TURPENTINE, OIL OF, sometimes called essence of turpentine. As found in commerce, it contains more or less ro sin, from which it may be freed by re distillation along with water. It is color less, limpid, very fluid, and possessed of a very peculiar smell. Its specific gravity when pure, is 0.870. It always reddens litmus paper, from containing a little succinic acid. According to Opper mann, the oil which has been repeatedly rectified over chloride of calcium, con sists of 84.60 carbon, 11.735 hydrogen, and 3.67 oxygen. When oil of turpen tine contains a little alcohol, it burns with a clear flame ; but otherwise it affords a very smoky flame. Chlorine inflames this oil ; and muriatic acid con verts it into a crystalline substance, like camphor. It is employed extensively in varnishes, paints, &c., as also in medi cine.
The spirit, or oil of turpentine, is ob tained from the crude article by distilla tion. When the volatile oil comes over, and colophony is left behind in the re tort; 250 lbs. of turpentine yield 60 lbs. of oil.
A patent was granted in 1847, for re fining turpentine for the production of the pine oil, as it is termed, for burning in lamps. The resinous matter is sepa rated by treating the turpentine with potassa, and in order to effect thorough admixture the liquid is forced through a succession of fine strainers. After this
operation, rain-water is added, and the whole suffered to stand for twelve hours, when the pure spirits will be found float ing above the water and impurities, from which it is drawn off.
A patent has been granted for an im provement in the distillation of crude turpentine, consisting merely of an agi tator or stirring apparatus, working with out the still, the shaft of the agitator passing through a stuffing box in the top of the still.
The stirring of various liquids in the operation of boiling is a common device, but has never been before applied in the production of turpentine, and is in this case, as asserted, attended with consider able advantages. Turpentine consists of two liquids, one boiling at a much high er temperature than the other, which is obvious from the very interesting fact, that while boiling without pressure its temperature may be raised more than 200°.
Mr. Viclette has adopted the process of distillation with steam, which he found so successful in the case of quicksilver (see MERcuRY, to the treatment of turpentine with great economy of time and fuel, and obtains a purer article. It is asserted that in this country Mr. Wade distilled turpentine with steam so long as three years back.