You may be interested in John Uri Lloyd’s Etidorhpa or the End of the Earth recently added to Project Gutenberg.
This is an interesting book. The title is Aphrodite spelled backwards. There’s a lot of speculation about spiritual themes and also themes of drug use in the work. You may be interested in checking out the Wikipedia articles about John Uri Lloyd and Etidorhpa.
The illustrations for this book were done by J. Augustus Knapp, and, while I had previously confused him here with Augustus John, more of his work can be found in Manly P. Hall’s opus The Secret Teachings of All.