I dunno if he got that habit of inserting nonfiction essays into the story from Hugo or Hugo got it from him (or did they get it from Zola?), but someone should have stopped both of them.

Zola's younger than Hugo, surely? (Since Hugo = Romantic Age, Zola = Realism/Naturalism in my long ago literary history.) So blaming Victor H. strikes me as more plausible. :)