§18Γένεσις μὲν οὖν ἐστὶν ἡ πρώτη μέθεξις ἐν τῷ θερμῷ τῆς θρεπτικῆς ψυχῆς, ζωὴ δ’ ἡ μονὴ ταύτης.
Generation, then, is the initial participation in heat by the nutritive soul, and life is the maintenance of this.
Νεότης δ’ ἐστὶν ἡ τοῦ πρώτου καταψυκτικοῦ μορίου αὔξησις, γῆρας δ’ ἡ τούτου φθίσις, ἀκμὴ δὲ τὸ τούτων μέσον.
Youth is the growth of the primary cooling part, old age is its decay, and the prime of life is the middle state between these.
Τελευτὴ δὲ καὶ φθορὰ βίαιος μὲν ἡ τοῦ θερμοῦ σβέσις καὶ μάρανσις· φθαρείη γὰρ ἂν δι’ ἀμφοτέρας ταύτας τὰς αἰτίας, ἡ δὲ κατὰ φύσιν τοῦ αὐτοῦ τούτου μάρανσις διὰ χρόνου μῆκος γινομένη καὶ τελειότητα.
Death and destruction, when violent, are the extinction and waning of the heat; for destruction can occur through both of these causes. But natural death is the waning of this same heat, occurring through length of time and completion.
Τοῖς μὲν οὖν φυτοῖς αὔανσις, ἐν δὲ τοῖς ζῴοις καλεῖται θάνατος.
In plants this is called drying up, but in animals it is called death.
Τούτου δ’ ὁ μὲν ἐν γήρᾳ θάνατος μάρανσις τοῦ μορίου δι’ ἀδυναμίαν τοῦ καταψύχειν ὑπὸ γήρως.
And of this, death in old age is the waning of the part through the inability to cool caused by old age.
Τί μὲν οὖν ἐστὶ γένεσις καὶ ζωὴ καὶ θάνατος, καὶ διὰ τίνας αἰτίας ὑπάρχουσι τοῖς ζῴοις, εἴρηται.
What generation, life, and death are, and through what causes they belong to animals, has now been said.
§19Δῆλον δ’ ἐκ τούτων καὶ διὰ τίν’ αἰτίαν τοῖς μὲν ἀναπνέουσι τῶν ζῴων ἀποπνίγεσθαι συμβαίνει ἐν τῷ ὑγρῷ, τοῖς δ’ ἰχθύσιν ἐν τῷ ἀέρι· τοῖς μὲν γὰρ διὰ τοῦ ὕδατος ἡ κατάψυξις γίνεται, τοῖς δὲ διὰ τοῦ ἀέρος, ὧν ἑκάτερα στερίσκεται μεταβάλλοντα τοὺς τόπους.
From these it is also clear for what cause it happens to breathing animals to drown in liquid, and to fish in air; for to the former cooling occurs through water, to the latter through air, and both are deprived of these when they change their places.
Ἡ δ’ αἰτία τῆς κινήσεως τοῖς μὲν τῶν βραγχίων τοῖς δὲ τοῦ πνεύμονος, ὧν αἰρομένων καὶ συνιζόντων τὰ μὲν ἐκπνέουσι καὶ εἰσπνέουσι τὰ δὲ δέχονται τὸ ὑγρὸν καὶ ἐξιᾶσιν, ἔτι δ’ ἡ σύστασις τοῦ ὀργάνου, τόνδ’ ἔχει τὸν τρόπον.
The cause of the movement, in the one case of the gills and in the other of the lung—by the raising and collapsing of which they breathe out and breathe in on the one hand, and receive and discharge the liquid on the other—and further, the structure of the organ, is in the following manner.
§20Τρία ἐστὶ τὰ συμβαίνοντα περὶ τὴν καρδίαν, ἃ δοκεῖ τὴν αὐτὴν φύσιν ἔχειν, ἔχει δ’ οὐ τὴν αὐτήν, πήδησις καὶ σφυγμὸς καὶ ἀναπνοή.
There are three things that occur concerning the heart, which seem to have the same nature but do not have the same, namely: palpitation, pulsation, and respiration.
Πήδησις μὲν οὖν ἐστὶ σύνωσις τοῦ θερμοῦ τοῦ ἐν αὐτῇ διὰ κατάψυξιν περιττωματικὴν ἢ συντηκτικήν, οἷον ἐν τῇ νόσῳ τῇ καλουμένῃ παλμῷ, καὶ ἐν ἄλλαις δὲ νόσοις, καὶ ἐν τοῖς φόβοις δέ· καὶ γὰρ οἱ φοβούμενοι καταψύχονται τὰ ἄνω, τὸ δὲ θερμὸν ὑποφεῦγον καὶ συστελλόμενον ποιεῖ τὴν πήδησιν, εἰς μικρὸν συνωθούμενον οὕτως ὥστ’ ἐνίοτ’ ἀποσβέννυσθαι τὰ ζῷα καὶ ἀποθνήσκειν διὰ φόβον καὶ διὰ πάθος νοσηματικόν.
