Note 176 — IV On the Use of Engraved and Carved Gems as Talismans
Reading edition
Konrad v. Megenberg, “Buch der Natur,” ed. Pfeiffer, Stuttgart, 1861, p. 448; see also Johannis de Cuba, “Hortus Sanitatis” [Strassburg, 1483], tractatus de lapidibus, cap. xliii.