§24.1Διὰ τί τὸ θερμὸν ὕδωρ, ἐὰν ἐπικεχρισμένοι ὦσιν ἐλαίῳ, ἧττον θερμόν ἐστι καταχεόμενον, τοῦ ἐλαίου θερμοῦ ὄντος;
Why is warm water, if people have been anointed with oil, less warm when poured over them, even though the oil is warm?
ἢ διὰ τὸ λεαίνειν ὀλισθαίνει καὶ ἧττον ἐνδύνει;
Or is it because, by making things smooth, it slips off and penetrates less?
§24.2Διὰ τί τὰ ὕδατα ἐν τοῖς φρέασι μετὰ μεσημβρίαν γίνεται τοῦ θέρους θερμά;
Why does the water in wells become warm in the afternoon during summer?
ἢ διότι τηνικαῦτα ἤδη κεκράτηκεν τὸ θερμὸν τὸν ἀέρα;
Is it because by that time the heat has already mastered the air?
πρὸ μεσημβρίας δὲ τὸ θερμὸν λύει τε τὸ ψυχρὸν καὶ παύει· οὐχ ἅμα δὲ πέπαυται καὶ κρατεῖ. ἀλλ’ ὅταν ἐπιχρονίσῃ.
Before noon, the heat dissolves and puts an end to the cold; but it does not put an end to it and master it at the same time, but only when time has elapsed.
§24.3Διὰ τί τὸ ὕδωρ θερμότερον ἐνίοτε τῆς φλογὸς γινόμενον οὐ κατακάει τὰ ξύλα, ἡ δὲ φλὸξ κατακάει;
Why does water, though sometimes becoming hotter than flame, not burn wood, whereas flame does?
ἢ ὅτι ἡ μὲν φλὸξ λεπτομερές, καὶ τὸ ἀπ’ αὐτῆς πνεῦμα, τὸ δὲ ὕδωρ μεγαλομερές, ὥστε οὐκ εἰσδύεται;
Is it because flame consists of fine parts, as does the vapor from it, whereas water consists of large parts, so that it does not penetrate?
ἡ δὲ φλὸξ καὶ τὸ ἀπὸ τῶν ἀνθράκων διὰ λεπτότητα εἰσιὸν διαλύει.
But the flame and the vapor from charcoal, owing to their finess, enter and dissolve things.
§24.4Διὰ τί τὸ μὲν ὕδωρ τὸ ζέον οὐ τήκει, ἡ δὲ κοιλία τήκει;
Why does boiling water not dissolve food, whereas the stomach does?
πότερον ὅτι τὸ μὲν θερμὸν τὸ ἐν τῇ κοιλίᾳ εἰσέρχεται διὰ λεπτότητα, τὸ δὲ ὕδωρ οὐκ εἰσέρχεται διὰ παχύτητα;
Is it because the heat in the stomach enters owing to its fineness, whereas water does not enter owing to its coarseness?
ἢ διότι καὶ τὰ ἄλλα κωλύει τήκεσθαι τὸ ὑγρόν;
Or is it because moisture also prevents other things from dissolving?
οὐθὲν γὰρ ἐν ὑγρῷ τήκεται.
For nothing dissolves in moisture.
ἐν δὲ τῇ κοιλίᾳ τὸ ὑγρὸν εἰς τὴν κύστιν ὑπονοστοῦν οὕτω λύει.
But in the stomach, the moisture, retiring into the bladder, thus dissolves the food.
§24.5Διὰ τί τῶν ἀγγείων ὁ πυθμὴν οὐ κάει ἐνόντος τοῦ ὕδατος καὶ ζέοντος, ἀλλὰ καὶ φέρουσι τοῦ πυθμένος ἐχόμενοι, ἐξαιρεθέντος δὲ κάει;
Why does the bottom of vessels not burn when there is water in them and it is boiling, so that people can even carry them by holding onto the bottom, but when the water is removed, it burns?
