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.

* 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.

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.