acid (sp. gr. 1·2) and 10 of water, the mixture being frequently shaken. No solid compound is produced by saturating the oil with anhydrous hydrochloric gas.

1

The greasy matter that is deposited from oil of bergamot soon after its extraction, and in small quantity is often noticeable in that of commerce, is called Bergaptene or Bergamot Camphor. We have obtained it in fine, white, acicular crystals, neutral and inodorous, by repeated solution in spirit of wine. Its composition according to the analysis of Mulder (1837) and of Ohme (1839) answers to the formula CH O3, which in our opinion requires further investigation. Crystallized bergaptene is abundantly soluble in chloroform, ether or bisulphide of carbon; the alcoholic solution is not altered by ferric salts.

Commerce-Essence of bergamot, as it is always termed in trade, is chiefly shipped from Messina and Palermo in the same kind of bottles as are used for essence of lemon.

Uses-Much employed in perfumery, but in medicine only occasionally for the sake of imparting an agreeable odour to ointments.

Adulteration-Essence of bergamot like that of lemon is extensively and systematically adulterated, and very little is sent into the market entirely pure. It is often mixed with oil of turpentine, but a finer adulteration is to dilute it with essential oil of the leaves or with that obtained by distillation of the peel or of the residual fruits. Some has of late been adulterated with petroleum.

The optical properties as already mentioned may afford some assistance in detecting fraudulent admixtures, though as regards oil of turpentine it must be borne in mind that there are levogyre as well as dextrogyre varieties. This latter oil and likewise that of lemon is less soluble in spirit of wine than that of bergamot.

CORTEX AURANTII.

Bitter Orange Peel; F. Ecorce ou Zestes d'Oranges amères; G. Pomeranzenschale.

Botanical Origin-Citrus vulgaris Risso (C. Aurantium var. a amara Linn., C. Bigaradia Duhamel).

The Bitter or Seville or Bigarade Orange, Bigaradier of the French, is a small tree extensively cultivated in the warmer parts of the Mediterranean region especially in Spain, and existing under many varieties.

Northern India is the native country of the orange tree. In Gurhwal, Sikkim and Khasia there occurs a wild orange which is the supposed parent of the cultivated orange, whether Sweet or Bitter.

The Bitter Orange reproduces itself from seed and is regarded, at least by cultivators, as quite distinct from the Sweet Orange, from which however it cannot be distinguished by any important botanical characters. Generally speaking it differs from the latter in having the fruit rugged on the surface, of a more deep or reddish-orange hue, with the pulp very sour and bitter. The peel as well as the flowers and leaves are more aromatic than the corresponding parts of the Sweet Orange, and the petiole is more broadly winged.

1 We are indebted to Mr. Robert Sanderson of Messina for placing at our disposal a

quantity of this deposit for chemical examination.

History-The orange was unknown to the ancient Greeks and Romans; and its introduction to Europe is due to the Arabs who, according to Gallesio,1 appear to have established the tree first in Eastern Africa, Arabia and Syria, whence it was gradually conveyed to Italy, Sicily and Spain. In the opinion of the writer just quoted, the bitter orange was certainly known at the commencement of the 10th century to the Arabian physicians, one of whom, Avicenna,2 employed its juice in medicine.

There is strong evidence to show that the orange first cultivated in Europe was the Bitter Orange or Bigarade. The orange tree at Rome said to have been planted by St. Dominic about A.D. 1200 and which still exists at the monastery of St. Sabina bears a bitter fruit; and the ancient trees standing in the garden of the Alcazar at Seville are also of this variety. Finally, the oranges of Syria (ab indigenis Orenges nuncupati) described by Jacques de Vitri, Bishop of Acon (ob. A.D. 1214) were acidi seu pontici saporis.3

The Sweet Orange began to be cultivated about the middle of the 15th century, having been introduced from the East by the Portuguese. It has probably long existed in Southern China, and may have been taken thence to India. In the latter country there are but few districts in which its cultivation is successful, and the Bitter Orange is hardly known at all. The name it has long borne of China or Portugal Orange indicates what has been the usual opinion as to its origin.

4

One of the first importations of oranges into England occurred in A.D. 1290, in which year a Spanish ship came to Portsmouth, of the cargo of which the queen of Edward I. bought one frail of Seville figs, one of raisins or grapes, one bale of dates, 230 pomegranates, 15 citrons and 7 oranges ("poma de orenge").5

Description-The Bitter Orange known in London as the Seville Orange is a globular fruit resembling in size, form and structure the common Sweet Orange, but having the peel much rougher and when mature of a somewhat deeper hue. The pulp of the fruit is filled with an acid bitter juice. The ripe fruit is imported into London; the peel is removed from it with a sharp knife in one long spiral strip, and quickly dried, or it is sold in the fresh state. It is the more esteemed when cut thin, so as to include as little as possible of the white inner layer.

