* The name ‘Fulcanelli’ may be a compound of Vulcan, patron deity of alchemy, and Helios, the sun god. The search for anagrams has proved inconclusive: Lucien Fall, fil nucléal, le cul final, etc. The preface to the second edition (1957) was written by the master’s young pupil, Eugène Canseliet. Canseliet belonged to a group called ‘The Brothers of Heliopolis’, two of whom lived in the Pigalle district, near Helbronner’s laboratory, at 59, Rue Rochechouart. They included an absinthe-addicted painter called Champagne, a son of Ferdinand de Lesseps (architect of the Suez Canal), and a man who worked for the Rhône-Poulenc pharmaceutical company. This address was listed in The Foreign Bachelor’s Secret Guide to Paris as the address of a male brothel called the ‘Sacré Cœur’. The Abwehr agent was evidently aware of this, and one can only imagine what adventures he had as a result.