An entire body of philosophy according to the principles of the famous Renate Des Cartes in three books, (I) the institution ... (II) the history of nature ... (III) a dissertation of the want of sense and knowledge in brute animals ... / written originally in Latin by the learned Anthony Le Grand ; now carefully translated from the last corrections, alterations, and large additions of the author, never yet published ... by Richard Blome.

(Book 5)

[illustration]

Book. 2. Part. 5. Chap. 1.

G. Freman I

I. Kip

To the Worship∣full Phillip-Bickerstaff of Chirton in the County of Nor∣thumberland Esq^r.

This Plate is humbly Dedicated by Richard Blome.

(Book 5)

The Fifth Part OF THE HISTORY OF NATURE. OF Things dug out of the Earth. (Book 5)

CHAP. I. Of Metals in General.

I. Whence the variety of the Metals that are in the Earth doth arise. THE great use that Metals afford to the Life and Convenience of Mankind, may seem in some de∣gree to excuse their Covetousness, who break up the Bowels of the Earth to come at them. For doth not Gold and Silver furnish us with Mony, Rings, Jewels, and a thousand Ornaments and Utensils, for our Cloaths, Houses and Tables? And who is ignorant of the absolute necessity of Iron, or of the great usefulness of Tin, Lead and Copper? Provident Nature having so order'd it, that there should be a variety of Metals, suitable to our several Necessities.

The Reason of this multifarious production, must be fetch'd from the different Juices that lodge in the Bowels of the Earth, and are con∣densed there; for seeing that to the generation of Metals are required sharp Spirits, Oily Exhala∣tions, and the Fumes of Quicksilver; these con∣tinually ascending from the Bowels of the Earth, to the more Exteriour parts, do there leave the Metalline particles they bring along with them, and according to their difference, are generated a great variety of Minerals, Metals, and other things dug out of the Ground. For as we find, that in the Fruits of Trees, the grosser Matter doth con∣stitute such parts of them, and the more pure and subtil, others: So sometimes in the same Vein many Metals are generated, whereof some require a more crude and less elaborate Matter, as Iron, Lead, &c. and others a better prepared and more refined Matter, as Gold. Which is the Reason why a greater quantity of ignoble Metals are found in the Mines, than of the pure and noble; forasmuch as Nature needs much more time for the bringing these to Perfection, than the other.

II. Why Me∣tals are malleable. All Metals, except Quicksilver, are Malleable.

This Property of Metals, is the consequent of their Nature and frame; for seeing that Metals are nothing else but hard Bodies, composed of many Integral parts, which, as to their figure are long and branchy, it cannot seem strange to any Considerative person, that they are malleable and ductil when they are forged on the Anvil, or drawn into Wire: For it may be easily con∣ceived, that their parts being thus figured, may be so disposed, as that they may glide a good while one over another, or side-ways to each other, without wholly separating from one another. After this manner Lead, Iron, Silver and Gold, more than any of them, may be drawn into Wire, or beat into Leaves, of an incredible thin∣ness.

III. Why Me∣tals are found at the Bot∣toms of Mountains, lying East and South. Mines of Metals are chiefly found under Moun∣tains, and especially in those parts that face the East or South-Sun.

The Reason is, because at the bottom of Moun∣tains there be many Cavities and Clefts, in which the sublimed particles of Metal may unite, and mount up together to the outward surface of the Earth, especially in those places which are most expos'd to the Sun, and admit its strongest and greatest heat. For tho' the Sun-beams do termi∣nate on the surface of the Earth, and do not penetrate to the inmost parts of it; yet is it not to be question'd, but that the Heat produc'd by them, doth reach to the most abstruse and inward parts of it, and most strongly affect those parts which they most directly strike against. For the Earth, by the heat of the Sun, being Cleft into Gaps and Slits, way is made for the more easy mounting of the Juices, that are hid in its Bowels, and which deposit their Burthens, to wit, the Metalline particles they are charg'd with in the Upper parts of the Earth. And for the same Reason it is, that Springs do frequently rise at the Foot of Mountains, because the water finds a more easie passage through, and more ready ascent to them. Wherefore, whensoever any

Mineral or Metal is found mingled with the Upper-part of the Earth, we may conclude, that the same was carried up thither, together with the ascending Vapours and Exhalations.

IV. What places do most a∣bound with Metals. And this is the Reason why Metals are most frequent in those places, which are most expos'd to the Solar Rays, and which receive most of their heat; because Heat, by wasting of the moisture, makes such places full of Clefts and Slits, through which the Juices and Metalline Exhalations, may more easily ascend.

V. Metals first de∣tected by the Burn∣ing down of Woods. Tho' Metals consist of several Juices, and are now generally found in the Mines; yet it seems very probable, that their first Invention or De∣tection was owing to the conflagration of Woods. Thus ARISTOTLE tells us, that in Spain, when some Shepherds had set a Wood on fire▪ which kindled the Earth ••••so, molten Silver was per∣ceived to run down in the same place. Neither will this seem strange to any who shall consider, that in many places the Veins of Metals are found, reaching to the Roots of Great Trees, about which they are wrapped▪ wherefore when such Trees are burnt down, no wonder if the said Metals, that are entangled amongst the Roots, do melt down with the heat of the fire: In like manner as in the dreadful Fire of London 1666, the Bells in some Steeples were melted.

VI. The Ground that is most rich in Metals, appears outwardly most bar∣ren. The Ground which is rich in Mines, is generally Barren: And besides exhales noxious steams and vapours, which are very prejudicial to the health of the Inhabitants, and are the cause of many Diseases.

The Reason of this Barrenness is, because the Alimentary Juice, appointed by Nature for the Nourishment of Herbs and Plants, is otherways diverted, viz. to furnish Matter for Metals. And it is for want of this Sap or Juice, that in such places the Trees do languish, Herbs wi∣ther, and the Earth it self is bereft of its Vigour, Beauty and Ornament. These parts of the Earth also are more subject to noxious Exhalations▪ be∣cause of the great quantity of steams and vapours that abound within the Bowels of them. For we must not suppose, that all their Matter is spent in the making of Metals, but that the more subtil part of them being agitated by the Matter of the first Element passeth through Clefts to the surface of the Earth, and there mingling with the Air, doth infect the same, and becomes injurious to those that breath in it. This may be seen in most of the Lakes and Pools of Zealand, from whence they dig their Turf, which abound with Bitumen, and in burning give forth a nasty stink: Yea, the steams and fumes that proceed from them, do, as it were, gild over all the Furniture and Utensils of Iron, Copper, Tin and Silver, that are in the Houses where it is commonly burnt, and discolour all things but Gold.

VII. Why Me∣tals are found in some Ri∣vers. Metals are sometimes found in Rivers, accord∣ing to what Historians tell us of the Rivers Tagus, Ganges and Pactolus, as abounding with particles of Gold and Silver, which are gathered by the Inhabitants, and melted down into In∣gots.

We must not imagin that Metals are gene∣rated in these Rivers, as they are in the Bowels of the Earth; but because the waters of those Rivers runing through the Grounds which abound with Metalick Veins, carry great store of their particles along with them. For Water of it self is not a fit Element for the generation of Metals, forasmuch as nothing can be expected from its onion with Earth, save only a little Mud or Clay.

VIII. Why Me∣tals are more ca∣pable of Rarefa∣ction, than Condensa∣tion. Metals are considerably rarefied by Heat; but are not subject to be condensed by Cold.

The Reason of this is, because Metals are already in the state of the highest compression, and have the whole weight o•• the Atm••••ph••••e lying ••••on them. Being there••ore already t••us com∣prest, they are not capable of any further conden∣sation; but well of Rarefaction. Thus we ob∣serve, that the Air is but little condensed by Cold, but very much rarefied by Heat; and that when∣ever it 〈◊〉〈◊〉 freed from the ••eight of the Air that ••••es upon it▪ it becomes much more extended; than it can be comprest or condensed by the most strong and effectual Engins.

IX. Why Cal∣cined Me∣tals flow like Sand, and being melted, run like water. When Metals are calcin'd, that is, are reduced into Powder, by the means of Corrosive Spirits, they flow in grains like Sand; but if they be melted, they run like water.

The Reason is, because in Calcination they are not resolved into the very least particles they are capable to be resolved into; but only into small grains, which are still capable of a further disso∣lution or division. But when the said Grains are dissolved by the violence of fire, they are divided into much smaller particles, and constitute a more continuous Body, like water.

X. Why Me∣tals are resolved into Va∣pours. And much for the same Reason it happens, that Metals, by reason of an Acid sulph••••s▪ which abounds in them, do fly away with it, and are dissipated into fumes. For when Silver is melted with Lead, as soon as a little Brimstone is cast into it, the Silver vanisheth, and is turned into fumes, except that its flight be stopt by wet Linnen. In like manner, Copper that is mixed with a piece of Gold, and cemented with common Salt, and the Powder of Bricks, it mounts up∣wards, and carries up some Gold along with it; except the Pot, in which the Operation is per∣formed, be covered. Because the Particles of the Metals are carried upwards by the force of the Fire, and do not quit their agitation, but by meet∣ing with some cold Body.

CHAP. II. Of Quicksilver and Brimstone.

I. Why Quick∣silver is more hea∣vy than any other Metals, besides Gold. QUicksilver, to which Chymists give the Name of Mercury, is the heaviest of all Metals, excepting Gold: And therefore all other Bodies swim on the top of it, without sinking to the bottom.

The Reason of this Ponderosity is, because there are fewer pores in Quicksilver for the subtil matter to pass through, than in other Metals: For the multitude or deficiency of Pores is the only Cause of the Heaviness or Lightness of Bodies. For tho it might be granted, that the Parts of other Metals are of the same bulk and figure, and alike moved; yet forasmuch as they have many more Pores, they must needs be lighter than it▪ And this is the only Reason why Gold is heavier than Quicksilver, and sinks down in it, even because it

hath fewer Pores, and doth not admit so much of the matter of the 1st Element; tho' indeed in this respect it doth not much exceed Quicksilver, seeing that the proportion between them, is as 44 to 43.

Which makes me the more admire, what ground PLINY could have to assert, lib. 33. cap. 3. that Gold is not so heavy as Lead, when experi∣ence assures us, that Gold is as heavy again, and compared with Blacklead, is as 10 to 6, and to common Lead, as 10 to 5 ¼.

II. What is the cause of the Flu∣idity of Quicksil∣ver. Quicksilver is liquid, and except it be contain∣ed in some Vessel, it runs away like water.

The Reason is, because Quicksilver is divided into many little Particles, which are agitated by peculiar motions differing from one another, and continually shift their places. And tho' it doth not wet or moisten the Hand that handles it, yet cannot this hinder its fluidity: Because Moistness and Liquidity are not one and the same Quality, nor are they of the same Nature. For Fire is liquid, and Molten Metals flow, and yet neither of them can be said to wet or moisten. Foras∣much as nothing else is required to constitute the nature of Fluidity, but the motion of the insen∣sible parts of any Body, or their being so loose, as to be easily put into motion by the subtil mater. The cause therefore of the Fluidity in Quicksilver is, because the Particles whereof it consists, are so smooth and slippery, that they cannot be closely compacted together, and because being thicker than the parts of the water, they scarcely afford any entrance to the Globuli of the 2d Element, but only to that most subtil matter, which we call the 1st Element.

III. Quicksil∣ver loseth nothing of its weight. Hence it is said, that Quicksilver when put on the Fire, doth not become dissipated into Fumes; but being received into a Vessel, it soon after re∣turns to the same form it had before, without the loss of any part of its weight.

IV. How Mer∣cury may be fixed, and after∣wards re∣duced to its liquid state again. Quicksilver that hath been fixed with Quick∣lime, being put into a coated Retort, passeth into the Recipient, and there appears in its former shape.

Quicksilver is fixed when the Particles of Brim∣stone, and of many other ingredients unite them∣selves with those of the Quicksilver, fixing the Points or extremities of their little Branches, in their Pores; and if it chance that the Particles of the Quick-lime, being put in motion by the Fire, carry away with them the Particles of the Brim∣stone, or of any of the other ingredients, that united themselves with those of the Quicksilver, and hindred them from being moved, whether by stopping the passage of the subtil matter, or by rendring their figures too irregular, the Quicksil∣ver returns again to its former state.

V. Why the drops of Quicksil∣ver are round. Quicksilver always forms it self into round drops.

Because the Intervals, which the Particles of the Quicksilver leave between themselves, are so little, that neither the more gross, nor the more subtil Air can enter them, and therefore can only act upon the surface of it, that is, by continually pushing back the parts of the Quicksilver towards the Center, until the said parts resist them equally on all sides; which they never do, till they form themselves into a spherical figure. Whence it fol∣lows, that the Air must of necessity make the drops of Quicksilver more exactly round, than those of any other Liquors whatsoever.

VI. How Quick∣silver may be fixed. But notwithstanding the parts of Quicksilver be thus Round, Polisht and Slippery, yet doth not this hinder, but that by means of Quick-lime, Brimstone and other Ingredients, it may be fixed, by darting the extremities of their little Branches into the Pores of it, which makes the surface of them so irregular, that the subtil matter which moved them before, being no longer able to agi∣tate them, the Quicksilver becomes changed into a hard Body.

VII. Why a Gold Ring at∣tracts Quicksil∣ver. Quicksilver seems to bear a great affection to Gold; and therefore they who are anointed with any Mercurial Ointment, if they hold a gold ring in their Mouths, the Quicksilver penetrating through the Body, fixeth it self on the Ring, and maketh it to appear as if it were Silver, but being put into the Fire recovers its former Bright∣ness.

The Reason is, because Quicksilver, which we have said to be a Fluid Body, and to have its parts in continual agitation, by a moderate heat doth exhale, and fly away into Fumes, and therefore being mixt with those Steams, which together with the Breath are thrust forth from the Lungs, it is car∣ried upwards to the Mouth, where meeting with the ring, which is a compact and cold Body, it is stopt there, and by the union of its parts returns to its former state▪ Much after the same manner as water, in an Alembick by heat is turned into Va∣pors, till meeting with a cold Body, it loseth its agitation, and is changed again into the form of water. The Quicksilver therefore doth not at∣tract the Gold, as some suppose, but only cleaves to it, and by thrusting it self into its Pores becomes coagulated again, and recoves its former state. And therefore Phisicians advise those that have been anointed, with such Mercurial Ointments, to keep a ring of Gold in their Mouths, or to take Gold inwardly, that the Fumes of the Quicksilver may stick to it. And therefore those persons, who do frequently handle Quicksilver, as those who Guild Metals, or are employed in Chymical operations, do commonly hold a piece of Gold in their Mouths, to catch the Fumes of Quicksilver, which otherwise might prove dangerous to their Bodies.

VIII. Why Quick∣silver be∣takes it self to Gold. But you'l demand of me, why the evaporating Fumes or Particles of Quicksilver, do rather tend towards the Gold, than any other way.

IX. Gold and Silver are delivered from their dross by▪ the means of Quick∣silver. The Reason is, because the most subtil parts of the Quicksilver, being carried away by the agita∣tion communicated to them, betake themselves that way, where they find it most easy for them to continue their motion; and it is certain that they can pursue the same more readily in the Gold, than in the Air, because there is nothing in the Pores of the Gold that doth oppose them, whereas the Particles of the Air do continually thwart and cross their tendency. And accordingly we find, that when we handle Quicksilver with one Hand, and have Rings on the other, the same presently become discoloured by the Quicksilver.

