The Chemical Constitution of Vegetable Aromatic Substances.
The sources of the odors derived from the vegetable kingdom can be divided, as stated above, into so-called essential oils, balsams, gum-resins or soft resins, and hard resins. Since the latter bear a certain relation to the essential oils from which they are formed through chemical combinations, we must consider them first.
The flowers, the fruits and their rinds, or even the wood of some plants form the receptacles of essential oils; if they are liquid they are called essential oils par excellence; if they are firm they are called camphors. Besides, there are intermediate states between them: oil of rose is always viscid and solidifies even at temperatures considerably above the freezing-point of water (see under Oil of Rose).
The bodies which are generally called essential oils are usually mixtures of a hydrocarbon with an oxygenated body, or an unchanged oil with another which has become altered by the influence of the oxygen of the air—a condition to which we shall recur later on. With reference to their elementary composition, essential oils may be divided into two groups:
1. Non-oxygenated essential oils.
2. Oxygenated essential oils.
The non-oxgenated essential oils consist only of two elements—carbon and hydrogen; the other group, as the name indicates, contains a third element in chemical combination, and consist of carbon, hydrogen, and oxygen. Most of the essential oils of the first group have the same chemical composition: C10H16 (10 atoms of carbon combined with 16 atoms of hydrogen). Despite the like chemical composition, all the essential oils display different physical qualities; they vary in density, in refractive power, in boiling-point (often by many degrees), and, a matter of the greatest importance for our purposes, in their odor. We may state at once that but few essential oils can be said to have a pleasant odor; that of most of them is even disagreeable and narcotic to the olfactory nerves; it is only after the oil has been extremely diluted that the odor begins to become pleasant and to resemble that of the plant from which the oil was derived.
According to their physical qualities, essential oils may be described as fluids of a specific narcotic odor, colorless but very refractive, and easily inflammable. Only a few essential oils can be produced in such a state of purity as to appear perfectly colorless; usually they are more or less dark yellow in color, and some even possess a characteristic tint; thus oil of acacia is reddish-brown, oils of rose and absinth are green, oil of chamomile is blue. But a simple experiment will show that the color is not inseparably connected with the oil, for certain tinted oils can be obtained perfectly colorless by being distilled with another, less volatile oil which retains the coloring matter.
The boiling-point of essential oils is in general very high —between 160° and 288° of the centigrade thermometer (C.), or 320° to 550° F. The fact that we smell the essential oils in aromatic plants so distinctly despite their high boiling-point is an evidence of their exceedingly strong influence on the olfactory nerves.
A peculiar property of essential oils, which is of great importance in their preparation, is that of distilling over in large quantities with steam—both ordinary and superheated—that is, at temperatures at most only slightly exceeding 100° C. or 212° F. For this reason essential oils are usually obtained in this way, since they are but slightly soluble in water. Still, most of the oils dissolve in water in sufficient amount to impart to it their characteristic odor and thus to render it often very fragrant. Aqua Naphæ triplex (orange-flower water), rose water, etc., are such as have been distilled over with the essential oils, contain a small quantity of the latter in solution, and hence have a very agreeable odor.
All essential oils dissolve readily in strong alcohol, petroleum ether, benzol, bisulphide of carbon, in liquid and solid fats, in glycerin, etc.; we shall again recur to this important subject under the head of the preparation of the essential oils.
If a freshly prepared essential oil is at once excluded from the air by being placed in hermetically sealed vessels which it completely fills, and is kept from the light, the oil will remain unchanged for any length of time. But if an essential oil is exposed to the air, a peculiar, chemical alteration begins, which proceeds more rapidly and obviously if direct light acts upon the oil at the same time. The odor becomes less intense, the oil grows darker in color and more viscous, and also acquires a peculiar quality: it has a strong bleaching effect which is easily seen on the cork closing the bottle, which is beautifully bleached. After a certain time the oil changes to a viscid, less odorous mass, into balsam, and the latter, after the prolonged influence of the air, finally changes into a brownish, odorless substance, into resin.
These remarkable physical and chemical alterations depend on the fact that the essential oil absorbs oxygen from the air, which it puts into a peculiar condition in which it exerts increased chemical activity and is termed ozonized oxygen. One of the most marked of these effects is the uncommonly strong bleaching power of ozonized or active oxygen. When an essential oil that has altered so far as to contain ozonized oxygen—which is shown by its bleaching vegetable coloring matters such as the juice of cherries, red beets, tincture of litmus, etc., agitated with it—is cooled, we notice the separation from it of a usually crystalline, colorless, and odorless body called stearopten, while the remaining liquid part is called elæopten. Stearopten always contains oxygen, while elæopten still consists only of carbon and hydrogen.
