308. 8 Opinion of the Court. brought in either district." We thus have an express declaration by Congress that under one particular set of circumstances a co-defendant may be sued in a district in which he does not reside. Expressio unius est exclusio alterius. This section follows directly after that which contains the general prohibition against suing a defendant in a district other than that in which he or the plaintiff resides, and constitutes one of the specified exceptions to the general prohibition. It shows, therefore, that the prohibition of § 51 expresses the deliberate purpose of Congress that a person shall not be compelled to submit to suit in the federal District Court in a State within which neither he nor the plaintiff resides, although a co-defendant may reside therein. The history of § 52 confirms this conclusion. It is substantially a reenactment of § 740 of the Revised Statutes. After the passage of the Act of 1887-1888 restricting the jurisdiction of the federal courts, considerable doubt arose as to whether the provisions of that act now contained in § 51 of the Judicial Code did not repeal § 740 of the Revised Statutes. Compare Petri v. Creelman Lumber Co., 199 U. S. 487. Congress reenacted in the Judicial Code this provision expressly permitting, in States having more than one district, all defendants resident within the State to be sued in any district thereof in which one of them resides; while it made no similar provision for the case where the several defendants reside in different States. If Congress, in reënacting the provisions of § 51, had intended that it should establish a rule with reference to defendants resident in different States contrary to the construction placed by the overwhelming weight of authority upon 1 See also Doscher v. United States Pipe Line Co., 185 Fed. Rep. 959; John D. Park & Sons Co. v. Bruen, 133 Fed. Rep. 806; New Jersey Steel & Iron Co. v. Chormann, 105 Fed. Rep. 532; Goddard v. Mailler, 80 Fed. Rep. 422; East Tennessee, V. & G. R. Co. v. Atlanta & F. R. Co., 49 Fed. Rep. 608. the identical provision contained in the earlier statute, it would have expressed that intention in unmistakable language. No reason appears, therefore, for refusing to apply here the rule of Smith v. Lyon, supra. The objection made below that the plea to the jurisdiction is bad because not limited by its terms to the question of jurisdiction over the particular defendant is highly technical, and was hardly insisted upon here; and the contention that his exemption from suit was waived by the acknowledgment on the summons of service is clearly unfounded. John M. Camp properly asserted his privilege by plea to the jurisdiction, and the plea should have been sustained. It follows that the judgment against him is void; that the judgment of the Circuit Court of Appeals, in so far as it affirms the judgment of the District Court against him, should be reversed; and the suit should be dismissed as to him. Second. The plea to the jurisdiction filed by P. D. and P. R. Camp was properly overruled. The objection was based wholly on the fact that John M. Camp was not suable within the district. This is an exemption from suit personal to the nonresident of the district. A resident co-defendant cannot avail himself of the objection.' If John M. had been an indispensable party, the failure to obtain jurisdiction over him would, of course, be fatal to the maintenance of the suit. Barney v. Baltimore City, 6 Wall. 280. But he was not an indispensable party; and under § 50 of the Judicial Code the trial court might, if it had sustained John M.'s plea to the jurisdiction, have rendered judgment against the other two defend 1 Tice v. Hurley, 145 Fed. Rep. 391, 392; Chesapeake & O. Coal Agency Co. v. Fire Creek Coal & Coke Co., 119 Fed. Rep. 942; Smith v. Atchison, T. & S. F. R. Co., 64 Fed. Rep. 1, 2; Jewett v. Bradford Sav. Bank & Trust Co., 45 Fed. Rep. 801; Bensinger Self-Adding Cash Register Co. v. National Cash Register Co., 42 Fed. Rep. 81, 82. 308. Opinion of the Court. ants; for this is an action on a joint contract, and one of the several joint-contractors is not an indispensable party defendant in such a suit. Clearwater v. Meredith, 21 How. 489. Third. P. D. Camp and P. R. Camp contend that, in view of the error in overruling John M. Camp's plea to the jurisdiction and proceeding to judgment against him, the court may not confine its action to correcting the error by setting aside the judgment and dismissing the suit as to him, but must set aside the judgment as against all the defendants, thus requiring a new trial as against the other two. But this is not a necessary result of erroneously retaining jurisdiction over John M. Camp; for, as above shown, John M. was not an indispensable party to a suit to enforce the liability of the other two joint obligors; and if the trial court had sustained his plea to the jurisdiction, the suit might, under § 50 of the Judicial