Whereas formerly the Spaniards at the Mines of Potosi in Peru, did separate the Gold and Silver from the Dross, with incredible charge and labour, Fernandes de Velasco taught them a more compen∣dious way, which they ever since put in practice,

to their great profit and advantage. He took Quicksilver and Salt, which he mixed with the Mine, and so put them together into close cover∣ed Pots, which he placed in convenient Furnaces, and by this means the Gold and Silver uniting themselves with Quicksilver, became separated from their dross, the Amalgama or mixture of the Quicksilver, and Silver being afterwards cleansed, and made bright by reiterated Lotion

X. Litharge mortifies the sour∣ness of Vi∣negar. Litharge when put into Vinegar, doth take a∣way its sharpness, and communicates a kind of sweet tast to it.

The Reason is, because the sharp pointed and unequal Particles of Vinegar, which do consti∣tute its sourness, cleaving to the Particles of the Litharge, are thrust down to the bottom with it, and therefore no wonder, if the Vinegar being freed from those sharp pointed Particles, prick the Gums and Tongue, appear to be of a sweetish tast.

XI. Sublimate loseth all is corrosive acrimony, by being sublimed with Quick∣silver. If to Mercury Sublimate, which is extreamly corrosive, an equal quantity of Quicksilver be added, and exposed to Sublimation, the Sublimate loseth all its venemous corrosiveness, and becomes insipid, and a good Medicin in many cases.

Because the added Particles of Quicksilver, be∣come increased in bulk by the Particles of Salt that are in Sublimate, by why means they be∣come thicker, and their Points are blunted. After the same manner as when Spirit of Vitriol, and Oyl of Tartar per Deliquium, when mingled to∣gether lose all their sharpness: For these Salts be∣ing of different kinds, the one an acid Salt, and the other an Alkali, are no sooner mixed, but they act upon one another, by which means both their Points are blunted, much in like sort as when by rubbing the edge of one Knife against the o∣ther, both thereby become blunted.

XII. Quicksil∣ver taken inwardly, in any con∣siderable quantity causeth Death. If a considerable quantity of Quicksilver be taken inwardly, it endangers the Life and often causeth Death.

The Reason is, because Quicksilver being a very Heavy and fluid Body, doth easily enter the Veins, and mingling with the Blood, doth interrupt or quite stop its motion. Forasmuch as by the weight of this Metal, the Blood becomes so condensed, and its motion so much retarded, that it cannot furnish Spirits enough to the Brain, for the sup∣ply of the Nerves. For the Particles of the Quicksilver, lying upon one another because of their weight, do condense the Blood, and stop its agitation; and by this means, so small a quantity of Spirits are conveighed from the Brain to the Nerves, that they can only interruptedly, and by intervals fill and distend the Muscles. And this is the true cause, why those who get Quicksilver out of the Miner have their Gums flaggy, and their Teeth loose, because the Mercury entring in∣to the inmost parts of the Body, doth destroy and weaken their connexion.

XIII. Quicksil∣ver is very hurtful to the Body of Man by reason of its Acidity. The Miners that labour in the Quicksilver M••nes of Carinthia, and others who are much con∣versant about Quicksilver, are generally subject to those Diseases, which are caused by the excessive use of Acid things, as with the Palsy, shaking of the Limbs, and other such like Diseases which af∣fect▪ the Nerves. For Sourness and Harshness, seems to be predominant qualities in Quicksilver. For by its Acidity, it doth corrode most Metals; and being mixed with Vitriol and Salt, doth pro∣voke copious Salivation; but when Alkalious or Lixivous Salts are mixed with it, it Salivates less, because these do mortifie the force of Acids. And tho' these Miners fasten Bladders to their Mouths, to keep off the poisonous fumes of this Metal, yet they commonly dye of the Consumption or Palsy; because Mercury by the tenuity of its parts, doth attack the original of the Nerves, and relaxes the Veins, and above all the Lymphatick Vessels.

XIV. How Mer∣cury ope∣rates upon the Body of Man. Whence we may take notice that Quicksilver then chiefly exerts its Virtue, when it is divided into the smallest Particles. For seeing that its parts are very Penetrative, they disturb the Mass of the Blood, excite Fermentations, and frequently hurt the Members of the Stomack, whence Bloody Fluxs, Vomiting of Blood, and terrible Gripes do proceed. Because the Blood, which by a conti∣nual Circulation runs through the Body, not be∣ing able to endure this troublesome guest, and finding it self unable to discharge him by Sweat or Urin, because the Pores of the Skin and Kidnies are too small for that purpose, sends all away by the Caeliacal Arteries, and so causeth a Bloody Flux or violent Loosness.

XV. Why Brim∣stone doth abound in the Coun∣try about Sienna in Italy, in some Is∣slands in Sicily, and in Naples. Brimstone is found in great quantity, in the Country about Sienna, and in several Islands in Sicily, and in Naples, which abound with Subter∣raneous Fires.

The Reason is, because the Branchy Particles of the Exhalations, which in conjunctions with those of sharp and Metallick pieces do constitute Brim∣stone, are put into motion by the force of the Sub∣terraneous ••eat, and carried upwards to the sur∣face of the Ground, where they are coagulated into a fat and oily concretion, which we call Brimstone. And for the same reason it is, that Grease and Fat, which likewise consist of soft and thin Particles, do affect hot places, as abounding most in those parts, where the heat is strongest, as a∣bout the Heart and Reins, and other such like where the heat abounds most. And as the Fat or Grease is generated in the Bodies of Animals, so is Brimstone formed in the Earth, when the most Oily parts, by heat are carried up, and become condensed about the surface of the Earth.

XVI. Why Brim∣stone is so inflam∣able. Brimstone is very apt to be kindled, and in a moment, as soon as it toucheth the Fire, breaks forth into a Flame.

The Reason is, because it consists of the Parti∣cles of sharp Juices, which are so intangled with the thin, and close Branches of an Oily matter, that many of the Pares between the said Branches, can only transmit the Particles of the first Element. Now it is evident, that the most thin parts are first put into motion, and seized by the intercur∣rent matter. And therefore Brimstone is judged by Physicians to be hot in a high degree.

But yet we are told, that a kind of Red Brim∣stone is dug up in Carniola, which neither burns like other sorts of Brimstone, nor hath a stink∣ing smell, but when it is put to the Fire it melts like Wax. And therefore the Romans and Grecians made use of this in the Expiation and Lustration, of their Houses and other Places.

CHAP. III. Of Salt.

I. Of the se∣veral sorts of Salt. THere be different kinds of Salt, which do vary according to the different places of their Generation. There is one sort of Salt that is dug out of the ground, and is called Salt Gem, which is either taken up with Sand, or cut out of Rocks. For there are Mountains of Salt in sever∣al places, where Salt is cut, as Stones out of a Quarry, and grows again. Not far from Astra∣can, there are 2 Mountains so vastly great, and so abounding with Salt, that tho' every day 20000 great pieces of Salt are cut out of them, yet they do not appear the least diminished, the same quan∣tity still growing up in the stead of that which was taken away. Another sort is that we call Sea Salt, which is made by conveighing the Sea∣water into certain Beds, where by the heat of the Sun it is turn'd into Salt, by the evaporation of its watry Particles. The last is Spring or Foun∣tain-Salt, which proceeds from Salt Springs or Well-water, and is boiled into Salt. All the difference between Salt that is dug out of the ground, and Sea or Spring Salt, is this, that the first of these, hath no watry parts mingled with it, and therefore doth not stand in need of any evaporation, as the other two sorts do.

The Reason of this difference is, because the water consists of 2 sorts of Particles, the one Flexible, the other Inflexible, which tho' they be confounded together, and constitute only one Body, yet do each of them retain their several Na∣ture; and are never so closely united, but that they may be separated by means of the Fire or the Sun. When therefore the Sea water, which hath been conveighed into Beds, yields Salt, this is not because the Particles of the water are coagu∣lated into Salt, as some suppose, but by the sepa∣ration of them, forasmuch as the Flexible and Fluid parts are evaporated into Fire, leaving the Stiff and Inflexible behind them. Whence we may conclude, that the different kinds of Salt that are in the World, are such, because of the different figure of their parts: For the Particles of some Salts are like Cylinders, that is, round and long, of an equal thickness: Whereas others ter∣minate in a Point, as may be experienced by the dissolution of them; and therefore an Acid Salt, will dissolve a mixt Body, which another cannot penetrate.

II. How Salt is generated in the Mountains. Salt is generated in Mountains, when the Salt water being conveighed thither in great abun∣dance, and separated from the flexible Particles of the fresh water running another way, the Salt Par∣ticles only remain in the cavities that happen to be there, and continually encreasing by the afflux of new Sea water, do at last wholy fill them up.

III. Why Salt water is Transpa∣rent. Salt water is more Transparent than Fresh water; as appears, in that the Bodies that are in the Sea, are more distinctly perceived, than in Fresh water.

The Reason is, because the matter of the 2d Element, which is contained within the Pores of Salt water, doth retain more of its motion, than that which passeth through the parts of Fresh wa∣ter, and consequently is more fit to transmit the action of Lucid Bodies. For water is therefore only said to be Transparent, because the Aethe∣real matter which fills the Pores of it, can trans∣mit the action of Lucid Bodies.

IV. Whence the different Virtue of Salts doth arise. All Salts, not only those of different kinds, but also those that are of the same kind, do differ in their Virtues. For we find, as was said before, that an Acid Salt, will dissolve a mixed Body, which other Salts of the same kind, cannot penetrate nor dis∣solve.

The Reason is, because the insensible parts of an Acid Salt, are of different sizes and figures, ac∣cording to the different size and figure, of the strait Pores of the inward part of the Earth where they are formed. Therefore it is that Vinegar dissolves Lead, which the Stygian waters cannot do: And Aquafortis dissolves Mercury or Quick∣silver, which Vinegar cannot penetrate: Aqua Regalis dissolves Gold, which Aquafortis will not touch; and on the contrary, Silver is dissolved in Aquafortis, which cannot fasten upon Gold. Now the reason of this variety of effects is, that amongst these Acid Salts, some have long, thick and stiff points, whereas those of others are short, thin, and somewhat flexible, wherefore also their Virtues must needs be different.

V. Why Nitre increaseth the heat of Fire, and streng∣thens the cold of wa∣ter. Nitre or Saltpeter, which in many things a∣grees with common Salt, increaseth the heat of Fire, and strengthens the coldness of water.

The Reason is, because the Needle-like Parti∣cles of Nitre are much more stiff than the sharp pointed Particles of the Fire, which are flexible, and therefore when these stiff Saline Needles, are mingled with those of the Fire, and are whirled about with them, they do much more strongly waste and consume, than the Fire which hath none of these mingled with it. And on the other hand, when these Saline Needle like Particles, fix their points into the Liquid Globuli, they retard their whirling about, and sometimes quite put a stop to it, and by this means it is very probable, that they promote congelation. Neither ought this di∣versity of effects be matter of any greater wonder to us, than when we see the same heat to soften Wax and harden Clay.

VI. Why Nitre cannot be kindled but by a burn∣ing coal, or Flame. Nitre cannot be set on Fire by the most intense heat, but with a Flame, or a burning Coal.

The Reason is, because there can be no Flame without Brimstone. Now we find, that as soon as any Brimstone is cast into a Crucible, wherein melted Nitre is, a Flame immediately breaks forth from it, because the volatile parts of the Nitre, do afford a vehicle to the Brimstone, by means whereof it flies away in the form of a Flame. And this is the reason, why Nitre cannot be kindled into a Flame, by the most violent heat, but only by Flame, or by casting of a burning Coal into it.

VII. Why com∣mon Salt crackles when it is cast whole into the Fire, but not so when it is be••ten small. Common Salt being cast into the Fire in whole Grains, crackles, but when beaten into Powder it doth not; as neither doth that which is generated in Lakes, by the heat of the Sun.

The Reason of this is, the rarefaction of the fresh water, which is pent up within the Grains of Salt. For seeing that the parts of Salt that con∣stitute these Grains, are only confusedly joyned together, without any intimate contact, they leave room enough, for some Particles of fresh water to come between them, which as long as they are not agitated, do continue there crowed

together: But when they begin to be tossed by a violent heat, they dilate themselves, and breaking their Prison walls, make their escape with a noise. But the smaller Powder of these Grains, as like∣wise that Salt, which is coagulated on the surface of Lakes, do not make any crackling noise in the Fire, because their Prison walls, are already suppo∣sed to be broken, and contain no water, that might be rarefied by the Fire. And hence also it is, that the Particles of Salt that have been dried with a slow Fire, do not melt without great difficulty, because they are destitute of all manner of moisture, and have no Liquor remaining, to promote their Fluxing.

VIII. Salt easily turns to a Liquor. Common Salt, Nitre, Salt of Tartar and any other such like, turns to Liquor. Thus the Salt of Tartar, for Example, being set in a Cellar in the Summer time especially, on a shelving plate, or dish, dissolves into a fattish kind of Liquor, which Chymists call the Oyl of Tartar per Deli∣quium.

This effect must be ascribed to the watry Par∣ticles that fly in the Air, under the appearance of Vapours. For Salt of Tartar being very ponder∣ous, it is easily penetrated by the watry Atoms that are in the Air, and which afterwards agita∣ting the Particles of the Salt, do separate them from one another.

IX. Why com∣com Salt Melts be∣ing exposed to the Air. For the same Reason it is, that common Salt melts when it is exposed to the Air; not as if the pure Air, which consists of thinner parts, were able to put the parts of Salt in motion, which it toucheth; but this is done by the Particles of wa∣ter, that fly up and down in the Air, in the form of Vapors; and hence it is, that Salt seldom melts, except the Weather be inclined to moisture.

X. Why distil∣led Salts diss••lve Metals. Acid Spirits distilled from Nitre, common Salt, Alom, Vitriol, &c. dissolve all manner of Me∣tals.

Because the Dart-like Particles of these distill'd Salts, entring the Pores of the Metals, do cut and tear them to pieces: For the insensible parts of these distill'd Salts, being in a continual motion cannot enter the Pores of these Bodies without dividing, and breaking them to pieces.

XI. Whether flowers may be raised from their Salt. Chymists boast, that they can resuscitate the Flowers of Plants from the Salt that is extracted from them, and restore them to a new life.

Tho' this be confidently asserted by some, yet I take it only to be a figment, without any suffi∣cient ground or Foundation. For we experience, that the Spirits distill'd from Vegetables, are en∣dued with very different Virtues from those that are in the Plant, whence they were extracted. Thus we find that Vinegar, Brandy and Wine, which tho' they be the product of the same Grapes, yet differ so much in their Virtues, as that they seem to have nothing common with one ano∣ther.

XII. Whence it is that the Sea water seems to sparkle by night. The Sea water, more especially at sometimes, seems to sparkle in the night.

The Reason is, because the Particles of Salt being stiff, and not in a condition to be bent or made plyable by the Action of the subtil matter, when they dash against a Rock, or meet with any hard Body in their way, these Saline▪ Particles do extricate themselves, from those of the fresh water, with which they were wrapt about, and thus stand∣ing singly, and at some distance from one another, they produce the appearance of sparks of Fire, not unlike to those that are struck out of a Flint. But yet all the Saline Particles, that are in the Sea water, do not produce this effect, but only those that move with their points forward. Which is the reason, why these sparks are not seen in all Waves, nor in all the Drops of one and the same Wave.

