Monday, October 30, 2017

Natural Rubber -- An Ancient Resource

Centuries upon centuries before the invention of artificial rubber, ancient peoples in Mesoamerica learned how to make natural rubber using plants. While not the first to make rubber, as far as has been found, among these peoples was the ancient Maya, who used it in several ways.

The Tree They Used
So far, it looks like the ancient Maya, and the peoples in Mesoamerica generally, looked to Castilla elastica. You may also see it called other scientific names -- including C. lactiflua, Ficus gummifera, C. gummifera, and Castilla panamensis. However, a common name for it is the rubber tree.

The rubber tree grows around 33 or 65 to 100 or 164 feet tall, has gray-brown bark, flowers as well as fruits, and has very long leaves (around 8 to 18 inches long!) When the tree's trunk gets cut, a lot of white latex -- a kind of sap -- comes out, and it is this latex that is one of the most important ingredients for ancient Maya and Mesoamerican rubber.

Making Rubber
You make rubber tree latex solid just by cooking it down like you do for stew -- but that doesn't make very good rubber. So how did the ancient Maya make bouncy and strong rubber? They (and the peoples in Mesoamerica generally) may have made rubber by mixing juice from the vines of tropical white morning glories (Ipomoea alba.) The juice has sulfur in it, which affects how the latex's molecules are connected to each other.

One way the ancient Maya used their rubber was to make balls for the ballgame. The rubber balls the players used were as heavy as 6 to 10 pounds! (It's also understood there were lighter ones too. These balls had hollow interiors -- made by placing a skull in the middle.)

Vase from 600 AD to 900 AD that shows a ball game.
From this page on the Los Angeles
 County Museum of Art's site. 

But it wasn't just balls for the ballgame that the ancient Maya made rubber. They also burned it in incense burners/incensarios; and they burned it with copal, or copal and chicle tree latex too. They burned these substances as part of their religious rituals.

An incense burner made of ceramic.
It came from Guatemala and dates to the
400s AD to 500s AD. From the Metropolitan Museum of Art.

"The Ancient Maya of Mexico: Reinterpreting the Past of the Northern Maya Lowlands"; Geoffrey E. Braswell; 2012

"Encyclopedia of the Ancient Maya"; Walter R.T. Witschey (editor); 2016

Trails of El Pilar: Rubber Tree

"Chicle: The Chewing Gum of the Americas, from the Ancient Maya to William Wrigley"; Jennifer P. Mathews, Gillian P. Schultz; 2009

Swarthmore College: ENVS 02 Human Nature, Technology, and the Environment: "Advancements in Rubber Processing"; Michael J. Pieropan; February 28, 2006

The Free Dictionary: Vulcanize

"Encyclopedia Book of the Year 2011"; Encyclopedia Britannica Inc.; 2011

Michigan State University College of Social Science Department of Anthropology: Rise of Civilization:  Mayan Ball Game

USDA Plants Profile: Tropical White Morning-Glory

Smithsonian Tropical Research Institute: Flora Barro Colorado Island: Castilla Elastica

"The Forest of the Lacandon Maya: An Ethnobotanical Guide"; Suzanne Cook; 2016

The Metropolitan Museum of Art: Seated Figure (Incensario)

No comments:

Post a Comment