Miscellaneous Intelligence. 283 
plosive when employed in gunnery or rock-blasting, in open vessels 
flash without fracturing them, or producing any report: In an exhaust- 
ed receiver, gunpowder is far less explosive than when subjected to 
atmospheric pressure in an open vessel. Nevertheless, when gun- 
which, when the temperature of the fire applied is sufficiently high, 
the explosive force is directly as the i veils before bursting, and 
this, of course, is commensurate with the strength of the confining 
boiler.’ 
The itigiedibats of ig toce sulphur, charcoal, and nitre, to pro- 
duce the greatest effect, require extreme comminution and intimate 
= 
mixture of nitre with combustible matter destitute of sulphur, is con- 
ceived to be du t only to the pre-eminent oe. of this 
substance, of vaporization and inflammation, but wise to its well 
teh ability to decompose a oxyds by attracting both the metal 
oxygen. Such an opinion was expressed in 1845, in the letter 
pre mentioned to Hien that the formation ‘as sulphid of potas- 
sium is the first step in the process of the explosive reaction of gun- 
powder, Faraday has alleged the flame of the compound to be, in the 
case in point, an important instrument in the propagation of fire through- 
out the mass. 
The hepatic odor of the fumes consequent to the firing of cannon, 
and likewise of the washings of a gun after the customary service, 
demonstrate the production of a sulphid. It has been found that a 
filtered solution of the residue ye sig when tested by iron, the red 
hue which indicates the presence of as nid. 
Agreeably, however, to a qeilitenive examination, the solid residue 
of exploded gunpowder consists mainly of nearly equal parts of car- 
bonate and sulphate of potash, while the gaseous residue is rg 
nearly of equal volumes of carbonic acid and nitrogen. Of c 
the sulphate may arise from the wr sean of sulphide, formed on wd 
outset 
by a pices Saclnegs, The grains did not take fire instantly, prob- 
ably because the vapor evolved prevented actual contact ; and when 
ignition did e ensue it extended only to the production of a feeble flash. 
if Sean it was found that a portion of the powder had escaped 
inflamm 
ra use place, a like weight of gunpowder was consolidated into 
a cylinder iy intense pressure. hus red and ignit ag by contact 
with an incandescent wire in ———— receiver, more than half of 
the cylinder remained unconsu 
