[a. F. caoutchouc, ad. Carib cahuchu (Littré).]
1. India-rubber, or Gum Elastic; the milky resinous juice of certain trees in S. America, the E. Indies, and elsewhere, which coagulates on exposure to the air, and becomes highly elastic, and is waterproof; it is now (late 19th c.) a most important substance in arts and manufactures.
‘Introduced to France early in the last century, but its origin was unknown till the visit of the French academicians to South America in 1735. They ascertained that it was the inspissated juice of a Brazilian tree, called by the natives Hhvé; and an account of the discovery was sent to the academy by M. de la Condamine in 1736’ (Penny Cycl.). Chiefly obtained from the Brazilian Siphonia elastica (Hevea caoutchouc) N.O. Euphorbiaceæ, and E. Indian Ficus elastica. But many other tropical plants, Euphorbiaceæ, Apocynaceæ, Artocarpads, and others, yield it in considerable quantity. Chemically it is composed entirely of carbon and hydrogen, but is not a simple proximate principle, but a mixture of substances.
1775. Phil. Trans., LXVI. 258. An elastic gum bottle, otherwise called boradchio or caout-chouc. Ibid. (1779), LXIX. 384. I take the tube out of the phial, and thrust it … into a small caoutchouck, or elastic gum bottle.
1788–9. Howard, New Royal Encycl., s.v., Caoutchouc in natural history … a very, elastic resin … Very useful for erasing the strokes of black lead pencils, and is popularly called rubber, and lead-eater.
1827. Faraday, Chem. Manip., iv. 122. Cloth is rendered air-tight by caoutchouc.
1870. Emerson, Soc. & Sol., Work & Days, Wks. (Bohn), III. 65. What of this dapper caoutchouc and gutta-percha, which makes water-pipes … and rain-proof coats for all climates?
1875. J. H. Bennet, Shores Medit., I. i. 25. The secret of the luxuriant verdure [in the Euphorbia] … is the existence of a kind of caoutchu in their white acrid juices.
b. attrib. or in comb.
1833. Brewster, Nat. Magic, viii. 206. The country where the caoutchouc-tree was indigenous.
1859. Jephson, Brittany, iv. 38. Drinking a delicious draught of the sparkling water of the Gouet out of my caoutchouc cup.
1861. Du Chaillu, Equat. Afr., x. 121. The native caoutchouc collectors. Ibid., 122. The caoutchouc-vine grows equally well.
c. = ‘Waterproof’ (cloak).
1867. [Elizabeth Tuckett], in Cornh. Mag., Jan., 59. With the large hood of her caoutchouc heavy with snow.
2. Artificial Caoutchouc: a substance formed by adding to a solution of glue tungstic acid or sodium tungstate, and then hydrochloric acid; it is elastic when warm. Mineral C.: = ELATERITE, a hydrocarbon found at Castleton in Derbyshire, and elsewhere. Vulcanized C.: caoutchouc kneaded with flowers of sulphur, with which it unites and becomes black and horny: see VULCANITE.
1863–72. Watts, Dict. Chem., I. 739. Sulphured or vulcanized caoutchouc is an excellent material for tubes for conveying water or gases.
