Caraway oil consists mainly of a terpene, C_{10}H_{16}, called

_carvene_, specific gravity 0.870, and of _carvol_, specific gravity

0.960. The richer the oil in carvol, the higher its specific gravity.

Good caraway oil should have a specific gravity of 0.900 to 0.910.

The carvol being the actual bearer of the aroma, the value of the oil

exclusively depends on the content of it. In the better varieties

of oil, the content of carvol amounts to from 45 to 50 per cent.,

while poorer qualities generally contain only from 40 to 42 per cent.

The carvol and carvene are now frequently separated by fractional

distillation. The carvol, which has three times as strong an odor and

taste as the carvene, dissolves with much greater facility in alcohol.

The carvene being offered at very low prices might be suitable for

perfuming cheap soaps.

Caraway oil obtained by distillation from the plant has a less

agreeable odor than that from the seed, and possesses an acrid resinous

taste.

The purity of caraway oil is recognized by its dissolving clear in

equal parts of 90 per cent. alcohol. If such is not the case, the oil

contains either an admixture of oil of turpentine or does not possess

the full normal content of carvol. Pure caraway oil does not detonate

with iodine, which is the case with oil containing oil of turpentine.

Caraway oil is chiefly used for perfuming soap; for handkerchief

perfumes it is not suitable.

_Cedar oil_ (_oleum cedri_) is obtained by distillation from the

shavings of the wood of the American or Virginia cedar (_Juniperus

virginiana_). For the distillation of oil the waste falling off in the

manufacture of lead-pencils is almost exclusively used. It yields about

2 to 3 per cent. of oil. The oil is thinly-fluid, of specific gravity

0.9622, of a greenish color, and an agreeable but not very penetrating

odor. It is a mixture of a terpene, boiling at about 540° F., and of

a hydrocarbon. The latter, which is called _cidrin_, forms the fluid

portion of the oil. It has a specific gravity of 0.984, and boils at

about 459° F.

Cedar oil is extensively used in the manufacture of toilet soap,

it serving as the basis for other perfumes. Care must, however, be

taken that its odor does not preponderate, as in such case it readily

produces an unpleasant effect. The oil being cheap, adulteration is

scarcely to be feared.

A volatile oil is also obtained by distillation from the leaves of the

_Juniperus virginiana_. In odor it resembles savin oil, and is unfit

for perfuming purposes.

_Cherry-laurel oil_ (_oleum laurocerasi_) is the volatile oil, which

contains prussic acid, obtained from the leaves of the cherry-laurel

(_Prunus laurocerasus, L._). Like bitter almonds, the leaves contain

some amygdalin. Hence they are macerated with water and allowed to

stand in a warm place for 24 hours. By subsequent distillation a

volatile oil is obtained which closely resembles oil of bitter almonds,

but differs in some respects. It is colorless or yellowish, rarely

reddish, and of specific gravity 1.05 to 1.06. In its behavior towards

air, solvents, and reagents, it does not essentially differ from oil of

bitter almonds.[5]

[5] Compare Kremel's observations, p. 91.

To detect oil of mirbane in cherry-laurel oil, Enrico Pega adds some

alcohol to the oil to be tested and then mixes it with some alcoholic

potash lye and a few drops of ferric chloride solution. After standing

for a few hours the mixture is shaken and distilled. A small portion

of the oil distilling over is freed from water, poured upon a few

small pieces of pure caustic potash in a test-tube, and heated over

a lamp. If the sample is pure it remains colorless; in the presence

of oil of mirbane it acquires a dark coloration in consequence of the

formation of nitrobenzide and aniline, a few drops of calcium chloride

solution brought into the mixture producing, for this reason, a violet

coloration.

Cherry laurel oil is but seldom used for perfuming purposes.

_Cinnamon oils._--There are four different kinds of this oil, viz.,

_Ceylon cinnamon oil_, _cassia oil_, _cinnamon root oil_, and _oil of

cinnamon leaves_. Though the first two are very much alike, the Ceylon

oil is considered the best.

_Ceylon cinnamon oil_ (_oleum cinnamoni ceylonici_).--Formerly this oil

was exclusively distilled from chips and waste of the genuine cinnamon

bark of the _Cinnamonum ceylonicum, Nees_, and came into commerce from

Ceylon. However, the fabrication of the oil from cinnamon waste or

chips is now extensively carried on in Germany, and this oil, being

prepared with the assistance of more perfect apparatus, has almost

entirely supplanted that exported from Ceylon.

When fresh, the Ceylon oil is colorless, but when stored for some

time it becomes first golden yellow and later on brownish. It is

thickly-fluid and heavier than water, its specific gravity being 1.060

to 1.090. It has an agreeable, aromatic odor and a biting but pure,

sweet taste. Its principal constituent is cinnamaldehyde (C_{9}H_{8}O),

and it contains, besides, 4 to 8 per cent. of eugenol. The presence of

the latter in cinnamon oil may be established by shaking with 15 per

cent. soda-solution, whereby the eugenol is dissolved, and decomposing

the aqueous solution with hydrochloric acid. The eugenol separated

thereby gives in alcoholic solution, when compounded with a trace of

ferric chloride, a beautiful blue color.

_Cassia oil_ (_oleum cassiæ_).--In China and Cochin China this oil is

obtained by distillation from the bark, unripe fruits, buds, and other

waste of the _Cinnamonum cassia_ or _Cinnamonum aromaticum, Nees_, a

tree indigenous to those countries. It has a pale yellow color, which

in time becomes brown. It is thickly-fluid, of specific gravity 1.05

to 1.07, and possesses a sweet taste with an acrid after-taste. Like

cinnamon oil, it consists chiefly of cinnamaldehyde, but contains no

eugenol, and hence can be readily distinguished from Ceylon oil by the

above-mentioned reaction. One part of pure cassia oil dissolves in two

parts of 80 per cent. alcohol.

_Cinnamon root oil and oil of cinnamon leaves._--Neither of these

oils contains cinnamaldehyde, but abundant quantities of eugenol, the

root oil as much as 50 to 70 per cent. The root oil is quite limpid

and has an agreeable odor of cinnamon and cloves. The leaf oil is

thickly-fluid, of the consistency of castor oil.

The Ceylon oil is frequently adulterated with cassia oil. Such

adulteration is very difficult to detect, and can only be recognized by

experts by the odor and taste.

The quality of cassia oil is recognized by the taste and odor,

especially on heating, and the high specific gravity, in consequence

of which the oil sinks in water. According to Hager, cassia oil is

frequently adulterated with oil of cloves. This is, however, scarcely

probable, the price of oil of cloves being, on an average, higher than

that of cassia oil. The latter, however, is frequently adulterated with

cheaper thickly-fluid volatile oils, especially with cedar oil. In this

case the oil does not dissolve in the above-mentioned proportion in

alcohol.

The value of cassia oil is dependent on its contents of cinnamaldehyde.

Hence, the establishment of its actual value requires a quantitative

determination of its contents of cinnamaldehyde, which unfortunately

presents great difficulties. For this purpose Schimmel & Co. proceed

indirectly as follows: 75 grammes of cassia oil in a capacious boiling

flask are mixed with 300 grammes of a boiling-hot 30 per cent. solution

of acid sodium sulphite, whereby cinnamaldehyde-sodium sulphite

is immediately separated. The whole is then vigorously agitated

and allowed to rest for a short time. (With oils rich in aldehyde

considerable heating generally takes place, which must eventually be

moderated by the addition of cold water.) Next add about 200 grammes of

hot water and heat the whole, with frequent shaking, in the water-bath

until the combination of the aldehyde with the acid-sodium sulphite

is _completely_ dissolved, and the non-aldehydes in the form of an

oily layer float upon the solution of the aldehyde salt. Now allow

the whole to cool, then shake twice with ether; first, with about 200

cubic centimeters, and then with 100; combine the ethereal extracts

of the non-aldehydes separated by means of a separatory funnel, and

filter them into a capacious, previously-weighed beaker provided with a

platinum wire, the lower end of which is bent in the form of a spiral.

Now evaporate the ether as much as possible, by placing the beaker in

hot water. When by swinging the beaker the remaining fluid no longer

foams up, allow to cool off and weigh. Now return the beaker-glass to

the water-bath for ten minutes, weigh again after cooling, and repeat

the operation until the difference between two weighings does not

amount to more than 0.3 gramme at the utmost. The weighing _previous to

the last_ is taken as the correct one.[6]

[6] The manner of expelling the ether is of great influence upon

the accuracy of the result. Though the non-aldehydes volatilize

with difficulty, they are volatile, and hence the ether must be

quickly expelled, and the beaker not allowed to stand longer upon the

water-bath than necessary for the evaporation of the ether.

The weight of the non-aldehydes thus obtained is deducted from the

cassia oil used, the difference giving the content of cinnamaldehyde in

the latter.

For example:--

Used 79.71 grammes of oil.

First weighing of the beaker after evaporating the ether 147.55 grammes

Second " " " " " " 146.84 "

Third " " " " " " 146.58 "

Tare of the beaker 128.34 "

Hence non-aldehydes in the oil 146.84 grammes.

Less tare 128.34 "

------

= 18.50 grammes.

Calculated to per cent., 23.1 per cent.

100 - 23.1 = 76.9 per cent. cinnamaldehyde.

By accurately following the directions given, the difference between

two controlling determinations will be only a few tenths per cent.,

seldom as much as 1 per cent. For practical purposes, for which alone

this method is intended, this is more than sufficient.

According to the reports of Schimmel & Co., all the cassia oil brought

into commerce from China was for a considerable time adulterated with

resin and petroleum, they having found as much as 30 per cent. of resin

in the oil. Such adulteration can be established by the determination

of the specific gravity and distilling the oil. Good cassia oil should

show a specific gravity of 1.05 to 1.07 at 59° F., and by distillation

90 per cent. of pure cassia oil must pass over. The residue should not

solidify after cooling and acquire the character of a brittle resin; it

must remain at least thickly-fluid, and under no conditions amount to

more than 10 per cent.

_Citron oil_ (_oleum citri_), from the peel of the fruit of _Citrus

medica_ or the citron tree. The oil is prepared in a similar manner

to that of oil of bergamot, either by expression or distillation, the

latter process yielding more and purer oil.

Rectified citron oil is colorless, of an agreeable penetrating odor

and acrid taste, and very sensitive to light and air. By exposure to

light it turns yellow, and if air be admitted at the same time, it is

first converted into a fluid which, on account of its content of ozone,

possesses strong bleaching powers. The oil at the same time acquires a

disagreeable odor, resembling that of oil of turpentine, and is finally

converted into a resinous mass.

Citron oil is frequently adulterated with oil of orange and sometimes

with oil of bergamot. These adulterations are readily detected by an

experienced person by the odor, this being in fact the best guide. The

specific gravity of citron oil is 0.850 at 59° F.; it boils at from

332.6° to 343.4° F. and congeals at 4° F.

_Citronella oil_ (_oleum citronellæ_) is chiefly distilled in Ceylon

from the lemon grass, _Andropogon Nardus, L._ It is quite limpid, of

a greenish-yellow to brown color, and has an odor resembling that

of genuine citron oil. Its specific gravity is 0.896 at 59° F., and

it boils at from 392° to 410° F. Of the various oils reaching the

market that with the trade-mark "Fisher" is most in demand, it being

distinguished by special purity. Edward Kremers has found in citronella

oil an aldehyde, C_{7}H_{14}O, a terpene, C_{10}H_{16}, citronellol,

which is isomeric with borneol; further, acetic acid and valerianic

acid.

The Indian distillers, it is claimed, adulterate the citronella oil

with petroleum, an addition up to 25 per cent. being not uncommon.

According to experiments by Schimmel & Co., pure citronella oil must

give a clear solution, when 1 part of the oil is vigorously shaken with

10 parts of 80 per cent. alcohol. If, in executing the test, the kind

of turbidity is observed, and whether the portion insoluble in alcohol

separates, after standing, upon the surface or on the bottom of the

fluid, and further, if the above-mentioned quantity of alcohol is not

added at one time, but at first only 1 or 2 parts of it, a conclusion

may be drawn as to the kind and quantity of the adulterant.

Petroleum causes a milky-white turbidity, while in the presence of fat

oil the mixture becomes turbid, but not actually milky. As a rule,

fat oil deposits, after standing, on the bottom, while petroleum

floats upon the surface of the fluid. Citronella oil adulterated

with fat oil does not dissolve in 1 to 2 parts nor in 10 parts of

80 per cent. alcohol, while oil adulterated with not too large a

quantity of petroleum, gives a clear solution with 1 to 2 parts. The

determination of the specific gravity may also serve for the detection

of adulterations. This holds good, however, only for petroleum, which

reduces the specific gravity, an addition of fat oil producing no

deviation in this respect. The specific gravity of the oil should not

be below 0.895 at 59° F.

Citronella oil is much used for perfuming cheap hair oils and toilet

soaps; it is the chief constituent of all perfumes for honey-soaps.

In the American soap industry it is extensively used, the yearly

consumption being estimated at 1½ million ounces.

_Cloves, oil of_ (_oleum caryophylli_), is obtained by distillation

with steam, or by extraction from the cloves of commerce, which are

the dried unexpanded flower buds of _Caryophyllus aromaticus, L._,

or the clove tree. Oil of cloves, when fresh, is almost colorless,

but on exposure to air acquires a brownish coloration and a thickly

fluid consistency. It has the aromatic taste and odor of cloves, and

a specific gravity of 1.300 to 1.065. It frequently shows a slightly

acid reaction, boils at 482° F., and congeals at 4° F. It is readily

soluble in alcohol, ether, and strong acetic acid. It consists of a

terpene (C_{10}H_{16}) and eugenol (C_{10}H_{12}O_{2}), the odor of

the oil being due to the latter. The terpene has a specific gravity of

0.918, and in distilling passes over first (light oil of cloves). The

eugenol, when fresh, is colorless, has the odor and taste of cloves, a

specific gravity of 1.063 at 65° F., boils at 487.4° F., is insoluble

in water and glycerin, but soluble in alcohol, ether and glacial acetic

acid. Its alcoholic solution is colored magnificently blue by ferric

chloride. If in an alkaline solution it is oxidized with potassium

permanganate, vanillin being formed.

An inferior quality of oil is obtained from the stems of the clove

buds. It dissolves with greater difficulty than the oil prepared from

the buds, and has a darker red-brown color.

To test the value of oil of cloves, introduce, according to Stohman,

into a graduated glass cylinder 10 volumes ether, 10 oil of cloves,

and 30 of a 10-per cent. soda solution. After vigorous shaking, the

eugenol dissolves; the increase in volume of the aqueous fluid is

then proportional to the quantity of eugenol present. For more exact

determinations, dissolve a weighed quantity of oil, repeatedly shake

the aqueous fluid with ether to remove the terpene, then decompose

the eugenol-sodium with dilute sulphuric acid, dissolve the separated

eugenol in ether and weigh after evaporating the ethereal fluid. Good

oil of cloves does not contain less than 80 per cent. of eugenol, and

frequently 90 per cent. or more.

Oil of cloves is chiefly adulterated with copaiba oil and cedar oil.

Such adulteration is recognized by the oil not forming a clear solution

in every proportion with alcohol, as is the case with pure oil of

cloves.

