174 PHILIPPINE RESINS, GUMS, AND OILS 
Bacon thought that lemon grass should be considered as a ‘* 
possible catch crop for the first few years of new Philippine 
plantations. He did not recommend it as a permanent crop on 
account of the limited demand for the oil. The grass from 
which oil has been extracted is burned under the distilling boiler 
and the ashes distributed over the fields as fertilizers. 
hausted grass is also used for making paper. 
The ex- 
Lemon grass is a tufted perennial with leaves up to 1 meter — 
in length and 1.4 centimeters in width. It is widely distributed, 
but not extensively cultivated in the Philippines and does not 
grow outside of cultivation. 
ANDROPOGON NARDUS var. HAMATULUS Hack. 
CITRONELLA OIL 
The typical form of this species is cultivated in India, Ceylon, 
and other tropical countries for the essential oil obtained from 
it. It probably could be cultivated in the Philippines also. 
When this grass is distilled it yields a pale yellow oil, which 
has a very strong odor and is known commercially as citronella 
oil. 
As the variety hamatulus, which occurs in the Philippines, 
has not been investigated chemically, it is not certain that it 
will yield citronella oil. 
On account of its low price, citronella oil is used chiefily for 
perfuming cheap soaps and also as a protection against the 
bites of insects. An ointment containing 25 per cent of oil of 
citronella is an excellent protection against mosquitoes.- Ac- 
cording to Parry * pure citronella oil has the following constants: 
Specific soravaty.:3. bool as oe ee 0.900 to 0.915 
ota tren 20 coh ont fs ta eee ee ee 0° to —15° 
Sp. gr. of Ist 10 per cent (distilled at 20-40 
TAIN)" teden a EAE ao. eee tee see eee eee eee eee above 0.858 
Refractive index of same at 205.2 2 ).2 2 above 1.4570 
Solubility in 80 per cent alcohol.............. to pass Schimmel’s test 
Geraniol#and serironel|l ese eee eee eee above 58 per cent 
(Calculated as total geraniol). 
Parry describes methods for preparing pure citronella oil. 
He also discusses methods for determining the purity and the 
presence of adulterants. 
Askinson + states that essence of Saoniall contains three 
ounces of citronella oil dissolved in one gallon of alcohol. 

* Parry, E. J. Chemistry of essential oils and artificial perfumes, 
(1908), page 171. 
+ Askinson, G. W., Perfumes and cosmetics (1915), page 161. 
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