This cause comes before us upon appeal, not from a final decree, but from an interlocutory order made in the court below, simply dissolving a provisional injunction; and, although upon the argument here, the whole case made by complainant’s bill was opened and discussed as if the issue was whether the court below had jurisdiction thereof, yet we have considered and determined the case solely upon the propriety of the dissolution of that injunction.
It was contended, however, that., if from the recitals in the bill it appeared to be necessary to appeal to the equitable jurisdiction of the circuit court at all- and for any purpose, that court should take jurisdiction of the whole subject matter, cite in all persons in any manner related thereto, and furnish such relief against each as his particular connection with the case might seem to authorize.
Accordingly the bill makes three classes of defendants, each occupying a different attitude in reference to the claims of the complainant, and against each of whom a different species of relief is prayed for, as follows:
1st. The heirs of one James Spence, through whom the complainant claims title to the premises described in the bill, *40are made defendants, and it is prayed that they may be perpetually enjoined from setting up any title, to those premises.
2d. Sundry persons to whom complainant has granted distinct and separate portions of the premises, some of whom, it is alleged, have threatened to commence suits upon the covenants in his deeds, are made defendants, but against them no specific relief seems to be demanded.
3d. The appellee, Cross, who is at once a grantee of the complainant of a portion of the same premises, and the plaintiff in a suit at law commenced against the appellant, upon the covenants in his deed, is a party, and as against him the prayer of the bill is, that he “ be decreed to have no cause of action,” and be perpetually enjoined from prosecuting his said suit at law.
To restrain the prosecution of that suit until the bearing of this, that special injunction issued against which the order was directed, from which this appeal is taken.
In effect, though not in precise terms, this court is asked to decree a nonsuit in a suit at law, and such a decree I think no court of chancery has ever pronounced. Courts of equity, when called upon to restrain proceedings at law, do not assume superiority over the court in which those proceedings are had, nor deny nor usurp its jurisdiction. But when it is made apparent to this court, not that the plaintiff in a suit at law “ has no cause of action,” but that he has a cause of action, a cause nevertheless, which by reason of some mistake, some accident or fraud, it is against conscience for him to prosecute, but against which a defense cannot well be made according to the rules of the common law which govern -those courts, then this court will interfere, and laying its injunction not upon the judgment of that other court, but directly upon the conscience of the party prosecuting, will inhibit him from wresting the process of a court of law to purposes of injustice and oppression. 2 Story’s Eq., § 875; Eden on Inj., ch. 2, p. 14; Mit. Eq. Pl., 128.
*41But the cause which is sought to be enjoined by the bill before us is of a very different character. The plaintiff in that suit has practised no fraud which he therein claims the advantage of; the defendant has made no mistake which has jeopard-ed his rights or endangered his defense, and the only accident complained of is the loss of the deed from Spence to Norton. Still it is no where asserted that the loss of that deed endangers the complainant’s defense to the suit at law. For aught that appears to us, its loss might very well be supplied upon the trial by parol proof of its contents, under rules of evidence of every day’s application in courts of law as well as in courts of equity.
I do not therefore discover any right of action in this respondent, which it is so inequitable and so manifestly against conscience for him to prosecute, as to warrant the exercise by a court of chancery of its most delicate and extraordinary prerogative, the writ of injunction.
To the argument of the complainant’s counsel, that the loss of that deed destroyed a link in the chain of his title, the respondent might well reply that that loss did not happen through his default, that he was injured equally with complainant thereby, that if, bj^ reason thereof, the complainant was unable to defend his covenant of seizin, he was equally unable to defend his own-possession, or to convey with safety, and that if complainant would invoke the aid of chancery to supply that lost link, he should do so without cost or prejudice to this respondent. .
But, waiving all consideration of the questions whether the circuit court could entertain the complainant’s bill for any purpose, and whether, if so, this defendant might not be a proper party, I am still unable to perceive how the complainant was aggrieved by the particular order appealed from. If the statements of his bill are true, the dissolution of that injunction removed the only protection which the respondent had against a nonsuit in the case enjoined. Eor whether the complainant *42could prove the execution of a deed from Spence to Norton or not, or whether in fact such a deed ever was executed or. not, the fact did remain nevertheless, and could be readily proved upon the trial, that Spence had taken a conveyance from Norton by way of-'mortgage which in good faith he had assigned, and we are all of opinion that he and his representatives or privies are thereby as clearly estopped at law as in equity, from setting up a prior and conflicting title in himself to defeat the mortgage which he has negotiated, and which has been foreclosed. 10 Barn. & Or., 181; 11 Paige, 384; 17 Johns., 161; 4 Peters, 83.
Order affirmed.