458 MR. G. B. BUCKTON AND DR. A. W. HOFMANN’S RESEARCHES ON THE 
0‘6216 grm. of salt thus crystallized gave 0*4636 of sulphate of barium. 
Acid salt. Neutral salt. Experiment. 
Percentage of barium . . 28*13 44*05 43*85. 
Disulphometholic Acid. 
To prepare this acid, the barium-salt is precipitated by a small excess of sulphuric 
acid which is again removed by means of oxide of lead. Hydrosulphuric acid is 
then passed through the liquid which becomes thus strongly acid. It may be con- 
centrated to a syrup without decomposition, and even carefully heated until white 
fumes appear. On cooling the liquid thus concentrated under the receiver of the 
air-pump, a crystalline mass of fine radiated needles is produced, exceedingly soluble 
in water and very deliquescent. They have a pure acid taste, with somewhat the 
flavour of tartaric acid. The attraction of this acid for water is so great, that we 
have failed in obtaining it in a solid condition by evaporation over sulphuric acid. 
It is not changed by boiling with nitric acid, and chlorine gas passed through the, 
aqueous solution does not liberate sulphuric acid. 
The corresponding salts are readily obtained by digesting the oxides or the car- 
bonates of the various metals with solutions of the acid. The barium-salt is imme- 
diately precipitated by adding chloride of barium to this solution. The salts are all 
soluble in water, but insoluble in alcohol. 
Disulphometholate of Silver 
crystallizes either in tufts of flat needles, or in broad tables of considerable size. It 
is produced when the aqueous solution of the acid is neutralized with carbonate or 
oxide of silver. We had hoped to obtain crystals of sufficient regularity for measure- 
ment of the angles ; but although they may be easily produced of sufficient size, the 
edges are mostly rounded and imperfect. 
It bears a temperature of 150° C. without decomposition, but blackens and froths 
when strongly heated, yielding sulphur, sulphurous acid, and metallic silver. It is 
insoluble in absolute alcohol, but may be crystallized from spirits of wine. 
I. 0*8066 grm. at 120°, by ignition, gave 0*4470 grm. of silver. 
II. 0*6045 grm. at 120°, by ignition, gave 0*3345 grm. of silver. 
III. 1*0151 grm. at 120°, burnt with chromate of lead, gave 0*1 110 grm. of car- 
bonic acid and 0*0534 grm. of water. 
Percentage composition.. 
I. 
III. 
55*49 
Silver . 
Carbon . . 
Hydrogen . 
II. 
55*33 
2*97 
0*58 
