I have the pleasure to remain, with great respect, Sir, your most obedient, humble servant, John Buddle. Sir H. Davy on his return to London, having been supplied by Mr. Buddle with various specimens of _fire-damp_, proceeded, in the first instance, to submit to a minute chemical examination the substance with which he had to contend. In less than a fortnight, he informed Dr. Gray by letter, that he had discovered some new and unexpected properties in the gas, which had led to no less than four different plans for lighting the mines with safety. TO THE REVEREND DR. GRAY. Royal Institution, Oct. 30. MY DEAR SIR, As it was the consequence of your invitation that I endeavoured to investigate the nature of the fire-damp, I owe to you the first notice of the progress of my experiments. My results have been successful far beyond my expectations. I shall enclose a little sketch of my views on the subject; and I hope in a few days to be able to send a paper with the apparatus for the committee. I trust the _Safe lamp_ will answer all the objects of the collier. I consider this at present as a _private_ communication. I wish you to examine the lamps I have had constructed, before you give any account of my labours to the committee. I have never received so much pleasure from the result of any of my chemical labours; for I trust the cause of humanity will gain something by it. I beg of you to present my best respects to Mrs. Gray, and to remember me to your son. I am, my dear Sir, with many thanks for your hospitality and kindness when I was at Sunderland, your obliged servant, H. DAVY. TO THE SAME. London, October 31, 1815. MY DEAR SIR, I sent yesterday a sketch of my results on the fire-damp. We have lately heard so much of East[28] Shields, that by a strange accident I confounded it with Bishop-Wearmouth, and addressed your letter to East Shields. I could not find any body to frank it, and you will find it a heavy packet; however, I could not lose a moment in giving you an account of results which I hope may be useful to humanity. If my letter has not reached you, it will be found at the Post Office, East Shields. With respects to Mrs. Gray, I am, my dear Sir, very sincerely yours, H. DAVY. [28] _Quere_--South Shields. The sketch alluded to in the foregoing letter, has been kindly placed in my hands by the Bishop of Bristol; it possesses considerable interest as an original document, displaying his earliest views, and tending to illustrate the history of their progress. "The fire-damp I find, by chemical analysis, to be (as it has been always supposed) a hydro-carbonate. It is a chemical combination of hydrogen gas and carbon, in the proportion of 4 by weight of hydrogen gas, and 11-1/2 of charcoal.