Fulcanelli is inextricably linked to the modern idea of alchemy. Fulcanelli is only known through his books Mystery of the Cathedrals (Le Mystere des Cathedrales) and Dwellings of the Philosophers (Les Demeures Philosophales) , first published in French in Paris in 1926 and 1929 respectively.
The books were published by Fulcanelli's pupils Eugene Canseliet and Jean-Julien Champagne. Many claim to have met Fulcanelli but since the two books are the only definite link to his identity, and these two are the ones through whom these books came to be published, all these claims are inherently improvable. Also, considering Canseliet's and Champagne's known writings, Fulcanelli's text cannot be attributed to them. The text bespeaks a mastery of symbology, architecture, art and history and an exceptional intellectual clarity and refinement of expression. The same feat has not been duplicated since. There are rumors of a third book, Finis Gloria Mundi, but this appears never to have been published.
In Le Mystere, Fulcanelli interprets messages encoded in the architecture and sculptures and reliefs of the French Gothic cathedrals. It appears that Fulcanelli cannot have inferred his expositions of alchemy from the art itself, rather he is using this art as a springboard for discussing a field of knowledge that he has been separately initiated to.
The most quoted passage of Fulcanelli is the analysis of the symbols of the cyclic cross of Hendaye, added at the end of Le Mystere in a subsequent edition. This passage discusses a double catastrophy to befall the world at a future time. This passage makes clear allusions to the end of a world age and a re-emergence on the other side of the change in a world created anew. This is among the more explicit references to something comparable to the Cassiopaean concept of the Wave.
There is an account of Eugene Canseliet having met Fulcanelli at a castle in the Pyrenees in 1954. This account described Fulcanelli as having acquired both male and female characteristics and other oddities of circumstance. However, upon Canseliet's return, events were only remembered as if through a hypnotic veil.
Laura Knight-Jadczyk discusses the subject of alchemy in the Grail and Wave series and Ancient Science. The general conclusion is that alchemy is a branch of the science of spiritual transformation and access to higher densities but that any materialistic or literal interpretation of the symbols was bound to lead one astray.
There is much undemonstrable myth but the written work stands on its own and the identity of Fulcanelli remains unestablished to this day.