Oil of cloves is much used for perfuming purposes.

_Eucalyptus oil_ (_oleum eucalypti_) is obtained from the leaves

of various trees of the eucalyptus family. According to Merk two

kinds of oil must be strictly kept apart: _oleum eucalypti_ from the

leaves of _eucalyptus globulus_ and _oleum eucalypti australe_, the

former being used in medicine, and the latter, which is considerably

cheaper, chiefly for perfuming purposes. However, Piesse's opinion that

eucalyptus oil, as far as its odor is concerned, does not deserve to be

classed among perfumes is undoubtedly correct. It has an odor between

that of oil of turpentine and cajeput oil, and as long as perfumery is

the art of sweet odors, such oil cannot be designated a perfume.

When not rectified, eucalyptus oil is mostly yellowish or bluish. In a

rectified state it is colorless, clear, limpid, lighter than water, of

a strong odor, and acrid taste. The oil from _eucalyptus globulus_ has

a specific gravity of 0.900 to 0.925, and dissolves in every proportion

in 90 per cent. alcohol. It is optically inactive or turns the plane of

polarization slightly to the right. On standing with sodium it acquires

a yellowish coloration, and does not detonate with iodine. The oil from

_eucalyptus australe_ has a specific gravity of 0.86 to 0.87, and is

but sparingly soluble in 90 per cent. alcohol, so that even a solution

prepared in the proportion of 1:15 is turbid. It turns the plane of

polarization strongly to the left; acquires, on standing with sodium, a

red coloration, and detonates with iodine.

Eucalyptus oil consists of eucalyptol and eucalyptene, and perhaps

other hydrocarbons. The content of the first, on which depends the

medicinal value of the oil, varies very much in the oils from the

different species of eucalyptus, the oil from some species, it is said,

containing no eucalyptol whatever.

Eucalyptol (C_{24}H_{20}O_{2}) is limpid, colorless, turns the plane

of polarization, has a specific gravity of 0.905, and boils at 347° F.

Its vapor mixed with air has an agreeable, refreshing taste, and its

dilute solutions remind one of roses. Eucalyptene (C_{24}H_{18}) has a

specific gravity of 0.836, and boils at 329° F.

_Fennel oil_ (_oleum fœniculi_) is derived by distillation from the

fruits of _Fœniculum vulgare, Gaertner_. Large quantities of it are

produced in Saxony, and also in Galicea. It is quite colorless,

limpid, of specific gravity 0.940 to 0.970 and, with a full content of

stearoptene, possesses a nauseous sweet taste and odor. It contains

60 to 70 per cent. of anethol and congeals at from 41° to 50° F. to a

crystalline mass. The leaves of the plant also contain a volatile oil,

which is, however, less valued than the seed-oil.

Good fennel oil should dissolve clear in 1 to 2 parts of 90 per cent.

alcohol. Direct adulterations of this oil do not occur, but the

stearoptene is frequently withdrawn by fractional distillation whereby

the oil loses much in value. Such oil freed from stearoptene does not

congeal, has a more bitter than sweet taste and does not dissolve in

the above-mentioned proportion in alcohol.

In perfumery fennel oil is but little used; sometimes in connection

with other volatile oils for perfuming soaps.

_Geranium oil_, _palmarosa oil_, _Turkish geranium oil_ is obtained

from _Andropogon Pachnodes_. It is yellowish, limpid, of specific

gravity 0.890 at 59° F., possesses a very agreeable rose-like odor

resembling that of geranium oils from _Pelargonium radula, Aiton_, and

for this reason is generally designated as Turkish geranium oil. The

odor of the oil is improved by shaking it with water containing lemon

juice, any content of copper being thereby removed. The washed oil is

then brought into shallow dishes and exposed for two or three weeks to

the sun, whereby its odor becomes still more like that of rose oil.

The oil thus prepared is much used for adulterating rose oil. Turkish

geranium oil is also much used for the adulteration of genuine geranium

oil and is itself adulterated with oil of turpentine. It is extensively

employed in perfumery, especially for perfuming hair oils and pomades,

and in conjunction with geranium oils for rose soap.

_East Indian geranium oil_ is obtained, chiefly in the Presidency of

Bombay, from _Andropogon Schoenantus, L._ It is greenish-yellow to

yellow-brown, has a specific gravity of 0.906 at 59° F., and consists

mainly of geraniol (C_{10}H_{18}O). Its odor is rose-like, though

modified by a lemon-like odor. It is principally used for perfuming

cheaper articles.

_French and African geranium oils_ (_oleum geranii_) are obtained

by distillation with water from the leaves of various species of

pelargonium. Many different kinds of this oil are found in commerce.

The finest and most expensive are the Spanish and French geranium

oils, so-called _rosé_, which are distinguished by their fine odor,

closely resembling that of rose oil. They are derived from _Pelargonium

radula_, and are either yellowish, brownish, or pale green, the

brownish oils being preferred. It congeals at 60.8° F. and turns the

plane of polarization to the right. Another good geranium oil is

the African, which is chiefly prepared in Algiers from _Pelargonium

roseum_, _Wildenow_, and _P. odoratissimum, Aiton_. It closely

resembles the French oil, but turns the plane of polarization to the

left.

French geranium oil is said to be frequently adulterated with fat or

copaiba oil; but geranium oil being soluble in 70 per cent. alcohol,

such adulterations are readily detected. Add to 5 cubic centimeters of

70 per cent. alcohol (specific gravity 0.890) at 59° to 62.5° F., 10

drops of the oil, and shake. If a clear solution results the oil is

very likely unadulterated.

The so-called Turkish geranium oil is frequently found mixed with

cocoanut oil. To detect this, place the oil in a test-tube in ice or a

cold mixture for several hours, whereby the cocoanut oil separates as

a white substance. Adulterations of upward to 20 per cent. are said to

frequently occur.

Reliable tests to detect an adulteration of the better qualities of

geranium oil with those of a lower grade do not exist, the odor being

the only guide.

_Jasmine oil_ or _oil of jessamine_, from the flowers of _Jasminium

officinale, L._, and _J. grandiflorum_.--The oil is exclusively

obtained by the absorption process, and is the most prized by the

perfumer. It is, however, exceedingly rare on account of the enormous

cost of its production. The extract of jasmine, the "essence de

jasmine" of the French manufactories, is a solution of the oil, as

obtained by extraction with lard or beef suet, in strong spirit of

wine. The odor of jasmine oil is so peculiar that it is without

comparison, and as such cannot be imitated.

_Juniper oil_ (_oleum juniperi_) is obtained by distillation from the

fruits of _Juniperus communis, L._, or juniper. The berries used for

the purpose should be fully grown and fresh and bruised before being

placed in the still. Unripe berries yield a smaller quantity and an oil

of somewhat different properties than ripe berries. The oil obtained by

distillation with steam is colorless and that by ordinary distillation

yellowish, the former having a specific gravity of 0.840 to 0.860

and the latter of 0.850 to 0.900. It consists mainly of terpenes. By

standing, a stearoptene is separated, which crystallizes in feathery

needles from hot spirit of wine. The odor and taste of juniper oil

remind one at the same time of juniper berries and oil of turpentine.

Juniper oil has a great tendency to thicken; it becomes resinous,

acid and thickly fluid, formic acid being formed. It should be kept

in well-closed bottles, and protected from light. It is frequently

adulterated with oil of turpentine and juniper-wood oil. It may be

tested by its behavior towards alcohol, as well as by the taste. A drop

of the oil rubbed up with sugar, and shaken with 500 grammes of water,

should not impart an acrid taste to the water. Juniper oil gives a

clear solution with ½ part absolute alcohol; by a larger quantity it

is rendered turbid.

_Lavender oil_ (_oleum lavandulæ_.)--Large quantities of this oil are

distilled in Southern France, in the neighborhood of Grasse and Nimes,

from the flowers of _lavandula officinalis, Chaix_, which grows wild

in that region. It is limpid, colorless, or yellowish, has a strong

odor and a pungent, aromatic, somewhat bitter taste. With 90 per cent.

alcohol it mixes clear in every proportion, boils at 320° F., and has a

specific gravity of 0.876 to 0.905. It turns the plane of polarization

to the left.

The best French lavender oil, distilled from pure flowers only, is

brought into commerce under the name, "Essence de Lavande Montblanc."

It is distinguished from all other kinds, in the preparation of which

more or less stems and leaves are used, by its extremely agreeable odor.

Lavender is also extensively cultivated in Mitchan and Hitchin,

England, and used for the preparation of an especially fine oil, the

odor of which surpasses even that of the best French product. It is,

however, comparatively expensive.

From the leaves and flowers of _lavandula spica_ the _spike oil_ is

obtained by distillation. It is colorless, or yellow, and in odor

approaches rosemary oil more than lavender oil. Its boiling point, like

that of lavender oil, is at 366.8° F., and its specific gravity 0.96.

Spike oil turns the plane of polarization only slightly to the left,

the deviation scarcely ever exceeding 0.8°.

Lavender oils are very sensitive to light and air, they becoming

ozonized under their influence, and acquire an odor like turpentine.

Hence they must be kept in well-closed vessels in a dark place.

Oil of lavender is frequently adulterated, chiefly with alcohol, fat

oils, oil of turpentine, and spike oil. To test the oil, mix a drop

of it with 10 cubic centimeters of warm water, and test the odor,

which should be pure and agreeably lavender-like. The taste of the

vigorously agitated water should be transiently bitter aromatic. One

volume of the oil should give a turbid mixture with one volume of

dilute alcohol (specific gravity 0.895), but a perfectly clear one

with three volumes. On shaking 0.5 cubic centimeter of the oil with a

few grains of rosaniline it remains uncolored, but, in the presence

of even a trace of alcohol, it acquires a red coloration. By mixing

in a graduated cylinder equal volumes of the oil and distilled water,

and shaking vigorously, the oil, after the water has settled, shows

a decrease in volume if alcohol be present. The presence of fat oil

can be readily recognized by bringing a drop of the oil to be tested

upon filtering paper; a grease stain is formed, which disappears

neither at the ordinary temperature nor by heating. Adulteration with

oil of turpentine is recognized by the boiling point, that of oil of

turpentine being 312.8° F., and that of oil of lavender, as previously

stated, 366.8° F.

Spike oil should mix clear with equal parts of 90 per cent. alcohol;

the contrary would indicate adulteration with oil of turpentine.

For perfumery, lavender oil is of great importance, it being much

employed by itself, as well as mixed with other oils.

_Lemon oil_ (_oleum limonis_) is obtained by various processes from the

rinds of lemons. The best and most delicately-scented oil is obtained

by the so-called sponge process in use in Southern Italy and Sicily.

The rinds are soaked from fifteen to twenty-five minutes in water, to

which sometimes a little soda is added. They are taken up singly in the

right hand and the outer surface of each is firmly pressed against a

large and rather hard-grained sponge held in the left hand and secured

by a strap. Two or three sharp turns of the wrist impart what may be

called a screw-pressure to the rind, thus effectually fracturing the

oil cells, the sponge absorbing the contents. The sponge is constantly

held over an earthen jar and occasionally squeezed into it. The fluid

in the jar quickly separates into three different products--the dregs

or deposit of mucilaginous and cellular matter, some fruit juice, and

the pure oil, which floats on the top. The latter, when bright and

clear, is passed, by means of a small glass siphon, into the cans of

thin copper, in which, after sealing, it is stored away for export.

The above described primitive mode of fabrication furnishes the most

highly prized oils of commerce; they are called hand-pressed oils

or _essences preparées a l'éponge_. In the same manner are obtained

the oils from the sweet and bitter pomegranate, the bergamotte, and

mandarin orange.

Another method of expressing the oil is that of the _écuelle à piquer_,

much used in the region about Nice. The oils obtained by this method,

which are also of a very fine quality, are marked _essence à l'écuelle_

or _au zeste_. The apparatus consists of a round shallow pan of copper

or brass, having a receptacle for the oil at its lowest part and a lip

on one side for pouring, and studded on its concavity by strong blunt

spikes. The workman takes the fruit and rolls it gently but quickly

around the inside of the _écuelle_; the spikes prick the oil sacs,

whereupon the oil, running down the spikes and the concavity of the

pan, collects in the reservoir at the lowest part. The oil is filtered

and then poured into clean glass bottles, in which the impurities are

allowed to settle.

In Reggio, where especially much bergamot oil is manufactured,

sheet-metal bowl-like vessels, studded inside with sharp ribs, are

used. Six to eight fruits are placed in the vessel. A movable lid

closes the vessel, so that there is just enough space for the fruits

between the lid and the bottom of the vessel. If now the lid be

revolved by hand-or steam-power, the rinds of the fruit are torn apart,

and the oil together with the juice runs through the sieve-bottom of

the apparatus into a cylindrical vessel where it clarifies.

The third method of obtaining the oil is by _expression_. The grated

rind is placed in hair mats, and subjected to powerful pressure by

means of a screw or lever press.

The process of _distillation_ is carried on as follows: The peels,

which should be from select fruit, are sprinkled with powdered salt,

and a few hours afterwards sufficient water to moisten them is poured

over them. A day or two afterwards more water is added, and the whole

is distilled until either no more oil separates or the steam, at first

purely fragrant, begins to acquire a rank and rather unpleasant smell.

The oil obtained by distillation is inferior to the others.

[Illustration: FIG. 20.]

Lately a combination of the écuelle and distilling processes has been

introduced by Domenico Monfalcone, which has given excellent results.

It is shown in Fig. 20. _F F_ is a hollow cylinder, of sheet-iron,

the interior surface of which is studded with a large number of

small metallic knife-points. This cylinder revolves on two axles

attached to it at diagonally opposite points. The cylinder having been

half-charged with lemons, together with a small quantity of water, is

set in motion by aid of the shafting and pulleys driven by the small

steam engine. The fruits are thereby made to come in contact with the

metallic lancets, and their whole surface gradually becomes punctured

sufficiently to rupture the cells containing the volatile oil, which

escapes. The cylinder _F F_ has double walls, the space between them

being intended for the circulation of a current of steam, which is

admitted to heat the water and to facilitate the extraction of the

oil, while at the same time the vapors are rarefied or aspirated by

the vacuum pump _L_. The axles of the cylinder on both sides are

hollow; that on the side looking towards the engine is imbedded in

such a manner that steam from the boiler _D_ may be admitted at will,

either into the double walls of the cylinder, or into the interior

of the cylinder itself, while the hollow passage in the other axle

communicates with a condensing worm, _G_, the outlet of which, _H_,

descends into a cylindrical vessel, _I_, intended to receive the

condensed products, consisting of water and volatile oil. When the

apparatus is first set in motion the pump _L_ begins to produce a

vacuum during the first revolutions of the cylinder. Steam being now

cautiously admitted into the double walls of the cylinder, the water is

raised to boiling at a comparatively low temperature, and the vapors

charged with the volatile oil pass over into the receptacle, where

they separate into two layers. The product obtained by this process is

claimed to be equal in quality to that obtained by mechanical means,

and the yield nearly double.

During the months of November to March the average yield from 1000

lemons in the factories of Palermo is 320 grammes of oil; in those of

Messina, where a better quality of fruit is employed, the yield is

about 400 grammes. The same number of lemons yield about 10 gallons of

juice, the collection of which is, of course, a necessary accompaniment

of the manufacture of volatile oil.

