27. Terebinthina, N.F.—Turpentine.
A concrete oleoresin obtained from Pi'nus palus'tris Miller (Fam. Pinaceae, U.S.P. 1900), and other species of Pinus.
BOTANICAL CHARACTERISTICS.—A large tree, 60 to 100 feet, with thin, scaled bark, and hard, very resinous wood. Leaves 10 to 15 inches long, in threes, from long sheaths. Sterile flowers rose-purple. Cones large, cylindrical or conical-oblong.
SOURCE AND COLLECTION.—Southern United States, particularly North Carolina. The oleoresin is secreted in the sapwood; some of it flows spontaneously, but it is generally obtained by a process called "boxing," as follows: During the winter from one to four excavations, each holding from 4 to 8 pints, are cut into the tree through the sapwood. After a few days the bark above these cavities is removed for about a height of 3 feet, and some of the wood is hacked off, the hacks being in the shape of the letter L. The oleoresin begins to flow about the middle of March, and continues until September or October. The turpentine is removed by means of dippers constructed for the purpose, and then usually distilled. That which flows the first year is considered the best, being termed "virgin dip," and yields about 6 gallons of oil per barrel, and "window-glass rosin;" that of the next and subsequent years is known as "yellow dip," yielding about 4 gallons of oil per barrel, and medium grades of rosin. The turpentine which hardens on the tree is known as "scrapings," and yields about 2 gallons of oil per barrel, leaving a dark resin.
DESCRIPTION OF DRUG.—In yellowish, opaque, tough masses, brittle in the cold, crumbly-crystalline in the interior, of a terebinthinate odor and taste. In warm weather it is a yellowish, viscid semiliquid when fresh, but ultimately, through exposure to the air, becomes perfectly dry and hard.
CONSTITUENTS.—Volatile Oil 20 to 30 per cent. (27b), abietinic anhydride, C44H62O4, in rosin (27c), the acid of which, abietic acid, C44H64O5. is crystalline, soluble in CS2, benzol, alcohol, ether, chloroform, glacial acetic acid, and alkalies.
27a. Terebinthinae Laricis, N. F.—Venice Turpentine.—A yellowish or greenish liquid of honey-like consistence, collected in Switzerland and portions of France from Larix europaea De Candolle. Obtained by boring holes into the center of the wood and dipping the liquid out as it accumulates. It received its name from having formerly been almost entirely distributed from the Venetian port. Genuine Venice turpentine is comparatively scarce in the markets to-day, most of it being a factitious brown liquid made by dissolving rosin in oil of turpentine.
A number of other turpentines are obtained from various species of pine, larch, and fir, but hardly any of them enter our markets. The turpentines all agree in their medical properties, and differ only slightly in their physical characteristics, all of them being liquid at first, thickening through the evaporation and oxidation of their volatile oil, and ultimately solidifying They melt by heat, and at a high temperature ignite with a white flame attended with dense smoke.
CONSTITUENTS.—Volatile Oil 20 to 30 per cent., resin (abietic anhydride, crystallizing out as abietic acid), a bitter principle, and traces of succinic and acetic acids.
ACTION AND USES.—The turpentines are rarely used internally, the volatile oil, to which the medicinal virtues are due, being used instead. Dose: 15 to 60 gr. (1 to 4 Gm.), in pills. Externally irritant and rubefacient, in ointments and plasters.