Code, have proceeded to judgment as against the other defendants. Whether the error committed in retaining jurisdiction over John M. requires a reversal of the judgment as against the other defendants depends upon whether that error may have prejudiced them. The record does not show that the error committed could have prejudiced them in any way; and their counsel admitted at the bar that the error had not prevented them from availing themselves of any defense, and had not influenced the admission or rejection of evidence, or the granting or refusal of any instruction asked or given. Only error which may have resulted in prejudice could justify reversal of a judgment. Compare Yazoo & Mississippi Valley R. R. Co. v. Mullins, 249 U. S. 531. It is, however, contended that the Virginia practice would require a reversal of the judgment as against all defendants, and that the Conformity Act (Revised Statutes, § 914) requires that the state practice be followed. If such were the Virginia practice, which is denied, it would not be binding on this court. The Conformity Act by its express terms refers only to proceedings in District (and formerly Circuit) Courts and has no application to appellate proceedings either in this court or in the Circuit Court of Appeals. Such proceedings are governed entirely by the acts of Congress, the common law, and the ancient English statutes. United States v. King, 7 How. 833, 844; Boogher v. Insurance Co., 103 U. S. 90, 95; Chateaugay Ore & Iron Co., Petitioner, 128 U. S. 544; St. Clair v. United States, 154 U. S. 134, 153; Francisco v. Chicago & A. R. Co., 149 Fed. Rep. 354, 358-359; United States v. Illinois Surety Co., 226 Fed. Rep. 653, 664. In cases coming from federal courts the Supreme Court is given by statute full power to enter such judgment or order as the nature of the appeal or writ of error (or certiorari, § 240 of the Judicial Code) requires. Revised Statutes, § 701. Circuit Court of Appeals Act of March 3, 1891, c. 517, § 11, 26 Stat. 826, 829. See also § 10 of the same act. Compare Ballew v. United States, 160 U. S. 187, 198, et seq.. And by Act of February 26, 1919, c. 48, 40 Stat. 1181, amending § 269 of the Judicial Code, the duty is especially enjoined of giving judgment in appellate proceedings "without regard to technical errors, defects, or exceptions which do not affect the substantial rights of the parties." The error in retaining jurisdiction over John M. Camp, does not, therefore, require that the judgment as against the other two defendants be set aside. Fourth. P. D. and P. R. Camp contend, however, that the judgment against them should be reversed also on the ground that there was error in the instructions as to the measure of damages. The contention must be examined, as the whole case is here on writ of certiorari and the objection was properly saved. Lutcher & Moore Lumber Co. v. Knight, 217 U. S. 257, 267; Delk v. St. Louis & San Francisco R. R. Co., 220 U. S. 580, 588. 308. Opinion of the Court. Gress was the owner of the entire capital stock of the Morgan Lumber Company, a corporation which held the title to saw-mill properties in Florida. The three defendants Camp were the owners of valuable timber lands near the mill. By contract under seal dated August 18, 1913, the Camps agreed to join with Gress in organizing a corporation under the name of Levy County Lumber Company to which Gress would convey the saw-mill properties which the parties valued at $125,000, and the Camps would convey the timber lands which they valued at $325,000; that Gress should receive, in exchange for the mill properties, five-eighteenths of the stock in the new company and the Camps, in exchange for the lands, thirteen-eighteenths of the stock; and that the parties should in that proportion finance the company. Gress was ready and willing and able to perform his part of the contract; and the Camps broke it by definitely refusing to perform. The only question in the case seriously controverted was the amount of damages recoverable. There was evidence that by reason of the breach of contract which resulted in depriving the mill of its timber supply its value depreciated heavily. The trial judge charged the jury that among the elements of damages recoverable was the amount of the depreciation in the market value of the mill between the date of the contract and the date of the breach. The objection made to this ruling was based wholly on the ground that, as the mill properties were vested in the Morgan Lumber Company, Gress could not recover more than nominal damages, although he owned all of its stock. The contention is that before it could be determined whether plaintiff, as owner of the stock of the Morgan Lumber Company, sustained any damages by reason of the depreciation in value of the mill property, an accounting and settlement of the Morgan Lumber Company's affairs would be necessary; and it is urged that the lower court, in rejecting a ruling to that |