68 PARA RUBBER. 



Collecting Tins. 

 Tin or iron receptacles for collecting the latex are not so good 

 ii a enamelled ones or those made of aluminium, as they are apt to 

 corrode on exposure and to leadto a discolouration of the rubber, 

 when the latex contains large quantities of tannin. In all methods, 

 except the herring-bone and spiral systems, it is necessary to fix 

 the tins on the trees and therefore to have some sharp point to 

 press against the bark for fixing. Where the herring-bone or spiral 

 systems are in vogue, a permanent channel is fixed at the base of 

 each line and the tins placed on the ground immediately under the 

 channel ; the latter arrangement is found to be economical. 



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