Latex is the protective fluid contained in tissue beneath the bark of the rubber tree, Hevea brasiliensis.
The tree originated from Brazil (hence its name), and latex was originally gathered from wild trees in the jungles of Brazil in the 1870's. By 1890, Britain had introduced rubber plantations in Malaysia (with the help of Kew gardens and the Singapore Botanical Gardens) and was harvesting latex.
Natural rubber latex (NRL) is a cloudy white liquid, similar in appearance to cows milk. It is collected by cutting a thin strip of bark from the tree and allowing the latex to exude into a collecting vessel over a period of hours.
The composition of the latex is detailed in table 1
| Constituent | % Composition |
|---|---|
| Rubber particles (cis-1,4-polyisoprene) | 30-40% |
| Protein | 2-3% |
| Water | 55-65% |
| Sterol glycosides | 0.1-0.5% |
| Resins | 1.5-3.5% |
| Ash | 0.5-1.0% |
| Sugars | 1.0-2.0% |
Initially, the rubber had to be solidified within 24 hours to stop
bacterial spoilage Footnote: This solidified rubber is also known as crepe.