Aristotle · a new plain-English translation from the original language
1| Why are the dark-leaved myrtles more thickly leaved than the pale-leaved myrtles? Is it because they are wilder in kind? A sign of this is that they grow in the fields and change least under cultivation. And all wild plants are more thickly leaved, because since they concoct their fruit less, the nourishment is turned instead into the leaves. BOOK 21. PROBLEMS CONCERNING BARLEY-MEAL AND BARLEY-CAKE AND SIMILAR THINGS. Why do pearl barley and flour become whiter when oil is poured on, even though oil is reddish-yellow? Is it because it is the nature of oil, when mixed with moisture, to froth up, and this frothing is whiteness? And the mixing comes about by rubbing and stirring. It mixes more readily with solid substances, and this happens in boiled dishes, which is why it also makes them whiter. Why is nourishment from wheat especially suited to the body, and more nourishing, than nourishment from barley? Is it because it has a moderate stickiness? Nourishment needs to have this quality, for it must attach and adhere to the body, and stickiness is the cause of this. But barley is crumblier, which is why well-kneaded barley-cakes are more nourishing than unkneaded ones. Why is it that with flours the first-milled portions are glossier, but with barley-meal the last-milled portions are glossier? Is it because what is parched and dry crumbles all around its edges, while what is soft gets pressed in? And in both cases the innermost part is the glossiest.
2| Why does bread look whiter when it is cold than when it is hot? Or is it for the same reason that, in a way, old olive oil is whiter than fresh oil? For water is the cause of the dark color, and there is more water in both when they are fresh; but as time passes, because it evaporates, less is left on the surface. In the case of oil, either time or the sun does the evaporating; but in the case of loaves cooling down, the heat going out has, when they are cold, already gone out, while in hot loaves it is still present. Why do unsalted loaves weigh more than salted ones, everything else about them being equal? One would expect the opposite, since salt is an addition, and salt is heavier than water. Or is it because salt dries things out? That is also why salted, preserved foods keep without rotting: the moisture, which rots under the action of heat, is used up and dried out by the salt. So in bread too the moisture is used up by the salt, and breathes out. That is also why day-old loaves are lighter than hot ones, being colder. But in unsalted loaves this moisture, being present in greater quantity, makes them heavier.
3| Why is it that cold loaves, when moistened, do not stick together if they touch one another, while hot loaves do? Is it because cold loaves, along with the vapor, give off the sticky moisture within them, and once this has gone out they do not cling (for the water with which they were moistened is rather crumbly by itself), whereas hot loaves still have some stickiness in them? So when, once they have been moistened, the vapor goes out, the heat passes through and off because of its fineness, while the sticky element, going out along with it and mixing with the moisture, makes them stick together. And mixing with the moisture makes them stick together. Why is it that, of the ground meals, barley-groats are the brightest, and of the barley-groats the last-sifted portion is brightest? Is it because the groats, being parched, break apart at the edges — which happens most to what is pounded longest — while the soft, fine flour, which is the innermost part of the wheat grain, is pressed out first? And in both cases the brightest part is the inner part. Why does barley-cake, the more it is kneaded, become harder to pass through the body, while bread becomes easier to pass? Is it because, through being kneaded hard, the dough becomes finer-grained? For that is what stickiness is like; but by the fire the moisture is drawn out of the bread on every side, so that, the moisture having been wholly removed, it becomes crumblier the more it is kneaded, because kneading makes it finer-grained, and what is crumbly is more digestible. Barley-cake, on the other hand, the more it is kneaded, becomes stickier, since the moisture is mixed in with it; and what is sticky is not easily divided. Such things are hard to digest, for what is to be digested must be divided into small parts.