In the formation of the stearopten we distinctly see the beginning process of resinification, which, therefore, is nothing but an oxidation (combination of the essential oil with oxygen). It should, however, be stated that as to many essential oils this is not proven by actual observation. Many of them are not known to us as naturally existing without any stearopten. Balsams are essential oils which have to a great extent changed into resin, which they contain in solution, and thereby have become more or less viscid. If the process of oxidation goes still farther, eventually the greater portion of the essential oil becomes oxidized, the entire mass grows firm, and then possesses only a very faint odor which is due to the last remnants of the unchanged essential oil.
Since aromatic substances during evaporation become mixed with air, it appears probable that they act upon the olfactory nerves only at the moment when they become oxidized.
The entire process of resinification of oil of turpentine can be followed very clearly on the pitch pine (Pinus austriaca, or other species of Pinus), just as oil of turpentine in general can be taken as an example of an essential oil on which the peculiarities of the non-oxygenated essential oils may be easily studied. In many localities the pitch pine is partly deprived of its bark when it has reached a certain age. From the trunk exudes oil of turpentine which in the air becomes more and more viscid by the absorption of oxygen and changes into balsam, called turpentine. The latter is collected and distilled with water, when the unchanged oil of turpentine passes over with the steam, while the odorless resin (rosin or colophony) remains behind in the stills.
The above-mentioned qualities of the essential oils indicate naturally how those used in perfumery, which are often very costly, are to be preserved. For this purpose small strong bottles should be chosen which are closed with well-fitting glass stoppers, over which is applied a glass capsule ground to fit tightly over the neck of the bottle. These bottles should always be completely filled (hence small bottles should be selected), and kept tightly closed, in the dark. As the action of oxygen is retarded by low temperatures, it is advisable to keep bottles containing essential oils in a cool cellar. But care must be had never to pour out an essential oil in the cellar near an open candle light. The vapors are very apt to take fire, as they are quite inflammable.
As there are a great many aromatic vegetable substances, so there are numerous odors, or, to retain the customary though incorrect appellation, numerous essential oils. All of these, however, cannot be used in the art of perfumery, as some of them do not possess a pleasant odor, as is the case, for instance, with oil of turpentine. (We may state here, however, that very pure oil of turpentine, distilled from certain Coniferæ, has an agreeable, refreshing odor which at present has found application in perfumery under the title of forest perfume or pine-needle essence.) Besides, there are numerous essential oils which, while possessing a very pleasant odor, still cannot be used in perfumery except for very cheap preparations, though they are employed in much larger quantities in the manufacture of liqueurs. Such oils are: oil of cumin, fennel, juniper, absinth, etc.
As we shall return to this subject in connection with the essential oils which are used in perfumery in general, we will now consider at greater length the aromatic vegetable substances which are employed for the manufacture of fragrant odors.
[CHAPTER IV.]
THE AROMATIC VEGETABLE SUBSTANCES EMPLOYED IN PERFUMERY.
Every fragrant portion of a plant can be used for the preparation of an aromatic substance, and therefore for the manufacture of a perfume. Hence we are unable, in the following enumeration of the aromatic vegetable substances, to make any claim to absolute completeness; for every new scientific expedition may acquaint us with hitherto unknown plants from which the finest odors may be obtained. We have said above that we have not yet even fixed in our perfumes all the odors of the known aromatic plants, and therefore there is still a large field open to the progressive manufacturer.
In the following pages we must restrict ourselves to the description of those aromatic vegetable substances which are used in the laboratories of the most advanced and scientific perfumers for the manufacture of odors. At the same time we lay particular stress on the fact that the knowledge of these raw materials is a matter of the greatest importance to the manufacturer of perfumes because it enables him to appreciate the differences, often very minute, between fine and inferior qualities. Every manufacturer who aims at the production of fine goods must make it the rule to use nothing but the best raw materials.
The price of the latter is apparently disproportionately high; for all that, only the most expensive materials should be bought, for it is the only kind that can be used. Let us give but two instances in illustration. We find in the market, grades of vanilla the prices of which are as one to four; the latter is fresh and contains the aromatic substance in large amount; the former is old, dry, and worthless, with an artificial glossy surface and little odor. The differences in the price are still greater in an aromatic substance of animal origin, musk, the cheapest grades of which are altogether artificial and perfumed with a mere trace of genuine musk.
