112 THE CHEMISTRY OF COLLIEEY EXPLOSIONS 



In 1882 Mallard and Le Chatelier, members of the French 

 Firedamp Commission, carried out extensive investigations 

 and experiments. They found that gaseons matters were 

 evolved from the coal-dust by the action of the firedamp 

 explosion, but arrived at the conclusion that no explosion 

 of importance could be attributed to the action of coal-dust 

 alone.* 



In Germany, the Firedamp Commission (Saarbriicken), 

 1884, found that a charge of blasting powder when fired 

 into an atmosphere laden with coal-dust ignited the dust, 

 and flame was propagated through the mixture to a limited 

 extent; but that certain descriptions of coal would, in the 

 same circumstances, give rise to explosive phenomena, 

 resembling the phenomena arising in the ignition of a mix- 

 ture of 7 per cent, of firedamp with air.f 



In addition to Marreco's investigations in this country, 

 Messrs. Gralloway, Hall, Cochrane, Sir Frederick Abel, and 

 others, carried out experiments, commencing in 1875, con- 

 firming the conclusions of Faraday, Vital, and Marreco, and 

 concluded that coal-dust itself, in the absence of firedamp, 

 would cause an explosion, which required for its origination 

 only the flame of an ignited local body of firedamp and air, 

 or a charge of blasting material. All the investigators, 

 from Farada}?-, in 1845, up to Professor Harold Dixon, in 

 1893, concluded that the function of coal-dust in an explo- 

 sion was that of a solid in a fine state of division, in 

 admixture with air, undergoing distillation at a temperature 

 at which the educts could enter into combination with the 

 atmospheric oxygen. This theory did not appear to take 



* Final E-eport of Royal Commission upon Accidents in Mines, 

 pp. 45, 46. 



J Second Report of Royal Commission upon Explosions from 

 Coal-dust, p. 6. 



