“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.
“If he should be so fortunate as to succeed in either the one or the other of these points, he will render the most essential benefit to the mining interest of this country, and to the cause of humanity in particular.”
After spending a few days in the district with Mr. Hodgson and Dr. Gray, in the course of which he saw and experimented with Dr. Clanny’s lamp, he went on a round of visits in Durham and Yorkshire, and arrived in London at the end of September. Early in October a quantity of fire-damp was sent to him by Mr. Hodgson, the receipt of which he acknowledged on the 15th, saying:—
“My experiments are going on successfully and I hope in a few days to send you an account of them; I am going to be fortunate far beyond my expectations.”
Four days afterwards he again wrote to Mr. Hodgson stating that he had discovered
“that explosive mixtures of mine-damp will not pass through small apertures or tubes; and that if a lamp or lanthorn be made air-tight on the sides, and furnished with apertures to admit the air, it will not communicate flame to the outward atmosphere.”
On the 25th October he gave an account of his work to the Chemical Club. On October 30th he wrote to Dr. Gray and to Mr. Hodgson, giving a description of three forms of safe lamps. His letter to Dr. Gray was as follows:—
“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.”