It was held at the trial in the court oí common pleas, that the defendant was not estopped, by the judgment recited in the replication, to avail himself, in defence to the present action, of the several matters stated in his answer. This ruling was erroneous, if the question here in controversy arose and was the subject of adjudication in the former suit; for it is an established principle in the administration of justice, that a matter once litigated and determined between the parties, in a court of competent jurisdiction, is forever afterwards to be considered as conclusively settled and at rest. Bigelow v. Winsor, 1 Gray, 301. Foote v. Gibbs, 1 Gray, 413.

The plaintiff alleges that the defendant owes him the amount of the promissory note of which a copy is annexed to the declaration. This is denied by the answer, which sets forth, as facts in avoidance of the action, that the note, though made and signed by the defendant, was extorted from him by duress, and was given for an illegal consideration. Upon these averments, the parties are at issue in relation to the alleged indebtedness of the defendant; the precise question between them being whether there is any thing due to the plaintiff upon the note declared on.

*116The same question was involved, and must have been determined, in the former suit. That was an action brought by the plaintiff, as mortgagee, to recover of the defendant, as mortgagor, possession of the mortgaged-premises, for the purpose of foreclosing his right of redemption. In all such cases, it is made, by the express provisions of the statute, the duty of the court to inquire and determine how much is due to the plaintiff upon the mortgage ; and thereupon judgment is to be entered, that if the defendant shall, within the next succeeding two months, pay to the plaintiff what is so found due to him, the mortgage shall be void; otherwise execution shall be had for possession of the premises. Rev. Sts. c. 107, § 5. If nothing is found due, the plaintiff can have no judgment. Thus it has been held, that payment of the debt is a complete defence to an action on a mortgage given to the payee as collateral security; for as the mortgagee has no right to hold the estate conveyed, except as a substitute for, or as a means of obtaining, the money to which he is entitled, when the debt has been discharged, and he ceases to be a creditor, there is no longer any basis upon which the claim of possession can be supported. Wade v. Howard, 11 Pick. 289. Holman v. Bailey, 3 Met. 55. Upon examination of the conditional judgment which was rendered in the former suit, it appears that the court did then determine that the amount of the note declared on in the present action was due to the plaintiff. The real question of indebtedness, therefore which is now in issue between the parties, was not only involved in the former suit, but was in fact made the subject of an actual adjudication.

But not only was the general question of the indebtedness of the defendant to the plaintiff, upon the note now declared on, embraced and determined in the former suit; but the precise ground of defence set up in this action was also set up and insisted upon in that. The extortion complained of, and the asserted illegality of the consideration of the note, were both specially assigned, as reasons why the plaintiff should not recover possession of the mortgaged premises; and they are repeated now, as reasons why the present action should not be maintained *117upon the note. The questions presented in the allegations and answers in the two actions are, in reference to these reasons, urged in both of them as special grounds of defence, precisely the same. The judgment in the first suit covered the whole ground, and was not, as was intimated in the argument for the defendant, founded upon any merely collateral matter, but upon the real point in controversy between the parties. It was therefore conclusive upon them both; and the defendant was thereby estopped from again availing himself of the grounds of defence upon which he then insisted.

Where new matter is contained in the answer in avoidance of the action, the plaintiff is authorized by the provisions of the statute to file a replication to it at any time before trial. We think the plaintiff seasonably availed himself, in the present case, of that privilege. Si. 1852, c. 312, § 19. The first trial having proved wholly ineffectual, by reason of the disagreement of the jury, none of the rights of the parties were in any degree affected by it; and the action stood thenceforward to be proceeded with as if nothing of that kind had taken place. Indeed, the former judgment could not have been set forth in a replication filed before the former trial; for it had not then been rendered. The defendant’s objection to the replication should therefore be overruled.

Exceptions sustained.