THE KOYAL ARTILLERY INSTITUTION. 
281 
The risk of accident resulting from the liability of explosive com¬ 
pounds to so-called spontaneous decomposition has been on several 
occasions exemplified in the past history of the two most important of 
these compounds—gun-cotton and nitroglycerine. Until within the 
last few years, it was believed that both these substances were in 
themselves so prone to change that their preservation for any length 
of time without undergoing spontaneous decomposition, resulting 
most probably in explosion, was regarded as, at best, a great uncer¬ 
tainty. They acquired this character for instability partly from the 
imperfect purification of specimens prepared from time to time for 
scientific or instructional purposes, and partly from repeated attempts 
to utilise their explosive properties, and therefore to produce them in 
considerable quantities, while their nature and properties were still 
very imperfectly understood (this being specially the case with gun¬ 
cotton). The liquid nature and some other peculiar properties of 
nitroglycerine delayed any important attempts at its application for 
many years; on the other hand, gun-cotton presented to the superficial 
experimenter so many alluring advantages as an explosive agent that 
its discovery was very soon followed by its manufacture and storage 
upon a large scale, which speedily resulted in such serious disasters 
that the material acquired, within a very brief period of its discovery, 
an unmerited, but for a long time completely damnatory, reputation 
for utter untrustworthiness. The stability of properly purified gun¬ 
cotton, as well as that of nitroglycerine, has, however, now been for 
some time past fully established, and no difficulty exists in carrying on 
with safety their manufacture on such a scale as to satisfy the con¬ 
tinually increasing demand for efficient preparations of these violent 
explosive agents. At the same time, the experience of the last few 
years has afforded repeated illustrations of the terrible risks and 
responsibilities incurred by manufacturers of these substances by the 
slightest departure from conditions essential to perfection and safety 
of manufacture, or by a relaxation of the strictest supervision in the 
production, purification, and storage of the materials. The calamitous 
explosion at Stowraarket in 1871, and many serious explosions at nitro¬ 
glycerine (or dynamite) factories during the last few years, in different 
parts of the Continent, have demonstrated the liability of these sub¬ 
stances to so-called spontaneous explosion, if the acids employed in 
their production are allowed to remain in contact with them for pro¬ 
tracted periods, even in very small quantities. Any negligence what¬ 
ever, therefore, in the production and purification of these substances, 
or the introduction, by accident or otherwise, of acid impurity into the 
finished materials, must in all probability prove destructive of their 
stability, and may lead to most serious disasters. 
In these respects the utilisation of explosive compounds of this class 
involves special risks not attendant upon the manufacture of gun¬ 
powder and modifications of that substance; in others, however, it 
presents important elements of comparative safety. Thus, with proper 
precautions, the conversion of glycerine into nitroglycerine may be 
carried on with safety; the purification of the substance is not attended 
by any danger, and the manipulations attendant upon its conversion 