XIII. Why Salt pricks and vellicates the Tongue. Salt put upon the Tongue, as soon as it begins to be dissolved by the Spittle, doth prick and pierce it.

Because Salt chiefly consists of slender and ••tiff parts, which bristling their points, do slash and cut the Pores and Fibres of the Tongue. For the Saline Particles are like so many small Darts, which entring the Pores of the Tongue, do with great force vellicate and rend the parts of it. Wherefore they who will not admit that a Salt Tast doth consist in this, that the parts of the Salt, do with their Points prick the Pores of the Tongue, forasmuch as they think they might as well touch the Pores, and Fibres of the Tongue sideways on∣ly, without penetrating them with their Points, ought to consider, that a Needle doth not prick but with its point, nor a Sword cut, but with its edge, the other parts of either of these being una∣ble to inflict any wound: So that since a great many of these Points, are found in every crum of Salt, it can no more be conceived, that when the same melts in the Mouth, it should strike none of its little Darts into the Pores of the Tongue, than it can be imagin'd, that a man should be able to walk with his Feet upon Thorns, without being hurt by them.

XIV. Why Salt preserves Meat from Corruption. Salt preserves Flesh from Corruption, and in time makes i to grow hard.

The Reason hereof may be gathered from the foregoing discourse; for the parts of the Salt en∣tring point-wise into the Pores of Flesh, do not only rid it of the moisture it did abound with; but besides are like so many Wedges, driven in between the parts of it, where continuing un∣moveable, they support the same, and hinder the more slippery and plying parts of the Flesh, to drive the others they are mixt with, out of their places, and by this means reduce the Body to Cor∣ruption. Salt therefore preserves Flesh and other things from Putrefaction, by the hardness and inflexibility of its parts; even as Boards are streng∣thened, and made more firm with Nails, and as the stiffness of a Sword keeps the Scabbard from breaking.

XV. Salt makes Bodies hard Thus we read that a Girl in Holland, by eat∣ing too much Salt became so stiff, and of so dry a Temperament, that she could no longer move the Members of her Body. And from a parity of reason it is, that the Venetians to harden the Wood, wherewith they design to build their Ships, whilst they are yet green, do lay them in water, and keep them there for many years; because by this means the Salt Alkali, is hindred from exhaling, by which means the Wood is made more hard, and less subject to Corruption.

XVI. How Salt promotes the Con∣coction of Meat in the Stomach. Common Salt helps and furthers the Concoction of Meat in the Stomach, and that because it doth penetrate and divide it by degrees, and so dis∣poseth it for its more ready and speedy Concoction, by the Ferment of the Stomach, and its reduction into the form of Chyle.

XVII. Salt makes the water liquid. Tho' Salt makes some Bodies harder, yet it makes the water more liquid; for the parts of the water being long and pliable, they can easily twirl themselves about those of dissolved Salt, which are long and stiff; which greatly facilitates their motion, because they move always bended, after one and the same manner: And it is for this Reason, that Salt hinders water from freezing, as Experi∣ence teacheth us.

XVIII. Salt makes the Earth fruitful, and pro∣duceth the same effect on fat or Cor∣pulent VVomen. Salt conduceth to the Fruitfulness of the Earth; and fat and corpulent Women, who for the most part are barren, by the moderate use thereof, be∣come fruitful.

The Reason is, because Salt penetrating into the pores of the Ground, doth suck up the noxious moisture. For Salt hath a signal drying virtue, as hath before been mention'd: And therefore when an Old Vine begins to grow barren, if old Urine be poured to the Roots of it, it will become fruitful; for being before choaked with over-much moisture, the salt that is in the Urine communi∣cating a new heat to it, which dries up its super∣fluous moisture, makes it to bring forth copious and fair Fruit. And for the same Reason, the moderate use of Salt may be of good use, to make fat and corpulent Women fruitful; because Salt, by its drying, heating and abstersive quality, corrects and removes the superfluous moisture of the Womb, which otherwise might hinder the most Spirituous parts of the Masculine Seed from reaching the Female Ovarium. It is also notorious, that Salt, by its acrimony, excites Lust not only in Women, but also in Men. Now that Salt is a great promoter of fruitfulness, may be proved from that prodigious increase of Mice and Rats which is observed in Ships; and because Women that are employed about Salt-works, are commonly more fruitful than others. And so likewise it is found, that the frequent eating of Oisters, Shrimps, Lob∣sters, Crabs, and other Shel-fish, do stimulate Venery. For tho' Salt of its own Nature be hard, and being destitute of all motion, may be said to be Cold; yet if we consider it with relation to the effects it produceth in the Blood, and the whole Body, we must denominate it hot, because it greatly excites and increaseth the heat of the Blood; forasmuch as it is a great promoter of Fermen∣tation.

XIX. A Grain of Salt, mixt with the Oil of a Lamp, hinders it from being so swiftly consumed. A Grain or 2 of Salt being added to the Oil that is in a Lamp, hinders it from being so soon wasted, as otherwise it would.

The Reason hereof is, because the Salt being shaken with the heat of the Lamp, becomes di∣lated, and communicates some adstringent parti∣cles, which being conveyed to the wiek, give some stop to the Oil in its passage, and prevent its ascending and evaporating so suddenly, as it would, if there were none of these saline Particles to hinder it.

CHAP. IV. Of Gold.

I. VVhy Gold is yellow. GOLD is of a yellow Colour, and the same very bright and pleasant.

To understand the Reason of this, we are to consider that the Nature of Colours consists in this, that the Particles of the subtil matter that trans∣mit the Action of the Light, are differently re∣ceived, by reason of the greater or lesser Roughness or Smoothness of the Bodies they light upon, and according as they obtain a stronger or weaker agitation from the manner or modification of their Reflexion; that is, according as the force of the rotation of the Globuli, that constitute the Rays of Light, doth exceed their motion in right Lines; or on the contrary. Thus, because the particles which constitute the Texture of Gold, are so very rough and solid, as to produce a reverberation, whereby the Globuli are less twirl'd round, than when they produce a red Colour, and less than when they represent a white; this makes the sur∣face of Gold to appear of a yellow Colour. For a yellow Colour seems to be nothing else, but a mix∣ture of white and red, as may be proved by the mingling of a red Liquor with a white, where∣upon a yellow Colour will ensue.

II. Gold struck yields a dull sound. Gold struck with a Hammer, or other Instrument, yields a dull sound.

The Reason is, because Gold hath but a few Pores, and those small ones too; and seeing that the Aiery matter contained in them, is the vehicle of the Sound, when the Body is struck upon, it is very evident, that where the quantity of Pores is less in largeness and number, there must also be a less concussion of the Air, and consequently a weaker impression made upon the Organ of Hear∣ing.

III. VVhy Gold cannot be consumed in the fire. Gold being melted by the violence of Fire, is not the least diminished thereby, or loseth any thing of its weight or built. Hence proceeds that Common Saying of the Chymists, Gold cannot be destroyed by Fire; for tho' it should continue for some Ages in a Furnace, it would not suffer any perceptible loss thereby.

The Reason is, because Gold consists of such thin particles, and those so firmly woven together, that they cannot be separated from one another. For tho' Gold, as well as all other Bodies, hath pores for the free passage of the most subtil mat∣ter; yet doth it not admit the Globuli of the 2d Element; which makes it extreamly solid, as con∣taining a great quantity of thick matter under a small bulk and surface. Now the solidity of any Body consists in nothing else, but the close con∣nexion of its parts, and the small number of its pores, both which make a Body indissoluble by any outward force.

IV. Gold is the Heaviest of all Bodies. Such is the weight of Gold, that it far exceeds that of the most heavy Bodies. According to the Paris Pound, a Foot square of it weighs 1368 pound: And compared with other Bodies, accord∣ing to the calculation of some Curious Enquirers, if so much Gold weigh 100 Pound, the like quantity of Quicksilver will weigh 71½; Lead, 60½; Silver, 54½; Copper, 47½; Iron, 42; Common Tin, 39; Loadstone, 26; Marble, 21; Common Stone, 14; Crystal, 12⅕; Wax, 5; Oil, 4¾.

The Cause of the great Heaviness of Gold is, because its Terrestrial and Aqueous parts, or, if you will, its Sulphur and Mercury are more perfectly and exactly mingled, than in any other Bodies; which is the Cause also, why their pores are less both in number and bulk: For besides this com∣pression and compaction of the parts, we can allow of no other thing to be the Cause of the Heaviness orgreater weight of Bodies.

V. Whence the malleabi∣lity and ductility of Gold doth proceed. Neither is there any Body that is more capable of being divided and dilated, than Gold is, seeing that one Ounce of it only, as PLINY informs us, may be beat out into 750 Leaves, each of them being 4 fingers-breadth square: Yea, some tell us, that an Ounce of Gold may be beaten out to that degree, as to cover 10 Acres of Ground. But tho' this extension of Gold into Leaves be very surprizing; yet is it not to be compared with that Extension which the Wire-Drawers give to it. For one single grain of Gold, will yield a Thred of 400 Foot long; so that proportionably an Ounce will afford a Thred of the length of 230400 Foot.

The Cause of this vast Extensibility must be ascribed to the softness of its parts, and the singu∣larity of their Texture; for the softness of the parts of Gold, makes them to yield without sepa∣ration, so as that those parts which before were close and compact, are now drawn out at length. We experience something like this in Potters-Clay, and fat Earth, wherein tho' there be less of Ex∣tension, yet may they, by reason of their softness, be dilated into a considerable amplitude, according to the degree of their closeness and solidity, which furnisheth a sufficiency for the Matter to be ex∣tended, and enlarged into a vast capacity of figure. For the closeness and compactness of a Body doth furnish parts, which the more they are diminished in depth, the more they grow in breadth. Thus Geometricians demonstrate, that there may be figures of equal capacity, which yet are of an unequal compass: So that amongst equally capacious fi∣gures, those which do most deviate from a Sphe∣rical figure, do acquire a greater compass, without any increase of their Capacity, but only diffe∣renced according to Length and Breadth; whereas before it was gathered together about a Common Point.

VI. The Con∣nexion of the Parts, doth great∣ly hinder its divisi∣bility. The peculiar Connexion which there is between the Parts of Gold, doth also greatly oppose their division and separation from one another: So that how much soever it be attenuated with a Hammer, or any other Instrument, it still retains the Con∣nexion of its parts; and tho' it be not without some little pores, yet are they so entangled and woven together, and become pervious, that the particles of Liquor may run every way through them.

VII. Why Gold suffers no diminution in the Fire. From the said close Connexion of the Parts of Gold, it is, as was said before, that it suffers nothing by the Fire; for tho' the parts of it being put into motion by the Fire, constitute a liquid or fluid Body; yet hath not the fire the power to separate any of them from one another, or to make them fly away into the Air. Provided it be pure Gold, such as is that which is found in the River Hebrus in Thrace, Pactolus in Lydia, Tagus in Spain, and the River Po in Italy. For whatsoever the Fire can separate from Gold, is something that is of a Foreign and Heterogeneous Nature to it, not being able to diminish or separate the least Integral part of it.

VIII. Neither can it be destroyed or spoiled by all the Co••r••••••ve Spirits of the Chy∣mists. And the same may be said of Stygian-water; for tho' these do with great ease dissolve and cor∣rode other Metals; yet cannot they enter the im∣pregnable Fortress of Gold, nor with their Dart∣like particles, loosen the Texture of its Parts. And tho' Gold may be dissolved in a peculiar Stygian-water, called by Chymists Aqua-Regia, as shall be said hereafter; yet is not the Gold in the least pre∣judiced by this Solution, or essentially changed: But may be restored to its former Condition, by pouring some drops of Oil of Tartar, into the Solution, with some Common-water, whereupon the Gold will fall to the bottom, and quit the par∣ticles of Salt which kept them suspended in the Menstruum.

IX. Why heated Gold doth burn and scorch more intensely, than any other Metals. Molten Gold, or that which is only heated, doth scorch more violently than other Metals, and pre∣serves its heat longer.

This Effect is also to be attributed to the Co∣haesion of its Parts; which being fat, and most closely compacted together, do long retain the fire that hath once entred them, and burn the Bo∣dies that touch them more vehemently. For see∣ing that the Pores of Gold are very small, and only make way for the Matter of the first Element, the Fiery particles become so entangled in them, that notwithstanding their most swift and rapid motion, they cannot in haste disentangle themselves again; which is the reason that the effect of them is so vehemently imprest upon combustible Bodies that touch it.

X. How Gold comes to be dissolved in Aqua-Regia. The Corrosive Spirit, called Aqua-Regia, which is distill'd from equal parts of Nitre and Vitriol dissolves Gold; but not if you add thereto an 8th Part of Common Salt, or a 4th Part of Sal-Armoniack; for then it dissolves only Lead and Silver.

This proceeds only from the various Contex∣ture of these Metals: For Gold hath its pores so disposed, as that the particles of Nitre and Vitriol may easily enter them, if they be alone without any mixture of common Salt, because of the like∣ness of figure that is between them. Whereas on the contrary the pores of Silver are so ranged, that they cannot admit the particles of Vitriol and Nitre. But the particles of Common Salt or Salt Armoniack being mixed with the Vitriol and Nitre, do so change the disposition of the parts of the Menstruum or Dissolvent, and make them so stiff, as to be able to thrust themselves into the pores thereof, and to dissolve it. There is also ano∣ther sort of Aqua-fortis made of Nitre, Alom and Vitriol, which dissolves Silver, and is used for to separate it from the Gold that is mixed with it, which it doth not touch. For the particles that are in these corrosive Spirits do dissolve the connexion, which was between the particles of Gold and Silver; and that because of the different sorts of little Bodies that are found in these Stygian-waters, whereof some do agree with the particles of Sil∣ver, and disagree with the particles of Gold; and others, on the contrary, have an Analogy with the particles of Gold, but do not harmonize with those of Silver.

XI. Why the Chymical Prepara∣ration, called Aurum-fulmi∣nans, doth make such a great Report, when it is fired. Gold reduced to Powder after a certain manner, and being afterwards kindled, gives a great Report, and like Thunder pierceth and breaks through whatsoever stands in its way, and therefore is called Aurum-fulminans, or Thundering-Gold.

This Effect will not appear so strange, if we consider the manner how this Powder is prepared. For first the Gold is dissolved in Aqua-Regia, and afterwards is precipitated with Oil of Tartar, and being taken out and dried, affords a Powder, which when it is heated by the fire, breaks forth into a

Flame, with a vehement noise: For all the particles of the Powder, being kindled in one and the same moment, the force of the Flame proceeding from them, opens the pores of the neighbouring Bo∣dies, and dissolves the contexture of their parts, to make way for the Gold that is flying away, which breaks forth with that suddainness and vi∣olence, that it seems to imitate the noise of thun∣der, and the quick Flame of Lightning, both at once.

XII. Aurum fulminans exerts its force up∣wards, as well as downwards Some have supposed, that the force of this Au∣rum fulminans did only tend downwards: But this is a mistake, and the contrary may be proved by experiment. For if we put 2 grains of this Powder into a Silver Spoon, and cover it with a Crown Piece; as soon as the bottom of the Spoon is made hot by holding a lighted Candle under it, we shall find not only a deep dint made in the Spoon, but also that the piece of Mony is carried upwards. Which is an evident argument, that the force of this Powder doth not only tend downwards, but is diffused every way.

