Aristotle's Problems

Why those who spin around contrary to custom [experience dizziness]. Macrobius. Why do those who turn themselves so that they often rotate in a circle suffer both dizziness of the head and dimness of the eyes, and finally, if they persist, they fall; since no other motion of the body brings about this necessity? Among the seven motions, only one is found in divine bodies—I mean the spherical motion by which the heaven is moved, by which the stars are moved, and by which the other elements are moved. To terrestrial animals, those six motions are especially familiar; but sometimes a seventh is also employed. However, those six, being direct, are also harmless. This same seventh motion, which creates circles, frequently disturbs the one turned around, and involves the humors of the head in a winding path, which serves the breath that ministers to the brain, which governs almost all the senses of the body. This is the breath that, surrounding the brain, provides its power to the individual senses. This is what provides strength to the nerves and muscles of the body. Therefore, when it is disturbed by dizziness and at the same time oppressed by agitated humors, it becomes languid and deserts its ministry. For this reason, those who are caught in rotations experience duller hearing and dimmer sight. Finally, as the nerves and muscles receive no power from it—as if it were failing—the whole body, which is sustained by them and raised up in strength, now deserted by its supports, slips into ruin. But against all these things, habit—which usage has pronounced to be according to nature—aids those who are often engaged in such motion. For the breath of the brain, which we mentioned a little before, being accustomed to a thing no longer new to it, does not fear this motion nor desert its ministries; therefore, even this agitation is harmless to those accustomed to it.

...the artery, I say, flowing down: since from the down-flowing moisture, that light membrane within, which is filled with evenness, also effects such an even exit of the spirit. Know that such is the trachea and the throat of goats on account of much moisture; and those who drink much oil are such. Further, I believe others have an uneven voice on account of continuous and loud shouting, or because of the dryness of the trachea. For the trachea of cranes and of birds that cry out harshly are made by nature entirely harsh. Finally, after the years of puberty, the goat-like bleating of boys ceases, because the trachea absolutely unfolds itself in every way, although by nature its part may lose its evenness.

Why does swallowed oil provoke vomiting, and especially yellow bile? Because since it is light and seeks higher places, it draws out the foods themselves by lifting them to the stomach; the stomach, being burdened, excites the expulsive power toward vomiting, especially yellow bile, as it is light and very thin and easily escapes upward. That oil seeks the top is manifest by experience itself; for if mixed with any liquid, it immediately retires to the upper parts.

Why among other liquids is only oil not mixed in? Because since it is glutinous and drawn into itself, it cannot be cut apart and divided into minute parts and mixed with other liquids; hence when poured on the ground, it does not immediately enter it.

Why do oil and water thicken with cold, but in no way wine, vinegar, or garum? Because oil is almost devoid of quality, and being rather temperate, it cools immediately, even to the point of cooling during evaporation; water, indeed, being cold, easily congeals when made colder than itself. But garum, being thin in its parts and hotter, does not immediately freeze; in the same way also wine. Vinegar, however, as it consists of the thinnest parts, rejects all congealing.

Why do things diverse in quality produce the same effect? For both cold and heat condense moisture; thus indeed snow and broth equally come together and congeal from cold. But plasters and stones in the bladder dry out and harden from heat. I say this happens by different actions. For heat consumes and uses up much moisture through its dryness. Cold, however, making it muddy by density, expresses the moisture that is sliding and becoming foul, just as a sponge compressed by the hands pours out the liquid contained in its passages.

Why is shivering often settled by another horror or a sudden noise arriving beyond the thought of the one affected by shivering, or by water immediately poured on? Because often when the humors have long been concocted and thinned, a sudden, vehement natural heat consumes, disperses, and distracts the humor from the skin inward. Theriac does the same, as do many hot and dry qualities that have achieved easy digestion.

Why do those who spin around contrary to custom fall? Because they force the animal spirit in the brain to be disturbed and moved within the humors; thereafter, it becomes unfit for receiving animal power, nor do they allow the sensory and motive power to carry action to the muscles and nerves; and likewise it is necessary that the weight of the body, not being carried and transported by the soul, is borne to the earth, toward which it previously inclined. On account of this, those see darkness in whom the visual spirit is disturbed; and indeed they do not use their other senses quite according to their will. But if they gradually become accustomed to spinning a great deal, this happens very rarely, because custom does not turn the soul away from nature, but over a long time makes it familiar. For that which happens suddenly and continually does not know how to resist, nor does it prepare any defense for itself against the change.

Why do glass mirrors shine so brightly? Because they are coated on the inside with tin. There is, however, a transparent nature in it; and likewise coupled with glass...