WHICH NITROGEN IS SUBSTITUTED EOE HYDROGEN. 
681 
is almost insoluble in water, very difficultly soluble in alcohol, and easily soluble in ether. 
Solutions of ammonia, potash, or carbonate of potassium dissolve the acid readily, the 
solution acquiring a yellow colour. On heating a little of the substance on platinum- 
foil, it fuses and is rapidly decomposed, the decomposition being accompanied by a 
violent evolution of gas. 
Cold dilute mineral acids act upon it but slowly ; on heating, however, speedy decom- 
position ensues. Acetic acid, even when highly concentrated, has no action in the cold, 
but on the application of heat destroys it. 
Platinum-salt of the Hydrochlorate of Diazobenzol-amidobenzoic Acid , 
€ 13 H n N 3 0 2 , 2HC1, 2Pt Cl 2 . 
This compound forms small yellowish-white indistinct plates, and is obtained by adding 
an alcoholic solution of bichloride of platinum to the ethereal solution of the diazo- 
benzol-amidobenzoic acid. 
07455 grm. of the substance gave, on ignition with carbonate of sodium, 0-234 grm. 
of platinum. 
€ 13 H,^, H 2 C1 2 , 2Pt Cl 2 . 
Calculated. Found. 
Pt=30-80 31-39 
Diazobenzol-amidobenzoic acid in its behaviour with bases is similar to a bibasic acid, 
since it combines with metallic bodies in two ways. All the salts formed are compara- 
tively stable ; those, e. g., which are soluble in water, as the potassium-salt, will even bear 
recrystallization. With the oxide of silver and barium it forms insoluble precipitates. 
A more minute description of these compounds I must defer to a future time. 
Compounds analogous to the diazobenzol-amidobenzoic acid are formed when amido- 
dracylic acid (isoamidobenzoic acid), amidoanisic acid, &c. are made to react in the 
manner previously described upon nitrate of diazobenzol. It is my intention to investi- 
gate these compounds more specially, and I therefore abstain from entering further 
upon their description, only noticing that they possess a remarkable resemblance to 
diazobenzol-amidobenzoic acid. 
IMIDOGEN COMPOUNDS OF DIAZOBENZOL. 
By this name are designated a peculiar class of diazobenzol-compounds obtained by 
the action of ammonia, ethylamine, and analogous organic bases upon perbromide of 
diazobenzol (G 4 H 4 N 2 , HBr, Br 2 ). All the compounds hitherto described exist in a 
solid state, and none of them can be volatilized without decomposition ; the new com- 
pounds to be described, on the other hand, are liquors which can be distilled, and which 
possess the narcotic odour of some vegetable bases, such as conidine and nicotine. 
.Beyond this odour, however, they have nothing in common with these natural bases. 
They are indifferent bodies, combining with neither acids nor bases. 
