Aristotle · a new plain-English translation from the original language
1| Book Theta. Problems Concerning Bruises, Scars, and Weals Why do freshly-flayed skins, applied to the body, and especially those of rams, and eggs cracked over the spot, prevent bruises? Is it because both of these prevent the gathering of fluid and its rising up? For a bruised area draws fluid to it and swells because of the heat; so the eggs, through their stickiness, glue it down and prevent it from swelling, in the way that heat-applications do, and like glue; and the skins too stick fast both through their stickiness, and at the same time, through their warmth, they concoct the swelling and stop the inflammation — for indeed people do not remove them for some days. Those who rub the spot with salt and vinegar also want to draw the inflammation out. Why are scars black on the rest of the body, but white in the eye? Is it because a scar takes on a color opposite to the color that was there before, as does everything that has been diseased? And the sores in the eye occur in the black part. Indeed, even on the body scars are not black right away, but white to begin with, nor are they always black in the eye either, but they settle back over time, either completely or more toward the original color. Why does the fennel-rod make the area around the blow red, but the middle of it white? Is it because it squeezes the blood out of the middle, where it strikes most, being round? But then for this very reason the blood ought to flow back again; rather, the redness is a gathering-together of blood, and the gathering runs toward the place that was struck.
2| Why, when someone is struck hard with a fennel-rod, does the middle of the flesh turn white and the area around it red, whereas with a piece of wood the middle turns redder? Is it because the fennel-rod, on account of its lightness, if it strikes hard, scatters the blood that is near the surface, so that where the blood has departed the flesh looks white, and where more blood has arrived it looks redder? And once the blow has caused swelling, the scattered blood does not quickly settle back, because there is little of it and because its movement runs uphill, as it were — for, being forced by the quantity, it must be carried along a course contrary to its nature. But blows from hard objects, because of their weight and force, produce both compression and bruising. What is compressed becomes hollow, what is bruised becomes porous; for a bruise is a kind of soft cutting and dividing. And once the middle has become hollow and porous, blood is carried into it from the surrounding surface areas; for blood naturally travels downward, and into porous places, since these yield to it. And once the blood has gathered there, as is reasonable, it reddens that spot, while the areas it has left behind, it whitens.
3| Why are the scars of people with diseased spleens black? Is it because they have corrupted blood, on account of the mixture of diseased and watery blood coming from the spleen? Now a scar has thin and superficial skin; and the blood, being watery and warm even though black, produces this kind of scar by showing through it; and indeed, in such people, the scar generally turns out blacker. And this comes about through the same cause: for through the weakness of the skin the blood is chilled, and as the heat evaporates out of it, it becomes blacker. In the same way, in old people too, both the complexion becomes blacker, and scars from birth become blacker than in the young; for their whole body is, so to speak, one great bruise, not because of the thinness of the skin, but because the heat has left them. Do all things that are causes of the same effect have the same power to produce it, or not? I mean, for instance, since bruises are drawn out both by bronze and by radish and by broad-bean chewed up and by lung-tissue and by clay and by certain other things, do they act by the same power, or does bronze act because it produces verdigris, and verdigris is medicinal, while the bean and the lung and the clay act by drawing the matter to themselves on account of their porousness, and other things act through other causes? Or is the ultimate effect the same in all such cases (for many opposite things too produce a single effect, just as both heat and cold do), while nothing prevents the causes prior to that ultimate effect from being different in each case?
4| Why do other scars turn out black, but those in the eye white? Is it because scars change, wherever they occur, toward the opposite of the surrounding colors, and since they occur in the black part of the eye, they must necessarily turn out white? Why is the blow of a fennel-rod more painful than that of some harder objects, if one considers the matter in proportion when striking? For it stands to reason that the blow of the harder object should be more painful, since it strikes harder. Is it rather because the flesh feels pain not only when it is struck, but also when it strikes? Now by hard objects the flesh is only struck (for it yields on account of their hardness), but from the fennel-rod both things happen to it: it is struck, and, because of the lightness of its weight, it also strikes back without yielding, so that the blow becomes, in effect, double.
5| Why do thapsia-resin and the bronze cup stop bruises, one at the start and the other later, though they are opposite in nature? For the cup is cold, just as the poet too says, "he took the cold bronze in his teeth," while thapsia is hot and burning. Is it that the cup acts like cold water on people who are fainting? For the coldness meeting the blood prevents the heat from going out of the blood that has run together at the surface because of the blow, and prevents it from congealing once the heat has gone out. For just as blood congeals when it is exposed outside, so too the blood near the surface, when it is under the skin, since its heat is prevented from passing through by the coldness of the bronze, does 〈not〉 congeal, but instead disperses again and returns to the place from which it had run together. Thapsia, being hot, produces the same effect: for, being hot, it prevents the blood from congealing. Why do bruises disperse when bronze objects, such as cups and the like, are applied to them? Is it because bronze is cold? So it prevents the heat from going out of the blood that has gathered from the blow, and it is when that heat goes out from the surface that a bruise forms. That is why one must apply it quickly, before the blood congeals. And thapsia mixed with honey helps for the same reason: being hot, it prevents the blood from being chilled.