TJie Rate of Explosions in Gases. 



153 



The Rate of Explosion of Electrolytic Gas with excess of Nitrogen 

 compared with calculated velocities. 



A glance at this table reveals the fact that the sound- 

 wave calculated by my formula does not agree in velocity 

 with the explosion wave of pure electrolytic gas ; but as 

 the electrolytic gas is more and more diluted, the observed 

 and calculated velocities come nearer together, until, not far 

 from the two limits of regular explosion, they are in close 

 agreement. Conversely we have seen that Berthelot's 

 formula gives the correct rate for pure electrolytic gas, but 

 diverges more and more from the observed rates as the gas 

 is diluted. Where Berthelot's "0" fails to represent the 

 facts, the ""S" I have calculated does so ; and vice versa. 



I advance the following hypothesis to account for this 

 divergence. At the high temperature of the explosion-ivave 

 the combination of hydrogen and oxygen is not complete ; or, 

 in other ivords, steam is partly dissociated under these 

 cofiditions. The temperature of the wave front is therefore 

 less than that calculated. As more and more inert gases 

 are added to electrolytic gas, the temperature of the explo- 

 sion is lowered by the division of the heat between the 

 diluent gases : more and more of the explosive gases are 

 thus able to combine. As the gases are diluted, therefore, 

 the temperature of the wave front comes nearer and nearer 

 to that calculated. 



Since steam is known to be partially dissociated under 



