The Creation

22. The phenomena of Huygens and Wren, if they are discovered, it is not difficult to render their cause from what has been said[cite: 1, 2].

Because, to be sure, in this state of our globe, struck or projected things are carried away more by the air and aether than by their own impetus, just as a moved water carries away things swimming or lying in it[cite: 1, 2]. And that is evident by this reason, because from the abstract [theory] of motion, the ratio…[cite: 1, 2].

[22]**

…from [abstract] reasons, nothing restores itself to its prior line even when an impediment is removed, because no endeavor without motion lasts beyond a moment[cite: 1]; but things struck and impelled upon a plane, when they encounter a small mound in their motion, slant their course as if by a certain art, and once the impediment is removed, they resume it[cite: 1].

This is because the impediment was objectified only to the body, not to the air or aether; as one [aether] vanishes, another succeeds it[cite: 1]. Just as two lights, on account of their rarity, penetrate each other without being confused, so those two aethers of the concurring bodies carry their own bodies along and are mutually transferred into the other[cite: 1]. From this comes that permutation of motions and regions after a concurrence[cite: 1].

The same is the cause of the Vibration of Pendulums, so many times repeated and gradually vanishing: the impetus of the impelling aether—collected by a particular condensation and dilation and restoring itself—carries the seized object even beyond the endeavor of its own gravity[cite: 1]. Thus, the object, having fallen down, is raised again to the other side, and soon, being dispersed and vanishing, the aether allows it to be cast down again by another aether that is now less elastic[cite: 1].

This matter is reciprocated until rest, so that the same cause applies to pendulums and vibrating strings[cite: 1]. From here also, the ratio of the isochronism of vibrations is rendered: for the higher the fall, the stronger it is; therefore, the greater the compression[cite: 1]. Therefore, as height diminishes, so does compression; but compression is the cause of restoration, and restoration is the cause of the speed of falling back[cite: 1]. Height, therefore, and speed (or force and space) are diminished together[cite: 1].

If the space is as much less as the force (or speed) is less, the motion will be isochronous, or completed in the same time[cite: 1]. Therefore, when the same aether from a moving thing strikes one that is resting or meeting it, it is transferred into the resting or meeting thing and deserts the impinging one[cite: 1]. This results in that divarication or permutation of paths and speeds of Huygens and Wren, of which we have given more examples in the problem of light in Theory of Motion, problem 11[cite: 1]. If it [the aether] is double, it sends each of its rays through the same opening at the same time without confusion[cite: 1].

Furthermore, from what has been said, it can be understood why a violent motion is weak at the beginning and end, but strong in the middle; or why it increases for some time and then soon decreases[cite: 1]. Suppose a stone or a lead bullet is projected by me or by gunpowder; at the beginning, the speed will increase because the motion imparted to the projectile is violent, while the motion of the projector is natural[cite: 1]. For my muscles, like a taut bow, relax and restore themselves to their natural state with great force[cite: 1].

The ratio is the same for gunpowder, whose compressed substance erupts from an open fire[cite: 1]. Now, the natural motion of a thing restoring itself increases continuously; therefore, the same motion, continuously accelerating itself, is impressed upon the projectile, which it exercises as long as it is strong enough to overcome the air[cite: 1].

But when the air has recollected itself and begun to react and restore itself, this motion of restoration in the air is likewise natural and accelerated[cite: 1]. Consequently, the decrement of the projectile’s impetus is accelerated by the increment of the reacting agent[cite: 1]. But to proceed, it has…[cite: 1]

[24]

…this also presents a difficulty if you look at the abstract reasons of motion: experience teaches that a larger thing outweighs a smaller one, and the impetus from a large thing is far stronger than from a small one; yet, in a free state of nature, it matters not at all for motion how great the length is in contiguous things, nor in continuous things according to Theory of Motion 23, 24, nor indeed how great the thickness or width is[cite: 1].

But sensible bodies appear to be continuous and contiguous rather than actually being so: hence, when the first part of a larger impetus has broken the [impetus] of a smaller adversary by its own destruction, the other discontinuous part—being animated even by the arrival of new air and aether—overcomes it easily with supervening recent forces[cite: 1]. But in truly continuous things, the impetus of all parts is consumed at once[cite: 1].

Whence, by the benefit of division, things not to be despised can be achieved in mechanics, which I trust I shall demonstrate at some time through use itself[cite: 1].

23. From gravity, the levity of less heavy things follows by accident, and the entire doctrine of Hydrostatics was first established by Archimedes[cite: 1]. Why is wood lighter than water?

