88 dictio:n^aey of popular names caoutchouc 



Mexico, Mcaragua, New Grenada, Bolivia, and other coimtries 

 of Central America. In some of these countries the elastic 

 juice is obtained by tapping ; in others the trees are cut down, 

 and rings are made in the stems at certain distances by cutting 

 out a few inches of the bark ; the trunk is then raised to a certain 

 angle, and vessels are placed under each ring into which the milk 

 flows ; it soon thickens by exposure to the air, but it is hastened 

 by adding the juice of the Convolvulaceous plant IpomcBa lona- 

 nox, and instead of being put into moulds like the Para rubber, 

 it is made into sheets and hung up to dry, when it is called 

 Sheet-rubber. 



3. Ceara, or Scrap - rubber of commerce, is the produce 

 of Mamhot Glaziomi, a thick-stemmed, low tree, with thick, 

 short branches, and palmately-divided leaves, belonging to the 

 Euphorbiaceae. It is a native of Ceara, a province of ISToith 

 Brazil; about 1000 tons of this rubber are exported annually. 



4. Borneo Eubber is the produce of a species of WilhtgJibeia, 

 formerly described as Urceola elastica, a large climber of the 

 Dogbane family (Apocynaceos), native of the islands of the Malay 

 Archipelago ; although a climber, the main stem becomes as 

 thick as a man's body, and yields a large quantity of milky sap, 

 charged with Caoutchouc. 



5. East Indian is the produce of Ficus elastica, a middle-sized 

 tree of the Mulberry family (Moracese), native of India, and 

 plentiful in Assam ; it is a much-branched tree, with large shining 

 elliptical leaves ; it produces a quantity of Caoutchouc, which, 

 however, is not so valuable as the American. In greenhouses in 

 this country the plant is well known by the name of India-rubber 

 Tree, and its leaves are greatly valued for skeletonising. 



6. African. In East and West tropical Africa Caoutchouc 

 is produced by several species of Landol^phia, a genus of the 

 Dogbane family (Apocynacese). Z. Owariensis is a large creepei, 

 with a stem 4 to 5 inches in diameter, which divides into 

 branches ; it has large snow-white, sweet-smelling flowers ; the 

 fruit is the size of an orange, with a hard sheU, containing a 

 sweet, rather acidulous pulp, which is eaten by the natives. 



