OXIDS OF CARBON, CARBONATES, ETC. 113 



the distillation of petroleum, after the removal of the 

 gasoline, benzine, and kerosene, are used for lubricating 

 purposes, and are called mineral oils. They have a boil- 

 ing-point from 250 to 350 C. 



135. Oil of Turpentine (C 10 H 16 ). Oil of turpentine is 

 obtained by distilling the resinous material which exudes 

 from incisions in certain species of pines. Resin is ob- 

 tained in the retorts. Oil of turpentine is inflammable, 

 and dissolves readily in ether, alcohol, and naphtha. It 

 is a valuable solvent, extensively used in the preparation 

 of varnishes and paints, and as a solvent for caoutchouc. 

 Turpentine belongs to the class of compounds known as 

 essential oils. 



136. Creosote. When wood tar is distilled, various 

 products are obtained which, after treatment with chemi- 

 cals for purification, are called wood- tar creosote. This 

 is a yellowish liquid with a smoky odor. It is a power- 

 ful antiseptic, and is the preservative employed in the 

 preparation of " smoked meats," as hams and fish. It 

 has no marked action on albuminous matter and in small 

 amounts is not poisonous. Because of its antiseptic powers, 

 wood creosote is used extensively for the preservation of 

 wood, as it prevents decay. When some kinds of wood, 

 as beech wood, are burned, the wood-tar condenses in 

 the chimney. 



137. Benzine or Benzol (C 6 H 6 ). When coal tar, ob- 

 tained in the manufacture of illuminating gas, is sub- 

 jected to fractional distillation, commercial products are 

 obtained known as coal tar, naphtha, middle oil, heavy 