Palpitation, then, is the condensation of the heat in the heart due to a cooling caused by residues or melting, as in the disease called tremor, in other diseases, and in fears; for those who fear are cooled in the upper parts, and the heat, escaping and contracting, causes palpitation, being condensed into so small a space that sometimes animals are extinguished and die of fear and of morbid affection.
Ἡ δὲ συμβαίνουσα σφύξις τῆς καρδίας, ἣν ἀεὶ φαίνεται ποιουμένη συνεχῶς, ὁμοία φύμασίν ἐστιν, ἣν ποιοῦνται κίνησιν μετ’ ἀλγηδόνος διὰ τὸ παρὰ φύσιν εἶναι τῷ αἵματι τὴν μεταβολήν.
On the other hand, the pulsation of the heart which occurs, and which it is seen to make continuously, is similar to tumors, which make a painful movement because the change in the blood is contrary to nature.
Γίνεται δὲ μέχρι οὗ ἂν πυωθῇ πεφθέν.
And this occurs until it has been concocted and turned into pus.
Ἔστι δ’ ὅμοιον ζέσει τοῦτο τὸ πάθος· ἡ γὰρ ζέσις γίνεται πνευματουμένου τοῦ ὑγροῦ ὑπὸ τοῦ θερμοῦ· αἴρεται γὰρ διὰ τὸ πλείω γίνεσθαι τὸν ὄγκον.
This affection is similar to boiling; for boiling occurs when liquid is vaporized by heat, since it is raised because the volume becomes greater.
Παῦλα δ’ ἐν μὲν τοῖς φύμασιν, ἐὰν μὴ διαπνεύσῃ, παχυτέρου γινομένου τοῦ ὑγροῦ, σῆψις, τῇ δὲ ζέσει ἡ ἔκπτωσις διὰ τῶν ὁριζόντων.
And the cessation in tumors is putrefaction, if it does not evaporate, because the fluid becomes thicker, while in boiling it is the overflow beyond the boundaries.
Ἐν δὲ τῇ καρδίᾳ ἡ τοῦ ἀεὶ προσιόντος ἐκ τῆς τροφῆς ὑγροῦ διὰ τῆς θερμότητος ὄγκωσις ποιεῖ σφυγμόν, αἰρομένη πρὸς τὸν ἔσχατον χιτῶνα τῆς καρδίας.
But in the heart, the expansion of the fluid constantly supplied from food, caused by heat, produces pulsation, raising itself toward the outermost membrane of the heart.
Καὶ τοῦτ’ ἀεὶ γίνεται συνεχῶς· ἐπιρρεῖ γὰρ ἀεὶ τὸ ὑγρὸν συνεχῶς, ἐξ οὗ γίνεται ἡ τοῦ αἵματος φύσις· πρῶτον γὰρ ἐν τῇ καρδίᾳ δημιουργεῖται.
And this occurs continuously; for the fluid from which the nature of blood is formed constantly flows in, since blood is first manufactured in the heart.
Δῆλον δ’ ἐν τῇ γενέσει ἐξ ἀρχῆς· οὔπω γὰρ διωρισμένων τῶν φλεβῶν φαίνεται ἔχουσα αἷμα.
This is clear in generation from the beginning; for before the veins are yet distinguished, the heart is seen containing blood.
Καὶ διὰ τοῦτο σφύζει μᾶλλον τοῖς νεωτέροις τῶν πρεσβυτέρων· γίνεται γὰρ ἡ ἀναθυμίασις πλείων τοῖς νεωτέροις.
And for this reason it pulses more in the young than in the old; for evaporation is greater in the young.
Καὶ σφύζουσιν αἱ φλέβες πᾶσαι, καὶ ἅμα ἀλλήλαις, διὰ τὸ ἠρτῆσθαι ἐκ τῆς καρδίας.
And all the veins pulse, and simultaneously with one another, because they are suspended from the heart.
Κινεῖ δ’ ἀεί· ὥστε κἀκεῖναι αἰεί, καὶ ἅμα ἀλλήλαις, ὅτε κινεῖ.
The heart is always in motion; so they also are always in motion, and simultaneously with one another, when it moves.
Ἀναπήδησις μὲν οὖν ἐστὶν ἡ γινομένη ἄντωσις πρὸς τὴν τοῦ ψυχροῦ σύνωσιν, σφύξις δ’ ἡ τοῦ ὑγροῦ θερμαινομένου πνευμάτωσις.
Palpitation, then, is the rebound that occurs against the condensation of the cold, while pulsation is the vaporization of the heated fluid.