4| Why does barley-cake become smaller when kneaded, while dough becomes larger? Is it because barley-groats, once moistened and kneaded, settle down through the moisture's binding, since the groats are loose and coarse-grained, while flour rises up because it is very dense? For dense things, when kneaded, are heated, and being heated and filled with air they rise up, just as flesh does. And why does dough, when put to the fire, become larger than barley-cake does? Is it because it contains moisture that has not been separated out, so that this moisture escapes when heated by the kneading; and from the heated moisture air is produced, and from more moisture more air must necessarily be produced? Why is it that, although honey is more binding than water, flour kneaded with honey-water becomes crumblier, when boiled or baked, than flour kneaded with water? Is it because water, under the action of fire, sets and solidifies [the water], while honey also causes it to solidify, but at the same time dries it out further, which is why it makes it crumblier — for crumbliness comes about through dryness?
5| Why do twice-baked loaves not become hard when they cool? Is it because wheat has within it a certain sweet, sticky juice, which is, as it were, its soul? Here is a sign: when the wheat is thoroughly dried out it is emptied of this, but when it is damp it sprouts. Since this juice is present in the flour, and most of all in the purest flour, when the flour becomes dough and is kneaded, this is what happens. Here is a sign: when boiled, dough becomes easier to pass through the body. Now when the loaf is first baked, its crumbly and light part evaporates off, along with the moisture from the bread, and the most bran-like part of the flour gets burned away. But when the dough is taken out and kneaded again, the smoothest part of the flour and the stickiest part of the moisture, being what is left, mix together more with each other, both because they have become more of that character and because of the baking; for their mixture, through the baking, becomes like a dye, so that the dough kneaded a second time becomes like flour that has been boiled. And indeed that too, once the dough has been kneaded and the finest flour and stickiest moisture have been left over, becomes, when baked, sticky and resistant to drying out; for what is sticky is hard to divide, and what is dense lets nothing pass through itself. This, then, is the moistest part, and bread is affected by fire in the way described because of it; and having moisture in it always, it does not become hard.
7| Why is it that we can go on for a long time using some foods, whether dry or moist — such as the food made from barley-groats and flour, and dry wines, and water — while we cannot with others, even though these others are more pleasant? Is it because some of the things we take in are the sort that rise to satisfy quickly and are nourishing, so that even when we have emptied ourselves, and the first food has been used up, a great capacity is still present in the body — digested as far as concerns the body's first working on it, but, as far as concerns the final stage and what happens through succession, still undigested? And most pleasant things are of this sort. For fatty, sweet, and rich foods seem most pleasant to us when we taste them, and these are all [the] nourishing and not indigestible and quick to satisfy, whatever the particular kind may be; so that their power remains present within us, provided one has been filled with them and the sensation does not quickly fade. For satisfaction does not occur only from what is present in the stomach, but also once the food has been distributed to other parts. Or is this not the only cause, but also that some things are by nature well-proportioned to us and akin to us? For all such things, because they are in accordance with nature, are more readily accepted by our bodies, while things contrary to nature are less so. Different things suit different constitutions: for example, honey is in accordance with nature for bees, so that they take only that — and yet their capacity is weak. So what is used up must not be lacking, but the quantity must be proportionate to the strength that comes from the constitution concerned. So whatever pleasant foods are of this sort appear pleasant, because they exist less in nature, but only for a short time; then they quickly satisfy us. But of the things that are in accordance with nature we always have need, so that even when we take them continuously, we are, on their account, less satisfied by them than by the most pleasant things, though satisfied by other things less.
8| Why do the same things appear pleasant to people who have grown accustomed to them, yet not pleasant to people who take them all too continuously? Habit is doing something often and continuously. Is it because habit produces in us a receptive state with respect to something, not a filling of it, while continuous consumption of something fills the appetite, and acts, so to speak, as a cause? For appetite too is something. Now states, when exercised, grow and increase, while vessels, when packed, do not become any larger. That is why habit, being a kind of exercise, increases the receptive state, whereas continuous consumption packs and fills the appetite, and once it is filled we no longer accept more, but it does not increase the appetite at all, for the reasons already stated about packing. Further, habit is pleasant not because it is always giving pleasure — for even habitual things cause pain if one does them continuously — but because it makes us accept the beginning of the activity with pleasure, and makes us able to do the same thing for a longer time than we could if we were unaccustomed to it. So in the very respect in which this too, though pleasant, causes pain, other pleasant things do so as well in that same respect; for things that occur or are consumed continuously cause pain in both cases. The cause is that we do not have unlimited receptive and productive capacities in these matters, but limited ones, which, when they meet with what is proportionate to them (for this is what is perceptible as increase when it occurs continuously), are in some cases filled, and in others become unable to function.
