Origin and Production1). In Russia also pine tar oil is only a by-product in the charcoal and tar industry. This industry is widely distributed throughout Russia wherever there are large pine forests. The principal localities for the production of charcoal and tar are in Archangelsk, Wologda, Kostroma, Wjatka, Nishnij-Nowgorod and Twer2).
In the first two mentioned governments the trees that have been used for the production of galipot, as described under Russian turpentine oil on p. 77, are allowed to die. The wood of the dead trees of Pinus silvestris, L. is cut into pieces which are subjected to destructive distillation in ovens that have a capacity of from 2 to 7 cbm. The vapors are passed by means of a copper tube through a condenser. According to this method 1 cbm. of wood yields 60 to 70 kg. tar and 6 to 8 kg. pine tar oil. The pyroligneous acid is discarded and the charcoal is used as a fuel for heating the apparatus.
The pine tar oil thus obtained, Terebenthine de four (Essence jaune de four), is of a brown color, and rendered impure by decomposition products, and has a very unpleasant odor. Hence it must be purified by rectification. This is accomplished by passing steam into a still containing the oil to which lime has been added. In this manner 75 to 78 p. c. of a l) M. Vezes, L'Industrie r6siniere en Russie. Bordeaux 1902. - Kowalewski, Die Produktivkrafte RuBlands. German translation. Leipzig 1898, p. 254, 255.
2) Chem. Industrie 34 (1911), 158.
Whereas in Archangelsk and Wologda the oleoresin secreted after wounding the pines is distilled for turpentine oil and rosin and the wood worked up for pine tar oils, in Kostroma the turpentine is allowed to remain on the trees and is distilled together with the wood. This operation is carried out in two successive steps in two apparatus, in the first with a gentle heat, in the second at a higher temperature. The first apparatus is an oven constructed of bricks with a capacity of 10 cbm. of wood. The products of distillation are carried off by means of wooden pipes which convey them to a copper worm condenser. The operation lasts 5 days. The pine tar oil is rendered impure by numerous decomposition products. The wood that remains after this operation is heated to a high temperature for the production of tar in iron retorts surrounded by a fire place of brick masonry. The distillate is collected in a chamber constructed of brick.
In Poland 1) the production of pine tar oil has the character of a house industry and is conducted in a primitive manner in ovens constructed of clay.
The crude pine tar oil of the smaller producers in Poland is used locally. The larger factories which also buy up the output of the smaller producers, purify the oil by rectification over milk of lime and freshly burnt charcoal. The wood vinegar is largely worked over into calcium acetate.
Properties. The sp. gr. of Russian pine tar oil is 0,862 to 0,872; the angle of rotation aD +15°25' to +24°2). It boils from 155 to 180°3). Upon fractionating a normal Russian oil, Tilden4) obtained 10 p. c. between 160 and 171°, 63 p. c. between 171 and 172°, and 24 p. c. between 172 and 185°.
1) According to a private communication by the late Prof. Dr. G. Wagner, of Warsaw, there were nearly 100 tar distilleries in Russian Poland in 1896, more particularly in the governments Lublin, Lomsha, and Suwalki. On the average each produced about 1500 to 2500 kilos of pine tar oil.
2) Comp. Armstrong, Pharmaceutical Journ. III. 13 (1883), 586.
3) Wallach, Liebig's Annalen 230 (1885), 245. - Tilden, Journ. chem. Soc. 33 (1878), 80 and Pharmaceutical Journ. III. 8 (1877), 447.
4) Loc. cit, p. 102, footnote 1.
Composition. Polish pine tar oil was examined by Tilden in 1877 and by Flawitzky1) in 1887. They found d-pinene; a terpene boiling at 171 to 172°, which Tilden regarded as identical with sylvestrene although he did not succeed in obtaining the hydrochloride melting at 72°; also cymene, the presence of which was demonstrated by means of bromine and sulphuric acid2). Wallach later confirmed the presence of a-p/nenes) and proved the presence of sylvestrene in fraction 170 to 180° by means of the hydrochloride melting at 72°. In the fraction about 180° he also found dipentene (dipentene tetrabromide) and a terpene which yielded a liquid bromo-addition product (terpinene?).
In the pinene fraction, j. Schindelmeiser4) demonstrated the presence of 3-pinene (m. p. of nopinic acid 126°). According to the same investigator, Russian pine tar oil contains in addition to sylvestrene, toluene, cymene, a substance having a pungent quinone-like odor and saturated hydrocarbons of the methane series. One of these, boiling at 98 to 99° is presumably heptane. In the highest boiling fraction a sesquiterpene has been found, which, according to Schindelmeiser, is identical with the optically inactive hydrocarbon that accompanies cadinene in oil of cade.