Origin and Properties. Like the Spanish oil of turpentine, the Greek oil has acquired a certain commercial significance only in recent years4). Turpentine is produced in all of the provinces of Greece. It is obtained exclusively from the Aleppo pine (Pinus halepensis, Mill.), mostly by the Austrian method (see p. 74), though in recent years a beginning had been made with the French method. In 1907 the turpentine harvest amounted to approximately 7000 tons.
Only a part of the crude turpentine is used for the direct production of turpentine oil and colophony. Of oil 20 to 26 p. c. are obtained, of colophony 70 p. c, the balance consisting of water and mechanical impurities. The larger part of the oil, however, is not distilled directly from the turpentine. This is added to grape juice (in the case of red wines after the removal of the skins), partly to increase the keeping qualities of the wine, partly to impart to it the desired resinous taste. From the oleoresin-containing yeast the turpentine oil is recovered by distillation, whereas the residue is worked up for colophony and calcium tartrate. This method of production accounts for the agreeable odor of the oil reminding of that of the wine1).
1) Chem. & Drugg. 71 (1907), 379. See also p. 55.
2) Judging from the properties of a sample of Portuguese oil of turpentine examined in the laboratory of Schimmel & Co. (d15° 0,8661; aD - 32° 35') the oil is obtained from the same species as is the Spanish.
3) Paper read before the Spanish Society for Physics and Chemistry, Nov. 8. 1909; Chem. Ztg. 33 (1909), 1341.
*) Comp. p. 53.
Properties. The oil frequently contains traces of alcohol which lowers the specific gravity and boiling temperature; d15 o,8605 to 0,8660; aD + 34 to +41°; nD20o1,465 to 1,474; soluble in 7 and more vols, of 90 p. c. alcohol. When fractionally distilled2) (754 mm.) 6 p.c. passed over between 152 and 156°, 28 p.c. between 156 to 157°, 30 p.c. between 158 and 159°, 16 p.c. between 159 to 160°, residue 10 p.c.
Composition. Greek turpentine oil consists very largely of d-a-pinene with a high angle of rotation. Hence it is desirable as first material whenever a high optical rotation is wanted. E. Gildemeister and H. Kohler3) isolated from Greek turpentine oil d-a-pinene with the following properties: b. p. 156° (760 mm.); d15o,8642; aD + 40°23'; nD20o1,46565.