684 
ME. P. GKRIESS ON A NEW SEEIES OF BODIES IN 
benzol. The fusing-point of the dinitrobenzol was in both instances 89° C. The pro- 
duction of dinitrocarbolic acid and of benzol can be expressed by the following equa- 
tion : — 
Nitrate of diazobenzol. Alcohol. Dinitrophenylic Benzol. Aldehyde. 
acid. 
Sulphate of diazobenzol, when distilled with alcohol, is acted upon in a similar manner. 
The alcoholic distillate contains the benzol, whilst the residue in the flask consists of 
sulphuric acid and a small quantity of an organic acid. 
Deportment of Nitric Acid and Nitrate of Diazobenzol. 
Ordinary nitric acid, as well as the fuming acid, has no action upon this compound 
in the cold. The diazo-compound was dissolved in the strongest fuming nitric acid, 
allowed to stand for one hour, and cautiously diluted with water so as to prevent any 
rise of temperature; solution of terchloride of gold was then added, which gave an 
immediate precipitate. Analysis showed this precipitate to be identical with the gold- 
salt of hydrochlorate of diazobenzol. 
0-8295 grm. gave, on precipitation with sulphuretted hydrogen and ignition of the 
tersulphide of gold, 0 - 3685 grm. of gold, corresponding to 44*42 per cent. 
€ 6 II 4 N 2 ,HC1, Au Cl 3 . 
Calculated. Found. 
Gold .... 44*37 44*42 
On boiling the solution of nitrate of diazobenzol in fuming nitric acid, trinitrophe- 
nylic acid is produced. By employing a somewhat weaker acid, an admixture of tri- and 
di-nitrophenylic acid is obtained. 
Action of Sulphuric Acid upon Sulphate of Diazobenzol. 
On dissolving the sulphate in a small quantity of concentrated sulphuric acid, and 
heating in a water-bath, a copious evolution of nitrogen gas ensues, and a brownish- 
coloured liquid remains, consisting of a mixture of the excess of acid employed and a 
new sulpho-acid. The separation of the two acids is readily accomplished by preparing 
their barium-salts. After diluting the brownish liquid with a sufficient quantity of 
water and adding carbonate of barium as long as the solution exhibits an acid reaction, 
the insoluble sulphate of baryta may be separated by filtration from the barium-salt of 
the new sulpho-acid. The filtrate is evaporated till a pellicle forms, when, on cooling, 
a large quantity of crystals of the barium-salt of the new sulpho-acid appears. After 
separating the crystals by filtration, and then evaporating the mother-liquor further and 
cooling, a new quantity of crystals is obtained. A single recrystallization from water 
renders them perfectly pure. This salt forms fine, white, well-developed prisms, attaining 
frequently to the length of half an inch, when the solution is allowed to cool very 
slowly. The crystals are readily soluble in hot, rather difficultly in cold water, and 
