265 



the addition of an alkali. The following formulae represent the 

 bodies of this series which have hitherto been studied : 



TV C fl H.N'"K T 



Diazophenyldiamme . . r; H N'" I 2 * 



Diazobromphenyldiamine . Q G jr 3 j/. XT/// [ N a . 



C H N'" 1 

 Diazotoluyldiamine . . p 7 j_r 6 -^,1, > N 2 . 



In the free state, these bases generally present themselves in the 

 form of yellow precipitates, insoluble in water. On account of their 

 comparative instability, they are little adapted for analysis ; I have 

 therefore generally fixed their composition by the analysis of their 

 nitrates and platinum-salts, most of which are splendidly crystallized. 

 The following formulae represent several of these compounds : 



C H N'" 1 

 Nitrate of diazophenyldiamine p 6 TT I nt f N 2 , (HN0 3 ) 2 . 



Gold-salt of diazobromphenyl- C 6 H 3 Br N'" 

 diamine C 6 H 3 BrN'" 



Platinum-salt of diazotoluyl- C. H, N"M >T nl /D , r<1 v 

 diamine C 7 H 6 N'" / ** ^ Ll (J U ^ 



My attention has been especially attracted by this last class of 

 new bodies, not only because of their peculiar constitution, but also 

 on account of the remarkable physical properties by which, as a 

 class, they are distinguished. One of their most striking features is 

 the tremendous power with which, under the influence of heat or 

 percussion, these substances explode. The greatest precaution is 

 necessary in manipulating with these compounds. 



I have scarcely commenced the study of the products of decom- 

 position of these bodies. The following observations, however, 

 justify the hope that they will not be without theoretical interest. 

 Nitrate of diazophenyldiammonium, when heated with water, is 

 rapidly decomposed according to the following equation : 



C 12 H 8 N 4 ,(HN0 3 ) 2 +2H 2 = 2C 6 H 6 O + 2HNO 3 + 4N. 



Nitrate of diazophenyl- Phenol. Nitric acid, 



diammonium. 



Qualitative experiments have proved that this substance undergoes 



