WHICH NITROGEN IS SUBSTITUTED EOR HYDROGEN. 
679 
In the formation of the above bodies two atoms of base enter into chemical action 
with one atom of nitrate of diazobenzol, forming, together with the diazo-amido-com- 
pound, the nitrate of the base employed. Naphtalidine (amidonaphtol), however, com- 
bines directly in equal numbers of atoms with nitrate of diazobenzol, giving rise to a 
compound which has the formula 
€i 6 H 14 N 4 © 3 , 
and which, as will be shown, must be viewed as nitrate of diazobenzol-amidonaphtol. 
This compound is obtained in an impure state as a violet crystalline precipitate on 
adding an aqueous solution of nitrate of diazobenzol to an alcoholic solution of naphta- 
lidine. It is purified by repeated washings with cold alcohol and recrystallization from 
the same, forming beautiful green prisms. 
0-2303 grm. gave 05235 grm. of carbonic acid and 00975 grm. of water, correspond- 
ing to 61 ‘99 per cent, of carbon and 4-70 per cent, of hydrogen. 
These numbers lead to the formula 
g 16 h 14 n 4 0 3 =| o 5^}nho 3 . 
Calculated. 
>v 
Found. 
f " ” 
©16 
192 
61-94 
61-99 
H 14 
14 
4-52 
4-70 
N 4 . 
56 
18-06 
— 
©3 
48 
15-48 
— 
310 
100-00 
The new compound is formed according to the equation 
€ 6 H 4 N 2 , NH© 5 fG 4 oH 9 N=0 16 H 14 N 4 © 3 . 
Nitrate of diazo- Naphtalidine. Nitrate of diazo- 
benzol. benzol-amidonaphtol. 
It is one of the finest bodies of which chemistry can boast. It crystallizes in well- 
defined prisms, which by reflected light are of a magnificent grass-green colour, but 
ruby-red by transmitted light. The crystals are almost insoluble in water and ether. 
Hot alcohol dissolves them freely, and redeposits them almost entirely on cooling. 
Diazobenzol-amidonaphtol, f? 2 j* 
This compound is obtained from the previous substance by removing the nitric acid 
by means of ammonia or potassa. It crystallizes in very brilliant ruby-red prisms, readily 
soluble in alcohol and ether, forming yellow liquids. Acids impart a beautiful violet 
colour to these solutions. Bichloride of platinum produces a purple-blue crystalline 
precipitate ; nitrate of silver a yellow precipitate, which consists of small fine needles. 
It is worth mentioning that these diazobenzol-amido-compounds can also be obtained 
by acting with an aqueous solution of the salts of the respective bases upon the com- 
