Wemmick was at his desk, lunching – and crunching – on a dry hard biscuit; pieces of which he threw from time to time into his slit of a mouth, as if he were posting them.
– Charles Dickens
Great Expectations, Chapter 24. The simile comparing Wemmick’s eating pieces of hard dry biscuit to “posting” them into his “slit of a mouth,” says much about his character. The mechanical robotic way of eating, as if he was posting letters, suggests a detached, unemotional approach to work and life.