Inasmuch as the physician, whose opinion as to the cause of the insanity was excluded, attributed that insanity to the injury, on the ground that there was no evidence that it had existed before, and inasmuch as the record before the court, and on which the appeal was being heard, did contain evidence of its previous existence, I consider that the exclusion was proper. The opinion was based upon an assumption as obviously mistaken in fact as if all the evidence of the other witnesses had been read before the physician testified. And if it should be necessary that the propriety of the exclusion be tested by only so much of the record as had been read to the jury up to that point, it seems to me improper to reverse the judgment now when we see that the excluded opinion was based on the mistaken assumption.