CINCHONA RUBRA 



403 



trate is soluble in water. A cold aqueous solution of the sulphate 

 remains unaffected by potassium iodide T. S. (difference from quini- 

 dine). The other prominent principles are: 



CINCHONIDINE, CigH^NaO isomeric with cinchonine, non-fluor- 

 escent; forms colorless, anhydrous crystals, soluble in 20 parts alcohol 

 (80 per cent.), 1680 of water, and 188 of ether. The sulphate is more 

 soluble in water than quinine, and the tartrate very insoluble. The 



FIG. 231. Cinchona succirubra Branch. 



Thalleoquin test (see above) gives a white precipitate. Represented 

 in Cinchonidinse Sulphas. 



CINCHONINE, C 2 oH 24 N 2 O white lustrous prisms, soluble in 3760 

 parts water, 116 parts .alcohol, and 526 parts ether; has exactly the 

 opposite action to cinchonidine and quinine upon polarized light. 



QUINIDINE, C2oH 2 4N 2 O 2 isomeric with quinine; crystallizes in 

 prisms soluble in 2000 parts water, 0.8 part alcohol, about 30 parts 



