The Leyden papyrus X (P. Leyden X) is a papyrus codex written in Greek at about the end of the 3rd century A.D. or perhaps around 250 A.D. and buried with its owner, and today preserved at Leiden in the Netherlands.
The Leiden papyrus was discovered at Thebes in Egypt, together with the , which was probably written by the same scribe, and many Greek magical papyri, in the early 19th century by an adventurer calling himself Jean d'Anastasi, holding the office of Swedish vice-consul in Alexandria. In 1828 he sold a number of papyri to the Dutch government, which were lodged at the Leiden University Library, and labelled alphabetically from A to Z.
The papyri were first published and translated into Latin by Conrad Leemans in 1885 (Papyri graeci musei antiquarii publici Lugduni Batavi). Papyri A to U relate to matters concerning Ancient Egyptian law. Papyri V, W and X deal with alchemy.
The related was found together with these, and Anastasy donated it to Sweden in 1832. It was first published by Otto Lagercrantz in 1913 (Papyrus Graecus Holmiensis). Whereas the Leiden papyrus X deals with metallurgy, the Stockholm papyrus deals with gems, pearls and textile dyeing.
Papyrus V contains a recipe for a mystical ink made of misy (oxidized pyrite ores, a mix of copper and iron sulfates), green vitriol, oak apple, gum, and of a substance composed of 7 perfumes and 7 flowers. It has a recipe for purifying gold with cement royal. It gives a list of 37 secret names of plants, invented by holy scribes, containing code names such as "snake's blood" , "rat's tail", and "lion's semen". Traces of this nomenclature survive in botanical names, like in German "Löwenzahn" and wolf's milk; also in dragon's blood, which probably still denotes the same resin as in ancient times. Some of these aliases are given by Dioscorides, but with different meanings.
Papyrus W contains magical invocations and Judaeo-Gnostic content. The 7 perfumes are given as: styrax dedicated to Saturn, malabathrum to Jupiter, costus to Mars, frankincense to the Sun, nard to Venus, cassia to Hermes, myrrh to the Moon. The 7 flowers are: nard, marjoram, lily, lotus, buttercup, narcissus, white violet.