delivered the opinion of the court, November 15th 1880.
Cross-examination must be confined to matters stated in the examination in chief, and to questions affecting the credibility of the witness. A party will not be permitted to leave out new matter constituting his own case: Jackson v. Litch, 12 P. F. Smith 451. Where the plaintiff testifies in his own behalf, the defendant has no right to introduce his defence on the cross-examination; at the time of making his defence he may examine the plaintiff in chief as if under cross-examination: Malone v. Dougherty, 19 P. F. Smith 46. The question, made the subject of the first assignment of error, was whether the plaintiff had not agreed to waive her right of damages for a consideration. That was matter of defence— it was not said to be for another purpose — and the court rightly overruled it.
The second assignment is the refusal of the court to permit tlie *439defendant, on cross-examination of the plaintiff, to ask whether she did not say to Stengle that she had been only a little scratched. The witness had already stated that Stengle was at her house the next day after the accident. In chief she testified that she was severely hurt. Had she answered the question affirmatively, it would have tended to show her view of the injury at the time; if negatively, ground would have been laid for contradiction. The question directly related to the subject of her examination in chief and was admissible.
Reese testified that a barricade was put up the next morning after the accident, and that was competent on the question of negligence: McKee v. Bidwell, 24 P. F. Smith 218. Then the plaintiff was allowed “ to ask the witness whether or not, immediately prior to the putting up of the barricade, he notified the party in charge of the work of the dangerous character of the place and that a barricade was necessary, for the purpose of showing an admission of negligence upon the part of the defendant company, by the erection of a barricade after the accident, and also to show that there rvas no such barricade before.” This notice was after the accident; so, also, was the admission of the person in charge of the work; altogether too long after for declarations of an agent to be competent. Frazier v. Pennsylvania Railroad Co., 2 Wright 104, cited in support of the offer does not apply. There testimony was rejected relating to the knowledge of the superintendent prior to the accident, and nothing in the case touches admissions by a laborer or agent. The admission by an agent as to a past occurrence is not evidence against his principal: Fawcett v. Bigley,. 9 P. F. Smith 411; Pennsylvania Railroad Co. v. Titusville & Pithole Plank Road Co., 21 Id. 350; Bigley v. Williams, 30 Id. 107. The third assignment of error must be sustained.
We are also of opinion that the fourth assignment is well taken. Miss Fern was acquainted with the plaintiff before the accident and was with her a number of weeks after. It does not appear that she had any experience whatever to qualify her to speak as an expert, and yet she was permitted to give her opinion of the effect of the injury upon the plaintiff’s health. She was positive that the accident had a very bad effect, but had she been an expert she might have been as doubtful of the cause of the plaintiff’s subsequent ill health as was Dr. Case. No better illustration than this can be given of the propriety of excluding opinions of persons who have no knowledge or experience on the subject. It was said by the present chief justice that no clearly defined rule can be found as to what constitutes an expert. Much depends on the nature of the question in regard to which an opinion is asked. While, undoubtedly, it must appear that the witness has enjoyed some means of special knowledge or experience, no rule can be laid down in the nature of things as to the extent of it: Ardesco Oil Co. v. Gilson, 13 P. F. *440Smith 146. This witness had no means of- special knowledge or experience, and the jury, not herself, should have drawn the inferences from the facts she narrated.
The fifth assignment is not sustained.
Judgment reversed, and a venire facias de novo awarded.