Pure oil of lemons is almost colorless and has the odor of the fruit.

Its specific gravity varies between 0.8752 and 0.8785; it boils at

298.4° F., and is soluble in all proportions in absolute alcohol and

glacial acetic acid. It contains, according to G. Bouchardat and

J. Lafont, besides a little cymene, several hydrocarbons, the most

abundant of which is citrene, C_{10}H_{16}, boiling near 352.5° F.,

having a rotatory power exceeding +105°, and yielding a solid optically

inactive dihydrochloride.

Oil of lemons is frequently adulterated with oil of turpentine. This

may be detected, according to G. Heppe, by slowly heating the oil in

a dry test-tube with a small piece of copper butyrate to about 338°

F., taking care that the temperature does not exceed 356°F. The copper

salt will dissolve in pure oil of lemons with a green color, while in

the presence of oil of turpentine a yellow turbid mixture is obtained,

reddish-yellow cuprous oxide being separated. This test is also

applicable to oils of bergamot and of orange-peel.

_Lilac oil_ is obtained from the flowers of _Syringa vulgaris_, the

lilac, by aqueous distillation and subsequent extraction with benzine.

It is also frequently prepared by the absorption process. It is used

for the most expensive perfumes, and is seldom found in commerce.

_Limes, oil of_ (_oleum limettæ_), is derived from the rind of the

fruit of _Citrus limetta_, or lime. The oil is obtained in the same

manner as oil of lemons, which it somewhat resembles. Its mean specific

gravity is 0.8734 at 84° F. The oil made by the écuelle process is of a

decidedly yellow color, varying in intensity, being darker in the fresh

product. The difference in flavor and aroma is so marked as scarcely to

require any other means of distinguishing the oil made by the écuelle

process from that obtained by distillation, the first having a decided

fragrant lemon smell, whilst the distilled oil is very inferior,

frequently possessing little more than the smell of turpentine. Large

quantities of oil of limes are manufactured in Dominica, but most of

the oil exported from there is of an inferior quality and was formerly

solely used for adulterating oil of lemons. Lately it has also been

employed for scenting soaps and in the manufacture of the common

essences and perfumes.

_Licari oil, linaloë oil_, is obtained, partially in Mexico and

partially in Cayenne, from the wood of the white cedar (_bois de rose

femelle_), _Licari canali_. It is limpid, has an agreeable odor,

reminding one of roses, and does not become solid at 4° F. Its specific

gravity is 0.868 at 59° F., and it boils at 388.4° F.

_Marjoram oils._--By distilling the leaves of _Origanum marjorana, L._,

the _marjoram oil_ (_oleum marjoranæ_) is obtained. It is yellowish

or green-yellowish, but becomes reddish-brown by age. If badly kept

it finally becomes thickly-fluid and sticky, sometimes depositing a

reddish stearoptene. The odor of marjoram oil is less agreeable than

that of the plant, and the taste peculiar, bitter, cooling. The oil

dissolves readily in 90 per cent. alcohol, and when mixed with equal

parts of it yields a clear solution. Its specific gravity is 0.89 to

0.91. It should be kept in entirely filled, well-closed bottles in a

shady place. On coming in contact with air, it absorbs oxygen with

avidity and forms a white, odorless, crystalline mass.

From _Origanum vulgare, L._, the ordinary marjoram oil (_oleum origani

vulgaris_) is obtained. It is yellowish or reddish, limpid, of specific

gravity 0.90 to 0.95, and has a camphor-like odor.

_Spanish marjoram_ (_oleum origani cretici_) is obtained by

distillation from the flowering plants of several varieties of marjoram

(_Or. creticum_, _Or. hirtum_, _Or. smyrnæum_). It is brought into

commerce from Trieste, Smyrna, Salonica, and other Mediterranean

seaports. The oil exported from France appears to be derived from

another variety of marjoram; at least it shows a different behavior

and approaches more the ordinary marjoram oil. The genuine oil is

thickly-fluid, generally yellow-brown; of specific gravity O.95 to

O.97; has a strong, aromatic odor, and produces upon the tongue a sharp

continued burning. It dissolves in equal parts of 90 per cent. alcohol.

It is chiefly adulterated with copaiba oil, the presence of which can

be recognized by the oil dissolving with greater difficulty.

The marjoram oils are but little used for perfuming purposes.

_Mignonette oil_ (_oleum résédæ_). The well-known mignonette, _Réséda

odoratissima_, yields a thick yellowish oil, either by maceration and

absorption, or by extraction with ether or petroleum-ether. It has a

penetrating, disagreeable odor, which can only be rendered agreeable by

greatly diluting the oil. In gathering the flowers care must be had not

to mix them with leaves, as this spoils the odor of the oil.

_Myrrh oil_ (_oleum myrthæ_) is obtained from the leaves of _Myrtus

communis, L._ It is yellowish, dextrorotatory, of specific gravity

0.910 at 60.8° F., and commences to boil at 320° F. As its principal

constituents, Jahns has established a terpene (C_{10}H_{16}), boiling

at from 316.4° to 320° F., and turning the plane of polarization

to the right, and cineol (C_{10}H_{16}O), which boils at 348.8° F.

Besides these principal constituents there seems to be present a very

small quantity of a camphor, corresponding very likely to the formula

C_{10}H_{16}O. Myrtol, which was formerly supposed to exist in myrtle

oil, has been found to be a mixture of the dextrorotatory terpene and

of cineol.

_Nutmeg oils._--From mace, the fresh aril of the nutmeg (_Myristica

fragrans, Houtt_, natural order _Myristicaceæ_), _mace oil_ (_oleum

macidis_), is obtained by distillation. It is straw-yellow or

yellowish, later on yellow-reddish, clear, somewhat thickly-fluid,

of a strong odor resembling that of mace, and a taste at first mild,

but later on pungent and aromatic. It mixes clear in every proportion

with absolute alcohol, but of 90 per cent. alcohol, 5 to 6 volumes are

required for a clear solution. The specific gravity of the oil varies

from 0.87 to 0.92. With iodine it detonates, vapors being emitted. The

oil obtained from dried mace has a less agreeable odor.

The oil is frequently adulterated with tincture of nutmeg prepared

with absolute alcohol. Such an adulteration, as well as any content of

alcohol, is recognized by shaking 0.5 cubic centimeter of the oil with

a grain of rosaniline. In the presence of alcohol the oil acquires a

red coloration, while pure oil remains uncolored.

From the nutmegs, the seed of _Myristica fragrans_, freed from the

seed-coat and aril, a volatile oil (_oleum nucistæ æthereum_) is also

obtained by distillation. It is generally yellowish, seldom colorless,

somewhat thickly-fluid and has the odor and taste of nutmegs. It is

readily soluble in alcohol and ether and of specific gravity, 0.93 to

0.95. It consists of two oils, one specifically lighter and fluid, and

the other heavy and crystalline. On standing it deposits a stearoptene,

called myristicin.

The nutmeg oils are but seldom used in perfumery.

_Opopanax oil_ is obtained from opopanax.[7] It is of gold-yellow color

and an agreeable balsamic odor reminding one somewhat of myrrh. Its

specific gravity is 0.9016, and it boils between 392° and 572° F.

[7] See later on under "Balsams and Resins."

On account of its strength, the oil must be very carefully handled

in perfuming, but if used in the correct proportion it is very

advantageous.

_Orange-peel oil_, also called _Portugal oil_ or _essence of Portugal_,

is obtained in Italy from the fresh peels of the orange, the fruit of

_Citrus vulgaris, Risso_. It is prepared in a manner similar to that of

oil of lemons (which see). In commerce a distinction is made between

the Messina oil, which is of inferior quality, and the Calabria oil,

which is of a better quality. The Messina oil has a yellow color,

frequently not much darker than that of oil of lemons, while the color

of Calabria oil is dark yellow, nearly brown. The oil prepared from the

peels of the bitter orange (_Citrus bigaradia, Duhamel_), is of the

same color as the sweet Messina oil. It is more used in the preparation

of liqueurs than for perfuming. Orange-peel oils are limpid and have a

specific gravity of 0.819 to 0.9. One part of orange-peel oil should,

according to its age, dissolve clear in 5 to 10 parts of 90 per cent.

alcohol.

Very similar to orange-peel oil, though differing somewhat in odor,

is the _mandarin oil_ obtained from the fresh peels of the mandarin

orange, the fruit of _Citrus sinensis_. It is brought into commerce

from Reggio and is said to form a constituent of the genuine

_ess-bouquet_. It has a specific gravity of 0.852 at 50° F. and is

dextrorotatory.

While from the peels the volatile oil is but seldom obtained by

distillation, this process is exclusively used for gaining volatile

oils from the flowers, leaves, and young branches. In this connection

two kinds of volatile oil have chiefly to be considered, viz:

_orange-flower oil_ and _petit-grain oil_.

_Orange-flower oil_ or _neroli oil_ (_oleum florum aurantii_; _ol.

neroli_; _ol. naphæ_) is obtained by distillation from the flowers of

the bitter orange; while the flowers of the sweet orange yield the

so-called _neroli-Portugal oil_, which is far inferior to the other.

On the French Riviera, the orange is especially cultivated for

obtaining blossoms and leaves for distilling purposes. At Cannes,

Le Cannet, Golfe-Juan, Vallauris, Biot, Vence, Le Bar, Antibes, Le

Cap, Nice, and Mentone, the bitter orange, whose flowers are very

numerous and especially suitable for perfumery, is chiefly cultivated.

Cannes and Le Cannet alone possess 150,000 to 160,000 such trees, and

Golfe-Juan and Vallauris 200,000. The flowers harvested in Golfe-Juan

amount to about 700,000 lbs., in Le Cannet to about 330,000 lbs., at

Cannes to about 130,000 lbs., and in Antibes, Mentone, and Nice to

about 260,000 lbs. One orange tree yields, according to its age, from

2 to 17 lbs. of flowers. The distillation of neroli oil has also been

lately commenced in Sicily and Calabria, but as far as quality is

concerned, the oil thus far brought into commerce cannot compete with

the French oil.

Oil of orange flowers is at first nearly colorless or straw-yellow,

but becomes reddish-yellow when kept for some time. In a clear glass

it opalizes bluish. It is limpid and has a slightly bitter taste and

a strong but very delicious odor. Its specific gravity varies between

0.85 and 0.90. It is but sparingly soluble in water, but imparts to

the latter an agreeable odor; the solution is colored red by sulphuric

acid. With 1 to 2 parts of 90 per cent. alcohol, the oil gives a clear

solution which becomes turbid by a further addition of alcohol and,

after standing quietly, a flaky separation of stearoptene is observed.

If not carefully kept the oil becomes darker and even acquires a

disagreeable odor. By rectification with water oil thus spoiled can

be restored. With sodium the oil does not evolve hydrogen gas; it

detonates with iodine.

Of the various oils of orange blossoms occurring in commerce "_Neroli

petale_" is the best.

Neroli oil being a very expensive oil is exposed to many adulterations.

Mierzinski even asserts that no genuine unadulterated neroli oil occurs

in commerce, because it is a well-known fact that what is sold as

genuine, pure neroli oil, consists on an average of 4/8 genuine neroli

oil, 1/8 oil of bergamot, and 3/8 petit-grain oil. Furthermore, it

is no secret that besides the flowers of all kinds of _Aurantiaceæ_,

unripe fruits or fresh peels of ripe fruits and even young shoots of

the branches and leaves are subjected to distillation. This assertion

perhaps goes too far, but nevertheless it is advisable to procure the

oil only from a thoroughly reliable firm.

A very frequent adulteration consists in an addition of petit-grain

oil. Such an addition can only be recognized by the taste and odor.

For this purpose add to 3 drops of oil in a small bottle 10 grammes

of distilled water, and, after shaking vigorously, test as to the

odor and taste. According to Chevalier, pour 1 or 2 drops of the oil

upon sugar and stir the latter in water; if the oil is not genuine the

water acquires a bitter taste. Hager recommends the following test:

Mix 3 drops of the oil in a test-tube with 40 to 50 drops of alcohol;

add, after complete solution, about ⅓ the volume of the solution of

concentrated sulphuric acid, and effect mixture by careful shaking.

Pure oil gives a turbid, reddish, dark-brown mixture (with old oil,

dark brown); almost all other oils, which may be substituted, give

paler-colored (reddish, red, or ocher-color) mixtures; or, in case the

genuine oil is adulterated with non-genuine, the mixture exhibits a

considerably less dark-color. When this test has been several times

executed with genuine oil, no room for doubt is left. If the mixture be

diluted with four times its volume of water, it becomes yellowish and

milky.

The odor of orange flowers is, according to Soubeiran, due to two

volatile oils, of which the one having the most delicious odor is

soluble in water. The other volatile oil, of which the neroli oil

of commerce chiefly consists, is sparingly soluble in water, and

does not possess such a delicious odor. This is the reason why good

orange-flower water cannot be prepared by saturating water with neroli

oil. The genuine orange-flower water is obtained as a by-product in

distilling the oil.

Neroli oil is much used for the finer perfumes, it being especially

a necessary constituent of _eau de Cologne_. It has to be carefully

protected from air and light. For perfuming purposes it is only

sufficiently ripe after having been stored for at least one year. If,

however, it becomes too old, it inclines towards rancidity, which may

be prevented by compounding it with an equal volume of fine spirit.

Portugal oil being of inferior quality can only be used for lower grade

products.

_Petit grain oil_ (_oleum petit grain_) is obtained by distillation

from the leaves, young shoots and unripe fruits of different

_Aurantiaceæ_. The best oil is that distilled from the leaves of the

bitter orange, it possessing an odor similar to that of neroli oil,

but, of course, not so fine. Southern France was formerly the chief

place for the production of this oil, but considerable quantities of

it are now manufactured in Paraguay, and the oil at present brought

from there into commerce being of quite a good quality and considerably

cheaper than the French oil, has almost entirely supplanted the latter.

_Orris root, oil of_ (_oleum iridis_), is obtained by distillation with

steam from the rhizomes of _Iris florentina_, which is cultivated in

Southern France, Dalmatia, and other regions. It has a yellow color

and, at an ordinary temperature, a quite solid consistency like butter

or wax, so that it can be rendered fluid only by heating. It consists

chiefly of a rigid odorless body to which the liquid odoriferous oil

adheres. The solid portion was formerly designated orris-stearoptene;

according to Flueckiger it is, however, myristic acid.

Oil of orris root is one of the oils which keep for years without

suffering injury. It is recommended to keep it in stock in alcoholic

solution so that the myristic acid contained in it may to a certain

degree be etherized, and cannot injuriously affect the odoriferous

principle.

Oil of orris root serves as a substitute and for strengthening the

natural odor of violets. It can, however, be employed only for very

fine expensive perfumery since, on account of the very slight yield

from the root (from 1000 parts ½ to ¾ part of oil), its price is

very high, generally exceeding that of rose oil.

An admixture of other volatile oils of less value would render the oil

fluid at the ordinary temperature.

_Patchouli oil._--By the name of patchouli are known, according to

L. Wray, Jr., the leaves of _Pogostemon patchouli, Pellet_, natural

order _Labiatæ_, indigenous to the East Indies, and known and used

for centuries in the various regions of China, Assam, and the

Malayan Islands. Most of the patchouli comes from the East Indies.

