This section is from the book "The Law Of Contracts", by William Herbert Page. Also available from Amazon: Commercial Contracts: A Practical Guide to Deals, Contracts, Agreements and Promises.
If the mortgage recites the consideration, such recital does not prevent the parties from showing the true consideration.1 The recital of a consideration in a mortgage does not preclude extrinsic evidence of an oral agreement that as part of the transaction under which the mortgage was given, the mortgagee had agreed to bequeath the notes to the mortgagor.2 Extrinsic evidence is admissible to show that the true amount of the debt which a mortgage is given to secure, although such evidence contradicts the amount of the debt, recited on the face of the mortgage,3 or to show that such mortgage is given to secure future advances,4 or to show that a part of the debt secured by the mortgage was a debt of another person which was assumed by the mortgagor.5 On the other hand, the fact that the mortgage recites the notes which it is given to secure, is said to preclude evidence to show that another debt was thus secured.
15 Johnson v. Elmer, 94 Tex. 168, 52 L. R. A. 162.
Contra, where the oral agreement to assume a mortgage would contradict a covenant of general warranty. Rooney v. Koenig, 80 Minn. 483. 83 N. W. 399.
16Ford v. Savage, 111 Mich. 144, 60 N. W. 240.
17Lathrop v. Humble, 120 Wis. 331, 97 N. W. 905.
18Koogle v. Cline, 110 Md. 587, 24 L. R. A. (N.S.) 413, 73 Atl. 672.
1 Alabama. Manchuria S. 8. Co. v. Donald, - Ala. - , 77 Ro. 12.
Arkansas. McClintock v. Skinner, 126 Ark. 591, 191 S. W. 230.
Iowa. Ball v. James, 176 Ia. 647, 158 N. W. 684.
Pennsylvania. Galligan v. Heath, 260 Pa. St. 457, 103 Atl. 878.
Vermont. Bean v. Parker, 89 Vt. 532, 96 Atl. 17.
Wisconsin. Glander v. Glander, 167 Wis. 12, 166 N. W. 446.
2 Ball v. James, 176 Ia. 647, 158 N. W. 684.
3 Galligan v. Heath, 260 Pa. St. 457, 103 Atl. 878; Bean v. Parker, 89 Vt. 532, 96 Atl. 17.
4 Manchuria S. S. Co. v. Donald, - Ala. - , 77 So. 12.
Contra, Union Machinery & Supply Co. v. Darnell, 80 Wash. 226, 154 Pac. 188.
5 McClintock v. Skinner, 126 Ark. 591, 191 S. W. 230.