— The redemption of mortgaged estates is, upon general principles, within the jurisdiction of courts of equity. This court, as a court of equity of limited power, has jurisdiction in such cases, specially conferred by statute. R. S. c. 96, § 10; c. 125. Where the jurisdiction of a court *311of equity which can determine the matter, has rightfully attached, it will in general be retained to afford complete relief, without turning the parties over to a suit at law. 1 Story, Com. Bq. § 64, p. 82; 2 Eonbl. Eq. B. 6,^c. 3, § 6. And where the court has jurisdiction for a purpose, it must have it as to the means to accomplish that purpose.
This suit by the mortgager against the mortgagee, is for the redemption of a mortgaged estate, and comes before us on a report from a hearing and decree of a Justice of this Court at Nisi Prius, under the provisions of the statute of 1852, c. 246, § 14. It appears that the defendant neglected on request, to render an account of the sum due upon the mortgage, before commencement of the suit. The bill, therefore, may be sustained, without an allegation or proof of tender of payment, upon the offer to pay and perform. It is no objection to the request that it was not made by the plaintiff in person. It was in writing, and sufficiently specific to inform the defendant of the requirement and the purpose of the plaintiff; and it was communicated in season, and in a manner unobjectionable. It authorized the defendant to leave his account of the amount due, with the attorneys of the plaintiff, if more for his accommodation, but did not require him to do so. But if the plaintiff’s request had been accompanied with directions to the defendant to present his account at a particular time and place, it might have been sufficient, notwithstanding. If the appointments of time and place were unreasonable, performance by the defendant could not be exacted. He had only to render the account in a reasonable time and manner. No unauthorized exactions by the plaintiff, would absolve the defendant from the performance of duties required in this respect, by the plain provisions of the statute. Roby v. Skinner, 34 Maine, 270.
In his answer, the defendant denies that the mortgage debt had been paid; but the master reports that it had been overpaid. His decision has not been impeached, and it must be regarded as conclusive upon the fact of overpayment.
*312The rule adopted by the master, in calculating interest upon the note secured by the mortgage, is objected to by both parties; but in our opinion the objections must fail. The effect of the rule is, to require the borrower to fulfil Ms contract with the lender, by paying the principal with interest semi annually, and interest upon the sums of unpaid interest, after they had accrued by the terms of the note, and according to the agreement of the plaintiff, as found by the master. It also gives to the lender just what he might have realized if the borrower had complied with the terms of his contract. This will do justice to both parties, without violating the statutes of usury. A contract to pay interest upon a sum due for interest, is but an agreement to pay interest on money due, and is not usurious. But where the contract is usurious, even equity requires the borrower to pay to the lender what is really and bona fide due to him. Scott v. Nesbit, 2 Bro. Ch. R. 641; Mason v. Gardiner, 4 Bro. Ch. R. 436; 1 Fonbl. Eq. B. 1, c. 4, § 7, n. k; 1 Story Com. Eq. § § 301, 302.
The decree at Nisi Prius is affirmed, with additional interest and costs.
Shepley, C. J., and Tenney and Appleton, J. J., concurred.