376 Mr Deuchar on the Nature of Flame. 
per, the flame of which was so near as to spread a little upon 
the tin-plate. In one minute the sulphur began to melt, and in 
25 seconds more it was all melted ; at the end of 10 minutes, 
neither of the powders appeared to be altered, but nearly one- 
half of the sulphur was converted into vapour ; at this time the 
plate was too hot to be touched by the hand. 
Exp. 7i-i-"A grain of the fulminating powder, and the sartie 
quantity of gunpowder, were put upon a tin-plate, at 2 inches 
distance ; and at the centre below was put a spirit-lamp. The 
following is the result of the time of explosion in several trials : 
Fulm. Powder. 
In 32 seconds. 
28 1 — 
25 
29 — 
40 
Gunpowder. 
In 46 seconds. 
44 
60 
62 — 
70 — 
Fulm, Powder. 
In 45 seconds. 
30 
40 
41 
60 
Gunpowder. 
In 85 seconds. 
60 
60 
60 
P2 — 
In obtaining these results, the distance at which the spirit-lamp 
was put below the tin-plate sometimes varied considerably, but it 
was always near enough to spread a little upon its surface. This, 
however, so far accounts for the great difference between the pe- 
riods'of explosion in the same powder. 
Should the firing succeed as regularly when applied to th^ 
gun itself, there could remain no doubt but that it would pos- 
sess all the proposed advantages. There was, therefore, fixed 
to a six pounder an apparatus similar to the one used for trying 
the experiments narrated in this paper, excepting that it wanted 
the long tube AB, for which the priming hole of the gun be- 
came a substitute, (See Figs. 7. and 8.) It was charged with cart- 
ridge, and, in several of the trials, with ball and cartridge ; and 
upon the same experiments being repeated ^th it, it gave the 
same uniform results. 
At the. request of Colonel Yule, I commenced, about the be- 
ginning of July last, a number of experiments, with the view of 
discovering a powder which should never miss inflaming the 
cartridge. The fulminating mercury, when the fifth part of a 
grain only was used, rent asunder the steel-plate at the top (D), 
and yet did not reach as far as the gunpowder at (B). Some 
of the antimonial preparations were found sometimes to fire the 
