Contains seventeen texts bound together, written in different hands. The margins are badly cropped, and some leaves are missing.
ff. 1r-2: Commentary to 'Mercher ad Fledium. Liber de lapide qui vocatur Rebis'.
ff. 2-68v: 'Experimenta' ('Experiments').
ff. 68v-72v: Alchemic recipes.
ff. 73r-99: 'Lumen luminum minus et perfecti magisteri' by Abū Bakr Muḥammad ibn Zakarīyā Rāzī (known in the West as 'Rhazes' and 'Rasis', version by Wynandus de Ruffo Clipeo).
ff. 94v-95r: Alchemic recipes.
ff. 95v-96v: Instructions on how to summon a demon called Baron (with table).
ff. 97r-99r: 'Liber de sculptura gemmarum' by Marbode of Rennes (?).
ff. 99r-102r: 'De sculpturis lapidum'.
ff. 102r-120r: 'De consecratione lapidum'.
ff. 121r-123r: List of the alchemic recipes contained in the 'Experimenta' (ff. 2-68v).
f. 123r: Alchemic recipe (in Latin).
f. 123v: Alchemic recipe (in German).
f. 124r: 'Figurae corporum planetarum').
f. 124r: 'Nota secretum lune et solis'.
f. 124r: 'Tuciam calcinationem'.
ff. 124v-125r: 'Synonima alchemica'.
f. 125v: 'Congelacio mercurii per scientiam sive sublimacio'.
The texts are described separately, under MS.121/ff. 1r-2; MS.121/; MS.121/ff. 2-68v; MS.121/ff. 68v-72v; MS.121/ff. 73r-99; MS.121/ff. 94v-95r; MS.121/ff. 95v-96v; MS.121/ff. 97r-99r; MS.121/ff. 99r-102r; MS.121/ff. 102r-120r; MS.121/ff. 121r-123r; MS.121/f. 123r; MS.121/f. 123v; MS.121/f. 124r; MS.121/f. 124r; MS.121/f. 124r; MS.121/ff. 124v-125r; MS.121/f. 125v;
The script, which is very round and clear in both main treatises, could be Spanish.
Ornamentation consists of rather roughly ornamented red capitals, ornamental scroll round Roman numerals marking foliation, and occasional hands in the margin.