370 



Chemical Theory of Gunpowder. 



[Feb. 23, 



In the same manner we obtain for the point of intersection corre- 

 sponding to equations (15) and (16) : 



16KN"0 3 + 20C = 8K2C0 3 + 12C0 2 + 8N 2 , 



and finally, the sides whose equations are (14) and (15), intersect in 

 point ?/ = 24 and 2 = 16, hence 



I6KNO3 + 24C + 1 6S = 8K 2 S 2 + 24C0 2 + 8N 2 . 



The geometrical construction of the co- efficients of equation (13) 

 possesses the great advantage of indicating by the co-ordinates of the 

 points of a triangle the composition of the infinite number of mixtures 

 of saltpetre, carbon, and sulphur which can transform themselves 

 during combustion according to equation (13), and enables us to 

 deduce geometrically, as is shown in the paper, the qualitative nature 

 and the quantitative relations of the products of combustion, as well 

 as the volume of gas and the amount of heat developed by each 

 mixture. 



(20.) It is proved in the paper that the composition of a powder 

 which can transform itself during combustion according to equation 

 (13), and for which E in equation (11) shall be a maximum, is in- 

 dicated by the co-ordinates of the point of intersection of the sides 

 of the triangle represented by the equations (14) and (15). 



If, therefore, such quantities of powders of different composition 

 are compared, which contain 16 molecules of saltpetre, the one com- 

 posed of 16KN"0 3 + 24C + 16S will possess the greatest energy. 



(21.) If E is calculated for equal weights of two powders of different 

 composition, the difference of the values of E is found to be very 

 small, if the powders contain from 21 to 24 atoms of carbon, and 

 from 8 to 16 atoms of sulphur for every 16 molecules of saltpetre. 

 Equal weights of the two mixtures 



I6KNO3+22C + 8S, 

 and 16KN0 3 + 24C + 16S, 



give for E [equation (11)] the values 16*84 and 16*95 respectively. 

 If, therefore, a mixture of saltpetre, carbon, and sulphur is required, 

 which shall possess the greatest or nearly the greatest amount of 

 energy, and at the same time contain the smallest amount of carbon 

 and sulphur compatible with this condition, theory would point to the 

 mixture 



I6KNO3 + 22C + 8S. 

 The gunpowders of most nations fluctuate about 

 16KN0 3 + 21-2C + 6-8S, 

 which numbers are very near those required by theory. 



