Perfumery. Perfumes are of two distinct classes—those derived from plants and those which are of animal origin.
Vegetable Perfumes.—The most ancient of the so-called primary odoriferous bodies are the so-called gum-resins which exude naturally from the trees which yield them, or from wounds accidental or purposely inflicted to increase the yield. The most important are benzoin, myrrh, opoponax, tolu, Peru, and storax. Gum-resins form the chief ingredients in 'Incense' (q.v.) and Pastilles (q.v.).
A second group is that large class of perfumes which are procured by distillation, and are mostly fluid bodies, and are termed Volatile Oils, Essential Oils, or Ottos—formerly Quintessences (see OILS). As soon as the Greeks and the Romans learned the use of the still, which was an invention imported by them from Egypt, they quickly adapted it to the separation of the odorous principle from the numerous fragrant plants indigenous to Greece and Italy. Long before that time, however, fragrant waters were in use in Arabia. Odour-bearing plants contain the fragrant principle in minute glands or sacs; these are found sometimes in the rind of the fruit, as the lemon and orange; in others it is in the leaves, as sage, mint, and thyme; in wood, as rosewood and sandalwood; in the bark, as cassia and cinnamon; in seeds, as caraway and nutmeg; in yet others in the petals, as in rose, lavender, or Ihlang-Ylang. The odour principle of orris is a solid resembling cocoa-butter, and is contained in what is really the rhizome of Iris florentina, though technically called orris-root. These glands or bags of fragrance may be plainly seen in a thin-cut stratum of orange-peel; so also in a bay leaf, if it be held up to the sunlight, all the oil-cells may be seen like specks. All the fragrance-bearing substances yield by distillation an essential oil peculiar to each; thus is procured oil of patchouli from the leaves of the patchouli plant, Pogostemon patchouli, a native of Burma; oil of caraway, from the caraway-seed; oil of geranium, from the leaves of the Pelargonium roseum; oil of lemon, from lemon-peel, Citrus limonis; and a hundred of others of infinite variety.
All the various essential oils or ottos are very slightly soluble in water, so that in the process of distillation the water which comes over is always fragrant. Thus, elder-water, rose-water, orange-water, dill-water are, as it were, the residue of the distillation for obtaining the several ottos. The process of Distillation (q.v.) is very simple: the fragrant part of the plant is put into the still and covered with water, and when the water is made to boil the ottos rise along with the steam, are condensed with it in the pipe, and remain floating on the water, from which they are easily separated by decanting. In this way 100 lb. of orange, lemon, or bergamot fruit peel will yield about 10 oz. of the fragrant oil; 100 lb. of cedar-wood will give about 15 oz. of oil of cedar; 100 lb. of nutmeg will yield 60 to 70 oz. of oil of nutmeg; 100 lb. of geranium leaves will yield 2 oz. of oil.
Every fragrant substance varies in yield of essential oil. The variety of essential oils is endless; but there is a certain relationship among odours as among tints. The lemon-like odours are the most numerous, such as verben, lemon, bergamot, orange, citron, citronella; then the almond-like odours, such as heliotrope, vanilla, violet; then spice odours, cloves, cinnamon, cassia. The whole may be classified into twelve well-defined groups. All these ottos are very soluble in alcohol, in fat, butter, and fixed oils. They also mix with soap, snuff, starch, sugar, chalk, and other bodies, to which they impart their fragrance.
The principal consumption of the cheaper sorts of fragrant ottos is for scenting Soaps (q.v.), most of which are perfumed while in a melted state with the several ottos or mixtures of them. The best qualities of soaps, however, are scented cold by grinding or squeezing the previously dried soap between granite rollers after having been mixed with the perfumes. With perhaps the exception of Tonquin bean, the 'scents' used for snuffs and tobacco can scarcely be termed perfumes. There is a large consumption of fragrant essential oils in the manufacture of toilet powders; under the various names of rose powder, violet powder, &c.; a mixture of starch and orris, differently scented, is in general demand for drying the skin of infants after the bath. Precipitated chalk and powdered cuttle-fish bone, being perfumed with otto of roses, powdered myrrh, and camphor, become 'Dentifrice.' The ottos of peppermint, lavender, rose, and others are extensively used in flavouring sweetmeats and lozenges.
It is found that some flowers either do not yield an essential oil by distillation or yield it in quantities too small to be commercially available. The perfume from these is collected by the process called enfleurage. The flower-farmers of the Alpes Maritimes follow this method on a very large scale with the following flowers: rose, orange, acacia, violet, jasmine, tuberose, and jonquil. In the valley of the Var there are acres of flowers, the blossoms of which are gathered by women and children, and placed in little panniers like fishermen's baskets hung over the shoulders. They are then carried to the laboratory of flowers and weighed. In the laboratory great quantities of grease, lard, and beef-suet have been collected, melted, washed, and clarified. In each laboratory there are several thousand châsses or châssis ('sashes'), upon which the grease to be scented is spread, and upon this grease the blossoms are sprinkled or laid. The châsse en verre is, in fact, a frame with a glass in it as near as possible like a window-sash, only that the frame is two inches thicker, so that when one châsse is placed on another there is a space of four inches between every two glasses, thus allowing space for blossoms. The flower blossoms are changed every day, or every other day. The same grease, however, remains in the châsse so long as the particular plant being used yields blossoms. Each time the fresh flowers are put on, the grease is 'worked'—i.e. serrated with a knife—so as to offer a fresh surface of grease to absorb odour. The grease being enflleurée or 'enflowered' in this way for three weeks or more—in fact, so long as the plants produce blossoms, or the fat is capable of absorbing more odour—is at last scraped off the châsse, melted, strained, and poured into tin canisters, and is now fit for exportation. Fat or oil is perfumed with these same flowers by the process of macération—i.e. infusion of the flowers in oil or melted fat. For this end purified fat is melted in a bain marie, or warm water bath, and the fresh blossoms are infused in it for several hours. Fresh flowers being procured, the spent blossoms are strained away, and new flowers added repeatedly, so long as they can be procured. Oil does not require to be warmed, but improved results are obtained when it is slightly heated.
