In this action the plaintiff alleges that while he was loading a certain freight car standing on the defendants’ track in Lawrence, under the authority and by the direction of the defendants, he was injured by reason of a freight train of the defendants being violently driven against the car. . Daniel Hardy, the station agent, was called by the defendants as a witness; and, on his cross-examination, testified that he never asked the plaintiff, or Gowan, the plaintiff’s partner, for a bill of the damage done to the plaintiff; that he never obtained of the *14plaintiff or bis partner more than one bill; that he never said that Clark, who was a clerk in the defendants’ freight office and was on the train that caused the collision, was going away and he wanted a bill of the damage as he wished to take the amount of it out of his wages, or make him pay it; that he had no recollection of more than one bill, or that he said to Gowan he would send a second bill to Boston; or that he said Clark was very careless. All this cross-examination related to matters not admissible in evidence, or pertinent to the case. There was no evidence tending to show that he had authority to ask for a bill of the damage, or to call on Clark for payment, or to make admissions as to Clark’s carelessness. And if he had been an agent, with authority to manage this business, his admissions, not connected with his acts as agent, would be inadmissible.
It is well settled that when a witness is cross-examined as to collateral matters, his answers are conclusive and he cannot be contradicted. The authorities are numerous; and it is sufficient to refer to Commonwealth v. Cain, 14 Gray, 7, and the authorities there cited. Gowan’s deposition was admitted to discredit Hardy. He deposed that Hardy did request him to make out a bill of the damage and hand it in, and he would send it to Boston to see if it would be allowed; also that he said Clark was very careless in the matter; also that he said Gowan had better go to Boston and see the parties there, and gave Gowan their names ; also that Hardy afterwards called on him for another bill of the damages, as Clark was going away and he wanted him to pay it. This testimony, which we understand was admitted with much hesitation and doubt, appears on careful consideration to be inadmissible, for the reasons above stated; it could not fail to influence the jury, and therefore the verdict must be set aside and a new trial granted.
As a new trial must be had, it is proper to express an opinion upon some other points that have been argued.
1. The defendants contend that the court erred in ruling that it was immaterial to whom the train belonged. But taking the whole ruling together, it is clearly right. The ruling is, that “ if *15the train by which the injury was caused was in the care of the defendants’ servants, subject to their exclusive direction and control at the time of the accident,” then it is immaterial who in fact were the owners of the engine and cars constituting the' train. This must be so; for if a wrong was done, it was by those who had the exclusive direction and control of the train at the time, and by no others.
2. The fourth instruction to the jury, as to the use of ordinary care, is objected to. It is contended that the plaintiff, being in a dangerous situation, should have used extraordinary care, and that the jury should have been instructed upon the evidence as matter of law that he did not use due care.
But the court are of opinion that the instruction was correct. Ordinary care is a term that has relation to the situation of parties and the business in which they are engaged. It is used here as synonymous with the term “ reasonable care ” as used by the courts in England. “ Care and diligence should vary according to the exigencies which require vigilance and attention, conforming in amount and degree to the particular circumstances under which they are to be exerted.” Holly v. Boston Gas Light Co. 8 Gray, 131.
There are cases where, there being no facts in dispute, ordinary care becomes a question of law; but this does not seem to be such a case. If the track where the plaintiff was loading his marble was one that was exclusively used for loading cars, then no care would seem to be required on his part to avoid collisions; but if it was one on which trains were deposited on their arrival, or used for shifting cars and making up trains, and if in doing such business it is customary and prudent to run a train against a car that happens to be standing on the track and push it out of the way, then ordinary care would require a person who should go into such a car thus exposed to be moved, and who should there engage in a business that would place him in danger if the car were moved, to make some reasonable provision for his safety, such as would be adapted to the circumstances. So far as the report states the case, it tends to show that the plaintiff exposed himself to danger *16without using any precaution. But the evidence is not fully reported. Enough appears, however, to show that the question of ordinary care depends upon many facts of a complicated character, and that the question should be left to the jury under instructions. The court are of opinion that each of the four instructions given to the jury was correct.
Exceptions sustained.