Particular causes of challenge are of two kinds:
1. For such a bias as when the existence of the facts is ascertained, in judgment of law disqualifies the juror, and which is known in this chapter as implied bias.
2. For the existence of a state of mind on the part of the juror, in reference to the case, or to either party, which satisfies the court, in the exercise of a sound discretion, that he cannot try the issue impartially, without prejudice to the substantial rights of the party challenging, and which is known in this chapter as actual bias.
R.L.1910, § 5858.