Chapter IV: Part 4

Hitherto we have declared the nature & powers of the loadstone, & also the properties & essence of iron; it now remains to show their mutual affinities, & kinship, so to speak, & how very closely conjoined these substances are. At the highest part of the terrestrial globe, or at its perishable surface & rind, as it were, these two bodies usually originate & are produced in one and the same matrix, as twins in one mine. Strong loadstones are dug up by themselves, weaker ones too have their own proper vein. Both are found in iron mines. Iron ore most often occurs alone, without strong loadstone (for the more perfect are rarely met with). Strong loadstone is a stone resembling iron; out of it is usually smelted the finest iron, which the Greeks call _stomoma_, the Latins _acies_, the Barbarians (not amiss) _aciare_, or _aciarium_. This same stone draws, repels, controls other loadstones, directs itself to the poles of the world, picks up smelted iron, and works many other wonders, some already set forth by us, but many more which we must demonstrate more fully. A weaker loadstone, however, will exhibit all these powers, but in a lesser degree; while iron ore, & also wrought iron (if they have been prepared) show their strength in all magnetick experiments not less than do feeble and weak * loadstones; & an inert piece of ore, & one possessed of no magnetick properties, & just thrown out[98] of the pit, when roasted in the fire & prepared with due art (by the elimination of humours & foreign excretions) awakes, and becomes in power & potency a magnet, * occasionally a stone or iron ore is mined, which attracts forthwith without being prepared: for native iron of the right colour attracts and governs iron magnetically. One form then belongs to the one mineral, one species, one self-same essence. For to me there seems to be a greater difference, & unlikeness, between the strongest {37} loadstone, & a weak one which scarce can attract a single chip of iron; between one that is stout, strong, metallick, & one that is soft, friable, clayey; amidst such variety of colour, substance, quality, & weight; than there is on the one hand between the best ore, rich in iron, or iron that is metallick from the beginning, and on the other the most excellent loadstone. Usually, too, there are no marks to distinguish them, and even metallurgists cannot decide between them, because they agree together in all respects. Moreover we see that the best loadstone and the ore of iron are both as it were distressed by the same maladies & diseases, both run to old age in the same way & exhibit the same marks of it, are preserved & keep their properties by the same remedies & safeguards; & yet again the one increases the potency of the other, & by artfully devised adjuncts marvellously intensifies, & exalts it. For both are impaired by the more acrid juices as by poisons, & the aqua fortis of the Chemists inflicts on both the same wounds, and when exposed too long to harm from the atmosphere, they both alike pine away, so to speak, & grow old; each is preserved by being kept in the dust & scrapings of the other; & when a fit piece of steel or iron is adjoined above its pole, the loadstone's vigour is augmented through the firm union. The loadstone is laid up in iron filings, not that iron is its food; as though loadstone were alive and needed feeding, as Cardan philosophizes[99]; nor yet that so it is delivered from the inclemency of the weather (for which cause it as well as iron is laid up in bran by Scaliger; mistakenly, however, for they are not preserved well in this way, and keep for years their own fixed forms): nor yet, since they remain perfect by the mutual action of their powders, do their extremities waste away, but are cherished & preserved, like by like. For just as in their own places, in the mines, bodies like to each other endure for many ages entire and uncorrupt, when surrounded by bodies of the same stuff, as the lesser interior parts in a great mass: so loadstone and ore of iron, when inclosed in a mound of the same material, do not exhale their native humour, do not waste away, but retain their soundness. A loadstone lasts longer in filings of smelted iron, & a piece of iron ore excellently also in dust of loadstone; as also smelted iron in filings of loadstone & even in those of iron. Then both these allied bodies have a true & just form of one & the same species; a form which until this day was considered by all, owing to their outward unlikeness & the inequality of the potency that is the same innate in both, to be different & unlike in kind; the smatterers not understanding that the same powers, though differing in strength, exist in both alike. And in fact they both are true & intimate parts of the earth, & as such retain the prime natural properties of mutually attracting, of moving, & of disposing themselves toward the position of the world, {38} and of the terrestrial globe; which properties they also impart to each other, and increase, confirm, receive, and retain each other's forces. The stronger fortifies the weaker, not as though aught were taken away from its own substance, or its proper vigour, nor because any corporeal substance is imparted, but the dormant virtue of the one is aroused by the other, without loss. For if with a single small stone you touch a thousand bits of iron for the use of mariners[100], that loadstone attracts iron no less strongly than before; with the same stone weighing one pound, any one will be able to suspend in the air a thousand pounds of iron. For if any one were to fix high up on the walls so many iron nails of so great a weight, & were to apply to them the same number of nails touched, according to the art, by a loadstone, they would all be seen to hang in the air through the force of one small stone. So this is not solely the action, labour, or outlay of the loadstone; but the iron, which is in a sense an extract from loadstone, and a fusion of loadstone into metal, & conceives vigour from it, & by proximity strengthens the magnetick faculties, doth itself, from whatever lode it may have come, raise its own inborn forces through the presence & contact of the stone, even when solid bodies intervene. Iron that has been touched, acts anew on another piece of iron by contact, & adapts it for magnetick movements, & this again a third. But if you rub with a loadstone any other metal, or wood, or bones, or glass, as they will not be moved toward any particular and determinate quarter of heaven, nor be attracted by any magnetick body, so they are able not to impart any magnetick property to other bodies or to iron itself by attrition, & by infection. Loadstone differs from iron ore, as also from some weaker magnets, in that when molten in the furnace into a ferric & metallick fused mass, it does not so readily flow & dissolve into metal; but is sometimes burnt to ashes in large furnaces; a result which it is reasonable to suppose arises from its having some kind of sulphureous matter mixed with it, or from its own excellence & simpler nature, or from the likeness & common form which it has with the common mother, the Great Magnet. For earths, and iron stones, magnets abounding in metal, are the more imbued & marred with excrementitious metallick humours, and earthy corruptions of substance, as numbers of loadstones are weaker from the mine; hence they are a little further remote from the common mother, & are degenerate, & when smelted in the furnace undergo fusion more easily, & give out a more certain metallick product, & a metal that is softer, not a tough steel. The majority of loadstones (if not unfairly burnt[101]) yield in the furnace a very excellent iron. But iron ore also agrees in all those primary qualities with loadstone; for both, being nearer and more closely akin to the earth above all bodies known to us, have in themselves {39} a magnetick substance, & one that is more homogenic, true & cognate with the globe of the earth; less infested & spoiled by foreign blemish; less confused with the outgrowths of earth's surface, & less debased by corrupt products. And for this reason Aristotle in the fourth book of his _Meteora_ seems not unfairly to separate iron from all the rest of the metals. Gold, he says, silver, copper, tin, lead, belong to water; but iron is of the earth. Galen, in the fourth chapter of _De Facultatibus Simplicium Medicamentorum_, says that iron is an earthy & dense body. Accordingly a strong loadstone is on our showing especially of the earth: the next place is occupied by iron ore or weaker loadstone; so the loadstone is by nature and origin[102]** of iron, and it and magnetick iron are both one in kind. Iron ore yields iron in furnaces; loadstone also pours forth iron in the furnaces, but of a much more excellent sort, that which is called steel or blade-edge; and the better sort of iron ore is a weak loadstone, the best loadstone being a most excellent ore of iron, in which, as is to be shown by us, the primary properties are grand and conspicuous. Weaker loadstone or iron ore is that in which these properties are more obscure, feeble, and are scarce perceptible to the senses.

