Superphysics Superphysics

NOTES on De Magnete, Part 2

by Gilbert
151 minutes  • 31963 words

[9] Page 3, line 1. Page 2, line 42. Marcellus.—“Marcellus Empiricus, médecin de Théodose-le-Grand, dit que l’aimant, appelé antiphyson, attire et repousse le fer.” (Klaproth, Sur l’invention de la boussole, 1834, p. 12.) The passage from Marcellus runs: “Magnetes lapis, qui antiphyson dicitur, qui ferrum trahit et abjicit, et magnetes lapis qui sanguinem emittit et ferrum ad se trahit, collo alligati aut circa caput dolori capitis medentur.” (Marcellus, de Medicamentis: in the volume Medici antiqui omnes, qui latinis literis morborum genera persecuti sunt. Venet., 1547, p. 89.)

[10] Page 3, line 11. Page 3, line 9. Thomas Erastus.—The work in question is Dispvtationvm de Medicina nova Philippi Paracelsi, Pars Prima: in qua quæ de remediis svperstitiosis & Magicis curationibus ille prodidit, præcipuè examinantur à Thoma Erasto in Schola Heydebergensi, professore. (Basiliæ, 1572. Parts 2 and 3 appeared the same year, and Part 4 in 1573.)

Gilbert had no more love for Paracelsus than for Albertus Magnus or others of the magic-mongers. Indeed the few passages in Paracelsus on the magnet are sorry stuff. They will mostly be found in the seventh volume of his collected works (Opera omnia, Frankfurt, 1603). A sample may be taken from the English work publisht in London, 1650, with the title: Of the Nature of Things, Nine Books; written by Philipp Theophrastus of Hohenheim, called Paracelsvs.

“For any Loadstone that Mercury hath but touched, or which hath been smeered with Mercuriall oyle, or only put into Mercury will never draw Iron more” (p. 23).

“The life of the Loadstone is the spirit of Iron; which may bee extracted, and taken away with spirit of Wine” (p. 32).

[11] Page 3, line 13. Page 3, line 11. Encelius (or Entzelt, Christoph) {8}wrote a work publisht in 1551 at Frankfurt, with the title De re metallica, hoc est, de origine, varietate, et natura corporum metallicorum, lapidum, gemmarum, atque aliarum quæ ex fodinis eruuntur, rerum, ad medicine usum deservientium, libri iii. This is written in a singular medley of Latin and German. Gilbert undoubtedly took from it many of his ideas about the properties of metals. See the note to p. 27 on plumbum album.

[12] Page 3, line 20. Page 3, line 21. Thomas Aquinas.—The reference is to his commentaries upon the Physica of Aristotle. The passage will be found on p. 96 bis of the Giunta edition (Venet., 1539). The essential part is quoted by Gilbert himself on p. 64.

[13] Page 3, line 39. Page 3, line 45. pyxidem.—The word pyxis, which occurs here, and in the next sentence as pyxidem nauticam, is translated compass. Eleven lines lower occurs the term nautica pyxidula. This latter word, literally the “little compass,” certainly refers to the portable compass used at sea. Compare several passages in Book IV. where a contrasting use is made of these terms; for example, on pp. 177 and 202. Calcagninus, De re nautica, uses the term pyxidecula for an instrument which he describes as “vitro intecta.” On p. 152, line 9, Gilbert uses the non-classical noun compassus, “boreale lilium compassi (quod Boream respicit),” and again on p. 178, line 3.

[14] Page 4, line 2. Page 4, line 2. Melphitani.—The inhabitants of Amalfi in the kingdom of Naples. The claim of the discovery or invention of the mariners’ compass in the year 1302 by one Joannes Goia, or Gioia, also named as Flavio Goia, has been much disputed. In Guthrie’s New System of Modern Geography (London, 1792, p. 1036), in the Chronology, is set down for the year 1302:

“The mariner’s compass invented, or improved by Givia, of Naples. The flower de luce, the arms of the Duke of Anjou, then King of Naples, was placed by him at the point of the needle, in compliment to that prince.”

In 1808 an elaborate treatise was printed at Naples, by Flaminius Venanson with the title, De l’invention de la Boussole Nautique. Venanson, who cites many authorities, endeavours to prove that if Gioia did not discover magnetic polarity he at least invented the compass, that is to say, he pivotted the magnetic needle and placed it in a box, with a card affixed above it divided into sixteen parts bearing the names of the sixteen principal winds. He alleges in proof that the compass-card is emblazoned in the armorial bearings of the city of Amalfi. This view was combatted in the famous letter of Klaproth to Humboldt publisht in Paris in 1834. He shows that the use of the magnetized needle was known in Europe toward the end of the twelfth century; that the Chinese knew of it and used it for finding the way on land still earlier; that there is no compass-card in the arms of the city of Amalfi; but he concedes that Gioia may have improved the compass in 1302 by adding the wind-rose card. The most recent contributions to the question are a pamphlet by Signorelli, Sull’ invenzione della Bussola nautica, ragionamento di Pietro Napoli Signorelli, segretario perpetuo della Società Pontaniana; letto nella seduta del 30 settembre 1860; Matteo Camera’s Memorie Storico-diplomatiche dell’ antica città e ducato di Amalfi (Salerno, 1876); and Admiral Luigi Fincati’s work Il Magnete, la Calamita, e la Bussola (Roma, 1878). An older mention of Gioia is to be found in Blundevile’s Exercises (3rd edition, 1606, pp. 257-258). See also Crescentio della Nautica Mediterranea, (Roma, 1607, p. 253), and Azuni, Dissertazione sull’ origine della bussola nautica (Venezia, 1797).{9}

There appears to be a slip in Gilbert’s reference to Andrea Doria, as he has confounded the town of Amalfi in Principato Citra with Melfi in Basilicata.

One of the sources relied upon by historians for ascribing this origin of the compass is the Compendia dell’ Istoria del Regno di Napoli, of Collenuccio (Venet., MDXCI.), p. 5.

“Nè in questo tacerò Amalfi, picciola terra, & capo della costa di Picentia, alia quale tutti quelli, che’l mar caualcano, vfficiosamente eterno gratie debono referire, essendo prima in quella terra trovato l’vso, & l’artificio della calamita, & del bussolo, col quale i nauiganti, la stella Tramontana infallibilmente mirando, direzzano il lor corso, si come è publica fama, & gli Amalfitani si gloriano, nè senza ragione dalli piu si crede, essendo cosa certa, che gli antichi tale instromento non hebbero; nè essendo mai in tutto falso quello, che in molto tempo è da molti si diuolga.”

Another account is to be found in the Historiarum sui temporis, etc., of Paulus Jovius (Florent., 1552), tom. ii., cap. 25, p. 42.

“Quum essem apud Philippum superuenit Ioachinus Leuantius Ligur a Lotrechio missus, qui deposceret captiuos; sed ille negauit se daturum, quando eos ad ipsum Andream Auriam ammirantem deducendos esse iudicaret. Vgonis uerò cadauer, ut illudentium Barbarorum contumeliis eriperetur, ad Amalphim urbem delatum est, in ædeque Andreæ apostoli, tumultuariis exequiis tumulatum. In hac urbe citriorum & medicorum odoratis nemoribus æquè peramœna & celebri, Magnetis usum nauigantibus hodie familiarem & necessarium, adinuentum suisse incolæ asserunt.”

Flavius Blondus, whom Gilbert cites, gives the following reference, in which Gioia’s name is not mentioned, in the section upon Campania Felix of his Italy (Blondi Flavii Forlinensis … Italia Illustrata, Basiliæ, 1531, p. 420).

“Sed fama est qua Amalphitanos audiuimus gloriari, magnetis usum, cuius adminiculo nauigantes ad arcton diriguntur, Amalphi suisse inuentum, quicquid uero habeat in ea re ueritas, certû est id noctu nauigandi auxilium priscis omnino suisse incognitum.”

There is a further reference to the alleged Amalphian in Caelius Calcagninus De re nautica commentatio. (See Thesaurus Græcarum Antiquitatum, 1697, vol. xi., p. 761.) On the other hand Baptista Porta, who wrote in Naples in 1558 (Magia Naturalis) distinctly sets aside the claim as baseless.

William Barlowe, in The Navigators Supply (1597, p. A3), says: “Who was the first inuentor of this Instrument miraculous, and endued, as it were, with life, can hardly be found. The lame tale of one Flauius at Amelphis, in the kingdome of Naples, for to haue deuised it, is of very slender probabilitie. Pandulph Collenutius writing the Neapolitane historie telleth vs, that they of Amelphis say, it is a common opinion there, that it was first found out among them. But Polidore Virgil, who searched most diligently for the Inuentors of things, could neuer heare of this opinion (yet himselfe being an Italian) and as he confesseth in the later ende of his third booke de inventoribus rerum, could neuer vnderstand anything concerning the first inuention of this instrument.”

According to Park Benjamin (Intellectual Rise in Electricity, p. 146) the use of the pivotted compass arose and spread not from Amalfi at the hands of Italians in the fourteenth century, but from Wisbuy, at the hands of the Finns, in the middle of the twelfth century.{10}

Hakewill (An Apologie or Declaration of the Power and Providence of God, London, 1673, pp. 284-285) says:

“But Blondus, who is therein followed by Pancirollus, both Italians, will not haue Italy loose the praise thereof, telling vs that about 300 yeares agoe it was found out at Malphis or Melphis, a Citty in the Kingdome of Naples in the Province of Campania, now called Terra di Lovorador. But for the Author of it, the one names him not, and the other assures vs, he is not knowne: yet Salmuth out of Ciezus & Gomara confidently christens him with the name of Flavius, and so doth Du Bartas in those excellent verses of his touching this subject.

“‘W’ are not to Ceres so much bound for bread,

Neither to Bacchus for his clusters red,

As Signior Flavio to thy witty tryall,

For first inventing of the Sea-mans dyall,

Th’ vse of the needle turning in the same,

Divine device, O admirable frame!’

“It may well be then that Flavius the Melvitan was the first inventor of guiding the ship by the turning of the needle to the North: but some German afterwards added to the Compasse the 32 points of the winde in his owne language, whence other Nations haue since borrowed it.”

[15] Page 4, line 14. Page 4, line 14. Paulum Venetum.—The reference is to Marco Polo. He returned in 1295 from his famous voyage to Cathay. But the oft-repeated tale that he first introduced the knowledge of the compass into Europe on his return is disposed of by several well-established facts. Klaproth (op. citat., p. 57) adduces a mention of its use in 1240 in the Eastern Mediterranean, recorded in a work written in 1242 by Bailak of Kibdjak. And the passages in the Iceland Chronicle, and in Alexander of Neckham are still earlier.

[16] Page 4, line 17. Page 4, line 17. Goropius. See Hispanica Ioannis Goropii Becani (Plantin edition, Antv., 1580), p. 29. This is a discussion of the etymologies of the names of the points of the compass: but is quite unauthoritative.

[17] Page 4, line 23. Page 4, line 26. Paruaim.—Respecting this reference, Sir Philip Magnus has kindly furnisht the following note. A clue to the meaning of Parvaim, which should be written in English letters with a v, not a u, will be found in 2 Chronicles, iii. 6. In the verse quoted the author speaks of gold as the gold of Parvaim, וְהַזָּהָב זְהַב פַּרְוָיִם‎, and פּרוים‎ Parvaim is taken as a gold-producing region. It is regarded by some as the same as Ophir. The word is supposed to be cognate with a Sanskrit word pûrva signifying “prior, anterior, oriental.” There is nothing in the root indicating gold. A form similar to Parvaim, and also a proper name, is Sepharvaim, found in 2 Kings, xix. 13, and in Isaiah, xxxvii. 13, and supposed to be the name of a city in Assyria.

[18] Page 4, line 35. Page 4, line 41. Cabot’s observation of the variation of the compass is narrated in the Geografia of Livio Sanuto (Vinegia, 1588, lib. i., fol. 2). See also Fournier’s Hydrographie, lib. xi., cap. 10.

[19] Page 4, line 36. Page 4, line 42. Gonzalus Oviedus.—The reference is to Gonzalo Fernandez de Oviedo y Valdès. Summario de la Historia general y natural de las Indias occidentales, 1525, p. 48, where the author speaks of the crossing of “la linea del Diametro, donde las Agujas hacen la {11}diferencia del Nordestear, ò Noroestear, que es el parage de las Islas de los Açores.”

[20] Page 5, line 8. Page 5, line 11. Petri cujusdam Peregrini.—This opusculum is the famous letter of Peter Peregrinus written in 1269, of which some twenty manuscript copies exist in various libraries in Oxford, Rome, Paris, etc., and of which the oldest printed edition is that of 1558 (Augsburg). See also Libri, Histoire des Sciences Mathématiques (1838); Bertelli in Boncompagni’s Bull. d. Bibliogr. T. I. and T. IV. (1868 and 1871), and Hellmann’s Rara Magnetica (1898). A summary of the contents of Peregrinus’s book will be found in Park Benjamin’s Intellectual Rise in Electricity (1895), pp. 164-185.

[21] Page 5, line 12. Page 5, line 15. Johannes Taisner Hannonius.—Taisnier, or Taysnier, of Hainault, was a plagiarist who took most of the treatise of Peregrinus and publisht it in his Opusculum… de Natura Magnetis (Coloniæ, 1562), of which an English translation by Richard Eden was printed by R. Jugge in 1579.

[22] Page 5, line 18. Page 5, line 23. Collegium Conimbricense.—This is a reference to the commentaries on Aristotle by the Jesuits of Coimbra. The work is Colegio de Coimbra da Companhia de Jesu, Cursus Conimbricensis in Octo libros Physicorum (Coloniæ, sumptibus Lazari Ratzneri, 1599). Other editions: Lugd. 1594; and Colon., 1596. The later edition of 1609, in the British Museum, has the title Commentariorum Collegii Conimbricensis in octo libros physicorum.

[23] Page 5, line 25. Page 5, line 31. Martinus Cortesius.—His Arte de Navegar (Sevilla, 1556) went through various editions in Spanish, Italian, and English. Eden’s translation was publisht 1561, and again in 1609.

[24] Page 5, line 26. Page 5, line 33. Bessardus.—Toussaincte de Bessard wrote a treatise, Dialogue de la Longitude (Rouen, 1574), which gives some useful notes of nautical practice, and of the French construction of the compass. Speaking of the needle he says: “Elle ne tire pas au pole du monde: ains regarde, au Pole du Zodiaque, comme il sera discoursu, cy apres” (p. 34). On p. 50 he speaks of “l’aiguille Aymantine.” On p. 108 he refers to Mercator’s Carte Générale, and denies the existence of the alleged loadstone rock. On p. 15 he gives the most naïve etymologies for the terms used: thus he assigns as the derivation of Sud the Latin sudor, because the south is hot, and as that of Ouest that it comes from Ou and Est. “Come, qui diroit, Ou est-il? à scauoir le Soleil, qui estoit nagueres sur la terre.”

[25] Page 5, line 28. Page 5, line 35. Jacobus Severtius.—Jacques Severt, whose work, De Orbis Catoptrici sev mapparvm mvndi principiis descriptione ac usu libri tres (Paris, 1598), would have probably lapsed into obscurity, but being just newly publisht was mentioned by Gilbert for its follies.

[26] Page 5, line 30. Page 5, line 38. Robertus Norman.—Author of the rare volume The Newe Attractiue, publisht in London, 1581, and several times reprinted. This work contains an account of Norman’s discovery of the Dip of the magnetic needle, and of his investigation of it by means of the Dipping-needle, which he invented. He was a compassmaker of the port of London, and lived at Limehouse.

[27] Page 5, line 32. Page 5, line 40. Franciscus Maurolycus.—The work to which the myth of the magnetic mountains is thus credited is, D. Francisci Abbatis Messanensis Opuscula Mathematica, etc. (Venet, MDLXXV, p. 122a). “Sed cur sagitta, vel obelus à vero Septentrione, quandoque ad dextram, {12}quandoque ad sinistram declinat? An quia sagitta, sicut magnes (cuius est simia) non verum Septentrionem, sed insulam quandam (quam Olaus Magnus Gothus in sua geographia vocat insulam magnetum) semper ex natura inspicere cogitur?”

[28] Page 5, line 35. Page 5, line 43. Olaus Magnus.—The famous Archbishop of Upsala, who wrote the history of the northern nations (Historia de Gentibus Septentrionalibus), of which the best edition, illustrated with many woodcuts, appeared in Rome in 1555. An English edition entitled A Compendious History of the Goths, Swedes, and Vandals, and Other Northern Nations was printed in London in 1658; but it is much abbreviated and has none of the quaint woodcuts. The reference on p. 5 appears to be to the following passage on p. 409 (ed. 1555). “Demum in suppolaribus insulis magnetum montes reperiuntur, quorum fragmentis ligna fagina certo tempore applicata, in saxeam duritiem, et vim attractivam convertuntur,” or the following on p. 89: “Magnetes enim in extremo Septentrionis veluti montes, unde nautica directio constat, reperiuntur: quorum etiam magnetum tam vehemens est operatio, ut certis lignis fagineis conjuncti, ea vertunt in sui duritiem, & naturam attractivam.” On p. 343 is a woodcut depicting the penalties inflicted by the naval laws upon any one who should maliciously tamper with the compass or the loadstone, “qui malitiosè nauticum gnomonem, aut compassum, & præcipuè portionem magnetis, unde omnium directio dependet, falsaverit.” He was to be pinned to the mast by a dagger thrust through his hand. It will be noted that the ships carried both a compass, and a piece of loadstone wherewith to stroke the needle.

There is in the Basel edition of this work, 1567, a note ad lectorem, on the margin of Carta 16a, as follows:

“Insula 30 milliarium in longitud. & latitud. Polo arctico subjecta.

“Vltra quam directorium nauticum bossolo dicũ uires amittit: propterea quòd ilia insula plena est magnetum.”

This myth of the magnetic mountains, probably originating with Nicander, appears, possibly from an independent source, in the East, in China, and in the tales of the Arabian Nights.

Ptolemy gives the following account in his Geographia (lib. vii., cap. 2):

Φέρονται δὲ καὶ ἄλλαι συνεχεῖς δέκα νῆσοι καλούμεναι Μανίολαι ἐν ἄις φάσι τὰ σιδήρους ἔχοντα ἥλους πλοῖα κατέχεσθαι, μήποτε τῆς Ἡρικλείας λίθου περὶ αὐτὰς γενομένης, καὶ διὰ τοῦτο ἐπιούροις ναυπηγεῖσθαι. Some editions omit the name of the Manioles from the passage.

No two authorities agree as to the place of these alleged magnetic mountains. Some place them in the Red Sea. Fracastorio, De Sympathia et Antipathia, cap. 7 (Opera omnia, Giunta edition, 1574, p. 63), gives the following reason for the variation of the compass:

“Nos igitur diligentius rem considerãtes dicimus causam, q˜ perpendiculum illud ad polum vertatur, esse montes ferri, & magnetis, qui sub polo sunt, vt negociatores affirmant, quorum species per incredibilem distantiam vsque ad maria nostra propagata ad perpendiculum vsq;, vbi est magnes, consuetam attractionem facit: propter distantiam autem quum debilis sit, non moueret quidem magnetem, nisi esset in perpendiculo: quare & si non trahit vsq; ac. principium, vnde effluxit, at mouet tamẽ, & propinquiorem facit, quo potest. Quod si naues sorte vllæ propinquiores sint illis montibus, ferrum omne earũ cuellitur, propter quod nauigijs incolæ vtuntur clauis ligneis astrictis.”

In the last chapter of his De Sympathia, Fracastorio returns to the subject {13}in consequence of some doubts expressed by Giambattista Rhamnusio, seeing that the loadstones in the Island of Elba do not sensibly deflect the magnet. Fracastorio replies thus (p. 76, op. citat.):

“Primum igitur vtrum sub Polo sint. Magnetis mõtes, nec ne, sub ambiguo relinquamus, scimus enim esse, qui scribãt planas magis esse eas regiones, de quo Paulus Iouius Ep˜us Nucerinus Luculẽtus historiarũ nostri tẽporis scriptor, circa eã Sarmatiæ partem, quæ Moscouia nũc dicitur, diligentẽ inquisitionem ab incolis fecit, qui ne eos etiã inueniri montes retulere, qui Rhyphei ab antiquis dicti sunt: meminimus tamẽ nos quasdam chartas vidisse earum, quas mundi mappas appellãt, in quibus sub polo montes notati erant (qui Magnetis montes inscripti fuerant). Siue igitur sint, siue non sint ij montes, nihil ad nos in præsentiarum attinet, quando per montes polo subiectos cathenam illam montium intelligimus, qui ad septentrionem spectant tanti, & tam vasti, ac Ferri & Magnetis feraces: qui, & si magis distant à nostro mari, q˜ Iluæ insulæ montes, potentiores tamen sunt ad mouendum perpendiculum propter abundantiam & copiã Ferri, & Magnetis. Fortasse autem, & qui in Ilua est Magnes, non multæ actionis est in ea minera: multi enim dũ in minera sunt, minus valent, q˜ extracti, q˜ spirituales species sua habeant impedimenta: signum autem parum valere in sua minera Iluæ insulæ Magnetem, q˜ tam propinquus quum sit nauigijs illac prætereuntibus, perpendiculum tamen non ad se cõuertit.”

Aldrovandi in the Musæum Metallicum (Bonon., 1648, p. 554) gives another version of the fable:

“Nonnulli, animadversa hac Magnetis natura, scripserunt naves, quibus in Calecutanam regionem navigatur, clavis ferreis non figi, ob magneticorum frequentiam scopulorum, quoniam facilè dissolverentur. Sed Garzias in Historia Aromatum id fabulosum esse tradidit: quandoquidem plures naues Calecutanæ regionis, & illius tractus, ferreis clauis iunctas obseruauit: immò addidit naues in insulis Maldiuis ligneis quidem clauis copulari, non quia à Magnete sibi metuant, sed quoniam ferri inopia laborant.”

According to Aldrovandi (p. 563, op. citat.) the magnetic mountains are stated by Sir John Mandeville to be in the region of Pontus.

Lipenius in his Navigatio Salomonis Ophritica illustrata (Witteb., 1660), which is a mine of curious learning, in discussing the magnetic mountains quotes the reply of Socrates to the inquirer who asked him as to what went on in the infernal regions, saying that he had never been there nor had he ever met any one who had returned thence.

The loadstone rock figures in several early charts. In Nordenskiöld’s Facsimile Atlas (Stockholm, 1889) is given a copy of the Map of Johan Ruysch from an edition of Ptolemy, publisht in Rome in 1508, which shows four islands within the ice-bound Arctic regions. South of these islands and at the east of the coast of Greenland is the inscription: Hic compassus navium non tenet, nec naves quæ ferrum tenent revertere valent. To which (on p. 63) Nordenskiöld adds the comment: Sagan on magnetberg, som skulle draga till sig fartyg förande jern, är gamal. And he recalls the reference of Ptolemy to the magnetic rocks in the Manioles. A second inscription is added to Ruysch’s map in the ornamental margin that borders the Arctic islands. Legere est in libro de inventione fortunati sub polo arctico rupem esse excelsam ex lapide magnete 33 miliarium germanorum ambitu. This refers to a matter recorded in Hakluyt’s Principall Navigations (Lond., 1589, p. 249), namely: “A Testimonie of the learned Mathematician, maister John Dee, {14}touching the foresaid voyage of Nicholas de Linna. Anno 1360 a frier of Oxford, being a good Astronomer, went in companie with others to the most Northren islands of the world, and there leaving his company together, he travelled alone, and purposely described all the Northern islands, with the indrawing seas: and the record thereof at his return he delivered to the king of England. The name of which booke is Inventio Fortunata (aliter fortunæ) qui liber incipit a gradu 54 usq. ad polum.”

