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
pods containing three speckled seeds which look like smooth,
slightly flattened nutmegs. When the seeds are ready to drop the
outer covering of the pod bursts with a loud report, the seeds
shooting in all directions.

This is Nature's clever scheme to spread the Hevea family. The
tree grows wild in the hot, damp forests of the Amazon valley and
in other parts of South America that have a similar climate. The
ideal climate for the rubber tree is one which is uniform all the
year round, from eighty-nine to ninety-four degrees at noon, and
riot lower than seventy degrees at night. The Amazon country has a
rainy season which lasts half the year, though the other season is
by no means a dry one, and so for half the time the jungles are
flooded.

These rubber storehouses had been growing for thousands of years
in the Amazon jungle with their wealth securely sealed up in their
bark, the peck of a bird, the boring of a beetle, or the scratch
of a climbing animal being the only draft upon their treasure. The
trees around the mouth of the river supplied whatever was needed
for the little manufacturing that was at first done. But the
discovery