This research project proposes a study of β’s textual tradition and a comparative lexical analysis of one or more specific fields of knowledge covered in this work. β is one of the Italian translations of Tresor and it is transmitted by 13 manuscripts and 3 ancient prints. It features a historical section that ends with Montaperti’s battle and Guelphs’ exile from Florence, so it can be relatable with the first version of Tresor. It has a significant number of didactic-doctrinal interpolations and many additions from the Bible. All β’s manuscripts are Tuscan, in particular three were written in Florence and one in Pisa. The latter is the most ancient codex dating back to 13th century; while the other ones were written between 14th and 15th century. Through an accurate selection of loci critici and different reading’s analysis, it will be possible to identify the relationships between these witnesses. In some cases, it could be necessary to compare β’s manuscripts to the other Italian translations’ ones, because previous studies suggest a contamination between different translations. The second part of the research will provide an analysis of the lexicon pertaining to one or more specific semantic fields. This analysis will offer a comparison between the readings of β, the French critical text of Tresor and its varia lectio, and the readings of the other Italian translations of Brunetto’s treatise. This study will be both philological and linguistic. In fact, it will be verified if a particular outcome could be due to the manuscript tradition. Finally, the readings of β and of the other Italian translations will be studied from a lexical and semantic point of view.