Chapter XLI: Book I: chap. i. and Book II. chaps, iii. xxxvi.; “Journal des

Savants” for January 1894; Houzeau et Lancaster, “Bibl. Gén.,”
Vol. II. p. 115; Larousse, “Dict. Univ.,” Vol. V. p. 687;
“Biogr. Gén.,” Vol. XII. pp. 651–657.

=Dominicus=, Maria Ferrariensis--“Novara”--Italian savant (1464–1514), taught astronomy at Bologna, Rome and elsewhere, and had for one of his pupils the celebrated Copernicus, who, later on, became an associate in his investigations. None of his writings have reached us.

Gilbert thus alludes to Dominicus as well as to Stadius at Chap. II. book vi. of his _De Magnete_: “According to Dominicus Maria’s observations, the north pole is raised higher and the latitudes of places are greater now than in the past: from this he infers a change of latitudes. But Stadius, holding the directly opposite opinion, proves by observations, that the latitudes have grown less. ‘The latitude of Rome,’ says he, ‘is given in the _Geographia_ of Ptolemy as 41⅔°; and lest any one should say that some error has crept into the text of Ptolemy, Pliny relates, and Vitruvius in his ninth book testifies, that at Rome on the day of the equinox the ninth part of the gnomon’s shadow is lacking. But recent observation (as Erasmus Rheinhold states) gives the latitude of Rome in our age as 41⅙°; so that you are in doubt whether one-half of a degree has been lost (_decrevisse_) in the centre of the world, or whether it is the result of an obliquation of the earth.’”

REFERENCES.--Borsetti (Ferrante Giovanni), “Hist. Gymn.
Ferrar.,” Vol. II. p. 50; Tiraboschi (Girolamo), “Storia della
Letteratura Italiana,” Vol. XIV. p. 296; Montucla (J. F.),
“Hist. des Math.,” Vol. I. p. 549; Houzeau et Lancaster, “Bibl.
Gén.,” Vol. II. pp. 215–216; “Biog. Gén.,” Vol. XXXVIII. p. 336.

=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.”

It may be added that the Atomic Doctrine of Leucippus and Democritus was opposed to the Homoiomeria of Anaxagoras of Clazomenæ--the last great philosopher of the Ionian School.

REFERENCES.--Ueberweg (Fr.), “History of Philosophy,” trans.
of G. S. Morris, New York, 1885, Vol. I. pp. 67–71; Larousse
(Pierre), “Dict. Univ. du XIX^e siècle,” Paris, 1870, Tome VI.
pp. 409–410; “La Grande Encyclopédie,” Paris, Tome XIV. pp.
66–69; “Nouvelle Biographie Générale” (Hœfer), Paris, 1855, Vol.
XIII. pp. 566–574; Franck (Ad.), “Fragments qui subsistent de
Démocrite,” in the “Mém. de la Société Royale de Nancy,” 1836;
Beazley (C. Raymond), “The Dawn of Modem Geography,” Oxford,
1906, Vol. I. p. 254 (the use by Democritus of magnetic stones,
mentioned by Solinus); Snyder (Carl), “The World Machine,” 1907,
p. 133 (work on the magnet); Zeller (Eduard), “Philosophie der
Griechen”; Ritter and Preller, “Historia Philosophiæ Græcæ”
(7th ed., Gotha, 1888); Mulloch (F. G. A.), “Democriti Abderitæ
operum fragmenta,” Berlin, 1843.

=Erasmus=, Reinholdus (1511–1553), a German savant, who taught astronomy and mathematics at Wittemberg, has left us “Commentarius Theoricæ Novæ Planetarum,” 1542, 1558, a work which, Delambre says, supplies the omissions of Purbacchius and must have cleared many of the passages of Ptolemy’s syntax. He also wrote “Almageste,” 1549;[63] made up the Prutenic (Prussian) astronomical tables (“Prutenicæ tabulæ cœlestium motuum,” 1551), from the observations of Copernicus, Hipparchus and Ptolemy, and he is believed to be the author of the anonymous work entitled “Hypotyposes orbium cœlestium ...” which appeared during the year 1568.

