and tug at the wound, the filling gives and stretches, true to the
task it has to perform.

This was the juice the crafty savage induced the tree to give up.
Wherever the bark was cut, the fluid poured forth to heal the
break and hardened like blood on a cut finger. The native caught
it while it was still soft and applied it to his simple needs.

This juice is not the sap of the rubber tree. Sap, which is the
life-blood of the tree, flows through the wood, but the juice we
are describing is contained in the inner bark, a thin layer
directly below the outer bark.

Scientific men call this juice latex. It is like milk in three
ways: it is white, it contains tiny particles that rise to the top
like cream, and it spoils quickly.

The particles in cow's milk are full of fats which make it good
for us to drink. But a rubber tree's milk has tiny atoms of rubber
and resin and other things, and it took time to discover which of
the vines and trees was the prize milker of the tropics and gave
the largest amount of pure rubber. Finally, the Hevea, the very
tree the Frenchman wrote about, proved to be the best, and,
although by no means the only rubber tree of commercial value, it
is acknowledged the greatest of rubber trees.

The Hevea tree grows sixty feet tall, and when full grown is eight
or ten feet around. It rises as straight as an elm, with high
branching limbs and long, smooth oval leaves. Sprays of pale
flowers blossom upon it in August, followed in a few months by