Shaw, C. J.

1. The court are of opinion that evidence tending to show that the testator was of feeble mind, and believed in ghosts and supernatural influences, had some tendency to show unsoundness of mind, or that weakness of mind which would be easily imposed upon by the exertion of undue influence. The testator’s statement of facts respecting Zebulon, his heir, were admissible, as showing his state of mind, but they raised no presumption that the facts themselves were either true or false. If they were not proved to be false, or inconsistent with the relations in which the parties stood to each other, and with other facts proved or admitted, and not so intrinsically improbable, wild and strange as of themselves to show un*471soundness of mind, they would not go far to prove insane delusion; but the question was one of weight and not of competency ; it was competent, and its weight was for the jury to consider.

2. We think the question put to Dr. Williams as an expert, asking his opinion whether, having heard the evidence, he was or was not of opinion that the testator was of sound mind, was not admissible in that form. This would be especially irregular where the evidence is conflicting, because it puts it in the, power of the expert to give an opinion upon the credibility of the testimony and truth of the facts, which is purely a question for the jury, and then upon the value and efficacy of the facts and circumstances, in his opinion thus proved, upon the question of soundness of mind. We think the question, as modified by the court and then admitted, was correct, to put the case hypothetically ; as thus: If certain facts, assumed by the question to be established by the evidence, should be found true by the jury, what would be his opinion upon the facts thus found true, on the question of soundness of mind.

3. We think the answer given by the judge to the question of the juror, in regard to a prior will said to have been executed by the testator, was strictly correct. It is stated, in the appellee’s argument, that such former will had been' read, and its contents, for some purpose, laid before the jury; but in the report it is merely said that it had been offered in evidence, without saying for what purpose, or whether it had been admitted or not. But, either way, it is immaterial to these issues ; if this will were set aside, it was a remote contingency whether such prior will was the last will, whether it was made and executed under such circumstances that it could be duly proved and admitted to probate. The question asked by the juror—Whose would be the property if this will were disallowed ?— could not be answered by the judge without assuming the truth of facts then impossible to be known; and we think the judge made the answer proper to be made in this case, that it was immaterial to this case and ought not to be considered by the jury.

*4724. We cannot perceive any inconsistency in the verdict, in finding affirmatively on the two issues, that the testator was of unsound mind, and that he executed his will under undue influence. Unsoundness of mind embraces every species of mental incapacity, from raging mania to that debility and extreme feebleness of mind which approaches near to and often degenerates into idiocy. Such feebleness of mind, or incipient idiocy, is the condition most likely to be unduly influenced by another. But even in the case of monomania and insane delusion a person by artful, false and repeated surmises and insinuations, operating upon a sensitive and excitable mind of another, may foster and exasperate, if not create, an insane delusion, and at the same time and by the same means obtain such an influence over him as to induce him to make a will, or do any other act, which he would not have done but for the existence of the insane delusion, and the undue influence concurring with it. Verdict confirmed, decree of probate court reversed, and probate of the will refused.

The appellant moved for costs, on the ground that it had been found by the jury that the will had been executed through the undue influence of the appellee.

Shaw, C. J.

There being a serious controversy, and the executor having offered the will, as he was bound to do, in the court below, and having followed it into this court on the appeal of the other party, no reason is shown for taking the case out of the general rule, which allows no costs in probate appeals.