328 CONSIDERATION OF CARBON COMPOUNDS. 



snow-white, loose, filiform 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 

 740 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 acid sulphate, Quininae bisulphas, (C 20 H 24 N 2 2 )H 2 S0 4 .7H 2 



= 548 (Bisulphate of quinine}. This salt is formed when the 

 common sulphate is dissolved in an excess of diluted sul- 

 phuric acid. It crystallizes in colorless, silky needles, has a 

 strongly acid reaction arid is soluble in 10 parts of \vater. 



Hydrochlorate of quinine, C 20 H 2i lSr 2 2 .HC1.2H 2 O = 396.4.^ 

 Hydrobromate of quinine, C 20 H 24 N 2 O 2 .HBr.2H 2 O = 440.8. 

 Valerianate of quinine, C 20 H 24 N 2 2 .C 5 H 10 2 .H 2 O = 444. 



The above three salts are obtained by dissolving quinine in 

 the respective acids; they are white, crystalline substances; 

 the first two are easily, the valerianate is sparingly soluble in 

 water. 



Citrate of iron and quinine is a scale compound obtained by 

 dissolving ferric hydrate and quinine in citric acid, evaporating, 

 etc. 



Analytical reactions for quinine. 



1. Quinine or its salts, dissolved in water or in diluted acids, 

 give, after having been shaken with fresh chlorine water, an 

 emerald-green color on the addition of ammonium hydrate. 



2. Solutions of quinine, treated with chlorine water, then 

 with fragments of potassium ferrocyanide, turn pink, then red 

 on the addition of ammonium hydrate not in excess. 



3. Solutions of quinine give with water of ammonia- a white 

 precipitate of quinine, which is readily dissolved in an excess of 

 ammonia. The precipitate is also soluble in about twenty 

 times its own weight of ether (the other cinchona alkaloids re- 

 quiring larger proportions of ether for solution). 



4. Most solutions of quinine, especially when acidulated with 

 sulphuric acid, show a vivid, blue fluorescence. 



5. Chlorine, passed through water holding quinine in sus- 

 pension, forms a red solution. 