The situation of the alleged loadstone rock is thus described by T. Blundevile in his Exercises in the chapter entitled A plaine and full description of Peter Plancius his vniuersall Map, seruing both for sea and land, and by him lately put foorth in the yeare of our Lord, 1592…. Written in our mother tongue by M. Blundeuill, Anno Domini 1594. The passage is quoted from p. 253 of the third edition (1606):

“Now betwixt the 72. and 86. degrees of North latitude he setteth downe two long Ilands extending from the West towardes the East somewhat beyond the first Meridian, and from the saide Meridian more Eastward he setteth downe other two long Ilandes … and hee saith further that right under the North pole there is a certaine blacke and most high rocke which hath in circuite thirtie and three leagues, which is nintie and nine miles, and that the long Iland next to the Pole on the West is the best and most healthfull of all the North parts. Next to the foresaide Ilandes more Southward hee setteth downe the Ilandes of Crocklande and Groynelande, making them to haue a farre longer and more slender shape then all other mappes doe…. Moreouer at the East end of the last Ilande somewhat to the Southwarde, he placeth the Pole of the Lodestone which is called in Latine Magnes, euen as Mercator doth in his Mappe who supposing the first Meridian to passe through Saint Marie or Saint Michael, which are two of the outermost Ilandes of the Azores Eastwarde, placeth the Pole of the stone in the seuentie fiue degree of Latitude, but supposing the first Meridian to passe through the Ile Coruo, which is the furthest Ile of the Azores Westwarde, he placeth the Pole of the Lodestone in the seuentie seuen degree of Latitude.”

Further, in the chapter on The Arte of Nauigation in the same work (p. 332, ed. citat.), Blundevile says:

“But whereas Mercator affirmeth that there should bee a mine or great rocke of Adamant, wherunto all other lesser rockes or Needles touched with the Lodestone doe incline as to their chiefe fountaine, that opinion seemeth to mee verie straunge, for truely I rather beleeue with Robert Norman that the properties of the Stone, as well in drawing steele, as in shewing the North Pole, are secret vertues given of GOD to that stone for mans necessarie vse and behoofe, of which secrete vertues no man is able to shewe the true cause.”

The following is one of the inscriptions in the compartments of the great Chart of Mercator entitled Ad Usum Navigantium, published in 1569:

“Testatur Franciscus Diepanus peritissimus nauarchus volubiles libellas, magnetis virtute infectas recta mundi polum respicere in insulis C. Viridis, Solis, Bonauista, et Maio, cui proxime astipulantur qui in Tercera, aut S. Maria (insulæ sunt inter Açores) id fieri dicunt, pauci in earundem occidentalissima Corvi nomine id contingere opinantur. Quia vero locorum longitudinis a communi magnetis et mundi meridiano iustis de causis initium sumere oportet, plurium testimonium sequutus primum meridianum per dictas C. Viridis insulas protraxi, et quum alibi plus minusque a polo deuiante {15}magnete polum aliquum peculiarem esse oporteat quo magnetes ex omni mundi parte despiciant, euum hoc quo assignaui loco existere adhibita declinatione magnetis Ratisbonæ obseruata didici. Supputaui autem eius poli situm etiam respectu insulæ Corui, ut iuxta extremo primi meridiani positus extremi etiam termini, intra quos polum hunc inueniri necesse est, conspicui fierent, donec certius aliquod nauclerorum obseruatio attulerit.”

Not all the map-makers were as frank as Paulus Merula, the author of a Cosmographia Generalis, printed by Plantin in 1605, at Leyden. For in the description of his tabula universalis (op. citat. lib. iii., cap. 9) he says that he does not believe in the magnetic islands; but that he has put them into his chart lest unskilful folk should think that he had been so careless as to leave them out!

In the well-known myth of Ogier the Dane, immortalized by William Morris in the Earthly Paradise (London, 1869, vol. i., p. 625), the loadstone rock is an island in the far North. But this story is not one of the Scandinavian sagas, and belongs to the Carlovingian cycle of heroic poems, of which the chief is the Chanson de Roland; and Ogier le Danois is really not a Dane but an Ardennois.

In the Middle-High German epic of Kudrun, the adventures of the fleet of Queen Hilda when attracted by the loadstone mountain at Givers, in the North Sea, are narrated at some length. (See Kudrun, herausgegeben und erklärt von Ernst Martin. Halle, 1872.) One stanza will serve as a sample:

  1. Ze Givers vor dem berge | lac daz Hilden her.

swie guot ir anker wæren, | an daz vinster mer.

magnêten die steine | heten si gezogen.

ir guote segelboume | stuonden alle gebogen.

which may be rendered:

  1. At Givers before the mountain | lay Hilda’s ships by.

Though good their anchors were, | upon the murky sea.

Magnets the stones were | had drawn them thither.

Their good sailing masts | stood all bent together.

Recent magnetic research has shown that while there are no magnetic mountains that would account for the declination of the compass in general, yet there are minor local variations that can only be accounted for by the presence of magnetic reefs or rocks. The reader is referred to the account of the magnetic survey of Great Britain in the Philosophical Transactions (1890) by Professors Rücker and Thorpe. The well-known rocky peak the Riffelhorn above Zermatt, in Switzerland, produces distinct perturbations in the direction of the compass within half a mile of its base. Such local perturbations are regularly used in Sweden for tracing out the position of underground lodes of iron ore. See Thalén, Sur la Recherche des Mines de Fer à l’aide de Mesures magnétiques (Soc. Royale des Sciences d’Upsal, 1877); or B. R. Brough, The Use of the Magnetic Needle in exploring for Iron Ore (Scientific American, Suppl. No. 608, p. 9708, Aug. 27, 1887).

Quite recently Dr. Henry Wilde, F.R.S., has endeavoured to elucidate the deviations of the compass as the result of the configurations of land and sea on the globe, by means of a model globe in which the ocean areas are covered with thin sheet iron. This apparatus Dr. Wilde calls a Magnetarium. See Proc. Roy. Soc., June, 1890, Jan., 1891, and June, 1891. {16}An actual magnetic rock exists in Scandinavia, the following account of it being given in the Electrical Review of New York, May 3, 1899:

“The island of Bornholm in the Baltic, which consists of a mass of magnetic iron ore, is much feared by mariners. On being sighted they discontinue steering by compass, and go instead by lighthouses. Between Bornholm and the mainland there is also a dangerous bank of rock under water. It is said that the magnetic influence of this ore bank is so powerful that a balanced magnetic needle suspended freely in a boat over the bank will take a vertical position.”

[29] Page 5, line 35. Page 5, line 43. Josephus Costa.—This is unquestionably a misprint for Acosta (Joseph de), the Jesuit, whose work Historia natural y moral de las Indias was publisht at Seville in 1590. An Italian edition appeared at Venice in 1596. The English edition, translated by E. Grimestone, The Naturall and Morall Historie of the East and West Indies, was publisht in London in 1604 and 1878. There are in Gilbert’s book references to two writers of the name of Costa or Costæus, Joannes Costa of Lodi, who edited Galen and Avicenna (see pp. 3 and 62), and Filippo Costa of Mantua, who wrote on antidotes and medicaments (see p. 141). The passage to which Gilbert refers is in Acosta’s Historia (ed. 1590, p. 64).

“Deziame a mi vn piloto muy diestro Portugues q˜ eran quatro puntos en todo el orbe, donde se afixaua el aguja con el Norte, y contaualas por sus nombres, de que no me acuerdo bien. Vno destos es el paraje de la Isla del Cueruo, en las Terceras, o Islas de Açores, como es cosa y a muy sabida. Passando di alli a mas altura, Noruestea, que es dezir, q˜ declina al Poniente … que me digã la causa desta efecto?… Porque vn poco de hierro de fregarse cõ la piedra Iman …

“Mejor es, como dize Gregorio Theologo, que a la Fe se sujete la razon, pues aun en su casa no sabe bien entenderse….”

[30] Page 5, line 36. Page 5, line 45. Livius Sanutus.—Livio Sanuto publisht at Venice in 1588 a folio work, Geografia distinta in xii Libri; ne’ quali, oltre l’esplicatione di nostri luoghi di Tolomeo, della Bussola e dell’ Aguglia, si dichiarono le provincie … dell’ Africa. In this work all Liber i. (pages 1-13) deals with observations of the compass, mentioning Sebastian Cabot, and other navigators. He gives a map of Africa, showing the central lakes out of which flow the Zaires fluvius and the Zanberes fluvius.

[31] Page 6, line 2. Page 6, line 5. Fortunius Affaitatus.—The work of Affaytatus, Physicæ ac astronomiæ considerationes, was publisht in Venice in 1549.

[32] Page 6, line 3. Page 6, line 6. Baptista Porta.—The reference is to his celebrated Magia naturalis, the first edition of which came out in 1558 at Naples. An English edition, Natural Magick by John Baptista Porta, a Neapolitaine, was printed in London, 1658. Book seven of this volume treats “Of the wonders of the Load-stone.” In the proem to this book Porta says: “I knew at Venice R. M. Paulus, the Venetian, that was busied in the same study: he was Provincial of the Order of servants, but now a most worthy Advocate, from whom I not only confess, that I gained something, but I glory in it, because of all the men I ever saw, I never saw any man more learned, or more ingenious, having obtained the whole body of learning; and is not only the Splendor and Ornament of Venice or Italy, but of the whole world.” The reference is to Fra Paolo Sarpi, better known as the historian of the Council of Trent. Sarpi was himself known to Gilbert.{17}

His relations with Gilbert are set forth in the memoir prefixt to the edition of his works, Opere di Fra Paolo Sarpi, Servita … in Helmstat, MDCCLXI, p. 83. “Fino a questi giorni continuava il Sarpi a raccorre osservazioni sulla declinazione dell’ Ago Calamitato; e poi ch’ egli, atteso il variare di tal declinazione, assurdità alcuna non trovava riguardo al pensamento dell’ Inglese Guglielmo Gilberto, cioè, che l’interno del nostro Globo fosse gran Calamita….” Here follows a quotation from a letter of Sarpi to Lescasserio:

“… Unde cuspidem trahi a tanta mole terrena, quæ supereminet non absurde putavit Gullielmus Gilbertus, et in eo meridiano respicere recta polum, cave putes observatorem errasse. Est Vir accuratissimus, et interfuit omnibus observationibus, quas plures olim fecimus, et aliquas in sui gratiam, et cum arcubus vertici cupreo innitentibus, et cum innatantibus aquæ, et cum brevibus, et cum longis, quibus modis omnibus et Hierapoli usus suit.”

Sarpi had correspondence with Gilbert, Bacon, Grotius, and Casaubon. He also wrote on magnetism and other topics in materia di Fisica, but these writings have perisht. He appears to have been the first to recognize that fire destroyed the magnetic properties. (See Fra Paolo Sarpi, the greatest of the Venetians by the Rev. Alexander Robertson, London, 1894; see also the notice of Sarpi in Park Benjamin’s Intellectual Rise in Electricity.)

[33] Page 6, line 7. Page 6, line 11.: R. M. Paulus Venetus. See preceding note.

[34] Page 6, line 21. Page 6, line 28.: Franciscus Rueus.—Francois de la Rue, author of De Gemmis Aliquot … (Paris, 1547). Amongst other fables narrated by Rueus is that if a magnet is hung on a balance, when a piece of iron is attracted and adheres to the magnet, it adds nothing to the weight!

[35] Page 6, line 25. Page 6, line 33.: Serapio.—This account of the magnetic mountains will be found in an early pharmacology printed in 1531 (Argentorati, G. Ulricher Andlenus), with the title “In hoc volumine continetur insignium medicorum Joan. Serapionis Arabis de Simplicibus Medicinis opus præclarum et ingens, Averrois Arabis de eisdem liber eximius, Rasis filius Zachariæ de eisdem opusculum perutile.” It was edited by Otho Brunsels. Achilles P. Gasser, in his Appendix to the Augsburg edition of Peregrinus, gives a reference to Serapio Mauritanus, parte 2, cap. 394, libri de medicinis compositis.

[36] Page 6, line 30. Page 6, line 39.: Olaus Magnus. See note to p. 5.

[37] Page 6, line 34. Page 6, line 44.: Hali Abas.—A reference is given in Gasser’s (1558) edition of Peregrinus to Haliabbas Arabs, lib. 2, practicæ cap. 45, Regalis Dispositionis Medicinæ. The passage to which Gilbert refers is found in the volume Liber totius medicinæ necessaria cōtinens … quem Haly filius Abbas … edidit … et a Stephano ex arabica lingua reductus. (Lugd., 1523, 4to.) Liber Primus. Practice, Cap xlv. de speciebus lapidum, § 466. “Lapis magnetes filis e vtute sadenego: & aiunt qm si teneatr in manu mitigat q sunt in pedibs ipis dolores ac spasmū.”

Mr. A. G. Ellis identifies the noun sadenegum as a Latin corruption of the Arabic name of hæmatite, shâdanaj.

[38] Page 6, line 36. Page 6, line 46.: Pictorius.—His poem was publisht at Basel, 1567. See also note on Marbodæus, p. 7, line 20, below.

[39] Page 6, line 36. Page 7, line 1.: Albertus Magnus.—Albertus, the celebrated Archbishop of Ratisbon, is responsible for propagating sundry of the myths of the magnet; and Gilbert never loses a chance of girding at him. {18}The following examples are taken from the treatise De mineralibus et rebus metallicis (Liber II. de lapidibus preciosis), Venet., 1542.

p. 171. “Et quod mirabile videtur multis his lapis [adamas] quando Magneti supponitur ligat Magnetem et non permittit ipsum ferrum trahere.”

p. 193. “Vnctus autẽ lapis alleo non trahit, si superponitur ei Adamas iterum non attrahit, ita quod paruus Adamas magnũ ligat Magnetẽ. Inventus autẽ est nostris tẽporibus Magnes qui ab uno angulo traxit ferrũ et ab alio fugavit, et hunc Aristot. ponit aliud genus esse Magnetis. Narrauit mihi quidam ex nostris sociis experimẽtator quod uidit Federicum Imperatorem habere Magnetem qui non traxit ferrum, sed ferrum uiceuersa traxit lapidem.”

The first edition of this work de mineralibus appears to have been publisht in Venice as a folio in 1495.

[40] Page 7, line 9. Page 7, line 15. Gaudentius Merula.—This obscure passage is from Liber IIII., cap. xxi., Lapides, of the work Memorabilium Gaudentii Merulæ… (Lugd., 1556), where we find:

“Qui magneti vrsæ sculpserit imaginem, quãdo Luna melius illuc aspiciat, & filo ferreo suspẽderit, compos fiet vrsæ cælestis virtutis: verùm cum Saturni radiis vegetetur, satius fuerit eam imaginem non habere: scribunt enim Platonici malos dæmones septentrionales esse” (p. 287).

“Trahit autem magnes ferrum ad se, quod ferro sit ordine superior apud vrsum” (p. 287).

The almost equally obscure passage in the De triplici vita of Marsiglio Ficino (Basil., 1532) runs:

“Videmus in specula nautarum indice poli libratum acum affectum in extremitate Magnete moueri ad Vrsam, illuc uidelicet trahente Magnete: quoniam & in lapide hoc præualet uirtus Vrsæ, & hinc transfertur in ferrum, & ad Vrsam trahit utrunq;. Virtus autem eiusmodi tum ab initio infusa est, tum continue Vrsæ radijs uegetatur, Forsitan ita se habet Succinum ad polum alterum & ad paleas. Sed dic interea, Cur Magnes trahit ubiq; ferrum? non quia simile, alioquin & Magnetem Magnes traheret multo magis, ferrumq; ferrū: non quia superior in ordine corporum, imò superius est lapillo metallum … Ego autem quum hæc explorata hactenus habuissem admodum gratulabar, cogitabamq; iuuenis adhuc Magneti pro uiribus inscluperet (sic) coelestis Vrsæ figuram, quando Luna melius illuc aspiciat, & ferro tūc filo collo suspendere. Sperabam equidem ita demum uirtutis me sideris illius compotem fore,” &c. (p. 172).

[41] Page 7, line 14. Page 7, line 20. Ruellius.—Joannes Ruellius wrote a herbal De Natura Stirpium, Paris, 1536, which contains a very full account of amber, and a notice of the magnet (p. 125) and of the fable about garlic. But on p. 530 of the same work he ridicules Plutarch for recording this very matter.

[42] Page 7, line 20. Page 7, line 27. Marbodæus Gallus.—This rare little book is entitled Marbodei Galli Poetæ vetustissimi de lapidibus pretiosis Enchiridion. It was printed at Paris in 1531. The Freiburg edition, also of 1531, has the commentaries of Pictorius. The poem is in Latin hexameters. After a preface of twenty-one lines the virtues of stones are dealt with, the paragraph beginning with a statement that Evax, king of the Arabs, is said to have written to Nero an account of the species, names and colours of stones, their place of origin and their potencies; and that this work formed the basis of the poem. The alleged magical powers of the magnet are recited in Caput I., Adamas. Caput XLIII., Magnes, gives further myths. {19}The commentary of Pictorius gives references to earlier writers, Pliny, Dioscorides, Bartholomæus Anglicus, Solinus, Serapio, and to the book de lapidibus erroneously ascribed to Aristotle.

The following is a specimen of the poem of Marbodeus:

Magnetes lapis est inuentus apud Trogloditas,

Quē lapidā genetrix nihilominus India mittit.

Hic ferruginei cognoscitur esse coloris,

Et ui naturæ uicinum tollere ferrum.

Ededon magus hoc primum ferè dicītur usus,

Conscius in magica nihil esse potentius arte.

Post illum fertur famosa uenefica Circe

Hoc in præstigijs magicis specialiter usa.

This poem was reprinted (1854) in Migne’s Patrologia. In 1799 Johann Beckmann issued an annotated variorum edition of Marbodeus (Marbodi Liber Lapidvm sev de Gemmis…, Göttingæ, 1799), in which there is a bibliography of the poem, the first edition of which appears to have been publisht in 1511, at Vienna, thirteen other editions being described. Beckmann adds many illustrative notes, and a notice of the Arabian Evax, who is supposed to have written the treatise de lapidibus. Not the least curious part is a French translation alleged to have been written in 1096, of which Chap. XIX. on the Magnet begins thus:

Magnete trovent Trogodite,

En Inde e precieus est ditte.

Fer resemble e si le trait,

Altresi cum laimant fait.

Dendor lama mult durement.

Qi lusoit a enchantement.

Circe lus a dot mult chere,

Cele merveillose forciere, &c.

[43] Page 7, line 21. Page 7, line 28. echeneidis.—The echeneis, or sucking-fish, reputed to have magical or magnetic powers, is mentioned by many writers. As an example, see Fracastorio, De Sympathia et Antipathia, lib. i., cap. 8, De Echineide, quomodo firmare nauigia possit (Giunta edition, Venet., 1574, p. 63). For other references to the Echeneis see Gaudentius Merula (op. citat.) p. 209. Also Dr. Walter Charleton, Physiologia Epicuro Gassendo-Charltoniana (Lond., 1654), p. 375. Compare p. 63, line 3.

[44] Page 7, line 33. Page 7, line 43. Thomas Hariotus, etc.—The four Englishmen named were learned men who had contributed to navigation by magnetic observations. Harriot’s account of his voyage to Virginia is printed in Hakluyt’s Voyages. Robert Hues (or Hood) wrote a treatise on Globes, the Latin edition of which appeared in 1593 (dedicated to Sir Walter Raleigh), and the English edition in 1638. It was republisht by the Hakluyt Society, 1889. Edward Wright, the mathematician and writer on navigation, also wrote the preface to Gilbert’s own book. Abraham Kendall, or Abram Kendal was “Portulano,” or sailing-master of Sir Robert Dudley’s ship the Bear, and is mentioned in Dudley’s Arcano del Mare. On the return of Dudley’s expedition in 1595, he joined Drake’s last expedition, which sailed that year, and died on the same day as Drake himself, 28 January, 1596. (See Hakluyt, ed. 1809, iv., p. 73.)

[45] Page 7, line 36. Page 8, line 1. Guilielmus Borough.—Borough’s book has the title: A Discours of the Variation of the Cumpas, or magneticall {20}Needle. Wherein is Mathematically shewed, the manner of the obseruation, effectes, and application thereof, made by W. B. And is to be annexed to The Newe Attractive of R. N., 1581 (London).

[46] Page 7, line 37. Page 8, line 2. Guilielmus Barlo.—Archdeacon William Barlowe (author, in 1616, of the Magneticall Aduertisements) wrote in 1597 a little work called The Navigators Supply. It gives a description of the ordinary compass, and also one of a special form of meridian compass provided with sights for taking the bearings by the sun.

[47] Page 7, line 37. Page 8, line 3. Robertus Normannus. See Note to p. 5.

[48] Page 8, line 14. Page 8, line 21. illo fabuloso Plinij bubulco.—The following is Pliny’s account from Philemon Holland’s English version of 1601 (p. 586): “As for the name Magnes that it hath, it tooke it (as Nicander saith) of the first inventor and deviser thereof, who found it (by his saying) upon the mountaine Ida (for now it is to be had in all other countries, like as in Spaine also;) and (by report) a Neat-heard he was: who, as he kept his beasts upon the aforesaid mountaine, might perceive as he went up and downe, both the hob-nailes which were on his shoes, and also the yron picke or graine of his staffe, to sticke unto the said stone.”

[49] Page 9, line 22. Page 9, line 30. Differentiæ priscis ex colore.—Pliny’s account of the loadstones of different colours which came from different regions is mainly taken from Sotacus. The white magnet, which was friable, like pumice, and which did not draw iron, was probably simply magnesia. The blue loadstones were the best. See p. 587 of Holland’s translation of Pliny, London, 1601. St. Isidore (Originum seu Etymologiarum, lib. xvi., cap. 4) says: “Omnis autem magnes tanta melior est, quanto [magis] cæruleus est.”

[50] Page 10, line 29. Page 10, line 42. Suarcebergo … Snebergum & Annæbergum.—In the Stettin editions of 1628 and 1633 these are spelled Swarcebergs … Schnebergum & Annebergum. The Cordus given as authority for these localities is Valerius Cordus, the commentator on Dioscorides.

[51] Page 11, line 3. Page 11, line 12. Adriani Gilberti viri nobilis.—“Adrian Gylbert of Sandridge in the Countie of Devon, Gentleman” is the description of the person to whom Queen Elizabeth granted a patent for the discovery of a North-West passage to China. See Hakluyt’s Voyages, vol. iii., p. 96.

[52] Page 11, line 17. Page 11, line 28. Dicitur a Græcis ηρακλιος.—The discussion of the names of the magnet in different languages by Gilbert in this place is far from complete. He gives little more than is to be found in Pliny. For more complete discussions the reader is referred to Buttmann, Bemerkungen über die Benennungen einiger Mineralien bei den Alten, vorzüglich des Magnetes und des Basaltes (Musæum der Alterthumswissenschaft, Bd. II., pp. 5-52, and 102-104, 1808); G. Fournier, Hydrographie (livre xi., chap. I, 1643); Ulisse Aldrovandi, Musæum Metallicum (Bononiæ, 1648, lib. iv., cap. 2, p. 554); Klaproth, Lettre à M. le Baron A. de Humboldt, sur l’invention de la Boussole, Paris, 1834; T. S. Davies, The History of Magnetical Discovery (Thomson’s British Annual, 1837, pp. 250-257); Th. Henri Martin, De l’Aimant, de ses noms divers et de ses variétés suivant les Anciens (Mémoires présentés par divers savants a l’Academie des Inscriptions et Belles-lettres, Ire série, t. vi., Ire partie, 1861); G. A. Palm, Der Magnet in Alterthum (Programm des k. württembergischen Seminars Maulbronn, Stuttgart, {21}1867). Of these works, those of Klaproth and of Martin are by far the most important. Klaproth states that in modern Greek, in addition to the name μαγνῆτις, the magnet also has the names ἀδάμας and καλαμίτα. The former of these, in various forms, adamas, adamant, aimant, yman, and piedramon, has gone into many languages. Originally the word ἀδάμας (the unconquered) was applied by the Greeks to the hardest of the metals with which they were acquainted, that is to say, to hard-tempered iron or steel, and it was subsequently because of its root-signification also given by them to the diamond for the same reason; it was even given to the henbane because of the deadly properties of that plant. In the writings of the middle ages, in St. Augustine, St. Isidore, Marbodeus, and even in Pliny, we find some confusion between the two uses of adamas to denote the loadstone as well as the diamond. Certainly the word adamas, without ceasing to be applied to the diamond, also designated the loadstone. At the same time (says Martin) the word magnes was preserved, as Pliny records, to designate a loadstone of lesser strength than the adamas. On the other hand, the word diamas, or deamans, had already in the thirteenth century been introduced into Latin to signify the diamond as distinguisht from the magnet. Adamas was rendered aymant in the romance version of the poem of Marbodeus on stones (see Beckmann’s variorum edition of 1799, p. 102), and in this form it was for a time used to denote both the magnet and the diamond. Then it gradually became restricted in use to the stone that attracts iron.

