73 



It is suggested that in this case also the plants should be cropped 

 when the fifth leaf is well developed. The oil from the roots contains 

 82 per cent, of citral. The citral estimation is carried out by Dr. de 

 Jong as follows: Thirty-five grams of crystallised sodium bisulphite 

 is placed in a "cassia flask" and dissolved in 50 c.c. of water, and to 

 it is added 12 grams of sodium bicarbonate in power and lO c.c. of oil. 

 The flask is shaken for an hour, then heated on the water-bath for 

 thirty minutes, and water added to the mark, and the flask set aside 

 for twelve hours. At the end of that time the quantity of unattacked 

 oil is read off, the difference between this and 10 c.c. being the citral 

 content of lo c.c. of oil. The Java oil is derived from a variety of 

 Andropogon citratus, and belongs to the group of " insoluble lemon- 

 grass oils," since it does not form a clear solution with two parts of 

 70-per-cent. alcohol. The author states that the present low price of 

 lemongrass oil is due to the use of the oil of Backhousia citviodora as a 

 source of citral, but this is very improbable. 



Rusa grass is grown in much the same way as citronella grass, 

 but in differs markedly from citronella and lemongrass in its smaller- 

 leaf production as well-developed stem and flower system. The yield 

 from fresh leaves and stems is generally about 0.6 per cent. The 

 value of the oil (palmarosa oil) depends on its geraniol content, vvhich 

 is generally from 80 to 90 per cent. An unidentified Andropogon sp., 

 which yields an oil rich in geraniol, is also known in Java. This 

 variety is similar to citronella grass in habit and yields only 0.2 to 0.3 

 per cent, of oil, which contains 40 to 60 per cent, of geraniol, and is 

 said to possess a more pleasantly rose-like odour than ordinary 

 palmarosa oil. 



Two varieties of Vetiver or Cuscus grass {Andropogon )nuricdtiis) 

 are known in Java, one native and the other introduced from British 

 India. The leaves are free from oil, which is obtained only from the 

 roots, to the extent of from 0.4' to 0.9 per cent. — {The Chemist and 

 Druggist.) 



6ADUNG. DiOSCOREA DAEMONA. 



This is a well known yam with large trefoil leaves, commonly to 

 be met with in Malay villages. Its tubers are used as food sliced and 

 left in running water for tw^o days before cooking, unless so washed 

 the yams are poisonous. Researches on the poison of this yam, under 

 the name of Dioscorea hirsuta Bl. are published in the Bulletin du 

 Department de L' Agriculture aux Indes Neerlandaises XLIV. The 

 principle is known as Dioscorine and Mr. Schutte finds that it pro- 

 duces cramps like those induced by picrotoxine, but it is less poisonous 

 than that drug. 



It is mentioned in the old series of this Bulletin as one of the 

 occasional ingredients in the Sakai-dart poison. -Ed. 



