33° 



for the future. There can be no doubt that were it not for the 

 faraway climate required for the growth of rubber trees, the interest 

 displayed by manufactures in the cultivation and exploitation of 

 rubber trees would long ago have assumed a practical shape of the 

 same kind as is shown by the manufactures of beet root sugar on 

 the Continent, and which is responsible for much of the enormous 

 development and success of that industry. 



Much has also been achieved in regard to the question as to 

 which of the numerous rubber trees offer the best prospects for the 

 purpose of methodical cultivation in different parts of the world, 

 although it cannot be said that this important question has finally 

 been settled in favour of one species or the other. 



But great uncertainty and much diversity of opinion still exists 

 regarding the most satisfactory method of tapping the trees, col- 

 lecting the latex, and, chief of all, concerning the most rational 

 process of converting the latex into the most perfect form of com- 

 mercial rubber. Indeed, we consider the most important prelim- 

 inaries in the exploitation of a rubber district to consist (i) in the 

 careful physiological examination of the tree, and (2) in the ex- 

 haustive investigation of the chemical and physical problems arising 

 in the coagulation of any given latex. Upon the first of these two 

 points depends the life of the trees under exploitation, upon the 

 second the quality and market value of the rubber produced. 



Now while the first of these two points has in the past received 

 a good deal of attention, the second is generally studiously neg- 

 lected, or more or less perfunctorily enquired into. In saying 

 this we are by no means unmindful of the valuable suggestions due 

 to Biffen, and of the interesting results obtained by M. HARNET 

 in the Soudan, but we are not aware that at present rubber exploita- 

 tion companies have realised the necessity of investigating in a 

 systematic manner and by the methods of modern chemical research 

 the best conditions for the coagulation of the latex. 



Coagulation of Latex. 



We have often felt that there seems to be some sort of unex- 

 pressed, but generally accepted notion that the mode of coagulation 

 may affect the general purity of the rubber produced, its colour, 

 percentage of occluded water, and general suitability, but that it 

 has no influence upon the intrinsic quality of the india-rubber itself. 

 In other words, it appears to be taken for granted that the india- 

 rubber exists in the latex of the tree as a substance identical with 

 that of its commercial forms, as is, for instance, certainly true of 

 the oils. We venture, therefore, to submit to the consideration of 

 those interested in this subject the following points which we be- 

 lieve to have an important bearing upon the quality of the rubber 

 produced from a latex : — 



1, It is extremely doubtful, if not altogether improbable, that 

 rubber as such does not pre-exist in the latex, but merely a sub- 

 stance capable of agglomeration by polymerisation (coagulation)- 



2. This being conceded, and the results of a careful chemical 

 and microscopical study of the latex leave very little room for doubt 