Some confusion has also arisen with respect to the Hebrew name of the magnet. Sir W. Snow Harris makes the following statement (Magnetism, p. 5): “In the Talmud it [the loadstone] is termed achzhàb’th, the stone which attracts; and in their ancient prayers it has the European name magnēs.” On this point Dr. A. Löwy has furnisht the following notes. The loadstone is termed in one of the Talmudical sections and in the Midrash, Eben Shoebeth (lapis attrahens). This would of course be written אבן שואבת‎. Omitting the ו‎ which marks the participial construction, the words would stand thus: אבן שאבת‎ A person referring to Buxtorf’s Lexicon Talmudicum would in the index look out for “Lapis magnesius,” or for “magnes.” He would then, in the first instance, be referred to the two words already quoted. Not knowing the value of the letters of the Hebrew alphabet, he reads אבן שאבת‎ thus: אכזשאבת‎ achzhab’th. It is true that Buxtorf has inserted in his Lexicon the vocable מַגְנִיסֵס‎, “corruptum ex gr. μάγνης, μαγνήτης, μαγνῆτις, named after the Asiatic city Magnesia.” He goes on to say, “Inde Achilles Statius istum lapidem vocavit μαγνήσιαν λίθον. Hinc אבן המגניסס חמשוך הברזל‎. Lapis Magnesius trahit ferrum.” Here he quotes from (Sepher) Ikkarem IV., cap. 35.

Kircher, in his Magnes, sive de Arte magnetica (Coloniæ, 1643), gives several other references to Hebrew literature. Others have supposed that the word חלמיש‎ khallamish, which signifies pebble, rock, or hard rock, to be used for the magnet.

As to the other Greek name, σιδηρῖτις, or λίθος σιδηρῖτις this was given not only to the loadstone but also to non-magnetic iron. In the Etymologicum magnum (under the word μαγνῆτις), and in Photius (Quæst. amphiloch., q. 131), it is stated that the name sideritis was given to the loadstone either because of its action on iron, or of its resemblance in aspect to iron, or rather, they say, because the loadstone was originally found in the mines of this metal. Alexander of Aphrodisias expressly says (Quætiones Physicæ, II. 23) that {22}the loadstone appears to be nothing else than γῆ σιδηρῖτις, the earth which yields iron, or the earth of iron.

[53] Page 11, line 19. Page 11, line 29. ab Orpheo.—The reference is to v. 301-328 of the Λιθικά. The passage, as given in Abel’s edition (Berol., 1881), begins:

Τόλμα δ’ ἀθανάτους καὶ ἑνήεϊ μειλίσσεθαι

μαγνήσσῃ, τὴν δ’ ἔξοχ’ ἐφίλατο θούσιος Ἄρης,

οὕνεκεν, ὁππότε κεν πελάσῃ πολιοῖο σιδήρου,

ἠύτε παρθενικὴ τερενόχροα χερσὶν ἑλοῦσα

ἠΐθεον στέρνῳ προσπτύσσεται ἱμεροέντι,

ὥς ἥγ’ ἁρπάζουσα ποτὶ σφετερὸν δέμας αἱεὶ

ἂψ πάλιν οὐκ ἐθέλει μεθέμεν πολεμιστὰ σὶδηρον.

[54] Page 11, line 20. Page 11, line 31. Gallis aimant.—The French word aimant, or aymant, is generally supposed to be derived from adamas. Nevertheless Klaproth (op. citat., p. 19) suggests that the word aimant is a mere literal translation into French of the Chinese word thsu chy, which is the common name of the magnet, and which means loving stone, or stone that loves. All through the east the names of the magnet have mostly the same signification, for example, in Sanskrit it is thoumbaka (the kisser), in Hindustani tchambak.

[55] Page 11, line 20. Page 11, line 32. Italis calamita.—The name calamita, universal in Italian for the magnet, is also used in Roumanian, Croatian, Bosnian, and Wendish. Its supposed derivation from the Hebrew khallamîsh is repudiated by Klaproth, who also points out that the use of καλαμιτα in Greek is quite modern. He adds that the only reasonable explanation of the word calamita is that given by Father Fournier (op. citat.), who says:

“Ils (les marins français) la nomment aussi calamite, qui proprement en français signifie une grenouille verte, parce qu’avant qu’on ait trouvé l’invention de suspendre et de balancer sur un pivot l’aiguille aimantée, nos ancêtres l’enfermaient dans une fiole de verre demi-remplie d’eau, et la faisaient flotter, par le moyen de deux petits fétus, sur l’eau comme une grenouille.” Klaproth adds that he entirely agrees with the learned Jesuit, but maintains that the word calamite, to designate the little green frog, called to-day le graisset, la raine, or la rainette, is essentially Greek. For we read in Pliny (Hist. Nat. lib. xxxii., ch. x.): “Ea rana quam Græci calamiten vocant, quoniam inter arundines, fruticesque vivat, minima omnium est et viridissima.”

[56] Page 11, line 20. Page 11, line 32. Anglis loadstone & adamant stone.

The English term loadstone is clearly connected with the Anglo-Saxon verb lœdan, to lead, and with the Icelandic leider-stein. There is no doubt that the spelling lodestone would be etymologically more correct, since it means stone that leads not stone that carries a load. The correct form is preserved in the word lode-star.

The word adamant, from adamas, the mediæval word for both loadstone and diamond, also occurs in English for the loadstone, as witness Shakespeare:

“You draw me, you hard-hearted adamant

But yet you draw not iron; for my heart

Is true as steel.”

Midsummer Night’s Dream, Act II, Scene 1.

[57] Page 11, line 21. Page 11, {23}line 33. Germanis magness, & siegelstein. The Stettin edition of 1628 reads Germanis Magnetstein, Belgis Seylsteen; while that of 1633 reads Germanis Magnetstein, Belgis Sylsteen.

[58] Page 11, line 26. Page 11, line 39. In this line the Greek sentence is, in every known copy of the folio of 1600, corrected in ink upon the text, θαλῆς being thus altered into Θαλῆς, and απομνεμονύουσι into απομνεμονεύουσι. Four lines lower, brackets have been inserted around the words (lapidum specularium modo). These ink corrections must have been made at the printers’, possibly by Gilbert’s own hand. They have been carried out as errata in the editions of 1628 and 1633. The “facsimile” Berlin reprint of 1892 has deleted them, however. Other ink corrections on pp. 14, 22, 38, 39, 47, 130, and 200 of the folio edition of 1600 are noted in due course.

[59] Page 11, line 29. Page 11, line 45. lapis specularis. This is the mediæval name for mica, but in Elizabethan times known as talc or muscovy stone. Cardan, De Rerum Varietate (Basil., 1557, p. 418), lib. xiiii., cap. lxxii., mentions the use of lapis specularis for windows.

[60] Page 11, line 31. Page 11, line 46.: Germanis Katzensilbar & Talke.—In the editions of 1628 and 1633 this is corrected to Germanis Katzensilber & Talcke. Goethe, in Wilhelm Meister’s Travels, calls mica “cat-gold.”

[61] Page 12, line 30. Page 12, line 35. integtum appears to be a misprint for integrum, which is the reading of editions 1628 and 1633.

[62] Page 13, line 4. Page 13, line 3. μικρόγη seu Terrella. Although rounded loadstones had been used before Gilbert’s time (see Peregrinus, p. 3 of Augsburg edition of 1558, or Baptista Porta, p. 194, of English edition of 1658), Gilbert’s use of the spherical loadstone as a model of the globe of the earth is distinctive. The name Terrella remained in the language. In Pepys’s Diary we read how on October 2, 1663, he “received a letter from Mr. Barlow with a terella.” John Evelyn, in his Diary, July, 1655, mentions a “pretty terella with the circles and showing the magnetic deviations.”

A Terrella, 4½ inches in diameter, was presented in 1662 by King Charles I. to the Royal Society, and is still in its possession. It was examined in 1687 (see Phil. Transactions for that year) by the Society to see whether the positions of its poles had changed.

In Grew’s Catalogue and Description of the Rarities belonging to the Royal Society and preserved at Gresham College (London, 1681, p. 364) is mentioned a Terrella contrived by Sir Christopher Wren, with one half immersed in the centre of a plane horizontal table, so as to be like a Globe with the poles in the horizon, having thirty-two magnet needles mounted in the margin of the table to show “the different respect of the Needle to the several Points of the Loadstone.”

In Sir John Pettus’s Fleta Minor, London, 1683, in the Dictionary of Metallick Words at the end, under the word Loadstone occurs the following passage:

“Another piece of Curiosity I saw in the Hands of Sir William Persal (since Deceased also) viz., a Terrella or Load-stone, of little more than 6 Inches Diameter, turned into a Globular Form, and all the Imaginery Lines of our Terrestrial Globe, exactly drawn upon it: viz. the Artick and Antartick Circles, the two Tropicks, the two Colures, the Zodiack and Meridian; and these Lines, and the several Countryes, artificially Painted on it, and all of them with their true Distances, from the two Polar Points, and to find the truth of those Points, he took two little pieces of a Needle, each of about half {24}an Inch in length, and those he laid on the Meridian line, and then with Brass Compasses, moved one of them towards the Artick, which as it was moved, still raised it self at one end higher and higher, keeping the other end fixt to the Terrella; and when it had compleated it Journy to the very Artick Points, it stood upright upon that Point; then he moved the other piece of Needle to the Antartick Point, which had its Elevations like the other, and when it came to the Point, it fixt it self upon that Point, and stood upright, and then taking the Terrella in my Hand, I could perfectly see that the two pieces of Needles stood so exactly one against the other, as if it had been one intire long Needle put through the Terrella, which made me give credit to those who held, That there is an Astral Influence that darts it self through the Globe of Earth from North to South (and is as the Axel-Tree to the Wheel, and so called the Axis of the World) about which the Globe of the Earth is turned, by an Astral Power, so as what I thought imaginary, by this Demonstration, I found real.”

[63] Page 13, line 20. Page 13, line 22. The editions of 1628 and 1633 give a different woodcut from this: they show the terrella lined with meridians, equator, and parallels of latitude: and they give the compass needle, at the top, pointing in the wrong direction.

[64] Page 14, line 3. Page 14, line 3. The Berlin “facsimile” reprint omits the asterisk here.

[65] Page 14, line 5. Page 14, line 6. erectus altered in ink in the folio to erecta. But erectus is preserved in editions 1628 and 1633. In Cap. IIII., on p. 14, both these Stettin editions insert an additional cut representing the terrella A placed in a tub or vessel B floating on water.

[66] Page 14, line 34. Page 14, line 39. variatione quadā. The whole of Book IIII. is devoted to a discussion of the variation of the compass.

[67] Page 16, line 28. Page 16, line 34. aquæ.—This curious use of the dative occurs also on p. 222, line 8.

[68] Page 17, line 1. Page 17, line 1. videbis.—The reading vibebis of the 1633 edition is an error.

[69] Page 18, line 24. Page 18, line 27. Theamedem.—For the myth about the alleged Theamedes, or repelling magnet, see Cardan, De Subtilitate (folio ed., 1550, lib. vii., p. 186).

Pliny’s account, in the English version of 1601 (p. 587), runs:

“To conclude, there is another mountaine in the same Æthyopia, and not farre from the said Zimiris, which breedeth the stone Theamedes that will abide no yron, but rejecteth and driveth the same from it.”

Martin Cortes, in his Arte de Nauegar (Seville, 1556), wrote:

“And true it is that Tanxeades writeth, that in Ethiope is found another kinde of this stone, that putteth yron from it” (Eden’s translation, London, 1609).

[70] Page 21, line 24. Page 21, line 25. Hic segetes, &c.—The English version of these lines from Vergil’s Georgics, Book I., is by the late Mr. R. D. Blackmore.

[71] Page 22, line 18. Page 22, line 19. quale, altered in ink in the folio text to qualis. The editions of 1628 and 1633 both read qualis.

[72] Page 22, line 19. Page 22, line 20. rubrica fabrili: in English ruddle or reddle. See “Sir” John Hill, A General Natural History, 1748, p. 47. In the De Re Metallica of Entzelt (Encelius), Frankfurt, 1551, p. 134, is a paragraph headed De Rubrica Fabrili, as follows: “Rubrica fabrilis duplex {25}est. à Germanis añt utraque dicitur rottel, röttelstein, wie die zimmerleüt vnd steynmetzen brauchen. à Græcis μίλτος τεκτονική. Est enim alia nativa, alia factitia. Natiua à Germanis propriè dicitur berckrottel. haec apud nos est fossilis…. Porro factitia est rubrica fabrilis, à Germanis braunrottel, quæ fit ex ochra usta, ut Theophrastus et Dioscorides testantur.”

[73] Page 22, line 19. Page 22, line 20. In Sussexia Angliæ.—In Camden’s Britannia (1580) we read concerning the iron industry in the villages in Sussex: “They are full of iron mines in sundry places, where, for the making and founding thereof, there be furnaces on every side; and a huge deal of wood is yearly burnt. The heavy forge-hammers, worked by water-power, stored in hammer-ponds, ceaselessly beating upon the iron, fill the neighbourhood round about, day and night, with continual noise.”

[74] Page 23, line 1. Page 22, line 44. in libro Aristotelis de admirandis narrationibus.—The reference is to the work usually known as the De Mirabilibus Auscultationibus, Cap. XLVIII.: “Fertur autem peculiarissima generatio esse ferri Chalybici Amisenique, ut quod ex sabulo quod a fluviis defertur, ut perhibent certe, conflatur. Alii simpliciter lotum in fornace excoqui, alii vero, quod ex lotura subsedit, frequentius lotum comburi tradunt adjecto simul et pyrimacho dicto lapide, qui in ista regio plurimus reperiri fertur.” (Ed. Didot, vol. ii., p. 87.) According to Georgius Agricola, the stone pyrimachus is simply iron pyrites.

[75] Page 23, line 22. Page 23, line 23. vt in Italia Comi, &c.—This is mostly taken from Pliny. Compare the following passage from Philemon Holland’s translation (1601), p. 514:

“But the most varietie of yron commeth by the meanes of the water, wherein the yron red-hot is eftsoones dipped and quenched for to be hardened. And verely, water only which in some place is better, in other worse, is that which hath ennobled many places for the excellent yron that commeth from them, as namely, Bilbilis in Spaine, and Tarassio, Comus also in Italie; for none of these places have any yron mines of their owne, and yet there is no talke but of the yron and steele that commeth from thence.”

Bilbilis is Bambola, and Tariassona the Tarazona of modern Spain.

[76] Page 24, line 28. Page 24, line 27. Quare vani sunt illi Chemici.—Gilbert had no faith in the alchemists. On pp. 19 and 21 he had poked fun at them for declaring the metals to be constituted of sulphur and quicksilver, and for pronouncing the fixed earth in iron to be sulphur. On p. 20 he had denied their proposition that the differences between silver, gold, and copper could arise from proportions of their constituent materials; and he likewise denounced unsparingly the supposed relation between the seven metals and the seven planets. He now denounces the vain dreams of turning all metals into gold, and all stones into diamonds. Later he rejects as absurd the magnetic curing of wounds. His detachment from the pseudo-science of his age was unique if not complete.

[77] Page 25, line 15. Page 25, line 16. Petro-coriis, & Cabis Biturgibus.—The Petro-corii were a tribe in the neighbourhood of Perigord; the Cubi Biturges another in that of Bourges.

[78] Page 25, line 21. Page 25, line 23. Pliny’s account, as translated by P. Holland (ed. 1601, p. 515), runs thus:

“Of all mines that be, the veine of this mettall is largest, and spreadeth it selfe into most lengths every way: as we may see in that part of Biscay that coasteth along the sea, and upon which the Ocean beateth: where there {26}is a craggie mountaine very steep and high, which standeth all upon a mine or veine of yron. A wonderfull thing, and in manner incredible, howbeit, most true, according as I have shewed already in my Cosmographie, as touching the circuit of the Ocean.”

[79] Page 26, Line 15. Page 26, line 12. quas Clampas nostri vocant.—The name clamp for the natural kiln formed by heaping up the bricks, with ventilating spaces and fuel within the heap, is still current.

[80] Page 26, line 39. Page 26, line 38. Pluebat in Taurinis ferrum.—The occurrence is narrated by Scaliger, De Subtilitate, Exercitat. cccxxiii.:

“Sed falsò lapidis pluviam creas tu ex pulvere hausto à nubibus, atque in lapidem condensato. At ferrum, quod pluit in Taurinis, cuius frustum apud nos extat, qua ex fodina sustulit nubes? Tribus circiter annis antè, quàm ab Rege provincia illa recepta esset, pluit ferro multis in locis, sed raris” (p. 434, Editio Lutetiæ, 1557).

“During the latter ages of the Roman Empire the city of Augusta Taurinorum seems to have been commonly known (as was the case in many instances in Transalpine Gaul) by the name of the tribe to which it belonged, and is called simply Taurini in the Itineraries, as well as by other writers, hence its modern name of Torino or Turin” (Smith’s Dictionary of Greek and Roman Geographies, p. 1113).

There exists a considerable literature respecting falls of meteors and of meteoric iron. Livy, Plutarch, and Pliny all record examples. See also Remarks concerning stones said to have fallen from the clouds, by Edward King (London, 1796); Chladni, Ueber den Ursprung der von Pallas gefundenen und anderer ihr ähnlicher Eisenmassen (Riga, 1794); Philosophical Transactions, vol. lxxviii., pp. 37 and 183; vol. lxxxv., p. 103; vol. xcii., p. 174; Humboldt’s Cosmos, vol. i. (p. 97 of London edition, 1860); C. Rammelsberg, Die chemische Natur der Meteoriten (Berlin, 1879); Maskelyne, Some lecture-notes on Meteorites printed in Nature, vol. xii., pp. 485, 504, and 520, 1875. Maskelyne denominates as siderites those meteorites which consist chiefly of iron. They usually contain from 80 to 95 per cent. of iron, often alloyed with nickel. This meteoric iron is sometimes so pure that it can at once be forged by the smith. An admirable summary of the whole subject is to be found in L. Fletcher’s An Introduction to the study of Meteorites, publisht by the British Museum (Nat. Hist.), London, 1896.

[81] Page 27, line 3. Page 26, line 41. vt Cardanus … scribit.—The passage runs:

“Vidimus anno MDX cum cecidisset è cœlo lapides circiter MCC in agrum fluvio Abduæ conterminum, ex his unum CXX pondo, alium sexaginta delati fuerunt ad reges Gallorũ satrapes, plurimi: colos ferrugineus, durities eximia, odor sulphureus” (Cardan, De Rerum Varietate, lib. xiiii., cap. lxxii.; Basil., 1557, p. 545).

[82] Page 27, line 9. Page 27, line 2. aut stannum, aut plumbum album. Although most authorities agree in translating plumbum album or plumbum candidum as “tin” (which is unquestionably the meaning in such examples as Pliny’s Nat. Hist., xxxiv. 347, and iv. 16; or Strabo, iii. 147), nevertheless it is certain that here plumbum album is not given as a synonym of stannum and therefore is not tin. That Gilbert meant either spelter or pewter is pretty certain. He based his metallic terms mainly upon Encelius (Christoph Entzelt) whose De Re Metallica was published at Frankfurt in 1551. From this work are taken the following passages:{27}

p. 61. De Plumbo candido. Cap. XXXI.

“Veluti plumbum nigrũ uocatur à Germanis blei simpliciter, od’ schwartzblei: ita plumbũ candidũ ab his uocatur weissblei, od’ ziñ. Impropriè autem plumbum hoc nostrum candidum ziñ, stannum dicitur. Et non sunt idem, ut hactenus voluerunt, stannum et plumbum candidum, unser ziñ. Aliud est stannum, de quo mox agemus: et aliud plumbum candidum nostrum, unser ziñ, quod nigro plumbo quasi est quiddã purius et perfectius….”

p. 62. De Stanno. Cap. XXXII.

“In præcedenti capite indicauimus aliud esse stannum, aliud esse plumbũ candidũ. Illa ergo definitio plumbi candidi, dess zinnes, etiã apud chimistas nõ de stanno, sed de plumbo candido (ut mihi uidetur) intelligenda est, cum dicunt: Stannum (es soll heyssen plumbum candidum) est metallicum album, non purum, lividum….”

p. 63. “Sic uides stannum, secundum Serapionem, metallicum esse quod reperitur in sua propria uena, ut forsitan apud nos bisemutũ: ecõtra nostrũ candidũ plumbũ, est Plinij candidũ plumbũ, das zin, quod cõflatur ut plumbum nigrum, ex pyrite, galena, et lapillis nigris. Deinde uides stannum Plinio esse quiddã de plumbo nigro, nempe primum fluorem plumbi nigri, als wann man vnser bley ertz schmeltzet, das erst das do fleüsset, zwäre Plinio stannum. Et hoc docet Plinius adulterari plũbo candido, mit vnserm zinn, vnd wann du ihm recht nachdenckest, daruon die kannen gemacht werden, das man halbwerck heist…. O ir losen vngelerten, vnckenbrenner. Stannum proculdubio Arabis metallum est preciosius nostro candido plumbo: sicuti apud nos bisemuthum quiddam plumbo preciosius.”

[83] Page 27, line 21. Page 27, line 17. venas … venis.—It is impossible to give in English this play on words between veins of ore and veins of the animal body.

[84] Page 28, line 23. Page 28, line 20. quem nos verticitatem dicimus.—See the notes on Gilbert’s glossary, ante. The word verticity remained in the language. On p. 140 of Joseph Glanvill’s Vanity of Dogmatizing (Lond., 1661) we read: “We believe the verticity of the Needle, without a Certificate from the dayes of old.”

[85] Page 29, line 15. Page 29, line 16. Nos verò diligentiùs omnia experientes.—The method of carefully trying everything, instead of accepting statements on authority, is characteristic of Gilbert’s work. The large asterisks affixed to Chapters IX. X. XI. XII. and XIII. of Book I. indicate that Gilbert considered them to announce important original magnetical discoveries. The electrical discoveries of Book II., Chapter II., are similarly distinguished. A rich crop of new magnetical experiments, marked with marginal asterisks, large and small, is to be found in Book II., from Chapter XV. to Chapter XXXIV.; while a third series of experimental magnetical discoveries extends throughout Book III.

[86] Page 31, line 30. Page 31, line 25. verticem.—The context and the heading of the Chapter appear to require verticitatem. All editions, however, read verticem.

[87] Page 32, line 12. Page 32, line 9. Gartias ab horto.—The passage from Gartias ab Horto runs as follows in the Italian edition of 1616, Dell’ Historia dei Semplici Aromati…. di Don Garzia dall’ Horto, Medico Portughese, … Venezia mdcxvi., p. 208.

“Nè meno è questa pietra velenosa, si come molti hanno tenuto; imperoche le genti di queste bande dicono che la Calamita presa per bocca, però in poca {28}quantità, conserva la gioventù. La onde si racconta, che il Re di Zeilan il vecchio’ s’haveva fatto fare tutti i vasi, dove si cocevano le vivãde per lui, di Calamita. Et questo lo disse à me colui proprio, che fu à questo officio destinato.”

[88] Page 32, line 29. Page 32, line 29. Plutarchus & C. Ptolemæus.—The garlick myth has already been referred to in the note to p. 1. The originals are Plutarch, Quæstiones Platonicæ, lib. vii., cap. 7, § 1; C. Ptolemæus, Opus Quadripartitum, bk. i., cap. 3. The English translation of the latter, by Whalley (London, 1701), p. 10, runs: “For if the Loadstone be Rubbed with Garlick, the Iron will not be drawn by it.”

