July 



[904.] 



THE INDIA RUBBER WORLD 



353 



him to meet the many contingencies which are certain to arise 

 after his calculations as to ordinary expenses have been most 

 carefully made. I may state that my own expenditure in six 

 years has been more than double what I calculated when I 

 began, though my estimates were made on what was then con- 

 sidered a liberal scale. 



Inquiries as to the yield of the rubber trees at maturity can 

 be answered much more definitely. I am speaking of Caitilloa 

 rubber, that being the kind almost exclusively cultivated in 

 Mexico, and the tree indigenous to the country. Taking the 

 results obtained by myself from tests on a somewhat extended 

 scale, and comparing them with those obtained by other workers 

 in the same field, the following figures maybe relied on as being 

 the yield of well developed trees at the ages specified: 



Age ok Trek. Yield of Latex. Dry Rubber. 



6 years 30 ounces 1 2 ounces. 



7 years 38 cunces 15.20 ounces. 



8 years 48 ounces tg.20 ounces. 



10 years 80 ounces 32 ounces. 



— the yield increasing proportionately up to a certain age of the 

 tree, probably thirty to fifty years. The yield of dry rubber here 

 indicated is based upon the latex yielding 40 per cent, of rubber. 

 I have in a great number of experiments only once found the 

 yield as low as 39 per cent., and regard 40 per cent, as a con- 

 servative estimate. 



As to the age at which a rubber tree should be first tapped 

 one must be entirely guided by its development. In this there 

 is a great diversity, some trees maturing much more" rapidly 

 than others, though all are growing apparently under precisely 

 similar conditions. I have obtained marketable results, though 

 only on an experimental scale, from (our year old trees, the rub- 

 ber being of excellent quality, while the trees have not suffered 

 in any way from the tapping. I believe if a tree be well de- 

 veloped it can be tapped safely at the end of the sixth year, but 

 I should recommend that ordinarily tapping should not take 

 place until the expiration of the seventh year. I am convinced, 

 as another planter has remarked, that the size of a tree has 

 much more to do with the amount of rubber it will produce than 

 its age. Also that the yield of the Castilloa depends more on 

 soil and climate than has hitherto been recognized. 



Two important considerations for the planter yet remain un- 

 settled — namely, in what season and by what mechanical means 

 the tapping of the Castilloa can be best undertaken. The 

 rough and ready methods of the native collector can only be 

 accepted when, as with him, the sole desire is to obtain at a 

 season when he can best make his way through the forest the 

 largest amount of rubber, with utter disregard to the future life 

 of the tree. It is this wholesale destruction by native collec- 

 tors of rubber bearing trees in all countries where they are 

 found which has concentrated attention of rubber cultivation. 

 The present barbarous method of collecting is universally con- 

 demned by planters, while there is divided opinion as to the 

 most suitable season for tapping. These points are requiring 

 earnest study for their solution. Proof leaves me no doubt that 

 the Castilloa can be tapped twice a year without suffering any 

 harm, provided sufficient time be allowed to lapse between the 

 two operations to enable the tree to recover its strength. I do 

 not believe that the yield will be thereby doubled, but the re- 

 sult will be a material increase of production. 



Fortunately the Castilloa is not a tree which succumbs read- 

 ily to injuries. Once it is safely through the caprices of the 

 first year, and well rooted in suitable soil, it is indeed hard to 

 destroy ; while it appears to be subject to none of the insect 

 visitations or fungoid growths affecting so many other trees 

 under cultivation. 



So far as regards the preparation of the rubber I would say, 



so long as all impurities are eliminated, follow nature methods 

 as much as possible. A long series of elaborate experiments 

 have convinced me that artificial means of coagulation, as by 

 the aid of chemicals, and infusions of native plants such as 

 Ipomoea bona nox or " bejuco de necta," while bringing about 

 speedy coagulation, have most pernicious after effects on the 

 rubber, which show themselves within a short time, and greatly 

 reduce its market value. It is vastly to the interest of all con- 

 cerned in the production of Mexican rubber that its quality 

 should be kept up to the standard to which it is capable of be- 

 ing raised. 



Castilloa rubber properly prepared comes next in value to 

 Pari, and there is no liklihood in view of the increasing de- 

 mand that for many years to come sufficient supplies will be 

 forthcoming to bring it down below 90 cents gold per pound, a 

 figure at which some recent samples of mine have been valued 

 in the London market. Very faithfully yours, 



GEO. CULLEN PEARSON. 



A REPORT ON GUTTA-PERCHA VALUES. 



THE Bulletin of the Imperial Institute (London), of March 

 31, contains a report on samples of Gutta-percha for- 

 warded to that institution from Penang, for chemical examina- 

 tion, with a view to determining their commercial value. 

 These samples are stated to have been prepared under compe- 

 tent supervision, without any admixture of foreign matters 

 whatever. 



Mention here will be made first of the product known to the 

 natives as "Gutta taban merah," from the forest tree Pala- 

 quium gutta (ilso known as Dichopsis gutta), which represents 

 the highest type of Gutta-percha. The experts to whom this 

 sample was referred gave its market value as 6 shillings 

 [=$[.46] per pound, subject to fluctuations, which may be re- 

 garded as the highest market value of Gutta percha at present. 

 The greater part of the gutta now marketed, however, brings 

 very much less, not only on account of the adulterations prac- 

 ticed, but because of the scarcity of the particular species of 

 Palaquium yielding it. 



Another sample was of the material known in the Malay 

 states as "Gutta taban putih," presumably from Palaquium 

 pustulatum. This sample, showing in analysis a much greater 

 percentage of resin, was valued commercially at 2 shillings 

 [=48.7 cents] per pound. The Institute was asked as to the 

 advisability of forming extensive plantations of this species 

 with a view to extracting gutta from the leaves at an earlier 

 age than it would be possible to obtain it from the trees. The 

 reply was that, in view of the yield probably being no larger 

 than from Palaquium gutta, and the product being worth only 

 one-third as much, preference should be given to planting the 

 latter. 



The tenor of the Institute's report, by the way, is hardly fav- 

 orable to the proposition to extract Gutta-percha from leaves. 

 " Several of the extraction processes," it says, " have been tried 

 upon a commercial scale in Europe [whither the leaves were, 

 imported from Singapore], but for various reasons the results 

 have been very unsatisfactory from a financial point of view, 

 and it is believed that at the present time all the factories es- 

 tablished in Europe have practically suspended operations." 

 It is understood that several processes are at present undergo- 

 ing practical trials in the East, but it is suggested that their re- 

 sults should be further studied before plantations are planned 

 on a large scale in connection with any of the processes. 



Still another sample—" Gutta simpor," from Palaquium 

 Maingayi — was appraised at is. 6d. [ = 36. 5 cents] per pound. 