Because in wood there is more aether than earth[cite: 1]. But why, then, does wood ascend in water, while a smaller amount of water in a larger amount—even if the water itself is lighter—does not ascend?

Because although water gravitates in water, nevertheless, due to a contrary [force] at every sensible point from any straight or curved line, I imagine the gravitation of imaginary cylinders in liquids in innumerable assignable ways…

Page [25]

…mutually, the gravity is canceled, and the liquid is arranged parallel to the horizon[cite: 1]. Therefore, a heterogeneous thing brought into water, since it raises as much water as the space it occupies, will create a cylinder in which it exists, unequal in weight to others; and consequently, it will sink if it is heavier, or be raised if it is lighter[cite: 1].

Similarly, if something is made lighter than the neighboring air, it will be raised in the air until it reaches a higher and more subtle region of air, and consequently a region lighter than itself, where it will hang: which is also the reason why clouds hang in the air and smoke ascends[cite: 1]. If, therefore, something could be prepared by human art lighter than air, there is hope that the art of flying could be reached[cite: 1]. According to the opinion of the most sharp Lana, as well as Vossius, this would be achieved if a concave vessel were provided so large that the air enclosed within it outweighed the container or vessel itself[cite: 1].

Therefore, with the air exhausted by an already known artifice and the vessel hermetically sealed (suppose it to be glass), the whole vessel will be lighter than an equal space of air[cite: 1]. Now, whatever is lighter than an equal space of liquid ascends in it: therefore, the given vessel will ascend in the air[cite: 1]. And to bring the matter to calculations (for Lana’s [calculations] are minor): let there be a glass bubble so small that the water contained and the glass containing it roughly balance in weight; let us call its semi-diameter, as a measure of magnitude, ($a$)[cite: 1]. Let the weight, whether of the glass or the water, which by hypothesis is the same, be called ($b$) as a measure of the destined weight[cite: 1]. Finally, from the observations of the most learned Boyle and others…

Page [26]

…let us suppose air to be a thousand times lighter than water.[cite: 1] Now let there be a glass bubble made of glass of equal thickness, a thousand times larger than the previous one, or whose semi-diameter is $1000a$.[cite: 1] Its spherical surface, or the glass container, will be greater than the glass of the measuring bubble in the duplicate ratio of the radius, and consequently will weigh $1,000,000b$.[cite: 1] And the water of this bubble will be greater than the water of the measuring bubble in the triplicate ratio of the radius, and consequently will weigh $1,000,000,000b$.[cite: 1] Therefore, if this bubble is not filled with water, but with air, since air is a thousand times lighter than water by hypothesis, it will weigh only $1,000,000b$.[cite: 1] And consequently, it will equipoise with the glass of the bubble.[cite: 1]

If the air is exhausted from the bubble as much as possible, it will weigh approximately as much as an equal space of air.[cite: 1] And if a bubble of radius $1500a$ is taken and exhausted, it will be notably lighter than an equal space of air, and consequently, it will ascend in it.[cite: 1] If the proportion of air to water were greater, the bubble should be made correspondingly larger.[cite: 1] But whether bubbles of such great magnitude can be conveniently made, and exhausted within, and remain without rupture and endure, I do not take it upon myself to say.[cite: 1]

25. Among the species of gravity, therefore, is aerostatics, upon which depends that entire apparatus of siphons, pumps, and baroscopes; and if Elater [elasticity/spring force] is added, of which we shall speak soon.[cite: 1] (Section 27).[cite: 1] Whatever stupendous things are performed with exhausted and compressed air.[cite: 1] To be sure, heavy things remain in suspension, and heavy things are raised upward, not from a “fear of a vacuum” (metu Vacui)…[cite: 1]

[27]**

…otherwise they could be raised to infinity, which experience refutes, but only until there is equilibrium with the aerial cylinder of the entire atmosphere.[cite: 1] For when water does not follow in a pump, it will follow the aerial cylinder equal to the width of the pump’s piston, or it must be compressed, or raised so far into the liquid aether from its own sphere as is the length of the pump.[cite: 1] Because only that much space in the pump is left as a vacuum, or certainly greatly exhausted, even if the most subtle aether enters it.[cite: 1] The ratio of the baroscope is similar.[cite: 1]

