362 
ME. F. A. ABEL’S CONTRIBUTIONS TO 
dynamite or other nitroglycerine preparations were always violently exploded by being 
bred at, nitroglycerine being much more readily susceptible of detonation by a blow. 
V.— INFLUENCE OF DILUTION, BY SOLIDS AND BY LIQUIDS, ON THE SUSCEPTIBILITY 
OF EXPLOSIVE COMPOUNDS TO DETONATION. 
It has been pointed out in my former memoir (p. 513) that solid explosive mixtures, 
consisting of one or more readily oxidizable substances intimately incorporated with 
an oxidizing agent, are less readily susceptible of detonation than .explosive compounds, 
and that the readiness with which their violent explosion can be developed through the 
agency of an initiative detonation is in direct proportion to their sensitiveness to ex- 
plosion by percussion. Mixtures consisting of a powerful oxidizing agent ( e . g. potas- 
sium chlorate) and a substance which is per se already endowed with explosive pro- 
perties approach (if they are not quite equal) to gun-cotton and even to nitroglycerine, 
in the readiness with which their detonation may be effected ; thus an intimate mixture 
of potassium picrate and potassium chlorate, in which the latter salt exists in the pro- 
portion required for the perfect oxidation of the former, may under favourable condi- 
tions be detonated by means of almost as small an amount of mercuric fulminate as the 
minimum required to detonate compressed gun-cotton*. 
a. Dilution with inert solids and with solid oxidizing agents. 
The extent to which the susceptibility to detonation of the more violent explosive 
compounds is affected by their intimate mixture with non-explosive substances is regu- 
lated partly by the physical or mechanical condition of the substance, and partly by the 
nature of the material with which it is mixed. Nitroglycerine may be very largely 
diluted by admixture with perfectly inert solid materials without diminution of its 
sensitiveness to detonation. Thus the preparation to which its inventor, A. Nobel, 
gave the name of dynamite , and which consists of nitroglycerine diluted with about 
one third its weight of the very bulky infusorial silica known as 44 Kieselguhr,” whereby 
it is converted into a plastic material, requires no more powerful initiative explosion to 
ensure its detonation than the undiluted liquid : other preparations of similar nature, 
based upon Nobel’s original idea of employing solid materials as media for the conve- 
nient application of nitroglycerine (and of which some contain not more than 20 per 
cent, of the explosive liquid), are not less sensitive to detonation. This is obviously 
due to the liquid nature of nitroglycerine, which permits of its being highly diluted 
with solid material, without isolation of different portions of the explosive by inert or 
much less explosive material. In the most diluted mixtures of this kind, provided 
they are not very carelessly prepared, each particle of the diluent is coated with a film 
of nitroglycerine, so that there is no break in continuity of the explosive agent in the 
* Abel “ On Explosive Agents,” Phil. Trans. 1869, vol. clix. p. 513. Yery interesting results have also been 
attained in a similar direction by Dr. Sprengel ( vide Journal of Chemical Society, 1873). 
