WHICH NITEOGEN IS SUBSTITUTED EOE HYDEOGEN. 
693 
of the original compound is decomposed, in the following manner : — 
2 (G 6 H 4 N 2 , NHO 3 H 3NH 3 =G 12 H n N 3 +N 2 + 2(NH 4 , N0 3 ). 
Hitrate of diazobenzol. Diazo-amidobenzol. 
Two atoms of nitrogen in two equi valents of diazobenzol have, therefore, been simply 
replaced by one of ammonia. 
Decomposition of the Platinum-salt of Diazobenzol , and of the Perbromide of Diazobenzol , 
by the action of heat. 
When speaking of the platinum-salt, I had occasion to mention that it detonates 
when heated. By mixing it, however, with a large excess of perfectly dry carbonate of 
sodium *, and heating the whole in a retort on a sand-bath, it is quietly decomposed. 
The decomposition begins at a moderate heat, and is marked at first by the evolution 
of gas, and subsequently by the distillation of an oily body. The residue in the retort 
consists of carbonate of sodium, metallic platinum, and chloride of sodium. The oily 
distillate contains chlorine. It is obtained perfectly pure by distilling once with chlo- 
ride of calcium, and forms an almost colourless oil, which is heavier than water and has 
the odour of benzol. These properties, as well as the chlorine determination, which 
was made by igniting the substance with caustic lime, prove that it is chloro-benzol, 
€ 6 H 5 Clf. 
0-205 grm. gave 0-268 grm. of chloride of silver. 
A>h 5 ci. 
Calculated. Pound. 
Chlorine . . 31-56 32-34 
The formation of chlorohenzol may be expressed by the following equation : — 
G 6 H 4 N 2 , HC1, PtCl 2 = € 6 H 5 C1+Pt+Cl 2 +N 2 . 
Platinum-salt. Chlorobenzol. 
The platinum-salt of the bromide of diahenzolj is decomposed in. an exactly similar 
manner. The resulting bromobenzol differs in no way from the bromobenzol obtained 
by Couper by the action of bromine upon benzol, as may easily be shown by converting 
it into nitrobromobenzol, which possesses all the properties of nitrobromobenzol pre- 
pared from coal-tar oil. 
Bromobenzol can also be produced by the decomposition of perbromide of diazobenzol 
by heat, according to the equation 
G 6 H 4 N 2 , H Br, Br 2 = G 6 H 5 Br + N 2 +Br 2 . 
Perbromide of diazobenzol. Bromobenzol. 
* It is self-evident that other carbonates, such as carbonate of barium, calcium, &c., may be used instead of 
carbonate of sodium. 
f In all probability it is identical with chlorobenzol obtained from benzol or phenol. 
+ This compound is obtained as an insoluble reddish-yellow precipitate, on mixing bibromide of platinum 
with an aqueous solution of nitrate of diazobenzol. 
4 z 2 