26. But from where does air rush into exhausted vessels with such force?[cite: 1] I ask in the same way: if you place a closed vessel in the middle of water and then open it with a large hole, why will the water rush in?[cite: 1] By the force (nisu) of its own gravity.[cite: 1] Therefore, the same applies to air.[cite: 1] Water, however, rushes in more slowly and not without resistance, because the air which has a difficult exit must be expelled.[cite: 1] But air rushing into a vacuum, which is full of aether thrust into that place by force, is not only not impeded by the aether, but is even helped; because the aether, collected there in a pool beyond its usual manner, is impeded in its circulation and cannot exit, even if pores are open.[cite: 1] For although a vacuum is given, a great vacuum is not given: the place deserted by the air must therefore be replenished.[cite: 1] Therefore, the GRAVITY of the aerial cylinder and the ELATER, or the force of the aether dispersing itself into its proper circulation, concur![cite: 1]

Page [28]

27. The same reasoning applies to compressed air collected as happens in loading pneumatic guns; for that phenomenon cannot be explained by the gravity of the air, but must therefore be explained by Elatere [elasticity], or the “appetite” for expanding itself. This effort of expansion does not come from the air, but from the aether: for when air is compressed, the aether is squeezed out of it by many strokes, exactly as juice is from bodies in a mortar. Once an opening is made, the aether—by the speed of its circulation which was previously disturbed and is now returning to order—enters again with the greatest force and scatters the air into its former rarity.

But why is the circulation thus disturbed? Because when air is exhausted, aether collects in a vessel in a quantity greater than is just; conversely, when air is compressed, the expressed aether is in a quantity greater than is just outside the vessel. But that quantity of aether, greater than is just, hinders the circulation of the aether around the center of the earth, where the circulation is nearer to the center: because the nearer the circulation is to the center, as it is with us, the smaller the circles are, and thus all things must be more constricted.

Hence, wherever you transfer an exhausted or distended vessel, even if you go a thousand leagues away (see below § 48), if you remain only in the same Circle, or at approximately the same distance from the center of the earth, there will persist (indeed, if you move closer to the center, it will be increased) the effort of the aether to restore its circulation to the proper density. Nor does it matter that we feel no constriction of air or aether around an exhausted vessel; for…

Page [29]

…this happens for the same reason that prevents divers from feeling the weight of the sea, and us from feeling the motion of the aether, due to the mutual resistance of parts in a liquid, or the effort supported from both sides, which holds stones together in arched work and generally in spherical things.

Nor does it seem probable what the most diligent Boyle thought: that the parts of air have the likeness of a fleece or springs so as to restore themselves when compressed, unless that is held from an abstract Theory of motion: nothing, however bent, will restore itself by its own force. Nor would there be such a great force in the elasticity of air—which we certainly feel to be the greatest of the powers known in nature thus far—if only the shaggy parts of the air were compressed; nor would the impetus be perpetually increased by increased compression or exhaustion, unless the state of the system itself were disturbed.

28. This is the reason for Exhalations being raised upward against natural gravity: The sea, as Becher ingeniously thinks, perpetually distills its more bituminous and heavier part through the spongy bottom toward the center of the earth, or into a certain interior receptacle or universal estuary of our globe. There, this sulfurous and bituminous mass having been digested and as if fermented, it emits through the earth vapors—that is, things rarer and therefore lighter than what the state and circulation of that sphere, closer to the center and thus denser, carries: from which [vapors] those that are aqueous, being subtler, light, and empty, go out higher…

Page [30]

…they go out, and are partly resolved into springs, captured by suitable silt as if in an alembic, or they depart through an open exit into the air and constitute meteors[cite: 1].

29. Although I would not deny that they also carry a certain subtle unctuosity or sulfur with them into the air. And the more unctuous part, intercepted either by stones or by that superior garden soil, goes there into metals, and here—with the addition of sublimation by the sun—into herbs, trees, fruits, and seeds[cite: 1]. I do not doubt with Hobbes, Derkennius, and Vossius (most versed in every kind of erudition) that most springs arise from those mountain cisterns and collections of snow or rain[cite: 1]; nevertheless, I think we must entirely agree with the Chemists, Brother Basil, Groschedelius, and Helmontius, that some are owed to subterranean vapors, from which also all mineral virtues of waters, and indeed other specific powers of simples, are to be sought[cite: 1]. Since the sun and air, the universal agents and patients, are varied if you add the state of the underlying earth, whether the light is now closer and direct, or now more oblique and remote[cite: 1].

