The obligation of joint obligors is single and indivisible. Therefore if for any reason going to the merits of the action, one obligor can no longer be sued, the others are in effect discharged. This principle is illustrated by a variety of cases. Thus, if judgment is entered against one or more joint obligors because of their failure to plead in abatement the non-joinder of the others, a subsequent action cannot be brought against the others.19 Even though the joint debtors omitted from the first suit were dormant partners whose existence was unknown to the creditor when he obtained judgment, the principle is none the less applicable.20
A judgment on the merits in favor of one joint obligor is as fatal to an action against the others as if the first action had terminated in favor of the plaintiff.21
Mints v. Tri-County Natural Gas Co., 259 Pa. 477, 103 Atl. 285, 286. And one of two joint obligees with the con-Bent of the other may use the obligation as an equitable defence in an action by the obligor against one of them alone. Ibid.
19King v. Hoare, 13 M. & W. 494; Kendall v. Hamilton, 4 A. C. 604; Mason v. Eldred, 6 Wall. 231, 18 L. Ed. 7S3 (overruling Sheehy v. Mande-ville, 6 Cranch, 253, 3 L. Ed. 391); United States v. Ames, 99 U. S. 35, 25 L. Ed. 295; Trafton v. United States, 3 Story, 646; Brady v. Reynolds, 13 Cal. 31; Scarborough p. Yarborough, 13 Ga. App. 792, 79 S. E. 1131; Wann v. McNulty, 2 Gilm. 355, 43 Am. Dec. 58; Moore v. Rogers, 19 111. 347; Jan-sen v. Grimshaw, 125 111. 468,17 N. E. 850; Travellers Ins. Co. v. Mayo, 170 111. 498, 500, 48 N. E. 917; Fleming v. Ross, 226 111. 149, 80 N. E. 92; Crosby v. Jeroloman, 37 Ind. 264; Lawrence v. Beecher, 116 Ind. 312, 19 N. E. 143; Mosle v. Hollins, 11 G. & J. 11, 33 Am. Dec. 684; Ward v. Johnson, 13 Mass. 148; Cowley v. Patch, 120 Mass. 137; Davison v. Harmon, 65 Minn. 402,
67 N. W. 1015; Coles v. McKenna, 80 N. J. L. 48, 76 Atl. 34; Robertson 0. Smith, 18 Johns. 459, 9 Am. Dec. 227; Candee v. Smith, 93 N. Y. 349; Ryck-man v. Manerud, 68 Or. 350, 136 Pac. 826; Smith v. Black, 9 Serg. A R. 142, 11 Am. Dec. 686; McFarlane v. Kipp, 206 Pa. 317, 55 Atl. 986; Lauer v. Bandow, 48 Wis. 638, 4 N. W. 774.
Also see Hammond v. Schofield,  1 Q. B. 453, holding that where judgment had been signed by consent against the defendant, it could not be set aside, even with his assent, in order that the writ might be amended by joining another defendant who had been discovered by the plaintiff to have contracted jointly with the defendant.
20 Kendall v. Hamilton, 4 A. C. 504; United States v. Ames, 99 U. S. 35, 25 L. Ed. 295; Moale v. Hollins, 11 G. A J. 11, 33 Am. Dec. 6S4; Smith v. Black, 9 S. A R. 142, 11 Am. Dec 683. See also Ryckman c. Manerud, 68 Or. 350, 136 Pac. 826, 831. But compare Scott 0. Colmesnil, 7 J. J. Marsh. 416.
21 Phillips v. Ward, 2 H. A C. 717;
But a foreign judgment against one joint debtor, it has been held, being of no higher nature than the original obligation, does not merge the right against the other obligors;22 and generally in the United States where the defendant in the subsequent action was not at the time within the jurisdiction of the court in which the prior judgment was rendered, the subsequent action may be sustained. In such a case, for reasons of necessity and justice perhaps rather than of logic, the prior judgment is held to be no bar.23