40 . Experiments vpoii the 



it still preserves its bitter taste. Mixed in this state with a 

 solution of sulphate of lime, it turns it green as before j 

 aione, the C(^lour inclines more to yellow. It precipitates 

 the emetic solutioji with this difTerence, that the precipitate 

 is whiter. 



Another portion of the infusion of the same cinchona, 

 completely precipitated by the emetic and filtered, still ren- 

 dered turbid the solutions of glue and of sulphate of iron, 

 but much less abundantly than formerly. The precipitate 

 formed by the emetic became slightly green by the addition 

 of some drops of sulphate of iron. 



It would seem, according to these experiments, that the 

 principle which precipitates emetic, glue, and sulphate 

 of iron, is the same; and that, if the liquor still preserves 

 the properly of precipitating glue and sulphate of iron, it is 

 because it retains some portions of the combination of this 

 principle with antimony, 'j his supposition, however, can- 

 not be reconciled with ihe very abundant precipitation of 

 glue by certain cinchonas, which by no means precipitate 

 emetic. It therefore follows, that the principle which 

 prccipiiatesgluc maybe diflcrentfrom that vv'hich decomposes 

 emetic. 



Such are the phasnomena which the infusion of yellow 

 cinchona presented to me with the above re-agents. 



I was desirous of ascertaining if this same cinchona, al- 

 ready exhausted bv cold water, v.ould present, by boiling it, 

 any diflerences with the^ same substances. But I found au 

 almost perfect analogy in this respect ; its decoction wgs 

 turbid upon cooling, and the precipitates which it furnished 

 with the re-agents were more abundant, and were more 

 promptly separated from the liquor. 



I shall add, that this decoction precipitates, like the in- 

 fusion, the solution of sulphate of copper in reddish yellow, 

 and that of the acetate of lead in yellowish while. 



Second Species. — Cinchona of Sanla-Fe. 



Tliis species of cinchona, newly introduced into com- 



fnerce, has been tried, with rcr-pect to its febrifuge tflects, 



* by 



