78 PROCEEDINGS OF THE AMERICAN ACADEMY. 



it with fuming nitric acid of specific gravity 1.52, or better a mixture of 

 this acid and sulphuric acid. As soon as the oil had dissolved in the 

 acid, the reaction was complete ; the boiling was stopped, and the prod- 

 uct precipitated by pouring the acid lic^uid into a large quantity of cold 

 water. The yellow crystals thus obtained were purified by crystallization 

 from alcohol, until they showed the constant melting point 117°. 



Detebmination op the Constitution of Metadibromdinitro- 



BENZOL BY THE ACTION OF AnILINE. 



Two grams of the dibromdinitrobenzol melting at 117° were heated 

 with an excess of aniline on the steam bath for half an hour. At the 

 end of this time the excess of aniline was removed by treatment with 

 dilute hydrochloric acid, and the ^^ellovv residue, after being washed thor- 

 oughly with water, was recrystallized from a mixture of alcohol and 

 benzol until it showed the constant melting point 185°, which is essen- 

 tially identical with 186°, that of the dianilidodinitrobenzol prepared 

 from dichlordinitrobenzol by Nietzki and Schedler.* As they established 

 the constitution (NHC6H5)2 1. 3. (N02)2 4. 6 for this body, the dibrom- 

 dinitrobenzol belting at 117° must have the corresponding structure 

 Bra 1. 3. (NOo), 4. 6. 



Action of Aniline on Symmetrical Dibromdinitrobenzol in 

 THE Cold : Bromanilidodinitrobenzol. 



Two grams of the dibromdinitrobenzol cooled by a freezing mixture 

 were moistened with aniline, and the mixture was allowed to stand 

 packed in ice for twelve to eighteen hours. The excess of aniline was 

 then removed by dilute hydrochloric acid, and the dense yellow residue, 

 after thorough washing with water, was purified by crystallization from 

 alcohol and benzol until it showed the constant melting point of 157°> 

 when it was dried at 100°, and analyzed, with the following result: — 



I. 0.0994 gram of the substance gave by the method of Carius 0.0558 

 gram of argentic bromide. 

 II. 0.2138 gram of the substance gave 0.1229 gram of argentic bromide. 



Calculated for Found. 



C6H2BrC,5H5NU(N02)2 I. II. 



Bromine 23.67 23.89 24.46 



* Ber. d. chem. Ges., XXX. 1G68 (1897). 



