382 GUTTA PERCH A. 



name for any gummy exudation, and is likewise applied 

 by them to' the Dammar and Gambier. The tree (Ico- 

 sandra gutta perchd) belongs to the Natural Order 

 Sapotacea, and has lately been described by Sir W. J. 

 Hooker. It is a large, high tree, with a dense crown of 

 rather small dark green leaves, and a round smooth 

 trunk. On incising the bark with a chopping-knife, a 

 quantity of rather thin white milky fluid exudes, which 

 gradually hardens on coming in contact with the air, in 

 which state it is the Gutta Percha of commerce. A West 

 Indian tree belonging to the same tribe, Achras Sapota, 

 abounds in a thick white tenacious milk, which might 

 possibly be applied to similar purposes ; and another Sapo- 

 taceous plant, the Bosnia longifolia, also yields a milky 

 sap, which is used on the continent of India in rheumatic 

 affections. The sap of Icosandra is not viscid and tena- 

 cious like that of the Ficus elastica, which is common in 

 Borneo, and of the other trees which yield a similar sub- 

 stance, as the Urceola elastica, which grows at Penan g, 

 and affords an excellent kind of caoutchouc, and that 

 other climbing plant, Willowgkbeia edulis, which is found 

 in the same island, but produces a very indifferent sort. 

 The advantage the Gutta Percha seems to have over the 

 other descriptions of caoutchouc, appears to consist in its 

 great tenacity, and in its retaining its form and solidity, 

 even in the tropics ; but on the other hand, it wants 

 elasticity. It is easily moulded into any form, by 

 steeping it in hot water, and forms very good catheters, 

 bougies, soles of shoes, riding- whips, gas pipes, ornaments 

 for picture-frames, &c. Several other plants yield sap 

 with similar useful properties, as the Hevea Guianensis, 



