I had been invited to dine with Sir Humphry Davy, on Wednesday the 5th of March 1823, for the purpose of meeting the Reverend Uriah Tonkin, the heir of his early friend and benefactor of that name.[80] On quitting my house for that purpose, I perceived that I had time to spare, and I accordingly called in my way at the Royal Institution. Upon descending into the laboratory, I found Mr. Faraday engaged in experiments on chlorine and its hydrate in closed tubes. It appeared to me that the tube in which he was operating upon this substance contained some oily matter, and I rallied him upon the carelessness of employing soiled vessels. Mr. Faraday, upon inspecting the tube, acknowledged the justness of my remark, and expressed his surprise at the circumstance. In consequence of which, he immediately proceeded to file off the sealed end; when, to our great astonishment, the contents suddenly exploded, and the oily matter vanished! [80] Sir Humphry had expressed to me, on the preceding Thursday, at the Royal Society, his wish to purchase the old house in Penzance, which, as the reader will remember, was the early scene of his chemical operations; and, at his request, I conversed with Mr. Tonkin upon the subject; but it immediately appeared that the interest which the Corporation of Penzance possessed in the estate presented an insurmountable obstacle to the accomplishment of his object. Mr. Faraday was completely at a loss to explain the occurrence, and proceeded to repeat the experiment with a view to its elucidation. I was unable, however, to remain and witness the result. Upon mentioning the circumstance to Sir Humphry Davy after dinner, he appeared much surprised; and after a few moments of apparent abstraction, he said, "I shall enquire about this experiment to-morrow." Early on the next morning, I received from Mr. Faraday the following laconic note: DEAR SIR, The _oil_ you noticed yesterday turns out to be liquid chlorine. Yours faithfully, M. FARADAY. It is well known that, before the year 1810, the solid substance obtained by exposing chlorine, as usually procured, to a low temperature, was considered as the gas itself reduced into that form: Sir Humphry Davy, however, corrected this error, and first showed it to be a hydrate, the pure gas not being condensable even at a temperature of-40° Fahrenheit. Mr. Faraday had taken advantage of the cold season to procure crystals of this hydrate, and was proceeding in its analysis,[81] when Sir Humphry Davy suggested to him the expediency of observing what would happen if it were heated in a close vessel; but this suggestion was made in consequence of the inspection of results already obtained by Mr. Faraday, and which must have led him to the experiment in question, had he never communicated with Sir Humphry Davy upon the subject. This avowal is honestly due to Mr. Faraday.