Note:  Do not rely on this information. It is very old.

Ebonite

Ebonite is formed by the incorporation of sulphur with twice its weight of caoutchouc by means of heat and pressure. As it is hard and takes a high polish it is much used for manufacture of combs, buttons, and other articles, and owing to the fact that it is easily electrified, and a poor conductor of electricity, it is also largely used in the manufacture of electrical apparatus.