Sir Edward Coke reduces the heads of challenge to four. 1st, _propter honoris respectum_; as if a lord of Parliament be impannelled. 2d, _propter defectum_; as if a juryman be an alien born, or be in other respects generally objectionable. 3d, _propter affectum_; for suspicion of bias or partiality: and 4th, _propter delictum_; or, for some crime that affects the juror's credit, and renders him infamous; In treason and felony, the prisoner is allowed the privilege of a limited number of _peremptory_ challenges; after which, as in misdemeanours, there is no limit to the number of challenges, if the party shows some cause for each challenge to the court. This cause is tried by persons appointed for that purpose by the court, when no jurymen have been sworn; but when two jurymen have been sworn, they are the parties who must adjudicate upon the qualifications of those who are afterwards challenged, who, except when the challenge is _propter delictum_, may be themselves examined upon oath. The crown, also, we have seen, can exercise this privilege, but with this difference, that no cause for challenge need be shown by the crown, either in felonies or misdemeanours, till the panel is exhausted, and unless there cannot be a full jury without the persons so challenged. When twelve men have been found, they are sworn to give a true verdict "according to the evidence," and the jury are then ready to hear the merits of the case. To fix their attention the closer to the facts which they are impannelled and sworn to try, the indictment, in cases of importance, is usually opened by the junior counsel for the crown--a proceeding, by which they are briefly informed of the charge which is brought against the accused. The leading counsel for the crown then lays the _facts_ of the case before the jury, in a plain unvarnished statement; no appeal is made to the passions or prejudices of the twelve men, who are to pronounce upon the guilt or innocence of the accused; but every topic, every observation, which might warp their judgment, or direct their attention from the simple facts which are about to be proved before them, is anxiously deprecated and avoided by the counsel for the prosecution. The witnesses for the crown are called one by one, sworn, examined, and cross-examined by the accused, or his counsel. When the case for the crown has been brought to a close, the defence commences, and the counsel for the defendant addresses the jury. It is the duty of the advocate, on such an occasion, to put forth all his powers in behalf of his client; to obtain acquittal is his object: he must sift the hostile evidence, he must apply every possible test to the accuracy of the testimony, and to the credibility of the witnesses; he may address himself to the reason, to the prejudices, to the sympathies, nay, even to the worst passions of the twelve men whose opinions he seeks to influence in favour of his client. He may proceed to call witnesses to disprove the