be proved by the opinion and belief of witnesses conversant with such articles, 46

3212. In general, the opinion of the witness is not evidence, for he must speak of facts; but when matters of skill or judgment are involved, a person competent particularly to understand such matters may be asked his opinion, and it will be evidence. It is the constant practice to examine on questions of science, skill, and trade, or others of the same kind, persons of known experience, who, for this reason, are sometimes called experts. These testify not only as to facts, but also give their opinions, which are properly received in evidence. It is for this reason the opinions of medical men are constantly admitted as to the cause of disease, or of death, or the consequences of wounds, and as to the sane or insane state of a person's mind, as collected from a number of circumstances; but medical or other scientific men cannot give their opinions as to the merits of the cause, but only their opinions upon the facts proved.47

The testimony of experts is inadmissible to prove facts which lie within the knowledge of all persons of ordinary intelligence, but they may be called upon to express an opinion as to facts which are incapable of direct proof, and can only be inferred from apparent symptoms, the connection between which and the facts in question is known only to persons of peculiar skill. Such, for instance, is the question of sanity, of the causes of death, and the various questions upon which medical experts are called. So where the probability of a future occurrence is in question, it is evident that the witness can only testify as to his belief, founded upon a peculiar acquaintance with the object. Such, for instance, would be the increase in value likely to accrue to adjacent land from laying out a street, or the sufficiency of a dam to resist freshets."

49

3213. A witness should not be asked, and if asked, he need not answer, any question which has a tendency to render him liable to any kind of punishment or to a criminal charge, or subject him to a forfeiture of his estate, or have a direct tendency to degrade his character.

3214. It is exceedingly clear that a witness is not compellable to criminate himself, and whether he has answered the question in part or not at all, he will be protected by the court; 50 still, he may answer if he chooses; and in such a case the party who put the question will be bound by the answer, because the court cannot try such collateral facts, and the parties and the witness do not come prepared for its full investigation. But where the answer will only subject him to a civil liability or pecuniary loss, or charge him with a debt, he is

46 Ohio R. R. v. Irwin, 27 Ill. 178.

51

1 Greenleaf, Ev. 8 440; 1 Phillipps, Ev. 290; Wogan v. Small, 11 Serg. & R. Penn. 141.

48 Hovey v. Sawyer, 5 All. Mass. 554; Derby v. Gallup, 5 Minn. 119.

49 Webber v. Eastern R. R., 2 Metc. Mass. 147; Porter v. Poquonnoc Co., 17 Conn.

249.

50 If the witness voluntarily and with full knowledge states part of a transaction in which he is criminally implicated, he is compellable to state the whole. Coburn v. Odell, 29 N. H. 540; Norfolk v. Gaylord, 28 Conn. 309; Foster v. Pierce, 11 Cush. Mass. 437; but otherwise if he merely states the part inadvertently.

51 1 Phillipps, Ev. 284. See Rex v. Rudge, 2 Peake, 232. It is the privilege of the witness alone to refuse to answer; if he chooses to do so, neither party can object. Commonwealth v. Shaw, 4 Cush. Mass. 594; People v. Mather, 4 Wend. N. Y. 229; Newcomb v. State, 37 Miss. 383.

The witness is to judge whether the answer will criminate him, for he alone can know the facts, and is not compellable to divulge them. And he may use his privilege where the question is manifestly one of a series the answers to some of which will criminate him, or where the cross-examination founded on his answer would have that effect. Printz. v. Cheeney, 11 Iowa, 469; French v. Venneman, 14 Ind. 282.

bound to answer." 52 A party interested in the cause cannot be compelled to answer, though not named on the record. 53

3215. When the answer will subject the witness to a forfeiture of his property he will be protected, as he is when his answer will expose him to a criminal prosecution or penalty.

