PROPERTIES AND COMPOSITION OF WO()1> TURPENTINE. 21 



and tars of the destructive process are often used as disinfectants, 

 cable coatings, wood preservatives, shingle stains, etc. 



The crude oils obtained by the steam distillation of long-leaf yellow 

 pine contain pinene, camphene, limonene, dipentene, terpineol, 

 borneol, fenchyl alcohol, camphor, cineol or eucalyptol, etc. They 

 are fractionated to two or three fractions, wood turpentine dis- 

 tilling at from 150-160 to 175-180 C., light pine oils between 

 170-180 and 210-225 C., and heavy pine oils at from 180-190 

 to 230-240 C. 



Steam-distilled wood turpentine consists essentially of pinene, 

 together with camphene, limonene, dipentene, cineol, and, depending 

 on care of fractionating, more or less, terpineol, borneol, terpinene, etc. 



The pine oils contain chiefly terpineol, borneol, and fenchyl alco- 

 hol, with small quantities of limonene, dipentene, terpinene, cineol, 

 and even less pinene and camphene. Pine oils are used in medicine, 

 in the manufacture of artificial camphor, terpeneol, and terpene 

 hydrate, as a solvent for pyroxylin in cheap varnishes and in other 

 varnishes. 



Many efforts have been made to remove from wood turpentine one 

 of its distinguishing characteristics, namely, its peculiar odor, but 

 so far with only partial success, as the odor often returns. Our own 

 experiments indicate that this odor is due chiefly, if not entirely, to 

 the heavy oils which wood turpentine usually contains. When these 

 are removed by careful fractionation, wood turpentine consists 

 almost wholly of the same constituents as gum spirits, which it also 

 closely resembles in odor. 



The first fractions obtained from crude steam-distilled turpentine 

 resemble gum spirits very closely in odor and composition, but the 

 yield of this portion is too small to justify the rejection of subse- 

 quent fractions. Hence, in separating from the crude oils all those 

 that have approximately the same specific gravity and behave like 

 turpentine when distilled, portions of the before-mentioned heavier 

 oils distill and mix with the light oils and it is probably the presence 

 of these heavy oils which accounts for the difference between gum 

 spirits and wood turpentine. Destructively distilled turpentine with 

 which the products of the distillation of rosin are mixed can not be 

 freed entirely from rosin spirits and its accompanying odor. The 

 following table shows the differences existing between commercial 

 gum and wood turpentines in regard to those properties by which 

 technical value is usually judged. The composition of wood turpen- 

 tine is also shown by the analyses given in Table 1 , page 58 . 



