124 THE CHEMISTEY OF COLLIEEY EXPLOSIONS 



energy, and the oxides of carbon would enter largely into 

 the composition of the products. 



The preceding observations show that immense disruptive 

 energy was exerted in the path of the coal-dust, and the 

 oxides of carbon were not present to the extent of the small 

 percentages appreciable by ordinary tests, because the 

 carbon constituent of the hydrocarbons was not appreciably 

 oxidised ; therefore the nascent educts of the coal-dust did 

 not undergo general combustion. 



I have elsewhere * suggested that the educts of the coal 

 were in excess of the relative combination volumes of atmo- 

 spheric oxygen present ; that the nascent free hydrogen in 

 the educts seized the principal part of the oxygen, and was 

 oxidised, liberating heat. A small quantity of oxygen would 

 be taken by some of the hydrocarbons, producing combustion 

 analogous to that known in the preparation of lamp-black 

 and diamond-black, disengaging more heat, and leaving 

 carbon in suspension in the products. 



Above the temperature of 1000° C some of the hydro- 

 carbons undergo dissociation, and at the temperature of 

 burning hydrogen, methane, the most stable hydrocarbon, 

 would be dissociated, since it decomposes at 1500° C ; more 

 carbon would thereby be thrown into suspension, and free 

 hydrogen placed at disposal for disruptive action. 



The heat in the products of the exploded powder is there- 

 fore suggested to have initiated a series of chemical actions 

 in the coal-dust, in which large quantities of heat were 

 disengaged, free hydrogen placed at disposal, and carbon 

 left in suspension. 



This series of actions was regenerative by virtue of the 

 heat disengaged, and instituted a similar series in the 

 adjacent coal-dust; and these activities were of constant 

 * The Origin and Eationale of Colliery Explosions. 



