Power is given to the Supreme Court to grant a trial or a new trial for sufficient cause shown, in cases tried either before them or before any Court of Common Pleas. Unless this involved the power to give parties leave to file pleas, it would in many cases be of no avail. This Court has repeatedly decided that where cases are brought before a Court of Common Pleas by appeal from Justices' Courts, the case must be *Page 131 tried upon the issue made in the pleadings before the justice, and that the Court of Common Pleas in such case has no authority to permit the filing of new pleas. The statute authorizes defendants in Justices' Courts to give all special matter in bar in evidence under the general issue. It is quite too common in such Courts to try cases, even before the general issue is filed, or any other pleas. *Page 132