The defendant was indicted for the murder of one Deady, and was convicted of murder in the first degree, in the District Court of El Dorado County. The defendant moved for a new trial and in arrest of judgment, both of which motions were overruled, and judgment having been rendered upon the verdict, the defendant appeals.

One of the errors assigned by the defendant is the illegality of the manner of impanneling the trial jury; and to show such illegality he relies wholly upon the affidavit of the Clerk of the District Court, which states that after the regularly summoned jury had been exhausted without completing the jury, the Court ordered ten special jurors to be summoned, and a jury was completed by calling the special jurors from the list, without having them names written upon the ballots and drawn from a box. The affidavit was filed at the time of filing the motions for a new trial and in arrest of judgment. The statement in the record, however, respecting the impanneling of the jury is as follows: “ This cause coming on for trial, the following named citizens were duly accejrted, impan *234 neled, and sworn as the jury to try the cause, to wit.” And following this, are the names of twelve jurors.

It does not appear from the record of the proceedings, nor from the statement on appeal, that any irregularity occurred in drawing or impanneling the jury, nor does it appear therefrom, or from said affidavit, that the defendant, at the time, pointed out any irregularity, or objected to any of the proceedings in drawing or impanneling the jury.

The defendant is entitled to have all the formalities observed . that are prescribed by law for the summoning, drawing, and impanneling of the jury, and if any omission or irregularity in that respect occurs, he is entitled to have the same corrected, and if not so corrected upon its being pointed out by the defendant, it is error; but as most of those proceedings are merely formal, and do not affect the substantial rights of the defendant, if he omits at the proper time to interpose his objections to any irregularity, he is deemed to have waived them. They cannot be raised for the first time on a motion for a new trial. He will not be permitted to take the chances of a trial before a jury that he knows has not been impanneled in strict conformity to law, and, after an adverse verdict, to move to set it aside on account of an irregularity that he can fairly be deemed to have assented to. This doctrine has been announced by this Court both in respect to grand and trial jurors. (People v. Roberts, 6 Cal. 215 ; People v. Chung Lit, 17 Cal. 321 ; People v. Romero, 18 Cal. 89 .)

Second—The defendant also assigned as error the refusal of the Court to give the instructions asked for by him; but he urges the point only in regard to the following instruction : “ The possession of a sound mind by the defendant at the time of the homicide, is requisite to constitute murder or any other crime.” This proposition is clearly not law. A man’s mind may be unsound in many respects—indeed, he may be a monomaniac upon any given subject—and yet his mind may be sound in all other respects. Such a man, though quite capable of judging between right and wrong in regard to an act of the nature of that of which he maybe accused, cannot be said *235 to be possessed, of a sound mind, yet he would be held responsible for the commission of a criminal act, except in a case where his peculiar unsoundness or monomania was involved.

The instruction is too broad and general in its terms, and would be satisfied by evidence of slight unsoundness in respect to matters that had not even a remote connection with the subject matter of the prosecution.

The unsoundness of mind, or insanity, that will constitute a defense in a criminal action is well described by Tindal, C. J., in answer to questions propounded by the House of Lords to the Judges (cited in Roscoe’s Cr. Ev. 953.) He says, “ that to establish a defense on the ground of insanity, it must be clearly proved that, at the time of committing the act, the party accused was laboring under such a defect of reason, from disease of the mind, as not to know the nature or quality of the act, or if he did know it, that he did not know he was doing what was wrong."

It is proper to remark here, that although we have followed the counsel of both parties in treating the above instruction as refused, and have, for the reason that they so treated it, taken it under consideration, there is nothing in the record showing that it was refused, except the marginal notes of the Clerk on the transcript. The defendant’s instructions are not marked and signed by the Judge as refused, and at the end of a series of seventeen - unnumbered instructions, which are denominated “ defendant’s instruction's given,” are the words, “ refused, and excepted to by the defendant,” and those words, if they had been signed by the Judge, would be construed as applying only to the last instruction.

The defendant also assigns for error, the giving of the following instruction by the Court: “ This defendant is presumed to be sane until the contrary is shown, and a doubt upon this question alone should not acquit, for insanity is an affirmative proposition, and should be made to appear beyond any reasonable doubt.

There can be no question, that in a criminal case, if the defendant relies upon insanity for his defense, the burden of *236 proof is cast upon him, and that the allegation of insanity is an affirmative proposition which must be fully and clearly proved in order to rebut the presumption of his sanity; but the only question of difficulty arising upon the instruction respects the amount of proof required to rebut the presumption.

The amount of proof required is neither increased nor diminished, because the evidence for the prosecution first raised the question of the defendant’s sanity, and, indeed, a part of the whole proof of the defendant’s insanity may result from the evidence offered by the prosecution,

It may be laid down as a general rule that preponderating proof is sufficient to establish a fact in the defendant’s favor. This was so held in People v. Milgate, 5 Cal. 129 ; also in People v. Stonecifer, 6 Cal. 410 .

In cases where insanity was set up as a defense, the decisions have not been as uniform as in respect to other matters of defense.

Mansfield, Chief Justice, in Billingham’s case, 1 Collinson on Lunacy, 636, says: “To support such a defense, (insanity,) it ought to be proved by the most distinct and unquestionable evidence that the person w'as incapable of judging between right and wrong; that it must be proved beyond all doubt that at the time he committed the act he did not consider that murder was a crime against the laws of God and nature, and that there was no other proof of insanity which would excuse murder or any other crime.”

In another case it was held “that the defense of insanity must be clearly made out;” and in a still later case it is said that “ every man is presumed to be sane, etc., until the contrary be proved to their entire satisfaction.”

Mr. Justice Norton, in delivering the opinion of the Court in the case of The People v. Myers, 20 Cal. 518 , says: “ If the burden of proving the existence of insanity rests upon the accused, it follows that this fact must be satisfactorily established, and that is by a preponderance of proof.”

In cases where the homicide is clearly established against *237 the defendant, the only object in proving his insanity is to negative the malicous intent of the defendant, presumed by law, from the act of killing; and if it is proved that the defendant was insane at the túne of the commission of the act, that presumption is rebutted.

Insanity, then, being a fact to be proved by the defendant, it must be established by evidence in the case with the same clearness and certainty as any other fact alleged by the defendant in his defense; that is to say, the proof must be such in amount, that if the single issue of the sanity or insanity of the defendant should be submitted to the jury in a civil case, they would find that he was insane. (People v. McCann, 16 N. Y. 58 .)

The instruction being erroneous, the judgment must be reversed, and it is ordered that the cause be remanded for a new trial.

Sardersor, C. J., having been of counsel for the people in the Court below, did not sit in the case.