Before exportation it is sorted into three qualities: 1. _Selected_,

consisting of leaves only. 2. _Mixed_, leaves with slight peduncles

and few stems. 3. _Stalky leaves._ The best quality occurs seldom in

commerce since the picking of the leaves does not cover the expense.

According to Wray, the leaves are intentionally mixed with those of

the _ruku_ (_ocimum basilicum, L._), an herb indigenous to the Malayan

Islands. The leaves of the latter are broader than those of _pogostemon

patchouli_, and the stalks thinner and round. Seed-capsules are also

frequently found among the leaves, though patchouli seldom flowers and

bears seeds.

In Europe, patchouli has been an article of commerce since 1841. In

the Orient it is highly esteemed as a perfume. The Arabs even ascribe

remedial properties to it, and it is customary with them to fill their

pillows with the leaves to protect them from infection and prolong

their lives.

The peculiar, penetrating, though not exactly agreeable, odor of

patchouli leaves, is due to a volatile oil, of which they contain 1.5

to 2 per cent. In the Orient this oil has for many years been obtained

by distillation.

In the Penang market two kinds of oil, one _green_ and the other

_gold-brown_, are distinguished. Though both are sold at the same

price, there is a greater demand for the green oil. According to the

statements of the distillers, the brown oil is derived from the leaves

of old plants and the green oil from the leaves of young plants. It

would seem, however, that the color is dependent on the soil upon which

the plants are grown, as well as upon atmospheric influences. When ruku

is distilled with patchouli leaves, the oil is yellow and thickly-fluid.

In Germany, the oil is now distilled from imported leaves. It is

thickly-fluid, of a brown color, and, in an undiluted state, possesses

a disagreeable, almost musty odor. However, when sufficiently diluted

and suitably mixed with other volatile oils, the odor is far more

agreeable, and for this reason it has for some time played an important

part in the manufacture of perfumery. It has the advantage of being

very yielding and lasting, but, on the other hand, possesses the

disadvantage of not combining with other perfumes, so that its odor is

always perceptible. It should always be used in very small quantities

or much diluted.

In commerce Penang oil and French oil are distinguished, the first

having a specific gravity of 0.959 and the latter of 1.012. When

kept for any length of time the oil deposits patchouli-camphor

(C_{15}H_{28}O) in prismatic crystals of 1.045 specific gravity and

melting at 127 to 129° F. These crystals have a peculiar, very lasting

odor.

Patchouli oil is soluble in equal parts of 90 per cent. alcohol, the

contrary indicating that it is not pure. It is chiefly adulterated with

cedar oil.

_Peppermint oil._--The _Mentha_ family furnishes commerce with three

oils differing essentially from each other--_oil of curled mint_,

_peppermint oil_, _and poley oil_.

_Oil of curled mint_ (_oleum menthæ crispæ_) is separated by

distillation with water from the leaves of _Mentha crispa, Linn._ It

is limpid, yellowish, sometimes greenish; in time it becomes darker

and more thickly-fluid. Its specific gravity varies between 0.890 and

0.965. It has a strong odor of curled mint and a pungent, somewhat

cooling, slightly bitterish taste. It is soluble in all proportions in

90 per cent. alcohol. In commerce a distinction is made between German

and American oil of curled mint, the latter generally containing oil

of turpentine and oil of sassafras. Odor, taste, and the alcohol test

suffice for the determination of the quality of the oil.

Oil of curled mint contains a terpene, C_{10}H_{16}, and a body

isomeric with carvol, the carvol of curled mint, C_{10}H_{14}O. Its

specific gravity, boiling point and chemical properties are the same as

those of the carvol of caraway oil, but it differs from it by its odor

and turning the plane of polarization to the opposite direction. In

conjunction with other volatile oils, oil of curley mint is sometimes

used for perfuming soaps.

_Peppermint oil_ (_oleum menthæ piperitæ_) is obtained from the fresh

flowering peppermint, _Mentha piperita_, natural order _Labiatæ_. In

commerce, German, English, American and Japanese peppermint oils are

distinguished. As regards fineness, the German oil is inferior to

the English and better kinds of American oils, but superior to the

Japanese. The best and most expensive oil is the English so-called

"Mitcham oil of peppermint," which dissolves in 50 parts of 50 per

cent. spirit of wine and possesses a fine, pure taste, it being for

this reason preferred by distillers for the fabrication of liqueurs.

For perfuming purposes, however, the American as well as the German

oils are very suitable. Of American oils that of H. G. Hotchkiss,

L. B. Hotchkiss, Hale & Parshall, and Fritzsche Bros. enjoy a high

reputation. The Japanese oil is distinguished from the rest by a

peculiar train-oil-like odor and taste, and is in but little demand.

Crude oil of peppermint is yellowish to greenish and contains much

mucus; it has therefore to be subjected to another distillation with

water. The rectified oil is clear as water, limpid, of a strong but

pleasant odor and a specific gravity of 0.900 to 0.902. Old oil

thickens and then shows an acid reaction. The greater portion of the

oil congeals at the freezing point of water; many kinds, however,

requiring but slight cooling in order to become solid. The solid

portion of the oil, _Menthol_, (C_{10}H_{12},H_{2}O) is a colorless,

finely crystallized body with an intense odor of peppermint. It melts

at 107.6° F., is quite fluid at an ordinary temperature and boils at

413.6° F. Menthol is found in all oils of peppermint most abundantly in

the Japanese oil, which contains from 50 to 55 per cent. of it. Mitcham

oil is also very rich in menthol, it containing from 40 to 45 per

cent., while the American oil contains only from 20 to 25 per cent.

American, German and English oils of peppermint may be distinguished as

follows: By adding to 5 or 6 drops of the oil, 25 to 30 drops of pure

white concentrated sulphuric acid, _American oil of peppermint_ becomes

heated and emits vapors, the mixture acquiring a dark brownish red

coloration. After mixing with 8 to 10 cubic centimeters of 90 per cent.

alcohol, the fluid becomes turbid, pale yellowish brown, or reddish

brown, and on boiling clear pale brown. When mixed with sulphuric acid,

_German oil of peppermint_ becomes heated without emitting vapors,

becomes yellowish red, not very dark, and turbid. After diluting with

alcohol, the fluid becomes turbid and yellowish red, and on boiling

somewhat more transparent and currant-red. _English oil of peppermint_

treated in the same manner as the others with sulphuric acid becomes

very slightly heated without any emission of vapor. After diluting with

alcohol, it becomes clear and raspberry red.

As adulterants of peppermint oil are mentioned: fat oils, alcohol,

oil of turpentine, copaiba oil, mustard oil, and ginger oil. The most

frequent adulteration is an admixture of oil of turpentine. It is

recognized by the oil not dissolving clear in equal parts of 90 per

cent. alcohol, as is the case with the pure product. To detect the

presence of copaiba oil, mix 5 drops of the oil to be tested with 15 to

20 drops of fuming nitric acid, shake and allow it to stand for 1 to 2

hours. After this time the oily portion should be neither entirely nor

partially congealed, but remain fluid. To detect traces of mustard oil,

bring 10 drops of the oil into a wide reagent glass, then add 3 to 4

cubic centimeters of absolute alcohol, 2 to 3 drops of silver nitrate

solution and 12 to 15 drops of ammonia. The mixture is clear and

colorless, and remains so on heating to boiling. In the presence of

mustard oil turbidity and blackening take place in consequence of the

formation of silver sulphide. After boiling, allow the fluid to stand

quietly for 2 or 3 hours. If it then shows a grayish turbidity, the oil

is adulterated with another volatile oil.

Instead of pure American oil of peppermint, a product compounded

with camphor oil, and mostly freed from menthol, is said frequently

to occur in commerce. According to E. C. Federer, this is recognized

by dissolving one volume of oil of peppermint in 2 volumes of 94 per

cent. alcohol, adding water and shaking. Pure peppermint oil is then

separated with a certain portion of the alcohol. For example, mix 10

cubic centimeters of oil of peppermint in a graduated cylinder of 45

to 50 cubic centimeters' capacity with 20 cubic centimeters of 94 per

cent. alcohol, then add 10 cubic centimeters of water of 50° F. and

shake. After allowing the mixture to stand quietly, two layers are

formed, the upper one of which, if the oil is pure, will amount to 14

cubic centimeters, but only to 12.5 cubic centimeters if the oil is

freed from menthol and compounded with camphor oil. A larger or smaller

addition of water to the alcoholic mixture is without influence upon

the height of the upper layer separated.

In perfumery peppermint oil serves chiefly for aromatizing dentifrices,

etc. It should be kept in well-closed bottles in a shady place; an

addition of 0.5 per cent. of alcohol helps to preserve the oil for a

long time.

_Poley oil_ (_oleum menthæ pulegii_).--In Southern France and Spain

this oil is obtained by distillation from the leaves of _Mentha

pulegium_. It has an odor resembling that of peppermint, is at first

colorless, but soon becomes yellow, has a specific gravity of 0.927,

boils at 361.4° to 370.4° F., and contains neither menthol nor carvol.

It is used for perfuming herb soaps.

_Pimento oil_, or _oil of allspice_ (_oleum pimenta_) from the bruised

fruit of _Eugenia pimenta_, allspice, natural order _Myrtaceæ_. The oil

is pale yellow, becoming reddish-brown by age; it has a very pungent

taste and intense odor, very much resembling that of cloves. It is

heavier than water, its specific gravity being from 1.021 to 1.037.

It mixes with glacial acetic acid in all proportions. When treated

with nitric acid, pure pimento oil assumes a red color, with strong

effervescence.

_Rose oil_ or _attar of roses_ (_oleum rosæ_) comes almost exclusively

from Bulgaria, where it is obtained by distillation with water

from the flowers of _Rosa damascena_. The small quantities of an

excellent quality of rose oil prepared in Southern France from _Rosa

provincialis_ remain in the country of their production and do not

even cover the local demand. The small productions of Persia and India

need also not be taken into consideration. In Tunis, where formerly

much rose water was prepared from _Rosa canina_ and also rose oil

of a very fine quality, the distillation of roses has, according to

Christo Christoff, been entirely abandoned, geranium oil only being now

produced. In the summer of 1884, Schimmel & Co., of Leipzic, Germany,

made the experiment to obtain oil on a large scale from indigenous

roses. The result was very satisfactory, 2000 lbs. of rose leaves

yielding about 1 lb. of oil, the extraordinarily agreeable odor of

which was so superior to that of the Turkish oil, that notwithstanding

the high price--double that of Turkish oil--it found ready purchasers.

At the ordinary temperature the Leipzic oil is solid, it only melting

at 89.6° F.

In Bulgaria, Kazanlik, in the Tundscha Valley, is the centre of the

entire industry and the principal market. Rose oil is there called

"_gul-jag_" (_gul_, the rose, and _jag_, oil). The annual production of

Kazanlik and neighboring places, amounting 50 years ago to from 450 to

650 lbs., has within a few years risen to the enormous figure of 5500

lbs.

In Kazanlik two varieties of roses, known as the "white rose" and "red

rose," are cultivated; the former being _Rosa alba, L._, and the latter

_Rosa damascena, Miller_. By distillation the white rose yields an oil

of little perfume, but rich in stearoptene. On account of its slight

odor, the white rose is seldom distilled by itself, but occasionally

white and red roses are mixed in order to obtain an oil rich in

stearoptene, so that a fraudulent admixture of a larger quantity of

geranium oil may be effected without great danger of detection. The

large plantations consist only of bushes of red roses. But on the edges

of the field a strip, a few feet wide, is planted with white roses,

so that only flowers of little commercial value may be plucked by

passers-by.

The flowers are gathered before sunrise, and, if possible, the same

day subjected to distillation. The latter is effected in a very crude

apparatus, over a direct fire. The flowers are distilled with double

their weight of water, one-half of which is drawn off. The product

of several operations thus obtained is combined and again distilled,

when, however, only one-sixth is drawn off. This distillate is allowed

to stand for one or two days in a place warmer than 59° F., when the

oil floating on the top is skimmed off. It may be supposed that on an

average 6600 lbs. of roses are required to obtain 2.2 lbs. of oil, and

that these 6600 lbs. of roses correspond to an area of 1 hectare (2.471

acres) planted with rose bushes.

Pure, carefully-distilled rose oil is at first colorless, but soon

turns yellowish.[8] Its specific gravity is between 0.830 and 0.890.

It consists of a liquid oil and a stearoptene, the content of the

latter varying very much. It is a pure hydrocarbon, odorless, of

specific gravity, 0.840 to 0.860, and distils at 572° F. Hence it is

lighter than the elæoptene on which alone the odor of the rose oil is

dependent. Rose oil generally congeals between 50° and 60° F., though

sometimes at a higher or lower degree, according to its content of

stearoptene. While some oils require the cold of winter for congealing,

others are in the heat of summer either entirely solid, or form a

fluid filled with many crystals. The odor of rose oil is peculiarly

honey-like, and too intense to be agreeable, its entire deliciousness

being only developed by strong dilution, be it by dissolving in water

or alcohol, or by distribution upon large quantities of rigid bodies,

fats, soaps, etc. In alcohol it dissolves with greater difficulty than

all other volatile oils, 1 part of it requiring for solution 140 to 160

parts of alcohol of 0.815 specific gravity.

[8] This, however, applies only to Bulgarian oil; French and Saxon

rose oils have a greenish color.

The larger or smaller content of stearoptene in rose oil seems to be

dependent on climatic conditions, it having been remarked that the

quantity is the greater the lower the temperature of the region. The

oil from the coldest and highest regions of the Balkan is richer in

stearoptene than that from the lower and warmer regions.

The genuineness of rose oil is generally judged by its odor, its

capacity of congealing, and the manner of its crystallization. The

odor is by all means the most reliable criterion, but requires

much experience, and especially reliable pure standard samples for

comparison. The capacity of congealing at certain conditions of

temperature, is, to be sure, also a requirement of genuine rose oil,

but, as previously mentioned, this property varies very much, and is

subject to different influences, so that a fixed standard at which pure

rose oil must congeal cannot be established. Attention must, however,

be called to the fact that the quality of a rose oil does by no means

rise with its greater capacity to congeal, since only the liquid

oxygenated portion possesses odor.

Schimmel & Co. bring at present into commerce a liquid rose oil freed

from stearoptene which can be highly recommended for finer alcoholic

perfumes. It remains fluid at 32° F., but in a cold mixture congeals to

a gelatinous mass, and hence is not absolutely free from stearoptene.

It has an extremely fine and powerful odor, and when dissolved in

alcohol does not give the disagreeable crystalline separations of the

ordinary rose oil, which produce a disturbing effect, especially in the

preparation of extracts.

For the insulation and determination of the stearoptene in rose oil,

Schimmel & Co. proceed as follows: Heat 50 grammes of oil together

with 500 grammes of 75 per cent. alcohol to from 158° to 176° F. In

cooling, the stearoptene separates nearly quantitatively. Separate it

from the fluid, treat it again in the same manner with 200 grammes of

75 per cent. alcohol, and repeat the operation until the stearoptene is

entirely free from odor. Two treatments of the crude stearoptene are

generally sufficient. In this manner Schimmel & Co. obtained from 1887

German rose oil 32½ per cent. stearoptene, from 1888 German rose oil 34

per cent., from 1887 Turkish rose oil 12 to 13 per cent., and from 1888

Turkish rose oil 14 per cent.

