18 
Indian- Forest Records. 
[VoL. IX 
PART IV. 
The Essential Oil from Andropogon Jwarancusa, 
Jones. 
Ill a recent communication from these laboratories (Journ. Chem. 
8oc. Trans. 1921. 119. 1645.) an account was given of the propertie-i 
and constituents of the essential oil from A. Jwarancusa Jones. The 
grass from which the oil was obtained was grown in the Hazara 
District and the oil was placed at the disposal of the author by the 
courtesy of Colonel C. R. Johnson. An examination of the oil showed 
that it contained approximately 77 per cent of the interesting ketone 
d-piperitone (/^'-^J-mentheu -3-one) and since this ketone in addition 
to being of scientific interest may prove to be of economic value it has 
appeared to the authors desirable to examine the oil obtained from the 
same grass grown under difierent climatic conditions. 
A quantity of the grass which occurs fairly extensively in Sind was 
supplied by the Divisional Forest Officer, Shikarpur and subjected to 
distillation in steam in the usual manner, when an oil was obtained 
which differed considerably in its properties from that obtained 
from the Hazara District. 
In Table I. the constants of this oil are given alongside those of 
the oil from Hazara, whilst for reasons which will appear later the 
constants are also given of an oil described by Roberts (Journ. Chem. 
Soc. Trans, 1915. 107. 1465.) which was obtained from Cymho'pogon 
Sennaarensis. Chiov. from the Soudan. 
TABLE I. 
Oil from 
Hazara. 
Oil from 
Sind. 
Oil from 
C. Sennaarensis. 
. . . 
30° 
0-9203 
0-9228 
1 s° 
D - 
15° 
0-9383 ^ 
. . . 
D 
1-481 
1-4858 
0-9422 ; 
30° 
[al ... 
D 
+61-68° 
+42-8° 
r -.20° 
+34-14° \ 
D 
+29-3°) 
Ketone per rent. 
77 
44 
45 
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