"Were not summer's distillations left
A liquid prisoner, pent in walls of glass,
Beauty's effect with beauty were bereft,
Nor it, nor no remembrance what it was;
But flowers distilled, though they with winter meet,
Leese but their show, their substance still lives sweet."
SHAKSPEARE.
The extensive flower farms in the neighborhood of Nice, Grasse,
Montpellier, and Cannes, in France, at Adrianople (Turkey in Asia), at
Broussa and Uslak (Turkey in Asia), and at Mitcham, in England, in a
measure indicate the commercial importance of that branch of chemistry
called perfumery.
British India and Europe consume annually, at the very lowest estimate,
150,000 gallons of perfumed spirits, under various titles, such as eau
de Cologne, essence of lavender, esprit de rose, &c. The art of
perfumery does not, however, confine itself to the production of scents
for the handkerchief and bath, but extends to imparting odor to
inodorous bodies, such as soap, oil, starch, and grease, which are
consumed at the toilette of fashion. Some idea of the commercial
importance of this art may be formed, when we state that one of the
large perfumers of Grasse and Paris employs annually 80,000 lbs. of
orange flowers, 60,000 lbs. of cassia flowers, 54,000 lbs. of
rose-leaves, 32,000 lbs. of jasmine blossoms, 32,000 lbs. of violets,
20,000 lbs. of tubereuse, 16,000 lbs. of lilac, besides rosemary, mint,
lemon, citron, thyme, and other odorous plants in large proportion. In
fact, the quantity of odoriferous substances used in this way is far
beyond the conception of those even used to abstract statistics.
To the chemical philosopher, the study of perfumery opens a book as yet
unread; for the practical perfumer, on his laboratory shelves, exhibits
many rare essential oils, such as essential oil of the flower of the
_Acacia farnesiana_, essential oil of violets, tubereuse, jasmine, and
others, the compositions of which have yet to be determined.
The exquisite pleasure derived from smelling fragrant flowers would
almost instinctively induce man to attempt to separate the odoriferous
principle from them, so as to have the perfume when the season denies
the flowers. Thus we find the alchemists of old, torturing the plants in
every way their invention could devise for this end; and it is on their
experiments that the whole art of perfumery has been reared. Without
recapitulating those facts which may be found diffused through nearly
all the old authors on medical botany, chemistry, pharmacy, and works of
this character, from the time of Paracelsus to Celnart, we may state at
once the mode of operation adopted by the practical perfumer of the
present day for preparing the various extracts or essences, waters,
oils, pomades, &c., used in his calling.
The processes are divided into four distinct operations; viz.--
1. _Expression_; 2. _Distillation_; 3. _Maceration_; 4. _Absorption_.
1. _Expression_ is only adopted where the plant is very prolific in its
volatile or essential oil,--_i.e._ its odor; such, for instance, as is
found in the pellicle or outer peel of the orange, lemon, and citron,
and a few others. In these cases, the parts of the plant containing the
odoriferous principle are put sometimes in a cloth bag, and at others by
themselves into a press, and by mere mechanical force it is squeezed
out. The press is an iron vessel of immense strength, varying in size
from six inches in diameter, and twelve deep, and upwards, to contain
one hundred weight or more; it has a small aperture at the bottom to
allow the expressed material to run for collection; in the interior is
placed a perforated false bottom, and on this the substance to be
squeezed is placed, covered with an iron plate fitting the interior;
this is connected with a powerful screw, which, being turned, forces the
substance so closely together, that the little vessels containing the
essential oils are burst, and it thus escapes. The common tincture press
is indeed a model of such an instrument. The oils which are thus
collected are contaminated with watery extracts, which exudes at the
same time, and from which it has to be separated; this it does by itself
in a measure, by standing in a quiet place, and it is then poured off
and strained.
[Illustration: Pipette to draw off small portions of otto from water.]