Of course, the same remark applies to the raw materials of animal origin and to the chemical products, all of which should be of the greatest purity obtainable.
The aromatic substances at present employed in perfumery for the extraction of odors are the following.
Allspice.
Latin—Pimenta; French—Piment; German—Piment; Nelkenpfeffer.
This spice consists of the fruit berries, at first green, later black, of the Eugenia Pimenta, indigenous to Central America and the Antilles. It is chiefly used in the manufacture of liqueurs, less in perfumery, though it may be employed as an addition to certain strong odors, particularly that of oil of bay; it serves very nicely for scenting cheap soap.
Anise.
Latin—Pimpinella Anisum; French—Anis; German—Anis.
This well-known plant, which is cultivated in many localities on a large scale, belongs to the Order of Umbelliferæ. The seeds contain about three per cent of a very aromatic essential oil which finds application in the manufacture of soap and in cheap perfumery; it is chiefly used as a flavoring for liqueurs. Good anise must have a light green color, an agreeable sweetish odor, and a sharp taste. In order to increase the weight, anise is occasionally moistened with water; such seeds look swollen, are apt to become slimy, and then furnish a less fragrant oil. Anise is not to be confounded with star-anise, which will be mentioned hereafter.
Balm.
Latin—Melissa officinalis; French—Melisse; German—Melissenkraut.
Melissa officinalis, an herbaceous plant with large, beautiful flowers, which grows wild in our woods, contains a very sweet-smelling oil in small quantities. This can be extracted by distillation from the fresh herb, and furnishes very fine perfumes.
Oil of Melissa of the market is, however, usually an East Indian oil, derived from Andropogon citratus. See under Citronella.
Bay (Sweet Bay).
Latin—Laurus nobilis; French—Laurier; German—Lorbeerfrüchte.
The fruits of the bay-tree contain much essential oil which is used less in the manufacture of perfumery than for scenting soap. Venice is the most important point of export. See the next article.
Bay (West Indian).
Latin—Myrcia acris; French—(Huile de) Bay; German—Bay (-Oel).
The essential oil obtained from the leaves of this tree, a native of the West Indies, possesses a very aromatic, refreshing odor somewhat resembling that of allspice. It is known in the market as bay oil or oil of bay. During the last decade or so its use has largely extended, and, while formerly almost unknown on the continent of Europe, has become an important article for the perfumer. An alcoholic distillate, prepared by distilling the fresh leaves with the crude spirit from which rum is otherwise obtained, is known as bay-rum, and is used as a pleasant and refreshing wash for the skin. Bay-rum may also be made by dissolving the oil, together with certain other ingredients, in alcohol.
Benzoin.
Latin—Benzoinum; French—Benjoin; German—Benzoëharz.
This gum-resin, which possesses a pleasant vanilla-like odor, comes from a tree belonging to the Order of Styracaceæ, the Styrax Benzoin, and probably another species of Styrax, indigenous to tropical Asia, especially Siam and Sumatra. The collection of benzoin is very similar to that of pine resin; the bark of the tree is cut open, the exuding juice is allowed to harden on the trunk, and is thus brought into commerce. Benzoin differs according to its origin, the age of the tree, etc., and in commerce a number of sorts (Siam, Penang, Palembang, and Sumatra) are distinguished. As a rule, benzoin comes in lumps ranging in size to that of a child’s head. They are of a light gray color and inclose white, almond-shaped pieces. The finest quality, known as Siam benzoin after its source, usually is in small pieces (Siam benzoin in tears) which are translucent, light yellow to brown externally, but milky white on fracture, and have a strong vanilla odor. Less fine but still very good is Siam benzoin in lumps, consisting of large reddish-brown pieces inclosing white particles. All other kinds mentioned above come from the island of Sumatra, in lumps the size of a fist. What was formerly known as Calcutta benzoin formed large friable pieces of a dirty reddish-gray color. Siam as well as Penang benzoin often contains, besides benzoic acid, also cinnamic acid; it is not known why it is not a regular constituent. The worst quality is sold as “benzoin sorts,” consisting of brownish pieces without white spots; they are often mixed with splinters of wood, bast fibres, and fragments of leaves, and can be used only for cheap perfumes.
