484 



[December, 1909. 



GUMS, RESINS, SAPS AND EXUDATIONS. 



THE PASSING OF FICUS ELASTIOA. 



(From the India Rubber Journal, Vol. 

 XXXVIII., No. 5, September, 1909.) 



Four years ago the question of the 

 relative advantages of planting " Hevea 

 brasiliensis " (Para rubber), or " Ficus 

 elastica " (Rambong), was considered an 

 open one, and the fact that the latter 

 was a native tree and grew freely in 

 Malaya induced some to prefer it to the 

 Brazilian plant. There are various diffi- 

 culties attending the treatment of Ficus 

 in regard to pruning it or allowing it to 

 form its aerial roots unchecked, in rela- 

 tion to tapping and prevention of en- 

 trance of boring insects and fungi into the 

 wounds ; also the direction and shape 

 of the branches and stems make the 

 collection of latex no easy matter. The 

 yields of dry rubber from rambong are 

 larger than from Para and market prices 

 excellent. The symmetrical stem of 

 the Para, the facilities for running the 

 latex into a single cup at the base of the 

 tree, regularity of its growth and its 

 reaction to a wound, have especially 

 commended this tree to the rubber 

 grower, so that rambong is no longer 

 considered as an alternative on equal 

 terms, and no further estates have been 

 planted with the native plant. From a 

 practical planter's point of view this 

 choice must perhaps be considered wise ; 

 but it is to be regretted that a tree yield- 

 ing so well and suited to local conditions 

 should have been entirely abandoned. I 

 have been carrying on experiments for 

 some two years past in regard to the 

 proper methods and instruments for 

 tapping " Ficus elastica " (Rambong), and 

 consider that a rotary pricker in which 

 the pins are at such a distance apart 

 tiiat the latex which runs from the 

 puncture joins that from those adjoining 

 is a more practical way of extracting 

 the latex than the making of a cut with 

 a knife. If the rubber which flows from 

 the various punctures made with a roller 

 pricker all over the surface of the stem 

 and branches is pulled off directly it has 

 coagulated, it will be found that the flow 

 will occur again and a second crepe-like 

 film of coagulated latex can be pulled 

 off. The absence of wound prevents the 

 attacks of borers and the tree can be 

 again pricked after a short time has 

 elapsed. When the flow from the 

 puncture is too great to allow it to 

 coagulate and it runs down, it can be 

 caught at the base of the tree by means 

 of rubber band or a metal ledge round 

 the tree to lead the latex into a cup or 



other receptacle. If a flow of latex is 

 preferred to the crepe-like scrap I have 

 described, then an application of water 

 by a brush or spray will run the latex 

 down to the base of the tree where it 

 can be caught. 



These questions are, however, becoming 

 of minor importance in the Federated 

 Malay States, as the passing of "Ficus 

 elastica " has begun, and each year sees 

 less of this interesting and profitable 

 tree cultivated. 



THE GUAYULE RUBBER INDUSTRY. 



(From the Indian Trade Journal, Vol. 

 XIV., No. 178, August 26, 1909.) 

 Mr. J. E. Kirkwood writes as under to 

 the Scientific American : — 



The increasing demand for rubber in 

 the various manufactures of the present 

 time makes the business of its production 

 one of the most important of modern 

 enterprises. Not only is the natural 

 source of the supply eagerly sought and 

 carefully guarded, but efforts for the 

 cultivation of rubber-bearing plants are 

 receiving attention in many parts of the 

 world. 



The rubber of commerce is derived 

 from a number of different plants ; in 

 fact, there are many plants of more or 

 less importance from the standpoint of 

 the quantity and quality of the rubber 

 they produce. Among those less gener- 

 ally known is a Mexican plant, called 

 guayule (pronounced gwyulie,) which 

 is identified botanically as Parthenium 

 argentatum. 



The guayule is a desert plant. It 

 thrives in those regions of relatively 

 little rain throughout the northern half 

 of Mexico and the neighbouring areas of 

 Texas. It is a small shrub, tree-like, and 

 rarely attains a height of four feet or a 

 stem diameter of more than three inches. 

 Its leaves are small and of a silvery 

 grey colour, whence its specific name 

 argentatum. The plant produces small 

 yellowish-green flower heads consisting 

 of many minute florets, only five of which 

 in each head are capable of producing 

 seeds, and each of these only one. 



Most of the rubber of commerce is 

 produced by plants having a milky juice 

 or latex as it is called, in which the gum 

 is found. The trees are tapped by 

 cutting into or through the bark, and 

 the latex is collected as it flows down 

 In the guayule plant no latex is pro- 

 duced, and it must be subjected to an 

 entirely different process to extract the 



