1908] 



on Explosive Gomhustion. 



85 



pared with about 1 ' 75 in the globe experiment, and an examination 

 of the products would show that the lower ratio is accounted for by 

 the much greater survival of acetylene, ethylene, and aldehydic pro- 

 ducts in the tube experiment. These facts, which are set forth in 

 the following table, are in complete harmony Avitli the hydroxylation 

 theory. 



Table III. — Inflammation of an Equimolecular Mixture of 

 Ethane and Oxygen. 



Experiment VI. — The experiments I have so far shown you, 

 refer more particularly to the initial period of " inflammation " in 

 explosive combustion, that is to say, to the conditions ordinarily 

 prevailing in hydrocarbon flames. The question may be asked 

 whether or not the views I have advanced are applical)le to the 

 extreme conditions of " detonation " or of explosions under high 

 initial pressures. The question may be put in the following form : 

 Is there any experimental evidence of discontinuity between " inflam- 

 mation^' and 'Uieto nation'' as regards the nature and sequence of the 

 chemical changes involved ? or. Is the hydrocarbon attacked by 

 oxygen in an entirely different way in explosive combustion at high 

 pressures, or in the explosion wave, to what it is in ordinary flames ? 

 This question can, I think, best be answered by a consideration of 

 the behaviour of an equimolecular mixture of ethane and oxygen 

 under these extreme conditions. 



It is difficult to set up detonation in this mixture ; the gases 