It is evident that such a valuable product as rose oil is much

subjected to adulteration, it being even said that oils containing

scarcely 10 per cent. of genuine rose oil occur in the market. The

chief adulterant used by the Bulgarians is the so-called geranium oil,

but actually ginger-grass oil derived from India, which is brought

by way of Arabia to Constantinople, and prepared for the purpose of

adulterating rose oil by treatment with lemon juice and bleaching in

the sun. The sophistication is generally effected by sprinkling the

ginger-grass oil thus prepared upon the rose leaves before distilling.

The general characters of this oil are so similar to those of rose oil

that detection, when the adulteration is kept within certain limits,

is very difficult, so that during the distilling time large buyers and

exporters of rose oil are forced to pay, besides their other officers

in Kazanlik, confidential native agents who constantly move around in

the distilling regions and report where distillation has been carried

on honestly, and where the ginger-grass oil bottle has been seen.

However, the prepared ginger-grass oil is frequently not even distilled

with the rose leaves, but simply mixed with the finished rose oil.

Whether a rose oil is free from geranium or ginger-grass oil is tested

in Bulgaria, according to Christo Christoff, by the freezing method,

which is, however, unreliable. It is based upon the fact that an

addition of geranium oil reduces the congealing point of rose oil. Pure

Bulgarian rose oil congeals at from 63.5° to 68° F.; by the addition

of geranium oil, the same oil congeals at 61.25°, 59°, 56.75°, or at

a still lower temperature, according to the quantity added. The buyer

when purchasing oil carries with him two basins, one containing hot

and the other cold water, which he mixes in order to obtain a fixed

temperature, the operation being controlled by a Réaumur thermometer.

In the water thus prepared he completely submerges a 20 gramme flask

containing 15 grammes of the oil to be tested. In three minutes,

needle-like crystals of the separating stearoptene must appear, and

in ten minutes crystallization must be complete. According to the

congealing point thus established, the product is paid for. Oil

congealing below 59° F. being evidently adulterated is rejected and

bargained for at a special price.

Many attempts have been made to fraudulently make this congelation

appear within the limits of temperature permitted, paraffine which

dissolves well in rose oil being formerly frequently added. In such

case the oil may congeal at from 65.75° to 68° F., but the crystals are

opaque, dirty yellow, and dissolve to a turbid paste which collects on

the surface. The simplest method is to distil white roses with the red.

The resulting product has not as fine an odor as that from red roses

alone, but is richer in stearoptene. Such oil, which, unadulterated,

congeals perhaps at 68° F., can by the addition of geranium oil be

reduced to from 63.5° to 65.75° F., thus keeping within the limits

permitted.

Numerous attempts have been made to find a rapid and sure way for the

detection of geranium oil in rose oil, but thus far in vain. Attention

must also be drawn to the fact that the adulterant is frequently itself

adulterated with oil of turpentine before being sold to the distillers

of rose oil.

Besides the above-mentioned ginger-grass oil, the actual geranium oils

from _Pelargonium odoratissimum_ and _P. roseum_, as well as rosewood

oil, sandal-wood oil, spermaceti, paraffine, and fat oils have been

mentioned as adulterants of rose oil. The geranium oils having a

by-odor of lemon oil, by which their presence could be readily detected

are not suitable for the purpose. Neither can rosewood or sandal-wood

oils be used, or at least such adulteration would be so clumsy as to be

immediately recognized. Attempts to adulterate rose oil by the addition

of a fat crystallizable body together with another volatile oil fail

on account of the characteristic properties of rose oil stearoptene,

which resembles no other body at present known. While rose oil

stearoptene is lighter than elæoptene and entirely volatile, spermaceti

possesses essentially different qualities. It does not form such long

and specifically light crystals as rose oil stearoptene; hence it

readily separates on the bottom and on shaking exhibits a peculiar

iridescent loamy formation. Furthermore it melts at 122° F., and not

being volatile, leaves, on heating, a greasy stain upon paper, while

the stearoptene melts at 95° F. and, on heating, volatilizes completely

without leaving a greasy stain behind.

If a rose oil is to be tested, expose the bottle containing the oil to

a moderate heat until the contents are entirely liquid; then gently

shake the bottle in order to bring about an intimate mixture of

elæoptene and stearoptene. Now pour some of the oil into a cylindrical

glass flask of 20 to 40 cubic centimeters' capacity and allow it

to congeal; then, while heating in the hand, observe how the rigid

portions act in liquefying. These rigid, crystalline portions should

be transparently clear and, being lighter than the fluid portion,

float, while liquefying, in the upper layer of the fluid. Hence, if

now the fluid be again allowed to congeal, the crystals should appear

within the upper half of the oil. The above-mentioned volatile oils

partially lack the property of separating a stearoptene in crystals at

from 33.8° to 50° F., and though they may have a rose odor, it is not

the mild, fragrant odor of genuine rose oil. To recognize the latter,

Guibourt makes use of pure concentrated sulphuric acid. Stir together

in a watch-crystal an equal number of drops of the oil and of the acid;

pure rose oil preserves its characteristic odor, while the foreign oils

exhibit a disagreeable odor even when mixed with genuine rose oil.

Schimmel & Co. give a method for an approximate quantitative

determination of spermaceti in rose oil: Boil 3 to 5 grammes of

stearoptene, separated in the manner above given, with 20 to 25 grammes

of 5 per cent. alcoholic potash lye for 5 to 6 hours; then evaporate

the alcohol and compound the residue with hot water. In cooling, the

greater portion of the stearoptene separates in a crystalline mass upon

the surface. Now pour off the alkaline fluid, wash the stearoptene

with cold water, then melt it again in hot water, allow it to cool,

pour off the water, and repeat the same operations until the wash-water

is neutral. The combined aqueous fluids are twice shaken with ether to

remove any stearoptene suspended in them. The alcoholic lye separated

from the ether is acidulated with dilute sulphuric acid and again

extracted with ether. After evaporation no residue (fatty acids) should

remain. To control the experiment weigh the regained stearoptene dried

at 194° F., adding, of course, the ether used for extracting the

alkaline fluid. There will be a small loss, since small quantities of

stearoptene always evaporate in drying.

_Rosemary oil_ (_oleum rosemarini_ or _ol. anthos_) is obtained in

Southern Europe, especially in Southern France, Dalmatia and Northern

Italy, by distillation from the flowering rosemary, _Rosmarinus

officinalis_, natural order _Labiatæ_. It is, when fresh, limpid,

colorless, or yellowish, of a penetrating, camphor-like odor and taste,

and specific gravity 0.880 to 0.915. By age it becomes darker and

thickly-fluid. The French rosemary oil is the best and most expensive.

It is distinguished from the Italian oil by its much more pleasant

odor. Pure French rosemary oil dissolves in an equal part of 90 per

cent. alcohol, while the Italian product requires 2 to 3 parts. The

cheaper rosemary oils are generally adulterated with oil of turpentine,

which is recognized by the oil not dissolving in the above-mentioned

proportion in alcohol, as well as by the iodine test. Rosemary oil does

not detonate with iodine, but simply dissolves with heating and perhaps

the emission of vapors.

The French rosemary oil forms one of the ingredients of _eau de

Cologne_ and is used in other perfumery.

_Rosewood oil or rhodium oil_ (_oleum ligni rhodii_), is obtained by

distillation from the wood of the root and lower trunk of _Convolvulus

scopiarius_ and _C. floridas, L._, two plants indigenous to the

Canaries. The waste falling off in the manufacture of rosewood beads

is chiefly used for the purpose. The oil is of a pale yellow color

becoming brown by age. It has a pleasant odor resembling in some

slight degree the fragrance of the rose. It is sometimes used in cheap

perfumery as a substitute for rose oil.

_Sandal-wood oil_ (_oleum ligni sandali_) is distilled from the

white West Indian or dark yellow East Indian sandal-wood (_Santalum

myrtifolium_). For the purpose of distillation the wood is rasped as

finely as possible. The oil obtained from the East Indian wood is the

better and more valuable. It has a dark yellow to brown color and a

pleasant intense, rose-like odor, while the West Indian oil is pale

yellow and of a less agreeable odor. Both oils are very thickly-fluid.

The quality and value of sandal-wood oil are best judged by the odor,

an adulteration with cedar oil being readily detected thereby.

_Sassafras oil_ (_oleum ligni sassafras_), from the bruised root of

the sassafras tree, _Sassafras officinale_, natural order _Lauraceæ_.

Sassafras is one of the most widely distributed trees of North America,

being found in Canada, in all of the United States, east of the

prairies, beyond the Mississippi, and in Mexico. The largest amount of

oil distilled is within sixty miles of Baltimore, Md., which is the

principal depot for its commerce.

Oil of sassafras varies in color from colorless to yellow and red.

Its taste is pungent and aromatic, being agreeable to most persons.

It has a pleasant odor resembling that of fennel, and is heavier than

water, its specific gravity being 1.08 to 1.09. It is soluble in 4 to 5

parts of alcohol of 0.85 specific gravity, and consists of a mixture of

various oils, among which is safrene (C_{10}H_{16}), a dextrorotatory

terpene which boils between 311° and 314.6° F. By strongly cooling in

a cold mixture, safrol, a crystallizing stearoptene of the composition

C_{10}H_{10}O_{2}, is separated. Safrol is the chief constituent of

sassafras oil. It is obtained in abundance by cooling, at a temperature

of 13° F., the portion boiling between 442.4° and 455° F. It melts at

46.4° F., and at a medium temperature forms a colorless clear oil of

pungent taste, characteristic odor, and specific gravity 1.104. When

the crystals have been heated to above 158° F., they congeal only after

remaining for weeks at a temperature below 32° F., but on being melted

at 68° F., the fluid mass again congeals readily on cooling. The safrol

is neutral, optically inactive, boils at 449.6° F., and is soluble in

alcohol and ether. Sassafras oil is said to be frequently adulterated

with oil of turpentine, which is, however, readily detected by the

energetic reaction and by distilling a sample of the suspected oil.

Safrol is very suitable for perfuming ordinary soaps. It has in a

still higher degree than camphor oil the property of removing the

disagreeable odor of some fats, while at the same time it imparts to

the soaps an aromatic, refreshing odor. As a rule 8 to 11 ozs. are

used for 220 lbs. of soap; but if it shall at the same time serve for

removing the disagreeable odor of low quality fats, especially those

extracted with bisulphide of carbon or benzine, it is advisable to

take 2.2 lbs., or still better, 4.4 lbs. for 220 lbs. of soap. In this

case the safrol should be added to the fat after melting and before

saponification and thoroughly mixed with it by stirring. An excellent

perfume for ordinary soaps is a mixture of safrol and citronella oil,

it being at any rate preferable to oil of mirbane.

The standard of value for safrol is its specific gravity, which should

not be below 1.104 at 59° F. Specifically lighter kinds contain camphor

oil and other impurities.

_Thyme oil_ is obtained in Southern France and Spain by distillation

from the flowering thyme, _Thymus vulgaris, L._ It is greenish-yellow

to red (red thyme oil, _oleum thymi rubrum_), but by rectification

becomes colorless (white thyme oil, _oleum thymi album_). Both oils

are quite limpid and possess a strong thyme odor. The specific gravity

of the red oil is 0.91 to 0.94, and that of the rectified oil 0.87

to 0.89. The oil prepared from the fresh plant shows, as a rule, a

higher specific gravity than that from the dried plant. Thyme oil

consists essentially of thymene (C_{10}H_{16}) besides some cymene

(C_{10}H_{14}) and thymol (C_{10}H_{14}O), the latter forming an

essential constitutent of the oil. Oils from which the thymol has

been withdrawn occur in commerce. Pure thyme oil dissolves clear in

every proportion in 90 per cent. alcohol; if such is not the case,

adulteration with oil of turpentine is probable.

The oil distilled from the field thyme, _Thymus serpyllum, L._, is

limpid, yellowish to gold yellow, and of specific gravity 0.89 to 0.91.

Old oil is red or brown and no longer limpid. Good oil is soluble in

every proportion in 90 per cent. alcohol and emits only slight vapors

when brought in contact with iodine. It consists largely of thymene and

cymene, and contains a few per cent. of phenol-like bodies.

_Turpentine, oil of._--Under the general name "oil of turpentine" are

comprised the volatile oils obtained by distillation from the resins

or other portions of different species of the pine. There is a large

number of these oils, the most important ones of which shall here be

mentioned, though but a few are of interest to the perfumer.

_Austrian oil of turpentine_, from _Pinus laricio, Poir_.--It is

colorless or yellowish, transparent; specific gravity, 0.864; boiling

point, 311° to 314° F.; turns polarized light to the left; soluble in 6

parts 90 per cent. alcohol. When rectified it has a specific gravity of

0.862, and is soluble in 7 parts of 90 per cent. alcohol.

_German oil of turpentine_, from _Pinus sylvestris_, _P. abies_, _P.

vulgaris_, _P. picea_, and _P. rotundata_, resembles the former;

specific gravity, 0.860 to 0.870; boiling point, 311° to 320° F.; turns

polarized light to the left. When rectified it is soluble in 7 parts of

90 per cent. alcohol.

_French oil of turpentine_, from French turpentine of _Pinus

maritima_.--It is colorless or faint yellowish; specific gravity,

0.860; boiling point, 313° to 315° F.; turns polarized light to the

left; odor peculiar; taste burning. With 7 parts of 90 per cent.

alcohol it gives a clear solution.

_Venetian oil of turpentine_, from Venice turpentine of _Larix decidua,

Mill._, is laevorotatory and resembles the preceding, but has a more

agreeable odor. Venice turpentine is mostly obtained in Southern Tyrol

and in Piedmont, and yields 18 to 25 per cent. of oil.

_American oil of turpentine_, from American turpentine of _Pinus

australis, Mich._, and _P. Taeda, L._--It resembles French turpentine,

but turns polarized light to the right. Specific gravity, 0.864;

boiling point, 302° to 312.8° F.

_Pine oil_ (_oleum abietis_) is obtained by distilling with water the

leaves or green cones of _Pinus picea, L._, _Abies pectinata, D. C._

Its odor is much finer than that of ordinary oil of turpentine. It is

soluble in 7 parts of 90 per cent. alcohol.

_Dwarf pine oil, Krummholz or Latschenoel_ (_oleum pini pumilionis_),

is obtained by distilling the young tops and cones of _Pinus

pumilio_ with water. It has an agreeable odor, reminding one of

juniper; specific gravity, 0.865; boiling point, 338° F. The oil is

laevorotatory and soluble in 12 to 15 parts of 90 per cent. alcohol.

_Pine-leaf oil_ is obtained by distilling the leaves of _Pinus

sylvestris_ or _P. abies_ by means of steam. It is dextrorotatory; has

a fine aromatic odor; boiling point, 320° F.; specific gravity, 0.875

to 0.876.

_Templin oil_ (_Kienoel_) (_oleum pini_, _ol. templinum_) is obtained

chiefly in some sections of Switzerland and Tyrol by distilling the

wood, branches, leaves, cones, etc., with water. It has a lemon-like

odor; specific gravity, 0.860 to 0.880; boiling point, 320° to 327° F.,

and is laevorotatory.

