That was one of the things that made alchemy so much fun; all the "instructions" were "encoded" and literally occult. Much of what they were doing was hunting for the keys to a known ciphertext (the Bible) that would give them the secrets of the universe, once they decoded it correctly.
Of course we're far too bright and sophisticated to fall into such folly today. You won't fond modern peoples, for example, having passionate arguments about the meanings of text generated by mechanical / statistical processes.
