The most universal illustration of the right of a creditor to sue on a promise to his debtor to pay the debt arises where the grantee of premises subject to a mortgage assumes and agrees to pay the mortgage debt. In England one who buys property expressed to be subject to a mortgage becomes thereby bound as by contract to indemnify the mortgagor from liability though no promise in terms is made to do so; 36 and the same construction is adopted in Pennsylvania.37 In the United States generally, however, no promise or legal or equitable obligation is implied from merely purchasing property subject to a mortgage, other than that the mortgaged property shall be primarily bound for the debt. It is necessary that there be a promise in terms to pay the mortgage, in order to impose personal liability. The word "assume" is the word of art ordinarily used to express such a promise.38 The rule generally prevailing in the United States seems sound. There is no reason why purchase of an equity of redemption should of itself imply an undertaking by the purchaser to pay the mortgage.39
35 Sheppard v. Bridges, 137 Ga. 616, 74 8. E. 245. Cf. Ford v. Finney, 35 Ga. 258, 261. See also Union City Ac. Co. 9. Wright, 145 Ga. 730, 89 S. E. 822; Leffler Co. v. Lane, 146 Ga. 741, 92 S. E. 214.
The early Indiana law allowed a remedy in equity only. Bird v. Lan-ius, 7 Ind. 615; and since the code has made legal and equitable procedure the same, it has still been recognised that the creditor's right is equitable. Davis v. Calloway, 30 Ind. 112, 95 Am. Dec. 671; Hendricks v. Frank, 86 Ind. 278, 281. How far under a statute in Virginia and West Virginia the creditor would be allowed more than an equitable right, is open to question. Apart from statute any right of the creditor is clearly derivative. In Virginia, see Vanmeters' Ex. v. Vanmeters, 3 Graft. 148 (in equity); Jones v. Thomas, 21 Gratt. 96 (semble recovery allowable). Contra is Stewart v. James River & Kanawha Co., 24 Gratt. 294. See also Mcllvaine v. Big Stony Lumber Co., 105 Va. 613, 64 8. E. 473; Casselman's Adm. v. Gordon, 118 Va. 653, 88 S. E. 68. In West Virginia, recovery was allowed in Hooper v. Hooper, 32 W. Va. 528, 9 S. E. 937; Bensimer v. Fell, 35 W. Va. 16, 29, 12 S. E. 1078. But see contra Johnson v. McClung, 26 W. Va. 669; King v. Scott, 76 W. Va. 58, 84 S. E. 964. Montana Civ. Code, See. 3102, provides that "a contract made expressly for the benefit of a third person may be enforced by him." But in McDonald v. American Nat. Bank, 25 Mont. 455, 495, 65 Pac. 896, the court said: "There must be a consideration passing from the third person by virtue of which he may assert the existence of a promise in his favor." See also Tatem v. Eglanol Mining Co., 46 Mont. 367, 123 Pac. 28.
36 Waring v. Ward, 7 Ves. 332; Mills v. United Counties Bank,  1 Co. 231.
37Faulkner p. McHenry, 235 Pa. 298, 83 Atl. 827. Though thus held liable to the mortgagor, yet by Act of June, 12, 1878, the grantee is not liable to the mortgagee; while he is so liable if he assumes the debt. See case cited infra, Sec.383, n. 49. See also Lamka v. Donnelly, 163 Ia. 255, 143 N. W. 869.