What metaphors does Hawthorne establish for Chillingworth’s probe? How do they further define Chillingworth’s character?

Chillingworth is described as a leech sucking the blood and soul out of the patient, hence the title of the chapter. The metaphor of a minor digging for gold (the truth in this case) while destroying what holds it, "He now dug into the poor clergyman's heart, like a miner searching for gold; or, rather, like a sexton delving into a grave, possibly in quest of a jewel that had been buried on the dead man's bosom, but likely to find nothing save mortality and corruption."