"Any special promise" in the act does not apply to promises implied in law ; Brandt, Sur. & Guar. § 53.
The following classes of promises have been held not within the statute, and valid though made by parol.
First, where there is a liability pre-exist ent to the new promise.
1. Where the principal debtor is discharg ed by the new promise being made; Gleason v. Briggs, 28 Vt. 135 ; Walker v. Penniman, 8 Gray (Mass.) 233; 1 Q. B. 933; Skelton v. Brewster, 8 Johns. (N. Y.) 376 ; Browne, Stat. Fr. §§ 166, 193 ; and an entry of such discharge in the creditor's books is sufficient proof ; Corbett v. Cochran, 3 Hill (S. C.) 41, 30 Am. Dec. 348. This may be done by agree ment to that effect; Wood v. Corcoran, 1 Al len (Mass.) 405; by novation, by substitu tion, or by discharge under final process; 1 B. & Ald. 297; Blankenship & Co. v. Tillman (Tex.) 18 S. W. 646; but mere forbearance. or an agreement to forbear pressing the claim, is not enough ; 1 Sm. L. Cas. 387 ; Har rington v. Rich, 6 Vt. 666.
2. Where the principal obligation is void or not enforceable when the new promise is made, and this is contemplated by the parties. But if not so' contemplated, then the new promise is void ; Burge, Surety 10; 1 Burr. 373. Rut see, on this point, Nabb v. Koontz, 17 Md. 283; Nelson v. Dubois, 13 Johns. (N. Y.), 175 ; Connerat v. Goldsmith, 6 Ga. 14.
3. So where the promise does not refer to the particular debt, or where this is un ascertained; 1 Wils. 305.
In these three classes the principal obliga tion ceases to exist after the new promise is made.
4. Where the promisor undertakes for his own debt. But the mere fact that he is in debted will not suffice, unless his promise refers to that debt ; nor is it sufficient if he subsequently becomes indebted on his own account, if not indebted when he promises, or if it is then contingent ; Suydam v. West fall, 4 Hill (N. Y.) 211. See Morris v. Gaines, 82 Tex. 255, 17 S. W. 538. The pro vision of the statute does not apply when ever the main purpose of the promisor is not to answer for another, but to subserve some pecuniary or business purpose of his own, although it may be in form a promise to pay the debt of another ; Davis v. Patrick,
141 U. S. 479, 12 Sup. Ct. 58, 35 L. Ed. 826. So, if the vendee of land promise to pay the pnrcbase-money on a debt due by the ven dor; Morris v. Gaines, 82 Tex. 255, 17 S. W. 538.
5. Where the new promise is in considera tion of property placed by the debtor in the promisor's hands ; Alger v. Scoville, 1 Gray (Mass.) 391; Maxwell v. Haynes, 41 Me. 559; Meyer v. Hartman, 72 III. 442. And where the new promise is made in a trans action which is in substance a sale to the promisor ; Brandt, Sur. & Guar. § 65.
6. Where the promise does not relate to the promisor's property, but to that of the debtor in the hands of the promisor.
7. Where the promise is made to the debt or, not the creditor ; because this is not the debt of "another" than the promisee; Alger v. Scoville, 1 Gray (Mass.) 391; 11 Ad. & E. 438.
8. Where the creditor surrenders a lien against the debtor or on his property, which the promisor acquires or is benefited by; Fell, Guar. c. 2; Brandt, Sur. & Guar. §§ 63, 64; 2 B. & Ald. 613; Mallory v. Gillett, 21 N. Y. 412; but not so where the surrender of the lien does not benefit the promisor ; Nelson v. Boynton, 3 Metc. (Mass.) 396, 37 Am. Dec. 148; Mallory v. Gillett, 21 N. Y. 412.
In the five last classes, the principal debt may still subsist concurrently with the new promise, and the creditor will have a double remedy; but the fulfillment of the new prom ise will discharge the principal debt, because he can have but one satisfaction. The re peated dicta, that if the principal debt sub sists, the promise is collateral and within the statute, are not sustainable; Cross v. Rich ardson, 30 Vt. 641. But the general doctrine now is that the transaction must amount to a purchase, the engagement for the debt be ing the consideration therefor, in whole or in part ; Alger v. Scoville, 1 Gray (Mass.) 391.