Dupuis. See Putaneus.
Empedocles, whom Gilbert merely names in Book V. chap. xii. of De Magnete, was a native of Sicily, distinguished as a philosopher as well as for his knowledge of medicine and of natural history.
Empedocles flourished about the year 442 or 460 B.C., and was pupil of Pythagoras or Anaxagoras, and, as others say, of Parmenides (“The Metaphysics of Aristotle” by the Rev. John H. McMahon, London, 1857, pp. 19–20, 34, 118).
“Rien n’est engendré, disait Empédocle, rien ne périt de la mort funeste. Il n’y a que mélange ou séparation de parties.... L’éclair, c’est le feu s’échappant du nuage où le soleil l’avait lancé. La foudre n’est qu’une plus grande quantité de feu. Le tonnerre, c’est ce même feu qui s’éteint dans le nuage humide.... Les phénomènes magnétiques viennent de la convenance parfaite des pores et des effluves de l’aimant et du fer. Dès que les effluves de l’aimant out chassé l’air que contenaient les pores du fer, le courant des effluves de fer devient si fort que la masse entière est entrainée” (“Dict. des Sc. Philos.,” Paris, 1852, Vol. II. pp. 206–214).
References.—Karsten, “Emped. Agrig. Carmin. Reliq.” in Vol. II of “Phil. Graec. vet. relig.,” Amst., 1838; and the extensive list of authorities cited in Larousse, “Dict. Univ.,” Vol. VII. pp. 457–458; Houzeau et Lancaster, “Bibl. Gén.,” Vol. I. part i. p. 401; Ueberweg, “Hist. of Philos.” (Morris), 1885, Vol. I. pp. 60–63; “The Works of George Berkeley,” by A. C. Fraser, Oxford, 1901, Vol. III. pp. 205, 247, 254, 290; Paul Tannery, “Pour l’histoire de la Science Hellène,” Paris, 1887, Chap. XIII. pp. 304–339; “Greek Thinkers,” by Theodor Gomperz, tr. of L. Magnus, London, 1901, Chap. V. pp. 558–562, 601; “A History of Classical Greek Literature,” by Rev. John P. Mahaffy, New York, 1880, Vol. I. pp. 123–128; Vol. II. pp. 48, 73, 77; “Essai Théorique et Historique sur la génération des connaissances humaines,” par Guillaume Tiberghien, Bruxelles, 1844, Vol. I. pp. 185–187.
We are told by Alex. Aphr. (Quæst. Nat., II. 23, p. 137, Speng) that, like Empedocles, Democritus sought to explain the attractive power of the magnet, upon which the latter wrote a treatise (according to Diog. IX. 47).
Democritus was born at Abdera in Thrace about 470 or 460 B.C., and, according to Thrasyllus, the grammarian, he died 357 B.C.—the same year as Hippocrates. He was considered, by far, the most learned thinker of his age, and, according to Carl Snyder, who dedicates “The World Machine,” 1907, to Democritus, he was justly esteemed by Bacon as the mightiest of the ancients, for he wrote illuminatively upon almost every branch of natural knowledge.
The following note to “The Atomistic Philosophy” appears at p. 230, Vol. II of Dr. E. Zeller’s “History of Greek Philosophy,” translation of S. F. Alleyne, London, 1881:
“Leucippus and Democritus derive all action and suffering from contact. One thing suffers from another, if parts of the latter penetrate the empty interspaces of the former.... Democritus thought that the magnet and the iron consist of atoms of similar nature but which are less closely packed together in the magnet. As, on the one hand, like draws like, and, on the other, all moves in the Void, the emanations of the magnet penetrate the iron, and pass out a part of its atoms, which, on their side, strain towards the magnet, and penetrate its empty interspaces. The iron itself follows this movement, while the magnet does not move towards the iron, because the iron has fewer spaces for receiving the effluences.”
The attraction of the magnet, as explained by Diogenes of Appollonia, is thus given by Alex. Aphr. (Quæst. Nat., II. 23, p. 138, Speng): “Empedocles supposed that, after the emanations of the magnet have penetrated into the pores of the iron, and the air which choked them has been expelled, powerful emanations from the iron pass into the symmetrical pores of the magnet, which draw the iron to itself and hold it fast.”