XIII. How this Action of Fulmina∣ting Pow∣der may be explained. This Powder is composed of 3 parts of Nitre, 2 parts of Salt of Tartar, and 1 part of Brim∣stone; which being heated in a Spoon, flies away with a thundring report. For it seems very pro∣bable, that the Brimstone and the Salt of Tartar contain abundance of the first Element in their Pores, which makes their parts very much disposed to swim on the said matter, and to fly away as soon as the volatil part of the Saltpeter is sufficient∣ly agitated by the heat of the Candle, to put them into motion; and as soon as the Acid Salt of Sul∣phur is sufficiently divided, for to penetrate the Salt of Tartar.

XIV. Why this Powder makes but a little noise, when it is kind∣led by a vehement Fire. Experience seems to confirm this, for when we kindle this Fulminating Powder with a vehement fire, it makes but very little noise, which proba∣bly proceeds from hence; because the Brimstome having not had time enough to melt, the Acid Salts could not sufficiently divide themselves, in order to their penetrating the parts of the Salt of Tartar; which makes the Salt to rise with more difficulty, and consequently less able to give a great report.

XV. In Gold is hidden a great vir∣tue against many Dis∣eases, if we may be∣lieve the assertion of some Physi∣cians. Gold contains a virtue, proper to cure many Dis∣eases. For it is found to afford manifest relief to those that are infected with the Venereal Distem∣per; it cures the Elephantiasis, which is supposed to be the same with the modern Leprosie: It fastens loose Teeth, and heals all Ulcers and Sores of the Mouth.

But for my part I cannot think that Gold can cure any Diseases in the Body of Man, unless it can be digested in the Stomach, or altered by the heat of the Body. For the virtue of a Medicament consists in this, that the particles of it do insinuate themselves into the Body, expel the noxious hu∣mours, or by their congruity, cherish and corrobo∣rate the diseased parts. But how can this be done as long as the Gold continues whole and entire, and loseth nothing of its substance? Is it not notori∣ous that the Leaf Gold wherewith the Apothecaries guild their Pills, doth pass through the Stomach and Bowels untoucht, and is cast out whole with the Excrements? And yet the said Leaves are so very thin, that if the natural heat could exert any effi∣ciency upon Gold, it would not fail to do it upon them, by reason of their great tenuity.

XVI. Whether there be any Potable Gold. Neither is it to any more purpose that Physici∣ans do boast of their Potable Gold, forasmuch as this is found a meer invention of some Mountebanks to pick peoples Pockets. But should we suppose that such a Potable Gold might be prepared, yet would it be of no use in Physick, because there would be no difference between this Potable Gold, and the common Solid Gold, but that the one is compact, and the other in a state of solution or fusion.

XVII. If Potable Gold could be had, it would be unprofitable and dange∣rous to be given in∣wardly. But you'l say, that Corrosive Spirits, distilled from Salts, can dissolve Gold, and make it fit for a Medicinal use. I do not deny that Gold can be dissolved in Saline Spirits; but yet I affirm, that this solution cannot be of any use to the Body for the cure of Diseases, because of the mixture of the said Corrosive Spirits which are of a Deleterious Nature. And tho' it be common with Physicians to order the boiling of pieces of Gold in the Broths and Gellies of their Patients, for the strengthning and reviving of them; yet is not this their pra∣ctice founded upon any sufficient experience, that Gold thus used, doth produce this effect; but on∣ly upon an inveterate Tradition received amongst them. For seeing that nothing of the substance of Gold is communicated to these Broths or Gellies, it doth not appear how they can be of any use to the Patient; so that this custom may very well be reckoned amongst those usages which neither hurt nor help, and are only, as we say, like a Chip in Pottage.

XVIII. Whether Lead or Iron may be changed into Gold. Chymists can change Lead and Iron into Gold, of which that famous Nail kept in the Duke of Florence his Repository of Rarities, is a pregnant instance, which is so far Gold, as it was dipt in a certain liquor by a German Chymist.

Tho' all persons that see this Nail, generally believe the one part of it to be pure Gold, and to have been made such by a transmutation of the Iron into Gold. Yet for my part, I am more apt to be of TACHENIUS his Opinion, who supposeth that this part of Gold hath been artifici∣ally joined to the Iron part of the Nail, by Appo∣sition, without any Transmutation at all. For af∣ter that this Artist had thus joined a piece of Gold to the part of an Iron Nail, it was easie for him to give to the Golden part the Colour of Iron, that so the whole Nail might appear to be Iron: But being afterwards put into the Fire, and then held in Oyl for sometime, the superadded part appeared to be true Gold.

XIX. Gold is not subject to Rust. Another thing observable in Gold is, that it is not obnoxious to Rust; and this because no steams proceed from it; and tho' sometimes it seem to be Tarnisht, this doth not proceed from it self, but from the too frequent handling of it.

CHAP. V. Of Silver and Tin.

I. Why Silver is hard to melt. SILVER doth strangely resist Fire, and is hard to melt, because its parts being very small and solid, makes a Body so compact and con∣tinuous, that the Fire cannot easily penetrate it; which is the reason that Silver Smiths and others, are obliged to make use of some expedients to make it melt the more readily.

II. Why Silver may be bea∣ten into thin leaves. Silver is easily extended under the Hammer, because its parts being long and branchy, they may glide a long while one over another, without breaking asunder.

III. Why Silver is of a white co∣lour. The reason of the whiteness of Silver is, the solidity of its parts, which reflect the whole light they have received; and with the same action wherewith they have received it. For the particles of Silver being of a Spherical Figure, and having a circular motion, consequently make no change in the Rays of Light; and tho' some of them may be conceived to be rough, yet do they reflect the Rays every way, and send them to the Eye, with∣out any detorsion, or turning of them aside. Yet is not this Colour constant and perpetual to this metal; for when it is polisht, it loseth its white∣ness, and becomes Bright and Shining; because its white particles do now reflect the Light towards one part, which makes all the other parts to look dark and black, as being hindred to reflect the Beams they have received, to the Eye.

IV. How it comes to pass that Silver draws black lines upon Paper. Silver, tho it be white, yet draws black Lines upon Paper; because by this rubbing of it against the Paper, some small particles of the Silver are rubb'd off; which forasmuch as they are thin and rough, do as it were imbibe or swallow the Beams of Light, and consequently exhibit a Black Colour But yet they retain something of their former splen∣dor, because some of the greatest particles stick out above the rest; which preserving their former Tex∣ture, do reflect the Rays after the same manner as they did before; because being very solid, and consequently very capable of being reduced under an even and polisht surface, they resist the Suns Beams; and causing them to be reflected under the same Angles, as they received them, they pro∣duce the sensation of Light, for the reasons we have set down at large in our Institution of Philo∣sophy.

V. Why Silver yields a shriller sound than Gold. Silver yields a most shrill sound, and being struck with a Hammer or other Instrument, doth affect the Ears with a more smart and loud noise than Gold.

The reason of this is, because Silver is bent like a Bow, whose parts being left at liberty, do presently return to their former state. For it is evident that the Strings of a Lute yield a shril∣ler or more Treble sound, the higher they are wound up, because it is then they are most swiftly moved, that is, make most frequent Ex∣cursions. Whereas Gold being softer, and having fewer pores, doth more easily give way to its being struck, and doth more slowly move the Air. Now the swiftness of the trembling motion, or undula∣tion of the Air, makes a shrill or Treble sound; as the slowness of them, a Base or Deep Sound. And therefore Speaking or Singing makes a greater noise, than a violent Wind, because the Air that strikes the Wind-Pipe, when we are Singing, is much more swiftly moved than the Winds are. Sil∣ver therefore gives forth a more shrill sound than Gold, because its bent parts do more swiftly drive the Air, and impart a greater trembling or undu∣lation unto it.

VI. If Brim∣stone be cast upon Silver that is melted, it reduceth it to powder. Melted Silver, by casting Brimstone upon it, becomes turned into a Calx, and is reduced into a small Powder.

This Change is brought about by the flaming Brimstone, which enters the pores of the Silver, and mingles with it, and by this means breaks some of the thinner parts of it, or drives some of them away from the rest, leaving the grosser, and in a manner, the whole substance behind. For by Calcination, the Chymists understand nothing else, but the reducing of the Body of a Metal into Pow∣der, by the ridding of it from its volatil parts only. This being the difference between the Ashes and Calx of a thing, that Ashes are the Remainders of those Bodies, whose greatest part hath been con∣sumed by Fire; but Calx of those Bodies, which do in a manner remain whole and entire after they have been burnt in the Fire.

VII. Spirit of Nitre easily dissolves Silver. Silver is readily dissolved in the Spirit of Nitre, or Aqua Fortis, but not in Aqua Regalis, which dissolves Gold.

The Reason is, because the Spirit of Nitre hath such an Analogy with the Pores of the Silver, that it enters the same, only accompanied with the matter of the first Element, by which means the particles of it have all the quickness of that Ele∣ment communicated to them, and thereby is made fit to unravel the whole Texture of that Metal. And the reason why the Aqua Regalis doth not touch Silver is, because the Pores of the Silver are so small, in comparison of those of Gold, that the Royal Water which enters the body of this lat∣ter only surrounded with the first Element, can∣not penetrate the Pores of the former.

VIII. The Pores of Silver are less than those of o∣ther Metals. That the Pores of Silver are lesser than those of Gold, and of all other Metals appears in that the particles of Lead in fusion, do mingle and join themselves more readily with any other Metal than with Silver, which they do only slide over. The same may also be gathered from this Experiment, that when we make the Infernal Stone, which is nothing else but Silver, made corrosive by the Salts of the Spirit of Nitre, we find that one ounce of Plate Silver is only encreased 3 drams in weight; whereas when we employ courser Silver for this Operation, we find the weight augmented no less than 5 drams. Which difference, in all probability, ariseth from hence; for that Plate Sil∣ver, being more fire and pure, hath lesser Pores than the courser Silver, which has an allay of other Metals, and therefore retain more of the acid parts of the Nitre.

IX. A Vessel that is tin'd over, doth more resist the Fire than another that is not. Tin, which Chymists, look upon as a middle thing between Silver and Lead, hath properties distinct from them both; for Vessels that are tin'd over, are found to resist the Fire better than others, and are not so easily melted.

The Reason is, because Tin, which abounds with Quicksilver, doth easily stop up the Pores and Cavities of Vessels, and therefore hinders the particles of the fire from separating the parts of it so readily, as they would otherwise do. And therefore Chymists commonly call Tin the Defen∣der of Metals, because it preserves them from the force of the Fire; for it enters so deep into the pores of the Metals, that it cannot, without extream heat, be expelled thence. But yet if we touch the Tin with a Red hot Iron, it presently melts; be∣cause by this means the particles of the Fire are introduced into the wider pores, which causeth the immediate separation of the parts of it.

X. Why Cal∣cin'd Tin is more heavy than that is not. Tin is the lightest of all Metals, but when Cal∣cined it is heavier, than when it is whole and entire.

The Lightness of Tin is not to be attributed to the less quantity of moisture it contains, in com∣parison of other Metals, as Silver, Copper, &c. but to the magnitude of the pores. For seeing that Tin is no simple Body, but contains many Hetero∣geneous Parts, which cannot so exactly close toge∣ther, consequently large intervals must be left be∣tween them, to be filled with the subtil matter. Now nothing is more evident, than that the Light∣ness of Bodies proceeds from the magnitude and multiplicity of their pores: And therefore the rea∣son why one Metal is lighter than another, is only this, because it hath more and wider pores, which set their parts at a greater distance from one ano∣ther. But that Calcined Tin should be more heavy than uncalcined, seems strange, forasmuch as we find the contrary in other Bodies. Thus Dough is more heavy than Baked Bread, and a Calcined Stone is much lighter than another that is not calcined: However no other reason can be assign∣ed hereof, but that the pores of the Tin, by Cal∣cination, are more contracted, which is sufficient to make it more heavy, than it was before Cal∣cination.

XI. How Tin may be re∣duced to Powder. But how comes it to pass, that seeing Tin is malleable, yet it may easily be turned to powder, if being melted, it be stirred continually till it be grown cold.

The Reason is, because this continual motion se∣parates its parts one from another, in such a man∣ner, as that they can no longer unite themselves together; not only because the Air, which is got between them opposeth their union; but also be∣cause their small Branches, being grown Cold, are not pliable enough to entangle one another, and therefore they remain in Powder.

XII. Why a Tin Bullet proves more dangerous to the Body that is wounded with it, than a Lead Bullet A Tin Bullet, shot into a Mans Body, makes a more dangerous wound than a Leaden Bullet, tho' they be both of the same bigness, and dis∣charged with the like quantity of Gunpowder.

The Reason is, because the outward parts of Tin are more rough, and abound with sharp pro∣minences: By this means, as they enter the Body, they do much more plentifully affect the Fibres, by tearing and rending them to pieces: Or else we may say, that those small Bits and Shavings as it were, which the Bullet leaves in the wound, do infect and taint it; as we see that the Teeth of a Mad Dog, and of a Viper, do poison the wound, which poison soon after is conveyed throughout the whole Body, and causeth the Death and Corruption of it.

CHAP. VI. Of Lead, and Copper.

I. Why Lead is so easily melted. LEAD is easily bent, and as readily melted when put upon the Fire.

The Reason hereof is, the weak and slender ad∣haesion of its parts; for Lead consists of such par∣ticles, as are all of them easily separable from one another, and therefore they are no sooner set up∣on the fire, but that they are immediately put into motion, and readily separated from one ano∣ther. For soft Bodies differ from Hard, in that the parts of the latter touch one another, and are at rest; whereas the parts of fluid Bodies, whose Nature soft Bodies partake of, are agitated with various motions, and whirl'd about their own Cen∣ters. Lead therefore readily melts, because the fire with great ease enters the pores of it, dissolves its parts, and varies their Position. Hence some have been of opinion that a Lead Bullet might be melted, meerly by a swift motion. But I cannot imagine that this can ever be effected by motion alone; for it was never found that Lead Bullets were ever found melted upon their being dischar∣ged from a Musquet.

II. Why Lead is more heavy than Iron. Lead doth not differ from Iron, save only in this, that it consists of parts that are less, and more smooth, and whose Branches are more ten∣der and pliable than those of Iron: For because the parts of Lead are smoother, therefore they lie more close together, and so compose a more compact Body, such as contains more of its own matter than Iron doth under an equal surface.

III Why Lead is less hard than Iron. And seeing that the Branchy Particles which constitute Lead, are more soft and pliant, than those that compose Iron, therefore they less resist division, and consequently are not so hard as those of Iron.

IV. How Lead comes to be useful in Physick and Chyrurgery. Lead is endowed with a Cooling Virtue, and mi∣tigates the praeternatural Heat excited in Mans Body: Yea some, whose recovery hath been doubt∣ed, have been restored to their former health, only by the application of a Plate of Lead; as it is related of a certain Musician, who wearing a Lea∣den Plate upon his Breast, only to preserve his Voice, was by the same means cured of a most dan∣gerous disease.

