THE URCtOLA ELASTICA. 171 



air, feparates into an elaftic coagulum, and watery- 

 liquid, apparently of no ule, after the leparation takes 

 place. This coagulum is not only like the American 

 caoat-chouc or Indian rubber, but poflelFes the fame 

 properties, as will be feen from the following experi- 

 ments and obfervations made on fome which had been 

 extracted from the vine about five months ago. A ball 

 of it now before me, is to my fenfe, totally void of 

 jfmell, even when cut into, is very firm, nearly iphe- 

 rical, meafures nine and a half inches in circumfe- 

 rence, and weighs feven ounces and a quarter, its co- 

 lour on the outiide is that of American caout-chouc^ 

 where frefh cut into of a light brown colour till the 

 adtion of the air darkens it; throughout there are nu- 

 merous fmall cells, filled with a portion of light brown 

 watery liquid above mentioned. This ball, in limply 

 falling from a height of fifteen feet, rebounds about 

 ten or twelve times, the firft is from five to feven feet 

 high, the fucceeding ones of courfe leiYcning by 

 gradation. 



This fubftance is not now foluble in the above men- 

 tioned liquid contained in its cells, although lb in- 

 timately blended therewith when firit 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 ltate. 



From what has been faid, it will be evident that 

 this caout-chouc, poflefies a confiderable fhare of foli- 

 dity and elasticity in an eminent degree. I compared 

 the laft quality, with that of American caout-chouc 

 by taking fmall flips of each, and extending them till 

 they broke ; that of Urceola, was found capable of 

 bearing a much greater degree of extenfion, (and 

 contraction) than the American : however, this may 

 be owing to the time the refpedtive fubflances have 

 been drawn from their plants. 



L2 The 



