ACTION OF SULPHURIC ACID UPON THE AMIDES AND NITRILES. 
471 
able interest, since in this case it would become highly probable that all the new 
bodies hitherto described in this memoir might be prepared, from the analogues of 
sulphobenzolic acid in their respective groups, by a simple assimilation of the elements 
of sulphuric acid. The method in question is in reality by far the best adapted for 
procuring the new acid in a state of purity, Sulphobenzolic acid obtained from the 
lead- or copper-salt is evaporated on the sand bath until the evolution of white fumes 
proves that the greater part of the water has been volatilized. It is advisable to heat 
the solution until a slight brown coloration indicates incipient decomposition. The 
acid is then introduced into a dry retort, together with an equal volume of strong 
Nordhausen acid, and the whole maintained at the boiling-point for two hours. The 
liquid is then reduced by evaporation nearly to the original bulk of the sulphoben- 
zolic acid employed. The new acid in this stage has a very dark colour which 
cannot be removed by boiling with charcoal. Treatment, however, with an excess 
of oxide of lead, and decomposition of the filtrate by hydrosulphuric acid, furnishes 
a liquid which is perfectly colourless. 
When this liquid is saturated with carbonate of barium and evaporated, an appa- 
rently amorphous mass is produced, which, however, under the microscope is 
distinctly crystalline, showing minute shuttle-shaped forms generally densely grouped 
together. This salt is very stable. Strongly heated, however, on platinum foil, it 
burns with evolution of sulphurous acid. 
0*3930 grrn., at 195°, gave 0*2436 grm. of sulphate of barium ; 
0*3046 grm,, ignited with chlorate of potassium, gave 0*3850 grm, of sulphate of 
barium, 
leading to the formula of disulphobenzolate of barium, 
C.3(H,Ba,) S,0,,. 
Theory. 
A 
Experiment. 
12 equivs. of Carbon . . 
( 
. 7'2 
19*30 
4 equivs. of Hydrogen . 
4 
1*07 
2 equivs. of Barium . . 
. 137 
36*72 
36*43 
4 equivs. of Sulphur . . 
64 
17*16 
17*35 
12 equivs. of Oxygen . , 
. 96 
25*75 
373 
100*00 
For comparison, we subjoin the corresponding number for sulphobenzolate of 
barium. 
C,2(H5Ba) S 2 Ofi. 
Barium .... 30*38 
Sulphur .... 14*19 
The preceding researches establish in two different groups of bodies the existence 
of a series of bibasic acids, containing 4 equivalents of sulphur, and which, irrespect- 