The Reason of this Refrigerating Virtue in Lead is, because its parts are very slowly and remisly moved; and lying upon one another, are in a manner quite at rest. For Cold doth not consist in absolute Rest, or a total privation of motion, but it is sufficient to constitute a Body Cold, if the parts of it be very slowly moved, and that the Organ of him that toucheth it, be more than or∣dinarily affected therewith. For a Body, whose parts are very swiftly moved, is more sensible of Cold, than another whose parts are more remisly agitated. A Plate of Lead therefore doth cool an overheated Body, because it diminisheth the motion of its particles, and doth mitigate and allay the noxious heat, which consists in motion. Hence it is that Plates of Lead are applied to the Reins of those who are troubled with involuntary Emis∣sions, caused by the heat of their Reins. CAL∣VUS, the Orator, made use of this means to quell and repress the motions of Lust, to the end he might preserve all his Bodily Vigour and strength, for his Study. Chyrurgeons also make use of Lead, for the drying and healing of Wounds; for by ob∣structing the pores of the Body, by its coldness, it stops the humour, and hinders it from spreading any further.

V. Why Lead, being melt∣ed, and stir∣red with a Stick till it be cold, turns to Powder. Molten Lead, being stirred with a Stick conti∣nually, turns into a fine Powder.

The Reason is, because by this vehement and continual motion, the more thin and slippery parts of the Lead, that kept the grosser parts together, fly away into the Air; as we see in Boiling Wa∣ter, which, when it is stirred, doth send forth a thicker smoak; for the heat having separated the particles of the Water, many of them fly up into the Air. And thus the more Oily particles of the Lead, being left by themselves, do come nearer

together, and are joined together more firmly than ever before, much after the same manner, as by the continual beating and concussion of Cream, its superfluous particles unite together, and constitute the Body of Butter, a-part from the Whey, where∣with they were mingled before.

VI. Why Lead cannot be dissolved in Aqua∣fortis. Lead is not dissolved in Aqua-fortis, tho' it be left in it never so long.

The Reason is, because the Particles of Lead are not proportioned to the bigness or figure of the Particles of that water, or corrosive Spirit, which therefore cannot penetrate them; or if they do, which indeed seems more probable, they pene∣trate them accompanied with the matter of the 1st and 2d Element, yea, and it may be with the more subtil part of the Air also, which makes the motion of them so slow, that they are not strong enough to break the Ranks and Files of the Particles of the Lead.

VII. Why Cop∣per is so hard to be melted ex∣cept is be kindled with Fire. Copper is accounted amongst the hard Metals, which because of the close connexion of its parts doth long resist the Fire, and is not melted except that it be first kindled, and shed so much Light, as that it appears like a bright shining Star in the Furnace.

The Reason hereof is, because the 1st Element is so shut up in the strait and narrow Pores of the Copper, that the insensible parts of that Metal swim upon it, and are so violently tost together by the said Element, and whirled round about their own Centers, that they affect the Optick Nerve at a distance, and the Nerves of the Touch nearer hand. However when it is thus melted, it cannot endure any moisture to touch it; for if water be pour'd upon it, or any moist Body be dipt into it, it causeth a great noise, and the Cop∣per leaps out of the Vessel. Because the water which is heavier than it, doth easily enter its Pores, where it becomes dilated because of the intense heat of the Copper, and being not able to continue there by reason of the straitness of the place, it breaks forth with violence, and carries the neighbouring Particles of the Copper along with it, and scatters and spills them: In a manner not much unlike to that whereby Gunpowder, that is covered over with little Stones, as soon as it is kindled, breaks forth with a noise and scatters all the Stones abroad.

VIII. Whence the Efferve∣scence or Ebullition proceeds which is seen in the dissolution of Copper. When Spirit of Nitre is poured upon Silver, it presently causeth a great Ebullition, so that it heats the Vessel, and continues till the dissolution of the Metal be performed.

The cause of this Effervescence is, because the Particles of the Spirit of Nitre, are of such a magnitude and figure, that they enter the Pores of the Copper only, accompanied with the matter of the 1st Element, which carries them along with it, with so much swiftness, as that they are able to separate the parts of the Copper, and to cause that Ebullition and heat which upon the solution of the parts is produced. Which is an evident proof, that the Pores of Copper are much more open, than those of any other Metals. For this great Effervence which happens upon the dissolution of Silver in this Spirit, seems probably to proceed from nothing else, but from the largness of the Pores of Copper, which are so great that the acid Par∣ticles of the Spirit of Nitre, enter into them sur∣rounded with much of the matter of the 1st Ele∣ment.

IX. Why Tin and Copper when mel∣ted together become so very hard. Copper and Tin being melted together grow very hard, beyond what each of them were apart, before they were mingled.

The Reason is, because the Tin doth penetrate and fill up the Pores of the Copper: For certain it is, that Tin is a Metal of such a penetrating sub∣tilty, that it joyns it self with other Metals, after a most peculiar manner; for it penetrates them e∣ven before that they be melted together, and by this means hardens them, as may be seen in Iron, that is tind over, and Pins, which when made red hot in the Fire, are dipt into Tin for to whiten them, and to bring them to that hardness which we find they have.

X. Why Copper contracts a Rust call'd Verdigrease Copper easily contracts a Blewish coloured Rust which is proper to it, and therefore called in La∣tin Aerugo, which grows to it, and sullies it.

This Aerugo or Copper rust proceeds from the Ex∣halations, and Sulphureous Particles, which con∣tiually steam forth from the Particles of the Cop∣per, and stop the Orifices of the Pores thereof. It derives its original from the moisture of the Air, which is mingled with the parts of the Copper, which being put into motion by the subtil matter, doth break forth, and being stopt on the surface of it, doth there grow together into a Rust. After the same manner as we see that an hoary moldiness doth grow on the outside of Flesh, Leather, Bread, and other like Bodies, if they be kept in a moist place, and especially if they be sprinkled with Salt, because the Salt doth open and widen their Pores, and makes an open way for the Sulphureous Spi∣rits to evaporate. Hence it is, that clean and smooth Copper, doth more easily contract its Rust, than that which hath a rough surface; because in smooth and scoured Copper the Pores are wider, and consequently the moist▪ Air doth with more ease insinuate it self into them.

XI. How Cop∣per Rust is caused, and why Gold is not sub∣ject to Rust. This Copper-rust is caused by sprinkling Salt, and Vinegar upon plates of Copper; because both these do open and widen the Pores of it, and makes a ready way for the steams to come forth: More∣over, this mixture of Salt and Vinegar stops the Particles of these Exhalations on the surface of the Copper, and causeth them to grow together there, so as to cover the top of it. And it is for the contrary reason, that Gold is not subject to any Rust, because no steams proceed from it, so that it is not subject to be sullied or discoloured by any thing that comes from it self.

CHAP. VII. Of Iron and Steel.

I. How Iron which is so hard a Metal comes to be extend∣ed by being made red hot. IRon is the hardest of all other Metals, as being more difficult to be melted than any of the rest; and yet being put into the Furnace and made red hot, it becomes extended in length. For if we take a Plate of Iron of the same bigness with a piece of Wood, and cast it into the Fire till it be red hot, we shall find upon the taking of it out, that it is grown longer than it was when we put it in.

The Reason is, because the Fire that is got into the Pores of the Iron doth widen them; for seeing that there can be no penetration of dimensions, and that 2 extended substances cannot be in one and the same place, it cannot be, but that the Iron must

be dilated by admission of the fiery Particles, and consequently acquire a new Extension.

II. Why Iron is one of the lightest Metals. Tho' Iron be hard to melt, yet it is one of those Metals that are lightest, and are most easily dis∣solved in corrosive Spirits, and destroyed by Rust; for the small Branches of the parts that compose it, being greater and at a farther distance from one another, than those of the other Metals, make this Metal much more Porous and Spungious, than some of the more compact and solid Metals.

III. By what means Iron may be changed into Cop∣per. Iron besmeared with Vinegar and Alom becomes like Copper. At Smolnick there is a Well, the water whereof being turn'd in Channels disposed in 3 rows, turns plates of Iron into Copper.

The cause of this Transmutation is not as some would have it, the loss of a former substantial Form, and the generation of a new one, but only an accession of new parts, whilst the Particles of Alom and Vinegar fill the parts of the Iron, and so change the former connexion of its parts. For seeing that Vinegar is of that sharpness, whereby it easily penetrates into the Pores of the Iron, by this its penetration it changeth the order and dis∣position of them, and by this means a new colour is produced in the Iron. Neither doth the Allom conduce less to this Transmutation, which being endued with a very adstringent Virtue, doth trans∣place those Particles which before stuck very close together, and were firmly entangled. And there∣fore it is no wonder, that when the Texture of the parts of Iron is changed, it should by this means come to resemble Copper.

IV. Why Iron grows harder by being cast into water when it is red hot. If Red-hot Iron be taken out of a Forge or Fur∣nace, and put into the water, it becomes harder, than when it is only exposed to the Air, and cool∣ed there by degrees.

The reason is, because the Pores of Iron when red hot, are very open, and only filled with the matter of the 1st Element, but mingled with many particles of the 3d Element, which swim∣ming upon the Fire, do continually enter them, and come out again. Whence it comes to pass, that when, in this state, it is exposed to the Air, to grow cool, the self-same particles of the Air, continuing their course through its pores, cause the pores to be straitned by degrees, and make the parts of the Iron to retain the same Form they had in the Furnace. Whereas, when red hot Iron is plunged into Water, it cannot indeed hinder the matter of the 1st Element from breaking out from the pores of the Iron; but because there is nothing that can take up those places, besides the subtil matter which is in the Water, whose particles are too small to keep the pores open in the same man∣ner as they did before, they thereupon become sud∣dainly straitned, and consequently come nearer to∣gether; which is the cause of its attaining a great∣er degree of hardness; which is nothing else but a close compression of the parts of a Body, and their mutual contact.

V. Why Rust stops, and hinders conception. Rust stops the Courses of Women, and given in∣wardly, hinders Conception.

The Reason is, because Rust consists of Sulphu∣reous, Branchy and Angulous parts, which are very adstringent, and stop-up the Orifices of the Pores they light into. As may be seen in the Hands of those that handle it, which cannot with∣out grat difficulty be washed clean.

VI. How it comes to pass that Iron and Steel have Pores turn∣ed like Screws. It is found by Experience, that Iron and Steel have abundance of Pores, which are turned and go winding like Screws, and that by means of these, it approacheth to the Loadstone.

The cause of these Screw-like Pores that are in Iron and Steel is, those little Striate Par∣ticles, which according to what we have de∣livered in our Institution of Philosophy, continually coming forth from the inward parts of the Earth, and passing into the outward, have so pene∣trated the substance of the Iron and Steel, as to make passages for themselves through it, which they will still keep open by continuing their mo∣tion through them. Which they could not do, without framing the Pores of the Steel and Iron like so many Screws, which differ nothing from the Screw-like Pores that are in the Loadstone, save only in this, that the little Branches of the Parti∣cles of the Iron and Steel, which rise in their Pores, stand in need to be beaten down, and smoothed by the Particles of the Loadstone, for to afford them a free passage.

VII. Wherein Iron and the Load∣stone do a∣gree. And therefore Iron is said to be of kin to the Loadstone, because both of them are dug out of the same Mines, and are of the same colour; but more especially, because they agree and correspond in their Fibres and Pores: For the striate matter finds a free passage through both of them, much in the same manner, as it doth through the midst of the Earth, which it cannot do through any other Body. Hence Iron is said to cherish and strengthen the Virtue and Life of the Loadstone, much in the same manner, as the water and Virtue of Foun∣tains, is preferved by conveniently disposed Chan∣nels for it to pass through.

VIII. Why Steel becomes softer by being cooled leisurely and by de∣grees. Steel that is made by fusion in a vehement Fire, becomes softer if it be made red hot again, and af∣terwards cooled by degrees.

The Reason is, because when it is thus cooled, the cornerd and rugged Particles of it, which by the force of the heat were driven from the sur∣faces of the Clots of it to the more inward parts, begin to appear outword, and entangling together, do as it were with little Hooks, joyn the Clots of the Steel together: By which means it happens, that these Particles are no longer so closely joyned to their Clots, nor do the Clots any longer so im∣mediately touch one another, but do only hang to∣gether as it were by Hooks or Links; and conse∣quently the Steel is not very hard and stiff, nor brittle, but soft and flexible. In which respect it doth not differ from the common Iron, save only in this, that when Steel is made red hot a 2d time, and afterwards suddainly quenched, its former hardness and stiffness is restored, whereas by the same means, the same is not performed in Iron.

IX. What is the reason that Wood in some Pools is changed into Iron. Some Historians tell us, that Wood by being put into some Pools, becomes turned into Iron. Thus MAGINUS tells us of a Pool in Ireland, into which if a Stake be thrust, that part which is covered with the Mud becomes changed into Iron, and the other that is covered with Water, into Stone.

The Reason of this is, because the Wood by being long buried in the Mud, becomes penetra∣ted by a Metallick steam, which insinuating it self betwixt the Fibres of it, becomes one Body with it, and filling up all its Pores by degrees, at last communicates to it the hardness and appearance of Iron.

X. How Bones and Wood are some∣times changed into Stone. In like manner, Bones and pieces of Wood are changed into Stone. Thus many Bones are to be seen at Rome, Amsterdam and in other places which have been turned into Stone. Thus pieces of Wood have sometime since been taken up at Aqua-Sparta in Italy, which seem to be nothing else, but the fragments of Stakes, which having for a long time been covered with the Earth, have been so penetrated by a Bituminous and Sulphureous steam, and grown to that Stony hardness, as to be no longer capable of being cleft. Thus likewise Cockle-shells are turned into Stone, by being fill'd with such a kind of Petrifying Juice, which in time reduceth them to the hardness and consistence of Stones. For the same Cockle-shells that abound on the Sea-shoar, have been often found far from the Sea on High Mountains. Thus in the Gueri∣nean Cavern or Grotto, Leaves of Oak, Holm, Alder, Poplar, Bay, Ivy and other Trees have been found turn'd into stone, by means of a Petrifying Humour.

XI. Why Steel is more stiff and brittle than Iron. Steel is more stiff and hard than Iron, and hath a greater force to leap back, than any other Metal.

The Reason is, because the parts of Steel are not joyn'd together with entangling Branches, as those of Lead are; but by a multiplicity of sur∣faces lying one upon another like Glass, which is the reason that when Steel is bent, the ranging of its Parts is not changed, but only the figure of its pores; upon the change whereof, the force of the Body running against them is increased. And by this means the Steel-Spring of a Watch is of great use to the performing of all the motions of it. And for the same Reason, Steel must needs be more brittle than Iron, because the Drops whereof it is composed, are only joyn'd together by the contact of their surfaces, which, like the parts of Glass, only touch one another in a few Points, and must therefore be somewhat Brittle.

XII. How Iron may be preserved from Rust. For the cleansing of Iron from Rust, Ceruss-Plaister, and other such like, are commonly made use of; but there is nothing that takes it away better or more speedily, than Oil of Tartar, which presently looseth the Rust, and is then easily wiped off. And to prevent Iron from Rusting, there is nothing better than to besmear it with the Marrow of a Deer, or with Oil, which by obstructing the pores by their clammy Matter, hinder any watry Moisture from entring into, or Steams from coming out of them.

CHAP. VIII. Of the various Generation of Stones.

