44 DISSERTATION ON THE 



All the re-aojerits had recourse to in experi- 

 ments the ninth and tenth established the evi- 

 dence of the resiniforni matter of Vauquelin, 

 and that it is to be obtained most abundant- 

 ly from the leaves, and least from the roots. 



From the effects of tartarised antimony, in 

 experiment the ninth, it would appear to con- 

 tain a principle which Dr. Duncan calls cin- 

 chonin.* 



similar to this second species of bitter principle exists in the 

 flowers of the arnica montana. Dr. Thomson thinks, that 

 bitter principle, which characterizes the worm- wood, sabine, 

 rue, milfoil, and chamomile, belonj^s to this second species. 

 It will hereafter appear, that the virtues of the eupatorium 

 perfoliatum, as an article of medicine, are very similar to 

 those for which these plants are distinguished; more par- 

 ticularly those of the anthemis nobilis. See Thomson's 

 Chemistry, vol. v. p. 95 : see also experiments on the 

 various species of cinchona, by M. VAvauELiN, in Ni- 

 cholson's Journal, 8vo. vol. 19, p. 204. 



* See Dr. Duncan's experiments on the Peruv. bark, in 

 Nicholson's Journal, 8vo. vol 6, p. 225. 



