Caoutchouc

{koo’-chuk) [S.American]. India-rubber. The chief substance contained in the milky juice that exudes upon incision of a number of tropic trees belonging to the natural orders Euphorbiacece, Artocarpacece, and Apocynacece. The juice is a vegetable emulsion, the caoutchouc being suspended in it in the form of minute transparent globules. white, soft, “When elastic,pure, and caoutchouc glutinous; is it nearly swells up in water without di olving; the best solvents are carbon disulphid and chloroform. It melts at about 1500 C, and decomposes at 2000 C. 172