ISOMERIDES OF ALIZARINE. 41 



Barium anthraflavate suspended in water is completely 

 decomposed by a current of carbonic acid ; and it is also 

 decomposed, though not so rapidly, when exposed to the 

 action of the atmosphere. 



Tetrabromanthraflavine, Cj^H^Br^O^.. When an excess 

 of bromine is added to an alcoholic solution of anthraflavine 

 the substitution-product is deposited at once in yellow 

 crystalline needles, which are almost insoluble in the usual 

 menstrua, such as alcohol, benzol, and glacial acetic acid. 



A determination of the C and H of the substance was 

 made, and yielded the following results : — 



0*3390 grm. of substance dried at 150° gave 0*3840 grm. 

 COi and 0*0334 grm. H,0. 



Theory. Experiment. 



^ A 



C,i 168 30-22 30*89 



H4 4 o'72 '"09 



B, 320 5755 



O4 64 11-51 



556 loo-oo 



A current of chlorine gas having been passed through an 

 alcoholic solution of anthraflavine, nothing was deposited. 

 The solution left, on evaporation, a brown amorphous re- 

 sidue, insoluble in water, but easily soluble in alcohol, which 

 was not further examined. 



Nitroanth7'aflavine is prepared by dissolving anthraflavine 

 in fuming nitric acid, and, after allowing the solution to 

 stand some time, adding water, which precipitates the 

 nitro-acid as a light-yellow crystalline powder. It is 

 obtained on spontaneous evaporation of its alcoholic solu- 

 tion in large well-defined rhombic crystals of a deep yellow 

 colour. Most of its salts, such as the potassium, sodium, 

 magnesium, barium, silver, and mercury salts, are soluble 

 in boiling water, and crystallize in lustrous needles varying 

 in colour from light yellow to brownish red. From a deter- 



