Aristotle · a new plain-English translation from the original language
1| 34. PROBLEMS CONCERNING THE MOUTH AND WHAT IS IN IT Why are those who have sparsely-set teeth not long-lived? Is it because long-lived creatures have more teeth, as for instance males have more than females — men more than women, rams more than ewes? Those with sparse teeth, then, seem to be, as it were, in the position of having fewer teeth. Why do the teeth, though stronger than flesh, nonetheless feel cold more? Is it because they are attached to passages in which the small amount of heat present, being quickly overpowered by the cold, produces the pain? Why do the teeth feel cold more than heat, while flesh is the opposite? Is it because flesh belongs to the middle range and is well-tempered, while the teeth are cold, so that they are more sensitive to their opposite? Or is it because they consist of fine passages, in which the heat present is small, so that they are quickly affected by their opposite; whereas flesh is warm, so that it is not affected at all by cold, but quickly perceives heat — for it is as though fire were coming upon fire?
2| Why is the tongue a sign of many things? For it shows fevers in acute diseases, and whether hailstone-like nodules are present in the body; and the tongues of dappled sheep are themselves dappled. Is it because the tongue is receptive of moisture, and lies close upon the lung, which is the source of fevers? Everything becomes many-colored on account of the many-colored character of the fluids; and a thing is dyed first by that through which it is first filtered; and the tongue is such a thing. And the hailstone-like nodules collect there because it is spongy; for a nodule of this kind is like an undigested pimple within the body. Why does the tongue never taste itself as sweet, but as bitter and salty and sour? Is it because these tastes are forms of corruption, and the tongue does not perceive its own natural state? Why does the tongue have as many colors as the skin has? Is it because the tongue is simply one part like any other external part of the body, only it happens to be enclosed within? And because the skin is thin there, even a slight variegation shows through. Or is it because water is what makes colors change, and the tongue is affected more than anything else by what one drinks?
3| Why do people breathe out from the mouth both hot and cold air? For when they blow, the breath is cold, but when they pant with open mouth, it is hot. A sign that the breath is in fact heated is this: if one brings one's hand close to the mouth in either case, the air, once set in motion, feels cold; but the one who blows sets the air in motion not all at once, but through the narrow opening of the mouth; so by exhaling only a little, he sets a great quantity of the outside air in motion, and within that quantity the heat coming from his mouth does not show, because it is so small a part of it. But the one who pants exhales all at once; that is why it feels hot. For panting differs from blowing in its concentration; panting is an exhalation done all at once. Why, if people exhale forcefully and all at once, are they unable to exhale again right away? The same holds for inhaling too; for they cannot do either one twice in succession. Is it because the one is a kind of expulsion and the other a contraction of a space, and each of these can only go on so far? It is clear, then, that the two must occur alternately, and that it is impossible to do either one twice in a row. Why, given that the passage by which food and drink go through is different from the one by which we breathe, do we choke if we swallow too large a mouthful? There is nothing strange in this; for we choke all the more not only if something falls into this passage, but even if it is simply blocked. These two passages run alongside one another, the one by which we take in food and the one by which we breathe. So when a larger mouthful falls in, it also blocks the breathing passage, so that there is no way out for the breath.
4| Why are those whose crease runs all the way across the palm of the hand the longest-lived? Is it because unjointed things are short-lived and weak? A sign of the weakness is found in the young, and a sign of the short life is found in creatures full of moisture. It is clear, then, that jointed things are the opposite. And such creatures are those in which even the parts that are by nature unjointed are, as far as possible, jointed. And of the hand, the inner surface is the least jointed part of all. Why, in prolonged breathing, does the belly collapse when one draws the breath in, and fill out when one breathes out? It would seem plausible for the opposite to happen. Is it because, in those who are breathing in, the belly, being pressed down by the ribs, appears to bulge outward, the way a bellows does? Why do we breathe? Is it because, just as moisture is dissolved into breath, so too breath is dissolved into fire? So when the natural heat turns a large quantity of the breath into fire, it produces pain, and also swelling in the passages of the body; and this is why we drive the fire out; and as the passages collapse and are chilled, pains arise again; so we draw the breath in once more. Then, once we have opened the passages of the body and given them relief, the fire arises again, and again, in pain, we send it out, and we go on doing this continuously — just as we also blink, when the tissue around the eye is chilled and dried out. And so too, when we walk, we attend with our mind to the walking, our thought steering it — though the text here trails off incomplete. In this same way, then, we manage the business of breathing as well: contriving to draw the air in, we breathe, and then draw it in again.