Superphysics Superphysics
Chapter 4b

What is Magnetick Force & Form and the cause of the Coition?

by Gilbert
6 minutes  • 1161 words

When iron is smelted out of its own ore, or steel (the more noble kind of iron) out of its ore, that is, out of loadstone, the material is loosed by the force of the fire, and flows away, and iron as well as steel flow out from their dross and are separated from it.

The dross is either spoiled by the force of the fire and rendered useless, or is a kind of dregs of a certain imperfection and of mixture in the prominent parts of the earth.

The material therefore is a purified one, in which the metallick parts, which are now mixed up by the melting, since those special forces of its form are confused and uncertain, by the approach of a loadstone are called back to life, as if to a kind of disponent form and integrity. The material is thus awakened and moves together into unity, the bond of the universe and the essential for its conservation.

On this account and by the purging of the material into a cleaner body, the loadstone gives to the iron a greater force of attracting than there is in itself. For if iron dust *or an iron nail be placed over a large loadstone, a piece of iron joined to it takes away the filings and nail from the loadstone and retains them so long as it is near the loadstone; wherefore iron attracts iron more than loadstone does, if it have been conformed by a loadstone and remains within the orbe of its communicated form.

A piece of iron even, skilfully placed near the pole of a loadstone, lifts up more than the loadstone.

Therefore the material of its own ore is better, and by the force of fire steel and iron are re-purged; and they are again impregnated by the loadstone with its own forms; therefore they move towards it by a spontaneous {70}approach as soon as they have entered within the orbe of the magnetick forces, because they were possessed by it before, connected and united with it in a perfect union; & they have immediately an absolute continuity within that orbe, & have been joined on account of their harmony, though their bodies may have been disjoined.

For the iron is not taken possession of and allured by material effluvia, after the manner of electricks, but only by the immaterial action of its form or an incorporeal progression, which in a piece of iron as its subject acts and is conceived, as it were, in a continuous homogeneous body, and does not need more open ways.

Therefore (though the most solid substances be interposed) the iron is still moved and attracted, and by the presence of loadstone the iron moves and attracts the loadstone itself, and by mutual forces a concurrency is made towards unity, which is commonly called attraction of the iron. But those formal forces pass out and are united to one another by meeting together; a force also, when conceived in the iron, begins to flow out without delay. But Julius Scaliger, who by other examples contends that this theory is absurd, makes in his 344th Exercise a great mistake.

For the virtues of primary bodies are not to be compared with bodies formed from and mixed with them. He would now have been able (had he been still alive) to discern the nature of effused forms in the chapter on forms effused by spherical magneticks. But if iron is injured somewhat by rust, it is affected either only slightly or not at all by the stone. For the metal is spoiled when eaten away and deformed by external injuries or by lapse of time (just as has been said about the loadstone), and it loses its prime qualities which are conjoined to its form; or, being worn out by age, retains them in a languid and weak condition; indeed it cannot be properly re-formed, when it has been corrupted.

But a powerful and fresh loadstone attracts sound and clean pieces of iron, and those pieces of iron (when they have conceived strength) have a powerful attraction for other iron wires and iron nails, not only one at a time, but even successively one behind another, three, four or five, end to end, sticking and hanging in order like a chain. The loadstone, however, would not attract the last one following in such a row, if there were no nails between. Drawing of nails by loadstone.A loadstone placed as at A draws a nail or a bar B; similarly behind B it draws C; and after C, D. But the nails B and C being removed, the loadstone A, if it remain at the same distance, does not raise the nail D into the air.

This occurs for this reason: because in the case of a continuous row of nails the presence of the loadstone A, besides its own powers, raises the magnetick natures of the iron works B and C, and makes them, as it were, forces auxiliary to itself. But B and C, like a continuous magnetical body, extend as far as {71}D the forces by which D is taken and conformed, though they are weaker than those which C receives from B. And those iron nails indeed from that contact only, and from the presence of the loadstone even without contact, acquire powers which they retain in their own bodies, as will be demonstrated most clearly in the passage on Direction. For not only whilst the stone is present does the iron assume these powers, and take them, as it were, vicariously from the stone, as Themistius lays down in his 8th book on Physicks[161].

The best iron, when it has been melted down (such is steel), is allured by a loadstone from a greater distance, is raised though of greater weight, is held more firmly, assumes stronger powers than the common and less expensive, because it is cast from a better ore or loadstone, imbued with better powers. But what is made from more impure ore turns out weaker and is moved more feebly. As to Fracastorio’s[162] statement that he saw a piece of loadstone draw a loadstone by one of its faces, but not iron; by another face iron, but not loadstone; by another both; which he says is an indication that in one part there is more of the loadstone, in another more of the iron, in another both equally, whence arises that diversity of attraction; it is most incorrect and badly observed on the part of Fracastorio, who did not know how to apply skilfully loadstone to loadstone. A loadstone draws iron and also a loadstone, if both are suitably arranged and free and unrestrained. That is removed more quickly from its position and place which is lighter; for the heavier bodies are in weight, the more they resist; but the lighter both moves itself to meet the heavier and is allured by the other.

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