35 



but only three ;ire comiucrcially important, as they arc the source of the three princii)a] oils of 

 turpentine. 



(1) The turpentine oi Pinus ^liiicstcr (.syu. I', maritima) collected in the southern departments 

 of France around Bordeaux. From it is obtained the French tnriientine, which yields 25 per cent 

 of volatile oil. 



(U) The turpentine from Tinun palusiris, P. to'da, P. Ciibenfiis, collected in the Southern sea- 

 bordering States from North Carolina to Texas. From them, princii)ally from the first source, is 

 obtained the English or American oil of turpentine, which yields 17 per cent of volatile oil. For- 

 merly the P. rif/ida was also worked for turpentine in the North Atlantic States, but it is now 

 exhausted. 



(3) The turpentine from Pinus laric-io var. Austrkiva, collected mainly in Austria and Galicia. 

 From it is obtained the German turpentine oil, which yields 32 i)er cent of volatile oil. 



The Russian oil of turijeutine is obtained from Pinus syli-cstris and Pinus Ledehourii, by the 

 direct distillation of the resinous wood, without jireviously collecting the turpentine. It is said 

 to be identical with the (rerman oil of turpentine, but more variable, as it contains products of 

 destructive distillation both of wood and rosin. 



The turpentines from the different sources differ from each other — (1) in their action uiwn 

 polarized light, (2) in the relative amounts of volatile oil they yield on distillation with steam, and 

 (3) in the nature of the volatile oils they contain. 



Colophon}/. — The rosin in the different varieties of turpentine is practically the same. It is 

 known as common rosin or colophony.* It consists chemically of a mixture of several resin 

 acids and their corresponding anhydrides. The chief constituent is abietic anhydride, C44H62O4, 

 abietic acid being C44ll64()s. Tht; crystals that are noticed in crude turpentine are the free abietic 

 acid; on melting the thick tiu'i)entine, or on distilling the volatile oil, the acid is changed to the 

 anhydride. Colophony is nonvolatile, tasteless, brittle, has a smooth shining fracture, sp. gr. 

 about 1.08. It softens at SO"^ C, and in boiling water melts completely at 135° C 



The voUdile oil. — The second principal ct)nstituent of turpentines are the volatile oils. The 

 chief ingredient of the three turiientine oils is a hydrocarbon of the same composition, OioHir; 

 nevertheless the three oils hiive distinct liydrocarl)ons differing from each other in physical if not in 

 chemical properties. The empirical formula of the hydro(!arbon is CiuHis, and according to the 

 latest researches of Wallacht it has the following structural formula: 



thus being a dihydro-para cymene, paracymene being OjoHu, 



CH(CHJ>i 



I 

 c 



c/\ 



CH 



CCHi 



The position of this particular terpens, pinene, will be best seen from the general classification 

 of terpenes taken from Wallach. J 



I. — Hemiterpenes, or Per.oenes of the formula CsHs. 

 II. — Terpenes or Dipeiitenes, of the formula CuiHie. 



(1) Pinene, obtained from many varieties of turpentine. 



(2) Camphene, obtained artificially from camphor. 



■ Colophon, a city of Ionia, whence rosin was obtained by the Greeks. 

 tAnn. Chem. (Liebig), 239, -19; Ber. d. Chem. Ge8.,24, 1545. 

 tAnn. Chem. (Leibig), 227, 300: Ber. d (Chem. Ges.), 24, 1527, 



