In 1823 Faraday read two papers to the Royal Society, one on Liquid Chlorine, the other on the Condensation of several Gases into Liquids. No sooner was the work completed than he dashed off a letter to De la Rive to tell him what he had accomplished. Under date March 24, 1823, he writes:-- I have been at work lately, and obtained results which I hope you will approve of. I have been interrupted twice in the course of experiments by explosions, both in the course of eight days--one burnt my eyes, the other cut them; but fortunately escaped with slight injury only in both cases, and am now nearly well. During the winter I took the opportunity of examining the hydrate of chlorine, and analysing it; the results, which are not very important, will appear in the next number of the _Quarterly Journal_, over which I have no influence. Sir H. Davy, on seeing my paper, suggested to me to work with it under pressure, and see what would happen by heat, &c. Accordingly I enclosed it in a glass tube hermetically sealed, heated it, obtained a change in the substance, and a separation into two different fluids; and upon further examination I found that the chlorine and water had separated from each other, and the chlorine gas, not being able to escape, had condensed into the liquid form. To prove that it contained no water, I dried some chlorine gas, introduced it into a long tube, condensed it, and then cooled the tube, and again obtained fluid chlorine. Hence what is called chlorine gas is the vapour of a fluid.... * * * * * I expect to be able to reduce many other gases to the liquid form, and promise myself the pleasure of writing you about them. I hope you will honour me with a letter soon. I am, dear Sir, very faithfully, your obedient servant, M. FARADAY. [Sidenote: CHLORINE LIQUEFIED.]