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.

The Second Part OF THE HISTORY OF NATURE. OF QUALITIES. (Book 2)

CHAP. I. Of Qualities in General.

I. Qualities, as they are commonly explained, are altoge∣ther unin∣telligible. A Student of Philosophy ought to ab∣hor nothing more than to assert things which he doth not under∣stand, or to endeavour the Demon∣stration of what he cannot define. But yet there be many that are guilty of this fault, who endeavouring to defend the opinion of some of the Antients concerning Qualities, do attribute such a Nature to them, which we can have no conception of. For of what use is it to tell us, that a Quality is that whence things are said to be Quales or such like? What Old Woman is there that doth not know as much? Is there any Country Fellow so blockish, that doth not know that by Whiteness things are made White, and by Redness, Red? They would do much better to acquaint us wherein precisely the Nature of a Quality doth consist, how it doth affect the Subject it belongs to, and after what manner it is diffused through the same. Let the Peripateticks therefore in good earnest tell us, what Representation they frame in their Minds of a Quality, and trouble us no more with their Words, which serve only to darken and sully Truth. Is Quality any thing Physically, or really distinct from the Substance wherein it is? Or is it superadded to the things that are denominated from it, as some new Entity? Let them therefore explain its Genuine Nature to us, and do it in such a manner, as that what they express in words, may be intelligible to us. If they cannot do this, which indeed I suppose is a thing impossible for them, why do not they quit these frivolous Qua∣lities, and following the Laws of Nature, espouse more Intelligible Principles?

II. Wherein the Nature of a Quali∣ty doth con∣sist. What is more Intelligible than Quantity, Mo∣tion, Situation, Figure and Rest? By which all natural effects may be made out, even the most abstruse and difficult of them. A Watch is mo∣ved, and without any outward force, measures and shews the Hours. A Key locks a Door, and opens it. Is there any necessity to conceive a fa∣culty in a VVatch, that may set its VVheels a go∣ing? Or in a Key any thing really distinct from it whereby the Lock is opened? What Man in his wits will not confess that it is more consonant to Reason, to attribute the constant motion of a VVatch to the Steel Spring, the disposition of the VVheels with their figure and contexture; and the power of shutting and opening that is in a Key, to the Figure and Ranging of its Parts; than to have recourse to Qualities, which they can never explain nor conceive? But this is to run out be∣yond what I have here designed, which is not to assert the Nature of Qualities by Arguments, but to confirm the same by Experiments.

III. There are no Qualities in the Sun that are really di∣stinct from it. The Sun hath a power to harden Clay, soften VVax, melt Ice and Butter, to resolve VVater in∣to Vapors, to whiten Linnen, to tan the Skin, to ripen Fruits, to hatch the Eggs of Fowl and Silk∣worms, and sometimes to produce I know not how many various effects. All which are not any di∣stinct Powers or Qualities in the Sun, but only the results of its Heat, which according to the dif∣ferent Texture of Bodies, and according to the different concourse of Cooperating Causes, is va∣riously determined.

IV. The Diffe∣rence of ••o∣dies pro∣ceeds from the diffe∣rent Figure and Con∣texture of their Parts. The Purest Spirits of VVine, when joined with the most highly Rectified Spirit of Urin, become united together in the appearance of Snow, which is caused by nothing else but a new Texture of Parts: As when the Spirit of Nitre, mingled with detonated Nitre resolved per deliquium, is turned into Saltpeter. Or, as when the Spirit of Salt being beaten with the VVhite of an Egg, doth communicate to it hardness, which it had not before.

V. The Sea∣water changeth its Colour by Agitati∣on only. When the Sea is tost and beaten with VVinds, it changeth its Colour, and what was a Seagreen Colour before, does now appear VVhite; as the same is Elegantly described by LUCRE∣TIUS.

As in the Sea when the mad Ocean Raves, And white Curles rise upon the foaming VVaves.

Now who can be imagin'd so weak in his Intelle∣ctuals, as to attribute this change to any superve∣ning Quality? For what Agent should effect this alteration? Or by what means could a real Entity be diffused through such a vast conf••ux of VVater? The Sea therefore becomes white b•• being ••urned into froth, that is, by the variatio•• o•• i••s parts in their Magnitude, Situation and Figure, and rising into little Bubbles; whence the reflected light being conveyed to our Eye, represents a white Colour.

VI. Great chan∣ges are pro∣duced in Bodies, only from the alteration of the Dis∣position of the parts. Thus, if Mercury Sublimate ••e put into hot water, and a few drops of Spirit of Urine dropt into it, and then filtrated, it becomes white like Milk. Thus Red Lead and Coral, by the infusion of Oil of Tartar, acquire a white Colour. Thus Gold being mixed with Silver, if afterwards it be ••e••arated by Aqua Fortis, a black Powder falls to the bottom, its first Colour being lost. Of which change no other cause can be assigned, than the Figure, Texture and Order, &c. of the Parts. For as LUCRETIUS expresseth it,

—In Bodies so, As their Seeds, Figure, Order, Motion do, The things themselves must change and vary too.

VII. How water after vari∣ous concocti∣ons, chang∣eth its •• r∣mer quali∣ties. Put water into a strong Pot or Vessel, and ha∣ving luted its Cover to it, and let it stand for some time upon Burning Coals, then remove it, and let it grow cold; then set it to boil again as before; and you'l find that by the repeating of these alte∣rations several times, the Colour, Taste and Smell of the water will be changed.

This change in the water proceeds from nothing else, but the new Order, Figure, Position, &c. of its parts. For the force of the Fire separating the particles of the Liquor, makes them to acquire another position than they had before, by which means different qualities are induced into the wa∣ter, and they made to affect our senses in a dif∣ferent manner from that they did before.

VIII. Various Bodies arise from other Bodies, on∣ly by the figuration and positi∣on of the parts. How many sorts of Plants do we see grow out of water only, into which they shoot their Roots, and attracting it for their nourishment, do encrease in weight, grow up, and spread their Branches. And indeed it is a matter of wonder to see hot and Caustick Plants, such as Crowfoot is, grow∣ing and encreasing in, and from the water alone; neither can this change be assigned to any thing else, but the meer change of the Figure and con∣texture of the Parts. Thus from churn'd Milk, without any other accession of a new form, but by a pure transposition of Parts, Butter and But∣termilk are produced. Thus Glass is made of Sand and Salt, and Roman Vitriol of Salt and Copper; for as Sand gives Glass its firmness, so Copper or Iron afford the same to Vitriol.

IX. Whence it is that Oi∣sters have some part of them Red in the Summer. And for the same reason it is that Oysters, in the hottest Months of Summer, have the appearance of Blood in them; which Colour towards the approach of VVinter vanisheth, because then for want of beat, the Oysters cannot concoct the Alimental Juice to that high degree, as to produce Blood. And suitably to this Physicians tell us that the Redness of the Blood proceeds from the acidity of the Vital Saline Spirit; much in the same manner, as Juleps by the instillation of a few drops of Spirit of Vitriol, acquire a Red Co∣lour.

X. Oyl of Tar∣tar dropt into an In∣fusion of Se∣na-leaves, changeth the colour of it. If you drop a few drops of Oyl of Tartar into an infusion of Sena-leaves in warm water, the water will presently turn Red, and become of a purple Colour, tho' there be no such Colour, either in the VVater, Leaves, or Oyl of Tartar.

The Cause of which Redn••••s is, for that the Oyl of Tartar, piercing into the substance of the Sena, doth so agitate and separate the parts there∣of that it makes way for the most minute particles of the water, to enter the Pores of the Sena; and changing their Text••••e, make the Beams re∣flecting from them to exhibit to our Eye a Red Colour. And that this Redness is by this means produced, may be plainly evinced, because ano∣ther Oyl, for instance, that of Vitriol, being in∣fused in the said water, will not not produce the same effect; because it wants the power to ••••ne∣trate ••he substance of the Sena, and separate its parts so, as to make way for the Particles of the water to enter.

XI. Why two cold Bodies mingled to∣gether do sometimes produce heat. And the same may be applied to other Qualities, as Heat, &c. for our Touch assures us, that there is an extream heat, in Stygian waters, or Corrosive Chymical Spirits when Metals are dissolved in them. And in the Spirit of Nitre, poured upon the butter of Antimony, or the filings of Lead; when yet the said Corrosive Spirits as well as Metals, are both cold.

XII. An Apple thrown a∣gainst a Wall, doth acquire new quali∣ties in that part where it hath been brui∣sed. An Apple when dasht against another Apple, or when bruised by falling down to the Ground, or being thrown against a Wall, that part of the Apple which is bruised will be found to differ from the rest in Smell, Taste, and other Qualities; and this change is so great, as that it seems to be quite of another nature, than the other part of the Apple.

Which change proceeds only from the Trans∣position of its Parts, for no new thing is super∣added to it by its bruise, but only the parts of the Apple are altered from the Position they had before. So likewise we see what a great change is produced in VVine, when it is changed into Vi∣negar; of which notwithstanding no other cause can be assigned, but a slight exhalation of some of its minute parts, or rather the change of their Configuration, by being shaped into little pointed Swords. And as by the exhalation of some parts this change is caused in VVine, so no less an Alte∣ration of things is often produced, by an accession of new parts.

Thus an Apple or Pear, by being rolled hard upon a Table, doth grow soft, and of a sweet Taste, by a gentle distribution of the Spirits into all the parts of it, as the Chymists express it, the unequal Distribution whereof is the cause of a harsh and sour Taste in Fruit: For hard Rolling is a mean between Concoction and simple▪ Matura∣tion. But of this we shall treat more largely in the Part concerning Plants.

* 1.1 CHAP. II. Of Heat.

WAter, which when cold is without motion in a Pot or Kettle, when it is hung over a Fire and boils, riseth up to the brim of it, when as before it scarcely filled one half of it.

The Reason is because the heat of the Fire doth put the parts of the Water into Motion, and sepa∣rate them from each other, and is the cause why by reason of the admission of Air, or some other insensible matter, they ca•• no longer be contained within the same bounds as they were before, but require a greater space for them to display them∣selves in. For it is common to all Bodies that are rarefied, to encrease in bulk by the reception of the subtil matter into their pores; and more espe∣cially where the Rarefaction is caused by some considerable Heat, which puts the parts into Mo∣tion, and separates them from each other.

II. Why the heat of the Sun is com∣monly vi∣vifying and vegi∣tative, and that of the Fire destru∣ctive. The Heat of the Sun promotes the vegetation and vivification of things; whereas the heat of the Fire is rather destructive, and generates no∣thing by its activity.

The Reason whereof is, because the heat of the Sun is moderate, and because of its distance and perpetual circling about the Earth very gradually dispenst. Whereas the heat of Fire, because it cannot reach far, and before it can produce any considerable effect, must approach nearer to Bo∣dies, than is for their preservation, doth present∣ly vanish, and either through the ignorance, or impatience of men, cannot be kept in that tempe∣rature which is necessary to the vegetation of things. But if so be, it can by the Art and In∣dustry of Men be reduc'd to a due Temperature, then nothing will hinder but that Eggs may be hatched by it, Plants produced, Insects generated, and all living things cherished by the warmth thereof.

III. A thing that is Lukewarm only, seems hot when touched with a cold Hand. A Lukewarm Body, touched with a hot Hand, seems cold to us; and hot when we touch it with a cold Hand.

Which different Sense doth not proceed from the thing that is Lukewarm, but from the Hands that touch it; for tho' the same force be in the Lukewarm Body to agitate both hands; yet be∣cause the commotion of the parts of the hot Hand, doth exceed the Agitation that is in the parts of the Lukewarm Body, it makes the heat of the Lukewarm Body to appear or feel cold. For the Agitation of the Particles of any Body considered in themselves, is not called heat, but only so far as it affects our Sense of Feeling.

IV. Why the same Baths are some∣times judg∣ed hot, and at other∣times cold. So they who enter Baths distinguisht by diffe∣rent degrees of heat, having continued for some time in those that are Lukewarm, before they en∣ter those that are more hot, find that that water which at first was so hot, that they could scarcely bear it, doth now seem cold to them; because their Body being thorough hot by the heat of the Baths, can no longer be affected by a weaker heat. Neither is it to be questioned, but what seems to be hot with Scythians, who live in a very cold Air, would be esteemed cold to Aethiopians, that live in a very hot Climate.

V. Collars and Caves un∣der ground, are not hot in Winter∣time. Wherefore 'tis a mistake in some, who con∣ceive that subterraneous places, as Cellars, and the like, are warmer in Winter, than in Summer: seeing that this difference of heat proceeds only from our Body, which is differently affected in Winter, from what it is in Summer: And we do not mind that the same thing may appear cold to one that is hot, and on the contrary, hot to one that is cold. For if it be so indeed, that Subter∣raneous Caverns are hot in Winter, whence is it that the Oyl that is kept in them congeals, which it doth not in Summer, when yet they appear to be cold? Subterraneous places therefore are judged to be hot in cold weather, because our Bo∣dies are cold when we enter into them; and in Summer, cold, because at that time our Body is hot.

VI. Why Gold burns more violently than Fire. A Molten Metal, and especially Gold, burns more strongly than the Flame whereby it is agitated, and whence it is put into its heat.

This proceeds from the compactness and close∣ness of the parts of Gold, which being fat and thick, cannot be dilated, or very little, which is the reason that it both burns more vehemently, and retains its heat longer. For the particles of the Fire, are as it were shut up in the Gold, with∣out being able to disentangle themselves. Whence it is that a Man cannot touch Gold in fusion, with his Hand, but that the Skin of it will be shrivel'd up and burnt immediately. And on the contrary, Iron produceth a greater heat in Aqua∣fortis, than Gold it self doth, because this Liquor enters the softer parts of Gold with less force and violence. For the same Reason boyling Oyl burns more violently than Water, because of the Con∣nexion of its fat and unctuous parts, which do more tenaciously keep the particles of Fire en∣closed, and suffer them not to get away.

VII. Why a Nail does not grow hot by the stroaks of a Hammer, till after it be dri∣ven home. A Nail struck with a Hammer, and driven into the hardest wood, doth not feel hot, whilst it is entring the wood, but is only perceived to grow hot, by those strokes of the Hammer that light upon it, after that it is driven home.

The Reason hereof is evident from the Nature of Heat, which doth not consist in the direct mo∣tion of Bodies, but only in the Agitation of the Insensible Parts.▪ So that it is apparent, that the Nail cannot be heated, as long as the whole of it is in motion, and is entring the wood; but when it is driven home, the Stroaks that afterwards light upon it, put the insensible particles of it in motion, wherein the nature of heat consists. But the con∣trary happens when wood is sawed with a Saw, or bored with an Auger, because then the Saw and the Auger grow hot, and not the Wood, be∣cause in this case the insensible parts of the Saw and Auger, are moved and not those of the wood.

VIII. Why the Iron that is Filed grows hot, and not the File it self. When a piece of Iron is filed, it is observed that it will grow hot, but the File remain cold.

IX. VVhy the Axeltree grows hot, and not the Iron Plate that is on the VVheel. And why the Bullet discharged from a great Gun is not heat∣ed. The Reason is, because the File excites a great commotion in the parts of the Iron, which produces heat. And tho' the parts of the File do suffer the same force, as the parts of the Iron, yet because they are much longer than it, they do not with the very same Testh touch the same part of the Iron twice; but there is always some space of time between the gratings of the parts of the File, du∣ring which, that part of the File, that began to be heated, loseth its heat again.

So likewise the Axeltree of a Coach or Cart grows hot, and not the Iron-plate that goes round the Wheel, because tho' it describes greater lines, yet are not its parts agitated amongst themselves, like that part of the Wheel, which rubs continu∣ally against the Axeltree: Because the Essence of heat doth not consist in the swiftness of the mo∣tion, wherewith any Body is moved, but in the violent and various agitation of the insensible parts

of Bodies. Thus the Bullet discharged from a Great Gun, and most swiftly moved, doth not burn the wood which it penetrates, nor the Bullet dis∣charged from a Cross bow, doth not fire a dry piece of Linnen that it is shot through; because tho' both these Bullet▪ be most swiftly moved, yet are not their parts put into any agitation.

X. Why the Breath we breathe forth with our open Mouths is warm, whereas that which we put forth with more force through our almost shut Mouth, is cold. The Breath we breathe with open Mouth into our Hand doth heat it, but if we blow it forth with vehemency through our Mouth almost shut, it is cold, and cools, suppose hot Pottage, or any thing else.

Our Breath causeth heat, when it is breathed forth gently, that is, when it consists of parts va∣riously agitated, and when it unequally lights against the hand. For the heat of Bodies is no∣thig else but the various determination of their insensible parts, whereby they are moved this way and that way. But the Breath we blow from our Mouths, driv••s out the heat from any Liquor; because it is swift and determined to one part only: For by this means the most subtil parts of the Li∣quor, cannot separately continue their own proper motions, because they are all driven and determi∣ned by the blast of our breath to one part; as the motion of all the parts of a River is determi∣ned one way.

XI. Why Quicklime, and some other Arti∣ficial Stones grow hot, when spink∣led with water. Quicklime grows hot when water is cast upon it, to that degree, that it burns more violently than a Flame.

The Reason is, because the Pores of the Lime∣stone which before only were open to the passage of the Globuli of the Second Element, have been more dilated by the Fire; so as that afterwards they were free to admit the particles of water also, but yet only such of them as were surrounded with the matter of the first Element, which rushing against the hard Particles of the Quicklime, do shake and separate them, especially if there be any store of them, and they do from divers parts, rush against one and the same same part of the Quick∣lime. And in like manner we see that an Artifi∣cial Stone made of Pitch, Tarr, Tartar, Brim∣stone, Saltpeter, Sarcocolla, and Oyl of Peter, equal parts, and as much Quicklime as all of them, mixed with the Yolks of Eggs, and kept for some days buried in Horse-dung, if it be sprinkled with fresh water doth break forth into a flame.

XII. Why the heat of Quicklime exceeds the heat of a Flame of Fire. The heat caused in Quicklime, by the aspersion of water, is more violent than the flame that pro∣ceeds from Fire, because the Quicklime consists of branchy particles, which when they are sepa∣rated from them the matter of the first Element, which surround the particles of water, do violent∣ly strike the hand, piercing and rending the Skin like so many Needles. And for the same reason a Coal, whose parts are intangled with long and various branchy parts, produce a greater heat than Flame doth. Thus melted Metal, and more especially Gold, burns more strongly than Oyl, and retains its heat much longer; because Gold consists of a more close and compact unctuous matter, and therefore is less subject to be dilated, and to let the particles of Fire it hath received to fly from it.

XIII. Why a Red hot Iron is hot mad•• use of for ••he cut∣ting of Glass Glass is commonly cut with the Edge of a red hot Iron, or with a Packthread dipt in Brim∣stone.

The Reason whereof is, as was before said, that the parts of the Glass being agitated by the heat, require more room, and therefore drive the neigh∣bouring Bodies from them. For it is impossible that the parts which are heated, should move swiftly and circularly, without taking up more space. This is evident, as in all other Bodies, so even in the most compact Bodies of Metals, which do somewhat swell, and become distended by heat.

XIV. How Heat comes to be produced by two cold Liquors mingled together. Liquors, that of themselves are cold, when pour'd together produce a great heat. Thus Spirit of Vitriol added to Oyl of Turpentine, grows very hot. It hath been also observed that Spirit of Wine, by degrees added to Aqua-fortis, or Spirit of Nitre, doth cause a great and lasting heat.

Which Heat is caused from the diversity of the parts whereof the Liquors do consist; as being of such Figures, as that upon their mixture, they can the better join together, than when they are separate and by themselves, and that in this closing together, they swim upon the matter of the First Element, at least at the time that they are percei∣ved to boil or effervesce. Which may be confirm∣ed from hence, that after their ebullition is ceased, it is evident that many of them are grown toge∣ther, constituting several hard Bodies. In the same manner, Oyl of Vitriol, when cold water is pour'd upon it, grows hot; and Aqua-fortis into which Salt Armoniack hath been infused, doth contract a heat, by casting into it some bits of Brimstone. Thus the Spirit of Salt Armoniack and Tartar, and the Filings of Lead, or the Oyl of Vitriol, and the Filings of Steel joined together are pro∣ductive of heat. And which may seem more won∣derful, Ice it self being put into the Oyl of Vitriol, causeth so great a heat, as to send forth Smoak. And so Fruits also, as Cherries, when put into Spirit of Nitre, produce a considerable heat.

XV. The ming∣ling of Brimstone with Steel, produceth Heat. We must not here omit a notable experiment, which is, that if you mix half a pound of Flower of Brimstone, with the same weight of Filings of Steel, and put this mixture into cold water, stirring it now and then, it will cause so great a heat, that the vessel will be too hot to be touched. Thus Quicksilver prepared after a peculiar man∣ner, and amalgamated with Gold, doth give such a heat, that it cannot be endured.

XVI. The Stone Magnesia dissolved in Oyl of Vi∣triol, pro∣duceth heat. In like manner the Stone MAGNESIA, which in hardness resembles the Loadstone, when put into the Oyl of Vitriol, stirs up a great heat, which is encreased by repeated affusions of water, and like Iron communicates a Red Colour to the Aqua∣fortis, sends forth a sharp and stinging fume; and when some of it is put upon Molten Glass, presently the Glass swells, which is common to it with Copper and Iron. Thus if you cast a little Filings of Brass into a great Bottle, in which there is only a small quantity of Aqua-fortis, there follows such an effervescence, that the Bottle seems to be full, and produceth so great a heat, that the Bottle can∣not be touched.

XVII. Two hot Bodies mixt toge∣ther, pro∣duceth sometimes a third, that is cold. Sometimes two hot Bodies mingled together, produce a third of a different Nature: For if you pour the Spirit of Nitre, which is very hot and piercing, upon Lix••vous Salt, the product of this conjunction will be Saltpeter, which cools rather, than is productive of heat.

The Cause whereof is, because the particles of Nitre and Salt become so intangled together, as that they lose their sharp points, whereby before they were used to dissolve Bodies. For the Bodies of the Nitrous Spirit, which before were volatile, and were easily sent away into the Air, being now kept down by the fixt Salt, can no longer fly away. And therefore it is no wonder that the Spirit of Nitre loseth the power of heating which it had before, and ceaseth to be Corro∣sive.

XVIII. How Snow comes to be condensed by heat. Notwithstanding that, it is the property of Heat to rarefie Bodies, and by loosning of their parts, to make them take up more room: Yet, for all that, we find that it doth condense Snow and Clouds. The Reason whereof is, because the fila∣ments of the particles of Ice, whereof Snow doth consist, being more thin and slender than the mid∣dle part of them, they are consequently upon the approach of Heat, more easily dissolved, and bend∣ing themselves this and that way, because of the agitation of the subtil matter that surrounds them, they, embrace the neighbouring particles of Ice, without quitting those they were intangled with before; and by this means constitute a more compact substance than they did before.

XIX. The same effect is produced by heat in the Clouds. This effect is still more clearly discoverable in the Clouds; for since the particles of Ice, whereof they consist, are at a greater distance from each other, and leave greater Intervals between them, they cannot approach to their neighbouring particles, but that at the same time they must be separated from some other; and therefore when they are bent, must needs take up less room, and consequently constitute a more close and compact Body.

XX. Heat turns Lime and Ashes into Glass. Lime and Ashes, by the heat of the Fire, are turned into Glass: For the Crystal Glasses of Ve∣nice are made of Stones which are found near the River Ticinus, and brought from Pavia, with an equal quantity of the Ashes of an Herb, which the Arabians call Kall, and which grows in the Desert between Alexandria and Ro∣setta.

