by Aristotle
[25] 15 · Why is it that we do not perspire in those parts of the body on which we are lying? Is it because the area with which we come into contact with anything is hot and therefore prevents the perspiration from passing forth, for it dries it up? Furthermore it is compressed, and pressure causes the blood to disperse, and, when this happens, the part tends to become cool. This can be illustrated from numbness, [30] which is a condition due to cooling and is caused by pressure or by a blow.
16 · Why do those who are asleep perspire more freely? Is it due to the heat being driven inwards? For the heat collects inside and expels the moisture.
17 · Why is it that one perspires most freely on the face, though it is far from [35] being fleshy? Is it because parts which are rather moist and rare perspire freely, and the head has these characteristics? For it possesses an abundance of natural moisture; this is shown by the veins which extend from it and the discharges which it produces and the brain-fluid and the numerous pores. That there are numerous pores extending outwards is shown by the presence of the hair. The perspiration then comes not from the lower parts of the body but from the head; and so one [868a1] perspires most readily and freely on the forehead, for it is the first thing below the top of the head, and moisture flows down and not up.
18 · Why is it that those who are perspiring are apt to vomit if they are [5] cooled either by water or by air? Is it because the moisture when cooled ceases to move and collects together, whereas before it was not at rest because it was in a state of flux? Or is it because the breath which turns into perspiration by being cooled as it passes out, being cooled internally before passing out turns into moisture and, attacking the body, causes vomiting?
19 · Why is it that sweat is given off from the head and feet of those who are [10] heated more freely than from any other part of the body? Is it because the part which is heated attracts the moisture to itself, and the moisture has nowhere where it can expend itself in these regions of the body, because they are bony, and therefore it finds its way out?
20 · Why do those who exert themselves perspire when they cease to exert [15] themselves? For since the exertion is the cause, they ought to perspire while they are exerting themselves. Is it because during their exertion the veins, being inflated with breath, cause the pores to close up, whereas, when they stop, the veins contract, and so the pores become wider and the moisture finds an easier outlet? Or is it because during the exertion the motion expels air from the solidified moisture and, [20] owing to the heat caused by the motion, the moisture becomes breath on the surface of the body; while on the other hand, when the exertion ceases, the heat also stops at the same time, and then the moisture, which we call perspiration, is generated from the condensation of the breath? [25]
21 · Is it more necessary to induce perspiration in the summer or in the winter? Is it not more necessary to do so at a time when, unless care be taken, the body would become too moist and in a dangerous condition? If so, it would be more necessary to perspire in the summer,2 when a violent change takes place in the body and the excretions are not thoroughly concocted. Again in the winter, since the body [30] is cool, it is also unnatural to perspire. It is clearly, therefore, more necessary to induce perspiration in the summer; for moisture of all kinds is then more apt to putrefy and should therefore be drawn off. This was the opinion of all the ancients and for the above reason.
22 · Why is it that, although the body is in a state of continual flux, and [35] effluvia are given off from the excrements, the body is only lightened if it perspires? Is it because the excretion in the form of effluvia is too little? For when liquid is transformed into air, much air is formed out of little liquid; for what is excreted in [868b1] liquid form is more abundant. The process of excretion, therefore, takes longer to begin, both for the above reason and because the excretion takes place through smaller pores. Further, the viscous and adhesive matter is expelled with the moisture, because it mingles with it, but it cannot be expelled with the breath; and it [5] is this thick matter in particular that causes pain. Therefore also vomiting lightens the body more than sweating, because that which is vomited, being thicker and more substantial, carries away this viscous matter with it. Or is there a further reason, namely, that the region in which the viscous and the adhesive matter is, is situated at a distance in relation to the flesh (and so it is difficult to make it change [10] its position), but near the stomach? For it is engendered either in or close to it; and therefore it is difficult to get rid of it in any other way.
23 · Why is it that one perspires less during actual exertion than when one ceases? Is it because while one is exerting oneself one is engendering perspiration, but the process of engendering it is only complete when the exertion is ended? This then is naturally the time when it is expelled from the body in greater quantities; for during exertion it is coming into being, but, when the exertion is finished, it actually [15] exists. Or is it because during exertion the pores of the flesh are closed, because the breath is held, but when the pressure of the breath is relaxed the pores open again? Consequently one perspires less when one is holding the breath.
24 · Why is it that perspiration is more copious not when one is running and the body is in motion, but when one stops? Is it because the same thing happens as [20] when flowing water is checked by the hand or by some other means and collects from every direction, and, when it is released, flows in greater volume than before; so perspiration can be stopped by the breath—like water in a water clock—and also [25] in the bladder, which keeps the moisture within. So too, while there is considerable movement, the breath is cut off inside the body, and so the veins are distended, the moisture being unable to find its way out. The moisture then, being cut off, collects, and when the breath is relaxed comes all out at once.
