PROFESSOR H. B. DIXON ON THE RATE OF EXPLOSION IN GASES. 117 
oxygen is only sufficient to bum the carbon to carbonic oxide, the following are tlie 
rates found when oxygen is added sufficient to burn the carbon to carbonic acid :— 
Rates found 
Marsh gas. 
Ethylene. 
Cyanogen. 
94 
92 
84 
The results are, therefore, in favour of the view that, in the explosion of these 
gases, the carbon is first burnt to carbonic oxide. ^ 
But stronger evidence on this point is obtained by comparing the explosion rates of 
these gases (l) when fired with oxygen sufficient to burn the carbon in them to 
carbonic acid, and ( 2 ) whien nitrogen is substituted for the oxygen in excess of that 
required to burn the carbon to carbonic oxide. We have seen that oxygen, added to 
electrolytic gas, hinders the explosion more than nitrogen. In precisely tlie same 
way oxygen, added to a mixture of equal volumes of cyanogen and oxygen, hinders 
the explosion more than the same volume of nitrogen. The conclusion we must come 
to is, that the oxygen, added to the mixture expressed by the formula C 3 N 3 + Oo, is 
as inert (so far as the propagation of the explosion-wave is concerned) as oxygen 
added to the mixture expressed by the formula Ho -f- 0. The same phenomena occur 
in the explosion of marsh gas, ethylene, and acetylene. 
The following tables contain the results of my last experiments on this subject. 
The rates come out on the whole somewhat higher than in my earlier experiments. 
This is mainly due to the later explosions having been made in a tube of larger 
diameter—9 mm. instead of 5 mm. 
Table XIV.—The Bate of Explosion of Cyanogen ( 1 ) with Oxygen, and ( 2 ) with 
Oxygen and Nitrogen. 
( 1 -) 
Mixture. 
1 vol. c3’anogen'l 
1 vol. oxygen f 
C2N0 + O3 
With addition of 
1 vol. oxygen. 
C2N2 + 2O2 
With addition of 
2 vols. oxygen. 
C 2 N 2 + 3O3 
Mean rate . 
2728 
2.321 
2110 
^ [It might be urged that, with defect of oxygen, the reactions reully are— 
1. CH^ + O 3 = CO, + HoO + H, 
2 . CoHj + := 2 CO 3 + 2K, 
3. C 2 N 3 -1-02 = COo -F C -h Nj 
If this wci’e true, and 100 represented the observed rates of explosion in each case, then on adding 
oxygen sufhcient for complete combustion, the rates should be 101,99, and 107 respectively.—Jan., 1893.] 
