394 EXPERIMENTS ON GUAIACUM. 



sively ; or if a Ifirse quantity be employed to form the solution ; 

 the product obtained by evaporation is then of a very diffei'enf 

 nature ; for it haslost all the characteristic properties of a resin, 

 having become equally soluble in water and alcohol; the solu- 

 tion of it in tliis state having an astringent bitter taste.* 

 Alkalis and 7. Guaiacum is copiously soluble in the pure and carbon- 



nates rlissolve ^ aikaiis, tormmg gveenisli-brown liquids, 

 guaiacum: Two ounces of a saturated solution of caustic potash took 



up. rather more than 65 grains of the resin; the same quantity 

 of licjuid ammonia dissolved only 25 grains. 

 — precipitable Nitric acid forrhed in these solutions a deep brown precipi- 

 by acids. ^^^^^ j|^g shades of which varied according to the quantity of 



acid which had been employed. 



This precipitate was found on examination to possess the pro- 

 perties of that formed by nitric acid in the solution of guaiacum 

 (2. E. ) in alcohol. 



Dilute sulphuric acid, when poured into any of the above 

 alkaline solutions, formed a flesh-coloured curdy precipitate. 

 Muriatic acid produced the same effect. 



The two last-mentioned precipitates differ from guaiacum, 



in being less acted upon by sulphuric ether and more solable 



in boiling water : their properties therefore approach nearer to 



extract. Moreover, when these precipitates were dissolved in 



ammonia, and were again separated by muriatic acid, the 



above-mentioned properties became more evident. 



Products of Sect. III. — 100 grains of very pure guaiacum in powder, 



uponguaia- '^^^^^ P"^ ^"^° ^ g^^^^ retort, to which the usual apparatus was 



cuQi' adapted. The distillation was gradually performed on an open 



fire, until the bottom of the retort became red hot. 



The following products were obtained : grains. 



Acidulated water S.fi 



Thick brown oil, becoming turbid on cooling 24.5 



Thin empyreumatic oil 30.0 



Coal remaining in the retort 30.5 



INIixed gases, consisting chiefly of carbonic acid 

 and carbonate hydrogen Q,o 



99-5 



*- Vide Mr. Hatchctt's two papers on an artificial substance 

 vhich possesses the principle characterbtic properties of tannin„ 

 -EiiiJ.,Traus. 1805, p. 211, and 285.- 



The 



