Secreta Secretorum (Antwerp: Mathias van der Goes, c. 1486-91)
Public domain
Incunable Latin edition of the 'Secretum secretorum' (Secret of Secrets), the medieval pseudo-Aristotelian letter of advice to Alexander the Great that blends statecraft, medicine, physiognomy, astrology and alchemy. A 22-leaf fifteenth-century printing from Antwerp, catalogued by NLM among its Incunabula. Digitized by the U.S. National Library of Medicine (public domain).
Downloading this requires a membership tier that includes downloads.