CHAPTER XIII. 

 The Preparation. 



I. COAGULATION OF THE LATEX. 



The rubber must be obtained from the fluid latex by 

 coao'ulation. This coagulation can be effected in different 



&> o 



ways; generally it is effected by the addition of an acid, 

 usually acetic. Before starting the operation, the latex 

 is strained through a sieve of fine copper gauze in order 

 to separate the impurities which are sometimes contained 

 in it and also the lump rubber which has already been 

 coagulated. 



Opinions differ with regard to the manner in which 

 the coagulation is best effected and about the quantity 

 of acetic acid to be added. Different processes may be 

 described. 



The following method was adopted on an estate in 

 Negri Sembilan. 



The latex was strained through a sieve into an earthen- 

 ware pot, fitted with a tap through which it can pass into a 

 wooden trough; in this pan it was mixed with acetic 

 acid which was sprinkled as a solution of i : 12.5 over the 

 latex, that is i oz to i gallon of latex which is the equi- 

 valent of i part solution of acetic acid to 160 parts latex. 



