473 
say that crude rubber without any of these impurities would in 
itself produce a minor revolution in a great many of our india-rubber 
manufactures. 
As a matter of fact, we already possess a method by which the 
rubber latex can readily be deprived of its albuminous substances, 
and this method, known as Biffen's centrifugal method,, can easily 
be applied on the rubber plantation. But it is also well known that 
the rubber after this treatment will readily coalesce into larger 
masses, which can then be handled ; it is also tolerably well known 
that this coalesced rubber differs not immaterially from coagulated 
rubber by its peculiar flabbiness or lack of “ nerve. ” I may further 
state, as the result of recent experiments, that this difference goes 
even much deeper, and that there is a very remarkable difference 
in the vulcanisation results obtained with coalesced and coagulated 
rubber respectively. The difference is certainly not in favour of 
the coalesced rubber. 
This unquestionably shows that the coagulation process must 
ha'’e an effect upon the rubber, the nature of which is at present 
only dimly recognised, but which I suggest will ultimately be found 
to consist in a polymerisation process. 
From this it must not, however, be argued that my plea for re- 
moving from the rubber latex all albuminous matter will have to be 
abandoned, but rather that we shall have to find a mode of treating 
the coalesced — albumen free— rubber in such a way as to impart to 
it the required condition of polymerisation in an unobjectionable 
manner. This is a problem which may puzzle the planter, but 
which is capable of solution by the chemist. Indeed, I have sub- 
stantial grounds for stating that this problem has already been 
solved with entire success, and is already practised on one of the 
largest rubber plantations in Central America. 
The treatment in question not being public property at this 
moment, it is impossible to do more at present but to state its 
existence. As to its efficacy there is no doubt. The rubber pro- 
duced by it is remarkably firm, almost colourless, and beautifully 
transparent. 
The treatment could, of course, not be extended to scrap rubber, 
but on a rubber plantation with proper organisation of the collection 
of the latex the proportion of scrap rubber produced could easily 
be kept at a very low figure. Nor is there any reason why the 
planter should not effect the cleaning of the scrap on the planta- 
tion. The scrap then would still produce a rubber at least equal to 
the best crude brands now on the market. 
The process of coagulating rubber latex by boiling, described in 
Mr. PEAR’S letter, is a piece of unmitigated barbarism invented by 
niggers, and about on a par with their intelligence. It is merely 
the solution of a problem by brute force, and it is to be hoped that 
with the advent of rubber planting this process will recede to the 
wilderness whence it came. — India-rubber and Gutta Percha 
Trades "Journal , June 23, 1^02. 
x ll70 
