556 
DR. H. DEBUS ON THE CHEMICAL THEORY OF GUNPOWDER. 
asked: in what proportions must the constituents of a given mixture of saltpetre, 
carbon, and sulphur react during the process of explosion, and what must be the ratios 
of the chief products of explosion, so that on one hand the total quantity of heat 
developed is as great as possible, and, on the other hand, the amounts of heat produced 
by the formation of the chief products shall stand to each other in a simple relation ? 
the answer would be: the combustion must take place according to equation (IV.). 
But not only does this equation correspond to the most simple relations of the heat 
of formation of the principal products, it likewise requires the most simple distribution 
of the oxygen of the decomposed saltpetre. If the combustion of a mixture of 
saltpetre, carbon, and sulphur is to produce potassic carbonate and sulphate, carbonic 
acid and nitrogen, and if the oxygen of each of the first three products is to stand 
to the oxygen of the others in the most simple ratios possible, then the mixture 
must burn according to equation (III.), p. 553, and as the proportions expressed by 
equation (IV.) closely approach to those of equation (III.), it follows that equation (IV.) 
fulfils all the conditions and consequences explained in the foregoing lines. And, 
perhaps, these relations are the cause why mixtures of saltpetre, carbon, and sulphur 
of different composition burn during the first stage of the explosion according to 
equation (IV.), and if they contain more carbon and sulphur than is required by 
this equation, the excess of the two elements will remain free. 
These interesting conclusions I deduce from the analytical data of Karolyi and 
the corrected results of Noble and Abel’s experiments. Their investigations, however, 
do not give any information about the reactions of the second stage of the combustion 
of gunpowder, the reduction of potassic sulphate by carbon, and the decomposition 
of potassic carbonate by sulphur. Hitherto it has been assumed that potassic mono- 
sulpbide is formed ; this is, however, a mistake. 
According to Berzelius and Mitscherlich* the products of the decomposition of 
potassic carbonate by sulphur at a white heat are potassic sulphate and disulphide : 
4K 2 C0 3 +7S=K 2 S0 4 +3K 3 S,+4C0 2 
The question we have now to solve is : which of the sulphides of potassium is 
formed by the action of carbon upon potassic sulphate at a white heat ? 
Bauer! and WittstockJ obtained potassic carbonate and a polysulphide, but the 
amount of sulphur in the polysulphide was not determined. 
A mixture of 
26'5 grins, of potassic sulphate 
10’54 „ „ carbonate 
2 '5 ,, charcoal 
* Gmelin-Kraut, ‘ Handbuch der Chemie,’ Bd. ii., p. 39. 
t Ibid., p. 33. X Ibid., p. 33. 