[89] Page 32, line 32. Page 32, line 33. Medici nonnulli.—This is apparently a reference to the followers of Rhazes and Paracelsus. The argument of Gilbert as to the inefficacy of powdered loadstones is reproduced more fully by William Barlowe in his Magneticall Aduertisements (1616, p. 7), as follows:

“It is the goodnesse of the Loadstone ioyned with a fit forme that will shew great force. For as a very good forme with base substance can doe but very litle, so the substance of the Loadstone bee it neuer so excellent, except it haue some conuenient forme, is not auaileable. For example, an excellent loadstone of a pound waight and of a good fashion, being vsed artificially, may take vp foure pounds of Iron; beate it into small pouder, and it shall bee of no force to take vp one ounce of Iron; yea I am very well assured that halfe an ounce of a Loadstone of good fashion, and of like vertue will take vp more then that pound will doe being beaten into powder. Whence (to adde this by the way) it appeareth manifestly, that it is a great error of those Physitions and Surgeons, which to remedy ruptures, doe prescribe vnto their Patients to take the pouder of a Loadstone inwardly, and the small filing of iron mingled in some plaister outwardly: supposing that herein the magneticall drawing should doe great wonders.”

[90] Page 33, line 11. Page 33, line 8. Nicolaus in emplastrum divinum….—Nicolaus Myrepsus is also known as Præpositas. In his Liber de compositione medicamentorum (Ingoldstat, 1541, 4to) are numerous recipes containing loadstone: for example, Recipe No. 246, called “esdra magna,” is a medicine given for inflammation of the stomach and for strangury, compounded of some forty materials including “litho demonis” and “lapis magnetis.” The emplastrum divinum does not, however, appear to contain loadstone. In the English tractate, Præpositas his Practise, a worke … for the better preservation of the Health of Man. Wherein are … approved Medicines, Receiptes and Ointmentes. Translated out of Latin in to English by L. M. (London, 1588, 4to), we read on p. 35, “An Emplaister of D. N. [Doctor Nicolaus] which the Pothecaries call Divinum.” This contains litharge, bdellium, and “green brasse,” but no loadstone.

Luis de Oviedo in his treatise Methodo de la Coleccion y reposicion de las Medicinas simples, edited by Gregorio Gonçalez, Boticario (Madrid, 1622), gives (p. 502) the following: “Emplasto de la madre. Recibe: Nuezes moscadas, clauos, cinamono, artemisia, piedraimon. De cada uno dos onças…. Entre otras differencias que ay de piedraiman se hallan dos. Vna que por la parte que mira al Septentrion, atrae el hierro, por lo quel se llama magnes ferrugineus. Y otra que atrae la carne, a la qual llaman magnes creaginus.”

An “Emplastrum sticticum” containing amber, mummy, loadstone, {29}hæmatite, and twenty other ingredients, and declared to be “vulnerum ulcerumque telo inflictorum sticticum emplastrum præstantissimum,” is described on p. 267 of the Basilica chimica of Oswaldus Crollius (Frankfurt, 1612).

[91] Page 33, line 12. Page 33, line 9. Augustani … in emplastrum nigrum….—Amongst the physicians of the Augsburg school the most celebrated were Adolphus Occo, Ambrosio Jung, and Gereone Seyler. This particular reference is to the Pharmacopœia Augustana … a Collegio Medico recognita, published at Augsburg, and which ran through many editions. The recipe for the “emplastrum nigrum vulgo Stichpflaster” will be found on p. 182 of the seventh edition (1621-2). The recipe begins with oil of roses, colophony, wax, and includes some twenty-two ingredients, amongst them mummy, dried earthworms, and two ounces lapidis magnetis præparati. The recipe concludes: “Fiat Emplastrum secundùm artem. Perquàm efficax ad recentia vulnera et puncturas, vndè denominationem habet.” The volume is a handsome folio not unlike Gilbert’s own book, and bears at the end of the prefatory address ad Lectorem identically the same cul de lampe as is found on p. 44 of De Magnete.

The contradictions as to the alleged medicinal virtues of loadstone are well illustrated by Galen, who in his De facultatibus says that loadstone is like hæmatite, which is astringent, while in his De simplici medicina he says it is purgative.

[92] Page 33, line 14. Page 33, line 12. Paracelsus in fodicationum emplastrum.—Paracelsus’s recipe for a plaster against stab-wounds is to be found in Wundt vund Leibartznei … D. Theoph. Paracelsus (Frankf., 1555, pp. 63-67).

[93] Page 33, line 17. Page 33, line 15. Ferri vis medicinalis.—This chapter on the medicinal virtues of iron is a summary of the views held down to that time. Those curious to pursue the subject should consult Waring’s Bibliotheca Therapeutica (London, 1878). Nor should they miss the rare black-letter quarto by Dr. Nicholas Monardus, of Seville, Joyfull Newes out of the New-found Worlde, translated by John Frampton (London, 1596), in which are recited the opinions of Galen, Rhazes, Avicenna, and others, on the medicinal properties of iron. In addition to the views of the Arabic authors, against whom his arguments are directed, Gilbert discusses those of Joannes Manardus, Curtius, and Fallopius. The treatise of Manardus, Epistolarum medicinalium libri viginti (Basil., 1549), is a résumé of the works of Galen and the Arabic physicians, but gives little respecting iron. Curtius (Nicolaus) was the author of a book, Libellus de medicamentis præparatibus et purgantibus (Giessæ Cattorum, 1614). The works of Fallopius are De Simplicibus Medicamentis purgentibus tractatus (Venet., 1566, 4to), and Tractatus de Compositione Medicamentorum (Venet., 1570, 4to).

[94] Page 34, line 7. Page 34, line 3. quorundã Arabum opiniones.—The Arabian authorities referred to here or elsewhere by Gilbert are:

Albategnius (otherwise known as Machometes Aractensis), Muhammad Ibn Jābir, Al-Battānī.

Avicenna (otherwise Abohali). Abou-’Ali al-’Hoséin ben-’Abd-Allah Ibn-Sinâ, or, shortly, Ibn Sîna.

Averroes. Muhammad Ibn Ahmed Ibn-Roschd, Abou Al-Walíd.

Geber. Abū Mūsā Jābir Ibn Haiyān, Al-Tarsūsi.

Hali Abas. ’Alí Ibn Al-’Abbás, Al Majúsi.{30}

Rhazes, or Rasis. Muhammad Ibn Zakarīyā.

Serapio. Yuhanná Ibn Sarapion.

Thebit Ben-Kora (otherwise Thabit Ibn Corrah). Abū Thabit Ibn Kurrah, Al Harrani.

[95] Page 34, line 38.: Page 34, line 40. electuarium de scoria ferri descriptum à Raze.—Rhazes or Rasis, whose Arabic name was Muhammad Ibn Zakarīyā, wrote De Simplicibus, ad Almansorem. In Chap. 63 of this work he gives a recipe for a stomachic, which includes fennel, anise, origanum, black pepper, cinammon, ginger, and iron slag. In the splendid folio work of Rhazes publisht at Venice in 1542, with the title Habes candide lector Continẽtem Rasis, Libri ultimi, cap. 295, under the heading De Ferro, are set forth the virtues of iron slag: “Virtus scorie est sicut virtus scorie [a]eris sed debilior in purgãdo: et erugo ferri est stiptica: et cũ superpositur retinet fluxus menstruorũ…. Ait Paulus: aqua in qua extinguitur ferrũ calens…. Dico: certificatus sum experientia q˜ valet contra emorryodas diabetem et fluxum menstruorum.”

[96] Page 35, line 16.: Page 35, line 13. Paulus.—This is not Fra Paolo Sarpi, nor Marco Polo, nor Paulus Jovius the historian, nor Paulus Nicolettus Venetus, but Paulus Aeginæ.

[97] Page 35, line 29.: Page 35, line 28. Sed malè Avicenna.—The advice of Avicenna to administer a draught containing powdered loadstone, reads as follows in the Giunta edition (Venice, 1608):

Lib. ii., cap. 470, p. 356. “Magnes quid est? Est lapis qui attrahit ferrum, quum ergo aduritur, fit hæmatites, & virtus ejus est sicut virtus illius…. Datur in potu [ad bibitionem limaturæ ferri, quum retinetur in ventre scoria ferri. Ipse enim extrahit] ipsam, & associatur ei apud exitum. Et dicitur, quando in potu sumuntur ex eo tres anulusat cum mellicrato, educit solutione humorem grossum malum.”

The passage is identical with that in the Venetian edition of 1486, in both of which the liquid prescribed is mellicratus—mead. Gilbert says that the iron is to be given in juice of mercurialis. Here he only follows Matthiolus, who, in his Commentaries on Dioscorides, says (p. 998 of the Basil. edition of 1598): “Sed (vt idem Auicenna scribit) proprium hujusce ferrei pharmaci antidotum, est lapis magnes drachmæ pondere potus, ex mercurialis, vel betæ succo.”

Serapio, in his De Simplicibus Medicinis (Brunfels’ edition, Argentorati, 1531), p. 264, refers to Galen’s prescription of iron scoriæ, and under the article de lapide magnetis, p. 260, quotes Dioscorides as follows: “Et uirtus huius lapidis est, ut quãdo dantur in potu duo onolosat ex eo cũ melicrato, laxat humores grossos.”

The original passage in Dioscorides, De Materia Medica, ch. 147 (Spengel’s edition of 1829) runs: “Τοῦ δὲ μαγνήτου λίθου ἄριστός ἐστιν ὁ τὸν σίδηρον εὐχερῶς ἕλκων, καὶ τὴν χρόαν κυανίζων, πυκνός τε κὰι οὐκ ἄγαν βαρύς. Δύναμιν δὲ ἔχει πάχους ἀγωγὸν διδόμενος μετὰ μελικράτου τριωβόλου βάρος· ἔνιοι δὲ τοῦτον καίοντες ἀντὶ αἱματίτου πιπράσκουσιν..”

In the Frankfurt edition of Dioscorides, translated by Ruellius (1543), the passage is:

“Magnes lapis optimus est, qui ferrum facile trahit, colore ad cœruleum uergente, densus, nec admodum gravis. Datur cum aqua mulsa, trium obolorum pondere, ut crassos humores eliciat. Sunt qui magnetem crematū pro hæmatite vendant….”

In the Scholia of Joannes Lonicerus upon Dioscorides In Dioscoridæ {31}Anazarbei de re medica libros a Virgilio Marcello versos, Scholia nova, Ioanne Lonicero autore (Marburgi, 1543, p. 77), occurs the following:

“De recremento ferri. Cap. XLIX.

“Σκωρία σιδήρου. scoria vel recrementum ferri. Quæ per ignem à ferro et cupro sordes separantur ac reijciuntur, et ab aliis metallis σκωρία uocantur. Omnis scoria, maxime uero ferri exiccat. Acerrimo aceto macerauit Galenus ferri scoriam, ac deinde excocto, pharmacum efficax confecit ad purulentas quæ multo tempore uexatæ erant, aures, admirando spectantium effectu. Ardenti scoria uel recrementum ἕλκυσμα, inquit Galenus.”

See also the Enarrationes eruditissimæ of Amatus Lusitanus (Venet., 1597), pp. 482 and 507, upon iron and the loadstone.

[98] Page 36, line 27. Page 36, line 29. eijcitur for ejicitur.

[99] Page 37, line 18. Page 37, line 22. ut Cardanus philosophatur.—Cardan’s nonsense about the magnet feeding on iron is to be found in De Subtilitate, lib. vii. (Basil., 1611, p. 381).

[100] Page 38, line 4. Page 38, line 7. ferramenta … in usum navigantium.—Compare Marke Ridley’s A Short Treatise of Magneticall Bodies and Motions (Lond., 1613), p. a2 in the Preface Magneticall, where he speaks of the “iron-workes” used in building ships. The phraseology of Marke Ridley throws much light on the Latin terms used by Gilbert.

[101] Page 38, line 36. Page 38, line 42. vruntur; changed in ink to vrantur in the folio of 1600; but uruntur appears in the editions of 1628 and 1633.

[102] Page 39, line 12. Page 39, line 12. virumque; altered in ink to virunque in all copies of the folio edition of 1600.

[103] Page 40, line 32. Page 40, line 33. ad tantos labores exantlandos.—Pumping, as it was in mining before the invention of the steam engine, may best be realized by examining the woodcuts in the De re metallica of Georgius Agricola (Basil., Froben, 1556).

[104] Page 40, line 34. Page 40, line 36. quingentas orgyas.—Gilbert probably had in his mind the works of the Rorerbühel, in the district of Kitzbühl, which in the sixteenth century had reached the depth of 3,107 feet. See Humboldt’s Cosmos (Lond., 1860, vol. i., p. 149).

[105] Page 43, line 34. Page 43, line 33. glis.—This word, here translated grit, does not appear to be classical Latin; it may mean ooze or slime.

[106] Page 45, line 25. Page 45, line 26. Motus igitur … quinque. The five kinds of magnetic motions correspond in fact to the remaining sections of the book; as follows: Coitio, Book II.; Directio, Book III.; Variatio, Book IV.; Declinatio, Book V.; and Revolutio, Book VI.

[107] Page 46, line 7. Page 46, line 8. Jofrancus Offusius.—The reference is to the treatise De divina astrorum faculitate of Johannes Franciscus Offusius (Paris, 1570).

[108] Page 47, line 15. Page 47, line 18. Græci vocant ἠλεκτρον, quia ad se paleas trahit. In this discussion of the names given to amber, Gilbert apparently conceives ἠλεκτρον to be derived from the verb ἑλκεῖν; which is manifestly a doubtful etymology. There has been much discussion amongst philologists as to the derivation of ἠλέκτρον or ἤλεκτρον, and its possible connection with the word ἠλέκτωρ. This discussion has been somewhat obscured by the circumstance that the Greek authors unquestionably used ἤλεκτρον (and the Latins their word electrum) in two different significations, some of them using these words to mean amber, others to mean a shining {32}metal, apparently of having qualities between those of gold and silver, and probably some sort of alloy. Schweigger, Ueber das Elektron der Alten (Greifswald, 1848), has argued that this metal was indeed no other than platinum: but his argument partakes too much of special pleading. Those who desire to follow the question of the derivation of ἤλεκτρον may consult the following authorities: J. M. Gessner, De Electro Veterum (Commentt. Soc. Reg. Scientt. Goetting., vol. iii., p. 67, 1753); Delaunay, Mineralogie der Alten, Part II., p. 125; Buttmann, Mythologus (Appendix I., Ueber das Elektron), Vol. II., p. 355, in which he adopts Gilbert’s derivation from ἕλκειν; Beckmann, Ursprung und Bedeutung des Bernsteinnamens Elektron (Braunsberg, 1859); Th. Henri Martin, Du Succin, de ses noms divers et de ses variétés suivant les anciens (Mémoires de l’Académie des Inscriptions et Belles-lettres, Tome VI., 1re série, 1re partie, 1860); Martinus Scheins, De Electro Veterum Metallico (Inaugural dissertation, Berlin, 1871); F. A. Paley, Gold Worship in relation to Sun Worship (Contemporary Review, August, 1884). See also Curtius, Grundzüge der griechischen Etymologie, pp. 656-659. The net result of the disputations of scholars appears to be that ἠλέκτωρ (he who shines) is a masculine form to which there corresponds the neuter form ἤλεκτρον (that which shines). Stephanus admits the accentuation used by Gilbert, ἠλέκτρον, to be justified from the Timæus of Plato; see Note to p. 61.

[109] Page 47, line 16. Page 47, line 19. ἅρπαξ dicitur, & χρυσοφόρον.—With respect to the other names given to amber, M. Th. Henri Martin has written (see previous note) so admirable an account of them that it is impossible to better it. It is therefore given here entire, as follows:

“Le succin a reçu chez les anciens des noms très-divers. Sans parler du nom de λυγκούριον, lyncurium, qui peut-être ne lui appartient pas, comme nous le montrerons plus loin, il s’est nommé chez les Grecs le plus souvent ἤλεκτρον au neutre,1 mais aussi ἤλεκτρος au masculin2 et même au féminin,3 χρυσήλεκτρος,4 χρυσόφορος5 et peut-être, comme nous l’avons vu, χαλκολίθανον; plus tard σούχιον6 ou σουχίνος7, et ἠλεκτριανὸς λίθος;8 plus tard encore βερενίκη, βερονίκη ou βερνίκη;9 il s’est nommé ἅρπαξ chez les Grecs établis en Syrie;10 chez les Latins succinum, electrum, et deux variétés, chryselectrum et sualiternicum {33}ou subalternicum;11 chez les Germains, Gless;12 chez les Scythes, sacrium;13 chez les Egyptiens, sacal;14 chez les Arabes, karabé15 ou kahraba;16 en persan, káruba.17 Ce mot, qui appartient bien à la langue persane, y signifie attirant la paille, et par conséquent exprime l’attraction électrique, de même que le mot ἅρπαξ des Grecs de Syrie. En outre, le nom de haur roumi (peuplier romain) était donné par les Arabes, non-seulement à l’arbre dont ils croyaient que le succin était la gomme, mais au succin lui-même. Haur roumi, transformé en aurum par les traducteurs latins des auteurs arabes, et consondu mal à propos avec ambar ou ambrum, nom arabe latinisé de l’ambre gris, a produit le nom moderne d’ambre, nom commun à l’ambre jaune ou succin, qui est une résine fossile, et à l’ambre gris, concrétion odorante qui se forme dans les intestines des cachalots. On ne peut dire avec certitude si le nom de basse grécité βερνίκη est la source ou le dérivé de Bern, radical du nom allemand du succin (Bernstein). Quoi qu’il en soit, le mot βερνίκη a produit vernix, nom d’une gomme dans la basse latinité, d’où nous avons fait vernis.18”

1 Voyez Hérodote, III., 115; Platon, Timée, p. 80 c; Aristote, Météor., IV., 10; Théophraste, Hist. des plantes, IX., 18 (19), § 2; Des pierres, § 28 et 29; Diodore de Sic., V., 23; Strabon, IV., 6, no 2, p. 202 (Casaubon); Dioscoride, Mat. méd., I., 110; Plutarque, Questions de table, II., 7, § 1; Questions platoniques, VII., 1 et 7; Lucien, Du succin et des cygnes; le même, De Pastrologie, § 19; S. Clément, Strom. II., p. 370 (Paris, 1641, in-fol.); Alexandre d’Aphr., Quest. phys. et mor., II., 23; Olympiodore, Météor., I., 8, fol. 16, t. I., p. 197 (Ideler) et l’abréviateur d’Etienne de Byzance au mot Ηλεκτρίδες.

2 Voyez Sophocle, Antigone, v. 1038, et dans Eustathe, sur l’Iliade, II., 865; Elien, Nat. des animaux, IV. 46; Quintus de Smyrne, V., 623; Eustathe, sur la Périégèse de Denys, p. 142 (Bernhardy), et sur l’Odyssée, IV., 73; et Suidas au mot ὑάλη.

3 Voyez Alexandre, Problèmes, sect. 1, proœm., p. 4 (Ideler); Eustathe, sur l’Odyssée, IV., 73, et Tzetzès, Chiliade VI., 650.

4 Voyez Psellus, Des pierres, p. 36 (Bernard et Maussac).

5 Voyez Dioscoride, Mat. méd., I., 110.

6 Voyez S. Clément, Strom., II., p. 370 (Paris, 1641, in-fol.). Il paraît distinguer l’un de l’autre τὸ σούχιον et τὸ ἤλεκτρον, probablement parce qu’il attribue à tort au métal ἤλεκτρον la propriété attractive du succin.

7 Voyez le faux Zoroastre, dans les Géoponiques, XV., 1, § 29.

8 Voyez le faux Zoroastre, au même endroit.

9 Voyez Eustathe, sur l’Odyssée, IV., 73; Tzetzès, Chil. VI., 650; Nicolas Myrepse, Antidotes, ch. 327, et l’Etymol. Gud. au mot ἤλεκτρον. Comparez Saumaise, Exert. plin., p. 778.

10 Voyez Pline, XXXVII., 2, s. 11, no 37.

11 Voyez Pline, XXXVII., 2, s. 11-13, et Tacite, Germanie, ch. 45. La forme sualiternicum, dans Pline (s. 11, no 33), est donnée par le manuscrit de Bamberg et par M. Sillig (t. V., p. 390), au lieu de la forme subalternicum des éditions antérieures.

12 Voyez Tacite et Pline, ll. cc.

13 Voyez Pline, XXXVII., 2, s. 11, no 40, Comp. J. Grimm, Gesch. der deutsch. Sprache, Kap. x., p. 233 (Leipzig, 1848, in-8).

14 Pline, l. c.

15 Voyez Saumaise, De homon. hyles iatricæ, c. 101, p. 162 (1689, in-fol.).

16 Voyez Sprengel, sur Dioscoride, t. II., pp. 390-391.

17 Voyez M. de Sacy, cité par Buttmann, Mythologus, t. II., pp. 362-363.

18 Voyez Saumaise, Ex. plin., p. 778. Il n’est pas probable que le mot βερνίκη ou βερενίκη nom du succin dans la grécité du moyen âge, soit lié étymologiquement avec le nom propre βερενίκη, qui vient de l’adjectif macédonien βερένικος pour φερένικος.

[110] Page 47, line 17. Page 47, line 20. Mauri vero Carabem appellant, quià solebant in sacrificijs, & deorum cultu ipsum libare. Carab enim significat offerre Arabicè; ita Carabe, res oblata; aut rapiens paleas, vt Scaliger ex Abohali citat, ex linguâ Arabicâ, vel Persicâ.—The printed text, line 18, has “Non rapiens paleas,” but in all copies of the folio of 1600, the “Non” has been altered in ink into “aut,” possibly by Gilbert’s own hand. Nevertheless the editions of 1628 and 1633 both read “Non.” There appears to be no doubt that the origin of the word Carabe, or Karabe, as assigned by Scaliger, is substantially correct. As shown in the preceding note, Martin adopted this view. If any doubt should remain it will be removed by the following notes which are due to Mr. A. Houtum Schindler (member of the Institution of Electrical Engineers), of Terahan.

Reference is made to the magnetic and electric properties of stones in three early Persian lapidaries. There are three stones only mentioned, amber, loadstone, and garnet. The electric property of the diamond is not mentioned. The following extracts are from the Tansûk nâmah, by Nasîr ed dîn Tûsi, A.D. 1260. The two other treatises give the first extracts in the same words.

“Kâhrubâ, also Kahrabâ [Amber],

“Is yellow and transparent, and has its name from the property, which it possesses, of attracting small, dry pieces of straw or grass, after it has been rubbed with cloth and become warm. [Note. In Persian, Kâh = straw; rubâ = the robber, hence Kâhrubâ = the straw-robber.] Some consider it a mineral, and say that it is found in the Mediterranean and Caspian seas, floating on the surface, but this is not correct. The truth is that Kâhrubâ {34}is the gum of a tree, called jôz i rûmî [i.e., roman nut; walnut?], and that most of it is brought from Rûm [here the Eastern Rome] and from the confines of Sclavonia and Russia. On account of its bright colour and transparency it is made into beads, rings, belt-buckles, &c. … &c.

“The properties of attraction and repulsion are possessed by other substances than loadstone, for instance, by amber and bîjâdah,1 which attract straws, feathers, etc., and of many other bodies, it can be said that they possess the power of attraction. There is also a stone which attracts gold; it has a pure yellow colour. There is also a stone which attracts silver from distances of three or two yards. There are also the stone which attracts tin, very hard, and smelling like asafœtida, the stone attracting hair, the stone attracting meat, etc., but, latterly, no one has seen these stones: no proof, however, that they do not exist.”

