Chapter III: Part 3

For that now we have declared the origin and nature of the loadstone, we think it necessary first to add a history of iron and to indicate the hitherto unknown forces of iron, before this our discourse goes on to the explanation of magnetick difficulties and demonstrations, and to deal with the coitions and harmonies of loadstone with iron. Iron is by all reckoned in the class of metals, and is a metal livid in colour, very hard, glows red-hot before it melts, being most difficult of fusion, is beaten out under the hammer, and is very resonant. Chemists say that if a bed of fixed earthy sulphur be combined with fixed earthy quicksilver, and the two together are neither pure white but of a livid whiteness, if the sulphur prevail, iron is formed. For these stern masters of metals who by many inventions twisting them about, pound, calcine, dissolve, sublime, and precipitate, decide that this metal, both on account of the earthy sulphur and of the earthy mercury, is more truly a son of the earth than any other; they do not even think gold or silver, lead, tin, or copper itself so earthy; for that reason it is not smelted except in the hottest furnaces, with bellows; and when thus fused, on having again grown hard it is not melted again without heavy labour; but its slag with the utmost difficulty. It is the hardest of metals, subduing and breaking all things, by reason of the strong concretion of the more earthy matter. Wherefore we shall better understand what iron is, when we shall declare what are the causes and substance of metals, in a different way from those who before our time have considered them. Aristotle takes the material of the metals to be vapour. The chemists in chorus pronounce their actual elements to be sulphur and quicksilver. Gilgil Mauritanus gives it as ashes moistened with water. Georgius Agricola makes it out to be water and earth mixed; nor, to be sure, is there any difference between his opinion and the position taken by Mauritanus. But ours is that metals arise and effloresce at the summits of the earth's globe, being distinguished each by its own form, like some of the other substances dug out of it, and all bodies around us. The earth's globe does not consist of ashes or inert dust. Nor is fresh water an element, but a more simple consistency of evaporated fluids of the earth. Unctuous bodies, fresh water devoid of properties, quicksilver and sulphur, none of these are principia of metals: these latter, {20} things are the results of a different nature, they are neither constant nor antecedent in the course of the generation of metals. The earth emits various humours, not begotten of water nor of dry earth, nor from mixtures of these, but from the substance of the earth itself: these humours are not distinguished by contrary qualities or substance, nor is the earth a simple substance, as the Peripateticks dream. The humours proceed from vapours sublimated from great depths; all waters are extracts and, as it were, exudations from the earth. Rightly then in some measure does Aristotle make out the matter of metals to be that exhalation which in continuance thickens in the lodes of certain soils: for the vapours are condensed in places which are less hot than the spot whence they issued, and by help of the nature of the soils and mountains, as in a womb, they are at fitting seasons congealed and changed into metals: but it is not they alone which form ores, but they flow into and enter a more solid material, and so form metals. So when this concreted matter has settled down in more temperate beds, it begins to take shape in those tepid places, just as seed in the warm womb, or as the embryo acquires growth: sometimes the vapour conjoins with suitable matter alone: hence some metals are occasionally though rarely dug up native, and come into existence perfect without smelting: but other vapours which are mixed with alien soils require smelting in the way that the ores of all metals are treated, which are rid of all their dross by the force of fires, and being fused flow out metallick, and are separated from earthy impurities but not from the true substance of the earth. But in so far as that it becomes gold, or silver, or copper, or any other of the existing metals, this does not happen from the quantity or proportion of material, nor from any forces of matter, as the Chemists fondly imagine; but when the beds and region concur fitly with the material, the metals assume forms from the universal nature by which they are perfected; in the same manner as all the other minerals, plants, and animals whatever: otherwise the species of metals would be vague and undefined, which are even now turned up in such scanty numbers that scarce ten kinds are known. Why, however, nature has been so stingy as regards the number of metals, or why there should be as many as are known to man, it is not easy to explain; though the simple-minded and raving Astrologers refer the metals each to its own planet. But there is no agreement of the metals with the planets, nor of the planets with the metals, either in numbers or in properties. For what connexion is there of iron with Mars? unless it be that from the former numerous instruments, particularly swords and engines of war, are fashioned. What has copper to do with Venus? or how does tin, or how does spelter correspond with Jupiter? They should rather be dedicated to Venus. But this is old wives' talk. Vapour is then a remote cause in the generation of the metals; the fluid condensed from {21} vapours is a more proximate one, like the blood and semen in the generation of animals. But those vapours and juices from vapours pass for the most part into bodies and change them into marcasites and are carried into lodes (for we have numerous cases of wood so transmuted), the fitting matrices of bodies, where they are formed as metals. They enter most often into the truer and more homogeneal substance of the globe, and in the process of time a vein of iron results; loadstone is also produced, which is nought else than a noble kind of iron ore: and for this reason, and on account of its substance being singular, alien from all other metals, nature very rarely, if ever, mixes with iron any other metal, while the other metals are very often minutely mixed, and are produced together. Now when that vapour or those juices happen to meet, in fitting matrices, with efflorescences deformed from the earth's homogenic substance, and with divers precipitates (the forms working thereto), the remainder of the metals are generated (a specifick nature affecting the properties in that place). For the hidden primordial elements of metals and stones lie concealed in the earth, as those of herbs and plants do in its outer crust. For the soil dug out of a deep well, where would seem to be no suspicion of a conception of seed, when placed on a very high tower, produces, by the incubation of sun and sky, green herbage and unbidden weeds; and those of the kind which grow spontaneously in that region, for each region produces its own herbs and plants, also its own metals.