I. Stones are generated of Sand or Clay. ALL Stones have their Rise either from Sand or Clay; and that either from Sand dis∣solved, or Sand consolidated.

Stones are generated of dissolved Sand, when any quantity thereof becomes coagulated; whence therefore proceeds a Stone, transpa∣rent like a grain of Sand, and of a different figure, as it is variously compressed by its Neigh∣bouring Bodies: So some Precious Stones are found of no distinct shape or figure, and others that have 6 sides or surfaces. Again, Stones are generated of consolidated Sand, that is, when a great num∣ber of the grains of Sand do grow together, by means of Steams or Exhalations filling the Inter∣vals between them, and joyning them together; and there fore these Stones are opake or dark, and rugged, by means of many Prominences, and therefore may be made use of for the sharpning of Stones. It may be also added, that Stones may be made of Clay, which by the admission of some petrifying Exhalations may become stone.

II. Whence it it that some Stones are found in Provence in France, of the figure of a Lozenge, or Quarry of Glass. There is a sort of Stones found in Provence in France, whereof some are Red, and others trans∣parent like Crystal, and of the figure of a Lo∣zenge, which when they are broken, fall into parts of the same figure, tho' subdivided never so often.

The Reason of this is to be attributed, to the more perfect and elaborate disposition of the Mat∣ter whereof these Stones are generated, which is so regularly distributed, that every one of its least particles bestow their own figure upon the whole, and upon the lesser, as well as greater parts of it. We must therefore suppose, that in the first formation of these Stones, some particles of the petrifying Juice, were by the force of Heat stretched out in length, to which others joyning, themselves, did by degrees constitute some small Tables, to which others afterwards were joyned, lying athwart them, so that the Angles somewhat resembled those of Talk or Izinglass. As we find that in the formation of Salts their basis is of a square figure. Thus the particles of Sal Gem are of a square figure like a Dice, and breaks into Bits of the same figure; and after the same manner, and for the same Reason, do these Stones before∣mentioned break into bits that express the figure of Lozenges, and tho' broke never so small, retain the same figure inviolably.

III. What is the Cause of those Glassy-Stones that are some∣times sound in the Earth. Sometimes Glassy-stones are found in the Earth, which do equal others in weight, as well as hard∣ness; save only that they are brittle like Glass, and are easily broke to pieces.

The Original of these Stones must be attributed to Sand, which being melted by a most vehement fire, and afterwards cooled, become as hard as Stone. After the same manner as the particles of Ashes, when agitated by a most vehement fire, have their Ruggedness pared off, and become smooth, and sticking together constitute Glass. Thus it sometimes happens, that after great Burn∣ings of the Earth, many of these Glassy-stones are digg'd forth from the Bowels of it, which are of different shapes and figures, according to the variety of those places into which the melted Salt lighted. PLINY is of Opinion, that the ma∣king of Glass was first found out by a Casual melting of Sand and Nitre: It is reported, saith he, that a Merchant's Ship, laden with Nitre, being arrived, when the Ships Company were about to prepare a Feast upon the Shoar, and wanted Stones to fix their Kettles upon, they took great lumps of Salt-Peter out of the Ship for that purpose, which catching fire, and being mingled with the Sand of the shoar, made transparent Rivulets of Liquid Glass to run down. Book 36. Chap. 20.

IV. How Stones are gene∣rated in the Body of Man. Stones are generated in the Body of Man, dif∣fering in bigness as well as hardness: For some of them are easily crumbled to pouder, whereas others are hard, and cannot easily be dissolved.

The Original of Stones, that are formed in the Kidneys, or in the Bladder, is the same with those

that are generated in the Earth, viz. when by reason of the obstruction of the pores, the grains of Sand are lockt in, and at last growing together, do constitute a hard Body. For it is certain, that the Blood and Urine are strained, and do carry along with them the particles of Terrestrial Bodies, which are endued with such figures, as that when the Blood or Urine are more slowly moved in the Reins or Bladder, they grow into a Stone. For the Sand or Gravel which is generated in the Body of Man, have very uneven and rough surfaces, by means whereof they are easily entangled together, and constitute a mass or lump of Stone. And this is the Reason why they are discharged out of the Body of Man with such extream pain; for being carried with the Urine, and hitting against the Membrans with their sharp Corners, they rend and tear them.

V. Why Wo∣men are less trou∣bled with the Stone, than Men. Women are less troubled with the Stone than Men, because they can discharge the peccant Matter with greater ease than they, by reason of the wideness of the Passages through which it is to pass, as also because they are both straiter and shorter, their Terms also being beneficial to them in this case. Moreover it is observed, that Fat and Pursy persons are most troubled with this Disease, because such Bodies abound with Earthy dregs and volatile acids; as also, for that by reason of the bulk and weight of their Body, they are fain to live an idle and sedentary Life, which alone contributes not a little to the forming of this Disease.

VI. Some sup∣pose that Stones are generated in the Body of Man, by a petrifying Spirit. Some suppose that there is a Petrifying Spirit in the Body of Man, which is the Cause of this generation of Stones, more especially in the pores of the Kidneys and Bladder, which transmutes the dreggy and thicker parts of the Blood into Stone, to which formation that Volatile Salt, which is hid in the Stone, and drawn thence by Chimistry, doth not a little contribute; for by means of these saline Volatile particles, the thicker parts of the Blood are joyned together. Now that there is such a Petri∣fying Spirit in Nature, may be proved from many Springs, which turn all the things that are cast into them into Stone; such as is that Spring which is near Bergen in Norway, and many others elsewhere. And therefore some think, that the like spirit may lye hid in the Bodies of Men, seeing that it is evident beyond contradiction, that a spirit not much unlike this is found in it, which changeth the parts of the Chyle into Bones, Gristles, &c.

VII. Sometimes the Kid∣neys them∣selves, yea, and whole Infants in the Womb, have been turned into Stone. That Stones in the Bodies of Men do sometimes grow to a great bulk, is testified by ISRAEL, a Professour of Heidelberg, who says, that a Woman had a Kidney cut out of her Body, that was wholly turned to stone: Yea, what is far more strange, he tells us, that a whole and entire Birth, compleat and formed in all his parts, and which the Mother had carried in her Body no less than 28 years, was after her Death found as hard as Marble, and taken out of her Body. Which wonderful Effect cannot be ascribed to any thing else, but this Petrifying or Volatile acid Spirit, which is always endued with a great virtue of acting, figuring, and con∣gealing: For the swiftness of this spirit doth rea∣dily pass through all pores, and clinging to them, makes the Body to become harder, much like Coral, which being taken out of the bottom of the Sea, is hardned by the Volatile Acid which is lodged in the Air, and becomes stony.

VIII. The Stone is esten Hereditary. The Disease of the Stone is frequently con∣veyed from Parents to their Children; for seeing that the Particles whereof the Stone is formed, owe much of their tendency towards the producing of this Disease, to the Texture of the Fibres through which they are strained; and that the same de∣pends on the first forming of the Parts of the Body, which proceeds from the Parents, this Dis∣ease may very well be said to be traduced by them to their Posterity.

IX. Of a Stone which lies still in Fresh-water; but being put into Vine∣gar moves up and down. MERSENNUS makes mention of a Stone, which being cast into Fresh-water lies quiet; but when put into Vinegar, or Spirit of Vitriol, is moved; and more in Spirit of Vitriol, than in Vinegar.

The Reason of this may be supposed to be, because this Stone is full of pores, which do readily admit the particles of Vinegar and Spirit of Vitriol; but are not fitted to receive the particles of Fresh-water. So that Particles of Vinegar entring the pores of this Stone, drive out the particles of the Air or Water, which dilating themselves at their coming forth, do lift up and agitate the same.

X. Whether it be true that Stone is turned into Wood, not far from Rome Some Historians tell us, that there are certain Quarries of Stone near Rome, the stones whereof are changed into wood.

But I should be much more apt to believe, that these Stones are not changed into the substance of Wood, but only represent the outward appear∣ance of it. Much in the same manner as that Vein of Stones which is found at Novigentum, on the River Sein, do imitate the figures of certain Plants and Trees.

XI. Of a Stone that being cast into the water, changeth its colour. There is a certain Stone as white as Alabaster, by some called the Eye of the World, which being for some time suffer'd to lye in the water, doth not only become more heavy, but likewise grows transparent, and receives a new Colour.

The Reason is, because the Liquor that enters into the pores of this Stone, doth more dilate and diffuse the Light, and refracts the Rays much in the same manner as the grains of Sand might do. For it cannot be doubted, but that this Stone hath many pellucid particles, and that the Air which is got into the pores, being thrust out by the par∣ticles of the water, make the stone to lose its transparency, and to be changed into a white Colour; for as soon as the Stone is dried, it loseth its white Colour, and becomes transparent, as before.

XII. How the Stones are produc'd, which are found at the bottom of Rivers. Stones are frequently generated in Rivers; yea, it hath been found that the whole bottoms of some Rivers have been changed into stone. PATRI∣TIUS tells us, that whilst he studied at Avig∣non, he frequently went to swim, in the lesser Arm or branch of the River Rhone, and that he found that the Bottom, which he had known before to be soft and smooth, was all cover'd with stone.

The Cause of this Change might be from the Earthquake, which sometime before hapned about the shut-up Valley, so called. For the Earth∣quake might probably cast up a great heap of Sand, which being conveyed from the River Sorga into the lesser Channel of the River Rhone, and setling there, might grow into a great mul∣tiplicity of stones. And this Conjecture seems the more probable; because those who frequent the the River Rhone and Druent, assure us, that they very often found at the Bottom of them, Horses∣shoes,

shees, Nails, and other Iron-work, to which the Sands did stick so close, and were grown so thick about them, that they were wholly cover'd with a Crust of stone, by the coalition or growing toge∣ther of the said Sands upon the Iron.

XIII. Whence those Stones proceed, which are found on the surface of the Ground. Great abundance of Stones are frequently found in Fields, that are in all respects like to those that we meet with at the bottom of Rivers; being of the same bulk and figure, somewhat Oval and in∣clining to a round figure.

It is probable, that these Stones were carried by the force of waters from the Tops of Moun∣tains to the Fields that lye under them, or else by the overflowing of the Rivers. For it is apparent that the Stones which are scattered up and down the Fields of Crautia, come from the overflowings of the Rivers Rhone and Druent, which left Mud and Sand enough behind them, for the forming of the said Stones. For all the Stones that are found there are not equal, but different in bulk, tho' not in figure: For those that are about the midst are bigger than the rest, and are lessened as they withdraw from it; and those are least of all that are towards the Extream parts; because the fore-mentioned two Rivers having stagnated there for a good while, more Sand was gathered about the midst, than about the other more remote and outward parts. And that this was the true Cause of the generation of these Stones may be gather'd from hence, that those Plains, which are far re∣mote from any Mountains, are destitute of these Stones, there being not so much as the least foot∣steps of them to be seen.

XIV. What is the cause of these Shells that are found near Bri∣stol. In some places not far from the City of Bristol, are found the shells of Fishes of a different colour and form; for some of them are twirl'd about like the Tendrils of a Vine; others, other∣wise.

As to the Original of these, it seems most pro∣bable, that they are not the effect of any Juice or Moisture, but were brought thither either by means of an Earthquake, or an Inundation; or by the entrance of some foreign Matter into their pores, which sticking there hath rendred them hard and stony.

XV. What is the Cause of those Stones which are found in Springs. Stones are likewise found to be generated in Springs; yea, sometimes the Bottom of them is so full of Stones, that they rise much higher than they were formerly. GASSENDUS makes men∣tion of a Fountain of Dinia, which covers all the Channels it runs through with a Stony Crust.

The Cause which generates Stones in Springs, is this: The Waters that constitute these Foun∣tains, running through Rocks, do carry some par∣ticles of them along to the said Spring; which being no longer swiftly agitated, as they were when they were when they passed through the Rocks, begin to settle and grow together. And that some Waters in their passage through Rocks, are impregnated with Stony particles, may be proved from that Fountain which is at Rome, which hath so covered all the sides of the Pipe that it runs through, that it hath long since been quite stopt with a kind of Alabaster. And the same happens in a Grotto near the City Tours in France, where the Drops of Water dropping down, are turned to Stone.

XVI. New Stones are formed daily. Wherefore we may conclude with P••ireskius, that all Stones were not created at the Beginning of the World; but that many are formed in process of time, as owing their original to certain proper Seeds, but their configuration, partly to Nature, and partly to chance. For seeing that a petrify∣ing Seed is found in several places, when the same is received into any Liquor, it immediately coagu∣lates the same, as Rennet doth milk, and imparts a special form to it.

XVII. Why Flints are for the most part of a round∣ish figure. Flints are for the most part of a round figure or approaching to it.

The Reason is, because the surface or outward part of the Earth abounding with many Slits, it cannot be, but that the Air which circulates continually in them, must force the parts of Flints, to range themselves into a round figure, because by this means they do less hinder or ob∣struct its motion.

CHAP. IX. Of Pearls and precious Stones.

I. Why preci∣ous Stones and Pearls have the same figure. GEMS and Pearls are commonly called Stones, but with addition of the Epithet Precious, because they are highly valued, and not acquired without great labor, or high price. Pre∣cious Stones agree with Pearls in this, that they have all the same Figure, and tho' they be the product of several places, yet are never of a different form.

The Reason is, because Pearls are generated in Shells, that are so smooth and polisht that they shine, which Politeness the Stones, that are gene∣rated in them do partake of. For Pearls in their first rise are a kind of swellings like Warts, or excrescences proceeding from the matter of the said Shells, which in progress of time become Pearls. But Gems owe their generation to certain exactly percolated Juices, which being only in small quantity, every drop of them constitutes a particular Gem, and cannot be encreased to a great∣er number, but by the occasion of more of these drops. And tho' it may be, they may differ in bulk, yet because the action of the subtil matter is the same in them all, they are all of them par∣takers of an uniform figure.

II. Various precious Stones have various figures. Hence it is that all Crystal is 6 cornerd, Em∣ralds cornerd, Diamants and Rubies 8 cor∣nerd, and so for the rest: Because in their coagu∣lation they are split, and multiplied like the Grains of an Ear of Corn, within the same sheath or hull, and that by reason of their special Seeds, ac∣cording to which Stones obtain as constant Configu∣rations, as either Plants or Animals. Thus we see that Jaspis Stones, Porphyry and Marble are naturally streak'd and embellisht with various colours, waved through one another. And a Nut∣meg in divers colours, represents the winding turn∣ings of the substance of the Brain. And the same may be observed in the Oak, Walnut and other Trees, which being sawn into Boards, and plain∣ed, exhibit a pleasing Labyrinth of multifariously windings Veins.

III. Whence the variety of colours that is in precious Stones doth proceed. Almost all precious Stones do differ in colour, for some of them are perspicuous, others are in a great measure Opake; neither do those that are Transparent agree in all things. For the Car∣buncle

is of a Purple Colour, an Emrald Green; a Saphire Blue, a facinth of a Fiery Yellow, an Amethyst of a Violet Colour, an Opal, vari∣ous, &c.