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CHAP. XVII.

That the globe of the earth is magnetick, & a magnet; & _how in our hands the magnet stone has all the primary_ forces of the earth, while the earth by the _same powers remains constant in a fixed direction in the universe._

Prior to bringing forward the causes of magnetical motions, & laying open the proofs of things hidden for so many ages, & our experiments (the true foundations of terrestrial philosophy), we have to establish & present to the view of the learned our New & unheard of doctrine about the earth; and this, when argued by us on the grounds of its probability, with subsequent {40} experiments & proofs, will be as certainly assured as anything in philosophy ever has been considered & confirmed by clever arguments or mathematical proofs. The terrene mass, which together with the vasty ocean produces the sphærick figure & constitutes our globe, being of a firm & constant substance, is not easily changed, does not wander about, & fluctuate with uncertain motions, like the seas, & flowing waves: but holds all its volume of moisture in certain beds & bounds, & as it were in oft-met veins, that it may be the less diffused & dissipated at random. Yet the solid magnitude of the earth prevails & reigns supreme in the nature of our globe. Water, however, is attached to it, & as an appendage only, & a flux emanating from it; whose force from the beginning is conjoined with the earth through its smallest parts, and is innate in its substance. This moisture the earth as it grows hot throws off freely when it is of the greatest possible service in the generation of things. But the thews and dominant stuff of the globe is that terrene body which far exceeds in quantity all the volume of flowing streams and open waters (whatever vulgar philosophers may dream of the magnitudes and proportions of their elements), and which takes up most of the whole globe and almost fills it internally, and by itself almost suffices to endow it with sphærick shape. For the seas only fill certain not very deep or profound hollows, since they rarely go down to a depth of a mile and generally do not exceed a hundred or 50 fathoms. For so it is ascertained by the observations of seamen when by the plumb-line and sinker its abysms are explored with the nautical sounder; which depths relatively to the dimensions of the globe, do not much deform its globular shape. Small then appears to be that portion of the real earth that ever emerges to be seen by man, or is turned up; since we cannot penetrate deeper into its bowels, further than the wreckage of its outer efflorescence, either by reason of the waters which gush up in deep workings, as through veins, or for want of a wholesome air to support life in the miners, or on account of the vast cost that would be incurred in pumping out such huge workings[103], and many other difficulties; so that to have gone down to a depth of four hundred, or (which is of rarest occurrence) of five hundred fathoms[104] as in a few mines, appears to all a stupendous undertaking. But it is easy to understand how minute, how almost negligibly small a portion that 500 fathoms is of the earth's diameter, which is 6,872 miles. It is then parts only of the earth's circumference and of its prominences that are perceived by us with our senses; and these in all regions appear to us to be either loamy, or clayey, or sandy, or full of various soils, or marls: or lots of stones or gravel meet us, or beds of salt, or a metallick lode, and metals in abundance. In the sea and in deep waters, however, either reefs, and huge boulders, or smaller stones, or sands, or mud {41} are found by mariners as they sound the depths. Nowhere does the Aristotelian element of _earth_ come to light; and the Peripateticks are the sport of their own vain dreams about elements. Yet the lower bulk of the earth and the inward parts of the globe consist of such bodies; for they could not have existed, unless they had been related to and exposed to the air and water, and to the light and influences of the heavenly bodies, in like manner as they are generated, and pass into many dissimilar forms of things, and are changed by a perpetual law of succession. Yet the interior parts imitate them, and betake themselves to their own source, on the principle of terrene matter, albeit they have lost the first qualities and the natural terrene form, and are borne towards the earth's centre, and cohære with the globe of the earth, from which they cannot be wrenched asunder except by force. But the loadstone and all magneticks, not the stone only, but every magnetick homogenic substance, would seem to contain the virtue of the earth's core and of its inmost bowels, and to hold within itself and to have conceived that which is the secret and inward principle of its substance; and it possesses the actions peculiar to the globe of attracting, directing, disposing, rotating, stationing itself in the universe, according to the rule of the whole, and it contains and regulates the dominant powers of the globe; which are the chief tokens and proofs of a certain distinguishing combination, and of a nature most thoroughly conjoint. For if among actual bodies one sees something move and breathe, and experience sensations, and be inclined and impelled by reason, will one not, knowing and seeing this, conclude that it is a man or something rather like a man, than that it is a stone or a stick? The loadstone far excels all other bodies known to us in virtues and properties pertaining to the common mother: but those properties have been far too little understood or realized by philosophers: for to its body bodies magnetical rush in from all sides and cleave to it, as we see them do in the case of the earth. It has poles, not mathematical points, but natural termini of force excelling in primary efficiency by the co-operation of the whole: and there are poles in like manner in the earth which our forefathers sought ever in the sky: it has an æquator, a natural dividing line between the two poles, just as the earth has: for of all lines drawn by the mathematicians on the terrestrial globe, the æquator is the natural boundary, and is not, as will hereafter appear, merely a mathematical circle. It, like the earth, acquires Direction and stability toward