Manchester Memoirs, Vol. Ivii. (1913), No. 15. 



XV. Experiments on Abel's theory that Incombustible 

 Dusts act catalytically in igniting weak mix- 

 tures of methane and air. 



By Harold B. Dixon, M.A., F.R.S., 



H. M. Lowe, M.Sc 



( Neadjaittiaty 21st, igiS- Received for pjiblication October 2^th, ^9^3-) 



In the year 1881 Sir Frederick Abel published a 

 series of experiments on the effect of certain dusts in the 

 propagation of an explosion. He had examined coal- 

 dusts from various parts of the Seaham Colliery and 

 arranged them in the order of " sensitiveness." He 

 showed that these coal-dusts had the property of extend- 

 ing an explosion in the presence of weak mixtures of 

 fire-damp and air. Thus, although 3% methane and 97% 

 air will not explode, this mixture exploded violently 

 when coal-dust was suspended in it. In making these 

 investigations Abel found that some of his most sensitive 

 dusts, i.e., those which could cause explosion of the 

 weakest mixtures, contained less coal-dusi than others 

 which were not so sensitive. He was thus led to try if 

 perfectly incombustible dusts, such as calcined magnesia, 

 etc., could of themselves extend or aggravate the effects 

 of a firedamp explosion. He came to the remarkable 

 conclusion that such was the case. He says in his report,* 

 " Mixtures of firedamp and air, in proportions bordering 

 on those which will ignite on the approach of flame, are 

 inflamed instantaneously if they contain in suspension 

 only a few particles of such non-combustible dust." 

 • Report of Royal Commission on Accidents in Mines, i88b. Appendix ix. 



November 21st, 1913. 