Precious Stones are Transparent, when the Steams and Vapours whereof the Juices consist, are not congealed till their slippery and fluid particles be exhaled, so as that the Globuli of the 2d Element can readily pass, and convey the action of Light through them. And on the other hand they be∣come Opake or Dusky, when the said Steams are stopt in some narrow Crevices of the Earth, and become there so entangled with several Terrestrial Particles, that the Globuli of the 2d Element can have no passage through them. The reason why some Precious Stones are adorned with several Co∣lours, proceeds from the various mixture of Metal∣line Particles, which variously reflect the Light, and differently affect our Eyes. This is evident from the mixture of Wine and Water, where the Colours of both are so confounded, that the Water espouseth the Redness of the Wine, and the Wine embraceth the Paleness of the Water.

IV. This vari∣ety of Co∣lours in Precious Stones, pro∣ceeds from the vari∣ous mix∣ture of Me∣tallick Par∣ticles. For we observe that coloured Gems are, for the most part, found in Mineral Veins, or near to them; and sometimes amongst the very Oar of Metals. Thus it is notorious, that Granates are found in the Iron Mines of Norway. And Mr. BOYLE assures us, that Amethysts are drawn out of Iron and Tin Mines. And those who have visited the Copper Mines of Hungary tell us, that besides the Vitriolick Water, which changeth Iron into Copper, there is found another White Water which changeth the remainder into a hard and white Stone: But if before its coagulation it pass through a Copper Mine, then it produceth a Stone called Malochis, of a Blue Colour, which Colour would be Brighter, and of the Tincture of a Tur∣kois, in case this petrifying Juice should happen to pass through a Mine, wherein it meets with any Silver Oar. From all which it appears highly probable, that the Colour of Gems proceeds from the mixture of Metallick Particles.

V. What is the Cause of those Spots that ap∣pear in some Preci∣ous Stones. Stains do arise in some Gems, and Spots in others, as in the Agat, &c.

The Reason is, because the juice, whereof they are formed, is gathered together in some recepta∣cles, as it were in a Matrix, and there rests for some time before it is coagulated, by which means, any thing of impurity contain'd in it, doth by de∣grees sink to the bottom. But if the Juices be congealed before that the Heterogeneous parts be sunk to the bottom, and united into one Mass, the Precious Stones become blemished with several Spots, or Streaks; thus Flies, Pismires and other Insects are found sometimes in Crystal, because falling into the Petrifying Juice, the same was coagulated into a hard lump, before they had time to settle to the bottom. Yea, Historians tell us, that a Serpent has been found in the midst of a Stone, and a live Toad in the midst of another, without the least footstep of any passage through which the Animal might have entred.

VI. Amber is a matter that is dug out of the Ground. From hence we may infer, how fabulous it is what some Authors relate of Amber, that there are some very high Trees in Norway, from whence it distils in the form of a Gum, and that falling down, it becomes hard. Seeing that it is well known, that Amber is dug out of the Earth in Sicily. Which may be farther confirmed from the Flies and other Insects that are found in it. And where∣as abundance of Amber is taken up in the Baltick Sea, we must conclude the same to have been car∣ried thither by the force of the Waves, which often driveth it to the Shoar, where it is frequently found.

VII. Crystal is frequently found in Mountains. Crystal is found in Mountains, especially those which are continually covered with Snow, and where the most intense Cold bears sway.

The Antients were of opinion, that Crystal was generated of Frost and Snow, or as others, that it was nothing but water, congealed to that degree of Hardness, by extream Cold. And ac∣cordingly SENECA expresseth himself thus concerning the Generation of Crystal, The Hea∣venly Water, that hath little or nothing of Earth∣ly Feculence mixt with it, being once congealed, by the obstinate continuance of Frost, grows still harder and harder; till that all the Air being ex∣cluded, it become most closely comprest in it self; so that that which before was Water, is now become a hard Stone. In the 3d Book of his Na∣tural Questions. But we have many Arguments to prove this a mistake. First, Because Crystal doth not melt when it is set to the Fire; neither is any thing diminished by the most intense heat, which yet is the Property of all moisture, that is coagulated by Cold only. Again, if Crystal owes its original to Snow Frozen to such a degree of Hardness, how comes it to pass, that Fire, by a strong Rubbing may be struck out of it? Who ever could strike Fire out of a piece of Ice, as it may be out of Crystal? Lastly, if places abound∣ing and covered with Snow, do favour the rise and growth of Crystal, why is it not found in those Mountains where the Snow is perpetual, and where the Cold never suffers intermission?

VIII. The Gene∣ration of Crystal is much like that of Sand. Conclude we therefore, that Crystal, as well as other Gems, is the effect of a strained petrifying Juice, and that the same derives its difference in Transparency and Hardness, from the diversity of the matter whereof it consists. We have great reason to believe this, because we find that Arti∣ficial Crystal is the product of Sand melted by the help of Salts. And tho' sometimes Crystal be found in Rocks, as if it were something produ∣ced by them; yet is this only to be ascribed to this Petrifying Juice, which falling into the Chinks of Rocks, becomes there congealed, in the form of falling drops.

IX. Why the Bottom of Precious Stones is somewhat dusky and dark. From what hath been said, we may understand the reason why Precious Stones have a thick and dark ground: For seeing that the clear Liquor whereof they are formed, doth for some time rest in their peculiar Vessel or Womb, it must needs happen, that whatsoever is impure in the said Liquor, must sink to the bottom; and this makes the ground of them more dull and dark than the other parts of them.

X. Precious Stones are formed of a clear Li∣quor. Now it is apparent, that not only Crystal but Diamonds and Amethysts derive their original from a Limpid Liquor. But yet we must not imagin, that when they are coagulated, the entire Liquor grows into one Lump or Mass, but that they are all by slits divided into several Stones; and like the many Grains in an ear of Corn are multi∣plied within the same Sheath; so as that accord∣ing to the peculiar nature of the Seed, they are

formed into a different Figure, as was mentioned before.

XI. Whether a Diamond cannot be hart by Fire, and yields only to the Blood of a Goat, by means whereof it may be re∣duced to Powder. The common or vulgar opinion concerning the Diamond is, that it is of an insuperable Hardness, which doth not in the least yield to any Iron In∣strument, Hammer or Anvil: No not to the force of Fire it self; for that being cast into the most violent hot Furnace, it never so much as grows hot; and yet is reduced to powder, by the newly shed hot Blood of a Goat.

These particulars, tho' commonly received, are by experience found to be false; for it is certain that a Diamond yields both to the force of Fire and Iron. Thus BODINUS assures us in his 2d Book of Nature, that a Diamond may with a Hammer be reduced to dust, and ground to powder with an Iron Pestel. The Fire also masters it, for by a continual flame it is reduced to a Calx. Neither is that common report truer than all the rest, that if the Powder of it be taken inwardly, it procures the Bloody Flux, since it is certain, that some Servants, to hide their Stealth, have swal∣lowed whole Diamonds, and without the least im∣pairing of their Healths, have voided them again. Yea, The Powder of it hath been given inward∣ly to the quantity of a whole dram, without prejudicing the Health of the Taker, any more than if he had eaten so much Bread. Cardan. 2d Book Tract. 5. Contrad. 9.

XII. The Ele∣ctrick Vir∣tue in Dia∣monds is hangeable. The Electrick Virtue in the Diamond is not al∣ways unchangeably one and the same. For Mr. BOYLE hath observed concerning a Diamond of his own, that this Electrick Virtue was frequent∣ly changed, being at some times much more strong, than at others.

The Reason is, for that a Diamond, tho' it be a Solid Body, and that its parts do seem very closely compacted, yet are not they altogether free from some inward motions; it being very proba∣ble that there are no Bodies so solid, but that their parts are more or less partakers of some motion. Now supposing this intestine motion in Bodies, it cannot seem strange, that upon the changing of the Texture of their parts, their virtue should be changed also. Besides the changes of Colour that are observed in a Diamond, are an evident proof of the motion of its parts; because being rubb'd, it shines and sparkles much more bright and briskly at one time than at another; which change cannot be without motion.

XIII. What is the Reason of the Spark∣ling Bright∣ness of a Diamond. A Diamond sparkles the brightest of all other Precious Stones, and striks the Eye with the most brisk and dazling splendor.

The Reason is, because it consists of a most pure Juice, whose parts are so divided by straining, that they Reflect and Refract the Rays they have re∣ceived from all sides of them. For all the parti∣cles of it are as so many Looking-Glasses, which reverberate the light after the same manner as they receive it. This effect may also be ascribed to the Tincture, whereof it is capable in a high degree, not because of any connate likeness, as some sup∣pose; but because such is the disposition and situ∣ation of its parts, that all the strokes of the Tin∣cture do appositely agree together, and take up all the Pores of it; which how much it doth conduce to the Reflexion of the Rays of light, those who are any thing versed in Opticks, cannot be ignorant of.

XIV. Precious Stones do not always afford the same ap∣pearance. Mr. BOYLE makes mention of a Turcois, which frequently changed its Colour, and afforded a different representation to the Eye. For after that it had caused a Painter to express most exactly the Colour of it, he found that at other times, it not only appeared to him variously from what it appeared when the Painter took a draft of it, but also perceived several Spots in it, which continu∣ally had shifted their places.

All this must certainly be attributed to that Inte∣stine Motion which is in the parts, even of the most solid Bodies. Tho' indeed this motion be im∣perceptible, and not subject to our Sight. For what other reason can be assigned why the Stones whereof Houses are built, grow harder in process of time, except we allow this motion of their parts, whereby they come closer together? Mr. BOYLE hath also observed the vanishing of a Spot that was in an Agate, and that the Electrical and Radiant Virtue is not always the same in a Diamond, but is at sometimes much more strong and brisk, than at others; which is a sufficient proof, that the parts of the most solid Bodies are not altogether exempt from motion.

XV. Whether there be any Medicinal Virtue in Precious Stones. Very considerable Physical Virtues are attribu∣ted to some Precious Stones, whereby not only out∣ward hurts, but many and great inward Diseases are cured.

It cannot be denyed, but that many things which are commonly reported concerning the Vir∣tues of Precious Stones, sound little better than Fables. But in case they have any such, which I would not absolutely deny, because it is a thing unanimously attested by many very Learned and Famous Men, they must proceed from some Mine∣ral Juices that are mingled with the matter of the Precious Stones, whilst they are yet fluid. And that such Juices do mingle with them, is evi∣dent from hence, because they may sometimes be separated from them, as we see they may in Gra∣nates; and for that they frequently encrease the specifick weight of Gems, and endue them with various Tinctures. For seeing that such penetrating Effluvia proceed from the hard Loadstone, and that Precious Stones are endued with an Electrical Virtue, it cannot be questioned, but that many thin and subtil steams do proceed from Precious Stones. Again, what a vast number of Minerals and Metals are there in the Bowels of the Earth, which may be coagulated with petrifying Juices, and unite themselves with the same before their coagulation; and being so united, may exert greater Virtues than are to be found in Minerals that are melted in the Fire, or dissolved in Stigi∣an Waters, and by means whereof Precious Stones may dry, adstringe, consolidate, and produce ma∣ny other effects.

XVI. Why Coral, which is soft under Water, grows hard as soon as it comes to the Air. Coral that grows under the Sea-water, in the manner of a Shrub, and is soft whilst it continues there, as soon as it is brought up into the Air, be∣comes hard, and loseth its former softness.

Supposing this to be true, the Reason may be, that Coral as long as it lies hid under the Sea-wa∣ter, doth abound with much Salt; but when taken up thence into the Air, it grows hard and solid by the exhaling of its moisture. For the fluid parti∣cles of moisture, that lie lurking in the pores of Bodies, do dilate them, and shake the other parts of them by their motion, which is the proper

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Book. 2. Part. 5. Chap. 10▪

G. Freman. In.

I. Kip.

To Leivtenant Collonell Andrew Pitcarne alias Wheler of Datchet in the County of Bucks, one of the Captains of their Ma^ties: first Regiment of foot Guards.

This Plate is humbly Dedicated by Richard Blome.

cause of the softness of those Bodies; but as soon as these fluid particles are evaporated, the remain∣ders are more closely joined together. Thus young and tender Plants, because of the great abundance of Moisture and Salt, which distend their parts, are easily bent or slit, but when they are old, they grow hard, because of the exhalation of their moi∣sture, and the Air entring, instead thereof, are much sooner broken, than bended or slit. Thus PETER PELLEPRAT tells us of a cer∣tain kind of Clay, which is found not far from the mouth of the River of the Amazons, which as long as it is covered with the Waves, is soft; but as soon as it toucheth the Air, grows so hard, that the Inhabitant Savages used in former times to make their Hatchets of it.

XVII. Coral is not soft whilst it is under water. But when I consider that Coral is of a Mineral Nature, and a kind of Precious Stone, I am more apt to believe, that it is the product of some Glu∣tinous Juice, which being turned into Stone by the binding Virtue of Salt, wherewith it abounds, springs up like a Shrub. For Salt conduceth very much to the encrease of Plants, and is that which causeth them to spread into Sprigs and Branches. And Signior Paulo Boccone witnesseth himself to have experienced as much, who being present, when some were fishing for Coral at Messina in Sicily, he put his Hand into the net before it was drawn out of the water, and found the Coral to be hard.

CHAP. X. Of the Magnet or Loadstone.

I. Why a Loadstone points to∣wards the North Pole. IF a Loadstone be hung up in the Air, or be suffered to swim on the top of Quicksilver, it will wave this way and that way, till one of its Poles look towards the North, and the other towards the South: Yet not altogether in an even Horizontal Situation, but so as that that part which points to the North, will be deprest beneath the Level of the Horizon, to the end it may the better be directed towards the Northern Pole of the Earth.

The Reason of this Conversion must be fetch'd from the striate matter, whence the Magnet receives all its virtue; the particles whereof are so twist∣ed, that those which proceed from the South Pole, cannot enter in at the opposite Northern Pole; and therefore rushing obliquely into the pores of the Loadstone, swimming in the Quicksilver, they do by the force they have, drive them to continue their motion according to Right Lines. And by this means it comes to pass, that the Magnet, af∣ter some motions this and that way, returns to its natural state. So that being left to its liberty, the South Pole of the Magnet tends to the North Pole of the Earth, and the North to the South; be∣cause the striate matter, which passeth from the North Pole of the Earth, and takes its course through the Air, towards the South, comes first from the South part of Heaven, through the midst of the Earth; as that comes from the Northern part of the Earth, which returns to the North. Furthermore the reason why the Loadstone doth not keep it self in an Horizontal Situation, but de∣clines towards the North Pole is, because we live in the North part of the World, and consequently have the North Pole nearer our Horizon, than the South.

II. Why one Loadstone approach∣eth to ano∣ther, or withdraws from it. Wherefore if you apply the North Pole of a Loadstone▪ you hold in your hand, to the North Pole of another swimming on Quicksilver; or wa∣ter with the help of a Cork; this latter will with∣draw from the Loadstone you hold in your hand, because the striate matter that proceeds from it, in taking its compass, doth hinder the other. But when this latter Loadstone turns its South Pole to that which is immoveable in your hand, then it will approach to it; because the interposing Air being driven away by the striate matter, the Loadstone, by how much the less resistance it finds, is the more forcibly driven on by the Air that doth surround it.

