DR. H. DEBUS OR THE CHEMICAL THEORY OF GUNPOWDER. 
579 
It will be observed that 
(XIV.) is the equation of B C 
(XY.) „ „ DC 
(XYI.) „ „ B D. 
The points of the side B C represent, by their coordinates, mixtures of carbon and 
sulphur with 16 mols. of saltpetre, which will by complete combustion produce no 
potassic carbonate; those of side D C such as will not form potassic sulphate, and 
finally, the coordinates of the points of side B D denote quantities of carbon and 
sulphur which will burn with 16 mols. of saltpetre without the formation of potassic 
disulphide. The coefficient of carbonic acid will never vanish, but be always positive, 
because if it is equated to zero it will represent the line G H in figure, which does not 
intersect the triangle B D C. 
All points outside the triangle B D C have coordinates which render at least one 
of the three coefficients of the potassium salts in equation (XIII.) negative, and con¬ 
sequently have reference to mixtures of carbon and sulphur with 16 mols. of saltpetre, 
which contain either too much or too little of one or both of the two elements named. 
The coordinates of the line B D represent mixtures of carbon and sulphur with 
16 mols. of saltpetre, which will burn without the formation of potassic disulphide, 
and those of the line B C, such as will not produce potassic carbonate; hence, it may 
be -concluded that the coordinates of B, the point of intersection of the two lines will 
correspond to a powder which will be transformed without formation of potassic 
carbonate and disulphide, and will only yield, as products of its combustion, potassic 
sulphate, carbonic acid, and nitrogen. The coordinates of point B are ; 
2/=8 
^ = 8 
and these values substituted in equation (XIII.). 
16KN0 3 +8C + 8S=8K 2 S0 4 +8C0 3 +8N 3 
or simplified : 
2KN0 3 +C+S=K 3 S0 4 +C0 3 +N 3 . 
Accordingly a mixture of 82*1 parts of saltpetre, 4'8 parts pure carbon, and 13 parts 
of sulphur may be expected to produce during complete combustion only potassic 
sulphate, carbonic acid, and nitrogen, and this conclusion is in perfect accord with the 
thermochemical relations of the reacting substances and with experimental results. 
And by a similar method of reasoning we arrive at the conclusion that the coordinates 
of the point D represent a mixture which will burn according to the equation : 
16KNO 8 +20C=8K a CO 3 +12CO 8 +8N 8 
