In bilateral contracts - that is, where the consideration for a promise is a promise - the whole contract may be intended by the parties to be contingent, so that obligation is to arise under it only upon the occurrence of some event or contingency. If A. offers to supply at a certain price such goods as B. may order, and B. promises to pay at that price for such goods as he may order, there is, of course, no contract, for B. has not promised to order any goods, and it is optional with him whether his promise to pay shall ever come into effect.71 Both parties must be bound or neither is bound; in other words, there must be mutuality of engagement.72 In such a case, indeed, if before the offer is withdrawn, B orders goods, A. is bound to sell at the price named.73

67 Sherwin v. Fletcher, 168 Mass. 413, 47 N. E. 197; Grand Lodge I. O. G. T. v. Farnham, 70 Cal. 158, 11 Pac. 592. See, also, Twenty-Third St. Baptist Church v. Cornell, 117 N. Y. 601, 23 N. E. 117, 6 L. R. A. 807; Town of Grand Isle v. Kinney, 70 Vt 381, 41 Atl. 130; Richelieu Hotel Co. v. International Military Encampment Co., 140 I11. 248, 29 N. E. 1044, 33 Am. St Rep. 234; Hodges v. Nalty, 104 Wis. 464, 80 N. W. 726. See "Subscriptions," Dec. Dig. (Key-No.) § 15; Cent. Dig. §§ 14-17.

68 BEATTY's ESTATE v. WESTERN COLLEGE OF TOLEDO, IOWA, 177 111. 280, 52 N. E. 432, 42 L. R. A. 797, 69 Am. St. Rep. 242, Throckmorton Cas. Contracts, 106, See, also, Irwin v. Lombard University, 56 Ohio St. 9, 46 N. E. 63, 36 L. R. A. 239, 60 Am. St. Rep. 727; Simpson Centenary College v. Tuttle, 71 Iowa, 596, 33 N. W. 74. See "Subscriptions," Dec. Dig. (Key-No.) § 15; Cent. Dig. §§ 14-11.

69 Trustees of Maine Cent. Inst v. Haskell, 73 Me. 140; Barnett v. Franklin College, 10 Ind. App. 103, 37 N. E. 427. And see Keuka College v. Ray, 307 N. Y. 96, 60 N. E. 325. See "Subscriptions," Dec. Dig. (Key-No.) § 5; Cent. Dig. §§ 6, 7.

70 Presbyterian Board of Foreign Missions v. Smith, 209 Pa. 361, 58 Atl. 689, per Thompson, J. See "Subscriptions," Dec. Dig. (Key-No.) § 5; Cent. Dig, §§ 6, 7.

71 American Cotton Oil Co. v. Kirk, 68 Fed. 791, 15 C. C. A. 540; Rafolovitz v. Tobacco Co., 73 Hun, 87, 25 N. Y. Supp. 1036; Chicago & G. E. Ry. Co. v. Dane, 43 N. Y. 240; Davie v. Mining Co., 93 Mich. 491, 53 N. W. 625, 24 L, R. A. 357; Teipel v. Meyer, 106 Wis. 41, 81 N. W. 982; Dennis v. Slyfield, 117

On the other hand, if A. offers to supply at a certain price all the goods of a certain kind which B. may need in his business for a certain time, and B. promises to buy such goods, the promises are mutually binding;74 for although B. may not need the goods, and hence is not absolutely bound to pay, in the event of the contingency of his needing the goods he is bound to buy them of A. So, if the agreement is for the purchase by B. of all or a certain part of all the goods of a certain kind that A. may produce in a certain period.75

Fed. 474, 54 C. C. A. 520. See "Contracts," Dec. Dig. (Key-No.) §§ 58, 59; Cent. Dig. §§ 346-348; "Sales," Dec. Dig. (Key-No.) §§ 21,, 25; Cent. Dig. §§ 49-52; "Vendor and Purchaser," Dec. Dig. (Key-No.) § 18; Cent. Dig. § 28.