Avicenna (Ibn Sinâ) gives the following under the heading of Karabe (see Canona Medicinæ, Giunta edition, Venet., 1608, lib. ii., cap. 371, p. 336):

“Karabe quid est? Gumma sicut sandaraca, tendens ad citrinitatem, & albedinem, & peruietatem, & quandoque declinat ad rubedinem, quæ attrahit paleas, & [fracturas] plantarum ad se, & propter hoc nominatur Karabe, scilicet rapiens paleas, persicè…. Karabe confert tremori cordis, quum bibitur ex eo medietas aurei cum aqua frigida, & prohibet sputum sanguinis valde…. Retinet vomitum, & prohibet materias malas a stomacho, & cum mastiche confortat stomachum…. Retinet fluxum sanguinis ex matrice, & ano, & fluxum ventris, & confert tenasmoni.”

Scaliger in De Subtilitate, Exercitatio ciii., § 12, the passage referred to by Gilbert says: “Succinum apud Arabas uocatur, Carabe: quod princeps Aboali, rapiens paleas, interpretatur” (p. 163 bis, editio Lutetiæ, 1557).

1 Bîjâdah is classified by Muhammad B. Mansûr (A.D. 1470) and by Ibn al Mubârak (A.D. 1520) under “stones resembling ruby”; the Tansûk nâmah describes it in a separate chapter. From the description it can be identified with the almandine garnet, and the method of cutting this stone en cabochon, with hollow back in order to display its colour better is specially mentioned. The Tansûk nâmah only incidentally refers to the electric property of the bîjâdah in the chapter on loadstone, but the other two treatises specially refer to it in their description of the stone. The one has: “Bîjâdah if rubbed until warm, attracts straws and other light bodies just as amber does”; the other: “Bîjâdah, if rubbed on the hair of the head, or on the beard, attracts straws.” Surûri, the lexicographer, who compiled a dictionary in 1599, considers the bîjâdah “a red ruby which possesses the property of attraction.” Other dictionaries do not mention the attractive property, but some authors confound the stone with amber, calling it Kâbrubâ, the straw-robber. The bîjâdah is not rubellite (red tourmaline) for it is described in the lapidaries as common, whereas rubellite (from Ceylon) has always been rare, and was unknown in Persia in the thirteenth century.

[111] Page 47, line 21. Page 47, line 25. Succinum seu succum.—Dioscorides regarded amber as the inspissated juice of the poplar tree. From the Frankfurt edition of 1543 (De Medicinali materia, etc.) edited by Ruellius, we have, liber i., p. 53:

Populus. Cap. XCIII.

“… Lachrymam populorum commemorant quæ in Padum amnem defluat, durari, ac coire in succinum, quod electrum vocant, alii chrysophorum. id attritu jucundum odorem spirat, et aurum colore imitatur. tritum potumque stomachi ventrisque fluxiones sistit.”

To this Ruellius adds the commentary:

“Succinum seu succina gutta à succo dicta, Græcis ἤλεκτρομ [sic], esse {35}lachryma populi albæ, vel etiam nigræ quibusdam videtur, ab ejusdem arboris resina. Dioscoridi et Galeno dicta differens et πτερυγοφόρος, id est paleas trahens, quoque vocatur, quantum ei quoque Galenus tribuit li. 37, ca. 9. Succinum scribit à quibusdam pinei generis arboribus, ut gummi à cerasis excidere autumno, et largum mitti ex Germania septentrionali, et insulis maris Germanici. quod hodie nobis est compertissimum: ad hæc liquata igni valentiore, quia à frigido intensiore concrevit. pineam aperte olet, calidum primo gradu, siccum secundo, stomachum roborat, vomitum, nauseam arcet. cordis palpitationi prodest. pravorem humorum generationem prohibet.

“Germani weiss und gelbaugstein et brenstein.

“Galli ambra vocant: vulgo in corollis precariis frequens.”

In the scholia of Johann Lonicer in his edition of Dioscorides, we find, lib. i., cap. xcviii., De nigra Populo:

“ἄιγειρος, populus nigra … idem electrum vel succinum αἱγείρου lachrymam esse adseverat [Paulus], cui præter vires quæ ab Dioscoride recensentur, tribuit etiam vim sistendi sanguinis, si tusum in potu sumatur. Avicennæ Charabe, ut colligitur ex Joanne Jacobo Manlio, est electrum hoc Dioscoridis, attestatur Brunfelsius. Lucianus planè nullum electrum apud Eridanum seu Padum inveniri tradit, quandoquidem ne populus quidem illa ab nautis ei demonstrari potuerit. Plinius rusticas transpadanas ex electro monilia gestare adfirmat, quum à Venetis primum agnoscere didicissent adversus nimirum vitia gutturis et tonsillarum. Num sit purgamentum maris, vel lachryma populi, vel pinus, vel ex radiis occidentis solis nascatur, vel ex montibus Sudinorum profluat, incertum etiam Erasmus Stella relinquit. Sudinas tamen Borussiorum opes esse constat.”

Matthiolus (in P. A. Mattioli … Opera quæ extant omnia, hoc est Commentarii in vi libros P. Dioscoridis de materia medica, Frankfurt, 1596, p. 133) comments on the suggestion of Galen that amber came from the Populus alba, and also comments on the Arabic, Greek, and Latin names of amber.

The poplar-myth is commemorated by Addison (in Italy) in the lines:

No interwoven reeds a garland made,

To hide his brows within the vulgar shade;

But poplar wreathes around his temples spread,

And tears of amber trickled down his head.

Amber is, however, assuredly not derived from any poplar tree: it comes from a species of pine long ago extinct, called by Göppert the pinites succinifer.

Gilbert does not go into the medicinal uses, real or fancied, that have been ascribed to amber in almost as great variety as to loadstone. Pliny mentions some of these in his Natural Historie (English version of 1601, p. 609):

“He [Callistratus] saith of this yellow Amber, that if it be worne about the necke in a collar, it cureth feavers, and healeth the diseases of the mouth, throat, and jawes: reduced into pouder and tempered with honey and oile of roses, it is soveraigne for the infirmities of the eares. Stamped together with the best Atticke honey, it maketh a singular eyesalve for to help a dim sight: pulverized, and the pouder thereof taken simply alone, or else drunke in water with Masticke, is soveraigne for the maladies of the stomacke.”

Nicolaus Myrepsus (Recipe 951, op. citat.) gives a prescription for {36}dysentery and diabetes confiding chiefly of “Electri vel succi Nili (Nili succum appellant Arabes Karabem).”

[112] Page 47, line 22. Page 47, line 26. Sudauienses seu Sudini.—Cardan in De Rerum Varietate, lib. iii., cap. xv. (Editio Basil., 1556, p. 152), says of amber:

“Colligitur in quadam penè insula Sudinorum, qui nunc uocātur Brusci, in Prussia, nunc Borussia, juxta Veneticum sinum, & sunt orientaliores ostiis Vistulæ fluuii: ubi triginta pagi huic muneri destinati sunt,” etc. He rejects the theory that it consists of hardened gum.

There exists an enormous literature concerning Amber and the Prussian amber industry. Amongst the earliest works (after Theophrastus and Pliny) are those of Aurifaber (Bericht über Agtstein oder Börnstein, Königsberg, 1551); Goebel (De Succino, Libri duo, authore Severino Gœbelio, Medico Doctore, Regiomont., 1558); and Wigand (Vera historia de Succino Borussico, Jena, 1590). Later on Hartmann, P. J. (Succini Prussici Physica et civilis Historia, Francofurti, 1677); and the splendid folio of Nathaniel Sendel (Historia Succinorum corpora aliena involventium, Lipsiæ, 1742), with its wealth of plates illustrating amber specimens, with the various included fossil fauna and flora. Georgius Agricola (De natura Fossilium, liber iv.), and Aldrovandi (Musæeum Metallicum, pp. 411-412) must also be mentioned. Bibliographies of the earlier literature are to be found in Hartmann (op. citat.), and in Daniel Gralath, Elektrische Bibliothek (Versuche und Abhandlungen der Naturforschenden Gesellschaft in Danzig, Zweiter Theil, pp. 537-539, Danzig and Leipzig, 1754). See also Karl Müllenhoff, Deutsche Altertumskunde, vol. i., Zweites Buch, pp. 211-224, Zinn und Bernsteinhandel (Berlin, 1870), and Humboldt’s Cosmos (Bohn’s edition, London, 1860, vol. ii., p. 493).

The ancient Greek myth according to which amber was the tears of the Heliades, shed on the banks of the river Eridanus over Phaethon, is not alluded to by Gilbert. It is narrated in well-known passages in Ovid and in Hyginus. Those interested in the modern handling of the myth should refer to Müllenhoff (op. citat., pp. 217-223, der Bernsteinmythus), or to that delightful work The Tears of the Heliades, by W. Arnold Buffum (London, 1896).

[113] Page 47, line 30. Page 47, line 36. quare & muscos … in frustulis quibusdam comprehensos retinet.—The occurrence of flies in amber was well known to the ancients. Pliny thus speaks of it, book xxxvii., chap. iii. (p. 608 of P. Holland’s translation of 1601):

“That it doth destill and drop at the first very clear and liquid, it is evident by this argument, for that a man may see diverse things within, to wit, Pismires, Gnats, and Lizards, which no doubt were entangled and stucke within it when it was greene and fresh, and so remain enclosed within as it waxed harder.”

A locust embedded in amber is mentioned in the Musæum Septalianum of Terzagus (Dertonæ, 1664).

Martial’s epigram (Epigrammata, liber vi., 15) is well known:

Dum Phaethontea formica vagatur in umbra

Implicuit tenuem succina gutta feram.

See also Hermann (Daniel), De rana et lacerta Succino Borussiaco insitis {37}(Cracov., 1580; a later edition, Rigæ, 1600). The great work on inclusa in amber is, however, that of Nathaniel Sendel. See the previous note.

Sir Thomas Browne must not be forgotten in this connexion. The Pseudodoxia (p. 64 of the second edition, 1650) says:

“Lastly, we will not omit what Bellabonus upon his own experiment writ from Dantzich unto Mellichius, as he hath left recorded in his chapter De Succino, that the bodies of Flies, Pismires and the like, which are said oft times to be included in Amber, are not reall but representative, as he discovered in severall pieces broke for that purpose. If so, the two famous Epigrams hereof in Martiall are but poeticall, the Pismire of Brassavolus Imaginary, and Cardans Mousoleum for a flie, a meer phancy. But hereunto we know not how to assent, as having met with some whose reals made good their representments.” See also Pope’s Epistle to Dr. Arbuthnot, line 169.

[114] Page 47, line 34. Page 47, line 40. Commemorant antiqui quod succinum festucas et paleas attrahit.—Pliny (book xxxvii., chap. ii., p. 606 of the English edition of 1601) thus narrates the point:

“Hee [Niceas] writeth also, that in Aegypt it [amber] is engendered…. Semblably in Syria, the women (saith hee) make wherves of it for their spindles, where they use to call it Harpax, because it will catch up leaves, straws, and fringes hanging to cloaths.”

p. 608. “To come to the properties that Amber hath, If it bee well rubbed and chaufed betweene the fingers, the potentiall facultie that lieth within, is set on work, and brought into actual operation, whereby you shall see it to drawe chaffe strawes, drie leaves, yea, and thin rinds of the Linden or Tillet tree, after the same sort as loadstone draweth yron.”

[115] Page 47, line 36. Page 47, line 42. Quod etiam facit Gagates lapis.—The properties of Jet were well known to the mediæval writers. Julius Solinus writes in De Mirabilibus, chapter xxxiv., Of Britaine (English version of 1587 by A. Golding):

“Moreover to the intent to passe the large aboundance of sundry mettals (whereof Britaine hath many rich mynes on all sides), Here is store of the stone called Geate, and ye best kind of it. If ye demaund ye beautie of it, it is a black Jewell: if the qualitie, it is of no weight: if the nature, it burneth in water, and goeth out in Oyle; if the power, rubbe it till it be warme, and it holdeth such things as are laide to it; as Amber doth. The Realme is partlie inhabited of barbarous people, who even frõ theyr childhoode haue shapes of divers beastes cunninglye impressed and incorporate in theyr bodyes, so that beeing engraued as it were in theyr bowels, as the man groweth, so growe the marks painted vpon him….”

Pliny describes it as follows (p. 589, English edition of 1601):

“The Geat, which otherwise we call Gagates, carrieth the name of a toune and river both in Lycia, called Gages: it is said also, that the sea casteth it up at a full tide or high water into the Island Leucola, where it is gathered within the space of twelve stadia, and no where else: blacke it is, plaine and even, of a hollow substance in manner of the pumish stone, not much differing from the nature of wood; light, brittle, and if it bee rubbed or bruised, of a strong flavour.” (Book xxxvi., chap. xviii.)

In the Commentary of Joannes Ruellius upon Dioscorides, Pedanii Dioscoridis Anazarbei de medicinali materia libri sex, Ioanne Ruellio Suessionensi interprete … (Frankfurt, 1543, fol., liber quintus, cap. xcii.) is the following description:


“In Gagatarum lapidum genere, præferendus qui celeriter accenditur, et odorem bituminis reddit. niger est plerunque, et squalidus, crustosus, per quam levis. Vis ei molliendi, et discutiendi. deprehendit sonticum morbum suffitus, recreatque uuluæ strangulationes. fugat serpentes nidore. podagricis medicaminibus, et a copis additur. In Cilicia nasci solet, qua influens amnis in mare effunditur, proxime oppidum quod Plagiopolis dicitur. vocatur autem et locus et amnis Gagas, in cujus faucibus ii lapides inveniuntur.

“Gagates lapis colore atro, Germanis Schwartzer augstein, voce parum depravata, dicitur. odore dum uritur bituminis, siccat, glutinat, digerit admotus, in corollis precariis et salinis frequens.”

And in the Scholia upon Dioscorides of Joannes Lonicer (Marpurgi, 1643, cap. xcvii., p. 80) is the following:

“De Gagate Lapide. Ab natali solo, urbe nimirum Gagae Lyciae nomen habet. Galenus se flumen isthuc et lapidem non invenisse, etiamsi naui parua totam Lyciam perlustravit: ait, se autem in caua Syria multos nigros lapides invenisse glebosos, qui igni impositi, exiguam flammam gignerent. Meminit hujus Nicander in Theriacis nempe suffitum hujus abigere venenata.”

There is also a good account of Gagates (and of Succinum) by Langius, Epistola LXXV., p. 454, of the work Epistolarum medicinalium volumen tripartitum (Francofurti, 1589).

[116] Page 47, line 39. Page 47, line 45. Multi sunt authores moderni.—The modern authors who raised Gilbert’s wrath by ignorantly copying out all the old tales about amber, jet, and loadstone, instead of investigating the facts, were, as he says at the beginning of the chapter, some theologians, and some physicians. He seems to have taken a special dislike to Albertus Magnus, to Puteanus (Du Puys), and to Levinus Lemnius.

[117] Page 47, line 39. Page 47, line 46. & gagate.—The editions of 1628 and 1633 both read ex gagate.

[118] Page 48, line 14. Page 48, line 16. Nam non solum succinum, & gagates (vt illi putant) allectant corpuscula.—The list of bodies known to become electrical by friction was not quite so restricted as would appear from this passage. Five, if not six, other minerals had been named in addition to amber and jet.

(1.) Lyncurium. This stone, about which there has been more obscurity and confusion than about any other gem, is supposed by some writers to be the tourmaline, by others a jacinth, and by others a belemnite. The ancients supposed it to be produced from the urine of the lynx. The following is the account of Theophrastus, Theophrastus’s History of Stones. With an English Version …, by “Sir” John Hill, London, 1774, p. 123, ch. xlix.-l. “There is some Workmanship required to bring the Emerald to its Lustre, for originally it is not so bright. It is, however, excellent in its Virtues, as is also the Lapis Lyncurius, which is likewise used for engraving Seals on, and is of a very solid Texture, as Stones are; it has also an attractive Power, like that of Amber, and is said to attract not only Straws and small pieces of Sticks, but even Copper and Iron, if they are beaten to thin pieces. This Diocles affirms. The Lapis Lyncurius is pellucid, and of a fire Colour.” See also W. Watson in Philos. Trans., 1759, L. i., p. 394, Observations concerning the Lyncurium of the ancients.

(2.) Ruby.

(3.) Garnet. The authority for both these is Pliny, Nat. Hist., book xxxvii., chap. vii. (p. 617 of English edition of 1601).


“Over and besides, I find other sorts of Rubies different from those above-named;… which being chaufed in the Sun, or otherwise set in a heat by rubbing with the fingers, will draw unto them chaffe, strawes, shreads, and leaves of paper. The common Grenat also of Carchedon or Carthage, is said to doe as much, although it be inferiour in price to the former.”

(4.) Jasper. Affaytatus is the authority, in Fortunii Affaitati Physici atque Theologi … Physicæ & Astronomicæ cōsiderationes (Venet., 1549), where, on p. 20, he speaks of the magnet turning to the pole, likening it to the turning of a “palea ab Ambro vel Iaspide et hujuscemodi lapillis lucidis.”

(5.) Lychnis. Pliny and St. Isidore speak of a certain stone lychnis, of a scarlet or flame colour, which, when warmed by the sun or between the fingers, attracts straws or leaves of papyrus. Pliny puts this stone amongst carbuncles, but it is much more probably rubellite, that is to say, red tourmaline.

(6.) Diamond. In spite of the confusion already noted, à propos of adamas (Note to p. 47), between loadstone and diamond, there seems to be one distinct record of an attractive effect having been observed with a rubbed diamond. This was recorded by Fracastorio, De sympathia et antipathia rerum (Giunta edition, Venice, MDLXXIIII, chap. v., p. 60 verso), “cujus rei & illud esse signum potest, cum confricata quædã vt Succinum, & Adamas fortius furculos trahunt.” And (on p. 62 recto); “nam si per similitudine (vt supra diximus) fit hæc attractio, cur magnes non potius magnetem trahit, q˜ ferrum, & ferrum non potius ad ferrum movetur, quàm ad magnetem? quæ nam affinitas est pilorum, & furculorum cum Electro, & Adamante? præsertim q˜ si cum Electro affines sunt, quomodo & cum Adamante affinitatem habebunt, qui dissimilis Electro est?” An incontestable case of the observation of the electrification of the diamond occurs in Gartias ab Horto. The first edition of his Historia dei Semplici Aromati was publisht at Goa in India in 1563. In chapter xlviii. on the Diamond, occur these words (p. 200 of the Venetian edition of 1616): “Questo si bene ho sperimentato io più volte, che due Diamanti perfetti fregati insieme, si vniscono di modo insieme, che non di leggiero li potrai separare. Et ho parimente veduto il Diamante dopo di esser ben riscaldato, tirare à se le festuche, non men, che si faccia l’elettro.” See also Aldrovandi, Musæum Metallicum (Bonon., 1648, p. 947).

Levinus Lemnius also mentions the Diamond along with amber. See his Occulta naturæ miracula (English edition, London, 1658, p. 199).

[119] Page 48, line 16. Page 48, line 18. Iris gemma.—The name iris was given, there can be little doubt, to clear six sided prisms of rock-crystal (quartz), which, when held in the sun’s beams, cast a crude spectrum of the colours of the rainbow. The following is the account of it given in Pliny, book xxxvii., chap. vii. (p. 623 of the English version of 1601):

“… there is a stone in name called Iris: digged out of the ground it is in a certaine Island of the red sea, distant from the city Berenice three score miles. For the most part it resembleth Crystall: which is the reason that some hath tearmed it the root of Crystall. But the cause why they call it Iris, is, That if the beames of the Sunne strike upon it directly within house, it doth send from it against the walls that bee neare, the very resemblance both in forme and also in colour of a rainebow; and eftsoones it will chaunge the same in much varietie, to the great admiration of them that behold it. For certain it is knowne, that six angles it hath in manner of the Crystall: but they say that some of them have their sides rugged, and the same {40}unequally angled: which if they be laid abroad against the Sunne in the open aire, do scatter the beames of the Sunne, which light upon them too and fro: also that others doe yeeld a brightnes from themselves, and thereby illuminat all that is about them. As for the diverse colours which they cast forth, it never happeneth but in a darke or shaddowie place: whereby a man may know, that the varietie of colours is not in the stone Iris, but commeth by the reverberation of the wals. But the best Iris is that which representeth the greatest circles upon the wall, and those which bee likest unto rainebowes indeed.”

In the English translation of Solinus’s De Mirabilibus (The excellent and pleasant worke of Julius Solinus containing the noble actions of humaine creatures, the secretes and providence of nature, the descriptions of countries … tr. by A. Golding, gent., Lond., 1587), chapter xv. on Arabia has the following:

“Hee findeth likewise the Iris in the Red sea, sixe cornered as the Crystall: which beeing touched with the Sunnebeames, casteth out of him a bryght reflexion of the ayre like the Raynebowe.”

Iris is also mentioned by Albertus Magnus (De mineralibus, Venet., 1542, p. 189), by Marbodeus Gallus (De lapidibus, Par. 1531, p. 78), who describes it as “crystallo simulem sexangulam,” by Lomatius (Artes of curious Paintinge, Haydocke’s translation, Lond., 1598, p. 157), who says, “… the Sunne, which casting his beames vpon the stone Iris, causeth the raine-bowe to appeare therein …,” and by “Sir” John Hill (A General Natural History, Lond., 1748, p. 179).

Figures of the Iris given by Aldrovandi in the Musæum Metallicum clearly depict crystals of quartz.

[120] Page 48, line 16. Page 48, line 18. Vincentina, & Bristolla (Anglica gemma siue fluor). This is doubtless the same substance as the Gemma Vincentij rupis mentioned on p. 54, line 16 (p. 54, line 18, of English Version), and is nothing else than the so-called “Bristol diamond,” a variety of dark quartz crystallized in small brilliant crystals upon a basis of hæmatite. To the work by Dr. Thomas Venner (Lond., 1650), entitled Via Recta or the Bathes of Bathe, there is added an appendix, A Censure concerning the water of Saint Vincents Rocks neer Bristol (Urbs pulchra et Emporium celebre), in which, at p. 376, occurs this passage: “This Water of Saint Vincents Rock is of a very pure, cleare, crystalline substance, answering to those crystalline Diamonds and transparent stones that are plentifully found in those Clifts.”

In the Fossils Arranged of “Sir” John Hill (Lond., 1771), p. 123, is the following entry: “Black crystal. Small very hard heavy glossy. Perfectly black, opake. Bristol (grottos, glass)” referring to its use.

The name Vincentina is not known as occurring in any mineralogical book. Prof. H. A. Miers, F.R.S., writes concerning the passage: “Anglica gemma sive fluor seems to be a synonym for Bristolla, or possibly for Vincentina et Bristolla. Both quartz and fluor are found at Clifton. In that case Vincentina and Bristolla refer to these two minerals, and if so one would expect Bristolla to be the Bristol Diamond, and Vincentina to be the comparatively rare Fluor spar from that locality.”

At the end of the edition of 1653 of Sir Hugh Plat’s Jewel House of Art and Nature, is appended A rare and excellent Discourse of Minerals, Stones, Gums, and Rosins; with the vertues and use thereof, By D. B. Gent. Here, p. 218, we read:

“We have in England a stone or mineral called a Bristol stone (because {41}many are found thereabouts) which much resembles the Adamant or Diamond, which is brought out of Arabia and Cyprus; but as it is wanting of the same hardnesse, so falls it short of the like vertues.”

[121] Page 48, line 18. Page 48, line 19. Crystallus.—Rock-crystal. Quartz. Pliny’s account of it (Philemon Holland’s version of 1601, p. 604) in book xxxvii., chap, ii., is:

“As touching Crystall, it proceedeth of a contrarie cause, namely of cold; for a liquor it is congealed by extreame frost in manner of yce; and for proofe hereof, you shall find crystall in no place els but where the winter snow is frozen hard: so as we may boldly say, it is verie yce and nothing else, whereupon the Greeks have give it the right name Crystallos, i. Yce…. Thus much I dare my selfe avouch, that crystall groweth within certaine rockes upon the Alps, and these so steepe and inaccessible, that for the most part they are constrained to hang by ropes that shall get it forth.”

