ME. CHIEF JUSTICE BEANTLT
delivered the opinion of the court.
The defendant was tried upon an information charging him with the crime of murder in the first degree. He was found guilty of manslaughter, and sentenced to confinement in the state prison for a term of not less than seven years and six months nor more than ten years. He has appealed from the judgment and an order denying his motion for a new trial.
The homicide occurred during the afternoon of May 3, 1915, on a farm owned by L. S. Briggs, a few miles from Bozeman, in Gallatin county. The defendant and deceased, Joseph Ennis, had been.in the employment of Briggs, who resided in Bozeman, and had charge of the cattle and horses belonging to him and kept on the farm. A feeling of jealousy had arisen between them as to the extent of the authority conferred upon them, respectively, by Briggs for the management and care of the stock. Blame for the supposed loss of a calf, while the defendant and a young son of the deceased were driving some cows with their calves to the farm from a neighboring farm where they had been kept, was charged by defendant to the son. *500Understanding that he was charged with a theft of the calf, the son reported the charge to the deceased. The pre-existing jealousy thus ripened into enmity, which found expression in threats by deceased that he would have a settlement with the defendant. On the afternoon of the day above stated, Briggs had gone out from Bozeman to deliver some cattle which he had sold to one Bowles. When the work of separating the cattle had been accomplished, Briggs and other persons present went to inspect a young stallion kept on the place. Defendant and deceased were both present. The former, expecting trouble, had armed himself with a revolver. The latter was not armed. During the course of the inspection the deceased accosted the defendant with reference to the alleged charge against his son. After the exchange of a few words the two began to fight with their fists. In the few moments during which the struggle continued, defendant’s revolver was discharged three times, the last shot inflicting upon the deceased a wound which resulted in his death about two hours later. The defense interposed by the defendant was that the revolver was accidentally discharged while he was using it as a club to protect himself from an assault upon him by deceased, he having drawn it for this purpose only.
Error is assigned upon rulings in the admission and exclusion of evidence, upon the giving and refusing to give certain instructions, upon insufficiency of the evidence to justify the verdict, and upon the ground that the verdict is contrary to law. Error is alleged also upon the conduct of the trial judge and county attorney by reason of which the defendant did not have a fair and impartial trial.
1. Counsel does not undertake in his brief to point out any [1] particular in which the evidence is insufficient. We shall therefore pass the assignment without comment, further than to say that we have examined the record with attention and find the evidence amply sufficient to justify the conclusion of the jury. Neither does counsel point out wherein the verdict is contrary to any of the instructions. In our opinion, the charge *501embodies tbe law applicable to tbe facts disclosed by the evidence, and fully and fairly submits every issue in the case. Questions presented by the refusal of the court to submit requested instructions will be noticed later.
2. During the trial, counsel seems to have proceeded upon [2] , the assumption that Chapter 135 of the Laws of 1915 (Laws 1915, p. 298) applies to criminal as well as civil cases, for no formal exceptions were reserved to the rulings upon the admissibility of evidence during the course of the trial. Neither were exceptions reserved to anything said or done by the trial judge or the county attorney. Whatever may have been counsel's view of the law upon the subject, the result is that none of the questions sought to be presented by the) assignments in these particulars are before us for review. Section 1 of the Act in question, except as therein provided, dispenses with the necessity of formal exceptions in civil cases, but has no application to criminal cases. The purpose of the Act, as appears upon its face, was to enlarge the application of section 6784 of the Revised Codes, which relates to exceptions in civil eases only. This being so, the provisions of the Codes, relating to exceptions in criminal cases, were left in full force and are controlling. These are found in sections 9340, 9346 and 9347 of the Revised Codes. It requires only a cursory examination of these, together with section 9271, to understand that in criminal cases specific objection and exception, reserved upon the particular ruling, are necessary to require or permit this court to review it.
3. Contention is made that the court erred in refusing to [3] submit to the jury a definition of the term * ‘ assault. ’ ’ The purpose for which the instruction was offered is not made clear by what transpired at the time the instructions were settled. The argument is that, inasmuch as the terms “assaulted,” “assailant,” etc., are found in the other instructions, a definition of the term “assault” was necessary to enable the jury to understand the others. While the court might properly have submitted the instruction, we do not think the defendant *502should be granted a new trial because it refused to do so. The terms in question, like the expression “preponderance of the evidence,” are of such common use that their meaning may be regarded as understood by the average juror without specific definition. Some latitude must be accorded to the trial court in such matters, in view of the facts in evidence and the character and apparent intelligence of the jury in the particular ease. (Band v. Butte El. R. Co., 40 Mont. 398, 107 Pac. 87.) [4] Moreover; in view of the defense interposed, the jury, we think, would not have been justified in finding the defendant guilty of the lesser offense of assault. He was guilty of unlawful homicide or should have been acquitted entirely. (State v. McGowan, 36 Mont. 422, 93 Pac. 552; State v. McDonald, 51 Mont. 1, 149 Pac. 279.) On neither theory, therefore, do we think the court was in error in refusing the instruction.
