Identifier: heveabrasiliensi00wrig (find matches)
Title: Hevea brasiliensis, or Para rubber, its botany, cultivation, chemistry and diseases
Year: 1906 (1900s)
Authors: Wright, Herbert
Subjects: Hevea
Publisher: Colombo, Messrs. A. M. & J. Ferguson
Contributing Library: NCSU Libraries
Digitizing Sponsor: NCSU Libraries

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s. If the pure latex is allowed to stand in a receptacle, itfinally coagulates and the caoutchouc globules with other substancesfloat to the top, leaving a more or less clear liquid behind. By the addition of chemical reagents or by subjecting the latex todifferent temperatures coagulation may be hastened or retarded.The coagulated substance after washing, pressing, and drying isultimately known as the rubber of commerce. In the production of rubber from latex the planter may eithertake advantage of the presence of coagulable constituents in the latexor adopt chemical and mechanical means for the separation of thecaoutchouc globules from the rest of the latex. Production of Rubber by Natural Coagulation. This change is due to the presence, in solution, of albuminous ojproteid matter, which quickly coagulates or becomes insoluble. Thecoagulated proteid carries witli it the suspended globules of caout-chouc and other bodies, so that the whole process is more or less one Series A. Pl 20-
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Photo ly C. H. Ken:LATEX IN SETTING OR COAGULATING PANS. PARA RUBBER. 109 of clarification, the liquid left behind usually containing onlythose ingredients of the latex which have remained in solution.The coagulation of the proteid material occurs as soon as the latexbecomes neutral or faintly acid, no matter what proportion ofsuspended globules of caoutchouc or other constituents may bepresent in the latex. Burgess states that the natural method of coagulation is onlypossible where a washing machine is used, and suggests that where thelatter is in use the latex might be allowed to stand for 24 or 36 hours,and the natural fermentation allowed to take place and producecoagulation. It is difficult to understand this contention, if by awashing machine is meant one similar to that recommended by thesame authority for the manufacture of crfpe rubber in the Straits—indeed, if it were so it would constitute a serious disadvantage to themethod of coagulation by natural means. As a matter of

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