You occasionally meet such persons, whose nature it seems impossible to affect by any method of treatment.

What was specially aggravating in Tom Gordon's place was that Zeigler seemed to feel no dislike of any one in the store besides himself.

He slurred him the first day he met him, and kept it up unremittingly.
Tom's first course was to accept these slurs in silence.

His face often flushed, when he saw the smiles on the countenances of the other clerks, excited by some cutting witticism of Zeigler at the expense of himself.
His tormentor accepted the silence as proof of the timidity or rather cowardice of the new employee, and rattled off his insults faster than ever.

While kindness as a rule will disarm a foe, there are some ingrates so constituted that it moves them the other way.