“that the hopes of this society ever seeing its most desirable object accomplished must rest upon the event of some method being discovered of producing such a chemical change upon carburetted hydrogen gas as to render it innoxious as fast as it is discharged, or as it approaches the neighbourhood of lights. In this view of the subject, it is to scientific men only that we must look up for assistance in providing a cheap and effectual remedy.” The society received a number of suggestions, for the most part wholly impracticable, and generally of the character of that of Dr. Trotter, who proposed to flood the mines with chlorine. A variety of air-tight or insulated lamps were suggested by Clanny, Brandling, Murray, and others, much on the same lines as that devised by Humboldt, but none of them appears to have been seriously tried. Under these circumstances it was decided to ask for the co-operation of Davy, and with that object Mr. Wilkinson called upon him at the Royal Institution, in the autumn of 1813, but found he had left for Paris. A few months after his return the Rev. Dr. Gray wrote to him on the subject, and received the following letter in reply:-- “_August 3, 1815._ “.... “It will give me great satisfaction if my chemical knowledge can be of any use in an enquiry so interesting to humanity, and I beg you will assure the committee of my readiness to co-operate with them in any experiments or investigations on the subject. “If you think my visiting the mines can be of any use, I will cheerfully do so. * * * * * “I shall be here ten days longer, and on my return South, will visit any place you will be kind enough to point out to me, where I may be able to acquire information on the subject of coal gas.” Dr. Gray, in reply, referred him to Mr. John Buddle, of the Wallsend Colliery. On August 24th, 1815, Mr. Buddle wrote to Dr. Gray:-- “Permit me to offer my best acknowledgments for the opportunity which your attention to the cause of humanity has afforded me of being introduced to Sir Humphry Davy. “I was this morning favoured with a call from him, and he was accompanied by the Rev. Mr. Hodgson. He made particular enquiries into the nature of the danger arising from the discharge of the inflammable gas in our mines. I shall supply him with a quantity of the gas to analyze; and he has given me reason to expect that a substitute may be found for the steel mill, which will not fire the gas. He seems also to think it possible to generate a gas, at a moderate expense, which, by mixing with the atmospheric current, will so far neutralise the inflammable air, as to prevent it firing at the candles of the workmen.