the Urcecla Elafaca. 157 



tiiral fue; half of one of them is removed, to (Iiow the feed 

 immerfed in pulp. A portion thereof is alio cut away, which 

 more clearly fliows tlie fituation and lliape of the feed. 



From wounds made in the bark of this plant there oozes 

 a milky fluid, which, on expofurc to the open air, feparates 

 into an elallic coajiulum and watery liquid, apparently of no 

 ufe after the feparation takes place. I'his coagulum is not 

 only like the American Caout-cbouc, or Indian rubber, but 

 polleires the fame properties, as v.ill be ieen from the follow- 

 ing experiments and obfervations made on fome which had 

 been €xtra6led from the vine about live months ago. A ball 

 of it now before me, is, to my fenfe, totally voidof fmell even 

 when cut into, is very firm, nearly fpherical, meafures nine 

 and a half inches in circumference, and weighs feven ounces 

 and a quarter; its colour on the outlide is that of American 

 Caout-cbovc where frcfli cut into, of a light-brown colour, 

 till the atSlion of the air darkens it : throughout there arc 

 numerous fmall cells filled with a portion of light-brown 

 \\aterv liquid above mentioned. This ball, in fimply falling 

 from a height of fifteen feet, rebounds about ten or twelve 

 times; the firft is from five to feven feet high, the lucceeding 

 ones of courfe Iclibning by gradation. 



This fubitance is not now foiuble in the above-mentioned 

 liquid contained in its cells, although fo intimately blended 

 therewith, when firft drawn from the plant, as to render it 

 fo thin as to be readily applied to the various purpofes to 

 which it is fo well adapted when in a fluid ftate. 



From what has been faid, it will be evident that this 

 ■Cuouf-chouc pollefles a confiderable {hare of folidity and 

 elafticity in an eminent degree. I compared the laft qualitv 

 with that of American Caout-chouc, by taking fmall flips of 

 each, and extending them till ihey broke; that of Urceola 

 was found capable of bearing a much greater degree of exten- 

 fion (and contraftion) than the Amtiican: however, this may 

 be owing to the time the refpeclivc iubitances have beeir 

 drawn from their plants. 



The Urceola Caout-chouc rubs out the marks of a black-' 

 lead pencil as readily as the American, and is evidently the' 

 fubftance of which the Ciiinefe niiike their elauic rings.. 



It 



