If the analysis in the preceding sections is sound the claim of the creditor is a derivative one. His only interest in the promise is the interest which he has in any property belonging to his debtor. This view has considerable support in the decisions in many jurisdictions in regard to promises to assume mortgages.47 A promise to assume and pay a mortgage for which the promisee is liable can hardly differ in principle from a promise to pay any other debt of the promisee, but the mortgage cases are frequently treated as a class by themselves. A few cases also of promises to pay unsecured debts are based on substantially this theory.48

47 See infra, Sec. 384.

48Jesup v. Illinois Central R. Co. 43 Fed. 483, 493; Mercantile Trust Co. v. Baltimore, etc., R. Co., 94 Fed. 722; Goff v. Ladd, 161 Calif. 257, 118 Pac. 792; Sheppard v. Bridges, 137 Ga. 615, 74 S. E. 24S; Congregational Soc. v. Flagg, 72 Vt. 248, 47 At!. 782; Vaumetera' Ex. v. Vanmeters, 3 Gratt. 148. In Forbes v. Thorpe, 209 Mass. 670, 95 N. E. 955, the court sustained a suit in equity, saying: "The contract being made by the firm for the benefit of their creditors, the latter may in equity enforce the rights of the copartners to compel the corporation to perform its agreement in this regard. This is a property right not subject to attachment which can be reached in equity and made available for the benefit of the creditor." Consider also the rights of a creditor of a trustee to reach the trust estate or cestui que trust. See supra, Sec. 313.