264 



represented by the following formulae : 



CHI 



Type : two equivalents of aniline Q B JJ T I N 2 . 



C 6 H, N'" ] XT 

 Azophenyldiamme C H I *" 



Azonitrophenyldiamine* . . . c' H' (NQ 2 ) N '" } NS ' 

 Azobromphenyldiamine c' H* Br f Na< 



Nearly all these bodies are beautifully crystallized, and some 

 possess very characteristic properties ; the greater number are ex- 

 tremely weak bases, which it is scarcely possible to combine with 

 acids. On the other hand, they readily produce double compounds 

 with dichloride of platinum and trichloride of gold, the composition 

 of which proves that these new bodies belong to the class of diatomic 

 bases, as expressed by the following formulae : 



Double compound of hydrochlo- 1 p TT wit -\ 



rate of azophenyldiamine and Iff* I N 2 , H 2 C1 2 , (PtCl 2 ) 2 . 



dichloride of platinum . . J 6 7 * 



Double compound of hydrochlo- ] p -o N ,,, -j 



rate of azobromphenyldiamine I ff it 3 D I N a , H 2 C1 2 , (PtCl 2 ) 2 . 

 and dichloride of platinum . J 6 7 



When exposed in alcoholic solution to the action of nitrous acid for 

 a second time, most of these bases again lose three equivalents of 

 hydrogen, which are again replaced by one equivalent of nitrogen, 

 a new class of compounds being thus formed possessing in a still 

 higher degree the peculiarities of the nitrogen- substituted bodies. 

 The following equation illustrates this reaction : 



~e 4 * ' j 

 Azophenyldiamine. New compound. 



In practice, however, the bases are never obtained in the free 

 state, but always as nitrates, from which they may be liberated by 



* This compound was obtained from the nitraniline discovered by Hofmann 

 and Muspratt. I have already pointed out that a second body of the same com- 

 position exists, which is produced by a similar process from Arppe's nitraniline. 

 Observations since made lead me to the conclusion that there is an isomeric 

 representative corresponding to every compound of the phenyl-group. 



