Mellen C. J.
delivered the opinion of the Court, at the ensuring July-term, in Waldo.
In this case, after a long and laborious trial, the jury, by therr verdict, have' pronounced that the testator at the time of making his will, was of a sound and disposing mind. The issue having been thus found against the appellant, his counsel have reserved for the consideration and decision of the court, numerous questions arising out of the proceedings at the trial and the rulings and instructions of the presiding Judge ; all of which we propose to consider in the order in which they have been presented in the argument by the respective counsel.
The first objection is founded in the proceedings on the part of the Judge in empannelling the jury. It appears that according to the course of business in court, the cause was in order properly to be tried by the first jury ; the foreman of which having been excused on account of his having formed and expressed an opinion, there being but one supernumerary juror, he was called on to supply the place of the excused juror ; and being objected to by the appellee, and inquired of, though not on oath, he stated that he had formed no opinion. But as strong- objections were still urged against him by the appellee, he was set aside by the Judge, who expressed a desire to have the cause decided by an unobjectionable jury; and thereupon one of the socond jury was called to sit in the trial of the cause; the appellant at the same time insisting that the supernumerary ought to have formed one of the panel. It appears also that one of the jurors, when called, was objected to by the appellant, and he was also set aside ; no objection thereto having been made. Is the order of the Judge, setting aside the supernumerary in the circumstances above mentioned, a legal ground j^r setting aside the verdict? The 9 th section of the act of 1821, c£. 84, re*51specting jurors, provides that the court on motion of either party, shall cause a juror to be examined on oath, as to his relationship to either of the parties, or whether he feels any prejudice or has expressed or formed any opinion j and if on such examination it shall appear that he does not stand indifferent iu the cause, “another juror shall be called or returned, and placed for the trial of that cause in his stead.” If the above provision would have in any manner availed the appellant, or imposed it as a duty on the court to have retained the supernumerary, as a juror on the trial, neither party moved that he should answer on oath $ and so the Judge’s order was not founded on, nor contrary to, any statute requirement or provision. Besides, if the juror had been sworn and answered all the statute questions in the negative, and the Judge had then, for satisfactory reasons, set him aside, no legal principle would have been violated j for the section before mentioned, makes it the duty of the court to set him aside when “ it shall appear to the court that such juror does not stand indifferent in the causebut in the case at bar, had the juror, on oath, answered that he had formed no opinion ; still there might have been various reasons which would have justified the court in setting such juror aside. Suppose the case that after a juror has answered that ha is disinterested and has formed no opinion, he should request to be excused on account of deafness or indisposition, or to avoid giving offence to one or the other of the contending parties, and incurring his displeasure, both parties being his friends and neighbors; shall it be said that in such cases a judge cannot excuse and set aside such juror, whether the parties consent or not ? Such a doctrine would certainly be a novel one, and opposed to a uniform course of practice ever since the statute was enacted. The Judge was influenced by commendable motives iu the proceeding under consideration, fu a cause of such magnitude and expectation, — -a cause which in a fruitless trial at a preceding term, had consumed nearly a week, — a cause in which so much fooling had been excited and was then existing, the object was to have the trial conducted on principles and decided by a jury as impartial and unobjectionable as possible.
*52But the counsel for tlie appellant has urged that the language of the 11th section of the statute is imperative, and he has cited the following proviso, viz,: “Provided, and in case of the court’s excusing for cause, any person of either of said juries, and there being any supernumeraries, the vacancy shall be supplied and the panels be filled and completed on the above mentioned principles, in the same manner as if the person excused had not been named on the jury list.” In reply to this it is enough for us to observe that this section has no connexion with or reference to th.e arrangement of the jury for the trial of any particular cause, but relates exclusively to the mode of empannelling juries at the commencement of a term, or at the first appearance of jurors to be qualified. It is the right apd duty of a Judge to superintend and direct as to the course of proceedings, — rto decide which jury shall decide a particular cause, or discharge them at his pleasure when they cannot agree, —to make all requisite arrangements according to his sound discretion, — to excuse jurors when he thinks proper, or call a juror from one jury to another. It belongs to him in his discretion to do all these things ; and we are by no means certain that such an order and proceeding as form the ground of this objection, are proper subjects of exception and open to revision and correction by the whole court. At least, they seem to be rather matters of judicial discretion than matters of law.
The second objection is that the order of the Judge was incorrect, ■by which the counsel for the appellant,were permitted to open and close the cause. The counsel admits'that the authorities are against him. They certainly are so; and we are satisfied the course of proceeding under the direction of the Judge was perfectly correct and proper in principle, as well as in accordance with the cas.es cited by the counsel for the appellee.
