DUE TO GAS DERIVED FROM COAL-DUST. 125 



and similar reproduction along the path of coal-dust, hydro- 

 carbons being dissociated and free hydrogen accumulated, 

 until a place was reached where large supplies of oxygen 

 were available ; and there being an ignition temperatnre 

 at command as the result of the oxidation referred to, 

 the accumulated hydrogen was oxidised with disruptive 

 energy, causing the destruction observed at the first 

 disruption. 



This explosion of hydrogen liberated a much larger 

 quantity of heat than that available from the exploded 

 mining powder ; therefore an advancing series of similar 

 changes to those described were again established in the 

 coal-dust beyond, causing a second explosion farther away, 

 where the conditions for the oxidation of the second accumula- 

 tion of hydrogen were complete ; and succeeding explosions 

 would be caused along every path of coal-dust where 

 adequate atmospheric oxygen was available, and no wet 

 surfaces intervened, to reduce the temperature below the 

 point at which the dry distillation of coal yields sufficient 

 free hydrogen to supply by its oxidation enough heat to 

 make the actions continuous. 



The explosions occurred at points in the paths of coal-dust 

 where the tunnels of normal sectional area suddenly ex- 

 panded into capacious places, as at junctions, or cavities in 

 the roof, and where the air became concentrated. The loci 

 of explosion were therefore coincident with the presence of 

 abnormal supplies of the atmospheric oxygen. 



There were inflammable materials in the paths of the 

 explosions which had been exposed to heat, but not con- 

 sumed. The hair of the horses was simply singed; the 

 hair of the victims was also singed ; their clothes were not 

 barned, and their burns were blisters, the skin and flesh had 

 peeled ; the calico food bags were not consumed, and the 



