THE ROYAL ARTILLERY INSTITUTION. 
887 
Combustion 
Volume. 
Analysis. 
Pressure. 
Temp. 
Vol. atO° 
and 1 metre. 
Original volume .. 
159-38 
0-3144 
19°8 
46-72 
After addition of air ... 
238-48 
0-4108 
19-4 
87-75 
After addition of oxygen 
293-77 
0-4436 
18-7 
121-98 
After explosion... 
248-16 
0-3954 
19-1 
91-71 
After absorption of CO 2 
181-12 
0-3504 
19-5 
59-19 
After addition of H.. 
251-65 
0-4344 
21-6 
101-32 
After explosion. 
174-85 
0-3389 
20-4 
55-15 
The quantity of carbonic acid obtained from the absorption analysis 
= 19T3. The nitrogen found by known methods is 1T37 volume. The 
combustible gases are determined, by the formula already mentioned in the 
case of the analysis in the Torricellian vacuum, as 
Carbonic oxide =P 1 — —^ =26*01, 
O 
gP _P 
Marsh-gas=—\— =6*51, 
Hydrogen = P—P 1 =2*83; 
in which P=35*35, P 1 =32*52, P 2 =27*44. The gun cotton used in the 
analysis corresponded to the formula C 34 H 17 N 5 0 38 , from which the water 
which cannot be directly determined, as well as the eliminated charcoal, may 
be found. Hence the mixture of gun cotton gases consist of—* 
Carbonic oxide. 
By volume. 
.... 28-95 
By weight. 
29-97 
Carbonic acid ..... 
.... 20-82 
33-86 
Marsh-gas ........ 
.... 7-24 
4-28 
Hydrogen. 
.... 3-16 
0-24 
Nitrogen .. 
.... 12-67 
13-16 
Carbon. 
.... 1-82 
1-62 
Aqueous vapour .. 
.... 25-34 
16-87 
100-00 
100-00 
As previously mentioned, the bursting vessels were filled with 10 grammes 
of cotton, which, by an accurate measurement, was found to yield a quantity 
of gas of 5740 cubic centims. at 0° and 1 metre pressure. The contents of 
the mortar at 16°and 0*7382 metre pressure amounts to 5292 cubic centims.; 
the quantity of gas issuing at this pressure amounted to 2939 cubic centims.; 
hence 10 grms. gun cotton yielded 8231 cubic centims. at 16° and 0*7382 
metre pressure. If the quantity of gas is calculated from the results of the 
analysis, it is found that 10 grms. of gun cotton yield 5764*2 of gases, which 
sufficiently agrees with the quantity actually found. 
Comparing the results of the above described analysis with those of the 
analysis in the Torricellian vacuum, it is found 
(1) That the gases in both cases are combustible from the large quantity 
of carbonic oxide they contain. 
(2) That the gases produced in vacuo contain a considerable quantity of 
binoxide of nitrogen, while by burning gun cotton under appropriate 
