Gutta-percha

The inspissated, milky juice of various trees of the Sapodilla family native to the Malaysian peninsula. It is a tough, pliable, moldable rubber-like material, although it lacks the elasticity of rubber and becomes brittle on exposure to air and sunlight. Gutta-percha vulcanizes with sulfur into a hard, waterproof material. From the late 1840s, it was widely used for golf balls, imitation leather, joints in doll limbs, electrical insulation (especially underwater cables), and dental fillings. The name gutta-percha was sometimes used for any dark-colored molding material. It sets faster than "caoutchouc," which must be heated far longer.