The Effect of reducing these to Glass, is never produced, but by a long continued Fire, and that in the highest degree: For seeing that the parti∣cles of Lime and Ashes are thick and irregular, they cannot so lie upon one another, as to stick or cleave together. Wherefore a strong Fire must be employed, to exercise its activity upon them; for then, whilst the thinner particles of the Third Element, together with the Globuli of the Second Element, are laid hold of, by the matter of the First Element, and proceed to move most swiftly about them, their Corners are by little and little worn off, and their surfaces being made more smooth, and some of them bended, flowing over one another, they no longer touch each other now in some points, but are joyned with their whole surfaces, and so sticking toge∣ther, constitute that Body which we call Glass.

CHAP. III. Of Cold.

I. No Body is altogether destitute of Heat. NO Body, how cold soever it may seem to the Touch, is wholly devoid of Heat. For water, which to our sense is most cold, is proved not to be destitute of all heat, because of the Va∣pours and Steams which we see do arise from Ri∣vers and Pools, even in the Winter time, and in the Night time.

The Reason is, because Cold is nothing else but the want of Heat; and as Darkness is the priva∣tion of Light, which is the companion of Heat, or the effect of it; so Cold seems to be nothing else but a privation of the said Heat; and therefore that which we call Cold, is nothing else but a more remiss degree of Heat.

II. Why a Hand be∣numb'd with cold, when held to the Fire, is seized with ex∣tream pain. It happens sometimes in very Cold Weather, that Mens Hands, and other parts of their Body grow numb'd; which when they come near the Fire, are seized with very sharp pricking and shoot∣ing pains.

The Reason whereof is, because the particles of Fire, being in continual motion, do with violence run a-tilt upon the Nerves of the Hands, or other Members that are benumb'd with cold, and wound them as it were with so many pointed Lances. Which Vellication of the Parts cannot be without causing great Pain. Wherefore to restore a Hand benumb'd with cold, we must not presently expose it to the Fire; but first gently rub it, and endea∣vour to bend and move the Joints, that by this means the chaced blood may be recalled, and the parts that were asleep or benumb'd, may again come to themselves. Wherefore in Swedeland, Denmark, and other cold Countries, when any one chanceth to be thus benumb'd with cold, or in danger to be seized with a Gangrene, they pre∣sently put the part into cold water, or Snow, for by this means the pores that were shut up by the cold, are opened by degrees, and make way for the banisht vital Spirits to return to them again, whereby the parts are soon after recovered to their former state.

III. What hap∣ned to K. James I. in Denmark. Thus BARCLAY tells us, that when King JAMES I. was in Denmark, and that by the cold, the end of his Nose, and the Lappets of his Ears were become without all feeling, and almost mortified, he by the advice of the Inhabitants, ap∣plied Snow to them, to preserve them from a Grangrene.

The Reason of this cure of frozen and be∣numb'd parts is, because the grossest matter of the Second Element, which got out by their pores, when the cold began to shut them up, cannot re∣enter again, in order to restore to those parts their former softness, without destroying their connexi∣on, which might cause a mortification or Gan∣grene, which is avoided by rubbing the parts with Snow, because the Snow contains nothing in its pores besides the most subtil matter of the Second Element, which is very proper and fit to open by degrees the pores of the congealed parts, till they be wide enough to let the more gross matter of the Second Element pass through them also.

V. How frozen Apples may be restored to their former state. Neither can any other Reason be given, why frozen Apples being put into cold water, are restored to their former condition, than that the cold water doth gently dissolve the congealed Humour in the Apples, and consequently causeth that effect of the Cold to cease.

V. Why the Air is so exceeding clear in Extream cold wea∣ther. During the most violent Cold of Winter, the Air is most thin and serene; but when the Cold is more remiss and moderate, it is generally Misty.

The Reason whereof is, First, because extream Cold doth more condense the thick Vapours of the Air, and by this means makes them to fall down, and consequently leave the Air more clear and serene than it was before. Secondly, Because ex∣tream Cold shuts up the pores of the Earth, by which means the Vapours are hindred from exhaling thence, and darkning the Air. Whereas moderate Cold produces a cloudy and misty Air; because the weak Heat which is joyned with that Cold, raises up Vapours from the Earth, which it is not strong enough to discuss or dissipate.

VI. Marble in the Heat of Summer retains its Coldness. Some Bodies never quit their Coldness, as Marble, and such like, which in the hottest season of the year feel very cold. So likewise Ice retains its hardness in the Summer, and is as cold then as in the Winter.

These familiar Instances make out, that Cold is nothing else than Rest or privation of motion. For the parts of Cold Bodies do cleave and stick fast together, so as to constitute a most close and compact Compound. But how doth it come to pass, that Marble, Ice, and other Bodies of like Nature, do preserve their Coldness, at all Seasons, in the same intense degree?

I Answer, That this proceeds from the Hea∣venly Globuli, which penetrate their pores; for the largest of them being endued with a stronger force of moving, do produce Heat: Whereas the lesser of them, which are inferiour in Force to others, do communicate Cold to Bodies, as will appear from the Experiment. Marble therefore is thus Cold, because the pores thereof are so strait and narrow, that they can only admit the very least particles of the most subtil Body, excluding the greater that cause motion. And forasmuch as Water does never freeze, except when the Matter which runs between its parts is more subtil than ordinary, it so happens that the pores of Ice, which are then formed according to the bigness of these particles of the most subtil matter, by this means become so narrow, that they shut out those particles that are never so little greater. And this is the reason why Ice continues to be most intensly cold in the midst of the greatest heats of Summer. This also may be perceived by the Dissolution of it; for Ice doth not melt like Wax, whose flexible particles, give way to the Agitation of the Fire, and by the force thereof are separated: For the narrowness of its pores hinders the Heat from en∣tring to its inward parts, save only as the outsides of it melt away, and are broken by the force of it.

VII. How water by means of Salt, may be turned into Ice. Put some Water into a Glass, and lay Snow mixt with Salt round about it, so as to touch the sides of the Glass; and as soon as the Snow and Salt begin to dissolve, the water will be turned to Ice, not only in the winter time, but at any other time of the year.

The Reason of this Experiment is, because the greater Globuli of the second Element, which by their agitation are the cause of the waters fluidity, being of more force than those which run betwixt the parts of the Snow, and finding a more con∣venient place for themselves to move in, the stiffer and smoother particles of the Salt and Snow do necessarily tend that way: And forasmuch as Nature doth not admit a penetration of Bodies, and that all motion is performed by means of a Circle, the lesser Heavenly Globuli contained in the Rain and Snow, upon the approach of the greater, strive to get out, and to return to the places they have left, through the pores of the Glass. But because these Globuli are not sufficient to continue the motion of the water, consequently thereupon it becomes congealed, and acquires the coldness and hardness of Ice. And on the con∣trary, the Snow mixed with the Salt, dissolves and runs to Liquor, because it is agitated by the greater Globuli, which before, by their motion, kept the water liquid.

VIII. Whence it is that the Spirit of Wine doth cool. And probably it is for the same Reason, that Spirit of Wine, which is hot of its own Nature, doth cure Inflammations and the Squinzy; and also cools and heals the part that is scorched with Gunpowder; viz. because the Spirit of Wine hath its pores so disposed, that being applied to the enflamed part, it only admits the lesser Globuli of the second Element, which by their more remiss and soft agitation of the parts, do asswage the pain.

IX. Diseases cured by likeness and sym∣pathy. Thus the Inflammation of the Emrods are cured with a Toasted-Onion, or fulminating Gold mixt with Brimstone. For the Juice of the Onion being very sharp, with a mixture of Sowrness, as Salt Armoniack and Tartar also are, which enter the composition of fulminating Gold, draw forth from the part affected, the Humour that is analagous with them, and mixt with it. It is a thing also owned by Physicians, that Diseases of Men may be communicated to Animals, by reason of the analogy of parts. Thus Mr. BOYLE tells us of a Potters Son, that was cured of the Kings-Evil by a Dogs often licking of it; the Disease having been by this means transplanted in the Dog.

X. Cold is very hurt∣ful to Plants. Cold doth great harm to Plants, and if we may speak with the Ancients, doth scorch and burn them up like Fire.

This indeed is commonly ascribed to Cold; but if we diligently weigh the matter, we shall find that according to Truth it can be no more than the remote cause of this effect; because it rather proceeds from the Heat which follows upon the breaking of the Frost. For seeing that the heat cannot enter the pores of the Plants that are shut up by frost; neither can it restore to their Inward parts that degree of softness, which they had before their congelation; since the said Frost hath spoiled the connexion and situation of the other parts, and therefore there cannot but follow an entire change of the whole, that is made up of these parts.

XI. Why some∣times the contrary happens. But yet sometimes it happens, that some certain parts of Plants, do without hurt endure Cold, as when the pores of Plants are shut up by Cold before that they begin to bud; for before that time they do not so much abound with that watry Juice, and their pores however narrowed by Cold,

are still open enough to give entrance to the subtil matter that may agitate the parts. For it is not necessary that their contexture should be de∣stroyed by it, which are the first that bear the onset, before the Inward parts be set upon.

XII. Why is cold Body, such as Marble, cools the Air that is near it. The Air that surrounds a cold Body, as Marble, is colder than that which is farther from it.

The reason whereof is, because scarce any but the most subtil matter hovers about Marble, either that which is about to enter the pores of it, or which flows out from it: And because this subtil matter, because of the tenuity of its parts, is not able to move the thicker particles of the Air, that might cause the Sense of Heat in us; for this Cause it is that the circumambient Air is per∣ceived to be cold.

XIII. What is the Rea∣son of the cold Air that is about Fountains. And it seems to be for the same Cause, that a cool Air is perceived about those Fountains, whence the water leaps up with great force; viz. be∣cause the thicker parts of the Air, which serve to excite Heat, are seized, and carried away by the water gushing forth, so that nothing but the Aethereal matter is left there.

XIV. Why Cold makes the water in a Weather-Glass to mount up∣wards. When Water, or Spirit of Wine, tinged with a Red or other Colour, is put into a weather Glass; this Liquor doth of it self rise or fall, according to the coldness or heat of the Weather.

The Peripateticks assign the Cause of this Effect to be the condensation of the Air, which is in the upper part of the Pipe; and that thereupon the water is forced to move upwards, that it may fill up the Empty space which the Air hath quitted. But what, s••all we conclude then, that an insen∣sible Body, such as the water is, can be so solici∣tously concern'd for the good of the Universe, that lest Nature should suffer a Vacuum, it rather mounts upwards, in downright contradiction to its own ponderosity? Wherefore they speak with a great deal more of probability, who say, that in Weather Glasses the Air is condensed, and the water driven upwards by the incumbent weight of the Air. For in these Glasses the Elastick virtue of the shut up Air is very much lessened, by which means the Circumambient Air does more press the Water, than the Spring of the pent up Air can bear.

XV. The Frost rarefies water. Water is dilated by Frost, and takes up more space than it did before, whereof we have an e∣vident instance in a Glass-vessel with a long Neck, for when we expose such a Vessel fill'd with warm Water to the Winter cold, the Water will sensibly sink down or decrease, until it be come to a cer∣tain degree of Coldness: And not long after, it will begin to swell again and mount upwards till at last being bound to its good behaviour by Frost, it stands still and remains immoveable.

The cause of this Rarefaction is, because the particles of the Liquor that are shut up in the Glass, before they begin to be Frozen by Cold, grow Stiff, by reason of the lessened Motion of the subtil matter, and take up crooked Figures; and therefore cannot cleave so closely together, as when they were soft and pliable. And hence it is, that being vehemently shaken by the subtil matter, they cannot reduce themselves to so nar∣row a room as they had before, but require a larger wherein to dilate themselves.

XVI. VVhy wa∣ter freez∣ing in a Glass, does sometimes break the Glass, and at other times not. It is worth our observing, that Frozen Water by reason of its Dilatation does commonly break the Glass-vials wherein it is contained, especially if the upper part be Frozen first: Because the Water being dilated by Frost, sticks fast to the sides of the Glass; so that when the Water that is under it comes to be congeled likewise, it breaks the Glass, because it finds no room wherein to expand it self. But we find a quite contrary effect, when Water is Frozen in the bottom of a Vessel, first by Snow and Salt laid about it. For then the upper part of the Water doth by little and little mount higher, and by this means prevents the breaking of the Glass.

XVII. VVhy some∣times very strong Vessels are broken by the freez∣ing of the water that is contained in them. Wherefore it is no wonder, if sometimes great Vessels of Marble are broken by the freezing of the water that is contained in them, which CA∣BAEUS tells us he hath been an Eye-witness of: Nay, what is more, Artificers sometimes find by Experience, that some of their Copper Vessels have been broken for no other cause. It is also an Ob∣servation of the Noble and Ingenious Mr. BOYLE, that the space of Frozen water hath been increased a ninth or tenth part more than it was before; for else, how could it be that Iron Pipes, such as are made use of for great Guns, fill'd with water, and shut up with the greatest care and industry, should break by being exposed to the cold Air? As hath been often experienced in England, and other parts of Europe.

XVIII. VVhat the Reason is of the stiffness of the Particles of Ice. Neither must it seem any strange thing to us, that the subtil matter should not be able to bend the stiff particles of the water, when yet it hath force enough to move them; forasmuch as a lesser Force is required to move Bodies, than to bind them: For we can easily with our Hand thrust a Bar of Iron out of its place, but find our selves altogether unable to bend it.

XIX. VVhy the Ground that is frozen riseth higher. This will also inform us with the Reason, why the Ground that is frozen riseth higher, and bursts into many slits, to the great damage of tender Plants, whose Root s are often pluckt up; except these Chinks in the Ground be cover'd either with Snow, or some seasonable warm Rain. For the Frost raiseth and distends the particles of the Earth and Water, and so makes them take up more room, than if they continued in their Natural figure.

XX. Cold also Condenseth hard Bo∣dies. As it is the property of Cold to Rarefie the Water, so it is endued with another quite opposite to this, which is that of condensing almost all hard Bodies. For as Heat rarefies Bodies, by making their parts that are circularly moved, to remove somewhat farther from each other; so Cold, which is opposite to it, is the Cause why these Bodies are condensed, by keeping their parts at Rest, or by making them lose the determina∣tion of their Circular motion. Thus we find by Experience, that the most hard and compact Bodies, such as Metals, Glass and Marble, do sensibly contract themselves in hard Frosts, and become more brittle than before, and upon a Thaw return to their former state.

XXI. Great Cold provokes frequent voiding of Urin. It is also from the same Cause that men, who swim in Cold water, or otherwise affected with the Circumambient cold Air, are almost conti∣nually provoked to make Water; because the Contraction, which is an effect of the Cold, is communicated to the Bladder, and so causeth the

list to make water. And therefore if the Hand of one that is fast asleep be dipt in Cold water, it causeth him immediately to let go his water. And for the same Reason it is, that those who come out of a warm Bed, as soon as their Bodies come to be exposed to the cold Air, find themselves to stand in need of making water: For as soon as the motion of the particles is allayed by Cold, and the parts thereby contracted, the same is also com∣municated to the Bladder, which thereupon endea∣vours to rid it self of its burthen.

XXII. H••w it coms to pass, that Ice can be pre∣served whole and entire all the Sum∣mer over. Ice may be so preserved, as to retain its hardness all the Summer over, so as that it will scarcely melt when laid near the Fire.

The Reason hereof is, because the pores of Ice are so narrow, that it can admit nothing, save only the particles of the most subtil matter, and consequently by excluding all greater particles, hinders the Heat from entring to the Inward parts, save only as the melting of the Outward parts make way for it.

XXIII. Whence cold Bodies have the power of changing Water into Ice. Cold Bodies, such as the Air, often change the water they touch into Ice.

The Reason is, because cold Bodies, by their Touch, do not only lessen the motion of the insen∣sible parts of the water; but also forasmuch as they contain many Icy particles, that is, smooth and stiff, they make the greater Globuli to pass out of the water into the pores of the cold Bodies; and on the other hand, cause the little Globuli to pass out of the cold Bodies into the water. And forasmuch as these little Globuli, because of their remiss degree of motion cannot preserve the water in its fluidity, their motion by this means ceaseth, and by this Rest of their parts are changed into Ice.

XXIV. Fruits and Stones too, are spoiled by Cold. Extream Cold is of that Malignity, that it is the Cause of the Corruption of Bodies, changing their Colour, and spoiling all their Comliness and Beauty. This we see not only in Eggs and Fruits, but also in Wood and Stone, which with Frost are sometimes made so brittle, as to be unfit to be used in the Building of Houses.

Frost causeth this Putrefaction in Bodies, by dilating the watry parts wherewith the pores of Bodies are fill'd; because by this dilatation the fibres and other solid parts, are broken or distorted. For nothing else can be understood by Corruption, but the Transposition of parts, when those which were joyned, are separated, and enter upon new Combinations. Hence it hath been observ'd, that when the Eyes of Animals have been frozen, the Crystalline Humour hath become of a white Colour, whereas it was transparent before.

And from the same cause it is, that Men in Russia, and other cold Countries, do lose their Nose, Ears, and other parts of their Body, by the Rigour of the Cold, which mortifies and putrifies the parts, as before hath been said.

XXV. Cold some∣times per∣verts the order of Parts. Such is the Power of Cold, that it sometimes perverts the Order and Texture of the parts of Bodies. For to what else can we impute, that great Beams of Timber in very Cold Countries, are to that degree frozen, that except they be thawed with a moderate Heat, they slit to pieces, and are altogether useless for Building? Whence is it that Marle, laid upon the Ground to dung it, does never obtain its end more, than when it is frozen by extream Cold? For the Moisture that was contained in its pores being by this means dilated, the Texture of its parts becomes dissolved; so that whenever a good Shower falls, they are the more easily dissolved and mingled with the Earth.

XXVI. The Cold preserves some Bo∣dies from Putrefa∣ction. And on the other hand, Cold preserves some Bodies from Putrefaction; whereof the Swallows are an incontestable Proof, which being stiff with Cold, and in appearance no other than dead, are kept all the Winter over in many of the Pools of Poland, without the least taint of Corrup∣tion.

The Reason of this is, because Cold, whose Nature consists in Rest, doth restrain the motion of the parts, and consequently hinders their sepa∣ration from each other: For the dissolution of parts is the ready inlet of Corruption, forasmuch as thereby the whole Texture of the Body is dis∣order'd.

In like manner we find, that all manner of Meats and Drinks, are better preserved in Winter, than in Summer; and that Flowers and Fruits are kept for a long time untainted in Snow and Ice-Houses. Hence it is also, that Dead Bodies cover'd in the Snow, continue a long time without putrefying. In Iseland they customarily expose their Fish and Flesh to the Air, and when they are throughly hard and dry, preserve them untainted a great while without any Salt at all added to them; because the Cold keeps their parts at Rest, and suffers them not to be separated from each other.

CHAP. IV. Of Heaviness and Lightness.

I. Two Bodies of unequal Bulk are moved with an equal mo∣tion, if they be Spherical. IF two Bodies of a round Figure, the one of Lead, the other of Wood, of the same or diffe∣rent bigness, should be let fall from the same Horizontal Line at the same moment of time, they will both of them come to the Ground at the same time; neither will any diversity be perceivable in their Descent, which GASSENDUS faith he hath frequently observed.

No other Cause of this uniform motion can be assigned, but the equal propension of the Celestial matter, to withdraw it self from the Center of the Earth. For tho' the said Matter doth always, in an equal space of time, and with all its force re∣cede from the Center; yet doth it not wholly exert its Power upon the Bodies it meets with, but only that part of it which answers, and is equal to the Body it lights on. And forasmuch as there is great difference in Bodies, in respect of their Com∣position: Some of them are more solid than others, having less pores, which can only admit the most subtil particles of the Matter of the first Element, and very few only of the Globuli of the second; such as are Gold, Quicksilver, Steel. And others are more loose, or less solid, as Wood, and the like, which because they have more lax and open pores, do contain more Celestial matter, and therefore do more readily comply with the motion of the Heavenly Globuli.

But to Apply this to the matter in hand: If the Celestial Matter, which is in the Leaden and Wooden Body, should be taken away from them,

and that the Terrestrial Matter, which is mixed with the Heavenly Globuli, should likewise be re∣moved from them, that which remains of the Ce∣lestial Matter in every subordinate Body, and ex∣exerts it force upon the same, acts upon the re∣maining part of the Terrestrial Matter. For the Leaden Body being more solid, and consequently more able to resist, stands in need of a greater force of the Celestial Matter to press it downwards; whereas that which is less solid, will be carried down with a less force, and consequently they will both of them come down to the Earth with an equal swiftness. For to the equality of motion nothing else is required, but that the Celestial Matter be proportionate to the Terrestrial; which latter, when it is greater, the greater activity is required to overcome its Resistance; and when it is less, a less force of the Celestial Matter will serve to push the Body downwards.

II. Why no Bo∣dy, except it be more heavy than water, doth sink in the water. Wherefore if a Body that is more heavy than the water, be put into it, it presently sinks to the bottom; but if it be lighter, according to the dif∣ferent degrees of the said Lightness, either it swims on the top of the water, or only some part of it sinks into it. Thus an Earthen Vessel, filled with Air swims upon the water; because it is lighter than it, being compared with a like proportion of it. Whereas the same Vessel, filled with water, sinks to the bottom, because compared with a like proportion of water, it is heavier than it. Hence it is that when a Cup, with the Mouth down∣wards, is put into the water, it doth not go to the bottom, because the Air contained in it is the same as if it were one Body with it, which being lighter than the water, must needs swim on the top of it, without sinking, till the water have en∣tred the hollow of it.

III. Why Gold doth not sink in A∣qua-fortis. But this seems to contradict another Experiment, whereby we find that the Grains of Gold and Silver, tho' they be more heavy than so much of Aqua-fortis or Regalis, yet do not sink in it. But this is to be ascribed to the Saline Bodies which are diffused through the said waters, and which, as it were by a continual chain from the bottom to the top, do support each other, and so bear up the Grains of Gold or Silver. That this is so, may be confirmed in that, when common water is poured to them, after the dropping in of some drops of Oyl of Tartar, immediately the Grains of the Metal sink down to the bottom.

IV. Liquors that have communi∣cation toge∣ther, are more or less he••vy, ac∣cording to the degrees of their height. Liquors that have communication by Pipes that contain them, do gravitate upon each other, not according to their Breadth, but according to their perpendicular Height.

The Reason is, because these Liquors are like so many hard Bodies, put into the 2 Scales of a Ballance, whereof the one cannot go down, with∣out causing the other to rise proportionably: For as these hard Bodies, tho' of unequal bulk, are nevertheless of equal weight, when their force is equivalent thereto, so likewise the Liquors contain∣ed in Pipes that communicate with one another, tho' they be of unequal breadth, yet must needs be of equal poise, when they are of an equal height. As for Example, in a Vessel of Liquor, clos'd on all sides except only 2 holes, if one of them be fourfold bigger than the other, and a spout adapted to each of them, the force of one pound of Liquor, forcing the little Spout, will equal the force of 4 pound weight, forcing the greater, which is supposed 4 times larger than the other, so that whatever proportion there may be between the holes, if the force applied to the said Spout, or Pipes be equal to the holes, the Liquors will be in equal poise.

V. When Li∣quors are said to be of equal poise. When we say that Liquors that Communicate together are in equal poise, when their heights are equal, this is to be understood only, when the 2 Pipes are filled with the same liquor: For if the Liquors be different, their height will be in the same proportion as their weight: So that because QUICKSILVER is almost 14 times more heavy than water, one thumbs breadth of Quick∣silver, will weigh very near as much as 14 thumbs breadths of water.

