ON GUTTA PERCHA 
133 
of being rolled out in long pieces or flat plates. When in 
the soft state, it possesses all the elasticity of common India 
rubber, but it does not retain these properties long ; it soon 
begins again to grow hard, and in a short time, varying 
according to the temperature and the size of the piece ope- 
rated on, regains its original hardness and rigidity. A ball 
1 inch in diameter was completely softened by boiling water 
in 10 minutes, and regained its hardness completely in less 
than half an hour. It appears to be capable of undergoing 
this alternate softening and hardening any number of times 
without change of property. 
It is also to a certain extent ductile. When soft it is 
easily torn across, but when hard it is very tenacious. A 
piece not an eighth of an inch in thickness, when cold, 
easily raised a weight of 42 lbs., and only broke when half 
a hundred weight was attached to it. 
From these properties, it seems capable of many appli- 
cations in the arts. Its solution appears to be as well adapt- 
ed as that of common caoutchouc for making water-proof 
cloth ; and, whilst softened, it can be made into solid arti- 
cles, such as knife-handles, door-handles, &c. Malays em- 
ploy it for the former of these, and prefer it to wood. A 
surgeon furnished with a small piece, could easily, with the 
aid of a little hot water, supply himself with bougies or 
pessaries of any size or form. — Chem. Gaz. from Edin- 
burgh Philosophical Journal. 
12* 
