§1Οἱ ἴλιγγοι γίνονται ὅταν ᾖ πνεῦμα ἀλλότριον περὶ τὴν κεφαλὴν, ἢ ὑγρότης περιττωματικὴ ἀπὸ τροφῆς ἐνίας, οἷον ἢ τοῦ οἴνου ἢ καὶ ἄλλου τινὸς χυλοῦ, ἢ τρίτον ὅταν κινῇ τις κύκλῳ τὴν κεφαλήν·
Dizziness occurs when there is an alien breath around the head, or residual moisture from certain food, such as wine or some other juice, or thirdly, when someone moves their head in a circle.
ὁ γὰρ τόπος ὁ περὶ τὸν ἐγκέφαλον φύσει μὲν ὑγρός ἐστιν, ὅταν δʼ ἔλθῃ τι πνεῦμα ἀλλότριον βιάζεται διαδυόμενον πρὸς τὰς φλέβας καὶ ὠθεῖ κύκλῳ τὸ προυπάρχον ὑγρὸν, ὥστε τρόπον τινὰ τὸ αὐτὸ συμβαίνει καὶ ἐάν τις προαιρέσει κύκλῳ κινῇ τὴν κεφαλήν.
For the region around the brain is moist by nature, but when some alien breath enters, it forces its way, creeping into the veins, and pushes the pre-existing moisture in a circle, so that in a way the same thing happens as when someone intentionally moves their head in a circle.
Οὐδὲν γὰρ διαφέρει ἔξωθεν ἢ ἔσωθεν εἶναι τὸ κινοῦν.
For it makes no difference whether the moving cause is from without or from within.
Οὔσης δὲ οἷον δίνης τινὸς τῆς φορᾶς καὶ τοῦ ὑγροῦ μὴ συνεχοῦς ὁμοίως ἀλλʼ ἐν τῇ κινήσει τοῦ μὲν ὑστεροῦντος τοῦ δὲ προτεροῦντος τὸ ὑφιστάμενον ἀντικροῦον ἵστησι, τὸ δʼ ἱστάμενον διὰ τὸ μὴ ἰσορροπεῖν ὁμοίως αὐτῇ ᾗ ἂν ῥέπῃ ταύτῃ φέρεται καὶ τὸν ἴλιγγον ποιεῖ καὶ καταβάλλει πολλάκις.
Since the movement is like a kind of vortex and the moisture is not equally continuous, but in the motion, as one part lags behind and another goes ahead, the underlying substance collides and stops the flow, and that which is stopped, because it does not balance equally, is carried in whichever direction it inclines, and causes dizziness and often throws one down.
§2Αἴτιον δὲ τοῦ μὴ δύνασθαι τὰ ὑγρὰ ῥᾳδίως στρέφεσθαι καὶ δινεῖσθαι διὰ τὴν λεχθεῖσαν * αἰτίαν, ὅτι οὐ συνεχῆ· παραπλήσιον γὰρ τὸ συμβαῖνον ὥσπερ ἐν τοῖς ὠοῖς τοῖς ὠμοῖς· οὐδὲ γὰρ ταῦτα δύναται δινεῖσθαι διὰ τὴν ὑγρότητα, τὰ δʼ ἑφθὰ δύναται.
The reason why the moisture cannot easily turn and rotate, for the cause mentioned, is that it is not continuous; for what happens is very similar to what occurs in raw eggs, for these too cannot rotate because of their liquidity, whereas boiled ones can.
Διότι τὰ μὲν ὑπὸ ὑγρότητος ἀνωμάλου καὶ οὐκ ἰσορρόπου οὔσης σφάλλεται τὰ δʼ οὔ;
Why is it that the former are destabilized by irregular and unbalanced moisture, while the latter are not?
διὰ τὸ μὴ ἔχειν τὸ σφάλλον ὑφιστάδο μενον ἑνὸς ὄντος καὶ συνεχοῦς τοῦ ἐντός.
Because, since the inside is single and continuous, the destabilizing factor has no underlying point of resistance.
§3Αἱ μὲν οὖν αἰτίαι σχεδὸν αὗται καὶ τοιαῦται τοῦ πάθους.
These, then, are roughly the causes of the condition, and of such a kind.
Ἀφʼ ὧν δὲ συμβαίνει γίνεσθαι τὰ καθʼ ἕκαστα περὶ ὧν ἀποροῦσι πρὸς ταῦτα ἀνάγειν πειρατέον.
But we must try to refer back to these principles the individual phenomena about which people raise difficulties as to how they happen.
Οἷον διότι κύκλῳ περιπατοῦντες ἰλιγγιῶσι καὶ ἔτι μᾶλλον ὅσῳ ἂν ἐλάττω κύκλον, κἂν θᾶττον θέωσι σφοδρότερον· κἂν μετὰ πολλῶν ἢ μόνοι, καὶ ἐπʼ ἀρίστερα θέοντες μᾶλλον ἢ ἐπὶ δεξιά, καὶ οἱ μακρότατοι δὲ μάλιστα.
