19 
Part VI.] Preparation of Turpentine , Rosin and Gum . 
therefore, no apparent reason why this Indian gum- 
oleo-resin should not be used in place of the African or 
Arabic product. At the present time there is little demand 
for frankincense in this country, its chief use being as an 
ingredient of incense.” 
Again, when in 1911, the Forest Economist selected this gum-oleo- 
resin as a subject for further investigation on account of the common 
occurrence of Boswellia serrata in the Indian Forests, it occurred to the 
writers that by splitting it up into different products, there was a far 
better prospect of placing it in quantity on the market than by utilizing 
it as “ olibanum ” or “ frankincense,” and this impression was con¬ 
firmed by the above-mentioned report published by the Imperial Insti¬ 
tute. As occasion permitted, the work has been carried out during the 
last four years, and the samples prepared in the Laboratory of the Forest 
Research Institute were submitted to interested parties for commercial 
valuation and criticism. By this procedure, indications as to the class 
and grade of products required by the market have been obtained, 
thus guiding the writers in their work. In this connection, we would 
like to thank the Director of the Imperial Institute, whose reports and 
criticisms have been of the greatest assistance. 
As the main object of the enquiry has been to develop a cheap com¬ 
mercial process by which the ingredients of Boswellia serrata gum-oleo- 
resin can be separated and to make samples for commercial valuation, 
it has not been considered necessary to verify the composition of Boswellic 
acid and other resins as already reported. On the other hand, the usual 
constants of the resin and oil were determined from time to time to arrive 
at standard constants for the Indian olibanum oil, while the composi¬ 
tion of redistilled oil is under study. The major portion of this redis¬ 
tilled oil consists of Dextro-Pinene mixed probably with Pinene. 
Phellandrene is absent in this major fraction of the oil. The 
residue left after the distillation of Pinene ^was too small to admit 
of a detailed examination, but which will be carried out by distilling 
larger quantities of oil as opportunity offers, and the exact chemical 
differences between this oil and that of the African frankincense wiil be 
discussed in a separate note. 
2. Preliminary analysis. 
The percentage composition of the samples of the Boswellia gum- 
-cjeo-resin received from the States of Gwalior and Kotah and other 
localities is given below. These samples, with one exception, are the 
results of very elementary methods of collection by forest tribes and do 
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