54

3216. No man is bound to degrade his own character; he is, therefore, not bound to answer a question when the answer has a direct tendency to degrade his character. This rule applies only to those cases where the inquiry is not relevant to the nature of the issue; for if it be relevant, it must be answered, however strongly it may reflect on the character of the witness.55

3217. A witness should not be asked, and he cannot be compelled, if asked, to disclose state secrets, or official communications between the heads of departments of state and their subordinate officers, or matter which is indecent or offensive to public morals, or injurious to the feelings and interests of third persons, the parties having themselves no interest except what they have themselves created.

3218. State secrets are those things which are known only to some of the officers of the government, or of some branch of it. Those are matters which concern the administration of penal justice, or those which concern the administration of the government. The principle of public safety is the same in both cases, and the rule of exclusion is applied no further than the attainment of that object requires; for example, in criminal trials the names of the persons employed in the discovery of crime are not permitted to be disclosed any further than is requisite to a fair trial of the question of the prisoner's innocence or guilt.56

3219. For the same reason, the public good, communications between the heads of departments of state and their subordinate officers are protected from disclosure; thus, communications between a provincial governor and his attorney general on the state of the colony and the conduct of its officers; 57 the President of the United States and the governors of the different states cannot be coerced to produce correspondence or official papers, or to disclose information communicated to them in their official capacity when in their opinion the disclosure would be injurious to the public interest; 58 when such original evidence cannot be admitted, secondary evidence of the same facts will not be received. It has already been stated that grand jurors cannot be examined when their answers would be injurious to the public interest as to what passed in the grand jury room.60

59

3220. When the public good requires it, the mere indecency of disclosures does not suffice to exclude them, for this reason, on an indictment for a rape, or when the sex of a person claiming an estate tail comes in question, the inquiry as to it is allowed, and the witness may be compelled to testify. But when the evidence is not necessary for the administration of public justice, but the questions have been raised by the parties themselves out of mere wantonness or sport, or in disregard of the rights of others, such questions cannot be answered;

52 Baird v. Cochran, 4 Serg. & R. Penn. 397; Ness v. Van Swearingen, 7 Serg. & R. Penn. 192; Bull v. Loveland, 10 Pick. Mass. 9; Conover v. Bell, 6 T. B. Monr. Ky. 157. 53 Mauran v. Lamb, 7 Cow. N. Y. 174; Rex v. Woburn, 10 East, 395.

Bull v. Loveland, 10 Pick. Mass. 9.

55 1 Phillipps, Ev. 279, and Cowen & Hill's Notes, note 521; 1 Greenleaf, Ev. 454, 455. 56 Rex v. Hardy, 24 St. Tr. 753, 811.

57 Wyat v. Gore, Holt, N. P. 299; Cook v. Maxwell, 2 Stark. 183; Anderson v. Hamilton, 2 Ball & B. Ch. Ir. 156, note.

58 1 Burr's Tr. 186, 187 ; Gray v. Pentland, 2 Serg. & R. Penn. 23.

59 Gray v. Pentland, 2 Serg. & R. Penn. 23, 31; Yoter v. Sanora, 8 Watts, Penn. 156. 60 See before, 3180.

as, where the parties laid a wager as to the sex of an individual," or whether an unmarried woman had a child.62

3221. After the party who called a witness has closed his examination in chief, he is handed over to the counsel of the other side to be cross-examined; but if he has simply been sworn inadvertently, and not examined by the party who called him, the other party cannot examine him as if he had been so examined, but he may examine him as his own witness in chief.63

Every party has a right to cross-examine a witness produced and examined by his antagonist, in order to test whether the witness possesses the knowledge of the things he testifies; and if, upon examination, it is found that the witness had the means and ability to ascertain the facts about which he testified, then his memory, his motives, every thing, may be scrutinized by the cross-examination.