Well-dried orange peel should be externally of a bright tint and white on its inner surface; it should have a grateful aromatic smell and [bitter taste. The peel is also largely imported into London ready dried, especially from Malta. We have observed it from this latter place of three qualities, namely in elliptic pieces or quarters, in broad curled strips, and lastly a very superior kind almost wholly free from the white zest, in strips less than of an inch in width, cut apparently by a machine. Such needless subdivision as this last has undergone must greatly favour an alteration and waste of the essential oil. Foreign-dried orange peel fetches a lower price than that dried in England,

1 Traité du Citrus, Paris, 1811. 222.

Opera, ed. Valg, 1564. lib. v. sum. 1. tract. 6. p. 289.-The passage which is the following seems rather inconclusive :".. succi acetositatis citri et succi acetositatis citranguli."

3 Vitriaco, Hist. orient. et occident., 1597. cap. 86.

4 Hence the Dutch Sinaasappel or Appel· sina and the German Apfelsine.

5 Manners and Household Expenses of England in the 13th and 15th centuries, Lond. (Roxburghe Club) 1841. xlviij.

Microscopic Structure-There is no difference between the tissues of this drug and those of lemon peel.

Chemical Composition-The essential oil to which the peel of the orange owes its fragrant odour, is a distinct article of commerce and will be noticed hereafter under a separate head. The other constituents of the peel probably agree with those of lemon peel. The substance mentioned under the name of Hesperidin (p. 104) appears to be particularly abundant in unripe bitter oranges.

Uses Bitter orange peel is much used in medicine as an aromatic tonic.

OLEUM NEROLI.

Oleum Aurantii florum; Oil or Essence of Neroli; F. Essence de Néroli; G. Neroliöl.

Botanical Origin-Citrus vulgaris Risso. (See page 111.)

History-Porta, the Italian philosopher of the 16th century referred to in connection with the essential oil of lemon (p. 106), was acquainted with the volatile oil of the flowers of the citron tribe ("Oleum_ex citriorum floribus") which he obtained by the usual process of distillation, and describes as possessing the most exquisite fragrance. That distilled from orange flowers acquired a century later (1675-1685) the name of Essence of Neroli from Anne-Marie de la Trémoille-Noirmoutier, second wife of Flavio Orsini, duke of Bracciano and prince of Nerola or Neroli. This lady employed it for the perfuming of gloves, hence called in Italy Guanti di Neroli.1 It was known in Paris to Pomet, who says the perfumers have given it the name of Neroli, and that it is made in Rome and in Provence.

Production-Oil of Neroli is prepared from the fresh flowers of the Bigarade or Bitter Orange by the ordinary process of distillation with water, conducted in small copper stills. The water which distills over with the oil constitutes after the removal of the latter from its surface, the Orange Flower Water (Aqua aurantii florum vel Aqua Napha) of commerce. The manufacture is carried on chiefly in the south of France at Grasse, Cannes, and Nice.

Description and Chemical Composition-Oil of Neroli as found. in commerce is seldom pure, for it generally contains an admixture of the essential oil of orange-leaf called Essence of Petit Grain.

By the kind assistance of Mr. F. G. Warrick of Nice, we have obtained a sample of Bigarade Neroli of guaranteed purity, to which the following observations relate. It is of a brownish hue, most fragrant odour, bitterish aromatic taste, and is neutral to test-paper. Its sp. gr. at 11° C. is 0.889. When mixed with alcohol, it displays a bright violet fluorescence, quite distinct from the blue fluorescence of a solution of quinine. In oil of Neroli the phenomenon may be shown most distinctly by pouring a little spirit of wine on to the surface of the essential oil, and causing the liquid to gently undulate. The oil is but turbidly miscible with bisulphide of carbon. It assumes a very pure, intense, and permanent crimson hue if shaken with a saturated solution Menagio, Origini della Lingua Italiana, 1685; Dict. de Trévoux, Paris, vi. (1771)

178. The town of Nerola is about 16 miles north of Tivoli.

2 Histoire des Drogues, 1694. 234. ii.

I

of bisulphite of sodium. Examined in a column of 100 mm., we observed the oil to deviate the ray of polarized light 6° to the right.

Subjected to distillation, the larger part of the oil passes over at 185° -195° C.; we found this portion to be colourless, yet to display in a marked manner the violet fluorescence and also to retain the odour of the original oil. The portion remaining in the retort was mixed with about the same volume of alcohol (90 per cent.) and some drops of water added, yet not sufficient to occasion turbidity. A very small amount of the crystalline Neroli Camphor then made its appearance, floating on the surface of the liquid; by re-solution in boiling alcohol it was obtained in crystals of rather indistinct form. The re-distilled oil gave no camphor whatever.

Neroli Camphor was first noticed by Boullay in 1828. According to our observations it is a neutral, inodorous, tasteless substance, fusible at 55° C., and forming on cooling a crystalline mass. The crystallization should be effected by cooling the hot alcoholic solution, no good crystals being obtainable by slow evaporation or by sublimation. The produce was extremely small, about 60 grammes of oil having yielded not more than 0.1 gramme. Perhaps this scantiness of produce was due to the oil being a year and a half old, for according to Plisson1 the camphor diminishes the longer the oil is kept.2 We were unable to obtain any similar substance from the oils of bergamot, petit grain, or orange peel.