For example, why people get dizzy when walking in a circle, and all the more so the smaller the circle, and if they run faster, more violently; and whether running with many or alone, and running to the left more than to the right, and the tallest people most of all.
Πάντων γὰρ τούτων καὶ εἴ τι ἄλλο τοιοῦτον ἐν τοῖς πρότερον εἰρημένοις αἱ αἰτίαι.
For the causes of all these and any other such things lie in what has been said before.
§4Εἴπερ γὰρ ὁ ἴλιγγος γίνεται εἴ τις ἐν τῷ αὐτῷ στρέφοιτο τάχιστʼ ἂν καὶ μάλιστα τῶν λοιπῶν ἰλιγγιῴη ὁ ἐγγυτάτω ἢ ὁ ἐν ἐλάττονι κύκλῳ στρέφων, καὶ ὅσῳ ἂν θᾶττον μᾶλλον.
For if dizziness occurs if one turns in the same spot, the one who turns closest to the center or in a smaller circle would get dizzy fastest and most of all compared to the rest, and the faster, the more so.
Διόπερ καὶ οἱ θέοντες τῶν περιπατούντων καὶ οἱ ταχέως τῶν βραδέως· θέουσι γὰρ ἐγκεκλικότες πρὸς τὸ κέντρον· ὡς ὅταν κατʼ εὐθὺ τὰ μήκη αὐτῶν ἐκπίπτῃ πρὸς μίαν κορυφὴν συνάπτειν καὶ γίνεσθαι κῶνον βάσιν δʼ εἶναι τὸν κύκλον.
That is why runners do so more than walkers, and fast runners more than slow ones; for they run leaning toward the center, as if their heights, extending straight, converge to a single apex and form a cone, of which the circle is the base.
§5Διόπερ συμβαίνει καθάπερ ἐν τῷ αὐτῷ στρέφειν τὴν κεφαλὴν καὶ ὅσῳ ἂν ἐλάττω κύκλον μᾶλλον, ὀξύτερος γὰρ ὁ κῶνος, καὶ ἐὰν θᾶττον πλεονάκις ἐν τῷ αὐτῷ γίνεσθαι κατὰ τὸν ἴσον χρόνον· καὶ τοῖς μακροτέροις δὲ μᾶλλον ὅσῳ ἐγκλίνουσιν· ἐγγυτέρω γὰρ ἔχει τὴν κεφαλὴν ὁ μείζων τῆς τοῦ κώνου κορυφῆς.
Therefore, the same thing happens as if they were turning their head in the same spot, and the more so the smaller the circle, for the cone is sharper; and if they run faster, they come to the same spot more times in an equal duration of time; and it happens more to taller people in proportion to how much they lean, for the taller person has their head closer to the apex of the cone.
Διὸ σχεδὸν ὥσπερ ἐν τῷ αὐτῷ συμβαίνει ἔχοντα τὴν κεφαλήν· οὕτω δὲ μάλιστα ὁ ἴλιγγος.
Therefore, it happens almost as if they had their head in the same spot, and in this way dizziness occurs most of all.
§6Καὶ οἱ εἰς τὰ ἀρίστερα θέοντες ἔτι μᾶλλον ἔσω νεύουσι καὶ ὀξυτέραν ποιοῦσι γωνίαν πρὸς τὸν κύκλον· ἐμβριθέστερα γὰρ ὄντα τὰ δεξιὰ προσβιάζεται μᾶλλον ἐντὸς διὰ τὴν ἀσθένειαν τῶν ἀριστερῶν.
And those who run to the left lean inward even more and make a sharper angle with the circle; for the right parts, being heavier, force their way more inward due to the weakness of the left parts.
Καὶ ἐὰν μετὰ πολλῶν θέωσι μᾶλλον καὶ θᾶττον ἢ μόνοι· πρὸς γὰρ τῇ κύκλῳ περιφορᾷ καὶ ἡ ὄψις αὐτὴ προσβάλλουσα τοῖς θέουσι καὶ συνεχὴς οὖσα ἐν τῷ ἐγκεφάλῳ ποιεῖ τινὰ κίνησιν ἑτέραν καὶ ταραχήν· ἀπὸ γὰρ τῶν ἔξω διαδίδοται καὶ πρὸς τὰ ἐντός·
And if they run with many, they get dizzy more and faster than when alone; for in addition to the circular movement, the sight itself, falling upon the runners and being continuous in the brain, produces another motion and disturbance; for it is transmitted from the outside to the inside.
ὥστʼ ἐπεὶ καὶ ἑκάτερον ποιεῖ τὸν ἴλιγγον, οἷον ἥ τε κύκλῳ κίνησις τῆς κεφαλῆς καὶ ἡ ὄψις συνεχῶς βλέπουσα τὸ κύκλῳ κινούμενον ἐξ ἀμφοτέρων εὔλογον θᾶττον καὶ μᾶλλον γίνεσθαι τὸ πάθος.
So, since each of the two causes dizziness—namely, both the circular motion of the head and the sight continuously watching what is moving in a circle—it is reasonable that the condition occurs faster and more violently from both.