the Urceola ElajUca. 139 



fentially from that of America, which Berniard reports to be 

 foluble in nitric aether. 



Where this fubftance can be had in a fiuid ftatc, there is 

 no neceflity for difTolving or foftening it, to render it appli- 

 cable to the various ufes for which it may be required ; but 

 where the dry Caout-chouc is only procurable, fulphuric 

 sther promifes to be an ufeful medium, by which it may 

 be rendered fo foft as to be readily formed into a variety of 

 {hapes. 



Like American Caout-chouc, it is foluble in the eflentini 

 oil of turpentine ; and I find it equally fo in Cajeput oil, an 

 eflential oil, faid to be obtained from the leaves oi Melaleuca 

 Leucadcndron. Both folutions appear perfcft, thick, and very- 

 glutinous. Spirits of wine, added to the folution in Cajeput 

 oil, foon united with the oil, and left the Caout-chouc float- 

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

 wafhed in the fame liquor, and expofed to the air, became ai 

 firm as before it was diflblved, and retained its elaillc powers 

 perfeftly, while in the intermediate ftatesj between femi-fluid 

 and firm, it could be drawn out into long tranfparent threads, 

 refembhng, in the polifli of their furface, the fibres of the 

 tendons of animals ; when they broke, the elafliclty was fo 

 great, that each end indantaneoufly returned to its refpedive 

 mafs. Through all thefe ftages, the leaft prefTure with the 

 finger and thumb united different portions as perfe6lly as if 

 they never had been feparated, and without any clamminefi 

 or ftickirig to the fingers, which renders mod of the folutions 

 of Cacut-chouc fo very unfit for the purpofcs for which they 

 are required. A piece of catgut, covered with the half-in- 

 fpiflated folution, and rolled between two fmooth furfaces, 

 foon acquired a pollfii and confidence very proper for bou- 

 gies. Cajeput oil I alfo found a good menftruum for Ame- 

 rican Caout-chouc, and was as readily feparated, by the addi- 

 tion of a little fpirit of wine or rum, as the other, and appears 

 ccjually fit for ufe, as I covered a piece of catgut with the 

 wafijed folution as perfectly as with that of Vrccohi. The 

 only difference I could obferve, was a little more adhefivc- 

 nefs, from it? not drying fo quickly ; the oil of turpentine had 

 greater atliaiLlon for the Caout-chouc than for the fpirlts of. 



8 wine, 



