169 
aware that this has been attributed to the comparatively large size 
of the rubber globules in the Castilloa latex, but for reasons, based 
upon evidence, I shall produce in another paper on this important 
subject, I believe this assumption to be erroneous. 
In my communication I showed that the latex of an ii year old 
Castilloa tree contains 31 per cent, of pure rubber, and it will, 
therefore, be seen from the above statement regarding the amount 
of albuminous matter in the latex that if we coagulate the latter 
without first removing from it this albuminous matter we obtain a 
rubber containing over 25 percent, of albuminous matter. The 
native rubber collectors prepare the rubber from the latex in such 
a wav that at least part of the aqueous vehicle of the latex is drained 
away before coagulation takes place, and consequently we never find 
a Central American rubber (crude) which contains as much as the 
above stated quantity (25 per cent, of albuminous matter), but lots 
containing from 9 to 13 per cent, are quite common. It is indeed 
the presence of such a large amount of albuminous matter in the 
Central .American and some other Castilloa rubbers which is largely 
responsible for their frequently reaching American and European 
ports in a state of pronounced putrid fermentation, of the atrocious 
smell they emit on washing, and of their often very unsatisfactory 
behaviour in the process of vulcanisation. When "such rubber in 
a state of ad vanced putrid fermentation is subjected to the wash- 
ing process a very considerable proportion of the coagulated albu- 
minour matter, rendered soluble by the fermentation, is removed 
but the rubber, although not taking itself an active part in this fer- 
mentation, is, nevertheless, found to have suffered more or less 
severely from it, to possess little strength, and. after vulcanisation! 
onl> very moderate distensibihty (elasticity). If, on the other hand, 
the rubber reaches the factory in fair condition, it contains prac- 
tically the whole of the albuminous matter in an insoluble condition 
and so intimately intermixed with the rubber that the washing al- 
together fails to remove more than a mere trace of it. We obtain 
then a washed rubber, which contains a very large proportion ot 
albuminous matter, the presence of which in the washed and dried 
rubber is scarcely noticeable, but which is the cause of such rubber 
forming invariably a peculiarly -'short” and pone-resilient vul- 
canisation pioduet. It will thus be seen that whatever happens to 
?r n f S 108 * k h alvva >' s a ^ inferior product from 
r m?gh j b ® *. f Ominous matter were kept out of it. In 
fact, J scarcely think I want any further justification for the state 
ment that the Castilloa rubber of the present day o win " to the' 
above discnssed detect, occupies a much lower position than it 
a ould hold considering the intrinsic quality of the pure rubber it 
contains. lam indeed, of the opinion that properly prepared 
Castilloa rubber is superior to most of the present day Para "rades 
quantises o alLr- 3 here tilAt the P resence ^ substantial 
quantities of albuminous matter not onlv Castilloa rubber but also 
to feZentT l } fnCan) brands > and the odo ^ they produce owing 
g,vei l to the now almost ineradicable 
Cr> taIe that m certain chstncts the rubber is coagulated by 
