Clavis Artis is an alchemical manuscript published in Germany in three volumes in the late 17th or early 18th century, attributed to Zoroaster (Zarathustra). It features numerous watercolor illustrations depicting alchemical images, as well as pen drawings of laboratory instruments.
The title page contains the following text:
rabbi and Jewish
The original was written by the author
over a skin of dragon
Year of the World
Following text was translated
from Arabic into German
in the Year of Christ
SVFR and AC
Three copies of the manuscript are known to exist, one at the Biblioteca dell’Accademia Nazionale dei Lincei in Rome, one at the Biblioteca Civica Attilio Hortis in Trieste, and one at the Bayerische Staatsbibliothek in Munich. There is no information about the author and the origin of the manuscript, but there are references to a Rosicrucian order (Orden der Gold- und Rosenkreutzer).