WHICH NITBOGEN IS SUBSTITUTED EOB HYDBOGEN. 
695 
PABT II. 
The peculiar and somewhat remarkable properties of the compounds derived from 
aniline in the manner previously described, have induced me to try whether bromani- 
line, nitraniline, &c., when similarly treated, would be converted into the corresponding 
substituted diazobenzols. 
This I have succeeded in doing, and the new substances thus obtained exhibited all 
the properties which I found so characteristic of the normal diazobenzol-compounds. 
They are, if anything, more stable, owing, if I may so express myself, to the compara- 
tively larger amount of more solid and stable materials which are more firmly combined 
with the extremely volatile and easily disturbed nitrogen. This property renders them 
more fit for many experiments in which the non-substituted diazobenzol-compounds are 
liable to give rise to dangerous accidents. They are likewise remarkable for great 
beauty, a property which certainly encourages a closer acquaintance. 
Nitrate of Diazobromobenzol, € 6 H 3 BrN 2 , NH0 3 . 
This compound may be prepared either by the action of nitrous acid gas upon nitrate 
of bromaniline or upon diazo-amidobromobenzol, and in an exactly similar manner to the 
nitrate of diazobenzol. If an aqueous solution of nitrate of bromaniline be employed, 
nitrous acid gas must be passed through very rapidly at first, or else diazo-amidobromo- 
benzol (even in the presence of much free nitric acid) begins to sep'arate. This it is 
very difficult to convert into the desired compound in an aqueous solution. Nitrate of 
diazobromobenzol remaining comparatively constant in aqueous solutions, it is possible 
to concentrate them, without any great loss, by spontaneous evaporation in the open air. 
In this manner solutions which are too dilute may be concentrated before precipitating by 
means of alcohol and ether. It can be obtained perfectly pure by repeatedly dissolving 
in alcohol and precipitating with ether, when it is obtained in the form of purely white 
scales which, when crystallizing out rapidly, present themselves in the form of regular 
rhombic plates. These crystals, like those of nitrate of diazobenzol, are exceedingly 
soluble in water, difficultly so in strong alcohol, and almost insoluble in ether. They 
explode when they are heated, struck, or compressed, though not so readily nor with 
the same violence as the nitrate of diazobenzol, and they can therefore be mixed without 
danger with oxide of copper and burnt in the usual mode of organic analysis. 
04692 grm. of the substance gave 0503 grm. of carbonic acid and 0-0745 grm. of water. 
These numbers correspond with the formula 
€ 6 H 3 BrN 2 ,NH0 3 . 
Calculated. 
A. 
Eound. 
4 
72 
29-27" 
29-24 
h 4 
4 
1-63 
1-76 
Br 
80 
32-53 
— 
n 3 
42 
17-07 
— 
€>3 
48 
19-50 
— 
246 
100-00 
