IQS 
GUNPOWDER. 
titles of the confliUient principles which enter into the 
compolition of gunpowder; as manufactured in Eng¬ 
land : 
75 parts of nitre, containing 
15 parts of charcoal 
10 parts of fulphur 
C Dry nitre 74-25 
l Water - 0-75 
5 Carbon - 13*13 
l Water - 1*87 
Sulphur io-oo 
And thefe again contain, viz. 
Potato. Oxygen. Azof. Hydrogen. Carbon. 
36-75 + 30-34 + 7-80 + o-i 1 = Nitre 75 
i-6o -f- 0-27 13*13 = Charcoal 15 
Sulphur 10 
100 parts of gunpowder, therefore, appear to confift of 
Potafh - - - 36-75 
Carbon - 13-13 
Sulphur - - - jo-oo 
Oxygen - - - 31^-94 
Azot - - - 7-8 
Hydrogen - 0*38 
“We know that the whole of the charcoal is not 
confirmed in the aCl of combuftion : Mr. Cruickfhank 
fays, three-parts remain of one hundred parts of gun¬ 
powder, therefore only 10*13 parts are deftroyed. Now, 
310-13 parts of carbon abforb - 26*05 °f oxygen 
And 10 parts of fulphur abforb 3-00 of oxygen 
Oxygen ufed - - 29-05 
Quantity of oxygen in ingredients 31 -95 
Surplus of oxygen - - a-90- 
“ It is clear that the fmalleft error in the quantity of 
charcoal ufed, will eaftly account for this difference of 
oxygen. On the above calculation it appears, that the 
quantity of each ingredient is pretty well regulated,, 
and that the gafes formed will be expended in pro¬ 
ducing the effects which we obferve in the combuftion 
of gunpowder. 
“The refiduum of fired gunpowder Mr. Howard 
thinks to be an alkaline fulphuret mixed with carbonat 
and fulphat of potafh. But by feveral trials I have 
fince made, I am induced to form the fame opinion, as 
to the qualities of this refiduum, as Mr. Cruickfhank : 
the quantity I have not had an opportunity of afcef- 
taining. Mr. Cruickfhank fays: “This refiduum is 
very deliquefcent, and when expofed to the air abforbs 
moifture l'ufficient to diffolve a part of the alkali ; in 
confequence, the charcoal becomes expofed, and the 
whole affumes a dark or black colour : that this refi¬ 
duum is potafh united with a frnall proportion of car. 
bonic acid, fulphat of potafh, a very frnall quantity of 
fulphuret of potafh and unconfumed clrarcoal : and, 
that one hundred grains of gunpowder yield fifty-three 
grains, of which three are charcoal.” 
On the difcharge of fire-arms, count Rumford re¬ 
marks, that there is always a portion of unconfumed 
grains of gunpowder blown out of them ; and what is 
very remarkable, as it leads direCtly to a difcovery of 
the catife of this effect, thefe unconfumed grains are 
not merely blown out of the muzzles of fire-arms, but 
come out alfo by their vents or touch-holes, where the 
fire enters to inflame the charge, as many perfons who 
have had the misfortune to (land with their faces hear 
the touch-hole of a mufket, when it has been difcharged, 
have found to be the faCt, by having the grains forced 
into the fkin. It feems extremely improbable, if not ab- 
folutely impoflible, that a grain of gunpowder actually 
in the chamber of the piece, and completely furrounded 
by flame, fhould, by the action of that very flame, be 
blown out of it without being at the fame time fet on 
fire. And, if this be true, it tends to prove not only 
that the combuftion of gunpowder is lefs rapid than it 
has generally been thought to be, but that a grain of 
gunpowder aCtually on fire, and burning with the ut- 
moft violence over the whole of its furface, may be pro¬ 
jected with fuch a velocity into a cold atmofphere, as 
to extinguifli the fire, and fuffer the remains of the 
grain to fall to the ground unchanged, and as inflam¬ 
mable as before. 
This extraordinary faCt has been afeertained, beyond 
all pofiibility of doubt, by the count’s experiments. 
Having procured from a powder-mill, in the neighbour¬ 
hood of the city of Munich; a quantity of gunpowder,, 
all of the fame mafs, but formed into grains of very 
different fizes, fome as frnall as the grains of the fineft 
Battel powder, he placed a number of vertical fereens 
of very thin paper, one behind another, at the diftance 
of twelve inches from each other; and loading a com¬ 
mon mulket repeatedly with this powder, fometimes 
without and fometimes with a wad, he fired it againft 
the foremoft fereen, and obferved the quantity and ef¬ 
fects of the unconfumed grains of powder which im¬ 
pinged againft it. The fereens were fo contrived, by 
means of double frames united by hinges, that the pa¬ 
per could be-changed with very little trouble, and it 
was actually changed after every experiment. 
The diftance from the muzzle of the gun to the firft 
fereen was not always the fame ; in fome of the expe¬ 
riments it was only eight feet, in others it was ten, and 
in fome twelve, feet. The charge of powder was va¬ 
ried in-a great number of different ways ; but the moft 
interefting experiments were made with one Angle large 
grain of powder, propelled by fmallerand larger charges 
of very fine-grained powder. Thefe large grains never 
failed to reach the fereen ; and though they fometimes 
appeared to have been broken into feveral pieces by 
the-force of the explofion, yet they frequently reached 
the fereen entire ; and fometimes paffed through all the 
fereens (five in number) without being broken. 
When they were propelled by large charges, and 
confequently with great velocity, they were feldom on 
fire when they arrived at the firft fereen; which was 
evident, not only from their not fetting fire to the paper, 
(which they fometimes did,) but alfo from their being 
found flicking in a foft board, againft: which they s ftruck, 
after having paffed through all the five fereens; or 
leaving vifible marks of their having been impinged 
againft: it, and being broken to pieces and difperfed by 
the blow. Thefe pieces were often found lyjng on the 
ground ; and from their forms and dimenfions, as well 
as from other appearances, it was often quite evident 
that the little globe of pow'der had been on fire, and 
that its diameter had been diminifhed by the combuftion 
before the fire was put out, on the globe being pro¬ 
jected into the cold atmofphere. That thefe globes or 
large grains of powder were always fet on fire by the 
combuftion of the charge, can hardly be doubted. 
This certainly happened in many of the experiments ; 
for they arrived at the fereens on fire, and fet fire to 
the paper; and in the experiments in which they were 
projected with frnall velocities, they were oftenfeen to 
pafs through the air on fire ; and when this was the: 
cafe, no veftige was to be found. They fometimes 
palled on fire through feveral of the foremoft fereens, 
without fetting them on fire, and fet fire to one or more 
of the hindmolt, and then went on and impinged againft 
the board, which was placed at the diftance of twelve 
inches behind the laft fereen. 
The count then proceeded to another experiment, in 
which the progreflive combuftion of gunpowder was 
Ihewn in a manner (till more (hiking, and not lefs con- 
clufive. A frnall piece of red-hot iron being dropped 
down into the chamber of a common horfe-piftol, and 
the piftol being elevated to an angle of about forty-five, 
degrees, upon dropping down into its barrel one of the 
frnall globes of powder (of the fize of a pea), it took 
