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This week's LabZone activity
April 5, 2006
Test a Dandelion for Latex
Latex is the plant sap that is used to produce natural rubber. Many plants contain latex. The common dandelion is one that's easy to examine.
You'll Need
- Bunch of dandelions
- Saucer
- Other plants for testing, such as milkweed, sagebrush, garden weeds
Break a dandelion stem in half and notice a milky white liquid slowly emerge. Squeeze drops of it onto the saucer, and see how much natural latex you can collect. Wait a few minutes for the water portion of the milky sap to evaporate, leaving only the latex. Scrape the latex off the saucer with your fingernail and roll it into a ball with your fingertips.
It's difficult to get much latex from dandelions, isn't it? Thomas Edison considered dandelions as a rubber source, and his friend Henry Ford researched using the plant as a source of latex to make rubber. Ford's experiments produced high-quality rubber from dandelions, but it was too difficult to grow them in large enough quantities to make much rubber.
What about other latex-producing plants? There are more than 400, including milkweed and sagebrush. Test some plants you find in your yard and see what you find. Researchers are still looking for the elusive new source for natural rubber.
Reprinted with permission from Thomas Edison for Kids: His Life and Ideas, 21 Activities by Laurie Carlson. Published by Chicago Review Press, distributed by Independent Publishers Group (www.ipgbook.com). Copyright © 2006 by Laurie Carlson.
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