A promise is a good consideration for a promise. (x)1 And it is so previous to performance and without performance. As, if one promises to become a partner in a firm, and another promises to receive him into the firm, both of these promises are binding, each being a sufficient consideration for the other. (y) So a promise by a seller to refund in case of deficiency in the thing sold is a good consideration for a promise to pay for any excess therein. (yy) If one promises to teach a certain trade, this is a consideration for a promise to remain with the party a certain length of time to learn, and serve him during that time; but, without such promise to teach, the promise to remain and serve, though it be made in expectation of instruction, is void. (z) The

(x) Nichols v. Raynbred, Hob. 88; Hebden v. Rutter, 1 Sid. 180; Strang-borough v. Warner, 4 Leon. 3; Gower v. Capper, Cro. E. 543; Parke, J., in Went-worth v. Bullen, 9 B. & C. 840; Cart-wright v. Cook, 3 B. & Ad. 703; Miller v. Drake, 1 Caines, 45; Rice v. Sims, 8 Rich. L. 416; Garret v. Malone, id. 335; James v. Fulcrod, 5 Tex. 512; Dockray v. Dunn, 37 Me. 442; The New York and New Haven Railroad Co. v. Pixley, 19 Barb. 428; Kiester v. Miller, 25 Penn. St. 481; Backus v. Spaulding, 116 Mass. 418. So in White v. Demilt, 2 Hall, 405, it was held, that in an action for the breach of the defendant's contract to sell and deliver certain goods to the plaintiff, the promise of the latter to accept the goods and pay for them is a good consideration for the defendant's promise to deliver them. So, in Howe v. O'Mally, 1 Murphey, 287, A conveyed to B a tract of land containing 221 acres more or less. Some years afterwards it was mutually agreed to have the land surveyed, and if it were found to contain more than 221 acres, the defendant should pay the plaintiff ten dollars per acre for the excess; if it fell short, the plaintiff was to refund to the defendant at the same rate. Here are mutual promises, and one is a good consideration to support the other.

(y) McNeill v. Reed, 2 M. & Scott, 89; s. c. 9 Bing. 68.

(yy) Seward v. Mitchell, 1 Cold. 87.

(z) Thus where the defendant had reason of *this is, that a promise is not a good consid- eration for a promise unless there is an absolute mutuality of engagement, so that each party has the right at once to hold the other to a positive agreement. (a) signed a written agreement to the following effect: " I hereby agree to remain with Mrs. Lees, of 302 Regent Street, Portland Place, for two years from the date hereof, for the purpose of learning the business of a dressmaker, & c. As witness my hand this 5th day of June, 1826," it was held, that as the agreement was all on one side, nothing being contracted to be done or performed by Mrs. Lees as a consideration or inducement for the defendant's remaining two years in her service, it was a nudum pactum; and that no action consequently could be brought upon it against the defendant, for leaving her mistress, and commencing business on her own account before the expiration of the two years. Lees v. Whitcomb, 2 Mo. & P. 86; s. c. 5 Bing. 34. So, where the written agreement was in the following terms: " Memorandum of an agreement made the 17th of August, 1833, by which I, William Bradley of Sheffield, do agree that I will work for and with John Sykes, of Sheffield aforesaid, manufacturer of powder-flasks and other articles, at and in such work as he shall order and direct, and no other jut-sou whatsoever, from this day henceforth, during and until the expiration of twelve months, and so on from twelve months' end to twelve months' end, until I shall give the said John Sykes twelve months' notice in writing, that I shall quit his service," it was held, that as this engagement was entirely unilateral, and nothing was to be given or done by John Sykes as a consideration for Bradley's promise to work for him by the year, and no one else, the agreement was a nudum pactum, and could not be enforced. Sykes v. Dixon, 9 A. & E. 693; s. c. 1 Per. & D. 463. See also Bates v. Cort, 3 Dow. & R. 676. So where the defendant signed the following instrument: "Mr. James ------, as you have a claim on my brother for £5 17s. 9d., for boots and shoes, I hereby undertake to pay the amount within six weeks from this date, 14th January, 1833," it was held, that the promise, being without consideration, was a nudum pactum, and gave no cause of action. James v. Williams, 5 B. & Ad. 1109.

1 Such a contract has been called a bilateral contract, while a promise given in consideration for actual performance or forbearance has been termed a unilateral contract. In the one case there is a promise on both sides, in the other on but one side. See Stevenson v. McLean, 5 Q. B. D. 346, 351; Davis v. Wells, 104 U. S. 159; Barrett v. Dean, 21 Ia. 423; Barry v. Capen, 151 Mass. 99; First Nat. Bank v. Watkins, 154 Mass. 385; Coleman v. Applegarth, 68 Md. 21; Stensgaard v. Smith, 43 Minn. 11, 15.

(a) McKinley v. Watkins, 13 Ill. 140; Lester v. Jewett, 12 Barb. 502; Nichols v. Raynbred, Hob. 88; Kingston v. Phelps, Peake, 227; Biddell v. Dowse, 6 B. & C.

255; Hopkins v. Logan, 5 M. & W. 241; Burton v. G. N. R. Co., 9 Exch. 507: Dorsey v. Roekwood, 12 How. 126; Stiles V,

McClellan, 6 Col. 89; Cool v. Cunningham, 25 S. C. 136. This necessity for the mutuality of the obligation, in order to render either party bound, is well illustrated by the later case of the Governor & Copper Miners v. Fox, 16 Q. B. 239. In that case a corporation brought an action on an executory contrail, seeking to recover damages for its Don-performance. The declaration stated that in consideration that the plaintiffs would sell to the defendants iron rails, the defendants agreed to furnish to the plaintiffs sections of the said railways, averring mutual promises, and alleging as a breach the non-delivery of the sections by the defendants. It appeared that the plaintiffs were incorporated by a charter, for the purpose of carrying on the business of copper miners, and that the contract in question, which was not under seal, had been made by an agent on behalf of the plaintiffs with the defendants. Held, that the action could not be maintained by the corporation, as the contract was not under seal, and did not fall within any of the exceptions to the general rule, that a corporation can only bind itself by deed: that the contract was not incidental or ancillary to earning on the business of copper miners, and was therefore not hi tiding on the corporation; that no other charter authorizing the company to deal in iron could be presumed to exist, the charter which was given in evidence not supporting such an authority; and that, as the corporation could not be sued upon this contract, and as the alleged promise by them formed the consideration for the defendant's promise, the corporation could not sue upon the contract. And sen that the doctrine cannot be supported, that a corporation may sue as plaintiff upon a simple contract, upon the ground that by so doing they are estopped from objecting that the contract was not binding upon them. At all events such an estoppel could only support an action of covenant, as upon a contract under seal. See also Payne v. New South Wales Co., 28 E. L. & E."579; s c. 10 Exch. 288. - If, however, a contract like the above, although not originally binding upon one party, by reason of some defect or inforno mutuality, and therefore no consideration for it. But after an engagement on the part of the promise which is sufficient to bind him, then the promisor is bound also, because there is now a promise for a promise, with entire mutuality of obligation. So, if the promisee begins to do the thing, in a way which binds him to complete it, here also is a mutuality of obligation. But if without any promise whatever, the promisee does the thing required, then the promisor is bound on another ground. The thing done is itself a sufficient and a completed consideration; and the original promise to do something, if the other party would do something, is a continuing promise until that other party does the thing required of him.