2. _Distillation._--The plant, or part of it, which contains the
odoriferous principle, is placed in an iron, copper, or glass pan,
varying in size from that capable of holding from one to twenty gallons,
and covered with water; to the pan a dome-shaped lid is fitted,
terminating with a pipe, which is twisted corkscrew fashion, and fixed
in a bucket, with the end peeping out like a tap in a barrel. The water
in the still--for such is the name of the apparatus--is made to boil;
and having no other exit, the steam must pass through the coiled pipe;
which, being surrounded with cold water in the bucket, condenses the
vapor before it can arrive at the tap. With the steam, the volatile
oils--_i.e._ perfume--rises, and is liquefied at the same time. The
liquids which thus run over, on standing for a time, separate into two
portions, and are finally divided with a funnel having a stopcock in the
narrow part of it. By this process, the majority of the volatile or
essential oils are procured. In some few instances alcohol--_i.e._
rectified spirit of wine--is placed upon the odorous materials in lieu
of water, which, on being distilled, comes away with the perfuming
substance dissolved in it. But this process is now nearly obsolete, as
it is found more beneficial to draw the oil or essence first with water,
and afterwards to dissolve it in the spirit. The low temperature at
which spirit boils, compared with water, causes a great loss of
essential oil, the heat not being sufficient to disengage it from the
plant, especially where seeds such as cloves or caraway are employed. It
so happens, however, that the finest odors, the _recherché_ as the
Parisians say, cannot be procured by this method; then recourse is had
to the next process.
[Illustration: Tap funnel for separating ottos from water and spirits
from oil.]
3. _Maceration._--Of all the processes for procuring the perfumes of
flowers, this is the most important to the perfumer, and is the least
understood in England; as this operation yields not only the most
exquisite essences indirectly, but also nearly all those fine pomades
known here as "French pomatums," so much admired for the strength of
fragrance, together with "French oils" equally perfumed. The operation
is conducted thus:--For what is called pomade, a certain quantity of
purified mutton or deer suet is put into a clean metal or porcelain pan,
this being melted by a steam heat; the kind of flowers required for the
odor wanted are carefully picked and put into the liquid fat, and
allowed to remain from twelve to forty-eight hours; the fat has a
particular affinity or attraction for the oil of flowers, and thus, as
it were, draws it out of them, and becomes itself, by their aid, highly
perfumed; the fat is strained from the spent flowers, and fresh are
added four or five times over, till the pomade is of the required
strength; these various strengths of pomatums are noted by the French
makers as Nos. 6, 12, 18, and 24, the higher numerals indicating the
amount of fragrance in them. For perfumed oils the same operation is
followed; but, in lieu of suet, fine olive oil or oil of ben, derived
from the ben nuts of the Levant, is used, and the same results are
obtained. These oils are called "Huile Antique" of such and such a
flower.
When neither of the foregoing processes gives satisfactory results, the
method of procedure adopted is by,--
4. _Absorption_, or _Enfleurage._--The odors of some flowers are so
delicate and volatile, that the heat required in the previously named
processes would greatly modify, if not entirely spoil them; this
process is, therefore, conducted cold, thus:--Square frames, about three
inches deep, with a glass bottom, say two feet wide and three feet long,
are procured; over the glass a layer of fat is spread, about half an
inch thick, with a kind of plaster knife or spatula; into this the
flower buds are stuck, cup downwards, and ranged completely over it, and
there left from twelve to seventy-two hours.
Some houses, such as that of Messrs. Pilar and Sons; Pascal Brothers; H.
Herman, and a few others, have 3000 such frames at work during the
season; as they are filled, they are piled one over the other, the
flowers are changed so long as the plants continue to bloom, which now
and then exceeds two or three months.
For oils of the same plants, coarse linen cloths are imbued with the
finest olive oil or oil of ben, and stretched upon a frame made of iron;
on these the flowers are laid and suffered to remain a few days. This
operation is repeated several times, after which the cloths are
subjected to great pressure, to remove the now perfumed oil.
As we cannot give any general rule for working, without misleading the
reader, we prefer explaining the process required for each when we come
to speak of the individual flower or plant.