Very similar oils are derived from other species of Melaleuca. That of M. ericifolia is pale yellow, sp. gr. 0.899-0.902; M. Wilsonii, sp. gr. 0.925; M. parvillora, amber-coloured, sp. gr. ; M. uncinata, peppermint-odour ; M. genistifolia, pale greenish-yellow ; M. squarrosa, green colour, disagreeable flavour ; M. linariifolia, light straw-coloured, pleasant odour and flavour, sp. gr. The plant called kayu-glum by the natives grows very extensively on the Malay Peninsula, and produces a similar oil to kayu-puti, but darker in colour. Fisher has distilled considerable quantities of it, and states it to be in wide medicinal use in the East.
Camphor-oils.—See Camphor, p. 578.
Caraway-oil.—A valued essential oil is obtained from the seeds of Carum Carvi (see Spices— Caraway). Distillation is performed with water, and without previous comminution of the seeds. Dutch seed yields about 5i per cent. of oil ; German, 7 per cent. ; and Norwegian, per cent. In England, preference is given to oil distilled from home-grown seed ; on the Continent, the oils from the caraways of Halle and Holland are esteemed finer than those prooured in S. Germany. An inferior oil is extracted from the refuse of the fruit, being mixed with turpentine-oil before distilling. The oil is colourless or pale yellow, thin, with strong odour and flavour of the fruit ; its sp. gr. is 0.91-0'97, It consists of about j carvene, boiling at 173° (343° F.), and having a sp. gr. of 0.861 at 15° (59° F.). Carvol, the odoriferous portion, boils at 224° (435° F.), and has a sp. gr. of 0.953 at 20° (68° F.). Caraway-oil is employed in medicine, but more largely as a scent for soaps.
parenchyma of the albumen and the embryo of cardamoms (see Spices —Cardamoms) contain a varying percentage of essential oil, amounting to 5 in Madras cardamoms, and 3.5 in Ceylon. It is extracted by aqueous distillation. It is pale-yellow in colour, with the odour and flavour of the seeds; sp. gr. 0.92-0.94.
bark of Croton Eluteria (see Drugs—Cascarilla, p. 797), distilled with water, affords about 1.1 per cent. of essential oil, which is rarely extracted, the bark itself being used by perfumers. The oil is dark-yellow, with an odour of camphor, lemons, and thyme, an aromatic, bitter flavour, sp. gr. 0.938, and commencing to boil at 180° (356° F.).
the pencil-makers' shavings of American cedar (Juniperus virginiana), is extracted an essential oil, in the proportion of about 28 oz. from 1 cwt. of the shavings. The true
Lebanon cedar (Cedrus Libani) affords an oil of very indifferent odour. Cedar-oil is a soft, white, crystalline mass, of peculiar aromatic odour, solidifying at 27° (809° F.) after desiccation, and distilling below 282° (539° F.). It is extensively used for scenting soaps, and is generally employed in America in lieu of savin-oil, being often called " N. American savin." or the rind of the scarcely ripe fruit of the citron (see Fruit, p. 1023) is obtained an essential oil, either by distillation or expression, much esteemed in perfumery. It is thin, colourless, or yellowish, of pleasant lemon odour, sp. gr. 0.840-0.860, boiling at l60°-175° (320°-347° F.). It is prepared in small quantity, and much of that sold under the name is fictitious, as the rind is in great demand for " oandying " (see Food Preservation, p. 1018).
the aqueous distillation of the herb and fruits of the celery (Apium graveolens), is obtained a colourless or pale-yellow oil, of penetrating odour, warm sweetish flavour, sp. gr. 0.881, and readily soluble in alcohol. At Grasse (S. France), the wild plant only is used, and yields about 1 lb. of oil from 400 lb.
flowers of the common or Roman chamomile (see Drugs, p. 798) afford per cent. of essential oil by aqueous distillation. It is at first bluish, but becomes yellowish-brown in the course of a few months; it has a pleasant lemon-like odour, and boils at 175° (347° F.). The yield of this oil from au acre of flowers is estimated at about 8 lb. At Mitcham, near London, the entire plants, deprived of their best flowers, are distilled, after drying in open sheds, excluding direct sunlight. The stills hold 1000-2000 gal., and a charge occupies 6-8 hours. The • distillation is conducted at the lowest possible temperature, and, so soon as the contents of the retort have reached the boiling-point, the fire is withdrawn. The finest and most fragrant oil comes over during the first 3 hours of the process, and the receiver is then changed.
An essential oil is also distilled from the flowers of the German chamomile (see Drugs— Chamomile, p. 799). It is thick, dark-blue in colour, with a strong odour of the flowers, and a hot aromatic flavour.