5o 



Getah Jelutong or Poutianac, is usually stated to be obtained from 

 Dyera costulata, a large tree which is fairly common throughout the 

 Malayan region, but it is probable that the material as met with in 

 commerce is a mixture of guttas derived from different sources, It 

 has been stated, in fact, that it is the custom of the natives to mix 

 the latex of the Jelutong tree with that derived from different species 

 of Willoughbeia, which yield inferior rubbers. The value of Ponti- 

 anac in the London market is about $19 to $20 per ton, but as al- 

 ready stated, the chief demand for the material is in the United 

 States, which in 1901 imported 9,371,037 lbs., valued at §248,838. 

 Of this total, 8,708,107 lbs. are returned as coming from the 

 British East Indies, probably through Singapore, whilst the re- 

 mainder, 662,980 lbs., was imported from the United Kingdom. 

 After undergoing certain treatment, the Poutianac is chiefly em- 

 ployed iii the United States as an ingredient in the mixtures used 

 for the manufacture of rubber goods of low quality, and its utilisa- 

 tion for such purposes appears to be extending. 



The sample of Getah Jelutong from Sarawak was almost identical 

 in appearance, composition and properties with commercial samples 

 of Pontianao, being remarkably free from admixture with vegetable 

 or mineral impurities, and it would, no doubt, be suitable for any 

 purpose for which the latter is employed. At present, however, the 

 material is of relatively small commercial value. 



Two specimens of the mineral substance used in the preparation 

 of Getah Jelutong were supplied : one o f the mineral as imported, 

 the other of the material prepared for use by heating. The mineral 

 proved to be a specimen of the fibrous variety of gypsum, known as 

 " satin spar'' (hydrated calcium sulphate) ; it was white, translucent, 

 crystalline and massive. 



The specimen which had been heated was white and opaque; it 

 was non-crystalline, but retained the fibrous form of the mineral, 

 and readily crumbled to powder in the fingers. It absorbed water, 

 but did not set like plaster of Paris. It contained only 2.48 per 

 cent, of water, so that in course of preparation the gypsum has 

 probably been heated to a high temperature, with the result that the 

 product does not set when* mixed with water. 



If, as is indicated, the addition of this substance is essential in 

 the preparation of the gutta, it is probably due to the fact that the 

 jatex is coagulated by a solution of calcium sulphate, as is known 

 jo be the case with several other rubber latices. 



Supplement to the Board of Trade Journal. July 9, /poj, p- f>5- 



Recent Publications on Rubber and its 

 Cultivation. 



In the E'tudes Coloniales for October 1903, Mr. OCTAVE J. A. j 



COLLET publishes an interesting and well illustrated paper on j 



'' L. Hevea Asiat'que," based on his experiences in the Malay j 



Peninsula, and well illustrated. He points out that at the end of ] 