_[70]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 {22} 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[71] without the scales is found in England, which also they use for craftsmen's ruddle[72]. In Sussex in England[73] 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_[74], "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 {23} 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 [Greek: stomôma]; 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[75], 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 {24} (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[76] 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.

* * * * * {25}

CHAP. VIII.

In what countries and districts iron _originates._

Plenty of iron mines exist everywhere, both those of old time recorded in early ages by the most ancient writers, and the new and modern ones. The earliest and most important seem to me to be those of Asia. For in those countries which abound naturally in iron, governments and the arts flourished exceedingly, and things needful for the use of man were discovered and sought after. It is recorded to have been found about Andria, in the region of the Chalybes near the river Thermodon in Pontus; in the mountains of Palestine which face Arabia; in Carmania: in Africa there was a mine of iron in the Isle of Meroe; in Europe in the hills of Britain, as Strabo writes; in Hither Spain, in Cantabria. Among the Petrocorii and Cubi Biturges[77] (peoples of Gaul), there were worksteads in which iron used to be wrought. In greater Germany near Luna, as recorded by Ptolemy; Gothinian iron is mentioned by Cornelius Tacitus; Noric iron is celebrated in the verses of poets; and Cretan, and that of Euboea; many other iron mines were passed over by these writers or unknown to them; and yet they were neither poor nor scanty, but most extensive. Pliny[78] says that Hither Spain and all the district from the Pyrenees is ferruginous, and on the part of maritime Cantabria washed by the Ocean (says the same writer) there is (incredible to relate) a precipitously high mountain wholly composed of this material. The most ancient mines were of iron rather than of gold, silver, copper or lead; since mainly this was sought because of the demand; and also because in every district and soil they were easy to find, not so deep-lying, and less beset by difficulties. If, however, I were to enumerate modern iron workings, and those of this age and over Europe only, I should have to write a large and bulky volume, and sheets of paper would run short quicker than the iron, and yet for one sheet they could furnish a thousand worksteads. For amongst minerals, no material is so ample; all metals, and all stones distinct from iron, are outdone by ferric and ferruginous matter. For you will not readily find any region, and scarcely any country district over the whole of Europe (if you search at all deeply), that does not either produce a rich and abundant vein of iron or some soil containing or slightly charged with ferruginous stuff; and that this is {26} true any expert in the arts of metals and chemistry will easily find. Beside that which has ferruginous nature, and the metallick lode, there is another ferric substance which does not yield the metal in this way because its thin humour is burnt out by fierce fires, and it is changed into an iron slag like that which is separated from the metal in the first furnaces. And of this kind is all clay and argillaceous earth, such as that which apparently forms a large part of the whole of our island of Britain: all of which, if subjected very vehemently to intense heat, exhibits a ferric and metallick body, or passes into ferric vitreous matter, as can be easily seen in buildings in bricks baked from clay, which, when placed next the fires in the open kilns (which our folk call _clamps_)[79] and burned, present an iron vitrification, black at the other end. Moreover all those earths as prepared are drawn by the magnet, and like iron are attracted by it. So perpetual and ample is the iron offspring of the terrestrial globe. Georgius Agricola says that almost all mountainous regions are full of its ores, while as we know a rich iron lode is frequently dug in the open country and plains over nearly the whole of England and Ireland; in no other wise than as, says he, iron is dug out of the meadows at the town of Saga in pits driven to a two-foot depth. Nor are the West Indies without their iron lodes, as writers tell us; but the Spaniards, intent upon gold, neglect the toilsome work of iron-founding, and do not search for lodes and mines abounding in iron. It is probable that nature and the globe of the earth are not able to hide, and are evermore bringing to the light of day, a great mass of inborn matter, and are not invariably obstructed by the settling of mixtures and efflorescences at the earth's surface. It is not only in the common mother (the terrestrial globe) that iron is produced, but sometimes also in the air from the earth's exhalations, in the highest clouds. It rained iron in Lucania, the year in which M. Crassus was slain. The tale is told, too, that a mass of iron, like slag, fell from the air in the Nethorian forest, near Grina, and they narrate that the mass was many pounds in weight; so that it could neither be conveyed to that place, on account of its weight, nor be brought away by cart, the place being without roads. This happened before the civil war waged between the rival dukes in Saxony. A similar story, too, comes to us from Avicenna. It once rained iron in the Torinese[80], in various places (Julius Scaliger telling us that he had a piece of it in his house), about three years before that province was taken over by the king. In the year 1510 in the country bordering on the river Abdua (as Cardan writes[81] in his book _De Rerum Varietate_) there fell from the sky 1200 stones, one weighing 120 pounds, another 30 or 40 pounds, of a rusty iron colour and remarkably hard. These occurrences being rare are regarded as portents, like the showers of earth and stones mentioned in Roman history. But that it ever rained other metals is not {27} recorded; for it has never been known to rain from the sky gold, silver, lead, tin, or spelter[82]. Copper, however, has been at some time noticed to fall from the sky, and this is not very unlike iron; and in fact cloud-born iron of this sort, or copper, are seen to be imperfectly metallick, incapable of being cast in any way, or wrought with facility. For the earth hath of her store plenty of iron in her highlands, and the globe contains the ferric and magnetick element in rich abundance. The exhalations forcibly derived from such material may well become concreted in the upper air by the help of more powerful causes, and hence some monstrous progeny of iron be begotten.

