61 · Why is it that quadrupeds of a small size most often give birth to [10] monstrosities, whereas man and the larger quadrupeds, such as horses and asses, do so less often? Is it because the small quadrupeds, such as dogs, pigs, goats, and sheep, have much more abundant progeny than the larger animals, which either always or usually produce only one offspring at a time? Monstrosities come into [15] being when the semen becomes confused and disturbed either in the emission of the seminal fluid or in the mingling which takes place in the uterus of the female. So birds too produce monstrosities; for they lay twin eggs, and their monstrosities are born from such eggs in which the yolk is not separated by the membrane.
[20] 62 · Why is the head in man more hairy than the rest of the body—in fact quite disproportionately so—while in the other animals the opposite is the case? Is it because some of the other animals send an excessive amount of their nutritive material into teeth, others into horns, others into hair? Those who expend their [25] nourishment on horns have less thick hair on the head; for the available material is used up in the horns. Those whose nourishment goes into teeth have thicker hair on the head than horned animals (for they have manes), but less thick than such creatures as birds. For birds have the same sort of covering as man; but, whereas in birds the covering is distributed all over the body owing to its abundance, in man it breaks out only on the head; for man is neither on the one hand devoid of hair, nor [30] on the other hand has he sufficient to cover the whole body.
63 · Why is it that in man alone of the animals the hair turns white? Is it because most of the animals shed their coats every year, for instance the horse and the ox, while others, though they do not do so, are short-lived, such as sheep and others (in which case the hair does not turn white, because it does not as it were [35] grow old)? But man does not change his hair and is long-lived, and so he grows white owing to age.
64 · Why is it that those in whom the distance from the navel downwards is [898b1] longer than that from the navel to the chest are short-lived and weak? Is it because their stomach is cold owing to its small size, and therefore it tends to cause excretion rather than concoction? Now such persons are unhealthy.
65 · Why is it that some animals come into being not only from the sexual [5] intercourse of animals with one another but also spontaneously, while others, such as man and the horse, can only be born as the result of sexual intercourse? Is it due, if to no other cause, at any rate to the fact that the former have a short period of coming to birth, so that the moment of birth is not protracted and can take place at the change of the seasons; but of the latter class the coming to birth is much [10] protracted, since they are born after a year or ten months, so that they must necessarily be born from the intercourse of animals with each other or not at all?22
66 · Why is it that the teeth of Ethiopians are white—indeed whiter than those of other nations, but their nails are not correspondingly white? Are their nails dark because their skin also is black and blacker than that of others, and the nails grow out of the skin? But why are their teeth white? Is it because those things turn [15] white out of which the sun extracts the moisture without adding any colour to them, as happens in the case of wax? Now the sun colours the skin, but it does not colour the teeth, but the moisture is evaporated out of them by the heat.
67 · Why is it that, when the head is removed, some animals die immediately [20] or very soon, while others do not? Does death occur less quickly in the bloodless animals, which require little nourishment, since they do not need food immediately and the heat in them is not diffused in moisture, whereas full-blooded animals cannot live without food and heat? The former can live after their heads are cut off, for they can live longer without breathing. The reason for this has been [25] stated elsewhere.
1 · Why is it that of all the senses the hearing is most liable to be defective from birth? Is it because the sense of hearing and the voice may be held to arise from the same source? Now language, which is a kind of voice, seems to be very [30] easily destroyed and to be very difficult to perfect; this is indicated by the fact that we are dumb for a long time after our birth, for at first we simply do not talk at all and then at length begin only to lisp. And because language is easily destroyed, and language (being a kind of voice) and hearing both have the same source, hearing is, [35] as it were, per accidens, though not per se, the most easily destroyed of the senses.1 Further evidence of the fact that the source of language is eminently easy to destroy may be taken from the other animals; for no animal other than man talks, and even [899a1] he begins to do so late, as has already been remarked.
2 · Why is it that the deaf always speak through their nostrils? Is it because they are near to being dumb? Now the dumb make sounds through their nostrils; [5] for the breath escapes by that way because their mouth is closed, and it is closed because they make no use of their tongue for vocal purposes.
3 · Why have all hot-natured men big voices? Is it because they necessarily have a large amount of cold air in them? For their breath, which is hot, attracts the [10] air to itself, and the more of it there is the more it attracts. Now a big voice arises from setting in motion a large quantity of air, and when the motion is swift, the voice is shrill, and when it is slow, it is deep.
[15] 4 · Why do the deaf always speak through their nostrils? Is it because the deaf breathe more violently? For they are near to being dumb; the passage therefore of the nostrils is distended by the breath, and those who are in this condition speak through the nostrils.
5 · Why are sounds more audible at night? Is it because there is more quiet [20] then owing to the absence of great heat? For this reason too there is usually less disturbance; for it is the sun which is the source of movement.
6 · Why do voices sound shriller at a distance? For example, those who try to imitate persons shouting from a very great distance utter shrill noises, like those of [25] an echo; and the sound of an echo is distinctly shriller, and it is a distant sound, being the result of refraction. Since then in sound the swift is shrill and the slow is deep, one would have expected voices to seem deeper from a distance, for all moving bodies move more slowly the farther they progress from their starting-point, and at [30] last fall. May not the explanation be that these mimics use a feeble and thin voice2 when they imitate a distant sound? Now a thin voice is not deep, and it is impossible to emit a small and feeble sound that is deep, but such a sound is necessarily shrill. Or is it true that not only do the mimics imitate for this reason, but also the sounds themselves become shriller? The reason is that the air which travels makes the [35] sound; and just as that which first sets the air in motion causes the sound, so the air in its turn must do likewise and be partly a motive power and partly itself set in motion. That is why sound is continuous, motive power continually succeeding to [899b1] motive power, until the force is spent, which results in falling in the case of bodies when the air can no longer impel the missile, while in the case of sound the air can no longer impel other air. Continuous sound is produced when air is impelled by air, while the missile continues its progress as long as there is air to keep a body in [5] motion. In the latter it is always the same body that is carried along until it drops, in the former it is always different air. Smaller objects travel more quickly at first, but do not go far. Therefore voices are shriller and thinner at a distance; for that which moves more quickly is shrill—a question which we have already raised. It is for the [10] same reason that children and invalids have shrill voices, whereas grown men and healthy persons have deep voices. That from near at hand one cannot clearly distinguish degrees of deepness and shrillness and that altogether the conditions are not the same as those of heavy bodies thrown, is due to the fact that the body thrown is one and preserves its identity throughout; whereas sound is air impelled by air. [15] Consequently a body falls in one particular spot, while the voice scatters in every direction, just as though a body thrown were, in the course of its flight, to be broken into infinitely many pieces, some particles even returning on their track.
7 · Why are newly plastered houses more resonant? Is it because their smoothness gives greater facility for refraction? They are smoother because they are free from cracks and their surface is continuous. One must, however, take a [20] house which is already dry and not one which is still quite wet; for damp clay gives no refraction of sound. It is for this reason that stucco has a higher degree of resonance. Perhaps the absence of disturbance in the air also contributes something; for when the air is massed together it beats back the air that strikes against it.
8 · Why is it that if a large jar or empty earthenware vessels are buried in the [25] ground and lids placed on them, the buildings in which they are have more resonance, and the same is true if there is a well or cistern in the house? Is it because, since an echo is due to refraction, the air when enclosed is necessarily massed together, and so the sound has something dense and smooth upon which it can strike3 and from which it can be refracted, these being the most favourable conditions for an echo? A well, then, or a cistern causes the contraction and massing [30] together of air, and jars and earthenware vessels also have dense surrounding walls, and so the phenomenon in question results in both cases. For anything which is hollow is particularly resonant; for which reason bronze vessels are particularly so. That resonance still continues when the vessels are buried need not surprise us; for the voice is carried downwards as much as in any other direction—indeed one [35] conceives of it as being carried in a circle in every direction.
9 · But why is it that there is more resonance where vessels are buried than where they are not? Is it because covered vessels receive the air and retain it better? [900a1] The result is that the impact of sound upon them is more violent.
10 · Why does cold water poured out of a jug make a shriller sound than hot water poured from the same vessel? Is it because the cold water falls at a greater [5] speed, being heavier, and the greater speed causes the sound to be shriller? Heat, on the other hand, makes water lighter by rarefying it and causing it to rise. We may compare the phenomenon that torches deal softer blows when they are alight.
11 · Why is it that the voice is rougher when one has passed a sleepless [10] night? Is it because the body, owing to absence of concoction, is moister than usual, especially in its upper part (which is also the cause of heaviness in the head), and moisture in the region of the windpipe necessarily makes the voice rougher? For roughness is due to unevenness, whilst depth is due to congestion; for the passage of sound is then slower. [15]
12 · Why does the voice become broken very readily after meals? Is it because the region in which it is produced is thoroughly heated by constant impacts, and, becoming heated, attracts the moisture? The moisture too is itself more copious and readier to hand when food is being taken.
[20] 13 · Why is the sound of weeping shrill, whereas that of laughing is deep? Is it because those who weep either set only a little breath in motion, because they are weak, or else exhale violently, which makes their breath travel quickly? Now speed makes for shrillness; for that which is hurled from a body which is tense travels quickly. (On the other hand, a man who is laughing is in a relaxed condition.) Those [25] who are weak make shrill sounds, for they set only a little air in motion, in some cases merely on the surface. Further, the air emitted by those who are laughing is warm, while the breath of those who are weeping is colder, just as pain is a chilling of the region round the breast. Now heat sets a great mass of air in motion, so that its progress is slow, whereas cold imparts movement to a little air only. The same [30] thing happens with flutes; when the player’s breath is hot, the sound produced is much deeper.
14 · Why do children and the young of other animals have shriller voices than the full-grown of their species, and that though shrillness involves a quality of violence? Is it because4 the voice is a movement of the air, and the swifter the [35] movement the shriller is the sound? Now a little air can be moved more easily and quickly than a large quantity, and it is set in motion owing either to its concretion or to its dissolution by heat. Now since we draw in cold air when we inhale, the air within us can become concreted by the act of inhalation; but exhalation, when heat sets air in motion, can become voice, for it is when we are exhaling that we speak, [900b1] not when we are inhaling. And since the young are hotter than their elders, and their interior passages are narrower, they may well have less air in them. So, as there is less in them of that which is moved and more motive power, namely heat, for [5] both reasons the movement of the air may be quicker; and, for the reasons already stated, the quicker the movement the shriller the voice.
15 · Why is the sound of weeping shrill and of laughter deep? Is it because those who weep, in uttering their cries, strain and contract the mouth? Owing to the [10] tension the air that is in them is impelled into swift motion, and the contraction of the mouth, through which it passes, makes its speed still greater. For both these reasons the voice becomes shrill. On the other hand, those who laugh relax the tension in doing so and open the mouth. Since then for this reason they emit the air from the mouth through a wide aperture and slowly, their voice is naturally deep.
[15] 16 · Why is it that persons without generative power, such as boys, women, men grown old, and eunuchs, have shrill voices, while adult men have deep voices? Is it because5 the thin voice has only one dimension, just as the line and other thin things have one dimension, while thick things have more than one? Now it is easier to create and set in motion one thing than several things. Now the breathing of the [20] persons mentioned above is feeble and sets little air in motion; and the air which has only one dimension is very small in quantity, for it will be thin for the reasons already stated. And the voice produced from it will be of the same quality, and a thin voice is shrill. This then is the reason why persons without generative power have shrill voices; whereas men who are vigorous set a large quantity of air in motion with their breath, and the air, being large in quantity, is likely to move [25] slowly and causes the voice to be deep. For shrillness of voice is, as we have seen, produced by a movement at once swift and thin, neither of which conditions is fulfilled in an adult man.
17 · Why are our voices deeper in the winter? Is it because then the air both inside and outside us is thicker, and, being such, its movement is slower and the [30] voice therefore deeper? Further, we are drowsier in the winter than in the summer and sleep longer, and we are heavier after sleeping. In the period then during which we sleep for a longer time than we are awake (namely, the winter), we may expect to have deeper voices than in the season when the contrary happens. For during the [35] short interval of wakefulness the condition set up during sleep persists and causes a tendency to drowsiness.
18 · Why is the voice deeper as a result of drinking and vomiting and cold weather? Is it due to the congestion of the larynx caused by phlegm, which makes [901a1] fluid matter collect in it? In some people vomiting and drinking, in others the season and the constriction resulting therefrom, make the larynx narrower, so that the passage of breath is slower; and its slow passage makes the voice deep. [5]
19 · Why is it that a deeper voice is more audible close at hand, but less so at a distance? Is it because a deeper voice sets a greater amount of air in motion, but not at a distance? So we hear it less well at a distance, because it travels less far, but [10] better from near at hand, because a greater mass of air strikes upon our sensory organ. A shrill sound is audible at a distance, because it is thinner; and that which is thin has greater longitudinal extension. It might also be said that the motion which causes it is quicker; this would be so, if the breath which sets the air in motion were at the same time dense and narrow. For, in the first place, air which is small in bulk [15] moves more readily (for the air which is set in motion by that which is narrow is small in bulk); and, secondly, that which is dense deals more impacts, and it is these which cause the sound. This can be illustrated from musical instruments; for, all other conditions being the same, it is the thinner strings that give shriller sounds.
20 · Why does the voice seem shriller to those standing at a distance, [20] whereas shrillness depends on the rapidity with which the voice travels, and that which travels moves more slowly the farther it goes? Is it because the shrillness of the voice depends not only on the rapidity with which it travels but also on the attenuation of sound? The farther one is away the more attenuated is the voice [25] when it reaches one, because very little air is set in motion. For the motion gradually diminishes; and just as number in diminishing terminates in the unit, so a body terminates in a single dimension, and this in a body is tenuity. So it is also with the voice.
[30] 21 · Why is it that both those who have taken violent exercise and those who are weak speak shrilly? Is it because those who are weak set only a little air in motion, and a little air travels more quickly than a larger quantity? Those who have taken violent exercise, on the other hand, set the air in vigorous motion, and air which is in vigorous motion travels more quickly, and in the voice quickness of motion causes shrillness.
[901b1] 22 · Why do those who shout after meals spoil their voices? Indeed, we can see how those who are training their voices, such as actors and chorus-men and all such persons, practise early in the morning and on an empty stomach. Is it because the spoiling of the voice is simply the spoiling of the region through which the voice [5] passes out? So too those who have sore throats have their voices spoilt, not because the breath which causes the voice is any worse, but because the windpipe is roughened. This region by its nature is especially liable to be roughened by violent [10] heat, and so neither can those who are in a fever sing, nor can those who have been suffering from a violent fever sing immediately after it leaves them; for their larynx is roughened by the heat. The consumption of food naturally increases and heats the breath, and it is reasonable to suppose that the breath being in this state makes the [15] windpipe sore and rough as it passes through; and when this happens the voice is naturally spoilt.
23 · Why is it that the voice, which is air that has taken a certain form and is carried along, often loses its form by dissolution, but an echo, which is caused by such air striking on something hard, does not become dissolved, but we hear it distinctly? Is it because in an echo refraction takes place and not dispersion? This [20] being so, the whole continues to exist and there are two parts of it of similar form; for refraction takes place at the same angle. So the voice of the echo is similar to the original voice.
24 · Why is it that, although the young of all other animals and infants have [25] shriller voices than the full-grown of their species, calves have deeper voices than full-grown oxen? Is it because in each species the young resembles the female of the same kind? Now among cattle cows have deeper voices than bulls, and the calves resemble the former rather than the latter; but in all other species the males have deeper voices.
[30] 25 · Why is it that when the orchestra of a theatre is spread with straw, the chorus makes less sound? Is it because, owing to the unevenness of the surface, the voice does not find the ground smooth when it strikes upon it and is therefore less uniform, and so is less in bulk, because it is not continuous? Similarly light too shines more on smooth surfaces, because it is not cut off by anything which intercepts it.
[902a1] 26 · Why does salt make a noise when it is thrown on fire? Is it because salt has a little moisture in it which is evaporated by the heat and violently bursting forth rends the salt? Now anything which is rent makes a noise.
27 · Why is it that some children, before they reach the age at which it is [5] time for them to express themselves clearly, find voice and say something distinctly, and then go on as before until the usual age for speaking arrives? Some regard such incidents as portents; and before now cases have been reported of children who spoke immediately after birth. Is it because generally the majority of children at [10] birth6 follow the usual course of nature (and so the phenomenon in question occurs only in a few), and their faculties keep pace with one another; and so they hear and find voice and understand what they hear and speak and express themselves clearly all at the same time? Sometimes, however, these things do not go together, but some children understand before the faculty by which they converse is set free for use, [15] while in others the opposite happens. The latter, then, would not converse intelligently (for they merely repeat what they hear); but when the time comes at which they can both speak and understand, they make a natural use of both functions. But in those in whose souls perception through hearing has been perfected before the organ7 by which the voice is first set in motion and speech is [20] formed, the full power and freeing of the organ of speech sometimes comes to pass when they already understand a great deal. This is especially likely to happen after sleep—the reason being that sleep makes the body and the faculties more sluggish by giving them a rest—or, if not after sleep, after some other similar change has taken place. We can do many things of this sort which require some short-lived [25] opportunity—after which the conditions are no longer suitable—when the organ of speech is in this state of freedom; and when there has been obviously present to their sensation something by which thought was stirred, in virtue of having heard it the child returns to it and utters it. Now tunes and phrases often occur to us without our choosing, but if we originally utter them by choice, we afterwards speak or sing [30] them without choosing and cannot get rid of them from our lips. So too when this happens in children, the part relapses again into its natural condition, until the time comes for it to become strong and to be separately constituted. [35]
28 · Why do some objects, chests for example, suddenly make a noise and move, when nothing perceptible sets them in motion? Yet that which causes motion is stronger than that which is moved. The same question arises in connexion with corruption and old age; for everything which is said to be ‘destroyed by time’ is destroyed by something imperceptible. Is it similar to dripping water and stones [902b1] lifted by the growth of plants, namely, that it is not the final effort but its continuity which raises or moves the object? This continuity of effort is imperceptible, but it results in a movement which is perceptible. So too that which is contained within [5] perceptible spaces of time moves and can be divided into imperceptible portions, but these cause motion and corruption by their sum and their continuity? Now continuity is not in the present time but in the period of time terminated by the present.
29 · Why does one hear less well when one is yawning? Is it because a [10] quantity of breath emitted in the yawn finds its way also into the ears from inside, so that the motion which it sets up in the neighbourhood of the ears makes a distinct impression on the perception, especially after sleep? Now sound is air or a certain condition of it. The sound then from outside enters the ear, and that from within [15] comes into collision with it, and the movement thus caused checks the progress of the sound from without.
30 · Why do children hesitate more in their speech than grown men? Is it because, just as when we are children, we always have less control over our hands and feet and at a still earlier age cannot walk at all, so the young cannot control [20] their tongue? Now when they are quite small, they cannot speak at all but can only make sounds like the animals, because they lack control. This is the cause not only of hesitancy in speech but also of lisping and stammering. Lisping is due to the inability to master a letter—not any letter but some particular one; stammering is due to the dropping out of some particular letter or syllable; hesitancy is due to the [25] inability to join one syllable to another sufficiently quickly. All three are due to want of power; for the tongue is not an efficient servant of the intelligence. The same thing occurs in those who are drunken and in the old; but always to a less extent than in children.