Good benzoin, besides the qualities named, must have a sweetish and burning sharp taste, it should be very friable, and when heated in a porcelain capsule should emit vapors (benzoic acid) of an acrid taste and a pronounced aromatic odor; it should dissolve completely in strong alcohol. In perfumery, benzoin serves for the preparation of many odors, washes, and the manufacture of benzoic acid. The latter will be further discussed under the head of aromatic substances obtained by means of chemistry.
Bergamot.
Latin—Citrus Bergamia; French—Bergamote; German—Bergamottefrüchte.
The bergamot is the fruit of a tree belonging to the Order of Aurantiaceæ, which is cultivated in Calabria. The tree is unknown in a wild state. The golden-yellow or greenish-yellow fruits, resembling a lemon in shape, have a bitter and at the same time acid pulp; the thin rind contains a very fragrant oil which is used largely in the manufacture of fine perfumery and soaps, and is exported chiefly from Messina and Palermo.
Bitter Almonds.
Latin—Amygdala amara; French—Amandes amères; German—Bittere Mandeln.
The well-known fruits of the bitter almond-tree (Amygdalus communis, var. amara). There are no definite botanical differences between the sweet and the bitter almond-tree. The only distinct difference is the character of the respective fruits. The aromatic substance obtained from bitter almonds is not present fully formed in the fruits, but results from the chemical transformation of the amygdalin they contain; the latter body is absent in sweet almonds.
Cajuput Leaves.
Latin—Folia Cajuputi.
The leaves of Melaleuca Cajuputi, a tree found in the Indian and Malay Archipelago, which have an aromatic odor resembling that of cardamoms. In the Orient the leaves are used as incense and for the extraction of the oil they contain.
Camphor Wood.
Latin—Lignum Camphoræ; French—Bois de camphre; German—Campherholz.
The wood of the Camphor-tree, native of China and Japan, is exceedingly rich in essential oil, the firm, white, and strong-scented camphor. The latter is usually prepared from the wood at the home of the tree, especially in Formosa and Japan, so that the wood hardly forms an article of commerce and is here enumerated only for completeness’ sake. In China and in Japan, however, it is largely used for the manufacture of cloth-chests, trunks and wardrobes, as these are never invaded by insects.
Caraway Seed.
Latin—Semen Carvi; French—Carvi; German—Kümmelsamen.
This plant, Carum Carvi, which is largely cultivated in Germany, contains in its seeds from four to seven per cent of essential oil which is extracted by distillation. Genuine caraway seed is brownish-yellow, pointed at both ends, quite glabrous on examination with a lens, and marked with five longitudinal ribs. Caraway is occasionally confounded with cumin seed, from Cuminum Cyminum, which is easily recognized with a lens: the seeds of the latter plant have fourteen longitudinal ribs and are hairy. The use of caraway in perfumery is limited to ordinary goods, but in the manufacture of liqueurs it is largely employed.
Cascarilla Bark.
Latin—Cortex Cascarillæ; French—Cascarille; German—Cascarillarinde.
This is the bark of a West Indian tree, Croton Eluteria, belonging to the Order of Euphorbiaceæ, native of the Bahamas. It occurs in commerce in the shape of pieces the length and thickness of a finger; externally it is white and fissured, internally of a brown color and resinous. Good qualities should be free from dust and fractured pieces (sifted cascarilla), of a warm aromatic taste, and a very agreeable odor which becomes more marked on being heated. Another variety of cascarilla derived from South Africa, Cascarilla gratissima, has very fragrant leaves which can be used immediately as incense, just as cascarilla in general is employed in perfumery chiefly for fumigating powders and waters.
Cassie.
Latin—Acacia farnesiana; French—Cassie; German—Acacie.
The flowers of Acacia farnesiana (Willd.), one of the true acacias, native of the East Indies, which flourishes farther north than the other varieties, cultivated largely in southern France for the delightful odor which resembles that of violets but is more intense. The flowers are collected and made to yield their odorous principle by one of the methods to be described hereafter. The plant which is generally but falsely called Acacia in this country, viz., Robinia pseudoacacia, likewise bears very fragrant flowers which undoubtedly can be made to yield a perfume by some one of the usual methods; but so far we know of no perfume into which the odor of Robinia flowers enters. Moreover, it is not alone the flowers of Acacia farnesiana which may be utilized for the preparation of the cassie perfume; the black currant, Ribes niger, contains in its flowers an odor closely resembling the former; this is actually used in the preparation of an oil sold under the name of “oil of cassie.” The latter plant flourishes in our northern States and would answer as a substitute for Acacia farnesiana, which cannot stand our northern winters.
