substances found in Guiana. 243 



We find, moreover, a number of different lactiferous trees 

 in Guiana, some of which, as the Haia-haia and Ducali pour it 

 out in great abundance at certain seasons. They also contain 

 a portion of elastic gum ; but too much modified with other 

 substances to be used as such, unless means could be found of 

 separating it. 



Balsamo Real, or Royal Balsam, 



This is produced by a species of Amyris. In scent it is 

 very like our hyowa, but more balsamic or glutinous ; the 

 hyowa soon becoming dry and brittle. I believe this sub- 

 stance to be in no respect inferior to the true balsam of Ona- 

 ica, or the produce of the Amyris gileadensis. 



This I know to be a valuable article as a vulnerary, and a 

 pectoral remedy ; and it is considered, I believe, with justice, 

 to be one of the best balsamics in cases of inward ulceration. 

 It forms also an excellent detergent and healing ointment for 

 old ulcers, prepared after the manner of the Ung. Elemi, with 

 the addition of a little calamine stone. 



The dose is about a drachm, once or twice a-day, beat up 

 with yolk of egg, or new milk and sugar. 



Vesicamo^ 



I may here allude in a cursory manner to a new resinous 

 substance with which I am very little acquainted. It is an 

 exudation of a deep sea-green colour, strongly adhesive, and 

 about the spissitude of crude or Venice turpentine. 



It is procured, by incision, from an unknown tree growing 

 up the rivers Barima and Amakuru. The Indians say the 

 tree is very much like the Bisi or Bishi, of which they chiefly 

 form their canoes and corials, a wood also resembling cedar. 



A small quantity of this resin was procured by Mr James 

 Fraser, on a journey to the Orinoko. Having brought a sam- 

 ple with me to London, I have recently committed it for ex- 

 amination to a gentleman of the highest chemical talents. 

 Professor Brande. 



It is not one of the aromatic resins, or has only a peculiar 

 odour, much fainter than most of those whose resin is modifi- 

 ed by an essential oil. 



