Vril, The Power of the Coming Race by Edward Bulwer-Lytton
The Victorian science fiction novel from which introduced the concept of 'Vril.
Legendary for his turgid prose ("it was a dark and stormy night...") Bulwer-Lytton's pioneering science fiction novel "Vril" was taken very seriously by 19th Century Atlantis fans (for instance, Scott-Elliot). Vril is a mysterious energy which is used by Lytton's subterranian race (refugees from the Deluge) to power their advanced civilization; it was later treated as a reality by occultists. The plot of this book was recycled for numerous 'B' pulp scifi movies and assorted crank theories.