[30] 31 · Why is it that the voice trembles in those who are nervous or afraid? Is it because the heart is shaken by the passing out of the heat? For this happens in both conditions, being an effect both of nervousness and of fear. When the heart is shaken, the impact is not one but many, like that from strings which are not [35] properly stretched.
32 · Why is it that those who are nervous have deep voices, but those who are afraid speak shrilly? Is it because in those who are afraid the region about the heart is chilled, because the heat passes downwards, and so they set only a little air in motion? For the force which sets the air in motion is derived from heat. In those [903a1] who are nervous the heat travels upwards, as happens in those who are ashamed; for it is through shame that nervousness is felt. In those who are ashamed the heat travels upwards to the face, as is shown by the fact that they tend to blush. The heat therefore dissolves and thickens the air with which they speak, and such air can only [5] be propelled slowly; and in the voice that which is slow is deep.
33 · Why are sounds more audible in the night than in the day? Is it for the reason that Anaxagoras gives, namely, that in the day-time the air, heated by the [10] sun, hisses and roars, but at night it is still because the heat has ceased, and that when there is no noise hearing is easier? Or is it because one hears more easily through a comparative void than through a plenum? Now in the day the air is dense, being full of light and of the sun’s rays; but at night it is rarer, for then the fire and the rays, which are bodies, have gone out of it. Or is it because in the [15] day-time the various bodies around us distract our intelligence, and so it is less able to distinguish8 what it hears? Also because we do all that we have to do preferably in the day rather than at night, our intelligence9 too is busy then; and the perception apart from intelligence does, if one may say so, only an imperceptible amount of [20] work—as the saying is, ‘It is the mind which sees, the mind which hears’. But at night when our sight has no work to do and our intelligence is more at liberty, the channel of hearing, being wider open, is just as receptive of sounds and better able to report them to the intelligence, because the latter is neither busy nor distracted by [25] the sight, as it is in the day-time.
34 · Why is it that persons without generative power, such as boys, women, men grown old, and eunuchs, have shrill voices, while adult men have deeper voices? Is it because of the weakness of the organ which sets the air in motion? For that which is weak sets only a little in motion; and a little air travels quickly, and [30] that which travels quickly is shrill. Or is it because the first passage through which the air passes is narrow in those who are without generative power, so that that which expels the air from it has little force, and the air, being small in volume, travels quickly through the larynx above, which is wide? But in the adult and fully developed men this passage is wide (just as also is that leading to the testicles), and [35] so the quantity of the air expelled is also greater; and so passing through more slowly it makes a deeper sound.
35 · Why is it that those who hesitate in their speech cannot speak softly? Is it because they are hindered from using their voice by some impediment? Since, [903b1] then, there is not equal force exerted and similar movement set up when there is some impediment to the movement and when there is none, a violent effort is required. Now the voice is a movement, and those who use more force speak louder; and so, since they have to force the hindrance out of the way, those who hesitate in [5] their speech must necessarily speak louder.
36 · Why do those who hesitate in their speech become worse when they are nervous, but better under the influence of drunkenness? Is it because their condition is a state resembling apoplexy of some interior part of the body which they cannot move and which by its coldness hinders their speech? Wine then, being naturally [10] hot, tends to get rid of the coldness, but nervousness creates coldness; for it is a form of fear, and fear is a chilling condition.
37 · Why is it easier to hear sounds from outside in a house than those from inside a house outside it? Is it because the sound from inside becomes dispersed because it travels over an immense space, so that each component part of the sound [15] is not sufficiently strong to make itself heard, or at any rate is less audible? On the other hand, a voice from without entering within into a smaller space and into stagnant air arrives in a close mass, and so being greater in bulk is more audible.
38 · Why are those who hesitate in their speech melancholic? Is it because [20] melancholy is due to their responding too quickly to appearances? Now this is characteristic of those who hesitate in their speech; for the impulse to speak outstrips their power to do so, the mind responding too quickly to that which has appeared to it. The same thing occurs in those who lisp; for in them the organs employed in speech are too slow.10 This is shown by the fact that men under the [25] influence of wine become lispers, since then they respond most to the appearances and not so much to the mind.
39 · Why do leeks contribute to loudness of the voice (for we find that this is so even with partridges)? Is it because, whereas boiled garlic makes the throat smooth, leeks contain a certain amount of adhesive matter, and this cleanses the larynx?
[30] 40 · Why is it that in all other creatures the sounds made are shriller when more violence is used, but man speaks more shrilly when he is weak? Is it because then he sets less air in motion, and this passes along quickly and its speed makes the sound shrill?
41 · Why can one hear better when one holds one’s breath than when one [35] exhales? This is why people when hunting tell one another not to breathe. Is it because the power of perception rises into the upper parts of the body when the veins are distended? For it sinks when one is asleep; and so those who are sleeping exhale [904a1] rather than inhale, and lose the sense of hearing. Or does the blood rise upwards when one exhales, so that the lower parts of the body become void, and one can hear better in a void? Or is it because breathing is a noise, and when it takes place in the act of exhaling it impedes the hearing?
42 · Why do small quantities of salt make a noise and explode more quickly, [5] but large quantities more violently? Is it because in the former case the particles burst quickly because they are small (for the fire does not have far to penetrate), but in the latter case slowly, since a large mass is more difficult to burst than a small? A small quantity makes a small noise because the impact is small, whereas a large [10] quantity makes a loud noise because the impact is greater; and sound is an impact. The stronger an object is, the greater is the explosion if it is struck; for it is less yielding.
43 · Why is it that if the same quantity of salt is thrown on to a large fire, it makes less noise than if thrown on a small fire, or else makes no noise at all? Is it because it is burnt up before it can burst? For it burns because the moisture is used up, and it makes a noise because it bursts. [15]
44 · Why does one hear less well when one is yawning? Is it because the action of yawning cuts off the breath internally and the breath so cut off accumulates in the region of the ears? This is shown by the fact that there is a noise in the ears when one yawns. Now the breath thus cut off hinders the hearing. Further one also makes a noise when one yawns, and this tends to impede the hearing. Also the organs of hearing must necessarily become compressed by the [20] distension of the mouth in yawning.
45 · Why is it that though the voice, since it is a kind of stream, is naturally inclined to travel upwards, yet it is more audible below from above than above from below? Is it because the voice is a kind of air mingled with moisture, and this air [25] being weighed down by the moisture is carried downwards instead of upwards, since it is the natural characteristic of moisture to be carried downwards? For this reason one hears better when one is below. Or is such a result characteristic only of the voice of a living creature (for it contains moisture), while the phenomenon which we are discussing is found also in other sounds? Just as the sight then, if it be allowed to [30] fall from a higher to a lower object, makes an upwards reflexion and vice versa, so the voice, which has a natural tendency to rise, coming into collision with the air which bars its progress, cannot overpower the air, which is greater in mass and [35] heavier, but the air which is set in motion by the voice, being refracted, is carried in a contrary direction and downwards, and so, being scattered in a downward direction, it is more audible below. Somewhat similar is that which happens in an echo, which is due to the refraction of the voice in a contrary direction.
46 · Why are the voices of drunken persons more broken than those of the [904b1] sober? Is it because their voice breaks easily owing to their state of repletion? This can be illustrated by the fact that chorus-men and actors practise not after a meal but on an empty stomach. Now since a person in a state of drunkenness is in a [5] condition of greater repletion, his voice is naturally more broken.
47 · Why can one hear shriller voices at a greater distance? Is it because shrillness in the voice is rapidity, and what is carried forcibly along moves more rapidly, and what is carried violently along is carried farther? [10]
48 · Why can we hear better if we hold the breath? Is it because breathing makes a noise? It is only natural therefore that we should hear better when the noise is less; for the noise is less when we hold the breath.
49 · Why is it that light cannot penetrate through dense objects, whereas [15] sound can do so, although light is rarer and travels11 farther and quicker than sound? Is it because light travels in a straight line, and so, if anything blocks its direct course, it is completely cut off, but sound, because it is a breath, can also [20] travel in a line that is not direct? So we can hear those who make sounds from any direction and not only those who are in a straight line with our ears.
50 · Why is the sound of laughing deep, whereas that of weeping is shrill? Is it because a voice which comes from those who are in a state of tension is shrill, and that which is shrill is weak? Now both these characteristics are found rather in [25] those who are weeping; for they are in a state of greater tension and they are weaker.
51 · Why is it that the voice, being air which has assumed a certain form and is carried along,12 often loses its form by dissolution, but an echo, which is formed by such air striking on something hard, does not become dissolved, but we hear it [30] distinctly? Is it because in an echo refraction takes place, not dispersion? It starts then as a complete whole and continues to be so. Also, the effect produced upon it is due to a similar agency; for it is refracted from the air in the hollow, not from the hollow itself.
52 · Why is it that when one person makes a sound and a number of persons [35] make the same sound simultaneously, the sound produced is not equal nor does it reach correspondingly farther?13 Is it because each of them thrusts forward his own portion of air and they do not all impel the same air, except to a very small extent? The result is much the same as when a number of persons throw stones but each throws a different stone, or at any rate most of them do so. Neither in the latter case [905a1] will any missile travel far (or at any rate not correspondingly farther), nor in the former case will the voice reach farther. For this great voice is that of many, not of one; so at a short distance it appears correspondingly greater (just as a number of missiles reaches the same spot), but at a great distance this is no longer so.
[5] 53 · Why do those who are nervous have deep voices, but those who are afraid speak shrilly, though a feeling of shame is a kind of fear? Or are the two conditions really very different? For those who feel shame blush (and nervousness is a kind of shame), whereas those who are afraid turn pale. It is clear then that in those who are afraid the heat fails in the upper part of the body, so that the breath, [10] being weak, sets only a little air in motion; and that which is small in bulk travels quickly, and in the voice quickness is shrillness. But in those who feel shame the heat in the region of the breast travels upwards, as is shown by the fact that they blush. Now a strong force sets a great mass of air in motion, and a great mass travels [15] slowly, and in the voice slowness is deepness.
54 · What is the cause of hesitation of speech? Is it due to the chilling of the region in which the sound is produced, and to a condition resembling apoplexy in that part of the body? This is why those who hesitate, if warmed with wine and deriving thence a continuity of speech, are better able to connect their words together.
55 · Why is it that of all animals man alone is apt to become hesitating in [20] speech? Is it because he alone possesses the power of uttering words, while the other animals only have voices? Now those who hesitate in their speech use their voice, but they cannot connect their words together.
56 · Why is the voice shriller in winter and in those who are sober, and [25] deeper in summer and in those who are drunken? Is it because the quicker a voice is the shriller it is, and it is quicker when it proceeds from one who is in a state of tension? The bodies of those who are sober are in a more solid condition than those of the drunken, and bodies are in a more solid condition in winter than in summer; for heat and warmth have a dissolvent effect upon the body.
57 · Why does the voice come to perfection later in man than in any other [30] creature capable of sound? Is it because there are many variations and kinds of sounds in the human voice? For the other animals can express few or no letters; and that which is most elaborate and contains a large number of variations takes a long time to perfect.
58 · Why is it that the sight cannot pass through hard objects, but the voice [35] can do so? Is it because the course of the sight can only take one direction, namely, a straight line (as is shown by the rays of the sun and the fact that we can only see what is directly opposite us), whereas the voice can take many directions, since we can hear from everywhere? When therefore the sight is prevented from making its way through in a straight line, because there is no continuous passage between the eye and the object, it is impossible to see through the impeding matter. But the air [905b1] and the voice, since they travel everywhere, find their way everywhere and make themselves audible. On the other hand, the sight can penetrate through liquids, but voices cannot be heard through them or hardly at all, although the liquid is rarer than the earth, because the passages are small and close together and continuous, [5] and so the sight is not prevented from travelling in a straight line. For the same reason it is possible to see through glass, although it is dense, but not through a fennel-stalk, although it contains rarities, because in the former the pores are continuous, in the latter they are irregular, and their size is no advantage if they are not straight.14 The voice is not audible through water, because the empty air-spaces [10] in it are too small and so cannot admit the voice or let it pass through, or only with difficulty; for the voice is a kind of air. For that which is rarer is not necessarily more penetrable, unless at the same time the passages are adapted to that which is passing through. So also that which is rarer is not necessarily more compressible, [15] unless its passages are of such a kind as to admit the passage of other bodies. But, it may be urged, that which is rare is soft and compressible. True, but in some things compression is impossible owing to the smallness of the passages—in glass, for example; for its passages cannot be contracted, although it may be rarer than a [20] fennel-stalk, for the reason already mentioned. So too with water and the like. This then is clear, that, although the rare and the soft are either identical or else of a very similar nature, yet it does not follow that the rarer a thing is the more it admits of contraction. The reason in all these cases is the same.
59 · Why is it that the sound produced becomes less if some of those who [25] produce it are withdrawn, but its character is unchanged? Is it because their voice had formed part of a general mingling of sound, and that which is mingled is not mingled in one part and not in another, but is mingled throughout? So when some of those who make the sound are withdrawn, the volume of sound comes forth in the same way as before from the various voices, and must therefore, though smaller, necessarily retain the same characteristics.
60 · What is the cause of hesitancy in speech? Are those who hesitate in too [30] great a hurry because of the heat that is in them, and so they stumble and stop? If so, they resemble those who are angry, for they too become full of panting, with the result that a large quantity of breath comes together. Or do they pant owing to the boiling of the heat, because it is abundant and cannot come forth before the proper moment of exhalation? Or is the right explanation the exact contrary, namely, that [35] it is the chilling rather than the heating of the region in which the sound is produced—a state resembling apoplexy in that part of the body? That is why those who hesitate, when warmed with wine and deriving thence a continuity of speech, are better able to connect their words together.
61 · Why are voices deeper in the winter? Is it because then the air is thicker and as a consequence its movement is slower, and therefore the voice is deeper? Or [906a1] is it because the air passes more slowly through narrow passages, and the region round the larynx is closed by the cold and by the phlegm which flows into it?
62 · Why is it that boys, women, eunuchs, and old men have shrill voices? Is [5] it because the movement of air which creates a shriller sound is quicker? Now it is more difficult to move a greater amount of the same thing, and so those who are in the prime of life draw in the air in greater quantities, and therefore this air, since it travels more slowly, makes the voice deeper. In boys and eunuchs the contrary occurs, because they contain less air. Old men’s voices tremble because they cannot [10] control them, just as, when invalids and children take hold of a long stick by one end, the other end shakes, because they have no control over it; this too is the cause of trembling in old men, namely lack of control. We must suppose also that trembling of the voice in those who are nervous or afraid or chilled is due to the same cause. For in one whose voice is in this state, since most of the heat collects [15] within as a result of the above conditions, the rest, which is small in quantity, cannot control the voice; consequently it shakes and trembles. This is the reason why artists who belong to the class of those who are conscious of nervousness speak in a low voice at first, until they settle down to their work; for by keeping the voice low they [20] can control it.
1 · Why is it that perfumes produced by burning affect the senses less at a short distance? Is it because the effluvium is pleasanter when mingled with the air in a weak form, as happens in medicinal myrrh? Or can the contrary of this be the [25] explanation, namely, that the fire destroys the odour in the immediate neighbourhood of the flames? For the odour is produced when the perfume evaporates; that is why near the embers the effluvium has no odour, but it appears purer and thinner the farther away it is.
2 · Why is it that the odours of burning perfumes and of flowers are less [30] sweet-scented at a close distance? Is it because particles of earth are given off with the odour, and these, owing to their weight, fall more quickly to the ground, and therefore the odour is pure at a greater distance? Or is the effluvium not at its strongest either quite near to its source or very far from it? For close at hand it has not yet gained strength, while at a distance it has become dissipated. [35]
3 · It is said that trees become sweet-scented upon which the rainbow has fallen. Is this true or false? And if it is true, what can be the cause of the phenomenon? That it does not happen always and as a universal rule is obvious; for [906b1] rainbows often occur without any visible effect on the trees. When it does happen (for it does occur sometimes and this has given rise to the saying), the effect is not produced on every kind of wood. The cause can only be attributed to the rainbow [5] per accidens, especially if the rainbow does not really occur in nature but is an effect produced on the eye by refraction. Now the phenomenon, as we said, does not occur whatever the condition of the wood; for shepherds say that sweet odour is noticeable after the rains which accompany the rainbow not in green or in dry trees but in [10] burnt wood, and in particular where briars and brambles grow and trees which have sweet-scented flowers. The reason for the sweet scent is the same as in the soil; for where the soil is hot and burnt through and through, anything which grows from it is at first sweet-scented. For things which contain but little moisture, if they are burnt at all, become sweet-scented; for the heat concocts this moisture. (So, of the [15] whole world, those parts towards the sun have a sweeter odour than those towards the north; and of the former those towards the east have a sweeter odour than those towards the south, for the districts of Syria and Arabia have more soil, but Libya is [20] sandy and free from moisture.) For there must not be a large amount of moisture—for much moisture is difficult to concoct—nor must there be a complete absence of it, or else there will be no evaporation. These conditions are fulfilled in newly burnt wood and wood which naturally has a sweet odour in itself. This is proved to be true by the flowers, for it is through them that the wood emits its scent. [25] The theory that sweet odour is engendered in any trees upon which the rainbow rests is due to the fact that this cannot happen without the presence of water; for it is when the wood has been wetted and has then concocted the moisture by the heat which is in it, that it gives out the vapour which is being engendered in it. But there must not be a large amount of water; for too much water drenches the tree and [30] extinguishes the heat previously caused by the burning. Now the rains which follow the rainbow, so far from being heavy, may almost be called slight. Also if there is a number of rainbows, the rain is not heavy, but it falls little and often. It is therefore natural under these circumstances that men notice nothing unusual except the rainbow and attribute to it the cause of the sweet odour.
[35] 4 · Why is it that flowers and burnt perfumes smell sweeter at a distance, whereas close at hand they have rather the smell either of vegetation or of smoke? Is it because scent is a form of heat and sweet-scented things are hot? Now heat is [907a1] light, and so, the further the perfumes penetrate, the more does their scent become purified from other concomitant odours produced by their leaves and by smoke, which is a watery steam; at a short distance, on the other hand, the mingled odours are simultaneously perceptible in the plants in which they are present.
[5] 5 · Why do things always emit a stronger odour when they are in motion? Is it because they fill a larger space of air than when they are at rest? The result is that the odour is thus transmitted more quickly to our perception.
6 · Why is it that we perceive odours less in the winter, especially in frosty weather? Is it because the air is more free from motion when it is cold? The motion [10] therefore set up by the body which produces the odour cannot have such a far-reaching effect owing to the difficulty of imparting motion to the effluvium and to the air in which it is present.
7 · Why do perfumes have a more pungent odour when they are burnt on ashes than on the fire? And why is their odour stronger and more persistent when [15] they are burnt on ashes? Is it because their odour is less thoroughly concocted on ashes, and therefore greater in bulk? Now fire by quickly concocting their natural force alters their odour; for concoction involves alteration in that which is concocted.
[20] 8 · Why do those roses in which the centres are rough smell sweeter than those in which they are smooth? Is it because those roses smell sweetest which partake most of the natural characteristics of the rose? Now the rose is naturally thorny, and so it smells sweeter when its characteristics are more natural.
