282 
Indian Forest Records. 
[VOL. I. 
. Ngai camphor from samples Nos. 3 and 4 . — It has not yet been 
possible to make an exact determination of the percentage of solid 
camphor in the oil obtained from the B. halsamifera. Small quantities 
of the oil from samples Nos. 3 ana 4 were, however, collected in a beaker 
which was covered with a watch glass. On coohng the latter, snow-like 
crystals of the camphor were seen subliming on the bottom of the watch 
glass. The appearance of these crystals when seen under the microscope 
is shown in Plate VI. 
The preceding determinations, as has been already stated, were made 
according to the method No. 2 described on page 277, above. In 
that method, since the volatile extractive matter is isolated from the 
plant by means of ether, the estimation of the volatile matter is therefore 
very accurate. It is, however, difficult to obtain in practice the yield 
of the volatile oil as determined by this method, for in that case the 
extraction is effected not by ether, but by means of water or steam 
distillation by which more or less of the volatile extractive matter is 
decomposed through the action of heat, water or other causes. Further, 
while ether can extract the whole of the volatile matter present in the 
plant, water may leave behind more or less of this volatile matter. 
To ascertain, therefore, the yield of the essential oil extractible by water, 
the following trials prehminary to experiments on distillation on a large 
scale were made by steam distilhng the plant according to the method 
No, 1 described on page 276, above. Another object of these pre- 
hminary trials was at the same time to determine the conditions most 
favourable for the extraction of essential oil by means of water. These 
trials were made only with the shade.dried plant, it having been discovered 
from the results of the preceding analyses that drying in shade had practi- 
cally no injurious effect on the quantity of the volatile oil. 
Sample No. 3.— Shade-dried leaves from Taungoo : 100 grams of the 
leaves were first distilled by passing a rapid current of steam over it, 
and the distillate collected in a receiver, and the isolation of the oil from 
the distillate proceeded with as directed in the method No. 2. The 
receiver in which the distillate was collected was at the temperature 
of the room in this trial. The percentage yield of the essential oil was 
found to be 0-209. 
It was observed during this trial that the quantity of camphor oil 
floating on the distillate became towards the end of the operation of dis- 
tillation somewhat less than in the first stages of distillation. It was 
bought that the loss was occasioned by the receiver not having been 
kept cool. 
