48 DISSERTATION ON THE 



The twenty-first, twenty-second, and twenty- 

 third experiments prove, that pure alcohol 

 extracts all the active principles which exist 

 in the decoction and infusion ; and in addition, 

 also a resinous matter. It will be perceived, 

 that alcohol takes up tannin from the leaves, 

 and that this constituent of the plant is not 

 extracted from the other parts by this men- 

 struum. Experiment the twenty-fourth proves 

 that the acid is not volatilized in the tempera- 

 ture of boiling alcohol. From experiment the 

 twenty-fifth, we have the resin more pure than 

 heretofore, and, comparatively speaking, in 

 liberal quantity. A portion of the resinous 

 matter was dissolved in warm water, and was 

 easily precipitated upon cooling. From the 

 last experiment we learn, that in the distilla- 

 tion of the plant with pure alcohol, the free 

 acid only is extracted. 



From the experiments which were institu- 

 ted, and the results which I have attempted 

 to deduce from them, it seems to be satisfac- 

 torily proved, that the eupatorium perfoliatum 



