delivered the opinion of the Court:

1. The first assignment of error is on an exception taken to permitting one of the medical witnesses to testify regarding the injury to the plaintiff’s nervous system. The witness, after describing the appearance and condition of the plaintiff, including the hernia and the condition of his bowels and the hemorrhages therefrom, proceeded to say that he was in a highly nervous state, and completely unstrung. Defendant objected to any evidence of nervous condition existing as a result of the accident. Witness was then permitted to say that plaintiff was tremulous; easily moved to tears; could not concentrate his thoughts; could not touch his fingers in front with his eyes shut; had vertigo and pain in the back of his head; cannot sleep; is forgetful; has lost weight; cannot bend over to work; cannot go on a scaffold, or to any height, would fall off. That these were results of his injuries. Cross-examined by defendant, he said that the shock to the nervous system was caused by the fall. His brain was affected to a *314certain, extent, and probably his spinal column was jarred. The nervous condition is the direct result of the fall. Another medical witness testified, without objection, to the nervous condition, and that it was the result of the injuries received at the fall. A motion was afterwards made to strike out the evidence of the first witness, but denied, and defendant again excepted. Counsel rely upon the case of Washington & G. R. Co. v. Dashiell, 7 App. D. C. 507, in support of their contention. In that case no exception was taken to the evidence of nervous disorders resulting from physical injuries. The question arose on an exception taken to the charge of the court. As stated in the opinion (p. 514) : “The jury were instructed that, in addition to- damages for pain and suffering, they could award damages for any impairment of the plaintiff’s nervous system, if such nervous impairment was produced as a direct result of the nervous shock received by her on the occasion of the collision: thus making the nervous shock and the consequences thereof a separate and independent ground for awarding damages.” On this ground the judgment was reversed. We are of the opinion that no error was committed. In assessing damages. for pain and suffering, mental and physical weakness, and the probable permanent continuation of plaintiff’s incapacity to labor, as the direct •consequence of physical injuries received, the jury were entitled to hear and weigh all of the evidence relating thereto. This is quite different from charging them to assess damages for impairment of the nervous system as a result of the nervous shock, in addition to the damages for pain and suffering and permanent incapacity. The learned trial justice was careful to avoid any such error in his charge defining the measure of damages, and no exception was taken to the charge on that point.

2. Another exception, on which error has been assigned, was taken to the introduction of evidence. This occurred in the cross-examination of Frank James, the scaffold builder, who was a witness for the defendant. This witness described the trestles, and said they were on solid ground, with nothing *315under them. That the scaffold was properly built;' examined the trestles as he put them up; saw nothing wrong with them; saw no dry rot; have to look closely at them when you pick them up and carry them around, and you could easily see if dry rot showed on the outside. That he has seen “dry rot” in boards, but saw none in these. Saw the broken trestle, but saw no dry rot in it. That he was around every morning and looked the scaffolds over, and saw nothing wrong. With the express purpose of laying a foundation for the impeachment of-the witness, counsel for the plaintiff asked the witness if he was not sent for by Dougherty to come to the scaffold after it had fallen, and said, Yes.” He testified that Dougherty said to him: “Go and look at that scaffold there,” and went away. He was then asked if Dougherty did not, in the presence of Warren and Smith, say to him: “Frank, what in hell did you use that old rotten trestle for?” — and, further, if he (witness) did not reply that it was the only one he had to use. He replied, “No,” to each question. This was objected to and exception reserved. Plaintiff was later permitted, over objection of defendant, to prove by two persons that they were present and heard Dougherty ask the question, and witness make the reply, which he had denied.

The rule for determining whether a fact inquired of in cross-examination is collateral is stated by the supreme court of Pennsylvania as follows: “The rule is well settled that if a witness is cross-examined to a fact purely collateral and irrelevant to the issue, and answers it without objection, he cannot be contradicted. The reason is obvious. The investigation might thus branch out into any number of immaterial issues upon the mere question of the credibility of a witness. * * * The test of whether a fact inquired of in cross-examination is collateral is this: Would the cross-examining party be entitled to prove it as a part of his case, tending to establish his plea?” [Hildeburn v. Curran, 65 Pa. 63.] The rule established by the weight of authority is that the statement must be material, in effect involve an assertion inconsistent with one made on the stand, and relevant; that is to say, a fact that the *316cross-examining party would be entitled to prove as part of his case. 1 Greenl. Ev. 16th ed. secs. 461e et seq.; Williams v. State, 73 Miss. 820-825, 19 So. 826. Nor is it necessary that the statement or declaration, offered to be proved, shall have been made by the witness himself, and of his own motion. It is sufficient if made by another to him, and assented to, or acquiesced in in such manner as to make it, in effect, his own declaration. Kirby v. State, 89 Ala. 63-71, 8 So. 110; State v. McGaffin, 36 Kan. 315-321, 13 Pac. 560.

