Mixed Metaphors

Critics shudder at mixed metaphors like ''that wet blanket is a loose cannon'', but admire ''Life''s but a walking shadow, a poor player'', and all the metaphors packed into Macbeth''s ''Tomorrow, and tomorrow, and tomorrow'' speech. How is it that metaphors are sometimes mixed so badly and other times put together so well?

In Mixed Metaphors: Their Use and Abuse, Karen Sullivan employs findings ...