companies are thereby put into a class to themselves and deprived of the benefit of the general rule of law which places upon one who sues in tort the burden of not only proving an injury, but also that the injury was the consequence of some negligence in respect of a duty owed to the plaintiff.

It is to be primarily observed that the statute is not made applicable to all actions against such companies. Its operation is plainly limited, first, to injuries sustained by passengers or employés of such companies; second, to injuries arising from the actual operation of railway trains or engines, and third, the effect of evidence showing an injury due to the operation of trains or engines is only "prima facie evidence of the want of reasonable skill and care on the part of the servants of the company in reference to such injury."

The law of evidence is full of presumptions either of fact or law. The former are, of course, disputable, and the strength of any inference of one fact from proof of another depends upon the generality of the experience upon which it is founded. For a discussion of some common law aspects of the subject see Cincinnati &c. Ry. v. South Fork Coal Co., 139 Fed. Rep. 528 et seq.

Legislation providing that proof of one fact shall constitute prima facie evidence of the main fact in issue is but to enact a rule of evidence, and quite within the general power of government. Statutes, National and state, dealing with such methods of proof in both civil and criminal cases abound, and the decisions upholding them are numerous. A few of the leading ones are Adams v. New York, 192 U. S. 585; People v. Cannon, 139 N. Y. 32; Horne v. Memphis &c. Ry., 1 Coldwell (Tenn.), 72; Meadowcroft v. The People, 163 Illinois, 56; Commonwealth v. Williams, 6 Gray, 1; State v. Thomas, 144 Alabama, 77.

We are not impressed with the argument that the Supreme Court of Mississippi, in construing the act, has de

clared that the effect of the statute is to create a presumption of liability, giving to it, thereby, an effect in excess of a mere temporary inference of fact. The statutory effect of the rule is to provide that evidence of an injury arising from the actual operation of trains shall create an inference of negligence, which is the main fact in issue. The only legal effect of this inference is to cast upon the railroad company the duty of producing some evidence to the contrary. When that is done the inference is at an end, and the question of negligence is one for the jury upon all of the evidence. In default of such evidence, the defendant, in a civil case, must lose, for the prima facie case is enough as matter of law.

The statute does not, therefore, deny the equal protection of the law or otherwise fail in due process of law, because it creates a presumption of liability, since its operation is only to supply an inference of liability in the absence of other evidence contradicting such inference.

That a legislative presumption of one fact from evidence of another may not constitute a denial of due process of law or a denial of the equal protection of the law it is only essential that there shall be some rational connection between the fact proved and the ultimate fact presumed, and that the inference of one fact from proof of another shall not be so unreasonable as to be a purely arbitrary mandate. So, also, it must not, under guise of regulating the presentation of evidence, operate to preclude the party from the right to present his defense to the main fact thus presumed.

If a legislative provision not unreasonable in itself prescribing a rule of evidence, in either criminal or civil cases, does not shut out from the party affected a reasonable opportunity to submit to the jury in his defense all of the facts bearing upon the issue, there is no ground for holding that due process of law has been denied him.

Tested by these principles, the statute as construed and

applied by the Mississippi court in this case is unobjectionable. It is not an unreasonable inference that a derailment of railway cars is due to some negligence, either in construction or maintenance of the track or trains, or some carelessness in operation.

From the foregoing considerations it must be obvious that the application of the act to injuries resulting from "the running of locomotives and cars," is not an arbitrary classification, but one resting upon considerations of public policy arising out of the character of the business. Judgment affirmed.

HERENCIA v. GUZMAN.

ERROR TO THE DISTRICT COURT OF THE UNITED STATES FOR PORTO RICO.

No. 46. Submitted November 29, 1910.-Decided December 19, 1910.

It is not the province of this court on writ of error to reverse if dissatisfied with the verdict of the jury; if there was evidence proper for the consideration of the jury, objection that the verdict was against the weight of evidence or that excessive damages were allowed cannot be considered.

An amendment to a bill of exceptions, after bond on appeal had been given and approved, so as to make the record conform to the fact as to the conditions under which certain testimony introduced by plaintiff in error on the trial was given, held not error, as it was not unjustified or objected to and the exception related simply to the inclusion of such testimony in the record.

A judgment cannot be set aside on an exception to the refusal of the trial court to allow an expert to testify where the record does not show what testimony the witness was expected to give or that he was qualified to give any.

THE facts are stated in the opinion.

219 U. S.

Opinion of the Court.

Mr. Willis Sweet for plaintiff in error.

Mr. Frederick L. Cornwell for defendant in error.

MR. JUSTICE HUGHES delivered the opinion of the court.

This action was brought in the District Court of the United States for Porto Rico to recover damages for personal injuries resulting from the fall of a portion of the building owned by the plaintiff in error which it was alleged he had negligently allowed to remain in a dangerous condition. It was tried by a jury who gave a verdict against plaintiff in error for the sum of $9,000. Judgment was entered accordingly and the case comes here on writ of error.

The argument on behalf of the plaintiff in error proceeds upon the assumption that this court may review the evidence as to negligence and as to the damages recoverable, and may reverse the judgment if the court is dissatisfied with the findings of the jury. This, however, is not the province of the court upon writ of error. As there was evidence proper for the consideration of the jury the objection that the verdict was against the weight of evidence or that the damages allowed were excessive cannot be considered. Express Company v. Ware, 20 Wall. 543; New York, Lake Erie & Western Railroad Company v. Winter's Administrator, 143 U. S. 60, 75; Lincoln v. Power, 151 U. S. 436-438; Humes v. United States, 170 U. S. 210.

Nor was any exception taken by the plaintiff in error to the instructions which the trial court gave to the jury. The only questions which are properly before us for review are as to certain rulings upon the admissibility of testimony.

Error is assigned in admitting the testimony of a physician, Dr. Joaquin Martinez Guasp, "as correct," and it is further urged that the court "erred in changing the record

relative thereto after the bond on appeal had been given and approved." It appears that the witness was appointed by the court to examine the plaintiff below in order to ascertain his condition at the time of the trial, and that this action was taken with the consent of the counsel for the defendant (the plaintiff in error). The examination was made and the witness subsequently testified without objection. In fact, the counsel for the plaintiff in error conducted the direct examination, and there was no cross-examination. No question, therefore, is presented with respect to the admissibility of this testimony. The bill of exceptions was amended so as to show that the court stated, when the testimony was introduced, not only that the physician's examination had been made by consent, but that counsel had "agreed that his evidence should be considered as correct." This amendment, as the District Judge states, was to conform the record to the fact. Assuming, as we must, that the statement was made by the court, it does not appear that it was unjustified or that it was objected to. The exception of the plaintiff in error is simply to its inclusion in the record.

It is further insisted that the court erred in refusing to allow one Dr. Gonzalez to testify. As to this the record merely sets forth that counsel "offered to present the testimony of one Dr. Gonzalez, as an expert, which testimony is not allowed by the court and to which ruling of the court counsel for defendant thereupon noted an exception." Manifestly the judgment cannot be set aside because of this ruling, for it does not appear what testimony the witness was expected to give, or that he was qualified to give any.

We have examined the other rulings of which plaintiff in error complains, with respect to the striking out of certain testimony, and we find no error.

Judgment affirmed.