VI. Why a Ball falling down from the top of the Mast into a Ship under Sail, yet falls down plum at the foot of the Mast. A Stone or Ball falling down from the Top of the Mast of a Ship in its full course, or tost up by one that rides on Horseback, falls down at the foot of the Mast, and on the hand of the Rider.

The Reason is, because the Ball in its descent or ascent doth not describe a Right, but an Oblique Line. For though it seem to them who are in the Ship to be Perpendicular, yet is it indeed Crooked or Parabolical. Which any one that plea∣seth may experience by casting up a Ball, or other thing into the Air, whilst he is riding in a Coach, for he shall find that the same, notwithstanding the progressive motion of the Coach, will fall di∣rectly into his hand; but if he shall command the Coach to stop immediately, he will see that the Ball doth not tend directly upwards, nor fall down perpendicularly, but obliquely, and so des∣cribes, as it were an Arch, or crooked Line, the one end whereof will be there where he casts up the Stone or Ball, and the other end, where he catches the same again. But the Reason why the Ball appears to him, to tend directly upwards, is because that as much as he moves forward, so much the Ball is advanced also. Now the Cause why the Ball▪deviates from a straight motion to á cooked is, because its motion is derived from a two∣fold moving force, viz. from that of the Arm casting it upwards, and from that of the Coach or Earth imprest upon the Arm Horizontally.

VII. Square Bo∣dies do un∣equally des∣cend to the Earth. All Bodies that are not of a Round Figure, are carried downwards by an unequal motion, as is evident in all Square, and other Ccorner'd Bodies, which tho' they consist of the same matter, and are of the same Bulk, yet differ in their motion, and unequally move downwards.

This difference of motion is caused by their Fi∣gure; which tho' it cannot be said to be the cause of their being prest downwards, yet doth much conduce to the diversity of their motion. For things that are Rough, do more slowly fall through the Water or Air; and the broader their surface is, the greater resistance do they make against the Body through which they pass; because they do not divide it uniformly and steddily. Thus Wa∣ter and Ice, are kept hanging in the Air; and greater Flocks of Snow congealed by cold, are more slow in their descent than drops of water. And it is for the same reason that Birds, with their spread Wings, keep themselves pois'd in the Air, viz. because the Air opposeth a greater re∣sistance to a spread or plain extension, and hinders its falling down.

VIII. Why the Bodies of some per∣sons drown∣ed, do after some time, rise up to the top of the water. Drowned Bodies do after some space of time rise from the bottom, and swim at the top of the water.

This Effect is commonly attributed to the break∣ing of the Gall, but this I look upon only as a Fable. Wherefore I suppose that the true Reason why drowned Bodies rise to the top of the water is, because that the water entring into their Bo∣dies, doth extend the Membrans thereof; by the expansion whereof, many other Cavities also are opened, which by taking in the Air, are distended to a greater space: for such Membrans as these, be∣cause of the connexion of their parts, do reject the water, and can only be filled with Air. By which means the Bodies having got greater exten∣sion, and made more light are driven upwards, and so swim on the top of the water.

IX. New laid Eggs are heavier than stale ones. In like manner it is the entring of Air, that makes Eggs to be lighter when they are stale, than when they are new laid; for when they are newly laid they are top-full with their own sub∣stance, without any air; but when they grow stale, some particles of the White and Yolk do ex∣hale, and leave an empty space, into which the subtil Air enters, and it may be the more gross also, through the pores of the Shell; so as that it must not seem strange to us, if they do not sink in the water as deep as they did▪ when newly laid.

X. Why the dead Bo∣dies of Men swim with their Faces upwards, and those of Women with their Faces down∣wares. Accordingly also, the reason is evident why Female Bodies swim on the water with their Faces downwards, but those of Men with their Faces upwards. For Women having greater Bel∣lies, and more Cavities in them, besides their Breasts, which are of a Spungy Substance, do take in more water in those parts, and therefore by the weight thereof are turned with their Body downwards: Whereas Men have more narrow Bellies, lesser Breasts, and strait Urinary Pas∣sages, with large Lungs and broad Shoulder-blades, which are the cause why their Bodies should swim with their Faces upwards.

XI. How Men may best hinder themselves from drowning. Wherefore Men, if whilst they are swiming▪ they find themselves in danger of being drowned, they can do no better for the avoiding of that danger, than to extend their Chest, and hold their Breath. And therefore Fishes, that they may swim with the more ease, have Bladders blown up with Air in their Bellies. And in like manner Bees, that they may the more lightly hover in the Air, have the Trunk of their Body fill'd with Air.

XII. Burnt Bricks are heavier▪ than they were before they were burnt. It is found by Experience, that burnt Bricks are heavier than unburnt.

The Reason whereof is, because the pores of unburnt Bricks are wider, and filled with Air on∣ly after that they are dried: Whereas Bricks after that they are burnt, have many Cavities, of such a bigness as is fit to admit the particles of water that run into them, when they are exposed to the Air to be cooled. For there is always great store of these particles in the Air, and which intruding themselves into the pores of the Bricks, do en∣crease their heaviness. A confirmation whereof may be, that if the same Brick be weighed a•• soon as it comes hot out of the Brick-kill, it will be found more light, than after it hath been for some time exposed to the Air; and if afterwards it be put into the water, it will still be found more heavy, because the particles of the water which are entred into its pores, cannot get out.

XIII. A Stick thrust into the water, mounts up with so much the stronger force, as the water is higher. If a Stick be plunged into the water perpendi∣cularly, it riseth up again with the greater force, as the water is higher.

The Reason of this is to be fetched from the nature of Gravity: For seeing that the Stick can∣not move upwards, but only in as much as it is driven up by the water, it must follow that the greater the force of the expelling Body is, so much the more strongly the Stick must rise out of the water: Now this force is by so much encreased, by how much the weight of the expelling water is greater, by the force whereof it drives up the Stick; and therefore it follows, that the higher the water is, with so much the greater force is the Stick driven upwards, and so much the swifter it ascends.

XIV. Bodies des∣cend by un∣equal num∣bers. The motion of Heavy Bodys is encreased ac∣cording to uneven numbers: As if suppose a Stone fall down one Ell in the first moment of time, in the second it will fall 3, in the third 5, and in the fourth 7, and so on according to the following un∣even numbers.

The Reason whereof seems to be, because the heavy Body, in the first moment of time hath by little and little acquired one degree of swiftness. Wherefore at the beginning of the second Time, having that degree of swiftness which it acqui∣red, it will pass through as much space again, as it did in the first moment; and moreover by little and little acquiring force by its weight, by means whereof it passeth also through an equal space to that which it measured during the first moment; it must needs follow, that being now moved by both these forces together, it will pass through a triple space to that it past at first. At the third moment of time likewise it hath two degrees of swiftness, whereby it measures four times as much space as the first was. And in the mean time also by this innate Gravity, whereby it is continually pressed, doth acquire another degree, whereby in like manner it measures the space of another Ell. Being therefore thus furnisht with three degrees of swiftness, it passeth through 5 times as much space, as it past at the beginning; and so afterwards continues to make its progress by uneven numbers, because the acquired degrees of swiftness always continue the same, as well as its natural heavi∣ness.

The Times being 1, 2, 3, 4, 5, 6, 7, 8.

The Intervals or Spaces are 1, 3, 5, 7, 9, 11, 13, 15.

XV. Whether Dead Bo∣dies be more heavy than L••∣ving. It is the common received opinion, that the Bodies of Animals, after death, are more heavy than when alive.

The Cause of this change is commonly attri∣buted to the want of Vital and Animal Spirits; which being supposed, not only to be active, but also very light, do fe••m to diminish their Gravity. And forasmuch as Flame is lookt upon as the most light of all Bodies; no wonder if some have ascri∣bed the Lightness of Living Bodies to that Flame, which being diffused through the whole Body of the Animal, doth vivisie it, and is therefore called Vital. But however, notwithstanding, this Rea∣son seems probable, yet I would have us rather trust to Experiment, than to this Reason. For Mr. BOYLE, for a trial, weighed a Mouse alive with a Packthread tied about its Neck,

wherewith it was strangled immediately after, and when dead, was found to have lost of its former weight 7/16 of a grain. And the same thing was experimented by him in a Whelp, which alive weighed 10 or 11 ounces, and being strangled, was found 4 grains lighter. Which Experiments absolutely contradict the common opinion, that Dead Bodies are more heavy than living, and that by the loss of Spirits they acquire a new degree of Gravity.

XVI. An Arrow ••••••nts▪and falls with the like swiftness. An Arrow shot into the Air upwards, descends from its point of Elevation with the like swiftness, as it was shot up thither by the Hand of the Ar∣cher, tho' not in the same manner.

The Reason is, because an Arrow, in the be∣ginning of its ascent, is not carried with more swiftness, than towards the end of its descent: Nor on the contrary more slowly towards the be∣ginning of its Descent, than at the end of its Ascent, and therefore it is necessary that the Des∣cent of the Arrow should be as swift as its Ascent.

XVII. Square Pieces of different matter, be∣ing laid upon one another, descend equally. A square piece of Wood, and another of Lead being let fall severally, make an unequal descent, but if the Wooden Square be laid upon the Leaden, they will both descend with equal swiftness.

The Reason why a Square Piece of Wood, and another of Lead do descend unequally is, because besides the force of the subtil matter driving down∣wards, there is a greater force in the square piece of Lead to resist the Air, than there is the Wooden Square. For if the square piece of LEAD be of 16 pound weight, and the Wooden Piece of 1 Pound, and the resistance of the Air as two, forasmuch as both the Cubes are supposed to be of the same magnitude, the Proportion of the Lead, must have the same proportion to the resistance of the medium, as 16 to 2, and of the Wooden Cube, as 1 to 2. And therefore it is necessary that the Leaden Cube should fall down more swift∣ly: but when the Wooden Cube is laid upon the Leaden, so as that no Air comes between them; the Gravitation of them both must needs be equal, since they have both the same Resistance, and the medium makes way for them both at once.

XVIII. Why water mounts up∣wards through the Leak of a Ship. Water, like to Light Bodies, mounts upwards through the Leaky Bottom of a Ship.

For seeing that Water is heavy, and presseth upon the Body it lies upon, it cannot be but that the water which flows about the bottom of the Vessel, must be thrust away by the water that lies above it. For the parts of water which are above, press downwards by their weight or heaviness, and force that which is under them, to enter through the Leak into the Ship; so that if there was a Pipe fitted to the said holes, there is no question but the water would rise up through the same, as it doth in Fountains.

XIX. Whence the different heaviness of Bodies doth pro∣ceed. Bodies are very different from one another in weight; as Quicksilver is much more heavy than water; neither are there any metals but differ from each other in this Quality. Thus Gold, if we will believe GASSENDUS, is 10 times heavier than Earth; Lead, 7 times; Silver, 5 times; Pewter or Tin, 4 times; Loadstone, 3 times, Whetstone as heavy again, &c.

And forasmuch as it is frequently of great use, to know the weight or heaviness of several Bodies, I shall here subjoin a Table, exhibiting the just weight of different Bodies, according to the Pa∣ris weight that every Square Foot of them weighs.

• A Cubical Foot of Water—72 Pounds
• A Cubical Foot of Wine—70⅘ Pounds
• A Cubical Foot of Oyl—66 Pounds
• A Cubical Foot of Tin—532⅘ Pounds
• A Cubical Foot of Iron—576 Pounds
• A Cubical Foot of Copper—648 Pounds
• A Cubical Foot of Silver—744 Pounds
• A Cubical Foot of Lead—828 Pounds
• A Cubical Foot of Quicksilver—977 1/7 Pounds
• A Cubical Foot of Gold—1368 Pounds
• A Cubical Foot of Earth—95½ Pounds
• A Cubical Foot of Bricks—130 Pounds
• A Cubical Foot of Sand—132 Pounds
• A Cubical Foot of Stone—140 Pounds
• A Cubical Foot of Marble—252 Pounds
• A Cubical Foot of Irish-slate—156 Pounds
• A Cubical Foot of Salt—117 2/2 Pounds
• A Cubical Foot of Honey—104 ••/5 Pounds
• A Cubical Foot of Wax—68 1••/••8 Pounds
• A Cubical Foot of Air—••/5 of an ounce. Pounds

All which different degrees of Ponderosity of Bodies proceed from the various Make and Tex∣ture of their parts, whether inward or outward. For it cannot be questioned but that there be ma∣ny Pores between the Particles of all Bodies, through which the subtil matter passeth continu∣ally from the abundance or fewness whereof the diversity of Bodies doth arise. Hence it is that Quicksilver is found to be so much heavier than Water, because it hath fewer of these Pores. For tho' we may imagin, that Water and Quicksilver consist of parts that are of the same bigness, and that their motions are alike, yet will their diversi∣ty clearly appear to us, if we consider the parti∣cles of Water to be like a soft and flack String, and the parts of Quicksilver, as having fewer Pores, to be like hard twisted Strings, that are much more stiff and hard. And the same is to be understood of those metals which are several times heavier than the Earth, since that all difference proceeds from the multitude or paucity of their Pores that admit the subtil matter, and do vari∣ously dilate and contract themselves in compliance with its motions.

XX. Lead seems more heavy while it passeth through one Body, than through another. Lead sinks more slowly in the Water, than in the Air; and a Log of Wood which is very bur∣thensom to the party that carries it, rests on the surface of the water, and scarcely seems to be of any weight at all.

A twofold weight may be understood to be in Bodies, the one Absolute, and which is not subject to any alteration, as being indistinguisht from the Body, and cannot be encreased, but by the addi∣tion of parts to it. Thus Gold is heavier than Lead, because its parts lie more snug and close together, and have straiter pores. The other weight of Bo∣dies may be called Relative, which varies accord∣ing to the different position of the matter; and according to this notion of Gravity, Lead is said to be less heavy in the Water than in the Air; because the water doth more strongly resist it, and by that means detracts much from its weight. Thus Wood swims upon the top of the Water, and doth not sink till it putrifie and corrupt,

because the water is heavier than wood, and drives it up to the surface. For the parts of water, in the same bulk, are more than twice as many as the parts of wood; and according to the Laws of Nature, Things that exceed in number, cannot be driven forwards by those that are fewer. Thus it hath been observed, that a Young man that weighed 130 pounds, did not weigh in the water above 8 Ounces.

XXI. How we may know the diffe∣rent weight of Bodies. And on the contrary, if a heavy Body, as for Example Copper do much exceed water in ponde∣rosity (for it is accounted to be 9 times heavier than water) it will lose a 9th part of its Gravity. So that if Copper should be hung up by a string first in the Air, and afterwards in the Water, then the 9th part of the weight is to be removed out of that Scale which hangs in the Air, that there may be an Equality. And by this means we shall easily perceive the true weight of every Body, and how much more heavier it is than the water.

XXII. The diffe∣rent Hea∣viness of Bodies in the Air, and in the Water. So in like manner it happens that those things, which when weighed in the Air, are in equal poise, do lose the said Equality when put into the water, by Example Copper and Lead: For Lead put into the water, takes up a less space than Copper of the same weight; and therefore when both these Bodies are weighed in the water, the Lead must of necessity out-weigh the Copper, with which it was in equal poise in the Air. And by this means it will not be difficult, to know what Metals, according to their bulk, are heavier than others. For if when they are weighed in the Air, neither of them exceed the other in weight, and that when put into the water, they are not in the same equal poise, that which out-weighs the other, according to its bulk, must be supposed heavier.

XXIII. Respective Gravity may be changed; but absolute cannot. Whence it follows, that the respective Gravity of a Body may be changed, whilst the absolute still continues the same: As suppose we put into one of the Scales of a Balance 100 Pounds, and in the other 50, then the absolute Heaviness of the first weight will be always of 100 Pounds; but the respective Heaviness will be only of 50 Pounds; nay, it will be no more than 20 or 30 Pounds, if we put in the other Scale a Body of 80 or 90 Pounds. And for the same Reason, if we hang the weight of 100 Pounds at the end of a Standard, tho' the said absolute weight continue, yet may the respective be changed every moment; according as the weighing Body is nearer or far∣ther from the fixed Point, than that weight is, which is at the other end of the Standard.

XXIV. Heavy Bodies increase their mo∣tion in falling. Heavy Bodies do not move equally in their Descent, but accelerate their motion; as is evident in Stones, which according to the greater distance from whence they fall, make the stronger impres∣sion upon the things they light on.

The Reason is, because a Body, at the beginning of its motion, moves but little; for the subtil matter, which takes up its place, and which alone acts upon it, does not drive it downwards with that swiftness wherewith it endeavours to with∣draw from the Center: But when the Body begins to descend, the subtil matter which is under the Body, and which with great endeavour strives to get above it, doth continually drive it downwards, and adds new degrees of Swiftness to those it had before.

Or else we may say, that the motion of Heavy things is accelerated; for that Bodies in their de∣scent do acquire a new Force. For tho' they pass but slowly at the first moment of their motion; yet at the second they must move more swiftly, because they retain their former motion, and receive an augmentation of it from the Action of the most subtil Matter.

XXV. A Bullet driven through a Pipe or Bore, moves unequally. Thus when a Bullet or Pellet is by the blast of our breath driven through a Pipe, the Breath that proceeds from our Lungs, doth with repeated Onsets strike against it, whereby the first impulse imprest upon it is increased, and new degrees of Swiftness added thereto, whereby it becomes more vehement than it was at first.

XXVI. Why Water falls down unequally through Pipes. Hence it is also, that the water which by Ex∣ample is fallen down 3 Foot and an half, hath its Force once and half as much increased, more than that water which hath made a descent of one Foot only; and that consequently the water which gusheth out of a Pipe fill'd to the height of 3 Foot and an half, must run twice and an half faster, than when it runs from a Pipe that is only full to the height of one Foot; for that by that time it is come to the end of the Pipe, it will have acquir'd in its descent twice and an half more Swiftness, ••••an it would have got, if it had only made a descent to the 4th parth of the Pipe.

XXVII. The accele∣ration of motion is performed by the ac∣quiring of a new de∣gree there∣of. Nevertheless, we must not imagin that the motion of Heavy Bodies doth increase conti∣nually, so as to have no bounds of its augmen∣tation: For the Air resists the motion of Bodies, and blunts their force. Hence it is that a Bullet discharged from a Canon at a great distance, doth less hurt, than if it were shot nearer. And so like∣wise we see in the Pneumatick Engin, that when all the Air is pumpt out of it, heavy Bodies do fall with a great force at the first, and do exert the entire force of their Gravity: Like as Bodies cast up into the Air, in the beginning of their motion, do exert the whole Swiftness they have received.

XXVIII. Why a Pail is not heavy in the water. A Pail full of Water, in a Well or Pool, loseth all its Gravity; seeing that with the least force it may be removed, this way or that way, upwards or downwards, without almost any perception of ponderosity.

The Reason is, because the parts of water, whilst they are mingled and hang together, do do not press one another; for being all of them equally solid, they are all equally prest towards the Center by the Celestial matter; and therefore the Pail, because of their equal pressure, is with the least force moved any way. In like manner a man that is sunk under water, is not sensible of any ponderosity; because the Waters which lie upon him, are less pressed by the Heavenly Globuli that run between them, than the man himself, who is a more solid Body, and consequently less pervious to the subtil matter.

Which is the Reason why Divers cannot come to the bottom of the Sea, without Weights hung upon them; because they are equally pressed by the water that surrounds them, and as much born up by that which is beneath them, as they are thrust down by that which is above them. So that if a Diver being at the bottom of the water, could apply and fasten to his Arm or Thigh, the lower part of a long Pipe, the other end thereof

standing out above the water; so that the water could not come in between them, that part of his Body would presently begin to swell, it being free from the pressure of the water, and the Blood would run thither from the other parts of the Body.

XXIX. A Body is more hin∣dred in its descent, by Running-water. Hence it is also that a Body is more born up by Running-water. For the force of swiftly Running-water, doth make the ponderosity of the Body almost insignificant; as we see in things that are thrown or cast upwards. Wherefore we find, that a Body doth more easily swim on the top of Run∣ning-water; because there are many more parts of the water that resist its sinking, since conti∣nually other new parts succeed to support and keep it up. And this is the foundation of the Art of Swimming.

CHAP. V. Of Taste.

I. Hard Bo∣dies, as Stone, Iron, and the like, are insipid. HArd Bodies, such as Stone, Iron, Lime, Harts∣horn, &c. are insipid, and do not at all affect the Tongue.

Because the particles of Hard Bodies cannot be separated from each other, and consequently be mingled with the Spittle in our Mouths. For when Bodies are so compact that they cannot dis∣solve and furnish those particles, which by the Vehicle of Moisture, may be conveyed into the pores of our Tongue, no wonder if they be insipid. For tho' Sugar, when melted, affords a sweet taste; yet when the same is brought into solid and compact pieces, it affords no taste at all, because its parts cannot readily be separated, to impress any taste upon the Organ. So for the same Reason Pills, when they are swallowed whole, are scarcely per∣ceived, because they do not stay long enough to have their outward parts dissolved, without which they cannot affect the Organ of Taste.

Thus Turpentine boiled, and made into Pow∣der, is lookt upon to be insipid; because the more subtil parts of it cannot be diffused or mingled with the Spittle: Whereas in its Liquid form, it exhibits a bitter taste. So that Experience teach∣eth us, that nothing else is wanting in these Bodies, to make them Savoury, but only the division of their parts; seeing that the Salts which enter the Composition of Glass, were savoury before they were compacted into that hard consistence, and that Metals reduc'd into very small powder, tho' before they were insipid, do now yield a most strong and intolerable taste.

II. VVhy Bo∣dies are distinguisht by Taste. Almost all Bodies are distinguishable by their tastes; as Honey is sweet, Wormwood bitter, &c.

The general Cause of all Tastes and Savours depends on the greatness and figures of the parts of savoury Bodies, which are capable of being diversified after an infinite manner of ways: And forasmuch as Bodies are in a manner all of them composed of parts that are of a different bigness and figure, it must not seem strange to us, that we meet with so great a variety of Tastes.

III. Hot Meat is more savoury than cold Meat. This difference of Tastes, is sometimes caused by the various agitation of the parts of Bodies; for we experience that hot Meat is more savoury than cold, because heat increaseth the motion of the parts of the Body; and besides, it is certain, that the more any Body is moved, the more fit it is to move another Body that toucheth it: And there∣fore it connot seem strange, that Meats, when hot, are a great deal more savoury to us, than when they are cold. This is the Reason also why dressed Meats are far more savoury than raw, because the heat of the fire that dresseth them, divides them into lesser parts, whereby their figures are changed, and so make them to be of a very different Taste from what they were, when Raw.

IV. Sweet things do sooner cloy the Sto∣mach, than Meat of a sharp taste. Sweet things do sooner fill than sharp. Thus we find that Milk-meats, Sweet-meats, Butter, Honey, &c. do sooner satisfie our Appetite, than sowre and sharp things.

Some suppose the Cause hereof to be, because Sharp things do afford little Nourishment, and much Excrement; but this Reason seems of no force, because Digestion does not immediately follow upon the taking down of our food: But the Cause why Sweet things do sooner glut the Appetite, than sharp and sowre things is, because these latter are made up of parts whose surface is very rough and rugged, that is, which have many Angles or Inequalities, which make them fit to twitch and vellicate the Bodies they touch or apply to; and by this their vellicating of the Stomach, do stir up the Appetite: Whereas Sweet things consisting of smooth Bodies, and such as gently affect the Stomach, without exciting of the Appetite, do presently fill and satiate.

