129 



(Saps and Exudations, 



The first noticeable thing in cutting the Para tree is the small yield. A 

 Castilloa tree when first tapped fills the cut with latex immediately, and the latex 

 runs in a small stream from the lower end. A Hevea when first cut shows no latex. 

 In a few seconds it begins to appear in drops on the cut surface, and after three or 

 five minutes begins to drip from the end ot the cut. The small yield at the first 

 tapping seems to be balanced by the fact that more can be got by multiple 

 tapping. In Ceylon, according to report, the yield increases each day, but here 

 I have noticed no increased yield. 1 tapped one tree nine days in succession, 

 and though it yielded every day (a thing which CastUloa would not do) the 

 yield decreased instead of increasing. The Hevea tree will not do here because 

 there is too much labour involved in multiple tapping. I think the trees here if 

 tapped rightly would yield as much as those in Ceylon, but as labour here costs 60 

 cents a day, and there teupence, it would not pay. I am confident from comparing 

 yields printed in the India Rubber World, that CastUloa will yield as muca with four 

 operations a year as Hevea will with ten or twenty when the trees aro the same 

 age. Hevea latex is superior to CastUloa without doubt in all points but one. It 

 coagulates very easily, and is therefore harder to bring from the field than CastUloa. 

 Hevea latex is finer than CastUloa. It has no black water. All that is necessary to 

 coagulate it into good rubber is to set it in a shallow dish and leave it twenty-four 

 hours. The piece of rubber can then be rolled to squeeze the water out, and then 

 be dried. The Hevea globules are finer than CastUloa, and they are not in masses. 

 For this reason Hevea latex cannot be coagulated by the blotter method, as the glo- 

 bules soak right through. It might work on porous tiles. 



Hevea rubber I do not consider superior to CastUloa. In point of strength 

 and elasticity my observations have seemed to show that it is inferior. Pieces of 

 CastUloa and Hevea rubber coagulated at the same time showed that Castilloa could 

 not be broken by stretching, while Hevea would break square across. The only 

 piece of Hevea I have seen which was stronger than Castilloa was a piece from 

 Ceylon, which was fully three times as thick as the CastUloa it was compared with. 

 It may be that there are some manufacturers' differences between Hevea and 

 Castilloa that may make Hevea superior, but in point of strength and elasticity it 

 is not so. 



THE CEARA RUBBER TREE (MANIHOT GLAZIOVII.) 



The Ceara rubber trees here are only two years of age, and are yet to be 

 tapped. They are very fast growers, and are nearly as large as four-year old 

 CastUloa trees. Their bark is not as thick in proportion, however, as CastUloa, and 

 for that reason they yield less. The latex runs as freely as Castilloa, but is finer, 

 and like Hevea has no black water. It is rather watery. The rubber has a pecu- 

 liar unpleasant odour. I have not seen enough of it to judge its qualities. 



The Ceara rubber trees are not doing well. They die from no apparent cause. 

 The very healthiest looking and fastest growers will suddenly begiu to wilt. Some 

 of them are attacked by insects, but these appeared to come only after the tree had 

 begun to die. I believe that they are sensitive to lightening, though I am not sure 

 of this. — Quarterly Journal, Liverpool Institute of Tropical Research. 



EXPORTING SEED OP PARA RUBBER. 

 As it is well known the seed of the Para rubber tree deteriorates very 

 rapidly after it is ripe and soon loses its germinating power ; it is not always easy 

 to send seed long distances without a very large percentage of losses, at the same 

 time the demand for the seed in distant parts of the world is very considerable 

 and a good many experiments have been tried in the Botanic Gardens in various 



