Under the spine

Bindings in past centuries thriftily reused paper for the concealed parts -

This book was published in 1864 -

Fry's/Cadbury's cocoa is still available, but Coleridge is probably read less these days - do they still teach "The Ancient Mariner" in school?

As for the cocoa - Fry's has been made since the 18th century; it's "Dutch processed", which reduces its antioxidant properties (and why would you eat any sort of chocolate if not for the antioxidant properties -?). Chocolate bars didn't happen till 1847 - and their chocolate easter eggs date back to 1873.