ἢ ὅτι σβέννυται τὸ ἐγγινόμενον θερμὸν ἐν τῷ πυθμένι ὑπὸ τοῦ ὕδατος;
Is it because the heat generated in the bottom is extinguished by the water?
διὸ καὶ οὐ τήκεται τὰ τηκτά, ἂν μὴ ψόφος ἐμπέσῃ.
Wherefore also meltable things do not melt, unless a noise occurs.
§24.6Διὰ τί οὐχ ὑπερζεῖ τοῦ χειμῶνος ὁμοίως καὶ τοῦ θέρους τὸ ὕδωρ, οὐ μόνον ὁμοίως θερμαινόμενον, ἀλλὰ καὶ μᾶλλον καὶ ὁμοίως θερμὸν ὄν, καὶ ἔτι μᾶλλον;
Why does water not boil over in winter in the same way as in summer, not only when it is heated in the same way, but even when it is heated more and is equally hot, and even more so?
ἢ διότι ἡ ὑπέρζεσίς ἐστιν ἡ ἀναβολὴ τῶν πομφολύγων;
Is it because boiling over is the throwing up of bubbles?
τὸ μὲν οὗν ὕδωρ αὐτὸ θερμαίνεται τότε οὐθὲν ἧττον ἢ τοῦ ψύχους, αἱ δὲ πομφόλυγες αἴρεσθαι οὐ δύνανται ὁμοίως διὰ τὸ τὸν περιέχοντα ἀέρα εἶναι ψυχρόν, ἀλλὰ ἐλάττους τε τὰ μεγέθη αἴρονται ὑπὸ τοῦ ψύχους θλιβόμεναι, καὶ διακόπτοντος τοῦ ἀέρος ταχὺ διαπίπτουσιν, ὥστε ἐλάττους τε τῷ ὄγκῳ καὶ τῷ πλήθει γίνονται τοῦ χειμῶνος, τοῦ δὲ θέρους τοὐνανττίον.
The water itself, then, is heated at that time no less than in the cold weather, but the bubbles cannot rise in the same way because the surrounding air is cold, but they rise smaller in size, being compressed by the cold, and quickly collapse as the air breaks them, so that they become smaller in volume and quantity in winter, while in summer the opposite occurs.
ἡ δὲ ὑπέρζεσις γίνεται διὰ τὸ πλῆθος καὶ τὸ μέγεθος τοῦ ἀφροῦ.
And boiling over happens because of the quantity and size of the foam.
§24.7Διὰ τί τὸ μὲν θερμὸν ὕδωρ ῥυτιδοῖ, τὸ δὲ πῦρ θερμὸν ὂν οὔ;
Why does warm water cause wrinkles, whereas fire, though being hot, does not?
ἢ ὅτι τὸ μὲν πῦρ ποιεῖ πνεῦμα, ὥστε ὀγκοῖ;
Is it because fire produces vapor, so that it swells the skin?
περιτείνεται γὰρ τὸ δέρμα.
For the skin is stretched tight.
ἡ δὲ κάμψις ῥυτίς ἐστιν.
And a wrinkle is a bending.
§24.8Διὰ τί τῶν ἀγγείων οἱ πυθμένες θερμαινομένου τοῦ ὕδατος, ἕως ἂν ᾖ ψυχρὸν τὸ ὕδωρ, θερμότεροί εἰσιν;
Why are the bottoms of vessels, while the water is being heated, as long as the water is cold, hotter?
ἢ διότι ψυχροῦ μὲν ἔτι ὄντος τοῦ ὕδατος ἐγκατακλείεται τὸ θερμὸν καὶ ἀντιπεριίσταται εἴσω, κωλυόμενον ἐξιέναι, ὅταν δὲ διαθερμανθῇ τὸ ἐνὸν ὕδωρ, οὐκέτι ἀποστέγοντος, ἀλλὰ διαπνέοντος καὶ ἐλάττονος γινομένου τοῦ πυρὸς ψυχρότερος γίνεται ὁ πυθμήν, ὁμοίως ὥσπερ καὶ τὰ βαλανεῖα·
Is it because, while the water is still cold, the heat is shut in and undergoes counter-coarctation inward, being prevented from escaping, but when the water inside is thoroughly warmed, since it no longer blocks but lets the heat transpire and the fire becomes less, the bottom becomes colder?
