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.
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.