EXPERIMENTS ON GUAIACUM. 3.9^ 



action of the reagent is however somewhat modified, by a small 

 quantity of lime which is also in solution. ^. 



One hundred grains of guaiac urn yielded about nine grains • 

 of this impure extractive matter. 



2. Alcohol dissolves guaiacum with facility, leavin«; some Alcholic soIa« 



, . , ,, , „ t on 'if gnaia- 



extraneous matter, which generally amounts to about 5 per cum considera- 

 cent. ^^y perfect. 



This solution is of a deep brown colour ; the addition of 

 u'ater separates the r<?sin, forming a milky fluid which passes 

 the filter. 



Acids produce the following changes : 



A. Muriatic acid throws down an ash-colourfed precipitate. Changes pro- 

 , . , . , ,• , 1 T 1 • I • T 1 • duced by acids: 



which is.not re-dissolved by heatmg the mxiture. In this case 



the resin appears but little altered. 



Bi_ Liquid ox3'-muriatic acid when poured into this solu- 

 tion-, forms a precipitate of a very beautiful pale-blue colour, 

 which may be preserved unaltered. ^ 



C. Sulphuric acid, when not added in tod large a quanti- 

 ty, separates the resin of a pale green colour. 



^D. Acetic acid does not form any precipitate. This acid 

 IS indeed capable of dissolving most of the resins. 



E. Nitric acid diluted with one-fourth of its weight of water, 

 causes no precipitate till after the period of some hours. The 

 liquid at first assumes a green colour, and if water be added at 

 this period, a green precipitate may be obtained; the green 

 colour soon changes to blue, (when by the same means a blue 

 precipitate may be obtained) ; it then becomes brown, and a 

 brown precipitate spontaneously makes its appearance, the 

 properties of which will be afterwards mentioned. 



The changes of colour produced by nitric, and oxy-muriatic — very remark- 

 acids, in the alcoholic solution ; are very remarkable, and I fial^to^GuSa^'^' 

 believe pecuhar to guaiacum : there is moreover much reason cum. 

 to suppose that the above alterations in colour are occasioned 

 by oxigen * It likewise appears from that which has been 



stated, 



* The following experiments appear to verify this supposition : 



Fifty grains of freshly pulverised ijuaiacurn were introduced into 

 a glass jar containing 60 cubic inches of oxy muriatic acid gas. 

 The resin speedily assumed a brown colour, having passed through 

 several shades of green and blue. Liquid ammonia was poured on 

 this brown substance, while yet immersed in the acid; the whole 



became 



