GUNPOW DER: 
+ would’ ce. Heothen ascertained, by an experi- 
ment, that air was increased in volume by a red heat 
J>times nearly. ‘This would make the volume of the 
der to that of generated ;air (as 1 to 1000 nearly. 
a force which would arise from such an increase of 
> volute, Mr Robins finds adequate to the effect of the 
- in practice; and in a very ample manner agreed 
with his theory. | ’ 
587 
phurous. acid | would.doubtless be formed, and the Gunpowder. 
smell of it would tbe very perceptible, in the fumes re. "yr" 
sulting from its decomposition; but no smell of this 
kind is perceived in the explosion of ordinary gun- 
ee 
. The following Table contains some of the proportions Proportions 
used by different manufacturers in this and other coun- . bo ingre- 
tries. = 
a eaainded 
+» We have to lament that these experiments were not 
made with more precision. The gases generated. were 
considered by Mr Robins as common air, the specific gra- 
vity of whicliis 1.>/These gases, however, being.a mix- 
+" ture: of: carbonic!acid, carbonic oxide, and azotic gases, 
* ~~ should have: been ‘taken at a :mean not less than 1.25. 
‘There is also some uncertainty ‘about the allowance 
made for the heat of the receiver ; and the-volume was 
not increased by that circumstance so much as\¢th of 
the whole, which he supposes to be the case. ‘The very 
little which was. known of gaseous chemistry sat the 
time Mr Robins made his experiments, does not admit 
of our wondering that no more was established by his 
labours. The constituents. ‘of nitre were then. little 
known ; and therefore the nature of the gases resulting 
from the decomposition of gunpowder could not:be as- 
certained, He-was satisfied with calling the gaseous pro- 
duct air, and supposed it to have only the properties of 
common air. In order'to apply the chemical facts at 
present known to explain the nature of gunpowder, we 
shall com the proportions of ‘the ingredients ‘used 
by different’ manufacturers, with, those «proportions 
which theory would’ point out, in order to: produce a 
maximum effect. ~ ! sd 
An intelligent account of making gunpowder has 
been given by Mr Coleman, of the royal gunpowder 
mills at Waltham Abbey. | (Phil. Mag. vol: ix.) In 
some observations atthe end of the paper, Mr Colernan 
has taken a very proper view of ‘the theory of gunpow- 
der, by giving some calculations relative “to the result- 
ing products. “He has taken into the account the wa- 
ter, which he rates at:4:per cent. \ It has ‘not been ‘as- 
eertained, that water undergoes any change in the de- 
composition of gunpowder ; nor, indeed, is it very pro- 
bable that any such effect takes “place, ‘He has also 
given too little oxygen for sulphurous acid. _ He states 
it’ to be 80 per cent. when it is actually 50.. It appears 
from experiments made in the firing »of gunpowder, 
that very little of ‘the sulphur enters into combination 
with the oxygen, and we believe not after the carbon is 
kindled. The residwum is always very near a complete 
sulphuret of potash ; and the quantity of sulphur ‘used 
in the composition is seldom more than is just sufficient 
to form the sulphuret.. ‘This is rendered highly proba- 
bable, from the fact of gunpowder possessing the same 
strength with: very different \proportions ‘of Sulphur. 
Indeed, M. Chaptal ‘has: made very good \gunpowder 
without sulphur. It is however different in'a mechani- 
eal point of view, and on that: aecount ‘would not an- 
swer in practice, It is‘therefore highly probable, that 
the sulphur does not: form ‘sulphurous: acid) when, the 
explosion takes place; since oxygen seems to unite with 
the carbon alone. The potash, when deserted by oxy- 
gen and the nitrogen, assumes the:form of a fine dust 
of powder, and the sulphur the form of vapour.) ‘These 
combine, forming a sulphuret of potash, which appears 
in white fumes, and adheres ‘to surrounding bodies, 
sf = moment this white efflorescence’ is touched with 
tongue, the exact taste of sulphuret ‘of’ potash is 
perceived. If the carbon were very defective in quan- 
_ tity, and the sulphur in the usual proportion, some sul- 
Varieties of Gunpowder. Nitre, |Charcoal Isulphur, 
-Mr Coleman; of the Royal 
Mills at Waltham Abbey,§ | 7%. | 1510 
Generally-used in France, , | 76 12 12 
War powder of France, . «| 75 12.5, | 12,5 
, Result of experiments by M. "7 14 9 
Chaptaly.e;esece vexenery te , 
Used in China,... 2... +. 75.7.) 144 | 9.9 
Result of Mr Napier’s me- 
thod of approximating the ¢| 80 15 5 
true proportions, ... . 
Average,’ ....- +). 76.45} 13.81} 9.73 
; 
Doubtless all these varieties are very good powder, 
which would not hhave beer’ the case had the charcoal 
been as uncertain in its proportions as the sulphur. 
©) It will be admitted on all hands, ‘that the: best gun- 
powder must ‘result from such materials as:explode 
the quickest, leaving the ‘least possible residuum, ‘and 
affording the greatest possible volume of elastic: fluid. 
Now, if sulphur did, by its combination with oxygen, 
form an elastic fluid, the resulting gas, which is sul- 
phurous acid, is nearly 1.5:times heavier than ‘carbo- 
nic acid, and therefore contributes less force in a given 
weight. It will be found, when -nitre is deflagrated 
with charcoal, that carbonic oxide is formed ‘as'well as 
carbonic acid, which contributes more elastic force than 
the same ‘weight of carbonic acid. 
There-is one good:veason to be given for the use of 
the ‘sulphur, although «it does not contribute to the 
production of any elastic fluid... The carbonic acid 
which is generated, would doubtless combine with the 
potash, ‘fit were not for the presence of the sulphur ; 
and thus so much elastic fluid would be lost. . That this 
is the case, we’ know from:the fact, that carbonate of 
potash is'always formed ‘when nitre is decomposed by 
charcoal alone. ‘This would’ be the case toa certain ex- 
tent with gunpowder made-withont sulphur; some car- 
bonate of potash: would be formed. 
It will appear from these facts and observations, that 
. the 2 ern for gunpowder will»be those in which 
the carbon:willjust:consume the oxygen of the nitte, 
and the sulphur as much’ as will exactly saturate the 
This will be effected .by-an atom each: of nitre - 
and:sulpbur;and three ‘atoms of carbon, or nitre 95.5 ; 
charcoal 16:2; and stdphur «15. These will give*in 
the 100mitre 75.4; of charcoal 11.8 ; and sulphur ‘12.8. 
These proportions with the best inpracticey: The 
bodies which -result from the decompositions of this 
compound, will -be in 126.7 parts, 60 of sulphuret 
potash’; 40.8 of:carbonic acid; 12.9 of carbonic oxide ; 
and 18 of azot, 
The three Jatter are elastic fluids, equal’ to 66.7 out 
of 126.7, ‘or 442 of the whole-nearly.. Mr Robins made 
the gaseous product 4, of the whole. This last num- 
ber, when the specific gravity of the gas is taken 
right, will differ very little from our calculation. 
In the 66.7 by weight, (suppose grains,) we have 
