First, where the principal obligation is pre-existent, there must be a new considera tion to support the promise; and where this consideration is the discharge of the princi pal debtor, the promise is original and not collateral, as the first requisite of a collater al promise is the existence of a principal obligation. This has been held in numerous cases. The discharge may be by agreement, by novation or substitution, by discharge on final process, or by forbearance under cer tain circumstances ; 4 B. & P. 124; Mallory v. Gillett, 21 N. Y. 412; Walker v. Penniman, 8 Gray (Mass.) 233.
But the converse of this proposition, that where the principal obligation remains, the promise is collateral, cannot be sustained, though there have been repeated dicta to that effect; Browne, Stat. Fr. § 193; Jack son v. Rayner, 12 Johns. (N. Y.) 291; denied in Mallory v. Gillett, 21 N. Y. 415; Langdon v. Brumby, 7 Ala. 54; Templeton v. Bas com, 33 Vt. 132.
The main question arising in cases under this head is whether the debtor is discharg ed; and this is to a great extent a question for the jury. But if in fact the principal debt is discharged by agreement and the new promise is made upon this considera tion, then the promise is original, and not collateral; Wood v. Corcoran, 1 Allen (Mass.) 405.
But where there is an existing debt, for which a third party is liable to the prom isee, and the promisor undertakes to be re sponsible for it, still the contract need not be in writing if its terms are such that it effects an extinguishment of the original lia bility ; Eden v. Chaffee, 160 Mass. 225, 35 N. E. 675.
A discharge of the debtor from custody, or surrender of property taken on an exe cution, is a good discharge of the debt; 11 M. & W. 857 ; Anderson v. Davis, 9 Vt. 137, 31 Am. Dec. 612; Mallory v. Gillett, 21 N. Y. 415.
Where the transaction amounts to a sale of the principal debt in consideration of the new promise, the debtor is discharged, and the promise is original; 3 B. & C. 855. So where a purchaser of goods transfers them to another, who promises the vendor to pay for them, this is a substitution and an orig inal promise; 5 Taunt. 450; Whitbeck v. Whitbeck, 9 Cow. (N. Y.) 266, 18 Am. Dec. 503; Rice v. Carter's Adm'r, 33 N. C. 298; Rowe v. Whittier, 21 Me. 545.
A mere forbearance to press the principal debt is not such a discharge of the debtor as will make the promise original; 1 Sm. L. C. 387; Mallory v. Gillett, .21 N. Y. 412; Jones v. Walker, 13 B. Monr. (Ky.) 356; but where the forbearance is so protracted as to dis charge the debtor, it may be questioned whether the promise does not become origin al ; Templeton v. Bascom, 33 Vt. 132.
Second, the promise will be original if made in consideration of some new benefit moving from the promisee to the promisor; Kutzmeyer v. Ennis, 27 N. J. Law, 371; Far
ley v. Cleveland, 4 Cow. (N. Y.) 432, 15 Am. Dec. 387; Bull. N. P. 281.
Third, the promise is original where the consideration is some loss to the promisee or principal creditor ; but it is held in many such cases that the loss must also work some benefit to the promisor ; 6 Ad. & E. 564; Abner v. Washington, 3 Strobh. Eq. (S. C.) 177; Lawrence v. Fox, 20 N. Y. 268. As to merely refraining from giving an execution to the sheriff, see Russell v. Babcock, 14 Me. 140.
There have been decisions which hold that the mere relinquishment of a lien by the plaintiff takes the case out of the statute; Slingerland v. Morse, 7 Johns. (N. Y.) 464. It would seem that a surrender of a lien merely is not sufficient consideration; Nelson v. Boynton, 3 Mete. (Mass.) 396, 37 Am. Dec. 148; but it must appear that the surrender is in some way beneficial to the promisor, as when he has an interest in the property released ; Prime v. Koehler, 77 N. Y. 91 ; Conradt v. Sullivan, 45 Ind. 180, 15 Am. Rep. 261 ; Curtis v. Brown, 5 Cush. (Mass.) 488.
The rule is well settled that when the leading object of a promisor is to induce a promisee to forego some lien, interest, or advantage, and thereby to confer on the promisor a privilege or benefit which he would not otherwise possess or enjoy, an agreement made under such circumstances and upon such a consideration is a new, orig inal, and binding contract, although the ef fect of it may be to assume the debt and dis charge the liability of another; 6 Maule & S. 204; Alger v. Scoville, 1 Gray (Mass.) 391. The advantage relinquished by the promisee must directly enure to the benefit of the promisor, so as in effect to make it purchase by the promisor ; Curtis v. Brown, 5 Cush. (Mass.) 488 ; Jackson v. Rayner, 12 Johns. (N. Y.) 291. It is stated in many cases that the promise is original where the considera tion moves to tlie promisor. The true test, however, must be found not in the consid eration, but in the nature of the promise. Wherever the new promisor undertakes_ for his own default ; where his promise is vir tually to pay his own debt in a peculiar way, or if, by paying the debt, he is really dis charging a liability of his own, his promise is original. The only case in which consid eration can affect the terms of the promise is where the consideration of the promise is the extinguishment of the original liability ; Colt v. Root, 17 Mass. 229 ; Rollison v. Hope, 18 Tex. 446 ; Emerson v. Slater, 22 How. (U. S.) 28, 16 L. Ed. 360.