The rule that a written contract merges all prior and contemporaneous oral negotiations, applies only to such oral negotiations as concern the subject-matter embraced in the written contract.1 Accordingly, a contract collateral to a written complete contract may be shown by extrinsic evidence if not contradictory.2 A party is not prevented from recovering for hauling lumber in reliance upon a subsequent oral contract, by the fact that he had entered into a prior written contract with reference to such lumber, if at the time of such written contract it was agreed orally that he should not be obliged to do such hauling.3 An oral contract by an actress for the fall and winter may be enforced, though she had made a contemporaneous written contract for the summer.4 So an oral contract to pay commissions on a sale of realty in addition to the price fixed in the written contract;5 an oral contract not to sell other lots at less than a given price; 6 an oral contract by the vendors of realty to lay pavement, to construct water mains, and to secure the extension of a street car line;7 an oral contract that the vendor shall keep the realty contracted for insured for the benefit of the vendee;8 an oral contract that if the mortgagee took out a policy on the property he should protect the interest of the mortgagor in addition to a written provision to the effect that if the mortgagor did not keep the property insured the mortgagee could insure his interest therein, and recover the premiums thus paid from the mortgagor;9 an oral contract made when a note is given to a bank to allow a deposit in the bank to be credited thereon;,10 and an oral contract that the vendee of stone should have a derrick ready to receive the stone and should settle any controversy over the amount of stone furnished, as shown by the tickets given by vendor before using the stone,11 are all of them so far collateral to the written contract as to be enforceable. A written lease does not exclude evidence of oral agreements collateral thereto, which do not change any of the rights or duties created by such lease.12 So an oral contract to extend a lease under certain contingencies has been held so far collateral to the lease as to be enforceable.13 A written lease of an apartment does not preclude a right of action upon an oral lease of a garage in connection therewith.14 So in an action on a note the whole transaction under which the note was given may be shown, and a counterclaim may be based on an oral contract collateral to the note, as on an oral contract to repurchase the stock for which the note was given.15 or to redeem in gold the bank-notes for which the note was given,16 or to place certain claims in the hands of the maker of the note to collect on commission.17 Where a note was deposited with A as collateral under a written contract, an oral agreement that A should not collect it could not be enforced; but an agreement that the payee should collect it as agent for A, was held to be a collateral consistent contract, and enforceable.18 Where A had given B a promissory note, an oral contract whereby B was to collect certain rent for A, and credit upon A's debt, is enforceable.19 Where a note is given,20 or a bill of exchange drawn,21 an oral contract that a set-off existing in favor of the maker or bearer was not,waived, may be enforced. The maker of a note which is given for the balance of a debt may show that the payee was indebted to him in an unliquidated amount and that it was agreed orally that such amount when liquidated should be applied upon the note.22 An oral agreement with reference to a loan is enforceable, although it is collateral to a written policy of insurance.23 An oral contract by which the seller of certain property agreed that upon the opening of a specified event he would repurchase it within a certain length of time, is enforceable as collateral to a written contract for the sale of such property.24 A written assignment of a patent right does not prevent extrinsic evidence of a contract to assign such interest to a corporation upon its formation in consideration of a certain portion of the stock of such corporation.25 A written conveyance by the mortgagor to the mortgagee does not preclude evidence of an extrinsic agreement that such conveyance shall not operate as satisfaction of the mortgage debt.26 The recital of the consideration for a conveyance as a specified mortgage and certain equities of redemption, together with an agreement on the part of the grantees to remove a specified building, does not prevent evidence of a subsequent agreement by which the grantees were to receive a certain amount for removing such building.27

21 Roberts v. Morgan, 56 Okla. 513, 156 Pac. 319.

1 California. Blahnik v. Small Farms Imp. Co., - Cal. - , 184 Pac. 661.

Iowa. Witthauer v. Wheeler (Ia.), 154 N. W. 423 [modifying opinion on rehearing, Witthauer v. Wheeler, 172 Ia. 225, 150 N. W. 46]; Armstrong v. Cavanagh, 183 Ia. 140, 166 N. W. 673.

Massachusetts. Searle v. Roman Catholic Bishop, 203 Mass. 493, 25 L. R. A. (N.S.) 992, 89 N. E. 809.

Minnesota. Virginia & Rainy Lake Co. v. Helmer, 140 Minn. 135, 167 N. W. 355.

New Mexico. Locke v. Murdoch, 20 N. M. 522, L. R. A. 1917B, 267, 151 Pac. 298.

North Carolina. Anderson v. American Suburban Corporation, 155 N. Car. 131, 36 L. R. A. (N.S.) 896, 71 S. E. 221; Sumner v. Graham County Lumber Co., 175 N. Car. 654, 96 S. E. 97.

North Dakota. Grand Forks, etc., Co. v. Tourtelot, 7 N. D. 587, 75 N. W. 901.

Oklahoma. Mackin v. Darrow Music Co., - Okla. - , 169 Pac. 497.

Vermont. Goodwin v. Barre Savings Bank & Trust Co., 91 Vt. 228, 100 Atl. 34.

