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The latex having been obtained and collected the " caoutchouc," or 

 rubber known to commerce, may be obtained from it in various ways. 

 The only method, however, that has met with practical success is that 

 of evaporation by which the watery portion of the latex is driven ofE 

 and solid caoutchouc remains. The object to be secured is that as- 

 little water and proteid matter shall remain in the caoutchouc, the pu- 

 trefaction of the caoutchouc, owing to the presence of these matters 

 being extremely detrimental to its elastic properties, and, therefore to 

 its market value. In the Amazon district the method followed is to 

 light a fire upon the ground and to invert over it a specially constructed 

 funnel-shaped chimney. From the narrow end of the funnel which is 

 open, the smoke and heated gases pour out in a concentrated form. 

 The fuel used for the fire consists, as a rule, of chips from any hard- 

 wood tree that grows handy to the Ltbourer's hut. The nuts- 

 of the " TJrucury palm" (Attalea excelsa) are sometimes used, 

 their smoke containing a trace of acetic acid and creosote being found 

 particularly effective in curing the rubber and preventing putrefaction. 

 It is, however, a mistake to suppose that all or even a large propo rtion 

 of the rubber coming from the Amazon district is cured in this way. 

 It is, on the contrary, very rarely that the rubber-cutter will be at the 

 trouble to collect these nuts, he nearly always prefers to use wood 

 chips which give him less trouble to procure. 



The fire having been made, and a large stream of hot smoke pouring 

 out of the chimney, the operator seats himself on a small stool by the 

 side of it. The latex is contained in a basin placed at hand. In hi& 

 right hand he holds a paddle-shaped piece of wood ; in his left hand a 

 small calabash. Dipping the calaba-h into the ba?in of latex he pours a 

 small quantity over the paddle which he then revolves in the smoke 

 issuing from the chimney. That having dried in a layer over the 

 paddle he repeats the operation. In course of time a "ball" or 

 " biscuit" of solid rubber is thus formed. In some parts where it is 

 the custom to manufacture very large balls or " pellets," an arrange- 

 ment is made by means of a pivot to rotate the ball over the chimney. 

 The wooden core is withdrawn through a slit made in the " biscuit" or 

 simply drawn out in the case of the " pellet". 



The latex of a tree named Maoaranduba" [Mimusops elata), and 

 more often that of a tree named locally ''Amapa," is sometimes used to 

 adulterate that of th.Q Hevea. In both cases the adulteration is extreme- 

 ly prejudicial to the quality of rubber produced. 



Three distinct qualities of rubber are manufactured in this district 

 named Fine" Entrefine" and Sernamby" respectively. "Fine" 

 rubber has been well smoked, and is free from putrefaction. " Entre- 

 fine" rubber has been either burnt whilst being smoked, or has been 

 insufficiently smoked, and has therefore putritied. It is due to care- 

 lessness on the part of the workman, which it should be possible to 

 avoid. " Sernamby" is the " negro-head" of commerce, and consists 

 of scraps, mixed with dirt, or strips peeled off the bark of the tree and 

 mixed with impurities of sorts. 



A very important factor, from the merchant's point of view, in the 

 rubber trade, is the loss of weight that is constantly taking place in 

 raw rubber. This loss is extremely variable, and a consignee has to 

 place the greatest faith in the consignor that the invoiced weight of 



