Academy of Sciences at Paris. 391 



though it resembles it in many properties, it differs from it in 

 others, and in these differences these two alkalis may be com- 

 pared to potash and soda. 



The alkali of yellow bark may be distinguished from cin- 

 chonine by the name of quinine. Quinine may be obtained by 

 precipitation as white and pure as cinchonine. It cannot be 

 crystallized by evaporation of its alcoholic solution, though 

 it may be obtained in transparent plates. It is as insoluble 

 as cinchonine, but is of a much more bitter taste. The 

 salts which it forms are different from those of cinchonine, 

 both in the proportion of their elements and the properties they 

 possess. They are generally more bitter, and are distinguished 

 by a nacrous pearly aspect. 



The weight of an atom of quinine is 45.9069. This base has 

 less capacity, of saturation than cmcAomne. The sulphate is 

 formed of 



Quinine 100 



Sulphuric acid 10.9147. 



The acetate of quinine is remarkable for the m?inner in which 

 it crystallizes ; its crystals are flat needles, of a nacrous ap- 

 pearance, which are grouped in silky massive bundles, or stars. 

 The acetate of cinchonine, on the contrary, crystallizes in small 

 lamellar crystals, not possessing any of the silky appearance 

 belonging to the former salt. The gallate, oxalate, and tartrate 

 of quinine, are, at least, as insoluble as the similar salts of 

 cinchonine. 



Quinine is very soluble in ether, cinchonine is not. Ether, 

 therefore, may be employed both as a test for the two sub- 

 stances, and as an agent to separate them one from the other. 



The analysis of the red quinquina (cinchona ohlongifolia) 

 followed. It was interesting to ascertain whether this febri- 

 fuge contained cinchonine or quinine. It was possible that 

 a third variety of alkali might be found in it, but what we 

 did not expect occurred, namely, a combination of the two 

 alkalies, cinchonine and quinine, proper to the species al- 

 ready analyzed. The cinchonine of red bark is exactly similar 



