"The Rosary of the Philosophers" ( Rosarium philosophorum sive pretiosissimum donum Dei ) by Spanish physician, religious reformer and alchemist Arnaldus de Villa Nova, is a 16th century essential alchemical treatise. It was published in 1550 as part II of De Alchimia Opuscula complura veterum philosophorum (Frankfurt). The treatise included a series of 20 woodcuts with German language captions, reproduced in this reprint in form of images.