146 
machine. It is obviously easier to clean a freshly coagulated 
rubber than it is to clean a dry, hardened rubber, in which the 
particles of dirt and other foreign material have become firmly 
enclosed; and from that point of view alone I think it is quite 
easy to understand how the planter came to instal washing 
machines. Moreover, at that time there was a great deal of 
talk about putrescible organic matter, the idea being that the 
purer your caoutchouc, the freer from other ingredients, the 
better the quality. Of course, these views have changed very 
much since then. Another point is that I think all planters 
will agree that the washing machine simplified the process a 
good deal on the rubber plantations. At the time of the intro- 
duction of the rubber-washing machine very little sheet was 
made; it was mostly biscuits. Now biscuits are small, and the 
trays in which biscuits are coagulated are of an inconvenient 
shape, and making biscuits entailed a great deal of handling. 
Moreover, the biscuits very frequently arrived in a more or 
less mouldy condition, and consequently there was continued 
trouble. Inthe case of crépe, on the other hand, much of the 
organic matter was so thoroughly washed out, that if the 
rubber was efficiently dried it always could be relied upon to 
arrive home in a clean condition and free from mould. These 
were the considerations which influenced the planter, I think, 
in adopting a washing machine and preparing crépe rubber. 
With regard to chemical analyses, I should like to refer to 
a very recent paper which has been published, and which seems 
to me to give us a means of carrying further our researches in 
regard to the protein matter. Reference has been made to 
the name of Dr. Spence. Dr. Spence is an English chemist 
working at the head laboratories of the greatest of the 
American rubber manufacturing companies, and he _ has 
recently succeeded in finding an easy means by which protein 
matter can be readily separated from the rest of the rubber. 
This is a very promising line of research, and [ think when we 
have separated the protein from different grades of rubber in 
different ways, and compared the proportion of that protein 
with the vulcanizing properties of the rubber, we shall quite 
possibly know more about this particular branch of the rubber 
industry than we did previously. 
Dr. S. RipraL: Mr. President and Gentlemen—I did not 
come here to speak, but to learn, because I have hardly looked 
at the subject from the technologist’s point of view. It is true 
that I am interested in plantations of Hevea in the East, and of 
Ceara and Funtumia, and therefore I know what these trees 
can produce when planted under known conditions. As a 
matter of fact, the produce of these three different kinds of 
tubber trees from estates with which I am personally connected 
