THE URCEOLA ELASTICA. 373 



Nitric acid reduced it in twelve hours to a foft, 

 yellow, unelaftic mafs, while the acid is rendered vel 

 low ; at the end of two days, the caout-chouc had ac- 

 quired fome degree of friability and hardnefs. The 

 fame experiment made on American caout-chouc was 

 attended with fimilar effects. Muriatic acid had no 

 effect: on it. 



Sulphuric aether only foftened it, and rendered the 

 different minute portions it was cut into eafily united, 

 and without any ieeming diminution of elafticity. 



Nitric aether I did not find a better menftrimm 

 than the vitriolic, confequently, if the aether I em- 

 ployed was pure, of which I have fome doubt, this 

 fubftance mull differ effentially from that oi America > 

 which Berxiard reports to be ioluble in nitric 

 aether. 



Where this fubftance can be had in a fluid ftate, 

 there is no neceility for diilblving or foftening it, to 

 render it applicable to the various uies for which it 

 may be required ; but where the dry caout-chouc is 

 only procurable, iulphuric aether promifes to be an 

 ufeful medium, by which it may be rendered fo foft 

 as to be readily formed into a variety of fhapes. 



Like American caout-chouc, it is foluble in the ef- 

 fential oil of turpentine, and I find it equally fo in 

 Cajeput oil, an effential oil, faid to be obtained from 

 the leaves of Melaleuca Leucadendron. Both folutions 

 appear perfect, thick, and very glutinous. Spirits of 

 wine, added to the folution in Cajeput oil, foon 

 united with the oil, and left the caout-chouc floating 

 on the mixture in a foft femi-fluid ftate, which, on 

 being warned in the fame liquor, and expofed to the 

 air, became as firm as before it was diflblved, and 

 retained its elaftic powers perfectly, while in the in- 

 termediate ftates between femi-fluid and firm, it could 



L 3 be 



