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.

CHAP. V. Of Loose and Close Bodies.

I. A Sponge becomes distended and swell'd by Liquor. A Sponge, by letting in of Water, or any other Liquor, swells and is pufft, and ••preads it self into a larger Bulk.

Some suppose that a Sponge is rarefied by the increase of some new Quantity; as if nothing of Foreign Matter did enter into it, but only that some ••upervening Quantity doth separate the parts of the Sponge, and increaseth its bigness. But who can believe that when Water is rarefied, and in a manner turned into Air, it is only thus dilated by the increase of new Quantity? Who perceives not that the Sponge sucks in Moisture, and hides the same within it self, which afterwards upon the squeezing thereof, runs out again, whereupon the Parts come closer together. A Sponge therefore becomes rarefied or dilated, when the parts of it are somewhat removed from each other, and that the Pores of it are fill'd with supervening Water. And the same Sponge again grows close, when its Parts are brought nearer together, by the Expul∣sion of that Matter, which before kept them at a greater distance. So that a Sponge may not only be said to be a Loose Body, whilst it is dry and free from all Moisture; but also, and more especially, when it hath all its Pores fill'd and stufft with Foreign Bodies.

II. Why some Bodies are more apt to be rare∣fied than others. Glass becomes dilated to a greater Space by Heat, than Metals; and of Metals, Iron is more dilatable than Copper; Copper, more than Silver; Silver, more than Gold; and Pewter more than Lead.

The Reason of all which must be fetch'd from the greater Porosity of those Bodies that are more light than others; for the more Pores there are in any Body that is capable of being Rarefied, the more Bodies may insinuate themselves into it, and by this means it becomes rarefied or distended.

III. The motion of Rare∣faction is more intense at the beginning. The Curious Searchers of Nature observe, that the Motion of Rarefaction is more intense at the beginning, and more slow and remiss towards the end thereof. They produce several Experiments to prove this; and more particularly from that of Weather-Glasses, exposed to the Heat of the Sun, uniformly, and continually applied to them; or set in Water that is kept in the same degree of Heat.

The Reason whereof is, because Rarefaction being caused by the admission of some thin Sub∣stance into the Pores, the more the said Pores are dilated by the violent ingress of new Matter, the more the Parts of the Body rarefied become distended, and therefore do still more and more resist and oppose any further distension.

IV. What is the Reason that Gates and Dores do easily shut in dry weather, and more hardly in Moist and Rainy. Gates and Doors frequently cannot be shut or opened, in Moist weather, without some difficulty: Whereas the contrary happens in the Boards where∣of Barrels are made, which when expos'd to the Air in Dry weather, do open and make the Vessels to become leaky.

The Reason is, because Gates or Doors do swell in Wet weather, for that the Water, or the Air fill'd with watry Vapours, penetrates the Pores of the Wood, and distends the Sides of them, which being dilated, the whole Bulk of the Body must needs be di∣stended likewise, and take up a greater Space than it did before. In like manner Linnen-Cloth is rare∣fied by the Accession of Water, Water by that of Air, Air by that of Aether, and Aether by that of a more subtil Body, if any such there be, and by this means take up more Room than they did before.

V. Why the Strings of an Instru∣ment do swell by the Moi∣stness of the Air. Thus also the Strings of a Violin, or other In∣strument, do swell in Moist weather, as appears by their breaking, and by the difficult winding of the Pegs. In like manner wooden Bowls are apt to get Slits, if they be put into Water, and the Water penetrate them. Some very credible Authors re∣late, that Earth taken up from those parts that are near to the River Nile, do increase every day in weight, from the time when that River begins to swell, until it be arrived to its greate••t height. Which cannot proceed from any thing else besides the Air; which being condensed at that time, and clogg'd with watry Particles, doth increase the weight of the Earth.

VI. How an Obelisk, moved out of its station, was put to rights again. By the same means an Obelisk at Constantinople, which was got out of its place, was put to rights again; for the Artificer, who had undertaken the Work, having caused very strong and thick Ropes to be tied to the Obelisk, and fastned to some strong Hold fast, caused the said Ropes to be moistned, by pouring great quantities of Water upon them, which causing them to swell, and consequently shortning their length, lifted up the Obelisk to its former situation upon its basis. For Ropes, con∣sisting of long and twifted Threads, by admitting the Moisture into their Pores or Intervals, the more they swell in thickness, the more contracted their length is.

