22 
It follows from the foregoing that from an oil adulterated in such 
manner, the adulterant can be separated by fractional distillation, and 
detected by its physical constants. For this reason Parry and Bennett, 
in a communication 1) published shortly before the closing of our Report, 
propose the following standard: that the first fraction, consisting of 
10 per cent, of the oil under examination, distilled under reduced 
pressure (20 to 40 mm) must have a specific gravity not below 0,858, and 
a refractive index, at 20°, not below 1,4570, and further, that citronella 
011 must dissolve either clear, or at most with the slightest opalescence, 
in 10 volumes of 80 per cent, alcohol at a temperature of 20^. 
We can only express our complete agreement with this proposal. 
The solubility-test in 80 per cent, alcohol (Schimmel's test) must be 
maintained, although it may perhaps be suitable to change the tem- 
perature of 15° originally proposed by us, into one of 20°; the 
distillation-test will make it also possible to identify those oils, which, 
being but slightly adulterated, have passed the solubility test. 
Under the designation ^'Java lemon olie" we have lately received 
several samples of oils, which can neither pass for lemongrass nor for 
palmarosa oil, and which should rather be considered as a kind of 
citronella oil, although they slightly differ from the latter in the odour. 
The mother-plant from which this oil is obtained, is presumably a species 
of Andropogorr. we know nothing definite about this, but will endeavour 
to ascertain further details of the origin of this oil. 
The samples obtained from different sources show a fair amount 
of similarity in their constants, as will be seen from the following 
short table: 
Total content 
^15° «!) (in 100 mm tube) ^D20° of C^^H^gO 
0,8889 4-13^26' 1,46466 49,097o 
0,8914 -f-io°6' 1,46684 50,9 „ 
0,8809 +14'' 52' 1,46496 „ 
The oils dissolve readily in 80 per cent, alcohol, but when the 
concentrated solution is diluted, turbidity occurs uniformly. To all 
appearances they do not contain geraniol, but this statement is subject 
to further verification, as in every case we have only had small samples 
at our disposal, and therefore were unable to make a thorough examination. 
From the sample mentioned last we have isolated the aldehyde 
contained in it, by shaking with bisulphite solution. In the odour 
it completely resembled citronellal, whose physical constants it also 
possesses: boiling point 205° to 208°, d^go 0,8567, nj)2oo = Ij4479 i; 
but it was found to be laevogyrate, as we observed 0^= — 3°. This 
^) The Chemist and Druggist 62 (1903), 408. 
