If there shall be impaneled, for the trial of any cause, any petit juror, who shall have been convicted of any crime which by law renders him disqualified to serve on a jury; or who has been arbitrator on either side, relating to the same controversy; or who has an interest in the cause; or who has an action pending between him and either party; or who has formerly been a juror in the same cause; or who is the employer, employee, counselor, agent, steward or attorney of either party; or who is subpoenaed as a witness; or who is of kin to either party; or any person who shall have served once already on a jury, as a talesman on the trial of any cause, in the same court during the term, he may be challenged for such causes; in either of which cases the same shall be considered as a principal challenge, and the validity thereof be tried by the court; and any petit juror who shall be returned upon the trial of any of the causes hereinbefore specified, against whom no principal cause of challenge can be alleged, may, nevertheless, be challenged on suspicion of prejudice against, or partiality for either party, or for want of competent knowledge of the English language, or any other cause that may render him, at the time, an unsuitable juror; but a resident and taxpayer of the state or any municipality therein shall not be thereby disqualified in actions in which such municipality is a party. The validity of all challenges shall be determined by the court.

R.L. 1910, § 4997.