Gilbert’s reference to Erasmus has already been given in connection with Dominicus.

REFERENCES.--Vossius (G.), “De Scientiis Mathem.,” Chap. XXXVI.
p. 14; Delambre (J. B. J.), “Hist. de l’astronomie moderne,”
Vol. I. pp. 142, 146, 164; Zedler (Johann Hch.); Mädler--Mædler
(Johann Henrich von), Vol. I. p. 168; Bailly (Jean Sylvain),
“Histoire de l’astronomie moderne ...” Vol. I. p. 366 and Vol.
II. p. 71; Jöcher (Johann Friedrich), “Bibliogr. Astronom.”;
Weidler (Christian Gottlieb), p. 353; “Biogr. Générale,” Vol.
XLI. pp. 928–929.

=Erastus=, Thomas--Thomas Lieber--(1524–1583) was a native of Switzerland, notable in medicine and famous in ecclesiastical polemics, who furiously combated the medical views of Paracelsus, notably in his “Disputationum de Medicina,” Basileæ, 1572–1573. Gilbert mentions him (_De Magnete_, Book I. chaps. i. and vii.), merely saying that, knowing naught of the nature of the loadstone, Erastus draws from it weak arguments against Paracelsus.

His numerous works are detailed in the “Biographisches Lexikon,” Vienna und Leipzig, 1885, Vol. II. pp. 292, etc., and a very complete account thereof is to be found at pp. 561–564 of “De Scriptis Medicis,” by Joannes Antonides Van Der Linden, Amstel., 1651.

REFERENCES.--Pluquet (François André Adrien), “Diction. des
Hérésies”; Moreri (Louis), “Le Grand Dictionnaire Historique”;
Wordsworth (Christopher), “Ecclesiastical Biography”; “New Int.
Encycl.,” New York, 1903, Vol. VI. p. 828; “Biog. Gén.,” Vol.
XXXI. pp. 174–175; “La Grande Encyclopédie,” Vol. XVI. p. 163;
Larousse, “Dict. Univ.,” Vol. VII. p. 788; Adam (Melchior),
“Vitæ Germanorum Medicorum,” pp. 107–109; Bolton, H. C., “Ch.
Hist. of Chem.,” p. 981.

=Evax=--Euace--a Latin naturalist who lived in the time of Tiberius and said to have been King of the Arabs, is the supposed author of “De nominibus et virtutis lapidum qui in artem medicinæ recipiuntur,” treating of gems, of which the MS.--now in the Oxford Library--was used by Marbodeus to make up his own work on precious stones.

Salmasius delivers it as his opinion that, by an error of transcribers, from Cratevas, who in some copies is also named Cratevas, this Evax has arisen. (“Gen. Biog. Dict.” of Alex. Chalmers, London, 1814, Vol. XIII. p. 411.)

REFERENCES.--“Journal des Savants” for June 1891 (“Traditions
... chez les Alchimistes du Moyen Age,” par Marcellin Pierre
Eugène Berthelot); Larousse, “Dict. Univ.,” Vol. VII. p. 1153;
Gilbert, _De Magnete_, Book II. chap. xxxviii.

=Fallopius=, Gabriellus (1523–1562), was a famous Italian anatomist and one of the three who, according to Cuvier, restored or rather created anatomy during the sixteenth century. The other two were Vassalli and Eustachi. His principal work is “Observationes Anatomicæ,” Venice, 1561; a list of the others--named in “Biog. Gén.,” Vol. XVII. pp. 66–69--embracing “De medicatis ... de metallis sev fossilibus ...” Venice, 1564; “De Simplicibus Medicamentis purgantibus tractatus,” 1566; “De Compositione Medicamentorum,” 1570; “Opera Genuina Omnia,” 1584, 1596, 1606. The collected edition of his complete works was published in Venice, 1584, and at Frankfort, 1600.

