292 POWDERED VEGETABLE DRUGS 



61. (Fig. 72.) CINCHONA. Cinchona. U. S. 

 Fl. ex. 60. Tinct. 60. 



Peruvian bark, Jesuit's bark, E. Chinarinde, G. Quinquina, Fr. 



The bark of several species of Cinchona, (C. Ledgeriana Moens, 

 C. Calisaya Wedd., and hydrids), Rubiaceae. 



Red cinchona Bright reddish yellow. 



Yellow cinchona Yellowish brown. 



Faintly aromatic; musty. 



Very bitter, astringent. . 



Large sclerenchymatous bast cells; few sclerenchyma cells; bark 

 parenchyma with simple starch granules and a few cells with micro- 

 crystalline calcium oxalate. 



Histologically the powders of red and yellow cinchona are practi- 

 cally identical. With potassium hydrate red cinchona forms a deep 

 blood red coloration, while yellow cinchona forms a yellowish brown 

 coloration. 



Ash 7.5 per cent. 



Various bark adulterations may be suspected. There are numer- 

 ous varieties of cinchona and a number of so-called "false cinchonas." 

 Various bitter barks having no botanical relationship to the true cin- 

 chonas have been used as adulterants. The adulterants of cinchona 

 barks are readily recognizable, because of the characteristic bast cells 

 of the true cinchonas. The Grahe test is carried out as follows. Into 

 a clean, dry test tube place about 0.5 gram of the powder and heat 

 over a Bunsen burner flame. As the powder chars black, purplish 

 fumes appear which condense on the sides of the tube. The distinct- 

 ness and volume of the purple fumes are proportionate to the amount 

 of alkaloids present. 