V. The Fire excites a sharp taste in Meat drest by it. Fire procures a sharp Taste to Meat; for we find that Rost-meat doth with more sharpness strike the Tongue, and affords a more grateful taste.

For it is evident that there is no food, but con∣tains some Salt, which is in a manner equally diffused throughout the whole Mass of it. Whence it is, that when Meat is agitated by the heat of fire, some part of this Salt is carried to the outside, and exhales with the other Liquid parts, and constitutes that Smoak which we see proceeds from Meat that is a Roasting. But whereas they are only the insipid particles that fly into the Air, those of the Salts can scarcely rise 2 or 3 fingers high; but that by their weight they are forced down again to the surface of the Meat, and there produce that sharp taste which we experience in Roast-meat.

VI. Sowre and Harsh things set the Teeth on edge. Things harsh and sowre, set the Teeth on edge; as unripe Fruits, harsh Wines, Verjuice, and the like.

The Reason is, because the fixt Salts that are in these Bodies, being entangled in a gross Sul∣phur, compose together with it parts, whose Surface is bristled with many Hairs variously bent, which entring into the pores of the Tongue, shut up the parts thereof.

VII. VVhy Bit∣ter things do heat, and Sowre, cool. Bitter things, as Orange-Peel, Venice-Treacle, and many purging Medicins do heat; but Sowre things, such as Juice of Orange, Sowre Grapes, &c. do cool.

Because Bitter things consist of sharp Salts, and gross Oils, which being agitated together, do excite and preserve heat; whereas the parts of Sowre things are long, stiff and pointed, and rather stop the motion of the fiery particles, than promote it, and for that Reason are esteemed of a Cooling Nature.

VIII. Why un∣ripe Grapes and Fruits are harsh. Unripe Fruits seem very harsh at the first taste, and cause a Roughness on the Tongue; but after∣wards they turn sweet, and acquire a pleasant relish.

The Reason is, for that Fruits, before that they are ripe, do consist of longish parts, which by their motion do, as it were, cut the fibres of the Tongue, and contract them; and afterwards they grow ripe by means of the fire or the heat of the Sun, which digests their raw Juice, and by ex∣haling the Heterogeneous parts, reduceth it to sweetness. For it is evident, that there is a con∣tinual resolution and division of parts in Fruits that tend to maturity, by means whereof they lay aside their hardness and harshness, and after perfect Concoction become soft and pleasant.

IX. A Tongue that is either too dry, or too moist, can taste nothing. A Tongue that is parch'd and over-dry, hath little or no taste; and so likewise when it abounds with over-much moisture.

The Reason is, because Taste doth not only consist in moisture or driness apart, but in a mixture of them both. And therefore it is no wonder, if a too dry and parched Tongue, cannot perceive the taste of solid food, seeing that the same cannot be macerated or dissolved without moisture, which is necessary in order to the Sense of Tasting. For the Tongue being a spongy and porous part, stands in need of moisture, which is the vehicle of Savours. Moreover, in a dry Tongue the fibres are too much contracted, an•• thereby are made unfit to receive that affection, which the savour of things doth impress on it. And on the other hand, a Tongue too moist, i•• not fit for the reception of Tastes, forasmuch as the Tongue, which is loose and spongy, having its pores already filled with Humour, cannot well admit that which conveys the Savoury particles of the food, and by this means cannot perceive the taste of it. And it is for this very Reason, that we cannot relish Wine after having eaten some sweet thing, and that in order to recove•• our taste we eat salt meat, that may open the pores of our Tongue.

X. Why we find no relish in those things which we eat often. Some find that they lose the relish of those things, which they feed too frequently upon, and that either because these common Aliments do leave some of their particles in the Tongue, which render the little Nipples of it immoveable; or, because the Soul gives less heed to those motions that are ordinary and common, than to those which are new and unfiequent.

XI. Why we can better discern Tastes in the Morn∣ing. Tastes are better discerned in the Morning, especially before we have eaten or drank any thing, that can byass the Tongue to a mistaken Verdict.

Because at that time the Tongue is like fair Paper, and as yet unting'd by any Savours. For that which receives, must be free from a Taint of the thing received. Which is true not only in the Taste, but also in Hearing, Smelling, and all the other Senses: For by right, the Sense of Hearing is sharpest, and Blind men do better retain things than others.

XII. Persons sick of the Jaundise, cannot rightly discern the taste of things. Men sick of the Jaundise, suppose all things to taste bitter.

The Reason is, because the Gall is diffused through their Tongues, which infects their Spittle; for the Gall consisting of sharp particles, doth so corrupt the Spittle, that it communicates a bit∣terness and an ungrateful taste to all the Food that is eaten, as if something of Soot were mixt with it. The Cause of which Depravation is, because the Raw humour, which runs through the Veins and Arteries, betakes it self to the Tongue, because of its loose and spongy Flesh, and filling the pores of it, vitiate the taste of all received Aliments. Which is the Reason why Physicians commonly order their Patients to put out their Tongues, that they may view the colour and disposition of it; for seeing that that Member, proportionable to its bulk, contains abundance of Blood, it accordingly also admits a considerable deal of the morbifick Matter, which there discovers it self by its Colour, and consequently also the Sickness which disturbs the Body.

XIII. Whence the Harsh taste of Verjuice doth pro∣ceed. The Juice of unripe Grapes constitutes that which is called Verjuice, which is of a sowre and somewhat harsh taste; whereas the Juice of ripe Grapes is sweet, and with a pleasant briskness accosts the Palat.

The harshness of Verjuyce proceeds from the Roughness and Inequality of its parts; for be∣cause the Juice of unripe Grapes is not sufficiently concocted, they retain a great deal of Crudity, which is owing to their long and inflexible par∣ticles.

Hence it is that the Verjuice which is made of Crabs, is a good Medicine to help the weakness of the Eyes; because its particles being like so many little grains of Sand, do wipe off the filth of the Eyes, and by this means restore the Visive faculty to its former clearness. And the same Reason may be given of the Water of some particular Fountains, which by reason of their Acrimony do not only purge the Eyes, but also the Optick Nerves, that so the Rays of Light may be the more freely transmitted.

XIV. Why New Wine is sweet. But New Wine is sweet, because it hath been sufficiently decocted by Heat, and all its parts are smooth and even. And as to its muddiness, that is only caused by those Heterogeneous parts, which are not yet separated from it; which as soon as they are either precipitated to the bottom, or raised up to the top, by fermentation, the Wine becomes elear, by admitting the Heavenly Glo∣buli.

XV. What is the Cause of that variety of Tastes which is in Fruits. All Fruits are distinguishable by their taste, some of them having a harsh bitter taste, others a harsh sowre, other a sowre, and all of them a sweet taste after they attain to their full ma∣turity.

This difference of Tastes in Fruits, proceeds from the various Texture of the particles, and the different structure of the Plants that bear them. For grafted Trees bear more delicate Fruits than others, because the Alimentary Juice is more ex∣actly strained through the double twisting and weaving of their fibres. The Harsh-sowre taste therefore of Fruits proceeds from this, that their Parts are not yet sufficiently straitned and digested; and because the surface of them, as was said, is bristled with many little Hairs, diversly bending this way and that way, which entring into the pores of the Tongue, do shut them up. As we find in the taste of Quinces, Medlars, and generally of all unripe Fruits. Other Fruits afford a smart or sharp taste to the Palat, because their particles are long, stiff, and very subtil; by which means they

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Book. 2. Part. 2. Chap. 6▪

G. Freman. Inv.

I. Kip▪

prick and divide the Tongue, and dilate the same with some kind of sense of heat. Ripe Fruits do generally afford a sweet taste, because the Juice of the Plant whence they proceed hath been well strained, and lost all its Crudity by the agitation of the heat of the Sun. Wherefore also such Fruits as these do pleasingly smooth and stroak the Tongue, and with a grateful softness enter the pores of it.

XVI. VVhence it 〈◊〉〈◊〉 that the same Food is not equally grateful to all. Nothing is of more obvious Experience, than that the same food is not alike grateful to all; and that frequently what is very pleasing to some, is very distasteful to others.

Which proceeds from the different disposition of the Organ. For they whose Tongues are fur∣nisht with stiff and less plyant fibres, will be less exact in discerning the Taste of things, because they stand in need of a greater Force to move them: Whereas those whose fibres are more deli∣cate and tender, do more exactly distinguish them, because the least Vellication is sufficient to affect them. Somewhat like that which is found in the hands of those that are grown hard by much labour, which without any sense of Pain do handle Briars and Thorns, when those that have tender Hands cannot, without great pain, so much as touch them.

XVII. VVhy the same thing seems some∣times to have a different Taste. Hence it is that sometimes the same person, upon some alteration in the Organ of his Taste, caused by Age or Sickness finds a different Taste in the same Objects from what he formerly per∣ceived in them: For the Texture of his Organ being changed, the particles of the Bodies do no longer accord with it, but cause a kind of rout and confusion in it. And it is for the same Rea∣son that young Women, and such as are with Child, do sometimes take delight in some Meats which they formerly abhorred.

XVIII. VVhy dif∣ferent men, affect dif∣ferent Sawces. Whence it is that different men are pleased with different Sawces, and that there must be different Sawces to please the same person at different times and seasons. For one loves sweet Sawces, others sowr; one man delights in the taste of Wine, another abhors it; and the same person that is greatly pleased with the taste of it, when he is in Health, doth loath it when he is sick of an Ague or Fever, because the fibres of his Tongue are otherwise disposed than they were before. This is visible in Girls, and Women big with Child, especially in the first Months after Impregnation, who frequently delight in, and long for those things which before they abhorred, or at least had no inclination to, forasmuch as the particles of those things enter more smoothly, into the pores of their Tongues than before.

XIX. The Mi∣stake of some Peri∣pateticks. From what hath been said, we have reason to conclude, that it is a great Errour to place the taste or savour of things in the savoury Objects, as some Peripateticks do: For besides that in so doing they ascribe to an Inanimate Body, a way of Existence which doth not agree with them, the consequence of this Opinion is, that 2 Men would never be able to find a different Taste in the same Object, which is contrary to Experience. So that we must conclude, that the Power of perceiving Tastes belongs to the Soul, as well as that of feeling Pleasure or Pain; and consequently, that Taste is nothing else, but a certain perception or sensation, which is exerted by the Soul, by the motions which Meats produce in the Nerves of the Tongue.

CHAP. VI. Of Smelling.

I. Animals▪ by their Sense of Smelling, discover what is good or hurtful to them. SO great is the Affinity between Taste and Smelling, that they are produced and affect the Organs almost in the very same manner. For we find that Animals hunt out their Prey by their Scent, and by the same distinguish what is good, from what is hurtful to them. Thus the Smell of Catmint allures Cats; Fennel, Serpents; Bazil, Scorpions; Rue, Weezels, &c. As on the contrary, they avoid what is harmful to them by the help of the said Organ. Thus Serpents flee from the Scent of Galbanum, Scorpions abhor Wolves-bane; Flies, Brimstone; Goats, Bazil; and Ants, Organy.

The Cause of this Sympathy, or Antipathy, must be derived from the Organ of Smelling; which receives the diversity of Odours, according to the different affection and disposition of its fibres. For if the Steam that proceeds from an odoriferous Object, be delicate, and doth smoothly affect the Nerves of the Nostrils, it will cause a grateful Odour; but if the said Nerves be more rudely shaken or vellicated, this gives an unpleasing Scent. For Odour is nothing else, but the thin and insensible parts of Bodies, which being separate from each other, fly up and down in the Air, and being by the drawing in of our Breath re∣ceived into our Nostrils, do excite a motion in the Extremities of the Nerves. So that the diversity of Motions, produceth difference of Odours; and as the fibres of the Organ are more softly or roughly struck upon, accordingly are they diver∣sified. For this Reason we find, that Roses, Musk, Ambergris, and such like, afford a sweet Smell; because the Steam that proceeds from them, consists of subtil and flexible Filaments, which easily enter the Organ, and without any roughness are communicated to the Nerves. But Brimstone affords a strong and unpleasant Smell, because of the Ruggedness and Unevenness of its filaments. For Brimstone being very easily inflammable, we must suppose it to consist of many fat Steams, which being mingled with a sharp Matter, do make the filaments rough and prickly, which can∣not but affect the fibres of the Organ unpleasantly and painfully.

II. How sweet Scents may be produ∣ced from strong and unpleasant things. And on the contrary, when the strong Scent of Brimstone, is dulled by the joyning of some other Body with it, a grateful Odour is produced. Thus tho' Civet in a bulk, and by it self, have a very strong Scent; yet if 3 Grains be mixed with 10 Grains of Ambergris, and one Drop of the Juice of Lemons, and ground together, it will produce a most rich and grateful Perfume. In like manner, Musk, when it is by it self, yields a strong and overcoming Scent; but being mixt with some of the Spirit of Roses, it affords a most pleasing and delightful Smell. And they who bring Musk from the Indies, after that the Smell of it is in great part exhaled, do wrap it up in the Skin of the Animal from whence it is taken, or in Bladders, and hang it up for some days in some stinking place, having first made several Holes in

the said Skins or Bladders; and by this means re∣cover the Musk to its former fragrancy. Foras∣much as by this Fermentation, its parts are so se∣parated and attenuated, that they cannot but grate∣fully tickle the Organs of Smelling.

III. How some Bodies that have little or no scent, may be made odo∣rous. And it is for the same Reason, that the Oyl of Roses, drawn by distillation, being put into wa∣ter in a considerable Quantity, hath almost no odour at all, but being mingled with the Salt of Tartar, it makes a fluid composition, whereof some part being put into water, yields a very great and sweet perfume; the reason whereof is, to be a ascribed to the Salt of Tartar, which being a very powerful Alkali, exalts the Oyl, and renders it more volatile, and consequently more proper to be attracted together with the Air in Respira∣tion.

IV. To the per∣ception of Odours, some di∣stance is required. When a Man is too near to odoriferous Bodies, he cannot so well perceive their Effluvia. And therefore it is that Flowers do smell more sweet∣ly when they are at some distance from the Organ, than when they are too near it.

The Cause is, because the smell or odour of Ob∣jects doth not consist in their more gross and moist, as before hath been said of Taste, but in their thin and dry parts; and therefore he who is too near to the odorous Object, doth not only take in the steams that proceed from it, but also those that come forth from the Earth. But if he be some∣what further at a distance from it, he receives no∣thing but the more vivid and subtil steams, be∣cause the Grosser cannot go far off, but soon fall down to the Earth again. Wherefore some di∣stance is necessary, that the more brisk particles of the odorous Object, may freely and purely exert its power, and excite a grateful smell.

V. Perfumes are least perceived when too near. Hence it is that Perfumes cannot be so power∣fully perceived when we are too near to them; for they consisting of nothing else but a steam, flow∣ing from the odoriferous Body, by passing through some interval it becomes more purified and dis∣charged from its more thick and terrene particles, which dull and allay the sweetness of the odour. As we find that Wine mixed with Water is less tasted, because water doth break and allay its force.

VI. Plants in Syria and Arabia do far excel ours in smell. Plants in hot Countries shed a far more fra∣grant odour than in cold. Thus it is known that in, Syria, Arabia, the East-Indies, &c. many Spices are produced, and that the Fruits of the Trees that grow there, have more lasting and pungent odours.

The Reason is, the heat of the Sun in those Countries, which conduceth very much to the briskness and sweetness of odours: For by means thereof the Alimentary Juice of Plants becomes exalted and depurated in the highest degree; and thereby prepared to yield copious matter for those odoriferous steams proceeding from the Leaves, Fruits, and Flowers of them. For it is certain that odours consist of Sulphur or Salt, and that those Bodies which abound with these, do shed more abundant odours. Because heat is a great strengthner and exalter of the Sulphureous Parts, causing them to exert their force with greater ef∣ficacy; for after that the watry Humour is sepa∣rated, the remaining substance is more throughly concocted, and consequently yields a more fragrant odour. And therefore in order to the preserving of this Fragrancy, we make use of Oyl wherewith to cover them, or else shut them up in Boxes, to hinder the vapour from exhaling continually. For we find that all odorous Bodies do smell more strongly when they are hot, than when cold; in the Day time, than in the Night; in the Spring, than in Winter; and in Summer, than in the Spring, because then their parts are in greater mo∣tion.

VII. Heat con∣duceth ve∣ry much to the sweet∣ness of Odours. For the same Reason it is, that Fruits attain a more grateful scent by being prepared with fire; and that all things smell sweeter during the heat of the Summer, than when they are congealed with cold; because then their Sulphureous Parts are lockt up: whereas in hot Seasons the same is agi∣tated and diffused through the Air. And therefore we find that there are very few Seeds that afford any sent from them: for being of a very com∣pact substance, and consisting of a clammy sub∣stance, they do not easily send forth any Effluvia. And on the contrary, we find that Contusion or Bruising is a great means to excite that sweetness of odour which is found in dry things. Thus the pricking of the Rinds of Citrons or Oranges, ren∣ders them much more odorous. And Spanish Wax, which is without odour before it be put to the Fire, becomes very odoriferous, by the resolution of some of its parts into Smoak. The same may be said of Incense, Myrrh, and many other odo∣riferous Gums and Drugs, which do not exert their fragrancy till they be dissipated into Air.

VIII. What is the Cause of that sweet or strong smel•• which pro∣ceeds from some per∣sons. All Men do not smell alike, for some yield a very fragrant and pleasing odour, which Histori∣ans relate concerning Alexander the Great, whose Sweat was very pleasing and grateful to all that smelt it. Whereas others stink, or scent very strongly; which is observed of Flat-nos'd Persons, who are commonly tainted with loathsom steams proceeding from them.

A Sweet Odour proceeds from those persons, whose Alimentary Juice is exactly and throughly concocted; which then happens, when by the agita∣tion of the Body, the Pores are opened, to let out the particles of any crude Humours. The same may also be an effect of the Temperament of Men, as when Heat is greatly predominant in them; for if the said Heat be free, and is disintan∣gled from any superfluous Humour, it cannot fail of producing a sweet odour. Now that such was the Temperament of Alexander the Great, is evi∣dent from his inclination to the excess of Anger, the continual exercise of his Body, and the smooth∣ness and thinness of his Skin. But when on the contrary, the Alimentary Juice is not well digest∣ed, or by some means or other becomes depraved, this must needs produce an abominable and loath∣som smell; such as we perceive commonly in Flat∣nos'd Persons, whose steams are observed to be very nauseous; and that because the Pores, through which the Snot or Snivel is conveyed from the Brain, is too much straitned, and by reason there∣of putrifies and corrupts there. For Corruption is the most genuine cause of Stinks.

IX. Of the va∣rious Ver∣tue and Nature of Odours. And accordingly some smells are very refresh∣ing, and conducing to Health, whereas other are very inimical to Nature, and our Vital Spirits. Thus we are told that there is a People in the most remote Borders of the East Indies, about the Springs of the River Ganges, called Astomi or

Mouthless, who (if we may give credit to some Historians) live only by the odours they take in from Flowers and Fruits. So likewise it is notori∣ous, that there be many Scents which recall Per∣sons that are in a Swoond; and more particularly the smell of Vinegar: And every body knows how much Cats are delighted with the Herb Nepota, or Catmint; which acceptableness and congruity proceeds only from the odour of these things. And on the contrary, some smells are the cause of distraction, as it is related of the Sabaeans, that they used to be stupified by odours: And of Cats, that they became mad by the smell of some Oint∣ments: because these exhalations cause so violent an agitation in the Organ, that thereby the na∣tural Temperament of the Brain is destroyed, whence proceeds that tumultuary confusion of the Spirits.

X. Why distil∣led Waters lose their fragrancy, when the Flowers from whence they are drawn, are in their Prime. Rose and Orange-flower Water, with other such like Waters distilled from Flowers, keep their sweet smell all the year, except only when the Flowers, from whence they are drawn, are most fragrant, for then they lose their Scent.

The Cause whereof is, not because those Wa∣ters are indeed destitute of all Odour at that time: but the Earth then abounding with Flowers, which diffuse their steams throughout the whole Air, the Organ of Smelling is so much charged with them, that it cannot be affected with the smell that proceeds from those waters; and upon this account they are supposed destitute of all smell.

XI. The Fra∣grancy of things may be separa∣ted from their gross Body. Tinctures, Essences, &c. of Roses, Cinamon, and such like odoriferous Bodies, retain the same smell, which the things themselves had before.

The Reason is, because the nature of Odour consists in a certain texture of Sulphur and Salt. By Sulphur, the Chymists understand a Fat and Oily Substance, which according to its various mixture in various Bodies is different. Now since this Substance may by Chymical Art be extracted from Bodies, it must not be thought strange that it retains the same Odour, which the Bodies them∣selves before did.

XII. They who are troub∣led with Cold, lose their Smel∣ing. They who have got a Cold, do in a manner perceive no Odours at all.

Because the Rheum doth so obstruct the Pipes of the Olfactory Organ, into which the Odorous Steams use to insinuate themselves, that they can no longer enter them. For in this case the ob∣struction sometimes is so great, that there is no passage left in the Nostrils to draw ones Breath; and therefore it is no wonder, if the Nerves, be∣ing filled with this humour, cannot admit the Steams proceeding from odorous Objects, or if they do, yet cannot receive any due impression from them.

XIII. Why we perceive the odours of things better in the Summer than in the Winter. In Cold Weather, odorous Objects do more weak∣ly affect our Organ of Smelling.

This is, because in Winter time the pores are ob∣structed and contracted, so that their odorous Steams do not then break forth from the Bodies to which they belong. To which may be added, that the Air is thicker and more gross at that time, which therefore the odorous Steams are less able to penetrate. Hence it is that Congealed Bodies shed no fragrancy or smell at all, because by reason of the obstruction of the Pores, the Steam cannot di∣sperse it self in the Air, nor affect the olfactory Organ. Whereas on the contrary, in the Sum∣mer-time, smells are much better and strongly perceived, because the intense heat doth then agi∣tate and excite the particles, and sends them in greater abundance to the Organ. We observe also, that according as the wind is for or against us, so we either smell odorous Objects, or not smell them; for when the wind comes from those Ob∣jects, the smell of them doth more strongly affect the Organ; whereas when it is contrary, it car∣ries the said odorous Steams from us, so as that we perceive no Scent at all.

XIV. Dogs ex∣ceed Men in the quickness of Smelling. Many Beasts excel Men in the sense of Smel∣ling; and more especially Dogs, who not only exceed Men, but all other Beasts in this re∣gard.

The reason whereof may very probably be ascribed to their Organ of Smelling, as abounding with very fine and subtil Fibres, and those more fitly disposed for the reception of Odours. For it is observed that the Olfactory Organ of Dogs is drier than that of other Creatures; be∣cause their Snot doth not flow the ordinary way, but through some Pores, which may distinctly be perceived at the end of their Noses. Or else the cause of this more quick Scenting that is in Dogs, may be attributed to their not being subject to those gross Fumes arising from the Stomachs of Men, who feed upon such various sorts of Meat, which hinder the reception or perception of the subtil odorous Steams proceeding from Objects. Hence it is that Dogs, that are too much conver∣sant in Kitchins, and are too much fed, do by de∣grees lose their Sagacity, and become much infe∣riour to those who are kept shut up, and are only fed with Food, proper for hunting Dogs.

