TJie Rate of Explosions in Gases. 129 



a carrier of oxygen to the carbonic oxide by a series of 

 alternate reductions and oxidations, an increase in the 

 amount of steam present, beyond that required to initiate 

 the reaction, should be accompanied by an increase in the 

 rate of combination up to a certain limit Attempts were 

 therefore made to detect such an increase by measuring the 

 velocity of the flame in a tube,* But while the difference in 

 the rate of explosion between the nearly dry and the moist 

 gases was well marked, the attempts to directly measure the 

 rate of the explosion of the moist gases failed, owing to the 

 great rapidity of the flame. In the spring of 1881 I 

 attempted to measure the rate of explosion of carbonic oxide 

 and oxygen with varying quantities of steam by photo- 

 graphing on a moving plate the flashes at the beginning 

 and end of a closed tube 20 feet long. The two flashes 

 appeared to be simultaneous to the eye, but no record of the 

 rate was obtained, for the apparatus was broken to pieces 

 by the violence of the explosion. Shortly after this attempt 

 was made the first of the brilliant series of papers by MM. 

 Berthelot and Vieille, and by MM. Mallard and Le Chatelier, 

 was read before the French Academy of Sciences. The 

 work of these French chemists has opened a new era in the 

 theory of explosions. 



In July, 1 88 1, two papers appeared in the Comptes 

 Rendus, one by M. Berthelot, the other by MM. Mallard 

 and Le Chatelier. Both papers announced the discovery 

 of the enormous velocity of explosion of gaseous mixtures. 

 Other papers by the same authors quickly followed. M. 

 Berthelot made the important discovery that the rate of 

 explosion rapidly increased from the point of origin until 

 it reached a maximum which remained constant, however 

 long the column of gases might be. This maximum M. 

 Berthelot stated to be independent of the pressure of the 



Phil, Trans., 1884, Pt. If., p. 635. 



