DR. H. DEBUS ON THE CHEMICAL THEORY OF GUNPOWDER, 
551 
that of the sulphide increased, the free sulphur would have decomposed potassic 
carbonate with production of potassic sulphate and sulphide ; in short, the products 
of combustion would have formed in similar proportions as we find them in Noble and 
Abel’s experiments. The products of several hundred grammes of powder remained 
in a fluid condition at a white heat in Noble and Abel’s steel cylinder from 60 
to 100 seconds in contact, whereas the 36 grms. of burning powder were scattered 
after the explosion of Karolyi’s brass cylinders over the cold sides of a large iron 
shell, and their combustion occupied only a very small fraction of a second. The 
reactions between the powder constituents had time to complete themselves in Noble 
and Abel’s steel cylinder, but they had not in Karolyi’s small brass vessel. And 
although the time of the combustion in the experiments of the last-named chemist 
was very short, less than one second, we find all the saltpetre of the powder decomposed, 
and its constituents incorporated in the potassium salts, carbonic oxide and carbonic 
acid, or set free as nitrogen. 
At the same time two of the potassium salts, the hyposulphite and sulphide, occur 
in such small quantities that we may regard them as secondary products, not 
connected with the chief reactions of the explosion, and accordingly neglecb them. 
Hence we have, as chief products formed in Karolyi’s experiments : potassic 
sulphate and potassic carbonate, carbonic acid and nitrogen, and perhaps carbonic 
oxide. 
The combustion of gunpowder accordingly consists of two distinct stages; a process 
of oxidation, which is finished in a very short time, occupying only a very small 
fraction of a second, and causing the explosion, and during which potassium carbonate 
and sidphate, carbonic acid, some carbonic oxide and nitrogen are produced, and 
a process of reduction, which succeeds the process of oxidation and requires a 
comparatively long time for its completion. As the oxygen of the saltpetre is not 
sufficient to oxidise all the carbon to carbonic, and all the sulphur to sulphuric acid, 
a portion of the carbon and a portion of the sulphur are left free at the end of the 
process of oxidation. The carbon so left free reduces, during the second stage of 
the combustion, potassic sidphate, and the free sulphur decomposes potassic carbonate. 
Hydrogen and marsh gas, which are formed by the action of heat upon charcoal, like¬ 
wise reduce potassic sidphate, and some hydrogen combines ivith sulphur, forming 
sidphuretted hydrogen. 
Great variations of pressure appear to affect the proportions of the different 
products in a very slight degree, so that it may be regarded as doubtful whether 
pressure has any influence on them. 
Karolyi’s experiments happen to be arranged in such a manner that the com¬ 
bustion of his powders could only proceed to the end of the first and the commence¬ 
ment of the second stage ; in Noble and Abel’s explosions, the reactions of the second 
stage were also completed. 
This view of the combustion of gunpowder explains not only the experiments of 
4 B 
MDCCCLXXXIL 
