French and Italian Oils.—Specific gravity at 15° C., 0.885-0.900; optical rotation, -2° to -9°; refractive index at 20° C., 1.459-1.464; esters, calculated as linalyl acetate, 20-40 per cent., occasionally higher; soluble in 1.5-3 volumes of 70 per cent. alcohol.
There was at one time a theory that the higher the proportion of ester the better the oil, but this theory has now to a very large extent become discredited, and there is no doubt that some of the finest oils contain less than 30 per cent. of esters.
Spanish Oil.—Specific gravity at 15° C., 0.900-0.915; optical rotation, -2° to +7°; esters, calculated as linalyl acetate, 2-6 per cent.; soluble in 1-2 volumes of 70 per cent. alcohol.
The chief constituents of lavender oil are linalyl acetate, linalol, geraniol, and linalyl butyrate, while the English oil also contains a distinct amount of cineol.
Lemon oil, prepared by expressing the peel of the nearly ripe fruit of Citrus limonum, and obtained almost entirely from Sicily and Southern Italy. Specific gravity at 15° C., 0.856-0.860; optical rotation, +58° to +63°; refractive index at 20° C., 1.4730-1.4750; aldehydes (citral), 2.5 to 4 per cent.
The principal constituents of the oil are limonene and citral, together with small quantities of pinene, phellandrene, octyl and nonyl aldehydes, citronellal, geraniol, geranyl acetate, and the stearopten, citraptene.
Lemon-grass (so-called verbena) oil, distilled from the grass Andropogon citratus, which is grown in India and, more recently, in the West Indies. The oils from these two sources differ somewhat in their properties, and also in value, the former being preferred on account of its greater solubility in alcohol.
East Indian.—Specific gravity at 15° C., 0.898-0.906; optical rotation, -0° 30' to -6°; aldehydes, by absorption with bisulphite of soda solution, 65 to 78 per cent.; refractive index at 20° C., 1.485-1.487; soluble in 2-3 volumes of 70 per cent. alcohol.
West Indian.—Specific gravity at 15° C., 0.886-0.893; optical rotation, faintly lævo-gyrate; refractive index at 20° C., 1.4855-1.4876; soluble in 0.5 volume of 90 per cent. alcohol.
Lime oil, obtained by expression or distillation of the peel of the fruit of Citrus medica, and produced principally in the West Indies.