127 



acetic acid solution to 400 parts of latex. The Manager 

 informed me that as little acetic acid should be added 

 as possible ; an excess of acid makes the colour of the 

 prepared product too dark. 



On a third estate, coagulation was effected with a 

 solution of 12 % acetic acid, in the proportion of i part 

 of acetic acid to 300 parts of latex. Here the Manager 

 thought that the chief thing was to coagulate as quickly 

 as possible, and the operation was done in about ten 

 minutes. The quick coagulation would turn out crepe 

 of a clear yellow (melon yellow) ; with slow coagulation 

 dark colour is obtained. 



Besides acetic acid I saw as an experiment, coagulating 

 with smoke. On a subsequent page I will refer again 

 to this. 



In the above mentioned cases, the latex was made 

 into crepe. Another form in which the rubber comes 

 on to the market is sheet. These are practically the 

 only two descriptions which are manufactured in the 

 Straits. 



2. FINISHING THE COAGULATED RUBBER. 



a. Sheet. 



Thin homogeneous sheets of rubber are so described. 



The preparation takes place as follows : 



The latex is coagulated in square enamelled dishes, 



such as are used for the development of photographic 



plates. Then the soft block of freshly coagulated rubber 



is taken out; in the thick creamy white mass nearly all 



the water is still present. This is taken out by rolling. 



