and Magazine of the Ce 



THE WORLD'S CULTIVATED 

 RUBBER AREA. 



Dr. Pehr Olsson-Seffer— who has been in 

 Ceylon and round the world— is very confident 

 Mexico is ahead of all other lands with its 

 extent under cultivation. We take leave to 

 doubt the correctness of this interence, and we 

 append (1) our Mexican friend's table as 

 we find it in "Modem Mexico" with (2) our 

 own corrections of the figures in a parallel 

 column, and of countries omitted in Italics : — 







Ceylon Observer 



Dr. 



O's Figures. Figured. 



Countries. 



Acres Planted. 



Mexico 



95,( 00 



9.\000 



Malay Peninsula . . 



92,0J0 



150,000 



Ceylon 



85,000 



155,010 



Africa 



30,000 



30,01 



Central America . . 



14,000 



14,00 i 



Java 



10,000 



20,000 



Sumatra 





14,U00 



India 



8,200 





ami Burmah 





15,000 



Brazil 



6,000 



0,000 



Venezuela 



3,400 



3,400 



Ecuador 



3.000 



3,000 

 1,000 



New Guinea 



2.500 



Borneo 



•2,000 



4,000 



Colombia 



1,800 



1,800 



West Indies 



1,600 



1,600 



Other countries 







(South Sea Islands, &c.) 1,000 



2.0U0 



Total acres 



355,500 



515,800 



The compiler was aware of our figures for 

 Ceylon ; but by taking 250 trees to the acre he 

 cut down the total area from 150,000 acres to 

 the figures he gives above. He should know 

 that Eastern rubber planters do not believe in 

 as many as 250 trees to the acre. 



RUBBER. 



New Source of .Rubber. — A tree of the 

 Moracea family growing in Tonquin, and called 

 by Dubord and Eberhardt {Comptes rendus dc I' 

 Acad, des Sc. ) Bleckrodea tonkinensis, has a latex 

 containing a higher percentage of caoutchouc 

 than that of Hcvca brasilicnsis, the rubber ob- 

 tained from it being, it is said, equal to high 

 quality " Para." 



Synthetic Caoutchouc. — In a recent note we 

 referred to Harries' views as to the possibility 

 of producing rubber from starch. Leon Grognot 

 olaimsto have effected this important synthesis 

 in another way, viz., by the action of heat upon 

 a mixture of glycerin and dibasic or polybasie 

 organic acids, in particular succinic acid. Cer- 

 tain of these acids form plastic compounds 

 with glycerin, which on further heating lose 

 water, and become converted into hydrocarbons 

 analogous to those of rubber. As an example 

 he describes the preparation of the rubber-like 

 material from succinic acid. About equal parts 

 of the acid and glycerin are heated rapidly in 

 a vessel provided with am agitator,- m iBifPall 



Ion Agricultural Society. 87 



parts of the contents are brought quickly into 

 contact with the heating surface. The vessel 

 is covered, but provided with a tubulure for the 

 escape of gases and water or other vapours, and 

 is heated over a direct flame or upon a sand or 

 oil bath. Water and then combustible gases are 

 evolved, and when the temperature reaches 200 

 to 220°C. the mixture suddenly changes to a 

 plastic mass of high consistency that may be 

 utilised in the rubber industry. The operation 

 is stopped at this point, or if greater hardness 

 is required heating is continued at a lower 

 temperature. The inventor represents the plastic 

 compound as an inner anhydride of the two re- 

 acting substances, and assumes that on dehydra- 

 tion and loss of carbonic acid, hydrocarbons 

 result, and concludes, "in this way a synthetic 

 caoutchouc is obtained,''— British and Colonial 

 Drier/gist, Nov. 15 



MIXED PLANTATIONS. 



So far the public, though they have been 

 advised otherwise, have plumped for plantations 

 possessing rubber trees only, and have shown 

 a distinct preference for estates of Hevea 

 brasiliensis. But have they ever thought 

 that the cultivation of that species, as a single 

 product, is yet in its infancy and that the best 

 results on which their opinions have been 

 formed are still only two or three years old ? 

 Do they know that Para rubber trees have, in 

 their native habitat, survived in the struggle for 

 existence, when grown in association with 

 neighbouring trees and shrubs ? Are they aware 

 that Para rubber trees, when widely planted, 

 can often be successfully grown with perma- 

 nent inter-crops of cacao and other products ? 

 We are doubtful whether many persons now 

 interested in rubber plantations are aware of 

 the dangers which forests of the same species 

 are generally liable to ; for our part, we are 

 inclined to believe that a planting policy which 

 allows a permanent soil rotation by means of 

 established crop and an isolation of groups of 

 one species by dissimilar species may be a more 

 permanent and not necessarily less remunera- 

 tive system of cultivation. The introduction of 

 other products on the same estate has its dis- 

 advantages, but the main objections against such 

 a system can be overcome by judicious manage- 

 ment. It is easily possible* to prevent a rubber 

 estate from beiug converted into an experimen- 

 tal garden and yet grow crops which have 

 survived together in their ntative countries. We 

 shall refer to other points of importance in subse- 

 quent issues,— India liubbeti Journal, Nov. lb. 



