252 MESSRS. DALE AND SCHORLEMMER ON AURIN. 



and pure paratoluidine. The product was converted into 

 the leuco compound^ from which, to their surprise, they 

 obtained, not as before, the hydrocarbon CjoHig, but one 

 having the composition C,gH,6, or the lower homologue of 

 the former. They found the new hydrocarbon to be iden- 

 tical with one already known, which was discovered by 

 Kekule and Franchimont, and called triphenylmethane, 

 CH(C6Hj)j, as it is marsh-gas or methane in which three 

 atoms of hydrogen are replaced by three phenyl groups. 

 Hemilian, who afterwards obtained the same hydrocarbon 

 by a different method, examined it more fully, and found, 

 amongst other results, that concentrated nitric acid con- 

 verts it into the trinitro compound C,gH,3(N02,)j. E. and 

 O. Fischer prepared the same body, which, by the action of 

 nascent hydrogen, was converted into a base having all 

 the characteristic properties of leucaniline. This was 

 heated with arsenic acid in order to abstract hydrogen by 

 oxidation ; and the rosaniline, which formed the starting- 

 point of their last investigation, was obtained again. 



From these results it follows that commercial rosaniline 

 consists principally of the base CjoHi^Nj, and is probably 

 a derivative of pseudotoluidine, while the rosaniline from 

 paratoluidine, and which has therefore been called para- 

 rosaniline, is its lower homologue, having the formula 

 Ci^Hj^Nj. The rosaniline which we obtained from aurin 

 is undoubtedly identical with the latter*, its formation 

 being readily explained by the following equation : — 



The question which has now to be solved is how to ex- 

 plain the formation of aurin. We have already made ex- 



* Since this was written, E. and O. Fischer prepared some pure aurin 

 according to our directions, and converted it into a leucorosaniline, from 

 which they also obtained triphenylmethane (Ber. deutsch. chem. Ges. xi. 

 473)- 



