WHICH NITROGEN IS SUBSTITUTED EOR HYDROGEN. 
729' 
The excess of ammonia is removed by evaporation, and the crystalline residue dissolved 
in a little hot water and treated with a solution of chloride of barium. On cooling, 
warty crystals, or globular groups of small plates, of the barium-salt are obtained, 
which can be freed from the difficultly-soluble tetrasulphodiphenylenate of barium with 
which it may still be contaminated, and also from the mother-liquor, by repeated 
crystallization from water. 
The analysis of this salt (dried at 130° C., at which temperature it turns to a dirty 
green colour owing to the loss of water of crystallization) gave the following numbers : 
0*526 grm. of substance gave 0*4403 grm. of carbonic acid and 0*0766 grm. of water. 
0*453 grm. gave 0*2535 grm. of sulphate of barium. 
0*3605 grm. gave 0*388 grm. of sulphate of barium. 
These amounts lead to the formula 
^12 S 3 H Ba 3 O n . 
Calculated. 
X 
Pound. 
^12 
144 
22*91 
22*80 
h 7 
7 
1*11 
1*60 
Ba 3 
205*5 
32*70 
32*80 
s 3 
96 
15*28 
14*78 
176 
28*00 
— 
628*5 
100*00 
Lead-salt , G 12 H 6 , -S 3 Pb 6 0 ]2 . 
White amorphous precipitate obtained by treating a hot solution of the barium-salt 
with a solution of neutral acetate of lead. 
0*711 grm., dried at 130°, gave 0*604 grm. of sulphate of lead. 
€ 12 H 6 , S 3 re- 
calculated. Bound. , 
Pb . . . . 58*63 58*05 
0*7375 grm., dried over sulphuric acid, lost at 130° 0*0265 grm. of water. 
G 12 H 6 S 3 Pb 6 0 12 + 2 H 2 0. 
Calculated. Pound. 
4H 2 0 . . . . 3*29 3*52 
Basic Lead-salt , G 12 H 6 , -S 3 Pb 6 0 12 , Pb 4 0 2 , 
is precipitated from a solution of the ammonium- or barium-salt with basic acetate of 
lead. It scarcely differs in its properties from the previous salt. 
0*750 grm., dried at 130°, gave 0*2483 grm. of carbonic acid and 0*0557 grm. of water. 
0*5395 grm., dried at the same temperature, gave 0*532 grm. of sulphate of lead. 