4. On the subject of reasonable doubt the court instructed the [5] jury as follows: “The term ‘reasonable doubt’best defines itself. In a legal sense, however, a reasonable doubt is a doubt which has some reason for its basis; a doubt for which there exists in the minds of the jurors a reason, and not a doubt arising from mere caprice or groundless conjecture.” It is argued that this instruction was prejudicial, in that it put upon the defendant the burden of furnishing to every juror a reason why he should have a reasonable doubt of defendant’s guilt; that it required each juror to have a reason which he could express in words, and was calculated to confuse rather than enlighten the jury. It is true, as counsel says, that this court has frequently approved as correct and sufficient to meet all requirements the instruction taken from Commonwealth v. Webster, 5 Cush. (59 Mass.) 295, 52 Am. Dec. 711, which counsel requested the court to give in this case. (Territory v. McAndrews, 3 Mont. 158; State v. Martin, 29 Mont. 273, 74 Pac. 725; State v. De Lea, 36 Mont. 531, 93 Pac. 814.) It does not follow, however, that it must for this reason condemn the instruction submitted. It is not open to the objections *503urged against it. It did not east any burden upon the defendant; nor did it require any juror to be able to state a reason for his conclusion; nor can it be said that it was misleading or confusing unless the use of the expression “reasonable doubt” itself imports confusion and uncertainty. On the contrary, like the expression “to a moral certainty,” its legal equivalent, it is in common use and well understood by any person of average intelligence. It is for this reason that many courts and text-writers characterize as futile efforts to define or explain it. (Miles v. United States, 103 U. S. 304, 26 L. Ed. 481; Hopt v. Utah, 120 U. S. 430, 30 L. Ed. 708, 7 Sup. Ct. Rep. 614; State v. Devis, 48 Kan. 1, 28 Pac. 1092; State v. Killion, 95 Kan. 371, 148 Pac. 643; Wigmore on Evidence, 2497; Chamberlayne on Modem Law of Evidence, 996 B.) It [6] may well be deemed sufficient, after the court has fully stated to the jury the presumptions of which the law gives the defendant the benefit, as was the case here, if they are told without further explanation that they must acquit him unless they are satisfied of his guilt beyond a reasonable doubt. We have frequently said it is safer for trial courts to use instructions which have been approved by this court (State v. Gibbs, 10 Mont. 213, 10 L. R. A. 749, 25 Pac. 289), instead of formulating new ones. Even so, we do not think error was committed in submitting the instruction in question. Other instructions refused were fully covered by the charge as given.
5. Contention is made that the court erred in giving oral instructions to the jury. The record furnishes no ground for this contention. At the close of the argument the court orally [7] directed the jury as to their conduct in the jury-room and as to the form in which they might return their verdict, and informed them that their verdict must be unanimous. There was no error. Directions as to such matters are not instructions on the law of the case which must be written. (People v. Bonney, 19 Cal. 426; State v. Potter, 15 Kan. 302.) If it be conceded that there was error, no objection was made at the time nor any exception reserved as required by the statute. (Rev. Codes, sec. 9271.)
*5046. It is said that the defendant did not have a fair trial by [8] reason of the bias and prejudice of juror Webster. We find in the record an affidavit by Frank P. Yan Ausdol, who served as a juror in the case, from which it appears that while the jury were discussing the reputation of Ennis, the deceased, Webster made the statement that the defendant was reputed to be a gambler, and that he had robbed his (Webster’s) boy twice, and that, upon being charged with entertaining prejudice against the defendant, he admitted that he did so.- There is also an affidavit by Webster in which he denies that he made any such statement. These affidavits cannot be considered for any purpose. The general rule is that a verdict cannot be impeached by the affidavit of jurors who rendered it. The one exception is that where it has been decided by means other than a fair expression of opinion by all the jurors. (Rev. Codes, sec. 9350; State v. Beesskove, 34 Mont. 41, 85 Pac. 376; State v. Wakely, 34 Mont. 427, 117 Pac. 95.) In State v. Beesskove it was said: “This section provides for the one exception, namely, cases where the verdict has been decided by lot, or by any means other than a fair expression on the part of all the jurors. In such case the impeaching affidavit may be made by members of the jury. (Code Civ. Proe., sec. 1171; Rev. Codes, sec. 6794.) This express exception, under the rule, ‘expressio unius est exd/wsio alterms,’ it would seem excludes all other exceptions.”
The judgment and order are affirmed.
Affirmed.
Mr. Justice Sanner and Mr. Justice Holloway concur.