188 



THE INDIA RUBBER WORLD 



[March i, 1906. 



LETTER FROM A NICARAGUA RUBBER PLANTER. 



To THE Editor of The India Rubber World : I 

 am as you know a rubber planter, having since 1898 

 planted near BluetieUis in Nicaragua, nearly 20c ,000 

 Caslilloa trees, which now measure mostly from 4 to 

 10 inches or more in diameter. I have given much time to the 

 problems of bleeding and curing and have so far marekted 

 in New York about a ton of cultivated rubber fully known to 

 Messrs. Poel & Arnold and the Manhattan Rubber Manu- 

 facturing Co. of New York. Belangers, Incorporated, of 

 the same place, have also carried on independent experi- 

 ments and marketed a quantity of very fine rubber. Our 

 yield has been very encouraging. 



We have not, however, accomplished anything like what 

 Mr. Etherington reports in your January number to have 

 been done by some of the Hevea planters of Ceylon. Yields 

 of s to 16 pounds from trees not exceeding 11 or 12 years 

 seem hardly credible. If your correspondent will not take 

 it as a discourtesy, I should like to challenge his state- 

 ments. They are so wonderful and so important to the 

 planting and manufacturing interests of the world as to be 

 spurned or at once verified even at great expense. 



In my neighborhood there are Castilloas enough, if they 

 can be made to do as well, to yield five years hence $5,000,- 

 000 worth of plantation rubber at the present market. The 

 total consumption of crude rubber in America is roughly 

 60,000,000 pounds a year, which at this Ceylon rate might be 

 satisfied in twelve years by the production of 4,000,000 trees 

 at a cost of $2,000,000. I had thought that planted rubber was 

 not likely to be felt in the markets for 25 years and that 

 with the gradual exhaustion of the wild rubber field and the 

 rise of wages in the tropics, which is sure to come, a rubber 

 famine was surely approaching. 



The methods of bleeding described by Mr. Etherington, 

 upon which so much depends, differ from those followed by 

 us in these respects : (i) Frequency of bleeding, (2) re- 

 opening the cuts, (3) pricking the wounds. Let us have 

 proof of the magic of these practices. 



The Ceylon methods of curing, described by Mr. Ethering- 

 ton, I have read with interest. I should like with yovir per- 

 mission to publish what we have done, so that we may have 

 the benefit of criticism by j-our readers. The coagulation of 

 rubber latex has so far been a difficult problem. Drying in 

 the sun in a moist tropical climate is tedious, and the sun is 

 injurious to Castilloa rubber. Drj-ing out of the sun is not 

 practicable. Drying by steam is expensive and all methods 

 of evaporation yield a Caslilloa rubber prone to the viscous 

 disintegration and tackiness, which characterize Centrals. 

 The same objections, I think, apply to the method of absorp- 

 tion by pouring the milk on blotting paper or porous clays 

 or bricks, followed by mj' neighbors Belangers. 



Because the best Para, in curing, is submitted to a heat 

 probably greater than 212° and because, on the best author- 

 ity, the most of the best Congo is boiled in the curing, I 

 tried boiling the Castilloa latex. The result was not satis- 

 factory. A large proportion of the rubber in the latex co- 

 agulated, but there remained always a residuum of milky 

 fluid which no amount of boiling would cause to give up its 



rubber. The Brazilian method was put aside as too expen- 

 sive. Blowing smoke through the milk by means of a black- 

 smith's blower attached to a furnace was tried, without any 

 success. When, however, the latex so smoked was boiled 

 the rubber separated completely leaving a lye colored water 

 without a trace of rubber. From these experiments the con- 

 clusion was made that smoke and heat would effect coagula- 

 tion. Having a steam boiler, the apparatus of which I pre- 

 sent a rough drawing was set up. 



RUBBER SMOKING APPARATUS. 



[a steamer boiler ; A— steam pipe ; c steam syphon ; rf— discharge pipe ; 



e latex vat ; f smolce making furnace. 



Steam passing from the boiler through the siphon con- 

 tinues through the discharge pipe drawing with it into the 

 latex the whole smoke supply of the fvirnace. The latex is 

 violently agitated and gradually reaches boiling heat. As 

 the boiling point is reached, the rubber completely coagu- 

 lates A few minutes of boiling is enough. The coagulated 

 mass is then lifted out and sliced thin and hung over poles 

 to dry. Because of the working of steam in the mass, it is 

 porous and drys very quickly. Indeed, there is no other 

 way of drying rubber except by reducing it to paper-like 

 sheets. The process is quick, simple, and cheap. Rubber 

 so coagulated has been kept six months without sign of vis- 

 cidity or shortness of grain. The method is in effect that of 

 Brazil, and its chief merit aside from solving coagulation is, 

 I venture to think, the diffusion through the rubber of the 

 preservative elements of woodsmoke. The active principle 

 of coagulation with heat is doubtless acetic acid. It has 

 been suggested to me bj' Professor Lang, of Toronto Uni- 

 versity, that crude wood alcohol, that is, alcohol from which 

 the acetic acid had not been removed, might be an effective 

 coagulant. 



It was fouud that it did not do to use woods for smoke pro- 

 duction which blazed readily and so, I venture, consumed the 

 necessarj' elements of smoke. At last, it was demonstrated 

 that the best fuel was the nuts of what is locally known as 

 the silico palm growing verj' extensively in the swamps of 

 Nicaragua and possibly identical with that producing the 

 rubber curing nuts of Brazil. No doubt, their virtue lies 

 solel}' in the fact that they give off a dense smoke and simu- 

 late a wood distillation. But I bow to the chemists. We use, 

 in bleeding, clay to make a continuous surface from the bark 

 into the receiving cups. Some of this clay mingles with the 

 latex and, if not removed by washing, will hinder by its 



