70 
SUBSTITUTES FOR GUNPOWDER. 
1’83. The acid is cooled artificially during the addition of glycerine, and the mixture 
is afterwards poured into water, when an amber-coloured oily fluid separates, which is 
insoluble in water, and possesses no odour, but has a sweet pungent flavour, and is very 
poisonous, a minute quantity placed upon the tongue producing violent headache, which 
lasts for several hours. 
The liquid has a specific gravity of 1*6, and solidifies at about 5° C. (40° F.); if flame 
is applied, nitro-glycerine simply burns; and if placed upon paper or metal, and held 
over a source of heat, it explodes feebly after a short time, burning with a smoky flame. 
If paper moistened with it be sharply struck, a somewhat violent detonation is produced. 
Alfred Nobel, a Swedish engineer, was the first to attempt the application of nitro¬ 
glycerine as an explosive agent, in 1864. 
Some experiments were, in the first instance, made with gunpowder, the grains of 
which had been saturated with nitro-glycerine. This powder burnt much as usual, but 
with a brighter flame, in open air. When confined in shells or blast-holes, greater 
effects were, however, produced with it than with ordinary gunpowder ; its destructive 
action is described as having been from three to six times greater than that of powder. 
The liquid could not be employed as a blasting agent in the ordinary manner, as the appli¬ 
cation of flame to it from a common fuze would not cause it to explode. But Mr. Noble 
has succeeded, by employing a special description of fuze, in applying the liquid alone 
as a very powerful destructive agent. The charge of nitro-glycerine having been intro¬ 
duced, in a suitable case, into the blast-hole, a fuze, to the extremity of which is 
attached a small charge of gunpowder, is fixed immediately over the liquid. The con¬ 
cussion produced by the exploding powder, upon ignition of the fuze, effects the explo¬ 
sion of the nitro-glycerine. 
The destructive action of this material is estimated, by those who have made experi¬ 
ments in Sweden and Germany, as about ten times that of an equal weight of gun¬ 
powder. Therefore, although its cost is about seven times that of blasting powder, its 
use is stated to be attended with great economy, more especially in hard rocks, a consi¬ 
derable saving being effected by its means in the labour of the miners, and in the time 
occupied in performing a given amount of work, as much fewer and smaller blast-holes 
are required than when gunpowder is employed. The material appears to have recently 
received considerable application in some parts of Germany and in Sweden ; but, in 
England, its employment has been confined to one set of experiments instituted in 
Cornwall last summer, upon which occasion a wrought-iron block, weighing about three 
hundredweight, was rent into fragments by the explosion of a charge of less than one 
ounce of nitro-glycerine placed in a central cavity. 
Nitro-glycerine appears, therefore, to possess very important advantages over gun¬ 
powder as a blasting and destructive agent, but the attempts to introduce it as a substi¬ 
tute for gunpowder have already been attended by most disastrous results, ascribable in 
part to some of its properties and the evident instability of the commercial product, but 
principally to the thoughtlessness of those interested in its application, who appear to 
have been induced, either by undue confidence in its permanence and comparative safety 
■or from less excusable motives, to leave the masters of ships, or others who had to deal 
with the transport of the material, in ignorance of its dangerous character. 
The precise causes of the fearful explosions of nitro-glycerine which occurred at As- 
pinwall and San Francisco will, in ail probability, never be ascertained; but they are 
likely to have been due, at any rate indirectly, to the spontaneous decomposition of the 
substance, induced or accelerated by the elevated temperature of the atmosphere in those 
parts of the ships where it was stored. Instances are on record in -svhich the violent 
rupture of closed vessels containing commercial nitro-glycerine has been occasioned by 
the accumulation of gases generated by its gradual decomposition ; and it is at any rate 
mot improbable that a similar result, favoured by the warmth of the atmosphere, and 
•'eventually determined by some accidental agitation of the contents of the package of 
nitro-glycerine, was the cause of those lamentable accidents. The great difficulties 
attending the purification of nitro-glycerine upon a practical scale, and the uncertainty, 
as regards stability, of the material, even when purified (leaving out of consideration its 
very poisonous character and its ex'treme sensitiveness to explosion by percussion v/hen 
•in the solid form), appear to present insurmountable obstacles to its safe application as 
;a substitute for gunpowder. 
The conversion of purified lignin or wood fibre into an explosive substance of the same 
