Synonym. - Caoutchouc. The prepared milk-juice of various species of Hevea (nat. ord. Euphorbiaceae), known in commerce as Para Rubber.

Habitat

In tropical countries.

Characters

In cakes, balls, or hollow, bottle-shaped pieces, externally brown to brownish-black, internally brownish or of lighter tint; very elastic.

Solubility

Insoluble in water, diluted acids, or diluted solutions of alkalies; soluble in Chloroform, Carbon Disulphide, Oil of Turpentine, Benzin, and Benzol. When heated to about 257o F.; 125o C, it melts, remaining soft and adhesive after cooling. Odor faint, peculiar; nearly tasteless.

Composition

1) A solid Hydrocarbon, C20H32. (2) Fat. (3) Volatile oil. (4) Coloring matters. On combining it with 10 per cent. of Sulphur, Vulcanized Rubber is obtained; with 50 per cent., and hardening by pressure Vulcanite or Ebonite is produced.

Uses of India-Rubber.

India-rubber is used for making plasters, bougies, pessaries, and syringes.