or Elq/Iic BltuiTien cf I^trhjifhire. 23 1 



rare is obfcure caout-chouc, but tranfparent in the light, in- 

 clofed in crvllalllzed fluor." Foffil caout-chouc, according' 

 to Mr. Mawe, is found alfo in fulphated baryies. 



If it be confidered that trees and other vegetables, which 

 produce natural caout-chouc in fuch abundance that the 

 matter can flow down and accumulate at the root of them 

 when the wind or any other accident lacerates the bark or 

 breaks the branches, are all exotic, it will be allowed that this 

 is a curious geological facl, which coincides with that of foflil 

 amber, which has been found, and is flill found, in fome coal 

 mines, and in turf foil of an antique origin, and which difl'ers 

 from that formed in the common airf molles. We are not 

 yet acquainted with anv vegetable produttions which furnifh 

 caout-chouc in abundance, but the following : 



ift, The vahea, a fpecies of apocinea, which grows in Ma^ 

 dacafcar, and of which Lamarc has given a tigure in his //-• 

 lujirations de Bolanique. 



ad, The urccola elajlica of Sumatra and of Pullo-Pinang, 



difcovered by Mr. Howifon, an Englifli furgeon at Fullo-Pi- 



nang, and defcribed in the fifth volume of the Ajlatic Re- 



Jearches by Dr. Roxburgh *. This plant is of the family of 



the apocineae. 



3d, The hevea Guianenjis, defcribed and exhibited in a 

 figure by Aublet in his Vhmtes de la Guiane, is a large tree 

 of the family of the euphorbia. It rifes to the height of 

 more than forty feet; its trunk is fometimes above two feet 

 in diameter; and the natives of Para make bottles, boots, and 

 other articles of the caout-chouc which diftils from it. It is 

 the fame as that mentioned bv M. de la Condamine in the 

 Memoirsof the Academy of Sciences for 1736, which grows 

 alfo in the province of Efmeralda, in Peru, which the Maina 

 Indians call caout-chouc, and of which they make bottles by 

 means of earthen moulds : they nfe it alfo for torches to give 

 them light. 



4th, The artocarpus integrifolia of South America, a tree 

 which approaches near to the mulberry and fig-tree. 



5th, The ficus rel'igiofa. 



6th, The ficus Indica. 



7th, The bippomane h'lglanduhfa (manchineal tree). 



8th, The cecropia peltata: the two laft among the eu- 

 phorbia produce alfo a milky juice analogous to the caout- 

 chouc. 



* See rhilofophical Magazine, vol. vi. 



0^4 XLI. Age- 



