3o6 



POPULAR SCIENCE MONTHLY. 



when ignited, but it can be quenelied by pouring water upon it. 

 When confined in the chamber of a gun or the bore-hole of a rock, 

 gun cotton will burn like gunpowder when ignited, if dry, and pro- 

 duce an explosion, but, in common 

 with nitroglycerin and other high 

 explosives, gun cotton is best ex- 

 ploded and develops its maximum 

 effect when detonated, a result 

 which is secured by exploding a 

 small quantity of mercury ful- 

 minate in contact with the dry 

 material. 



Mercury fulminate is made by 

 dissolving mercury in nitric acid 

 and pouring the solution thus pro- 

 duced into alcohol, when a violent reaction takes place and the ful- 

 minate is deposited as a crystalline gray powder. This powder is 

 loaded in copper cases and, after drying, it is primed with dry-mealed 



Ikon Cylihder filled with Water and 

 CONTAINING A Naval Detonator. Be- 

 fore and after tiring, shows the work ac- 

 complished by thirty -five grains of mer- 

 cury fulminate. 



Smokeless I'owdeks. In the bottle is iiulurite in flake grains. Tlit hir>rcr grains are cylin- 

 drical and Jie.xagonal multiperforated United States army grains. The bent grain in the 

 foreground, looking like a piece of rubber tubing, is a grain of Maxim powder with a 

 single canal. The flat strips in tlie foreground on the left are grains of the French B. N. 

 powder. The flat strips in the foreground on the right are grains of the United States 

 navy '• pyrocclbilosc " ]>owder. 



gun cotton, the mouth of the case being cluicJ with a sulphur-glass 

 plug, through which pass two copper leading wires joined by a bridge 

 of platinum-iridium wire, two one-thousandths of an incli in diame- 



