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— 282 INDUSTRIAL PLANTS 
of crude rubber for various articles including water-vessels, 
shoes, and torches. Similar prehistoric use was made by the 
Kast Indians of the product they obtained from the india- 
rubber tree (Fig. 271) which yet remains one of the more 
important Asiatic sources of this remarkable substance. 
Simple, primitive methods of obtaining the raw material 
are still practised very generally by the natives of to-day who 
in various parts of the world collect the rubber which is ex- 
Fic. 271.—India Rubber-tree (Ficus elastica, Mulberry Family, Moracee). 
Tip of branch showing leaves, the youngest unfolding and still partly 
enwrapped by the protective stipule-case. (Original.)—Tree growing 
' 30 m. tall; leaves thick and glossy; flowers similar to those of the fig 
fee page 102); fruit fig-like, greenish-yellow. Native home, Tropical 
ported to Europe and America for manufacture. First, ax 
cuts are made in the bark of a good-sized tree in such a 
way that the milk which flows from the wounds will run into 
little cups so placed as to receive it. The collector on his 
rounds empties the contents of these into a larger vessel 
which he finally carries to where the milk is to be curdled. 
The separation of the caoutchouc from the whey-lke part 
of the milk is accomplished variously; as for example, by 
mere exposure to the air, or by the addition of water or vari- 
ous salts; but the best rubber is obtained by the process of 
smoking as practised in Brazil. Over a smoky fire, made by 
burning Brazil-nut shells or certain palm seeds, the operator 
holds the broad end of a clay-covered paddle which has been 
dipped in the fresh milk, and turns it slowly till an even layer 
