196 MUNROE-HOWELI^PRODUCTS OF DETONATION OF TNT. 



contact with air they will ignite and burn, though there may not be 

 time for their complete combustion, hence the results of the detona- 

 tion of TNT in air under ordinary pressure would be represented 

 partly by the first expression and partly by the second. 



When the explosion takes place out of contact with air or oxy- 

 gen in a confined space so that high pressures and temperatures are 

 developed and maintained, the products first formed tend to dis- 

 sociate or to react with one another to produce new associations so 

 that, dependent on the primary reactions, the pressures and tem- 

 peratures attained, and the rate of cooling, the kind of products, 

 and the quantities of the several kinds of products will differ from 

 those represented in (i) and (2). One such case may be repre- 

 sented by the expression 



(3) 2QH,(NO,)3 -^ 12CO 4- 2CH, -f H, -f 3N, ■ 



In practice TNT is exploded by a detonator, or, as in H.E. shell, 

 by a primer and booster. Since TNT is less sensitive to detonation 

 than dynamite, gun cotton and the better known high explosives it 

 is advised that a No. 8 mercury fulminate, potassium chlorate de- 

 tonator be employed to detonate it. Where " weaker " detonators, 

 or those containing less than two grams of the detonant, have been 

 employed to explode TNT in the open the explosive efifect of the 

 latter has been less and the smoke given off was grey. 



In all cases detonators of some kind are used to explode TNT. 

 They usually consist of copper capsules, which in the form of 

 electric detonators are provided with copper leading wires and re- 

 sistance bridges sealed in by sulphur plugs, and they are charged 

 with determined weights of mercuric fulminate alone, or mercuric 

 fulminate and potassium chlorate mixed, or mercuric fulminate and 

 a tetryl booster, or with lead azide or other detonant, and on ex- 

 plosion they will give rise to gaseous and other products which will 

 be mingled with the products from the TNT itself. It is true that 

 the weight of the charge of detonant is, as a rule, but a small frac- 

 tion of the weight of the TNT charge detonated but in any precise 

 investigation of the products of detonation of TNT the products 

 from the detonator used should be taken into account. 



Although solid explosives, such as TNT is, when employed for 



