SIR HUMPHRY DAVY (1778-1829). Original Pen and Ink Sketch for Davy's Bakerian Lecture "On the Relation of Electrical and Chemical Changes". London: 1826.

A small sketch in Davy's hand in preparation for the 1826 Bakerian lecture "On the Relations of Electrical and Chemical Changes" read on June 8th and which was the last lecture he was to give on the subject before his death two years later. This lecture also earned him the Royal Society's Royal Medal in 1827 "For his Bakerian Lecture, On the Realtions of Electrical Changes, considered as the last link, in the order of time, of the splendid chain of Discoveries in Chemical Electricity, which has been continued for so many years of his valuable life." This great chemist and discoverer of Potassium, Sodium, and other elements, was particularly keen on the science of electrochemistry, and this small sketch is an excellent example of his mind at work, which was quite adept at scientific experimentation. The lecture was published in the 1826 issue of Philosophical Transactions, page 383. An abstract of the paper states that "the instruments used in the experiments of this paper for detecting and estimating electric currents of small intensity, were constructed on the principles of the multiplier of Schweigger, and the galvanometer of Prof. Cumming; the suspended needle being surrounded, in the direction of its length, with several coils of silked wire, and having its directive forced counteracted by two other needles exterior to the coils." The needles and silked wire appear to be what are depicted in the sketch offered here. The script at the bottom of the sketch, which identifies the illustration, is in a different, though perhaps contemporary hand. The sketch measures 4.5 x 3 inches and has light toning and wear, with slight remnants of a matting board on the reverse. Sketches in Davy's hand of his experiments are extremely rare.