128 Mr. Harold B. Dixon oji 



The Rate of Explosions in Gases. By Harold B. Dixon, 

 M.A., F.R.S., Professor of Chemistry in the Owens 

 College. 



(Received March yt/i, i8gj.) 



§1. The rapid act of chemical change, which follows the 

 kindling of an explosive mixture of gases, has of late years 

 attracted the interest both of practical engineers and of 

 theoretical chemists. To utilize for motive power the 

 expansive force of ignited gases ; to minimize the chance 

 of disastrous conflagrations of fire-damp in coal mines ; to 

 follow the progress of chemical changes under the simplest 

 conditions, are some among the problems presented in 

 industry or science, demanding for their solution a know- 

 ledge of the phenomena of the explosion of gases. 



Thirty-six years ago Bunsen described a method of 

 measuring the rapidity of the flame in gas explosions. 

 Passing a mixture of explosive gases through an orifice at 

 the end of a tube and igniting the gases as they issued into 

 the air, he determined the rate at which the gases must be 

 driven through the tube to prevent the flame from passing 

 back through the opening, and exploding inside the tube. 

 By this method he found that the rate of propagation of the 

 ignition of hydrogen and oxygen was 34 metres per second, 

 while the rate of ignition of carbonic oxide, marsh gas, and 

 coal gas with oxygen was less than i metre per second. 

 Bunsen applied these results to the rate of explosion of 

 gases in closed vessels, and his results were accepted without 

 cavil for four-and-twenty years. 



The idea of using the rate of explosion as a means of 

 determining the course of a chemical reaction occurred to 

 me in 1877, when investigating the influence of steam on 

 the union of carbonic oxide and oxygen. If steam acts as 



