On the Magnet/I-7
and its uses.
- Here corn exults, and there the grape is glad,
- Here trees and grass unbidden verdure add.
- So mark how Tmolus yields his saffrone store,
- But ivory is the gift of Indian shore;
- With incense soft the softer Shebans deal;
- The stark Chalybeans' element is steel:
- With acrid castor reek the Pontic wares,
- Epirus wins the palm of Elian mares.
But what the Chemists (as Geber, and others) call fixed earthy sulphur in iron is nothing else than the homogenic earth-substance concreted by its own humour, amalgamated with a double fluid: a metallick humour is inserted along with a small quantity of the substance of the earth not devoid of humour. Wherefore the common saying that in gold there is pure earth, but in iron mostly impure, is wrong; as though there were indeed such a thing as natural earth, and that the globe itself were (by some unknown process of refining) depurate. In iron, especially in the best iron, there is earth in its own nature true and genuine; in the other metals there is not so much earth as that in place of earth and precipitates there are consolidated and (so to speak) fixed salts, which are efflorescences of the globe, and which differ also greatly  without the scales is found in England, which also they use for craftsmen's ruddle. In Sussex in England is a rich dusky ore and also one of a pale ashen hue, both of which on being dried for a time, or kept in moderate fires, presently acquire a liver-colour; here also is found a dusky ore square-shaped with a black rind of greater hardness. An ore having the appearance of liver is often variously intermingled with other stones: as also with the perfect loadstone which yields the best of iron. There is also a rusty ore of iron, one of a leaden hue tending to black, one quite black, or black mixed with true cobalt: there is another sort mixed either with pyrites, or with sterile plumbago. One kind is also like jet, another like bloodstone. The emery used by armourers, and by glaziers for glass-cutting, called amongst the English Emerelstone, by the Germans Smeargel, is ferruginous; albeit iron is extracted from it with difficulty, yet it attracts the versorium. It is now and then found in deep iron and silver diggings. Thomas Erastus says he had heard from a certain learned man of iron ores, of the colour of iron, but quite soft and fatty, which can be smoothed with the fingers like butter, out of which excellent iron can be smelted: somewhat the same we have seen found in England, having the aspect of Spanish soap. Besides the numberless kinds of stony ores, iron is extracted from clay, from clayey earth, from ochre, from a rusty matter deposited from chalybeate waters; In England iron is copiously extracted in furnaces often from sandy and clayey stones which appear to contain iron not more than sand, marl, or any other clay soils contain it. Thus in Aristotle's book De Mirabilibus Auscultationibus, "There is said" (he states) "to be a peculiar formation of Chalybean and Misenian iron, for instance the sort collected from river gravel; some say that after being simply washed it is smelted in the furnace; others declare that it and the sediment which subsides after several washings are cast in and purified together by the fire; with the addition of the stone pyrimachus which is found there in abundance." Thus do numerous sorts of things contain in their various substances notably and abundantly this element of iron and earth. However, there are many stones, and very common ones, found in every soil, also earths, and various and mixed materials, which do not hold rich substances, but yet have their own iron elements, and yield them to skilfully-made fires, yet which are left aside by metallick men because they are less profitable; while other soils give some show of a ferruginous nature, yet (being very barren) are hardly ever smelted down into iron; and being neglected are not generally known. Manufactured irons differ very greatly amongst themselves. For one kind is tenacious in its nature, and this is the best; one is of medium quality: another is brittle, and this is the worst. Sometimes the iron, by reason of the excellency of the ore, is wrought into steel, as to-day in Noricum. From the finest iron, too, well wrought and purged from all dross, or by being plunged in water after heating, there issues what the Greeks call στόμωμα; the Latins acies; others aciarium, such as was at times called Syrian, Parthian, Noric, Comese, Spanish; elsewhere it is named from the water in which it is so often plunged, as at Como in Italy, Bambola and Tarazona in Spain. Acies fetches a much larger price than mere iron. And owing to its superiority it better accords with the loadstone, from which more powerful quality it is often smelted, and it acquires the virtues from it more quickly, retains them longer at their full, and in the best condition for magnetical experiments. After iron has been smelted in the first furnaces, it is afterward wrought by various arts in