It has often been held, that the jurisdiction, as regards parties, can only be exercised between citizens of different States, and that a mere residence is not sufficient; but this has been said to distinguish a temporary from a permanent residence. To constitute a good plea to the jurisdiction, it must negative those qualities and rights which enable an individual to sue in the Federal courts. This has not been done; and on this ground the plea was defective, and the demurrer was properly sustained. No implication can aid a plea in abatement or in bar; it must be complete in itself; the facts stated, if true, must abate or bar the right of the plaintiff to sue. This is not the character of the above plea. The facts stated, if admitted, are not inconsistent with other facts, which may be presumed, and which bring the plaintiff within the act of Congress. The pleader has not the boldness to allege that this plaintiff is a slave, as that would assume against him the matter in controversy, and embrace the entire merits of the case in a plea to the jurisdiction. But beyond the facts set out in the plea, the court, to sustain it, must assume the plaintiff to be a slave, which is decisive on the merits. This is a short and an effectual mode of deciding the cause; but I am yet to learn that it is sanctioned by any known rule of pleading. The defendant's counsel complain, that if the court take jurisdiction on the ground that the plaintiff is free, the assumption is against the right of the master. This argument is easily answered. In the first place, the plea does not show him to be a slave; it does not follow that a man is not free whose ancestors were slaves. The reports of the Supreme Court of Missouri show that this assumption has many exceptions; and there is no averment in the plea that the plaintiff is not within them. By all the rules of pleading, this is a fatal defect in the plea. If there be doubt, what rule of construction has been established in the slave States? In Jacob _v._ Sharp, (Meigs's Rep., Tennessee, 114,) the court held, when there was doubt as to the construction of a will which emancipated a slave, "it must be construed to be subordinate to the higher and more important right of freedom." No injustice can result to the master, from an exercise of jurisdiction in this cause. Such a decision does not in any degree affect the merits of the case; it only enables the plaintiff to assert his claims to freedom before this tribunal. If the jurisdiction be ruled against him, on the ground that he is a slave, it is decisive of his fate.