* * * * *

CHAP. IX.

Iron ore attracts iron ore.

From various substances iron (like all the rest of the * metals) is extracted: such substances being stones, earth, and similar concretions which miners call veins because it is in veins[83], as it were, that they are generated. We have spoken above of the variety of these veins. If a properly coloured ore of iron and a rich one (as miners call it) is placed, as soon as mined, upon water in a bowl or any small vessel (as we have shown before in the case of a loadstone), it is attracted by a similar piece of ore brought near by hand, yet not so powerfully and quickly as one loadstone is drawn by another loadstone, but slowly and feebly. Ores of iron that are stony, cindery, dusky, red, and several more of other colours, do not attract one another mutually, nor are they attracted by the loadstone itself, even by a strong one, no more than wood, or lead, silver, or gold. Take those ores and burn, or rather roast them, in a moderate fire, so that they are not suddenly split up, or fly asunder, keeping up the fire ten or twelve hours, and gently increasing it, then let them grow cold, skill being shown in the direction in which they are placed: These ores thus prepared a loadstone will now draw, and they now show a mutual sympathy, and when skilfully arranged run together by their own forces.

* * * * *

{28}

CHAP. X.

*

Iron ore has poles, and acquires them, and settles _itself toward the poles of the universe_.

Deplorable is man's ignorance in natural science, and modern philosophers, like those who dream in darkness, need to be aroused, and taught the uses of things and how to deal with them, and to be induced to leave the learning sought at leisure from books alone, and that is supported only by unrealities of arguments and by conjectures. For the knowledge of iron (than which nothing is in more common use), and that of many more substances around us, remains unlearned; iron, a rich ore of which, placed in a vessel upon water, by an innate property of its own directs itself, just like the loadstone, North and South, at which points it rests, and to which, if it be turned aside, it reverts by its own inherent vigour. But many ores, less perfect in their nature, which yet contain amid stone or earthy substances plenty of iron, have no such motion; but when prepared by skilful treatment in the fires, as shown in the foregoing chapter, they acquire a polar vigour (which we call verticity[84]); and not only the iron ores in request by miners, but even earth merely charged with ferruginous matter, and many rocks, do in like manner tend and lean toward those portions of the heavens, or more truly of the earth, if they be skilfully placed, until they reach the desired location, in which they eagerly repose.

* * * * *

{29} CHAP. XI.

*

Wrought Iron, not excited by a loadstone, _draws iron_.

