Complete Works of Plutarch — Volume 3: Essays and Miscellanies

by Plutarch

One of the strangers at the the table, who took wonderful great delight in drinking of cold water, had some brought to him by the servants, cooled after this manner; they had hung in the well a bucket full of the same water, so that it could not touch the sides of the well, and there let it remain, all night: the next day, when it was brought to table, it was colder than the water that was newdrawn. Now this gentleman was an indifferent good scholar, and therefore told the company that he had learned this from Aristotle, who gives the reason of it. The reason which he assigned was this. All water, when it hath been once hot, is afterwards more cold; as that which is prepared for kings, when it hath boiled a good while upon the fire, is afterwards put into a vessel set round with snow, and so made colder; just as we find our bodies more cool after we have bathed, because the body, after a short relaxation from heat, is rarefied and more porous, and therefore so much the more fitted to receive a larger quantity of air, which causes the alteration. Therefore the water, when it is drawn out of the well, being first warmed in the air, grows presently cold.

Whereupon we began to commend the man very highly for his happy memory; but we called in question the pretended reason. For if the air wherein the vessel hangs be cold, how, I pray, does it heat the water? If hot, how does it afterwards make it cold? For it is absurd to say, that the same thing is affected by the same thing with contrary qualities, no difference at all intervening. While the gentleman held his peace, as not knowing what to say; there is no cause, said I, that we should raise any scruple concerning the nature of the air, forasmuch as we are ascertained by sense that it is cold, especially in the bottom of a well; and therefore we can never imagine that it should make the water hot. But I should rather judge this to be the reason: the cold air, though it cannot cool the great quantity of water which is in the well, yet can easily cool each part of it, separate from the whole.

QUESTION V. WHAT IS THE REASON THAT PEBBLE STONES AND LEADEN BULLETS THROWN INTO THE WATER MAKE IT MORE COLD? A GUEST, PLUTARCH, AND OTHERS.

I suppose you may remember that what Aristotle says in his problems, of little stones and pieces of iron, how it hath been observed by some that being thrown into the water they temper and cool it. This is no more than barely asserted by him; but we will go farther and inquire into the reason of it, the discovery of which will be a matter of difficulty. Yes, says I, it will so, and it is much if we hit upon it; for do but consider, first of all, do not you suppose that the air which comes in from without cools the water? But now air has a great deal more power and force, when it beats against stones and pieces of iron. For they do not, like brazen and earthen vessels, suffer it to pass through; but, by reason of their solid bulk, beat it back and reflect it into the water, so that upon all parts the cold works very strongly. And hence it comes to pass that rivers in the winter are colder than the sea, because the cold air has a power over them, which by reason of its depth it has not over the sea, where it is scattered without any reflection. But it is probable that for another reason thinner waters may be made colder by the air than thicker, because they are not so strong to resist its force. Now whetstones and pebbles make the water thinner by drawing to them all the mud and other grosser substances that be mixed with it, that so by taking the strength from it may the more easily be wrought upon by the cold. But besides, lead is naturally cold, as that which, being dissolved in vinegar, makes the coldest of all poisons, called white-lead; and stones, by reason of their density, raise cold in the bottom of the water. For every stone is nothing else but a congealed lump of frozen earth, though some more or less than others; and therefore it is no absurdity to say that stones and lead, by reflecting the air, increase the coldness of the water.

QUESTION VI WHAT IS THE REASON THAT MEN PRESERVE SNOW BY COVERING IT WITH CHAFF AND CLOTHS? A GUEST, PLUTARCH.

Then the stranger, after he had made a little pause, said: Men in love are ambitious to be in company with their sweethearts; when that is denied them, they desire at least to talk of them. This is my case in relation to snow; and, because I cannot have it at present, I am desirous to learn the reason why it is commonly preserved by the hottest things. For, when covered with chaff and cloth that has never been at the fuller's, it is preserved a long time. Now it is strange that the coldest things should be preserved by the hottest.

Yes, said I, it is a very strange thing, if true. But it is not so; and we cozen ourselves by presently concluding a thing to be hot if it have a faculty of causing heat, when as yet we see that the same garment causes heat in winter, and cold in summer. Thus the nurse in the tragedy,

In garments thin doth Niobe's children fold,
And sometimes heats and sometimes cools the babes.

The Germans indeed make use of clothes only against the cold, the Ethiopians only against the heat; but they are useful to us upon both accounts. Why therefore should we rather say the clothes are hot, because they cause heat, than cold, because they cause cold? Nay, if we must be tried by sense, it will be found that they are more cold than hot. For at the first putting on of a coat it is cold, and so is our bed when we lie down; but afterwards they grow hot with the heat of our bodies, because they both keep in the heat and keep out the cold. Indeed, feverish persons and others that have a violent heat upon them often change their clothes, because they perceive that fresh ones at the first putting on are much colder; but within a very little time their bodies make them as hot as the others. In like manner, as a garment heated makes us hot, so a covering cooled keeps snow cold. Now that which causes this cold is the continual emanations of a subtile spirit the snow has in it, which spirit, as long as it remains in the snow, keeps it compact and close; but, after once it is gone, the snow melts and dissolves into water, and instantly loses its whiteness, occasioned by a mixture of this spirit with a frothy moisture. Therefore at the same time, by the help of these clothes, the cold is kept in, and the external air is shut out, lest it should thaw the concrete body of the snow. The reason why they make use of cloth that has not yet been at the fuller's is this, because that in such cloth the hair and coarse flocks keep it off from pressing too hard upon the snow, and bruising it. So chaff lying lightly upon it does not dissolve the body of the snow, besides the chaff lies close and shuts out the warm air, and keeps in the natural cold of the snow. Now that snow melts by the evaporating of this spirit, we are ascertained by sense; for when snow melts it raises a vapor.

QUESTION VII. WHETHER WINE OUGHT TO BE STRAINED OR NOT. NIGER, ARISTIO.