145 
substance. It crystallises in yellow needles, which are 
almost insoluble in the usual menstrua, such as alcohol, 
benzol, and glacial acetic acid. 
Nitroanthraflavic Acid, a body already referred to in 
the paper of 1871, is prepared by dissolving anthraflavine 
in fuming nitric acid and after allowing 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 solution in large well-defined 
rhombic crystals of a deep yellow colour, the composition of 
which is expressed by the formula 0i 4 H 4 (NO 2 ) 4 O 4 . Most of 
the salts, such as the potassium, sodium, magnesium? 
barium, silver, and mercury salts, are soluble in boiling 
water, and crystallise in lustrous needles, varying in colour 
from light-yellow to brownish-red. By reduction with tin 
and. hydrochloric acid the nitro-acid yields a dark-blue 
powder, which is almost insoluble in alcohol, glacial acetic 
acid, &c., but dissolves in caustic alkalies with a fine violet 
colour like that of alkaline solutions of alizarine. 
Diacetylanthraflavine has already been described by 
Perkin* We found its melting point to be at 227°G. 
Diethylanihraflavine, C 14 H 6 (C H 5 ) 2 0 4 was prepared by 
heating a mixture of anthraflavine, caustic soda, iodide of 
ethyl, and a little alcohol in sealed tubes to 120°, and crys- 
tallising the product from boiling alcohol. It crystallises in 
light yellow needles, which are soluble in benzol and glacial 
acetic acid, but insoluble in water. It fuses at 232°. The 
fused substance on cooling is converted into a mass of pris- 
matic crystals. The spectrum of the solution in concentrated 
sulphuric acid, which is red, shows a well-defined absorption 
band between the green and blue. 
Dimethylanthmflavine, the preparation of which is 
similar to that of the preceding, has almost the same pro- 
perties as the ethyl compound. It fuses at 247°-248°. 
# Journal Chem. Soc. XXYL, p. 20. 