III. Arguments proving that there is a Vortex of the Mag∣netick Mat∣ter. Now that the Magnetick matter doth make a kind of Vortex about every Loadstone, may be evinced by several Arguments. We find that the Needle of a Compass, is put into various situations, according as it is differently posited about the Loadstone: being placed even with the Poles of the Loadstone, it lies in a straight line, and makes one Line with the Axis of the Loadstone; but is variously inclined when it is otherwise placed. Another experiment that makes out this, is, that if you pour out the filings of Steel upon Paper, having a Loadstone fitly placed in the midst of it, we shall find in the said filings the plain draught and appearance of a Vortex. For upon the shaking of the Paper, we shall with pleasure behold the filings of Steel ranging themselves, as it were, in∣to certain Rings, whereof those are the largest which shall return to those parts that are nearer to the Poles. And if afterwards another Magnet be laid near to the former, then those Rings of the Vortex will appear under another Figure, to the end they may pass now through the Poles of this last placed Loadstone, in case that care be taken, that the South Pole of the one of these Magnets, be turned towards the North Pole of the other. Which Experiments demonstrate to the Eye, the various Rings and turnings the magnetical matter makes about every Loadstone.

IV. When a Loadstone is divided, its Poles are changed. When a Loadstone is divided in length, its Poles by this means are changed, and those parts of the Fragments or Pieces, which before this Divi∣sion were join'd together, and pointed to the same Poles, do now withdraw and flee from one ano∣ther. For if the Parts A and a were before join'd together, and so likewise B and b at the other end; as soon as this division is made, a will turn to B, * 1.1and b towards A; so that the North Pole of the one doth no longer agree with the North Pole of the other; nor the South with the South Pole.

The Reason is, because the Southern striate Par∣ticles, which come forth through the Northern Part of one Section, must enter into the other through the Southern Part, and come forth through the North. Forasmuch therefore as the striate Par∣ticles, which come forth from the greater Frag∣ment AB, are Southern, they must turn about the upper piece a b, and so fit and dispose the same, as that they may freely enter through a, and go out again through B. For A is supposed to be the South Pole, by which the Southern Particles do enter, that come forth from the other part of the Segment or Division through b, and which there∣fore

cannot enter through b into the upper part of the Loadstone, because it is Northern, and therefore unfit to admit the Northern striate mat∣ter.

V. How a Knife that hath ac∣quired a Magnetick Virtue, by being rub∣bed on a Loadstone, comes to be deprived of its Virtue. A Knife that hath been rubb'd with a Loadstone, attracts Iron after the same manner as the Magnet it self doth; but if we pass it over the Pole of the Loadstone, a quite contrary way, than we passed it at first, it will lose the virtue of drawing Iron, which by the former rubbing or passing of it over the Loadstone it had acquired.

The Reason hereof is, because the Knife by be∣ing passed over the Loadstone, or rubb'd against it, was become a perfect Loadstone, for this rea∣son only, because the magnetical matter had open∣ed its Pores, and had smoothed those prominent little Branches of the metallick particles in the said pores that before hindred their free and ready pas∣sage through them. And so in like manner it lo∣seth the quality of a Perfect Loadstone, by being passed in a quite contrary way over the same Pole of the Loadstone; because the magnetical matter, exerts now a contrary effect upon the Knife to what it did before, that is, it now raiseth again the prominent extremities of the Branchy Particles in the Pores of the Knife, which it had before couched, and smoothed.

Now that this is so, appears evidently from this Experiment, that if we lay some filings of Steel upon a Paper, as was before-mentioned, and draw or pass a Loadstone over them, we shall see that the parts of the said filings will range themselves one upon the top of another, and constitute, as it were, so many Hairs, which all of them lie one way; and if then we pass the Loadstone over them the contrary way, we shall find the said Hairs to turn themselves, and to lay themselves a quite contrary way to what they were before.

VI. What is the Cause of the Declinati∣on that is found in the Magnet. The Poles of the Loadstone do not always point directly to the Poles of the World, but variously decline from the same, as may be seen in Dr. GIL∣BERTS Treatise of the Loadstone, who gives us an account of the observation of one Mr. BOR∣ROUGHS, who in the year 1580 at Limehouse near London, observed that the Declination of the Loadstone was 13 degrees and 35 minutes: And of Mr. GUNTER, who in the year 1622 found the said Declination to be only of 6 degrees, and 13 minutes: And last of all his own observa∣tion, who in the year 1634, found it to be only of 4 degrees and 2 minutes.

The decrease of these Declinations, proceeds from the Earths inequalities. For it is certain that some places abound with Iron Mines more than others, and that the Loadstone is not equally dis∣perst in all places; but is found much more plentiful in one than another. And therefore it is that the striate particles, which find a more free passage through the Magnetical Bodies than through any other, breaking forth from the in∣ward part of the Earth, do flow in more abun∣dance towards some places, than towards others: And by this means do frequently deviate from their course, and turn aside towards other Bodies, through which they pass more easily and readily. And forasmuch as the turning of the Poles of the Magnet, or of the Points of the Needle, doth only depend on the course of those Particles, it must needs point that way where there is a greater quantity of matter, that is proper to draw it. This is evident in any Loadstone that is not of a Round or Spherical Figure: For if a small Needle be applied to the different parts of it, it will not always turn it self to the Poles of it in one and the same manner, but will frequently decline a little from them. And therefore it cannot seem strange to us, if the Declination of the Loadstone be changed in one and the same place; and that in process of time its Poles do not exactly point to the Poles of the Earth; Because this matter may shift its place; as for instance, in the bot∣tom of the Sea, or in the cavities of the Earth; or the Iron may be dug out of the Earth in some parts, or be corrupted, and degenerate into ano∣ther Body.

VII. Magnetical Bodies are not always turned from South to North. Hence it appears, with how little reason some Philosophers do endeavour to explain the Declina∣tion of the Magnet, by the Deviation of the Lit∣tle Bear, or of the Poles of the Ecliptick, from the Pole of the World: Seeing that there be many places found, where this Declination is towards the West, as it is generally on the Eastern side of the North part of America; on the Western Coast of Nova Zembla; on the Eastern Shoar of Africa, and the Western of Goa. Yea, in the Azores Islands, which lie betwixt Europe to the East, and America to the West, it declines neither way: As in Trinity Isle, at the Promontory of Needles, near to the Promontory or Cape of Good Hope, at Vi∣enna in Austria, and other places.

VIII. VVhat ••s the Reason that a less Declinati∣on is found in a Load∣stone that is placed upright on one of its Poles. Some tell us that a Spherical Loadstone being placed upright on one of its Poles, hath less decli∣nation, than when its Poles are at an equal distance from the Earth.

The Reason of this may be, because the striate particles that are in the upper part of this our Earth, do not only turn from one Pole to the other, by Lines that are at an equal distance from its center; but also because every where (the Equator only excepted) some of the said particles do ascend from its inward parts, the turning of the Magnet set upright on its Poles, depending on these latter particles, but its declination chiefly on the former.

IX. Iron, being touched by a Loadstone, acquires a Magnetick Virtue. The Loadstone communicates its virtue to Iron, and doth so change it with a Touch, as to make it point towards the Poles of the World, in the same manner as it self doth. The famous GAS∣SENDUS observes, that the Iron Cross, which had been fixt a long time on the top of the Great Church of Aix, being cast down by a Storm, did acquire a Magnetick Virtue from the Earth, so as that the parts of it did attract Iron Nails, and turn themselves towards the Poles of the World. So likewise it is observed, that when a Rod of Iron has toucht the Earth, the lower part of the Rod draws the point of the Needle of a Compass that points to the South, to it self.

This happens because of the great affinity there is between the Loadstone and Iron: for they are so much alike, that the Loadstone may be called Raw and Undigested Iron; and Iron the Riper and more Pure part of the Loadstone. For Iron is melted out of the Loadstone, as out of its proper Vein. Hence it is, that in England, Germany, Ita∣ly, and other places where Iron is found, the Load∣stone is found also, as proceeding both of them from the same Matrix. But as for the manner how

Iron is made partaker of the Virtue of the Magnet, and by touching it, doth acquire the same Inclina∣tion: This we shall understand if we suppose that Iron is endued with fit pores to receive the striate matter, and that it wants nothing towards the obtaining of this Magnetick Virtue; but only that some little branchy particles sticking out in the pores of it, which do make them somewhat rough and uneven, must be bended one way for the easie passage thereof. Now upon the ap∣plication of a Loadstone to Iron, the striate matter which continually takes a round from one Pole of the Earth to another, with vehement force and in great quantity, rushing like a Torrent into the Pores of the Iron, doth bend these prominent ex∣tremities of the branchy particles all one way; and therefore effects whatsoever is necessary to the making of it fit partaker of this Magnetical Virtue.

X. Why Steel is more pro∣per and fit to admit this Mag∣netick Vir∣tue than Iron. Hence it is that Steel is more proper to receive this Magnetick Force than Iron, because it hath more, and more accurately framed Pores for the reception of these striate particles. And doth also preserve the said Virtue longer, because the promi∣nences of the extremities of these branchy particles that are in the Pores of the Earth, are less flexible, and therefore cannot so easily be bent the contrary way.

XI. How Steel Scissars may be made par∣takers of Magnetick Virtue. The Famous Mathematician Mr. BUOT hath found by experience, that Steel Scissars or Penknives having been heated in a Forge till they be of a Red Colour, and then suddainly extinguisht in cold water, and afterwards neal'd in the fire again, till they be of a Blue or Purple Colour, and then whetted and made bright on a Whetstone, if presently after they be made to cut, or pierce through Plates of Iron or Steel, by this means a Magnetick Virtue will be communicated to them, so as to attract Iron Nails. Of which no other reason can be assigned, but this, because the Pores are so disposed in Steel prepared after this manner, that the Heavenly matter can with more ease have Egress and Regress through them: So as that no out flowing particles from the Magnet do remain, but doth only afford a free passage to the External matter.

XII. Why an Armed Leadstone doth at∣tract stron∣ger than one that is Unarmed. The Armed Loadstone A, doth bear up more Iron B and C, than another that is not: For GA∣LILAEUS hath observed, that a piece of Load∣stone weighing 6 ounces, will scarcely bear 2 ounces unarmed; whereas the same Loadstone armed will bear up 160 ounces; so as that it attracts 8 times more than when it is unarmed, and a weight 25 times greater than its own weight.

The cause of this encrease of the attractive Vir∣tue * 1.2is, because the Iron DE, wherewith the Mag∣net A is armed, is endued with Magnetical Parts, that are purged from Terrestrial Filth, and Hete∣rogeneous Impurities; for which reason its Pores do most fitly correspond and agree with the Pores of the Iron that hangs at it B and C, and by this means the striate particles that pass through these Pores from the one Iron into the others, do drive away all the intermediate air, and makes their surfaces to touch one another immediately; by which means they cannot, without great difficul∣ty, be separated; and therefore the weight B, or C, doth stick more strongly to the Iron DE For nothing can be more proper to join 2 Bodies together, than immediate contact.

XIII. A Loadstone throughly heated lo∣seth its force to draw Iron. A Loadstone, being throughly heated, loseth its force of drawing of Iron, and doth no longer turn towards the Poles of the World. For if you heap live Coals about a Loadstone, you will see a Blue Sulphurous Flame to break forth from it; upon the dissipation of which you will judge it to have lost its attractive Virtue.

The Cause of this Loss of the Magnetical Vir∣tue is, for that the Fire entring into the Pores of the Magnet, many of its thin and slippery parts are driven away; upon the removal whereof, a new texture of Parts is produced in the Magnet. As we see that a Stick being put into the Fire, becomes crooked by degrees; because the force of Heat brings some of its parts closer together, and at the same time separates others of them. The Fire therefore having thus changed and confound∣ed the former situation of the particles of the Loadstone, the striate matter which was used to pass through them, finding the Pores much wider than they were before, doth exert but a very small force, or rather none at all upon them.

XIV. A Magnet that hath been heat∣ed, may re∣cover its lost Virtue again. Tho' there be many great Philosophers, who deny that a heated Magnet can ever recover its lost Virtue again; yet the contrary hath been found by experience. Some indeed have observed, that a Magnet that hath been made red hot, is by this means robb'd of the gre••test part of its Virtue, and changeth its Poles in ••ase it be p••ace•• to cool in an inverted situation towards the North. Or if when it is a cooling, the situation of it be frequent∣ly changed from one position to another that is opposit, it will wholly change its Poles▪ so 〈◊〉〈◊〉 that that which was before the North Pole, will become the South, notwithstanding that the Load∣stone be then placed perpendicularly upon the Ho∣rizon.

XV. Glass drops when put to the Fire, lose their Elastick Virtue. Thus those Glass-Drops, which upon the break∣ing off of their Points become shattered into the smallest Dust, being by degrees pu•• to the fire, do lose their Elastick virtue.

The Reason is, because the Parts which before were stretched, are made wider by the admission of Heat, and by degrees sit looser from one ano∣ther; and thus the Texture of the parts being changed, they are now no longer like Sticks, with Wreaths twisted hard about them, and there∣fore do not so strongly resist the force of the Hammer, and become wholly deprived of their Elastick virtue.

XVI. A Loadstone upon the changing of its Poles, doth lose its Virtue also. But if a Piece of Iron be applied to the Pole of a Magnet from the Right to the Left, it pre∣sently loseth the virtue it had before acquired; because the parts of the Magnet are changed, by this contrary passage of the subtil matter through them, and the pores differently ranged and forme▪ from what they were before. And on the con∣trary, it hath been frequently found by Experi∣ence, that the Iron-bars of Windows looking to∣wards the North or South, do retain a perpetual Magnetick virtue: Because the striate Matter that proceeds from the said Poles, by process of time, do hollow pores for themselves through the said Iron-bars.

XVII. How a Magnet may be some time hindred from draw∣ing the Needle to it. A Plate of Iron, which we have said before, being joyned to the Pole of the Loadstone, doth increase its force to bear Iron, doth hinder the virtue it hath of turning Iron towards it. For the Iron-Plate DCD, doth hinder the Loadstone

* 1.3 AB, to whose Pole it is joyned, from drawing the Needle EF towards it.

The Reason is, because the striate Particles that proceed from the Loadstone, do rather pass through Iron, than any other Body; and therefore the said particles are diverted by the Iron-Plate, from passing through the Air to EF. And certainly, besides the Iron or Magnet, no other Body can be substituted in place of the Iron-plate CD, by which the Loadstone AB is hindred from exerting its force upon the Needle EF; as hath been said in the Institution of Philosophy.

XVIII. Whether there be any thing of Truth in the story of Maho∣mets Tomb. There is a Common Story goes of MAHO∣MET's Tomb, that it is pois'd in the midst of the Air, between 2 Loadstones, without touching either the top or the bottom of the Temple at Mecha.

I take this to be a meer Fable: For it is be∣yond the power or wit of Man, to get 2 or more Magnets that are altogether of the very same force and virtue; and if these could be got, yet would it still be as impracticable, or rather impossible to place them so, as that the Iron placed between them, should not be drawn in one part of it more than in the other: Seeing that a very small and inconsiderable difference in the Loadstone, Iron, or in the place it self, would be sufficient to over∣throw that Equality. Neither are we to ascribe any greater Authority to the Stories that some Authors tell us of the Horse of Bellerophon, and of the Statue that was in the Temple of Serapis. These being nothing else but pure invented Stories, which have gained Authority by the Credulity of the Vulgar.

Notes

• * 1.1

  Figure 21.
• * 1.2

  Figure 22.
• * 1.3

  Figure 45. in the In∣stitution.