The Magical Elements (Heptameron):

According to Joseph Peterson, the Magical Elements is a concise handbook of ritual magick, and was translated by Robert Turner in 1655. It appeared in Turner’s collection of esoteric texts along with pseudo-Agrippa's Fourth Book of Occult Philosophy. The text is attributed to Peter de Abano (1250-1316), though Mr. Peterson feels that this is probably spurious, since de Abano’s work betrays “no acquaintance with the occult sciences.” The Magical Elements is primarily based upon Solomonic literature, and even appears in the Hebrew Key of Solomon (Mafteah Shelomoh, fol 35a ff) under the title The Book of Light.

Agrippa published his Three Books… without including any practical ceremonies. In the last chapter of the third book, he tells us his reason: “For we have delivered this art in such a manner, that it may not be hid from the prudent and intelligent, and yet may not admit wicked and incredulous men to the mysteries of these secrets, but leave them destitute and astonished, in the shade of ignorance and desperation.”

However, there was apparently some call for a “how to” section of the work regardless of Agrippa’s original intention. Thus the Magical Elements was written as a companion volume, including the necessary circle castings, invocations, consecrations, seals, etc. As Mr. Peterson suggests above, the book was very likely not written by the famed physician Peter de Abano. The death of Abano occurred in 1250, while the Heptameron did not make its appearance for another two hundred years.