CAOUTCHOUC, India rubber.
Siang-pi, . . . . CHIN. Comma elastica, IT., PORT. Gummi, . . DA., Sw. Clirit mural, . Verderhars, . DUT. Borracha, . . PORT.
Corn elastick, . „ Goma elastica, . . SP.
Gomme elastique, FR. Realm, Ule, . . „ Feder Harz ; Kauts chuk , GER.
India rubber, or caoutchouc, is a vegetable compound which is found in all plants with a milky juice, as in the moracew, euphorbiacea3, artocarpacem, apocynacem, cichoracem, papa veraceaz, campanulacem, and lobeliacem. India .rubber has long been known to the natives of the East Indies and South America. It was not, however, till the expedition of the French acade micians to S. America in 1785 that its properties .and nature were made known in Europe, by a memoir upon it by M. de la Condamine. And subsequent notices of it were sent to the French Academy in 1751 by M. Fresnau, and in 1768 by Macquer. It is used for machinery, in electric and surgical apparatus, weaving, and clothing. Great Britain Imports. British India Exports.
Cwts. Value. Cwt.. Value..
1830, 464 .., 1874, 16,837 £117,775 1840, 6,640 ... 1875, 19,893 108,618 1857, 22,000 ... 1876, 15,258 97,861 1874, 129,163 £1,326,605 1877, 13,308 90,169 1878, 149,724 1,313,209 1878, 13,794 89,381 1879, 10,033 61,683 The selling prices in London per lb. are— African, ls. 5d. ; Borneon, Is. 9d. ; S. and Cen tral America, 2s. ; and Madagascar, 2s. 3d.
The plants yielding the caoutchouc of com merce are Ficus elastica, Assam. Hancornia speciosa of Per.
Chavannesia esculenta, nambuco, in S. America.
Burma. Manihot glazionii, the Urceola, Borneo. Ceara tree of S. America.
Vahea, Madagascar. Hevea Benthamiana Mull., Landolphia, Africa. of S. America ; also Castillo°. elastica, S. Brasiliensis, discolor, America. Guyanensia, lut ea, C. Markhamiana, Collins, pauciflora, rigidifolia, S. America. apruceana.
Caoutchouc is obtained in Borneo from three trees, — manoongan, manoongan putib, and manoongan manga, from 50 to 100 feet high, and about 6 inches diameter,—seemingly three species of Willughbeia.
The American sources of the commercial supply are from the Hevea Braziliensis, H. Gwyanensis, Castilloa elastics and C. Markhamiana, and Han cornia speciosa. The African caoutchouc is got from the Vahea gummifera of Madagascar, and Landolpbia. Owariensis ; and the Asiatic plants are Ficus elastica, Urceola elastica. of Sumatra, Borneo, and Penang, Willughbeia edulis, and Chavannesia esculeuta. Other plants are named, viz. Siphonia elastica, S. calinehu, Jatropha elastica, and Melo dinus monogynus. The banyan tribe generally yields a milky juice, which, for many purposes to which caoutehouc is applied, might be rendered serviceable. So long ago as 1836, Dr. Royle re
ported fully on the Assam caoutchouc from the Ficus elastica. The Ficus elastica has been intro duced into the Tenasserim Provinces, and appears to grow as well as an indigenous plant. Caoutchouc from Ficus elastica was brought to Arakan in 1878 by clans of the Shandoo or Poor race, who receive it in barter from the Lushai. They reside north and south of the Blue Mountains. The plant is indigenous for thirty miles south of the Bite Mountains. In 1873 the Government of India formed plantations of it. It has aerial roots, and grows to a large size, above 100 feet, in the evergreen forests at the foot of the Assam hills.
Chavannesia esculenta, a troublesome creeper in the Burma forests, attains a girth of 11 inches, and its crown covers an area of 300 square feet. Its caoutehouc is similar in quality to that of the Ficus elastics, Species of Ficus produce the caoutchouc brought from Java ; and. F. radula, F. elliptica, and F. prinoidos are amongst those mentioned•as afford ing a portion of that brought from America. Next to the Moracere, the order Euphorbiaceaa yields the largest quantity of caoutchouc.
Siphonia elastica, a plant found in Gayalla, Brazil, and extending over a large district of Central America, yields the beat kinds of India rubber that are brought into the markets of Europe and America. The caoutchouc which is brought from the islands of the Indian Archipelago is from the Urceola elastica, a climbing plant of very rapid growth and gigantic dimensions. A single plant is said to yield, by tapping, from 50 to 60 lbs. annually. It is also obtained from the juices of Callophora utilis and Caineraria latifolia, plants of South America and Willughbeia edulis, in the East Indies. Caoutchouc, whilst it is in the tissues of the plant, is evidently in a fluid condition ; but after its separation from the other fluid parts, it forms a solid mass similar in its external characters to vegetable albumen. In this state it is dense and hard, but may be separated and rolled out so as to form a sheet resembling leather. Caoutchouc is employed to rub out pencil marks made on paper, and largely for waterproofing. When distilled, it yields oils which have a composition similar to oil of turpentine. In N.E. India, an India rubber tree grows to some 70 to 100 feet high. Immense forests of it are found on the west side of the Brahmaputra, extending along the Miri and Abor mountains. The rubber from this tree from some chemical property cannot bear the heat of a passage to Europe. It becomes a fluid during the voyage. Otherwise, in cold climates it is equal to other rubbers.