728 
ME. P. G-EIESS ON A. NEW SEEIES OF BODIES IN 
0-3135 grm.* gave 0-2755 grm. of sulphate of lead, corresponding to 60-04 per cent, 
of lead and 9-28 per cent, of sulphur. 
•g 12 h, 
3 S 4 Pb 8 0 16 . 
Calculated. 
Found. 
r~ 
© 12 
144 
10-57 
10-16 
h 6 
6 
0-45 
0-59 
Pb 8 
828 
60-79 
60-04 
s 4 
128 
9-39 
9-28 
^16 
256 
18-80 
— 
1362 
100-00 
Basic Lead-salt , G 12 H 6 , -S 4 Pb 8 
^16 + ^4 0; 
This salt is obtained by treating the hot solution of the ammonium-salt with basic 
acetate of lead. It is a white amorphous precipitate. 
0-5935 grm., dried at 150°, gave 0-592 grm. of sulphate of lead. 
€ 12 H 6 S 4 Pb 12 0 18 . 
Calculated. Found. 
Pb . . . . 68-69 68-14 
Tetrasulphodiphenylenic acid is easily to be obtained in a free state, either by decom- 
posing the lead- or silver-salt with sulphuretted hydrogen, or by treating the barium-salts 
with an equvalent quantity of sulphuric acid. The filtered aqueous solution is evapo- 
rated on a water-bath to a syrupy consistence, and placed over sulphuric acid; after 
some time white needles or plates are obtained, which are very soluble in water and 
alcohol, but not deliquescent in the air. I have not yet analyzed this acid ; but accord- 
ing to the above-mentioned salts it seems very probable that it can exist in two different 
states, as expressed by the formulte © 12 H 6 , S 8 H 6 0 15 and C 12 H 6 , -S 8 H 8 0 16 . 
The second compound (trisulphodiphenylenic acid) to which the reaction of sulphuric 
acid or sulphate of tetrazobenzidol gives rise deserves likewise a few passing remarks. 
The separation of its barium-salt from the barium-salt of tetrasulphodiphenylic acid 
by means of hot water has already been described. The aqueous extracts thus obtained, 
sufficiently evaporated and allowed to cool, will generally solidify to a gelatinous mass 
from which distinct crystals cannot be obtained, even by repeated solution and evaporation. 
Crystallization may, however,. be effected thus; The gelatinous salt is converted into the 
ammonia-compound, by boiling with an aqueous solution of carbonate of .ammonium. 
* This substance was boiled with concentrated nitric acid till red fames ceased to be evolved, and evapo- 
rated to dryness. The sulphate of lead was then collected on a filter and well washed with alcohol ; the alco- 
holic filtrate contains neither a trace of lead nor sulphuric acid. 
