Proposed Substitutes for Gunpowder. 83 
the public generally to the necessity of adopting measures 
for reducing as much as possible, the risk of occurrence of 
such disastrous accidents. Hence, much interest has recently 
been excited by a well-known method of rendering gun- 
powder less dangerous in its character, which has been 
brought prominently before the public by Mr. Gale, and 
which consists of diluting powder, or separating its grains 
from each other, by means of a finely powdered non-explo- 
sive substance. Attempts have several times been made in 
‘ past years to apply to practical purposes the obvious fact, 
of which nobody acquainted with the nature of gunpowder, 
could be ignorant, that, by interposing between the grains 
ot powder, a sufficient quantity of a finely divided material, 
which offers great resistance to the transmission of heat, the 
ignition of several grains of the entire mass may be accom- 
plished without risk of inflaming contiguous grains. In 
1835, Piobert made a series of experiments with the view 
to apply this fact practically, to reduce the explosiveness 
of gunpowder, and similar experiments of an extensive 
character were carried on by a Russian chemist, Fadéiff, 
between 1841 and 1844. These experimenters found that 
the object in view might be attained by diluting gunpowder 
with any one of its components; they also employed very . 
fine sand (a substance closely allied in its physical charac- 
ters to the powdered glass, which Mr. Gale now proposes 
to use); but the preference appears to have been given to 
a particular form of carbon. It was not attempted alto- 
gether to prevent the burning of a mass of gunpowder, 
when a spark or flame reached any portion, but to reduce 
the rapidity of combustion so greatly as to prevent the oc- 
currence of a violent explosion. No more than this is 
accomplished by the employment of powdered glass in the 
proportions directed by Mr. Gale. Indeed, as the quantity 
of diluent required to give to different kinds of gunpowder 
the character of equally slow burning materials increases 
with the explosiveness of the particular powder and with 
the size of its grain, the proportion of powdered glass with 
which the gunpowder employed in rifled cannon would 
have to be mixed to render it only slow burning, would be 
about double the quantity required for almost altogether 
preventing the ignition of fine grain powder, or of the com- 
paratively weak blasting powder with which Mr. Gale’s public 
experiments appear generally to have been instituted. 
Although a sufficient dilution of gunpowder may secure 
such comparative safety in the neighbourhoods of large 
