674 
ME. P. GrEIESS ON A NEW SEEIES OE BODIES IN 
Calculated. 
Eound. 
g 6 
72 
20-87 
20-98 
H 5 
5 
1-45 
1-60 
N, 
00 
CM 
8-12 
— 
Bl-3 
240 
69-56 
70-89 
345 
100-00 
Perbromide of diazobenzol, which crystallizes in yellow plates, is insoluble in water, 
rather difficultly soluble in alcohol, and insoluble in ether. It is comparatively stable 
when in a dry state. Its alcoholic solution, on the other hand, rapidly decomposes, 
even in the cold, with evolution of gas. For this reason it is impossible to recrystallize 
it without loss. In order to purify this unstable perbromide, it is most advantageous 
to dissolve it in cold alcohol, and to allow the solvent to evaporate spontaneously in 
shallow vessels in the open air. Very fine crystals are usually obtained in this manner, 
but contaminated with trifling quantities of an oily product of decomposition, which, 
however, may be removed by washing with a little cold ether. On application of heat 
this compound deflagrates at a comparatively low temperature. The constitution of 
the perbromide of diazobenzol seems the same as the periodide of tetrethylammonium 
and similar compounds of other bases. 
Platinum-salt of Hydrochlorate of Diazobenzol, G 6 H 4 N 2 , H Cl, Pt Cl 2 , 
is obtained by the addition of bichloride of platinum to a rather concentrated aqueous 
solution of the nitrate of diazobenzol. The fine yellow prisms which are precipitated 
are almost insoluble in alcohol and ether. They are rather stable ; when kept for 
some time, however, they acquire a brownish colour, and are gradually but completely 
decomposed. On heating they deflagrate, hence it is impossible to estimate the platinum 
by simple ignition. 
0-760 grm., ignited with carbonate of sodium, gave 0-241 grm. of platinum, corre- 
sponding to 31-71 per cent. 
G 6 H 4 N 2 ,HC1, Pt Cl 2 . 
Theory. Experiment. 
Pt=31-82 31-71 
Gold-salt of Hydrochlorate of Diazobenzol, € 6 H 4 N 2 , HC1, AuC1 3 . 
By the addition of terchloride of gold to a dilute aqueous solution of the nitrate of 
diazobenzol, this compound is obtained in the form of a light-yellow crystalline precipi- 
tate, insoluble in water, but soluble in alcohol, especially when warm, from which, 
on cooling, it is deposited in the form of small golden-yellow plates. This salt cannot, 
however, be recrystallized without some loss, especially when the alcoholic solution 
is heated to boiling. The decomposition is indicated invariably by an evolution of 
gas; continued boiling with alcohol destroys it completely. 0*6965 grm. of this salt 
