68 TlMEHRI. 
Of all the plants mentioned, Hevea is the most valu- 
able. Thirty per cent of its milky juice consists of pure 
caoutchouc, while the juice of Ficus elastica, the next 
in value, is often found to possess not a third of this. 
The existence of India-rubber was made known in 
Europe nearly five hundred years ago by the first visit of 
Columbus to the West Indies. The facts here mention- 
ed regarding the history of the India-rubber have been 
principally derived from a course of lectures, by Thomas 
Bolas, F.C.S., published in the Journal of the Society of 
Arts. The natives were reported to be in the habit of 
making playing-balls of an elastic gum. The ances- 
tors of most of the existing tribes, Ackawoi, Arecu- 
na, Caribisi, Macusi, originally from the islands, hav- 
ing migrated hither, probably at different periods 
before the advent of Europeans in the New World, and 
are the living representatives of the extinct island- 
ers from whom the earliest acquaintance with Caout- 
chouc was obtained. The juice from which they make 
these balls is derived from a medium sized tree, 
probably a species of Urostigma, thirty to forty feet 
high, with a trunk about eighteen inches in diameter. 
It runs very freely, and is caught, when it at once con- 
geals, and is worked up by the fingers rapidly till a ball 
large enough to roll under the palms of the hands is made. 
This is continued for three or four hours, by which time 
the ball has become several inches in diameter. The 
rubber appears to be of the finest kind. The balls pos- 
sess an extraordinary elasticity, springing high off the 
ground when dropped, by the mere force of their own 
weight. They are used at the paiwarie feasts : the 
