576 



The Supplement to the Tropical Agriculturist. 



"THE RUBBER TREE OF TONKIN 

 AND NORTH ANNAM." 



'• BLEEKEtODEA TONKINENSIS." 

 We have received a most interesting bro- 

 chure written in French, by M. Ph. Eberhardt, 

 Inspector of Agriculture in Indo-China, and 

 M. Dubard. It is entitled " The Rubber Tree 

 of Tonkin and North Annam, Bleekrodea Ton- 

 kinensis," and gives an account of this tree, 

 which, it is stated, is indigeneous to the whole 

 of north of Indo-China ; that is to say, in a 

 latitude in which Hevea cannot be developed. 

 From the plantation point of view the tree 

 presents the same advantages as Hevea, and 

 the rubber is as easy to collect as that of the 

 Ficus. It is excellent in quality, midway be- 

 tween Hevea and Ficus and nearer, perhaps, to 

 Hevea to which it is very little inferior. 



Attention was first seriously drawn to the 

 tree in 1905, but it was not until two years 

 later that M. Eberhardt and M. Dubard set out 

 on an expedition to collect botanical samples, to 

 tap some trees, and bring away some latex. 



The result of their investigation is shown in 

 an exhaustive botanical and scientific study of 

 the plant in the brochure under review. Tap- 

 ping was first done by natives, who accidentally 

 discovered the value of the product, in a very 

 haphazard way which, if it did not result in 

 the death of the tree, caused it to undergo a 

 long period of non-production. The natives, 

 however, being lazy, gave it up after a time, 

 as they did not find it worth their while. They 

 made use of several methods of tapping. 



In the first case they made, in the base of the 

 trunk, about throe feet from the ground, and 

 on the large branches as many incisions as pos- 

 sible, by means of any cutting instrument, con- 

 vinced that the more incisions they made, the 

 more latex they would get. The quantity of 

 rubber gathered in this way— instead of being 

 more — is, on the contrary, less, for the normal 

 flow ot the liquid is no longer permitted, the cir- 

 culation being interrupted ; in addition, the 

 latex gathered under these conditions contains 

 a very large quantity of organic debris such as 

 pieces of bark, lichens, and mosses. 



Another way, one which is employed for the 

 creepers, is to take off with a hatchet, or more 

 often a simple knife, a large portion of bark. 



In addition, by a third method, cruder even 

 than the first two, more especially reserved for 

 creepers, they divide the plants into parts 

 and extract from each piece the latex which it 

 contains, by warming one of the extremities 

 over a slow fire. In this case, beside the latex, 

 they gather at the same time the sap of the 

 plant which oozes out of the piece just like a 

 large amount of water. 



In whatever way, however, he taps the tree, 

 the native receives the latex in the little re- 

 ceptacles formed from an internode of bamboo, 

 fluted at about two-thirds of its height in order 

 to be able to apply this part of least thickness 

 to the base of each wound. If he were con- 

 tent to gather his latex in this fashion, the 



bamboo would contain but a relatively small 

 quantity of foreign matter ; but that process 

 would be too long, so he makes an odd twenty 

 or so incisions with his knife in the same 

 part of the trunk and, as he cannot place 

 and hold there an equal number of bamboo 

 tubes, he gathers with his finger the 

 milk which flows from the wounds thus 

 made and then wipes it on the edge of the 

 bamboo tube. One can thus see how much 

 foreign matter he is forced to introduce into it 

 at the same time, scraping in some degree the 

 whole surface of the bark which he naturally 

 does not take the trouble to wipe or wash be- 

 forehand. The gathering having terminated, 

 the bamboos are transported either to the vil- 

 lage or to a neighbouring stream of water; there 

 they are put into a pot full of water which 

 without any care, is boiled. Drawn from the 

 bamboo tube, the product obtained by coagu- 

 lation is in the form of a "black pudding." 

 This nearly always contains a certain quantity 

 of organic matter generally found in the centre. 

 The presence of this organic matter has been 

 characterised as a fraud, but it is not really 

 — for what follows is what actually happens : 



Tho latex of the Bleekrodea coagulates 

 very quickly ; a part even coagulates of 

 itself in the receptacle in which it is 

 carried. This coagulation is still further facili- 

 tated by the movement which the latex is 

 submitted in transport and which acts as a 

 sort of churning, releasing sufficient heat to 

 separate a certain number of globules of the 

 serum and hasten their adhesion. In this 

 first coagulation, however, all foreign or- 

 ganic matters are imprisoned ; when, shortly 

 afterwards, all is subjected to heat, all the 

 globules not separated during the voyage stick 

 to the core formed by the first coagulation, 

 the " black pudding " lengthens at the two 

 ends and imprisons in its midst the impure 

 mass. Sometimes, before putting the latex in 

 boiling water, the natives draw out the first 

 ball formed, which explains the presence in 

 the market of unformed balls, generally very 

 much reduced, and of an inferior quality. 



There is no doubt, however, that the Bleek- 

 rodea Tonkinensis will become one of the great 

 economic products of the colony. We give 

 the following translation to show its commercial 

 value : — 



"The commercial value of Bleekrodea rubber 

 has been determined by Messrs Hecht Brothers 

 from two samples which were sent them by 

 Mr. E Perrot, the learned professor of the 

 School of Pharmacy, to whom we had sent 

 them, at his request, to obtain an estimate. One 

 was a sample which had been treated with ether, 

 deprived of foreign matter ; it was priced at 

 from 8 francs to 8 - 50 francs a kilo 1 2-2 lb. ) The 

 other was a crude sample carelessly gathered 

 by natives and containing many impurities. It 

 had naturally coagulated without the help of 

 any acid and was valued, despite its impurities, 

 at 5*50 francs a kilo. It should be added that 

 this estimate was made when Para was valued 

 at 9'50 francs. Bleekrodea rubber is, therefore, 

 a rubber of a very fair quality." 



