203 Chemical Examination of the Fire-Damp. 



in the pneumatic trough, a portion of water instantly rushed in, 

 showing both that the means of securing the gases had proved 

 effectual, and that the gases within the mine were in a more rare 

 state than in my laboratory. 



As one of the principal objects of the inquiry was to determine in 

 how far the gas of different mines varied in chemical constitution, 

 it was material to multiply as much as possible the samples of 

 gas submitted for examination. The number of samples actually 

 received and examined by me, amounted to twelve. The result 

 of this analysis will be given in a tabular form at the close of this 

 communication. The general conclusion deducible from them is, 

 that the essential and sole inflammable material of fire-damp, as 

 formerly found by Dr. Henry and Sir Humphrey Davy, is the 

 light carburetted hydrogen, or marsh gas of chemists, which is- 

 sues in a state of purity from coal, wholly free from admixture 

 with hydrogen, carbonic oxide, or olefiant gases, and but rarely 



communicate with the committee of the coal trade to ask their valuable co-opera- 

 tion and assistance ; for this purpose he addressed the following letter to Robert 

 William Brandling, Esq., the chairman. 



Copy. 



" Newcastle, January 9th', 1836. 



" Sir, — I beg leave respectfully to state, that at the last meeting of the Natural 

 History Sociey, after reading a paper on the gas of mines, it was resolved that the 

 Society should do all in its power to promote an investigation into the nature of 

 the gas evolved in our different collieries, for the purposes of ascertaining if any 

 other, and what gas, occurs besides the common carburetted hydrogen, it having 

 been stated in evidence before the late Parliamentary Committee, that free hydro- 

 gen and olefiant gas are both to be found in the mines of Wales. I was directed 

 by the Society to bring the matter before the Committee of the Coal Trade, and 

 request their valuable co-operation and assistance in obtaining an extensive analy- 

 sis by one of the first chemists of the day, so as at once to set at rest the question 

 as to the nature of coal gas spontaneously evolved in this district. Dr. Turner was 

 mentioned as the person best fitted for the task, not only from his great skill as an 

 analyst, but from his extensive knowledge as a geologist, and the attention he has 

 paid to the chemistry of nature, so to speak. 



" This investigation will not be an expensive one, and it was thought, from the 

 deep importance of the question as connected with the safety-lamp, that the Coal 

 Trade would have no objections to join the Society in the cost. The Society are 

 anxious that the investigations should be made speedily, as they are about going to 

 press with a conclusion of the second volume of their Transactions, where they 

 would wish this to appear as forming an appropriate Appendix to the many valu- 

 able papers in tiie work connected wilii our local geology and mining. If the 

 Committee of the Coal'Trade agree to give their assistance in this matter, the So- 

 ciety will furnish them with any number of copies of tlie results of the investiga- 

 tion they may require ; and, individually, I most respectfully beg to offer my per- 



