All five editions in this Sammelband are OF THE GREATEST RARITY. A number of esoteric writings of varying lengths went under the title of "Solomon's Key" and mostly circulated in manuscript. Some seventeenth and eighteenth-century editions survive, but they are poorly described in the literature. Luppius was a printer in Halle, and apart from having bookshops in Wesel, Duisburg and Frankfurt, he used Jacob Claus's bookshop "in der Princen-Strasse" in Amsterdam as a retail outlet for his "Mystique Schrifften."