PARA RUBBER. 77 



the composition of only one series of samples, and should not be 

 taken as showing the constant composition of rubber from trees of the 

 ages quoted. The rubber from two-year-old trees was sticky, and 

 snapped when slightly stretched ; it was obviously unfit for sale. 

 The illustration on Plate 7, Series 1). shows the tree from which 

 the rubber was obtained, and it is perfectly clear that the available 

 tapping area on such trees is very small. 



Parkin proved that the preparation of good rubber from young 

 stems and leaves of Hevea brasiliensis was an impossibility, and 

 other observers have shown that rubber from young trees is adhesive 

 and lacks the required elasticity and strength ; nevertheless, it is still 

 the subject of much discussion as to whether age is the only criterion 

 for cultivators of Para rubber in the East. 



Stanley Arden has shown that in parts of the Straits the rubber 

 from trees 3i to 4 years old is decidedly inferior. His results have 

 been quoted in the section dealing with " Yields of Rubber," and it is 

 only necessary to point out that the yield from trees up to four years 

 old was exceedingly small, and that rubber in paying quantities 

 was only obtained when the trees were about or over seven years 

 old. He calculated that by the time the trees in the Straits are 

 six years old, 75 per cent, should give an average yield of 12 ounces. 



On certain Malacca rubber properties the Para rubber trees, 

 even though catch crops have been taken off the ground during the 

 first few years, attain in four years a circumference of 18 inches, 

 and in seven years 35 to 40 inches. These trees are planted 15 feet 

 apart and can be tapped after the fourth year. 



Samples of Para rubber from four-year-old trees have, however. 

 been depreciated in certain quarters . and in one case they were classed 

 as being similar to common African" sorts for hardness, but superior 

 in cleanliness. They were described as being soft, and would not 

 stand much working on the machine, and the value put upon them 

 was only equal to that for '"Congo ball or a similar quality of 

 African." 



Ace and Size. 

 With regard to our experience in Ceylon it should be pointed 

 out that under favourable circumstances the Para rubber tree will 

 show an increase in circumference of about 4 to 5 inches per year up 

 to the first six or eight years, and that though the rubber from two 

 to six-year-old trees is adhesive, and may have a high percentage 

 of resinous compounds, it is by no means always the case. The 

 analyses of Para rubber from 2, 4. and 6-year-old trees have been 

 previously given, and though the results cannot be accepted as con- 

 clusive, it was pointed out by Mr. rvelway Bambert that the rubber 

 did not possess a very high percentage of resin, and in this respect 

 was certainly quite contrary to what Weber and others have observed 

 in the rubber from young Castilloa trees. But when one considers 



* India Rubber Journal. 



f Committeeof Agricultural Experiments, Peraderuj a. M. Kelway Bamber. 



