Caraway. [See Medicinal, Condimental and Aro matic Plants, page 460.] Long-leaf Pine (Pinus palustris, Mill.). Coniferm. Fig. 723; also Fig. 55, Vol. I.
American turpentine oil consists of the more volatile constituents of the resinous exudate ob tained by wounding the trunk of the various species of pine, chiefly the long-leaf pine. The outer living wood is chopped away in such manner as to open a large area of young wood rich in turpentine. During the warm months this pitch exudes and runs down into a pot connected by a spout to the tree or into a "box" cut in the trunk itself, from which it is removed every month or fortnight. The pitch is then distilled, with the result that the more volatile part, the oil of turpentine, is separated from a heavy residue, the resin. This volatile oil is further purified by recti fication.
The southeastern states, from North Carolina to Florida, are the chief source of American turpen tine oil. Wilmington, N. C., is the chief commer cial center for this and related pine products, such as resin and tar. The turpentine supply is threat ened in the United States by the destruction of the forests. Synthetic substitutes have not been secured.
Spearmint (Mentha viridis, Linn., M. spicata, Linn.). Labiatm. (Fig. 1392, Cyclopedia of American Horticulture.) A low perennial herb (one to three feet high) propagated by numerous running rootstocks, with ascending or reclining, somewhat hairy, square cornered, green stems, hearing slightly hairy, aro matic, sessile, veiny, oblong leaves, and the dense, narrow, terminal leafless spike of small lavender colored flowers.
This European plant has been widely distributed over the eastern part of the United States, where it occurs wild in damp fields and waste places. It has been grown in Europe for centuries on a small scale as a garden plant. It has been cultivated on a commercial scale at Mitcham, England, but chiefly in the United States in Michigan and in Lyons county, New York, where its culture is practiced with that of peppermint [see Peppermint, page 463]. The methods of cultivation and distillation are similar to those employed in the case of pepper mint. The yield is about twenty pounds of oil per acre. The total American yearly output seems not to exceed about 12,000 pounds, which amount makes the American product the determining factor in the world's market. An oil grouped with spearmint oil
commercially was formerly produced on a small scale in Thuringia, Germany, but it has ceased to be a factor in the market.
The oil is used as a flavoring agent in confec tionery and cosmetics and to a less extent in medi cine. Both the dried herb and the oil are official in the U. S. Pharmacopoeia. The dried herb meets with a limited demand from crude drug dealers.
Sweet Birch (Betula lento, Linn.). Betulacece. Fig. 724.
A tree of medium size, reaching a height of seventy-five feet, having a close dark brown bark, the inner lining of which is sweet and aromatic when chewed. The leaves are cordate, ovate, acu minate at the apex, with finely serrated margins. The flowers are in long, slender catkins. A native tree of rich forests of eastern North America.
The bark of the sweet birch (cherry birch or black birch) yields on maceration and distillation a volatile oil which is frequently known commer cially as oil of wintergreen and has practically a like composition. The birch bark from young trunks and branches is removed usually in late summer, cut up into small pieces and macerated for twelve hours with enough water thoroughly to moisten the bark, and distilled with steam. The characteristic substance of the oil is methylsalicy late, formed by the action of the ferment gaulthe rase (betulase) on the glucoside gaultherin. The yield is about .23 per cent. The oil of sweet birch and of wintergreen is used chiefly as a flavoring agent in candies and medicinal preparations.
Vetiver. Andropogon squarrosus, Linn. (A. maim toe, Retz. Vetireria zizanioides, Nash.). Gram inece. Vetivere, Cuscus, Khus-khus, Khuschus, Kuskus, Koosa.
Vetiver is a perennial tufted grass, native in rich moist soils in the coast region of India and in Bengal, and also on the plains of the Punjab and Northwest provinces. It is -rown for its roots, the filaments of which are used for making scented mats. screens, fans, ornamental baskets and various fancy articles, and are tied in bundles, weighing about two ounces each, which are used for scenting drawers. The latter is the Louisiana utilization of the plants. From the roots (called khan or khas khas) is distilled a fragrant oil used in perfumery. Vetiver is closely related to citronella (.Al nd ropogon NardiO, from the leaves of which citronella oil is distilled.