XV. Why the Sense of Smelling is weaker in Men than in Beasts. Neither is there any question to be made, but that if Men lived only upon vegetables, they would far excell others in this Sense, who fare more deliciously, and pamper themselves with Flesh and variety of Meats. Thus Sir Kenelm Digby, in his Treatise of Bodies, relates this story of one John of Liege, who fleeing into the Woods to avoid the violence of some Soldiers, li∣ved there many years, feeding all the while on Wild Apples, Acorns and Roots; who after he had been catched by some Country People, after having attained the use of speech, he declared to them, That as long as he lived in the Woods, he could by his smelling find out his Food, and distinguish that which was good, from that which was hurt∣ful; that by the same he was aware frequently of Hunters that had a design to take him, and by this means oft escaped their Hands. Which Ex∣ample makes it evident, that the quickness of the Sense of Smelling is spoiled by the vapours of di∣vers and dainty Viands; and the chief reason why Men are inferiour to Beasts in this Sense is, because their Diet is not so simple as theirs is.

XVI. Some Ani∣mals are signal for their quick∣ness of Smelling. It may also be allowed, that many Animals do exceed Man in this Sense, because of the vivacity of their Organs; as it is evident in Ravens, Vul∣tures and Dogs, which by their Sagacity pursue their Prey, or follow the footsteps of their Ma∣sters: Tigers, who by their smelling, follow them who have taken away their Whelps: Roughfooted Pigeons, who by the same sense, fetch back their Young, tho' carried into some House above 200 paces distant from them. Neither is it any

contradiction to what is here alledged, that Dogs in hunting, are sometimes at a loss, beecause this only proceeds from the great distance either of time or place in which the Odour is diffused, or when the odorous Steams are carried away by the Wind, or being mingled with other Steams pro∣duce a confusion.

XVII. How some odorous Bo∣dies may retain their Sent for a long time. It is certain that odorous Bodies by continual ex∣piration, become flaggy and are consumed; be∣cause their substance is continually wasted and dis∣persed by the exhalations that proceed from them▪ Yet as to the great, and almost inconceivable sub∣tilty of these Fumes, we have a very pregnant de∣monstration, in a piece of Ambergris, which af∣ter a continual expiration of odorous Steams for several years together, doth to our senses appear to be of the same Bulk. So that it may seem pro∣bable, that these Fumes do by a continual Circu∣lation return to their source again: Much in like manner as we have shewed in our Institution of Philosophy, that the Striate Matter moves circu∣cularly about the Loadstone; according to which Hypothesis it may be made out, that an odorous Body may continually shed its exhalations without losing ought of its substance by that means.

CHAP. VII. Of Sound.

I. Liquid Bodies when dasht together, make a noise. SOund doth not only proceed from hard and solid Bodies, but also from fluid, and which because of the pliablness of their parts, do give way to the motions of other Bodies. For the Air, when it is struck, conveys a Sound to our Ears; the Waves when they dash against each other, cause a great noise; and all Waters, ac∣cording as they run through a plain Channel, or are interrupted with Rocks and Stones, make a different impression upon the Nerves.

The Reason is, because the parts of the Air, as well as of other liquid Bodies, by their beating against each other, become divided into innume∣rable small particles, which being most swiftly moved, and dashing against each other, must needs produce a Sound. For a Sound is nothing else but a trembling and waving motion of the Air: And as we see that by the throwing of a Stone into the water many Circles are formed, which uni∣formly extend themselves to the Shoar or Banks; so likewise the Sound that proceeds from Bodies that are struck, is by reciprocal vibrations propa∣gated through the Air.

II. How a Sound comes to be dispersed round. Which will more clearly appear in the Figure. Let there be supposed a String that is struck, which may be conceived as a Cylinder, whereof the semisection will make an half Circle, MBR, so as that whilst it restores it self, every one of its points are moved with a strait motion, and by parallel Lines, as AB, PC, OD, NE, MF, Let us then suppose in the several points of this Section some particles of pure Air, or Moisture, which may be considered as Globuli, or small * 1.2round Bodies L, K, I, H, G, &c. which touch the Section in the points BCDEF: Now if right Lines be drawn from the Center A, through the foresaid points, they will terminate in the Centers of the Globuli; and if one Globe fall upon another, it will move the same by a Line joining the Centers of both together: So that the Arc MB, of the Section of the Circle, diffuseth that most light matter according to the Angle MAB, and in like manner the Arc BR, according to the Angle BAR.

III. Why the Breath that is sent out of our Lungs is not heard. Thus we observe that our Breath, when gently sent forth from our Lungs, is not heard, nor when it is easily blown through a Pipe, because there are none of those frequent wavings, between the sides of the VVind-Pipe and the Pipe, which are necessary to convey the stroaks of them to the Organ. In like manner, as we see that a Hammer gently ap∣plied to the Anvil, doth produce no sound at all, because the Air is not sufficiently beaten back or undulated, as to produce that frequency of motion that may reach the Ear.

IV. Why Musi∣cal Instru∣ments are commonly hollow. Musical Instruments are commonly made hol∣low, and often approach to a Sphaerical Figure.

The Reason is, because the passing and repas∣sing percussions of the Air, are multiplied in a Hollow, and therefore do the longer detain and please the Ear. For in hollow Bodies, not only the outward Air is agitated by frequent concussi∣ons, but also the Internal. The depth also of Musical Instruments is of great use, because then Sounds are the better mingled in them, and one part being agitated, doth more easily make the other parts partaker of the Motion.

V. The make of the In∣strument, and the Place, do conduce to the variety of Sounds. Thus Hawk-bells, by reason of the slit and holes they have on their sides, do yield a greater Sound, than when in the open Air we strike upon any Brass Vessel; because the Sound of the Bell being pent up within the sides of it, doth break forth whole and strong. And it is for the same reason, that Musick within doors in cold weather is more agreeable, because then the Strings or VVood of the Instruments are more wrinkled, as it were, and become more hollow and porous. And on the other hand it is observed, that the Sound of Musical Instruments is not so distinct in Chambers that are hung, as in those that are VVainscotted, because the Sound doth more briskly rebound from a smooth and hard body, than from that which is soft and yielding. For indeed all soft Bo∣dies are less fit for the generation of Sounds, and do easily transmit them. And it is for the same Reason, that the Sound of hot Iron is more dull, than that which is cold, even because it is more soft, and the parts of this latter do yield more frequent vibrations.

VI. What is the Reason that a Deaf Man can per∣ceive the Sound of a Lute, whilst he holds his Teeth upon the Neck of it. A person that is Deaf may perceive the Sound of a Lute, or any other Instrument, whilst he holds the Neck of it between his Teeth.

Some have conceived that this is to be attribu∣ted to some conveyances, reaching from the Mouth to the Ears, which carry the Sound thither, and impress the same affection upon them, which is transmitted by the Organ of Hearing. But that this is not so, is apparent, because the same effect doth not follow when we hold our Mouth open. Besides, if this were sufficient, why might not sounds be perceived by the touch of the Forehead or Nose; seeing that from these parts there be pas∣sages to the Ears, and an equal communication between them?

Conclude we therefore, that the Sound of a Lute can therefore be heard or perceived by those who hold the Neck of it between their Teeth, because the vibrations of the Strings being trans∣mitted

[illustration]

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Book. 2. Part. 2. Chap. 7.

G Freman. Inv.

I. Kip Sculp

from the Lute to the Teeth, are from thence communicated to the Membran that covers the sockets of the Teeth, and presently after shaking the Drum of the Ear, by means of the shut up Air, do also agitate the Connexion or Chain of the 3 little Bones. For a Body is then properly said to yield a sound, when being struck, it per∣forms several Vibrations by a tremulous motion, which by the Vehicle of the Air is diffused through the Bodies that are between the sounding Object and the Organ. For there is a consent betwixt the Nerves, which are disperst throughout the inward parts of the Mouth, and those which run through the Muscles of the Ear. An Argument whereof is, that harsh and grating Sounds, do stupifie and signally afflict the Teeth.

VII. Why a grating, skreaking Noise is very offen∣sive to the Ears. But of all Sounds, none are more ungrateful to the Ear, and indeed intolerable, than the skreaking Noise of a Saw, or the filing of Iron.

The Reason whereof is, because the particles of the Air, which strike against the Ear, do, because of their irregular figure, too violently vellicate the fibres of the Auditory Nerves, so as that thereby they are in danger of being broken, and sometimes break actually, whence that trou∣blesom and painful Sensation doth arise. The same also, tho' in a less degree, is caused by the hearing of false Tones, which is extreamly offen∣sive to a Musical Ear. And accordingly, by means of the foresaid Sounds the Teeth are sometimes set on edge; forasmuch as by this inordinate undu∣lation of the Air, the Nervous fibres which are at the Root of the Teeth, are in a manner loosed and separated from their former stability.

VIII. What is the Reason why, when the one of two Unison Strings are struck, the other trembles. If 2 Lutes or Citterns, whose strings are made Unison, are placed at some distance from each other, when the strings of the one are smartly struck, those of the other tremble also, and that so strongly, that they will shake off a bit of Paper laid upon them.

The Reason is, because the string being struck by a certain number of Vibrations, shakes the Air, which lighting upon the Unison strings of the other Instrument, doth shake it likewise. And this more especially, if the said strings be consonant in an Eighth or Fifth, for then their Vibrations will be less confused, and agree in their certain and frequent Intervals. For in an Eighth, all the Vibrations of a more lax and longer Chord or String, agree with a Second, Fourth and Fifth of a more stretched and shorter Chord; in a Fifth, with a Third, Sixth and Ninth, and so of the rest.

Wherefore this Trembling motion never follows where two Strings are differently tuned: Whereas Concords do not only excite each other, but others also, by reason of the similitude of their motions, and do so assist each other, as mutually to impart the same Affections. As may be experienced in any Musical Instrument.

IX. Whether there be such a thing as white Gunpow∣der, where∣by Guns may be discharged without Noise. It is a common Report amongst the many, that there is a White Gunpowder, with which Guns may be discharged without giving any Re∣port.

This, tho' very confidently asserted, appears to be a meer figment. For it is impossible that the pent up Air should be able to break forth without making a Noise: For that which is of such a force as to be able to drive a Bullet with as great swift∣ness, as the Flame breaks forth from the Gun∣powder, must needs strike the Air with a like force, and consequently produce an answerable Sound.

X. Why Men and Birds only can give forth Musical Sounds. Of all Animals, Men and Birds only are able to make Musical Sounds.

The Reason hereof must be fetch'd from the structure of the Throat and Wind-pipe, the Rings whereof in Men and Birds are capable of being contracted and extended. For there is a double recurring Nerve in the Wind-pipe, which turning round about it, doth by the help of some of its Branches move the Rings of it downwards; and forasmuch as the same is terminated in the Nerve, proceeding from the Plexus Ganglioformis, it moves the folds of the Wind-pipe upwards. So that whilst the Rings of the Wind-pipe, by means of the recurrent Nerve, are moved downwards, it causeth a deep or bass Tone; which becomes more high and shrill, when the said Rings are raised higher by the Branches of the 6th pair of Nerves, disseminated in the Wind-pipe; because the Wine-pipe being strained by this means, doth in a manner break the Sound that passeth through it.

XI. The Smoak of a Can∣dle, is agi∣tated by the motion of the Strings of a Musical Instrument. If a Lute be play'd upon near a Smoaking-Candle, the same motion of the Strings will be communicated to the Smoak.

The Reason hereof is, because the trembling Vibrations of the Strings do move the fluctuating Air, by the reiterated onsets whereof, the Flame (which of it self is very moveable) begins to be shaken, and to conform it self to the motions of the Strings. Hence it is, that when a Ray of the Sun is let in into a dark Room, and a Musical Instrument be plaid upon near the said Ray or Sun-beam, the Motes in the Sun will be seen to leap and skip in the Air, and, as it were, to dance to the Musick of the Instrument. The same may be also observed in the Water, when the Surface of it is very smooth and even; for then upon the Noise of stringed Instruments, it will become ruffled and curled. The same also may be ob∣served in 2 Glasses, into which if we put water to the height of 1 or 2 Fingers breadth, and bring them to an Unison, (which may be easily done by the Ear, in drawing our Finger round the Edge of them;) for then, if we fix a Crooked-Pin upon the Brim of one of the Glasses, we shall see it move and skip, as we press the Brim of the other Glass with our Fingers.

XII. Tones, or Musical Sounds, are not so proper to cause sleep, as some other Na∣tural sounds. Musical Sounds are not so conducive to provoke Sleep; as the Humming of Bees, the Noise of the Wind, the Murmur of Running-water, and an equal and smooth Tone of Reading.

For seeing that the Sound is diffused from the Sonorous Body to the Drum of the Ear, and from thence to the Acoustick Nerve, and so to the Brain, the Center of the Nerves, and last of all from thence to the Arteries, Veins and Guts, it cannot be but that the Blood and the Spirits must be moved also: And because Musical Sounds are not carried with an Equal Course, nor do pass by the Ears, they do affect the Sense of Hearing more than other Sounds, and more awake the Attention, which is the reason that they are not so fit for the provoking of Sleep.

XIII. Musick corrupts Manners. Long Experience hath taught, that soft and Effeminate strains of Musick, are very proper to corrupt the Manners of men: Whereas, on the other hand, the Sound of Cornet, Trumpets and Drums, do fill Men with a Couragious and War like Spirit.

For seeing that Human Affections are nothing but Sensations, produced by the motion of the Spirits, we need not wonder that the Sound arri∣ving at those Vessels in which the Passions are ge∣nerated, should produce various Passions. And forasmuch as the Manners of Men commonly follow their Passions, it is evident that Sounds must needs be of great use, either for the corrupting or correcting of Mens Manners. Accordingly PLA∣TO was of Opinion, that all soft Tunes ought to be banished out of a well-governed City. And the Lacedaemonians assign'd a great Punishment to those that used any soft or effeminate kind of Musick; and made a Law, that none should play upon a Harp that had above 7 strings.

XIV. Why upon the stop∣ping of our Ear, we hear a kind of humming Noise. When we stop our Ear with our Finger, we suddenly hear a buzzing kind of Noise.

Because it is owned by Physicians, that a Steam or Vapour, doth proceed out of the Hollow∣winding of the Ear; so that when the Ear is stopt, this pent up Steam, as well as the Air, seeking to get out, do beat and distend the Drum of the Ear; from which Motion, an Affection is produced like to a great Buzzing. Yea, it is frequently found, that the Ears, tho' not stopt by our Finger, are fill'd with this Buzzing Noise, produced by the blast of a most thin Steam or Vapour breaking forth from some little Artery or Vein, which striking against the Drum of the Ear, affects it much in the same manner, as it would be by the sound of a Bell.

XV. Sound more easily passeth through a Beam of Wood, than through the Air. A Sound is more easily diffused through the length of a Beam, struck at one end, than through the Air only. For as soon as one end of the Beam is moved, in the same instant the motion is communicated to the other.

The Reason is, because there is a greater Con∣tinuity of Parts in the Beam, than in the Ai••. For, when you move one end of the Beam A, at the same time the other B is moved also; but if you push the Air at C, it must at least move as far as D, before it can move E, because all its parts give way like a Sponge; and because it takes up * 1.3some time in passing from C to D, it loseth also part of its Force. Whence it comes to pass, that the Sound, which is nothing else but a motion of the Air, is both sooner and more strongly heard at the Point D, than at the Point E.

XVI. Why Sounds are more clear∣ly and distinctly heard near the Banks of Rivers. Which is the Reason why the sounds of Great Guns and Bells, are more distinctly perceived along the Banks of Rivers, than when we are at a distance from them; and it is universally true, that all and every sound is both sooner, and at a greater distance, communicated by water; for the parts of the water being more close and stiff than those of the Air, when once put in motion, do com∣municate their Force to others. To this moreover may be added, the smooth surface of the water▪ which doth not in the least break or turn aside the sound. Thus by laying our Ear to the ground, we can perceive the trampling of Horses at a great distance; and if a Drum be set upon the Ground, and the Ear laid to the upper Skin of it, the Noise of the marching of Horses can be per∣ceived at some Miles distance.

XVII. How the Voice of one man comes to be diffused to the Ears of so many. The Voice of a Preacher in a Church, or Actor upon a Stage, reacheth the Ears of some Thou∣sands of his Hearers.

This is not, because the whole Voice of one man comes to the Ears of all that hear him; for the Voice, as soon as it comes forth out of the Mouth, is broken into many parcels all like the whole; much in like manner as when Fullers spout out water out of their Mouths; for then the water is dispersed into innumerable drops, and fills a very large space. From the Mouth of the Speaker an entire Voice doth indeed proceed; but is afterwards divided into innumerable Voices: And therefore sure it is, that no two Auditors receive the same Voice, tho' they be said to hear the same, because of the likeness of these divided partial Voices, with the entire or total Voice. In the same sense, as they are said to drink the same Liquor, who drink out of the same Foun∣tain.

XVIII. Sounds are diffused along some certain Tract or Currents, more than others. Tho' Experience shews, that the whole Atmo∣sphere of the sonorous Body, is moved to such a proportionate Circumference; yet is not the said fluctuation of the Air equally diffused through all parts of the Air, but the sound seems rather to be carried along some certain Tracts or Cur∣rents. And therefore it is that the Words of a Preacher or Oratour, tho' they move the whole Atmosphere of the Auditory; yet it agitates that Tract most which his Mouth more directly answers to, where the Auditors do also more di∣stinctly hear his Voice, than those who are more remote from that Tract. Thus it is well known, that those only hear the hissing Noise of a Bullet, discharg'd from a Musquet, who are near to the Line described by the Bullet, whilst those who are at some distance perceive nothing of it.

XIX. Sounds are equally diffused. Sounds that are excited in any one place, be they Loud or Low, are in equal time conveighed to the place, where they are heard.

The Reason is, because the Air being a Conti∣nuous Body, when struck, is formed into Orbs or Circles: As we see that still-water, when a Stone is cast into it, becomes waved into Circles; and as the said Circles, at an Equal distance, spread themselves to the Banks, whether they be caused by a little or great Stone; so likewise doth the sound, at an equal distance of Time, come to the Ear, whether it proceed from a great Gun, or a Musquet, or any other thing.

XX. Whence it is that a double Sound is perceived from the striking of one String. It sometimes happens, that 2 Sounds are heard, when one only string is struck.

This proceeds from some defect in the string, which when they are false and uneven do admit 2 several kind of shakings at one and the same time, whereof the one, and which gives the deeper sound, proceeds from the whole string; the other, which affords a more shrill sound, depends on the unevenness of the string. Suppose, for Example, that when the string A B is struck, as often as it passeth and repasseth from 1 to 6, to produce its Natural sound, at the same time the Unevenness * 1.4of its parts produce another shaking in it, by means whereof, when it hath moved from 1 to 2, it runs back to 3, and from thence towards 4, and from 4 to 5, and lastly to 6, which produceth a sound that is by a Twelfth more shrill than the

former: In like manner, if the second shaking be only double to the former, it will yield an Eighth; if Quadruple, a Fifth; and if Quintuple, a Seven∣teenth more than before.

XXI. Why we see the Lightning before we hear the Thunder. A Sound takes more time to arrive at our Ears, than the Light to come to our Eyes; which is the Reason why we perceive the Lightning before we hear the Thunder; and we see the Ax of one that hews Timber, when we are at some considerable distance, lifted up to make a second stroke, before we hear the first.

The Cause whereof is the Air, which altho' it consist of subtil parts, and divided from each other; yet being withal Branchy and flexible, when one of them is moved, the other parts are not presently moved at the same instance, but by degrees; so as that one part being agitated, pusheth on the next, and so on; like the Circles in the Water, which do not in an instant spread them∣selves over the whole surface of it, but proceed in a continual order till they come to the Banks of the River, or that they cease upon the failing of the force, which caused them at first. But Light is much more swiftly conveighed to our Eyes, as being caused by inflexible and solid Globuli. For it is the Nature of solid Bodies, that when one end of them is prest upon, the said pression is felt at the same moment of time, at the other end of it. Whence it is that, as was said before, a Sound is sooner conveighed through a whole Beam, than through the Air; because the parts of the Beam are more closely joyned together, than the parts of the Air, which are flexible, and easily give way to other Bodies.

XXII. Strings of an unequal length, yield a different sound. Let there be 2 Strings of the same thickness, and wound-up at the same height, whereof the one is longer than the other; that which is the shorter of the two will yeild the shrillest, or most treble sound; and the longer, the deeper sound and less perceptible.

This difference of the Sound proceeds from the more frequent, or fewer Vibrations of the said strings: For seeing that a shorter String makes more wavings, and beats the Air with more re∣iterated stroaks, by so much shriller is its sound, and the sooner it conveighs the sound to the Ear. Because the difference of a deep and shrill sound, doth not proceed from the more swift or slow motion of a string, as ARISTOTLE was of Opinion, but from the variety of the Vibrations, which, if they be frequent, produce a treble or shrill sound; but if fewer, are the cause of a deep or bass sound.

XXIII. In like manner we may give an account, why the lesser of 2 strings that are wound-up alike, but of different length, makes its Vibrations more swiftly. The Reason is, because tho' both the strings make their Excursions with an Equal mo∣tion, with respect to Space and Time; yet because the lesser, by its motion of Contraction, runs through a less space than the longer; and that a less Space is sooner run through with an Equal motion than a Greater, it must needs be that the motion of the Lesser Cord be swifter.

Why the Sound ceaseth upon touch∣ing the Strings with ones Finger. Whence it is evident, that if you lay your Fin∣ger upon a String presently after you have struck it, before it have made many of its Vibrations, you will indeed hear some kind of Noise, but without being able to distinguish whether it be shrill or deep, because your Finger hinders the Vibrations, and doth not suffer the string by its pression to dilate the Air, and to drive it away by a successive beating of it. Hence it is that a slow and soft blast, blown into a Pipe, produceth no sound, nor that which from the Lungs is breathed out by the Mouth; because there is no rebounding of the Air, between the sides of a Pipe, nor in the Wind-pipe or Mouth of an Animal, which bound∣ing this way and that way, is the cause of a sound; and according as their Repetitions are more swift or slow, so they produce either a shrill or deep sound.

XXIV. Why the Eccho re∣peats the same Voice several times. An Eccho doth frequently repeat the same Voice, and renders the same sound at distinct Intervals. So CLAUDIAN makes mention of one that rendred the Voice no less than 7 times: And GASSENDUS tells us, that he had Experi∣enced, that in the Chapel of Charenton, which is about 3 or 4 Miles distant from Paris, one Syllable pronounced at either end of it, was repeated 17 times, and that the same word spoken in the midst of it, was as many times repeated from both Sides.

The Cause of this is, the Reflection of the Sound from some interposed let or hindrance: For as innumerable Rays are conveighed from the visible Object, not only to the Eye, but every way round; so besides the Voice which is carried to the Ear, innumerable other sounds are dispersed in the Air, which meeting with hard and concave Bodies, are dispersed through the Air, which makes the same Voice to rebound several times. For Sound is not conveighed like the Light, in one moment, but stands in need of time, to propagate it self: And therefore when the former sound becomes extinct, or vanisheth in the neighbouring Air, another is generated in that which is farther off; which being reflected from solid and tolerably smooth Bodies, doth frequently beat the Air that is nearer the Ear. A Sound therefore is often∣times repeated by the Eccho in the Chapel at Cha∣renton; because the place there is so disposed, that the nearer places do first repeat the Voices, and the more distant afterwards. It conduceth also to the forming of an Eccho, that the Bodies which reflect the Sound be opposite to each other, and send back the same by turns; as it was in the Chapel at Charenton, before that the Monastery of the Car∣melites was built there: For at that time there was a double Row of Pillars, between which the uttered Voice was rebounded; much like a Ball, which lighting against one Wall, rebounds thence to the other.

