Clavis Artis

[Paul Ferguson]

"Much like the images it contains, the three-volume Clavis Artis remains a mystery of nearly unchartable depths. We know this much: the alchemical manuscript was published in Germany, sometime between the late seventeenth and early eighteenth centuries, although its title page claims it is thirteenth century (and written on dragon skin)."

https://publicdomainreview.org/collection/clavis-artis/

https://commons.wikimedia.org/wiki/Clavis_Artis