VII. How Mil∣stones are separated from the Rocks, whereof they were a part. It is after this manner that Mill-Stones are sepa∣rated from the Rocks. For they make abundance of Holes about the said Rocks, into which they drive wedges of Wood that have been dried in an Oven; which Wedges being placed around in the form of a Cylinder, according to the bigness that we would have the Mill-Stones to be of, when Moist weather comes these Wedges swell, and by their swelling separate the Mill-Stones from the rest of the Rocks; so that it is evident, that this Separa∣tion is made by the Vapours, which would be very difficult to perform any other way.

VIII. VVhy the Staves of Barrels are contracted in hot and dry wea∣ther. The Staves of Barrels take up less room in Dry weather; for seeing that their Parts are agi∣tated by Heat, some of them fly away into the Air; which being gone, it is no wonder if the rest come closer together, and do not take up so much place as they did before.

IX. A Bar of Iron put into the Fire, swells and be∣comes di∣lated. Take a Bar of Iron, for Example, of 2 Foot long, and a Stick or piece of Wood of the same bigness; then put the Iron Bar into a strong Fire, till it be red-hot, and then compare it with the piece of Wood which was of the same dimensions with it, when it was first put into the Fire, and you'l find the Iron to have been increased, not only in Breadth, but in Length also, and in both

to exceed the Piece of Wood which was equal to it before; but as soon as it is grown cold, we shall find it restor'd to the same dimensions it had before it went into the Fire.

The Cause whereof is the subtil Body, which enters the Pores of the Iron, viz. the particles of Fire, which dilate it to a greater Extension. For the parts of Fire being in continual motion, must needs distend the Sides of the Iron Bar; which when expos'd to the Air, and being cooled, returns to its former Extension, because the particles of Fire leaving its Pores, and those of the Air entring into them, and not being moved with the swiftness and violence that those of the Fire are, they do less distend them, and consequently the Bar of Iron must take up less room than it did before.

X. Why a hot-Iron cuts Glass. Hence also it is, that with a Red-hot Iron, or with a piece of Packthred dipt in Brimstone and set on fire, Glasses are cut; because the particles of the Glass being agitated by the heat of the Fire, require a greater Space, and consequently drive their contiguous Parts further from them. And it is for the same Reason, that Metals in fusion swell, and take up more room than they did be∣fore.

XI. Water ra∣refied into Vapour, takes up an hundred fold larger Space, than it did be∣fore. Water, by the virtue of the Sun, is lifted up into the Air, and becomes thereby so diffused, as to take up a greater Space than it did before; for if we may believe the account that some give us, Water turned into Vapour, fills a Space 100 times larger than that was which it took up be∣fore.

The Cause of which Diffusion is not to be at∣tributed to the parts of Water, as some falsly do imagine; since it is impossible that the Dimensions of a thing should be increased, except that some other Body be added to it. And consequently the Water becomes dilated, when its Parts remove farther from each other, and so give way for the entring of some Foreign Body between them. After the same manner as when a Heap of Dust, by the Wind is lifed up, and dispersed in the Air: For this Expansion is not to be attributed to the particles of Dust; but to the Air, which fills the Intervals between them, and separates the particles of Dust from each other.

XII. Why Bodies that are condensed, become of a white Colour. Condensed Bodies, and such as after Rarefaction are reduced to a less Room, are commonly of a white Colour; as Butter, Grease, Oil, and such like.

The Reason whereof is, because in Condensation those particles are expell'd, which swell'd the Grease or Oil into a greater Room, whereupon their parts must needs come closer together, and be con∣tracted, as it were, into small round Pellets, which afterwards, like so many round Looking-Glasses, do reflect all the Light, and produce a white Colour in the condensed Subjects. For there are two things especially, by means whereof Bodies acquire a white Colour: The First is, That they consist of little and innumerable Surfaces, disposed to receive and reflect the Light in such a manner, as that it may suffer no loss, either by Refraction, or by the mixture of Shadow. The Second is, That the whole Light which shines upon a Body be re∣flected, without having any Beams swallowed up in the Pores of it. To the effecting whereof little round Bodies do conduce most; as will appear, when we come to speak of Heat.

