Arthurs et al. v. Hart. plaintiffs must be content to submit to the law as settled in Weems v. George. They, therefore, do not rely upon the bill of exceptions to the admission of Francis Armstrong as a witness, but contend that, upon the face of the pleadings and the whole record, the judgment of the court below was erroneous, and may be reversed by this court. In Field v. The United States, 9 Pet., 202, as cited by Justice Grier, in Weems v. George, Marshall, C. J., in delivering the opinion of the court, says: "As the case was not tried by a jury, the exception to the admission of evidence was not properly the subject of a bill of exceptions. But if the district court improperly admitted the evidence, the only effect would be that this court would reject that evidence, and proceed to decide the cause as if it were not on the record. It would not, however, of itself, constitute any ground for the reversal of the judgment. If the record, therefore, is found to disclose other grounds than an exception to the admission of evidence, for the reversal of the judgment below, this court may reverse a judgment even in a cause submitted to the court below, under the Louisiana practice. The court will look into the whole record." In Garland v. Davis, 4 How., 131, it was decided, "this court can notice a material and incurable defect in the pleadings and verdict, as they are represented in the pleadings to have existed in the court below, although such defect is not noticed in the bill of exceptions, nor suggested by the counsel in argument here." *The defendant's answer in this case was materially *10] and incurably defective on its face. Let it be presumed, therefore, that the evidence objected to in the bill of exceptions was strong enough to sustain all and every allegation stated in the answer, still, the plaintiffs were entitled to a verdict for the whole amount of their bill of exchange; for, admitting that the proof did sustain the allegations of the answer, the defense was utterly unsound in law. Although the bill of exceptions to the evidence in this case may not, for the reasons already stated, be available to the plaintiffs to the full extent of a bill of exceptions to a cause tried with a jury, according to the common law practice; yet, being part of the record, it discloses the fact that the question as to the sufficiency of the defendant's answer, as a defense in this suit, was fully argued, and after argument, decided in the court below. The plaintiffs contend that this decision was erroneous. Mr. Lawrence, for the defendant in error, maintained: Arthurs et al. v. Hart. 1. That the judge having determined both the facts and the law, this writ of error cannot be sustained upon the ground that improper testimony has been admitted. There was other testimony in the case, and upon that alone the judgment of the court may have been founded. Field v. United States, 9 Pet., 202; United States v. King, 7 How., 833; Weems v. George, 13 How., 195, 196. 2. The testimony was admissible for the purpose of showing downright fraud on the part of the plaintiffs in error, in procuring the acceptance. Bayley on Bills, 528; Ledger v. Ewen, Peake, 216. 3. The evidence was admissible for the purpose of showing the consideration on which the bill was accepted, in order to prove a failure of consideration. Coupy's Heirs v. Dufau, 13 Mart. (La.), 90; Le Blanc v. Sanglier, 12 Id., 402; Russell v. Hall, 20 Id., 558; 13 Johns. (N. Y.), 54; 2 Stark, 166, 204. 4. The evidence was admissible under the plea in reconvention. This is a Louisiana contract. The bill was drawn, indorsed, and accepted in Louisiana. Both the lex loci contractus and the lex fori are to be regarded in any action upon it. By the law of Louisiana, the defendant may plead in reconvention any damages, even unliquidated damages, if they are necessarily connected with the same transaction. Here, the bill was accepted in payment of the mill and engine; and the damages arose from the defects in this very mill and engine. Code of Practice, 374-377; Boyd v. Warfield, 6 Mart. N. S., 671; Orleans Navigation Co. v. Bingay, Id., 688; 2 Id., 73, 122; 6 Id., 145. Mr. Justice NELSON delivered the opinion of the [*11 court. This is a writ of error to the Circuit Court of the United States for the eastern district of Louisiana. The plaintiff's seek to recover the amount of a bill of exchange, drawn by the firm of Nicholson and Armstrong, upon the defendant, for $2,540.65, and accepted by him, in favor of James Arthurs and Brothers, dated March 1, 1848, and payable twelve months from date, and indorsed by the payees to the plaintiffs. The bill of exchange is set forth in the petition, according to the practice in the state of Louisiana, with a prayer that the defendant be condemned to pay the amount due. The defendant, in his answer, denies the allegations in the petition; and also sets up, that the bill was accepted for the balance of the price of a sugar-mill constructed by the drawers, for his plantation in West Baton Rouge; that the mill was Arthurs et al. . Hart. badly constructed, and defective both in the workmanship and materials, and had failed in its operation to do the work intended; that on making known the defects to the drawers, they promised to send competent workmen, before the next ensuing season for grinding sugar, to make the necessary repairs, and put the mill in complete working order, at their own expense; that, confiding in this promise, the defendant accepted, unconditionally, the bill in question. The answer also sets forth, that the drawers had failed to send hands to repair the mill, as agreed, whereby the defendant has suffered damages to the amount of $1,835.65, which sum he demands in reconvention, and asks judgment against the plaintiffs. The defendant further sets forth, that the payees and indorsees had notice of the defects in the mill, and of the undertaking of the drawers at the time of the acceptance, before the negotiation or transfer of the same. The cause was tried without a jury; and, on the trial, the defendant admitted the signatures to the bill; and also gave evidence, which was admitted but excepted to, of the facts set up in the answer. The court gave judgment for the plaintiffs, for $1,743.50. The case is now before us on a writ of error, brought by the plaintiffs, claiming that they were entitled to judgment for the full amount of the bill. Two preliminary objections have been taken by the counsel for the