EAN UNCU LACE M 531
roses) has been described by Schimmel & Co.^1 The fraction boiling at
95° to 96° at 4 mm., or about 255° to 260° at normal pressure, is treated
with sodium and again fractionated until the boiling-point is as nearly
258° to 261° as possible, and the laevo-rotation at its highest point.
The fraction is dissolved in about 200 c.c. acetone, diluted with 35
c.c. water, and to the clear solution 15 grams of powdered potassium
permanganate are gradually added. The unattacked oil, which boils at
104° to 105° (5 mm.) is removed by fractionation and the distillation-
residue treated with semi-carbazide. The reaction-product is left stand-
ing overnight, when, after the addition of water, it is deposited as an oily
precipitate, solidifying in part after prolonged cooling in ice when stirred
with alcohol. The semi-carbazone, repeatedly recrystallised from hot
alcohol, melts at 234°, and, with a semi-carbazone of the same melting-
point and constants, prepared from gurjun balsam oil for purposes of
comparison, suffers no depression of melting-point.
Two species of Dipterocarpus are mentioned by Pearson^2 as being
used for the preparation of gurjun balsam, namely Dipterocarpus turbi-
natus and Dipterocarpus tuberculatus. Both of these have been examined
by Schimmel & Co.,
3
who report thereon as follows :—•
" Dipterocarpus turbinatus is a large tree which is found throughout
tropical Burma, in Bengal, and on the Andaman Islands. Its balsam is
specially known there by the name of ' gurjan oil'. It is collected in
large quantities and is used as a paint for houses and ships, as well as
a preservative for articles of bamboo. The balsam is exported from
Chittagong (Bengal). The sample received by us consisted of a faintly
acid, milky liquid; acid value 109 ; specific gravity 09811 (15°). When
allowed to stand, especially in the warmth, it separated out into a brown
oil which floats on the surface and a viscous, whitish-grey, emulsion-like
mass. The constants of the oily layer were as follows : d 150 0 9706 ; aD -
10° 8'; WD 2 0° 151200; acid value 73 ; ester value 19. By steam distil-
lation we succeeded in separating out from the total balsam 46 per cent,
of a pale yellow oil of a balsamic odour, possessing the following con-
stants ; dl50 09271; aD - 37°; ™D 20 ° 150070 ; acid value 0; ester value
1 9; soluble in 7 volumes a.m. 95 per cent, alcohol.
" Dipterocarpus tuberculatus yields a balsam of very different appear-
ance. It is known in Burma as in oil,' and plays a very subordinate
part compared with ' gurjan oil'. The balsam is of a pale-brown
colour ; its consistency is that of turpentine, and its specific gravity at 15°
is 1029; acid value 178 ; ester value 0. The oil which was separated
out from it by steam distillation (yield 33 per cent.) was of a yellow-
brown colour, and dissolved in 6 volumes a.m. of 95 per cent, alcohol.
Its constants were as follow: d 150 09001; aD - 99° 40'; wD20° 150070, It
•did not contain saponifiable constituents (saponification value 0). With
Turner's colour-reaction both the balsams and the oils gave the char-
acteristic violet colour. This test consists in dissolving 3 or 4 drops of
the balsam or oil in 3 c.c. of glacial acetic acid, adding to the solution 1
drop of freshly prepared 10 per cent, sodium nitrite solution, and pouring
the mixture very carefully on 2 c.c. of concentrated sulphuric acid."
(^1) Report, April, 1912, 108.
(^2) Commercial Guide to the Great Economic Products of India (1912), 140.
3
Report, April, 1913, 68.