RUTACEALS. Polypetalous exogens, having monodichlamydeous symmetrical flowers, axial placente, imbricated calyx and corolla, definite _ Stamens, and embryo with little or no albumen. By the older bota-hists the Ruracears were all considered as one order. De Jussieu places them among his dicotyledonous hypogens, which have the stamens inserted upon the receptacle under the ovary. Dr. Lindley es the group into thirteen natural orders, as follows:—

and shrubs, bark almost smooth, and filled everywhere with little ent n for volatile oils;succulent indehiscent fruit;leaves eceptaes CLXX. Aurantiacee. » altern:ma en com artic with the petiolar petals and oa ce‘ anoand reeshadd“and—fi,equal or double of the latter. Includinguding oranges,

‘: detect eS ie tor in beilattl:—_ alternate or — —;8 Xi terminal flowers in sabtons orpenis es; pel: cg CLXXI, Amyridacese vara wi; stamens twice the number; fruit hard, dry and see ae Dances trees, with alternate pinnate leaves, without stipules;Howers in . petals, fouror five gl ns free or monodelphous; double in t CLXXII. Cedrelacer. Cas fruit; senda winged; numerous. wees or with leaves, d iternate, sometimes opposite;non- i 3 foie na or a imperfectby abortion;fruit, CLXXIIT. Meliacez. oFcapsular; stamens monodelphous; re eigen Hen ae

Trees or shrubby —— with alternate gor or orci bof ger 3 CLXXIV. Anacardiacee. leaves; Seeuciaal axillary flowers with bracts; apocarpo singlee ovule rising from the baseof the cell.

Trees or shrubby, sometimes climbing exogens, with compound leaves; terminalorsyeviomct flowers in racemes or panicles; apocarpal fruit, and CLXXV. Connaracee.

IN Trees shru sy xogens, rarely herbaceo 3 leaves non-stip late, log or aversate, plesk with eit va Me dots; axi dlaey CLXXVI. Rutacez. or terminal gece fruit few-seeded, Renogennt anacarpous; pericarp

Trees shrubby PRET with non.siipuiste, alternate. rdccna 7 leaves: flowers axillary or termi nal; fruit few-seeded, becom‘ | CLXXVII. SP Nace pous; pericarp earn intonga aa perso pendulous ies see 5 _ Smooth trees or under simple, or toothedwith ruit one- CLXXVITI. Ochnacee. seeded, tec apocarpous; oat a ct a conical torus.

Trees or shrubs, leaves alternate, compound, sometimesrene i CLXXIX. Simarubacez. sae: peduncles axillary;few-seeded fruit, Tecunag anac:

shrubs, or herbaceous exogens, with opposite iad! ibe Xygophylla- usuallyunequally pinnate; flowers wc in _ or jag Bstaree mc CLXXX. cer. dite; fruit few-seeded, finalally anacarpous us dry an croscopic; seed peuned

Small annual exogens, with opposite leaves; stipules oo the; petioles; jajonulens flowers, and many-seeded anacarpous frui t ae

Herbaceous exogens, with capillary a Peg or tue very CLXXXII. ee imperfect flowers;many-seeded anacarpous

The group of exogens of which the well-known and humble Rue is the type, includes the Orange, the Melon, the Lime, the Shaddock, Forbidden Fruit, and the Citron in the Aurantiaceé; incense-yielding trees or shrubs in the Amyridacee; a substitute for Peruvian Bark, is the Bastard Cedars, in Cedrelacee. The Anacardiacee include the Cashews. Pistachia vera, a tree fifteen feet high, originally from Syria, yields the fruit so much esteemed as the Desert Nut. Gum mastic is drawn from P. /entiscus. The aromatic bark of Rhus cotinus (the Wild Olive, or Sumach) is one of the substitutes for Peruvian bark. The order generally yields resinous products of considerable commercial value. The Rutacee agree with the Aurantiacee in haying dotted leaves, — definite stamens, and fleshy disc. The plants of this order emit offensive odour from the glands which cover them. In the case of some of the genus Dictamnus the glands are filled with volatile oil, and in hot weather the surrounding atmosphere becomes — so charged with it that a light coming in contact will inflame the air. The Xanthroxylacee are tropical plants of Asia, Africa, and America, and all possess in various degrees aromatic pungent properties. “The Simarubacee, or Quassias, are known,” says A. de Jussieu, “from all the rutaceous plants by the coexistence of these characters—namely: ovaries with one ovale,

indehiscent drupes, exalbuminous seeds, a membranous integument to the embryo, and by the radicle being retracted within thick cotyledons.” The plants of the order are intensely bitter— _ 80 bitter that the Ptinie, which attack all other dried specimens, refuse to attack Simaruba versicolor. The Orange (Citrus aurantium), which is at once the best known and most highly appreciated fruit, is a fine evergreen tree, originally from China, the islands of the Indian Ocean, and of those which are scattered over the Pacific. It is now largely cultivated in all the warm countries of the globe. Its glossy leaves are simple or compound, with one or many pairs of leaflets; the terminal ones, on winged leafy footstalks, are oval or lanceolate, and entire. When examined through a strong li¢ht these leaves present little bright spots,

Se OZ Which ae are so many ves- Ss —_ Sels full of an odorous FEB ES Volatile oil. Its flowers, Al Whose elegance and de- BYLINE licate perfume are so well

Own, are composed of 4 somewhat bell-shaped yx, adhering slightly “F222 » cog0e2*Pt the diss: corolla with Fig. 411,—SectionofanOrange.

