Aristotle · a new plain-English translation from the original language
1| Book 12. Problems Concerning Fragrant Things Why do people perceive fragrances less when they are close to them? Is it because the emanation, when mixed with a larger volume of air, is less concentrated and so more pleasant, as with the myrrh doctors use? Or might it rather be the opposite, so that fire takes away the smell because it burns it? For the smell belongs to things being burned as incense. That is also why there is no smell right at the coals, while farther off it appears purer and very fine. Why are smells less fragrant close up than farther away, in both incense and flowers? Is it because particles of earth travel along with the smell, and these are carried down first because of their weight, so that the smell becomes pure farther away? Or is it that, neither close to the source is the flow at its greatest, nor too far away — for near the source it is not yet abundant, while far away it is dispersed?
2| For it is said that trees become fragrant wherever a rainbow has struck down upon them. Is this true, then, or false? And if true, what would be the cause of what happens? That it does not happen to all trees, nor always, is clear; for often a rainbow has occurred, yet the trees show no sign of it. And when this does occur, it does not occur in every kind of material, since it does happen on occasion — that is why it is even said. The cause must be assigned as incidental to the rainbow, especially if the rainbow is not a nature at all, but an affection of sight, bent back. It occurs, as was said, not when the material is in just any condition; for it happens neither in green trees nor in dry ones, but shepherds say that in burnt material, after the rains that come with a rainbow, the fragrance becomes noticeable — most of all where there is camel's thorn and buckthorn, and whatever plants have fragrant flowers. The cause of the fragrance is the same as in the case of the earth; for when it is thoroughly heated and scorched, whatever grows out of it smells sweet at first. For things that have been burned in some way, when they have only a little moisture, become fragrant.
3| For heat concocts this moisture. That is why, over the whole earth, the regions toward the sun smell sweeter than those toward the north. And of these, the regions toward the east smell sweeter than those toward the south, because the area around Syria and Arabia is more earthy, while Libya is sandy and lacking in moisture. For the moisture must be neither abundant—since abundant moisture is unconcocted—nor entirely absent, since then no vapor is produced. This is what happens also with newly kindled wood, and with any kind of matter such as to have a fragrance in itself. It is shown in the case of flowers, for they release their scent in this way. And it seems to happen wherever the rainbow strikes, because nothing can come about without water: for the matter, once wetted and concocted by the heat within it, releases the vapor that forms in it. Nor should the water be abundant, for too much water washes it away entirely and quenches the heat that is present there from the burning; and the rains after a rainbow are not heavy, but moderate, so to speak. And even if many rainbows occur, the water is not abundant—rather it comes often, but little each time. This is why, reasonably enough, since this happens and people see no other difference except the rainbow, they attributed the cause of the fragrance to it.
4| Why do flowers and things burned as incense smell more pleasant from a distance, but up close smell more grassy in some cases and more smoky in others? Is it because scent is a kind of heat, and fragrant things are hot, and heat is light, so that for this reason, as they pass through more distant air, the scent becomes less mixed with the accompanying scents from the leaves and from the smoke, which is a watery vapor; whereas when things are close by, what is mixed in with them smells along with whatever they are in? Why do all things smell more when they are in motion? Is it because, in motion, they fill more air than when at rest? So the scent is transmitted to our perception more quickly this way. Why do we smell things less in winter, and least of all during frosts? Is it because the air is less mobile in the cold? So the motion coming from the body that has the scent does not arrive in the same way, because of the difficulty of movement of both the emanation and the air in which it travels. Why do aromatic spices smell more pungent when burned as incense on ashes than on fire, and why do they hold their own scent longer and more strongly when burned on ashes? Is it because the scent on ashes is less concocted, and for that reason also more abundant? Fire, by quickly concocting their power, alters the scent; for concoction is an alteration of what is being concocted.
5| Why do roses whose calyx is rough smell more pleasant than those whose calyx is smooth? Is it because things smell more pleasant the more fully they have attained their own nature? The rose is by nature thorny. So the one that has more of what accords with its nature smells more pleasant. Why are the scents of both incense and flowers less fragrant up close? Is it because up close the earthy element is carried along with them, so that, being mixed in, it weakens the power of the scent, whereas at a distance the scent alone travels onward? This is also why flowers, when rubbed, lose their scent. Are scents smoke, or air, or vapor? For there is a difference, in that the one comes about by fire, while the other comes about even without it. And does something travel from our perception toward those objects, or from those objects toward our perception, always setting the neighboring air in motion? And if it flows off from the objects, they ought to diminish; and yet we see that the most fragrant things last the longest. Why do aromatic spices smell more pungent when burned as incense on ashes than on fire? Is it because the scent on ashes is less concocted, and for that reason also more abundant? A great deal of the earthy element rises up along with it, then, and becomes smoke; whereas the fire burns away their earthy element beforehand, so that the scent arrives purer and unmixed, without the smoke. This is also why flowers, when rubbed, are less fragrant: for the rubbing stirs up the earthy element too, and the slow heat does not destroy it.