440 DYNAMITES. 



combustible substance, and for the sake of simplicity the char- 

 coal will be considered as pure carbon. 



All systems which satisfy the condition of total combustion 

 reduce themselves to the following formula : 



4C 3 H 2 (N0 3 H) 3 + 0] + </(N0 3 NH 4 + C). 

 They produce 



The corresponding weight is 



(230z + 86y) grms. 

 The heat liberated (gaseous water) is equal to 



325-7z + 79% ; 

 Or, for 1 kgm., 



The volume of the gases is 



(7iz + 4Jy) 22-32 litres (1 + at)= 



Jti 



The permanent and the theoretical pressure at a density of 

 charge - are immediately deduced from the above data. 



3. For instance, let 



jc=l;y=16 



be the corresponding weight : 230 + 1376 = 1606 grms. 

 The percentage of the immediate composition will be 



Nitroglycerin ............ 14-1 



Ammonium nitrate ............ 79-6 



Charcoal ............... 6-3 



4. The heat liberated = 1593 Cal. (gaseous water), or 1938 

 Cal. (liquid water) ; or, for 1 kgm., 992 Cal. gaseous water, or 

 1207 Cal. liquid water. 



^ 5. The reduced volume of the gases (gaseous water) = 1769 

 litres, or 642 litres (liquid water) ; or, for 1 kgm., 1101 litres 

 gaseous water, or 400 litres liquid water. 



6. The permanent pressure (liquid water) = 4QO atm - > with 



fli U'O7 



the usual reservation as to the liquefaction of the carbonic acid 

 when n falls below a certain limit. 



7. The theoretical pressure = -- 5*5t a va i ue higher 



than the theoretical figure for ordinary 75 per cent dynamite 

 (p. 425). 



