Mr Deucliar on the Nature of Flame. S77 
gunpowder ; but they left a cake of crocus behind, which stop^ 
ped up the holes, and could not easily be removed. 
Indeed, all the usual fulminating powders were tried without 
success ; but I was fortunate enough at last to hit upon one 
which has never failed to produce the desired effect. 
For the composition of the different powders, and the advan- 
tages of this mode of firing ordnance, the reader is referred to 
the third volume of the Wernerian Society Transactions, just 
published* 
II. Having established as far as was at pre sent necessary Col. 
Y ule’s proposed application of the apparatus, I next directed 
my attention to the effect that might be produced by retarding the 
motion of the flame. This was^ therefore, tried in various ways 
which had not yet been noticed. 
Eoop. 8. — A piece of cartridge flannel was tied over the under 
part (B) of the tube, and about one grain of the new powder was 
exploded at the top (A). The flame was seen to dart from the 
bottom. The flannel, when examined after the discharge, had 
not the slightest appearance of having been scorched ; but it was, 
however, blackened a little at the spot through which the flame 
had passed. 
Eocp. 9. — The 8th experiment was repeated with several 
pieces of flannel at once. After each discharge with two pieces, 
the interior one was a little scorched, but the exterior one ap- 
peared as formerly. When three pieces of the flannel 
were used, the flame seemed with difficulty to pierce them ; 
that in the interior was more scorched than when there 
were two pieces only, and part of it tv^as entirely gone ; the 
middle flannel was also slightly scorched. When four pieces of 
flannel were applied, the interior two were much burnt, and the 
third a little ; but the flame did not pierce through the fourth 
piece. When this last was several times repeated in a very dark 
situation, there could not be discovered the slightest appearance 
of the flame at the bottom of the tube. 
Exp. 10. — When two pieces of thin coarse paper were put at 
the bottom of the tube (B), the flame passed through, making 
a rent in the paper, without burning it in the least. When the 
paper was examined, it presented, on each side of the hole, the 
separated threads, as if it had been torn with the hand. With 