9 · Why are the odours both of burnt perfumes and of flowers less pleasant at [25] a short distance? Is it because at a short distance the earthy element is transmitted with the scent, and so mixing with it lessens its strength, whereas the odour travels to a distance? It is for this reason too that flowers when rubbed lose their scent.
10 · Are scents smoke [or air]1 or vapour? For it makes a difference, in that the former is produced by fire, the latter without it. And is something transmitted [30] from the sense to the objects producing the scent or vice versa, causing a continuous motion in the adjoining air? Also, if any effluvium is given off by these objects, one would expect them to become less; yet we see that those things which have the strongest scent last the longest.
11 · Why have perfumes a more pungent odour when they are burnt on [35] ashes than on fire? Is it because their odour is less thoroughly concocted on ashes and is therefore greater in bulk? Consequently a large quantity of the earthy element is vaporized in the process and becomes smoke; but the fire burns up the earthy element before it can escape, and so the odour is purer and reaches the senses [907b1] untainted by the smoke. This is also the reason why flowers when rubbed smell less sweet; for the rubbing imparts motion to the earthy element and the slow heat does not destroy it.
12 · Why is it that sweet-smelling seeds and plants promote the flow of urine? Is it because they contain heat and are easily concocted,2 and such things [5] have this effect? For the heat which is in them causes quick digestion and their odour has no corporeal existence; for evil-smelling plants, such as garlic, by reason of their heat promote the flow of urine, but their wasting effect is a still more marked characteristic. But sweet-smelling seeds contain heat, because odour is in general engendered by heat; while evil-smelling things are unconcocted. Now [10] anything which is to promote the flow of urine must be not only hot but also easily concocted, in order that it may accompany the liquids in their downward course and effect their digestion.
13 · Why is it that wines mixed with water have a less strong odour3 than when they are unmixed? Is it because wine mixed with water is weaker than unmixed wine? Now the weaker is more easily changed by any force acting upon it [15] than the stronger. So wine mixed in the water is more easily affected than unmixed wine. Now it is characteristic of that which is easily affected4 to yield5 to something else or to receive something which does not belong to it; unmixed wine, therefore, has a strong odour, but wine mixed with water is odourless.
[20] 1 · Why is it that urine acquires a more unpleasant odour the longer it remains in the body, whereas ordure becomes less unpleasant to the smell? Is it because the latter becomes drier the longer it remains in the body (and what is dry is [25] less liable to putrefaction), but urine thickens, and the fresher it is the more like it is to the original liquid drunk?
2 · Why is it that things of unpleasant odour do not seem to have an odour to those who have eaten them? Is it because, owing to the fact that the scent penetrates to the mouth through the palate, the sense of smell soon becomes satiated and so it [30] no longer perceives the odour inside the mouth to the same extent—for at first every one perceives the odour, but, when they are in actual contact with it, they no longer do so, as though it had become part of themselves—and the similar odour from without is overpowered by the odour within?
3 · Why have flowers an unpleasant odour when they are rubbed? Is it because the earthy element, which is in the flower, mingles with the odour?
[35] 4 · Why is it that no living creature is pleasant to the smell except the leopard—which is pleasing even to animals, for they are said to find pleasure in its odour—and when they decay they are unpleasant to the smell, but many plants when they decay and wither become still more pleasant to the smell? Is it because [908a1] the cause of evil odour is an unconcocted condition of excretion? For this reason the perspiration of some people is sometimes unpleasant, particularly in those whose perspiration is not usually unpleasant, as the result of disease. Also farts and belches of those who are in an unconcocted state are unpleasant. The same cause [5] must be ascribed for evil odour in the flesh and in that which is analogous to it (by which I mean that which in other animals corresponds to flesh); for here too there is sometimes unconcocted excretion. This then when it putrefies is a cause of evil odour in living creatures and in decaying bodies. For this reason too the fat and the bony parts and the hair have no evil odour, because the fat and bones are already [10] concocted, while the hair contains no moisture. Now plants contain no excretion. Or is there excretion in them also, but, because plants are naturally dry and hot, is the moisture in them more easily concocted and not of a muddy consistency? This can be illustrated from the soil, which is pleasant to the smell in hot regions, such as Syria [15] and Arabia, and from the fact that the plants which come from there are sweet-smelling, because they are dry and hot; and such plants are not liable to decay. But animals are not dry and hot, and so their excretions are unconcocted and malodorous, and likewise their exhalations, and when they decay the moisture putrefies. This does not happen in plants, because they contain no excretions.
5 · Why are things of unpleasant odour more unpleasant when they are hot [20] than when they are cool? Is it because odour is a vapour and an effluvium? A vapour, then, and an effluvium is caused by heat; for a movement takes place, and heat is the source of the movement. Cold, on the contrary, is a source of stagnation and contraction and downward movement; but heat and all odours have an upward [25] tendency, because they are in the air, and the organ which perceives them is above and not below; for odour penetrates to the brain and so causes perception.
6 · Why, if one eats garlic, does the urine smell of it, whereas this does not happen when other things are eaten which have a strong odour? Is it because, as some of the followers of Heraclitus say, vaporization takes place in the body just as [30] in the universe, and then, when the process of cooling succeeds, moisture is formed in the universe and urine in the body, so the vaporization from the food, when it is formed by intermixture, causes the odour(for it is odour after it has undergone change)? If so, should not all the foods too which have a strong odour produce this [35] effect, which we know they do not? Furthermore, concretions from vapour do not resume their original form—which would result in wine, for example, being produced from the vapour of wine instead of water, as actually happens—and so this part of their theory is also untrue. The truth is that garlic, alone of foods which [908b1] have an odour which is strong and also promotes the flow of urine, has the quality of inflating the lower part of the belly; all other such foods (radishes, for example) engender breath higher up or else do not promote the flow of urine. But garlic1 has these three qualities: it promotes the flow of urine, it engenders breath, and it does so in the lower part of the body. The region round the privy parts and the bladder [5] feels the effect of such foods owing to its nearness and because it is liable to admit breath; that this is so is shown by the distension of the privy parts. It is clear therefore that the excretion of garlic is more liable than that of any other such food to reach the bladder with the breath, and this excretion mingling with the urine imparts its odour to it. [10]
7 · Why is it that the mouths of those who have eaten nothing, but are fasting, have a stronger odour, ‘the smell of fasting’, as it is called, but when they eat the odour ceases, when one would expect it to increase? Is it because, as the stomach becomes empty, the air becomes hotter from the absence of motion and causes the breath and the excretions of phlegm to putrefy? That the air becomes hotter is [15] proved by the fact that fasting also induces an increase of thirst. When food is taken, the odour ceases because it is less than that of the food; for the heat in the food overcomes the internal heat, so that it cannot undergo any process of change.
[20] 8 · Why has the armpit a more unpleasant odour than any other part of the body? Is it because it is least exposed to the air? Such parts have a particularly unpleasant odour because putrefaction takes place in them owing to the stagnation of fat. Or is it because the armpit is not moved and exercised?
9 · Why is it that those who have a goaty odour are still more unpleasant [25] when they anoint themselves with unguents? Is it because this kind of thing happens in many instances; for example, if something acid and something sweet are mixed, the resulting whole is sweeter? Now any one who perspires has an unpleasant odour, and unguents are productive of heat and therefore induce perspiration.
10 · Why is it that the odour of the breath of those who are bent and [30] deformed is more unpleasant and oppressive? Is it because the region round the lungs is contracted and bent out of an upright position, so that it does not give a free passage to the air, but the moisture and the breath, which tends to be enclosed within, putrefies?
11 · Why is it that most unguents are unpleasant when they mingle with [35] perspiration, but others have a sweeter or at any rate not a more unpleasant odour? Do those which change as a result of movement or friction deteriorate in odour, whereas those which do not are improved? There are some such perfumes, just as [909a1] there are some flowers from which scents are made, which deteriorate when rubbed or heated or dried, white violets, for example; but others remain the same, for instance roses. The unguents too made from flowers of the former class change, while those made from the latter do not; and so rose-perfume is least liable to [5] change. Also unguents have a more unpleasant odour on those whose perspiration is malodorous, through mingling with their opposite, just as honey when mixed with salt becomes not sweeter but less sweet.
12 · Why do objects always produce a stronger odour when they are in motion? Is it because they fill up the air? The result is that the odour is thus [10] transmitted more quickly to our perception.
1 · Why are those who live under conditions of excessive cold or heat brutish in character and aspect? Is the cause the same in both cases? For the best mixture [15] of conditions benefits the mind as well as the body, but excesses of all kinds cause disturbance, and, as they distort the body, so do they pervert the mental temperament.
2 · Why is it that in Pontus corn, if exposed to the cold, keeps intact for many years? Is it because the extraneous moisture is evaporated together with the heat, as happens in grapes? For some things are evaporated by the cold and others with the [20] heat.
3 · Why do burning fevers occur more frequently in the coldest season? Is it because the cold imprisons the heat within? In the summer the contrary occurs, the interior of the body being cooler than the exterior. Burning fever is the inflammation in which,1 the exterior of the body being cold, the interior is in a condition of [25] excessive heat.
4 · Why are the Ethiopians and the Egyptians bandy-legged? Is it because the bodies of living creatures become distorted by heat, like logs of wood when they become dry? The condition of their hair too supports this theory; for it is curlier than that of other nations, and curliness is as it were crookedness of the hair. [30]
5 · Why is it that in damp regions copulation is more likely to lead to the birth of female offspring? Is it because a large amount of moisture thickens more slowly, and in damp regions the semen is moister owing to the presence of more moisture in the temperament?
6 · Why is it that in marshy districts sores on the head are quickly cured, but [35] those on the legs only with difficulty? Is it because the moisture, since it contains an earthy element, is heavy, and heavy things are carried downwards? Thus the upper parts of the body are easily concocted, because the impurities are carried downwards; but the lower parts become full of abundant excretion which easily putrefies.
7 · Why is it that those who live in airy regions grow old slowly, but those [909b1] who inhabit hollow and marshy districts age quickly? Is it because old age is a process of putrefaction, and that which is at rest putrefies, but that which is in motion is either quite free from, or at any rate less liable to, putrefaction, as we see in water? In lofty regions, therefore, owing to the free access of the breezes, the air [5] is in motion, but in hollow districts it stagnates. Furthermore, in the former, owing to its movement, the air is always pure and constantly renewed, but in marshy districts it is stagnant.
8 · Why are the inhabitants of warm regions cowardly, and those who dwell in cold districts courageous? Is it because there is a natural tendency which [10] counteracts the effects of locality and season, since if both had the same effect mankind would inevitably be soon destroyed by heat or cold? Now those who are hot by nature are courageous, and those who are cold are cowardly. But the effect of hot regions upon those who dwell in them is that they are cooled, while cold regions [15] engender a natural state of heat in their inhabitants. Both races are large of stature—those who live in cold regions because of the innate heat in them, and those who inhabit hot districts owing to the heat in which they live; for increase of stature occurs both in those who are hot and as a result of heat, whereas cold has a contracting effect. Since then those who live in cold districts have a powerful [20] principle of growth in themselves, and those who live in hot regions encounter no external cold which prevents their growth, both naturally admit of considerable increase in stature. But this is less true of those who live in our latitudes, because the principle of growth in them is less strong, and those who live in cold regions feel the contracting effect of cold.
[25] 9 · Why are those who live in hot regions longer-lived? Is it because their natural condition is drier, and that which is drier is less liable to putrefaction and more lasting, and death is as it were a kind of putrefaction? Or is it because death is due to the chilling of the interior heat, and everything is chilled by a surrounding [30] medium which is colder than itself? Now in warm regions the surrounding air is hot, but in cold regions it is cold and so more quickly and effectively destroys the interior heat of the body.
10 · Why are those who live in hot regions longer-lived? Is it because they [35] preserve their heat and moisture better? For death is the corruption of these.
11 · Why is it that we become drowsier in marshy districts? Is it because there we are more cooled, and cooling, being a kind of rest, induces sleep, and sleep occurs during rest?
[910a1] 12 · Why is it that those who live on board ship, though they spend their time on the water, have a healthier colour than those who live in marshes? Is the weather and the free access of the breezes the cause? Now water makes men pale when it putrefies, a process which is due to the absence of movement; that is why those who live in marshy regions are rather pale.
[5] 13 · Why is suffocating heat very frequently experienced in wintry regions, much more so than in warm districts? Is it because of the moisture in the air? For as a result of the same heat applied to it water becomes hotter than air, and therefore damper air2 becomes hotter than dry air.3 Or perhaps the air is not really hotter4 in these regions, but only seems so by contrast with the general coolness, as the sun [10] emerging from a cloud seems hotter in contrast with its effect when it is behind a cloud.
14 · Why do those who live in southerly climes tend to have black eyes? Is blueness of the eyes due to excess of internal heat, whereas blackness is due to its absence, as Empedocles affirms? Just, therefore, as those who dwell in the north [15] have blue eyes, because the internal heat is prevented from escaping owing to the external cold; so in those who dwell in southerly climes the moisture cannot escape owing to the surrounding heat, but the heat escapes because there is nothing to bar its exit, and the moisture left behind causes blackness; for when light departs that [20] which is left behind is dark. Or does the pigmentation of the eye assimilate itself to the colour of the rest of the body? If so, the eyes of those who live towards the north are blue, because they are themselves white (for blue is akin to white); and those who dwell in the south being black, their eyes also are black. [25]
15 · Why are those who live in warm regions wiser than those who dwell in cold districts? Is it for the same reason as that for which the old are wiser than the young? For those who live in cold regions are much hotter, because their nature recoils owing to the coldness of the region in which they live, so that they are very like the drunken and are not of an inquisitive turn of mind, but are courageous and [30] sanguine; but those who live in hot regions are sober because they are cool. Now everywhere those who feel fear make more attempt to inquire into things than do the self-confident, and therefore they discover more. Or is it because the race of those who live in warm regions is more ancient, the inhabitants of the cold regions having perished in the Flood, so that the latter stand in the same relation to the [35] former as do the young to the old?
16 · Why are the inhabitants of warm regions cowardly, and those who dwell in cold regions courageous? Is it because human beings have a natural tendency which counteracts the effect of locality and season (for, if both had the [910b1] same tendency, they would soon be destroyed)? Now those who are hot by nature are courageous and those who are cold are cowardly. The effect of hot regions upon their inhabitants is to cool them (for, their bodies having rarities, the heat escapes out of them), but those who live in a cold climate become heated in their nature, [5] because their flesh is condensed by the external cold, and when it is in this condition the heat collects internally.
1 · Why is it that of all the lines which divide a rectilinear figure into two [10] parts that drawn from angle to angle alone bears the name of diameter? Is it because the diameter, as its name implies, divides the figure of which it is the diameter into two parts without destroying it? The line therefore which divides it at [15] its joints (by which I mean the angles) will be the diameter; for it does not destroy the figure but divides it, like those who divide up implements of war for distribution. But a division which cuts through a composite figure in the lines which form it destroys the figure; for a rectilinear figure is constructed on angles.
2 · Why is the diameter so called? Is it because it is the only line which divides a rectilinear figure into two parts, as though one should call it the [20] ‘dichameter’?1 And why2 is it the only one that bears this name of all the lines which divide a rectilinear figure into two parts? Is it because it is the only line which divides the figure at the points where its limbs bend, whereas all other lines divide it in its sides?
3 · Why do all men, barbarians and Greeks alike, count up to 10 and not up to any other number, saying for example, 2, 3, 4, 5 and then repeating them, [25] one-five, two-five, just as they say eleven, twelve?3 Or why do they not stop at some point beyond ten and repeat from there? For every number is made up of one, two, &c, combined with a preceding number, and thus a different number is formed; but the counting always proceeds in fixed sets of ten. For it is clearly not the result [30] of chance that all men invariably count in tens; and that which is invariable and universal is not the result of chance, but is in the nature of things. Is it because ten is a perfect number? For it combines every kind of number, odd and even, square and cube, length and surface, prime and composite. Or is it because ten is the original [35] number, since one, two, three, and four together make ten? Or is it because the bodies which move in the heavens are nine in number? Or is it because in ten proportions four cubic numbers result, from which numbers the Pythagoreans declare that the whole universe is constituted? Or is it because all men have ten fingers and so, as though possessing counters that indicate the numbers proper to [911a1] man, they count all other things by this quantity? One race among the Thracians alone of all men count in fours, because their memory, like that of children, cannot extend farther and they do not use a large number of anything.
[5] 4 · … because the earth is a centre? For the shapes which appear to us are always similar. This does not seem4 to be so unless one views them from the centre, but they would sometimes appear triangular, sometimes irregular foursided figures, and sometimes take other forms. Now the earth would appear to us to be the centre of the universe, if we could view it from the heavenly bodies.5 For the earth being spherical, the centre of the universe and of the earth will be the same. But we dwell [10] on the surface of the earth, so that it is not from the centre but at the distance of half the diameter that the heavenly bodies appear to have the shapes that they do appear to have. What reason then is there why the appearance of their shapes should not remain the same when the distance is increased?
5 · Why is it that, although the sun moves with uniform motion, yet the increase and decrease of the shadows is not the same in any equal period of time? Is [15] it because the angles to the objects seen, that is the angles made by the rays of the sun and subtending equal arcs, are equal? Now if these are equal, so also are the angles which the rays when produced6 make in the triangle formed by the first ray and the object seen and the shadow. If the angles are equal, the line which is farther from the object seen must be greater than that which is less far; for we know that [20] this is so. Let the circumference, therefore, be divided into any number of equal parts, and let the object seen be H. When therefore the sun at A falling on H makes the shadow HL7 the ray must fall on L. But when the sun comes to B, the ray from B will fall within HL, and similarly again when the sun comes to C; otherwise one [25] straight line will touch another straight line at two points. Since therefore AB is equal to BC, the angles which subtend them at D will also be equal, for they are situated about the centre. But if the angles on this side of D are equal, so also are the corresponding angles in the triangle; for they are at the apexes of the first pair of angles. So while the angle is divided into two equal parts, the line LE will be greater [30] than the line EF within LH.8 So too with the other angles formed by the rays from the circumference. At the same time it is clear that the shadow must be shortest at midday and that then its increases are least. For the sun is most over our head at midday, and stifling heat occurs both for the reason just mentioned and because [35] there is no wind; for wind is caused when the sun dissipates the air near the earth. If therefore it does so simultaneously in both hemispheres, midnight and midday [911b1] would naturally be windless.
6 · Why does the sun penetrating through quadrilaterals form not rectilinear shapes but circles, as for instance when it passes through wicker-work? Is it because the projection of the vision is in the form of a cone, and the base of a cone is a circle, [5] so that the rays of the sun always appear circular on whatever object they fall? For the figure also formed by the sun must be contained by straight lines, if the rays are straight; for when they fall in a straight line on to a straight line, they form a figure contained by straight lines. And this is what happens with the rays; for they fall on [10] the straight line of the wicker-work, at the point where they shine through, and are themselves straight, so that their projection is a straight line. But because the parts of the vision which are cut off towards the extremities of the straight lines are weak, the parts of the figure about the angles are not seen; but what there is of straight line [15] in the cone describes a straight line, while the rest does not, but the sight falls on part of the figure without perceiving it. For there are many things to which the sight penetrates without our seeing them, objects, for instance, which are in darkness. A similar phenomenon is the fact that a quadrilateral figure appears polygonal, and at a greater distance circular. Now since the projection of sight is in the form of a cone, [20] when the figure is removed to a distance the parts of the vision which are cut off towards the angles, because they are weak and few, do not see anything when the distance is increased; but the parts of the vision which fall upon the centre of the [25] figure, being numerous and strong, are more persistent. When, therefore, the figure is near at hand, they can9 see the parts in the angles; but, when the distance is greater,10 they cannot do so. For this reason too a curved line removed to a distance appears straight, and the moon on the eighth day seems to be contained by straight [30] lines, if the vision falls upon the line which encloses it and not on its breadth. For when the circumference is near, the sight can discern how much nearer one part of the circumference is than another; but when it is distant, the sight does not perceive it clearly, and it seems to be equally distant; and so it appears to be straight.
[35] 7 · Why, though the moon is spherical, do we see it straight when it is half-full? Is it because our vision and the circumference of the circles which the sun [912a1] makes when it falls upon the moon are in the same plane? Whenever this happens, the sun appears as a straight line; for since that which casts its vision on a sphere must see a circle, and the moon is spherical, and the sun looks down upon it, there [5] must be a circle which is caused by the sun. When therefore this is opposite to us, the whole is visible and the moon appears to be full; but when it changes owing to the altered position of the sun, its circumference becomes on a plane with our sight and so it appears straight, and the rest appears circular, because a hemisphere is [10] opposite our vision, and this has the appearance of a semicircle; for the moon is always facing our vision, but when the sun sheds its rays we do not see it. And after the eighth day it begins to fill out from the middle, because the sun as it passes on makes the circle incline more towards us; and the circle being thus presented to view [15] resembles the section of a cone. It assumes a crescent-like appearance when the sun changes its position; for when the circle of the sun reaches the extreme points, which make the moon seem half-full, the circumference of the circle appears; for it is no longer in a straight line with the vision, but passes beyond it. When this happens and the circle passes through the same points, it must necessarily appear to have a [20] crescent shape; for a part of the circle is directly on a plane with the eye (a part of the circle, that is, which was formerly opposite to us), so that part of the brightness is cut off. Then the extremities too remain in the same position, so that the moon must have a crescent shape to a greater or less extent according to the sun’s movement; for when the sun changes its position, the circle upon which it looks also [25] turns, remaining on the same points; for it might assume an infinite number of inclinations, since an infinite number of the largest circles can be described through the same points.
8 · Why is it that the sun and moon, which are spherical, have the appearance of being flat? Is it because all things of which the distance is uncertain [30] seem to be equidistant, when they are more or less distant? And so in a single body composed of parts, provided that it is uniform in colour, the parts must necessarily appear equidistant, and the equidistant must appear to be uniform and flat.
9 · Why does the sun make long shadows as it rises and sets, and shorter when it is high in the heavens, and shortest of all at midday? Is it because, as it rises, [35] it will at first make a shadow parallel to the earth and cast it to an infinite distance,11 and then make a long shadow, which grows ever less because the straight line from the higher point falls within that from the lower point. Let AB be the gnomon, and C and D two positions of the sun. The ray from C, the line CF, will fall outside the line DE;12 and the shadow BE is formed when the sun is higher in the [912b1] heavens, and BF when it is lower, and it will be shortest when13 the sun is at its highest and over our head.
10 · Why are the shadows thrown by the moon longer than those thrown by the sun, though both are thrown by the same perpendicular object? Is it because the [5] sun is higher than the moon, and so the ray from the higher point must fall within that from the lower point? Let AD be the gnomon, B the moon, and C the sun. The ray from the moon is BF, so that the shadow will be DF; but the ray from the sun is CE, and its shadow therefore will necessarily be less, viz. DE. [10]
11 · Why is it that during eclipses of the sun, if one views them through a sieve or a leaf—for example, that of a plane-tree or any other broad-leaved tree—or through the two hands with the fingers interlaced, the rays are crescent-shaped in the direction of the earth? Is it because, just as, when the light shines through an aperture with regular angles, the result is a round figure, namely a cone (the reason [15] being that two cones are formed, one between the sun and the aperture and the other between the aperture and the ground, and their apexes meet), so, when under these conditions part is cut off from the orb in the sky,14 there will be a crescent on the other side of the aperture from the illuminant, that is, in the direction of the earth (for the rays proceed from that part of the circumference which is a [20] crescent)? Now as it were small15 apertures are formed between the fingers and in a sieve, and so the phenomenon can be more clearly demonstrated than when the rays pass through wide apertures. Such crescents are not formed by the moon, whether in eclipse or waxing or waning, because the rays from its extremities are not clearcut, but it sheds its light from the middle, and the middle portion of the [25] crescent is but small.
12 · Why does the parhelion not occur either when the sun is in mid-heaven or above the sun or below it, but only at the side of it? Is it because the parhelion is produced when our visual ray to the sun is refracted, and this stationary condition of [30] the air, on the occasion of which the vision is refracted, cannot occur either near the sun or far away from it? For, if it is near, the sun will dissolve it, whereas, if it is far away, the sight will not be refracted; for, if it is strained to a distance, it is weak when refracted from a small refractor. (So too a halo does not form.) If then a [35] refractor forms opposite the sun and near to it, the sun will dissolve it, whereas if it be far away, the incidence of the sight upon it will be too weak. If, however, it forms at the side of the sun, it is possible for the refractor to be at such a distance that neither does the sun dissolve it nor does the sight ascend weakened16 by passing under the earth. It does not form below the sun because, being near the earth, it [913a1] would be dissolved by the sun; whereas, if it were above the sun when the sun is in mid-heaven, the sight would be distracted. And it cannot form at all even at the side of the sun when it is in mid-heaven, because, if the sight is directed too far under the earth, very little of it will reach the refractor, so that, when it is refracted, it will be very weak.
[5] 13 · Why does the extremity of the shadow caused by the sun seem to tremble? For it is not due to the fact that the sun is travelling along; for it is impossible for it to move in contrary directions, and it is of such motion that trembling consists. (Moreover it is uncertain why a shadow changes its position, as also why the sun itself moves.) Is it due to the movement of the so-called motes in [10] the air? These can be seen in the rays which enter through a window; for they move even when there is no wind. These then being constantly carried from the shadow into the light and from the light into the shadow, the common boundary between the light and the shadow is seen to move similarly. For changing17 from side to side of it, these motes cause as it were shadow in one place and light in another; so that the [15] shadow appears to move, though it is not really it but the motes which move in this way.18
1 · Why is it that the bases of bubbles in water are white, and if they are [20] placed in the sun they do not make any shadow, but, while the rest of the bubble casts a shadow, the base does not do so but is surrounded on all sides by sunlight? And, what is still more wonderful, even if a piece of wood is placed on the water in the sunlight, the shadow is cut off by the water at that point.1 Is no shadow really formed? Is the shadow dissolved by the sun? If then a shadow is to be defined as [25] anything which is not visible to the sun, the whole mass of the object all round must be visible to the sun; but the impossibility of this has been demonstrated in the treatises on optics, for even the largest optical system cannot see the whole circumference of the smallest visible object.
2 · Why are bubbles hemispherical? Is it because the radii between the centre and the outer air extend in every direction upwards to the same distance and thus necessarily produce a hemispherical form? The corresponding hemisphere [30] below is cut off by the watery surface in which the central point is situated.
3 · Why is it that in magnitudes of uneven weight,2 if you set the lighter part of them in motion, the object thrown revolves in a circle, as happens, for example, with loaded dice if you throw them with the unweighted side turned towards you? Is [35] it because the heavier part cannot travel at the same speed as the lighter when hurled with the same force? Now the object must travel as a single whole, but cannot move alike in all its parts; therefore if the parts were moved with equal speed [913b1] they would move in the same line, while since one part travels more quickly than the other, the object necessarily revolves as it moves; for it is only in this manner that the parts which are always opposite one another can follow unequal paths in the same time. [5]
4 · Why is it that objects which fall to the earth and rebound describe similar angles to the earth’s surface on either side of the point at which they touch the surface? Is it because all things naturally tend to travel at right angles to the earth? Objects, therefore, which fall upon the ground at right angles, striking the surface perpendicularly and diametrically, when they rebound, form angles of that size, [10] because the diameter divides the angle at the surface into equal parts. But objects which fall obliquely, since they do not strike the ground perpendicularly but at a point above the perpendicular, when they are thrust back by that against which they strike, travel in the opposite direction. This in the case of round objects is due to the [15] fact that, striking against it in their course, they revolve in an opposite direction to that in which they are thrust back, whether their central point is at rest or changes its position. In the case of rectilinear objects it is due to the fact that their perpendicular is thrown backwards after being brought forward;3 just as happens to those whose legs are sheared away from under them or whose scrotum is pulled [20] downwards, for such persons always fall in a contrary direction and backwards, because their perpendicular is raised above the ground4 and then thrust forward. For clearly the opposite of perpendicularity will be to fall backwards and downwards, and objects carried downwards would be heavier. That, therefore, which in these persons involves a fall, becomes movement in rebounding objects. [25] Neither round nor rectilinear objects therefore rebound at right angles, because the perpendicular divides the objects in motion into two parts depthways,5 and there cannot be several perpendiculars to the same plane surface cutting one another, [30] which will happen if a perpendicular is formed at the moment of their impact at the point where the object in motion strikes the plane surface;6 so that the original perpendicular along7 which it travelled must necessarily be cut by the new perpendicular. Now since the object will be borne back, but will not be borne back [35] at a right angle, it remains that the angle on either side of the point of impact with the plane surface must be an acute angle; for the right angle forms the division between the opposite angles.
5 · Why is it that a cylinder, when it is set in motion, travels straight and describes straight lines with the circles in which it terminates, whereas a cone revolves in a circle, its apex remaining still, and describes a circle with the circle in [914a1] which it terminates? Both move with a circular motion, but the cylinder describes straight lines on the plane surface, while the cone describes circles because the circles which compose the cone are unequal and the greater circle always moves more quickly than the less about the same centre. Now since all the circles [5] composing the cone move at different rates, it results that the outermost circles travel over most space and describe the longest line in the same time (hence they must move in a circle); for all the circles are described by the same straight line, and when the straight line revolves the various points on it do not describe an equal line [10] in the same time, but can travel along an equal line only if they proceed in a straight direction. But in the cylinders, since all the circles are equal and about the same centre, the result is that, since they touch the plane surface at all the points on them at the same time, as they roll they travel at a uniform speed (because cylinders are [15] uniform throughout), and reach the plane surface again simultaneously when each has completed its own circuit; thus the straight lines described on the plane surface are also equal, for the circles describe them by contact, since they both are equal and travel at the same speed. Now the lines described by the same line travelling in a straight direction are straight, and so the cylinder would travel straight along [20] them; for it makes no difference whether you drag the cylinder over the plane surface at the line where it first8 touched the plane surface, or whether you roll it over it; for the result will always be that an equal and similar line made up of points on the cylinder will touch the plane surface, both when the cylinder is dragged and when it is rolled along.
[25] 6 · Why is it that if a scroll is cut level and straight, then if you cut it parallel to the base, the edge becomes straight when unrolled, but if it is cut obliquely, the edge becomes crooked? Is it due to the fact that, since the circles in the first section are in the same plane, the result is that the oblique section is not parallel but is [30] partly more and partly less distant from the first section, so that, when the roll is unfolded, the circles, which are in the same plane and have their origin in the same plane, assume, when unrolled, the line which they themselves form? For the resulting line is formed from the circles which are in the same plane, so that the line, being on a plane, is also straight. But the line of the oblique section when it is [35] unrolled, not being parallel to the first section, but partly more and partly less distant from it (this being the position of the section relative to it), will not be on a plane and therefore not straight either; for part of a straight line cannot be in one plane and part in another.
7 · Why is it that magnitudes always appear less when divided up than when [914b1] taken as a whole? Is it because, though things which are divided always possess number, in size they are smaller than that which is single and undivided? For that which is great is said to be great owing to its continuity and because it is of a certain size, but the number of its parts is always greater than the number of any undivided [5] magnitude. So it is only natural that the whole should appear greater than the parts into which it is divided; for, though the whole and its parts are identical, the whole, being continuous, possesses more of the quality of magnitude, while the parts have more of the quality of number.
8 · Of the phenomena which occur in the water-clock the cause seems to be in general that ascribed by Anaxagoras; for the air which is cut off within it is the [10] cause of the water not entering when the tube has been closed. The air, however, by itself is not the cause; for if one plunges the water-clock obliquely into the water, having first blocked up the tube, the water will enter. So Anaxagoras does not adequately explain how the air is the cause; though, as has been said, it certainly is [15] the cause. Now air, whether impelled along or travelling of itself without any compelling force, naturally travels in a straight line like the other elements. When therefore the water-clock is plunged obliquely into the water, the air preserving its straight course is driven out by the water through the holes opposite to those which [20] are in the water, and, as it goes out, the water flows in. But if the water-clock is plunged upright into the water, the air not being able to pass straight up, because the upper parts are closed, remains round the first holes; for it cannot contract into itself.9 The fact that the air can keep out the water by its immobility can be [25] illustrated by what happens with the water-clock itself. For if you fill the bulb itself of the water-clock with water, having stopped up the tube, and invert it with the tube downwards, the water does not flow along the tube to the outlet. And when the outlet is opened, it does not immediately flow out along the tube but only after a moment’s interval, since it is not already at the outlet of the tube but passes along it [30] afterwards, when it is opened. But when the water-clock is full and in an upright position, the water passes through the strainer as soon as ever the tube is opened, because it is in contact with the strainer, whereas it is not in contact with the extremities of the tube. The water does not, therefore, flow into the water-clock, for [35] the reason already mentioned, but flows out when the tube is opened because the air in it being set in motion up and down causes considerable movement10 in the water inside the water-clock. The water then, being thrust downwards and having itself also a tendency in that direction, naturally flows out, forcing its way through the air [915a1] outside the water-clock, which is set in motion and is equal in force to the air which impels it but weaker than it in its power of resistance, because the interior air, since it passes through the tube, which is narrow, flows more quickly and violently and forces the water on. The reason why the water does not flow when the tube is closed [5] is that the water on entering into the water-clock drives the air forcibly out of it. (That this is so is shown by the breath and noise engendered in it.) As the water enters, driving the air forcibly along, it rushes into the tube itself, and11 like wedges of wood or bronze driven in by cleavage, remains in position without anything else to [10] hold it together, until it is expelled from the opposite direction, as pegs which are broken in wood are knocked out. This occurs when the tube is opened for the reasons already mentioned. If this is the reason, it is only natural that it should not flow out or make its way forth, since the air forcibly prevents it and becomes inflated.12 (The [15] noise which is made shows that the water is drawn up by the air, and this is a common phenomenon.) All the water then, being drawn up and being in itself continuous, remains in the same position under the pressure of the air, until it is thrust away again by it; and, since the first part of the water remains in the same position, the rest of the water is dependent from it in one continuous mass. It is only [20] natural that this should be so; for it is the property of the same thing to move something from its own place and to hold it when it has moved it,13 and to do so for a longer time, if that which holds and that which is held are of equal force, or if that which holds is stronger, as occurs in the present case; for air has greater force than water.
[25] 9 · Why is it that the parts of plants and of animals which are not instrumental are all round—in plants, for instance, the stem and the shoots, and in animals the calves, thighs, arms, and chest—and no whole or part is triangular or polygonal? Is it due, as Archytas used to say, to the fact that in natural movement [30] the proportion of equality is always present (for he holds that all things move in a proportion), and that this is the only proportion which can return to itself, and so it forms circles and rotundities wherever it occurs?
10 · Why do extremities always take rounded forms? Is it because nature makes everything as excellent and as beautiful as the available material permits, [35] and a rounded form is the most beautiful, being as uniform as possible?
11 · Why does a circular object when it is thrown at first describe a straight line, but, as it ceases to move, describe a spiral, until it falls? Does it describe a straight line at first, because the air on either side of it alike keeps it upright? The [915b1] inclination then to either side being equal, the line also which it describes must be of such a nature that it divides the space on either side of it equally, and such a line is a straight line. But when it inclines to one side, because the air on either side of it is not even, it no longer describes an equal line with its inner and with its outer edge, but is forced to describe a circular line. [5]
12 · Why is it that in magnitudes of uneven weight,14 if you set the lighter part of them in motion, the object thrown revolves in a circle, as happens for example with loaded dice if you throw them with the unweighted side towards you? Is it because the heavier part cannot travel at the same speed as the lighter when [10] hurled with the same force? Now since it must necessarily move, but cannot do so in the same manner, that is in a straight line, it must take an inward direction and revolve; just as, if part of the object had as a whole remained motionless owing to a weight in the centre, the part next to the person setting the object in motion would have moved so as to occupy the position of the part away from him, while the farther side would have moved towards him. But when the whole object moves and, as it [15] travels, has a weight in the middle, it must necessarily behave in the same manner.
13 · Why is it that objects which are travelling along, when they come into collision with anything, rebound in a direction opposite to that in which they are naturally travelling, and at similar angles? Is it because they move not only with the impetus which accords with their own nature but also with that which is due to the [20] agent which throws them? Their own impetus then ceases when they reach their own proper position (for everything comes to rest when it reaches the position to which it is naturally carried), but, owing to the extraneous impetus, it is forced to continue to move, not, however, in a forward direction, because it is prevented from doing so, but either sideways or in a direct line. Now every object rebounds at [25] similar angles, because it is travelling to the point to which it is carried by the impetus which was imparted by the person who threw it; and at that point it must be travelling at an acute angle or at a right angle. Since then the repelling object stops the movement in a straight line, it stops alike the moving object and its impetus. As [30] then in a mirror the image appears at the end of the line along which the sight travels, so the opposite occurs in moving objects, for they are repelled at an angle of the same magnitude as the angel at the apex (for it must be observed that both the angle and the impetus are changed), and in these circumstances it is clear that moving objects must rebound at similar angles. [35]
1 · Why do those who are unsymmetrical appear larger when set side by side with other men than by themselves? Is it because that which is symmetrical is one, and symmetry more than anything else gives unity to a thing, and that which is one [916a1] tends to be indivisible, and the indivisible is smaller, whereas asymmetry by causing diversity creates a multiplicity? When things therefore are seen by themselves, their dimensions are less likely to be noticed; but this is not so when they are seen side by [5] side with one another. That then which is indivisible appears to be one, and the impression which it makes on the beholder is one because of its symmetry. But that which is unsymmetrical makes a greater impression, as though it were many, and appears greater because, though in reality only one, it seems to be many; for it partakes of the nature of magnitude, because it is continuous, and of number, [10] because of the inequality of its parts; and so being increased in both these respects, it naturally appears great by the side of that which is simple and one.
2 · Why do animals and plants grow more in length than otherwise? Is it because length increases three times over, width twice, and depth once? For length [15] is the first and original dimension, and so it increases both of itself, and secondly in combination with width, and thirdly in combination with depth. But width implies an increase in two dimensions only, in itself and at the same time in depth.1
In what sense must we understand the terms ‘prior’ and ‘posterior’? As those who lived in the time of Troy are prior to us, so are those who lived before them prior [20] to them and so on ad infinitum? Or since there is a beginning and a middle and an end of the universe, and when a man, as he becomes old, reaches the limit and turns again towards the beginning, that which is nearer to the beginning is earlier, what prevents our being nearer to the beginning than to the end, in which case we should [25] be prior? Just as the course2 of the firmament and of each of the stars is a circle, why should not also the coming into being and the decay of perishable things be of such a kind that these things again come into being and decay? This agrees with the saying that ‘human life is a circle’. To demand that those who are coming into being [30] should always be numerically identical is foolish, but one would more readily accept that they were identical in kind. And so we should ourselves be prior, and one might suppose the arrangement of the series to be such that it returns back in a circle to the point from which it began and thus secures continuity and identity of composition. For Alcmaeon declares that men perish because they cannot link [35] together the beginning to the end—a clever saying, if one supposes that he uses it metaphorically and the literal meaning is not insisted upon. If then human life is a circle, and a circle has neither beginning nor end, we should not be prior to those who lived in the time of Troy nor they prior to us by being nearer to the beginning.
1 · Why is it that some people, if they begin to read, are overcome by sleep [916b1] even against their will, whereas others wishing to be overcome by sleep are kept awake by taking up a book? Is it because in those in whom movements of breath take place owing to the coldness of their nature or of melancholic humours, which [5] by their coldness engender an unconcocted excretion of breath—in such people, the intelligence, when it is set in motion and does not think of anything with concentrated attention, is checked by the second movement, which has a cooling effect, and this causes a tendency to sleep? But when they fix the intelligence firmly upon something, as happens in reading, they are impelled by the heating movement, [10] which is unchecked by anything, and so they cannot go to sleep. In those who are in a natural condition, however, when the intelligence, which is very powerful, stands at a single point and does not keep changing from one subject to another, every function in that region (whose inactivity involves sleep) is at a standstill;1 and when the intelligence stands still and is as it were weary, being situated in the head, it [15] weighs it down and produces sleep. But as long as the mind moves naturally, it does not go to sleep; for it is then that it is most alive, and wakefulness rather than sleeping is the cause of life.
2 · Why are contentious disputations useful as a mental exercise? Is it because they involve frequent victories and defeats? They therefore quickly instil a [20] spirit of rivalry; for, when men are victorious, they are induced by their joy to contend yet more, and, when they are defeated, they continue the struggle in hopes of turning defeat into victory. Those engaged in struggles of other kinds act in the same way, and so when fighting and getting the worst of it often refuse to come to terms.
3 · Why is it that in rhetorical displays men prefer examples and stories [25] rather than enthymemes? Is it because they like to learn and to learn quickly, and this end is achieved more easily by examples and stories, since these are familiar to them and are of the nature of particulars, whereas enthymemes are proofs based on generalities, with which we are less familiar than with the particular? Further, we [30] attach more credence to any evidence which is supported by several witnesses, and examples and stories resemble evidence, and proofs supported by witnesses are easily obtained. Further, men like to hear of similarities, and examples and stories display similarities.
4 · Why do we talk of an orator, or a general, or a business man as being [35] clever, but not use the term of a musician or of an actor? Is it because the powers of the two last are exercised apart from any desire of gaining an advantage (for their aim is pleasure), whereas the three first aim at some advantage? For a good orator [917a1] or general or business man is one who can gain some advantage, and cleverness consists mainly in getting the better of some one else.
5 · Why is the philosopher generally regarded as superior to the orator? Is it because the philosopher treats of the nature of injustice, while the orator says that such and such a person is unjust, and the orator states that such and such a person is [5] a tyrant, while the philosopher discusses the nature of tyranny?
6 · Why is it that some men spend their time in pursuits which they have chosen, though these are sometimes mean, rather than in more honourable professions? Why, for example, should a man who chooses to be a conjurer or an actor or a piper prefer these callings to that of an astronomer or an orator? Is it [10] because some men would prefer to undertake the more honourable professions but do not do so because they do not feel confident that they would succeed in them? Or is it because each man chooses the calling in which he thinks he can excel and devotes himself to that which he chooses, giving up the greater part of each day to it, in order that he may improve his own proficiency in it? Now when men have chosen [15] a calling from the first and have become accustomed to it, they lose the power of discriminating between the higher and the lower; for their mind is warped by their bad choice.
7 · Why is it that some persons, if they begin to read, are overcome by sleep even against their will, whereas those who wish to go to sleep are made unable to do [20] so if they take up a book?2 Is it because in those in whom movements of breath take place owing to the coldness of their nature or of melancholic humours, which by their coldness engender an unconcocted excretion of breath—in these when the intelligence is set in motion and does not think of anything with concentrated attention, the intelligence is checked by the second movement,3 and so they undergo [25] a great mental change and go to sleep (for the movement of breath is overcome)? But when they fix their intelligence on something, as happens in reading, they are impelled by the movement of breath unchecked by anything, and so cannot sleep. But in those who are in a natural condition, when the intelligence is fixed on one [30] thing and does not keep changing from one subject to another, every function in that region (the inactivity of which involves sleep) is at a standstill. (Similarly during a rout, if the leader halts, all the forces under his command halt also.) For naturally that which is light rises, while the heavy sinks. As long, therefore, as the mind moves naturally, it does not go to sleep; for it is then that it is most alive.4 When the mind [35] stands still and is as it were weary, the intellect undergoes a change, and the corporeal elements rise to the head and produce sleep. Reading might be expected to prevent sleep; but wakefulness is not due to the fact that we are thinking (for then our mind is most concentrated) but to the constant change; for the intellectual activities which cause wakefulness are those in which the mind searches and finds [917b1] difficulties rather than those in which it pursues continual contemplation; for the former cause lack of concentration, while the latter do not.
8 · Why is it that in contentious disputes no verbosity can ever occur? Is it because such reasoning is apparent deduction, and deduction involves only a brief [5] discussion; and, if it be prolonged, after a time the false reasoning is detected and the disputant can withdraw the premisses which he has granted?
9 · Why do we feel more pleasure in listening to narratives in which the attention is concentrated on a single point than in hearing those which are concerned with many subjects? Is it because we pay more attention to and feel more [10] pleasure in listening to things which are more easily comprehended, and that which is definite is more easily comprehended than that which is indefinite? Now a single thing is definite, but a plurality partakes of the nature of the infinite.
10 · Why do we like to hear of events which are neither very old nor quite new? Is it because we discredit events which occurred long before our time and take no pleasure in events which we discredit, while we can still as it were perceive very [15] recent events and so take no pleasure in hearing about them?
1 · Why do those who are grieving and those who are enjoying themselves alike have the flute played to them? Is it in order that the distress of the former may be lessened and the pleasure of the latter increased? [20]
2 · Why is it that, when the same person uses the same vocal power, the sound travels farther when he is singing or shouting with others than when he does so by himself? Is it because the doing of anything with a number of other people—compressing, for instance, or pushing something—does not produce an effect in simple proportion to the number of persons; but, just as a line two feet long describes a circle which is not double but quadruple that described by a line a foot long, so collective actions have greater force in proportion to their number than [25] when they are carried out separately? When, therefore, a number of persons sing together, the force of their voice unites, and impels the air simultaneously, so that it travels many times as far; for the voice produced by all is the multiple of each single voice.
[30] 3 · Why does the voice waver most when singing parhypate and to no less a degree than when singing nete and the higher notes, although the interval is greater? Is it because the interval is more difficult to sing and is in primary element? Now the difficulty is due to the straining and pressure of the voice; and these require an effort, and things which require an effort are more likely to fail.
[35] 4 · But why is parhypate difficult to sing, but hypate easy, although there is only a quarter-tone between them? Is it because hypate is accompanied by relaxation of the voice and also because after tension it is easy to slacken?1 It is probably for the same reason that what a man says with violence,2 he says with this note or paranete. For one must… with a consciousness of the character which one [918a1] is representing and under conditions most akin to it according to one’s purpose. But what is the cause of concordant music?3
5 · Why do men take greater pleasure in listening to those who are singing such music as they already know than music which they do not know? Is it because, [5] when they recognize what is being sung, it is more obvious that the singer is as it were achieving his aims, and this is pleasant to contemplate? Or is it because it is less4 pleasant to learn? And the reason for this is that in the one case there is acquisition of knowledge, in the other the use and recognition of it. Further, that which is familiar is always pleasanter than the unfamiliar.
[10] 6 · Why does recitation with a musical accompaniment have a tragic effect when introduced into singing? Is it owing to the resulting contrast? For the contrast gives an expression of feeling and implies extremity of calamity or grief, whereas uniformity is less mournful.
7 · Why did the ancients, when they gave the scale seven notes, leave in [15] hypate and not nete? Is this a false statement, since they left in both and omitted trite, or is the truer answer that the lower note contains the sound of the higher note,5 so that hypate gives the impression of the octave above better than nete for the high note is a sign of more force, while the low note is easier to utter?
8 · Why does the low note contain6 the sound of the high note? Is it because [20] the low note is greater and resembles an obtuse angle, while the high note resembles an acute angle?
9 · Why do we listen with greater pleasure to a solo when a man sings it to the accompaniment of a flute or lyre? Yet the same tune is sung note for note with or without accompaniment. For if there is more of the same thing, it ought to be still more pleasant when accompanied by a large number of flute-players. Is it because [25] the singer is more obviously achieving his aim when he is accompanied by a flute or lyre? And the accompaniment of a number of flute-players or lyres does not add to the pleasure, because it drowns the singing.
10 · Why, if the human voice is more pleasant than an instrument, is the voice of a man singing without words—as, for example, when singing nonny-noes—not [30] so pleasant as a flute or lyre? Or is it true that even in the case of an instrument we get less pleasure if it is not expressive of meaning? The instrument, however, has an advantage even in its actual effect; for while the human voice is pleasanter, instruments strike the note better than the human mouth, which is why they are pleasanter to hear than nonny-noes.
11 · Why is the voice higher when it echoes back? Is it because it is smaller, [35] having become weaker?
12 · Why does the lower of two strings sounded together always give the tune? For if one omits paranete, when one should sound it with mese, the tune is given none the less; but if one omits mese, when one should sound both, the tune is lost.7 Is it because the low note is large and therefore strong, and the less is contained in the greater? So too if hypate is stopped down in the centre, two netes [918b1] are produced.
13 · Why is it that the low note in the octave gives the effect of unison with the high, but not vice versa? Is it because, if possible, the sound of both notes is in both notes, but, failing that, in the low note, since it is greater? [5]
14 · Why does the accord in the octave escape notice, and why does there appear to be a simple unison, as for example in the Phoenician lyre and in the human voice? For the upper and lower notes do not give the same sound but are analogous to one another at the octave. Is it because their sound appears to be [10] practically the same because analogy is equality in sounds, and equality is of the one? The same deception occurs also in the pipes.
15 · Why were ‘nomes’ not composed in antistrophes like all other songs, that is, choric songs? Is it because the ‘nomes’ were assigned to virtuosi, and as these were already able to imitate different characters and sustain their parts, the songs [15] composed for them became long and elaborate? Like the words, therefore, the music conformed to the imitation, becoming constantly different; for it was more essential for the music to be imitative than the words. (For this reason too dithyrambs, since they have become imitative, no longer have antistrophes, as they had formerly.) The reason is that in old days free citizens themselves formed the [20] choruses; it was difficult, therefore, for a large number to sing together like virtuosi, so they sang enharmonic songs. For it is easier for a single person to make many changes than for a large chorus, and for a professional than for those who are preserving the character of the music. And so they made the music more simple for [25] them. Now the antistrophic song is simple; for there is one rhythm8 and one unit of metre. For the same reason songs executed from the stage are not antistrophic, but those sung by the chorus are so; for the actor is a virtuoso and an imitator, but the chorus is less imitative.
[30] 16 · Why is antiphonal accompaniment more pleasing than symphonic accompaniment? Is it because in the former the consonance is more obvious than when the accompaniment of the singing is symphonic? For of the two notes played by the instrument one must be in unison with the note sung, and so two notes contending against one drown the other note.
17 · Why is it that singing in fifths does not give the effect of antiphony? Is [35] it because the symphonic notes are not the same as are the notes which are an octave apart? For in the octave the deep note in the lower part of the scale is analogous to the high note in the upper part; it is, therefore, as it were at once the same and different. But this does not occur in fifths and fourths so that the sound of the antiphonal note does not appear, for it is not identical.
18 · Why is it that the accord in the octave alone is used in singing? For in [919a1] ‘magadizing’, this and no other accord is used. Is it because it alone is made up of antiphonal notes, and with antiphonal notes, if but one be sung, the same effect is produced as if both were sung? For the one note in a way contains the sounds of both, so that, when one is sung, the concordant note at this interval is also sung; and [5] when they sing both, or when one note is sung and the other played on the flute, they both as it were sing one note. Therefore the accord in the octave alone is sung, because the antiphonal notes have the sound of one note.
19 · But why does the power of producing the effect of a single note belong [10] only to antiphonal notes? Is it because they alone are equidistant from mese? The presence then of this mean creates a certain similarity in their sounds, and the ear seems to tell us that it is the same note and that they are both extremes.
20 · Why is it that, if after tuning the other strings, one alters mese and uses the instrument, the ear is offended and an unmusical effect is produced not only [15] when mese is used, but in the rest of the piece as well, whereas, if lichanos or any other string is altered, it only seems to make a difference when that particular string is used? Surely this is only natural; for in all good music mese occurs frequently, and all good composers have frequent recourse to mese, and, if they leave it, they [20] soon return to it, as they do to no other note. Similarly in language, if certain connecting particles are removed, such as τε and καί, the language is no longer Greek; whereas the omission of some particles does not offend the ear, because certain particles must be frequently used, if there is to be language, but others not. [25] So mese is as it were a connective among sounds, and particularly in good music, because its sound occurs more often.
21 · Why is it that of singers those who are singing low notes are more conspicuous if they sing out of tune than those who are singing high? So too those [30] who make mistakes in time in the lower notes9 are more conspicuous. Is it because the period of time occupied by the low note is longer, and this longer period is more perceptible (for,10 lasting for a greater time, it creates a deeper sense-impression), whereas a quick,11 high note escapes notice owing to its swiftness? [35]
22 · Why does a large choir keep better time than a small one? Is it because they look more to one man, their leader, and begin more slowly and so more easily achieve unity? For mistakes occur more frequently in quick singing.
23 · Why is nete double hypate? Is it because in the first place, when half [919b1] the string is struck and when the whole string is struck an accord in the octave is produced? So too with wind instruments, the sound produced through the middle hole and that produced through the whole flute give an accord in the octave. Again, [5] in the flutes an accord in the octave is obtained by doubling the length, and this is how flute-makers produce it. Similarly they obtain a fifth by means of a length in the ratio of 3 to 2.12 Again, those who construct Pan-pipes stuff wax into the extreme end of the hypate-reed, but fill up the nete-reed to the middle. Similarly [10] they obtain a fifth by means of a length in the ratio of 3 to 2, and a fourth by means of a length in the ratio of 4 to 3. Further, hypate and nete on triangular stringed instruments, when they are equally stretched, give an accord in the octave when one is double the other in length.
24 · Why, if one strikes nete and then stops it down, does hypate alone seem [15] to resound? Is it because the vibration produced from hypate is very much of the same nature as the sound of nete, because it is in accord with it? When it is increased by the addition of its like, it alone is audible, the other sounds being imperceptible owing to their smallness.
25 · Why is mese so called in the scale, though there is no middle of eight [20] notes? Is it because in the old days scales had seven notes, and seven has a middle?
26 · Why do most men sing high when they sing out of tune? Is it because it is easier to sing high than low? Or is it because singing high is worse than singing [25] low, and a mistake is doing what is worse?
27 · Why is it that of all things which are perceived by the senses that which is heard alone possesses character? For music, even if it is unaccompanied by words, yet has character; whereas a colour and an odour and a savour have not. Is it because that which is heard alone has movement, not, however,13 the movement in us to which the sound gives rise (for such movement exists also in the other things [30] which affect our senses, for colour also moves our sight), but we perceive the movement which follows such and such a sound? This movement resembles character both in the rhythms and in the melodic disposition of the high and low notes, but not in their commingling; for symphony does possess character. This does [35] not occur in the other objects of sense-perception. Now these movements are connected with action, and actions are indicative of character.
28 · Why are the ‘nomes’ which are sung so called? Is it because before men knew the art of writing they used to sing their laws in order not to forget them, as [920a1] they are still accustomed to do among the Agathyrsi? They, therefore, called the earliest of their subsequent songs by the name as their earliest songs.
29 · Why do rhythms and tunes, which after all are only voice, resemble characters, whereas savours do not, nor yet colours and odours? Is it because they [5] are movements, as actions also are? Now activity possesses and instils character, but savours and colours have no similar effect.
30 · Why is neither the Hypodorian nor the Hypophrygian mode suitable for use by the chorus in tragedy? Is it because they do not admit of antistrophic [10] melody? They are used, however, from the stage, because they are imitative.14
31 · Why were Phrynichus and his contemporaries primarily musicians? Is it because in those days the lyrical portions of tragedies were many times longer than the purely metrical?
32 · Why is the diapason so called and not named after the number of notes [15] an octave, like the fourth and the fifth? Is it because the notes were originally seven in number, and then Terpander took away trite and added nete, and in his time it was called diapason and not octave, since there were seven?
33 · Why is it more satisfactory to pass from a high to a low note than from a [20] low to a high note? Is it because the former amounts to beginning at the beginning, for the mese, or leader,15 is the highest note in the tetrachord? But in passing from a low to a high note one begins not at the beginning but at the end. Or is it because a low note is nobler and more euphonious after a high note?
34 · Why are a double fifth and a double fourth not concordant, whereas a double octave is? Is it because neither a double fifth nor a double fourth is . . .16 [25] though a fourth and a fifth are so?
35 · Why is the accord in the octave the most beautiful of all? Is it because its ratios are contained within integral terms, while those of the others are not so contained? For since nete is double hypate, as nete is two, so hypate is one; and as [30] hypate is two, nete is four; and so on. But nete is to mese in ratio of 3 to 2 (for a fifth is in this ratio), and that which is in the ratio of 3 to 217 is not contained within integral terms; for as the lesser number is one, so the greater number is one with the addition of a half, so that it is no longer a comparison of whole numbers, but parts are left over. The like happens also with the fourth; for the ratio of 4 to 3 gives the [35] lesser18 plus a third of it. Or is it because the accord which is made up of both the other two is the most perfect, and because it is the measure of the melody?
. . .19 in any body which is displaced the movement is most violent in the middle and gentler at the beginning and end, and when the movement is most violent the [920b1] sound of that which is displaced is shriller? For this reason also strings which are tightly stretched give a shriller note, for their movement is quicker. Now if a sound is the displacement of air or of something else, a sound which is in the middle of its [5] course must be shrillest. If this were not so, there would be no displacement of anything.
36 · Why is it that if mese is altered, the sound of the other strings also is spoilt,20 but if on the other hand mese is left alone and one of the other strings altered, the note which is altered alone is spoilt?21 Is it because for all strings being in tune means standing in a certain relation to mese,22 and the arrangement of each [10] is already determined by mese? If, therefore, that which is the cause of their being in tune and which holds them together is taken away, their proper relationship appears to be no longer maintained. But if one string is out of tune but mese is not altered, naturally the defect lies in that string only;23 for all the others are in tune. [15]
37 · Why is it that, though height in a voice is in accordance with smallness and lowness in accordance with largeness (for a low note is slow owing to its largeness, and a high note quick owing to its smallness), yet more effort is required to sing a high than a low note, and few can sing the top notes, and the ‘Orthian [20] songs’ and high music are hard to sing owing to the strain which they involve? Yet it requires less effort to set in motion that which is small than that which is large, and this ought to be true also of the air. Is it because the possession of a naturally high voice and the singing of high notes are not the same thing, but naturally high voices are always due to weakness because of the inability to set more than a little air in [25] motion, and the little air thus set in motion is carried quickly along? But height of note in singing is a sign of strength; for that which is carried violently along is carried swiftly—so that height of note in singing is a sign of strength. Hence persons in robust health24 can sing high. And it requires an effort to sing the high notes, but the low notes are easier.25
38 · Why do all men delight in rhythm and melody and concords in general? [30] Is it because we naturally rejoice in natural movements? This is shown by the fact that children rejoice in them as soon as they are born. Now we delight in the various types of melody because of habit; and we delight in rhythm because it contains a familiar and ordered number and moves us in a regular manner; for ordered [35] movement is naturally more akin to us than disordered, and is therefore more in accordance with nature. This is shown by the fact that by working and eating and drinking in an ordered manner we preserve and improve our nature and strength, whereas if we do these things irregularly we destroy and derange our nature; for [921a1] diseases are disturbances of the natural order26 of the body. And we delight in concord because it is the mingling of contraries which stand in proportion to one another. Proportion, then, is order, which, as we have said, is naturally pleasant. Now that which is mingled is always more pleasant than that which is unmingled, [5] especially if, being perceived by the senses, it contains equally the force of both extremes; and in a concord the proportion has this characteristic.27
39 · Why is ‘antiphony’28 more pleasant than ‘homophony’? Is it because ‘antiphony’ is concord in the octave? For ‘antiphony’ is produced by young boys and [10] men whose voices are separated in pitch as nete is from hypate. Now any concord is more pleasing than a simple note for the reasons already stated, and of concords that in the octave is the most pleasing; whereas ‘homophony’ produces only a simple sound. ‘Magadizing’ is in the concord of the octave, because, just as in verses the [15] feet stand to one another in the proportion of equal to equal, or two to one, or some other proportion, so too the sounds in a concord stand in a proportion of movement to one another. In the other concords the termination of one of the two notes is incomplete since it coincides with the end of only a half of the other; and so they are not equal in force, and being unequal they make a different impression on the sense-perception, as happens in a chorus when at the conclusion they are singing [20] louder than others. Furthermore, hypate happens to have the same conclusions to the periods in its sounds; for the second stroke which nete makes upon the air is hypate. As, then, these notes, though they do not do the same thing, terminate together, the result is that they carry out one common task, like those who are playing a stringed accompaniment to a song; for these, though they do not play the [25] same other notes as the singer, yet, if they finish on the same note, give more pleasure by their conclusion than they give pain by the differences which occur earlier in the piece, because after diversity the unity due to the accord in the octave is very pleasing.29 Now ‘magadizing’ is made up of contrary notes, and for this [30] reason it is carried out in the octave.
40 · Why do men take greater pleasure in listening to those who are singing tunes which they already know than if they do not know them? Is it because it is more obvious that the singer is as it were achieving his aim when they recognize what is being sung, and when they recognize it the contemplation of it is pleasant? [35] Or is it because the listener is in sympathy with one who sings what he himself knows? For he sings with him; and every one enjoys singing when he is under no compulsion to sing.
41 · Why are a double fifth and a double fourth not concordant, whereas a [921b1] double octave is? Is it because a fifth is in the ratio of 3 to 2, and a fourth in that of 4 to 3? Now in a series of three numbers30 in a ratio of 3 to 2 or 4 to 3, the two extreme numbers will have no ratio to one another; for neither will they be in a superparticular ratio nor will one be a multiple of the other. But, since the octave is in a ratio of 2 [5] to 1, if it be doubled the extreme numbers would be in a fourfold ratio. So, since a concord is a compound of sounds which are in a ratio31 to one another, and sounds which are at an interval of two octaves from one another are in a ratio to one another [10] (while double fourths and double fifths are not), the sounds constituting the double octave would give a concord (while the others would not) for the reasons given above.
42 · Why is it that, if one strikes nete and then stops it down, hypate seems to respond? Is it because nete, as it ceases and dies down, becomes hypate? (This is [15] indicated by the fact that it is possible to sing nete from hypate; for the similarity can be taken from hypate as being a response to nete?32) And since an echo is a response to a note,33 and when nete ceases a sound is set in motion34 which is the same as the note of hypate, it is only natural owing to the similarity that nete should [20] seem to set hypate in motion. For we know that nete is not35 in motion, because it is stopped down, and seeing that hypate itself is not stopped down and hearing its note we think that it is hypate which is giving forth a sound. (This kind of thing is quite [25] common, where we cannot grasp the exact truth either by reasoning or by the senses.) Again, it would be nothing extraordinary if, after nete is struck when it is very tightly stretched, the bridge were set in motion; and it would not be strange if, when the bridge moved, all the strings were set in motion with it and made a sound. [30] Now the sound of nete is alien to the other notes both in its end and in its beginning, but is the same as hypate in its end. This having been added to the movement of hypate itself, it would not be strange that the sound should seem to be entirely that of hypate; and it will be louder than the combined sound of the other notes, because the latter, being as it were impelled by nete, give only a soft sound, whereas nete, [35] being the most violent of notes, sounds with its full force; and so naturally its second sound would be louder than that of the others, especially if only a slight movement has taken place in them.36
[922a1] 43 · Why do we listen37 with greater pleasure to a solo sung to a flute than to one sung to a lyre?38 Is it because anything becomes still more pleasant when mingled with what is more pleasant?39 Now the flute is more pleasant than the lyre, so that singing would be more pleasant when it mingles with the flute than with the lyre. Further,40 that which is mingled is more pleasant than that which is [5] unmingled, if there is a simultaneous perception of both the elements. For wine is pleasanter than honey-wine, because natural mixtures are more thoroughly mingled than those which we make ourselves. For there is also wine which is mingled of bitter and sweet savours, as is shown by the so-called vinous pomegranates. Singing, [10] then, and the flute mingle with one another owing to their similarity, for they are both produced by breath. But the sound of the lyre, since it is not produced by breath or is less perceptible than the sound of the flute, mingles less well with the voice and, causing a contrast in the perception, has a less pleasing effect, as has been said of savours. Furthermore, the flute by its own sound and by its likeness to the [15] voice covers up many of the mistakes of the singer; but the sounds of the lyre, which are isolated and mingle less well with the voice, since they are observed show up the mistakes of the singing separately, actually41 providing as it were a standard for criticizing it. And when there are many mistakes in the singing, the combined effect [20] of the singing and the accompaniment must necessarily be worse.
44 · Why is mese42 so called, though there is no middle of eight notes? Is it because in the old days the scales had seven notes, and seven has a middle? Again, since of the points which fall between two extremes the middle alone forms a kind of starting-point, that which lies between the points which verge towards either end in [25] an extended space, being also a starting-point—that will be the middle.43 And since nete and hypate are the extremes of the scale44 and the other sounds lie between them, of which the one which is called mese alone is the starting-point of the second tetrachord, the name mese is amply justified; for of the points lying between certain extremities, as has been shown, the middle alone forms a starting-point.
45 · Why does a large chorus keep the rhythm better than a small one? Is it [30] because they look more to one man, their leader, and begin more slowly, and so more easily achieve unity? For mistakes occur more frequently in quick singing. Now a large chorus attends to its leader, and no one by differing from the rest would [35] render himself conspicuous by making himself heard above the rest: in a small chorus, on the other hand, individuals make themselves more conspicuous; they, therefore, vie with one another instead of looking to their leader.
46 · Why do most men sing high when they sing out of tune? Is it because it is easier to sing a high note than a low note? They have at all events a tendency to [922b1] sing high and make mistakes in what they sing.
47 · Why did the ancients, when they made the scales consist of seven strings, leave in hypate but not nete? Or should we say that they omitted not nete but what is now called paramese and the interval of a tone? They treated mese, [5] then, as the lower note of the upper ‘pycnon’; whence came the name mese. Or is it because it was the end of the upper tetrachord and the beginning of the lower, and was in pitch in an intermediate relation between the extreme notes?
48 · Why do the choruses in tragedy not sing either in the Hypodorian or in [10] the Hypophrygian mode? Is it because these modes have very little of the kind of tune which is specially necessary to a chorus? Now the Hypophrygian mode has a character of action (hence in the Geryone the sortie and arming are composed in this mode); and the Hypodorian is magnificent and steadfast, and so is the most suitable of all the modes to accompaniment by the lyre. Now both these are [15] unsuited to the chorus and more proper for the characters on the stage; for the latter imitate heroes, and among the ancients the leaders alone were heroes, and the people, of whom the chorus consists, were mere men. So a mournful and quiet character and type of music are suited to the chorus, for they are human. These [20] characteristics belong to the other modes, but least to the Phrygian among them—for it is exciting and orgiastic. In accordance with this mode, then, we are affected in a certain way, and the weak are more readily affected than the strong; and so this mode is appropriate to choruses. When we use the Hypodorian and Hypophrygian modes, on the other hand, we are active, and action is not fitting for [25] choruses; for the chorus is in attendance and takes no active part, for it simply shows goodwill towards those with whom it is present.
49 · Why is it that of the sounds which form a consonance the softer is the [30] lower note? Is it because melody is in its own nature soft and tranquil, but becomes harsh and full of movement by the admixture of rhythm? Now since the low note is soft and tranquil, and the high note full of movement, of the notes which maintain the same melody the lower would rather be softer in the same melody; for melody in itself,45 as has been shown, is soft.
[35] 50 · Why is it that the sounds produced from two jars of the same size and quality, one empty and the other half-full, give an accord in the octave? Is it because the sound produced from the half-full jar is double that produced from the empty jar? This surely is just what happens in the pipes. For the quicker the [923a1] movement, the higher seems the note, and in larger spaces the air collects more slowly, and in double the space in double the time, and proportionately in the other spaces. A wine-skin too which is double the size of another, gives an accord in the octave with one which is half its size.
[5] 1 · Why is it that celery can endure salt water, but the leek cannot? Is it because the roots of the latter are weak, but those of the former are strong, and that which is stronger is less liable to be affected?
2 · What is the reason for the saying:
Mint should neither be eaten nor planted in season of warfare?
[10] Is it because mint has a cooling effect upon the body, as is shown by the corruption which it causes in the semen? This is opposed to courage and spirit, being the same in kind.
3 · Why is it that some plants, though they have blossom, have no fruit, such as the cucumber and the pumpkin and the pomegranate? Or have they fruit, the [15] blossom being the fruit? For example the part which blossoms is a fruit-case, and the cucumber is a fruit-case.
4 · Why is it that some plants are edible only after they have been boiled, while others can be eaten raw? Do the juices of such plants as are not at first edible become sweeter when the plants have been warmed by heat, whilst in others the juices are originally sweet, and these can be eaten raw? [20]
5 · Why is it that some plants are boiled, others roasted? Is it because the moister plants are not dry enough, while the drier plants must not be further dried? Now anything which is boiled becomes moister and softer, and that which is less moist becomes dry if exposed to the fire.
6 · Why are some plants edible and others inedible? Is it owing to their [25] juices? For plants which in their raw state have unconcocted juices and, when heated, do not undergo change, are inedible. Now those of which the juice is edible but somewhat strong are used as condiments; for plants which have a strong savour in a small compass serve to flavour those of which the savour is distributed over a large bulk.
7 · Why is it that some plants live only until they have produced seeds and [30] having borne seeds dry up—grass, for instance, and the so-called herbs—while others do not, but bear seeds time after time? And of those which live only until they have produced seed why are the majority annuals, while horse-parsley produces its fruit in the second year and having done so dries up? Is it because all things flourish [35] until they are at their prime as far as their seed is concerned (for man too continues to grow until the age of thirty, sometimes in mass and sometimes in bulk), but when they can no longer produce seed, as in the case of man, they begin to dry up and grow old—in some cases slowly and in proportion? The reason why some forms of [923b1] life are long-lived and others short-lived is to be the subject of another treatise. But since the perfection of the seed is the limit in all cases, it necessarily follows that the short-lived bear fruit only once or only a few times, and the long-lived many times; [5] so that the weakest bear only once and so necessarily dry up; and those of them which can bear seed in a year are annuals, whilst others, like horse-parsley, do so in the second year, both plants and trees alike.
8 · Why is it that if one digs down to the roots of celery and surrounds them [10] with barley-husks, and puts earth over these and then waters the plants, the roots become very large? Is it because the barley-husks, being hot and spongy, hold the nourishment in a mass so that it does not rise upwards, but, being hot, causes concoction, and so considerable growth takes place? [15]
9 · Why is it that if one buries gourds or pumpkins in the ground when they are still small, they become large? Is it because the wind and the sun dry everything up and prevent growth, and make everything smaller in bulk but closer in texture? (As can be seen in the difference between trees growing in windy and sunny1 [20] localities and those in hollow and moist places, the latter being large and spongy in texture, the former small and dense.) Now the burying of things in the earth is the contrary of this and produces a contrary result. (A similar difference occurs in [25] fruits placed in vessels; if cucumbers are placed in hollow fennel-stalks or boxes, and pomegranates or apples in earthenware jars, the apples become large and spongy, but the cucumbers become small and hard because they grow against a resisting surface.)2 The reason then is that the nutriment is increased, because it is not dispersed by the wind or dried up; for the covering of earth prevents it from being thus affected.
[30] 10 · Why are the seeds of pungent plants more pungent than the roots and the leaves? Is it because everything is derived from the seed and distributed to the other parts from it, as it were pre-existing in it, as some contend, including the juices and odours, since the odours always become distinctive as soon as the seeds are [35] formed? If, therefore, the pungency in the rest of the plant is derived from the seed, it is only natural that it should be present in the greatest degree in the seed.3
11 · Why are thin radishes more pungent? Is it because the larger radishes are more concocted owing to the lapse of time?
[924a1] 12 · Why is it that the caper-plant will not grow easily in tilled ground—for the experiment has often been made of transplanting the roots or sowing the seed (for in some places it is more profitable than roses)—but grows best among the [5] tombs because the ground is most untrodden? As regards this and similar questions the principle must be accepted that all things do not come into being and grow from the same matter, but some things originally come into being and grow from the corruption of other things—for instance lice and the hair on the body when its [10] nutriment is corrupted and when the body is in a state of continual deterioration. As therefore in the body certain products are engendered from the excrement of nutriment (which means that concoction is incomplete), and since, when nature cannot prevail over the excrement, the commonest excretions are absorbed into the bladder and bowels, while from others living organisms are engendered (and so [15] these attain the greatest growth in old age and disease), so in the earth some products are engendered and grow from the concoction of nutriment, others from excretions and matter that is in a condition which is the opposite of concoction. Now tillage concocts the nutriment and makes it productive, and from this the cultivated [20] fruits are formed. The products, therefore, of this cultivation are called cultivated because they are benefited by art, undergoing as it were a kind of training. Plants, on the other hand, which cannot be so benefited or are formed from an opposite condition, are ‘wild’ and will not grow in a highly tilled soil. For tillage spoils them by trying to train them; for they are engendered from corruption. It is to this class that the caper-plant belongs.
3 · Why is it that, when radishes are in their prime in the winter, if one cuts [25] off the leaves and heaps earth round them and treads it in so as to keep out the water, they grow to an extraordinary size in the summer? Is it because the heaping up of the earth round them secures them from becoming corrupted by preventing the water from rotting them, and the nutriment, which the plant used to send into the shoot, enters into the radish, so that it must either itself increase in size or send [30] out lateral shoots and grow other roots, as do onions? For onions, if they are not pulled up each year but are left in the ground during the winter, become multiplied. Now onions are among the plants which send out shoots laterally; but the radish does not do so, and must therefore increase in bulk, because it absorbs all the [35] nutriment.
14 · Why is it that if one plants pumpkins or cucumbers near a well and, when they are ripe, lets them down into the well and covers them over, they remain green for a whole year? Is it because the vapour from the water cools them and prevents them from drying up and keeps them in good condition, and the covering of [924b1] them up fosters the breath which has formed in them? Their conservation is due to the fact that they still receive nutriment, because their roots are left undisturbed; for even if one removes the shoots, when they have borne fruit, and after cutting them away heaps earth round the roots and treads it down, the plant will produce early cucumbers, because the roots can survive; for the cucumber is not a biennial. [5] The plants themselves will bear fruit more quickly than seedlings, because the root, the most important part of their organism, is already present in their growth, whereas in seedlings the roots must grow first. Furthermore,4 the heaping of earth round the root engenders warmth, so that it is preserved and sends up a shoot more [10] quickly. So too if one sows cucumber seeds during the winter in small wicker baskets and waters them with hot water and carries them out into the sun and places them by the fire, very early cucumbers will be produced if one plants them out in the ground, as they are, in the baskets, when the proper season arrives.
15 · Why are plants watered at dawn or at night or in the evening? Is it in [15] order that the sun may not consume the water? Or is it because, when the water is warm it corrupts the plants which are watered with it?
16 · Why is it that sweet-smelling seeds and plants promote the flow of urine? Is it because they contain heat and are easily concocted, and such things have this effect? For the heat which is in them causes quick digestion, and their odour has no corporeal existence; for evil-smelling plants, such as garlic, owing to [20] their heat, promote the flow of urine, but their wasting effect is a more marked characteristic. But sweet-smelling seeds contain heat, because odour is entirely engendered by the presence of some heat; but evil-smelling things are unconcocted. Now anything which is to promote the flow of urine must be not only hot but also [25] easily concocted, so that it may accompany the liquids in their downward course and effect their digestion.
17 · Why is it that vegetables which are produced from older seed (for example two or three years old) produce more stalk than those grown from fresh seeds? Is it because, just as in animals that which is at its prime produces semen [30] most readily, so too very old seeds lose their vigour by evaporation, and those which are produced from fresh seeds are too weak because they still contain excrement which is alien to them, but those which are of moderate age are strongest, because the moisture has left them, and so they produce seed more readily? And the production of seed is the same process as the production of stalk, since the seed comes from the stalk.
[35] 18 · Why does rue grow best and most abundantly if it is grafted on to a fig-tree? Now it is grafted inside the bark and plastered with clay. Is it because the roots of the rue require heat and warmth (and this is why they are benefited by being surrounded with ashes), and the fig-tree contains heat? That this is so is [925a1] shown by the fact that its sap is the most pungent of all and by the amount of smoke which it produces when burnt. It therefore possesses the same kind of heat and moisture as ashes, so that if ashes benefit rue, it must necessarily flourish greatly when grafted on the fig-tree, since, whereas ashes give off no fluid, the flow of liquid [5] from the fig-tree is continuous, its moisture being never exhausted.
19 · Why do some plants always produce empty stalks? Are they among those plants which have to produce something other than stalk?
20 · Why is it that in Attica, while all other fruits are very sweet, thyme is [10] very bitter, yet thyme is a kind of fruit? . . .5 so that the plants which grow there do not contain much moisture? In plants, then, which are naturally sweet, owing to the moderate quantity of moisture which they contain, when the sun has absorbed the greater part of it the remainder is easily concocted; for it is difficult for a large amount, but easy for a moderate amount, to be ripened. Fruits, therefore, which are [15] naturally sweet become more so; but in those which are naturally dry and not sweet, the natural moisture fails, because it is scanty, and is very far from being sweet. For the sun absorbs the sweetest and lightest part of it; and these fruits have no superfluous moisture, as have other fruits.
21 · Why do pennyroyal and narcissi and onions bloom if hung up at the [20] time of the summer solstice? Is it because there is unconcocted nutriment in them, which6 in winter does not become concocted owing to the cold, but at the summer solstice owing to the season becomes concocted, and so the growth takes place? This growth, however, because there is no influx of moisture, quickly dies down; for if they have not some source of nutriment or influx of moisture, they dry up. A similar phenomenon occurs in Scythia, where, owing to the presence of abundant snow, the [25] corn remains a long time in the earth and then suddenly shoots up.
22 · Why does the onion alone make the eyes smart to such an excessive degree (hence it is said to derive its name because it makes one cover up the pupil), whereas marjoram and other pungent plants do not have this effect? For the nasturtium, though it is more stinging, does not cause tears to the same extent if [30] placed near the eyes, whereas the onion has this effect both when so placed and when eaten. Is it because many differences attach to each of the pungent plants, which give each its peculiar property? The nasturtium then, because it is hotter, is so dry that it prevails over the liquefaction which it causes; for it causes tears when [35] it is eaten, but it does not cause tears when placed near the eyes, because it does not give off any thin vapour, being too dry and hot to do so. But marjoram and such warm plants are dry, though only slightly so; and that which is to cause tears must [925b1] be stinging and moist and viscous. This is why olive oil causes tears, though its sting is weak; for it penetrates owing to its viscosity and tenuity and causes pain, and the pain causes melting. Now the onion has such properties that its moisture and the [5] vapour which it gives off are hot and tenuous and viscous; and so, when it is placed near the eye, it causes tears, because the vapour which it gives off is of such a character and carries with it a thin moisture; and, when it is eaten, the exhalation penetrates . . .7 Garlic, on the other hand, is hot and pungent and contains moisture, [10] but is not viscous; and so does not cause tears.
23 · Why is it that myrtle-berries which have been compressed in the hand seem to us sweeter than those which have not been so compressed? Is it for the same reason as makes dried grapes sweeter than fresh clusters and undried grapes? For [15] dried grapes are, it appears, flavoured by the must, which is naturally sweet (for they are even externally saturated by it), but the grapes which are still in the cluster are not so flavoured. So too myrtle-berries, which are naturally sweet and have their sweetness within, like grapes when they are compressed, become saturated by the [20] sweetness which is within them and are clearly sweeter externally.
24 · Why is it that, the smaller myrtle-berries are, the more they tend to have no stones, and the same is also true of dates and clusters of grapes, in which8 the small grapes have no stones at all or only smaller stones? Is it because, being less [25] perfect, they have less distinctly formed stones? For the purpose of the stone is to contain the seed. Now the berries are smaller, because they are mere offshoots and imperfect, and they are less sweet than those which have proper stones; for they are less concocted, and concoction is a process which produces perfection.
25 · Why is it that in some fruits the parts which are near the root are more [30] bitter (for example in the cucumber), but in others the parts towards the upper extremity (for example in acorns)? Is it because in the former the nutriment in that part is unconcocted, because there is a continual influx along the root; while the latter are naturally dry, and so, when the sweetness is drawn off from the extremity and has become concocted, they are henceforward dry and the bitterness is left [35] behind like salt? Now as anything becomes dry, it becomes more bitter, just as olives and acorns become bitter as they grow old.
[926a1] 26 · Why do some plants sprout when they are not in the earth, but either cut off or placed in store, lily-stalks, for example, and garlic and onions? Is it because they all have nutriment within themselves and not in some separate place?9 [5] [It is therefore their superabundance of nutriment which makes them sprout, as is clear from the fact that squills and purse-tassels do the same.]10 Now each of them grows not merely because it contains nutriment, but only when that nutriment is concocted and distributed; it therefore contains nutriment before, but it only grows when the season comes at which this process takes place owing to the concoction caused by the season, as happens also to crocodiles’ eggs. The growth, however, is [10] not continuous, because there is no influx of more nutriment.
27 · Why is it that garlic and onions grow better according as they are drier when planted, whilst other plants grow worse under such conditions? Is it because all plants of this kind are exceedingly full of moisture? If, then, they are planted in [15] this condition, they enjoy equable conditions. A further reason is that they are less likely to rot if they are dried before being planted.
28 · Why is it that garlic and onions alone among plants sprout when they are stored away? Is it because they are full of moisture and nutriment? It is abundance of nutriment, then, which makes them sprout, as is clear from the fact [20] that squills and purse-tassels do the same. But they grow only when the proper season for each of them comes.
29 · Why is it that plants which are watered with cold water are sweeter than those watered with warm water? Is it because the warm water when it becomes enclosed in the plant is saltier (just as that which is saltier is hotter, and that which is sweet is the opposite, that is, in a sense, cold)? Now the nutriment of vegetables is [25] liquid, and it is this which gives them their juices.
30 · Why is it that garlic has a stronger odour when it has run to stalk than when it is young? Is it because, when it is young, there is still a large quantity of alien moisture in it which deprives it of its strength? When, however, the plant has ripened, the alien moisture having been already excreted, it then has its own proper odour; and this is naturally pungent. Similarly, all other fruits when they are young [30] are more watery. This is the reason why young onions are less pungent.
31 · Why is it that, if myrtle-branches are not preserved, the berries rather than the leaves drop off, whereas, if they are preserved with seaweed, the leaves drop off but the berries do not? Is it what naturally happens if the branches are not [35] preserved, for the berries naturally drop off when they become ripe? This does not occur when the branches are stored away, but the moisture in the seaweed only prevents the moisture in the berries from undergoing change. The leaves, on the other hand, drop off as the branches become dry, and the seaweed, which is salty, [926b1] has a drying effect upon them. The leaves thus undergo different processes when they remain on the tree and when they are stored away.
32 · Why do melons grow best in marshy plains which are humid, for [5] example, round Orchomenus and in Egypt, which appears to be a well-watered country? Now marshy districts are full of water and melons themselves are somewhat moist; and this is why those grown in gardens are poor. Is it because they have to be planted deep owing to the hardness of the ground? For clayey, flat ground becomes very hard, and plants grow best which are deeply planted. Or is it [10] because the ground must be dry, because the plant itself is naturally moist? For thus being pulled in opposite directions it will attain the mean. Now ground which is somewhat marshy but deep contains nutriment owing to the depth of the soil and the locality, but not in an excessive quantity, because the ground dries up again. [15]
33 · Why is it that rue and certain unguents give the perspiration an evil odour? Is it because things which have a heavy and pungent odour, mixing with the excretory fluids, make the odour of these still more unpleasant?
34 · Why is rue said to be a remedy against the evil eye? Is it because men [20] think they are victims of the evil eye when they eat greedily or when they expect some enmity and are suspicious of the food set before them? For instance, when they take anything for themselves from the same course, they offer some one else a portion, adding the words, ‘so that you may not cast the evil eye upon me’. All therefore will take with alarm of what is offered them, whether liquid or solid, of [25] those foods, the constriction or vomiting forth of which causes the solids to be carried upwards and ejected or the flatulence from the liquid to give rise to pain and writhing. Rue, therefore, being eaten beforehand, since it is naturally warming, rarefies the organ which receives the food and the whole body, with the result that [30] passes out the flatulence enclosed within it.
35 · Why is it that marjoram, being thrown into the must, makes the wine sweet, and two cupfuls are thrown into a jar of wine? Is it because it takes away the elements which cause harshness by absorbing into itself by its dryness the watery [35] and sedimentary parts? That it is these which cause harshness is shown by the fact that wines are less soft if water is added or if they have been allowed to stand a long time on the lees. Also when they make sweet wine, they expose the grapes for a long time to the sun, which draws out the watery element and concocts the remainder. [927a1] Now marjoram produces the same result, for it is dry and hot, and so naturally has a lasting effect.
36 · Why do black myrtle-trees have thicker foliage than white? Is it because they are a wilder species? That they are so is proved by the fact that they [5] grow in the fields and undergo very little modification as a result of cultivation. Now wild plants invariably have denser foliage; for, because their fruit is less concocted, the nutriment is diverted into the foliage.
[10] 1 · Why is it that barley-gruel and wheaten-flour become whiter if oil is poured on to them, though oil is reddish in colour? Is it because oil naturally foams when it is mixed with liquid, and foaming causes whiteness? Now mixing is carried out by pounding and motion, and is most complete in the case of corporeal [15] substances. This process occurs in foods which are boiled, and so makes them whiter.
2 · Why is it that foods made from wheat suit our bodies best and are more nourishing than those made from barley? Is it because wheat contains a moderate [20] amount of stickiness, and food ought to have this quality, since it ought to cling and adhere to the body, and its stickiness causes it to do so? But barley1 is less cohesive, and so cakes in which the barley is well kneaded are more nourishing than those in which it is not kneaded.
3 · Why is it that of wheaten-flour that which is ground first is whiter, but of barley-meal that which is ground last? Is it because barley, being dry, breaks into [25] pieces, whereas wheat is soft and crushes? Now in both it is the inner part which is whitest.
4 · Why do loaves appear whiter when they are cold than when they are hot? Is it somehow for the same reason that stale oil is whiter than fresh? For the cause [30] of the blackness is the water which in both cases is present in larger quantities when they are fresh; but after a time, owing to evaporation, the water remaining near the surface becomes less. Now it is either the passage of time or the heat of the sun which causes evaporation from the oil; and from loaves the heat goes forth as they cool and has entirely departed when they are cold, whereas it is still present when they are warm.
5 · Why do loaves which contain no salt weigh heavier than those which are [35] salted, the other ingredients being exactly the same? The contrary would be expected, since salt is added, and salt is heavier than water. Is it because the salt causes drying to take place? This is why things which are preserved with salt remain uncorrupted; for the moisture in them is taken up and dried up by the salt, and it is the moisture in things that is corrupted by heat. So too in bread the moisture is [927b1] taken up by the salt and evaporates outside. Stale bread therefore is lighter than hot bread, since it is cooler. Now in loaves which do not contain salt this moisture is present in greater quantities and makes them heavier. [5]
6 · Why is it that loaves which have become cold, if they are moistened and placed in contact with one another, do not cohere, whereas hot loaves do so? Is it because the cold loaves give off with the vapour the sticky moisture which is in them, and, because this has gone forth, do not cohere (for the water with which they were wetted is too uncohesive); but the hot loaves contain a certain amount of [10] stickiness, and so, when they are moistened and the vapour comes forth, the heat, owing to its rarity, is given off, but the sticky matter, which comes out with it and mingles with the moisture, causes the loaves to adhere together?2
7 · Why is it that of wheaten-flour that which is ground first3 is whiter, but [15] of barley-meal that which is ground last? Is it because barley, being dry, breaks into pieces, and this happens most when it is ground for a very long time, but the flour which is inside the wheat is soft and fine and is crushed out at first? Now in both cases it is the inner part which is whitest. [20]
8 · Why is it that barley-cake becomes more indigestible the more it is kneaded, whereas wheaten-bread becomes easier to digest? Is it because dough becomes less by being much kneaded (and this is the nature of that which is sticky), but the moisture has been expelled from every part of the loaf by the fire, so that, when the moisture has been entirely expelled, the loaf becomes more uncohesive the [25] more it is kneaded, because in the kneading it is divided up into smaller particles? Now that which is uncohesive is more easily concocted. Barley-cake, on the other hand, the more it is kneaded becomes more sticky, as the liquid mingles in it; and that which is sticky is not easily divided up, and such foods are not easily concocted; [30] for that which is to be concocted must be split up into small parts.
9 · Why does barley-cake become less when it is kneaded, whereas dough becomes more? Is it because barley-meal when moistened and kneaded unites owing to the binding quality of the moisture, because it is of even texture and [35] granulated, but wheaten-flour rises, because it is very dense? For that which is dense grows hot when kneaded and, when it is hot and inflated, it rises, as does the flesh.
10 · But why does dough increase more when it is heated than barley-cake [928a1] does? Is it because dough contains moisture which is not separated in such a way that it can escape when warmed, owing to the kneading? When therefore it is warmed, breath is engendered, and more breath is necessarily engendered from a greater amount of moisture.
[5] 11 · Why is it that although honey is more adhesive than water, wheaten-flour is more uncohesive, when it is boiled or baked, if it is mixed with honey-water than with water? Is it because water becomes stiff and solid under the influence of the heat, whereas the honey becomes solid but also has a drying effect, and so makes [10] the food more uncohesive (for this quality is produced by dryness)?
12 · Why do twice-baked loaves, when they are cool, not become hard? Is it because wheat has in it a certain sweet and sticky juice, which is as it were its ‘soul’? This can be illustrated by the fact that when it is dried it becomes quite empty, but, [15] when it is wetted, it expands. This juice, therefore, being present also in wheaten-flour, especially in that of the purest quality, when the flour is made into dough and the dough is kneaded the same thing4 happens, as is proved by the fact that when it is boiled it becomes more digestible. When, therefore, the bread is baked for the first time, the thin and light part of the moisture5 is evaporated from the bread, and [20] the part of the flour which most resembles chaff is burnt out. But when the dough is taken out and kneaded again, the smoothest part of the flour and the stickiest part of the moisture being left mingle more with one another, owing to the fact that they have become smoother and stickier, and owing to the effect of the heat; for their [25] mixing resembles the process of dyeing, so that the dough, when subsequently kneaded, is like boiled flour. For when the dough is kneaded and the lightest flour and the stickiest moisture are left, the bread, when it has been exposed to the fire, becomes glutinous and does not dry up; for that which is sticky cannot be separated, [30] and that which is dense does not of itself give up any moisture. Twice-baked bread then undergoes this same process6 for the reasons mentioned above, and, always containing moisture, does not become hard.
13 · Why is it that we can go on partaking of some kinds both of solid and of [35] liquid food for a long period—for instance, food made from barley-meal and wheaten-flour and dry wines, and water—whereas we cannot partake continually of others, though they are pleasanter to the taste? Is it because some of the foods which we take tend to float on the stomach and are highly nutritious, so that when one has discharged them, though their first nutriment has been consumed, a considerable force still remains in the body, concocted for the first bodily process [928b1] but unconcocted for its final purpose and for the succeeding process? Now most of the pleasing foods belong to this class; for the fatty and sweet and rich foods seem pleasantest to our taste, and these, however they differ from one another, are all [5] foods which are nutritious, and not difficult of concoction, and apt to float on the stomach; their force is therefore lasting, if one takes one’s fill of them, and the perception of them does not quickly pass away;7 for the feeling of satiety does not only continue while they are in the stomach but also when their nutriment has been distributed to other parts of the body. Or is this not the only reason, and is there a [10] further reason, namely, that some foods are naturally suited and akin to us? For our bodies accept all such foods more readily because they are natural, while they accept less readily those which are unnatural. And different foods suit different temperaments; for example, honey is the natural food of bees, so that they take no [15] other, though they are physically weak; so that what they consume must be small in amount, but must be to their strength as what men eat is to theirs. And so any pleasing foods which are of this kind seem pleasing because they are present in small quantities in our nature, but they only appear so for a short time, and then soon cause a feeling of satiety. But we always need the natural foods, so that we feel [20] less satiety from foods continually taken other than those which are most pleasing in themselves.
14 · Why is it that the same things seem pleasant when we are becoming accustomed to them and not pleasant if we partake of them too continuously, though being accustomed to anything is doing it often and continuously? Is it [25] because custom engenders a receptive habit but does not bring satiety, whereas taking anything continuously fills up the desire, just as a vessel8 is filled; for desire is a kind of void?9 Now habits, when exercised, increase and grow, but vessels when they are filled full do not become any bigger. Hence custom, being an exercise, [30] increases the receptive habit; but that which is continuously taken fills up and satisfies the desire, and, when this is satisfied, we no longer receive any more, and nothing can increase the desire for the reasons already stated regarding the filling of vessels. Furthermore, custom is not pleasant through constantly giving pleasure (for such things too cause pain through continual practice), but because we enter upon [35] the beginning of the process with pleasure and can continue doing the same thing longer than if we were unaccustomed to it. In the same way then as custom, which is pleasant, causes pain, so too do all other pleasant things; for things which happen and foods which are taken continuously, both alike cause pain. The reason is that the powers of acceptance and action which we possess in ourselves are not unlimited [929a1] but limited, and when they have reached their full capacity (and this is continually visible to an increasing extent) the receptive powers are satisfied, and the powers for [5] action can no longer function.
15 · Why does dough become white when it is kneaded, while barley-cake becomes blacker? Is it because the surface of the barley-meal becomes drier, and it is the10 heat in the moisture which causes the whiteness? Or is it because, through exposure to the heat, the surface of barley-meal attracts the moisture, since it [10] consists of larger particles?
16 · Why does barley-meal adhere better together when mixed with water than with oil, though oil is more viscous? Yet that which is viscous is more binding, and oil is more viscous than water. Is it because water is thinner and so penetrates [15] into everything and makes the barley-meal soft, and the grains adhere together better and are compressed into one another, even though pressed together without any kneading?
17 · Why does bread which is either not kneaded or very much kneaded break up? Does the unkneaded bread do so because it is not sufficiently bound together? Now it is the kneading that binds the bread; so that unkneaded bread is [20] already on the way to breaking up. Further, it contains much moisture not properly mixed in. Bread which is very much kneaded is dry, because it has very little moisture; for when it is heated, the moisture all escapes. So that in both cases the bread breaks up because much moisture goes forth; for much moisture is actually present in the unkneaded bread, and in the over-kneaded bread much escapes11 compared to what remains behind.
[25] 18 · Why is the admixture of barley-meal and liquid lighter than the two things together when unmixed? Is it because, when they are mixed, air is enclosed in them? Or is it because part of the water is evaporated by the heat in the barley-meal, and so the mixture becomes smaller in bulk? The air, however, if it were also mixed in, would not make the mixture any lighter; for air enclosed in air [30] possesses weight.
19 · Why do milk and sweet wine appear sweeter if drunk with barley-meal? Do they appear sweeter in contrast with anything which is not sweet (for barley-meal is not sweet)? Or is it because the barley-meal continues to hold [35] sweetness, and so the perception of it is prolonged?
20 · Why does the same potion seem less strong if it is drunk with barley-meal? Is it because the barley unites what has one quality with what has another, or because the barley-meal interferes with the potion and destroys it, absorbing it into itself?
21 · Why does gruel take up more water than the wheat from which such [929b1] gruel is made? Is it because the gruel is a kind of flour, and flour takes up more water (for its bulk is greater than that of the wheat, for even the particles of the wheat are packed closely together)? Now that which is more holds more both for this reason12 and also because both flour and gruel contain heat, and heat both [5] attracts the moisture more and expends it by evaporation.