_Balsam-pine oil_ (_oleum abietis canadensis_) is obtained in Canada

from the branches of _Abies balsamea, D. C._ It has a slightly

yellowish color, a very agreeable and refreshing odor; specific

gravity, 0.902; boiling point at 320° to 330.8° F., and turns

polarized light to the right.

Of the different varieties of oil of turpentine mentioned only pine oil

and dwarf pine oil are used in perfumery.

Oils of turpentine must be kept carefully protected from light and air.

When badly kept they gradually become resinous with formation of formic

and acetic acids. When exposed to the air oil of turpentine absorbs

ozone; with iodine it detonates violently. When brought in contact with

a mixture of concentrated sulphuric acid and nitric acid it ignites.

_Verbena, oil of_, from the lemon verbena, _Aloysia citriodora,

Hooker_. The plant is cultivated in the gardens of Grasse. The oil is

extracted from the leaves by distillation in August, but on account of

its high price is almost out of market, it being everywhere substituted

by the oil of lemon grass, _Andropogon citratus_.

_Violet, oil of._--The perfume of the violet, _Viola odorata_, natural

order _Violaceæ_, is due to a volatile oil of a green color and of such

a penetrating odor as to cause headache; it acquires the agreeable odor

of the violet only by strong dilution. The violet farms from whence the

flowers are procured for the production of the oil, are very extensive

at Nice and in the neighborhood of Florence. The oil is only obtained

by the absorption process, all other methods to procure it having

failed up to this time. It is scarcely obtainable in commerce, as the

French manufacturers, who prepare the greater part of it, use the very

small yield for manufacturing fine perfumery.

_Vitivert or vetiver oil_ (_oleum iva ranchusa_) from the so-called

cuscus, the rhizome of an Indian grass, _Anathereum muricatum_. The

oil is obtained by distillation, either from the fresh root in India,

or from the imported dried root in Europe. The yield is very small.

The oil is thickly-fluid, of a red-brown color, and has an intense,

but agreeable odor very much like that of oil of orris root. Like the

latter, it possesses the valuable property of diffusing a lasting

perfume. Its value can only be judged by the odor, and hence it should

only be purchased from a thoroughly reliable firm.

_Wintergreen oil_ (_oleum gaultheriæ_) is obtained by distillation

from the wintergreen, _Gaultheria procumbens_, a plant common in North

America. It is thickly fluid, yellowish green to gold yellow, of a

sweetish, aromatic, pungent taste and penetrating, narcotic odor, which

becomes agreeable only by strongly diluting the oil. By rectification

the oil becomes entirely colorless. Its specific gravity is 1.170 to

1.190 (according to Gladstone, 1.142). It is sparingly soluble in

water, but readily so in alcohol, ether, chloroform, etc. The aqueous

or dilute alcoholic solution is colored deep violet by ferric chloride.

Wintergreen oil boils at 392° F.; the boiling point, however, soon

rises to 431.6° F., when it remains constant. Between 392° and 428° F.

a terpene (C_{10}H_{16}) constituting about 1/10 of the oil distils

off; the rest corresponds to the composition C_{8}H_{8}O_{3}; it is

methyl salicylate

= C_{6}H_{4} {OH

{CO.OCH_{3}.

Wintergreen oil is also obtained by distillation from _Gaultheria

punctata_ and _Gaultheria leucocarpa_. An oil, very closely resembling

wintergreen oil, is in this country distilled from the young shoots of

the American species of birch, _Betula lenta_, variously called sweet

birch, black birch, cherry birch, and mountain mahogany. According

to Procter, the oil does not exist in the birch but is formed by the

action of the water upon an odorless body, called gaultherin, which

is converted into volatile oil by the reaction of another substance

analogous to emulsin. Hence the formation of oil is similar to that

of oil of bitter almonds. To obtain the oil from _Betula lenta_,

the material is chopped up and placed in the still, as much as this

will hold, a sufficient quantity of water being then added to fill

the still about one-third full. The still is generally permitted to

remain in this condition over night, a fire is made in the morning

and distillation proceeds nicely. The manufacture of birch oil is

carried on at quite a large scale by Mr. A. H. Seidle, of Middleport,

Schuylkill County, Pa.

Methyl salicylate may also be artificially prepared by heating a

mixture of methyl alcohol, sulphuric acid and salicylic acid whereby

at first methyl-sulphuric acid is formed which is then converted into

methyl ether and sulphuric acid:--

{OH {OCH_{3}

SO_{2}{ + CH_{3}OH = SO_{2}{ + H_{2}O

{OH {OH

{OCH_{3} {OH

SO_{2}{ + C_{6}H_{4}{ =

{OH {COOH

{OH {OH

C_{6}H_{4}{ + SO_{2}{

{CO.OCH_{3} {OH.

Etherification succeeds without difficulty, it being sufficient to

heat the mixture for some time and then pour it into water whereby

the ether separates as a heavy layer of oil. After washing with water

distil in a direct current of steam. The ether thus obtained is as

clear as water and, as regards its other properties, does not differ

from the naturally occurring oil. This artificial wintergreen oil is

now much used for perfuming purposes.

Wintergreen oil is said to be frequently adulterated with sassafras oil

which is also specifically heavier than water. If, according to Hayer,

5 drops of the oil in a test-tube be mixed with 10 drops of crude

concentrated nitric acid, a deep blood-red fluid results in one minute

if oil of sassafras is present. In the course of another minute, the

fluid separates a brown resinous mass. Pure oil, on the other hand, is

but little altered.

According to P. MacEwan the adulteration of wintergreen oil with

camphor oil is carried on at a large scale. The presence of camphor

oil may be recognized by the specific gravity, 0.900, while that of

pure wintergreen oil is, on an average, 1.18. A crude test--which is,

however, readily executed--is as follows: Stir a few drops of the

suspected oil in water. If pure, the oil in a few seconds sinks to the

bottom, but if it contains camphor oil several minutes elapse before it

deposits, and there is time to observe that the particles of oil assume

different forms, but not a globular one.

_Ylang-Ylang oil_ (_oleum unonæ_) is obtained by distilling the flowers

of _Unona odoratissima_, indigenous to the Philippine Islands, the

Straits of Malacca, and Indian Archipelago. The oil is colorless to

yellowish. Its color and specific gravity, however vary very much,

according to the season of the year in which it is prepared, the oil

distilled in the cold season being more colorless and limpid than that

produced in the warm season. The oil has an exquisite odor, partaking

of the jasmine and the lilac, and is used in the manufacture of the

finest perfumery. Various kinds are found in commerce, that marked

"Sartorius" being preferred.

The difference in quality of the many kinds of oil found in commerce

is chiefly due to the method of preparation and the selection of the

flowers, which possess the finest aroma when freshly gathered. In

distilling, the first light volatile portions passing over have an

incomparable perfume, while the oil distilling over later on possesses

an insipid odor. Hence the manufacturer, who only obtains the first

portions, will furnish the finest quality of oil, and it is this

method of preparation which has gained the "Sartorius" oil its high

reputation. While according to Schimmel & Co.'s report, 220 lbs. of

fresh ylang-ylang flowers yield 2.64 lbs. of oil, Sartorius for the

preparation of his fine oil distils off only about half the quantity.

_Conanga oil_ is a poorer quality of ylang-ylang oil, obtained from

the same plant. Two varieties are distinguished in commerce, viz: the

_Javanese_ and _Indian_. The Java oil is the best, and may be used

where ordinary qualities of ylang-ylang oil will do. According to

Schimmel & Co.'s report the cheaper Indian oil is very resistant and

durable in soaps, especially when combined with licari or linaloë oil.

CHAPTER V.

RESINS AND BALSAMS.

The term _resins_ is applied to certain organic substances which are

very closely related to volatile oils, in so far as many of them are

formed from the latter by oxidation. As previously mentioned, by

exposure to the atmospheric air all volatile oils undergo a change,

whereby they thicken and are finally converted into substances

possessing the character of resins. In nature most resins also occur

mixed with volatile oils.

The elementary constituents of resins are carbon, hydrogen, and oxygen;

but, generally speaking, they are poor in oxygen and rich in carbon.

Chemically they behave like weak acids, their solutions frequently

reddening litmus and sometimes expelling, on boiling, the carbonic acid

from alkaline carbonates.

Independent of a possible content of volatile oil, every naturally

occurring resin consists of several resins which, however, can, as a

rule, be separated only with difficulty.

The resins are generally divided into _hard resins_, _soft resins_

or _balsams_, and _gum-resins_. The hard resins are, at the ordinary

temperature, solid, hard, and brittle, can be readily pulverized, and

contain little or no volatile oil. The soft resins or balsams are

kneadable, and sometimes even semi-fluid; they represent solutions of

resins in volatile oils, or a mixture of volatile oil and resin. On

exposure to the air they are changed by the volatile oil suffering

oxidation, they becoming then more or less hard, and may be converted

into actual resins. The gum-resins are mixtures of vegetable gum,

resin, and volatile oils, and are obtained by inspissation of the milky

juice of several plants. When triturated with water they yield a milky,

turbid fluid, and dissolve only partially in alcohol.

The resins are widely diffused in the vegetable kingdom, there

being scarcely a plant which does not contain resin in one form or

another. Some families of plants and organs of plants are, however,

distinguished by their special wealth of resins. The resins are, as a

rule, secreted simultaneously with volatile oils in special reservoirs,

from which they flow out naturally at certain periods, or are obtained

by incisions made in the plants. A few bodies of the character of

resins also occur in the animal kingdom, and a series of them, the

fossil resins, are generally classed in the mineral kingdom, though

most of them are very likely derived from plants. Some resins, such as

the aldehyde resins, etc., are purely artificial products.

Of the hard resins, benzoin alone is used in perfumery; of the balsams,

Peru balsam, Tolu balsam, and storax balsam; and of the gum-resins, the

myrrh.

_Benzoin_ is exclusively obtained from _Styrax benzoïn, Dryand_

(_Benzoïne officinale, Hayne_), a tree which grows in Java, Sumatra,

and Siam. The bark of the tree is slit to allow a fluid to flow out,

which concretes on the trunk in the form of grains, or is collected

in vessels in which it congeals and assumes the form of lumps

("tampangs"). Older trees which have been frequently tapped for resin

yield a product of a lower quality; the grains ("tears") forming, as a

rule, the better varieties. When the benzoin collects in large masses

it always shows an amygdaloid structure, the grains ("almonds") of a

roundish form, smooth termination, homogeneous structure, and paler

color, appearing imbedded in a dark, porous, or resiniform mass.

According to the appearance of the product three varieties are

distinguished: Benzoin in tears (_B. in lacrimis_), _amygdaloid

benzoin_ (_B. amygdaloides_), and lump benzoin (_B. in sortis_, _B.

in massis_). The _benzoin in tears_ forms loose, smoothly terminated,

longish, homogeneously appearing masses of an opal-like lustre, and

first of a whitish, and later on, of a yellowish, reddish, or brownish

color. The separate pieces are up to 3 millimeters in diameter, though

the Siam benzoin in tears frequently consists of still larger and

generally decidedly flattened pieces.

_Amygdaloid benzoin_ consists chiefly of white pieces, becoming, later

on, brownish, of a waxy lustre and imbedded in a lustrous brown-red

resinous mass. The _lump benzoin_ or _ordinary benzoin_ has also an

amygdaloid structure but is not so rich in almonds as the preceding

variety and possesses either a fine granular or colophony-like

ground-mass and is frequently contaminated by parts of plants. The

exterior of the variety occurring in commerce in large lumps shows,

according to the mode of packing, the imprint of leaves or of coarse

pack-cloth.

Benzoin generally consists of cinnamic and benzoic acids which occur in

a crystalline state in the grains as well as the ground-mass; further,

of several amorphous resins soluble in alcohol, and coloring matter.

The content of cinnamic and benzoic acids amounts to from 12 to 20 per

cent. The best varieties from Sumatra and Singapore contain no benzoic

acid, and those from Siam no cinnamic acid.

All varieties of benzoin possess a peculiar odor, that of the better

varieties being agreeable, and a sweet, aromatic, but pungent taste.

The melting point generally lies between 176° and 203° F., that of the

tears and of the almonds being lower than that of the ground-mass.

A low melting-point is accepted as a mark of quality, Siam benzoin,

which is considered the best, melting at 167° F. Some varieties, for

instance, those recently imported from Singapore, have a pronounced

vanilla-like odor; the presence of vanillin has been established in

them. The Sumatra benzoin has a storax-like odor.

Benzoin is sparingly soluble in chloroform, only partially so in ether,

and completely in alcohol. On mixing the alcoholic solution with water,

the resin is separated. Petroleum-ether and benzine withdraw only

benzoic acid from the dry, powdered benzoin. All varieties of benzoin

dissolve in concentrated sulphuric acid to a beautiful purple colored

fluid, from which benzoic acid, if present, is separated in crystals

by the gradual addition of water. The establishment of the presence

of cinnamic acid is best effected as follows: Boil the sample in milk

of lime, filter, and treat the solution with hydrochloric acid. The

precipitate thereby separated is thoroughly washed, triturated with

potassium permanganate and water, and heated, whereby in the presence

of cinnamic acid, oil of bitter almonds is formed from the latter,

which is readily recognized by the odor.

If benzoin containing benzoic acid be heated, white vapors are emitted

which, on cold surfaces, deposit in very delicate, lustrous, acicular,

or foliated crystals of benzoic acid, the so-called benzoin flowers

(_Floris benzoes_.) Benzoic acid thus prepared possesses an agreeable,

vanilla-like odor, since by heating the benzoin the greater portion

of the odoriferous substance contained in it escapes. Benzoic acid

separated by the wet method is odorless.

Benzoin is especially used for fumigating pastilles. It is also of

great importance on account of its property of preventing fats from

becoming rancid, if added to them in small quantities.

_Peru balsam_ (_Balsamum Peruvianum_) is the produce of the Balsam

Coast, San Salvador, Central America, where Sansonate forms the

central point of the industry. In the mountain forests, back of the

coast, grows the balsam tree (_Myroxylon Pereiræ, Klotzch_; _Toluiferæ

Pereiræ, Baillon_), natural order, _Papilionaceæ_. The gaining of

balsam commences when the tree is five years old, the collecting time

beginning in the dry season in the first days of November. The trunks

of the trees are belabored with hammers on four places (according to

other statements, on twenty to thirty), so that the bark is detached

in strips. After a few days the bark thus loosened is burnt off by

means of torches, whereupon a balsamic fluid oozes from the young wood,

which is absorbed by pieces of cloth or rags, placed upon the denuded

places. When the rags are thoroughly saturated with balsam, they are

squeezed out and then thrown into an earthen pot filled with boiling

water, whereby the balsam is detached and collects on the bottom of

the vessel. By this process the _Balsamo de trapó_ is obtained. By

boiling the bark, which falls off, a small quantity of a poorer quality

of balsam, called _tacuasonte_, is obtained, which, it would seem,

is frequently added to the better quality. Crude Peruvian balsam is

a gray-green to dirty-yellow fluid, of the consistency of syrup. The

process of purification in use on the Balsamic Coast is as follows: The

crude balsam is brought into large iron vessels, holding from 1300 to

1500 lbs. each, and allowed to clarify by quietly standing from 8 to

14 days, the heavy impurities settling on the bottom, while the light

dirt, together with the water, appears as foam on the surface. After 8

to 14 days the balsam is drawn off through a cock, located about 4¾

inches above the bottom of the vessel, into a tinned iron boiler, and

boiled over an open fire at a moderate heat for 2 to 3 hours. The foam

which forms is skinned off, and boiling continued until no more foam

appears.

