Evening star., 1925-08-23

for several decades if the good nature
of the trees is not imposed upon by
too much tapping or by disease al
| lowed to attack them from lack of
care. Tapping is. then, an important
episode in the life of the rubber tree.
1t is a science that the natives have
long practiced, and in which they
have gained remarkable deftness. 1t
is also something about which the
cultivator is still learning.
Care Is Required.
A daily call upon the rubber tree
and wide slashes upon its skin Is
giving way to alternate tapping and
more restricted slashing. Tapping is
an early morning act, beginning at
daylight and stopping by nine in the
| morning. A thin shaving of bark is
taken off diagonally across varying
part of the trees circumference with
sharp tool like a furrier's blade.
1t requires deftness and care, for
cut too deep exposes the tree to dis
ease and one cut too thin impedeS
the flow of juice. There are vari-
ations in tapping incisions, but they
all seek to reach the valuable lateX
to free it so that it will gather in the
porcelain cups at the lower end of the
incision. The properly tapped tree
VIII heal quickly, but just how long
plantation trees will live and yield
under scientific and careful handling
is still in the realm of conjecture.
Time has not yet been long enough to
allow conclusions
Once the rubber tree had yielded
up the gift that nature stored within
1t, men turned his inventive genius
to transform it. From the porcelain
cups the sticky fluid is emptied into
milk cans, dusky natives gathering
the run under tropic suns, much as
far north Vermonters gather maple
sap under the cold blue of an early
Spring sky.
Prepared i'm Several Forms.
For the market the Para rubber is
prepared in several forms. The more
crude method of making "biscuits"-
rich brown, 60-pound biscuits. of
crude rubber-still prevails some
what, particularly in Brazil. A wood
en- paddle dipped in the fluid, held
over the smoke of burning leaves,
dipped again and again, gradually ac-
quired its rubber biscuit
Newer practices, the American Ma
ture Association points out. have i'm
proved the handling. There are
three main forms of preparation
smoked sheet, thin pale crepe and
thick pale crepe. The first looks for
all the world like black molasses
candy. 1t has it's thickness of about
| quarter inch, it's rich blackness and
shiny surface, but it smells something
like bacon. 1t has been coagulated by
smoke bath and various planta-
tlons generally stamp their particular
brand
The thin pale crepe is about the
thickness Hn10T of lam
flannel. The thick pale crepe would
pass for tripe in any company with
Its lemon tinting and half inch thick
ness. A chemical, usually acetic acid
IS used TO hasten coagulation and the
heavier mass. after straining and
mixing the acid, is milled and pressed
into one or the other of the crepe
forms. After a brief drying it is
ready to be baled and shipped off to
the myriad factories waiting to turn
1t INTO tires, tubes, bathing caps,
erasers, rubber bands, balloons and
thousand and one other things.
French explorers of early DAYS made
special studies of rubber. Neverthe-
less 1t was regarded main'- as a
curiosity for a long time. Native
products come from the colonies in
South America and haphaZard expert
ment went on in several Latin coun-
tries. 1t was in England, however,
that the first success at manufac-
ture was won, and an Interesting
page In nature economic history writ
ten.
After failure of a patent in 1771
for waterproofing cloth with a thin
layer of melted rubber, and the col
lapse for want of proper machinery
OF an attempt to weave strips of rub
Der, Charles Macintosh of Glasgow
IN 1928 obtained patent and started
making cloth with rubber between
two layers of fabric. He gave his
name to this type of material and so
1t is known today. About the same
time Thomas Hancock was expert
menting and making successfully ar
tlcies using the elasticity of rubber
Vulcanizing Discovered by Accident.
; Early attempts to manufacture rub
ber in the United States were made
during the first 40 years of the nine
teenth century. They were not very
successful, although Nathaniel Hay
ward, experimenting with the rubber
stock in a Weburn, Mass, factory that
had failed, worked out a process of
mixing rubber with sulphur and treat
ing it with acid gas fumes. Charles
Goodyear of Connecticut, had previ-
ously figured out a similar method
but neither were entirely satisfactory.
Goodyear purchased the Hayward
rights and set about to devote his
fortune and his life to tanning rubber
1t is told that he had made a mixture
of rubber with sulphur and was dis
cussing it with friends one cold night
in the kitchen. A piece of rubber in
his hand hit the red hot door of the
kitchen stove. 1t stuck to the stove
and hardened without melting. Good
year excitedly got knife, scraped the
lump from the stove and washed it.
He had discovered vulcanized rubber
and forged the link that connected
rubber with the thousands of uses it
has today.