substances found in Guiana. 237 



its essential oil, and is reduced almost to the state of a simple 

 resin. 



I may take this opportunity of observing, that the vapours 

 of the balsamics, as hyowa, capivi, and laurel oil, may have 

 soothing effects, and a healing tendency, after or along with 

 those of the mineral ones, as of mercury, arsenic, &c. especi- 

 ally if a gentle degree of heat, as that of boiling water, be used 

 to elicit them, producing no decomposition of the essential oils, 

 which must ensue with heated stoves or irons, and which must 

 also occur in the process of boiling tar, as it requires a much 

 greater degree of heat. 



It is reasonable to suppose that these volatile oils, in a state 

 of vapour, conjoined with that of hot water, must excite some 

 sensible action on ulcerated surfaces. The volatile oil itself 

 will thus be actually applied to the diseased part. iU 



It will probably be less offensive or irritating to the tender 

 organs, than the fuliginous matter and carbu retted hydrogen, 

 evolved from tar, and the like resinous substances, in a state 

 of combustion, — as in this case the volatile oils will be separated, 

 and rise along with the watery vapour ; and it is certain, as 

 asserted by Mr Brande in his Elements of Pharmacy, that 

 the active principle of balsam capivi resides in its volatile oil. 



The three substances just cited, viz. hyowa, capivi, and 

 laurel oil are well proved to possess balsamic or healing pro- 

 perties in an eminent degree ; they are capable of direct appli- 

 cation to the lungs in a state of vapour undecomposed ; and, 

 therefore, we are encouraged to expect some benefit from them 

 as topical applications, used in conjunction with general con- 

 stitutional alteratives.* 



In its recent state it is an excellent balsamic in ulcerous dis- 

 orders of the bladder and urinary organs, and especially if 

 made use of in very liberal doses. 



Arakusiri. 



This is another species still more fragrant but less abundant. 

 It is known amongst the Arowaks by the name of Ara-ku-siri. 



* For a mercurial fumigation, calomel seems, from trials, the best pre- 

 paration J but, for external sores, I should, from trials made with different 

 forms of the mineral, be inclined to ^ive the preference to corrosive sub- 

 limate- 



