A principle which lies at the bottom of the doctrine is that the person seeking it must have paid the debt under grave ne cessity to save himself a loss. The right is never accorded to a volunteer ; /Etna Life Ins. Co. v. Middleport, 124 U. S. 534, 8 Sup. Ct. 625, 31 L. Ed. 537 ; Sheld. Subr. § 240 ; Shinn v. Budd, 14 N. J. Eq. 234 ; Hoover v.
lEpler, 52 Pa. 522 ; Gadsden v. Brown, Speer's Eq. (S. C.) 37, 41, in which is a statement of the doctrine by Johnson, Ch., of which Miller, J., said in /Etna Life Ins. Co. v. Middleport, 124 U. S. 549, 8 Sup. Ct. 625, 31 L. Ed. 537: "This is perhaps as clear .a statement of the doctrine on this subject as is to be found anywhere." But under the Louisiana code the pay ment of a mortgage debt by an ordinary creditor subrogates him to the rights of the mortgagee ; Hall v. Hawley, 49 La. Ann. 1046, 22 South. 205; so also of a grantee of the premises who has paid the mortgage in good faith relying on representations that there were no junior liens; Johnson v. Tootle, 14 Utah 482, 47 Pac. 1033 ; but a mortgagee, who, for his own convenience, with knowledge of the facts, accepts several mortgages in discharge of the original one, is not entitled to subrogation ; Seieroe v. Homan, 50 Neb. 601, 70 N. W. 244.
Where a bank lent money to a contractor to be used in carrying out his contract and some of it was used by him for paying la borers and material men, the bank was not entitled to subrogation to the claims of the latter ; Lawrence v. U. S., 71 Fed. 228. As to subrogation to rights of labor, etc., claims, see McClung v. IL Co. (Tenn.) 42 S. W. 53 ; RECEIVER.
Persons are not entitled to the right of subrogation where such alleged right arises from tortious conduct of their own. A per son who invokes the doctrine of subrogation must come into court with clean hands; Ger man Bk. of Memphis v. U. S., 148 U. S. 573, 13 Sup.. Ct. 702, 37 L. Ed. 564.
Legal subrogation takes place to its full extent— First, for the benefit of one who being himself a creditor pays the claim of an other who has a preference over him by reason of his liens and securities. For in this case, it is ,said, it is to be presumed that he pays for the purpose of securing his own debt; and this distinguishes his case from that of a mere stranger. Domat,
Civ. Law. And so, at common law, if a junior mortgagor pays off the prior mort gage, he is entitled to demand an assign ment thereof ; Appeal of Mosier, 56 Pa. 76, 93 Am. Dec. 783; Miller v. Whittier, 36 Me. 577.
Second, for the benefit of the purchaser of an immovable, who uses the price which he paid in paying the creditors to whom the inheritance was mortgaged.
Third, for the benefit of him who, being held with others or for others for the pay ment of the debt, has an interest in dis charging it.
Subrogation takes place for the benefit of co-promisors or co-guarantors, as between themselves, and for the benefit of sureties against their principals. But between co guarantors and co-promisors subrogation ben efits him pays the debt only to the ex tent of enabling him to recover from each separately his portion of the debt. As against his co-sureties, the surety increasing the value of their joint security is entitled to subrogation only to the amount actually paid; Tarr v. Ravenscroft, 12 Gratt. (Va.) 642. Any arrangement by one co-surety with the principal enures to the benefit of all the co-sureties ; Tyus v. De Jarnette, 26 Ala. 280 ; Taylor v. Morrison, 26 Ala. 728, 62 Am. Dec. 747.
If one tenant in common pays a mortgage or other incumbrance upon the property, he may be subrogated to such lien to secure contribution from his co-tenants. A person who has lent money to a debtor for the purpose of discharging a debt may be sub rogated by the debtor to the creditor's rights, and if the party who has agreed to ad vance the money for the purpose employs it himself in paying the debt and discharg ing the incumbrance on land given for its security, he is not to be regarded as a volun teer. After such an agreement with the debtor, he is not a stranger in relation to the debt, but he may in equity be entitled to the benefit of the security which he has satisfied with the expectation of receiving a new mortgage or lien upon the land for the money paid ; Haverford L. & B. Ass'n v. Fire Ass'n, 180 Pa. 522, 37 AU. 179, 57 Am. St. Rep. 657.