Oil of Gera′′nium. Syn. Oil of ginger grass, O. of spikenard. The oil of commerce which passes under this name and which was formerly imported from the East Indies, was not obtained from any species of Geranium or Pelargonium, but probably from a species of Andropogon. Of recent years, however, genuine geranium oil, obtained from the rose geranium (Pelargonium roseum) has been and continues to be met with in our markets. This essential oil is manufactured in immense quantities, at La Trappe de Staonelli not far from the Bay of Sidi Ferruch, in Algiers, where about forty acres of the plant are in cultivation. “Three harvests are gathered every year, and each yields from 170 to 200 kilograms of oil, or equal to 500 to 600 kilograms per annum. The value of this product never falls below forty francs the kilogram, the average gross value being therefore from 20,000 to 25,000 francs or at least £20 per acre. Seven distillatory apparatus are employed in this manufactory.”[65] A finer oil is yielded by the rose geranium, when grown in France, but it is much dearer. It is often employed to adulterate otto of roses. See Oil, Grass (below).
[65] “The Paris Exhibition,” ‘Pharmaceutical Journal,’ 3rd series, No. 433.
Oil of Gin′ger. Syn. Oleum zingiberis, L. From the dried root (rhizome) of Zingiber officinale, or ginger of commerce. Bluish-green; possesses a less agreeable odour than
that of good ginger, without any pungency. Prod. 11⁄16 of 1% (M. Raybaud).
Oil of Goosefoot. (Ph. U. S.) Syn. Oleum chenopodii. Distilled from the seeds of Chenopodium anthelminticum.—Dose. From 4 to 8 drops, with treacle or milk, for 3 nights in succession, for children. For adult, 1⁄2 dr. Vermifuge.
Oil of Grain-spirit. Syn. Grain oil. Two distinct substances are found in spirit distilled from fermented grain; one of which is butyraceous and highly offensive (corn oil of Mulder——?), the other liquid (crude fusel oil). The relative proportions of these substances to each other, and to the spirits which they contaminate, vary with the materials and the management of the process. The ‘Grain oil’ of the London rectifiers consists chiefly of fusel or potato oil, mixed with alcohol and water, and with small and variable proportions of solid ethyl and amyl-compounds of certain fatty acids (œnanthic and margaric). The latter are said to be similar to the butyraceous matter before referred to, as well as the solid fat of the whisky distilleries conducted on the old plan. According to Mr. Rowney, the fusel oil of the Scotch distilleries contains capric acid. See Oil of Corn (above), and Fusel oil.
Oil, Grape. Syn. Brandy oil, Cognac o. This is essentially the sulphate of amyl. It is prepared by dissolving the fusel oil of marc-brandy in strong rectified spirit, and then adding concentrated sulphuric acid; alcohol and excess of acid is removed by washing the newly formed compound with water. Dissolved in rectified spirit, it forms ‘BRANDY ESSENCE,’ which is used to impart the Cognac flavour to plain spirit. See Sulphate of Amyl and Amyl-ether, also Oil of Marc-brandy (below).
Oil, Grass. Several of the grasses (Graminaceæ) yield fragrant volatile oils. See Oil of Geranium, Grass oil (of Namur), Oil of Lemon-grass, Oil of Spring-grass, &c.
Oil, Grass (of Namur). Syn. India grass Oil. From Andropogon Calamus aromaticus (Royle), supposed to have been the “sweet cane” and “rich aromatic reed from a far country” of Scripture; formerly supposed to be obtained from Andropogon Iwarancusa. Stimulant and highly fragrant. See Oil of Spikenard.
Oil of Hops. Syn. Oleum lupuli, L. From commercial hops, by distillation along with water. It may also be collected during the brewing of beer. Odorous; acrid; narcotic; soluble in water; becomes resinous by exposure and age. Sp. gr. ·910. Chiefly used to increase the aroma and flavour of old or damaged hops.