North and South, as the earth does; also it has a circular motion toward the position of the earth, wherein it adjusts itself to its rule: it follows the ascensions and declinations of the earth's poles, and conforms exactly to the same, and by itself raises its own poles above the {42} horizon naturally according to the law of the particular country and region, or sinks below it. The loadstone derives temporary properties, and acquires its verticity from the earth, and iron is affected by the verticity of the globe even as iron is by a loadstone: Magneticks are conformable to and are regulated by the earth, and are subject to the earth in all their motions. All its movements harmonize with, and strictly wait upon, the geometry and form of the earth, as we shall afterwards prove by most conclusive experiments and diagrams; and the chief part of the visible earth is also magnetical, and has magnetick motions, although it be disfigured by corruptions and mutations without end. Why then do we not recognize this the chief homogenic substance of the earth, likest of substances to its inner nature and closest allied to its very marrow? For none of the other mixed earths suitable for agriculture, no other metalliferous veins, nor stones, nor sand, nor other fragments of the earth which have come to our view possess such constant and peculiar powers. And yet we do not assume that the whole interior of this globe of ours is composed of stones or iron (although Franciscus Maurolycus, that learned man, deems the whole of the earth's interior to consist of solid stone). For not every loadstone that we have is a stone, it being sometimes like a clod, or like clay and iron either firmly compacted together out of various materials, or of a softer composition, or by heat reduced to the metallick state; and the magnetick substance by reason of its location and of its surroundings, and of the metallick matrix itself, is distinguished, at the surface of the terrene mass, by many qualities and adventitious natures, just as in clay it is marked by certain stones and iron lodes. But we maintain that the true earth is a solid substance, homogeneous with the globe, closely coherent, endowed with a primordial and (as in the other globes of the universe) with a prepotent form; in which position it persists with a fixed verticity, and revolves with a necessary motion and an inherent tendency to turn, and it is this constitution, when true and native, and not injured or disfigured by outward defects, that the loadstone possesses above all bodies apparent to us, as if it were a more truly homogenic part taken from the earth. Accordingly native iron which _sui generis_ (as metallurgists term it), is formed when homogenic parts of the earth grow together into a metallick lode; Loadstone being formed when they are changed into metallick stone, or a lode of the finest iron, or steel: so in other iron lodes the homogenic matter that goes together is somewhat more imperfect; just as many parts of the earth, even the high ground, is homogenic but so much more deformate. Smelted iron is fused and smelted out of homogenic stuffs, and cleaves to the earth more tenaciously than the ores themselves. Such then is our earth in its {43} inward parts, possessed of a magnetick homogeneal nature, and upon such more perfect foundations as these rests the whole nature of things terrestrial, manifesting itself to us, in our more diligent scrutiny, everywhere in all magnetick minerals, and iron ores, in all clay, and in numerous earths and stones; while Aristotle's simple element, that most empty terrestrial phantom of the Peripateticks, a rude, inert, cold, dry, simple matter, the universal substratum, is dead, devoid of vigour, and has never presented itself to any one, not even in sleep, and would be of no potency in nature. Our philosophers were only dreaming when they spoke of a kind of simple and inert matter. Cardan does not consider the loadstone to be any kind of stone, "but a sort of perfected portion of some kind of earth that is absolute; a token of which is its abundance, there being no place where it is not found. And there is" (he says) "a power of iron in the wedded Earth which is perfect in its own kind when it has received fertilizing force from the male, that is to say, the stone of Hercules" (in his book _De Proportionibus_). And later: "Because" (he says) "in the previous proposition I have taught that iron is true earth." A strong loadstone shows itself to be of the inward earth, and upon innumerable tests claims to rank with the earth in the possession of a primary form, that by which Earth herself abides in her own station and is directed in her courses. Thus a weaker loadstone and every ore of iron, and nearly all clay, or clayey earth, and numerous other sorts (yet more, or less, owing to the different labefaction of fluids and slimes), keep their magnetick and genuine earth-properties open to view, falling short of the characteristic form, and deformate. For it is not iron alone (the smelted metal) that points to the poles, nor is it the loadstone alone that is attracted by another and made to revolve magnetically; but all iron ores, and other stones, as Rhenish slates and the black ones from Avignon (the French call them _Ardoises_) which they use for tiles, and many more of other colours and substances, provided they have been prepared; as well as all clay, grit[105], and some sorts of rocks, and, to speak more clearly, all the more solid earth that is everywhere apparent; given that that earth be not fouled with fatty and fluid corruptions; as mud, as mire, as accumulations of putrid matter; nor deformate by the imperfections of sundry admixtures; nor dripping with ooze, as marls; all are attracted by the loadstone, when simply prepared by fire, and freed from their refuse humour; and as by the loadstone so also by the earth herself they are drawn and controlled magnetically, in a way different from all other bodies; and by that inherent force settle themselves according to the orderly arrangement and fabric of the universe and of the Earth, as will appear {44} later. Thus every part of the earth which is removed from it exhibits by sure experiments every impulse of the magnetick nature; by its various motions it observes the globe of the earth and the principle common to both.