defendant in error: 1. That, inasmuch as other evidence was given on the trial in the court below than that which has been brought on the record, or is found in the bill of exceptions, for aught that appears, the judgment may have been founded upon that evidence; and, 2. That the cause having been tried without a jury, and the judge having deter mined the case upon both the facts and the law, error *12] will not lie for the admission of improper testimony. It was decided in Phillips v. Preston, 5 How., 278, in the case of a writ of error to the circuit court of the United States in Louisiana, and where the trial by jury had been waived, that the state practice regulating appeals for reviewing the decisions of the inferior courts, which required the return of all the evidence to the appellate court, did not apply; and that only so much of it need be returned, and, indeed, no more should be returned, than was necessary to present the legal questions decided by the court, and which were sought to be reviewed. Evidence bearing exclusively upon questions of fact involved in the case, only incumber the record and embarrass the hearing in this court, as these questions are not the subject of review on error. The mere fact, Arthurs et al. v. Hart. therefore, that other evidence was given on the trial besides that which is found in the bill of exceptions, furnishes no objection to an examination of the questions of law presented by it. If that evidence bore upon these questions, and might influence our decison upon them, the defendant in error should have brought it upon the record, or incorporated it in the bill of exceptions. His neglect to do so implies that it could properly have no such effect, if returned. As to the other objection. It was held, in Field and others v. The United States, 9 Pet., 182, and recognized in several subsequent cases, that in a cause where the trial by jury had been waived, the objection to the admission of evidence was not properly the subject of a bill of exceptions; and the reason given is, that if the evidence was improperly admitted this court would reject it, and proceed to decide the cause as if it were not in the record. This, perhaps, is unobjectionable; it certainly is so, as far as the evidence improperly admitted bears upon a question of fact in the cause; for, when rejected, if there is still any proper evidence tending to support the judgment of the court below, the decision cannot be reviewed on a writ of error. The error, in this aspect, would be unimportant, because not the subject of an exception, the question involved being one of fact. If, upon the rejection of the evidence, no testimony would remain necessary to support the judgment of the court, then the mistake would be one of law, and the proper subject of a writ of error. The case of the refusal of proper evidence on the trial is subject to very different considerations from those applicable to the improper admission of it. The exclusion of the evidence might change the legal features of the cause, and lead to a determination of it upon principles wholly inapplicable. in case the evidence *had been admitted; nor can we assume that the testimony offered and rejected would [*13 have been proved, if it had not been excluded, and revise the judgment of the court upon that assumption; because the offer of evidence to prove a fact, and the ability to make the proof, are very different matters. If the court, instead of rejecting, had allowed the evidence, the party might have failed in the proof, and the case in the result remain the same as before the improper exclusion. We think, therefore, that the improper rejection of testi mony on the trial before the judge, where the jury has been dispensed with, should constitute the subject of review on the writ of error, as in the case of a trial before the jury. Arthurs et al. . Hart. There is one qualification applicable to this peculiar mode of trial, that should be noticed. If the testimony rejected is but cumulative, and relates exclusively to a question of fact involved in the case, the rejection may be immaterial, as the decision of that question upon the evidence already in, by the judge, may be regarded as well-warranted. This principle is sometimes applied in cases of writs of error, where the trial below has been before a jury, if it be seen that the admission of the testimony could not have properly influenced the jury to a different conclusion on the question of fact. The cases will be found collected in Cowen and Hill's notes, vol. 4, pp. 775, 776 (3d ed.); see, also, 1 Duer, (N. Y.), pp. 431-434. It must be admitted that the courts which have adopted this principle apply it with great caution where the trial has been had before a jury, and require a clear case to be made out that the rejection has worked no prejudice to the party. Other courts have denied its application altogether, and refused to look into the record to see whether the evidence might or might not have influenced the jury. In cases where the trial by jury has been waived, and the facts as well as the law submitted to the judgment of the court, a more liberal application may be safely indulged; though, if the determination of the question of fact be against the party offering the evidence, we do not perceive why the rejection should not be regarded as error review. able on a bill of exceptions. A more difficult question arises in these cases, where the facts as well as the law are submitted to the court, in reviewing on exceptions the correctness of the ruling of the law involved in rendering the judgment. In trials before a jury, these come up on the instructions prayed for, or by exceptions to the charge. The questions of law are thus separated from the questions of fact, the former to be determined by the court, the latter by the jury. But, where both questions are submitted to the court, and both determined at the same time, and by the same *14] tribunal, the separation is more difficult. The principles of law applicable to the case are so dependent upon the facts, and the finding of these in the case supposed exclusively within the province of the judge, who is substituted for the jury, it would seem, as a general proposition, nearly impracticable for the appellate court to ascertain from the case the principles of law that had governed the decision; especially in the absence of his opinion in the case. But these principles must be ascertained. to enable the court |