The sp. gr. of this non-poisonous oil is 1·051. (G. Whippell.) That of pure colourless hydride of benzoyl is 1·043; it boils at 356° Fahr., is soluble in 35 parts of water, and in all proportions in alcohol and ether. Exposed to the air, it greedily absorbs oxygen, and becomes converted into a mass of crystallised benzoic acid. The purified oil of almonds does the same, only less rapidly.
Oil of Almonds (Facti′′tious). Syn. Essence of mirbane, Nitrobenzol. The preparation of this article on the small scale is explained under Nitrobenzol. It is now extensively prepared as a substitute for the oil of almonds obtained by distillation. The following is Mansfield’s process:—The apparatus consists of a large glass worm, the upper end of which is divided into two branches, gradually dilating so as to form two funnel-shaped tubes. Into one of these concentrated nitric acid is poured, and into the other benzol, which need not, for this purpose, be chemically pure. These bodies meet at the point of junction of the two tubes, and the rate of their flow is regulated by any appropriate means. Chemical reaction instantly takes place, and the new compound is cooled by its passage through the worm, which is refrigerated for the purpose. It has then only to be washed with water or a very weak solution of carbonate of soda for the process
to be complete. The product has the sp. gr. 1·209, boils at 415° Fahr., has an intensely sweet taste, and an odour closely resembling, but not actually identical with, that of oil of bitter almonds. Unlike genuine oil of almonds or hydride of benzoyl, it is insoluble in water, and does not distil without suffering partial decomposition. It is chiefly used to scent soaps, and to adulterate the genuine oil. The benzol for this purpose is obtained from coal-tar. See Benzol and Nitrobenzol.
Oil of Boxwood. (Ph. L. 1746.) Syn. Oleum buxi empyreumaticum. Distilled from fragments of boxwood in a retort, with a sand bath gradually increased in heat. Anodyne, antispasmodic, and diaphoretic.—Dose, 10 to 20 drops. (Jourdan says 4 to 5 drops in gonorrhœa.) It relieves toothache.
Oil, Brandy. See Oil of Grape.
Oil of Bu′chu. Syn. Oleum barosmæ, O. diosmæ, L. From the leaves of Diosma crenata. Yellow; lighter than water; smells of the leaves.
Oil of Caj′eput. Syn. Cajeputi oil, Kyapootie o.; Cajeputi oleum (B. P.), Oleum cajeputi (Ph. L. E. & D.), L. From the dried leaves of the Melaleuca Cajeputi (Melaleuca minor, B. P.). Colourless, when pure (that of commerce is usually green); odorous; aromatic; taste hot and penetrating. Its odour has been compared to a mixture of those of camphor and cardamoms. It boils at 343° Fahr. Sp. gr. ·925 to ·927. When rectified, about 3⁄4ths of the quantity passes over colourless, and has the density ·897; the remaining portion is green, and has the density ·920 to ·925. Its green colour is derived from chloride of copper, the presence of which may be recognised by the red precipitate occasioned by agitating the oil with a solution of ferrocyanide of potassium. (Guibourt.) From the East Indies.
Pure oil of cajeput is slightly soluble in water; entirely and freely soluble in alcohol; dissolves iodine; and when dropped on water, rapidly diffuses itself over the surface, and soon completely evaporates. A spurious kind (FACTITIOUS OIL OF CAJEPUT), made of oil of rosemary, flavoured with camphor and the oils of peppermint and cardamoms, and coloured with verdigris, is occasionally met with in the shops.
Oil of cajeput is a powerful antispasmodic and diffusible stimulant.—Dose, 3 to 6 drops, on sugar; in cholera, colic, epilepsy, hysteria, rheumatism, spasms, toothache, &c.
Oil of Cam′phor. Syn. Liquid camphor; Oleum camphoræ, O. c. volatile, L. Obtained from incisions in the wood of the camphor tree of Borneo and Sumatra (Dryobalanops aromatica), in which it exists in cavities in the trunk; also by distillation from the branches of the Camphora officinarum, or laurel camphor tree. Colourless when rectified. Sp. gr. ·910. Prod. 60 lbs. of the crude brown