548 
DR. H. DEBUS ON THE CHEMICAL THEORY OF GUNPOWDER. 
under high pressure mure potassic sulphide is produced than would be formed by the 
same powder under lower pressures. 
The experiments of Fedorow, however, do not prove anything of the kind. He 
fired powder from a pistol and from a 9-pounder cannon, and it appears that the 
solid products of the powder fired from the pistol were collected in a glass tube. A 
charge of 0‘75 grm. of powder gave a residue with proportionally more potassic 
sulphate and less of potassic sulphide than one of 1*5 grms., and relatively still 
smaller was the potassic sulphate and greater the sulphide in the residue obtained by 
the firing of 3 lbs. of powder from the cannon. 
M. Fedorow concludes : “A smaller amount of powder remains unconsumed, less 
potassic sulphate, but more sulphide and carbonate are formed under higher than 
under lower pressures. Time acts like pressure. If the combustion of the powder 
is retarded the same effects follow as if the pressure had been increased. A charge of 
1*5 grms. of a mixture consisting of 100 parts of meal powder, and 0*5 part of 
stearic acid, gave a residue with less potassic sulphate, but with more carbonate and 
hyposulphite than a similar charge of ordinary powder would have done/’ 
Potassic sulphide is, as is well known, a substance endowed with great attraction 
for oxygen, not only at high, but also at ordinary temperatures. It appears that the 
air was not excluded from the glass tube into which M. Fedorow fired his charges 
for the collection of the solid residues. A greater percentage of the potassium sulphide 
formed by a small charge, than of the sulphide of the products of a larger charge, 
will in this manner be oxidised. 
It thus appears that M. Fedorow’s experiments can be explained without reference 
to pressure. But as far as the retardation of the combustion by stearic acid is 
concerned, we cannot ascribe to retardation an effect which is due to the stearic acid 
itself. Stearic acid at a red heat reduces potassic sulphate to sulphide and probably 
carbonate. 
M. Fedorow could not collect and examine the gases. 
The experiments of Fedorow do not establish a relation between pressure and 
the nature and quantities of the products of explosion, and, consequently, do not 
invalidate the conclusions of Karolyi, as stated on page 547. 
We will now proceed to explain, by means of the analytical results of Karolyi, 
some of the reactions which take place during the combustion of gunpowder. For this 
purpose it will be desirable to express the composition of the Austrian powders, and 
the products of explosion, by chemical formulae. 
