120 THE CHEMISTRY OF COLLIERY EXPLOSIONS 



to the condition that would arise by shaking a feather-bed 

 tick in the air. 



This condition of the atmosphere afforded an explanation 

 of the sponge-like form of the depositions of carbon on the 

 side walls, which were evidently accumulations formed by 

 successive settlements of particles previously in atmospheric 

 suspension, and the deposition of striated filaments could 

 arise in no other way. 



The carbon having been originally in atmospheric sus- 

 pension, its origin in that atmosphere must now be sought. 

 The explosions broke down the ventilating doors, filled the 

 tunnels with occasional falls, and stopped the circulation of 

 the air currents ; the products of the chemical actions in the 

 explosions and in the intervals, were imprisoned between the 

 falls. The spaces between the disruptions were therefore 

 filled with still atmospheres, that could only be displaced by 

 diffusion. The exploring parties frequently advanced into 

 these atmospheres to make apertures through the falls, that, 

 in addition to displacement by diffusion, the motive column 

 of the ventilation could be made effective to force the stag- 

 nant gases along the tunnels to the upcast shaft. The 

 explorers were constantly standing in the still atmospheres, 

 in which their candles burned brightly, and it was only 

 after exposure for some time that they felt sensations of 

 faintness, stupefaction, and unconsciousness, necessitating 

 retreat into pure air, until diffusion was exerted to enable 

 them to advance again. 



During the occurrence of the explosions in Camerton 

 Collieries four men were working in the North Branch. 

 They received their air by a current through Probert's 

 dipple, which the explosion there, had suspended. They 

 felt a change due to the suspension of their supply of air, 

 and immediately retreated through the products of Nos. 8, 



