1 46 



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. In the case of crepe, 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 1 and preparing crepe 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 I 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. 



D<r. S. RIDEAL: 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 

 rubber trees from estates with which I am personally connected 



