512 
ME. E. A. ABEL’S CONTRIBUTIONS TO 
must, therefore, be applied in the latter instance, if the explosion of the same substance 
is to be accomplished by it. 
The power possessed by the violent explosion of a particular material (such as gun- 
cotton or nitroglycerine) to determine the apparently simultaneous explosion of perfectly 
separate masses of the same substance, does not excite surprise. Instances of the appa- 
rently simultaneous explosion of numerous distinct and even somewhat widely separated 
masses of explosive substances (such as simultaneous explosions in several distinct build- 
ings at powder-mills) do not unfrequently occur, in which the generation of a disruptive 
impulse by the first or initiative explosion, which is communicated with extreme rapidity 
to contiguous masses of the same nature, appears much more likely to be the operating 
cause, than that the simultaneous explosion should be brought about by the direct ope- 
ration of heat and mechanical force developed by the starting explosion. In submitting 
this proposition I confidently believe that I am not advancing a view which possesses 
any claim to novelty, but that I am only contributing some support, by the result of 
experiment, to an opinion which has been strongly entertained by many. 
It appears remarkable that two substances so analogous as gun-cotton and nitrogly- 
cerine in their chemical constitution and general characters as explosive agents, should 
exhibit the very great differences which have been observed in their susceptibility to 
explosion by the effects of a detonation. An explosive mixture (such as percussion-cap 
composition) which will not detonate gun-cotton if used in considerable quantities and 
strongly confined, explodes nitroglycerine even if used in as small proportion as 0-2 grm. 
(3 grains) ; 0-32 grm. (5 grains) of the strongly confined fulminates is required to deto- 
nate gun-cotton, while 0-07 grm. (1 grain), and perhaps even less, will explode nitro- 
glycerine. The detonation of gun-cotton by means of chloride of nitrogen can only be 
accomplished by employing about 3 ‘25 grms. (50 grains) of that substance, while 0T 
grm. (T5 grain) suffices for the explosion of nitroglycerine. It is obvious from these 
results that a comparatively very small amount of mechanical force, suddenly applied, 
suffices to develope the violent decomposition of nitroglycerine ; it is therefore not diffi- 
cult to understand why this substance, though incapable of detonating gun-cotton, even 
when used in considerable quantities, should be itself readily exploded by means of the 
latter. It was impossible to determine how small a proportion of gun-cotton would 
suffice for that purpose, because, in the necessary experiments, the gun-cotton would 
have to be placed in very close proximity to, or contact with, the nitroglycerine, in which 
case the fulminate-charge required for detonating the gun-cotton would alone much more 
than suffice for exploding the nitroglycerine. 
The comparatively very great sensitiveness of this substance to explosion through the 
agency of a detonation may probably be ascribable in part to its physical character as a 
liquid, and in part to the fact that the proportion of oxygen to oxidizable elements is 
much more considerable in nitroglycerine than in gun-cotton. 
