The chief benzenoid compounds used as perfumes are aldehydes, oxyaldehydes, phenols and phenol ethers. Benzaldehyde has the odour of almonds, cinnamic aldehyde of cinnamon, and cumin aldehyde gives the odour to cumin oil. Of oxyaldehydes salicylaldehyde gives the odour to spiraea oil, and vanillin is the active ingredient of vanilla (q.v.). Anisaldehyde smells like hawthorn, and is extensively used under the name aubépine for scenting soaps and extracts. Carvacrol and thymol are isomeric methyl propyl phenols; both have the odour of thyme. Of phenol ethers eugenol (allyl guaiacol) has the odour of cloves, and anethole (allyl phenyl methyl ether) is the chief constituent of anise oil, being chiefly used in the manufacture of liqueurs. Several piperonyl compounds are of commercial importance. The aldehyde, CH2[O]2.C6H3·CHO(1,2,4), piperonal, has the odour of heliotrope; an allyl derivative, safrole CH2[O]2.C6H3·C3H5(1,2,4), occurs in sassafras, while apiole or dimethoxy safrole has the odour of parsley oil. Of other synthetic perfumes amyl salicylate is used under the names of orchidée or trefol as the basis of many perfumes, in particular of clover scents, methyl anthranilate occurs in the natural neroli and other oils, and has come into considerable use in the preparation of artificial bergamot, neroli, jasmine and other perfumes (the Trolene, Marceol and Amanthol of the Actien Gesellschaft für Anilin Fabrikation have this substance as a base); the “artificial musks” are derivatives of s-trinitrobenzene; coumarin is the principle of woodruff; and β-naphthol methyl ether is used for the preparation of artificial neroli.
The Odophone.—The most important element in the perfumer’s art is the blending of the odorous principles to form a mixture which gratifies the sense of smell. Experience is the only guide. It is impossible to foretell the odour of a mixture from the odours of its components. Septimus Piesse endeavoured to show that a certain scale or gamut existed amongst odours as amongst sounds, taking the sharp smells to correspond with high notes and the heavy smells with low. He illustrated the idea by classifying some fifty odours in this manner, making each to correspond with a certain note, one-half in each clef, and extending above and below the lines. For example, treble clef note E (4th space) corresponds with Portugal (orange), note D (1st space below clef) with violet, note F (4th space above clef) with ambergris. It is readily noticed in practice that ambergris is much sharper in smell (higher) than violet, while Portugal is intermediate. He asserted that properly to constitute a bouquet the odours to be taken should correspond in the gamut like the notes of a musical chord—one false note among the odours as among the music destroying the harmony. Thus on his odophone, santal, geranium, acacia, orange-flower, camphor, corresponding with C (bass 2nd line below), C (bass 2nd space), E (treble 1st line), G (treble 2nd line), C (treble 3rd space), constitute the bouquet of chord C.
Other Branches of Perfumery.—As a natural outcome of the development of the perfume industry, scented articles for toilet and other uses are now manufactured in large quantities. Soaps, toilet powders, tooth powders, hair-washes, cosmetics generally, and note-paper have provided material on which the perfumer works. For the preparation of scented soaps two methods are in use; both start with a basis either of fine yellow soap (which owes its odour and colour to the presence of resin), or of curd soap (which is hard, white and odourless, and is prepared without resin). In one process the soap is melted by superheated steam, and while still hot and semi-fluid mixed by means of a stirrer of wood with iron cross-bar, technically called a “crutch,” with the attars and colouring matter. It is then removed from the melting pan to a rectangular iron mould or box, the sides of which can be removed by unscrewing the tie-rods which hold them in position; when cold the mass is cut into slabs and bars with a thin brass wire. In the other or cold process the soap is first cut into chips or shavings by a plane or “chipping machine,” then the colouring matters are added and thoroughly incorporated by passing the soap between rollers; the tinted soap emerges in a continuous sheet but little thicker than paper. The perfumes are then added, and after standing for about twelve hours the soap is again sent through the rolling machine. It is next transferred to a bar-forming machine, from which it emerges as a continuous bar almost as hard as wood. Soap thus worked contains less than 10% of water; that prepared by melting contains 20 and even 30%. The amount of perfume added depends upon its nature, and amounts usually to about 7 or 8%. The finest soaps are always manufactured by the cold process.
Toilet Powders are of various sorts. They consist of rice-starch or wheat-starch, with powdered orris-root in varying proportions, and with or without the addition of zinc oxide, bismuth oxide or French chalk. The constituent powders, after the addition of the perfume, are thoroughly incorporated and mixed by sifting through a fine sieve. Violet powder for the nursery should consist entirely of powdered violet root (Iris florentina), from the odour of which the powder is named. It is of a yellowish tint, soft and pleasant to the touch. The white common so-called “violet powders” consist of starch scented with bergamot, and are in every sense inferior.
