July, 1910.] 



5 



Saps and Exudations. 



IX. 



The Congress advises the governments 

 of the States of Para, Aniazonas, and 

 Matto-Grosso to send competent persons 

 to countries where the cultivation of 

 the Hevea has been successfully tried, 

 in order to study and verify by sight 

 the methods there employed, either to 

 cultivate or to prepare the latex and the 

 rubber, as also the extensive distribution 

 of any report presented by such agents. 



X. 



The Congress advises the governments 

 of Para, Amazonas and Matto-Grosso, and 

 of the continguous republics, to estab- 

 lish one or more permanent expositions 

 of india-rubber, of an instructive or 

 educatioual character, managed by com- 

 petent parties and having annexed 

 physiological and chemical laboratories. 



XI. 



The Congress, in accord with unques- 

 tionable authorities on the subject like 

 Mr. Henry C. Pearson, for one, advises 

 the seringueiros (rubber planters) not to 

 abandon the smoking process. 



This process may be yet improved 

 upon by means of simple and inexpensive 

 mechanisms, that would lighten the 

 work of the seringueiro and at the same 

 time protect his health. In this connec- 

 tion, the attention of every one inter- 

 ested is called to the machine exhibited 

 by the Arm of Dannin and Mello, of 

 Para, which seems to fulfil the necessary 

 requisites. 



For use on planted rubber trees, we 

 call the attention of those interested to 

 the machine invented by Commendador 

 Simao da Costa. 



XII. 



Meanwhile the Congress can but ap- 

 plaud the efforts made to discover new 

 processes of coagulation, and it recom- 

 mends that the governments and mer- 

 cantile associations offei prizes for the 

 best processes, especially for the coagula- 

 tion of the latex of rubber. It must be 

 seen to that all attempts in this sense 

 should aim at producing a better product 

 from caucho than is obtained by fumi- 

 gation, 



XIII. 



The Congress absolutely condemns all 

 and every process of coagulation by 

 acids or by alum, because unfortunately 

 such processes depreciate the value of 

 the latex of the Hevea, to the serious 

 injury of the manufacturer and of the 

 state exchequer. 



XIV. 



The Congress earnestly urges the gov- 

 ernments and associations to enact 



repressive re gulations against fraud in 

 the preparation of rubber, including the 

 mixture of the latex of different species 

 of gummiferous trees, and the wrongful 

 designation of type or origin. 



XV. 



The Congress calls attention of the 

 governments and of merchants to the 

 urgent necessity of organizing a series of 

 well-defined grades of the different 

 qualities of india-rubber, taking into 

 consideration for this classification, not 

 alone the physical qualities, but also 

 the origin of the rubber. The standards 

 of those grades should be kept in 

 permanent expositions mentioned in 

 Article X. 



THE SCIENCE AND PRACTICE OP 

 PARA RUBBER CULTIVATION : 

 THE NEW TROPICAL INDUSTRY 

 OF THE EAST.* 



By John Parkin, m.a., f.l.s. 



(From Science Progress, No. 16, 

 April, 1910.) 



Part //—Rubber Preparation- 

 The simplest method of obtaining solid 

 rubber is to allow the latex to dry natur- 

 ally. There are several objections to 

 this plan. Impurities, such as particles 

 of bark and soil, are apt to be incor- 

 porated, lowering considerably the 

 quality of the rubber produced. An 

 undesirable amount of water is also 

 liable to be enclosed in the caoutchouc- 

 mass. Further, if the latex be allowed 

 to dry in the open air, it may become 

 exposed to direct sunlight, and the heat 

 from the sun's rays in the tropics is 

 sufficient to cause permanent stickiness, 

 rendering the rubber of little value. 

 Moreover, many latices, notably those of 

 Hevea and Manihot, putrefy on stand- 

 ing, and an evil-smelling caoutchouc of 

 inferior grade is the result. Even it the 

 latex be strained to remove foreign 

 particles and a preservative be added to 

 prevent putrefaction, ordinary drying 

 is a very slow and tedious process, 

 especially as the latex usually requires 



* Continued from p. 416. As this article is 

 appearing in two parts, it may be well to point 

 out that the first part dealt principally with the 

 Extraction of the Latex from the Para rubber 

 tree (Hevea brusiliensis), the chief interest 

 lying in the phenomenon known as wound- 

 response. This, the concluding part, deals 

 mainly with the Preparation of the Rubber 

 from the Latex with Coagulation as the central 

 feature. 