[122] Page 48, line 18. Page 48, line 20. Similes etiam attrahendi vires habere videntur vitrum … sulphur, mastix, & cera dura sigillaris. If, as shown above, the electric powers of diamond and ruby had already been observed, yet Gilbert was the first beyond question to extend the list of electrics beyond the class of precious stones, and his discovery that glass, sulphur, and sealing-wax acted, when rubbed, like amber, was of capital importance. Though he did not pursue the discovery into mechanical contrivances, he left the means of that extension to his followers. To Otto von Guericke we owe the application of sulphur to make the first electrical machine out of a revolving globe; to Sir Isaac Newton the suggestion of glass as affording a more mechanical construction.

Electrical attraction by natural products other than amber after they have been rubbed must have been observed by the primitive races of mankind. Indeed Humboldt in his Cosmos (Lond., 1860, vol. i., p. 182) records a striking instance:

“I observed with astonishment, on the woody banks of the Orinoco, in the sports of the natives, that the excitement of electricity by friction was known to these savage races, who occupy the very lowest place in the scale of humanity. Children may be seen to rub the dry, flat and shining seeds or husks of a trailing plant (probably a Negretia) until they are able to attract threads of cotton and pieces of bamboo cane.”

[123] Page 48, line 23. Page 48, line 25. arsenicum.—This is orpiment. See the Dictionary of metallick words at the end of Pettus’s Fleta Minor.

[124] Page 48, line 23. Page 48, line 26. in convenienti cœlo sicco.—The observation that only in a dry climate do rock-salt, mica, and rock-alum act as electrics is also of capital importance. Compare page 56.

[125] Page 48, line 27. Page 48, line 31. Alliciunt hæc omnia non festucas modo & paleas.—Gilbert himself marks the importance of this discovery by the large asterisk in the margin. The logical consequence was his invention of the first electroscope, the versorium non magneticum, made of any metal, figured on p. 49.

[126] Page 48, line 34. Page 48, line 36. quod tantum siccas attrahat paleas, nec folia ocimi.—This silly tale that basil leaves were not attracted by amber arose in the Quæstiones Convivales of Plutarch. It is repeated by Marbodeus and was quoted by Levinus Lemnius as true. Gilbert denounced it as nonsense. Cardan (De Subtilitate, Norimb., 1550, p. 132) had already contradicted the fable. “Trahit enim,” he says, “omnia levia, paleas, festucas, ramenta {42}tenuia metallorum, & ocimi folia, perperam contradicente Theophrasto.” Sir Thomas Browne specifically refuted it. “For if,” he says, “the leaves thereof or dried stalks be stripped into small strawes, they arise unto Amber, Wax, and other Electricks, no otherwise then those of Wheat or Rye.”

[127] Page 48, line 34. Page 48, line 38. Sed vt poteris manifestè experiri….

Gilbert’s experimental discoveries in electricity may be summarized as follows:

  1. The generalization of the class of Electrics.

  2. The observation that damp weather hinders electrification.

  3. The generalization that electrified bodies attract everything,

including even metals, water, and oil.

  1. The invention of the non-magnetic versorium or electroscope.

  2. The observation that merely warming amber does not electrify it.

  3. The recognition of a definite class of non-electrics.

  4. The observation that certain electrics do not attract if roasted or


  1. That certain electrics when softened by heat lose their power.

  2. That the electric effluvia are stopped by the interposition of a sheet

of paper or a piece of linen, or by moist air blown from the mouth.

  1. That glowing bodies, such as a live coal, brought near excited amber

discharge its power.

  1. That the heat of the sun, even when concentrated by a burning mirror,

confers no vigour on the amber, but dissipates the effluvia.

  1. That sulphur and shell-lac when aflame are not electric.

  2. That polish is not essential for an electric.

  3. That the electric attracts bodies themselves, not the intervening air.

  4. That flame is not attracted.

  5. That flame destroys the electrical effluvia.

  6. That during south winds and in damp weather, glass and crystal, which

collect moisture on their surface, are electrically more interfered

with than amber, jet and sulphur, which do not so easily take up

moisture on their surfaces.

  1. That pure oil does not hinder production of electrification or exercise

of attraction.

  1. That smoke is electrically attracted, unless too rare.

  2. That the attraction by an electric is in a straight line toward it.

[128] Page 48, line 35. Page 48, line 39. quæ sunt illæ materiæ.—Gilbert’s list of electrics should be compared with those given subsequently by Cabeus (1629), by Sir Thomas Browne (1646), and by Bacon. The last-named list occurs in his Physiological Remains, published posthumously in 1679; it contains nothing new. Sir Thomas Browne’s list is given in the following passage, which is interesting as using for the first time in the English language the noun Electricities:

“Many stones also both precious and vulgar, although terse and smooth, have not this power attractive; as Emeralds, Pearle, Jaspis, Corneleans, Agathe, Heliotropes, Marble, Alablaster, Touchstone, Flint and Bezoar. Glasse attracts but weakely though cleere, some slick stones and thick glasses indifferently: Arsenic but weakely, so likewise glasse of Antimony, but Crocus Metallorum not at all. Saltes generally but weakely, as Sal Gemma, Alum, and also Talke, nor very discoverably by any frication: but if gently warmed at the fire, and wiped with a dry cloth, they will better discover their Electricities.” (Pseudodoxia Epidemica, p. 79.)

In the Philosophical Transactions, vol. xx., p. 384, is A Catalogue of Electrical Bodies by the late Dr. Rob. Plot. It begins “Non solum succinum,” and ends “alumen rupeum,” being identical with Gilbert’s list except that he calls “Vincentina & Bristolla” by the name “Pseudoadamas Bristoliensis.”

[129] Page 49, line 25. Page 49, line 30. non dissimili modo.—The modus {43}operandi of the electrical attractions was a subject of much discussion; see Cardan, op. citat.

[130] Page 51, line 2. Page 51, line 1. appellunt.—This appears to be a misprint for appelluntur.

[131] Page 51, line 22. Page 51, line 23. smyris.—Emery. This substance is mentioned on p. 22 as a magnetic body.

[132] Page 52, line 1. Page 51, line 46. gemmæ … vt Crystallus, quæ ex limpidâ concreuit. See the note to p. 48.

[133] Page 52, line 30. Page 52, line 32. ammoniacum.—Ammoniacum, or Gutta Ammoniaca, is described by Dioscorides as being the juice of a ferula grown in Africa, resembling galbanum, and used for incense.

“Ammoniack is a kind of Gum like Frankincense; it grows in Lybia, where Ammon’s Temple was.” Sir Hugh Plat’s Jewel House of Art and Nature (Ed. 1653, p. 223).

[134] Page 52, line 38. Page 52, line 41. duæ propositæ sunt causæ … materia & forma.—Gilbert had imbibed the schoolmen’s ideas as to the relations of matter and form. He had discovered and noted that in the magnetic attractions there was always a verticity, and that in the electrical attractions the rubbed electrical body had no verticity. To account for these differences he drew the inference that since (as he had satisfied himself) the magnetic actions were due to form, that is to say to something immaterial—to an “imponderable” as in the subsequent age it was called—the electrical actions must necessarily be due to matter. He therefore put forward his idea that a substance to be an electric must necessarily consist of a concreted humour which is partially resolved into an effluvium by attrition. His discoveries that electric actions would not pass through flame, whilst magnetic actions would, and that electric actions could be screened off by interposing the thinnest layer of fabric such as sarcenet, whilst magnetic actions would penetrate thick slabs of every material except iron only, doubtless confirmed him in attributing the electric forces to the presence of these effluvia. See also p. 65. There arose a fashion, which lasted over a century, for ascribing to “humours,” or “fluids,” or “effluvia,” physical effects which could not otherwise be accounted for. Boyle’s tracts of the years 1673 and 1674 on “effluviums,” their “determinate nature,” their “strange subtilty,” and their “great efficacy,” are examples.

[135] Page 53, line 9. Page 53, line 11. Magnes vero….—This passage from line 9 to line 24 states very clearly the differences to be observed between the magnetical and the electrical attractions.

[136] Page 53, line 36. Page 53, line 41. succino calefacto.—Ed. 1633 reads succinum in error.

[137] Page 54, line 9. Page 54, line 11. Plutarchus … in quæstionibus Platonicis.—The following Latin version of the paragraph in Quæstio sexta is taken from the bilingual edition publisht at Venice in 1552, p. 17 verso, liber vii., cap. 7 (or, Quæstio Septima in Ed. Didot, p. 1230).

“Electrum uero quæ apposita sunt, nequaquàm trahit, quem admodum nec lapis ille, qui sideritis nuncupatur, nec quicquā à seipso ad ea quæ in propinquo sunt, extrinsecus assilit. Verum lapis magnes effluxiones quasdam tum graves, tum etiam spiritales emittit, quibus aer continuatus & iunctus repellitur. Is deinceps alium sibi proximum impellit, qui in orbem circum actus, atque ad inanem locum rediens, ui ferrum fecum rapit & trahit. At Electrum uim quandam flammæ similem & spiritalem continet, quam quidem {44}tritu summæ partis, quo aperiuntur meatus, foras eijcit. Nam leuissima corpuscula & aridissima quæ propè sunt, sua tenuitate atque imbecillitate ad seipsum ducit & rapit, cum non sit adeo ualens, nec tantum habeat ponderis & momenti ad expellendam aeris copiam, ut maiora corpora more Magnetis superare possit & uincere.”

[138] Page 54, line 16. Page 54, line 18. Gemma Vincentij rupis.—See the note to p. 48 supra, where the name Vincentina occurs.

[139] Page 54, line 30. Page 54, line 35. orobi.—The editions of 1628 and 1633 read oribi.

[140] Page 55, line 34. Page 55, line 42. in euacuati.—The editions of 1628 and 1633 read inevacuati.

[141] Page 58, line 21. Page 58, line 25. assurgentem vndam … declinat ab F.—These words are wanting in the Stettin editions.

[142] Page 59, line 9. Page 59, line 9. fluore.—This word is conjectured to be a misprint for fluxu but it stands in all editions.

[143] Page 59, line 22. Page 59, line 25. Ruunt ad electria.—This appears to be a slip for electrica, which is the reading of the editions of 1628 and 1633.

[144] Page 60, line 7. Page 60, line 9. tanq materiales radij.—The suggestion here of material rays as the modus operandi of electric forces seems to foreshadow the notion of electric lines of force.

[145] Page 60, line 10. Page 60, line 12. Differentia inter magnetica & electrica.—Though Gilbert was the first systematically to explore the differences that exist between the magnetic attraction of iron and the electric attraction of all light substances, the point had not passed unheeded, for we find St. Augustine, in the De Civitate Dei, liber xxi., cap. 6, raising the question why the loadstone which attracts iron should refuse to move straws. The many analogies between electric and magnetic phenomena had led many experimenters to speculate on the possibility of some connexion between electricity and magnetism. See, for example, Tiberius Cavallo, A Treatise on Magnetism, London, 1787, p. 126. Also the three volumes of J. H. van Swinden, Receuil de Mémoires sur l’Analogie de Electricité et du Magnétisme, La Haye, 1784. Aepinus wrote a treatise on the subject, entitled De Similitudine vis electricæ et magneticæ (Petropolis, 1758). This was, of course, long prior to the discovery, by Oersted, in 1820, of the real connexion between magnetism and the electric current.

[146] Page 60, line 25. Page 60, line 31. Coitionem dicimus, non attractionem.—See the remarks, at the outset of these Notes, on Gilbert’s definitions of words.

[147] Page 60, line 33. Page 61, line 1. Orpheus in suis carminibus.—This passage is in the chapter Λιθικά of Orpheus, verses 301 to 327. See Note to p. 11, line 19.

[148] Page 61, line 15. Page 61, line 19. Platonis in Timæo opinio.—The passage runs (edition Didot, vol. ii., p. 240, or Stephanus, p. 80, C.):

Καὶ δὴ καὶ τὰ τῶν ὑδάτων πάντα ῥεύματα ἔτι δὲ τὰ τῶν κεραυνῶν πτώματα καὶ τὰ θαυμαζόμενα ἠλέκτρων περὶ τῆς ἕλξεως καὶ τῶν Ἡρακλείων λίθων, πάντων τούτων ὁλκὴ μὲν οὐκ ἔστιν οὐδένι ποτε, τὸ δὲ κενὸν εἶναι μηδεν περιωθεῖν τε αὑτὰ ταῦτα εἰς ἄλληλα, τό τε διακρινόμενα καὶ συγκρινόμενα πρὸς τήν αὑτῶν διαμειβόμενα ἕδραν ἕκαστα ἰέναι πάντα, τούτοις τοῖς παθήμασι πρὸς ἄλληλα συμπλεχθεῖσι τεθαυματουργημένα τῷ κατὰ τρόπον ζητοῦντι φανήσεται.

[149] Page 61, Line 30. Page 61, line 38. The English version of the lines of Lucretius is from Busby’s translation.

[150] Page 62, line 5. {45}Page 62, line 7. Iohannes Costæus Laudensis.—Joannes Costa, of Lodi, edited Galen and Avicenna. He also wrote a De universali stirpium Natura (Aug. Taurin., 1578).

[151] Page 63, line 3. Page 63, line 4. Cornelius Gemma 10. Cosmocrit.—This refers to the work De Naturæ Divinis Characterismis … Libri ii. Avctore D. Corn. Gemma (Antv., 1575, lib. i., cap. vii., p. 123).

“Certè vt à magnete insensiles radij ferrum ad se attrahunt, ab echineide paruo pisciculo sistuntur plena nauigia, à catoblepa spiritu non homines solùm, sed & alta serpentum genera interimuntur, & saxa dehiscunt.”

See also Kircher’s Magneticum Naturæ Regnum (Amsterodami, 1667, p. 172), Sectio iv., cap. iii., De Magnete Navium, quæ Remora seu Echeneis dicitur. See the note to p. 7, line 21.

[152] Page 63, line 6. Page 63, line 7. Guilielmus Puteanus.—Puteanus (Du Puys) wrote a work De Medicamentorum quomodocunque Purgantium Facultatibus, Libri ii. (Lugd., 1552), in which he talks vaguely about the substantial “form” of the magnet, and quotes Aristotle and Galen.

[153] Page 63, line 21. Page 63, line 25. Baptistæ Portæ.—The passage in the translation is quoted from the English version of 1658, pp. 191, 192.

[154] Page 64, line 4. Page 64, line 9. Eruditè magis Scaliger.—Gilbert pokes fun at Scaliger, whose “erudite” guess (that the motion of iron to the magnet was that of the offspring toward the parent) is to be found in his book De Subtilitate, ad Cardanum, Exercitatio CII. (Lutetiæ, 1557, p. 156 bis).

[155] Page 64, line 7. Page 64, line 11. Diuus Thomas.—On p. 3 Gilbert had already spoken of St. Thomas Aquinas as a man of intellect who would have added more about the magnet had he been more conversant with experiments. The passage here quoted is from the middle of Liber vii. of his commentaries on the de Physica of Aristotle, Expositio Diui Thome Aquinatis Doctoris Angelici super octo libros Physicorum Aristotelis, etc. (Venice, Giunta edition, 1539, p. 96 verso, col. 2).

[156] Page 64, line 16. Page 64, line 24. Cardinalis etiam Cusanus.—Cardinal de Cusa (Nicolas Khrypffs) wrote a set of dialogues on Statics, Nicolai Cusani de staticis experimentis dialogus (1550), of which an English version appeared in London in 1650 with the title, The Idiot in four books; the first and second of wisdom, the third of the minde, the fourth of statick experiments. By the famous and learned C. Cusanus. In the fourth book of statick Experiments, Or experiments of the Ballance, occurs (p. 186) the following:

“Orat. Tell me, if thou hast any device whereby the vertues of stones may be weighed.

“Id. I thinke the vertue of the Load-stone might be weighed, if putting some Iron in one scale, and a Load-stone in the other, untill the ballance were even, then taking away the Load-stone, and some other thing of the same weight being put into the scale, the Load-stone were holden over the Iron, so that that scale wou’d begin to rise; by reason of the Load-stones attraction of the Iron, then take out some of the weight of the other scale, untill the scale wherein the iron is, doe sinke againe to the æquilibrium, or equality still holding the Load-stone unmovable as it was; I beleeve that by weight of what was taken out of the contrary scale, one might come proportionably to the weight of the vertue or power of the Load-stone. And in like manner, the vertue of a Diamond, might be found hereby, because {46}they say it hinders the Load-stone from drawing of Iron; and so other vertues of other stones, consideration, being alwayes had of the greatnesse of the bodyes, because in a greater body, there is a greater power and vertue.”

In the 1588 edition of Baptista Porta’s Magiæ Naturalis Libri xx., in lib. vii., cap. xviii., occurs the description of the use of the balance to which Gilbert refers.

[157] Page 67, line 21. Page 67, line 22. aëris rigore.—All editions read thus, but the sense seems to require frigore.

[158] Page 67, line 27. Page 67, line 31. Fracastorius.—See his De Sympathia, lib. i., cap. 5 (Giunta edition, 1574, p. 60).

[159] Page 68, line 5. Page 68, line 6. Thaletis Milesij.—See the note to p. 11, line 26.

[160] Page 68, line 30. Page 68, line 35. Ità coitio magnetica actus est magnetis, & ferri, non actio vnius.—See the introductory remarks to these notes. There is a passage in Scaliger’s De Subtilitate ad Cardanum (Exercitat. CII., cap. 5, p. 156 op. citat.) which may be compared with Gilbert’s for its use of Greek terms: “Nã cùm uita dicatur actus animæ, acceptus est abs te actus pro actione. Sed actus ille est ἐντελέχεια, nõ autem ἔργον. At Magnetis attractio est ἔργον, non autẽ ἐντελέχεια.” To which Gilbert retorts: “non actio unius, utriusque ἐντελέχεια; non ἔργον, συνεντελέχεια et conactus potius quam sympathia.” He returns on p. 70 to the attack on Scaliger’s metaphysical notions. There is a parallel passage in the Epitome Naturalis Scientiæ of Daniel Sennert (Oxoniæ, 1664), in the chapter De Motu.

[161] Page 71, line 4. Page 71, line 8. vt in 8. physicorum Themistius existimat.—See Omnia Themistii Opera (Aldine edition, 1533, p. 63), Book 8 of his Paraphrase on Aristotle’s Physica.

[162] Page 71, line 9. Page 71, line 14. Quod verò Fracastorius.—Op. citat., lib. i., cap. 7, p. 62 verso.

[163] Page 73, line 2. Page 73, line 2. si A borealis.—The editions of 1628 and 1633 omit the twelve words next following.

[164] Page 73, line 9. Page 73, line 11. ex minera.—Minera is not a recognized word, even in late Latin. It occurs again, p. 97, line 12.

[165] Page 77, line 2. Page 77, line 2. multo magis.—This is an à fortiori argument. It is interesting to find Gilbert comparing the velocity of propagation of magnetic forces in space with the velocity of light. The parallel is completed in line 13 by the consideration that as the rays of light require to fall upon an object in order that they may become visible, so the magnetic forces require a magnetic object in order to render their presence sensible.

[166] Page 78, line 14. Page 78, line 16. Orbem terrarum distinguunt.—The editions of 1628 and 1633 here add a figure of a globe marked with meridians and parallels of latitude, but with an erroneous versorium pointing to the south. These editions also both read existentiam for the word existentium in line 20.

[167] Page 83, line 5. Page 83, line 5. magnes longior maiora pondera ferri attollit.—Gilbert discovered the advantage, for an equal mass of loadstone, of an elongated shape. It is now well known that the specific amount of magnetism retained by elongated forms exceeds that in a short piece of the same material subjected to equal magnetizing forces.

[168] Page 83, line 24. Page 83, line 28. Non obstant crassa tabulata.—Gilbert has several times referred (e.g., on p. 77) to the way in which magnetic forces penetrate solid bodies. The experimental investigation in this chapter {47}is the more interesting because it shows that Gilbert clearly perceived the shielding action of iron to be due to iron conducting aside or diverting the magnetic forces.

[169] Page 85, line 26. Page 85, line 31. non conveniant.—The editions of 1628 and 1633 both read et conveniant.

[170] Page 86, line 3. Page 86, line 3. illud quod exhalat.—Literally, that which exhales, in the sense of that which escapes: but in modern English the verb exhale in the active voice is now not used of the substance that escapes, but is used of the thing which emits it. It must therefore be rendered that which is exhaled (i.e., breathed out).

[171] Page 86, line 13. Page 86, line 15. Ita tota interposita moles terrestris.—Gilbert’s notion that the gravitational force of the moon in producing the tides acts through the substance of the earth may seem curiously expressed. But the underlying contention is essentially true to-day. The force of gravity is not cut off or screened off by the interposition of other masses. A recent investigation by Professor Poynting, F.R.S., has shown that so far as all evidence goes all bodies, even the densest, are transparent with respect to gravitational forces.

[172] Page 86, line 18. Page 86, line 20. Sed de æstus ratione aliàs.—There is no further discussion of the tides in De Magnete. But a short account is to be found in Gilbert’s posthumous work De Mundo nostro Sublunari Philosophia nova (Amsterdam, Elzevir, 1651), in Lib. v., the part which in the manuscript was left in English, and was turned into Latin by his brother. It comprises about fifteen quarto pages, from Cap. X. to Cap. XIX. inclusive, beginning with a characteristic diatribe against Taisnier, Levinus Lemnius, and Scaliger. But in assigning causes he himself goes wide of the mark. Proceeding by a process of elimination he first shows that the moon’s light cannot be the cause that impels the tides. “Luna,” he says, “non radio, non lumine, maria impellit. quomodo igitur? Sane corporum conspiratione, acque (ut similitudine rem exponam) Magnetica attractione.” This cryptic utterance he proceeds to explain by a diagram, and adds: “Quare Luna non tam attrahit mare, quàm humorem & spiritum subterraneum; nec plus resistit interposita terra, quàm mensa, aut quicquam aliud densum, aut crassum, magnetis viribus.”

[173] Page 87, line 7. Page 87, line 9. armatura.—Here this means the cap or snout of iron with which the loadstone was armed. This is apparently the first use of the term in this sense.

In the Dialogues of Galileo (p. 369 of Salusbury’s Mathematical Collections, Dialogue iii.), Sagredus and Salviatus discuss the arming of the loadstone, and the increased lifting power conferred by adding an iron cap. Salviatus mentions a loadstone in the Florentine Academy which, unarmed, weighed six ounces, lifting only two ounces, but which when armed took up 160 ounces. Whereupon Galileo makes Salviatus say: “I extreamly praise, admire, and envy this Authour, for that a conceit so stupendious should come into his minde. … I think him [i.e., Gilbert] moreover worthy of extraordinary applause for the many new and true Observations that he made, to the disgrace of so many fabulous Authours, that write not only what they do not know, but whatever they hear spoken by the foolish vulgar, never seeking to assure themselves of the same by experience, perhaps, because they are unwilling to diminish the bulk of their Books.”

[174] Page 87, line 12. Page 87, line 15. The reference to lib. 3 is {48}a misprint for lib. 2. It is corrected in the edition of 1633, but not in that of 1628.

[175] Page 87, line 17. Page 87, line 21. conactu.—The editions of 1628 and 1633 read conatu.

[176] Page 88, line 2. Page 88, line 3. Coitio verò non fortior.—This heading to chap. xix., taken with the seven lines that follow, and the contrast drawn between unitio and coitio, throw much light on the fundamental sense attached by Gilbert to the term coitio. It is here clearly used in the sense of mutual tendency toward union. Note also the contrasted use in chap. xx. of the verbs cohære and adhære. Adhærence connotes a one-sided force (an impossibility in physics), cohærence a mutual force.

[177] Page 90, line 9. Page 90, line 9. nempè vt alter polus maius pondus arripiat.—This acute observation is even now not as well known as it ought to be. Only so recently as 1861 Siemens patented the device of fastening a mass of iron to one end of an electromagnet in order to increase the power of the other end. The fact, so far as it relates to permanent magnets was known to Servington Savery. See Philos. Transactions, 1729, p. 295.