Jasmine and tuberose produce best perfumed grease by enfleurage, but rose, orange, and acacia give more satisfactory products by maceration; while violet and jonquil grease is best obtained by the joint processes—enfleurage followed by maceration. In the place of glass the space is filled with a wire-net on which is laid a molleton, or thick cotton fabric—moleskin, soaked with oil; on this the flowers are laid, just as with solid grease. In due time—that is, after repeated changing of the flowers—the oil becomes fragrant, and it is then pressed out of the moleskin cloth. Oil of jasmine, tuberose, &c. are prepared in this way. In order now to obtain the perfume of these flowers in the form used for scenting handkerchiefs, we have only to infuse the scented fat or oil, made by any of the above methods, in strong alcohol.
In extracting the odour from solid fat it has to be chopped up as fine as suet is chopped, put into the spirit, and left to infuse for about a month. In the case of scented oil it has to be repeatedly agitated with the spirit. The result is that the spirit extracts all the odour, becoming itself 'perfume,' while the grease again becomes odourless; thus is procured the essence of jasmine, essence of orange-flowers, essence of violets, and others already named, rose, tuberose, acacia, and jonquil. It is right to mention that the reason for producing a pomade—as these scented fats are technically termed—of orange-flowers is that the odour of the essential oil obtained by the distillation of orange-blossoms with water has not, in the least degree, the odour of the orange-blossoms from which it is obtained. The otto in fact undergoes a chemical change, and is no longer orange so far as odour is concerned. It is called Neroli, and is valued at from £16 to £20 the lb. weight, the variation depending upon the crop, which is of course greatly influenced by the season. The same remarks apply, though in a less marked degree, to rose.
Some idea of the magnitude of the flower industry may be gained from the following summary showing the weight of these particular flowers grown in the south of France in 1889: orange-blossoms, 1860 tons; roses, 930; violets, 147; jasmine, 147; tuberose, 74; cassia, 30; jonquil, 15. The seat of the rose industry for the production of otto of roses is Bulgaria, more especially the cantons of Kezanlik and Karlova. Here no less than 5660 lb. were produced in 1889 at an average value of say 20s. per oz.
Perfumes of Animal Origin.—Only four of these are used in perfumery—viz. Musk (q.v.), Ambergris (q.v.), Civet (q.v.), and Castor (q.v.). The aroma of musk freely imparts odour to every body with which it is in contact. Its power to impart odour is such that polished steel will become fragrant of it if the metal be shut in a box where there is musk, contact not being necessary. In perfumery manufacture tincture of musk is mixed with other odorous bodies to give permanence to the more evanescent perfumes or bouquets, the musk acting to them almost as a mordant does to a dyestuff. The usual statement as to the length of time that musk continues to give out odour is exaggerated. If fine musk be spread in thin layers upon any surface, and fully exposed to a changing current of air, all fragrance, it is said, will be gone in from six to twelve months. The finest musk, that which indeed is only really useful in perfumery, is distinguished as Tonquin musk, the average price of which is about 90s. per oz.
Civet is exceedingly potent as an odour, and when pure, and smelled at in the bulk of an ounce or so, is utterly insupportable from its nauseousness; in this respect it exceeds musk. When, however, civet is diluted so as to afford but minute quantities to the olfactories, then its sweet perfume is generally admitted; the fragrant principle is the same as that breathed by the beautiful narcissus. Civet is extensively used duly attenuated in perfumery. Its powerful and lasting odour enables it to be used in some soaps, and especially in sachets. It is one of the perfumes of 'Spanish Leather,' or Peau d'Espagne; the first gloves used in England were scented with it. Several thousand ounces are annually imported, the average price of which is about 9s. per oz.
Castor is in our day said to be almost obsolete as a perfume, but this is not so; for although it cannot be largely used in any given perfume on account of the almost blackness of its tincture, still when properly diluted it is extensively employed. Its perfume, when old especially, is exceedingly pleasant, and its fixing power is at least equal to that of musk. About 1500 lb. are annually imported, which fetch on the market about 36s. per lb.
Of late years the progress of scientific chemistry has led to the production of numerous odiferous substances, some identical with the active odiferous principles of plants. Among them may be mentioned vanillin, the principle of vanilla (methyl protocatechinic aldehyde); coumarin, of Tonquin bean (coumaric anhydride), and many derivatives of phenol; but the majority of this class of bodies are more used in confectionery for flavouring than in perfumery. The artificial musk of L. Bauer is a delightful perfume, and has many applications in perfumery; but it differs widely in odour from true musk.
The perfumes or bouquets of the shops are really mixtures of some or several of the primitive odours of the two above-mentioned groups. An example or two will illustrate this. 'Jockey Club Bouquet' is thus compounded: 2 gal. extract of orris; gal. each of cassia, rose, and tuberose pomades; gal. civet; gal. musk; gal. spirits of wine; 8 oz. bergamot otto; oz. rose. 'White Rose': 2 pints extract rose pomade; 1 pint each cassia and jasmine; pint spirits of wine; oz. rose otto; 1 drn. patchouli otto. It is obvious that the possible variety is infinite, since there are some sixty or more primitive odiferous substances.
See the Rose Industry of Bulgaria, by Christo Christoff, Kezanlik (trans. by C. H. Piesse); and the 5th edition of Piesse's Art of Perfumery (Lond. 1891).