GUN-COTTON AND DYNAMITE. 445 



3. Gun-cotton is practically only used for military purposes, 

 since its high price prevents it becoming a rival of dynamite, 

 which, besides, is more easily adapted to the requirements of 

 miners. 



In Austria, Eussia, and France, even up till recently, dynamite 

 has been preferred to it as a war explosive, whereas in England 

 and Germany gun-cotton has the preference. The Marine 

 Artillery in France l also uses it, and the French army autho- 

 rities evince a tendency to go back to its use on account of its 

 safer preservation. 



4. However, gun-cotton being, like dynamite, susceptible of 

 detonation from the shock of a ball at a short distance, en- 

 deavours have been made to reduce this sensitiveness. In order 

 to effect this it suffices to incorporate with it from ten to fifteen 

 per cent, of water or paraffin. Damp gun-cotton is much better 

 able to resist mechanical agents. 



In this state it cannot be inflamed by contact with a body in 

 ignition, or by spontaneous decomposition. Gun-cotton, when 

 mixed with paraffin, is also less sensible to shock, but it is not 

 safe from the risk of inflammation. 



On the other hand, the detonation of moistened or paraffined 

 gun-cotton is more difficult ; it requires the employment of a 

 very strong dose of fulminate, or a small hand-made cartridge 

 of dry gun-cotton primed with fulminate. 



The presence of water, as also of paraffin, further lessens the 

 force of the explosion. 



The application of water is subject to variations owing to 

 spontaneous evaporation, which is a serious difficulty. 



In the German army paraffin is employed. The application 

 of this is simpler, and it is not subject to variations on account 

 of the weather. Nevertheless, sensibility to detonators does not 

 appear to be the same in paraffined gun-cotton which has been 

 recently or for some time prepared, probably on account of the 

 change in structure, which is the result of the slow crystallisa- 

 tion of the paraffin. 



5. Gun-cotton does not, like nitroglycerin, contain a suffi- 

 cient quantity of oxygen for the combustion of its elements ; 

 hence the proposal to associate it with potassium, barium, or 

 ammonium nitrate, or with potassium chlorate ; bodies which 

 would supply it with oxygen. 



Abel's glyoxyline contains potassium nitrate and nitro- 

 glycerin. 



The most varied compounds have from this point of view 

 been proposed, and continue to be proposed daily. We shall 

 particularly mention Schultze powders, formed by nitrified 



1 See " Memorial des Poudres et Salpetres " (Rapport sur 1'emploi du coton- 

 poudre aux operations de guerre), par H. Sebert, Commissions des Explosive 

 Substances, p. 109. 1882. 



