 Rubber
is a sticky, elastic solid produced from a milky liquid called
"latex(胶乳，乳液),"
which has different properties than the sap
found in trees. Although latex is found in the bark, roots, and
stems, branches, leaves, and fruit of over 400 different plants
and trees, the bulk is found, and extracted,
from the inner bark of the branches, and from the trunk, of the
rubber tree. Quite simply, it would not be cost-effective to
extract the latex from rubber producing plants, such as the dandelion(蒲公英),
the milkweed, and the sagebrush.
Just visualize some poor soul laboring over one of these with a syringe!
Rubber, derived from the gum
of a tree, has existed since prehistoric
times. For example, fossils of rubber-producing plants date back
almost 3,000,000 years. Crude rubber
balls, discovered in ruins of ancient Incan
and Mayan civilizations(印加和玛雅文化)
in Central and in South America, are, at very
least, 900 years old. Natives of Southeastern Asia used rubber,
prepared from the "juice" of trees to waterproof their
baskets and jars. Even Columbus, on his second voyage to the New
World, observed Haitian natives playing with balls made from
"the gum of a tree."
Latex consists of tiny particles of liquid, solid, or semi-fluid
material, that appears in the form of a watery liquor, not to be
drunk! The breakdown on this
watery liquid is only about 33% rubber, with the remainder
being, not surprisingly, water! When the rubber particles in the
latex join together, they form a ball of rubber.
Rubber producing plants grow best within 10 degrees of the
Equator, where the climate is hot and moist, and the soil is
deep and rich. For this reason, the area of about 700 miles on
each side of the Equator is known as the "Rubber
Belt." Brazil, from whence the best, and top-producing
rubber tree hails, is firmly planted within the Rubber Belt.
This Latino tree with a Latin name, Hevea
brasiliensis(橡胶树), produces approximately 96%
of the world's supply of natural rubber, and now is cultivated
in other Rubber Belt countries.
Most likely, the French, prior to the 1800s, were the first
white men to take advantage of rubbers' elasticity. They
manufactured "rubber bands" for use with their garters
and their suspenders, to help to keep their pants up. Rubber
belts did not exist at that time.
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