The third objection is that the ruling of the Judge was incorrect in permitting the questions to be answered, which were proposed to Doctor Greene and Doctor Bates; inasmuch as the answers only imported the expression of their opinions as to the capacity of the testator to make a will; and also in admitting testimony on the part of the appellee, contradicting those answers. — Starkie, in his learn*53cd treatise on the law of Evidence, vol. 3, page 1753, lays down the law as settled in England, that “ whenever the credit of a witness is to be impeached by proof of any thing he has said or done in relation to the cause, he is first be asked, upon his cross examination, whether he has said, declared, or done that which is intended to be proved.” Queen's case, 2 B. & B. 300. This principle has not been admitted in Massachusetts; Tucker v. Welsh, 17 Mass. 160; nor has it in practice in this State. Before proceeding to the examination of these grounds of objection, it may be proper to observe that Doctor Greene bad been the attending physician of the testator, during his last sickness, and of course possessed tho most accurate knowledge as to tho situation of bis mind and memory and Ins legal power to dispose of bis property, lie had been examined in chief as to the acts and declarations of the testator for the purpose of proving him to have been incapable of making a legal disposition of his estate ; and the cross examination was intended to draw forth' answers from him, for the purpose of disproving their truth by other witnesses, and of thus impeaching his credit and weakening the force of his testimony. The motive was tho same in the cross examination of Doctor Bates. — -It is contended that this course of proceeding was contrary to the established principles and rules of evidence. W e apprehend that the correctness of this position, according to the most approved authorities on the subject, will depend on the nature of the proposed questions upon tho cross examination; and that the true line of distinction is that which has been established between those questions which are merely collateral, and have no immediate connexion with tho cause, and those which intimately relate to the subject of inquiry. The law on the point before us is laid down in very clear language by Starckie, vol. I, page 134, and many authorities are there collected by him. lie says, “ It is here to be observed that a witness is not to ho cross examined as to any distinct, collateral fact for the purpose of afterwards impeaching his testimony by contradicting him ;” and he cites the case of Spencely v. Willot, 7 East. 108, as an illustration of the principle. It was a penal action for usury, in which the defendant’s counsel were not permitted to cross examino as *54to other contracts made on the same day with other persons, in order to show that the contracts in question were of the same nature and not usurious, if the witness answered one way, or to contradict him if he answered the other way; and should such a question be-answered, evidence cannot afterwards be adduced for the purpose of contradiction ;” and he cites Harris v. Tippet, 2 Camp. 638, and Rex v. Watson, 2 Stark. Ca. 149. He observes*, “ The same rule obtains if a question as to a collateral fact be put to a witness for the purpose of discrediting his testimony, his answer must be taken as conclusive, and no evidence can afterwards be admitted to contradict it.” He cites the two last cases and Rex. v. Teale, in support of the position, and then adds, “ This rule does not exclude the contradiction of the witness as to any facts immediately connected with the subject of inquiry.” As an illustration of this rulé, he observes, “ a witness may be asked whether, in consequence of his having been charged with robbery of the prisoner, he has not said that he would be revenged upon him; and in case of denial he may contradict him. Yervin's case, 2 Camp. 638. In such a case the inquiry is not collateral, but most important in order to show the motives and temper of the witness in the particular transaction.” The same doctrine is laid down in pages 145, 146; and after repeating the rule, that “ no evidence can be given of particular, collateral facts, for the purpose of contradicting” the witness, he assigns the reason of it; “ for this would cause the inquiry, which ought to be simple and confined to the matter in issue, to branch out into an indefinite number of issues; besides this, no man could come prepared to defend himself against charges which might thus be brought against him, without previous notice.” Numerous cases are cited in support of the reasons thus assigned.
We have thus presented a summary of the law on the particular subject under consideration, and it now remains for us to inquire how far the facts on which the objection is founded bring it within the range and influence of the rule above stated. In the course of the trial all evidence of mere opinion as to the sanity of the testator was excluded, except that of the subscribing witnesses ; and therefore, it has been contended that as Doctor Greene and Doctor Bates *55could not have been permitted to testify their opinions, as physicians, to establish the insanity of the testator, their answers on the cross examination that they had expressed their opinions of his sanity, and the questions proposed for the purpose of drawing out these answers, were all improperly admitted. But if those questions were not collateral, but intimately related to the subject of the inquiry, they were proper, and the answers thereto 5 according to the authorities before cited, as laying the foundation for impeaching their testimony by contradicting them, or for the purpose of discrediting them by their answers; although their opinions could not have been offered in evidence by the appellant to establish the fact of insanity. So that we are conducted directly to the point whether the questions proposed to Doctor Greene and Doctor Bates were in their nature collateral to the cause and related to distinct and collateral facts, or whether they wore intimately connected with the immediate subject of inquiry, and so were proper on the cross examination. On this question it would seem that two minds could not seriously entertain more than one opinion. The sanity of the testator was the only fact in issue 5 and to prove and disprove it was the whole effort and labor of the parties; and in this view of the subject we are all satisfied that the cross examination of those witnesses was conducted on proper principles ; and such being our opinion on this point, it follows, as a legitimate consequence, that the witnesses offered to disprove the truth of their answers and thereby impeach their testimony, were on legal principles clearly admissible for that purpose.