XXV. Why the Eccho is heard only in one part. Tho' the Eccho be a Sound which is every way circularly extended, yet can it only be heard in one part of the Circle; because it can only be received from the Reflexion of that part of the Circles, which is the farthest extended; and in that part where the said Reflexion is made. As we observe, that when a Stone is cast into a River, the Circles which are there formed; are further extended towards that part, where the Stone was cast in, than towards the opposite.

XXVI. A reflected Sound is of longer continu∣ance, than one that is not reflected. A Sound that hath been frequently rebounded, is preserved or continued a longer time, than that which without repercussion is propagated in a Right line.

The Reason is, because by the several Bodies and Cavities against which the Repercussion is

made, the sound is strengthned and increased, and therefore is longer a vanishing, than if it were only extended in a Strait line, without reper∣cussion. Moreover, it is evident from the Obser∣vations of many, that in the Village of Simonetta, about a mile distant from Milan, the Voice is often repeated 30 times, and in every one of its passings and repassings, it runs through 156 Paces and upwards; whence it follows, that the same Voice being separated 32 times, before it be altogether extingu••••ht, must run through 5002 Paces and upward. From whence it may be easily gathered, that the sound must needs be greatly increased in the said Concamerations, by means whereof it is enabled to continue so long, seeing it doth not seem possible, that by continual direct Motion, a sound should be able to reach 5 Miles, in which motion of the sound 25 Horary minutes must be spent.

XXVII. A Sound is hindred by the Inter∣position of a solid Body. When a Man speaks to another, a thick Glass Window being between them, his Voice will scarcely be heard; but if there be only a Paper Window between them, the Voice may be well enough discerned.

The Reason is, because the sound is an effect of the motion of the Air, and therefore because little or no Air can pass through the pores of the Glass, the Organ of Hearing cannot be affected thereby. Forasmuch as the Intervening Glass is supposed to be so firm, that it is not capable of being shaken by the sound; whereas the Air easily passeth through the pores of Paper, especially if the same be stretched, because by this means it is the more easily shaken, and its pores are made more lax and open.

XXVIII. A Bell when struck on the upper part of it, yields a shriller sound, than when hit lower. A Bell yields a more shrill sound when struck on the upper part of it, than when it is hit Lower.

The Reason is, because the hollowness con∣duceth to the Deepness of a sound; and because the further that the sound is propagated the more Bass or deep it is. Thus the lower Holes of a Recorder afford a deeper sound; for the slower the beating of the Air is, the deeper is the sound. As we find that the more water there is in a Glass, when we press our Finger round the Edge of it, the more shrill the sound is, for then the Vibra∣tion of the Air is the swifter, as when less water is in the Glass, so much the more deep the sound is.

XXIX. How it comes to pass, that Glass may be broken by a Voice or sound. It is observed, that a Drinking Glass may be broken by a man's Voice only, and that by reason of the repeated Vibrations of the parts of a more solid Body. For the effecting whereof, first, we must try by a stroak with our Finger, what Tone the parts of the Glass do yield, and then must set our Voice as near as we can to the same Tone, and increase the same by degrees, till we come beyond a Diapazon or Eighth: Whereupon the insensible parts of the Glass being struck with iterated stroaks, become agitated by a tremulous motion, which increaseth as they are struck in fit places, so that at last, by the augmentation of the force of the sound, the parts of the Glass leap asunder. But for this Experiment, a smooth and even Glass must be made choice of, and such as when filipt with the Finger doth not sound so shrill, but that the Voice of him that sings, may equal it, or go beyond it.

XXX. Why a Sound can sometimes be better heard by one that is a•• a distance, than by him that is nearer. Sir KENELM DIGBY relates in his Treatise of Bodies, that he had seen the Walls of a large and round Tower (tho' I rather suppose it to have been of an Elliptical figure) which were so Artificially built, that 2 men standing at the opposite points of the Diameter, might easily and distinctly talk together, whilst those that stood in the midst, could not perceive the least of any thing that was spoken.

The Reason of this must be fetched from the Coition or meeting of all the sounds, which are dispersed through the whole Room: For seeing that all the Air in the Room is shaken by the uttered Voice, the motions thereof being diffused through that large Space, are reflected from the Wall of an Elliptical figure, and so by Reflexion become united in the uttermost part of the Cham∣ber; and therefore he that lays his Ear, must needs hear the Voice of him that speaks at the other end, tho' with a very Low Voice.

XXXI. How a Sound be∣comes in∣creased by the means of a Pipe. Upon the same account it is, that by means of a Pipe, contracted in manner of a Cone, sounds may be increased, and made to be heard further off, better than nearer hand; and this, because the sound is increased proportionably, as the Tube is contracted; for by this means the sound must needs be increased in its passage through the Pipe. And accordingly they who are Deaf, make use of a Horn, whereof the one end is wider than the other, which they apply to their Ear, by it to receive the Voice of him that speaks to them. And by this means, a Prince might easily hear the Voices of those that walk in his Garden, by having Pipes conveyed from thence to his Closet, the widest Mouths of them being set outward, and the narrowest inward.

XXXII. How a Sound comes to be propagated at that great di∣stance by the Stente∣rophonick Tube. The Stenterophonick Tube, sometime since In∣vented by Sir SAMUEL MORELAND, which carries the Voice to the distance of a Mile or two; and that other Trumpet, which ALEX∣ANDER the Great made use of, in giving Orders to his Army; whereof the Figure is to be seen in an Ancient Manuscript of the Vatican Library, are made after another manner; for they are streight or narrow at the Mouth, to the end that the particles, which are to make the Reflexion, being close together, may be the more easily beaten, and from thence the Trumpet grows wider and wider to the very end of it, in order to augment the agitation of the Air, by the multiplication of all the Reflexions which are made throughout the whole length thereof; yet with this Circumstance, that the Bore of the Pipe might be so great, and the Trumpet so long, that the sound would be no longer increased, because the Reflexions would become so weak, as not to be longer in a condition to move the particles of the Trumpet, and consequently cause a new Re∣flexion.

XXXIII. Why bees, when they swarm, are recall'd by making of a Noise. Swarming Bees are recalled by beating upon Frying-pans and Sithes.

Some suppose the cause hereof to be, because Bees are delighted with these Noises, and being thereby allured, do all unite themselves in one great hanging Bunch or Cluster. But this is not at all probable, because when the Bees are got up into any height of the Air, how much soever the said Instruments may be beaten, this will not bring them down, or hinder them from flying away.

Wherefore the true Cause hereof seems to be, be∣cause the Air being much shaken, and agitated with the Sound, the Bees not being able to bear the same, are forced to unite themselves and settle in a heap. For Bees have very thin VVings, not feathered ones like Birds, but consisting of a thin Skin; by means whereof they cannot endure this concussion of the Air: Which probably also is the reason, why they never leave their Hives when there is a great VVind, or at Midnight, but only in calm and hot weather.

CHAP. VIII. Of Light.

I. Light may be excited without a Luminous Body. UPON the rubbing of our Eye, tho' it be shut, there appears a round spot of Light, and the same will be by so much clearer, the nearer the rubbed part of the Eye, is to the bot∣tom of it.

This is an Argument that Light doth not exist without the Eye, but is only in the Eye of him that sees; and consequently that the Bodies, which are commonly called Luminous, are only said to be such Potentially; that is, in case they strike the Eye of the Seer: So that if there were no living Creatures in the World, which could see the Light, neither could any Light properly be said to be in it. And therefore we must conclude, that Light is not in the things which are called Bright or Luminous, but in him that perceives it; in like manner, as Pain is not in the Sword, but in him that feels it.

II. Why the Rays of ••ight, by passing through a narrow hole, do cross each other. The Light passing through a small hole into a Dark Room, enters the same cross-wise.

The Reason is, because the Rays flow from each point of the Lucid Body, in Right Lines: Wherefore because the Object, without the hole, is bigger than it, it is impossible the Rays should pass through it, without crossing each other; and by this means it comes to pass, that the situation of the whole Lucid Body is represented upside-down, on an Opake Body.

III. Light pas∣sing through the holes of two Walls, is not per∣ceived by those who are in the Room. Let a hole be made in one of the VValls of a Room of that bigness as may admit the flame of a Torch or Candle; and just over-against the said hole, let another more large be made in the oppo∣sit VVall; then in the Night let the Flame of a Candle be held on the outside of the less hole, so as that the Rays that pass through it, may be ad∣mitted by the opposit hole, and pass through it also; by which means the whole Chamber will continue dark, as if no Rays at all were transmit∣ted through it.

The Reason of this Experiment is, because none of the Rays that pass through the Chamber, do reach the Eye, nor affect it; and yet must, before any vision can follow. And for the same Reason it is, that those who in a clear Night lift up their Eyes on high, perceive all spaces above the Hori∣zon to be equally covered with Darkness; when as yet those immense Spaces, except only that part of them which is vail'd by the Cone of the Earths Shadow, are no less guilded by the Sun, than they were at Noon-day. And this because the Rays which are diffused through those immense Spaces, cannot reach our Organs, nor produce any motion in them.

IV. There can be no Light without the Eye. From which Experiment it is evident, that the Light depends on the Eye; so that if there were no Eye, or no Eye open, neither could there be any Light, or Brightness, such as we perceive when we lift up our Eyes to Heaven, and behold this most beautiful appearance of things.

V. A Spark of Fire, by means of a Prospective may be per∣ceived at 50 Leagues distance. A Spark of Fire sheds its Light through a very large space. For a Spark of Fire, without any Prospective Glass, may be perceived in the Night, at the distance of 500 paces; and with a Prospe∣ctive may be discerned at the distance of 50 Leagues, and probably much farther.

It seems strange to some, that such a small Lu∣cid Body should be of so great a force, as to push the intervening matter of the Second Element in a Right Line. But this their wonder will cease, if they consider that this subtil matter, which is diffused through the Pores of Diaphanous Bodies, is like a most Fluid Liquor, whereof one part can∣not be prest upon, but that all the part must be moved by it. As for Example, let there be a * 1.5double Tube or Pipe, ABC, filled with water, and of a length as great as you please; if whilst the water is at rest, and destitute of all motion, you put a drop of water into one of the ends, viz. A, no Body will deny but that the weight of that one drop will be sufficient to raise the water to∣wards the other end C, and consequently to put the whole mass of water contained in the said Pipe, ABC into motion.

And for the same Reason, who will not acknow∣ledge that a Spark of Fire may be sufficient to agi∣tate the Heavenly Matter, diffused through a large space of Air? Forasmuch as the action of Fire doth far surpass the force of Gravity; as also because the subtil matter which is contained within the pores of the Air, and of the Water too, is more fluid than either of them. Wherefore it is evident, that the flame of a Candle, must needs move the subtil matter that is contain'd in the round of 50 leagues Diameter; forasmuch as by the force of its motion it pusheth the circumambi∣ent Air, much in the same manner, as a Stone that is whirl'd round in a Sling, presseth down the bottom of it; and by the vertue of its Circu∣lar motion, doth extend the String of it in a straight Line. For the subtil matter, which on every side surrounds the Spark, is also turned round, and strives to withdraw from that place.

VI. How it comes to pass, that the Rays of Light do not hinder one ano∣ther. But from this Explication of Light, no small Difficulty seems to arise, viz. how it comes to pass, that the Spark which pusheth the subtil mat∣ter contained in the Pores of the Air to Right Lines, can be perceived, when another of the same force and virtue is opposed to it. For let us suppose some one Globule of the Air ABCD, whose Center is E; and at A and B, 2 Lucid Bo∣dies of the same force, it will follow, that either the said Lucid Bodies will not be perceived from the opposit places C and D, which is contrary to Experience; or that the subtil matter in the Cen∣ter E, will be in many places at once, which is * 1.6repugnant to the nature of Bodies. Which may be thus proved; A cannot be perceived at C, but that the subtil central matter E, must be push'd towards C. in a straight Line: And by the same reason B cannot be seen at D; but that the same matter E, must be driven towards D; and the

same may be said of infinite Lucid Bodies, placed on the surface of that Globe.

This Difficulty only ariseth from hence, be∣cause it is hard for us to apprehend how the parts of Liquid Bodies can receive various actions at one and the same time; because we have observed, that a hard Body cannot at the same time be mo∣ved divers ways at the same time. When yet in liquid things we know it is so; as may be seen by Experience in 2 or 3 Tubes, by Example AC, BD, FG, whose Diameter I suppose to be equal, and which are so placed crossing one another, as that the space in the middle E, be common to them all 3, and yet no greater than if it served only for one of them. For let us suppose that 3 Men do blow into the ends of all 3 of them ABF, the Air which is in the midst of these 3 Pipes; E will at the same time be driven towards C, D, and G. Not as if therefore it were possi∣ble, for every one of the said parts to remove at the same time to these 3 several points; but it is sufficient if some one of them be moved towards C, others towards D, and others again towards G, and that 3 times swifter, than those that fill the other parts of these Pipes; which is credible e∣nough, forasmuch as they are with triple stronger force push'd forwards. Now to apply this to the subtil matter, it will by this instance be easily conceiv'd, how the same transmits the different Actions of various Lucid Bodies, to different parts at one and the same time.

VII. How it comes to pass, that a Man who shakes a Torch, doth at the very same in∣stant per∣ceive the same in an opposit Look∣ing-Glass. When a Man in the Night hath a lighted Torch in his Hand, and shakes it towards a Look∣ing-Glass, at a quarter of a miles distance, he will no sooner perceive the shaking in his own Hand, but that at the same time he will perceive it in the opposit Looking-Glass.

The Reason is, because Light is rather an en∣deavour or tendency toward motion, than motion it self. For tho' motion cannot be performed in an instant; yet is it not repugnant, for the action of Light to be transmitted in a moment at any distance whatsoever. For it is one thing to say, that motion is performed in an instant, and another, that Light is transmitted in an in∣stant. The Light is transmitted after the manner of the Action of a Stick, every part whereof may be perceived or felt, at either end of the Stick, at the very same instant wherein it is produced. And consequently nothing hinders but that a light∣ed Torch, being shaken, may be perceived in a Looking-Glass at a distance, at the same instant that the shaking is felt in the Hand; because the propagation of Light is momentaneous, and needs no time for its passage.

VIII. Why a cer∣tain Stone, found near Bononia, doth retain a Light in the Dark. Some Stones shine in the Night, especially the Diamond. There is a Stone very common in the Country about Bononia, which if it be gently calcin'd, and afterwards exposed to the Sun, doth take in so much Light, that when put into a dark Room, it is observed to retain some part of it, much like a glowing Coal that is covered with a little Ashes, the Light whereof decreaseth by de∣grees, and is at last quite put out.

We must not imagin, with some, as if the Light of the Sun were preserved in the foresaid Stone; forasmuch as that Light, upon the with∣drawing of the Sun, doth altogether vanish, as not being able to subsist a moment without its presence; but rather conclude, that within the Pores, made by the Fire in the said Stone, there be some Fibres, so very moveable, as that upon the presence of the Light they are put into a great agitation, and upon the withdrawing there∣of do still continue the motion imprest upon them; and consequently move the surrounding Glo∣buli of the Second Element. And therefore, when either in process of Time, or by the strength of Fire, such Fibres are taken away, that Luminous Virtue immediately vanisheth. The Light of this Stone, as was said, can only be perceived in a Dark Room, because it is very weak, and there∣fore easily overcome of a stronger Light. As is evident in Rotten-wood, Crickets, and other things that shine in the Night, which by Day give no Light at all.

IX. Why a Di∣amond shines in the Night. The Reason why a Diamond shines in the Dark, seems to be this, because in the Pores thereof the particles of the 3d Element are so comprest, that those of the 2d Element being push'd out, some of them are surrounded only with the 1st Element, by which they are carried away, and the Globuli are driven or push'd forwards.

X. Why it is that when a Man is struck on the Head, he perceives Sparks of Light. When we receive a knock on the Head, or a blow on the Eye, we seem to perceive many Sparks of Light.

The Reason is, because the motion of the Glo∣buli is very much accelerated by the striking Fist, which makes them break forth from the Eye with great force, and so cause the appearance of those Sparks, which we see at that time. For by means of such a stroke, the Humours are put into a great Commotion, and more especially the Arterial Blood, which driving with a great force against the Optick Nerve, seems to exhibit the appearance of many Sparks of Light. For the Sense of See∣ing is nothing else but a local Motion, or rather Pression, whereby the fine filaments of the Net∣like Coat of the Eye are struck.

XI. Why if we shut our Eyes after that we have, for a good while, been ga∣zing on the Sun, we perceive an appearance of Light or Fire. The Affection which the Light impresseth up∣on the Eye, doth continue for some time. For when we shut our Eyes, after we have beheld the Sun, we think we see an appearance of several Colours.

The Reason whereof is, because the fine Fibres of the Optick Nerve, do still continue agitated by an unusual motion. But forasmuch as the said Commotion wherewith they are shaken, even after that the Eyes are shut, is not strong enough to afford such a clear Light, as that is from whence it did proceed, therefore it represents only to us some weak Colours. And for the same Reason it is that some persons do perceive some kind of Light, for some time after that a Light hath been put out. Yea sometimes, tho' there be no Lucid Body to affect the neighbouring Air; yet some∣times some sharp Humour or Vapor, only moving the Filaments of the Retina, causeth an appearance of Light to the Eye.

XII. The Light of a Can∣dle doth appear more at Night, than in the Day time. The Light of a Candle, doth appear greater at Night, than in the Day-time, if the Eye be at some distance from it.

This may proceed from 2 Causes. First, It may be occasioned by something in him that sees, who when he doth not exactly know the distance of the Candle, may imagin that it is as far from him as a Star. Moreover, seeing that the Image of a Candle, framed in the bottom of the Eye,

doth much exceed that of a Star; it may make him think that it is really greater than a Star. Another Cause of this mistake, may be from the thing it self which is seen. For when at Night we look upon a Candle, that shines at a distance, we do not only perceive the Light, which comes to the Eye in a straight Line, but that also which proceeds from the thick Air, and the Opake Bo∣dies that surround it; for they also convey to the Eye the Light they have received, which being ascribed to the Candle it self, it cannot but appear much greater, than indeed it is.

XIII. Why some Worms and Flies do shine in the Dark. Some Worms and Flies do shine in the dark, shedding a kind of Brightness from their Bodies, through the Air.

It is probable that these Insects have a certain matter exhaling from them, that resembles the sweat of other Animals; and that the same push∣eth the Globuli of the 2d Element. And this seems to be the more probable, because these Animals cease to shine as soon as they are dead.

XIV. Some Plants do shine. Thus we see that Rotten Wood appears shining and Bright in the Dark, because by the access and recess of its parts, the Pores thereof are so straitned, that they contain nothing else but the first Element, whereby the 2d is agitated. Thus Sea-water, being vehemently driven and beaten with Oars and Storms, doth appear all on a flame, because the Sea-water doth consist of stiff particles of Salt; for by these penetrating little Bodies, the particles of the 2d Element they meet with in their way, may be so expelled, as that some of the particles of the 3d Element, may be only sur∣rounded with the 1st Element, and by it be car∣ried away, and driven on to the Eye, by a conti∣nued Range of the Globuli.

XV. How Cats and Owls see by night. 'Tis commonly believed that some Animals do emit Light from their Eyes, and thereby see in the dark, as Cats, Owls, Dogs, and other Creatures that hunt their Prey at Night, avoid dangers, and search out hidden things.

But for all this is so confidently asserted, I questi∣on not but that it will be found otherwise. For if any Light did proceed from the Eye, the same might be perceived by others, or might be concen∣trated in a Burning Glass, which could never yet be proved by any Experiment. We are there∣fore to conclude, that the foresaid Animals, do only see by that Action which proceeds from the objects. For there is always more or less of Light in the Night; and therefore we see that Snow gives some Light in the dark, because it reflects the Rays of Light it hath received, better than other Bodies, that are less white than it self. Wherefore Cats, Owls, and other Animals per∣ceive Objects in the Night, not because they shed Light from their Eyes, which is afterward reflected from the Object to their Eyes again; but because their Retina is more accurately framed, and more fit to receive the Beams of Light, so as that it can be affected by a very weak Light. For it is notorious, that the Apple of the Eye in Cats is so straitned in the Day-light, especially when the Sun shines strong, that it appears scarce so broad as a Thread; whereas in the shadow it is so enlarged, as to be almost equal to the whole Eye.

XVI. The Rays of Light do more easily pass through Glass, than the Water. The Rays of Light do more easily pass through Glass than Water, and through Water than Air.

The Reason is, because the Action of the Sub∣til Matter, wherein the Nature of Light doth con∣sist, is more hindred by the Parts of the Air that are soft and not well knit together, than by those of the Water, which do more strongly resist it. For the more firm and solid the parts of any Pellucid Body are, so they be small, the more easily do they transmit the Light. Hence it is that Glass and Crystal, because of the firmness of their parts, do the more easily admit the Beams of Light.

XVII. Why Paper dipt in Oyl is Transpa∣rent. And much the same Reason may be given, why Paper besmear'd with Oyl, becomes diaphanous; because the Oyl entring into the Pores of it, which before, by reason of their winding or crookedness, could not transmit the Rays of Light, it doth smooth them, and change the Figure and bigness of them; and by this means causeth a different disposition of the parts of the Paper.

XVIII. Why Refle∣cted Light is less bright, than that which is not Re∣flected. Reflected Light is always less bright and shining, than that which is direct, or not reflected. For take the smoothest Looking-Glass, and the most perfectly polish'd, whether by Nature or Art, yet will it never be endued with an entire and most absolute continuity of its parts, without any inequality of the Pores, roughness or sign of di∣vision. Hence it is, that tho' all the Beams of Light fall upon it, yet some entring into the Pores, are swallowed up of them; or if they do reflect from it, because of some inconspicuous inequality of the extream parts, yet are they insensibly dis∣persed; so that the entire Light is never so dully reflected, but that more or less it is lost, and never reaches the Eye.

CHAP. IX. Of Colours.

I. Whether the Colours of a Pea∣cocks Tail, and the Necks of Doves be true Co∣lours. A Peacocks Tail, and the Feathers of a Pigeon do wonderfully change their Colours; as LUCRETIUS elegantly expresseth it.

So Plumes that grow around the Pigeons Head, Sometimes look brisker with a Deeper Red; And then in different position seen, Shew a gay Skie, all intermixt with Green: And so in Peacocks Tails, all fill'd with Light, The Colour varies with the change of sight.

These Colours are caused when the Peacocks Tails, and Necks of Pigeons are turned towards the Light; and by reflexion or refraction do send back the said Rays to the Eye. They are com∣monly called appearing Colours only, and reckon'd amongst those Images that deceive us, and whose entire Essence or Nature consists in their appearance, or seeming such. But the reason why they assert this, I cannot apprehend: For if they admit Co∣lour to be nothing else, than the Light it self, modified in the surface of Bodies, why may not they own those Colours, which they call seeming, to have as truly the Nature of Colour as any other? For can the short duration of the Cause, destroy the Truth of the Effect? Or doth not a Son de∣serve that name, because he dies almost as soon as he is born? Who will affirm, that the Greenness of Grass or Herbs, which for some days only doth delight our Eyes, is less a Colour than the Greenness of an Emrald, which continues so much

longer? For by the same Argument, the flame of Lightning or Gun-powder will be no true Flame, because of its suddain vanishing and disappearance. For the lasting or continuance of Colours imports nothing to their Truth and Reality; and those which continue only for a moment, are no less Colours, than those which lastingly do affect the Eyes.

