1891.] 



on the Bate of Explosions in Gases, 



447 



some well-known mixtures ; (2) to measure the rate of the explosion 

 wave in carbonic oxide with different quantities of steam ; and (3) to 

 determine the influence of inert gases on the propagation of the 

 wave. 



1. The results obtained with hydrogen and oxygen, with hydrogen 

 and nitrous oxide, and with marsh gas and oxygen in exact proportions 

 for complete combustion, were in close accordance with the mean 

 results of Berthelot ; for ethylene, acetylene, and cyanogen my 

 numbers differed appreciably, but in no case differed by more than 

 7 per cent, from the rates observed by Berthelot : — 



TABLE II. 



Velocity of Explosion in Metkes per Second. 



The general agreement between these measurements left no room 

 for doubt about the substantial accuracy of Berthelot's experiments. 

 The formula he gives does, therefore, express with a close degree of 

 approximation the rates of explosion of many gaseous mixtures. 



2. The formula fails for the explosion of carbonic oxide with 

 oxygen or nitrous oxide. This was to be expected if, in the detona- 

 tion of carbonic oxide in a long tube, the oxidation is effected 

 indirectly by means of steam, as it is in the ordinary combustion of 

 the gas. Measurements of the rate of explosion of carbonic oxide 

 and oxygen in a long tube showed that the rate increased as steam 

 was added to the dry mixture, until a maximum velocity was attained 

 when between 5 and 6 per cent, of steam was present. 



3. When electrolytic gas was mixed with an excess of either 

 hydrogen or oxygen the rate of explosion was found to be altered ; 

 the addition of hydrogen increasing the velocity, the addition of 

 oxygen diminishing it. The addition of an inert gas nitrogen, 

 incapable of taking part in the chemical change, produced the same 

 effect as the addition of oxygen — one of the reacting substances — 

 only the retarding effect of nitrogen was less marked than that of an 

 equal volume of oxygen. The retardation of the explosion-wave 



