CONTRIBUTIONS TO THE HISTORY OF EXPLOSIVE AGENTS. 75 
5. Cold infusions of orange peel and cinnamon may serve as vehicles; with other aro¬ 
matics it can only be given in the form of powder. 
6. It does not possess any astringent properties, and cannot be given with infusions of 
remedies containing tannin. 
7. With resolvents and hepatic remedies (aloes, gall, taraxacum, carduus bened., etc.) 
it can only be given in pilular form, and with solution of iodide of potassium only by 
taking the iron syrup afterwards. 
8. It must take the place of all other iron preparations as an antidote to arsenic. Rab¬ 
bits were given O'1345 grm. As0 3 , and afterwards, at intervals of ten minutes, four doses 
of grm. saccharated oxide of iron; they fed again eighteen hours afterwards. When 
poisoned, the quantity of urine was very small, and it contained albumen ; after eighteen 
hours the secretion of urine was regular, and both arsenic and iron were found in it.— 
Buchner's N. Repert 1869, 36-42. From Berlin. Klinische Wochenschr. Halle , July 
1 5th, 1868. 
CONTRIBUTIONS TO THE HISTORY OF EXPLOSIVE AGENTS. 
BY F. A. ABEL, F.R.S., FOR. SEC. CHEM. SOC. 
(Abstract.) 
The degree of rapidity with which an explosive substance undergoes metamorphosis, 
as also the nature and results of such change, are, in the greater number of instances, 
susceptible of several modifications by variation of the circumstances under which the 
conditions essential to chemical change are fulfilled. 
Excellent illustrations of the modes by which such modifications may be brought 
about are furnished by gun-cotton, which may be made to burn very slowly, almost 
without flame, to inflame with great rapidity, but without development of great explo¬ 
sive force, or to exercise a violent destructive action, according as the mode of applying 
heat, the circumstances attending such application of heat, and the mechanical condition 
of the explosive agent, are modified.* The character of explosion and the mechanical 
force developed, within given periods, by the metamorphosis of explosive mixtures such 
as gunpowder, is similarly subject to modifications; and even the most violent explosive 
compounds known (the mercuric and silver fulminates, and the chloride and iodide of 
nitrogen) behave in very different ways, under the operation of heat or other disturbing 
influences, according to the circumstances which attend the metamorphosis of the ex¬ 
plosive agent ( e . g. the position of the source of heat with reference to the mass of the 
substance to be exploded, or the extent of initial resistance opposed to the escape of the 
products of explosion). 
Some new and striking illustrations have been obtained of the susceptibility to modi¬ 
fication in explosive action possessed by these substances. 
The product of the action of nitric acid upon glycerine, known as nitro-glycerine or 
glonoine, which bears some resemblance to chloride of nitrogen in its power of sudden 
explosion, requires the fulfilment of special conditions for the development of its explo¬ 
sive force. Its explosion by the simple application of heat can only be accomplished if 
the source of heat be applied, for a protracted period, in such a way that chemical de¬ 
composition is established in some portion of the mass, and is favoured by the continued 
application of heat to that part. t Linder these circumstances, the chemical change pro¬ 
ceeds with very rapidly accelerating violence, and the sudden transformation into gase¬ 
ous products of the heated portion eventually results,—a transformation which is in¬ 
stantly communicated throughout the mass of nitro-glycerine, so that the confinement 
of the substance is not necessary to develope its full explosive force. This result can be 
obtained more expeditiously and with greater certainty by exposing the substance to 
the concussive action of a detonation produced by the ignition of a small quantity of 
fulminating powder, closely confined and placed in contact with, or proximity to, the 
nitro-glycerine. 
The development of the violent explosive action of nitro-glycerine, freely exposed to 
air, through the agency of a detonation, was regarded until recently as a peculiarity of 
* Proceedings of the Royal Society, vol. xiii. pp. 205, et se%. 
