35 
For paring the cuts there were many knives exhibited and 
gold medals went to the Bowman- North way and JVIiller knives, 
both of which are simple, keep sharp, and pare thin shavings with- 
out any dragging of the cut edges. It is very important that the 
shaving should be thin, as the bark should be made to last about 
four years before it is all cut away, in order to allow the renewed 
bark time to ripen fully. 
The yields obtained on some estates have been phenomenal, 
but it is probable that in many of these cases the bark has been 
too rapidly cut away, and that a period of waiting for the renewed 
bark to ripen will ensue. It is not- as yet safe to count on more 
than a pound a year a tree, if so much, but even this means 150-200 
lbs. an acre, an amount sufficient at present prices to yield an 
enormous profit. 
Hitherto the Ceylon rubber has mostly appeared upon the 
market in form of ‘ 4 biscuits ’’—flat pancakes about 10 inches in 
diameter. The Malayan has mostly been in 14 sheets ” about two 
feet long. But both these forms seem destined to disappear in 
favour of block— rubber prepared by blocking the sheets, biscuits, 
or other form under high pressure. Some samples of block were 
shown by Tanadron Estate, Johore, and similar samples have 
lately been getting the highest prices on the market. 
The Cey-lon and Malayan rubber has been obtaining higher 
prices per pound than any of the ‘ wild ’ rubbers, even 4 fine Para ’ 
the standard of the market, but pound for pound of pure rubber is 
really getting lower prices, for the Para rubber contains about 
20 per cent of moisture. Why this should be so is one of the 
greatest problems before the investigr-tion at the present moment. 
Anyone comparing a sample of fine Para with one of any 
plantation rubber — Ceylon, Malayan, or Mexican — can see at once 
that the former is more springy, returning more readily to its 
original shape when stretched. The higher price really obtained 
for this rubber may therefore probably be explained on this con- 
sideration. 
Now is it because the trees are young that the rubber is 
weaker, or because the rubber is not smoke-cured ? Is it because 
the rubber is in biscuit or sheet instead of in blocks ? Is it that 
it is too much dried (Para rubber contains 20 per cent of mdisture) ? 
Is it that it is too pure and too much washed ? Or is it that it is 
not coagulated in the best way ? All these, singly or in combina- 
tion, are possible explanations, and there may be others. 
There is no doubt that older trees give stronger rubber, but 
that if even the oldest trees in Ceylon — 30 years old — is not equal 
to South American rubber. Smoke-curing (without coagulation at 
the same time) seems to strengthen the rubber, and block rubber, 
besides its saving in cost of freight, and exposure of less surface to 
oxidation, seems actually stronger than sheets or biscuits. The 
great dryness of the plantation rubber may also have something to 
do with it, and experiments are now being tried by the Peradeniya 
institution in the preparation of block from wet biscuits. 
