33 



at the same time attacked, yields to remedies 

 which do not operate by the same principle, by 

 the same mode of action on the same organs, 

 by the same play of chemical and electrical at- 

 tractions ? We shall here confine ourselves to 

 this observation, that, in the species of the genus 

 cinchona, like antifebrile virtues do not appear 

 to reside in the tannin (which is only accident- 

 ally mingled in them), or in the cinchonat of 

 lime; but in a resiniform matter, soluble both 

 by alcohol and by water, and which, it is be- 

 lieved, is composed of two principles, the cm- 

 chonic bitter and the cinchonic red*. Can it 

 then be admitted, that this resiniform matter, 

 which possesses different degrees of energy ac- 

 cording to the combinations by which it is mo- 

 dified, is found in all the febrifuge substances ? 

 Those by which the sulphat of iron is precipitat- 

 ed of a green colour, like the real cinchona, the 

 bark of the white willow, and the horned peris- 

 perm of the coffee tree, do not on this account 

 indicate an indentity of chemical composition-^ ; 



* In French, Pamer et le rouge cinchoniques. 



f The cuspare bark (cort. angusturae) yields with iron a 

 yellow precipitate j yet it is employed on the banks of 

 the Oroonoko, and particularly at the town of St. Thomas of 

 Angostura, as an excellent cinchona ; and on the other hand, 

 the bark of the common cherry tree, which has scarcely 

 any febrifuge quality, yields a green precipitate like the 

 real cinchonas. (Vauquelin, Annales de Chimie, T. 59, page 

 143. Reuss, in the Journal de Pharmacie, 1815, page 505. 



VOL. III. P 



