The oil of santal wood (also called sandal-wood oil) has a thick, honey-like consistence and an agreeable, rose-like odor. Formerly it was sometimes used for the adulteration of oil of rose, but can also very well be used alone for several perfumes and fumigating preparations.
Oil of Sassafras (Oleum Sassafras)
is yellow, spicy, with a burning odor and taste; in the cold it crystallizes only in part. The odor of this oil recalls that of fennel. The purest form of it, or rather substitute for it, is safrol, its main constituent, which is, however, now extracted more economically from crude oil of camphor, in which it likewise forms an ingredient.
Oil of Meadow-sweet (Oleum Spirææ).
Several species of Spiræa, and especially Spiræa ulmaria, furnish very pleasant odors. This oil consists mainly of salicylic aldehyde.
Despite its pleasant odor and the facility of its production, this substance has thus far found little application in perfumery. The natural oil of meadowsweet, owing to its extremely high price, can hardly ever be used.
Oil of Star-Anise (Oleum Anisi Stellati; Oleum Illicii)
resembles in its properties the oil of anise, even in its odor; but all connoisseurs agree that the odor of the oil of star-anise far surpasses that of the oil of anise, hence the former is used especially for fine perfumes. This preference, however, does not extend to all preparations. For certain liqueurs, such as anisette, the oil obtained from common anise (Saxon anise) is usually preferred. Many also regard the odor of star-anise as inferior to that of fine European anise.
Oils of Thyme (Oleum Thymi).
The essential oils of thyme (chiefly Thymus vulgaris) and some related plants are very frequently used for scenting cheap soaps. The oils of these plants are light yellow, and so similar in odor that it is not possible to distinguish them except by direct comparison.