On the Action of Nitrous Acid upon Nitrophenylenediamine. 459 
undergo, indeed, the transformation, which he has already proved for 
so many derivatives of ammonia, with the greatest facility. 
On passing a current of nitrous acid into a moderately concen- 
trated solution of the nitrate of the base, the liquid becomes slightly 
warm, and deposits on cooling a considerable quantity of brilliant 
white needles, the purification of which presents no difficulty: spa- 
ringly soluble in cold, readily soluble in boiling water, the new com- 
pound requires only to be once or twice recrystallized. Thus puri- 
fied, this substance forms long prismatic crystals, frequently inter- 
laced, white as long as they are in thé solution, but assuming a 
shghtly yellowish tint when dried, and especially when exposed to 
100°: they are readily soluble both in alcohol and in ether. The 
new body exhibits a distinctly acid reaction ; it dissolves on applica- 
tion of a gentle heat in potassa and in ammonia, without, however, 
neutralizing the alkaline character of these liquids; it also dissolves 
in the alkaline carbonates, but without expelling their carbonic acid. 
The new acid fuses at 211° C., and sublimes at a somewhat higher 
temperature, with partial decomposition. The sublimate consists of 
small prismatic crystals. 
Analysis proves this substance to contain 
C, H, N, 0,, 
a formula which is confirmed by the analysis of a silver-compound, 
| C, (H, Ag) N,O,, 
and of a potassium-salt, 
C, (H, K) N, O,. 
The analysis of the new compound shows that, under the influence 
of nitrous acid, nitrophenylenediamine exchanges three molecules of 
hydrogen for one molecule of nitrogen, three molecules of water 
being eliminated. 
C, H, N, 0,+H NO,=2H,0+C, H, N’’N, O,. 
—_.+=,-——_—’ —————---—-—_—— 
Nitrophenylene- New acid. 
diamine. 
I do not propose a name for the new compound, which can claim 
but a passing interest, as throwing, by its formation, some light on 
the constitution of nitrophenylenediamine. 
The composition of the new acid, and of its salts, shows that in the 
crimson-red base four hydrogen molecules are still capable of re- 
placement ; in other words, that this body contains four extra-radical 
molecules of hydrogen. The result of these experiments appears to 
confirm the view which, in the commencement of this Note, I have 
taken of the constitution of this body; at all events, the mutual 
relation of the several bodies is satisfactorily illustrated by the 
formulze— : 
