Alchemical Ciphers: Knowledge Networks & Material Culture of the Book
On Tuesday, March 12, 2024, I was invited by the Albert Lepage Center for History in the Public Interest to share my research into textual technologies of alchemical secrecy through the lens of seventeenth-century textual materiality. Using the case study of a father-son medical notebook housed at the British Library, I unpacked the alchemical and astrological themes of prognostication, projection, and transmutation present in this manuscript, as well as the evidence of seventeenth-century knowledge networks illustrated through manuscript culture — emphasizing the historical conclusions that can be drawn through interdisciplinary scholarly collaboration.
I began my talk by introducing my methodology of ‘material bibliographical analysis’ and the ways in which my skills complement and enhance the knowledge and training of my collaborators. I illustrated the evidence and historical leads that can be gleaned from a close, material investigation of the alchemical manuscript Sloane MS 1902.
Much of the knowledge contained on the pages of medical notebook Sloane MS 1902 was produced by Elizabethan polymath John Dee (1527–1608), later compiled and added to by his son Arthur Dee (1579–1651). This small composite manuscript (10 cm x 12 cm), held by the British Library, is a source of insight into the types of medical alchemy and astrology engaged in by physicians and adepts alike during the sixteenth and seventeenth centuries.
A ciphertext, tabula recta, and cipher key are all present in the manuscript Sloane MS 1902. A collaborative effort was necessary to decrypt the ciphertext, aided by the scholarly community of HistoCrypt.
In the context of early modern alchemy, ciphers are most commonly found in laboratory notes or medical notebooks. The inclusion of this alchemical recipe for producing the Philosophers’ Stone within the manuscript in which it was discovered illustrates the effort to simultaneously obscure and circulate alchemical and astrological medical knowledge among practitioners.
Our initial assumption for the cryptanalytical process for Hermeticae Philosophiae Medulla was that the cipher table was used in both the encryption of the plaintext solution and the decryption of the adjacent ciphertext. For the given cipher table, the letters A to M can encipher, or decipher, only to the letters N to Z, and the converse.
However, the cipher table in Sloane MS 1902 contains a crucial error.
The first row corresponding to (AB) should be 24 letters in alphabetical order, but the letter following “l” in the top register is “n” rather than “m.” This initial mistake causes a ripple effect that renders this cipher table unusable as corresponding letters are off by one register throughout. The cipher table in its erroneous form could not have been used to encrypt the adjacent recipe.
By locating the most frequent Latin word that could possibly correspond to a ciphertext word, it was possible to derive part of the key phrase for the cipher. Then, the cipher key can be used for selecting which of the rows of the cipher table will be used for each letter in the ciphertext.
Each letter in the key is adjacent to corresponding letters in the cipher table which comprise the Latin phrase:
Sic alter Iason aurea felici portabis uellera colcho
“Like a new Jason you will carry the Golden Fleece to the lucky Colchian.”
Once we decrypted the alchemical recipe for the coveted ‘Philosophers’ Stone’ contained within the ciphertext, we were able to connect this example of the Hermeticae Philosophiae Medulla cipher to other alchemical manuscripts in diverse collections, and ultimately craft a potential practical chemical experiment performed by the historical actors involved.
Arthur Dee is explicit in the dedication of his original manuscript, Arca Arcanorum (1634), that he has successfully achieved the Philosophers’ Stone.
I have at last (by divine help) solved the riddles of knowledge. An example of this, in this climax of my life, with some select manuscripts I dedicate (under your auspices) to devotees of alchemy.
To conclude the talk, I presented an example from the Falvey Library Distinctive Collections stacks of astrological prognostication found in the breviary, Martyrologium Romanum Gregorii XIII (1661).
Dr. Meg Piorko is the Distinctive Collections Librarian and an Adjunct Professor at Villanova University.
Relevant publications for further reading:
