Although Sir Walter Scott, in his Demonology, alludes to the influence of this Society in diminishing the reigning superstition, he does not appear to have been acquainted with the circumstance here alluded to.
[65] I state this opinion with the greater confidence, from a conviction that it is not singular. On conversing lately upon the subject with a gentleman to whom the Royal Society is deeply indebted for the sound judgment and discretion he displayed on occasions greatly affecting its interests, he replied, "Sir, we require not an Achilles to fight our battles, but an Agamemnon to command the Greeks."
[66] It was well known to his friends that, had his health not declined, he would have carried into effect a reform which he had long contemplated, and by which the Royal Society would have become, at once, more dignified and more useful.
[67] Davy observes, that there are many facts recorded in the Philosophical Transactions, which prove the magnetising powers of lightning: one in particular, where a stroke of lightning passing through a box of knives, rendered most of them powerful magnets.—Philosophical Transactions, No. 157, p. 520, and No. 437, p. 57.
[68] The phenomena of many crystallized minerals which become electric by heat, and develope opposite electric poles at their two extremities, offered an analogy so striking to the polarity of the magnet, that it seemed hardly possible to doubt a closer connection of the two powers. The developement of a similar polarity in the Voltaic pile pointed strongly to the same conclusion; and experiments had even been made with a view to ascertain whether a pile in a state of excitement might not manifest a disposition to place itself in the magnetic meridian.—Herschel's Discourse, p. 340.
[69] The hypothesis was this:—"In galvanism, the force is more latent than in electricity, and still more so in magnetism than in galvanism; it is therefore necessary to try whether electricity, in its latent state, will not affect the needle." This passage may be thus explained: When the Voltaic circuit is interrupted, it possesses opposite electrical poles; and when continuous, it no longer affects the electrometer, or the electricity becomes latent, which is the condition theoretically required for the manifestation of its magnetic action: and the fundamental experiment of Oersted proved that, under these circumstances, the compass needle was affected.
[70] Mr. Herschel, in speaking of the pertinacity with which Oersted adhered to the idea of a necessary connection between electricity and magnetism, observes, that there is something in it which reminds us of the obstinate adherence of Columbus to his notion of the necessary existence of the New World.
[71] For this discovery, the President and Council of the Royal Society adjudged to M. Oersted the medal on Sir Godfrey Copley's Donation for the year 1820.
[72] I find from a note addressed to Mr. Pepys, that on the 21st of June, 1822, Davy worked the two batteries of 1000 plates each at the London Institution, before the Prince Royal of Denmark. The experiments were principally electro-magnetic.
[73] It would appear that M. Arago likewise discovered this fact at about the same period; but it is evident that the French and English philosophers arrived at the result independently of each other; for the experiments which led to it were made by Sir H. Davy in October 1820; while the September number of the "Annales de Physique," containing the first account of the Researches of M. Arago, was not received in London until the 24th of November in that year; and it may be farther observed, that the numbers of this journal were very commonly published several months after the affixed date.