part 31

.

[474] _Traité du Citrus_, 1811. 118.

[475] _Hesperides, seu de malorum, aureorum cultura et usu_.

[476] _Nederlantze Hesperides_, Amsterd. 1676. fol. (an English translation in 1683).

[477] _Citrologia_, Ferrariæ, 1690.

[478] _Instruction pour les Jardins fruitiers ... avec un traité des Orangers_, ed. 2, 1692.

Volkamer of Nuremberg, who produced a fine work on the Citron tribe in 1708, has a chapter on the _Limon Bergamotta_, which he describes as _gloria limonum et fructus inter omnes nobilissimus_. He states that the Italians prepare from it the finest essences, which are sold at a high price.[479]

But, as shown by one of us,[480] the essential oil of bergamot had already, in 1688, a place among the stores of an apothecary of the German town of Giessen.

The name Bergamotta was originally applied to a large kind of pear, called in Turkish “beg-ârmûdî,” _i.e._ prince’s pear.[481]

=Production=—The bergamot is cultivated at Reggio, on low ground near the sea, and in the adjacent villages. The trees are often intermixed with lemon and orange trees, and the soil is well irrigated and cropped with vegetables.

The essential oil (_Oleum Bergamottæ_) is obtained from the full-grown but still unripe and more or less green fruits, gathered in the months of November and December. They are richer in oil than any one of the allied fruits. It was formerly made like that of lemon by the sponge-process, but during the last 20 years this method has been generally superseded by the introduction of a special machine for the extraction of the essential oil. In this machine the fruits are placed in a strong, saucer-like, metallic dish, about 10 inches in diameter, having in the centre a raised opening which with the outer edge forms a broad groove or channel; the dish is fitted with a cover of similar form. The inner surface both of the dish and cover is rendered rough by a series of narrow, radiating metal ridges of blades which are about ¼ of an inch high and resemble the backs of knifes. The dish is also furnished with some small openings to allow of the outflow of essential oil; and both dish and cover are arranged in a metallic cylinder, placed over a vessel to receive the oil. By a simple arrangement of cog-wheels moved by a handle, the cover, which is very heavy, is made to revolve rapidly over the dish, and the fruit lying in the groove between the two is carried round, and at the same time is subjected to the action of the sharp ridges, which, rupturing the oil-vessels, cause the essence to escape, and set it free to flow out by the small openings in the bottom of the dish. The fruits are placed in the machine, 6, 8, or more at a time, according to their size, and subjected to the rotatory action above described for about half a minute, when the machine is stopped, they are removed, and fresh ones substituted. About 7,000 fruits can thus be worked in one of these machines in a day. The yield of oil is said to be similar to that of lemon, namely 2½ to 3 ounces from 100 fruits.

[479] _Hesperides Norimbergenses_, 1713. lib. 3. cap. 26. and p. 156 b. (We quote from the Latin edition.)

[480] Flückiger, _Documente zur Geschichte der Pharmacie_, Halle, 1876. 72.

[481] Information, for which I am indebted to Dr. Rice.—The name has no reference to the town of Bergamo, where bergamots cannot succeed.—F. A. F.

Essence of bergamot made by the machine is of a greener tint than that obtained by the old sponge-process. During some weeks after extraction it gradually deposits a quantity of white greasy matter (bergaptene), which, after having been exhausted as much as possible by pressure, is finally subjected to distillation with water in order to separate the essential oil it still contains.

The fruits from which the essence has been extracted are submitted to pressure, and the juice, which is much inferior in acidity to lemon juice, is concentrated and sold for the manufacture of citric acid. Finally, the residue from which both essence and juice have been removed, is consumed as food by oxen.

=Description=[482]—Essential oil of bergamot is a thin and mobile fluid of peculiar and very fragrant odour, bitterish taste, and slightly acid reaction. It has a pale greenish yellow tint, due to traces of chlorophyll, as may be shown by the spectroscope. Its sp. gr. is 0·86 to 0·88; its boiling point varies from 183° to 195° C.

