396 



THE INDIA RUBBER WORLD 



[August i, 1909. 



The Rubber of South America. 



UNSMOKED AMAZON 'PARA" BVBBEH. 



THE appearance in the market of the rubber of the same 

 character as "'Para," as the result of the work of planters 

 in British Asia, and selling at a higher price than any 

 rubber from the Amazon regions — the home of rubber of this 

 character — has lent a great stimulus to the serious efforts which 

 have been made in Brazil for years past to improve tlie quality 

 of the rubber produced there. 



While local scientific men have labored to impress upon the 

 Brazilian trade the desirability of improvements, the rubber pro- 

 ducers themselves, so long as they held in their hand a monopoly 

 of the production of "Para" rubber, naturally were not con- 

 cerned about improving conditions. They were not concerned 

 when so important a rubber manufacturer as the late Joseph 

 Banigan, of the United States, asserted in a public address that 

 the manufacturers of this country annually paid $5,000,000 for 

 "dirt and water" in buying the rubber needed for their business. 

 There was no way in which they could do better, and so long 

 as they were obliged to buy from Para the producers of rubber 

 back of that port did not need to trouble themselves about 

 removing the cause of complaint of Mr. Banigan and his 

 fellow buyers. 



The appearance in the market, however, of a new grade of 

 Para rubber, produced on the other hemisphere, and preferred 

 by many manufacturers to the original Para grades at a higher 

 price, made a profound impression in the Amazon regions, par- 

 ticularly when it was attended by a rate of profit which had 

 never been dreamed of in Brazil. The latest result of the experi- 

 ments which have been made by scientific men in Brazil exist 

 in the shape of specimens of rubber as clean, and showing as 

 small a degree of shrinkage, as the best products of plantations 

 in Ceylon and the Malay states. 



It is not reasonable to assume that better rubber can be made 

 in Asia than in South America, having the late.x of the same 

 species as the basis, and it was only necessary to have the at- 

 tention of scringiiciros in the latter country to appreciate the 

 preference given by consumers to clean rubber to stimulate an 

 interest there in the producticn of rubber of this kind. Further- 

 more, from the earliest times smoking the latex of Hevea 

 has been regarded in Brazil as essential, but the success attained 

 by the Eastern planters in producing rubber without the agency 

 of smoke has encouraged the thought on the Amazon that smok- 

 ing may not after all be a requisite. 



Specimens of rubber which have reached the United States 

 recently, prepared from the latex of Hevea without smoking, 

 have all of the desirable qualities of the best plantation Para 

 produced in the Far East, together with the "nerve" which is 

 admittedly lacking in the best plantation sorts. Dr. Carlos de 

 Cerqueira Pinto, a physician and chemist of Para, Brazil, who 

 has been a recent visitor to the United States, for many years 

 has been among those who studied and worked to learn if it 

 were not possible to coagulate the late.x of both Hevea and 

 "caucho" iCastiUoa') in a better and more cleanly manner. He 

 has not by any means confined his researches to the laboratory. 

 For six years he traveled up the various rivers that are affluents 

 of the Amazon and rubber gathering as few men have done. 



The first result of Dr. Pinto's research was the production of a 

 cheap and simple preservative compound to be added to the 

 late.x immediately after collection, to prevent coagulation in 

 transit to the smoking camp, and also to prevent fermentation 

 in case it should be desirable to hold the latex for any length of 

 time before smoking. Later he produced coagulating compounds, 

 the addition of which to latex facilitates its conversion into 

 rubber without the necessity nf smoking. Dr. Pinto is of the 



opinion that a certain degree of excellence of Para rubber pre- 

 pared by the native method is due to the property derived from 

 the smoke. In the preparation of his coagulant, therefore, he 

 has sought materials which will give the same properties to the 

 rubber without giving certain other less desirable properties. 



Taking his system as a whole, the addition of the preservative 

 to the latex retards coagulation until such time as the latex is 

 to be fortned into rubber, and by preventing fermentation of the 

 material keeps it in a condition which permits of its being 

 strained — a process, by the way, not usual among Brazilian serin- 

 gueiros to-day. When the time arrives for coagulation, the 

 strained latex being placed in shallow tins and a small amount 

 of the coagulant added, the rubber speedily solidifies to a degree 

 that renders it susceptible to mechanical pressure to remove the 

 moisture. 



The samples of Hevea rubber brought to the United States by 

 Dr. Pinto as the result of his process are very fine. The rubber 

 is tough, it has the characteristic mahogany tint usual in fine 

 Para, but it is free from the familiar smell that characterizes 

 the smoked product. If both the preservative and the coagulant 

 could be generally adopted it would result in cleaner rubber and 

 in a greater proportion of "fine," as "medium" would not be 

 made, and a small proportion of "coarse." The importance of 

 this fact alone is indicated by the fact that the proportions of 

 these grades exported through Para of late has been about 61 

 per cent, of fine, 11 per cent, of medium and 28 per cent, of 

 coarse. Dr. Pinio has experimented not only with Para rubber, 

 but with caucho and mangabeira, the quality of which as produced 

 by him is vastly superior to the normal qualities of these grades. 



The Brazilian government has granted to Dr. Pinto fiv.; patents. 

 The letters patent themselves do not reveal the nature of the 

 compounds to which they relate. It can only be stated here 

 that the patents cover the following inventions : 



Xo. 4,227. "Seringuina," for retarding fermentation for short 

 period. (This was first referred to in The Indi.\ Rubber World, 

 in its issue of March i, 1905, page 183. At that time the 

 question of preparing rubber without smoking had not been 

 taken up.) 



No. 4,751. "Seringuina liquida," for retarding fermentation 

 indefinitely ; this has been done for three years or more. 



No. 4.750. "Mangabina." a coagulant for mangabeira rubber. 



No. 5,191. "Lactina," a coagulant for fine Para rubber. 



No. 5,192. "Cauchina," a coagulant for caucho. 



While these letter patents do not embrace specifications, The 

 Indi.^ Rubber World has in hand a copy of a Mexican patent 

 granted to Dr. Pinto (No. 8,413 — October 6. 1908) covering his 

 coagulant "Cauchina," designed for use in connection with the 

 latex of the CastiUoa elastica. The patent claim is for — 



.\ chemical compound jalap, prepared in any form, and creosote in all its 

 forms, regardless of whether these substances are used separately or to- 

 gether in their natural state, or dissolved in alcohol or any other solvent, 

 or whether they are present in liquid or pastry form or in the form of a 

 paste, or in a compressed state, mi.xed with pulverizing substance or 

 substances in a state of amulsion, for the purpose of using the same for 

 the coagulation of the sap of the rubber plant and other plant saps. 



Alcohol is well known to be a good coagulant of rubber. Jalap 

 is derived from the roots of the Convolvulacea;, that of one of 

 the Ipomeas being the most important and a relative of the 

 "amole" vine used throughout Central America in the coagulation 

 of rubber by the natives. Creosote acts probably as a preserva- 

 tive. The compound seems a good one and should do the work. 



Dr. Pinto at Rio received a letter from the Continental 

 Coautchouc- und Guttapercha Compagnie, of Hanover, saying: 



"We received your sample of late.x, as well as the corresponding 

 coagulating agent, which we delivered to our laboratory for 

 examination. It is really interesting that this latex, although 