72 Keep v. Goodrich, 12 Johns. (N. Y.) 397; Ewins v. Gordon, 49 N. H. 444; Burnet v. Bisco, 4 Johns. (N. Y.) 235: McKinley v. Watkins, 13 I11. 140; L'Amoreux v. Gould, 7 N. Y. 349, 57 Am. Dec. 524; Thayer v. Burchard, 99 Mass. 50S; Smith v. Weaver, 90 I11. 392; Bean v. Burbank, 16 Me. 45S, 33 Am. Dec. 681; Mers v. Insurance Co., 68 Mo. 127; Stembridge v. Stembridge's Adm'r, 87 Ky. 91, 7 S. W. 611; Shenandoah Val. R. Co. v. Dunlop, 86 Va. 346, 10 S. E. 239; Barker v. Critzer, 35 Kan. 459, 11 Pac. 382; Warren v. Cos-tello, 109 Mo. 338, 19 S. W. 29, 32 Am. St. Rep. 669; Greybill v. Brugh, 89 Va. 895, 17 S. E. 558. 21 L. R. A. 133, 37 Am. St Rep. 894; Wagner v. J. & G. Meakin. 92 Fed. 76, 33 C. C. A. 577: Morrow v. Express Co., 101 Ga. 810. 28 S. E. 998. See, also, eases cited, p. 146, note 59. See "Sales," Dec. Dig. (Key-No.) §§ 21,, 25; Cent. Dig. §§ 49-52.

73G. N. Railway Co. v. Witham, L R. 9 C. P. 16; Johnston v. Trippe (C. C.) 33 Fed. 530; Moses v. McClain, 82 Ala. 370, 2 South. 741; Wisconsin, I. & N. Ry. Co. v. Braham, 71 Iowa, 484, 32 N. W. 392; Davis v. Robert, 89 Ala. 402, 8 South. 114, 18 Am. St. Rep. 126; Ross y. Parks, 93 Ala. 153, 8 South. 368, 11 L. R. A. 148, 30 Am. St. Rep. 47; Thayer v. Burchard, 99 Mass. 508; Cooper v. Wheel Co., 94 Mich. 272, 54 N. W. 39, 34 Am. St Rep. 341. See, also, Michigan Bolt & Nut Works v. Steel, 111 Mich. 153, 69 N. W. 241. Filing of bill by vendee for specific performance has been held to supply mutuality. Dynan v. McCulloch, 46 N. J. Eq. 11, 18 Atl. 822. But most of the cases are to the contrary. See cases cited ante, note 72. See "Sales," Dec. Dig. (Key-No.) §§ 24,, 25; Cent. Dig. §§ 1,9-52.

74 See Sheffield Furnace Co. v. Coke Co., 101 Ala. 446, 14 South. 672; Wells v. Alexandre, 130 N. Y. 642, 29 N. E. 142, 15 L. R. A. 218; Smith v. Morse, 20 La. Ann. 220; Minnesota Lumber Co. v. Coal Co., 160 I11. 85, 43 N. E. 774, 31 L. R. A. 529; Hickey v. O'Brien, 123 Mich. 611, 82 N. W. 241, 49 L. R. A. 594, 81 Am. St. Rep. 227; E. G. Dailey Co. v. Can Co., 128 Mich. 591, 87 N. W. 761; Manhattan Oil Co. v. Lubricating Co., 113 Fed. 923, 51 C. C. A. 553; Excelsior Wrapper Co. v. Messinger, 116 Wis. 549. 93 N. W. 459; Loudenback Fertilizer Co. v. Phosphate Co., 121 Fed. 298, 58 C. C. A. 220, 61 L. R. A. 402. Contra, Bailey v. Austrian, 19 Minn. 535 (Gil. 465). An agreement by a wholesale dealer to supply a retailer, which leaves it practically optional to increase or diminish his orders with the rise or fall of prices, held void for want of mutuality. Crane v. C. Crane & Co., 105 Fed. 869, 45 C. C. A. 96. See, also. Cold Blast Transp. Co. v. Bolt & Nut Co., 114 Fed. 77. 52 C. C. A. 25, 57 L. R. A. 696. See "Sales," Dec. Dig. (Key-No.) §§ 21,, 25; Cent. Dig. §§ 49-52.

Somewhat similar in character are the considerations which consist in conditional promises;76 as, for instance, where a person promises to do something for a reward, but the other party only binds himself to pay the reward upon the happening of an event which may not be under the control of either party. Such would be the case in a building contract where the promise to pay for the work to be done is made conditional upon the approval of the architect. Again, the promise may be conditional on something happening, as in case of promises in a charter party which are not to take effect if certain specified risks occur. In the one case the promise depends for its fulfillment upon a condition precedent; in the other it is liable to be defeated by a condition subsequent. In neither case does its conditional character prevent it from forming a sufficient consideration for promises given in return. These cases are for consideration in a subsequent chapter.77