Sulphur when warmed with caoutchouc combines with it, and on this fact the vulcanization of rubber depends, and also the production, with an excess of sulphur, of the hard black material known as vulcanite or ebonite.
Rubber hardened by over-vulcanization is largely manufactured under the name of ebonite or vulcanite.
A kind of vulcanite which contains a large proportion of vermilion or other mineral pigment is used, under the name of dental rubber, for making artificial gums and supports for artificial teeth.
House industry is still widely diffused in Milan itself, especially as regards working in gold, silver, vulcanite, bronze and leather.