WHICH NITROGEN IS SUBSTITUTED EOR HYDROGEN. 
691 
Action of Potassa upon Nitrate of Diazohenzol. 
On mixing diluted aqueous solutions of these two bodies*, a yellow liquid is obtained, 
which possesses a peculiar aromatic odour and soon begins to evolve nitrogen gas, a red- 
dish-brown neutral substance being simultaneously formed. At the common temperature 
this reaction is very slow, and requires several weeks to be completed. If, however, 
heat is employed, the decomposition proceeds rapidly, and the reddish-brown substance 
is separated as a resinous, semifluid mass, quite insoluble in water, and only very slightly 
soluble even in boiling alcohol. Ether dissolves it readily. I have not been able to 
obtain this substance in crystals. By allowing its ethereal solution to evaporate spon- 
taneously it is left behind in a resinous state. As a powder it is very electric. Boiling 
with nitric acid produces a new yellowish crystalline body. 
In order to purify the amorphous product of decomposition, I have first washed it 
thoroughly with water, then boiled with alcohol, and finally dissolved it in ether ; the 
substance remaining after the evaporation of the ether was submitted to analysis. 
I. 0-2958 grm., dried in vacuo , gave 0-8888 grm. of carbonic acid and 0-1447 grm. 
of water. 
II. 0-220 grm. gave 0-6667 grm. of carbonic acid and 0-1082 grm. of water. 
III. 0-3926 grm. gave 29*8 cub. centims. of nitrogen at 0° C. and 760 millims. pressure. 
IV. 0-5054 grm. gave 32-0 cub. centims. of nitrogen at 0° C. and 760 millims. pressure. 
These numbers agree best with the formula 
€ 24 H 18 N 2 0. 
Calculated. 

Round. 
II. 
III. 
IY. 
^24 
288 
82-29 
81-95 
82-68 
— 
— 
H 18 
18 
5-14 
5-44 
5-45 
— 
— 
n 2 
28 
8-00 
— — 
— 
9-53 
7-66 
0 
16 
4-57 
— 
— 
— 

350 
loMO 
The formation of this substance can be expressed by the following equation : — 
4(G 6 H 4 N 2 , NH0 3 )+H 2 0=C 24 H 18 N 2 0 + 4NH0 3 + 6N. 
If instead of an aqueous, an alcoholic solution of potassa be added to the nitrate of 
diazobenzol, dissolved in water, the reaction which takes place is much more compli- 
cated. In this case, in addition to the reddish-brown body, two volatile substances are 
formed, viz. benzol and phenyl, 0 12 H 10 , the hydrocarbon recently discovered by FiTTiGf . 
When the reaction is conducted in a retort, on the application of heat the benzol passes 
over with the alcohol, and may be separated from it by the addition of water. The 
* The compound of hydrate of potassium and diazobenzol (page 675) does not seem to he formed in this case, 
as I was only able to separate this substance when very concentrated solutions of the nitrate of diazobenzol and 
potassa had been employed in its preparation, 
t Ann. der Chem. und Pharm. Bd. cxxi. p. 363. 
4 Z 
MDCCCLXIV. 
