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.
It is still said in some jurisdictions that a past consideration which, though without request, moved directly from the plaintiff to defendant and inured directly to defendant's benefit, was binding and created a legal liability where none existed before. This statement must, however, be regarded as obiter, since the promise was supported by a future consideration as well as a past consideration.1 A promise to pay for past and future drainage of a mine has consideration in such future drainage.2 Some authorities even hold that past services not rendered at the promisor's request are a consideration for a subsequent promise,3 or deed.4 Care and attention to a sick guest, not imposing legal liability at the time, may amount to such consideration as will support a subsequent express promise to pay therefor.5 B dug a well on A's realty at the request of B's tenant, X, who had no authority to bind A by such contract. The improvement inured to A's benefit and A subsequently promised to pay B a certain sum of money therefor. Such improvement was held to be a sufficient consideration for such promise.6 If A has the right to oil in certain land while B has the right to the gas therein, and A drills a well which produces gas, there is sufficient consideration for B's promise to repay to A the cost of such well.7
The theory that a subsequent promise is the equivalent of a previous request 8 has been repudiated, however, in the jurisdiction which is probably chiefly responsible for its adoption by any of our courts.9
10 Moore v.Elmer, 180 Mass. 15, 61 N. E. 259. (This was either a promise to make a gift, or else a wager.)
11Hoeven v. Morley, 36 S. D. 421, 155 N. W. 191.
1 Boothe v. Fitzpatrick, 36 Vt. 681.
2Fisk Min. & Mill Co. v. Reed, 32 Colo. 506, 77 Pac. 240.
3 Lycoming v. Union, 15 Pa. St. 166, 53 Am. Dec. 575; Spencer v. Potter's Estate, 85 Vt. 1, 80 Atl. 821.
4 Doran v. McConlogue, 150 Pa. St. 98, 24 Atl. 357.
5 Spencer v. Potter's Estate, 85 Vt. 1, 80 Atl. 821.
6 Edson v. Poppe, 24 S. D. 466, 26 L. R. A. (N.S.) 534, 124 N. W. 441. See obiter in Glenn v. Savage, 14 Or. 567, 13 Pac. 442, where no subsequent promise was shown.
7 Pittsburg Vitrified Pav. & Bldg. Brick Co. v. Cereleus Oil Co., 79 Kan. 603, 100 Pac. 631.
8Gleason v. Dyke, 39 Mass. (22 Pick.) 390.
If the promisee foregoes a legal right, sufficient consideration exists, even if the contract relates in part to past transactions. Thus a waiver by lessee of his right to remove improvements made by him,10 or waiver by a contractor of his right to remove windows inserted by him in the wrong house by mistake,11 are valuable considerations.