GUN-COTTON. 23 



suddenly raised, although it may explode at as low as 144°. 

 By gradual elevation of the temperature, so as not to exceed 

 five degrees per minute, the liability of explosion is considera- 

 bly lessened. Care should be taken to pack it in vessels which 

 will not convey heat interiorly, since metallic vessels may be- 

 come heated to 144° by exposure to the sun's rays. 



Averos (Comptes Rendus, xxiii.) gives the following as the 

 results of his experiments on gun-cotton : 



1. Equal parts of sulphuric and nitric acids, and clean 

 cotton. 



2. Time of exposure, 10-15 minutes. 



3. The mixture may be used again. 



4. The cotton should not project above the liquid. 



5. It should be slowly dried, and not exposed to a heat 

 above 212°. 



6. The cotton acquires more force by impregnation with 

 saltpeter. 



Explosive paper is prepared, according to Pelouze, by dipp- 

 ing it for 20 minutes in concentrated nitric acid, washing it 

 thoroughly with water, and drying it at a gentle heat. It 

 takes fire at 356°, and explodes with great violence, leaving 

 no residue. 



Cotton has the formula C^JH^fi^^, and gun-cotton C^^H^gN^ 

 0^^=C,.JIj5 0,g-f 5N0.. Hence, 5 eq. water (HO) are re- 

 moved from cotton and replaced by 5 eq. nitric acid ; or H^ are 



TT 



removed and replaced by 5NO4, thus, C^^ /-^q \^ 0^^. 



1 grm. gun-cotton yields by explosion 588 cub. cent, gas 

 (at 32° and O.TG'" pressure), which has the following composi- 

 tion by volume : 



17.03 carbonic acid. 

 47.45 carbonic oxide. 

 20.41 nitric oxide. 

 6.75 nitrogen. 

 8.36 carburetted hydrogen (CH). 



100.00 



