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. Grotliseh, " Turpentine," U. S. Dept. Agr. Bui. 898, 1920. 
9 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. ccliinata, shortleaf ; P. taeda, loblolly; p. pon- 
derosa, western yellow ; and P. serotina, pond pine ; in France, P. pinaster or maritima, 
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. thimbergii, Japanese black 
pine. (From U. S. Dept. Agr. Bui. 898.) 
