The American Cyclopædia (1879)/Turpentine

From Wikisource
Jump to: navigation, search

TURPENTINE, a term applied to several oleoresins which exude from coniferous trees, and also from the pistacia terebinthus, the tree called by the Greeks τερέβινθος, which furnished the principal variety known to the ancients. Of commercial turpentine there are several varieties, which consist of a resin more or less dissolved in a volatile oil, called oil of turpentine. American turpentine is chiefly obtained from the pinus australis or “long-leaved” pine, which is abundant on the coast of the Carolinas and Georgia; it is also obtained from “old field” pine or pinus tæda; the largest quantity is produced in North Carolina. Canada turpentine, called also Canada balsam and balsam of fir, is the product of abies balsamea or balm of Gilead fir, a small tree which grows in Canada and the state of Maine. The German turpentine is principally derived from the Scotch fir, pinus sylvestris; French or Bordeaux turpentine is obtained from pinus maritima, which grows in southern Europe and along the Mediterranean coast; Strasburg turpentine from the silver fir, abies picea, and from spruce fir, abies excelsa. That from silver fir is quite liquid, having the odor of lemons and a sharp, bitter taste; that from spruce fir has a strong balsamic odor and a sweetish, aromatic taste. Venice turpentine is obtained from the larch, larix Europæa; it is a ropy liquid, of a transparent brownish or greenish color and a bitter taste. Hungarian and Carpathian turpentines are from pinus pumilio and pinus cembra. Cyprian, Syrian, or Scio turpentine is obtained in Scio from pistacia terebinthus, and in Syria from pistacia vera, which is also the tree that furnishes pistachio nuts; it has the odor of fennel and an aromatic taste like mastic.—When exposed to the air, turpentine slowly hardens, partly from evaporation of the oil, and partly from oxidation. It softens and liquefies by heating, takes fire readily, and burns with a dense smoky flame. It is completely soluble in alcohol and ether. On boiling with water the volatile oil passes off with the steam, while the resin remains intimately mixed with a small quantity of oil and water, forming a dingy, turbid mass called “boiled turpentine.” At a stronger heat the water and remaining portion of oil are expelled, and colophony remains, as a transparent resin, more or less colored. Colophony was formerly regarded as a mixture of two isomeric acid resins, pinic and sylvic acids; but recent investigations of Maly have shown it to consist mainly of abietic anhydride, C14H62O4 which when treated with aqueous alcohol takes up water and is converted into abietic acid, C14H62O5.—The turpentines are the sources of the oil of turpentine of commerce, which constitutes from 10 to 25 per cent. of crude turpentine. The remainder is principally rosin, from which the turpentine is distilled. (See Rosin, and Turpentine, Oil of.)