Early in the following year Faraday was experimenting on chlorine, a subject that had attracted a great deal of Davy's attention. At Davy's suggestion he enclosed some of the gas in an hermetically sealed glass tube, that he might "work with it under pressure, and see what would happen by heat." What "happened" was that on several occasions the tube exploded, twice doing injury to Faraday's eyes. On one of the occasions when Faraday was at work, Dr. Paris happened to enter the laboratory, and seeing an oily liquid in the tube rallied him on his carelessness in using dirty vessels. When, afterwards, the end of the tube was filed off, there was an explosion, and the oily matter disappeared. Early on the following day Dr. Paris received this note:-- "Dear Sir,--The _oil_ you noticed yesterday turns out to be liquid chlorine. "Yours faithfully, M. FARADAY." He had in fact succeeded in converting chlorine gas into a liquid by means of its own pressure. This was an important discovery which led to numerous experiments with other gases, and with like results. On May 1st, 1823, Faraday's certificate as a candidate for fellowship in the Royal Society was read for the first time. Such a distinction was no doubt a coveted one in Faraday's eyes, and it must have been extremely painful to him when he found that Sir Humphry Davy was opposed to his election. It is interesting to observe, however, that the very first signature on his certificate is that of Dr. Wollaston. Such being the case it seems impossible that the old charge against Faraday in regard to electro-magnetic rotation could have been revived, and yet so it was. Wollaston himself had expressed perfect satisfaction, and the matter seemed definitely settled. Much as this revival of an untrue charge must have distressed a man of Faraday's uncompromising integrity, to find Davy, of all men, opposing him must have been yet more distressing. That Davy's opposition was active may be surmised from the following, which is told by Faraday himself: "Sir H. Davy told me I must take down my certificate. I replied that I had not put it up; that I could not take it down, as it was put up by my proposers. He then said I must get my proposers to take it down. I answered that I knew they would not do so. Then he said, I, as President, will take it down. I replied that I was sure Sir H. Davy would do what he thought was for the good of the Royal Society."