330 
PROFESSOR H. B. DIXON ON THE MOVEMENTS 
is two-thirds burnt, and the carbonic oxide is one-third burnt at the moment oi 
measurement, then the velocities of the reflexion-waves correspond to the following 
temperatures :— 
Table IV. 
Temperatui’e calculated from j 
Mixture of gases. 
Hypothetical state of reaction when 
velocity of reflexion-wave. 
wave is measured. 
7 for diatomic gases = l'41. 
7 for triatomic gases = 1 • 28. 
6 H 2 + 3 O 2 
4 H 2 O + 2 H 2 + O 2 
°C. 
3010 
6 H.^ + 6 N 2 O 
4H oO + 2 H 9 + O 2 + 6^ 2 
3290 
6 C 6 + 3 O 2 
2 CO 2 + 4 C 0+200 
3070 
C 2 N 2 + O 2 
2 C 0 +N 0 
3330 
6 C 2 N 0 + 12 O 2 
4COo + 8 CO + 46.> + 6 N. 
.3220 
6 C 2 H 2 + I 0 O 2 
4 CO 2 + SCO + 4HoO + 2 H 2 + 50, 
2850 
It will be observed that the teinj^eratures calculated as above, in Tables III. and IV., 
are of the same order as those calculated by Bunsen as the maximum temperatures 
of the explosion. But the photographs plainly show that they do not represent the 
temperatures reached in the detonation-wave itself. These calculated temperatures 
correspond to a period of the explosion subsequent to the jDassage of the v-ave—the 
period during whicli Bebthelot and Le Chateliee measured the “ effective ” 
pressures produced. The photographs therefore confirm Le Chatelier’s statement 
that the “effective’" pressures measured in the French experiments are not the 
maximum pressures produced in the explosion."^ 
PABT III. 
Velocity of a Sound-Wave in the Flame of Exploded Gases. 
{In conjunction with Pt. H. Jones, B.Sc., and J. Bo wee, B.Sc.) 
The interest attaching to the determination (even approximately) of the tempera¬ 
tures produced in the explosion of gases led us to attempt the measurement of the 
rate of a true sound-wave (of small displacement) in the gases produced by the 
detonation-wave. 
In our first experiments the glass explosion tube A (fig. 18), was fitted to a steel 
piece, B, containing a tap of large bore and a small bye-tap, and connected by a pipe 
Some of our photographs showing the reHexion-waves were exhibited before the Chemical Section of 
the British Association at Liverpool in 1896, ‘ B.A. Report,’ 1896, p. 746, 
