79 — 



bears some relation to the differences among the corresponding raw 

 material from which the oil has been distilled; the readily-soluble East 

 Indian (i. e. Malabar, Cochin or Travancore) lemongrass oil being derived 

 from Cymbopogon flexuosus, Stapf, and the so-called West Indian lemongrass 

 oil, which is distinguished by its slight solubility, from C. citratus, Stapf. 

 Experiments in the cultivation of these two species of lemongrass 

 made by J. F. Jowitt 1 ) at Bandarawela (Ceylon) have confirmed Stapf s 

 theory. The oils prepared by Jowitt from the cultivated grasses have been 

 examined by Samuel S. Pickles 2 ) at the Imperial Institute in London and 

 the botanical origin of the corresponding raw material has again been 

 carefully tested by Stapf. It was found that the oils of C. citratus gave 

 no clear solution even with 10 vols of 90°/o alcohol, while C. flexuosus 

 yielded an oil which was soluble in 2,2 vols, and more of 70°/o alcohol. 

 The oil yield of the first-named grass was from 0,22 to 0,37%, of the 

 second 0,31°/o and the properties of the oils were as follow: — 



Parent Plant 



di50 



«D 



Citral Content 



(Bisulphite Method) 



C. citratus 



0,892 



— 0°25' 



75% 



» 



0,891 



— 0°39' 



74% 



11 



0,893 



+ 1° 7' 



76% 



C. flexuosus 



0,916 



+ 0°35' 



67,5% 



The exceptionally high sp. gr. of the oil from C. flexuosus is remarkable, 

 for as a rule this value does not exceed 0,905 in lemongrass oil. Perhaps 

 the fact that the distilling material was not quite uniform has some bearing 

 on the matter, for according to the statement published by the Imperial 

 Institute it is not impossible that the grass of C. flexuosus was mixed in 

 this particular case with a little Mana-grass (see p. 49). Another sample 

 of the same species of grass, distilled by Jowitt a year previously, contained 

 so large an admixture of Mana-grass that the distillate behaved as if it were 

 a mixture of citronella and lemongrass oil. It is probable that in the earlier 

 stages of cultivation Mana-grass was more plentiful, but that in the course 

 of time Cymbopogon flexuosus has more and more gained ground upon it. 



From the tubers and the rhizomes of Andropogon citratus, essential 

 oils have been distilled at Buitenzorg 8 ) of which the constants are given 

 in the subjoined table: 



*) Comp. Report October 1909, 42. 



2 ) Circulars and Agricultural journal of the Royal Botanic Gardens, Ceylon, Vol. V. 

 No. 12, November 1910, 137. Also comp. Bull. Imp. Inst. 8 (1910), 144. 



3 ) Jaarboek van het Departement van Landbouw in Nederlandsch-Indie, 1909, 64. 



