Gams, Resins, 



412 



[November, 1908. 



THE GUM OF GREVILLEA 110BUSTA. 



(Des Grottes and Riviere, iu Jonm. 

 d' Agr. Trop. Si August, 1908, p. 225.) 

 Abstracted by J. C. Willis, 



This gum has often been studied, 

 but so far without any practical results. 

 Samples recently sent from Travaucore 

 showed a reddish colour, slight solu- 

 bility, and brilliant resinous fracture. 

 Cooke, in the "Gums and Resins of 

 India." says that a tree exudes 10 

 ounces a year. 



On an estate in Travancore, a herd 

 of elephants rubbed against many 

 Grevilleas along a road, and soon after- 

 wards these trees exuded gums varying 

 much in colour. This is put down to 

 infection from different microbes 

 carried on the elephants. A reference 

 to M. Achalme, Director of the Colonial 

 Laboratory at the Museum, and to 

 Prof. Bernard of the Pasteur Laboratory, 

 goes to confirm this. They are of 

 opinion that gum-formation is due to 

 microbes. 



The work is suggestive, and indicates 

 that we may some day be able to guide 

 and control the formation of gums. 



NOTES ON FUNTUMIA ELASTICA. 



By Frederick de Valda. 



West African rubbers have not at the 

 present time a very favourable reputa- 

 tion in the European markets. In the 

 endeavour to obtain rubber for sale, the 

 juices of many different trees, some of 

 them quite innocent of any caoutchouc, 

 are mixed with good latices of Funtumia, 

 Landolphia, &c. Putrefaction of the 

 proteid constituents soon sets in, and the 

 delectable preparations known to the 

 trade as Gold Coast paste, lnmp, soft 

 ball, &c, are the evil-smelling results. 

 These different rubbers are valued at 

 from lOd. to Is. 9d. per pound, and re- 

 quire a man with a very strong stomach 

 indeed to handle them. Some excep- 

 tions, it is true, have a very favourable 

 reputation ; fine nigger-ball, for instance, 

 has obtained as much as 3s. to 3s. 6d. per 

 lb. ; but if we search for the reason of 

 the higher price these latter rubbers 

 have obtained, we invariably find that 

 they consist either of unadulterated 

 Funtumia, Landolphia, or one or two 

 other fine rubbers. 



While Para rubber has always reached 

 the European markets more or less 

 unadulterated, and has thus an excellent 

 reputation behind it, Funtumia elastica 

 has very rarely been shipped to Europe 

 in its pure state. When this has been 

 done, a price equal to hard Para has 



always been obtained. The bad quality 

 of West African rubbers will always 

 continue as long as the collection and 

 preparation of the rubber are carried 

 out in the native fashion. These natives 

 have not the same intelligence that the 

 Central and South American collectors 

 have. The local merchants and traders 

 are to blame for not encouraging the 

 production of high-grade rubbers by 

 paying a corresponding price for them.* 



The only way to establish F. elastica 

 in the eyes of the manufacturer is to 

 cultivate it on the same basis, and with 

 the same thoroughness, that Hevea 

 brasiliensis has been taken up and culti- 

 vated in the East. The planter will 

 then find that he has fewer difficulties 

 to contend with in establishing his 

 plantation, and simpler methods will 

 suffice to produce the cured article from 

 the milk of the trees. 



It is impossible, within the space of 

 this short article, to compare point for 

 point the qualities of F. elastica and 

 H. brasiliensis. Their main points of 

 similarity and divergence will therefore 

 have to be shortly epitomized. 



Planting.— The H. brasiliensis is being 

 planted out at distances varying from 

 15 to 20 feet. F. elastica can be planted 

 out 8 by 6 ft., the yield per individual 

 tree of H. brasiliensis, by most ex- 

 haustive tapping methods, is said to 

 have been raised to 10 to 12 pounds per 

 year. This statement looms largely in 

 some prospectuses issued by rubber- 

 planting companies and is to be con- 

 sidered more as an exception — a very 

 great exception— than a rule. It is safer 

 to assume that an eight-to-ten-year -old 

 Para tree yields 1 lb. of rubber per year. 

 In the case of Para this would give a 

 yield per acre per year of 190 lbs. of 

 rubber. In the case of F. elastica no 

 claims of such high individual yields are 

 made, but I have found, as the result of 

 numerous tappings, that \ lb. per tree 

 per year is to be relied upon in an eight- 

 to-ten-year-old tree. Thus, planted 8 

 feet by 8 ft., an acre of F. elastica would 

 yield 335 lb. of rubber, or 175 per cent, 

 greater yield than that same acre would 

 have given, planted with Para 15 ft. by 

 15 ft. Para requires a rainfall of HO to 

 100 in. to do well ; F. elastica gets along 

 nicely on 55 to 60 in. per year. Para is 

 liable to many diseases— canker, fungoid, 

 blights, &c. ; F. elastica is not liable to 

 such diseases to nearly the same extent 



* The natives have good leasons for not put- 

 ting a better rubber on the market. They are 

 intelligent enough to know that they can make 

 more money out of the mixed rubber, as at 

 present exported, jthan out of the true 

 article,— Ed. T. L. 



