London, Wellcome Institute MS. 3830. 557 pages. 200x140mm. 18th Century [c. 1750.] Bernardo Perez de Vargas. De re metallica. En qual se tratan muchos i diversos secretos del conocimiento de toda suerte de minerales... En la... Villa de Madrid en casa de Pierre Cosin. Aņo MDLXIX. [Illustrated with carefully executed wash drawings of chemical apparatus. This MS. is a transcript of the very rare printed edition.]