CHAPTEH II. 



NATIVE GUM-ELASTIC OR CAOUTCHOUC. 



The Boracca of Brazil and varieties of gum-elastic. India gum. Its solvents. Mode of 

 gathering. The Para gum. The virgin gum. Properties of the native gum. Extracts 

 from scientific works respecting caoutchouc and its varieties. Gutta Perclia. 



" This substance is now indiscriminately called gum-elastic, 

 caoutchouc, and India rubber. It is sometimes called by the 

 Brazilians, boracca ; but it is more commonly called by the In- 

 dians, seringa. The pronunciation of caoutchouc, the aboriginal 

 name, is similar to that of cahuchee." It is found in most, if not 

 all countries under and near the equator. The importation of 

 this article has in former years been chiefly from the city of 

 Para, in the province of Para, South America. Very recently the 

 trade in it has extended to the western coast of South America, 

 where it is said to be most abundant, and of the best quality. 



The sap, when it exudes from the tree, is of a milky whiteness, 

 about the consistence of honey, resembling that of the poppy 

 or milkweed of northern latitudes, which also contain a minute 

 portion of an elastic substance, very much hke India rubber. 

 It will not flow to any considerable distance from the tree, before 

 it coagulates, or separates from the whey, or liquid part of the 

 sap, and it is, therefore, drawn into clay cups attached to the 

 tree, in the manner hereafter described. 



There are three varieties of the genuine gum-elastic, among 

 which, there is a marked difference, although it is not in the 

 present stage of the manufacture, sufficient to cause any great 

 difference in the quality of the goods made from them. 



The first which I shall describe, is India gum. This has 

 heretofore been imported mostly from the islands of Borneo, 



d 