The oil is miscible with spirit of wine (0·83 sp. gr.), absolute alcohol, as well as with crystallizable acetic acid. Four parts dissolve clearly one part of bisulphide of carbon, but the solution becomes turbid if a larger proportion of the latter is added. Bisulphide of carbon itself is incapable of dissolving clearly any appreciable quantity of the oil. A mixture of 10 drops of the oil, 50 drops of bisulphide of carbon and one of strong sulphuric acid has an intense yellow hue. Perchloride of iron imparts to bergamot oil dissolved in alcohol a dingy brown colour.

Panuccio’s oil of bergamot examined in the same way as that of lemon (p. 120) deviates 7° to the right, and has therefore a dextrogyre power very inferior to that of other oils of the same class.[483] But it probably varies in this respect, for commercial specimens which we judged to be of good quality deviated from 6·8° to 10·4° to the right.

=Chemical Composition=—If essential oil of bergamot is submitted to rectification, the portions that successively distill over do not accord in rotatory power or in boiling point, a fact which proves it to be a mixture of several oils, as is further confirmed by analysis. It appears to consist of hydrocarbons, C₁₀H₁₆, and their hydrates, neither of which have as yet been satisfactorily isolated. Oil of bergamot, like that of turpentine, yields crystals of the composition C₁₀H₁₆ + 3H₂O, if 8 parts are allowed to stand some weeks with 1 part of spirit of wine, 2 of nitric 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.

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 C₉H₆O₃, 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.

[482] The characters are taken from some Essence of Bergamot presented to one of us (15 May 1872) as a type-sample by Messrs. G. Panuccio e figli, manufacturers of essences at Reggio and also large cultivators of the bergamot orange.

[483] See however _Oleum Neroli_, p. 127.

=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_[484] 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.

=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,[485] 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,[486] employed its juice in medicine.

[484] From the Basque “bizarra” = beard (Rice, _New Remedies_, 1878. 231), or from the Sanskrit Bijouri.

[485] _Traité du Citrus_, Paris, 1811. 222.

[486] _Opera_, ed. Valgrisi 1564. lib. v. sum. 1. tract. 9. p. 289.—The passage, which is the following, seems rather inconclusive:—“ ... succi acetositatis citri et succi acetositatis citranguli.”

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_.[487]

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_[488] or _Portugal Orange_ indicates what has been the usual opinion as to its origin. It probably alludes more exactly to a superior variety brought about 1630 from China to Portugal.[489]

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_”).[490]

=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 white zest, in strips less than ⅛ 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.

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

[487] Vitriaco, _Hist. orient. et occident._ 1597. cap. 86.

[488] Hence the Dutch _Sinaasappel_ or _Appelsina_ and the German _Apfelsine_.

[489] Goeze, _Beitrag zur Kenntniss der Orangengewächse_, Hamburg, 1874. 29.

[490] _Manners and Household Expenses of England in the 13th and 15th centuries_, Lond. (Roxburghe Club) 1841. xlviii.

=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. 116) particularly abounds 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 124.)

=History=—Porta, the Italian philosopher of the 16th century referred to (p. 118), 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_.[491] It was known in Paris to Pomet, who says[492] 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 flowers of all the allied plants are far less aromatic. 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 Naphæ_)[493] of commerce. The manufacture is carried on chiefly in the south of France at Grasse, Cannes, and Nice. The yield is about 0·6 to 0·7 per cent. of oil from fresh flowers, as stated by Poiteau et Risso.[494] The flowers of the sweet orange afford but half that amount of oil.

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

[491] Menagio, _Origini della Lingua Italiana_, 1685; _Dict. de Trévoux_, Paris, vi. (1771) 178.—The town of Nerola is about 16 miles north of Tivoli.

[492] _Histoire des Drogues_, 1694. 234. ii.

