The oil distilled from the field thyme, Thymus serpyllum, L., is limpid, yellowish to gold yellow, and of specific gravity 0.89 to 0.91. Old oil is red or brown and no longer limpid. Good oil is soluble in every proportion in 90 per cent. alcohol and emits only slight vapors when brought in contact with iodine. It consists largely of thymene and cymene, and contains a few per cent. of phenol-like bodies.
Turpentine, oil of.—Under the general name "oil of turpentine" are comprised the volatile oils obtained by distillation from the resins or other portions of different species of the pine. There is a large number of these oils, the most important ones of which shall here be mentioned, though but a few are of interest to the perfumer.
Austrian oil of turpentine, from Pinus laricio, Poir.—It is colorless or yellowish, transparent; specific gravity, 0.864; boiling point, 311° to 314° F.; turns polarized light to the left; soluble in 6 parts 90 per cent. alcohol. When rectified it has a specific gravity of 0.862, and is soluble in 7 parts of 90 per cent. alcohol.
German oil of turpentine, from Pinus sylvestris, P. abies, P. vulgaris, P. picea, and P. rotundata, resembles the former; specific gravity, 0.860 to 0.870; boiling point, 311° to 320° F.; turns polarized light to the left. When rectified it is soluble in 7 parts of 90 per cent. alcohol.
French oil of turpentine, from French turpentine of Pinus maritima.—It is colorless or faint yellowish; specific gravity, 0.860; boiling point, 313° to 315° F.; turns polarized light to the left; odor peculiar; taste burning. With 7 parts of 90 per cent. alcohol it gives a clear solution.
Venetian oil of turpentine, from Venice turpentine of Larix decidua, Mill., is laevorotatory and resembles the preceding, but has a more agreeable odor. Venice turpentine is mostly obtained in Southern Tyrol and in Piedmont, and yields 18 to 25 per cent. of oil.
American oil of turpentine, from American turpentine of Pinus australis, Mich., and P. Taeda, L.—It resembles French turpentine, but turns polarized light to the right. Specific gravity, 0.864; boiling point, 302° to 312.8° F.
Pine oil (oleum abietis) is obtained by distilling with water the leaves or green cones of Pinus picea, L., Abies pectinata, D. C. Its odor is much finer than that of ordinary oil of turpentine. It is soluble in 7 parts of 90 per cent. alcohol.
Dwarf pine oil, Krummholz or Latschenoel (oleum pini pumilionis), is obtained by distilling the young tops and cones of Pinus pumilio with water. It has an agreeable odor, reminding one of juniper; specific gravity, 0.865; boiling point, 338° F. The oil is laevorotatory and soluble in 12 to 15 parts of 90 per cent. alcohol.
Pine-leaf oil is obtained by distilling the leaves of Pinus sylvestris or P. abies by means of steam. It is dextrorotatory; has a fine aromatic odor; boiling point, 320° F.; specific gravity, 0.875 to 0.876.