go 
Mr. Brande’s chemical Experiments 
§n. 
i. When pulverised guaiacum is digested in a moderate 
heat with distilled water, an opaque solution is formed, which 
becomes clear on passing the whole through a filter. 
The filtrated liquor is of a greenish-brown colour ; it has a 
peculiar smell, and a sweetish taste. 
It leaves on evaporation a brown substance, which is soluble 
in alcohol, nearly soluble in boiling water, and very little 
acted upon by sulphuric ether. 
This solution was examined by the following re-agents. 
Muriate of alumina occasioned a brown insoluble precipi- 
tate after some hours had elapsed. 
Muriate of tin formed a brown flaky precipitate under the 
same circumstances. 
Nitrate of silver gave a copious brown precipitate. 
Suspecting the presence of lime in the solution, I added a 
few drops of oxalate of ammonia, when the liquid imme- 
diately became turbid, and deposited brown flakes, which, 
after having been treated with boiling alcohol, yielded traces 
of oxalate of lime. 
These effects, therefore, indicate the presence of a sub- 
stance in guaiacum, which possesses the properties of extract;* 
the action of the reagent is however somewhat modified, by 
a small quantity of lime which is also in solution. 
One hundred grains of guaiacum yielded about nine grains 
of this impure extractive matter. 
* By the term extract, I mean that substance, which by chemists is called the 
Extractive Principle of Vegetables. Vide Thomson’s Syst. of Chemistv, 2d edit. 
Vol. IV. p. 2-/6. 