25 · Why is it that, when one is drinking, one perspires less if one eats [30] something as well? Is it because the food sucks up the moisture, as though a sponge were applied, and, just as a stream can be stopped by blocking up its channels, so by stopping3 the pores through administering food it is possible to a large extent to prevent the flowing of moisture?
26 · Why is that the feet of those who are nervous perspire and not the face? [35] For it would be more natural that the feet should perspire only when the whole body perspires; for the feet are the coldest region of the body and therefore least liable to perspire. Also in sickness physicians order the feet in particular to be wrapped up, because they are especially susceptible to cold and so readily give rise to cold in the rest of the body also. Is it because nervousness does not cause a displacement of [869a1] heat—such as takes place from the upper to the lower parts of the body under the influence of fear (hence the relaxation of the bowels in those who are alarmed)— but an increase of heat such as is caused by anger? For anger causes the heat round the heart to boil up; and one who is nervous is affected not by fear or cold, but by an [5] increase of heat.4
27 · How is it that one can become red in the face without perspiring? Is it due to excessive warmth which results in the heat on the surface drying up the [10] moisture in the face, while it liquefies the moisture in the feet because, though less than the heat on the surface, it is more powerful than the natural heat already existent in the feet?
28 · Why is it that we perspire more when asleep than when awake? Is it because perspiration originates internally, and the interior parts of the body are hotter, and so the internal heat melts and expels the internal moisture? Or5 is it [15] because in all probability there is always something given off from the body, but it is not apparent because there is nothing with which it can come into contact and by which its escape can be arrested? That this is so is shown by the fact that the hollow parts of the body perspire continually.
29 · Why is it that persons in vapour baths perspire more freely when it is cold? Is it because the heat does not find a way out, because it is surrounded by the [20] cold, which prevents its exit, but collects internally, and, remaining there, di
ssolves the moisture in our body and engenders perspiration from it?
30 · Why is it that perspiration, even though it be less profuse, is more beneficial if it be induced by running naked rather than clothed? Is it because [25] exertion in general is better than non-exertion, and perspiration which is induced by exertion is better than that which is produced without exertion, and that which is due in a greater degree to exertion is better than that which is due in a less degree? Now perspiration involves more exertion if induced by running about naked: for a naked man cannot perspire at all unless he runs with considerable energy; whereas, [30] if he be clothed, owing to the heat produced by his garments, he soon perspires although he runs only moderately fast. Those too who run naked in the summer have a healthier colour than those who wear garments; for just as those who live in regions open to the air have a better colour than those who live in a stifling [35] atmosphere, so too a man, when he is as it were in a well-aired condition, acquires a better colour than when he is stifled and surrounded by considerable heat, as he is more likely to be when he runs clothed. For this reason too those who sleep much [869b1] have a less healthy colour than those who sleep a moderate amount; for a man who is asleep is in a stifled condition.
31 · Why is it that our feet perspire, but not our faces, when we are in a state [5] of nervousness, whereas under ordinary conditions our faces perspire most and our feet least? Is it because nervousness is a kind of fear connected with the beginning of an action, and fear causes a cooling in the upper part of the body; this is also why those who are nervous are pale-faced. On the other hand they move and dance their [10] feet about, thus resembling those who are taking exercise; therefore they naturally perspire in those parts which they are exercising. Also they rub their hands together and bend and stretch themselves and keep jumping up and can never remain still; for they are eager for action, because the heat within them is collected in the region of the chest, which is one of the more substantial parts of the body, and this heat and [15] the blood rushing thence through their whole body results in frequent and varied movement. But they perspire most in the feet, because these are being continually exerted, whereas the other parts of the body obtain rest in the changes of position and movement.
[20] 32 · Why is it that in a vapour bath one perspires most freely not when the heat is applied all at once nor when it is gradually diminished, but when it is gradually increased? For if the heat is gradually introduced into the vapour bath, one perspires more freely than if the full amount were admitted at first. Is it because heat which is great from the beginning, finding the flesh on the surface dry, burns [25] the skin and bakes it hard, and the flesh when it is in this condition holds the perspiration within?6 Less heat on the other hand tends to relax and rarefy the flesh and as it were stimulates the internal moisture to separate itself and come forth. This condition being established, when more heat is gradually introduced and [30] penetrates deep into the flesh owing to its rarity, it vaporizes the already softened humours and separating those which are light expels them with the breath.
33 · Is it more necessary to induce perspiration in the summer or in the winter? In winter does not the heat collecting within the body concoct and vaporize [35] our internal humours, and so, because all or most of them are expended, there is no need to supply an appropriate method of expelling them? In the summer, on the other hand, because the flesh is in a state of rarity, the heat escapes and our internal humours become less concocted and therefore need to be drawn off. For if they are [870a1] allowed to remain, they putrefy owing to the season and cause disease; for anything that putrefies does so owing to heat that is not its own, whereas its own natural heat causes concoction. Consequently in the summer the external heat prevails, and so everything within the body tends to putrefy; but in the winter the natural heat [5] predominates, and so the winter does not cause putrefaction.