Ce three to five petals, broad at the base, sometimes slightly com- - bined, inserted on the outside of a hypogynous disk; the stamens, : equal in number, double or any multiple of the number, distinct _ © united at the base—are disposed at the summit of a peduncle ne hag Paucifloral bouquets. The fruit we need not describe; it is _ Separated by membranous divisions into many cells (Fig. 411), _ ‘Sentaining seeds at their inner angle; it is filled with soft and a:Juicy pulp, sweet and slightly acid. | ie vere are numerous varieties of the Orange; the best are the Chinese, the Maltese, the Lisbon and St. Michael’s, and, later -™ the season, an excellent variety comes from Valentia. The

St. Michael’s should be small, and flattened at the ends, with a thin smooth rind, the glands small, and the flesh a light ash-coloured pulp; but many coarse varieties come to market. Those from Valentia resemble St. Michael’s. Lisbon and Malta oranges are larger, thicker in the rind, with glands; but the Chinese orange, when obtained of the best variety, excels all others for delicate flavour, sugary juice, and delicate aroma. The skin of this variety is always smooth and shining, and so thin that it is separated with difficulty from the flesh. The St. Michael’s is probably a variety of this orange. The Bitter or Seville Orange is the fruit of Citrus vulgaris, but there are many varieties. This is the fruit from which the delicate condiment, orange marmalade, is prepared, and from which orange-flower water is produced. The Orange is extensively cultivated in order to extract from its flowers and leaves the essential oil which they contain. In the South of France, but especially in Provence and Nice, the Orange is largely and successfully cultivated. In the South of Italy, about Sorrenta, whole forests of Oranges exist, the fruit of which is carefully harvested.

‘On th hore, where the sea of Sorrenta At the foot of the Orange unrolls its blue wave,”

sings Lamartine, France’s great modern poet.

The Orange sometimes attains great age and dimensions. In the orangery of Versailles a magnificent Bitter Orange (C. biga-radia), known as “ the Great Constable,” is known to be upwards of four hundred and forty years old; its trunk is twenty feet in circumference, and its head rises forty feet high. It was planted in 1421 by the gardener of the Queen of Navarre, and came by — cession to Chantilly. In 1532 Francis I., having confiscated all Lord of Chantilly, who de Bourbon, the property of the Constable had been driven into open rebellion to his king and country by tyranny, had the precious tree, which was quite unique in E vssuripl transported to his orangery of Versailles, where it remains 1 a highly flourishing state. The Bigaradier of the Dominicans, at Rome, dates from the year 1200. It is about thirty-three feet im height. The largest of these shrubs recorded was a former

inhabitant of the garden of the Dominicans, and is said to have been fifty feet high. The principle to which odoriferous plants owe the qualities which render them so useful at the toilet has received the name of essential or volatile oil. The oils, volatile or essential, are met with most habitually in the flowers and the leaves; very rarely in the fruit. It happens sometimes that distinct oils exist in the same plant. Let us take the Orange for example. The essence drawn from the flowers of the Orange is very different from that furnished by the leaves. The essence furnished by the leaf differs again from that produced by the fruit.

The volatile oil is contained in the vesicles or cells which pervade all its parts; and so completely are these enclosed, that the plants may be dried without divesting them of the odorous principle, which still remains in the cavities. In other cases, particularly in the flowers, the essence forms itself on the surface of the organ, and is volatilised at the rate at which it is produced in the interior of the organs of the plant.

The mode of extracting these essences varies according to their nature and condition. Some of them may be extracted by simple expression. This may be done with the essential oils of the Citron and the Orange, which reside in the rind or envelope of the fruit. ‘They are reduced to a pulp, adding water afterwards to the liquor produced by pressure, when the oil will swim on the surface of the water added.

But the greater part of these essences are produced by distillation. This process is performed by placing the leaves, flowers, or fruits of plants, with a sufficient quantity of water, in an alembic or still. The essential oils only enter into ebullition at a higher temperature than water, since their point of ebullition rises in general to 130° or 140° OC. Nevertheless the steam, which is renewed unceasingly, escapes so rapidly into space that it is condensed in the bosom of the alembic. Let us explain. The Vapour of the essential oils diffuses itself in the steam which fills the alembic, which, however, is condensed; a new supply of steam Succeeds, which in its turn is saturated with the vapour of the oil. _ 4n this manner we can explain the rapid and continued evapora- __ tion of oils which only enter into ebullition at 140° in steam

which has itself only a temperature of 100°C. In order to increase the temperature of the water, marine salt, which boils at 109°, is added. This has the effect of increasing the evaporation of the oil. But the practice has its disadvantages, and in order to prevent the plants from being burnt by coming into contact with the bottom of the furnace, it is usual to place on the lower bars of the furnace a diaphragm pierced with holes, which supports the bed of leaves or flowers being distilled.

The steam which is thus condensed in the worm of the alembic is a mixture of water and essential oil, in which however the oi performs only a small part. In order to separate the two liquids and secure the oil, a very ingeniously conceived vase, known as the Florentine receiver, is employed. This vase separates the oil from the water on the simple principle of their respective specific gravities. Oil is lighter than water, consequently it floats on the surface; and if the mixed liquid is received in a vase or jar having a tube rising from the bottom, but whose highest part is placed at a lower level than that of the neck of the vase, as long as the united liquid flows from the still, the water will sink to the bottom and flow off, while the oil will accumulate on its surface.

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