From the ore, which is converted, or separated, partly into metal, partly into slag, by the intense heat of fires, iron is smelted in the first furnaces in a space of eight, ten, or twelve hours, and the metal flows away from the dross and useless matter, forming a large and long mass, which being subjected to a sharp hammering is cut into parts, out of which when reheated in the second hearth of the forge, and again placed on the anvil, the smiths fashion quadrangular lumps, or more specially bars which are bought by merchants and blacksmiths, from which in smithies usually it is the custom to fashion the various implements. This iron we term _wrought_, and its attraction by the loadstone is manifest to all. But we, by more carefully trying everything[85], have found out that iron merely, by itself alone, not excited by any loadstone, not charged by any alien forces, attracts other iron; though it does not so eagerly snatch and suddenly pluck at it as would a fairly strong loadstone; this you may know thus: A small piece of cork, the size of a hazel-nut, rounded, is traversed by an iron wire up to the middle of the wire: when set swimming on still water apply to one end of it, close (yet so as not to touch), the end of another iron wire; and wire draws wire, and one follows the other when slowly drawn back, and this goes on up to the proper boundaries. Let A be the cork with the iron wire, B one end of it raised a little above the surface of the water, C the end of the second wire, showing the way in which B is drawn by C. You may prove it in another way in a larger body. Let a long bright iron rod (such as is made for hangings and window curtains) be hung in balance by a slender silken cord: to one end of this as it rests in the air bring a small oblong mass of polished iron, with its proper {30} end at the distance of half a digit. The balanced iron turns itself to the mass; do you with the same quickness draw back the mass in your hand in a circular path about the point of equilibrium of the suspension; the end of the balanced iron follows after it, and turns in an orbit.

* * * * *

CHAP. XII.

*

A long piece of Iron, even though not excited by a _loadstone, settles itself toward North and South._

Every good and perfect piece of iron, if drawn out in length, points North and South, just as the loadstone or iron rubbed with a magnetical body does; a thing that our famous philosophers have little understood, who have sweated in vain to set forth the magnetick virtues and the causes of the friendship of iron for the stone. You may experiment with either large or small iron works, and either in air or in water. A straight piece of iron six feet long of the thickness of your finger is suspended (in the way described in the foregoing chapter) in exact æquipoise by a strong and slender silken cord. But the cord should be cross-woven of several silk filaments, not twisted simply in one way; and it should be in a small chamber with all doors and windows closed, that the wind may not enter, nor the air of the room be in any way disturbed; for which reason it is not expedient that the trial should be made on windy days, or while a storm is brewing. For thus it freely follows its bent, and slowly moves until at length, as it rests, it points with its ends North and South, just as iron touched with a loadstone does in shadow-clocks, and in compasses, and in the mariners' compass. You will be able, if curious enough, to balance all at the same time by fine threads a number of small rods, or iron wires, or long pins with which women knit stockings; you will see that all of them at the same time are in accord, unless there be some error in this delicate operation: for unless you prepare everything fitly and skilfully, the labour will be void. Make trial of this thing in water also, which is done both more certainly and more easily. Let an iron wire two or three digits long, more or less, be passed through a round cork, so that it may just float upon water; and as soon as you have committed it to the waves, it turns upon its own centre, and one end tends to the North, the other to the South; the causes {31} of which you will afterwards find in the laws of the direction. This too you should understand, and hold firmly in memory, that * as a strong loadstone, and iron touched with the same, do not invariably point exactly to the true pole but to the point of the variation; so does a weaker loadstone, and so does the iron, which directs itself by its own forces only, not by those impressed by the stone; and so every ore of iron, and all bodies naturally endowed with something of the iron nature, and prepared, turn to the same point of the horizon, according to the place of the variation in that particular region (if there be any variation therein), and there abide and rest.

* * * * *

CHAP. XIII.

*

Wrought iron has in itself certain parts Boreal and Austral: A magnetick vigour, verticity, and determinate _vertices, or poles_.

Iron settles itself toward the North and South; not with one and the same point toward this pole or that: for one end of the piece of ore itself and one extremity also of a wrought-iron wire have a sure and constant destination to the North, the other to the South, whether the iron hang in the air, or float on water, be the iron large rods or thinner wires. Even if it be a little rod, or a wire ten or twenty or more ells in length; one end as a rule is Boreal, the other Austral. If you cut off part of that wire, and if the end of that divided part were Boreal, the other end (which was joined to it) will be Austral. Thus if you divide it into several parts, before making an experiment on the surface of water, you can recognize the vertex[86]. In all of them a Boreal end draws an Austral and repels a Boreal, and contrariwise, according to the laws magnetical. Yet herein wrought iron differs from the loadstone and from its own ore, inasmuch as in an iron ball of any size, such as those used for artillery or cannon, or bullets used for carbines or fowling-pieces, verticity is harder to acquire and is less apparent than in a piece of loadstone, or of ore itself, or than in a round loadstone. But in long and extended pieces of iron a power is at once discerned; the causes of which fact, and the methods by which it acquires its verticity and its poles without use of a loadstone, as well as the reasons for all the other obscure features of verticity, we shall set forth in describing the motion of direction.

