— 49 — 



the geraniol content was estimated separately by the phthalic anhydride 

 method 1 ), the citronellal-content being calculated from the difference. This 

 test showed that the relation of geraniol to citronellal varied as irregularly 

 in these two grass oils as did the other properties, the variation being 

 similar in each case. In some, such as the Lenabatu oils, geraniol pred- 

 ominated; in others, as for instance, the Maha- Pengiri oils, citronellal. 

 These and all other details are best seen in the table on the next page. 

 Setting aside samples 11 and 12, the constants of the two oil-varieties 

 lie within the following limits: — 



Oil of C. Nardus Oil of C. Nardus 



var. Linncei var. confertiflorus 



d 15C 0,894 to 0,926 0,900 to 0,929 



«d +4° 54' to —6° 32' + 12° 12' to —2° 11' 



Total geraniol . 43,5 to 64,7% 39,1 to 64,2%. 



As already stated above, there is therefore no particular difference 

 between the oils of the two mana-grasses. Samples 11 and 12 show 

 greater deviations; they attract attention because of their high sp. gr., 

 their very pronounced dextrorotation and their low total-geraniol content. 

 These samples, however, are abnormal, and they have therefore been left 

 out of account in drawing up the limits of value, because, according to 

 Stapf, the corresponding grasses are to be regarded as degenerate forms. 



None of these mana grasses is thought to possess any commercial 

 interest. Apart from the fact that the oil-yield is generally small, the oils 

 themselves are of such poor quality that they cannot compete with the 

 citronella oils of commerce. We cannot form an opinion on the question 

 how far this judgment is correct, not having had an opportunity yet of 

 handling oils of this kind. 



From Lenabatu- grass, now called Cymbopogon Nardus, Rendle, lenabatu, 

 by Stapf, Jowitt prepared four oils which behaved like the ordinary 

 commercial oils. The yield varied from 0,42 to 0,56 °/o and the constants 

 lay within the following limits: d 16 o 0,913 to 0,917, a D — 11 °53' to — 14° 16', 

 total geraniol 57,8 to 62,1 %. The citronellal content was from 24,4 to 33,6%. 

 All the four samples gave a clear solution with 1 vol. of 80% alcohol, 

 the solution becoming opalescent upon the addition of 10 vols, of the solvent. 



Of 3 Maha-Pengiri oils, from Cymbopogon Winterianus, Jowitt 2 ) the 

 highest yield, 0,77 %, was obtained from a grass distilled in November, 

 two samples of grass distilled in June and August only yielding 0,59% 

 each. The November oil also gave the highest total-geraniol content 

 (84,8% as compared with 79 and 83,5% for the two others); for the rest 

 all the three oils agreed with Java citronella oil. 



*) Report October 1899, 24. 



2 ) Comp. Report October 1909, 41. Stapf also considers it correct to designate the 

 Maha-Pengiri species (Winter's grass) with the special name of Cymbopogon Winterianus. 



4 



