Day, Ch. J.
I. The plaintiff introduced as a witness one John McKenzie, who testified that he repairs cars for á living, and had about seven years experience in 1. EXPERT testimony: róent ot neg-ligenee by. . , , greasing cars, but quit it about seven years ago, and that he is not now employed by the company, ^ J 1 ° and has not been for some time, and that he knows about the substance formed on the boxing of car wheels, but does not know of any poisonous substance that is ever formed on the brasses of the boxes of the car wheels. The witness was then asked this question: “When ought they to be removed?” This question was objected to as incompetent and immaterial, and upon the ground that it is not shown that the witness is competent to judge. The objection was sustained, and this action is assigned as error.' Appellant insists that “this question was propounded to show that the brasses should always be removed before they are worn as thin as a knife, before they become broken, or before the old axle grease burns into the broken brass, and thereby causes a poisonous substance, which failure to remove would constitute the elements oí" negligence.” We think, however, that the proposed fact is not competent to be established by the opinion of a witness offered as an expert. *287The effects of allowing tbe brasses to become worn thin and broken should be shown. Then the jury would be competent to determine whether it was negligence to fail to remove them before such condition existed. To allow a witness to testify as an expert to such fact, would be to substitute the witness for the jury.
II. This same witness further testified that he knew the custom of railroads in removing these old brasses. He was „ , repalrhw6 ln Sieeof~eus-tom‘ then asked the following question: “What is the custom in reference to the time when they should be removed — before they get so they break, or afterward?” This question was objected to, and the objection was sustained. The custom of railroads as to the removal of the brasses before they break is not material/ They might remove them before they be'come so thin as to break, for. the purpose of preventing injury to the axles, or accidents to the train. The real question in this case is, do the brasses accumulate a poisonous substance if not removed before they become so thin as to break? The custom of railroads as to the time of removal could throw no light upon this question.
III. The appellant complains of the giving of the third instruction, as follows: “The main questions for you to determine S. -: injury to em- . ploye: contributory negligence : means ol knowledge. herein, and to which your attention is directed, are as follows: 1. Was the plaintiff directed to go and remove, and did he go and remove, the brasses from the car wheels at River Sioux, in obedience to a direction of the master mechanic? 2. Were the brasses so removed, at the time of removal, poisonous? 3. If they were poisonous, then did the defendant, through its officers, whose duty it was to keep the cars in repair, have knowledge that the same were poisonous, or would said officers by the exercise of ordinary care have had such knowledge? 4. If the brasses were poisonous, then did plaintiff have knowledge that they were poisonous, or would he by the exercise of reasonable care have had such *288knowledge? 5. If plaintiff was injured, then did bis injury occur by reason of tbe impurity of plaintiff’s blood? If you answer tbe ^first, second and third questions in tbe negative, then there can be no recovery for plaintiff. If you answer tbe fourth in tbe affirmative, there can be no recovery. If tbe fifth is answered in tbe affirmative, there can be no recovery.” Appellant insists that tbe fourth division of this instruction is erroneous, in that it bolds that, if the employe could have, by ordinary care, discovered the poisonous com dition of the brasses, he cannot recover. Appellant also insists that the fourth instruction of the court is erroneous, which in substance directs the jury that plaintiff cannot recover if he knew, or by the exercise of that care with respect thereto which a reasonable man, under the same circumstances, would have exercised, could have known, that the brasses were poisonous. In support of this objection, appellant relies upon Muldowney v. Illinois Central Railway Co., 36 Iowa, 462. The doctrine of this case was limited and explained in Way v. Illinois Central Railway Co., 40 Iowa, 341. See also Muldowney v. Illinois Central Railway Co., 39 Id., 615; Money v. The Lower Vein Coal Co., 55 Id., 671. The instructions, in the matter complained of, are not erroneous.