The material issue in the case was whether defendant’s employee, charged with the duty of erecting the scaffold, had negligently used a defective trestle in its construction. Plaintiff had introduced evidence tending to prove the fact. The witness, Tames, had been called to rebut the plaintiff’s evidence, and had testified that care had been exercised by him in erecting the trestles, and that they were sound and safe. Had he made a voluntary statement that he had used a rotten trestle, he undoubtedly could be cross-examined concerning it. Such a statement would be inconsistent with his statement in evidence, and he could be cross-examined in regard to it. If admitted, he would discredit himself: if denied, witnesses could be called to discredit him. His reply to Dougherty, if made, that he had no other than a rotten trestle to use, was inconsistent with his statement made as a witness.

Tested by the rules above stated, we think there was no error in overruling the objections.

3. The various assignments of error founded on exceptions to instructions given and refused will be considered together.

The first two instructions given at request of plaintiff were to the effect that it was the duty of the defendant to provide a reasonably safe place for the plaintiff to perform Ms services, and if the scaffold was dangerous and unsafe, of which plaintiff had no knowledge, and could not have acquired knowledge by the exercise of ordinary care, and that as a result of the defendant’s failure to provide a safe scaffold, the same fell and injux-ed plaintiff, he would be entitled to a verdict; and that the mere fact of the falling of the scaffold does not pxuve *317negligence, nevertheless the fact that it fell may be taken into ■consideration with all the other facts and circumstances in determining whether defendant was guilty of negligence that caused the plaintiff’s injuries. Assuming, for the purposes ■of the argument, that these instructions were too broad, all possible misunderstanding of them was obviated by the special instructions given at the request of the defendant, and by the .general charge. Defendant’s special instructions 2 and 3 (given) were to the effect that if the defendant had caused a ■scaffold to be constructed that was reasonably safe for the purposes for which it was intended, and that plaintiff made, or •directed changes in the same which rendered it unsafe, the defendant would be entitled to a verdict.

Special instruction 4, that was refused, was an elaboration •of the matter contained in 2 and 3; and moreover, its substance was contained in the general charge. Refused instruction 5, relating to the burden of proof, was substantially given in the general charge. Instruction 6, given at request of defendant, was to the effect that it was incumbent upon plaintiff to prove not only that the timber was in fact defective, but that defendant was negligent in not discovering the defect, — “the rule being that defendant is not responsible for injuries resulting from latent defects in the material used in the construction of the scaffold, of which he has no knowledge or means of knowledge. The word ‘negligent’ in the foregoing instruction is defined as the failure of defendant to exercise such care in inspecting said timber as an ordinary man under like circumstances would liave exercised."

Defendant’s special instruction 7 and 8, that were given, related to the discovery of latent defects, and the care required of the defendant, and informed the jury that it was not required to employ unusual or extraordinary tests. Special instruction 10 charged the jury that no duty was devolved upon defendant to furnish a pole scaffold, or one of different design. Special instruction 12 was rightly refused because it instructed the jury in relation to damages, substantially, that it was negligence on the part of plaintiff not to follow the *318advice of his surgeon in respect to submission to an operation. Instructions 13 and 14, which left it to the jury to determine whether the plaintiff was wanting in reasonable care in not following the advice of his surgeon, were given by the court. Moreover, the general charge contained a clear and full statement of the question to the jury, in entire accordance with the rule relating thereto, as declared in American Realty Co. v. Thomkins, 37 App. D. C. 87-93.

The rule of law is well settled that it is the duty of an employer to provide reasonably safe structures and appliances for the use of his employee in carrying on the labor in which he is engaged; and this duty cannot be avoided by intrusting its performance to some other employee. That notwithstanding this duty, there is no guaranty that the structure is absolutely safe. That when an injury is received in such employment, the fact of accident carries with it no presumption of neglect of duty on the part of the employer; and the burden rests upon the employee to show such negligence as an affirmative fact; it is not sufficient to show that the employer may have .been guilty of negligence, — the evidence must point to the fact that he was. Butler v. Frazee, 25 App. D. C. 392—401, and cases there cited.

The general charge embodied these propositions in a clear and lucid manner, and also charged the jury that ordinary •care only was required of the employer; and that the plaintiff •could not recover, if he knew, or might, by the exercise of ordinary care, have known that the trestle was defective, or if the fall of the scaffold was caused by his own act in erecting ,the mortar-box platform on the same.

The charge contained a correct, clear, and fair statement of the law, and of the issues to be determined by the jury; and omits nothing that the defendant was entitled to.

Perceiving no error in the proceedings, we must affirm the judgment, with costs. Affirmed.