The fourth objection seems to be placed on an unstable foundation. The authorities cited clearly establish the principle that an impeached or contradicted witness cannot be supported by the party who called him, by proof of his declarations made at other times and to other persons, coinciding with his testimony. Such being the case, we do not in the present instance, see any reasons for coilsidoring it as removed from the influence of the general principle. Indeed it would seem objectionable on another ground, namely, that such declarations were mere expressions of the opinions of those witnesses as medical men; all which kind of evidence was exclu*56ded on the trial when offered to prove insanity, excepting the opinions of the subscribing witnesses to the will as before mentioned.
The fifth objection is that the declarations of the appellant should not have been admitted. They were made two or three weeks before the testator’s death, and were distinctly expressive of his opinion of the testator’s sanity at that time; and, admitting that a witness cannot be allowed to testify his opinion upon a question of sanity, as contended, does it follow that a person may not express such an opinion in conversation and afterwards, when such person has become a party on record and a party in interest, his opinion, as before expressed, may not be proved against him ? And though his rights in a case like this, are not to be impaired or affected by the opinion of others, does it follow that those rights may not be impaired or affected by his own opinion ? By law the confessions of a party may always be given in evidence against him and his interest, though not thereby to defeat or impair the rights of others claiming 'under him. In the case before us, there are no such rights. The case of Phelps v. Hartwell is relied on. The facts of that case are very uncertain as to the declarations offered to be proved. It does not appear when they were made, or on what they were founded. They might have been made months before, or months after the death of the testator. Indeed the facts are so loosely reported that the case cannot be relied on. Besides, the court were divided in opinion, and that opinion was given in the hurry of a jury trial, without examination or time for any. On the whole we cannot sustain this objection.
The sixth objection is that certain books on medical subjects, mentioned in the report, and alleged to be of high reputation, when offered as evidence, were improperly excluded. It was admitted in argument that there seemed to be no authorities having any direct bearing on the point. The books mentioned in some of the authorities, as admissible in evidence, are of a totally different character ; and they are only exceptions from the general rule which is unquestioned. In the first place, those medical books contain only opinions or facts, stated by their respective authors. They do not come into court, as all other evidence must, either by consent or *57under the sanction of an oath. Without such consent or sanction, their contents are mere declarations and hearsay. But it is urged as being more safe to read the opinions of distinguished physicians, as they have published them to the world, and thus learn the nature, tendency and effect of bodily disease, or the illusions of the imagination, upon the powers and operations of the mind, than to receive the opinions and facts from the mouths of witnesses on the stand, who have acquired all their knowledge on those subjects, perhaps, from those very books : — that such a course as the latter is founded on the idea that a copy is more perfect than an original. In answer to this it may be observed that the benefit of cross examination would be lost by allowing books of such a character to be evidence ; and such cross examination is justly deemed a matter of great importance in the search after truth. The absence of all authority of adjudged cases on the point, is a strong argument against the admission of such evidence. The practice, if by law allowed, would lead to endless inquiries and contradictory theories and speculations. In a word, if one book is evidence, so is another; and if all are admitted, it is to be feared that truth would be lost in the learned contest of discordant opinions.
The seventh objection is that John Jones’s letters were improperly excluded. This has been but little relied upon, and we do not perceive how they could have had any influence in deciding the question as to the testator’s sanity. They contained the more declarations of a crazy man.
The eighth objection is that the answer or declaration of Fletcher to Spaulding, while the appellee was with them in his store, ought to havo been admitted. Had the declaration in question been made by the appellee himself, it would have been admissible for the same reason which we have given in our answer to the fifth objection ; and it is contended that upon well known principles it should have been admitted, because spoken in the appellee’s presence. On this point there is some uncertainty in the facts reported. The appellee was present in the store; but whether he heard the excluded declaration is not certainly known to us. It is evident that he heard a part of Fletcher’s reply to Spaulding, because he echoed the *58words, “ it is of no use”; and it is said we must infer that he heard the whole, the reason assigned as well as the answer given. How far we are at liberty to draw this conclusion, not knowing how near the parties were to each other ; how the appellee was then employed, and in how loud a voice Fletcher spoke, deserves consideration, and is not readily to be answered. It would have been an easy matter for Fletcher to state whether the appellee was attending to the conversation, and in a situation to hear it all; and yet on this point not a word has been testified. But in relation to this objection there is another answer which has not been'noticed by any of the counsel. The reason why declarations made by a third person in the presence and hearing of a party are admissible, is, that his silence is construed to be an assent to the truth of those declarations ; for every man is presumed to guard his own interest, and never yield his claims by a tacit acknowledgement of any thing which has a tendency to impair them. Now in the present case, when the declarations were made, the appellee was no party to this suit; he had no interest in the property to which the suit relates $ the testator was then living 5 it does not appear that the appellee knew that he had been appointed executor, or even that any will had been made. The appellee'in legal contemplation was then a stranger and had no interest in the conversation 5 nor was he .in a situation to be committed by his silence under the then existing circumstances, though he might have been, had he then been a party in interest. In a dispute about a piece of property conveyed by a father to his son, can a plaintiff in an action against the son for the recovery of that property, give in evidence declarations made by a third person in the presence of the son, before he became owner of the property, going directly to defeat his title ? We apprehend the principle has never been carried to such an extent. We think this objection also must be overruled.
