Uno sconosciuto trattato ortografico di Giorgio Valla: il "De recto modo scribendi liber" (ante 1469)

The article presents a treatise on Latin spelling by Giorgio Valla hitherto unknown to scholars. This treatise has come down to us in two version, each one certified by just one witness : the Schlägl, ms. Cpl. 153 and the Toledo, ms. BCT 99-29. After a description of the two codexes, the content is analysed, starting from a comparison with the latter and much shorter printed work by the same author : the De ratione scribendi. The core of the work consists of an examination of the two manuscript versions, with special attention to the author’s attitude towards the subject matter, the sources used, and the different target readership. The Schlägl codex is the copy of a text prepared by Valla for his students, probably carried out by Johann von Rabenstein, while the Toledo codex is an extended and corrected revision of that text, which Valla prepared as a gift to Count Giovanni Attendolo Bolognini.