BRICKELL, J.
The general rule is, that a defendant in an action of trespass cannot give any matter in evidence, under the general issue, which amounts to a justification or excuse of the act complained of, or to a discharge of the trespass. The general issue is a mere denial of the allegations of the complaint. It casts upon the plaintiff the burden of proving that the defendant committed the act averred to be tortious. *505The plea advises the plaintiff to come prepared only to prove that act. 9 Bac. Abr. 546. When the plaintiff proves the act, the cause of action is established. Every matter of defence, which admits the defendant to have been primé facie a trespasser, must be specially pleaded. 2 Greenl. Ev. 625; Speck v. Phillips, 5 Mees. & Welsby, 278. Under the general issue, the defendant cannot show, in mitigation of damages, that the act complained of was done in obedience to a writ from a court of competent jurisdiction. If such is the fact, it is a complete justification, and must be specially pleaded. 1 Chitty’s Pl. 500. In such case, there is no denial, but an admission of the allegations of the complaint, and an offer to show that the defendant had authority for the acts, which, in the absence of authority, were wrongful. Of such defence, the general issue gives the plaintiff no information, and he has not an opportunity of being prepared to meet it with evidence. The proposition, at last, is, although it may be expressed only as an offer to mitigate the damages, to legalize the act of the defendant as done under valid process, which, of itself, is a complete justification, and must be specially pleaded, or established rules of pleading disregarded. The result generally would be, as in this case, that the defendant would, under the general issue, obtain all the benefit he could have derived from a special plea of justification, not only a mitigation of damages, but a verdict of not guilty. Coats v. Darby, 2 Comstock, 517. The court erred in receiving in evidence the writ of attachment, and the charge given was also erroneous.
It is not necessary to notice the remaining question, as it can scarcely arise- on another trial.
The judgment is reversed and the cause remanded.