Sir Humphry Davy, Bart, 01 



slighting mention of him, occupied the important station 

 of president more successively, and with greater benefit to 

 science than any other individual who ever held it since 

 the time of Newton. It would be invidious to point out 

 the individuals who were encouraged and supported in the 

 prosecution of science by Sir Joseph Banks, but that some 

 of our most eminent men of science were under deep obli- 

 gations to him is sufficiently well known. It is also cer- 

 tain that the evening meetings at his house continued till 

 his death, while those of Davy were discontinued in 1826. 

 What his motives were for discontinuing them do not 

 appear. In August, 1819, he made an excursion to Scot- 

 land, and in October of the same year, directed his atten- 

 tion to the experimental results of Oersted. The first notice 

 of this is contained in a letter to his brother, dated Decem- 

 ber, ** I have ascertained" he observes " (repeating some 

 vague experiments of Oersted) that the voltaic pile is a 

 powerful magnet, i. e, that by the union of the + and — 

 electricities, magnetism is produced in the same combina- 

 tions as heat. I am deeply occupied with this, which 

 promises to explain so much for the theory of the earth : 

 do not say any thing on the subject. I hope in two or 

 three days to be able to give ydti the whole details of which 

 you will immediately perceive the importance." His 

 knowledge of the experiments of Oersted, was first derived 

 at second hand, by a letter from a friend at Geneva. 



This important discovery, which consists in the fact that 

 when the extremities of a voltaic pile or battery are united 

 by a -perfect conductor, as a metallic wire, and the com- 

 pass is .brought near it, the needle is attracted by the wire 

 and may be made to deviate from its natural direction. 

 This Davy verified, and inferred that the uniting wire must 

 have become magnetic, which he found correct. He found 

 the same magnetic power to be exhibited by the Leyden 

 battery, and conjectured that the magnetism of the earth 

 might be owing to electrical currents. In July, 1821, he 

 published in the Philosophical Transactions, his *' Farther 

 Researches on the Magnetic Phenomena produced by Elec- 

 tricity," &c. In this paper he points out some remarkable 

 facts in reference to electrical conduction ; he shews that 