Appellant also complains of the fifth sub-division of the third instruction. The evidence very strongly tended to evidence: in-' struction. show that the injury to plaintiff did not result from any poisonous condition of the brasses, and " x to raise a strong presumption that it arose solely from an ordinary cut, in connection with a depraved condition of the plaintiff’s system. The evidence strongly preponderates against the view that any poisonous substance accumulates upon the brasses before they are removed from the axles. No instance of poisoning from the brasses was shown, although the witnesses testified to the receiving of frequent cuts in the removal of the brasses. The injury to plaintiff, which was a small cut upon the finger, was inflicted *289on Sunday. The finger did not become inflamed until Tuesday. The plaintiff claims that bis finger was poisoned by verdigris on the brasses. The testimony of experts is that, if verdigris is applied to a flesh wound, its action would be immediate, and that if the wound was made upon the finger,' and it did not become inflamed for two days, the verdigris had nothing to do with it. The jury were fully authorized to find from the testimony that the injury to plaintiff did not at all result from any poisonous condition of the brasses. The instruction complained of was both pertinent to the evidence and proper. The twelfth instruction of the court is to the same effect as the fifth sub-division of the third instruction, and, for the reasons already assigned, is proper.
IY. Appellant complains of an instruction given at the request of defendant, as follows: “The' jury are instructed 6--ligeuce: means of knowledge. neg_ that the uncontrovertible testimony in the case discloses that defendant and its employes had no knowledge of the existence of any poisonous substance on the said brasses in question, at. the time of said injury; and if, from the experience of defendant and its employes, as disclosed by the evidence, they had no cause or reason to believe that there was any poisonous substance on said brasses, there can be no recovery in this action.” It is said that this instruction assumes that the railroad company must possess actual knowledge, when the law only requires means of knowledge, and also assumes that the experience of a railroad company will excuse any negligence that it may be guilty of. The instruction is not vulnerable to the criticism made. As already stated, the evidence strongly preponderates against the view that any poisonous matter accumulates upon the brasses before their removal from the axles. If nothing had ever occurred in the experience of defendant to suggest the existence of such poisonous accumulation, it did not possess such knowledge as would render it negligent in not discovering the existence of poisonous matter on the brasses in question.
*290V. Appellant assigns as error the giving of .the following instructions: “In determining whether the defendant Trn~ SA1~~E. was negligent, you must consider the light and knowledge the defendant had at the time of the alleged injury; and if at that time it had no knowledge that there was.&ny poisonous substance on the brasses in question, and by the exercise of ordinary care would not have had such information; and if there had been no injurious substance in the use of such brasses prior to said alleged injury in the' operation of defendant’s railroad, then the defendant was' not negligent.” This instruction is clearly correct. Surely, the defendant was not negligent, if'there had existed no injurious substance in the prior use of the brasses, and the defendant did not know, and by the exercise of ordinary care would not have known, that there was any poisonous substance on the brasses in question.
VI. Appellant assigns as error the giving of an instruction to the effect that the plaintiff cannot recover through or 6iioJ™orrect wrongmap-plication. by reason of any negligence on the part of a co-employe of plaintiff, if the injury was not occasioned while the plaintiff was engaged in the „ , „ , , . operation ot delendant’s road, or m a manner connected with the operations of the road. It is not claimed that the instruction is in itself erroneous, but that it had no application to the case, because the action was not based upon the statute, but upon the theory of the master’s liability to the servant. If this be true, the giving of the instruction could have worked no prejudice.
. VII. The appellant complains of the giving of the following instruction: “If the jury find from the testimony i bailkoads-SffST knowledge. defendant used upon its cars the same kind of oil that was generally used upon the cars of xailroad companies at the time of said alleged injury, and had no knowledge, and, by the exercise of ordinary care, would not have obtained any knowledge, that there was any poisonous substance on the brasses in question, *291then the plaintiff cannot recover.” There is nothing whatever in the evidence to show that the oil used by defendant was impure, or that it might not be properly used. Appellant claims, however, that from this instruction the jury may have presumed that, if the oil used was not of itself poisonous, the company was not responsible. It is clear that this construction cannot properly be placed upon the instruction. The defendant’s immunity is expressly made to depend upon its want of knowledge, or of the means of knowledge, in the exercise of ordinary care, that there was any poisonous substance upon tbe brasses. The instructions asked, so far as applicable and proper, are covered by the instructions of. tbe court. The record discloses no error..
Affirmed.