Dec. 1906.] 



445 



Saps and Exudations. 



METHODS OP EXTRACTING RUBBER. 



We have, curiously enough, mainly confined ourselves to extracting latex by 

 methods of tapping which obviate the destruction of the tree. But it is well-known 

 that there are plants such as the Mexican shrub (Guayule) which can be grown 

 quickly, uprooted, and the coagulated latex from the whole of the tissues extrac- 

 ted by a process of maceration and washing ; the Landolphias, Root rubbers, and 

 other plants might be similarly dealt with, and good yields of rubber obtained 

 therefrom— sometimes without the use of such machinery. It would indeed be a 

 fortunate discovery if some herbaceous plant capable of being cultivated in the East 

 as a subsidiary rubber crop in a clearing of Para, Castilloa or Ceara rubber could be 

 found. We have now secured the machinery to extract rubber from dead bark 

 tissues, and it has been questioned in connection with some of our arborescent plants, 

 whether the rubber obtainable at the end of the fourth or fifth year by felling or 

 lopping the tree and macerating the bark is not worthy of consideration. The idea 

 may appear fanciful and even absurd for trees of Para rubber, but it is of consider- 

 able interest in connection with the prunings and bark, etc., of Ceara rubber, or of 

 plants which cannot stand tapping. We may subsequently find that we are in the 

 beginning of a new era in the extraction of rubber from some tree forms, by methods 

 other than tapping. 



COMPARISON OP PLANTATION YIELDS IN 1905, 



Be the growth or methods of cultivation and extraction what they may, the 

 features on which the prosperity of our new cultivation largely rests are the yields 

 obtainable and the period over which such can be guaranteed. 



It is certainly too early to make a definite statement on this subject, but it is 

 fairly safe to say that good and most promising yields have been obtained from trees 

 of Para rubber, An annual yield of one pound of dry rubber per tree is perhaps above 

 the average for mature Ceara rubber trees, and many have even questioned whether 

 such an amount can be obtained from Castilloa trees of a fair size and age, whether 

 in the East or West. Para, Ceara and Castilloa can be planted at approximately the 

 same distance apart ; so that the yield per tree affords a fairly reliable basis for a 

 comparison of their relative values. The whole of the results which have been 

 obtained up-to-date in Ceylon, Malaya., the Straits and India are not available, but 

 it i 3 interesting to find that in 1905— our first genuine year of working with Para 

 or Hevea rubber trees — we obtained according to the only figures in my possession — 

 in Ceylon from 138,655 trees, 189,743 lb. of rubber ; the Straits obtained from a 

 certain 58,860 trees approximately 57,000 lb. of rubber, (these figures do not, of 

 course, give any idea of the total quantities of rubber exported from these countries) 

 an I specimens in Africa and India show a promised yield of form f to over 1 lb. of 

 rn bber per tree. To put it briefly, an average yield of about 1 to H lb. per tree 

 hn? been obtained from nearly 198,000 trees, at a time when the methods of extrac- 

 tion were novelties, and our knowledge of a scanty range- 



YIELDS AT HENARATGODA. 



Results for several years in succession are available from the Henaratgoda 

 G .rdens, where it is hoped to take you before the Exhibition is over. In the old 

 days, when the trees were lightly tapped only every second year on an antiquated 

 system, a yield of lJs lb. per tree was obtained, per year, for a period of nine years. 



That was from a tree which when first tapped was about fifty inches in circum- 

 ference and approximately twelve years old. Since then various experiments have 

 been made on the closely-planted Henaratgoda trees, and a yield of from ten ounces to 

 15 lb. dry rubber per tree has been obtained in less than twelve months, by methods 

 which will certainly not kill the trees under four years. Some old and apparently 



