PROCEEDINGS OF THE POLYTECHNIC ASSOCIATION. 501 



particular cases, as in the charging of shells. Among these, one 

 of the most important was the invention of the percussion powder 

 and percussion cap. Gun cotton will not take the place of gun- 

 powder, not only because it burns too quickly, but because it 

 will not burn without the presence of air. Gunpowder contains 

 within itself oxygen enough to burn its other constituents ; but 

 gun. cotton does not. If it is necessary to have a composition 

 to explode more quickly than gunpowder in charging shells, I 

 do not know anything better than gun cotton saturated with 

 chlorate of potassa. 



Mr. Fisher. — While the improvements in warfare may not 

 cause any greater destruction, or give civilized nations any ad- 

 vantage over one another, yet they are valuable in rendering it 

 impracticable for barbarians to overrun civilized nations. The 

 more knowledge is required, and the more skill and capital are 

 invested in these improvements, the safer we are from attacks by 

 barbarous nations. 



A visitor suggested that the more destructive the weapons of 

 war the greater must be the distance of the contending parties, 

 and hence the less the actnal loss of life. It is, therefore, a 

 humane act to make such improvements. 



Prof. Joy, of Columbia College, stated that within the last 

 few years Prof. R. Bunsen had made some interesting chemi- 

 cal analyses of gunpowder, the result of which varied much 

 from our previous information upon the subject. The compo- 

 sition of the gunpowder was : 



Saltpetre _ 78.99 



Sulphur 9.84 



Carbon 7.69 



H3'drogen __ 41 



Oxygen 3.07 



100.00 

 After explosion, the residue was found to consist chiefly of 

 sulphate and carbonate of potassa, the analysis being : 



Sulphate of potassa _ 56.62 



Carbonate of potassa , 27.02 



Hypo-sulphite of potassa _ 7.57 



Sulphide of potassium _ 1.06 



Potassa 1.26 



Sulpho-cyanide of potassium .86 



Saltpetre 5.19 



Carbon _ 97 



100.52 



