Origin. Like Pinus Sabiniana, P. Jeffreyi, Murray occurs in the Sierra Nevada of California, but is found at higher altitudes. The turpentines of both pines resemble each other closely, and the oils appear to be identical. The abietene mentioned in connection with Pinus Sabiniana appears to be obtained indiscriminately from both species4).
From the excretions of recently felled trees, Blasdale5) obtained 3 p. c. of a colorless oil. After treatment with sulphuric acid, washing and drying, it boiled largely between 96 and 98°. d 0,6863; aD0; nD 1,3905.
Composition. Like the oil of Pinus Sabiniana, this oil consists principally of n-heptane. The investigations of E. P. Venable3) were not conducted, as he supposed, with the hydrocarbon of P. Sabiniana but, as Wenzell later pointed out, with the abietene of P. Jeffreyi.
As already pointed out on p. 57, the constantly increasing consumption of turpentine oil on the one hand and the disappearance of the pine forests suitable to the production of turpentine on the other hand, have caused the United States of North America to improve the methods of production and thereby to increase the yield of turpentine. One source for the production of a technically valuable waste-product from pitchy pine stumps that occurred everywhere in large numbers, was for a long time practically neglected. It is true that in a few localities early attempts1) were made to utilize resinous wood and the waste of saw mills by subjecting them to destructive distillation for the production of pine tar oil, tar, pyroligneous acid and pitch. However, because of the former low prices of turpentine oil, this industry does not appear to have been very remunerative at any time, hence did not expand. It is only in very recent times that the so-called wood turpentine oil has acquired a certain significance and has become the product of a flourishing industry.
1) Journ. chem. Soc. 35 (1878), 296; Chem. Zentralbl. 1879, 565. - Liebig's Annalen 198 (1879), 364.
2) Journ. Americ. chem. Soc. 23 (1901), 162. - Chem. Zentralbl. 1901, I. 1143.
3) Berl. Berichte 13 (1880), 1649.
4) E. Kremers, Pharm. Review 18 (1900), 165. - W. T. Wenzell, ibidem 22 (1904), 408.
5) Journ. Americ. chem. Soc. 23 (1901), 162; Pharm. Review 25 (1907), 363.
Wood turpentine oil is neither a genuine turpentine oil, nor a pine tar oil (Ger. Kieno/). Like the latter, it is obtained from the resinous wood (Ger. Kien) of trunks and stumps, however, not by destructive, but by steam distillation. It has been introduced under such names as light wood oil, oil of fir, long-leaf pine oil, wood turpentine, steamed wood turpentine and stump turpentine. The lower boiling fractions have been designated wood spirits of turpentine-), the higher ones as white and yellow pine oil. Because of the method of preparation, those constituents produced at high temperature and characteristic of the pine tar oils, viz., phenols, pyroligneous acid, furfurol, diacetyl etc., are wanting in the wood turpentine oils. But they also differ from genuine turpentine oils both physically and chemically. They contain a number of oxygenated substances that are entirely wanting in turpentine oil. Hence, the terpenes being less significant quantitatively, the specific gravity is higher and the viscosity greater. This difference in chemical composition is probably due to the process of resinification (Ver-kienungsprozess) which takes place in the stumps and roots, resulting in the formation of alcohols (borneol, terpineol, fenchyl alcohol), ketones (camphor), oxides (cineol) and phenol ethers (methylchavicol) from the terpenes contained in the oleoresin. In part, this process of Kienbildung probably takes place in the living tree. As a result of the wound, a large number of resinous ducts are formed near the surface of the wound, which are gradually filled with oleoresin. This oleoresin differs from the ordinary turpentine merely by its lower terpene content. Due to repeated wounding, the part of the trunk beneath the wound becomes saturated with oleoresin. If for any reason (e. g. wind) the tree weakened by the boxes falls, the stump saturated with oleoresin and known as light wood remains often to a height of from 10 to 15 ft. the height of the tapped places. Its oleoresin content preserves it, whereas the portions rich in sap soon decay.
1) C. Mohr, Pharm. Rundsch. (New York) 2 (1884), 163. - A description of modern plants for the utilization of the waste of saw mills is given by J. E. Teeple in his paper "Pine Products from Pine Woods." Seventh International Congress of Applied Chemistry, London 1909. Section IV A, 1, p. 54.
2) Report of Schimmel & Co. October 1911, 90.