: - SCIENTIFIC NOTES ON ESSENTIAL OILS. 29 
, Meantime the above-named Institute’) has examined five more distillates originating 
from various parts of the Madras Presidency. Only two of these oils were soluble 
in 70 p.c. alcohol, viz., one from Kayankulam (2 vols., 68,5 p.c. of aldehyde) and one 
from Alwaye (1,75 vol., 77 p.c. of aldehyde), whereas the remaining three (2 from 
Alwaye and 1 from Cochin) did not give a clear solution at all in 70 p.c. alcohol. 
Of 80 p.c. alcohol 2/3 vol. was required for a clear solution, but-turbidity set in 
whenever more of the solvent was added. As indifferent solubility had never been 
observed in East Indian lemongrass oils formerly, it was surmised that the method 
of distillation had been altered”) or that in such cases a different variety of grass 
was used as raw material. In order to probe the matter, the Imperial Institute caused 
two samples of oil to be sent, one from white-stalked grass, the other distilled from 
the red-stalked variety. Both kinds grow wild in the Madras district, but the red- 
stalked grass is also cultivated to a fairly large extent in northern and central 
Travancore; wild as well as cultivated Bf288, however, appears to be used indiscrimi- 
nately for Eistiliation purposes. 
The oil from the white-stalked grass was of yellow colour, and in odour as well 
as in its other properties it resembled citronella oil more than lemongrass oil: 
dis0 0,909; a)— 10°50’; aldehyde percentage (bisulphite method) 9 p.c.; soluble in 
0,8 volumes and more of 80 p.c. alcohol, in 4 volumes slight turbidity; not soluble 
in 70 p.c. alcohol. A botanical examination will afford further particulars as to the 
mother-plant. 
The oil obtained from red-stalked grass was reddish brown in colour and had 
the typical lemongrass oil odour: dji5.0,925; aldehyde contents (bisulphite method) 
71,5 p.c. It did not give a clear solution with 5 volumes of 70 p.c. alcohol, but 
dissolved readily in 0,8 volume and more of 80 p.c. alcohol; but on addition of 
5 volumes of the solvent turbidity supervened. When rectified with steam 78,7 p.c. 
of the oil passed over. The distillate contained 81 p.c. of aldehyde and dissolved 
clearly in 2,4 volumes, and more, of 70 p.c. alcohol. The residue consisted of an oil 
of reddish brown colour, and of great viscosity. From the above figures the Imperial 
- Institute draws the conclusion that the indifferent solubility of the original oil is — 
probably caused by its having been distilled too long, causing bodies to pass into the 
oil which were less volatile, and but sparingly soluble. Nothing is said as to whether 
* this variety is also to be subjected to a closer botanical examination. 
A so-called West Indian lemongrass oil, distilled in Annam, had the following 
properties*): dis0 0,8846; a) —0°4’; soluble in 0,25 volumes of 80 p.c. alcohol, on 
further addition of the solvent milky turbidity set in; the oil contained 75 p.c. of citral. 
According to Murat there are extensive plantations of Andropogon citratus in Annam. 
For a lemongrass oil from Mayotte, Roure-Bertrand Fils*) give the following con- 
Stants: diso 0,8917; #) —0°22’; soluble in 0,4 volumes of 80 p.c. alcohol. When 
adding more than 2 volumes, strong turbidity set in. The solution of the oil in 90 p.c. 
alcohol began to opalize after 2,5 vols. It is here a case of a so-called West Indian 
lemongrass oil which contained 87 p.c. of constituents reacting with sodium bisulphite. 
Lemongrass oils of this origin have been mentioned by us before now’). 
*) Bull. Imp. Inst. 12 (1914), 222. — 7?) Comp. Report October 1918, 69. — 3%) Berichte von Roure- 
Bertrand Fils April 1914, 10. — *) Ibidem 12. — 5) Report April 1918, 72; October 1913, 69. 