Orange Flower Water is a considerable article of manufacture among the distillers of essential oils in the south of Europe, and is imported thence for use in pharmacy. According to Boullays it is frequently acid to litmus when first made,-is better if distilled in small than in large quantities, and if made from the petals per se, rather than from the entire flowers. He also states that only 2 lb. of water should be drawn from 1 b. of flowers, or 3 tb. if petals alone are placed in the still. As met with in commerce, orange flower water is colourless or of a faintly greenish yellow tinge, almost perfectly transparent, with a delicious odour and a bitter taste. Acidulated with nitric acid, it acquires a pinkish hue more or less intense, which disappears on saturation by an alkali.

Uses Oil of Neroli is consumed almost exclusively in perfumery. Orange flower water is frequently used in medicine to give a pleasant odour to mixtures and lotions.

Adulteration-The large variation in value of oil of Neroli as shown by price-currents1 indicates a great diversity of quality. Besides being very commonly mixed, as already stated, with the distilled oil of the leaves (Essence de Petit Grain), it is sometimes reduced by addition of the less fragrant oil obtained from the flowers of the Portugal or Sweet Orange. In some of these adulterations we must conclude that orange flower water participates: metallic contamination of the latter is not unknown.

1 Journ. de Pharm. xv. (1829) 152.

2 Yet we extracted it from an old sample labelled "Essence de Néroli Portugal Méro."

Bulletin de Pharm. i. (1809) 337-341. Thus in the price-list of a firm at Grasse, Neroli is quoted as of four qualities, the

lowest or "commercial" being less than half the price of the finest.

5 We have been informed on good authority that the Neroli commonly sold contains of Essence of Petit Grain, and of Essence of Bergamot, the remaining being true Neroli.

OTHER PRODUCTS OF THE GENUS CITRUS.

Other Products of the genus Citrus.

115

Essence or Essential Oil of Petit Grain-was originally obtained by subjecting little immature oranges to distillation (Pomet1692); but it is now produced, and to a large extent, by distillation of the leaves and shoots either of the Bigarade or Bitter Orange, or of the Portugal or Sweet Orange. The essence of the former is by far the more fragrant and commands double the price.

The leaves are obtained in the lemon-growing districts of the Mediterranean where the essence is manufactured. Lemon-trees being mostly grafted on orange-stocks, the latter during the summer put forth shoots, which are allowed to grow till they are often some feet in length. The cultivator then cuts them off, binds them in bundles, and conveys them to the distiller of Petit Grain. The strongest shoots are frequently reserved for walking-sticks. The leaves of the two sorts of orange are easily distinguished by their smell when crushed. Essence of Petit Grain which in odour has a certain resemblance to Neroli, is used in perfumery and especially in the manufacture of Eau de Cologne.

According to Gladstone (1864) it consists mainly of a hydrocarbon probably identical with that from oil of Neroli.

Essential Oil of Orange Peel-is largely made at Messina and also in the south of France. It is extracted by the sponge-, or by the écuelle-process, and partly from the Bigarade and partly from the Sweet or Portugal Orange, the scarcely ripe fruit being in either case employed. The oil made from the former is much more valuable than that obtained from the latter, and the two are distinguished in price-currents as Essence de Bigarade and Essence de Portugal.

These essences are but little consumed in England, but are largely used in Germany. They are employed in liqueur-making and in perfumery. For what is known of their chemical nature, the reader can consult the works named at foot.1

Essence of Cedrat-The true Citron or Cedrat tree is Citrus medica Risso, and is of interest as being the only member of the Orange tribe the fruit of which was known in ancient Rome. The tree itself which appears to have been cultivated in Palestine in the time of Josephus, was introduced into Italy in about the 3rd century. In A.D. 1003 it was much grown at Salerno near Naples, whence its fruits were sent as presents to the Norman princes.2

At the present day, the citron appears to be nowhere cultivated extensively, the more prolific lemon tree having generally taken its place. It is however scattered along the Western Riviera, and is also grown on a small scale about Pizzo and Paola on the western coast of Calabria, in Sicily, Corsica and the Azores. Its fruits which often weigh several pounds, are chiefly sold for being candied. For this purpose the peel, which is excessively thick, is salted and in that state shipped to England and Holland. The fruit has a very scanty pulp.3

1 Gmelin, Chemistry, xiv. (1860) 305. 306; Gladstone, Journ. of Chem. Soc. xvii. (1864) 1; Wright (and Piesse) in Yearbook of Pharmacy, 1871. 546; 1873. 518; Journ. of Chem. Soc. xi. (1873) 552, &c.

Gallesio, Traité du Citrus, 1811. 222.
Oribasius who lived in the second half

of the 4th century and who was physician and friend of the emperor Julian the Apostate, accurately describes the citron as a fruit consisting of three parts, namely a central acid pulp, a thick and fleshy zest and an aromatic outer coat.-Medicinalia collecta, lib. i. c. 64.