Part VI.] Preparation of Turpentine , Rosin and Gum. 
31 
the extraction of the gum-oleo-resin at a fixed point in order to produce 
this mixed substance. 
Part VI.—Industrial uses of the products and their commercial 
valuation. 
1. Boswellia Turpentine Oil. 
As already remarked, the Boswellia turpentine oil consists mainly 
■of dextro-pinene, and as such is as good as the best American and French 
-oils of turpentine and its uses are the same as those of the latter. 
With a view to corroborating the above statement, samples of tur¬ 
pentine prepared at the Forest Research Institute were submitted to 
the Imperial Institute, London, to the Ordnance Department and to 
Indian firms, whose reports are quoted in original below :— 
(i) Imperial Institute of the United Kingdom, the Colonies and India . 
Report on Turpentine oil prepared from the Gum-resin of Boswellia serrata in India, 
The sample of turpentine oil. prepared from the gum-resin of Boswellia serrata, 
which is the subject of this report, was forwarded to the Imperial Institute by the 
Forest Economist at Dehra Dun with letter No. D. 0. 690-18, dated 16th April 
1914. It was stated that the oil had been obtained by steam distillation of the 
gum-resin and that it had afterwards been fractionally distilled. 
Description of Sample.. 
“ Boswellia Turpentine made at the Forest Research Institute Dehra Dun.” 
Weight about 2\ lbs. 
A mobile liquid oil with a slight greenish-yellow tinge and a sweet, agreeable 
odour. 
Results of examination. 
The oil being examined at the Imperial Institute was found to have the following 
•constants :— 
Commercial turpentine oil. 
Boswellia 
turpentine 
oil. 
American. 
French. 
Sp. Gr. at 15°-15°C. .... 
0-8446 
0-858 to 0-8770- 
865 to 0-875 
Optical rotation « D 
+ 31° 24' 
—9 to—14° 17' 
(rarely 
slightly 
laevo-rota- 
tory). 
—29° to—33° 
Ester Value, before acetylation 
2-6 
Ester /alue, after acetylatipn . 
36-4 
•• 
d2 
[ 333 ] 