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{45}

BOOK SECOND.

_CHAP. I._

ON MAGNETICK Motions.

Divers things concerning opinions about the magnet-stone, and its variety, concerning its poles and its known faculties, concerning iron, concerning the properties of iron, concerning a magnetick substance common to both of these and to the earth itself, have been spoken briefly by us in the former book. There remain the magnetical motions, and their fuller philosophy, shown and demonstrated. These motions are incitements of homogeneal parts either among themselves or toward the primary conformation of the whole earth. Aristotle admits only two simple motions of his elements, from the centre and toward the centre; of light ones upward, heavy ones downward; so that in the earth there exists one motion only of all its parts towards the centre of the world,--a rude and inert precipitation. But what of it is light, and how wrongly it is inferred by the Peripateticks from the simple motion of the elements, and also what is its heavy part, we will discuss elsewhere. But now our inquiry must be into the causes of other motions, depending on its true form, which we have plainly seen in our magnetick bodies; and these we have seen to be present in the earth and in all its homogenic parts also. We have noticed that they harmonize with the earth, and are bound up with its forces. Five movements[106] or differences of motions are then observed by us: Coition (commonly called attraction), the {46} incitement to magnetick union; Direction towards the poles of the earth, and the verticity and continuance of the earth towards the determinate poles of the world; Variation, a deflexion from the meridian, which we call a perverted movement; Declination, a descent of the magnetick pole below the horizon; and circular motion, or Revolution. Concerning all these we shall discuss separately, and how they all proceed from a nature tending to aggregation, either by verticity or by volubility. Jofrancus Offusius[107] makes out different magnetick motions; a first toward a centre; a second toward a pole at seventy-seven degrees; a third toward iron; a fourth toward loadstone. The first is not always to a centre, but exists only at the poles in a straight course toward the centre, if the motion is magnetick; otherwise it is only motion of matter toward its own mass and toward the globe. The second toward a pole at seventy-seven degrees is no motion, but is direction with respect to the pole of the earth, or variation. The third and fourth are magnetick and are the same. So he truly recognizes no magnetick motion except the Coition toward iron or loadstone, commonly called attraction. There is another motion in the whole earth, which does not exist towards the terrella or towards its parts; videlicet, a motion of aggregation, and that movement of matter, which is called by philosophers a right motion, of which elsewhere.

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CHAP. II.

On the Magnetick Coition, and first on the Attraction of Amber, or more truly, on the _Attaching of Bodies to Amber_.