KUPATORIUai PERFOLIATUM. 45 



It is scarcely necessary to remark, that the 

 virtues of the eupatoriiim are extracted in a 

 considerable degree by means of the cold wa- 

 tery infusion. From what has been stated, it 

 will be recollected, that the infusion of the 

 root of this plant, like the decoction made of 

 the same part, afforded the darkest colour ; 

 and that while the decoction of the flowers 

 was darker than that made with the leaves, 

 that the infusion of the leaves w^as considera- 

 bly deeper than that prepared from the flowers. 



Experiment the eleventh was instituted for 

 the purpose of ascertaining how far its active 

 properties were imparted to the cold infusion. 

 The same re-agents as were employed with the 

 decoction were tried with the infusion of the 

 flowers. The results were nearly similar ; the 

 presence of an acid, of tannin, and of extrac- 

 tive matter was proved, though the astringent 

 principle was not so abundant. Experiments 

 twelfth and thirteenth fully evince that in the 

 leaves reside the most active properties of the 

 plant ; the dark green precipitation caused by 

 7 