large worksteads or mills, the metal acquiring consistency when hammered with ponderous blows, and throwing off the dross. After the first smelting it is rather brittle and by no means perfect. Wherefore with us (English) when the larger military guns are cast, they purify the metal from dross more fully, so that they may be stronger to withstand the force of the firing; and they do this by making it pass again (in a fluid state) through a chink, by which process it sheds its recremental matter. Smiths render iron sheets tougher with certain liquids, and by blows of the hammer, and from them make shields and breastplates that defy the blows of battle-axes. Iron becomes harder through skill and proper tempering, but also by skill turns out in a softer condition and as pliable as lead. It is made hard by the action of certain waters into which while glowing it is plunged, as at Bambola and Tarazona in Spain: It grows soft again, either by the effect of fire alone, when without hammering and without water, it is left to cool by itself; or by that of grease into which it is plunged; or (that it may the better serve for various trades) it is tempered variously by being skilfully besmeared. Baptista Porta expounds this art in book 13 of his Magia Naturalis. Thus this ferric and telluric nature is included and taken up in various bodies of stones, ores, and earths; so too it differs in aspect, in form, and in efficiency. Art smelts it by various processes, improves it, and turns it, above all material substances, to the service of man in trades and appliances without end. One kind of iron is adapted for breastplates, another serves as a defence against shot, another protects against swords and curved blades (commonly called scimitars), another is used for making swords, another for horseshoes. From iron are made nails, hinges, bolts, saws, keys, grids, doors, folding-doors, spades, rods, pitchforks, hooks, barbs, tridents, pots, tripods, anvils, hammers, wedges, chains, hand-cuffs, fetters, hoes, mattocks, sickles, baskets, shovels, harrows, planes, rakes, ploughshares, forks, pans, dishes, ladles, spoons, spits, knives, daggers, swords, axes, darts, javelins, lances, spears, anchors, and much ship's gear. Besides these, balls, darts, pikes, breastplates, helmets, cuirasses, horseshoes, greaves, wire, strings of musical instruments, chairs, portcullises, bows, catapults, and (pests of human kind) cannon, muskets, and cannon-balls, with endless instruments unknown to the Latins: which things I have rehearsed in order that it may be understood how great is the use of iron, which surpasses a hundred times that of all the other metals; and is day by day being wrought by metal-workers whose stithies are found in almost every village. For this is the foremost of metals, subserving many and the greatest needs of man, and abounds in the earth above all other metals, and is predominant. Wherefore those Chemists are fools who think that nature's will is to perfect all metals into gold; she might as well be making ready to change all stones to diamonds, since diamond surpasses all in splendour and hardness, because gold excels in splendour, gravity, and density, being invincible against all deterioration. Iron as dug up is therefore, like iron that has been smelted, a metal, differing a little indeed from the primary homogenic terrestrial body, owing to the metallick humour it has imbibed; yet not so alien as that it will not, after the manner of refined matter, admit largely of the magnetick forces, and may be associated with that prepotent form belonging to the earth, and yield to it a due submission.in firmness and consistency: In the mines their force rises up along with a twofold humour from the exhalations, they solidify in the underground spaces into metallic veins: so too they are also connate by virtue of their place and of the surrounding bodies, in natural matrices, and take on their specific forms. Of the various constitutions of loadstones and their diverse substances, colours, and virtues, mention has been made before: but, now having stated the cause and origin of metals, we have to examine ferruginous matter not as it is in the smelted metal, but as that from which the metal is refined. Quasi-pure iron is found of its proper colour and in its own lodes; still, not as it will presently be, nor as adapted for its various uses. It is sometimes dug up covered with white silex or with other stones. It is often the same in river sand, as in Noricum. A nearly pure ore of iron is now often dug up in Ireland, which the smiths, without the labours of furnaces, hammer out in the smithy into iron implements. In France iron is very commonly smelted out of a liver-coloured stone, in which are glittering scales; the same kind
The page and line references given in these notes are in all cases first to the Latin edition of 1600, and secondly to the English edition of 1900.
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 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.