The ninth objection relates to the instruction of the Judge to the jury, so far as it had reference to the testimony of Doctor Greene. On examination of this, it appears that the only instruction given them was, that “ being in the case it would be taken into consideration by them, in connexion with the other testimony.” Surely *59there is nothing incorrect in this. It is true that the Judge prefaced this plain and obvious instruction with some remarks on the different degrees of knowledge which different persons probably possessed as to tho capacity of the testator at the time of making his will, and the different degrees of influence which such knowledge, if legally conveyed to the minds of a jury, would probably have upon their decision of the question of sanity or capacity ; and after noticing the difference between affirmative proof, and that which is merely of an impeaching character, and making an application of these remarks to the case then in trial, by way of illustration, he concluded by the instruction before mentioned. If has never been deemed a subject of legal exception, for a Judge to make his observations on the evidence, the different kinds of it, and its bearings on tho points in issue, and to illustrate his meaning and enforce his observations in such manner as he may think proper; — taking care, in so doing, not to encroach upon the province of the jury in the decision of the facts, as they may think proper in view of the evidence, which they are to weigh. A Judge in the faithful discharge of, his duty* may and ought to state, arrange, compare and comment upon the evidence, so far as he may deem it necessary fairly to present the cause to their minds in as plain and clear a manner, as may be in his power. This proceeding on his part is often a most laborious duty, and he is to be governed, in the discharge of it, by a sound' discretion; and the manner in which he performs this duty is not a subject of revision, by virtue of our statute, as a dry question of law. If any specific instructions are desired, counsel may always request a Judge to give them, and should he improperly decline to give them, his refusal is a proper subject of legal exception and revision by the whole court.
The tenth and last objection urged, is that the Judge erred in not giving to the jury the explicit instructions which were requested by the appellant’s counsel. The general answer to this objection reposes on the principle that the question of sanity is of such a character as to render it highly proper for the consideration and decision of that tribunal'; and such was the opinion of the appellant before the commencement of tho trial. By our statute on this subject, the *60question may be decided by the court, without the intervention of a jury, or it may be tried by a jury. As in this instance it was the desire of the appellant that it should be s.o tried, the court were not disposed to deny his request; and now that a verdict has been returned against him, there seems no reason for listening to the objection with any particular indulgence. The question of sanity often depends on a multitude of circumstances, various and minute, peculiar and contradictory, and where lights and shades are sometimes almost lost in each other. Besides, it is perhaps almost impossible for a Judge to draw any certain divisional line, and present it beforehand (or the regulation of the jury. The line of separation between the powers and provinces of court and jury, in the decision of such cases, we apprehend it is also equally difficult to draw; and in those cases, cited by the counsel for the appellant, from the celebrated speeches of Erskine, to shew the various manners in which insanity displays itself and operates on the powers of the mind, it appears that the subjects of investigation were then before the jury for-^decision. In addition to these remarks, we would observe that the authorities sanction, in clear language, the course pursued on the trial of this cause., Starkie, vol. 3, page 1707, says, “The question of sanity is so peculiarly a question of fact for the decision of a jury, that a will of real estate cannot be set aside in equity, without being first tried at law on an issue of devisavit vel non.” On the whole, after a careful examination of this cause, the authorities cited and the able arguments of the respective counsel, we are all of the opinion that the motion for a new trial cannot be sustained. Our opinion, we are sensible, has been extended to an unusual length ; but it is the consequence of a desire on our part, to assign reasons for our judgment, and, as far as in our power, give satisfaction to the parties, by a careful consideration of every objection urged at the argument, in a cause involving the decision of property to so largo an amount.
From the proceedings which we have witnessed since the cause was removed into this court for final decision, we are satisfied that there was a reasonable ground for prosecuting the appeal 5 and, in view of all the circumstances of the case, we do not allow costs to the appellee.