34 · Why is it that, whereas perspiration is due to internal heat or else to heat attacking the body from without, yet we sometimes shiver while we perspire? Is it because, when owing to the internal heat the perspiration is expelled from a large area into a small space, it collects7 on the surface of the body and entirely blocks up the channels through which the heat circulates, and so shivering ensues? [10] Another reason is that the flesh becomes saturated and the heat escapes. On the other hand the external heat attacking the flesh at first rarefies it, and then the internal natural heat as it is given off causes the shivering.
35 · Why are hot sweats considered to be better than cold? Is it because all [15] perspiration is the rejection of some excretion, and it is natural that a small excretion should become heated, whereas a more abundant excretion is less likely to do so, and so a cold sweat would be an indication of a copious excretion; consequently the disease, the presence of which it indicates, is likely to last longer? [20]
36 · Why is it that, although perspiration is caused by heat, we perspire less in front of a large fire? Is it because, when the body is subjected to considerable heat, the humours are dissolved into vapour; or else we do not feel the moisture, because it makes its way out and quickly dries on the surface? [25]
37 · Why is it that, though the sun heats us more if we wear no clothing, yet we perspire8 more freely when we are clothed? To this we shall give the same answer as to the last problem.
38 · Why is it that, though brisk movements are generally regarded as more heating than slow movements, walking up a steep hill, which is a slower movement, [30] induces more perspiration and obstructs the breathing, as though it were more heating than walking down hill? Is it because it is natural for heavy things to be carried downwards and unnatural for them to be carried upwards? Consequently the nature of the heat which carries us along does not undergo any strain when we [35] are going down hill, but has to bear a continual burden when we are walking up hill; and so it grows exceedingly hot by movement of this kind and causes more profuse perspiration and obstructs the breath. The bending, too, of the body involved in walking up hill contributes to prevent the free passage of the breath by obstructing [870b1] it.
39 · Why is it that, although more perspiration is induced by additional clothing, it is not those who wear most clothing that perspire most? To this question we shall give the same answer as we gave above. [5]
40 · Why is it that, although our bodies are drier in the summer than in the winter, we are more disposed to perspire in the summer? Is it because, our bodies being in a condition of rarity in the summer, not much natural heat is contained in them? This, therefore, dissolves the humours into vapour. In the winter on the [10] contrary, our bodies being externally in a dense condition, the considerable amount of natural heat enclosed within does not dissolve the humours into vapour. Moreover, in the summer we swallow liquid in large quantities, but in small quantities in the winter.
41 · Why is it that in healthy persons spontaneous perspiration is not [15] considered to be as good as that produced by exertion? Is it because exertion continually drains off the superfluous moisture and makes the flesh drier, so that the hollows of the pores are healthy and there is no obstruction to the straining off of [20] the heat? On the other hand the so-called spontaneous perspiration (which really occurs of necessity when the natural pores are disturbed by excessive moisture, and the heat is not completely retained, but can still resist and expel the moisture) is rightly regarded as a sign of disease. For then, owing to the presence of a more than [25] proportionate amount of moisture, a natural process of cooling takes place, and the flesh becoming saturated assumes a most unhealthy condition.
42 · Why is it that in the winter perspiration is given off less freely and we do not feel the same desire to induce it, although our bodies are moister in the winter? [30] Do we perspire less, because in winter our humours are congealed and solidified to a considerable extent, and are consequently less easily dissolved? The reason why we do not think it necessary to induce perspiration in the winter is because the condition in which we are is a healt
hy one, and any one who induces perspiration dissolves and upsets that condition; moreover, by creating in the body a condition of [35] greater rarity than it ought to have, he expels and reduces the natural heat, so that it cannot so effectively resist the surrounding cold; also external moisture will more easily burst its way into the body when the pores are rarefied by process of perspiration.
BOOK III
PROBLEMS CONNECTED WITH THE DRINKING OF WINE AND DRUNKENNESS
[871a1] 1 · Why is it that, though wine is hot, the drunken are unable to endure cold and are very readily attacked by pleurisy and similar diseases? Is it because a large quantity of moisture, if it be cooled, forms a mass of cold and so overpowers the [5] natural heat? For this is similar to what happens when, if a garment is soaked in cold water, the flesh beneath it also becomes cold.
2 · Why is it that it is not those who are very drunk that are most troublesome in their cups, but those who are only half blotto? Is it because they have neither drunk so little that they still resemble the sober nor so much that they are in the incapacitated state of those who have drunk deep? Further, those who are [10] sober have more power of judgement, while those who are very drunk make no attempt to exercise their judgement; but those who are only half blotto can still exercise their judgement because they are not very drunk, but they exercise it badly because they are not sober, and they are ready to despise some of their neighbours and imagine that they are being slighted by others. [15]