The collection of balsam continues until the first rain falls in April

or May, when the work ceases. A vigorous tree, well treated, yields

balsam for 30 years in succession, and if then allowed to rest 5 or 6

years can be used several years longer. The annual yield of balsam from

100 trees is said to be about 550 lbs.

From the very odoriferous flowers of the balsam tree or, according

to others, by expressing the fruits, a _white_ Peruvian balsam is

obtained, which is, however, seldom found in commerce. It is of the

consistency of honey, pale-yellow, smells of vanilla and melilot, and

has an aromatic bitter taste. On standing for some time it deposits

crystals of myroxocarpin.

Ordinary (black) Peruvian balsam is a black-brown fluid, transparent

and dark (honey-yellow in thin layers), which retains its consistency

even after being kept for years and deposits no crystals. It shows

a slight acid reaction, has an agreeable odor reminding one of gum

benzoin and vanilla, and at first a mild, but, later on, a sharp and

pungent taste.

The specific gravity of pure Peru balsam formerly varied between 1.14

and 1.16, but at present between 1.135 and 1.145, this change in the

specific gravity being very likely due to a different process of

purification.

Peru balsam is miscible in every proportion with absolute alcohol,

while ether leaves behind undissolved a black, smeary residue, and

hot oils of turpentine or almonds dissolve only about one-half. It

is miscible with acetone, chloroform, amyl alcohol. By digesting the

balsam with aqueous potash lye, _Peru balsam oil_, which constitutes

about 60 per cent. of the balsam, separates on the surface. In an

undecomposed state the oil is, according to Kachler, chiefly benzyl,

cinnamate, or cinnamein. The potash solution separated from the Peru

balsam oil, contains cinnamic acid, benzoic acid, and resin. The

latter, according to Stotze, can be separated into two portions, one

soluble, and the other insoluble, in aqueous alcohol.

Benzine and petroleum-ether dissolve from the Peru balsam only the

nearly colorless cinnamein of which it contains up to 45 per cent.

The behavior of Peru balsam towards bisulphide of carbon is very

characteristic, 3 parts of it giving, according to Flückiger, a clear

solution with 1 part of bisulphide of carbon; if, however, 8 parts

more of the latter be added, up to 30 per cent. of a dark resin is

separated, while the bisulphide of carbon is but slightly colored.

From San Salvador 11,000 to 13,000 lbs. of Peru balsam are annually

brought to Europe, it being generally imported in tin cans, and more

rarely in earthen jars surrounded by a kind of plaited matting.

According to whether the product comes by way of England, New York,

Bremen, or Hamburg, it is distinguished as English, American, Bremen,

or Hamburg Peru balsam. The supply being frequently insufficient, the

balsam is subjected to many adulterations. A cheap, so-called London

Peru balsam always contained colophony and had a specific gravity of

1.133. There can be no doubt that pure unadulterated Peru balsam is

difficult to obtain.

As adulterants, are used: Alcohol, volatile oils, fat oil, especially

castor oil; further, copaiba balsam, Canada balsam, gurjun balsam,

storax, benzoin, and asphaltum. The establishment of these adulterants

is connected with difficulties; but the properties of Peru balsam are

so characteristic that it is quite easy to detect whether it is genuine

and pure, or not, the specific gravity and proportions of solubility

deserving especial attention in this respect. The test by the specific

gravity is available, since most of the adulterants render the balsam

specifically lighter, especially alcohol, but also copaiba balsam

(specific gravity, O.95), castor oil (0.96), oil of turpentine (0.87),

gurjun (0.96), etc. The customary procedure is as follows: Prepare a

common salt solution of 1.25 specific gravity, by dissolving 1 part of

dried sodium chloride in 5 parts of distilled water; drop the balsam

into the solution; every drop of pure Peru balsam sinks in a roundish

form to the bottom; but if the drop again comes to the surface and

spreads out upon it, it is a sure sign of some kind of adulteration.

However, the change in the specific gravity by the admixture of fat

oils is but very slight, since the balsam can only be mixed with them

to a conformable fluid in the proportion of from 7 to 10 to 1. Castor

oil forms an exception in this respect, it being miscible also in other

proportions.

Petroleum-ether is an excellent testing agent. Bring into a test-tube

about 2.5 grammes of Peru balsam, and 6 to 7 centimeters of

petroleum-ether, close the tube with the finger and shake vigorously;

a brown, thickly-fluid mass adheres in unequal layers to the sides of

the tube, and before running together remains in this position 1 to

2 minutes after the petroleum-ether has been poured into a porcelain

saucer. If, however, the mass is thinly-fluid, and does not, in the

above-mentioned manner, adhere to the sides of the tube, but, after

shaking, collects below the petroleum-ether, the balsam is adulterated.

After shaking, immediately pour off the petroleum-ether; if the latter

is almost colorless, or but slightly colored yellowish, the balsam is

pure; if, however, it is turbid, and soon forms a sediment, or if it is

yellow or brownish, or brown, the balsam is adulterated.

Alcohol is added either by itself or in the form of saturated

solution of storax, benzoin, or Canada balsam, by which means the

specific gravity of the balsam is but slightly changed. Bring the

above-mentioned common salt solution, together with 20 grammes of the

Peru balsam to be examined, into a small flask, and distil off about 5

grammes; gradually mix the distillate with 5 drops of caustic potash

lye and potassium iodide solution saturated with iodine, shaking gently

until the mixture acquires a slightly yellow-brownish coloration. If

this coloration does not disappear in one minute, add drop by drop

more of the potash lye until discoloration appears. In the presence

of alcohol, yellow crystals of iodoform, which are readily recognized

under the microscope by their form, collect on the bottom of the fluid.

Adulteration with a volatile oil is recognized in the distillate by

odor and taste.

Fat oil, Canada balsam, copaiba balsam, gurjun balsam, and volatile

oil may be recognized by the following tests: If pure Peru balsam in

a porcelain saucer is thoroughly mixed with an equal volume of pure

concentrated sulphuric acid, the mixture thereby becomes heated, vapors

of a pungent odor being emitted, and if then set aside to cool, it

congeals. In the presence of fat or volatile oils, copaiba balsam,

gurjun balsam, or Canada balsam, it remains, however, more or less

thickly fluid or more or less soft-smeary. If the balsam be pure, the

cold mixture, after washing with water, should yield a hardish or

soft-friable mass, which, when kneaded with the fingers, should not

prove smeary or sticky.

Fat oils are also very readily recognized by the use of warm

petroleum-ether. The extract is evaporated, saponified with potash lye,

extracted with alcohol, evaporated and decomposed with hydrochloric

acid. A mixture of cinnamic acid and any of the fatty acids present in

the Peru balsam is thereby obtained, which, after treatment with water,

remains in the residue.

Of copaiba balsam, Peru balsam can take up as much as 25 per cent.

From such adulterated balsam benzine dissolves the copaiba balsam,

together with cinnamein, and the adulteration can then be recognized by

the odor. Cinnamein treated with sulphuric acid acquires a cherry-red

color, while in the presence of copaiba balsam or gurjun balsam, a

yellow-brown coloration appears. The detection of an adulteration of

Peru balsam with storax is, according to Denner, effected as follows:

Shake in a test-tube 5 parts of the balsam to be examined with 5 parts

of a 15 per cent. soda solution (soda lye of 1.60 specific gravity)

and 10 parts of water. Then shake with 15 parts of ether, and after

settling pour off the ether as much as possible. Repeat the shaking

with 15 parts of fresh ether. Now heat the aqueous residue to boiling,

acidulate with hydrochloric acid, add cold water, remove the resin

separated thereby from the fluids, dissolve it in about 3 parts of soda

lye of the above-mentioned strength, dilute with 20 parts of water,

heat to boiling, and precipitate with barium chloride solution. Bring

the precipitate upon the filter, and, after allowing it to drain off,

dry it in the water-bath. Then extract it with alcohol, evaporate the

alcoholic extract, take it up with concentrated sulphuric acid, add

chloroform, and shake. In the presence of gum benzoin or storax, the

chloroform acquires a violet to blue color. This method is a sure test

for the recognition of even very small admixtures.

A content of asphaltum is readily detected by mixing the Peru balsam

with ether compounded with about ⅛ alcohol. Any asphaltum present

remains undissolved, and may be collected upon a filter.

In perfumery Peru balsam is chiefly used for pomades and fumigating

pastilles, but also for cosmetics and soaps.

_Tolu balsam_ is the produce of _Myroxylon toluiferum, Humb._, _Bonpl._

et _Kunth_, _Toluifera balsamum, L._, a tree of the natural order

_Papilionaceæ_, growing in Northwestern South America. It exudes during

the heat of the day, and is collected in gourds. It soon hardens, by

which it is distinguished from Peru balsam. In commerce two varieties

of Tolu balsam are found, one of the consistency of turpentine and the

other solid. The first variety, Brazilian balsam, forms a semi-fluid,

turpentine-like, sticky mass, of the color of copaiba balsam. By long

storage it becomes hard and brownish. The solid variety, Tolu, or

Carthagena balsam, is a brittle, more or less translucent yellow-brown

or red-brown resin of a granular or crystalline appearance. It softens

at about 86° F., and melts between 140° and 149° F. Viewed under the

microscope, it appears rich in crystals of separated ciannamic and

benzoic acids. Its specific gravity varies between 1 and 2. Both

varieties of Tolu balsam have an aromatic, slightly pungent and sourish

taste, resembling somewhat that of Peru balsam. They are readily

soluble in ordinary spirit of wine, alcohol, acetone, chloroform, and

potash lye, but insoluble in petroleum-ether and bisulphide of carbon.

In Tolu balsam have been found toluene, cinnamic and benzoic acids, and

several resins not yet sufficiently examined. According to Scharling,

toluene constitutes about 1 per cent. of the Tolu balsam. It forms

a colorless, limp oil, boils, according to Deville, at 338° F., and

according to E. Kopp, at between 309° and 320° F., and has a specific

gravity of 0.858. It has a sharp, pungent, pepper-like taste, and an

odor resembling that of elemi. In the air, it is gradually converted by

oxidation into a soft resin, without, however, becoming colored.

On boiling Tolu balsam with water, cinnamic and benzoic acids are

separated from the solution. When treated with potash lye the resinous

acids are fixed, and the toluene floats upon the fluid.

Commercial Tolu balsam is frequently more or less mixed with vegetable

remains, which, however, can be readily detected with the microscope,

especially after the solution of the resinous constituents. It

is frequently adulterated with turpentine or pine resin. Such

adulterations may be detected by bisulphide of carbon, which completely

dissolves these substances, but not the Tolu balsam. When pure Tolu

balsam is triturated with concentrated sulphuric acid, a cherry-red

fluid is, according to Ulex, obtained, which does not evolve sulphurous

acid, as is the case in the presence of turpentine-resins.

Tolu balsam is chiefly used for fumigating pastilles. The tincture

prepared from it is also frequently used with advantage to give

durability to the scent of handkerchief perfumes.

According to Holmes and Nalor, a Tolu balsam differing in its chemical

behavior is found in the English wholesale trade. In thick layers

it is yellow-brown, but perfectly transparent and gold-yellow in

thin layers and extraordinarily sticky. By storage it hardens but

slightly, and does not become brittle even if exposed for several days

to a temperature of 212° F. Its odor reminds one somewhat of glue,

and it develops a pungent, sharp taste only after chewing it for a

few seconds. Its melting point lies at 136.4° F., being lower than

that of ordinary Tolu balsam, from which it also differs in that it

completely dissolves in ether as well as in benzine, while it is only

partially dissolved by potash lye. The balsam contains no toluene, nor

a hydrocarbon, boiling at 320° F. Further investigations have shown it

actually to be a natural product, the derivation of which, however,

could not be ascertained.

_Storax_ is the produce of _Liquid ambar orientale, Mill_, a

plantain-like tree which reaches a height of about 32 feet. In

Southern Asia Minor, especially in Cyprus, the tree forms handsome,

dense forests. According to Flückiger, the balsam is extracted from

the peeled-off bark, with the assistance of warm water. The mass thus

melted out sinks down in the water, and is later on combined with the

substance obtained by expressing the boiled bark while still warm. This

mixture forms the _liquid storax_ (_Storax liquidus_). The residue

remaining after expression is dried in the sun and forms, under the

name of _Cortex thymiamatis_, an article of commerce, which is used for

fumigating purpose, for the preparation of ordinary storax, etc. The

crude storax is brought to Smyrna, Syra, and Kos, and comes into the

European market almost exclusively from Trieste.

Liquid storax is a sticky, opaque substance of the consistency of

turpentine. It has a mouse-gray color, which by contact with the air

becomes brown on the surface, an agreeable benzoin-like odor, and a

sharp, pungent, aromatic taste. It is heavier than water, its specific

gravity being 1.112 to 1.115. On losing its content of moisture (by

drying out when heated) it becomes brown and clear. When exposed to

the air in a thick layer it does not completely dry, and in a thin

layer only after considerable time; but when pressed with the finger

always shows a certain stickiness. It is partially soluble in spirits

of wine, yielding with it a more or less turbid solution. It is also

incompletely soluble in oil of turpentine, benzine, petroleum-ether,

and chloroform. Viewed under the microscope liquid storax appears as a

colorless thickish fluid, intermingled with larger and smaller drops,

fragments of bark tissue, and now and then, perhaps, with crystals of

styracin and cinnamic acid.

Liquid storax contains styrol (10 to 15 per cent.), styracin, and

cinnamic acid (10 to 15 per cent.). Styrol or cinnamol seems to be

the most important carrier of the odor and taste of liquid storax. If

20 parts of liquid storax are subjected to distillation together with

15 parts of crystallized soda and 200 parts of water, the cinnamol

collects in the form of a yellowish, very mobile liquid upon the

distillate. By rectification it can be obtained colorless, but is

thereby partially converted into metastyrol, an isomeric, amorphous,

odorless, and tasteless substance which is solid at an ordinary

temperature. By exposure for some time to a heat of 608° F. it is

reconverted into styrol. Styrol (C_{8}H_{8}) forms a clear, colorless,

mobile liquid having an odor of benzine and naphthalene. Its specific

gravity is 0.924 and its boiling point lies at 294.8° F. In water it

is but sparingly soluble, but is miscible in all proportions with

anhydrous spirit of wine, chloroform, benzine, ether, and oils. It

stands in the same relation to cinnamic acid as benzol to benzoic acid,

and is formed by distilling a mixture of cinnamic acid and barium oxide.

