282 



INDUSTRIAL PLANTS 



of crude rubber for various articles including water-vessels, 

 shoes, and torches. Similar prehistoric use was made by the 

 East Indians of the product the.y 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- 



Fn:. 271. — India Rubljur-trcc {Ficu^ cla.^liai, Mulberry Fanul\', Moracccv). 

 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 ghissy; flowers similar to those of the fig 

 (see page 102); fruit fig-like, greenislr-\^ellow. Nati\-e honie. Tropical 

 Asia. 



ported to Europe antl 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 wotmds 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 th(> milk is to be curdled. 

 The separation of the caoutchouc from the whey-like part 

 of the milk is accomplished variously; as for example, by 

 mer(> ex[)osui'e (o the air, or by the adtlition of water or vari- 

 ous salts; but the b<'st rubber is obtained by the process of 

 smoking as ])ractised in Ei'azil. ()\'(>r a smoky lire, made by 

 burning Ijrazil-nut shells or certain palm .seeds, the operator 

 holds the broad end of a rla\'-covcred jiaddle which has lieen 

 dipi)ed in Ihe fresh inillx, mikI luiiis il slowly till an e\'eu layer 



