Pari I.] Puran Singh: Turpentine Oil and Indian Rosin. 23 
the heavy turps found in the crude Bhowali oil are solely due to the 
high temperature employed in distillation. 
The colophony obtained was dried over an open fire to drive off 
all traces of water, free acid, etc. In dried form, it was very 
transparent, bright and had a fine pale lemon colour. On examina¬ 
tion it gave the following constants: — 
Acid number ...... 156-65 
Saponification number . . . . . 169-90 
Specific gravity ...... 1 -082 
These constants show the colophony to be of standard quality 
which does not deteriorate on the addition of acetic acid. 
(ii) Recovery of Acetic Acid. 
The acetic acid used could be easily recovered from the distillate 
by first converting it into lime acetate by neutralizing the 
distillate with lime water, and then distilling the lime acetate with 
strong sulphuric acid in a special still. The quantity actually 
recovered from the distillate in the laboratory amounted to 75 per 
cent, of the total quantity used. Instead of recovering acetic acid 
from the distillate, it will be a better plan to neutralize the collected 
watery distillate with soda carbonates and to recover from it the 
sodium acetate in crystalline form. This by-product could be 
easily sold at good rates. 
A preliminary report on this process and its commercial possi¬ 
bilities was submitted to the President, Forest Research Institute, 
with a recommendation that the plant used in w T ater distillation at 
present should be replaced by a battery of copper steam distillation 
stills tinned inside, connected with a boiler. But as this would 
have entailed expensive alterations in the existing plant, the pro¬ 
posal of trying the method on a commercial scale was finally given 
up. Moreover acetic acid would necessarily have some destructive 
effect on the plant. 
Methylated spirit process .—To avoid any changes in the stills 
at present in use and other disadvantages, instead of acetic acid, 
methylated spirit was mixed with the crude resin and the latter 
distilled with steam as mentioned before. Methylated spirit 
answered the purpose well and the oil obtained was of the same 
[ 23 ] 
