When, therefore, as in this case, the necessary averments as to citizenship are made on the record, and jurisdiction is assumed to exist, and the defendant comes by a plea to the jurisdiction to displace that presumption, he occupies, in my judgment, precisely the position described in Bacon Ab., Abatement: "Abatement, in the general acceptation of the word, signifies a plea, put in by the defendant, in which he shows cause to the court why he should not be impleaded; or, if at all, not in the manner and form he now is." This being, then, a plea in abatement, to the jurisdiction of the court, I must judge of its sufficiency by those rules of the common law applicable to such pleas. The plea was as follows: "And the said John F.A. Sandford, in his own proper person, comes and says that this court ought not to have or take further cognizance of the action aforesaid, because he says that said cause of action, and each and every of them, (if any such have accrued to the said Dred Scott,) accrued to the said Dred Scott out of the jurisdiction of this court, and exclusively within the jurisdiction of the courts of the State of Missouri; for that, to wit, the said plaintiff, Dred Scott, is not a citizen of the State of Missouri, as alleged in his declaration, because he is a negro of African descent; his ancestors were of pure African blood, and were brought into this country and sold as negro slaves, and this the said Sandford is ready to verify. Wherefore, he prays judgment whether this court can or will take further cognizance of the action aforesaid." The plaintiff demurred, and the judgment of the Circuit Court was, that the plea was insufficient. I cannot treat this plea as a general traverse of the citizenship alleged by the plaintiff. Indeed, if it were so treated, the plea was clearly bad, for it concludes with a verification, and not to the country, as a general traverse should. And though this defect in a plea in bar must be pointed out by a special demurrer, it is never necessary to demur specially to a plea in abatement; all matters, though of form only, may be taken advantage of upon a general demurrer to such a plea. (Chitty on Pl., 465.)