[493] Naphé or Naphore—according to Poiteau et Risso, _Hist. Nat. des Orangers_ 1873. 211, these names perhaps originated in Languedoc.

[494] _L. c._ 211.

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 redistilled 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 Plisson[495] the camphor diminishes the longer the oil is kept.[496] 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 Boullay[497] 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 lb. of flowers, or 3 lb. 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-currents[498] 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_)[499], 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 participate: metallic contamination of the latter is not unknown.

[495] _Journ. de Pharm._ xv. (1829) 152.

[496] Yet we extracted it from an old sample labelled “_Essence de Néroli Portugal—Méro._”

[497] _Bulletin de Pharm._, i. (1809) 337-341.

[498] 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.

[499] We have been informed on good authority that the Neroli commonly sold contains ⅜ of Essence of Petit Grain, and ⅛ of Essence of Bergamot, the remaining ⁴/₈ being true Neroli.

Other Products of the genus Citrus.

=Essence or Essential Oil of Petit Grain=—was originally obtained by subjecting little immature oranges to distillation (Pomet—1692); 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. Poiteau and Risso[500] state that the leaves of the Brigaradier with bitter fruit are by far the richest in essential oil among all the allied leaves; they 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, in liqueur-making and in perfumery. For what is known of their chemical nature, the reader can consult the works named at foot[501].

=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[502].

[500] _Loc. c._, edition of 1873. 211.

[501] 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. We may moreover point out the existence of a crystallized constituent of the oil of orange peel from the island of Curaçao. It was noticed as long ago as the year 1771 by Gaubius: “Sal aromaticus, nativus, ex oleo corticum mali aurei Curassavici,” in his book, “Adersariorum varii argumenti, lib. unus.” Leidae, 1771. 27.

[502] Gallesio, _Traité du Citrus_, 1811. 222.

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 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[503].

Essence of Cedrat which is quoted in some price-lists may be prepared from the scarcely ripe fruit by the sponge-process; but as it is more profitable to export the fruit salted, it is very rarely manufactured, and that which bears its name is for the most part fictitious.

FRUCTUS BELÆ.

_Bela_; _Bael Fruit_, _Indian Bael_, _Bengal Quince_.

=Botanical Origin=—_Ægle Marmelos_[504] Correa (_Cratæva Marmelos_ L.), a tree found in most parts of the Indian peninsula, which is often planted in the neighbourhood of temples, being esteemed sacred by the Hindus. It is truly wild in the forests of the Coromandel Ghâts and of the Western Himalaya, ascending often to 4,000 feet and growing gregarious when wild.

It attains a height of 30-40 feet, is usually armed with strong sharp thorns and has trifid leaves, the central leaflet being petiolate and larger than the lateral. The fruit is a large berry, 2 to 4 inches in diameter, variable in shape, being spherical or somewhat flattened like an orange, ovoid, or pyriform[505], having a smooth hard shell; the interior divided into 10-15 cells each containing several woolly seeds, consists of a mucilaginous pulp, which becomes very hard in drying. In the fresh state the fruit is very aromatic, and the juicy pulp which it contains has an agreeable flavour, so that when mixed with water and sweetened, it forms a palatable refrigerant drink. The fruit is never eaten as dessert, though its pulp is sometimes made into a preserve with sugar.

The fruit of the wild tree is described as small, hard, and flavourless, remaining long on the tree. The bark of the stem and root, the flowers and the expressed juice of the leaves are used in medicine by the natives of India.

=History=—The tree under the name of _Bilva_[506] is constantly alluded to as an emblem of increase and fertility in ancient Sanskrit poems, some of which as the Yajar Veda are supposed to have been written not later than 1000 B.C.—Constantinus Africanus was acquainted with the fruit under notice.

[503] Oribasius 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.

[504] _Ægle_, one of the Hesperides.—_Marmeloes_ from the Portuguese _marmelo_, a quince.—Fig. in Bentley and Trimen,