[178] Page 92, line 3. Page 92, line 4. Suspendit in aëre ferrum Baptista Porta.—Porta’s experiment is thus described (Natural Magick, London, 1658, p. 204): “Petrus Pellegrinus saith, he shewed in another work how that might be done: but that work is not to be found. Why I think it extream hard, I shall say afterwards. But I say it may be done, because I have now done it, to hold it fast by an invisible band, to hang in the air; onely so, that it be bound with a small thread beneath, that it may not rise higher: and then striving to catch hold of the stone above, it will hang in the air, and tremble and wag itself.”

[179] Page 97, line 29. Page 97, line 33. Sed quæri potest …—The question here raised by Gilbert is whether the lifting-power of magnets of equal quality is proportional to their weight. If a stone weighing a drachm will lift a drachm, would a stone that weighs an ounce lift an ounce? Gilbert erroneously answers that this is so, and that the lifting-power of a loadstone, whether armed or unarmed, is proportional to its mass.

The true law of the tractive force or lifting-power of magnets was first given in 1729 by James Hamilton (afterwards Earl of Abercorn) in a work entitled Calculations and Tables Relating to the Attractive Virtue of Loadstones … Printed [at London?] in the Year 1729. (See also a paper in the Philos. Transactions, 1729-30, vol. xxxvi., p. 245). This work begins thus:

“The Principle upon which these Tables are formed, is this: That if Two Loadstones are perfectly Homogeneous, that is, if their Matter be of the same Specifick Gravity, and of the same Virtue in all Parts of one Stone, as in the other; and that Like Parts of their Surfaces are Cap’d or Arm’d with Iron; then the Weights they sustain will be as the Squares of the Cube Roots of the Weights of the Loadstones; that is, as their Surfaces.”

Upon lifting-power see also D. Bernoulli, Acta Helvetica, iii., p. 223, 1758; P. W. Haecker, Zur Theorie des Magnetismus, Nürnberg, 1856; Van der Willigen, Arch. du Musée Teyler, vol. iv., Haarlem, 1878 ; S. P. Thompson, Philos. Magazine, July, 1888.

In the book of James Hamilton, p. 5, he mentions a small terrella weighing 139 English grains, which would sustain no less than 23,760 grains, and was valued at £21 13s. 10¾d.


In the Musæum Septalianum of Terzagus (Dertonæ, 1664, p. 42) is mentioned a loadstone weighing twelve ounces which would lift sixty pounds of iron.

Sir Isaac Newton had a loadstone weighing 3 grains, which he wore in a ring. It would lift 746 grains.

Thomson’s British Annual, 1837, p. 354, gives the following reference: “In the Records of General Science, vol. iii., p. 272, there is an interesting description of a very powerful magnet which was sent from Virginia in 1776 by the celebrated Dr. Franklin to Professor Anderson, of Glasgow. It is now in the possession of Mr. Crichton. It weighs 2½ grains, and is capable of supporting a load of 783 grains, which is equivalent to 313 times its own weight.”

[180] Page 99, line 10. Page 99, line 11. Manifestum est.—In this, as in many other passages, Gilbert uses this expression in the sense that it is demonstrable rather than meaning that it is obvious: for the fact here described is one that is not at all self-evident, but one which would become plain when the experiment had been tried. For other instances of this use of manifestum see pages 144, line 20; 158, line 19; 162, line 10.

[181] Page 100, line 20. Page 100, line 24. si per impedimēta … pervenire possunt.—All editions agree in this reading, but the sense undoubtedly requires non possint. Compare p. 91, line 21.

[182] Page 102, line 4. Page 102, line 4. capite 4.—This is a misprint for capite 40, and is retained in the later editions. In the quotation from Baptista Porta, where the English version of 1658 is adhæred to, the words “& deturbat eam” have been omitted by the translator.

[183] Page 107, line 16. Page 107, line 18. Cardanus scribit.—The alleged perpetual motion machine is mentioned in De rerum varietate, lib. 9, cap. xlviii. (Basil., 1581, p. 641). See also the Note to p. 223. For Peregrinus and for Taisnier, see the note to p. 5, lines 8 and 12.

[184] Page 107, line 19. Page 107, line 21. Antonij de Fantis.—His work is: Tabula generalis scotice subtilitatis octo Sectionibus vniuersam Doctoris Subtilis Peritiā cōplectēs: ab excellentissimo doctore Antonio de Fātis taruisino edita … Lugd., 1530.

[185] Page 108, line 26. Page 108, line 31. Cusani in staticis.—See the note to p. 64, line 16.

[186] Page 108, line 33. Page 108, line 41. Languidi … tardiùs acquiescunt.—The editions of 1628 and 1633 omit these seven words.

[187] Page 109, line 11. Page 109, line 13. halinitro.—Either native carbonate of soda or native carbonate of potash might be meant, but not saltpetre. Scaliger, in his De Subtilitate ad Cardanum (Lutet., 1557, p. 164), Exercitatio CIII., 15, under the title, Nitrum non est Salpetræ, says: “More tuo te, tuaque confundis. Salpetræ inter salis fossilis ponis hîc. Mox Halinitrum inter salis, & nitri naturam, speciem obtinere.”

“Sal nitrum is salt which is boiled out of the earth, especially fat earth, as in stables, or any place of excrements.” (A Chymicall Dictionary explaining Hard Places and Words met withall in the Writings of Paracelsus …, Lond., 1650.)

[188] Page 109, line 20. Page 109, line 23. arte ioculatoriâ.—Edition 1628, joculatoriâ; edition 1633, jaculatoriâ.

[189] Page 110, line 11. Page 110, line 12. qualis fuit Antonij denarius.—The Elizabethan version of Pliny (book xxxiii., ch. ix., p. 479) runs thus: {50}“To come now unto those that counterfeit money. Antonius whiles hee was one of the three usurping Triumvirs, mixed yron with the Romane silver denier. He tempered it also with the brasen coine, and so sent abroad false and counterfeit money.”

Georgius Agricola (De Natura Fossilium, p. 646) says:

“Sed ea fraus capitalis est, non aliter ac eorum qui adulterinas monetas cudunt, argento miscentes multam plumbi candidi portionem, aut etiam ferri, qualis fuit Antonii denarius, ut Plinius memoriæ tradidit. Nunc dicam de candido plumbo, nam majoris pretii est quàm aes. In quod plumbum album, inquit Plinius, addita aeris tertia portione candidi adulteratur stannum.”

[190] Page 111, line 3. Page 111, line 3. Meminerunt Chatochitis lapis Plinius, atque Iulius Solinus.—The passage in Pliny (English version of 1601, book xxxvii., ch. x., p. 625) runs:

“Catochitis is a stone proper unto the Island Corsica: in bignesse it exceedeth ordinarie pretious stones: a wonderfull stone, if all be true that is reported thereof, and namely, That if a man lay his hand thereon, it will hold it fast in manner of a glewie gum.”

[191] Page 111, line 7. Page 111, line 7. Sagda vel Sagdo.—Albertus Magnus in De Mineralibus (Venet., 1542, p. 202) says:

“Sarda quem alij dicunt Sardo lapis est qui se habet ad tabulas ligni sicut magnes ad ferrū, et ideo adhæret ita fortiter tabulis nauium quòd euelli nō possit, nisi abscindatur cum ipso ea pars tabulæ cui inhæserit, est autē in colore purissimus nitens.”

And Pliny (op. citat., p. 629):

“Sagda is a stone, which the Chaldeans find sticking to ships, and they say it is greene as Porrets or Leekes.”

[192] Page 111, line 8. Page 111, line 8. Euace.—Evax, king of the Arabs, is said to have written to Nero a treatise on the names, colours, and properties of stones. See the note on Marbodæus, p. 7, line 20.

[193] Page 113, line 14. Page 113, line 19. repulsus sit. The words read thus in all editions, but the sense requires repulsa sint.

[194] Page 113, line 23. Page 113, line 29. Electrica omnia alliciunt cuncta, nihil omninò fugant vnquam, aut propellunt. This denial of electrical repulsion probably arose from the smallness of the pieces of electric material with which Gilbert worked. He could hardly have failed to notice it had he used large pieces of amber or of sealing-wax. Electrical repulsion was first observed by Nicolas Cabeus, Philosophia Magnetica, Ferrara, 1629; but first systematically announced by Otto von Guericke in his treatise Experimenta Nova (ut vocantur) Magdeburgica, de Vacuo Spatio (Amstel., 1672).

[195] Page 113, line 29. Page 113, line 37. cùm de calore quid sit disputabimus.—The discussion of the nature of heat is to be found in Gilbert’s De Mundo nostro Sublunari (Amstel., 1651), lib. i., cap. xxvi., pp. 77-88.

[196] Page 115, line 23. Page 115, line 23. trium vel quatuor digitorum.—Here as in all other places in Gilbert, digitus means a finger’s breadth, so that three or four digits means a length of two or three inches, or from six to eight centimetres.

[197] Page 117, line 26. Page 117, line 25. ille Thebit Bencoræ trepidationis motus.

“Trepidation in the ancient Astronomy denotes a motion which in the Ptolemaic system was attributed to the firmament, in order to account for {51}several changes and motions observed in the axis of the world, and for which they could not account on any other principle.” (Barlow’s Mathematical Dictionary.)

[198] Page 118, line 10. Page 118, line 8. cuspis is aut lilium.—Gilbert uses cuspis or lilium always of the North-pointing end of the needle. Sir Thomas Browne speaks of “the lilly or northern point”; but he differs from Gilbert in saying “the cuspis or Southern point” (Pseudodoxia Epidemica, 1650, p. 46). Only in one place (p. 101, line 5) does Gilbert speak of cuspis meridionalis. Everywhere else the south-pointing end is called the crux.

[199] Page 118, line 15. Page 118, line 13. nam æquè potens est.—Later observation showed this view to be incorrect. The horizontal component of the earth’s magnetic field is not equally strong all over the globe, and the sluggishness of the needle’s return to its position of rest is not due to the supporting pin becoming blunt with wear. The value of the horizontal component is zero at the north magnetic pole, and increases toward the magnetic equator. It is greatest near Singapore and in Borneo, being there more than twice as great as it is at London. (See Captain Creak in Report of Voyage of H.M.S. Challenger, Physics and Chemistry, vol. ii., part vi., 1889.)

[200] Page 119, line 5. Page 119, line 2. lapis.—Both Stettin editions read lapidis.

[201] Page 119, lines 9-11. Page 119, lines 7-9. The gist of the whole book is summarized in these lines. They furnish a cardinal example of that inductive reasoning which was practist by Gilbert, and of which Bacon subsequently posed as the apostle. Compare pages 41 and 211.

[202] Page 120, line 8. Page 120, line 5. dicturi sumus.—Change of verticity is treated of in book iii., chap. x., pp. 137 to 140.

[203] Page 125, line 24. Page 125, line 29. appositam.—All editions give this word, though the sense requires appositum.

[204] Page 128, line 9. Page 128, line 11. non nimis longum.—The editions of 1628 and 1633 read (wrongly) minus instead of nimis.

[205] Page 130, line 12. Page 130, line 14. The word hunc in the folio of 1600 is corrected in ink to tunc, and the Stettin editions both read tunc.

[206] Page 132, line 9. Page 132, line 10. minimus & nullius ponderis.—The editions of 1628 and 1633 both wrongly read est for &.

[207] Page 132, line 28. Page 133, line 1. nutat.—The editions of 1628 and 1633 both wrongly read mutat.

[208] Page 134, line 22. Page 134, line 25. in rectâ sphærâ.—The meaning of the terms a right or direct sphere, an oblique sphere and a parallel sphere are explained by Moxon on pages 29 to 31 of his book A Tutor to Astronomy and Geography (Lond., 1686):

“A Direct Sphere hath both the Poles of the World in the Horizon … It is called a Direct Sphere, because all the Celestial Bodies, as Sun, Moon, and Stars, &c. By the Diurnal Motion of the Primum Mobile, ascend directly Above, and descend directly Below the Horizon. They that Inhabit under the Equator have the Sphere thus posited.”

“An Oblique Sphere hath the Axis of the World neither Direct nor Parallel to the Horizon, but lies aslope from it.”

“A Parallel Sphere hath one Pole of the World in the Zenith, the other in the Nadir, and the Equinoctial Line in the Horizon.”

[209] Page 136, line 1. Page 136, line 1. præsenti.—The editions of 1628 and 1633 read sequenti, to suit the altered position of the figure.

[210] Page 137, line 24. {52}Page 137, line 28. atque ille statim.—The Stettin editions both wrongly read illi.

[211] Page 139. There is a curious history to this picture of the blacksmith in his smithy striking the iron while it lies north and south, and so magnetizing it under the influence of the earth’s magnetism. Woodcuts containing human figures are comparatively rare in English art of the sixteenth century; a notable exception being Foxe’s Acts and Monuments with its many crude cuts of martyrdoms. The artist who prepared this cut of the smith took the design from an illustrated book of Fables by one Cornelius Kiliani or Cornelius van Kiel entitled Viridarium Moralis Philosophiæ, per Fabulas Animalibus brutis attributas traditæ, etc. (Coloniæ, 1594). This rare work, of which there is no copy in the British Museum, is illustrated by some 120 fine copper-plate etchings printed in the text. On p. 133 of this work is an etching to illustrate the fable Ferrarii fabri et canis, representing the smith smiting iron on the anvil, whilst his lazy dog sleeps beneath the bellows. The cut on p. 139 of Gilbert gives, as will be seen by a comparison of the pictures just the same general detail of forge and tools; but the position of the smith is reversed right for left, the dog is omitted, and the words Septrenio and Auster have been added.

Source engraving.

In the Stettin edition of 1628 the picture has again been turned into a copper-plate etching separately printed, is reversed back again left for right, while a compass-card is introduced in the corner to mark the north-south direction.

In the Stettin edition of 1633 the artist has gone back to Kiliani’s original {53}plate, and has re-etched the design very carefully, but reversing it all right for left. As in the London version of 1600, the dog is omitted, and the words Septentrio and Auster are added. Some of the original details—for example, the vice and one pair of pincers—are left out, but other details, for instance, the cracks in the blocks that support the water-tub, and the dress of the blacksmith, are rendered with slavish fidelity.

It is perhaps needless to remark that the twelve copper-plate etchings in the edition of 1628, and the twelve completely different ones in that of 1633, replace certain of the woodcuts of the folio of 1600. For example, take the woodcut on p. 203 of the 1600 edition, which represents a simple dipping-needle made by thrusting a versorium through a bit of cork and floating it, immersed, in a goblet of water. In the 1633 edition this appears, slightly reduced, as a small inserted copper-plate, with nothing added; but in the 1628 edition it is elaborated into a full-page plate (No. xi.) representing the interior, with shelves of books, of a library on the floor of which stands the goblet—apparently three feet high—with a globe and an armillary sphere; while beside the goblet, with his back to the spectator, is seated an aged man, reading, in a carved armchair. This figure and the view of the library are unquestionably copied—reversed—from a well-known plate in the work Le Diverse & Artificiose Machine of Agostino Ramelli (Paris, 1558).

In the Emblems of Jacob Cats (Alle de Wercken, Amsterdam, 1665, p. 65) is given an engraved plate of a smith’s forge, which is also copied—omitting the smith—from Kiliani’s Viridarium.

[212] Page 140, line 2.. Page 140, line 2. præcedenti.—This is so spelled in all editions, though the sense requires præcedente.

[213] Page 141, line 21. Page 141, line 24. quod in epistolâ quâdam Italicâ scribitur.—The tale told by Filippo Costa of Mantua about the magnetism acquired by the iron rod on the tower of the church of St. Augustine in Rimini is historical. The church was dedicated to St. John, but in the custody of the Augustinian monks. The following is the account of it given by Aldrovandi, Musæum Metallicum (1648, p. 134), on which page also two figures of it are given:

“Aliquando etiam ferrum suam mutat substantiam, dum in magnetem conuertitur, & hoc experientia constat, nam Arimini supra turrim templi S. Ioannis erat Crux a baculo ferreo ponderis centum librarum sustentata, quod tractu temporis adeò naturam Magnetis est adeptum, vt, illivs instar, ferrum traheret: hinc magna admiratione multi tenentur, qua ratione ferrum, quod est metallum in Magnetem, qui est lapis transmutari possit; Animaduertendum est id à maxima familiaritate & sympathia ferri, & magnetis dimanare cum Aristoteles in habentibus symbolum facilem transitum semper admiserit. Hoc in loco damus imaginem frusti ferri in Magnetem transmutati, quod clarissimo viro Vlyssi Aldrouando Iulius Caesar Moderatus diligens rerum naturalium inquisitor communicauit; erat hoc frustum ferri colore nigro, & ferrugineo, crusta exteriori quodammodo albicante.” And further on p. 557.

“Preterea id manifestissimum est; quoniam Arimini, in templo Sancti Ioannis, fuit Crux ferrea, quæ tractu temporis in magnetem conuersa est, & ab vno latere ferrum trahebat, & ab altero respuebat.” See also Sir T. Browne’s Pseudodoxia Epidemica (edition of 1650, p. 48), and Boyle’s tract, Experiments and Notes about the Mechanical Production of Magnetism (London, 1676, p. 12).


Another case is mentioned in Dr. Martin Lister’s A Journey to Paris (Lond., 1699, p. 83). “He [Mr. Butterfield] shewed us a Loadstone sawed off that piece of the Iron Bar which held the Stones together at the very top of the Steeple of Chartres. This was a thick Crust of Rust, part of which was turned into a strong Loadstone, and had all the properties of a Stone dug out of the Mine. Mons. de la Hire has Printed a Memoir of it; also Mons. de Vallemont a Treatise. The very outward Rust had no Magnetic Virtue, but the inward had a strong one, as to take up a third part more than its weight unshod.” Gassendi and Grimaldi have given other cases.

Other examples of iron acquiring strong permanent magnetism from the earth are not wanting. The following is from Sir W. Snow Harris’s Rudimentary Magnetism (London, 1872, p. 10).

“In the Memoirs of the Academy of Sciences for 1731, we find an account of a large bell at Marseilles having an axis of iron: this axis rested on stone blocks, and threw off from time to time great quantities of rust, which, mixing with the particles of stone and the oil used to facilitate the motion, became conglomerated into a hardened mass: this mass had all the properties of the native magnet. The bell is supposed to have been in the same position for 400 years.”

[214] Page 142, line 13. Page 142, line 15. tunc planetæ & corpora cœlestia.—Gilbert’s extraordinary detachment from all metaphysical and ultra-physical explanations of physical facts, and his continual appeal to the test of experimental evidence, enabled him to lift the science of the magnet out of the slough of the dark ages. This passage, however, reveals that he still gave credence to the nativities of judicial Astrology, and to the supposed influence of the planets on human destiny.

[215] Page 144, line 14. Page 144, line 14. ijdem.—The editions of 1628 and 1633 erroneously read iisdem.

[216] Page 147, line 27. Page 147, line 29. ex optimo aciario.—Gilbert recommended that the compass-needle should be of the best steel. Though the distinction between iron and steel was not at this time well established, there is no reason to doubt that by aciarium was meant edge-steel as used for blades. Barlowe, in his Magneticall Advertisements (Lond., 1616), p. 66, gives minute instructions for the fashioning of the compass-needle. He gives the preference to a pointed oval form, and describes how the steel must be hardened by heating to whiteness and quenching in water, so that it is “brickle in a manner as glass it selfe,” and then be tempered by reheating it over a bar of red hot iron until it is let down to a blue tint. Savery (Philos. Trans., 1729) appears to have been the first to make a systematic examination of the magnetic differences between hard steel and soft iron.

Instructions for touching the needle are given in the Arte de Nauegar of Pedro de Medina (Valladolid, 1545, lib. vi., cap. 1).

[217] Page 149, line 8. Page 149, line 9. per multa sæcula.—Compare Porta’s assertion (p. 208, English edition) “iron once rubbed will hold the vertue a hundred years.” Clearly not a matter within the actual experience of either Porta or Gilbert.

[218] Page 153, line 2. Page 153, line 2. Cardani ab ortu stellæ in cauda vrsæ.—What Cardan said (De Subtilitate, Edit. citat., p. 187) was: “ortum stellæ in cauda ursæ minoris, quæ quinque partibus orientalior est polo mundi, respicit.”

[219] Page 153, line 21. Page 153, line 26. sequitur quod versus terram magnam, siue continentem … à vero polo inclinatio magnetica fiat.—Gilbert {55}goes on to point out how, at that date, all the way up the west European coast from Morocco to Norway, the compass is deflected eastward, or toward the elevated land. He argued that this was a universal law.

In Purchas his Pilgrimes (Lond., 1625), in the Narrative, in vol. iii., of Bylot and Baffin’s Voyage of 1616, there is mentioned an island between Whale-Sound and Smith’s Sound, where there had been observed a larger variation than in any other part of the world. Purchas, in a marginal note, comments on this as follows: “Variation of the Compass 56° to the West, which may make questionable D. Gilbert’s rule, tom. 1., l. 2, c. 1, that where more Earth is more attraction of the Compass happeneth by variation towards it. Now the known Continents of Asia, &c., must be unspeakably more than here there can be, & yet here is more variation then about Jepan, Brasil, or Peru, &c.”

Gilbert’s view was in truth founded on an incomplete set of facts. At that time, as he tells us, the variation of the compass at London was 11⅓ degrees eastward. But he did not know of the secular change which would in about fifty-seven years reduce that variation to zero. Still less did he imagine that there would then begin a westward variation which in the year 1816 should reach 24° 30’, and which should then steadily diminish so that in the year 1900 it should stand at 16° 16’ westward. For an early discussion of the changes of the variation see vol. i. of the Philosophical Transactions (Abridged), p. 188. Still earlier is the classical volume of Henry Gellibrand, A Discovrse Mathematical on the Variation of the Magneticall Needle (Lond., 1635). Gilbert heads chapter iii. of book iiii. (p. 159) with the assertion Variatio uniuscuiusque loci constans est, declaring that to change it would require the upheaval of a continent. Gellibrand combats this on p. 7 of the work mentioned. He says:

“Thus hitherto (according to the Tenents of all our Magneticall Philosophers) we have supposed the variations of all particular places to continue one and the same. So that when a Seaman shall happly returne to a place where formerly he found the same variation, he may hence conclude he is in the same former Longitude. For it is the Assertion of Mr. Dr. Gilberts. Variatio vnicuiusq; Loci constans est, that is to say, the same place doth alwayes retaine the same variation. Neither hath this Assertion (for ought I ever heard) been questioned by any man. But most diligent magneticall observations have plainely offred violence to the same, and proved the contrary, namely that the variation is accompanied with a variation.”

In 1637 Henry Bond wrote in the Sea-Mans Kalendar that in the year 1657 the variation would be zero at London. Compare Bond’s Longitude Found (Lond., 1676, p. 3).

As to inconstancy of the variation in one place see further Fournier’s Hydrographie (Paris, 1667, liv. xi., ch. 12, p. 413), and Kircher, Magnes (Colon. Agripp., 1643, p. 418).

[220] Page 157, line 4. Page 157, line 5. perfecto.—Though this word is thus in all editions, it ought to stand perfectâ, as in line 10 below.

[221] Page 157, line 11. Page 157, line 13. varietas, for variatio.

[222] Page 160, line 20. Page 160, line 23. in Borrholybicum.—This name for the North-west, or North-North-West, is rarely used. It is found on the chart or windrose of the names of the winds on pp. 151 and 152 of the Mécometrie de l’Eyman of G. Nautonier (1602). Here the name Borrolybicus is given as a synonym for Nortouest Galerne, or Ὀλυμπιάς, while the two winds on the points next on the western and northern sides respectively are called Upocorus and Upocircius.


In Swan’s Specvlvm Mundi (Camb., 1643, p. 174) is this explanation: “Borrholybicus is the North-west wind.”

In Kircher’s Magnes (Colon. Agripp., 1643, p. 434) is a table of the names of the thirty-two winds in six languages, where Borrolybicus is given as the equivalent of Maestro or North-West.

