ISOMEKIDES OF ALIZARINE. 47 



0"i370 grm. of substance gave O'loio grm. C,4.H804 or 

 7372 p. c, the calculated amount being 74*07 p. c. 



Diethylisoanthraflavine, CT^^(,[CJl^)Syi^- — This com- 

 pound was prepared in the same way as diethylanthraflavine, 

 which it closely resembles. It crystallizes from alcohol in 

 long, light-yellow, shining needles. Glacial acetic acid and 

 benzol dissolve it more readily than alcohol or ether. It 

 melts at 193°- 194°. It dissolves in concentrated sulphuric 

 acid, forming a purple solution, the spectrum of which 

 shows two faint absorption-bands — one in the yellow, and 

 the other in the green. The analysis of the substance led 

 to the following results : — 



0*1814 grm. of substance dried at 120° gave 0*4824 grm. 

 COi and 0*0890 grm. H^O. 



Theory. Experiment. 



Cj, 216 72'97 * 72'52 



His 16 5-41 5-45 



O^ 64 21-62 



296 lOO'OO 



By treatment with fuming nitric acid isoanthraflavine 

 yields a nitro- acid resembling nitro-anthraflavine; but want 

 of material has prevented our examining it minutely. 



We will conclude with a few remarks on the action of 

 caustic alkalies on anthraflavine and isoanthraflavine. On 

 a former occasion it was stated by one of us that anthra- 

 flavine, acted on by fusing potassium hydrate, yields aliza- 

 rine ; and it was this supposed convertibility into alizarine 

 which led Liebermann and others to the conclusion that 

 anthraflavine was identical with monoxyanthraquinone. 



We are now in a position to assert confidently that the 

 product of the action is not alizarine. On repeating the 

 experiment with a larger quantity of anthraflavine, we ob- 