Tooth Powders consist for the most part of mixtures of powdered orris-root with precipitated chalk, and some other constituent destined to particularize it as to properties or flavour, such as charcoal, finely pulverized pumice, quassia, sugar, camphor, &c. The perfume of the contained orris-root is modified, if required, by the addition of a little of some perfume. Tooth Pastes are formed of the same constituents as the powders, and are worked into a paste by the addition of a little honey or glucose syrup, which substances are usually believed ultimately to have an injurious effect on the teeth.
Perfume Sachets consist either of a powder composed of a mixture of vanilla, musk, Tonqua beans, &c., one or other predominating as required, contained in an ornamental silk sac; or of some of the foregoing substances spread upon card or chamois leather or flannel after being made into a paste with mucilage and a little glycerin. When dry the card so prepared is daintily covered with various parti-coloured silks for sale. Where the ingredients employed in their manufacture are of good quality these cards, known as “peau d’Espagne” sachets, retain their odour unimpaired for years.
Adulterations.—There is, as might be expected, considerable scope for the adulteration of the “matières premières” employed in perfumery. Thus, in the case of musk, the “pods” are frequently found to be partially emptied of the grain, which has been replaced by hide or skin, while the weight has been increased by the introduction of lead, &c. In other instances the fraud consists in the admixture of refuse grain, from which the odour has been exhausted with spirit, with dried blood, and similar substances, whilst pungency is secured by the addition of ammonium carbonate. Attar of rose is diluted with attar of Palma rosa, a variety of geranium of only a quarter or a fifth of the value. The main adulterant of all the natural essential oils, however, is castor oil. This is a bland neutral body, practically odourless, and completely soluble in alcohol; it therefore presents all the requisites for the purpose.
Bibliography.—See generally, J. C. Sawyer, Odorographia, vol. i. (1892), vol. ii. (1894); G. W. Askinson, Perfumes (Eng. trans. by Isidor Furst, 1892); S. Piesse, Art of Perfumery (1891); Paul Hubert, Plantes à parfumes (1909); M. Otto, L’Industrie des parfums (1909). Synthetic perfumes are treated in detail in C. Deite, Manual of Toilet Soap-making (Eng. trans. by S. I. King, 1905), and in E. J. Parry, Chemistry of the Essential Oils and Artificial Parfumes (2nd ed., 1908). Reference may also be made to T. Koller, Cosmetics (1902). The standard works on the essential oils are given in the article Oils. G. Cohn, Die Riechstoffe (1904), treats the chemistry, and Zwaardemaker, Physiologie des Geruchs (1895), the physiology of perfumes. See also the reports and bulletins of Schimmel & Co. and Rouse Bertrand et Fils.
PERGA (mod. Murtana), an ancient city of Pamphylia, situated about 8 m. inland, at the junction of a small stream (Sari Su) with the Cestrus. It was a centre of native influences as contrasted with the Greek, which were predominant in Attalia, and it was a great seat of the worship of “Queen” Artemis, here represented as a human-headed cone and a purely Anatolian nature goddess. There Paul and Barnabas began their first mission in Asia Minor (Acts ix. 13). A much frequented route into Phrygia and the Maeander valley began at Perga, and Alexander made it the starting-point of his invasion of inner Asia Minor. Long the metropolis of Pamphylia Secunda, it was superseded in Byzantine times by its port Attalia, which became a metropolis in 1084. The extensive ruins all lie in the plain south of the Acropolis. The walls are well preserved, but of late Roman or Byzantine reconstruction. The lines of intersecting streets can be easily made out, and there are ruins of two sets of baths, two basilicas and a forum. But the most notable monument is the theatre, which lies outside the walls on the south-west, near the stadium. This is as perfect as those of Myra and Patara, but larger than either, and yields the palm only to those of Aspendus and Side. Modern Murtana is a large village, long under the dominion of the Dere Beys of the Tekke Oglu family.
See C. Lanckoronski, Villes de la Pamphylie et de la Pisidie, vol. i. (1890); Sir W. M. Ramsay, Church in the Roman Empire (1893). (D. G. H.)
PERGAMENEOUS (Lat. pergamena, parchment), a technical
term used of anything of the texture of parchment, as in zoology
of the wing-covers of insects.
PERGAMUM, or Pergamus (mod. Bergama), an ancient city of Teuthrania, a district in Mysia. It is usually named Πέργαμον, by Greek writers, but Ptolemy has the form Πέργαμος. The name, which is related to the German burg, is appropriate to the situation on a lofty isolated hill in a broad fertile valley, less than 15 m. from the mouth of the Caïcus. According to the belief of its inhabitants, the town was founded by Arcadian colonists, led by Telephus, son of Heracles. Auge, mother of
