1. In general it is not allowable for a witness to state his opinions, but it is sometimes permissible for him to testify to the result of his judgment and observation upon couceded facts. Thus, where a witness stated, that from his knowledge of .the debtoPs circumstances, the latter was able to pay a certain amount, and that during a certain time after his escape, he must have spent from $800 to $100.0, as deponent believed, the testimony was considered admissible — not being an abstract opinion merely. Griffin v. Brown, 2 Pick. Rep. 304. In questions of the value of property, witnesses have often been permitted to testify to their opinions, as there is no unerring and certain standard in such cases, to which reference can always be had. Kellogg v. Krauser, 14 Serg. & R. Rep. 137; Rochester v. Chester, 3 N. Hamp. R. 349; Morse v. Connecticut, 6 Conn. R. 9; 1 Greenl. Ev. 488, et seq.; Chenault v. Walker, at the last term.
The inquiry of the witness, “ how much corn per month it would require to supply the wants of said plantation,” was *367preceded by a statement that he lived near the plantation of the defendant’s intestate, and believed he knew about the number of hands, horses and mules employed thereon. If the plaintiff furnished corn for a definite time, it is difficult to perceive how he could have shown the quantity by more satisfactory proof, unless there had been some witness to its delivery ; and it cannot be inferred that he could have adduced such evidence, as he had the sole management of the plantation — the intestate giving himself but little concern about it, and rarely visiting it.
If the witness had stated how much com it required for the subsistence of a single slave, horse or mule, there could certainly have been no objection to the competency of such evidence. Upon principle, there can be no difference between such testimony and that which a direct answer to the question would have elicited; so that if the witness could say what precise quantity one slave, horse or mule would probably consume within a given period, he might certainly state how much would be required for a greater number. This would be a mere matter of arithmetical calculation, about which there could be no mistake.
2. One of the grounds of the defence on the trial, as indicated by the bill of exceptions, was, that the note declared on was without consideration, or was obtained by the plaintiff by fraud or other undue means, and to sustain this defence the defendants, among other things, proposed to show that their intestate was a man of imbecile intellect, impaired by a long continued habit of intemperance, which he practised from boyhood up to the period of his last sickness. The question is, whether for this purpose, it was allowable to inquire of a witness “ whether the intestate was a man of strong or weak intellect?” We have already said, that witnesses should depose to facts, and as a general rule cannot be allowed to state their opinions or mental conclusions merely. Now although the question in form, seems to contemplate a direct and positive response, yet an answer to it must of necessity he the result of the witness’s observation, or reasoning from certain premises not disclosed, and we cannot there* fore think it was admissible. The witness might have stated the facts and circumstances which tended to indicate the *368grade of the intestate’s intellect, as, his general demeanor, the character of his conversation, his usual employment, and his habits generally, so far,as these would enable a jury to form an estimate of his powers of mind. Crowwell v. Kerr et al. 3 Dev. L. Rep. 355; 2 Phil. Ev. C. & H’s Notes, 759, et seq.; Roberts v. Trawick, 13 Ala. 68.
3. The statement in the.deposition of the witness, Nance, that he was well acquainted with the defendant’s intestate, lived near him, and saw him frequently from 1836 to the time of his death, in 1841, “and that such were the habits, and such the mental incapacity of the intestate, that he was very liable to be imposed on in any settlement he might undertake to make; especially so when under the influence-of ardent spirits, which was almost always the case,” was rightfully excluded. Here the witness assumed to pass-judgment upon the intestate’s habits and powers of mind — to-affirm that the former were irregular and objectionable, and that the latter was imbecile ; that the effect of these causes-combined, made him the dupe of other men, who might readily impose on him at all times; and especially when intoxicated. Instead of stating his premises in general terms* and thus summarily deducing a conclusion, the state of the intestate’s habits should have been specially-narrated, and the manifestations of imbecility particularly pointed out, that the jury might draw their own conclusions, or at least be-able to determine whether that of the witness was warranted by the facts. This conclusion seems to result from what we-said upon the preceding point.
4. We think the book kept by the plaintiff, and professedly indicating the state of accounts between himself and his employers, M. G. Woods and the plaintiff, was inadmissible to the extent and under the circumstances which it was al--lowed to go to the jury as evidencé. If it had been received-to establish the facts indicated by the writing or figures in M. G. Woods’s hand-writing, made with a pencil, there could have been no objection to its admissibility. The relevaut and irrelevant testimony Was so commingled, that the onlycourse-was to allow the entire book to be taken by the jury in their retirement, with such special instructions as would have prevented them from- doing injustice- to the defendants. See *369Fowle v. Bigelow, 10 Mass. Rep. 380. But instead of thus restricting the effect of the evidence, the court permitted the book to go to the jury, not only so far as they might be satisfied that the figures in M. G. W’s hand-writing were intended, or did show his approval of certain entries, but also to the extent to which they were satified the entries had received the sanction of the intestate, or an agent of either of them ? Now there was no proof that the plaintiff’s book of entries had ever been admitted by the intestate to be correct in any particular, though there was an effort to show that this had been done by one who occasionally acted as the intestate’s agent, and actually made figures on the book. The admission of the book, founded upon the idea that the intestate had personally, or by agent admitted its correctness in some respects, could not in point of law have had any beneficial effect in the adjustment of the matters in controversy. The only safe course was for the jury upon that hypothesis to have disregarded it, and looked alone to the figures in the handwriting of M. G. W.; otherwise they would most probably have been misled. In the F. & M. Bank v. Whinfield, 24 Wend. Rep. 419, it was held to be a fatal error to permit irrelevant testimony to go to the jury, if the chances are equal, that it may have had an injurious tendency on the minds of the jurors; when it is perfectly obvious that no prejudicial consequences could have resulted from its admission, perhaps the error would not warrant a reversal of the judgment.
5. It was not allowable for the plaintiff to inquire of his witness, whether a person with whom the intestate was unacquainted, or in whom he did not have confidence could, or could not take advantage of him in a trade. This question calls upon the witness for an expression of his opinion, and not the disclosure of special facts, which would enable the jury to rest a conclusion upon the points; and when too it is susceptible of more definite proof. What we have said upon the second and third points in the cause, is quite sufficient to manifest the error in the ruling of the court upon this.
If the defendants had invited such an irregular examina*370tion of witnesses, by testimony introduced by themselves, then perhaps they should not be allowed to object to it; but the inquiries on their part, in which opinions were elicited, were addressed to professional men, and for any thing appearing to the contrary, came within the exception applying to such witnesses.
6. We can perceive no objection to the declarations of Fike, under the circumstances in which they were made. The witness observed him delivering some cotton to the plaintiff, and inquired “ what they were about,” Jo which Fike remarked, “ that he had sold his crop to the plaintiff.” Witness saw the cotton unginned, supposed it would make about ten bales, and a part of it was delivered in his presence. The declaration was admissible as part of the act done, viz : the delivery of the cotton. It was for the jury to weigh and determine the influence to which it was entitled. It was perhaps altogether insufficient to establish the title of Fike to the cotton, and the bill of exceptions does not show that it was offered with that view. We merely determine, that it was admissible as tending to establish a sale.
This view is decisive of all the points made upon the record, and sufficiently indicates the error of the circuit court, in several of the questions adjudged. Without therefore stopping to recapitulate, we will only add, that the judgment is reversed and the cause remanded.