London, Wellcome Institute MS. 520. 66 folios. 310x215mm. 15th Century [1453.] Miscellanea Alchemica XV. 1. f1-34 J. de Rupescissa. De consideratione Quintae Essentiae. 2. f34v-44v R. Lullius. Ars operativa. 3. f44-49 [Receipts for the Aurum potabile.] 4. f49-51 Frater Elias. Vade mecum. 5. f51-65 [Miscellaneous medical receipts.]