ACROSS UNKNOWN SOUTH AMERICA 
coagulating latex into solid cakes, a primitive lever 
arrangement was used — merely a heavy wooden bar, one 
end of which was inserted into the cavity of a tree, above 
the wooden mould, while at the other end of the bar heavy 
logs of wood were suspended. One night was sufficient 
for the latex to coagulate thoroughly and be properly 
compressed into cakes, weighing each about 22% kilo¬ 
metres. The cakes were lifted out by belts of liane which 
had been previously laid into the moulds. 
The discoverer of the method of coagulating rubber 
with alum was Henry S. Strauss. He also found that 
by keeping the latex in hermetically sealed vessels it could 
be preserved in a liquid state. The same result could be 
obtained with ammonia. 
In the Amazon and Para provinces a different process 
was used. The latex was coagulated by placing it near 
the fire. The heat evaporated the aqueous part and 
coagulated the vegetable albumen. In order to make 
a gcirrafa, or large ball of rubber — some weighed twenty, 
thirty, forty kilometres and more — a small ball of latex 
was made to coagulate round a horizontal bar of wood. 
That ball was gradually increased in circumference by 
smearing it over with more latex, which became gradu¬ 
ally coagulated and dried by the heat and smoke pro¬ 
duced by the burning of certain woods, and of the oily 
seeds of the urucuri palm, technically known as the 
Attalea epcelsa. In this process the rubber did not remain 
white, as with the alum process; in fact, it became dark 
brown, almost black, owing, of course, to the smoke. 
Locally, the smoking process was said to be the better 
of the two, for the coagulation with alum took away 
somewhat from the elasticity of the rubber. 
Interesting was the sorveira (Collophora utilis ), a tree 
which gave latex that was quite delicious to drink, but 
could not be coagulated. The trees, to any untrained 
person, closely resembled the seringueira, only the leaves 
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