9| Why does dough become white when it is kneaded, while barley-cake becomes rather dark? Is it because in barley-meal the surface dries out more — as when something is hot in a moist medium, which is what produces the whiteness? Or is it because, since it has been roasted, it draws the moisture into itself, being made of larger particles? Why do barley-meal hold together better when kneaded with water than with oil, though oil is stickier? And yet the sticky is more adhesive, and oil is stickier than water. Or is it that water is thinner, so that it penetrates into everything and makes it soft, and the parts grow together more and are pressed together against one another, even though they are pressed together apart from the kneading as well? Why do loaves that have not been kneaded, and those that have been kneaded excessively, both crack apart? Is it because the unkneaded ones crack because they are not bound together — for kneading binds them, so their way is already prepared for cracking; further, they contain their moisture unmixed and in quantity. Those that have been kneaded excessively, on the other hand, are extremely dry because they have little moisture left, for when they are heated all of it comes out. So both crack because much moisture is escaping — in the unkneaded loaves it is present in large amount absolutely, in the kneaded ones it is large relative to what remains.
10| Why does the mixture become lighter than the two ingredients, the moisture and the barley-meal, were separately? Is it because when they are mixed, breath is enclosed together with them? Or is it because, under the heat present in the barley-meal, some of the water evaporates, so that the mixture becomes smaller? As for air — even if it does get mixed in, it would not make anything lighter, since air too has weight when it is in air. Why does milk, and sweet wine, taste sweeter when drunk along with barley-meal? Is it because it appears sweeter by contrast with what is not sweet — for barley-meal is not sweet? Or is it because the barley-meal lingers, carrying its sweetness with it, so that perception has a longer time in which to act? Why does the same drink seem less unmixed with wine when it is drunk with barley-meal? Is it because one thing tempers another when mixed with it? Or is it because the barley-meal blocks the drink and hides it, drawing it away into itself? Why does groats take in more water than the wheat from which such groats were made? Is it because groats is in a way flour, and flour takes in more? For indeed the resulting bulk is greater than that of the wheat — since the material within the wheat has been packed tight, and what is packed less tight makes room for more. This is also because both flour and groats have heat in them, and what is hot both draws in moisture more and, by evaporating, uses it up.
11| Why does flour, when kneaded, increase in size much more, proportionally, than barley-meal does? Is it because the one takes in much water, the other little? And why does it take in more? It is more reasonable that barley-meal should — for it has been roasted, while flour has not; and what has been roasted is drier. Or is it rather because flour undergoes more kneading? The cause of this is that it is made of smaller particles. So then, in whatever proportion it is, by its fineness, more capable, in that same proportion it takes in water. For it uses water as glue, just as Empedocles too transferred the term in his Physics when he spoke of "gluing barley-meal with water." And for this reason it uses up a great deal. And why does dough, once it has been baked, become larger than barley-cake does? Is it because it contains moisture that is not separated out, so that when it is heated the moisture escapes without turning into breath, and is unable to escape as it does in barley-cake, because of the density of the dough — for what is made of smaller particles is dense — [therefore] it lifts the mass and produces the bulk? Further, it also contains more moisture, from which, when it is heated, breath is produced; and from more, more must necessarily be produced. Why do those who work at processing grain — those who work with barley become pale and afflicted with catarrh, while those who work with wheat stay in good bodily condition? Is it because wheat is more easily digested than barley, and that is also why its effluvia are as they are?