"various Species of Cinchona, 



51 



Talk of the Effects produced hy the Cinchonas brought hy 

 Messrs. Humholdi and Bonpland, luith the Rc-agents 

 marked asainst them. 



In order to acquire some more light upon the nature of 

 the principles of the cinchonas, I exanained compat-ativelv 

 several other vegetable substances which seemed to have 

 analogi(;'s with them, and the composition of which is a 

 little less known ; such as gall-nuts, oak bark, the angus- 

 tura, and some others. 



• Gail-Nuts. — The infusion of this substance gave in a so- 

 lution of glue an abundant white precipitate; with iron, a 

 blue; with emetic, a yellowish-white precipitate; with in- 

 fusion of yellow cinchona, diity white tlakcs ; with copper, 

 yeliovvish-brown; and wilh lead, a yellowisli-white precipi- 

 tate. 



It did not precipitate the infusion of Santa-F^ cinchona, 

 nor the infusion of Ian. 



Tlie inkisioii uf gull nuts, therefore, coniprthen3s, like 

 D L' the 



