Leiden MS. Vossianus Chym. O. 4. 209 folios. Paper, with f142/173 in parchment. 155x120mm. Second half of 15th Century. Liber de Arte alchemiae [in Latin and German.] 1. f1 [Incantatory poems in German.] 2. f1v [Recipe in German.] 3. f2-5v [Recipes for potions of simples.] 4. f6-8, 11v-13v Vera et probata opera de alchemia sive parva practica. 5. f16-39v Quaedam et optima in alchemia [in Latin and German.] 6. f41 Jacob Ortlein, Albatio [in German.] 7. f42-69 [Recipes.] 8. f70-72v Libellus Alani. 9. f98-101v Pseudo Thomas Aquinas, Liber de modis transmutandi metalla. 10. f104-106 De auro et lazuro [in German.] 11. f106v-130 [Recipes.] 12. f143-148r Practica alchemiae [in German.] 13. f148v-153r Sehstha-Ben-Plat, Natura id est medicina oculorum. 14. f154v Versus de ponderinus in medicinis. 15. f161-176 [Various short pieces.] 16. f177-179v Proverbia philosophorum. 17. f185-193 [Systematic table of contents.] 18. f194v [Recipe for the red tincture.] 19. f196v-205 [Table of contents by place.] 20. f205v-209v [Additions, mostly on the making of soaps.]