The combustible bases of the fixed alkalies seem to be repelled as other combustible substances, by positively electrified surfaces, and attracted by negatively electrified surfaces, and the oxygen follows the contrary order; or the oxygen being naturally possessed of the negative energy, and the bases of the positive, do not remain in combination when either of them is brought into an electrical state opposite to its natural one. In the synthesis, on the contrary, the natural energies or attractions come in equilibrium with each other; and when these are in a low state at common temperatures, a slow combination is effected; but when they are exalted by heat, a rapid motion is the result; and as in other like cases with the production of fire. FOOTNOTES: [Footnote 28: From the _Transactions of the Royal Society of London_.] XXVI MICHAEL FARADAY 1791-1867 _Born on September 22, 1791, at Newington, Surrey, England, Michael Faraday was the son of a blacksmith. After an early and very elementary education, he was apprenticed in 1805 to a book-binder in whose service he read widely and thus educated himself. Developing an interest in physics, he attended the evening lectures of Sir Humphrey Davy who, in 1813, engaged him as an assistant. Seven years later he wrote a history of electro-magnetism and succeeded, in the same year, in getting a needle to rotate fully around a live wire. In 1823 he liquefied chlorine, an experiment which destroyed the old notion of the permanent distinction between gases and liquids. In 1831 he discovered magneto-electric induction and advanced the conception of “lines of magnetic force.” In 1845, in trying to send polarized rays of light through heavy magnetized glass, he found that the magnet’s action interrupted the passage of the light and that magnetization caused the plane of polarization to rotate. He died August 25, 1867._ ON FLUID CHLORINE[29] _Read March 13, 1823._ 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; and that Sir Humphrey Davy first showed it to be a hydrate, the pure dry gas not being considerable even at a temperature of 40° F. I took advantage of the late cold weather to procure crystals of this substance for the purpose of analysis. The results are contained in a short paper in the Quarterly Journal of Science, Vol. XV. Its composition is very nearly 27.7 chlorine, 72.3 water, or 1 proportional of chlorine, and 10 of water.