II. How Co∣lours come to be vari∣ed. The Cause therefore of the variation of Colours in the Peacocks Tail, and the Necks of Doves, is the different Reflexion and Refr••ction of the Rays, made by the thin Hairs of their Feathers, because of their various admission of the Luminous Beams. Thus those Pictures, made of Feathers, which are brought out of the East Indies, according to the variety of their situation, do exhibit a Violet Colour, or bright Blue, or a curious Emrald Green; forasmuch as the soft Feathers whereof they do consist, have their surfaces so ordered, as diversly to reflect the Light.

But this being besides my present scope, I re∣turn to prosecute my Experiments.

III. Two Look∣ing-Glasses, made of different Marble, do differently reflect the Image of the Sun. Let two Llooking-Glasses be made, the one of white, the other of black Marble; that of white being exposed to the Suns Beams, will represent to us a more clear and distinct Image of the Sun, than that of the black, from which only some weak Rays will rebound, which being not suffici∣ently united together, will only produce a confu∣sed Image or Similitude of the Object.

The Reason of this is, because the action of the Light, whereby the Parts of the Subtil Matter, push'd on by the Lucid Body, do tend towards the Black Marble, is almost quite extinguish'd or swallowed up by it, so as that very few of the Rays are reflected: Whereas the White doth altogether remit the Action of Light, and almost reflect all the Beams that fall upon them. For tho' White and Black Marble, consist almost of the very same parts, and no difference is discernible between them by sense; yet it is not to be questioned, but that in the Black some soft parts are to be found, which swallow up part of the Beams, and break the force of them. So that the Black Marble dif∣fers from the White, much alike as a Pumice-stone, whose Pores are filled with melted Pitch, differs from another Pumice-stone, whose Pores are only filled with Air: For as the Grains of Sand cast against the latter, would rebound thence, whereas those cast against the other would be deaded; in like manner, all the Light which falls upon the White Marble is reflected; whereas that which lights on the Black, is mostly swallowed up.

IV. What is the Cause of the White∣ness that is in Bodies. The same is apparent in other Bodies; for if Water, for instance, be strongly agitated and sha∣ken together, it becomes of a White Colour, and after that the Bubbles of the Froth are broken, it is Transparent; which is a great Argument, that the cause of this Whiteness is, when the Light is wholly and entirely reflected from the small Bub∣bles of the Froth, as from so many Looking-Glas∣ses. And accordingly the Black Marble is like Hangings, which upon the casting of a Ball a∣against it, doth receive motion, but doth not re∣bound; whereas the White is like a hard Wall, which sends it back, and without any motion of its own, doth reflect it.

V. W••y White Marble is less su••••••∣ptive of Heat, than Black Mar∣ble. Hence it is, that if you take 2 Polish'd pieces of Marble, the one White, the other Black; and in hot weather expose them to the Sun-beams for some time, you'l find that the Black will be very hot, whereas the White will, for all that, in a great measure, continue cold. Whereof no other reason can be given, but that the Black, because of its many Cavities, doth freely admit the Globuli of Light; whereas the White, because of its closeness, doth reverberate the received Light, retaining no∣thing of it. Accordingly as we daily observe in whited Rooms, which do reflect more Light, and do, in a manner, send it all back again from them. Hence it is, that when the Light of the Sun is ad∣mitted into a Darkned Room, through a little hole, if the Rays be received upon a white Paper, they appear very bright and shining; whereas they shew very weak and faint, when they light upon a black Body.

VI. Polish'd Marble ap∣pears of a blacker Co∣lour than that which is Rough. Polish'd Marble is of a blacker Colour, than that which is Rough.

The Reason is, because in the Rough there be many Prominences, which every way reflect the Light. For the Ray which is reflected from one part of the Body, goes one way, and that which is reverberated from another part, another way. But a Polish'd Body, forasmuch as it consists only of one continued Superficies, therefore it reflects fewer Rays to the Eye. Moreover, seeing there is no Body, in Nature, so Black, which doth not consist of many parts, which being separated from the rest, would constitute a white Body, as the difference there is between the Polish'd and Rough Marble doth abundantly testifie: We may say that Polish'd Marble is most black, because its white parts do reflect the Light they receive, to∣wards the same part; where if there be never an Eye to admit it, it is the same with respect to it, as if the Light were quite extinquish'd. But when the Eye is placed in that part to which the re∣flexion tends, it perceives this Light in the Mar∣ble, together with the Colours and Figure of the Objects, from whence the Light doth proceed; no otherwise than if it did proceed from a Look∣ing-Glass.

VII. A perfectly Polish'd Bo∣dy can only be seen on one side. Now that an absolutely Polish'd Body doth on∣ly reflect one Ray to the same point of the Eye, may be thus demonstrated. Let BF, be suppos'd to be a perfectly polish'd Plain, and let the Light be in the Point A, and the Eye at H, let the re∣flex Ra•• be DH, so as that the Angles ADB, and HDF be equal; it is evident, that no other Ray derived from A, will be reflected to H, sup∣posing that the surface BF, be absolutely smooth and even. For let there be any other Ray of in∣cidence, * 1.7suppose AC, I say, that the Angle ACB, is greater than the Angle ADB; wherefore sup∣posing an equal Angle of Reflexion ACI, the re∣flected Ray, CI, will never reach to H, nor will ever concur with DH, but rather fall wider from it, the further it is drawn. And the same must be said of all the other direct incident Rays be∣tween B and D. Wherefore there will only one Ray be reflected at H, viz. DH. I have said before, if the Body be perfectly smooth, for if it be not, the case will be otherwise, upon the chan∣ging of the nature of the Plain.

VIII. Some Bodies retain al∣ways the same con∣stant Colou••▪ as Coals, Snow, &c. Some Bodies do constantly keep the same Co∣lour, and which way soever they are turned to∣wards the Light, do always reflect it a••ter same manner; so Coals always appear Black, common Snow, White.

The cause of this constant Colour is to be ascribed to the Disposition and Situation of the Parts, which as long as it continues the same in Bodies, they admit the Light at certain Angles, and accordingly reflect it to the Sight. For Char∣coal is black, because its surface is rough and un∣even, by reason of innumerable furrows and chinks, which choak the Rays of Light, and break their force. Which may be evinced, not only by reason, but by our very Senses. For if a man do gently handle Charcoal, he will be sensible of a kind of Roughness, something like that we feel in a Pumice-stone; which, as I said before, is not capable of being polished. For whilst Wood is burning, much Smoak and Exhalation flies away from it, by the force of the Heat; and therefore the Fire being rarefied between the Cavities of the Wood, doth break its prison and dilate the pores; into which, when the Rays of Light enter, they are there swallowed up and entangled, so that they cannot rebound to the Eye.

IX. In what sense it is that Co∣lours are said to be in Bodies. But yet we must not imagine with some, that Colours do formally exist in Bodies, but effectively only, inasmuch as they produce them in the Eye, by means of a certain disposition of the Insensible parts, and the Reflexion of the Light: In the same manner as a Needle, which is destitute of all pain, yet being thrust into the Skin, doth by its motion, figure and hardness, produce Pain there.

Thus all Sulphurous matters exhibit a Red Colour: As when the Spirit of Turpentine being digested with the Calx of Lead, yields a deep Red; and the Spirit of Soot mixt with any acid Liquor, or Common water, affords a white or milky Colour. Thus the Light proceeding from 2 Lanthorns, the one of red Glass, the other of blew, being receiv'd on a Paper, will represent there a Purple Colour. All which Instances manifestly evince, that Colour is not inherent or fixed in a Body, but only a result of the Reflexion of Light.

X. Why beaten Glass seems to be white. Glass, when it is whole and extended in Panes, is transparent, that is, of no Colour, or if it have any, it is rather of a black than white Colour; but when beaten in a Mortar, it appears white.

The Reason is, because beaten Glass hath many Surfaces, which every one of them do receive the Light and reflect it again, as so many Looking-Glasses. For seeing that Glass is destitute of all Moisture, and that all its parts are of a round figure, as may be experienc'd by the help of a Microscope, one of them reflects one part of the Light, and the other, another, and so on, so that they reflect the whole Light, and that after the very same manner as they have received it. Hence it is that White Bodies are, of all others, the least opake; be∣cause they reflect the Rays of Light from every point of them, and suffer none to be swallowed up of any of their Cavities.

XI. What is the Cause of the Whiteness in Snow. Neither is there any other Cause of the white∣ness of Snow, which consisting of Bubbles, doth send the Rays to the Eye, according to the multi∣tude of the Bubbles whereof it is composed. No•• is this contrary to what hath been said before, tha•• from every Bubble, one Ray only is sent to the Eye: For since they are not sensible, neither do they hinder, but that abundance of continual Rays may be directed to the Eye. Hence it is that Snow, which is nothing else but Frozen-water, yet doth appear whiter than Ice; for seeing that the surface of Ice is not so much curled, as the surface of Snow, and that there are many Devexities or Roundings in Snow, from whence the Light may be reflected, which are not to be found in Ice; i•• cannot be, but that Snow must appear whiter than Ice. And for the same Reason it is, that water beaten together, turns to froth, by its being divided into round and small parts: For if the Bubbles, whereof the Froth consists, be so great, they will cease to yield a white Colour. Thus likewise the Whites of Eggs, when beaten, lose their Transpa∣rency, and become white; and Crystalline Glass, heated in a strong Fire, and quenched with water, is resolved into so many slits, that it appears altoge∣ther white.

XII. Fishes tending to putrefacti∣on, do yield no Colour at all in the Pneu∣matick Engin. Rotten Wood, as also stinking Fish, are of a kind of whitish Colour, when exposed to the Air; but when put into the Pneumatick Engin, upon the extraction of the Air, do lose all Colour.

The Reason is, because the particles of putre∣fying Bodies, are agitated in such a manner as is necessary, for the causing of the Sense of Light. For the Corruption of any Body is caused by the motion of its parts, whereof some fly away and are separated from the rest; and those that remain, impart their Vibration or Motion to the inter∣jacent Air, and by this means do afford a weak Light to it. But seeing that all the Air is supposed to be extracted out of the Pneumatick Engin, it needs not seem strange to us, if the Fish which shined before, doth no longer shed any Light. For the Air, by its Elastick virtue, doth assist the agitation of the Light, and where its motion is stronger, there the Light also is increased.

XIII. Why the lower part of the Blood in a Porringer appears of a darker Colour, than that at the top. Thus FRACASI is of Opinion, that the Reason why the Blood appears of a darker Colour at the bottom of a Porringer, than at the top, is not because, as the common Opinion is, that part is the more Melancholy portion of the Blood; but because the lower part of the Blood is not so much exposed to the Air, and therefore appears less Ruddy and Florid, than that which is on the top.

XIV. Why the Blood that is contain'd in the Ar∣teries and Veins, is Red. Why the Blood that is in the Arteries and Veins is Red, appears from what hath been said in my Institution of Philosophy, viz. That the motion of the Globuli of the second Element, which are the Cause of Light, is twofold, the one whereby in a strait Line they are carried to our Eye; the other, whereby they are whirled about their own Centers. So that if they be whirl'd about much slower, than they move in a right Line, then the Body whence they are reflected will appear blew to us; but if they be whirl'd about much swifter, then it will seem red. Now no Body can be dis∣posed to make them whirl about more swiftly, but such an one as consists of Branchy parts, and those so thin and near one another, as to have nothing about them, save only the Matter of the first Element, such as the Parts of Blood are. For the Globuli of the second Element meeting with the Matter of the first Element in the sur∣face of the Blood; which Matter doth without ceasing obliquely pass through the same, and that with great swiftness, out of one pore into another, so as to be moved after a different manner from the Globuli; they are forced to whirl about their own Centers, by the Matter of the first Element,

and that more swiftly than they could be forced by any other Cause, because the first Element exceeds all other Bodies in swiftness.

XV. Why bu••n∣ing Coals, or Red hot-Iron are not so red as Blood. And the same is the Reason, why Red-hot-Iron and Burning-Coals are red; even because very many of their pores are fill'd only with the first Element. But because the said pores are not so narrow as those of the Blood, and that there is much of the first Element in them, to produce Light, hence it is that their Redness differs from the Redness of the Blood.

XVI. Of a Person that distin∣guisheth Colours by the touch of his hand. Very Famous and Credible persons give us an account of a certain blind Organist, who lived near Utrecht upon the Maes, who had such an ••xactness of Feeling, that by the touch of his Hand only, he was able to distinguish several Colours.

It will not be very difficult to assign the Rea∣son of this wonderful Effect, if we consider that the interruption of parts in Bodies, doth very much conduce to the production of Colours; forasmuch as it is evident, that most Colours proce••d from the roughness of Bodies, and the figure, order, situation and motion of the parts. As is evident in red Marble, the polisht part whereof is very different in Colour, from that which is rough. So likewise we may perceive by a Microscope, that the yellow parts in a piece of Silk, are very different from the blew. Forasmuch therefore as there is so great a variety of Parts in Colour'd Bodies, which may admit a Reflexion or Refraction of Rays, we may conclude, that it seems probable enough that the foresaid blind Man might have such a quick Touch, as to be able to distinguish colour'd Objects by the roughness or unevenness of their parts.

XVII. The mix∣ture of Bodies produceth new Co∣lours. Several Bodies mingled together obtain a diffe∣rent Colour from what they had before: Thus Oil of Anniseed, mixed with Oil of Vitriol, turns red; Spirit of Turpentine poured upon Sugar of Lead, or calcin'd Lead, produceth a red Tincture; and the yellow Gall in Animal Bodies, according to the Opinion of Physicians, is the product of the mixture of adust Sulphur and Salt.

This production of different Colours is caused by the inward disposition of the parts of Bodies. For it is certain, that from the alteration of the least parts of one Body, a different Colour must arise; as appears evidently to the Eye in Herbs that are beaten in a Mortar. For the temperament and ranging of the Parts, is, as it were, the first Rudiment of Colours, which upon the appearance of Light, and its being diversly reflected and re∣fracted from those particles, doth super▪add the last and most absolute perfection to Colours. Thus the Stone Magnesia, which for colour and hard∣ness doth resemble a Load-Stone, being in a cer∣tain proportion added to Glass, renders it per∣spicuous, and quits it of its green Colour; but if more than is necessary be added to it, it makes it black. Thus an Apple cut in two, at first appears white, then turns yellow, and last of all black, according as the surface of it becomes differently disposed, by the drying of its parts.

XVIII. How two pe••••••••id Bo••••es can pr••duce a black Body. The transparent and clear Infusion of Galls being mixed with a Solution of Vitriol, makes Ink; to which if you afterwards add Spirit of Vitriol, or Aqua-fortis, the black Ink will become trans∣parent again, as Spring▪water; and if you drop some Drops of Oil of Tartar into this clear Li∣quor, it will be turned again into Ink. The blew Tincture of Violets, infused into the Oil of Vitriol, becomes of a purple Colour; to which if you add a few Drops of Spirit of Harts-horn, the purple Colour will be changed to a green.

The Reason why 2 clear Liquors mingled toge∣ther make Ink, is, because the particles of either of them are brought nearer together, so as to hinder the passage of the Rays of Light. And whereas the said Ink afterwards, upon the pouring another Liquor into it, becomes clear again, the Reason is, because the particles of the new added Body, do separate the Parts that before were contiguous, and consequently make an open passage for the Light, to pass freely, as be∣fore.

XIX. The Cause of the variety of Colours, proceeding from the mixture of Liquors. The Difference of Colours proceeding from the mixture of Liquors, is to be fetch'd from the small particles contained within the pores of each Liquor, which being changed in situation and position by the Liquor that is poured into them, do transmit the Rays of Light, variously refract or reflect them, and consequently produce different appearances of Colours. For, as was mentioned before, when the Globuli have more Right motion than Circular, they afford a Violet Colour; if they have more Circular motion than Strait, the Liquor appears yellow; but if the Globuli have much more Circular motion, than Right motion, they produce a Red colour'd Liquor: Again, if the Aethereal Globuli have more Right motion, than Circular; but yet less than the Globuli of those Rays that produce a Violet Colour, then they yield a blew. And in like manner we are to conclude concerning all other Colours, the variety and sud∣den changes whereof, in Liquid Bodies, is chiefly to be attributed to precipitation.

XX. Sharp and sowre Salts alter the Colours of Bodies. Thus we find, that sharp and acid Salts cause a thousand changes in the Colours of those Liquors with which they are mixed, according to the diffe∣rent Nature of the said Liquors. As for Instance, the Oil of Vitriol makes a black composition, with the infusion of Galls. Common Brimstone dissolved in the Oil of Tartar, becomes of a fair Citron colour. Spirit of Nitre turns the Juice of Herbs as white as Milk. Spirit of Wine turns red, when it hath been digested a while with the Salt of Tartar. The Syrup of Violets turns green, by the mixture of an Alkali; and red, by adding an Acid to it. Acids, or Sowre things destroy blew Colours, and Alkali's do restore them again. The Infusion of the Indian Wood, affords an amber Colour, when mingled with Acids. And the Solu∣tion of Common Brimstone, made by an Alkali, turns white, by adding an Acid to it. All which solely proceeds from those Dispositions which Acid and Alkali Salts produce in the pores of those Liquors to which they are added, which is such, that the Light which penetrates them, re∣ceives all the Modifications that are necessary for the several Colours we find produced by these mixtures.

XXI. Why Pow∣ders are generally white. Most Powders are white, if they be dry and beaten, or ground very small.

Because all those small Bodies into which the Powder is resolved, are Spherical, and like so many Globuli, which reflect all the Rays of Light to one point. And if it happen that the grains of any

Powder do terminate in a Point or Angle; then they do not give a white Colour, but some other. For I have often taken notice, by making use of a good Microscope, that the grains of white Sand are either Round, or approaching to a Conical figure, that is, of a smooth crooked surface; but that the grains of Sand of any Colour, were Rough and furnished with many prominent An∣gles.

XXII. Why Veal, after it is drest by the Fire, looks white. Veal, and Hens or Capons, are of a white Colour, when boiled or roasted, and lose the red Colour they had, when they were yet Raw.

The Reason is, because the Heat hath chas'd away the Moisture that was before in the Veal, as well as in the flesh of Hens, &c. for moisture shut up in the pores of Bodies, is a hindrance to White∣ness, as is evident in all dry things, which by the separation of their moisture become white; be∣cause Moisture doth not permit so much fraction as the Air doth; and yet so much is necessary to cause Reflexion. Hence it is, that a Body that is newly whited with Quick-lime, appears at first to be of a dusky Colour, and afterwards, in success of time, becomes white; because at first it hath much moisture mixed with it; which being exhal'd into the Air, and the Quick-lime dried, yields a white Colour.

XXIII. Cloth ex∣pos••d to the Sun chang∣et•• its Colour. Colours wherewith Cloth or Silks are died, do soon lose their Lustre, by being long exposed to the Sun, and degenerate into a faint Liveless Colour.

This proceeds from a twofold Cause: First, Because many of the particles of Dyed Bodies, which compose the Tincture are exhaled, by the Suns agitation. Secondly, Because many little Bodies, that wander up and down the Air, do thrust themselves into the pores of the Cloth, which by covering its Lustre, efface its former Colour. Wherefore they that deal in Cloaths, have a care that they be not long exposed to the Air, but keep them shut up.

XXIV. The Spirit of Vitriol is hurtful to the Teeth. Some make use of the Spirit of Vitriol, to whiten their Teeth.

But this may well be reckon'd amongst Vulgar Errors, since it is notorious, that the Spirit of Vitriol, in conjunction with an Alkali, doth pro∣duce a yellow: And forasmuch as something of an Alkalous Nature is continually transfused from the Gums and other parts of the Body, it must follow that the Spirit of Vitriol being commixt with such a Salt, must rather make them of a yellow Colour, than any whit conduce to the whitening of them.

XXV. Sugar, and hot Meat, blacken the Teeth. It is observed, that the frequent use of Sugar, and too hot Meat, does blacken the Teeth; because Sugar abounds with Volatile Salt, whose sharp∣pointed particles do Worm-eat the substance of the Teeth, and make great pores in them; wherein the Lucid Rays being suffocated, do produce a black Colour. And the same effect is also caused by hot Meat, the agitation of whose particles do likewise bore many Cavities in the Teeth.

XXVI. What is the cause of those various Colours which appear in a long figur'd Glass ex∣pos'd to the Su••. A Glass Vessel of a long figure, like a Gourd or Cucurbit, being fill'd with water, and expos'd to the Sun-beams, so as that they may enter obliquely through the narrow Mouth, at the upper part of the Vessel; these Sun-beams falling upon a white Paper, or piece of Linnen, will represent various Colours. For the uppermost Colour will be Red, the Lowermost Blew, and the Middlemost Whitish.

The Reason of this appearance, is to be fetch'd from the various Transmission of the Rays: For Experience tells us, that Rays passing obliquely or slantingly through a Hole, must needs be refracted, which Refraction is the cause of all this variety of Colours; forasmuch as the parts of the subtil matter, which we conceive as so many little round Bodies, which role continually through the pores of Earthly Bodies, are variously moved, according to the diversity of the Causes which determine their motion. So as that the Colour, which is represented at the upper part of the Glass, is red; because the Heavenly Globuli, which transmit the Action of the Light, are much more swiftly whirl'd round, than they tend in a Right line. But a blue Colour is represented in the lower part, because the same Globuli are more slowly in their circular motion, than in their direct and strait tendency. Because there is supposed to be a Caus•• which hinders their Circumvolution. But in the Midst a white Colour is seen, because the Heavenly Matter there hath an equal proportion of Circum∣rotation and Procession. For those Bodies are called White, in which the circular motion of the Globuli is equal to their tendency in Right lines. So that the whole difference of Colours doth only depend on the different proportion of these moti∣ons of the Celestial Matter. As hath been more at large declared in my Institution of Philo∣sophy.

XXVII. Of a Wood brought from Mexi∣co, which gives a various colour to Water. ATHANASIUS KIRCHERUS, in his Book of the Art of Light and Darkness, tells us of a sort of Wood growing about Mexico, which the Inhabitants call Coati, which communicates a great variety of Colours to water. For if a Vessel be made of the same, and filled with the clearest water, it after a little time standing turns the water into a blue Colour, which continues in the water as long as it stands in the said Vessel; but being poured out into a Crystalline Bottle, and expos'd to a full Light, it recovers its former per∣spicuity; but if it be brought into the shade, it turns green, and if it be brought into a yet darker shade, it appears red, and that very deep, as ap∣proaching somewhat to blackness.

The water put into a Vessel of this Wood, appears first to be of a blue Colour, because it cannot be question'd, but that the infused Liquor doth enter the pores of the Wood, and fetcheth out many of the small particles thereof; which being mixed with the moisture, are the cause why the Rays of Light are in that manner refracted and reflected, as is necessary for the production of a blue Colour. Again, when this water is pour'd into a Glass Bottle, it appears clear and transparent, because of the full brightness of the Sun, to which it is exposed. For tho' the par∣ticles, which the water had fetched out of the wood, did reflect or refract some of the beams; yet now the prevailing power of the Light doth efface that disposition of Parts, and makes its way without any let or hindrance through the water. Thus we find by daily Experience, that the Sun shining through a Glass Prism, doth not exhibit the Colours of the Rainbow, tho' they be exactly represented on a piece of Paper that receives the said Rays. Then afterwards this Bottle being

removed out of this great and strong Light▪ into a more moderate or shaded Light, is turned into a curious and pleasant Green; because from the brightness of the Sun, which affords abundance of Light, the blue Colour, which the Wooden Vessel did produce, is changed into a green, which is compounded of a blue and a yellow. And last of all, when the Bottle is brought into a more shady place, the water appears of a deep or dark red; because the Redness is weakned by the decrease of the Light, and is changed into a kind of Rusty Colour.

