Rose Oil (Artificial).—Several good and fairly cheap artificial rose oils are now obtainable, consisting chiefly of citronellol, geraniol, linalol, phenyl ethyl alcohol, and citral. In some cases stearopten or other wax is added, to render the oil more similar in appearance to the natural article, but as these are inodorous, no advantage is gained in this way, and there is, further, the inconvenience in cold weather of having to first melt the oil before use.
Safrol, an ether which is the chief constituent of sassafras oil, and also found in considerable quantity in camphor oil. It is sold as an artificial sassafras oil, and is very much used in perfuming cheap toilet or household soaps. Its specific gravity at 15° C. is 1.103-1.106; refractive index at 20° C., 1.5373; and it dissolves in fifteen volumes of 80 per cent. alcohol.
Santalol, the alcohol or mixture of alcohols obtained from sandalwood oil. Its specific gravity at 15° C. is 0.9795; optical rotation, -18°; and refractive index at 20° C., 1.507.
Terebene, a mixture of dipentene and other hydrocarbons prepared from turpentine oil by treatment with concentrated sulphuric acid, is used chiefly in medicated soaps. Its specific gravity at 15° C. is 0.862-0.868; the oil is frequently slightly dextro- or lævo-rotatory; the refractive index at 20° C., 1.470-1.478.
Terpineol, an alcohol also prepared from turpentine oil by the action of sulphuric acid, terpene hydrate being formed as an intermediate substance. It has a distinctly characteristic lilac odour, and on account of its cheapness is much used in soap perfumery, especially for a lilac or lily soap. Its specific gravity at 15° C. is 0.936-0.940; refractive index at 20° C., 1.4812-1.4835; and boiling point about 210°-212° C. It is optically inactive, and readily soluble in 1.5 volumes of 70 per cent. alcohol.
Vanillin, a white crystalline solid, melting at 80°-82° C. and prepared by the oxidation of isoeugenol. It has a strong characteristic odour, and occurs, associated with traces of benzoic acid and heliotropin, in the vanilla bean. It can only be used in small quantity in light-coloured soaps, as it quickly tends to darken the colour of the soap.