In 1803, he was chosen a fellow of the Royal Society, and in 1805, a member of the Royal Irish Academy. He now enjoyed the friendship of most of the distinguished literary men and philosophers of the metropolis, and enumerated among his intimate friends, Sir Joseph Banks, Cavendish, Hatchett, Wollaston, Children, Tennant, and other eminent men. At the same time he corresponded with the principal chemists of every part of Europe. In 1806, he was appointed to deliver, before the Royal Society, the Bakerian lecture, in which he displayed some very interesting new agencies of electricity, by means of the celebrated galvanic apparatus.[1] Soon afterwards, he made one of the most brilliant discoveries of modern times, in the decomposition of two fixed alkalies, which, in direct refutation of the hypothesis previously adopted, were found to consist of a peculiar metallic base united with a large quantity of oxygen. These alkalies were potash and soda, and the metals thus discovered were called potassium and sodium, Mr. Davy was equally successful in the application of galvanism to the decomposition of the earths. About this time he became Secretary of the Royal Society. In 1808, Mr. Davy received a prize from the French Institute. During the greater part of 1810, he was employed on the combinations of oxymuriatic gas and oxygen; and towards the close of the same year, he delivered a course of lectures before the Dublin Society, and received from Trinity College, Dublin, the honorary degree of LL. D. In the year 1812, Mr. Davy married his amiable lady, then Mrs. Apreece, widow of Shuckburgh Ashby Apreece, Esq. and daughter and heiress of the late Charles Kerr, of Kelso, Esq. By his union with this lady, Mr. Davy acquired not only a considerable fortune, but the inestimable treasure of an affectionate and exemplary wife, and a congenial friend and companion, capable of appreciating his character and attainments. A few days previously to his marriage, he received the honour of knighthood from his Majesty, then Prince Regent, being the first person on whom he conferred that dignity. We now arrive at the most important result of Sir Humphry Davy's labours, viz. the invention of the SAFETY-LAMP for coal mines, which has been generally and successfully adopted throughout Europe. This invention has been the means of preserving many valuable lives, and preventing horrible mutilations, more terrible even than death; and were this Sir Humphry Davy's only invention, it would secure him an immortality in the annals of civilization and science. The general principle of this discovery may be described as follows: