by Aristotle
20 · Why is it that we see other things better with both eyes, but we can judge of the straightness of lines of writing better with one eye, putting it close to the letters? Do both eyes falling on the same point cause confusion, as the writers on [959b1] optics say, whereas, when we look with one eye, straightness is more apparent to the straight vision, just as it is when a measuring rod is used?
21 · Why does smoke make the eyes smart more than any other part of the [5] body? Is it because they alone are very weak, since the inner parts of the body are always the weakest? (This is shown by the fact that vinegar and anything pungent causes not the outer but the inner flesh to smart, because the latter is the rarest flesh in the body and contains most pores.) For the vision finds its exit through certain pores, and so what causes most stinging within is drawn away from the outer flesh. [10] The onion too has a similar effect and anything else which causes the eye to smart, and of liquids olive-oil more than any other, because it is composed of very small particles and so sinks in through the pores. Vinegar is used as a medicament for the rest of the flesh.
22 · Why is it that the eye, although it is very weak, is the only part of the [15] body which does not feel the cold? Is it because the eye is of a fatty consistency and does not partake of the nature of flesh, and such substances are unaffected by the cold? For if the eye is really a fire, this is not the reason why it does not feel cold, for its fire is not at any rate of such a character as to engender heat.
23 · Why are tears warm when we let them fall in weeping, but cold when [20] we shed them owing to an affection of the eyes? Is it because that which is unconcocted is cold, while that which is concocted is hot? Now every malady certainly proceeds from lack of concoction, and the tears of those whose eyes are affected are unconcocted and therefore cold. It is for this reason that physicians [25] regard cold sweating as a sign of serious illness, while on the contrary they consider that hot sweating tends to get rid of disease. For if the excretion is abundant, the internal heat cannot concoct it, so that it must necessarily be cold; but when it is scanty, the internal heat prevails over it. Now all diseases are caused by excretions. [30]
24 · Why is it that, though the parts of the body on the right side are more easily moved, the left eye can be closed more easily than the right? Is it because the parts of the body on the left always contain more moisture, and things that are moist [35] naturally close up more easily?6
25 · Why is it that though both a short-sighted and an old man are affected by weakness of the eyes, the former places an object, if he wishes to see it, near the eye, while the latter holds it at a distance? Is it because they are afflicted with different forms of weakness? For the old man cannot see the object; he therefore [960a1] removes the object at which he is looking to the point at which the vision of his two eyes meets, expecting them to be able to see it best in this position; and this point is at a distance. The short-sighted man, on the other hand, can see the object but cannot proceed to distinguish which parts of the thing at which he is looking are [5] concave and which convex, but he is deceived on these points. Now concavity and convexity are distinguished by means of the light which they reflect; so at a distance the short-sighted man cannot discern how the light7 falls on the object seen; but near at hand the incidence of light can be more easily perceived.
26 · Why is man alone, or at any rate more than the other animals, liable to [10] squinting? Is it because he alone, or more than the other animals, suffers from epilepsy in his youth, at which time squinting always begins?
27 · Why are men alone among the animals liable to squinting? Is it because they have the smallest distance between their eyes and their eyes are in a straight [15] line, so that any distortion is very obvious? Or is it because the eyes of the other animals tend to be of one colour only, and if the eyes were of uniform colour there could be no squinting? Or is it because man alone in the animal world is liable to epilepsy, and epilepsy, whenever it occurs, causes squinting as in the other parts of the body? Squinting, however, sometimes occurs quite late in life, namely, in those [20] to whom the illness comes late.
28 · Why is it that we can see better against the light of a lamp or the sun, if we place the hand in front of the light? Is it because the light of the sun or of the lamp falling on our vision makes it weaker by its excess of brightness, since by this [25] excess it destroys those very things which are akin to it? But if the light is shaded by the hand, it does not hurt the sight, and the object seen is equally in the light; so the sight sees8 better and the object seen is just as visible.
29 · Why is there a difference between the left and the right hand and foot, [30] while this is not so with the eyes and ears? Is it because the elements, when they are pure, show no variation, but variations occur where the elements are compounded? Now these senses consist of pure elements—the sight of fire and the hearing of air.
BOOK XXXII
PROBLEMS CONNECTED WITH THE EARS
[35] 1 · Why is it that, though the ears are the most bloodless part of the face, they are most affected by blushing in those who feel shame? Is it because extraneous moisture naturally makes its way most easily into a void, and so, when the moisture is dissolved by the heat engendered in those who feel shame, it collects [960b1] in the ears? Or is it because the ears are near the temples, where the moisture most collects? Now under the emotion of shame the moisture flows into the face and causes blushing. But the ears have less depth than any other part of the face and are naturally very warm and fresh coloured, unless they have been long numbed by the cold; they are then the most fresh coloured of all the parts of the face, and so the [5] heat, when it is dispersed, being nearest the surface in the ears, makes them red.
2 · Why is it that the ear-drums of divers burst in the sea? Is it because the ear, as it fills with water, is subject to violent pressure, because it retains the breath? Surely, if this is the reason, the same thing ought to happen in the air. Or is it [10] because a thing breaks more easily if it does not yield, and more readily under pressure from what is hard than from what is soft? Now that which is inflated is less yielding, and the ears, as has been said, are inflated because the breath is retained in them; and so the water, which is harder than the air, when it presses upon them bursts them.
3 · Why do divers tie sponges round their ears? Is it in order that the sea may [15] not rush violently in and burst the ear-drums? For thus the ears do not become full, as they do when the sponges are removed.
4 · Why is the wax in the ears bitter? Is it because sweat is corrupt? It is, therefore, a salty, corrupt substance; and that which is corrupt and salty is bitter. [20]
5 · Why do sponge-divers slit their ears and nostrils? Is it in order that the breath may pass more freely? For it is by this way that the breath seems to pass out;1 for it is said that they suffer more from difficulty of breathing by being unable to expel the breath, and they are relieved when they can as it were vomit the breath [25] forth. It is strange, then, that they cannot achieve respiration for the sake of its cooling effect; this appears to be a greater necessity. Is it not quite natural that the strain should be greater when the breath is held, since then they are swollen and distended? But there appears to be a spontaneous passage of the breath outwards; and we must next consider whether breathing inwards is so also. Apparently it is; [30] for they enable the divers to respire equally well by letting down a cauldron; for this does not fill with water, but retains the air, for it is forced down straight into the water; since, if it inclines at all from an upright position, the water flows in.
6 · Why do some people cough when they scrape their ears? Is it because the [35] hearing is connected with the same duct as the lungs and the wind-pipe? This is shown by the fact that, if these parts are filled up, a man becomes deaf. When, therefore, heat is set up by friction, moisture is caused by melting and flows downwards from the duct2 into the wind-pipe and causes coughing.
7 · Why is it that, if a hole is pierced in the left
ear, it generally closes up [961a1] more quickly than in the right ear? It is for this reason that women call the right ear the ‘male’ and the left the ‘female’. Is it because the left parts of the body are moister and hotter, and such things close up very quickly? This is why green plants [5] grow together again; and why wounds close up more readily in the young than in the old. This is a sign that the parts on the left side of the body are moister and, generally speaking, partake rather of feminine characteristics.
8 · Why is it that in those who feel shame the extremities of the ears turn red, but in those who are angry it is the eyes that do so? Is it because shame is a cooling [10] in the eyes accompanied by fear, so that the heat naturally leaves the eyes? So, when it withdraws thence, it travels to the region best adapted to receive it, and this is the extremity of the ears; for the region of the face is otherwise bony. In those who are angry the heat travels in the other direction and makes itself most manifest in [15] the eyes owing to their white colour.
9 · Why is it that buzzing in the ears ceases if one makes a sound? Is it because the greater sound drives out the less?
10 · Why is it that, if water has flowed into the ear, one pours olive oil in, though the moisture in the ear cannot pass out through another liquid? Is it because [20] the oil floats on the surface of the water and, owing to the adhesive nature of the oil, the water clings to it when it comes out, the object being to make the water come out with the oil? Or is it in order that the ear may be lubricated and the water therefore come out? For oil being smooth acts as a lubricant.
11 · Why is it that the ear-drums of divers are less liable to burst if they pour [25] olive-oil beforehand into them? Does the reason for their bursting already mentioned still hold good, but the oil poured into the ears cause the sea-water, which subsequently enters the ear, to glide smoothly over its surface, just as happens on the exterior parts of the bodies of those who anoint themselves? The sea-water gliding smoothly along does not make a violent impact upon the inside of [30] the ear, and so does not break the drum.
12 · Why is it that, although the ears are the most bloodless part of the face, they turn red in those who feel shame? Is everything carried to that part which is most devoid of it? Now in a man who feels shame the blood seems to be carried upwards in a heated condition; it therefore passes into the part which is most devoid of it and causes it to become red. The same thing happens also in the cheeks. A [35] further reason is that the skin of the ears, which is tightly stretched, is very thin and therefore very transparent.
13 · Why is it that no one scrapes out his ears while yawning? Is it because, when one yawns, the drum of the ear, by means of which he hears, is inflated? That this is so is shown by the fact that one hears least well while yawning; for the breath, as happens also in the mouth, finds its way into the interior of the ears and thrusts the membrane outwards and prevents the sound from entering. If, therefore, one [961b1] touches the seat of hearing when in this condition in such a way as to scrape it, one might cause considerable damage to it; for the impact would be against a resisting and unyielding surface inflated by the breath, and it is obvious that the skin and the membrane are far from being solid; and so great pain is caused and a wound might [5] result.
BOOK XXXIII
PROBLEMS CONCERNING THE NOSE
1 · Why is it that sneezing stops hiccuping but does not stop belching? Is it because they are not affections of the same region, but belching is a cooling and lack [10] of concoction in the stomach, while hiccuping is a similar affection of breath and moisture in the region of the lungs? Now the regions about the head (the ears,1 for example) are closely connected with the lungs. This is proved by the facts that deafness and dumbness are found together, and that the diseases of the ears become diverted into affections of the lungs; also in some persons coughing results when the [15] ears are scratched. That there is a connection between the region of the nose, in which the sneeze takes place, and the lungs is shown by the fact that both share in respiration; and so, while the nose sneezes when that region becomes hot, the lower region, where hiccuping takes place, also sneezes in sympathy. Now heat causes concoction; hence vinegar stops hiccups, as also does holding the breath if the [20] hiccup is only slight, for it heats the breath which is constricted. So too in sneezing the counter-constriction of the breath has this effect and exhalation takes place properly and from the upper region; for it is impossible to sneeze without exhaling. The impetus then dispels the enclosed breath which is the cause of the hiccup. [25]
2 · Why is it that if, when one is about to sneeze, one rubs the eye, one sneezes less? Is it because what causes the sneeze is a kind of heat, and friction produces heat, which, owing to the close proximity to the eyes of the region in which [30] the sneeze occurs, destroys the other heat, just as the lesser fire fades away before the greater?
3 · Why is it that one generally sneezes twice, and not once or many times? Is it because there are two nostrils? The channel, therefore, through which the breath passes is divided between the two. [35]
4 · Why is it that one sneezes more after one has looked at the sun? Is it because the sun engenders heat and so causes movement, just as does tickling the nose with a feather? For both have the same effect; by setting up movement they cause heat and create breath more quickly from the moisture; and it is the escape of this breath which causes sneezing.
[962a1] 5 · Why do sneezing and holding the breath and vinegar stop hiccups? Does sneezing, since it is a displacement of the lower breath, act in the same sort of way as medicines which, though applied in the upper part of the body, affect the lower part of the stomach? Holding the breath stops weak hiccups, because the slight [5] impetus of the breath which comes forth represses and stifles and completely dispels the hiccup, just as happens in coughing, which2 ceases if you hold it back. Vinegar stops hiccuping because by its heat it vaporizes the surrounding moisture, which prevents belching; for belching takes place when the moisture in the upper part of [10] the stomach is vaporized and concocted, whereas hiccuping occurs when by the action of moisture breath is retained in an excessive quantity in the region of the lungs; for this, gaining impetus and being unable to break through, causes a spasm, and this spasm is called a hiccup. Hence hiccuping seizes those who are cold, because the cold causes the moisture to acquire consistency3 from the breath, and [15] the rest of the breath, being still enclosed, gives a leap, and its movement is hiccuping.
6 · Why do we sometimes pour cold water over a person’s face when his nose is bleeding? Is it because the heat is thus driven inwards? If, therefore, the blood is [20] near the surface, it tends to liquefy it.
7 · Why do we regard sneezing as divine, but not coughing or running at the nose? Is it because it comes from the most divine part of us, namely, the head, which is the seat of reasoning? Or is it because the other affections are the results of disease, but sneezing is not?
[25] 8 · Why does rubbing the eye stop sneezing? Is it because by this means evaporation is given to the moisture? For the eye sheds tears after friction, and sneezing is due to an abundance of moisture. Or is it because the lesser heat is destroyed by the greater? Now the eye when rubbed acquires more heat than is [30] contained in the nose; and for this reason, even if we rub the nose itself, the sneezing stops.
9 · Why is it that the emission of other kinds of breath, e.g. farting and belching, are not regarded as sacred, but that of a sneeze is so regarded? Is it because of the three regions of the body—the head, the thorax, and the lower [35] stomach—the head is the most divine? Now farting is breath from the lower stomach and belching is from the upper stomach, but sneezing is from the head; because, therefore, this region is most sacred, the breath also from it is revered as sacred. Or is it because all discharges of breath show that the above-mentioned parts are in a better state generally (for without any discharge of excrement the breath in its passage out lightens the body), and so too sneezing shows that the [962b1] region of the head is in a healthy
condition and capable of concoction? For when the heat in the head overcomes the moisture, the breath turns into a sneeze. This is why men test the dying by applying something which will cause sneezing, with the idea that, if this does not affect them, their case is indeed desperate. Thus sneezing is [5] revered as sacred as being a sign of health in the best and most sacred region of the body, and is regarded as a good omen.
10 · Why does man sneeze most of all animals? Is it because in him the ducts are wide through which the breath and scent4 pass in? For it is with these when they are full of breath that he sneezes. That these ducts are wide is shown by [10] the fact that man has a weaker sense of smell than any other animal, and those who have narrow ducts have a keener sense of smell. If, therefore, the moisture, the evaporation of which causes sneezing, enters in larger quantities and more often into wide ducts, and man more than any other animal has such ducts, he might naturally be expected to sneeze more often. Or is it because5 his nostrils are [15] particularly short, and so the heated moisture can quickly become breath and be expelled, whereas in other animals owing to the length of their nostrils it cools before it can evaporate?