MUNROE-HOWELL— PRODUCTS OF DETONATION OF TNT. 195 



should however be stated that notwithstanding its excellent quali- 

 ties the cost of manufacture will probably prevent TNT per se 

 being used as a commercial explosive and that its use under the 

 conditions noted above would not have been advised except for the 

 necessity of promptly disposing of it and the lack of available funds 

 to devote to its conversion into a more useful form. 



As is pretty generally known, TNT is produced by the nitration 

 of toluene but by such nitration, according to the way it is carried 

 out, a large number of mono-, di- and tri-nitrotoluenes are pro- 

 duced. The existence of six different isomeric trinitrotoluenes is 

 recognized as possible. By the methods now in commercial use the 

 material which is produced in the largest quantity and in a pure, or 

 nearly pure, condition is the a- or symmetric trinitrotoluene, and ' 

 it is this material that was adopted as a military explosive and to 

 which the distinctive name of TNT has been given. The criterion 

 used for ascertaining the purity of TNT is its setting point after 

 having been melted. Our War Department specifies for acceptance 

 a S.P. of 80° C. for Grade I; of 79.5° C. for Grade II; and of 

 ^6° C. for Grade III. Grade I was produced in but small quantity 

 especially for use in booster charges, though some was, perhaps 

 unwisely, specified for demolition purposes. 



The chemical reactions which TNT may undergo when ex- 

 ploded will differ with the circumstances under which it is exploded. 

 When TNT is completely detonated unconfined much black smoke 

 is given off, for not only are gases, and perhaps vapors, formed but 

 carbon is set free. A theoretical expression for the reaction of the 

 TNT per se is 



(1) 2QH,(NO,)3 ^ 12CO + 5H, + 3N, + 2C. 



When TNT is completely burned with oxygen the reaction may 

 run as follows 



(2) 4C,H5(NO,)3 + 21O, -^ 28CO, -f loH.O + 6N.. 



From the presence of the easily ignitible and readily combustible 

 gases, carbon monoxide and hydrogen, and of free carbon in ex- 

 pression (i) it is apparent that when these substances, in the highly 

 heated condition they must be in at the time of explosion, come in 



