581 
BE,. H. DEBUS ON THE CHEMICAL THEOBY OE GUNPOWDEH. 
for mixtures which will bum with production of equal quantities of potassic 
sulphate. 
This is the equation of a line parallel to the side D C. All these parallel lines 
intersect the line D B. If, then, we know the quantity of potassic sulphate corre¬ 
sponding to each point of D B, we shall likewise know the amount of this salt which 
any mixture, the composition of which is represented by the coordinates of one of the 
points of the triangle, can produce by its combustion. Now the powders, the com¬ 
position of which is given by the coordinates of the points of B D produce by their 
combustion an amount of potassic sulphate which in molecules is directly expressed by 
the length of the corresponding abscissae of the points. 
Since a: has been taken constant =16, the sum of the molecules of the potassium 
salts must always be =8, and as the points of the line B D represent only mixtures 
which burn with the production of two of these salts, potassic carbonate and sulphate, 
it is only necessary in order to know the respective quantities of each of these salts 
for a point F on B D, to subtract the value of the abscissa of F from 8 to obtain the 
molecules of potassic carbonate which would be produced by the combustion of a 
mixture the composition of which is given by the coordinates of F. 
The coefficient of potassic disulphide in equation (XIII.) is = —160 + 8 ^+ 122 , from 
which we deduce the equation : 
c +160 
8 
which is the equation of a line parallel to side B D. The points of such a line 
represent by their coordinates mixtures which will burn with the production of the 
same amount of potassic disulphide, which amount is constant for the same line, but 
changes from one to another. This amount is found for a mixture represented by the 
coordinates of a point P, if through P a line is drawn parallel to B D, and the abscissa 
of the point of intersection with the side D C is ascertained; half the length of this 
abscissa represents the number of molecules of potassic disulphide formed by the 
combustion of the mixture represented by point P. 
For mixtures which are to burn with the evolution of the same quantity of carbonic 
acid we have : 
— 64+20y+162=c 
or 
c -f- 64 
20 
an equation which represents a line parallel to G H, on which for two points y, z and 
y, z, five times the difference of the ordinates is equal to four times the difference of 
the abscissae. 
The line D Y in our figure is parallel to G H. In order to find the amount of 
