§21Ἡ δ’ ἀναπνοὴ γίνεται αὐξανομένου τοῦ θερμοῦ, ἐν ᾧ ἡ ἀρχὴ ἡ θρεπτική.
Respiration, on the other hand, occurs as the heat increases, in which is the nutritive principle.
Καθάπερ γὰρ καὶ τἆλλα δεῖται τροφῆς, κἀκεῖνο, καὶ τῶν ἄλλων μᾶλλον· καὶ γὰρ τοῖς ἄλλοις ἐκεῖνο τῆς τροφῆς αἴτιόν ἐστιν.
For just as other things require nourishment, so does that heat, and even more than the others; for indeed, for the others, that heat is the cause of their nourishment.
Ἀνάγκη δὴ πλέον γινόμενον αἴρειν τὸ ὄργανον.
Therefore, as it becomes greater, it must raise the organ.
Δεῖ δ’ ὑπολαβεῖν τὴν σύστασιν τοῦ ὀργάνου παραπλησίαν μὲν εἶναι ταῖς φύσαις ταῖς ἐν τοῖς χαλκείοις· οὐ πόρρω γὰρ οὔθ’ ὁ πνεύμων οὔθ’ ἡ καρδία πρὸς τὸ δέξασθαι σχῆμα τοιοῦτον· διπλοῦν δ’ εἶναι τὸ τοιοῦτον· δεῖ γὰρ ἐν τῷ μέσῳ τὸ θρεπτικὸν εἶναι τῆς φυσικῆς δυνάμεως.
And we must conceive the structure of the organ to be very similar to the bellows in smithies; for neither the lung nor the heart is far from accepting such a shape; and such an organ must be double, for the nutritive part of the natural power must be in the middle.
Αἴρεται μὲν οὖν πλεῖον γενόμενον, αἰρομένου δ’ ἀναγκαῖον αἴρεσθαι καὶ τὸ περιέχον αὐτὸ μόριον.
Now, as it becomes greater, it is raised, and when it is raised, the part surrounding it must also be raised.
Ὅπερ φαίνονται ποιεῖν οἱ ἀναπνέοντες· αἴρουσι γὰρ τὸν θώρακα διὰ τὸ τὴν ἀρχὴν τὴν ἐνοῦσαν αὐτῷ τοῦ τοιούτου μορίου ταὐτὸ τοῦτο ποιεῖν· αἰρομένου γάρ, καθάπερ εἰς τὰς φύσας, ἀναγκαῖον εἰσφέρειν τὸν ἀέρα τὸν θύραθεν, καὶ ψυχρὸν ὄντα καὶ καταψύχοντα σβεννύναι τὴν ὑπεροχὴν τὴν τοῦ πυρός.
This is just what breathing creatures are seen to do; for they raise the chest because the principle of such a part existing within it does this very same thing; for when it is raised, just as into bellows, it is necessary to draw in the air from outside, which, being cold and cooling, extinguishes the excess of the fire.
Ὥσπερ δ’ αὐξανομένου ᾔρετο τοῦτο τὸ μόριον, καὶ φθίνοντος ἀναγκαῖον συνίζειν, καὶ συνίζοντος ἐξιέναι τὸν ἀέρα τὸν εἰσελθόντα πάλιν, εἰσιόντα μὲν ψυχρὸν ἐξιόντα δὲ θερμὸν διὰ τὴν ἁφὴν τοῦ θερμοῦ τοῦ ἐνόντος ἐν τῷ μορίῳ τούτῳ, καὶ μάλιστα τοῖς τὸν πνεύμονα ἔναιμον ἔχουσιν· εἰς πολλοὺς γὰρ οἷον αὐλῶνας τὰς σύριγγας ἐμπίπτειν τὰς ἐν τῷ πνεύμονι, ὧν παρ’ ἑκάστην παρατέτανται φλέβες, ὥστε δοκεῖν ὅλον εἶναι τὸν πνεύμονα πλήρη αἵματος.
And just as this part was raised when the heat increased, so when it decays it must collapse, and as it collapses, the air that entered must go out again—entering cold but going out hot because of contact with the heat existing within this part, and especially in those who have a lung rich in blood; for the tubes in the lung fall into many channels, as it were, along each of which veins are stretched, so that the entire lung seems to be full of blood.
