542 
DR. H. DEBUS ON THE CHEMICAL THEORY OF GUNPOWDER. 
Sulphur. 
Potassic sulphate . 
Contained in 
original solution. 
. . 0*2180 
Found by- 
analysis. 
0*291 
„ sulphide . . 
. . 1*4366 
• • 
,, hyposulphite . 
. . 0*0384 
0*318 
Cupric oxide .... 
. . 0*0000 
1*120 
1*693 
1*729 
From these experiments we conclude that by treatment of a solution containing 
potassic tersulphide, carbonate, and sulphate with cupric oxide, not only potassic 
hyposulphite but also potassic sulphate is formed. 
Experiments with potassic monosulphide . 
A solution of 5 grms. of pure potassic hydrate, in 100 cub. centims. of water, was 
divided into two equal parts, one of these was saturated with sulphuretted hydrogen 
and then mixed with the other. 
20 cub. centims. of this solution gave, after evaporation with hydric chloride, 
1'1015 grms. of neutral potassic chloride, corresponding to 0*812 grm. of potassic 
monosulphide (K 3 S). 
20 cub. centims. of the solution of the monosulphide were mixed with 2*219 grms. 
of potassic carbonate and 0*950 grm. of sulphate, and the mixture digested with pure 
cupric oxide at common temperatures, in a stoppered bottle, until all the potassic 
sulphide had been decomposed. 
The contents of the bottle were treated in the same manner as in former 
experiments. 
The filtrate of the cupric oxide measured 415 cub. centims. 
160 cub. centims. required 2*1 cub. centims. of the iodine solution, therefore we 
have, in 415 cub. centims of the filtrate, 0*1.03 grm. of potassic hyposulphite. 
It was ascertained, by special experiment, that the original potassic monosulphide 
did not contain hyposulphite. 
60 cub. centims. of the liquid gave 0*185 grm. of baric sulphate, corresponding to 
0*953 grm. of potassic sulphate in 415 cub. centims. of the filtrate. 
100 cub. centims. gave with manganous sulphate a precipitate from which 0*174 grm. 
of carbonic acid and 0*428 grm. of Mn 3 0 4 were obtained. It follows from these 
numbers that 415 cub. centims. of filtrate contain 0*758 grm. of monosulphide and 
2*261 grms. of carbonate of potassium. 
40 cub. centims. of the filtrate evaporated with hydric chloride, and the remaining 
potassic chloride converted by means of hydric sulphate into potassic sulphate, gave 
