On the Vine vktci afferis Cao^ut-chtuc , tr India rubber^ ^j^ 



III. 



A Botanical Drfcnption of Urceola Elqftica, or Caout-chouc J'inr of Sumatra and Ptillo 

 Pinanf ; with an account of the properties of its infpiffaied Juice, co?npared with thqfe 

 of the Amtrican Caout-chouc, By Wiiaaam RoxByRGH, M. p.^ 



JC OR the difcovery of this ufeful vine, we are, I believe, mdebtecl to Mr. Ilozvi/on^ 

 late Surgeon at Pullo-piiiang ; but it would appear he had no opportunity of determining 

 its botanical charafter. To Doftor Charles Ca?npbell of Fort Marlborough, we owe 

 the gratification arifing from a knowledge thereof.- 



About twelve months ago I 'received: from that gentleman, by means of Mr. Fleming, 

 very complete fpecimens, in full foliage, flower, and fruit. From thefe I was enabled 

 to reduce it to its cfafs and order in the Linnazan Syftcm. It forms a new genus in the 

 elafs Pentandria, and order Monogynia, and comes in immediately after Tabcniasmon- 

 tana, confequently belongs to the thirtieth natural order, or clafs called Contortae by 

 Linneeus in his natural method of clafTification or arrangement. One of the qualities 

 of the plants of this order is, their yielding, on being cut, a juice which is generally 

 milky, and for the moll part deemed of a poifonous nature. 



The generic name, Urceola, which I have given to this plant, is from the ffrufture of 

 the corol, and the fpecific' name from the quality of its thickened juice. So far as I 

 can find, it does not appear that ever this vine has been taken notice of by any Europeaa 

 till now. I have carefully looked over the Hortus Malabaricus, Rump/iius's Herbarium 

 Amboinenfe, &c. &c. Figures of Indian plants, without being able to find any one that 

 can with any degree of certainty be referred to, A fubftance of the fame nature, and 

 probably the very fame, was difcovered in the ifland of Mauritius, by M. Poivre, and 

 from thence fent to France ; but, fo far as I know, we are Hill ignorant of the plant 

 that yields it. 



The impropriety of givmg to Caout-chouc the term gum, rcfin, or gum-refin, every 

 one feeras fenfible of, as it poffefTes qualities totally different from all fuch fubflances a* 

 are ufually arranged under thofe generic names : yet it flill continues, bymoft authors 1 

 have met with, to be denominated elaflic refin, or elaftic gum. Some term it fimply 

 Caout-chouc, which I wilh may be confidered as the generic name of all fuch concrete 

 vegetable juices (mentioned in this memoir) as pofTefs elafticity, inflammability, and are 

 foluble in the effential oils, without the afliftance of heat. 



In a mere definition, it would be improper to flatewhat qualities the objefl does not 



* Afiaiic Refearckcs, vol. v. 167^ 



pofTefs ;: 



