A specific lien upon real property to secure the payment of money or the performance of some other obligation, which a court of equity will recognize and enforce, in accordance with the clearly ascertained intent of the parties to that effect, but which lacks the essential features of a legal mortgage, either because it grows out of the transactions of the parties without any deed or express contract to give a lien, or because the instrument used for that purpose is wanting in some of the characteristics of a common-law mortgage, or, being absolute in form, is accompanied by a collateral reservation of a right to redeem, or because an explicit agreement to give a mortgage has not been carried into effect. See 4 Kent, Comm. 150; 2 Story, Eq. Jur. § 1018; Ketehum v. St. Louis, 101 U. S. 306
, 25 L Ed. 999 ; Payne v. Wilson
, 74 N. Y. 348
; Gessner v. Palmateer, 89 Cal. 89, 26 Pac. 789, 13 In R. A. 187; Cummings v. Jackson, 55 N. J. Eq. 805, 38 Atl. 763; Hall v. Railroad Co., 58 Ala. 23; Bradley v. Merrill, 88 Me. 319, 34 Atl. 160; Carter v. Holman, 60 Mo. 504. In English law, the following mortgages are equitable:
(1) Where the subject of a mortgage is trust property, which security is effected either by a formal deed or a written memorandum, notice being given to the trustees in order to preserve the priority.
(2) Where it is an equity of redemption
, which is merely a right to bring an action in the chancery division to redeem the estate.
(3) Where there is a written agreement only to make a mortgage, which creates an equitable lien on the land.
(4) Where a debtor deposits the title-deeds of his estate with his creditor or some person on his behalf, without even a verbal communication. The deposit itself is deemed evidence of an executed agreement or contract for a mortgage for such estate. Wharton.