30. Thus far concerning the phenomena of the whole globe; now we must come to the appearances of species, which nevertheless arise mostly from the phenomena of the globe[cite: 1]. Furthermore, the phenomena of species are either sensible qualities or motions: even if all those qualities are insensible motions[cite: 1]. Sensible qualities are either sight, or hearing, or smell, or taste, or touch[cite: 1]. The qualities of…

Page [31]

…sight are Light and Colors. Light is a very swift rectilinear motion of the aether toward the sense, propagated everywhere around every sensible point[cite: 1]. See above section 7 and below section 6. Nor is the Cartesian “propensity toward motion” sufficient, because every propensity toward motion that is not followed by motion does not last beyond a moment (add above section 23 and below section 57)[cite: 1]. Furthermore, light is either that primigenial light in the sun (of which in sections 4 and 5), or second-born; and that is either original or imitated[cite: 1]. Original light is in the fire generated among us, which occurs from aether explosively heaped up by the rupture of innumerable bubbles (of which soon)[cite: 1]; Imitated light is in mirrors, and in things which collect rays during a long period in the open air, such as the Bolognian Stone and the firefly[cite: 1]. Some things produce light through digestion, fermentation, or internal motion, and from there—if strong enough—they produce either light or fire sensible to sight alone, as in rotting wood; or even common fire, as accumulated wet hay does[cite: 1].

31. Colors are remarkably illustrated by the experiment of the Prism, and the real assertions of the blind man left to posterity by that man of greatest diligence, Robert Boyle[cite: 1]. He said that he perceived by touch the very rough surface of white and black, and the very smooth surface of red (although sometimes a varying blue was presented)[cite: 1]. He perceived black to be rougher than white, and that other colors, as they depart from the extremes, seem to decrease in roughness[cite: 1]. If this is so, I would believe that white is more [conducive] to light…

Page [32]

…to present more convexity, and black more concavity: whence the former reflects light, and the latter hides it; and the surface of black will have less flatness and more of “stings” or prickles[cite: 1]. Boiling likewise creates redness because it scours away inequalities[cite: 1]. But these things are mentioned in passing, for our task in this place is rather to reduce motions to their principles than qualities[cite: 1]. Shadows have no proper “effluvium” of their own, but appear only as a distance or a gap between parts noted by the sensory organ as being affected by light; or you may conclude this from the fact that they are collected by no mirrors or lenses[cite: 1]. Add to this: where there is much aqueous humor, there is much blackness, because that is entirely alkalized or empty (of which more below); therefore it is transparent, therefore admitting light and not reflecting it[cite: 1]. Add also that colors in most things arise not from reflection alone, but also from a certain subtle light or internal fire mixed in, no less than the effluvia of odors, in a perpetual explosion; and although it is rare in darkness without another light moving the eyes, perhaps they can sometimes vary[cite: 1].

32. Sound does not consist in the motion of the air; for I call “air” that thing whose gravity is felt in the Baroscope, which can be compressed, exhausted, and weighed[cite: 1]. Now it is established that when vessels are exhausted and closed in any way, a bell struck inside can be heard from the outside[cite: 1]. Sound consists, therefore, in the motion of the aether, but a moderate motion that goes out in circles, as we see when a stone is cast into water; whereas light consists in a strong and straight motion of a more subtle part[cite: 1].

Page [33]

But odor consists in the air: For since air is subtle water, it happens that by its flow it dissolves the subtle parts of salts no less than thick water dissolves thick ones[cite: 1]. Just as, therefore, we perceive saltiness in water by taste, so we perceive subtle salts dissolved in the air by smell: so that the nostrils are as it were the place where we “taste” the air[cite: 1]. By “salt,” however—lest there be a question about the word in this place (for below “voice” is used in a far different sense)—I mean with Geber whatever is soluble in any liquor[cite: 1].

33. No solution of this kind which occurs without reaction is central. For a central solution occurs by the opening of central bubbles, whence comes the action and transformation of which we shall speak soon; a superficial solution, on the contrary, occurs only by the opening of the surfaces of the bubbles, by a central disintegration, which happens in reality by liquid parts proportioned to themselves creeping into the pores.

Whence soon, when another dissimilar [part] supervenes, precipitation occurs[cite: 1]. Superficial bubbles, however, are formed only by a thick, sensible, and external fusion, but a weak one, whence dissolved metals can be reduced into a body by fire; central ones are formed by a certain insensible and internal fusion, and—as long as we have not found the key nor shaken out the secrets of nature—they are formed by a slow but firm fusion; although nature often produces similar species in an instant[cite: 1].