delivered the opinion of the court. The question is, whether, under the plea of nil debet, the record of the judgment in Pennsylvania, ought to have been proved.
1. If the plea of nil debet had any effect or operation, I think it was incumbent on the plaintiff to prove the record. *257It is the general issue, which admits nothing, and is a total and general denial of the plaintiff’s right of action.(a)
2. The question whether the plea was proper, arises on the face of the record, and, if improper, it ought to have been answered by demurrer, or not to have been answered at all, and treated as a nullity. By taking issue upon it, the plaintiff has treated it as a regular and competent plea. Having done this, he cannot afterwards consider it as a nullity, and, on that ground, dispense with proof which would otherwise be required. It is unnecessary here to determine, whether nil debet, or nul tiel record, is the proper plea to an action of debt on a judgment given in another state.(b) This would 'demand a consideration of the constitution of the United States, and the act of congress (4th article of the constitution, and act of the 26th May, 1790, Laws of the United States, (vol. 1, p. 115,) relating to the mode of proof, and the effect of such judgment, which present a question of considerable moment. We think it sufficient, to decide the present case, that the plaintiff , has admitted the propriety of the plea of nil debet, by joining issue *258upon it,(a) and that the question on its merits cannot thus be regularly decided.
New trial granted.(b)