oflighHng the Mines so as to prevent its Explosion. 445 



the resources of modern science had been fully employed; and 

 that a mode of preventing accidents was only to be sought for 

 in a method of lighting the mines free from danger, and which, 

 bv indica'tiug the state of the air in the part of the mine where 

 inflammable air was disengaged, so as to render the atmosphere 

 explosive, should oblige the miners to retire till the workings 

 were properly cleared. 



An account of an ingenious apparatus for burning a candle 

 supplied with atmospherical air by a bellows through water, has 

 been published in the Philosophical Transactions by Dr, Clanny; 

 but I believe this apparatus has not yet been used in any of the 

 collieries. 



The common means employed for lighting those parts of the 

 mine where danger is apprehended from the fire-damp, is by a 

 steel wheel, which being made to revolve in contact with flint, 

 affords a succession of sparks: but this apparatus always re- 

 quires a person to work it; and, though much less liable to ex- 

 plode the fire-damp than a common candle, yet it is said to be 

 not entiielv free from danger. 



Mr. Buddie having obligingly shown to me the degree of light 

 required for .working the collieries, I made several experiments^ 

 with the hope of producing such a degree of light, without ac- 

 tive inflammation ; I tried Kunckel's, Canton's, and Baldwin's 

 phosphorus, and likewise the electrical light in close vessels, but 

 without success ; and even had these degrees of light been suf- 

 ficient, the processes for obtaining them, I found, would be too 

 complicated and difficult for the miners. 



The fire-damp has been shown by Dr. Henry, in a very in- 

 genious paper published in the nineteenth volume of Nicholson's 

 Journal, to be light carburetted hydrogen gas, and Dr. Thomson 

 has made some experiments upon it ; but the degree of its com- 

 bustibilty, as compared with that of other inflammal^le gases, 

 has not, I believe, been examined, nor have many different spe- 

 cimens of it been analysed ; and it appeared to me, that some 

 minute chemical experiments on its properties ought to be the 

 preliminary steps to inqairieJ3 respecting methods of preventing its 

 explosion. I therefore procured various specimens of the fire-damp 

 in its purest stace, and made a number of experiments upon it. 

 And in examining its relations to combustion I was so fortunate 

 as to discover some properties belonging to it, which appear to 

 lead to very simple methods of lighting the mines, without dan- 

 ger to the miners, and which, I hope, will supply the desidera- 

 tum so long anxiously required by humanity. I shall in the fol- 

 lowing pages have the honour of describing these properties, and 

 the methods founded upon them, to the Royal Society, and I 

 shall conclude with some general observations. 



The 