Cedar Wood.
Latin—Lignum Cedri; French—Bois de cèdre; German—Cedernholz.
The wood met with in commerce is derived from the Virginian juniper tree, Juniperus virginiana, which is used in large quantities for inclosing lead pencils. The chips, the offal from this manufacture, can be employed with advantage for the extraction of the essential oil contained therein. Long uniform shavings of this wood are also used for fumigation, and the sawdust for cheap sachet powders. Cedar wood is reddish-brown, fragrant, very soft, and splits easily. In the perfumery industry it usually passes under the name of the “cedar of Lebanon,” although the wood from the last-mentioned tree (Cedrus libanotica) has quite a different agreeable odor, is very firm, reddish-brown, and of a very bitter taste—qualities by which it is readily distinguished from the other.
Cinnamon.
Latin—Cinnamomum; French—Canelle; German—Zimmtrinde.
Cinnamon consists of the bark of the young twigs of the cinnamon-tree, Cinnamomum zeylanicum, indigenous to Ceylon. Good cinnamon consists of thin, tubular, rolled pieces of bark which are smooth, light brown (darker on fracture), of a pronounced characteristic odor, and a burning and at the same time sweet taste. The most valuable in commerce is that from Ceylon; the thicker bark is less fine.
Chinese cinnamon or cassia (French, Cassie; German, Zimmtcassia) consists of the bark of the cassia-tree, an undetermined species of Cinnamomum indigenous to Southern China; this is grayish-brown and has the general properties of true cinnamon, but it as well as the oil extracted from it has a less fine odor than cinnamon or oil of cinnamon. A very fine kind of Cinnamon has for a number of years past appeared on the market under the name of Saigon cinnamon. It is very rich in oil, and is exported from Cochin-China. Besides the true oils of cinnamon and cassia, other essential oils are met with in commerce under the names of oil of cinnamon flowers and oil of cinnamon leaves, but their odor is not so fine as that of the former. The so-called cinnamon flowers are the unripe fruits of various cinnamon laurels, collected after the fall of the blossoms. They form brownish cones the length of the nail of the little finger, and furnish an essential oil whose odor resembles that of cinnamon.
Citron.
Latin—Fructus Citri; French—Citron; German—Citronenfrüchte.
The fruit of a tree, Citrus medica, indigenous to northern India, but largely cultivated in the countries situated around the Mediterranean and in other countries. It is cultivated both for the pleasant acid juice of the fruit and for their fragrant rinds. Only the latter are of value for our purposes. It occurs in European commerce under the name of Citronat or citron peel. Good commercial citron peel should be in quarters and as fresh as possible, which is shown by its softness, the yellow color, and the strong odor. Old peel looks shrunken and brownish and has but little pleasant odor.
Citron Flowers.
Latin—Flores Citri; French—Fleurs de citron; German—Citronenblüthen.
The flowers of the citron-tree (Citrus medica) are white, fragrant, and contain a very aromatic essential oil; but as the oil is always extracted from the fresh flowers, the latter do not form an article of commerce.
Cherrylaurel Leaves.
Latin—Folia Laurocerasi; French—Laurier-cérise; German—Kirschlorbeerblätter.
The leaves of this tree (Prunus Laurocerasus), which is largely cultivated for officinal purposes, furnish an odorous substance completely identical with that contained in bitter almonds, or, rather, formed in them under certain conditions. As the extraction of the odorous substance from bitter almonds is much cheaper, cherry-laurel is but rarely used.
Citronella.
Latin—Andropogon Nardus; French—Citronelle; German—Citronella.
This grass, which, like the oil prepared from it, is called citronella, is a native of northern India, and is largely cultivated in Ceylon, where large quantities are worked for the oil; for this reason the grass itself is seldom met with in commerce. Its odor is somewhat similar to that of the Indian lemon grass, that of verbena, and that of several other aromatic plants, in place of which citronella is frequently employed.
Much confusion exists in much of the current literature regarding the source and synonymy of the Indian grass oils and allied products. The following list contains the most important ones:
1. Andropogon citratus DC.—Lemon Grass. The oil is known as Lemon Grass Oil, Indian Verbena Oil or Indian Melissa Oil, or simply Oil of Verbena or Oil of Melissa.
