2. The grand jury are sworn to inquire into all offences which have been committed, and of all violations of law, without fear, favor, or affection. Vide Grand Jury. When a juror is influenced by bias or prejudice, so that there is not sufficient ground for a principal challenge, he may nevertheless be challenged for favor. Vide Challenge, and Bac. Ab. Juries, E; Dig. 50, 17, 156, 4; 7 Pet. R. 160.