78 TURPENTINE (Oil. OF) vary slightly as to specific gravity and boiling point, but more particularly in regard to their optical rotatory power ; but many of them are derived from several sources, and as before remarked vary when of the same origin on account of different modes of preparation. French turpentine oil, obtained from French or Bordeaux turpentine, consists of a hydro- carbon, OioHu, called by Berthelot tereben- thene. It cannot be readily obtained from the commercial oil, which is too much contamina- ted with products of transformation, but may be obtained pure by treating French turpentine with an alkaline carbonate, and distilling it first over a water bath and then in a vacuum, by which transformation by heat or reagents is avoided. Terebenthene obtained in this way has a constant specific gravity of 0*864, a boil- ing point of 321-8 F., and a rotatory power of 13-3. (See LIGHT, OPTICS, and saccharim- etry in the article SUGAR.) This oil also con- tains an isomeric hydrocarbon, terepentilene, boiling below 356 F., and also a polymeric oil, parterebenthene, which boils at about 482. The principal oil contained in English turpen- tine is australene, or austraterebenthene, hav- ing the same specific gravity and boiling point as the French oil terebenthene, but an optical rotatory power of +2T5 . The English oil also contains, according to Berthelot, an iso- meric body called australene. Both the Eng- lish and French oils, before their constituents are separated, possess rather less rotatory pow- er. Venetian oil of turpentine has a rotatory power of 5"2. All these oils possess the com- mon property of absorbing oxygen from the air and ultimately becoming resinous, at the same time producing carbonic, acetic, and formic acids. In this gradual oxidation ozone is produced, as it is more rapidly by dipping a warm glass rod in a jar filled with vapor of turpentine; and turpentine oil exposed for some time to the sun's rays contains oxygen and ozone in solution. A paper soaked in oil of turpentine and immersed in a jar of chlo- rine takes fire, producing a dense black smoke and white fumes of hydrochloric acid. When treated with excess of iodine the combination takes place explosively. Turpentine oil is violently acted upon by nitric acid, often taking fire, producing nitro-benzene. Oil of turpen- tine, besides being used in making varnishes, is, on account of its solvent action generally on oils and resins insoluble in water, used for discharging such substances from cloth, rags, fec. It is one of the most energetic of volatile oils. Its vapor is quickly destructive to plants and to many insects. It acts more powerfully on the lower animals than on man, easily blis- tering the skin of the horse. It is used in medicine as a diuretic and anthelmintic, and as a stimulant to the mucous membranes of the bowels and genito-urinary organs. It is often of great benefit in the ulcerated condition of the small intestines consequent upon typhoid fever, and also in diarrhoeas. It also possesses TURQUOISE many interesting chemical characteristics, tho study of which has been of great advantage to the progress of theoretical chemistry. TURPIN, Tnlpln, or Tilpin, archbishop of Rheims, a friend and companion of Charle- magne, died Sept. 2, 800. He was originally a Benedictine monk of the convent of St. Denis, and was made archbishop about 763. His name is prefixed to a Latin chronicle, which relates the expedition of Charlemagne against the Saracena of Spain and the fight of Roncesvalles. Turpin's authorship of the chronicle is disputed, though Pope Calixtus II. in 1122 declared it to be authentic. The work is among the earliest productions relating to the events of Charlemagne's reign, and from it the tales of chivalry of the middle ages were largely taken. It was translated from Latin into French in 1206 by a clerk of Renaud, count of Boulogne. The original was first printed in the collection of Schardius (fol., Frankfort, 1566). The best editions are by Ciampi (Florence, 1822) and by Reiffenberg in Chronique de Philippe Mousket (2 vols., Brus- sels, 1836). See Gaston Paris, De Pseudo- Turpino (Paris, 1865). TURQUOISE, a native hydrated phosphate of aluminum, found in the mountains near Nisha- pur, in Khorasan, Persia, and much valued as a gem. It is called by the Persians biruta, and is probably the callau of Pliny. An inferior variety is also found at Jordansmuhle in Sile- sia, and at Oelsnitz in Saxony. Major Mao- ri onald discovered in Arabia Potnea, near Mt. Sinai, a variety of turquoise in a layer of red sandstone ; it is darker and said to be of a finer blue than the Persian turquoise, but unfortu- nately it changes color, especially under the wheel of the lapidary. Persian turquoise has the chemical composition represented by the formula 2AUOj,P a O,5IIO; it is uniform and stalactitic in structure, of hardness 6 on a scale of 10 ; sp. gr. 2-6 to 2'8 ; color a peculiar bluish screen to azure-blue and white, slightly trans- lucent to opaque, with small conchoidal frac- ture. Specimens of a fine blue are much the most highly prized. "When heated, the turquoise decrepitates strongly, gives off water, and, if colored, turns black. It tinges the blowpipe Harne green, and with fluxes gives reactions of iron and copper. An analysis by Hermann of a blue oriental turquoise gave 28'9 of phosphoric anhydride, 47'45 alumina, 2-02 cupric oxide, I'l ferric oxide, 0*5 manganic oxide, 1'85 Ime, and 18-18 water. The turquoise is much used in oriental countries for ornamenting har- ness, girdles, swords, amulets, and charms, and is believed to have the power of protecting its wearer against contagion, or, when he is af- fected with disease, of changing color and be- coming pale. Several antique cameos and in- taglios cut in turquoise are in the Vatican at Rome. Fragments of the gem, which appear to have been parts of amulets, are often met with in Egyptian ruins. The shah of Persia is supposed to have in his possession all the
