Ebonite
MOULDABLE HARD RUBBER COMPOUND
Hard rubber; Vulcanite (rubber); Vulcanite (hard rubber)
Hard vulcanized India rubber, black in color. Specific resistance in
ohms per cubic centimeter at 46º C. (115º F.): 34E15
(Ayrton); specific
inductive capacity, (air = 1): 2.56 (Wüllner); 2.76 (Schiller);
3.15
(Boltzmann). It is used in electrical apparatus for supporting members
such as pillars, and is an excellent material for frictional generation
of potential. Its black color gives it its name, and is sometimes made a
point of distinction from Vulcanite, q. v.