Fennel-oil.—The fruits of Famiculum officinale [vulgare] afford a volatile oil by aqueous distilla tion. It is pale-yellow, with a sweetish aromatic odour and flavour of the fruit, ap. gr. at 20° (68° F.); solidifies below 10° (50° F.); may be used for perfuming soap. The plant grows wild in S. France, and is distilled entire in July-August, giving 1 lb. of oil from 500 lb.
Fusel-oil.—The name " fusel-oil " is applied to a series of volatile liquids obtained in tho rectification of alcoholic liquors made by fermenting grain, potatoes, &c., and whose separation is a matter of great importance (see Alcohol, p. 212). The oil varies much in quantity and composi tion, according to its source ; it is practically always present in greater or leas degree in commercial spirits. It is employed industrially as a source of amylic alcohol, which is its chief constituent.
The rhizome of Alpinia officinarum (Bee Spices—Galangal), by aqueous distilla tion, affords about 0.7 per cent. of an essential oil, with an odour and constitution resembling cajuput-oil, and readily soluble in alcohol.
' (see Resinous Substances) affords about 7 per cent. of volatile oil by aqueous distillation. It is colourless or slightly yellowish, with mild, aromatic flavour, galbanum-like odour, sp. gr. 0'901, and boils at 160° (320° F.).
leaves of Myrica Gale, when distilled with water, give a brownish-yellow essential oil, thickish at 12° (53° F.), of peculiar, pleasant, balsamic odour, mild, then hot and lastingly styptic flavour, ep gr. 0.876, soluble in 40 parts of alcohol at 0'875 sp. gr.
Garlic-oil.—The bulbs of garlic (Allium sativuni), when distilled with water, afford a volatile oil, which does not seem to pre-exist in the plant. In the crude state, it is brownish-yellow, with an intense odour of garlic ; it is slowly soluble in water, and suffers partial decomposition by rectifying. An identical oil is yielded by several Cruciferce. (See also Allium, p. 1414).
name " geranium-oil" is properly confined to oils afforded by different species of Pelargonium, but is often applied also to ginger-grass-oil (p. 1422). P. Radula, the rose-leaved geranium, is cultivated in France, both in the south, and at Montfort-Lamaury, in the depart ment Seine-et-Oise. It is propagated by slips taken in September, and generally planted out in February, though the latter may be done at almost any season. The cultivation is very easy, and,
with proper manuring and irrigation, the plants grow 3-4 ft. high, and yield an abundance of foliage, which is reaped by a sickle. About 3000 plants occupy an acre, and they require renewing every 3-4 years. The leaves and flowers are distilled with water, 1 cwt. yielding about 2 oz. of essential oil. The oil obtained in Seine-et-Oise has a better odour than that produced in S. France. It is colourless, greenish, yellowish, or brownish, the last being most esteemed, boils at 206°-220° (421°-428° F.), and solidifies at 16° (61° F.); the odour closely resembles that of the rose. P. odoratissimum is much cultivated in Algeria and Valencia, and yields a very similar oil. It requires deep, well-worked, fertile soil, and succeeds well in the red soils of Sabel, in Alger, and in tho cool, eandy eoil of Staoneli. The slips are planted in lines, 18-26 in. by 8-10 in. apart, at the beginning of winter, and yield 3 cuttings annually. The cultivation is maintained for 3 years, and gives 250-300 and even 475 cwt. of leaves per hectare (of 2i acres) per annum. The whole plant is cut down to within 4 in. of the ground. The first cutting, in May, requires 1200 1400 lb. of leaves to afford 1 lb. of essential oil, but in July, 800 lb. will give the same yield. All these geranium-oila are used in perfumery, and largely as adulterants of otto of rose (see Rose-oil, p. 1427). They are likewise themselves adulterated extensively with ginger-grass-oil (p. 1422).
rhizomes of Zingiber officinale (see Spices—Ginger), when distilled with water, afford a thin, yellowish, essential oil, with a strong odour of ginger, a burning aromatic flavour, Bp. gr. 0.893, boiling at 246° (475° F.).
Ginger-grass-oil.—An essential oil known as " ginger-grass," often also as ruse or "rose-oil," and as "geranium-oil," is the produce of Andropogon Schtsnanthus, a grass indigenous to N. and Central India. The leaves are distilled in the Khandesh collectorate of the Bombay presidency. The oil ,produced in the Namar district of the Nerbudda valley is sometimes called " grass-oil of Namar." The export of the oil from Bombay during the year ending March, 1867, was 41,643 lb. It is shipped to England, and to the ports of the Red Sea. Its largest consumption is for the adul teration of otto of roses (see Rose-oil, p. 1427).