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.
Since B's giving up a right to a third person would be a consideration, B's giving up a right to one of two promisors is a consideration for the promise of both. So where A, a physician, entered into a contract with B and C, whereby A bought B's practice, and B and C both agreed not to compete with A, C's promise was supported by a sufficient consideration.1
On the other hand, it has been held without much thought upon the question that if A owns certain land and conveys it to B, who buys it in reliance on the promises of A, of X who is A's husband, and of Y, to whom B conveys as trustee for A to secure the unpaid purchase price, that the purchase money paid in by A will first be
1 Jones v. Robinson, 1 Exch. 454. 2 Jones v. Robinson, 1 Exch. 454. 3 Jones v. Robinson, 1 Exch. 454. 1Tweeddale v. Tweeddale, 116 Wis applied to discharge a lien on such land, there is no consideration for the promises of X and Y.2
517, 96 Am. St. Rep. 1003, 61 L. R. A 509. 93 N. W. 440.
1 Ryan v. Hamilton, 205 111. 191, 68 N. E. 781 [reversing 108 111. App. 2121.