154 Nitro-Glycerine : [April, 
tically useless. The whole mass of explosive liquid must be violently 
concussed, and to produce the required concussion the nitro-glycerine 
must be in a confined space, while, immersed in the liquid, there 
must be a small bag of gunpowder, or a percussion cap of extra 
strength, firmly fixed on the end of a gunpowder fuse. Thus it 
will be seen that nitro-glycerine almost requires to be coaxed into an 
explosive mood ; and if people could only be brought to look on the 
explosions at Newcastle, San Francisco, Aspinwall, and one or two 
other places, without prejudice, it would universally be admitted that 
nitro-glycerine is not only not that frightfully dangerous material 
which many people in their ignorance believe it to be, and which 
some of them in a panic-stricken mood propose to “ stamp out,” but 
that it is even less dangerous than gun-cotton and gunpowder, and 
more completely under control than they are. We know that this 
is a very heretical and unorthodox utterance, still it is one that can 
be most indisputably supported and established by a great accumula- 
tion of facts resulting from the observations and experience of many 
persons whose minds are perfectly unbiassed. 
Taking advantage of the circumstance that nitro-glycerine is 
soluble in wood spirit or methyl-alcohol, Mr. Nobel, nearly two 
years ago, made the happy discovery that it could almost instan- 
taneously be rendered inexplosive, and that its explosiveness could 
be restored to it with equal readiness. The method of making it 
inexplosive is at once simple and effective. It is to mix with it 
from five to ten per cent. of wood spirit, when all attempts at ex- 
ploding it are rendered utterly futile. Five per cent. of methyl- 
alcohol is said to be amply suflicient to transform the nitro-glycerme 
into the inexplosive or protected state, but Mr. Nobel now always 
adds ten per cent. before sending any of his blasting liquid into the 
market. A commission, appointed by the Hamburg Association for 
the Promotion of Arts and Useful Professions, made an extensive 
series of experiments on nitro-glycerine protected by the addition of 
five per cent. of methyl-alcohol, in October, 1866. One of the 
experiments was an attempt to explode the liquid in the ordinary 
way with fuse and percussion cap. ‘Lhe experiment was twice 
repeated, but in neither case did the detonation of the cap affect the 
liquid. In another instance the protected liquid, in a tin bottle, 
was fired at with a bullet, but it was found impossible to produce 
an explosion. “In the opinion of the commissioners,” the official 
report concludes, the protected blasting liquid “is perfectly inex- 
plosive.” When this protected liquid is exposed to heat in a proper 
vessel, the volatile solvent escapes, and in course of time, under the 
influence of a high temperature, the nitro-glycerine explodes, but 
not with the usual amount of violence because, probably, the explo- 
sion occurs before all the methyl-alcohol volatilizes: If protected 
nitro-glycerine be spread over the surface of an anvil, and then 
