So far the chemical nature of the liquid globules of the latex is unknown, and the exact character of the change into solid caoutchouc remains to be determined.
Denham (Colombo, 1906); Yves Henry, Le Caoutchouc dans t' Afrique occidentale frarKaise (Paris, 1906); E.
In connexion with the production of rubber the most important factor is the proportion of caoutchouc it contains.
The technical value of caoutchouc chiefly depends on the extent to which it is capable of being stretched without breaking, and the extent to which it at once returns to its original dimensions.
The existence of caoutchouc or rubber was first observed soon after the discovery of America.
A dimethyl ether of inactive inosite is dambonite which occurs in caoutchouc from Gabon.
It was not until the middle of the 18th century that the trees which yielded caoutchouc were identified, chiefly by French observers.
When the vulcanization of rubber is carried too far, from the presence of a very large proportion of sulphur and an unduly long action of heat, the caoutchouc becomes hard, horn-like, and often black.
The trees and plants whose latices furnish caoutchouc in considerable quantity chiefly belong to the natural orders Euphorbiaceae, Urticaceae, Apocynaceae, Asclepiadaceae.
The properties of caoutchouc clearly show, however, that its actual molecular structure is considerably more complex than is represented by the empirical formula, and that it is to be regarded as the polymer of a terpene or similar hydrocarbon and composed of a cluster of at least ten or twenty molecules of the formula C5H8.