was scarcely accommodated to the convention of theatrical form. Pérez Galdós became a member of the Spanish Academy, and was also elected to the Cortes; but it is solely as a romancer that his name is familiar wherever Spanish is spoken, as a national novelist of fertile talent, and a most happy humorist who in his eccentrics and oddities is hardly inferior to Dickens. (J. F.-K.)
PERFUMERY (Lat. per, through, and fumare, to smoke), the preparation of perfumes, or substances which are pleasing to
the sense of smell. Perfumes may be divided into two classes, the
first of which includes all primitive or simple odoriferous bodies
derived from the animal or vegetable kingdom, as well as the
definite chemical compounds specially manufactured, while
the second comprises the various “bouquets” or “mélanges”
made by blending two or more of the foregoing in varying
proportions—toilet powders, dentifrices, sachets, &c. To the
former class belong (1) the animal products, ambergris, castor,
civet, musk; (2) the essential oils (also called attars), mostly
procured by the distillation of the stems, leaves, flowers and other
parts of plants; (3) the philicome butters or oils, which are
either solid or liquid fats charged with odours by the processes
of inflowering or maceration; (4) the odoriferous gum-resins or
balsams which exude naturally or from wounds in the trunks of
various trees and shrubs, such as benzoin, opoponax, Peru, Tolu,
storax, myrrh; (5) the large number of synthetic perfumes
which simulate the odour of the natural scents. The second
class contains the endless combination of tinctures sold under
fancy names which may or may not afford a clue to their composition,
such as “comédie française,” “eau de senteur,” “eau de
Cologne,” “lavendre ambrée,” “blumengeist.” In general,
they are mixtures of a number of perfumes dissolved in alcohol.
Strictly speaking, most of the perfumes on the market belong to
the second class, since, in most cases, they are prepared by
blending various natural or artificial odorous principles.
Natural Perfumes.—The animal perfumes are extremely limited in number. Ambergris (q.v.), one of the most important, is secreted by the sperm whale; musk (q.v.), the best known scent of this class, is secreted by the male musk-deer and other animals—musk-ox, musk-rat, &c.; civet (q.v.) is a musky scent named from the animal which secretes it; and castor or castoreum is a somewhat similar secretion of the beaver (q.v.). More important are the scents yielded by flowering plants. As a general rule fragrant flowers flourish in hot climates, but the more delicate perfumes are yielded by plants having a colder habitat; it must be remembered, however, that some costly perfumes are obtained from the plants of Ceylon, the East Indies, Mexico and Peru. In Europe, Grasse, Cannes and Nice are the centres of the natural perfume industry. Cannes is famous for its rose, acacia, jasmine and neroli oil; Nîmes for its thyme, rosemary and lavender; and Nice for its violets. Citron and orange oil come from Sicily; iris and bergamot from Italy; and roses are extensively cultivated in Bulgaria, and in European Turkey. England is unsurpassed for its lavender and peppermint, which flourish at Mitcham and Hitchin.
The natural sources of the attars or essential oils are the different parts of the plants which yield them—the wood (lign, aloe, santal, cedar), the bark (cinnamon, cascarilla), the leaves (patchouli, bay, thyme), the flowers (rose, lavender, orange-blossom), the fruit (nutmeg, citron), or the seeds (caraway, almond). Some plants yield more than one, such as lemon and bergamot. They are mostly obtained by distilling that part of the plant in which they are contained with water, or with high-pressure or superheated steam; but some few, as those from the rind of bergamot (from Citrus bergamia), lemon (citron zeste, from C. Limonum), lime (C. Limetta), by “expression.” The outer layer of the cortex is rasped off from the unripe fruits, the raspings placed in a canvas bag, and squeezed in a screw or hydraulic press. The attars so obtained are separated from the admixed water by a tap-funnel, and are then filtered. Certain flowers, such as jasmine, tuberose, violet, cassia, either do not yield their attars by distillation at all, or do it so sparingly as not to admit of its collection for commercial purposes; and sometimes the attar, as in the case of orange (neroli), has an odour quite different from that of the fresh blossoms. In these cases the odours are secured by the processes of inflowering (enfleurage) or by maceration. Both depend upon the remarkable property which fats and oils possess of absorbing odours. Enfleurage consists in laying the leaves or flowers on plates covered with a layer of fat. The flowers are renewed every morning, and when the fat has sufficient odour it is scraped off, melted and strained. Maceration consists in soaking the flowers in heated fat; in due time they are strained off and replaced by fresh ones, as in the enfleurage process. The whole of the necessary meltings and heatings of the perfumed greases are effected by means of water-baths, whereby the temperature is kept from rising too high. For the manufacture of perfumes for the handkerchief the greases now known as pomades, butters or philocomes are treated with rectified spirit of wine 60° overproof, i.e. containing as much as 95% of absolute alcohol by volume, which practically completely abstracts the odour.
The gum-resins and resins have been employed as perfumes from the earliest times. The more important are incense, frankincense and myrrh (q.v.). They are largely used in the manufacture of perfumes, both for burning as pastilles, ribbon of Bruges, incenses, &c., and in tinctures, to which they impart their characteristic odours, affording, at the same time, a certain fixity to other perfumes of a more fleeting nature when mixed with them.
Synthetic Perfumes.—Under this heading are included all perfumes in which artificial substances are odorous ingredients. Although the earliest perfumes of this class were introduced in about the middle of the 19th century, the important industry which now prevails is to be regarded as dating from the ’seventies and ’eighties. Three main lines of development may be distinguished: (1) the chance discovery of substances which have odours similar to natural perfumes; (2) the elucidation of the composition of the natural scents, and the chemical constitution of their ingredients, followed by the synthetic preparation of the substances so determined; and (3), which may be regarded as connected with (2), the extraction and separation of the essential oils yielded by less valuable plants, and their reblending to form marketable perfumes.
The first synthetic perfume was the “essence of Mirbane” introduced by Collas in about 1850; this substance was the nitro-benzene discovered by E. Mitscherlich in 1834. Soon afterwards many esters of the fatty acids simulating the odours of fruits were introduced; and in 1888 Baur discovered the “artificial musks,” which are derivatives of s-trinitrobenzene. The above are instances of the first line of progress. The second line has for early examples the cases of artificial oil of wintergreen, which followed Cahour’s discovery that the natural oil owed its odour, in the main, to methyl salicylate, and of artificial oil of bitter almonds which followed the preparation of benzaldehyde from benzal chloride in 1868. The synthesis of coumarin, the odorous principle of hay and woodruff, by Sir W. H. Perkin in 1868; of vanillin, the odorous principle of vanilla, by F. Tiemann and W. Haarmann in 1875; and of ionone, almost identical with the natural irone, the odorous principle of violets, by Tiemann and P. Kruger in 1898, are to be regarded as of the highest importance. Equally important are the immense strides made in the elucidation of the constitution and syntheses of the terpenes (q.v.), a group of compounds which are exceptionally abundant as odorous principles in the essential oils.
The present state of our knowledge does not permit a strict correlation of odour and chemical constitution. One theory regards odour as due to “osmophores” or odour-producing groups, in much the same way as colour is associated with chromophores. Such osmophores are hydroxyl (OH), aldehyde (CHO), ketone (CO), ether (·O·), nitrile (CN), nitro (NO2), &c.; we may also notice the isonitrile group (·NG) associated with an unpleasant odour, and the iso-thiocyanate group (·NCS) to which the mustard oils owe their characteristic smell. The same group, however, is not invariably associated with the same odour, or even any odour at all, as, for instance, in such closely related