22 · Why does wheaten-flour increase much more in proportion than barley-meal when it is kneaded? Is it because flour admits a large quantity of water, but barley-meal only a little? (But why does it admit more, for barley-meal would [10] naturally be expected to do so, because it has been exposed to heat, whereas the flour has not, and that which has been exposed to heat is drier?) Or is it because flour admits of more kneading, the reason being that it is composed of smaller particles? As therefore it is potentially as it were more manifold by reason of the smallness of its parts, so much the more water does it take up. For it uses the water [15] as a glue—a metaphor employed by Empedocles in the Physics, when he says ‘gluing barley with water’—and it consumes much water for this reason.
23 · Why does dough increase more when it has been heated than barley-cake does? Is it because it contains moisture which is not separated in such a way that it can escape when it is warmed, and this13 moisture, becoming breath and not [20] being able to escape (as it can in the barley-cake) owing to the density of the dough (for that which is made up of smaller particles is dense), makes the dough, therefore, rise and causes the mass to be greater? Furthermore, the moisture which it contains is more considerable, and it is from this, when it is heated, that the breath is engendered; and from the greater amount of moisture more breath must necessarily be engendered. [25]
24 · Why is it that, of persons engaged in the preparation of cereals, those who handle barley become pale and are subject to catarrh, while those who handle wheat are healthy? Is it because wheat is more easily concocted than barley, and therefore its emanations are also more easily concocted?
25 · Why is it that bread, if one toasts it, becomes harder, whereas, if one [30] warms it, it becomes moister up to a certain point? Is it because, when it is toasted, the moisture goes out of it, and so it becomes harder, whereas, when it is warmed, the moisture having acquired consistency is liquefied again by the fire, and so the bread becomes moister?
26 · Why does flour, as it cools, become less closely packed, but barley-meal [35] more so? Is it because things which are made up of small particles contain no vacant spaces, and heavy things, by the pressure which they exert, take up the same space whether they are more or less14 numerically? Barley-meal then is soft; when it cools, therefore, it becomes less, so that the less is more compressed.15 But wheaten-flour [930a1] already consists of small particles, and so it does not cool because of this, but in such a way as to become lighter and not so as to become more closely packed by compression; for wheaten-flour is naturally heavier than barley-meal.
[5] 1 · Why is it that the volume of food necessary for repletion is not proportionate in the same persons if they eat fruit at the beginning and at the end of a meal? Is it because fruit is much heavier than solid food? This can be illustrated by the fact that figs, though eaten last, are vomited out last. If, therefore, they are [10] eaten first, owing to their weight they sink downwards and leave ample space above, so that one can easily contain the volume of solid food. If, however, the converse takes place, the solid food when it enters in, because it does not sink downwards, quickly occupies the vacant upper space.
2 · Why is it that, although sweet foods are more akin to us than pungent, we [15] are more quickly sated by the former? For the contrary might have been expected, since we might naturally be supposed to be less sated by foods which are akin to us. Is it because the organ whereby we receive replenishment and the body, which is nourished, are not sated equally quickly, but sometimes the stomach is full, in those, for instance, who are thirsty, but the thirst is not less? For we do not cease being thirsty because the stomach is full, but when each part of the body has drawn in its [20] own particular moisture; and we cease being thirsty only when they have received this in sufficiency. The same thing also occurs when we are hungry.
3 · Why are we more quickly sated by sweet than by pungent foods? Is it [25] because we cease desiring sweet things sooner? Or, while it is not generally admitted1 that we become satiated as the stomach is filled by sweet foods, yet might it not be said that our desire is more quickly sated by them? Or is it because desire is simply a lack, which occurs when we no longer have any nutriment in us or very [30] little? Pungent foods then are not nourishing, but contain little nutriment and a considerable amount of excrement. We therefore naturally seek to eat them in large quantities, and yet do not satiate our desire with them, because we still lack nutriment and they do not contain it. But all sweet foods are nutriment, and the [35] body derives a large amount of nutriment from a small quantity of them. When, therefore, it derives a large amount of nutriment, it can no longer eat, because it cannot tolerate more. We are therefore naturally more quickly satisfied by sweet foods.
4 · Why is it that fruits and meat and the like remain uncorrupted if placed in skins, when these are tightly inflated, as also do substances placed in closely [930b1] covered vessels? Is it because all things become corrupt through being in motion, and things which are full are without motion (for it is impossible for anything to be moved without there being a void), and these vessels are full?
5 · Why does wine seem bitter when drunk after the eating of rotten fruits? [5] Is it because such rottenness contains bitterness? That, then, which remains on the tongue, mingling with the draught and becoming diffused in it, makes the draught bitter. The fruit by itself, when eaten, seems less bitter, because juice of this kind takes effect at many different points and is divided up into small particles. [10]
6 · Why should dried fruits be eaten? Is it in order that we may drink sufficiently? For we ought not only to drink to satisfy the thirst which is engendered by solid food, but also when the solid food is finished.
7 · Why do roasted nuts deteriorate when they become cool, and also bread [15] and acorns and many such things, but improve when they are heated again? Is it because, when they become cold, the juice congeals, but when they are warmed up it becomes liquid again, and it is the juice which is pleasing?
8 · Why is it that, for the proper enjoyment of fruits such as figs and the like, [20] one ought to drink with them either unmixed wine or water, which are the opposites of one another? Is it because fruit is both hot and moist owing to the manner of its growth? For it contains much both of fire and of moisture; and so, owing to the fire, the juice causes as it were a boiling within, such as must makes on the surface (though the others, the hard-shelled fruit, also have this force, but in a less degree), [25] while the large quantity of moisture causes an unconcocted condition. Water then, owing to its coldness, extinguishes the boiling, as wine also usually does by its heat; for it takes away its power, just as one fire sometimes diminishes the force of another if the latter be less. And wine by its heat is better able to concoct the [30] moisture, and by its weight it prevails over the scum formed on the surface by the boiling.
9 · Why is it that those dried figs are sweetest which are cut in half and not those which are cut either many times or not at all? Is it because, if they are cut many times, most of the sweetness escapes and evaporates with the moisture, whereas in those which are entirely closed the watery element is considerable, [35] because it has not been turned into vapour? Those, however, which have been cut but not many times, do not suffer from either of these disadvantages.
10 · Why is it that figs when they are cooled in an oven are harder if they are [931a1] left to cool in the oven than if they are taken out to cool? Is it because in the oven all the moisture is evaporated by the heat, whereas outside the surrounding air cools the moisture and prevents it from escaping and the moisture retains its consistency [5] rather than evaporates?2 Now what is dry is hard, and what is moist is soft.
11 · Why is it that wine and water seem sweeter when taken with something sour, if, for instance, one munches acorns or myrtle-berries or something of the kind? Is not this natural and does it not happen in other things too? For everything seems to assert its identity more forcibly when compared with its contrary and here [10] the tastes of the contraries are in a way opposed. Or is it because, as in objects which are being dyed, the tongue has already been permeated by the sour matter and opens its pores, and so the sweetness can penetrate better? For objects which are being dyed are for this reason first of all moistened in sour liquid—because what is [15] permeated takes the dye better.
12 · Why do sweet things seem to be less sweet when they are hot than when they are cold? Is it because two sensations of the two qualities are present together, and so that of heat dispels the other? Or is it because that which is sweet3 is also hot, and it is therefore a case of ‘fire upon fire’, and thus the heat prevents the perception [20] of the sweetness? Or is it because fire takes away the power of everything, since it causes motion? Things, then, which are hot are nearer to change, but when they cool they become stable again.
13 · Why is it that chaff concocts hard fruits and does not corrupt those which are already concocted? Is it because chaff is both hot and absorbent? It, [25] therefore, by its heat causes concoction, while owing to its absorbent property it attracts the corrupted sap, which therefore does not cause corruption.
14 · Why do figs, which are soft and sweet, destroy the teeth? Do they, owing to their stickiness, penetrate into the gums, and, because they are soft, [30] insinuate themselves into the spaces between the teeth, and, being hot, quickly cause decay? Perhaps also, owing to the hardness of the seeds, the teeth are quickly caused to ache in the process of chewing them up.
1 · Why is it that the waves do not ripple in the deep open sea, but only where [35] it is confined and shallow? Is it because a small amount of liquid, as it is carried along, is more divided up by the wind than a large amount?
2 · Why do the waves sometimes begin to move before the winds reach them? Is it because the portion of the sea near the source of the wind being impelled along first has continually the same effect upon the adjoining part, and so, since the [931b1] sea is continuous, the same effect is caused in every part of it, as though from one continuous impetus? Now this occurs simultaneously, with the result that the first and the last parts of the sea are set in motion at the same time. This effect is not produced in the air, because it is not a single body (since many hindrances affect it [5] from all sides, which often cut short the first and most vigorous movement); the sea, however, suffers from no such impediments, because it is heavier and less easily disturbed than the air.
3 · Why do ships seem to be more heavily loaded in harbour than out at sea, and why do they travel more quickly from the open sea towards the land than from [10] the land towards the open sea? Is it because the greater quantity of water offers more resistance than1 the less, and the vessel sinks deeper into the latter, because it prevails more over it, for it pushes up the water from below? Now in a harbour the sea is shallow, but deep out at sea; so that a vessel will seem to carry a heavier load [15] in harbour and will move with greater difficulty, because it is sunk deeper into the water, which offers less resistance. But in the open sea the contrary happens.
4 · Why is it that if anything (for example an anchor) is thrown into the sea when it is rough, a calm ensues? Is it because the sea is stopped by the descending [20] object, with which a certain amount of air is carried down, and this air, carried in a direct course downwards and drawn thither, draws with it also the lateral force which is disturbing the sea? Now a wave does not move downwards from above but along the surface, and, when it ceases, a calm ensues. Furthermore, the sea, as it [25] closes in upon the space opened by the descending object, makes an eddy, and eddies move in a circle. Now since a straight line touches a circle at a point (and waves travel obliquely in a straight line), the result would be that the waves touch the circumference of the eddy only at a point, both for the reasons stated and because the eddy pushes the wave off as soon as it comes into contact with it. The place, [30] then, where the eddy is, being without waves, the result is that there is a calm where the surface is broken, because the air, which descended with the object thrown in, subsequently ascending and thrusting the sea upwards, causes it as it were to [35] bubble; for a bubble consists of moisture thrust up by air from below. Now every bubble is smooth and still. An indication that the above process takes place is given by the fact that the sea at the point where the object is thrown in rises a moment later to a higher level than the surrounding sea.
5 · Why is it that sometimes vessels which are journeying over the sea in fine [932a1] weather are swallowed up and disappear so completely that no wreckage even is washed up? Is it because, when a cavernous space breaks open in the earth beneath the sea, the ship at the same time follows the rush of air into the sea and into the cavern? And in like manner the sea, being carried everywhere round in a circle, is [5] borne downwards; and this constitutes a whirlpool. And ships in the Straits of Messina suffer the same fate owing to the flow of water, which causes eddies, and are swallowed up into the abyss, for the reasons stated above and also because the sea is deep and the land cavernous to a great distance. The eddies, therefore, overpower the ships and carry them thither, and so no wreckage is washed up. The [10] flow occurs when, the former wind having stopped, a contrary wind blows over the sea when it is running under the impulse of the former wind, and especially when the contrary wind is the south wind. For the currents flowing against one another try to thrust one another aside, as happens in rivers, and eddies are formed. And the [15] original movement, which is strong, is borne whirling round and round from above. Since then the currents cannot travel laterally (for they are mutually repelled), they must be thrust down into the depths, and so whatever is caught by the eddy must necessarily be carried down too. Hence they build ships with slanting ends; for cases [20] have been recorded before now in which a ship with straight ends has been swallowed up.
6 · Why is the water whiter in the Black Sea than in the Aegean? Is it owing to the refraction of the vision from the sea into the air? For in the region of the [25] Black Sea the air is thick and white, so that the surface of the sea appears to be similar, whereas in the Aegean it is blue, because it is clear to a great distance, and so the sea too reflecting the air appears to be similar. Or is it because all lakes are whiter than the sea, and the Black Sea has the character of a lake because many [30] rivers flow into it? Now lakes are whiter than the sea, and than rivers; at any rate, painters picture rivers as pale yellow and the sea as blue. Or is it because the sight cannot penetrate quickly through fresh water and is refracted into the air,2 but is not refracted upwards from the sea, because the water is not smooth, but the sight [35] tires of trying to penetrate into the depths, and so the sea appears black? But in seas of a lake-like character, since the fresh water is on the surface and the salt water below, the sight does not penetrate, but is refracted towards the daylight; and so the surface of the sea appears white.
7 · Why is the sea less cold than fresh water, and salt water in general than [932b1] sweet? Is it because the sea is denser and has more body? Now such things are less susceptible to cold, just as they are more easily heated; for owing to their density they are better able to retain heat. Or is it because the sea is of a more fatty composition and so does not extinguish fire? (And similarly in other cases.) And the [5] more fatty anything is the hotter it is. Or is it because it contains much earth and is therefore drier, and the drier a thing is the hotter it is?
8 · Why is the sea more transparent than fresh water, although it is thicker? For fresh water is rarer than salt. Or is the cause not its rarity but the fact that in it there are direct interstices which are very numerous and wide? Fresh water, [10] therefore, has density owing to the small particles of which it is composed, whereas salt water contains great voids. Or is it because the sea is purer? For there is no earth in it, but the sand, which is heavy, is precipitated; but fresh water is earthy, and the earth floating in its midst is easily stirred into mud. [15]
9 · Why is the sea more transparent when the wind is in the north than when it is in the south? Is it because the sea has colour when it is calm? For there is something fatty in the juice of salt water, as is shown by the fact that in hot weather an oily substance is excreted from the sea. When, therefore, the sea is calm and [20] warmer, juice of this kind forms on the surface of the sea owing to its lightness. This is less likely to happen when the wind is in the north, owing to the cold. Now water is more transparent than oil; for oil has colour, but water, presenting itself without colour to the vision, gives a clearer image.
10 · Why does one dry more quickly after washing in the sea, although sea [25] water is heavier than fresh? Is it because the sea is thicker and earthy? Since, therefore, it has little moisture in it, it dries more quickly.
11 · Why are the waves windy? Is it because they are a sign of wind in the future? For wind is a massing together of air, which3 occurs because the air is [30] continually thrust forward. But the wind begins to thrust the air forward when it is not yet blowing continuously but only just beginning. The first breath of wind then as it were dies down before having any effect, but it thrusts forward another breath and drives on another mass of air and then dies away. It is clear therefore, when the wave which is thrust forward is already present, that that which sets it in motion [35] will also come; for it causes this effect when it first begins to blow.
12 · Why do the waves break forth before the wind? Is it because the wind does not cease to blow4 and the sea to be rough at the same time, but the sea ceases later? For5 it is possible that the wind which set the wave in motion perishes before [933a1] it becomes perceptible; and so the wave is not prior to the wind, but the former is noticeable, while the latter is not. Or do the winds not blow everywhere at the same time, but at first only in the quarter from which they arise? Now as soon as they begin to blow, they set in motion the sea which is near them, and this sets in motion [5] the adjoining sea; and thus it would be possible for the wave to break forth before the wind reaches it. For the movement is due to the sea and not to wind, being a movement of the sea which travels more quickly than that of the air.6
13 · Why is it easier to swim in the sea than in a river? Is it because the [10] swimmer always leans on the water as he swims, and we receive more support from that which is of a more corporeal nature, and sea water is more corporeal than river water, for it is thicker and able to offer more resistance to pressure?
14 · Why can one remain longer in the sea than in a river? Is it because river [15] water is rare and therefore penetrates more into the body and chokes one?
15 · Why is the sea combustible, while water is not? Or does water also burn, while the reason why the sea has less power to extinguish fire is because it is of a more fatty composition? (And that it is so indicated by the fact that an oil is given [20] off from sea water.) Or are the interstices less able to adapt themselves to fire because they are too wide, and all the more so owing to the presence also of salt? As, therefore, that which is dry has less power to quench than that which is moist, so that which is drier is proportionately more capable of being burnt, one thing being [25] more so than another, since the drier a thing is the more closely allied is it to heat;7 and the sea possesses both these qualities to a greater extent.
16 · Why is it that the wind blows cold in early morning from rivers, but not from the sea? Is it because the sea extends over open spaces, but rivers are in narrow [30] places? The breeze, therefore, from the sea is dispersed over a wide area and is consequently weak; whereas the breeze from a river is carried along in a mass and is stronger and therefore naturally seems colder. Or is the reason other than this, [35] namely, that the rivers are cold, but the sea is neither hot nor cold? Now a breeze or an exhalation is due to the heating or cooling of liquids; for whichever of these two processes they undergo, evaporation takes place, and, when water evaporates, the resultant air is set in motion, and this is a breeze. That which is produced from cold liquids naturally blows cold, while that which blows from very hot liquids cools and becomes cold. One would, therefore, find that all the rivers are cold, but that the sea [933b1] is neither very hot nor very cold. That which blows from it, therefore, is not cold, because it is not itself cold, nor does it cool quickly, because it is not very hot.
[5] 17 · Why do waves calm down more slowly in the wider open sea than in shallow waters? Is it because everything calms down more slowly after much motion than after little? Now in the wide open sea the ebb and flow is greater than in shallow waters; there is, therefore, nothing strange if that which is greater is more slow in calming down. [10]
18 · Why is it that salt water when it is cold is not fresh, but becomes more fresh when it is heated, and when it is heated and then cooled? Is it because a thing naturally changes from one opposite into the other? Now fresh water is the opposite of salt water; and, when salt water is heated, the salt is boiled out, and, when it [15] cools, is precipitated.
19 · Why is it that waters near the sea are usually sweet and not salty? Is it because water which is strained becomes more fresh, and the nearer water is to the sea the more it is strained? [20]
20 · Why does salt water not flow readily? Is it because that which is heavy is stationary, and salt water is heavy? Hence only warm salt waters flow readily, for they have lightness in them which prevails over the heaviness which is in their saltness; for that which is hot is lighter. Furthermore, water which flows readily is [25] strained through the earth; and if water is strained, the thickest and heaviest part of it is always carried to the bottom, while the light and clean element becomes separated. For salt water is heavy and sweet water is light. And so flowing water is sweet. It is for the same reason that salt water, when it is set in motion and [30] undergoes change, becomes sweeter; for it becomes lighter and weaker owing to the motion.
21 · Why is it that in Libya, if one digs a hole near the sea, the water that first comes is fresh, but afterwards quickly becomes salty, but this happens less elsewhere? Is it because the water which comes first is the water which was already [35] there and has been concocted by the earth, but after a time the sea also is strained through and, because it is new, makes the water more salty? Elsewhere, however, there is either no water or abundant water, because the ground is not dried up.
22 · Why does salt water melt salt more quickly than fresh water? Is it [934a1] because the process of melting anything is its dissolution by moisture or heat penetrating into it so that it becomes liquid? Now those things do not cause melting which either cannot penetrate at all or penetrate in such a way as not to touch the substance. Those things which pass through easily scarcely cause any melting, but [5] those which enter in with violence dissolve substances very quickly. Now those liquids which are composed of very large particles do not penetrate, for they are too large for the pores; while those which are composed of small particles pass through without touching. Now fresh water is rare, while salt water is thicker; and so the former, passing through easily owing to its rarity, scarcely causes any melting, [10] whereas the latter penetrates, but percolates through8 to a less extent, because it is composed of larger particles, and forces its way in more quickly.