Another essential oil is procured from Oreodaphne opifera, in British Guiana, and on the Orinoco, by boring holes into the heart of the tree. It flows out in a clear stream, and is collected in basins. When rectified and desiccated, it is colourless, with an odour of turpentine and lemons, and aromatic pungent flavour ; its sp. gr. is 0'864; boiling-point, 150°-163° (302°-325i° F.); it is used medicinally, and is an excellent solvent of indiarubber. A third oil is distilled from the fruit of this tree.
Oreodaphne californica (the Californian bay laurel), is an evergreen tree indigenous to California and the Pacific slope, growing abundantly in the vicinity of ravines, and moist shady localities. All parts yield a volatile oil, but the leaves give moat-4 per cent. by distillation. It is straw coloured, limpid, with pungent aromatic odour, warm camphoraceous flavour, sp. gr. 0.936. It has medicinal virtues.
A fixed oil from the laurel is described under that section (see p. 1393).
Lavender-oil.—Several species of Lavandula are cultivated for the sake of their essential oil. L. Vera, commonly called " female lavender," is a native of S. Europe, N. Africa, and Persia ; it is tho kind chiefly grown, and occupies a large area of ground in France, as well as at Mitcham (Surrey), and Hitchin (Harts), in England. L. Spica, or "male lavender," is raised principally on the Continent, and affords an inferior product, termed " oil of spike." A lavender plantation in this country should be sun-exposed, and away from hedges and trees, as these tend to keep the air too moist, and make the flowers liable to be cut off by spring frosts. The best soil is loam, with chalky subsoil. In October, slips from old plants are placed in previously-prepared beds, and kept carefully clipped for 12 months. At the end of this time, they are set out in fine weather, 3 ft. apart in rows 4 ft. apart (or 3547 plants on an acre). They are not yet allowed to flower, but are still clipped, and regularly dressed with short dung, or superphosphate of lime, to strengthen them. The harvest takes place in August, when the plants are cut down by the sickle, and immediately packed in quantities of about z cwt. in pieces of bast matting (see Fibrous Substances —Raphia spp., p. 994, Tilia, p. 998), for protection from the sun during conveyance to the stills. The yield is greatest and best from 4-year-old plants ; but it is a singular fact that the product from 2-year-old plants is larger than from those of either 1 year or 3 years. Sometimes the crop is continued on the same ground for 6 years in succession, by judiciously replacing old plants ; but more commonly, some other crop is raised every fourth year. The yield of oil varies greatly with the season and the soil. The average at Mitcham is 10-12 lb. an acre. Perks, at Hitchin, removes the flowers from the stalks before distilling, and finds that though the operation of stripping entails an extra expense, the product is greatly improved in quality, and very little less in quantity. Usually the whole herb is thrown into the still, in which case, the oil is divided
into hits and 2nds ; the former, including about f-g- of the total, is reserved for making "lavender water," while the latter serves for perfuming soaps and greases. The best French oil is got from flowers grown on the highest points in the department Alpes-Maritimes; 150-200 lb. of flowers give 1 lb. of oil in a good season. The oils of L. Spica and L. Stcechas are used by painters an porcelain, and in artists' varnishes. The oil produced in England fetches four times the price of any other. It is thin, pale-yellow, with a pleasant odour of the flowers, n burning, bitter, aromatic flavour, sp. gr. boils at 185°-188° F.), and dissolves readily in alcohol.
Lemon-oil and Citron-zeste.—The rind of the Lemon (see Fruit—Lemons, p. 1025), when rasped and subjected to expression, or when distilled, affords an essential oil, known as " essence of lemon," or "citron-zeste," according to the method adopted. The oil is extracted largely in the neighbourhood of Palermo, in Sicily, at Reggio, iu Calabria, and at Mentone and Nice, in France. The fruits are used while still rather green and unripe, being then richer in oil ; only small and otherwise unmerchantable fruit is employed. The operation is conducted in November-December. In Sicily and Calabria, the "sponge process" is adopted, as described in another section of this article (see p. 1457). The yield is very variable, 400 fruits affording 9-14 oz. of oil. The pulp and exhausted peel are pressed, to extract "lemon-juice," and then sometimes distilled. At Mentune and Nice, recourse is had to the ecuelle, whose construction and use is also recorded in another portion of this article (see p. 1457). These kinds of oil are much superior to a third which is obtained by grating the peel of fresh lemons, or of those which have been submitted to the and distilling with water. The oils obtained by the sponge and ecuelle are thin liquids, of faint yellow colour, exquisite odour, and bitterish aromatic flavour ; their sp. gr. is and their boiling point, 170°-180° F.). The oil (or essence) of lemon is shipped mostly from Messina and Palermo, in copper bottles, called " jars " or ramieri, holding 25-50 kilo. or more, some times in tin bottles of less size. The total quantity of lemon-, orange-, and bergamot-oils exported from Sicily in 1871 was 368,800 lb., value 144,5201., about LI coming to England ; and the exports from Messina in 1877 were 306,948 kilo. The British imports of lemon-oil alone are estimated at 85,000-90,000 lb. annually. It is most extensively consumed in perfumery.