2 United States. Lucas v. Bradley, 246 Fed. 693.

Arkansas. Lasker-Morris Bank & Trust Co. v. Jones, 131 Ark. 576, 199 S. W. 900.

California. Savings Bank v. Asbury, 117 Cal. 96, 48 Pac. 1081; Blahnik v.

Small Farms Imp. Co., - Cal. - ,184 Pac. 661.

Kentucky. Short's Administratrix v. Reserve Loan Life Ins. Co., 175 Ky. 554,

194 S. W. 773.

Maryland. Hieatzman v. Braecklein, 131 Md. 482, 102 Atl. 917.

Massachusetts. Glackin v. Bennett, 226 Mass. 316, 115 N. E. 490. . Michigan. Cutler v. Spens, 191 Mich. 603, 158 N. W. 224; Seaman v. Rindge,

195 Mich. 417, 161 N. W. 919. Minnesota. Germania Bank v. Osborne, 81 Minn. 272, 83 N. W. 1084; King v. Dahl, 82 Minn. 240, 84 N. W. 737; Virginia & Rainy Lake Co. v. Helmer, 140 Minn. 135, 167 N. W. 355.

Missouri Brown v. Bowen, 90 Mo. 184, 2 S. W. 398.

Nebraska. Huffman v. Ellis, 64 Neb. 623, 90 N. W. 552.

New Hampshire. Webber v. Loran-ger, - N. H. - , 103 Atl. 1050.

New Mexico. Locke v. Murdoch, 20 N. M. 522, L. R. A. 1917B, 267, 151 Pac. 298.

North Carolina. Sumner v. Graham County Lumber Co., 175 N. Car. 654, 96 S. E. 97.

Oklahoma. Mackin v. Darrow Music Co., - Okla. - , 169 Pac. 497.

Pennsylvania. Gandy v. Weckerly, 220 Pa. St. 285, 18 L. R. A. (N.S.) 434, 69 Atl. 858; Noel v. Kessler, 252 Pa. St. 244, 97 Atl. 446.

South Carolina. Glenn v. Rudd, 68 S. Car 102, 102 Am. St. Rep. 659, 46 S. E. 555.

South Dakota. Emerson-Branting-ham Implement Co. v. Edgar, 39 S. D. 139, 163 N. W. 575.

Tennessee. Quigley v. Sliedd, 101 Tenn. 560, 58 S. W. 266.

Vermont. Goodwin v. Barre Savings Bank & Trust Co., 91 Vt. 228, 100 Atl. 34.

3 Noel v. Kessler, 252 Pa. St. 244, 97 Atl. 446.

4 Drake v. Alien, 179 Mass. 197, 60 S. E. 477.

5 Lasker-Morris Bank & Trust Co. v. Jones, 131 Ark. 576, 199 S. W. 900; Hall v. McNally, 23 Utah 606, 65 Pac. 724.

6 Rackemann v. Improvement Co.,

167 Mass. 1, 57 Am. St. Rep. 427, 44 N. E. 990.

7 Anderson v. American Suburban Corporation, 155 N. Car. 131, 36 L. R A. (N.S.) 896. 71 S. E. 221.

8 Keefer v. Ins. Co., 29 Ont. 394; Parcell v. Grosser, 109 Pa. St. 617, 1 Atl. 909.

9 Seaman v. Rindge, 195 Mich. 417, 161 N. W. 919.

10 Roe v. Bank, 167 Mo. 406, 67 S W. 303.

11 Mt. Vernon Stone Co. v. Sheely, 114 Ia. 313, 86 N. W. 301.

12Witthauer v. Wheeler (Ia.), 154 N. W. 423 [modifying opinion on rehearing, Witthauer v. Wheeler, 172 Ia. 225, 150 N. W. 46].

l3Armington v. Stelle, 27 Mont. 13. 94 Am. St. Rep. 811, 69 Pac. 115 (under Sec. 2186 of the statutes of Montana).

14 Armstrong v. Cavanagh. 183 la. 140, 166 N. W. 673.

15Germania Bank v. Osborne, 81 Minn. 272, 83 N. W. 1084.

16 Racine County Bank v. Keep, 13 Wis. 209.

17 Singer Mfg. Co. v. Potts, 59 Minn. 240, 61 N. W. 23.

18 Jenkins v. Shinn, 55 Ark. 347, 18 S. W. 240.

19Stebbins v. Lardner, 2 S. D. 127,

48 N. W. 847; Jones v. Keyes, 16 Wis. 562.

20 Bennett v. Tillmon, 18 Mont. 28, 44 Pac. 80.

See also, Strassheim v. McGuire, 37 N. D. 289, 164 N. W. 26.

21 Bohn Mfg. Co. v. Harrison, 13 Mont. 293, 34 Pac. 313.

22 Lucas v. Bradley, 246 Fed. 693.

23 Short's Administratrix v. Reserve Loan Life Ins. Co., 175 Ky. 554, 194 S. W. 773.

24 Corey v. Woodin, 195 Mass. 464, 81 N. E. 260.