Galen, On the Composition of Drugs according to Kind 1.1

Galen’s surviving work is vast, and there was once even more of it. Here he learns the hard way about the importance of keeping a backup copy…

ἤδη μοι καὶ πρόσθεν ἐγέγραπτο πραγματεία, δυοῖν μὲν ἐξ αὐτῆς τῶν πρώτων βιβλίων ἐκδοθέντων, ἐγκαταλειφθέντων δὲ ἐν τῇ κατὰ τὴν ἱερὰν ὁδὸν ἀποθήκῃ μετὰ τῶν ἄλλων, ἡνίκα τὸ τῆς Εἰρήνης τέμενος ὅλον ἐκαύθη, καὶ κατὰ τὸ παλάτιον αἱ μεγάλαι βιβλιοθῆκαι. τηνικαῦτα γὰρ ἑτέρων τε πολλῶν ἀπώλοντο βιβλία καὶ τῶν ἐμῶν ὅσα κατὰ τὴν ἀποθήκην ἐκείνην ἔκειτο, μηδενὸς τῶν ἐν Ῥώμῃ φίλων ἔχειν ὁμολογοῦντος ἀντίγραφα τῶν πρώτων δυοῖν. ἐγκειμένων οὖν τῶν ἑταίρων αὖθίς με γράψαι τὴν αὐτὴν πραγματείαν, ἀναγκαῖον ἔδοξέ μοι δηλῶσαι περὶ τῶν προεκδοθέντων, ὅπως μή τις προεντυχὼν αὐτοῖς ποτε ζητοίη τὴν αἰτίαν τοῦ δίς με περὶ τῶν αὐτῶν πραγματεύσασθαι.

I had previously written this treatise, and published the first two books of it, leaving them in the warehouse on the Sacred Way with the other books, when the Temple of Peace was entirely destroyed by fire, along with the great libraries on the Palatine. At that time the books of many other people, and my own, which were in storage in that warehouse, were all destroyed, and none of my friends in Rome said that they had copies of those first two books. So, as my pupils have been asking me to write the same treatise anew, I thought that I must explain about the first edition, so that no one who happens upon those books will ask the reason for my having treated the same subjects twice over.

This fire in the area of Rome around the Temple of Peace took place in AD 192.