68 
Indian Forest Records. 
[Vol. IY. 
Indian oil was still sticky wliere the layer was thick and “ tacky 55 
where it was thin, whereas the London sample had dried to a thin 
“tacky” layer. The Indian oil finally left 1\ grams of residue 
whilst the London oil left only \ gram. 
The varnish-making properties of the two oils were also com¬ 
pared by using them to prepare solutions of zinc resinate. On 
leaving the oils for IT days in contact with an excess of the resinate, 
the London oil proved to be the more powerful solvent of the two, 
giving a very thick syrupy liquid which had to be diluted with 
more oil before it could be used; whilst in the case of the Indian oil 
only a thin syrupy solution was obtained. This thin solution, how¬ 
ever, when painted on sized wood gave a very satisfactory varnished 
surface, so that it appears that the Indian oil can be used quite well 
for varnish-making. 
Remarks. 
The previous examination of Indian turpentine oil at the Im¬ 
perial Institute showed that only one-third of the oil of Finns longi- 
folia is pinene, boiling at 157'5° C., and that the remaining two- 
thirds is mainly composed of terpenes boiling at a considerably 
higher temperature, viz., 173° C. (see Imperial Institute Report, 
dated 27th July 1909). These facts and the results of the present 
investigation show that there is no possibility of this turpentine 
oil being accepted in commerce as similar to American and French 
turpentine oils, which are pinene oils. 
In the Laboratory it is possible by repeated distillations to 
separate the pinene from the other terpenes, but it is very unlikely 
that this could be done profitably on a large scale. It, therefore, 
seems inevitable that the oil must be sold on its own merits as 
Indian turpentine oil, when it may be expected to realise a price 
equal to or somewhat better than that of Russian turpentine oil. 
* % * * * * * 
* * * * * * * 
The analytical results quoted by the Forest Chemist in the letter 
forwarding the present samples C and D show a marked improve¬ 
ment in the oil distilled with methylated spirit or acetic acid, com¬ 
pared with the oil as ordinarily obtained. Trials at the distillery 
[ 68 ] 
