§21 disqualification for bias

The basis of the disqualification is that 'personal bias or prejudice' exists, by reason of which the judge is unable to impartially exercise his functions in the particular case. It is a provision obviously not applicable save in those rare instances in which the affiant is able to state facts which tend to show not merely adverse rulings already made, which may be right or wrong, but facts and reasons which tend to show personal bias or prejudice. It was never intended to enable a discontented litigant to oust a judge because of adverse rulings made, for such rulings are reviewable otherwise, but to prevent his future action in the pending cause.