[223] Page 161, line 2. Page 161, line 2. Insula in Oceano variationem non mutat.—The conclusions derived from the magnetic explorations of the Challenger expedition, 1873-1876, are briefly these: That in islands north of the magnetic equator there is a tendency to produce a local perturbation, attracting the north-seeking end of the needle downwards, and horizontally towards the higher parts of the land; while south of the magnetic equator, the opposite effects are observed. (See Challenger Reports, Physics and Chemistry, vol. ii., part vi., Report on the Magnetical Results by Staff-Commander Creak, F.R.S.)

[224] Page 162, line 2. Page 162, line 3. quarè & respectiuum punctum … excogitauit.—The passage referred to is in The newe Attractiue of Robert Norman (Lond., 1581), chap. vi.

“Your reason towards the earth carrieth some probabilitie, but I prove that there be no Attractive, or drawing propertie in neyther of these two partes, then is the Attractive poynt lost, and falsly called the poynt Attractive, as shall be proved. But because there is a certayne point that the Needle alwayes respecteth or sheweth, being voide and without any Attractive propertie: in my judgment this poynt ought rather to bee called the point Respective … This Poynt Respective, is a certayne poynt, which the touched Needle doth alwayes Respect or shew …”

[225] Page 165, line 2. Page 165, line 2. De pyxidis nauticæ vsitatæ compositione.—Gilbert’s description of the usual construction of the mariner’s compass should be compared with those given by Levinus Lemnius in The Secret Miracles of Nature (London, 1658); by Lipenius in Navigatio Salomonis Ophiritica (Witteb., 1660, p. 333); and with that given in Barlowe’s Navigators Supply (London, 1597). See also Robert Dudley’s Dell’ Arcano del Mare (Firenze, 1646).

[226] Page 165 deals with the construction; the process of magnetizing by the loadstone had already been discussed in pp. 147 to 149. It is interesting to see that already the magnetized part attached below the compass-card was being specialized in form, being made either of two pieces bent to meet at their ends, or of a single oval piece with elongated ends. The marking of the compass-card is particularly described. It was divided into thirty-two points or “winds,” precisely as the earlier “wind-rose” of the geographers, distinguisht by certain marks, and by a lily—or fleur-de-lys—indicating the North. Stevin in the Havenfinding Art (London, 1599), from which work the passage on p. 167 is quoted, speaking on p. 20 of “the Instrument which we call the Sea-directorie, some the nautical box, … or the sea compasse,” mentions the “Floure de luce” marking the North.

The legend which assigns the invention of the compass to one Goia or Gioja of Amalfi in 1302 has been already discussed in the Note to page 4. Gilbert generously says that in spite of the adverse evidence he does not wish to deprive the Amalfians of the honour of the construction adopted in the compasses used in the Mediterranean. But Baptista Porta the Neapolitan, who wrote forty years before Gilbert, discredited the legend. “Flavius saith, an Italian found it out first, whose name was Amalphus, born in our {57}Campania. But he knew not the Mariners Card, but stuck the needle in a reed, or a piece of wood, cross over; and he put the needles into a vessel full of water that they might flote freely.” (Porta’s Natural Magick, English translation, London, 1658, p. 206.) See also Lipenius (op. citat. p. 390).

The pivotting of the needle is expressly described in the famous Epistle on the Magnet of Peter Peregrinus, which was written in 1269. Gasser’s edition, Epistola Petri Peregrini … de magnete, was printed in Augsburg in 1558. In Part II., cap. 2, of this letter, a form of instrument is described for directing one’s course to towns and islands, and any places in fact on land or sea. This instrument consists of a vessel like a turned box (or pyxis) of wood, brass, or any solid material, not deep, but sufficiently wide, provided with a cover of glass or crystal. In its middle is arranged a slender axis of brass or silver, pivotted at its two ends into the top and the bottom of the box. This axis is pierced orthogonally with two holes, through one of which is passed the steel needle, while through the other is fixed square across the needle another stylus of silver or brass. The glass cover was to be marked with two cross lines north-south and east-west; and each quadrant was to be divided into ninety degrees. This the earliest described pivotted compass was therefore of the cross-needle type, a form claimed as a new invention by Barlowe in 1597. The first suggestion of suspending a magnetic needle by a thread appears to be in the Speculum Lapidum of Camillus Leonardus (Venet., 1502, fig. k ij, lines 25-31): “Nã tacto ferro ex una pte magnetis ex opposita eius pte appropinquato fugat: ut expiẽtia docet de acu appenso filo.”

The earliest known examples of the “wind-rose” are those in certain parchment charts preserved in the Biblioteca Marciana in Venice. These go back to 1426 or 1436, the best being ascribed to Andrea Bianco. They have the North indicated by a fleur-de-lys, a trident, a simple triangle, or a letter T; while the East is distinguisht by a cross. The West is marked with a P. (see Fincati, op. citat.). The eight marks in order, clock wise, run thus,

Lily. (or T). G. Cross. (or L) S. O. A (or L). P. M.

The letters correspond to the Italian names of the principal winds:

Tramontano North. Greco North-East. Levante East. Sirocco South-East. Ostro South. Africo or Libeccio South-West. Ponente West. Maestro North-West. Wind-roses marked with the names of the minor winds are found in Nautonier’s Mécometrie de l’Eyman (Vennes, 1602-1604, pp. 151-152), and Kircher’s Magnes Siue de Arte Magnetica (Colon. Agripp., 1643, p. 432). The description above given of the early Venetian wind-roses exactly describes the compass-card as depicted by Pedro de Medina in his Arte de Nauegar (Valladolid, 1545, folio lxxx.), in the sixth book entitled “las aguias de navegar”; while in the Breve compendio de la sphera of Martin Cortes (Sevilla, 1551, cap. iii., de la piedrayman) a similar wind-rose, without the letters, is found.


In the De Ventis et navigatione of Michaele Angelo Blondo (Venet., 1546, p. 15) is given a wind-rose, described as “Pixis uel Buxolus instrumentum et dux nauigantium,” having twenty-six points inscribed with the names of the winds, there being six between north and east, and six between south and west, and only five in each of the other quadrants. In the middle is a smaller wind-rose exactly like the early Italian ones just mentioned.

In the Della Guerra di Rhodi of Jacobo Fontano (Venet., 1545, pages 71-74) is a chapter Dei Venti, e della Bvssola di nauicare di Giovanni Quintino, giving a wind-rose, and a table of the names of the winds, the north being indicated by a pointer, at the cusp of which are seven stars, and the west by an image of the sun. The other cardinal points are marked with letters.

Barlowe, in The Navigators Supply (Lond., 1597), speaks thus:

“The merueilous and diuine Instrument, called the Sayling Compasse (being one of the greatest wonders that this World hath) is a Circle diuided commonly into 32. partes, tearmed by our Seamen Windes, Rumbes, or Points of Compasse.”

It is a disputed point with whom the method of naming the winds originated. Some ascribe it to Charlemagne. Michiel Coignet (Instruction novvelle … touchant l’art de naviguer, Anvers, 1581, p. 7) ascribes it to Andronicus Cyrrhestes. See Varro, De Re Rustica, iii., 5, 17, and Vitruvius, i., 6, 4.

Gilbert’s complaint of the evil practice of setting the needles obliquely beneath the card, with the intention of allowing for the variation, is an echo of a similar complaint in Norman’s Newe Attractiue. In chapter x. of this work Norman thus enumerates the different kinds of compasses:

“Of these common Sayling Compasses, I find heere (in Europa) five sundry sortes or sets. The first is of Levant, made in Scicile, Genoüa, and Venice: And these are all (for the most parte) made Meridionally, with the Wyers directlye sette under the South, and North of the Compasse: And therefore, duely shewing the poynt Respective, in all places, as the bare Needle. And by this Compasse are the Plats made, for the most part of all the Levants Seas.

“Secondly, there are made in Danske, in the Sound of Denmarke, and in Flanders, that have the Wyers set at 3 quarters of a point to the Eastwards of the North of the compasse, and also some at a whole point: and by these Compasses they make both the Plats and Rutters for the Sound.

“Thirdly, there hath beene made in this Countrey particulary, for Saint Nicholas and Ruscia, Compasses set at 3 seconds of a point, and the first Plats of that Discoverie were made by this Compasse.

“Fourthly the Compasse made at Sevill, Lisbone, Rochell, Bourdeaux, Roan, and heere in England, are moste commonly set at halfe a point: And by this Compasse are the Plats of the East and West Indies made for their Pylotes, and also for our Coastes neere hereby, as France, Spayne, Portugall, and England: and therefore best of these Nations to bee used, because it is the most common sorte that is generally used in these Coastes.”

Bessard (op. citat., pages 22 and 48) gives cuts of compasses showing the needle displaced one rumbe to the East.

Gallucci, in his Ratio fabricandi horaria mobilia et permanentia cum magnetica acu (Venet., 1596), describes the needle as inclined 10 degrees from the south toward the south-west.

The frontispiece of the work of Pedro Nuñez, Instrumenta Artis Navigandi, Basil., 1592, depicts a compass with the lily set one point to the east.

Reibelt, De Physicis et Pragmaticis Magnetis Mysteriis (Herbipolis, 1731), depicts the compass with the needle set about 12 degrees to the East of North. See also Fournier, Hydrographie (Paris 1667); De Lanis, Magisterium Natvræ et Artis (Brixiæ, 1684); Milliet Deschales, Cursus seu Mundus {59}Mathematicus (Lugd., 1674). Both the latter works give pictures of the compass-cards as used in South Europe, and in North Europe, and of the various known shapes of needles.

[227] Page 168, line 29. Page 168, line 33. Directio igitur inualidior est propè polos. Here as in many passages direction means the force which directs. A similar usage prevails with the nouns variation and declination, meaning frequently the force causing variation or declination respectively.

Page 172, line 13. perquirere. The edition of 1633 reads perquirero, in error.

[228] Page 172, line 29. Page 172, line 33. Ad pyxidis nauticæ veræ & meridionalis formam … fiat instrumentum.—An excellent form of portable meridian compass, provided with sights for taking astronomical observations, is described by Barlowe (The Navigators Supply, London, 1597), and is depicted in an etched engraving. An identical engraving is repeated in Dudley’s Arcano del Mare (Firenze, 1646). Gilbert’s new instrument was considerably larger.

[229] Page 174, line 19. Page 174, line 21. addendo vel detrahendo prostaphæresin.—“Prosthaphæresis, conflata dictione, ex additione et subtractione speciebus logistices, nomen habet ab officio, quia vt in semicirculo altero ad æquabilem motum adijcitur, ita in altero subtrahitur, vt adparens motus ex æquabili taxetur: atque hinc fit, quòd quæ Prosthaphæresis dicitur Ptolemæo, ea vulgò æquatio vocetur.” (Stadius, Tabulæ Bergenses, Colon. Agripp., 1560, p. 37.)

[230] Page 174, line 28. Page 174, line 31. Stellæ Lucidæ.—According to Dr. Marke Ridley (Magneticall Animadversions, London, 1617, p. 9), this chapter xii. of book iv., with the Table of Stars, was written by Edward Wright, the author of the Prefatory Epistle of De Magnete. Wright was Lecturer on Navigation to the East India Company, and author of sundry treatises on Navigation.

[231] Page 187, line 14. Page 187, line 16. hic qui versus boream constitit … meridionalis est, non borealis, quem antè nos omnes existimabant esse borealem.—Earlier on, on pages 15 and 125, Gilbert had mentioned this point. His insistence caused Barlowe (Magneticall Aduertisements, 1616, p. 4) to speak of the south-pointing end of the needle as the “true North,” and thereby drew on himself the animadversions of Marke Ridley.

[232] Page 188, line 15. Page 188, line 16. in rectâ sphærâ.—See note to p. 134.

[233] Page 190, line 14. Page 190, line 19. declinans in Borealibus.—Dipping as it does in northern regions; that is, with the north-seeking or true-south pole downward.

[234] Page 195, line 20. Page 195, line 24. multa maiora pondera.—Many greater weights. All editions read multa, but the sense requires multo: “much greater weights.”

[235] Page 196, line 10. Page 196, line 12. constans est.—This must not be read “is constant,” for it is constant only in any given latitude.

[236] Page 196, line 15. Page 196, line 18. De proportione declinationis pro latitudinis ratione.—Gilbert here announces, and proceeds in the next seven pages to develop, the proposition that to each latitude there corresponds a constant dip to a particular number of degrees. If this were accurately so, then a traveller by merely measuring the dip would be able to ascertain, by calculation, by reference to tables, or by aid of some geometrical appliance, {60}the latitude of the place. In this hope Gilbert fought to perfect the dipping-needle; and he also worked out, on pages 199 and 200, an empirical theory, and a diagram. This theory was still further developed by him, and given to Thomas Blundevile (see the Note to p. 240). Briggs of Gresham College, on Gilbert’s suggestion, calculated a table of Dip and Latitude on this theory. It was found, however, that the observed facts deviated more or less widely from the theory. Kircher (Magnes, 1643, p. 368) gives a comparative table of the computed and observed values. Further discovery showed the method to be impracticable, and Gilbert’s hope remained unfulfilled.

[237] Page 197, line 18. Page 197, line 21. progressionis centri.—Note Gilbert’s precision of phrase.

[238] Page 200, line 12. Page 200, line 11. subintelligūtur.—This is printed subintelligitur, and is altered in ink in all copies of the folio edition. The editions of 1628 and 1633 read subintelliguntur. Similarly in line 14 the word ducit has had a small r added in ink, making it read ducitur, as also the other editions.

[239] Page 203. This figure of the experiment with the simple dipping needle suspended in water in a goblet is due to Robert Norman. In his Newe Attractiue (London, 1581, chap. vi.) he thus describes it:

“Then you shall take a deepe Glasse, Bowle, Cuppe, or other vessell, and fill it with fayre water, setting it in some place where it may rest quiet, and out of the winde. This done, cut the Corke circumspectly, by little and little, untill the wyre with the Corke be so fitted, that it may remain under the superficies of the water two or three inches, both ends of the wyer lying levell with the superficies of the water, without ascending or descending, like to the beame of a payre of ballance beeing equalie poysed at both ends.

“Then take out of the same the wyer without mooving the Corke, and touch it with the Stone, the one end with the South of the Stone, and the other end with the North, and then set it againe in the water, and you shall see it presentlie turne it selfe upon his owne Center, shewing the aforesay’d Declining propertie, without descending to the bottome, as by reason it should, if there were any Attraction downewards, the lower part of the water being neerer that point, then the superficies thereof.”

[240] Page 212, line 7. Page 212, line 8. ex altera parte.—The sense seems to require et altera parte, but all editions read ex.

[241] Page 213, line 1. Page 213, line 2. The passage here quoted from Dominicus Maria Ferrariensis, otherwise known as the astronomer Novara, does not occur in any known writing of that famous man. It is, however, quoted as being by Novara in at least three other writings of the same epoch. See the Tabulæ secvndorum mobilium coelestium of Maginus (Venet., 1585, p. 29, line 19 to p. 30, line 11); the Eratosthenes Batavvs of Willebrord Snell (Lugd. Batav., 1617, pp. 40-42); and the Almagesti novi (Pars Posterior) of Riccioli (Bonon., 1651, p. 348). The original document appears to have perisht. See a notice by M. Curtze in Boncompagni’s Bullettino di Bibliografia, T. iv., April, 1871.

[242] Page 214, line 26. Page 214, line 31. Philolaus Pythagoricus.

“Philolaüs a le premier dit que la terre se meut en cercle; d’autres disent que c’est Nicétas de Syracuse.”

“Les uns prétendent que le terre est immobile; mais Philolaüs le pythagoricien dit qu’elle se meut circulairement autour du feu (central) et suivant un cercle oblique, comme le soleil et la lune."—(Chaignet, Pythagore et la Philosophie pythagoricienne, Paris, 1873.)

It appears that the first of these dicta is taken from Diogenes Laërt., viii. 85; and the second from Plutarch, Placit. Philos., III. 7. The latter {61}passage may be compared with Aristotle, De Coelo, II. 13, who, referring to the followers of Pythagoras, says: “They say that the middle is fire, that the earth is a star, and that it is moved circularly about this centre; and that by this movement it produces day and night.”

[243] Page 214, line 34. Page 214, line 42. Copernicus.—His work is De revolutionibus orbium coelestium, libri vi. (Basil., 1566).

[244] Page 215, line 27. Page 215, line 24. quæ … in cælo varijs distantijs collocata sunt.—This remark appears to be Gilbert’s one contribution to the science of Astronomy; the stars having previously been regarded as fixed in the eighth sphere all at the same distance from the central earth, around which it revolved.

[245] Page 220, line 6. Page 220, line 6. quem nycthemeron vocamus.—The 1628 and 1633 editions read nyctemoron.

[246] Page 221, line 10. Page 221, line 11. poli verè oppositi sint.—For verè, the 1628 and 1633 editions read rectæ. All editions read sint, though sunt seems to make better sense.

[247] Page 223, line 7. Page 223, line 8. ad telluris conformitatem.—The word conformitas is unknown in classical Latin.

[248] Page 223, line 16. Page 223, line 17. Omitto quod Petrus Peregrinus constanter affirmat, terrellam super polos suos in meridiano suspensam, moveri circulariter integrâ revolutione 24 horis: Quod tamen nobis adhuc videre non contingit; de quo motu etiam dubitamus.

This statement that a spherical loadstone pivotted freely with its axis parallel to the earth’s axis will of itself revolve on its axis once a day under the control of the heavens, thus superseding clocks, is to be found at the end of chap. x. of Peregrinus’s Epistola De Magnete (Augsb., 1537).

Gilbert, who doubted this experiment because of the stone’s own weight is taken to task by Galileo, in the third of his Dialogues, for his qualified admission.

“I will speak of one particular, to which I could have wished that Gilbert had not lent an ear; I mean that of admitting, that in case a little Sphere of Loadstone might be exactly librated, it would revolve in it self; because there is no reason why it should do so” (p. 376 of Salusbury’s Mathematical Collections, London, 1661). The Jesuit Fathers who followed Gilbert, but rejected his Copernican ideas, pounced upon this pseudo-experiment, as though by disproving it they had upset the Copernican theory.

[249] Page 227, line 6. Page 227, line 7. This line is left out in the 1628 edition. In the 1633 edition it was also left out by the printer, and subsequently printed in in the margin, being page 219 of that edition.

[250] Page 234, line 35. Page 234, line 40. vt poli telluris respectus à polis.—If it may be permitted to read respectu for respectus the sense is improved, and the passage may then be translated thus: “that just as it was needful … that the poles of the Earth as to direction should be 23 degrees and more from the poles of the Ecliptick; so now, &c.”

[251] Page 237, line 19. Page 237, line 22. vt motus quidem obscuri saluarentur.—It has been conjectured that quidem is here a misprint for quidam, but the adverb quidem adds a satirical flavour to his argument against the folly of those who held the doctrine of the moving spheres. The verb salvare does not occur in classical Latin.

[252] Page 240, line 13. Page 240, line 17. à Copernico (Astronomiæ instauratore).—Gilbert was the first in England to uphold the doctrines of {62}Copernicus as to the motion of the earth on its axis and its revolution around the sun. He considered that his magnetic observations brought new support to that theory, and his views are quoted with approbation by Kepler, Epitome Astronomiæ Copernicanæ … Authore Ioanne Keplero … (Francofurti, 1635); and by Galileo, Dialogus de Systemate Mundi (Augustæ Treboc., 1635), an English translation of which appeared in Salusbury’s Mathematical Collections and Translations (London, 1661, pp. 364 to 377).

For this the book De Magnete was considered by many as heretical. Many of the copies existing in Italy are found to be either mutilated or else branded with a cross. For example, the copy in the library of the Collegio Romano in Rome has book VI. torn out. Galileo states that the Book of Gilbert would possibly never have come into his hands “if a Peripatetick Philosopher, of great fame, as I believe to free his Library from its contagion, had not given it me.” In England Barlowe, in his Magneticall Aduertisements (1616), expressly repudiated Gilbert’s Copernican notions, while praising his discoveries in magnetism. Marke Ridley, while upholding Gilbert’s views, in his Magneticall Animadversions (1617) did not consider him “skilfull in Copernicus.” The Jesuit writers, Cabeus, Kircher, Fonseca, Grandamicus, Schott, Leotaudus, Millietus, and De Lanis, one and all, who followed Gilbert in their magnetic writings, repudiated the idea that the magnetism of the globe gave support to the heretical modern Astronomy.

The works referred to are:

Cabeus, Philosophia Magnetica, in qua Magnetis natura penitus explicatur … auctore Nicolao Cabeo Ferrarensi Soc. Jesv. (Ferrariæ, 1629).

Kircher, Magnes, Siue de Arte Magnetica, Libri tres, Authore Athanasio Kirchero … e Soc. Iesv. (Romæ, 1641).

Grandamicus, Nova Demonstratio immobilitatis terræ petita ex virtute magnetica (Flexiæ, 1645). This work is most beautifully illustrated with copper-plate etchings of cupids making experiments with terrellas.

Schott, Gaspar, Thaumaturgus Physicus (Herbipolis, 1659).

Leotaudus, R. P. Vincentinii Leotavdi Delphinatis, Societ. Iesv., Magnetologia; in qva exponitvr Nova de Magneticis Philosophia, (Lvgdvni, 1668).

Millietus (Milliet Deschales), Cursus seu Mundus Mathematicus (Lugd., 1674), Tomus Primus, Tractatus de Magnete.

De Lanis, Magisterium Natvræ et Artis. Opus Physico-Mathematicvm P. Francisci Tertii de Lanis, Soc. Jesv. (Brixiæ, 1684).

[253] Page 240, line 24. Page 240, line 31. hic finem & periodum imponimus.

On February 13 [1601] Gilbert wrote to Barlowe (see Magneticall Aduertisements, p. 88):

“I purpose to adioyne an appendix of six or eight sheets of paper to my booke after a while, I am in hand with it of some new inventions, and I would haue some of your experiments, in your name and inuention put into it, if you please, that you may be knowen for an augmenter of that arte.”

This he never did. Perhaps his appointment (in February, 1601) as chief physician in personal attendance on the Queen interfered with the project; or his death, of the plague, in 1603, intervened before his intention had been carried into effect. But it is probable that the substance of the proposed additions is to be found in the chapter, publisht in Gilbert’s lifetime, in Blundevile’s Theoriques of the seuen Planets (London, 1602), thus described in the title-page of the work: “There is also hereto added, {63}The making, description, and vse, of two most ingenious and necessarie Instruments for Sea-men, to find out thereby the latitude of any Place vpon the Sea or Land, in the darkest night that is, without the helpe of Sunne, Moone, or Starre. First inuented by M. Doctor Gilbert, a most excellent Philosopher, and one of the ordinarie Physicians to her Maiestie: and now here plainely set downe in our mother tongue by Master Blundeuile.”

Of these two instruments the first consists of a mechanical device, with movable quadrants, to be cut out in cardboard, to be used in connection with the diagram of spiral lines which Gilbert had given as a folding plate between pages 200 and 201 of De Magnete. The intention was that the Sea-man having found by experiment with a dipping-needle the amount of the dip at any place, should by applying this diagram and its moving quadrants, ascertain the latitude, according to the theory expounded in book V., chap. VII.

The second instrument is a simplified portable dipping-needle, having the degrees engraved on the inner face of a cylindrical brass ring.

Blundevile adds a Table, calculated by Briggs, and “annexed to the former Treatise by Edward Wright, at the motion of the right Worshipful M. Doctor Gilbert.” This gives the values of the dip for different latitudes, as calculated from Gilbert’s empirical theory.

The other work, De Mundo nostro Sublunari Philosophia Nova, which Gilbert left in manuscript at his death, does not contain any additional matter on the magnetical investigations. Though it contains several direct references to the de Magnete, and particularly to Book VI. on the rotation of the earth, it is doubtful whether it was written after or before the publication of de Magnete. On pages 137 to 144 of the posthumous edition (Amsterdam, 1651) Gilbert refers to Peregrinus’s alleged perpetually revolving sphere, and denies its possibility. The greater part of the work is an anti-Aristotelian discussion on Air, Meteorology, Astronomy, the Winds, Tides, and Springs.

Any Comments? Post them below!