In chapter ten of The Scarlet Letter, Hawthorne depicts Chillingworth as anything but the kindly doctor so many in the town once considered him. Instead, he uses a series of metaphors to describe the actions of the leech on his patient. In the beginning, Chillingworth saw himself as a judge, desiring simply to find and know the truth. He saw it as some sort of mathematical puzzle or equation which could be solved if the correct figures were in place. Soon, though, the metaphors change to something much more insidious and invasive:
But, as he proceeded, a terrible fascination, a kind of fierce, though still calm, necessity seized the old man within its grip, and never set him free again, until he had done all its bidding. 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.
As a miner digging for gold, he would be persistent and motivated and, to a large degree, greedy to find what he most coveted--gold. Or, in this case, the truth about the sickness of his patient's heart. As a sexton (a grave-digger), he was also digging, hoping to uncover a body so as to steal, perhaps, any valuable jewelry--again out of greed. Both metaphors show the change which has occured in this kindly physician and his single-minded desire to get to the root of Dimmesdale's inner sickness.