136 PROFESSOR H. B. DIXON OX THE RATE OF EXPLOSION IN GASES. 
3. Cyanogen with Nitrous Oxide and Nitrogen. 
Mixture. 
CoN, + 2N,,0 
C.N^ -t- 2 N 2 O + No 
CoNo + 2N.oO + 2No 
" " 
Mean rate . 
2454 
228.3 
2098 
2 . . . . 
2416 
2237 
2093 
4. Cyanogen with Nitric Oxide. 
Mixture. 
CoNo + 2NO 
Mean rate 
2760 
V 
2763 
This comparison shows that the formula, which makes the velocity of sound in 
cyanogen burning to carbonic oxide equal to the observed rate of explosion, also gives 
for the velocity of sound in the same gases diluted with oxygen or nitrogen numbers 
closely concordant with the observed rates of explosion. The same formula holds for 
the explosion of cyanogen with nitrous oxide and when this mixture is diluted with 
nitrogen. Lastly, by firing a cartridge of fulminate in a steel cylinder filled with a 
mixture of cyanogen and nitric oxide I succeeded in propagating the explosion from 
the cylinder through a long leaden tube filled with the gases. The rate of explosion 
so obtained agreed exacfly witli the calculated sound-wave. I believe this was the 
first time thaT a mixture of cyanogen and nitric oxide had been exploded in a tube. 
Berthelot, who fired this mixture in a bomb, states that the ivave is not propagated 
in these gases. I found that neither a strong spark, nor an initial explosion of 
hydrogen and nitric oxide, would set up the explosion-wave in cjmnogen and nitric 
oxide. The details of these experiments are given in the Appendix. 
The formula that I have given was thus found to agree with all the cyanogen 
explosions. It is therefore, at all events, an empirical expression which can be 
applied to calculate the rates of explosion of cyanogen burning to carbonic oxide and 
nitrogen under a fairly wide range of conditions. It was accordingly a matter of 
considerable interest to apply the formula to the rates found when electrolytic gas was 
exploded by itself and when diluted ^^dth hydrogen, oxygen, and nitrogen. In the 
following table the rates for electrolytic gas with excess of hydrogen and of oxygen 
are compared with the numbers calculated from Berthelot’s formula [6), and with 
the sound wave {%) calculated as before. In calculating S the contraction which 
occurs on the union of hydrogen and oxygen is taken into account, but not the 
existence (which is possible) of free atoms of oxygen :— 
