In his Latin sentences he found the parts fit into each other like
dovetailing; finding the terms of equations, he said, was like
inventing machines, and he soon grew clever at solving them. It
was not from his manual abilities alone that his father had given him
the name of GuttaPercha Willie, but from the fact that his mind, once
warmed to interest, could accommodate itself to the peculiarities of
any science, just as the guttapercha which is used for taking a
mould fits itself to the outs and ins of any figure.
- from Gutta-Percha Willie by George MacDonald
In my office, I have a desk that was made by my
great-great-grandfather. I've had it since I was a kid. Clearly, my
parents have no respect for antique furniture. The desk is
unremarkable, except for the drawer pulls. There are eight of them,
all alike, seemingly carved in an intricate pattern of leaves and
berries. People who see the desk usually ask me if my
great-great-grandfather carved all those drawer pulls. The answer, of
course, is no. He didn't. They look like wood, but upon closer
inspection they reveal themselves to have been stained
or painted to give them that appearance. Furthermore, a trained eye can see that they've been cast in some sort of mold. They're gutta percha!
What is it?
Gutta percha, also known as Gutta-percha, gutta-taban, gutta-percha
depurata, and gummi-plasticum, is a rubbery substance made from the
latex-bearing sap of Palaquium Gutta or Isonandra Gutta trees. The trees are
native to the Malayan archipelago, especially Singapore, and the
name "Gutta percha" is generally agreed to have come from
the Malay words "getah" (sap) and "perca" (strip of cloth).
Gutta Percha was one of the first natural plastics to be exploited
by man. Chemically, it is the same as that other tree extract -
rubber - but the shape of the molecule gives it different properties.
It is usually dark brown in color. It softens in warm water, can be molded into whatever shape you like, and is hard but not brittle when it cools. It has a tendency to deteriorate in direct sunlight.
Uses
Gutta percha is a good electrical insulator. It's also waterproof.
The fact that it deteriorates in sunlight doesn't matter when it's
underwater. So one of the the first uses of gutta percha was as a
sheathing for transatlantic telegraph cables. By the end of the
nineteenth century, over 250,000 miles of gutta-percha-insulated
telegraph cable was in use. This application continued for 100 years,
until polyethylene replaced gutta percha as the insulator of
choice.
It wasn't long before people began to find other uses for gutta
percha. By 1850, it was being used for so many purposes that
cartoonists regularly made fun of its ubiquity. Jewelry and
golf balls were two particularly popular applications.
These days it's mostly used by dentists to make temporary
fillings. The name Gutta Percha is often used to describe any dark
coloured Victorian molding material, from horn to shellac and
Bois Durci to genuine gutta percha. So if you find something in an
antique shop that's labelled gutta percha, it may actually be
something else.
How is it made?
Latex, collected by felling or girdling the tree, is allowed to
coagulate. It is then put into a pot of warm water and kneaded to
remove particles of wood and bark. This process is repeated several
times, and then the mass is molded into bricks for shipping.
Aggressive harvest of gutta percha has made the trees almost
extinct. Efforts are underway to breed the tree in China, where
it is valued for its medicinal
uses.
Sources:
collections.ic.gc.ca
education.yahoo.com
english.peopledaily.com.cn
www.bartleby.com
www.cwhistory.com
www.mcg.edu
www.johannesen.com
www.plastics-museum.com
www.quinion.com
www.webcom.com/oldgolf