* * * * *

{32} CHAP. XIIII.

Concerning other powers of loadstone, and its _medicinal properties_.

Dioscorides prescribes loadstone to be given with sweetened water, three scruples' weight, to expel gross humours. Galen writes that a like quantity of bloodstone avails. Others relate that loadstone perturbs the mind and makes folk melancholick, and mostly kills. Gartias ab Horto[87] thinks it not deleterious or injurious to health. The natives of East India tell us, he says, that loadstone taken in small doses preserves youth. On which account the aged king, Zeilam, is said to have ordered the pans in which his victuals were cooked to be made of loadstone. The person (says he) to whom this order was given told me so himself. There are many varieties of loadstone produced by differences in the mingling of earths, metals, and juices; hence they are altogether unlike in their virtues and effects, due to propinquities of places and of agnate bodies, and arising from the pits themselves as it were from the matrices being soul. One loadstone is therefore able to purge the stomach, and another to check purging, to cause by its fumes a serious shock to the mind, to produce a gnawing at the vitals, or to bring on a grave relapse; in case of which ills they exhibit gold and emerald, using an abominable imposture for lucre. Pure loadstone may, indeed, be not only harmless, but even able to correct an over-fluid and putrescent state of the bowels and bring them back to a better temperament; of this sort usually are the oriental magnets from China, and the denser ones from Bengal, which are neither misliking nor unpleasant to the actual senses. Plutarch and Claudius Ptolemy[88], and all the copyists since their time, think that a loadstone smeared with garlick does not allure iron. Hence some suspect that garlick is of avail against any deleterious power of the magnet: thus in philosophy many false and idle conjectures arise from fables and falsehoods. Some physicians[89] have that a loadstone has power to extract the iron of an arrow from the human body. But it is when whole that the loadstone draws, not when pulverized and formless, buried in plasters; for it does not attract by reason of its material, but is rather adapted for the healing of open wounds, by reason of exsiccation, closing up and drying the sore, an effect by which the arrow-heads would rather be retained in the wounds. Thus vainly and preposterously do the sciolists {33} look for remedies while ignorant of the true causes of things. The application of a loadstone for all sorts of headaches no more cures them (as some make out) than would an iron helmet or a steel cap. To give it in a draught to dropsical persons is an error of the ancients, or an impudent tale of the copyists, though one kind of ore may be found which, like many more minerals, purges the stomach; but this is due to some defect of that ore and not to any magnetick property. Nicolaus puts a large quantity of loadstone into his divine plaster[90], just as the Augsburgers do into a black plaster[91] for fresh wounds and stabs; the virtue of which dries them up without smart, so that it proves an efficacious medicament. In like manner also Paracelsus to the same end mingles it in his plaster for stab wounds[92].

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CHAP. XV.

The Medicinal Virtue of Iron.[93]

