' ' OJ the Urceala or Caout-chouc Plant. 437 



• Seeds, very numerous, reniform, immerfed in firm flefhy pulp. 



Explanation of the Figures, 



1. A branclilet in flower, natural fize. 

 2.' A flower m-ignified. 



3. The fame laid open, wliicH expofes to riew the fituation of the ftamens inferted' 

 into the bottom of the corol, the neftarium furrounding the lower half of the two germs, 

 their upper half with hair}' margins, the ftyle and ovate party-coloured ; ftigma appear- 

 ing above ihe neftary. 



4. Oiitfide of one of the ffamensT u -c j 

 ^ • \ much magnihed. 



5. Infide of the fame J 



6. The ncftarium laid open, expofmg to view the whole of the piftil. 



7. The two feed vefTels (called by Linnaus follicles}^ natural fize; half of one of 

 tliem is removed,- to fhew the feed immerfed in pulp. A portion thereof is alfo cut 

 away, which more clearly fhews the fituation and fhape of the feed. 



From wounds made in tlie bark ot this plant there oozes a milky fluid, which, on 

 cxpofureto the open air, feparates into an elaflic coagulum, and watery liquid, appa- 

 rently of no ufe, after the feparation takes place. This coagulum is not only like the 

 American caout-chouc or Indian rubber, but poffeffes the fame properties, as will be 

 feen from the following experiments and obfcrN'ations made on fome which had been ex- 

 fratied from the vine about fiv^e months ago. A ball of it now before me, is to my fenfe» 

 totally void of fmell, even when cut into, is very firm, nearly fpherical, nieafures nine 

 and a half mches in circumference, and weighs feven ounces and a ^juarter, its colouf 

 on the outfide is that of American caout-chouc, where frefh cut into of a light brown 

 colour till the aftion of the air darken it ; throughout there are numerous fmall cells,, 

 filled with a portion of light brown watery liquid above mentioned. This ball, in fimply 

 falling from a height of fifteen feet, rebounds about ten or twelve times, the firff is from 

 five to feven feet high, the fucceeding ones of courfe lefTening by gradation. 



This fubflance is not now foluble in the above mentioned liquid contained in its cells, 

 although fo intimately blended therewith when fir/l 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 caout-chouc, pofTefTes a confi- 

 derable fliare of folidity, and elafticity in an eminent degree. I compared the lafl 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 contraftion) than the American: however, this may be owing to. 

 the time therefpeftive fubftances have been drawn from their plants. 

 Vol. III. — January 1 Sec 3L The 



