588 
DR. H. DEBUS ON THE CHEMICAL THEORY OF GUNPOWDER. 
The two mixtures 
I 6 KNO 3 + 22 C + 8 S 
and 16KNO s +22C+15S 
differ by the same amount of sulphur. 
The two former show, for E', the difference 0‘75, the latter only 0‘03; indeed, many 
of the various mixtures for which y and z have high values, give, when equal weights 
are considered, almost the same number for E'. 
If we draw a line through the triangle BCD (see fig. l), from the point y— 22 , 
z —8 to the point y= 8 , z= 8 , it will be observed that for mixtures represented by the 
coordinates of the points on the right-hand side of this line, the value of E' only 
increases very little if the sulphur is increased beyond 8 atoms and the carbon kept 
constant. This circumstance is of great practical importance. The analyses of mili¬ 
tary and sporting powders known to me, all give for 16 mols. of saltpetre an amount 
of sulphur which varies between 5'5 and 8*7 atoms. There would be very little, if any, 
gain in energy if, for 16 mols. of saltpetre, more than about 8 atoms of sulphur were 
introduced into the powder; especially would this be the case with mixtures in which 
for 16 mols. of saltpetre more than 16 atoms of carbon are present. 
E' obtains its maximum value, 16'95, when the powder contains : 
16KNO a +24C + 16S. 
Such a large amount of sulphur does not, according to the foregoing remarks, 
contribute much to the value of E r , whereas, on the other hand, it must be very 
detrimental to the metal of the ordnance. For the mixture 
I 6 KNO 3 + 22 C+ 8 S 
we have E'=16’84, hence, only 0'67 per cent, less than for L6KN0 3 -j-2&C+16S. 
If carbon and sulphur undergo a further diminution, the decrease of E becomes 
more rapid; for 
16KN0 3 +2lC+4S 
E =16’54. If, therefore, we had to choose between the two mixtures 
16KN0 3 +24C+16S 
and 16KN0 3 + 22 C+ 8 S 
for the composition of a service powder the second would recommend itself as the 
more suitable. 
We will now compare the composition and energy of the ordinary gunpowders with 
the results of the foregoing theoretical considerations. 
The composition of the powders of Waltham Abbey can be represented by the 
symbols: 
16KNOj, + 2X’18C+6*63S 