Not foreign to our present purpose will it be to treat briefly also of the medicinal virtue of iron: for it is a prime remedial for some diseases of the human body, and by its virtues, both those that are natural and those acquired by suitable preparation, it works marvellous changes in the human body, so that we may the more surely recognize its nature through its medicinal virtue and through certain manifest experiments. So that even those tyros in medicine who abuse this most famous medicament may learn to prescribe it with better judgment for the healing of the sick, and not, as too often they use it, to their harm. The best iron, Stomoma, or Chalybs, Acies, or Aciarium, is reduced to a fine powder by a file; the powder is steeped in the sharpest vinegar, and dried in the sun, and again soused in vinegar, and dried; afterwards it is washed in spring water or other suitable water, and dried; then for the second time it is pulverized and reduced on porphyry, passed through a very fine sieve, and put back for use. It is given chiefly in cases of laxity and over-humidity of the liver, in enlargement of the spleen, after due evacuations; for which reason it restores young girls when pallid, sickly, and lacking colour, to health and beauty; since it is very siccative, and is astringent without harm. But some who in every internal malady always talk of obstruction {34} of the liver and spleen, think it beneficial in those cases because it removes obstructions, mainly trusting to the opinions of certain Arabians[94]: wherefore they administer it to the dropsical and to those suffering from tumour of the liver or from chronic jaundice, and to persons troubled with hypochondrical melancholia or any stomachic disorder, or add it to electuaries, without doubt to the grievous injury of many of their patients. Fallopius commends it prepared in his own way for tumours of the spleen, but is much mistaken; for loadstone is pre-eminently good for spleens relaxed with humour, and swollen; but it is so far from curing spleens thickened into a tumour that it mightily confirms the malady. For those drugs which are strong siccatives and absorb humour force the viscera when hardened into a tumour more completely into a quasi-stony body. There are some who roast iron in a closed oven with fierce firing, and burn it strongly, until it turns red, and they call this Saffron of Mars; which is a powerful siccative, and more quickly penetrates the intestines. Moreover they order violent exercise, that the drug may enter the viscera while heated and so reach the place affected; wherefore also it is reduced to a very fine flour; otherwise it only sticks in the stomach and in the chyle and does not penetrate to the intestines. As a dry and earthy medicament, then, it is shown by the most certain experiments to be, after proper evacuations, a remedy for diseases arising from humour (when the viscera are charged and overflowing with watery rheum). Prepared steel is a medicament proper for enlarged spleen. Iron waters too are effectual in reducing the spleen, although as a rule iron is of a frigid and astringent efficiency, not a laxative; but it effects this neither by heat nor by cold, but from its own dryness when mixed with a penetrative fluid: it thus disperses the humour, thickens the villi, hardens the tissues, and contracts them when lax; while the inherent heat in the member thus strengthened, being increased in power, dissipates what is left. Whereas if the liver be hardened and weakened by old age or a chronic obstruction, or the spleen be shrivelled and contracted to a schirrus, by which troubles the fleshy parts of the limbs grow flaccid, and water under the skin invades the body, in the case of these conditions the introduction of iron accelerates the fatal end, and considerably increases the malady. Amongst recent writers there are some who in cases of drought of the liver prescribe, as a much lauded and famous remedy, the electuary of iron slag, described by Rhazes[95] in his ninth book _ad Almansorem_, Chap. 63, or prepared filings of steel; an evil and deadly advice: which if they do not some time understand from our philosophy, at least everyday experience, and the decline and death of their patients, will convince them, even the sluggish and lazy. Whether iron be warm or cold is variously contended by {35} many. By Manardus, Curtius, Fallopius and others, many reasons are adduced on both sides; each settles it according to his own sentiment. Some make it to be cold, saying that iron has the property of refrigerating, because Aristotle in his _Meteorologica_ would put iron in the class of things which grow concreted in cold by emission of the whole of their Heat: Galen, too, says that iron has its consistency from cold; also that it is an earthy and dense body. Further that iron is astringent, also that Chalybeate water quenches thirst: and they adduce the cooling effect of thermal iron waters. Others, however, maintain that it is Warm, because of Hippocrates making out that waters are warm which burst forth from places where iron exists. Galen says that in all metals there is considerable substance, or essence, of fire. Paolo[96] affirms that iron waters are warm. Rhazes will have it that iron is warm and dry in the third degree. The Arabians think that it opens the spleen and liver; wherefore also that iron is warm. Montagnana recommends it in cold affections of the uterus and stomach. Thus do the smatterers cross swords together, and puzzle inquiring minds by their vague conjectures, and wrangle for trifles as for goats' wool, when they philosophize, wrongly allowing and accepting properties: but these matters will appear more plainly by and by when we begin to discuss the causes of things; the clouds being dispersed that have so darkened all Philosophy. Filings, scales, and slag of iron are, as Avicenna makes out, not wanting in deleterious power (haply when they are not well prepared or are taken in larger quantity than is fit), hence they cause violent pain in the bowels, roughness of the mouth and tongue, marasmus, and shrivelling of the limbs. But Avicenna wrongly[97] and old-womanishly makes out that the proper antidote to this iron poison is loadstone to the weight of a drachm taken as a draught in the juice of mercurialis or of Beet; for loadstone is of a twofold nature, usually malefiant and pernicious, nor does it resist iron, since it attracts it; nor when drunk in a draught in the form of powder does it avail to attract or repel, but rather inflicts the same evils.

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CHAP. XVI.

That loadstone & iron ore are the same, but iron an _extract from both, as other metals are from their own_ ores; & that all magnetick virtues, though _weaker, exist in the ore itself & in smelted iron._