384 
MINUTES OF PKOCEEDINGS OF 
filled with mercury, and the Torricellian vacuum produced in the usual 
manner. By means of a galvanic battery the wire could be ignited, and 
hence the gun cotton exploded; thereupon all eudiometrical operations were 
carried out in the tube in the usual manner, after a preliminary experiment 
had shown that the gas produced in this manner consisted of nitrogen, 
binoxide of nitrogen, carbonic acid, carbonic oxide, marsh-gas, and aqueous 
vapour. 
Vol. at 0° 
Volume. 
Pressure. 
Temp, and 
lm. 
Original volume. 
374*53 
0*1156 
12 
42*37 
In the steam bath. 
415*83 
0*1768 
95 
64*56 
After absorption of NO 2 
361*80 
0*1078 
11*2 
37*47 
After absorption of CO 2 
328*06 
0*0850 
10*5 
26*85 
After addition of air. 
481*25 
0*2372 
12*3 
109*26 
After addition of oxygen 
497*56 
0*2510 
12*5 
119*41 
After explosion . 
466*21 
0*2212 
11*2 
99*07 
After absorption of CO 2 
430*57 
0*1855 
10*4 
76*97 
After addition of H 
477*25 
0*2301 
11*7 
105*29 
After explosion . 
443*38 
0*1983 
12*6 
84*08 
mtity of NO 2 and 
CO 3 is 
obtained 
from the 
absorptions, the 
quantity of water from the increase in volume in the steam-bath; the 
quantity of nitrogen is obtained from the volume 76*97, which remains after 
removing the carbonic acid resulting from the combustible gases, by sub¬ 
tracting the uncombined oxygen and the nitrogen contained in the atmospheric 
air added; while the combustible gases are calculated from the formulae in 
Bunsen's gasometric method. 
2P _p 
Carbonic oxide =P 1 — —^—, Marsh-gas = 
Hydrogen.... =P—P^ 
in which P is the quantity of combustible gases, V 1 the carbonic acid 
produced in combustion, P 2 the oxygen used in combustion. 
Hence the gases from gun cotton contain in 100 parts, 
By volume. 
By weight. 
Carbonic oxide . 
... 28*55 
28*92 
Carbonic acid . 
... 19*11 
30*43 
Marsh-gas ... 
... 11*17 
6*47 
Binoxide of nitrogen 
... 8*83 
9*59 
Nitrogen. 
... 8*56 
8*71 
Carbon. 
... 1*85 
1*60 
Aqueous vapour. 
... 21*93 
14*28 
100*00 
100*00 
The gun cotton used had the average composition C 24 H 17 N 5 0 38 , from 
which, after subtracting the results of the analysis, the separated carbon is 
obtained which is included in the above analysis. 
This simple and apparently faultless method has repeatedly shown that, 
by using a somewhat large quantity of gun cotton under the same circum¬ 
stances, when therefore the combustion takes place under comparatively 
greater pressure, the quantities of the products of combustion change, and 
the quantity of binoxide of nitrogen diminishes as the pressure increases. 
