The Democratic advocate. [volume] (Westminster, Md.) 1865-1972, 1874-04-04

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the product Of flowers, plants, fruits, or
the juice Of certain odoriferous woods
Essential oils differ from the fixed oils OBJ
tanned from fatty substances; for while the
latter are compounds Of gIycerin and fatty
acids, the former are generally hydroear-
bons, but sometimes contain also oxygen
and sulphur The fixed oils combine with
'alkalies to form soaps, but the essential
oils do not. All essential oils have pow
erful odors, and many Of them have hot,
aromatic taste. The odor is sometimes
agreeable, and at other times repulsive.
The most fragrant are oil Of rose, jessa-
mine, tuberose, orange flowers, heliotrope,
violet, bergamot, and lavender. Paper is
rendered permanently transparent by an
application of fixed oils but only tempo
nrily so byt use of volatile preparations,
Essential oils are soluble in alcohol and
ether but only partially SO when immersed
in water. Many of them are found ready
formed in plants, aud give the peculiar
odor to the leaves, flowers, aud fruits which
make the acquaintance of our olfactories.
The volatile oils are, in many instances,
isomcrie, that is, composed Of the same
elements and the same proportions, but
with different properties. Chemical sci.
ence, however, has not yet been able TO
convert the one into the other, most proba-
bly, on account of the different groupings
of the same number Of elements.
Oil Of lemon and oil Of orange peel arc
obtained by placing tho rinds in a linen
cloth and subjecting them to a powerful
pressure between iron plates The vessel
in which the pressure is applied should have
a discharge pipe at the bottom. The oils
thus obtained are impure, but extraueous
matter is separated by cereful filtration.
Orange flowers, or neroli, has the same
chemical composition as the above, but is
possessed Of more fragrance. In obtaining
the last named, more care Is necessary, and
the petals are subjected to distillation with
the vapor Of water. Oil oforange flowers
when fresh from the still, Is almost color,
less; but by ago and exposure it soon
acquires red color. It is easily rendered
soluble in alcohol, and is extensively used
in the manufacture Of cologne water. Oil
Of rose is the most expensive as well a,
the most fragrant of all the essential oils
There are two varieties Of this article, one
of which is obtained from the East Indies
and is the product of the rosa nloschata
the other comes from the Leyaut, aud is
obtained from rosa semperrirens. In the
east, the petals Of the rose and other flow,
ers are collected, immersed in spring
water, and afterward exposed to the direct
rays of the sun. In the course of few
days yellow drops of oil collect ON top. and
are taken up by bunch of cotton tied to
the end Of stick When sufficient il
gathered in this way, the oil is pressed out
Of the cotton. In some seotious the whole
flower is subjected to distillation, the calyx
remaining entire as It is plucked from the
stem. In Egypt the petals of flowers, and
especially roses, are subjected to distilla.
tion with water in copper stills. Some
manufacturers of essential oils place alter.
nate layers Of rose leaves and sesame seeds
in vessel, where they are allowed to
remain about a fortnight, when fresh
layers Of roses are added, and this opera.
tion is repeated several times, or until the
seeds have absorbed sufficient oil, when
they are subjected to pressure, the rose oil
collecting on top, and the oil of the sesame
seeds separating and settling to the bottom.
Oil Of rose Is thick yellow liquid, which
solidihes at low temperature, and becomes
viscid mass. When concentrated, its
odor is so strong as to cause headache, aud
It is only when diluted that its fragrance
can be best appreciated It's sweetness is
not injured by the action Of sulphuric
acid.
There are said to be over one hundred
varieties of essential oils, very similar in
chemical properties, but differing greatly
in taste and smell. The oil is hidden
away in little cells which require to be
broken before the flower exudes its real
fragrance. Violet, heliotrope, and several
other delicate perfumes are subjected 10
infusion and absorption in melted tallow
or lard, and in this manner their oil is
secured.
Jessamine, tuberose, and other flowers
that are injured by heat are subjected TO
absorption alone, This process is extern
slyely used in several parts Of France, and
Is termed saFemage. Oil of eamphor Is
obtained from the wood or gum by distiIa.
tion with water; it is subsequently, purified
by repeated sublimation. The wood,
however, is the most generally used for
this purpose. 1t is insoluble in water, but
easily soluble 10 alcohol, ether, and the
fixed oils. Oil of turpeniine is obtained
by distilling the crude juice alone or in
water, and is made pure BY repeated
rectifcation with water. It is a colorless
liquid with strong aromatic but disa-
greeable odor- Il is of great value in the
arts, and for medicinal purposes. Oil Of
juniper has different composition. but is
obtained from fresh berries after being
thoroughly and macerated several
hours in water. The subsequent process
Of distillaiion is much the. same as in
respect to turpentine. Oils Of sassafras
aud hemlock are obtained in manner