Styracin is cinnyl cinnamate. On distilling liquid storax with water,

styrol passes over. If now from the residue the cinnamic acid be

withdrawn by means of soda-solution, and the resin, which remains

behind, be treated with cold spirit of wine, styracin is left, which

crystallizes from ether, hot alcohol, or benzol. It forms colorless,

odorless, and tasteless crystals which melt at 113° F. and remain for

a long time fluid after melting. It is insoluble in water, but soluble

in 25 parts cold, and 2 parts boiling, spirit of wine, as well as in 5

parts ether. By oxidizing substances it is converted into bitter almond

oil and benzoic acid, and by the action of potassium hydroxide it is

decomposed to cinnyl alcohol and cinnamic acid.

Good liquid storax should yield to 90 per cent. alcohol at least so

much soluble matter that the dried residue of the filtered alcoholic

solution amounts to 65 per cent. of the quantity of storax.

Ordinary liquid storax, which has not been stored too long, contains

10 to 20 per cent. of water and about the same quantity of impurities

(fragments of plant tissue) which remain behind on treatment with the

above-mentioned solvents.

Liquid storax is said to be adulterated with the turpentines of some

species of larch and pine. Such adulteration is primarily detected,

according to Hager, by the specific gravity. Take up a drop of the

balsam with a knitting-needle, and by heating the needle make it

fall into a cold solution of 1 part common salt and 8 parts water. On

stirring, the drop must sink, otherwise adulteration with turpentine

is very likely. Next bring 5 grammes of the storax into a test-tube,

melt it in the water-bath, add ½ volume of absolute alcohol, and

mix by shaking; then compound the mixture with several times its

volume of petroleum-ether, shake vigorously, allow to settle, and

decant the layer of petroleum-ether. Repeat twice this shaking with

petroleum-ether; then evaporate the petroleum-ether solution in a tared

flask in the water-bath. The residue remaining after evaporation is

colorless, bluish opalescent, and of an agreeable odor; in the presence

of turpentine it is yellowish and has the, not to be mistaken, odor of

turpentine.

_Storax in grains_ consists of round, longish grains of a brown-black

color and smooth, lustrous surface, which soften by the warmth of the

hand. It is nothing but liquid storax brought into a granular form and

by storing freed more or less from impurities.

_Ordinary storax_ (_Styrax calamitus_ or _St. vulgaris_) is an

artificial product prepared by mixing liquid storax with various

comminuted vegetable substances. Formerly the above-mentioned bark of

the storax tree (_Cortex thymiamatis_) was only used for this purpose,

but at present sawdust and exhausted cinnamon are also taken. This

storax forms a reddish or brown-black, humus-like mass, which is

generally moist. When dried it is very friable and has a storax-like

odor distinctly calling to mind that of cinnamon. Good qualities are

abundantly covered with crystalline efflorescences (of cinnamic acid

and styracin); poorer qualities prepared with the addition of sawdust

have a musty odor. The admixed vegetable tissue can, according to

Wiesner, be readily recognized by boiling the storax with alcohol,

and after washing treating with dilute chromic acid, to which a small

quantity of sulphuric acid has been added.

Liquid storax was already used for fumigating purposes by the ancient

Greeks and Jews, and it forms to-day a constituent of fumigating

pastilles, essences, etc. Storax tincture furthermore possesses the

property of giving more constancy to scents resembling it. Piesse says,

in regard to the odor of liquid storax, that it combines the agreeable

with the disagreeable, it possessing partially an odor similar to that

of the tuberose and partially one reminding of coal-tar oil. However,

it possesses this disagreeable odor only in a concentrated state; when

finely divided or diluted, it diffuses a very agreeable perfume.

Under the name _American storax_, _white Peru balsam_, _white Indian

balsam_ or _liquid ambar_ is found in commerce a product similar

to storax, which is derived from _Liquidambar styraciflua, L._, a

tree indigenous to Mexico and Louisiana. This balsam forms a clear,

transparent, brownish-yellow, semi-fluid mass. It has a storax-like

odor, and a sharp and pungent taste. It is only partially soluble in

alcohol, specifically lighter than water, and shows an acid reaction.

It is said to consist of 24 per cent. styracin, 1 per cent. benzoic

acid, volatile oil, etc. It is sometimes used for fumigating purposes,

but chiefly serves for the adulteration of Tolu balsam.

_Myrrh_ (_Gummi-resina myrrha_, _Gummi myrrha_) is a gum resin, the

produce of _Balsamodendron Ehrenbergianum, Berg_, and, perhaps, also

of _Balsamodendron Myrrha, Nees_. The first-named tree is found in

the countries bordering on the Red Sea, and extends into Africa to

the Somali Coast, where the principal supply of myrrh is collected.

The gum-resin exudes naturally as a white oil-like mass, which, after

hardening, whereby it becomes considerably darker, is collected by the

natives and brought chiefly to Berbera, a small seaport opposite Aden,

to be exchanged for English and Indian goods. From there, by way of

Aden and Bombay, it reaches the European market. In Bombay the first

sorting takes place, which is, however, superficial, and hence has to

be repeated in Europe (London). According to Parker, ten different

resins are admixed with myrrh, especially bdellium resins.

In commerce _Myrrha electa_ and _Myrrha vulgaris_ or _in sortis_ are

distinguished. _Myrrha electa_, the best quality, occurs in pieces of

irregular form and variable sizes, consisting of tears--either distinct

or agglomerated--usually covered with a fine powder or dust. The

surface is seldom smooth, but generally rough or granular. The color

varies, being pale reddish-yellow, red, or reddish-brown. The fracture

is conchoidal, seldom smooth, but rather granular, rough, of a fatty

lustre, and sometimes shows whitish striæ or veins, or opalesces like

flint. The fractured edges are more or less translucent; thin disks

or splinters are translucent or transparent. The specific gravity is,

according to Hager, 1.195 to 1.205, and according to Ruickholdt, 1.12

to 1.18. A _Myrrha electa_ is the better, the more fragile, friable,

and paler in color it is, and the more rapidly it ignites and burns

with a yellow, sooty flame. Poorer qualities may be recognized by the

dark-brown color and dirty appearance. Myrrh is with difficulty rubbed

to a fine powder, this being possible only after drying, which must,

however, be done at a very moderate heat in order to prevent loss of

volatile oil.

According to Hager, myrrh consists in 100 parts of about 2.5 parts

volatile oil (myrrhol), 25 to 35 parts resin (myrrhin), 55 to 65 parts

gum soluble in water, 3 to 8 parts salts, impurities, and water. Water

forms with myrrh an emulsion, and dissolves the gum. The resinous

constituents are dissolved by spirit of wine.

The gum, which forms the portion of the myrrh soluble in water,

but insoluble in alcohol, and amounts to from 57 to 59 per cent.,

is, according to Oscar Koehler, a hydrocarbon of the formula

C_{6}H_{10}O_{5}. The portion soluble in alcohol is, according to

the same chemist, a mixture of various resins, an indifferent soft

resin of the formula C_{26}H_{34}O_{5}, soluble in alcohol and ether,

forming the greater portion of it. There are further present two resin

acids, one of which has to be considered a bibasic acid of composition

C_{12}H_{16}O_{8}, and the other as a monobasic acid of the formula

C_{26}H_{32}O_{9}. The principal constituent of the volatile oil

of which, according to Koehler, 7 to 8 per cent. is present, while

Ruickholdt formerly found only 2.18 per cent. corresponds to the

formula C_{10}H_{14}O. The volatile oil is laevorotatory, and when

diluted with bisulphide of carbon becomes, according to Flückiger,

violet by the action of bromine. An extract of myrrh, prepared with

bisulphide of carbon, gives the same reaction with bromine vapor.

Hydrochloric or nitric acid also colors myrrh violet, which also

applies to the volatile oil.

Petroleum-ether should, at the utmost, take up 6 per cent. of the

myrrh, and the extract must be colorless.

Myrrh is frequently contaminated with bark, which forms either a film

of cork as thick as paper or a crust of a fibrous and, at the same

time, brittle nature. Sand or small pebbles are also frequently mixed

with the myrrh. Other varieties of gum or gum-resin, which considerably

decrease the value of the product, are often found in the commercial

article, the inferior qualities especially being adulterated and

mixed with dark pieces of Suakim gum, gum of the plum or cherry tree,

bdellium, and similar substances, which are partially moistened with

myrrh tincture, and scattered over with myrrh powder. Adulteration

with gum-arabic, gum of the plum or cherry tree, which are coated

with alcoholic myrrh solution, is recognized by the paler lustre,

greater transparency, and mucilaginous taste. Pieces of resin melt on

heating, while myrrh only swells up. Bdellium is detected by the dark

or black-brown color, toughness, less bitter taste, and by crackling

and spitting when held in the flame of a candle, as well as by the

reaction of myrrh with nitric acid discovered by Bonastre. By mixing

5 cubic centimeters of alcoholic myrrh tincture with 5 to 10 drops of

fuming nitric acid, a rose-color coloration passing into red results.

Parker gives the following method for testing myrrh: Prepare a tincture

of 1 part myrrh and 6 parts spirit of wine. Saturate with this tincture

white filtering paper, allow it to drain off, and then wrap it around

a glass rod moistened with nitric acid of 1.42 specific gravity. With

genuine myrrh the paper immediately becomes deep yellow-brown and then

black, while the edges of the paper strip appear dark purple-red.

When a few drops of the tincture of myrrh are allowed to dry in, a

transparent residue remains behind. The tinctures of spurious articles

(with the exception of bissabol) give turbid residues.

Myrrh was already in Moses's time an article used in the sacrifices

of the Israelites. It seems to have been made use of by Democrates.

Dioscorides enumerates eight varieties of it, and Pliny seven, which he

obtained from Abyssinia. Herodotus and Diodorus Siculus mention Arabia

as the home of the myrrh tree.

In perfumery, myrrh is chiefly used for dentifrices and fumigating

pastilles and essences.

_Opopanax_ is the inspissated juice of the root of _Opoponax Chironium,

Koch_, or _Ferula Opoponax, L._ It forms grains or lumps of a

red-yellow or brown color, and has a fracture of a waxy lustre. It can

be rubbed to a gold-yellow powder. It has a strong and peculiar odor,

and a very bitter and balsamic taste. With water it forms an emulsion,

while it is only partially soluble in spirit of wine. It contains very

little volatile oil, and a resin which melts at 212° F., and is soluble

in ether and aqueous alkalies. It further contains gum, organic and

inorganic salts, and foreign admixtures. Opopanax is but little used in

perfumery. For _Extraits_ the opopanax oil is better adapted than the

tincture prepared from the gum, the latter coloring the _Extrait_ dark.

_Olibanum or Frankincense_ is the inspissated juice of various

varieties of _Boswellia_, partially indigenous to Africa and partially

to Asia. The pure pieces are pale yellow, seldom reddish, transparent,

or opaque, brittle, covered with a mealy coating and of a splintery

fracture. The specific gravity of olibanum is 1.22; its odor is

slightly balsamic, and its taste bitter and pungent. It melts only

incompletely when exposed to heat, diffusing an agreeable odor. It

consists in 100 parts of 5 to 7 parts of a clear volatile oil, boiling

at 323.6° F., and of specific gravity 0.86, 56 parts of acid resin,

and 30 to 36 parts gum, which corresponds with gum-arabic. With water

it forms a milky fluid, and is mostly dissolved by spirit of wine.

Selected olibanum (_Olibanum electum_) is the best commercial variety,

while _Olibanum naturale_, _O. in lacrymis_, and _O. in sortis_, form

darker pieces intermingled with separate paler grains, and contaminated

by pieces of bark, and wood and sand.

Olibanum is only adulterated with sandarac and naturally exuded pine

resin, inspissated to tears by exposure to the air. The former is

recognized by the fracture being glassy and transparent, and the latter

by completely dissolving to a clear solution in spirit of wine.

Olibanum serves as an addition to fumigating pastilles, etc.

_Sandarac_ is the resin exuding from the bark of _Thuja articulata,

Desf._, or _Callitris quadrivalvis, Vent._, which grows in Barbary. It

forms pale yellow, transparent, brittle grains with a glassy fracture,

which have a specific gravity of 1.06 to 1.09 and fuse readily. Its

odor is slightly balsamic and its taste somewhat bitter. Sandarac

softens at 212° F. and melts at 275° F. It dissolves in hot absolute

alcohol, ether, and amyl alcohol, is less soluble in chloroform,

petroleum-ether, and volatile oils, and insoluble in benzol. In 90

per cent. alcohol ⅘ of it dissolve; the term _sandaracin_ has been

applied to the insoluble portion. According to Unverdorben, sandarac

consists of three different resins. It is sometimes employed in

fumigating pastilles. CHAPTER VI.

PERFUME-SUBSTANCES FROM THE ANIMAL KINGDOM.

Musk is a peculiar concrete secretion obtained from _Moschus

mochiferus, L._, an animal bearing a close resemblance to the deer

in shape and size, and indigenous to the high plateaus of Asia. The

musk is contained in an oval, hairy, projecting sac, found only in the

male, situated between the umbilicus and the prepuce. It is from 2 to 3

inches long and from 1 to 2 broad.

In commerce, several varieties of musk are distinguished, the principal

ones, however, being Tonkin and Kabardin musk.

_Tonkin_, _Thibet_, or _Oriental musk_, _Yunnan musk_ (_Moschus

tonquinensis_, or _orientalis_, or _transgangetanus_) is the best

variety. It comes from China, Tonkin, and Thibet. It consists of sacs

of a puffed-up appearance, more roundish than longish, varying in

size, being at the utmost 1.77 inches long, up to 1.57 inches broad

and 0.59 to 1.18 inches thick, and weighing from 8.46 drachms to 1

oz. 9.39 drachms each. The hairy side of the sac is concave and the

other flat. Fig. 21 shows an unshorn Tonkin musk sac of medium size

from the concave or hairy side and Fig. 22 the same from the side. The

envelop of the sac consists of a double skin, the outer skin being

gray-brown. One side of the sac is covered with stiff, yellowish hair

with red-brown points, generally cut short. The original packages,

containing usually 24 sacs each, consist of longish, four-cornered

boxes lined with lead-foil and covered outside with some silken stuff.

Each sac is separately wrapped in tissue paper. The musk-substance

appears as a dark red to black-brown mass intermingled with hair, and

forming roundish grains. The odor is penetrating and the taste bitter.

[Illustration: FIG. 21.]

[Illustration: FIG. 22.]

[Illustration: FIG. 23.]

_Kabardin_, _Siberian_, or _Russian musk_ (_Moschus sibirius_, or

_cabardinicus_) is a cheaper variety of an inferior quality, which is

brought from Mongolia and Siberia. The sacs (Fig. 23) are longish,

generally pear-shaped, flatter in proportion to their longitudinal and

latitudinal dimensions, and not of a puffed-up appearance, the surface

being frequently even shrivelled or wrinkled. The outer skin is denser

and harder, and on the convex side covered with longer hair (up to 0.9

inch long), of nearly a silver or brownish color. Towards the edge of

the sac the hairs are, however, frequently so trimmed and shorn as to

give the sac a resemblance to the Tonkin article. The musk-substance

inclosed in the sac amounts to from 8.46 drachms to 1 oz. It is

somewhat paler, more brown or yellow-brown, soft, almost unctuous, when

fresh, but after storing, solid or granular-pulverulent, like ground,

burnt coffee. The odor is weak, offensive, more urinose, resembling

that of castor, or horse sweat.