608 CONSIDERATION OF CARBON COMPOUNDS. 



Pelletierine tannate of the U. S. P. is a mixture of the tannates of four 

 alkaloids (ptmicine, iso-punicine, inethyl-punicine, and pseudo-punicine) ob- 

 tained from Punica Granatum. 



The quinoline group of alkaloids. 



Cinchona alkaloids. The bark of various species of cinchona 

 contains a number of alkaloids, of which the most important are 

 quinine, cinchonine, quinidine, and cinchonidine. These alkaloids 

 exist in the bark in combination with a peculiar acid, termed kinie 

 acid. The quantity and relative proportion of the alkaloids vary 

 widely in different barks, but the official bark should contain not less 

 than 5 per cent, of total alkaloids, and at least 4 per cent, of anhy- 

 drous ether-soluble alkaloids. 



Quinine, Quinina, C 20 H 24 N 2 O 2 .3H 2 O = 375.46. This formula 

 represents the official alkaloid, but it is also known anhydrous, and 

 in combination with either one or two molecules of water. The 

 anhydrous quinine is a resinous substance, while the crystallized 

 quinine is a white, flaky, amorphous or crystalline powder, having 

 a very bitter taste and an alkaline reaction. It is nearly insoluble in 

 water, but soluble in alcohol, ether, ammonia water, chloroform, and 

 dilute acids. When heated to about 57 C. (134 F.) it melts ; at 

 100 C. (212 F.) it loses 2 molecules of water, the remainder being 

 expelled at 125 C. (257 F.). 



Quinine sulphate, Quininse sulphas, (C 20 H 24 N 2 O 2 ) 2 H 2 SO 4 .7H 2 O 

 = 866.15. This salt, containing two molecules of the alkaloid in 

 combination with one of sulphuric acid and seven of water, is the 

 common form of quinine sulphate. It forms snow-white, silky, light 

 and fine, needle-shaped crystals, fragile and somewhat flexible, making 

 a very light and easily compressible mass ; it has a very bitter taste 

 and a neutral reaction ; it is soluble in 720 parts of cold and in 30 

 parts of boiling water ; soluble in 65 parts of alcohol, but nearly 

 insoluble in ether and chloroform ; it readily dissolves in diluted 

 sulphuric or hydrochloric acid. 



Quinine bisulphate, Quininse bisulphas, C 20 H 24 N 2 O 2 .H 2 SO 4 .7H 2 O 

 = 544.33. This salt is formed when the common sulphate is dis- 

 solved in an excess of diluted sulphuric acid. It crystallizes in color- 

 less, silky needles, has a strongly acid reaction, and is soluble in 8.5 

 parts of water. 