2. Andropogon laniger Desf.—This is the Juncus odoratus or Herba Schoenanthi of older pharmacy. No oil is prepared from this.
3. Andropogon muricatus Retz.—Cuscus or Vetiver. Source of Oil of Vetiver.
4. Andropogon nardus L.—Citronella. Source of Oil of Citronella.
5. Andropogon Schoenanthus L.—Ginger Grass. The oil is known as Oil of Ginger Grass, Oil of Geranium Grass, Oil of Indian Geranium or simply Oil of Geranium, also Oil of Rose Geranium [“Rose” is here a corruption of the Hindostanee name of the plant, viz., Rusa], Oil of Rusa Grass, Oil of Rusa, Oil of Palmarosa.—The two terms “Oil of Geranium” and “Oil of Rose Geranium” should be abandoned for this oil, to avoid confusion with the “Oil of (Rose) Geranium” obtained from Pelargonium. See under “Geranium.”
Clove.
Latin—Caryophylli; French—Clous de girofle; German—Nelkengewürz.
This well-known spice comes from a tree, Caryophyllus aromaticus, native of the Moluccas, and largely cultivated at Zanzibar, Pemba, and elsewhere. It consists of the closed buds. The main essential of good quality is the greatest possible freshness, which may be recognized by the cloves being full, heavy, reddish-brown, and of a fatty aspect, and they must contain so much essential oil (about 18 per cent) that when crushed between the fingers the latter should be stained yellowish-brown. Before buying, this test should always be made, and attention paid to the fact whether the whitish dust is present in the wrinkles about the head. We have found in commerce cloves from which the essential oil had been fraudulently extracted with alcohol and hence were worthless; such cloves may be recognized by the faint odor and taste, but especially by the absence of the whitish dust.
Cucumber.
Latin—Cucumis sativus; French—Concombre; German—Gurke.
The well-known fruits of this kitchen-garden plant, though not strictly sweet-scented, possess a peculiar refreshing odor which has found application in perfumery. Certain products belonging under this head require the odor of cucumber, and therefore this plant is to be included among the aromatic plants in a wider sense.
Culilaban Bark.
Latin—Cortex Culilavan; French—Ecorce culilaban; German—Kulilabanrinde.
The bark of Cinnamomum Culilavan Nees, a plant indigenous to the Molucca islands, used to occur in commerce in the shape of long, flat pieces of a yellowish-brown color, with an odor like a mixture of cinnamon, sassafras, and clove oils. It is rarely met with now.
Dill.
Latin—Semen Anethi; French—Aneth; German—Dillsamen.
This plant, Anethum graveolens, which is indigenous to the Mediterranean region and southern Russia, contains in all its parts, particularly in the seeds, an oil of a peculiar odor, which is used as a perfume for soap, also in cheap perfumery, and especially as a flavoring for liqueurs.
Elder Flowers.
Latin—Flores Sambuci; French—Sureau; German—Hollunderblüthen.
This bush, Sambucus niger, which grows wild in Europe, bears umbellar flowers which are officinal, but contain besides a pleasant odor which can be extracted from them. The odor of the flowers deteriorates on drying, hence in perfumery only the fresh flowers should be used. The American elder (Sambucus canadensis) could easily be used in place of it.
Fennel (Seed and Herb).
Latin—Fœniculum; French—Fenouil; German—Fenchel.
This plant, Fœniculum vulgare, Order Umbelliferæ, is largely cultivated in Europe. It contains an essential oil in all its parts, but especially in the seeds. The plant is rarely used in perfumery, but more frequently in the manufacture of liqueurs. The herb, dried and comminuted, enters into the composition of some cheap sachets.
Frangipanni (see Plumeria).
Geranium.
Latin—Pelargonium roseum; French—Géranium; German—Geranium.
This plant, originally indigenous in South Africa, contains in its leaves an essential oil whose odor closely resembles that of roses. At present it is cultivated on a large scale in many parts of France and in Turkey, solely for the purposes of perfumery. This plant would grow freely in our Southern and Middle States, and could be cultivated with advantage for the extraction of its highly valued perfume.
The terms “Oil of Geranium” and “Oil of Rose Geranium” ought to be restricted in commerce to the oil obtained from true geranium (Pelargonium). Unfortunately, they are yet very commonly applied to an East Indian oil obtained from a species of Andropogon (see under Citronella).