ee are fo called, becaufe they are da aoe of 
being volatilized by heat without decompofition. en any 
of them, e. g. tly oil, is heated in a clofe difillscory ap- 
uid its boiling point 
—_ 
jos} 
jee} 
. 
hydrogen and carbene acid: 
in the receiver ; "while the cians two, 
retaining in folution a portion of oil, efcape in the form of 
permanent gas: and when every thing volatile has been 
driven off, nothing remains in the retort but a litle tl 
oal. The oil which is found i 
Q 
This is more peat ie the cafe when the pulp is heated. 
If it be prefled co 
ft 
olive. All the fixed oils, except the Hien are obtained 
from the cotyledons of feeds; and it is remarkable that no 
feed with one cotyledon affords a fixed oil Oil may be 
air not only by preffure, which is the moft common 
t by immerfion in hot water. In this latter cafe, 
oe a orn from the other ingredients with which it is 
naturally mixed, a rifes deel the force of igo) to the 
furface of the water, from which it is fkim off. Re. 
cently drawn oil is more or lels 3 impure, on account of its 
containing a variable proportion of mucilage, a and 
perhaps other {nbftances: of thefe a part is always rate ted 
a relt, efpecially if the conta& of the air is not w 
a 
oils, vai ‘‘ rancidity,’’ is principally owing. The ey a 
ned from animals, fuch as whale oil and ck S- 
All animals, except thofe er in the clafs of infeéts, 
contain oil; the quantity of which, as well as its ed in 
the Deeg is fubje& to penne” a 
R Membrane, Apeprs, and Srpacic cid. See allo 
Fina of Birps, Fisu, and aaa, ) While the 
fat remains in the living body, it is always in a fluid or femi- 
fluid ftate; but its confiftence changes, when it is extra@ted 
and expo ofed to the common temperature. The oil or fat, 
invetting the kidnies of quadrupeds, is called fuet or eee. 
and is the hardeft and moft folid of any; the next in hard- 
nef is the fat of the bones, and that in which the mufcles 
are imbedde t th ey 
fo folid as hog’s lard, and in many fpecies is aCtually fluid. 
The fat or oil of fith is almoft always fluid at the common 
temperature. ‘There is alfo fat in the yolk of eggs, which 
may be sopaate ie fimple preflure, after the yolk has been 
aie demi by 
fixed vegetable oils, aide agrees wih thefe in the changes 8 pro- 
duced upon it by the alkalies and other chemical re-agents. 
All 
