_Born December 17, 1778, in Cornwall, Sir Humphrey Davy was apprenticed in 1794 to a surgeon-apothecary at Penzance in whose service he became interested in chemistry. Made superintendent of a hospital in 1798, he had opportunities for gaining acquaintance with influential men who in turn recommended him to Count Rumford. Through the latter’s assistance he was appointed lecturer on chemistry at the newly-founded Royal Institution where, in spite of his unattractive appearance, he gained considerable reputation. In 1807 he advanced a theory which partly explained electrolysis; in the following year he discovered strontium and magnesium; and in 1809, chlorine. In 1812 he was knighted; and shortly after his marriage, in the same year, he injured an eye while experimenting and was compelled to interrupt his work for a short time. In 1815 he invented the safety-lamp used by miners. In 1818 he was created a baronet, and was elected President of the Royal Society in 1820. He died May 29, 1829, at Geneva, Switzerland, at the age of fifty-one._ ON SOME NEW PHENOMENA OF CHEMICAL CHANGES PRODUCED BY ELECTRICITY[28] _Read November 19, 1807._ INTRODUCTION. In the Bakerian Lecture which I had the honour of presenting to the Royal Society last year, I described a number of decompositions and chemical changes produced in substances of known composition by electricity, and I ventured to conclude from the general principles on which the phenomena were capable of being explained, that the new methods of investigation promised to lead to a more intimate knowledge than had hitherto been obtained, concerning the true elements of bodies. This conjecture, then sanctioned only by strong analogies, I am now happy to be able to support by some conclusive facts. In the course of a laborious experimental application of the powers of electro-chemical analysis, to bodies which have appeared simple when examined by common chemical agents, or which at least have never been decomposed, it has been my good fortune to obtain new and singular results. Such of the series of experiments as are in a tolerably mature state, and capable of being arranged in a connected order, I shall detail in the following sections, particularly those which demonstrate the decomposition and composition of the fixed alkalies, and the production of the new and extraordinary bodies which constitute their bases.