The only sign but you have to know are the fingernail scrapings on the ceiling.

This was written in prison by Dr. Manette himself, in scrapings of soot and charcoal mixed with his own blood.

By taking the scrapings from their pathetic lives as they register in 100 won coins just to drive a compact car, do you think life will improve?

He actually discovered bacteria by looking at dental scrapings, which, when you keep in mind that people didn't brush their teeth much if at all back then, he must have had a lovely bunch of bacteria to look at.