XXVIII. Brazile Wood com∣municates a Red tin∣cture to water. In like manner we know, that Brazile Wood communicates a red Colour to the water wherein it is boiled; which being put into a Drinking glass, if a little distill'd Vinegar be added to it, it imme∣diately is turned into the colour of Straw or Amber▪ From which sudden change of Colours, we have good reason to conclude, that all Colours do arise from the various texture of the parts, and the different reflexion of the Light.

XXIX. Nephritick Wood yeilds a Golden, blue, and yellow Colour. There is also another kind of Wood, which hath taken its name of Nephritick Wood, from the great use it is of in curing the Gravel, the parts whereof being infused in water, and put into a Glass Vial, do after a few hours ••••••ge the water of a Golden Colour if the Vial be placed between the Eye and the Window, but if the Eye be placed between the Window and the Vial, it will appear of a blue Colour. For when the Rays of Light do enter into the Liquor, they become tinged with a yellow Colour; but the same represent a blue, when the Rays reflect from the Vial. And if you pour an Acid Liquor upon it, then the blue Colour will vanish, and the whole Liquor will appear of a Gold Colour.

The Reason of this is probably no other, than that of the foregoing: For it is evident, that this Wood doth consist of Tinging particles, which are easily resolved in the water, and so far seem to be much of the Nature of Salt; which particles entring the pores of the Water do so refract the Rays, that they appear tinged with a Gold Colour. And if you admit the Light of the Sun through some Hole, into a dark Room, and place the Vial full of the Infusion of this Nephritick Wood, partly within the Cone of Light, and partly with∣out it, you will observe a vast variety of Colours, caused by the various degrees of the Refraction of the Light. Now the Reason why, after that the blue Colour hath been extinguisht by an Acid Liquor, it should be restored by the Affusion of Oil of Tartar, or a Sulphureous Salt; and on the contrary why, when the Gold Colour is vanished, it is restored by the addition of an Acid Liquor, is, because Acid Salts do cut and slash the tinging particles into lesser divisions, or at least precipitate them, and so make the Colour to appear more weak and dilute.

CHAP. X. Of Occult Qualities.

I. What Oc∣cult Qua∣lities are. OCcult Qualities, are by the Peripaticks called Hidden Powers, by which Natural things do act or suffer any thing, and whereof no prior Reason can be assigned, as immediately proceeding from the substantial Forms of things. But our Modern Philosophers are at a loss about what the ARISTOTELEANS means by all this Gib∣berish, who denying all substantial Forms, despair of ever knowing what these Occult Qualities are, which are the immediate products of them. Wherefore the abstruseness of some Qualities doth seem only to depend on the different Hypotheses of Natural Principles; so as that to those who fol∣low the Peripatetick Hypothesis, the Ebbing and Flowing of the Sea, and the Conjunction of the Iron with the Load-stone, appear to be abstruse and hidden Qualities; whereas, according to the Principles of Corpuscular Philosophy they are most clear and evident effects.

II. Of the Common Opinion, that a Sponge attracts water. A Sponge is commonly supposed to attract water, and to draw it upwards.

If we warily consider the thing, we shall find that a Sponge is very improperly said to attract water; whereas on the contrary, the water doth rather mount upwards to the Sponge, and intrude it self into its pores. For as soon as the Sponge toucheth the water, it somewhat presseth the some, and makes the pressed part of the water to mount up, and enter into the pores of the Sponge, as is evident in a writing Pen, which no sooner touch∣eth the Ink, but it mounteth up into the Pen by means of the Slit of it. For if the Point of a Pen without a Slit be applied to the Ink, no part of the Liquor will ascend; or if any part of it stick to the Quill, it immediately drops down. The mounting up therefore of the Water is caused by the pression of the Sponge, whereby the Air is thrust out of its place; which Air afterwards push∣ing against the surface of the Water, drives it upwards, and by some Force makes it to enter the Body that lies upon it.

III. How New Bread at∣tracts wa∣ter. New Bread put into Wine, or any other Liquor, will draw up the same 2 or 3 Fingers breadths high, and contrary to the Laws of Nature, without any Pression, operates at a distance.

The Wine enters into the Cavities of the Bread, because they are bigger than is necessary, for admitting the parts of the Air only; and therefore the parts of the Air that are shut up in them, are on every side surrounded with the Subtil Matter, which doth more swiftly agitate them, than they would be moved elsewhere, in case they continued entangled amongst themselves. And forasmuch as all Bodies, which move in places that are too narrow for them, do strive to get out of them; it accordingly happens, that whilst the parts of the Air do go forth from the pores of the surface of the Liquor, that toucheth it, the parts of the Water, or any other Liquor, do immediately follow it, and possess themselves of the relinquisht place. And because also the parts of the Liquor do better fill the Cavities of the Bread, they are not so swiftly agitated in them, as the parts of the Air; and therefore do not endeavour to quit the same, except only in order to enter the higher pores of the Bread, and take up the place of the Air, which strives to get out of the Pores thereof.

IV. How water comes to mount up∣wards in Calcin'd▪ Lead. For it cannot be question'd, but that the pores of New Bread, how crooked or winding soever they may be, do much assist the ascent of the Liquor: For they are as so many Pipes, through which the water leisurely passeth, when it is pressed by the external Air. Mr. BOYLE hath proved this by a like Experiment: For he

[illustration]

[illustration]

Book. 2. Part. 2. Chap. 10

G. Freman I••.

I. Kip.

To the Right Honourable Thomas Herbert Earle of Pembrock and Montgomery, Baron Herbert of Shurland, Cardiff, Ross of Kendale, Parr, Marmion & S^r. Quintin, Lord of the Lordships of Ʋsk, Carleon, Newport and Tredeg, Lord Leivtenant of Wiltshire, one of the Lords of the Admiralty, Lord Privy Scale, and one of the Lords of their Ma^tys. most Honou∣rable Privy Councell &c.^a.

This Plate is humbly Dedicated by Richard Blome.

took a long Glass Pipe, and fill'd it with Red Lead, and then put the lower end of the Pipe into the water, which by degrees mounted up the heighth of 40 Fingers breadths; by means of those pores, which, like so many Pipes, do convey the water upwards.

V. A Sheep flees from a Wolf, a Chick from a Kite, and a Pigeon from a Hawk. A Sheep trembles at the sight of a Wolf; a Chicken at the sight of a Kite; and the Pigeon, dreads the approach of a Hawk.

Philosophers commonly attribute these Aversions to the mutual hatred that is between these Crea∣tures; but without sufficient ground. For a Wolf doth not hate a Sheep, but is delighted with it, and pursues it as a convenient Good for him. And the same may be said of a Kite, that pursues a Chicken; and of a Hawk, that sets upon a Dove. A Sheep therefore at the sight of a Wolf betakes himself to flight, because it is endued with such a Texture of Fibres, that the Light reflected from the Wolfs Body, doth produce such an affe∣ction, upon which the motion of running follows. For there are some Rays or Spirits which are con∣tinually darted from the Wolfs Body, which painfully affecting the thin Fibres of the Sheeps Optick Nerves, do suitably move the Brain and the Spirits contained therein, and convey them in∣to the Muscles, in such a manner, as is necessary to put them upon a flight. For these Spirits are of a wonderful force to affect and agitate the Body which they push upon, and whose most inward parts they pierce into.

VI. Whether any shade can be hurtful to the Body. Some Shades are commonly accounted to be of a hurtful nature, and to cause either Pain, or some other inconvenience. Thus a Serpent flees the shade of an Ash. And those who sit down in shady places, are apt to be overtaken with sleep.

These Effects are not caused by the Shade, which being somewhat Privative, cannot have any positive Vertue or Effect; but from the steam∣ing current of particles proceeding from Bodies, and more particularly from the neighbouring Trees, Plants, Pools, or any other Bodies. And that a person that sits, or lies down in the Shade, is very susceptive of these steaming particles that continu∣ally flow from Bodies, and very like to be affected by them, may be easily conceived, for that in Summer-time the Pores of the Body are more open, and stand ready to receive these outflowing little Bodies; and therefore no wonder if they be affe∣cted by them.

VII. How Quicksil∣ver kills Worms. Thus the Effects do prove that subtil and in∣visible Steams do continually proceed from Quick∣silver; for which Reason those Artificers, who are much conversant about it, are used to keep Gold in their Mouths, with which they intercept the noxious Steams of the Quicksilver, which set themselves about the Gold, and cleave to it, and discolour it. Moreover, drops of Quicksilver have been found in the Heads of these Artificers, and in other parts of their Bodies. For there are cer∣tain pure and subtil Effluvia or out-flowings, which proceed almost from all Bodies, which retain the Nature and Vertue of the Body whence they pro∣ceed. Neither is it to be doubted, but that Quick∣silver boil'd in Water, doth communicate a Ver∣tue to it, of killing Worms.

VIII. There is no vertue in bare words. It is a common assertion amongst the Cabbalists, that there is a great Vertue in Words; as by which, extraordinary Effects may be performed. And I remember to have read somewhere in Para∣celsus, that upon pronouncing the words Osy, Osya, Serpents stop their motion, and lie still as if they were dead.

But this is an ungrounded Opinion of the Cab∣balists, forasmuch as the bare words of the most wor∣thy Tongue have no efficacy at all; no more than the Vertue of a Man, or the signification of some Holy Thing, can communicate any Vertue to the Words pronounced by the one, or importing the other. For tho' it cannot be denyed, but that Orators and Poets do excite Passions in the Minds of their Au∣ditors; yet this is not by any hidden Vertue that is in their Words, but by the strength of their Rea∣sons, and the aptness and Musical cadence of their words. Wherefore what PLINY tells us in the 2d Chapter of his Natural History of the Preser∣vation of the Fruits of the Earth from harm, by some words pronounced over them, and of the charm∣ing of Serpents, ought to be lookt upon as Ficti∣on. Seeing that words can operate nothing in a natural way, and have nothing of any Sympathe∣tical Connexion with intelligences or the Powers of Heaven.

IX. That a Nose cut out of another mans flesh, doth rot or pe∣rish upon the death of that man. It is a common Story, that a Nose cut out of the Flesh of another Man, upon the death of him from whom it was taken, corrupts and rots as the Body of the dead Person doth. And the same is said of the effect of the biting of a Mad Dog, which continues till the Death of the Dog, and then ceaseth.

No sufficient Reason can be given to verifie these Effects; and therefore I suppose that these things are reported by Authors without sufficient faithfulness; or if any such thing ever hapned, that it was an effect of chance, and not of any Phy∣sical Causality.

X. Whether VVounds at a di∣stance are curable by the Sympa∣thetick Powder. It is also believed by many, that wounds at any distance may be healed by the Sympathetical Pow∣der, by applying the Powder to the Weapon that made the Wound, or to a Rag that hath any of the Blood of the Wound upon it.

But tho' many great Authors maintain this for a truth, yet I am not easily persuaded to confide therein. For we do not find in calcined Vitriol, which is the Basis of that Powder, any thing con∣ducive to the healing of Wounds, besides an ad∣stringent Vertue, which is very proper to stop Blood, and to close and heal a Wound. And tho' the Spirits proceeding from the Vitriol, may be sup∣posed to exert some of their efficacy at a small distance, yet is it not certain, that the Power there∣of can be conveyed so far as is reported. Neither will the instances that are brought to prove this effect, be of any great weight with those who consider how apt the Minds of Men are to be∣lieve any stories, and how many do seem to take delight in being imposed upon, rather than to be lookt upon as incredulous. So that it seems that these Cures ought rather to be attributed to the cleanness of the Wounds; since in the Sympathe∣tical Cure, charge is always given to wash them with Urin, which is endued with an abstersive Power, by reason of the Salt that is contained therein. And this is no more than the Dogs them∣selves do, who are used to cure their wounds by licking them.

XI. By what means some may be cu∣red by the Sympathe∣tick Pow∣der. But if wounds, at any time, have been cured with this Powder, the same must be performed by the Effluvia of little Bodies: Which tho' not al∣ways, yet very frequently retain the nature of those Bodies from whence they stream forth, and transmit the same to a vast distance; and by this means the particles proceeding from one Body, en∣tring the pores of others, may there produce the same effect, and move the Senses much in the same manner as the said Bodies themselves would do by Corporal Contact.

XII. VVhence it is that that Twins are touched with the same affe∣ctions. There is a great Sympathy observed between Twins; so that if one of them chance to be sick of any disease, the other is frequently seized with the same.

The Reason whereof is, because they both have the same Texture of their Fibres, and the same Temperament of Humours; so that if it happen, that if by any distemper of the Air, or by any hurtful Meat or Drink, the one of them falls sick, it cannot well be otherwise, but that the same effect must happen to the other, because of the great conformity of their Frame and Tem∣per. And therefore it is that they are subject to the same motions of Passions; so that what produceth loathing in one, will effect it in the other; and whatsoever is desired by one, will also be desired by the other; because a like Tex∣ture receives the same affection from one and the same Object, and consequently stirs up the same Appetite and Passion.

XIII. How some Old VVo∣men be∣witch little Children. It is commonly said, that some Old Women be∣witch Infants.

Which may be, because these Old Women, by the strength of their Imagination, intending their Nerves and Muscles, may dart forth from their Eyes some noxious Spirits, whereby the tender and easily susceptive Body of the Infant may be greatly prejudiced, especially if the Infant be near to the Woman. For bewitching, as PLINY tells us, proceeds from the Spirits of the Witch, en∣tring through the Eyes of the Bewitched, into their very Heart. Indeed it seems probable e∣nough, that by this darting forth of Spirits, much mischief may be done; since it is notorious, that a Woman that hath Those upon her, doth produce Spots and Stains in a Looking-Glass: And that one who Coughs, stirs up Coughing in others; and one that Yawns, a Yawning in him that sees him.

XIV. VVho are most ob∣noxious to VVitch∣craft. Whence we may understand the Reason, why all are not equally obnoxious to Witchcraft or Fascination, but only Infants and Youth, and others who have their Pores more open; and therefore are liable to suffer from the incursions of the Spi∣rits and effluvia proceeding from others: Especi∣ally if the imagination of the Witch be heightned by Love or Hatred; because in this case they at∣tack the party bewitched with greater force and violence. Wherefore care ought to be taken to keep little Children at a distance, and out of the sight of such persons.

XV. How a Scor∣pion appli∣ed to the place stung by him, draws out the Poison. A Spider or Scorpion that hath bit or stung a person, being bruised, and applied to the part af∣fected, draws out the poison.

The Reason is, because the substance of a Spi∣der or Scorpion is like a Sponge; which, whilst the parts that are sever'd by the contusion, shrink by means of the Nerves, do take up the adhering venom, and draw away that which is got in. For this is effected much in the same manner, as Oyl is washed out of a Cloath by means of Soap; for as the particles of Oyl which are got into the Cloath, do easily embrace those of the Soap, as be∣ing of a like nature, and are carried away with them: So the particles of the Poison sticking to the wound, do easily join themselves with those that are found in the bruised Animal applied to it, and by this means the wound is freed of them.

XVI. VVhence it is that some Stones perform the like effects. KIRCHER tells us, that in China there be many Serpents, which are called by the Portu∣guese Hat-bearers, because they have a Skin that starts up on their Heads, not much unlike a Hat, in which little stones are found, which being redu∣ced to Powder, and mixed with Terra Sigillata, and applied to a poisonous wound, stick fast to it and draw out all the Poison, and then fall off from the wound of themselves, which are after∣ward washed clean in Milk, in order to be used again as before. For indeed most poisons are bet∣ter overcome by Alexipharmacs, than by Vomits or Purges.

XVII. VVhether a VVolf causeth a Hoarsness in those whom he sees first. It is commonly believed, that a Man who is seen of a Wolf before he sees him, grows dumb, and is unable to utter a word, or make the least noise.

Tho' this be an old Story, yet there appears no ground at all for it: Seeing that Experience teacheth, that whether a Wolf see a Man first, or or whether a Man see the Wolf, the same commo∣tion or disturbance follows. I my self have very often lookt upon Wolves, yet never perceived thereby any Hoarsness, or the least defect in my Voice; but on the contrary, have many times by my shouting, made them run away. But how does it come to pass then, that some persons at the sight of a VVolf do contract a Hoarsness, and become Dumb of a suddain? Why this pro∣ceeds only from Fear, when the great concern they either have for their own lives, or for the safety of their Company, puts them into a suddain consternation; for then endeavouring suddainly to cry out for help, they hurt their Lungs by the great force put upon them, and the VVind Pipe by fetching in of too much breath, becomes, as it were, choaked. To which may be added, that the Muscles of the Tongue being slackned, by the great defect of Spirits, cannot readily be made use of, for the forming of the voice. So that by the failing of all these Instruments, it cannot be otherwise but that a Hoarsness must be caused, and the Tongue disabled from uttering an articulate sound.

XVIII. VVhat is the Reason of the An∣tipathy which is found amongst Plants. Some Plants have an Antipathy against each other; as the Oak and the Olive Tree, Cabbage and Rue, Fern and Reed, which cannot endure the neighbouring of each other, nor can touch one another without some prejudice.

The Reason of this hatred is, because these Plants are desirous of one and the same Alimen∣tal Juice; and therefore the stronger of them doth draw all that juice to it self, and by this means robs the weaker of its necessary food, which must needs hinder it from growing and thriving as otherwise it would. Or else we may say that Plants set near one another, may hinder each others growth, in that the emanations or effluvia

which proceed from their Roots, may be noxious to each other. For the Olive Tree communicates such a bitterness to the ground round about it, that it spoils the Cabbage and Lettice that grows near it. And Fern hinders the growth of Reeds by the steams proceeding from it, which obstructs their Pores, and disturbs the Texture of their Fibres.

XIX. VVhat the Reason is of the Sun∣flower turn∣ing towards the Sun. The Heliotrope or Sun-flowers, always turns it self towards the Sun, and doth so follow its moti∣on, as to face it continually. Theophrastus makes mention of some of these Heliotropick Plants, growing about the River Euphrates, which at the going down of the Sun, do so drop their Heads and Flowers into the River, that they cannot be reached with the Hand; but as soon as the Sun riseth, lift them up again to their former height.

This, I suppose happens, because that Plant abounds with much and gross moisture, which be∣ing agitated by the Beams of the Sun, and thereby rarefied, cannot be contained within the same bounds, and therefore strives to make its way through the most open Pores, that is, those which are over against the Sun: and forasmuch as the Neck of this Plant is very plyable, the agitated moisture which breaks forth from it in the finest Threds, turns it self that way towards which the particles of the moisture tend. The extraordinary moisture of this Flower may be confirmed from that Dew which lies upon the midst of it, when the Sun is at the highest and hottest; which cannot be said to be the re∣mainders of the morning Dew; forasmuch as that vanisheth a few hours after the Sun Rising; and therefore must be that humour, which upon the presence of the Sun, doth flow from its Stalk, and is carried up to the Flower.

XX. The Expli∣cation of a wonderful Sundial. In like manner a reason also may be given of that admirable Dial, invented by F. Linus at Liege, whereby a little Ball, swimming upon the water, did shew the hours, and exactly imitate the moti∣on of Heaven, after the Example of KIRCHER, who having put some Seeds of the Sun-flower into a piece of Cork, found that they turned the Cork towards the Sun, and that by fixing a hand to it, they exactly pointed out the hours placed round the inside of the Vessel. For seeing that the Sun-flower is turned towards the Sun, not only Eastward, but VVestward also, it must needs point to the hours noted on the sides of the Vessel.

XXI. VVhether the Bones of Animals, and Shell∣fish be ful∣ler at full Moon, than in the wane of it. The Bones of Animals are filled with Marrow at the full Moon; and Crabs at the same time do more abound with flesh; whereas in the wane of the Moon both are decreased.

These Effects, tho' commonly asserted to be so, yet many most exact observers of the works of Na∣ture testifie, they could never discern in either of these any such encrease or decrease, but that the Bones of Animals, as also Shell-fish at any time of the Moon are promiscuously found either full or empty, or more or less fleshy, according as it may happen from other accidental Causes.

XXII. Why Crabs and Lob∣sters are more full of fl••sh at one time than another. So that if at any time it happen that Crabs, Lob∣sters or Oysters be found more full of flesh at one time than at another; the reason is, because they have then met with more plentiful Aliment: For we find that of Fishes that are taken at the same time, and in the same place, some are much fuller of flesh and fatter than others; and that those Fish which are taken out of the Nets, as soon as they are caught, are fuller of flesh, than those which are left in the Net a good while before that they be taken out.

XXIII. VVhy the Skin of a Stag swims above all other Skins. The Skin of a Stag, if it be put by Tanners at the bottom of their Fat, and the Hides of other Beasts laid upon it, as soon as water is poured into it, never rests till it have got above them all, at the top of the Tanning Pit.

GASSENDUS imputes the cause hereof to the wider cavity of the Stags Hairs (for the Mi∣croscope assures us, that the Hairs of Animals are all of them so many hollow Pipes) which being filled with Air, endeavour to get above the wa∣ter, as a Bladder full of Air doth. He supposeth also, that this is a great help and furtherance to the swiftness of that Animal, because the said Pipes be∣ing dilated by the heat of the motion of the Stag, doth much contribute to their Lightness: as it is also very probable, that the Quill part of the Fea∣thers of Birds are a great help to their being easily supported in the Air.

XXIV. VVhy Per∣sons bit of the Taran∣tula, do skip and dance. They who are bit by the Tarantula, are so de∣lighted with some certain Tunes, as to be thereby stirred up to strong and continual Dancing.

The Reason whereof is, because the poison of the Tarantula doth alter the Temperament of the Body, and particularly so affect the Organ of Hear∣ing, as to comport with those Tunes, wherewith that Insect is delighted. For as there are several sorts of these Tarantulae, whereof some are affected with these Tunes, some with others; so that as the Piper or Fidler plays these, or the other Notes, so these, or other of their Insects begin to frisk, and cease as soon as ever the Tune is done. Ac∣cordingly it seems, that the venom of these Insects, being diffused through the Body of Man, and min∣gled with the Spirits, and afterwards excited by such notes, is moved after the same manner, and also impresseth the same motions on the Spirits, which by means of the Nerves and Muscles, produce a Dancing, corresponding with such notes. And this is the Cause of the recovery of him that is bit, be∣cause by this quick motion, the poison is discust and exhaled together with the Sweat, provoked on this occasion.

XXV. How Medi∣caments do purge. Some Medicaments do purge by their smell on∣ly; others by being handled, or applied to the Navel.

The Reason is, because the odour only of a Me∣dicament doth as strongly affect the Nerves, as they are affected by it, when taken inwardly; that is, when the Fibres or Strings of the Stomach and Guts are twinged and vellicated after the same man∣ner, as they are when the Medicin is swallowed down into the Stomack. For the parts of Medi∣caments are commonly very small and sharp, hard, swiftly agitated, and very penetrative; so as that by this means they do irritate and excite the Mem∣branous and Nervous parts of the Body, and pro∣voke them to expulsion. Whence we may con∣clude, that almost all the properties and virtues of Medicaments, which are commonly added to the Catalogue of occult Qualities, may be explained and resolved by mechanical Principles and Affecti∣ons, whether they produce these effects, by a like∣ness, analogy and familiarity of Nature, or whe∣ther they exert this their efficacy by way of irri∣tation.

Notes

• * 1.1

  I. Why boil∣ing water riseth up to the very bri•• of the Vessel, when before it reached on∣ly half way.
• * 1.2

  Figure 8.
• * 1.3

  Figure 9.
• * 1.4

  Figure 10.
• * 1.5

  Figure 11.
• * 1.6

  Figure 12.
• * 1.7

  Figure 13.