Καλεῖται δ’ ἡ μὲν εἴσοδος τοῦ ἀέρος ἀναπνοή, ἡ δ’ ἔξοδος ἐκπνοή.
And the inflow of air is called inspiration, and the outflow expiration.
Καὶ ἀεὶ δὴ τοῦτο γίνεται συνεχῶς, ἕως περ ἂν ζῇ καὶ κινῇ τοῦτο τὸ μόριον συνεχῶς.
And this indeed occurs always continuously, so long as the animal lives and keeps this part continuously in motion.
Καὶ διὰ τοῦτο ἐν τῷ ἀναπνεῖν καὶ ἐκπνεῖν ἐστὶ τὸ ζῆν.
And for this reason, life consists in breathing in and breathing out.
Τὸν αὐτὸν δὲ τρόπον καὶ τοῖς ἰχθύσιν ἡ κίνησις γίνεται τῶν βραγχίων.
In the same manner, the movement of the gills occurs also in fish.
Αἰρομένου μὲν γὰρ τοῦ θερμοῦ τοῦ ἐν τῷ αἵματι διὰ τῶν μορίων αἴρονται καὶ τὰ βράγχια, καὶ διιᾶσι τὸ ὕδωρ· κατιόντος δὲ πρὸς τὴν καρδίαν διὰ τῶν πόρων καὶ καταψυχομένου συνίζουσι, καὶ ἀφιᾶσι τὸ ὕδωρ.
For when the heat in the blood rises through these parts, the gills are also raised, and they let the water pass through; but when the heat descends toward the heart through the passages and is cooled, they collapse, and they discharge the water.
Ἀεὶ δ’ αἰρομένου τοῦ ἐν τῇ καρδίᾳ, ἀεὶ δέχεται πάλιν καταψυχομένου.
And as the heat in the heart is always rising, it always receives it again when it is cooled.
Διὸ κἀκείνοις τοῦ ζῆν καὶ μὴ ζῆν τὸ τέλος ἐστὶν ἐν τῷ ἀναπνεῖν, καὶ τούτοις ἐν τῷ δέχεσθαι τὸ ὑγρόν.
Therefore, just as for those creatures the limit of living and not living is in breathing, so for these it is in receiving the liquid.
Περὶ μὲν οὖν ζωῆς καὶ θανάτου καὶ τῶν συγγενῶν ταύτης τῆς σκέψεως, σχεδὸν εἴρηται περὶ πάντων.
Thus, concerning life and death and all matters akin to this inquiry, nearly everything has been said.
Περὶ δὲ ὑγιείας καὶ νόσου οὐ μόνον ἐστὶν ἰατροῦ ἀλλὰ καὶ τοῦ φυσικοῦ μέχρι του τὰς αἰτίας εἰπεῖν.
On the other hand, regarding health and disease, it belongs not only to the physician but also to the natural philosopher to state their causes up to a certain point.
Ἧι δὲ διαφέρουσι καὶ ᾗ διαφέροντα θεωροῦσιν, οὐ δεῖ λανθάνειν, ἐπεὶ ὅτι γε σύνορος ἡ πραγματεία μέχρι τινός ἐστι, μαρτυρεῖ τὸ γινόμενον· τῶν τε γὰρ ἰατρῶν ὅσοι κομψοὶ ἢ περίεργοι, λέγουσί τι περὶ φύσεως καὶ τὰς ἀρχὰς ἐκεῖθεν ἀξιοῦσι λαμβάνειν, καὶ τῶν περὶ φύσεως πραγματευθέντων οἱ χαριέστατοι σχεδὸν τελευτῶσιν εἰς τὰς ἀρχὰς τὰς ἰατρικάς.
But we must not fail to notice how they differ and in what different ways they investigate them, since the fact itself witnesses that their study is, up to a certain point, borderland; for those of the physicians who are refined or inquisitive say something about nature and claim to derive their principles from there, and the most accomplished of those who have treated of nature end up nearly at medical principles.