To an assignment of errors, the defendant may plead or demur. Pleas in error are comnion or special. The common plea, or joinder as it is more frequently called, is in nullo esl erratum, or that there is no error in the record or proceedings; which is in the nature of a demurrer, and at once refers the matter of laM. arising thereon to the judgment of the Court. Special pleas contain matters in confession and avoidance, as a release of errors, or the statute of limitations, &c.; to which the plaintiff in error may reply or demur. 2 Tidd’s Prac. 1150, 1154.