καὶ γὰρ ταῦτα τοῦ χειμῶνος θερμότερα ἢ τοῦ θέρους διὰ τὸ ἐγκατακλείεσθαι τὸ θερμὸν ἐν τῷ χειμῶνι μᾶλλον ἢ ἐν τῷ θέρει ὑπὸ τοῦ περιέχοντος ἀέρος ὄντος ψυχροῦ.
Just as is the case with baths; for these too are warmer in winter than in summer, because the heat is shut in during winter more than in summer by the surrounding air, which is cold.
§24.9Διὰ τί τὸ μὲν ὕδωρ ζέον οὐκ ἐκπαφλάζει, τὸ δὲ ἔτνος καὶ ἡ φακῆ;
Why does water when boiling not sputter out, whereas thick soup and lentil soup do?
καίτοι κουφότερον τὸ ὕδωρ τούτων, τὰ δὲ κοῦφα ῥᾷον ῥῖψαι πόρρω.
And yet water is lighter than these, and light things are more easily thrown far.
ποιεῖ δὲ καὶ τὸ ἀργύριον ταὐτό, καὶ τοῦτο καθαιρόμενον· διὸ οἱ ἐν τῷ ἀργυροκοπείῳ καλλύνοντες κερδαίνουσιν· τὸ γὰρ διαρριπτούμενον συγκαλλύνοντες λαμβάνουσι τὰ λείψανα.
Silver also does the same when it is being purified; wherefore those who sweep in silver-foundries make a profit, for by sweeping they collect the remnants thrown about.
ἢ διότι ποιεῖ μὲν τὸν ἐκπαφλασμὸν τὸ θερμὸν ἐξατμίζον καὶ βιαζόμενον τὰ ἀντικραύοντα τῇ κατὰ φύσιν αὑτοῦ φορᾷ;
Or is it because the heat, as it evaporates, causes the sputtering by forcing its way against things that resist its natural motion?
τὸ μὲν οὖν ὕδωρ διὰ κουφότητα καὶ λεπτότητα οὐκ ἀποβιάζεται, ὥστε οὐκ ἀθροίζεται πολὺ θερμόν, ἀλλὰ πρὶν ἁλισθῆναι φθάνει διακόψαν τὸ ἀεὶ προσελθόν.
Water, then, owing to its lightness and fineness, is not forced out, so that much heat does not gather, but before it can collect, it succeeds in breaking through what always comes upon it.
τὰ δὲ ἔχοντα ἐν αὑτοῖς σῶμα, οἷον τὰ ῥοφήματα ἢ ὁ ἄργυρος, διὰ βάρος τὸ σωματοειδὲς ἔχοντα πολύ, καὶ ἀνταπωθοῦντα διὰ τὸ ἀποβιάζεσθαι βίᾳ, ἐξιόντος ἀποσφαιρίζεται ᾗ ἂν κρατήσῃ τὸ θερμόν·
But those things which have much substance in themselves, such as soups or silver, being very heavy owing to their bodily nature and resisting strongly because they are forced out by violence, are thrown off in spheres when the heat escapes, wherever the heat prevails.
οὐ γὰρ δίεισι διὰ πυκνότητα, ἀλλὰ κρατεῖ, ἕως ἂν ὑπὸ τοῦ ἐπιρρέοντος θερμοῦ ἀπορριφθῇ.
For it does not pass through owing to their density, but prevails until it is thrown off by the inflowing heat.
γίνεται δὲ πληγή, οὐκ ὦσις, διὰ τὸ ταχὺ φέρεσθαι τὸ θερμὸν κάτωθεν ἄνω.
And a blow occurs, not a push, because the heat is carried rapidly from below upward.