4 BULLETIN 1064, U. S. DEPARTMENT OF AGRICULTURE. 



and turpentine are obtained as the products of distillation. The 

 " gum turpentine " distilled from oleoresin is distinguished from 

 " wood turpentine," which is obtained from the steam or destructive 

 distillation of the resinous heartwood of stumps or dead or down 

 timber. 



Fresh gum spirits of turpentine distilled from the southern pines 

 of the United States consists of several similar or closely related 

 compounds known as terpenes, together with small and varying 

 quantities of oxidized derivatives thereof. 8 The empirical formula 

 of the terpenes is C 10 H 16 , indicating that turpentine consists almost 

 entirely of carbon and hydrogen. Of the terpenes, the one known as 

 pinene occurs in the highest proportion in spirits of turpentine. 

 Alpha pinene is found to the extent of 80 to 85 per cent in the average 

 pure, fresh, American gum spirits of turpentine. Among the other 

 terpenes which have been found in small quantities in turpentine oil 

 may be mentioned beta pinene, camphene, silvestrene, and dipentene, 

 the last two being found also in destructively distilled wood turpen- 

 tine. American pinene, the greater part of which is obtained from 

 longleaf pine {Pinus palustris) gum, has optical properties different 

 from those of the French. The pinene from slash pine {Pinus 

 caribaea) , however, resembles the French in this particular. Other- 

 wise the turpentine oils of slash and longleaf pines are very similar, 

 whether obtained from the wood or from the leaves. 9 



STRUCTURE OF WOOD OF TURPENTINE PINES. 



Of fundamental significance for the understanding of the produc- 

 tion of naval stores is the structure of the wood of the pine, espe- 

 cially of Pinus palustris Mill, (longleaf pine), and Pinus caribaea 

 Morelet (slash pine), which are the chief turpentine pines of the 

 southern United States and produce approximately 75 per cent of 

 the world's supply of naval stores. 10 It is from the outer wood 

 next the bark in the living pine that oleoresin is obtained. Here 

 also the responses to turpentining, differing according to the methods 

 practiced, are clearly registered in the woody tissue that is formed 

 after the scarifications have been made. 



8 Veitch, F. P., and V. E. Grotlisch, "Turpentine," U. S. Dept. Agr. Bui.. 898, 1920. 



Schorger, A. W., " Constribution to the Chemistry of American Conifers." Trans. 

 Wis. Acad, of Sci. Arts and Letters, 19 : March, 1919, p. 742. 



10 Oleoresin is also obtained in relatively small quantities from various other species of 

 pine, including : In the United States, P. echinata, shortleaf ; P. taeda, loblolly ; p. pon- 

 derosa, western yellow; and P. serotina,, pond pine; in France, P. pinaster or maritime., 

 maritime pine ; in Greece and Algeria, P. halepensis, Aleppo pine ; in Italy, P. pinea, 

 stone pine ; in Austria, P. laricio, austriaca-, or nigra, black pine ; in India, P. longifolia, 

 chir pine ; and P. excelsa, the Himalayan or Bhotan pine ; in Mexico and Central 

 America, P. ayacahuite, the Mexican white pine ; in central Germany, Poland, and 

 northern Russia, P. silvestris, Scotch pine ; and in Japan, P. thtm-oergii, Japanese black 

 pine. (From U. S. Dept. Agf. Bui. 898.) 