REFERENCES.--Tiraboschi (Girolamo), “Biblioteca Modenese,”
Vol. II. p. 236; Nicéron (J. P.), “Mémoires,” Vol. IV. p. 396;
Gilbert, _De Magnete_, Book I. chaps. i. and xv. also Book II.
chap. xxxviii.; Larousse, “Dict. Univ.,” Vol. VIII. p. 67.

=Fernelius=, Joannes Franciscus (1497–1558), celebrated French physician, called the modern Galen, is the author of many works which are cited at pp. 477–483, Vol. XVII of the “Biographie Générale,” the principal ones being “De naturali parte medicinæ,” 1542, “De vacuandi ratione liber,” 1545, and “De Abditis Rerum Causis,” 1548. Gilbert alludes to the last named (_De Magnete_, Book I. chap. i.), saying that Fernel believes there is in the loadstone a hidden and abstruse cause: elsewhere he says this cause is celestial; and he does but explain the unknown by the more unknown. This search after hidden causes, he adds, is something ignorant, beggarly and resultless.

REFERENCES.--Thou (François Auguste de), “Historiarum sui
temporis”; Sc. de Sainte Marthe, “Elogia Doct. Gallorum”; Eloy,
“Dict. Hist. de la Médecine,” Mons, 1778, Vol. II. pp. 208–221;
Larousse, “Dict. Univ.,” Vol. VIII. p. 259.

=Ficino=, Marsilia (1433–1499), was the son of Ficino, the physician of Cosmo de Medici, and was one of the leading scholars of the Renaissance. He was celebrated as the most distinguished translator of Plato and as the reviver of Platonic philosophy in Italy. One of his biographers has said that the most important feature of his philosophy is his claim to harmonizing Platonic idealism with Christian doctrine.

Gilbert says that “Ficinus chews the cud of ancient opinions, and to give the reason of the magnetic direction seeks its cause in the constellation Ursa. Ficinus writes, and Merula copies, that in the loadstone the potency of Ursa prevails, and hence it is transferred into the iron” (_De Magnete_, Book. I. chap. i.; Book III., chap. i.; Book IV. chap. i.).

His complete works (published in two volumes, Venice, 1516, Basle, 1561, 1576, Paris, 1641), embrace “Theologiæ Platonicæ,” 1488; “De Vita libri tres,” 1489; “Iamblichus, de mysteriis ...” 1497; “Apologiæ in qua medicina, astrologia ...” 1498.

REFERENCES.--Corsi (Raimondo Maria), “M. Ficini Vita,” Pisa,
1772; Symonds (John Addington), “Remains in Italy,” London,
1875, and “Renaissance in Italy,” New York, 1888, pp. 324–328;
“English Cyclop.” (Biography), Vol. II. p. 908; “The Rise of
Intellectual Liberty from Thales to Copernicus,” by Frederic May
Holland, New York, 1885, pp. 279–280; Larousse, “Dict. Univ.,”
Vol. VIII. pp. 331–332; “Journal des Savants” for May 1894;
Houzeau et Lancaster, “Bibl. Gén.,” Vol. II. p. 131; “Biog.
Générale,” Vol. XVII. pp. 634–638; “The Works of Geo. Berkeley,”
by A. C. Fraser, Oxford, 1901, Vols. II. p. 268; III. pp.
216–217, 221–223, 260, 296–297; “Dict. of Philos. and Psych.,”
by J. M. Baldwin, New York, 1901, Vol. I. p. 381.

=Fracastorio=, Hieronymo (1483–1553), Italian physician and one of the most learned men of his day, is said to have been made Professor of Logic at the University of Padua when but nineteen years of age. J. B. Ramusio admitted that he owed to Fracastorio the idea and much of the material for his great work “Rac. di Navigazioni e Viaggi,” first published in 1550.

Fracastorio made many important astronomical observations, and it was he and Peter Apian who first made known in Europe the fact that comets’ tails are always turned away from the sun, so that their line of prolongation passes through its centre.

Gilbert alludes to Fracastorio (_De Magnete_, Book I. chap. i.;