XIII. What is the Cause of Fermen∣tation in New Beer or Ale. New Beer or Wine, if it be put into Bottles, doth swell and work with that Violence, that it fre∣quently breaks them.

Which Fermentation is caused by the Hetero∣geneity, or the Diversity of the parts of Liquor; which cannot unite together, by reason of the variety of their figures, and therefore endea∣vour to extricate themselves from the Society of each other. And that this is the true Cause of the Fermentation of Liquors, appears from hence, that after these Liquors are separated from their Heterogeneous parts, they are no longer agitated with any such tumultuary Motions; as is evident in Burning Spirits, Distill'd Water, and the like; which may be kept a long time without suffering any Change. For the Spirit of Wine being kept closely stopt, is not capable of any agitation of its parts; but if a little Turpentine be mixed with this Spirit, the parts presently begin to tumultuate, and endanger the breaking of Vessels Hermetically sealed.

XIV. Bread made of sprouting Corn fer∣ments of it self. If Bread be made out of the Flower of grown or sprouted Wheat, it will ferment and rise with∣out the addition of any Leaven of Yest.

The Cause whereof is, because the stiff and sharp particles of sprouted Wheat do infold them∣selves; and, as the Chymists express it, are in their greatest Exaltation: Wherefore, as soon as the Dough begins to grow hot in the Oven, the parts thereof become tumultuarily agitated, and driving the resisting Bodies before them, do in a manner prae∣cipitate them, and by this means the Bread be∣comes spongy and light.

XV. How the Air comes to be con∣densed or rarefied in a Wea∣ther-Glass. Let a Weather-Glass be fill'd with Aqua-fortis; but so as that when fill'd, there may be some Space left, taken up by the remaining part of the Air, which was before in the Glass, Tube or Pipe: You'l find that this part of Air, be∣ing dilated by a more intense Heat, upon the recess of the Aqua-fortis, retiring it self into the lower Head of the Tube, will fill the whole Capa∣city of the Tube; and that on the contrary, by Cold it will be contracted into so narrow a room, as that the whole Tube almost will seem to be filled with the Aqua-fortis.

Which Variety proceeds from the continual ingress of new Matter through the pores of the Glass, which doth so rarefie the impure Air con∣tained in the Glass, that by the separation of its particles from each other, it drives the Aqua-fortis, being unable to resist its place; whereas upon the egress of the subtil Matter through the Pores of the Glass, the particles of the Air com∣ing then closer together again, the Aqua-fortis returns to its former place, being drawn into it by the Air that enters at the lower end of the Glass. And if the weather be very Cold, that part of the Air which is in the upper part of the Glass, upon the recess of the subtil Matter, doth so greatly decrease, as that the whole Glass becomes fill'd with the Aqua-fortis.

XVI. Why a Chest-Nut cast into the Fire breaks with a great noise. A Chest-Nut put into the Fire, first swells, and soon after bursts, giving a great Report. Which doth not proceed from any foreign Matter that enters the Chest-Nut, but from the grosser parts of it, which the action of the subtil Matter entring into the Pores thereof, separates from each other, and doth so agitate, that at last they burst the Shell with a great noise.

XVII. How a Marble Pillar was broken to shivers. In like manner, a vast Marble Pillar mentioned by CABAEUS, was broken all to shivers, by kindling a Wood Fire round about it: For the heat of the Fire rarefying the Air contained in the Pores of the Marble, makes, that it cannot be lodged in the narrow Room it took up before, and therefore in striving to get forth into a large Space, it breaks and rends the Marble to pieces.

XVIII. The vast dilatation of a grain of Gun-powder. This Dilatation of Bodies, is the Cause some∣times that a very small Body becomes diffused into an incredible distension; as we see in Smoak, Va∣pours and Flame, which Dilatation is so great, that one Grain of Gun-powder, according to the De∣monstration of Joh. Chrysost. Magnenus, when kindled, becomes dilated into a flaming Sphere 3804 times greater than it was.