The object of the cross-examination is to sift the evidence and try the credibility of the witness who has been called and has given evidence in chief. It is one of the principal tests which the law has devised for the ascertainment of truth, and it is certainly one of the most efficacious. By this means the situation of the witness with regard to the parties and the subject of litigation, his interest, his motives, his inclinations, and his prejudices, his means of obtaining a correct knowledge of the facts respecting which he testifies, the manner in which he used those means, his powers of discerning the facts in the first instance, and his capacity of retaining them and describing them, are fully investigated and ascertained. However artful he may be, the witness will seldom be able to elude the keen perception of an intelligent court and jury, unless, indeed, his story is founded on truth; when false, he will be liable to detection at every step. 64

tender

65

Under a cross-examination the counsel may put any question at all relevant to the cause he may think fit, and in a manner however leading; but this is allowed because the witness is presumed to be favorable to the other side, and the rule already mentioned, as to the right of putting leading questions under an examination in chief, equally extends to a witness under cross-examination; when it appears that the person is not a witness of the truth, but evidently endeavoring to conceal it from the counsel who is examining him, whether for or against the plaintiff, the most leading questions are permitted. But this right of putting leading questions appears to be somewhat qualified, for when a witness betrays an anxiety to serve the party against whom he was called and examined in chief, a direct leading question will not be permitted in cross-examination. This rests very much in the discretion of the judge and the conduct and manner of the witness.

66

61 Da Costa v. Jones, Cowp. 729.

62 Ditchburn v. Goldsmith, 4 Campb. 152.

63 3 Chitty, Gen. Pr. 897.

64 Starkie, Ev. 96; 1 Phillipps, Ev. 227; Fort, 2, 4; Vaugh. 143; Bacon, Abr. Evidence, E.

65 It is an open question whether the cross-examination can be extended to the whole case, or must be confined to the matters stated in the examination in chief and matters affecting the credibility of the witness. The Supreme Court of the United States have established the latter as the rule; and if the party wishes to examine the witness farther, he must make him his own witness and call him again at the proper stage. Philadelphia R. R. v. Stimpson, 14 Pet. 448. So held also in Wilhelmi v. Leonard, 13 Iowa, 330; Campau v. Dewey, 9 Mich. 381; Beaulieu v. Parsons, 2 Minn. 37; Brown v. State, 28 Ga. 199; Patton v. Hamilton, 12 Ind. 256; Ray v. Bell, 24 Ill. 444.

The other rule is held in Massachusetts and Vermont, where a witness called merely as attesting witness to prove the execution of a deed may be cross-examined as to the whole case. Linsley v. Lovely, 26 Vt. 123; Beal v. Nichols, 2 Gray, Mass. 262.

1 Starkie, Ev. 162, n. (c).

A witness cannot be asked under a cross-examination any thing as to a collateral fact for the purpose of afterward impeaching his testimony by other witnesses who may contradict him.67 But with regard to any material fact in issue, a question may be asked of a witness for the purpose of contradicting him.

Much discretion is required in making a cross-examination; the witness will probably look upon the counsel for the party who cross-examines him with much distrust; the first effort of the counsel ought, therefore, to be to gain his confidence by acting toward him with perfect justice, and by appearing to consider him, as most witnesses are, disposed to tell the truth. It is only when he shows a perverse determination to conceal the truth that a searching crossexamination ought to take place. There is a great risk in the cross-examination, for if unfavorable evidence be elicited by such examination, it will be taken most strongly against the party so cross-examining.68

After the witness has been cross-examined, the party who examined him in chief has a right to re-examine him to the same matter. He may ask all questions proper to draw forth an explanation of the sense and meaning of the expressions used by him on his cross-examination when they are doubtful, and also the reasons why he used them. This evidence ought properly to be confined to the cross-examination, and it should not extend to any new matter.

3222. The party may call as many witnesses as he pleases, and submit each one to an examination and cross-examination. If any one of his witnesses should turn out differently from what he expected, and instead of testifying for him his evidence should be in favor of the other party, it is a disputed point whether he can be impeached by him; it seems but reasonable, however, that when a party has called a witness and given him credit that he should not afterward be allowed to impeach the credit which he has given him. He may, however, establish by other witnesses the same point denied by a witness he had himself called.69

3223. When records are given in evidence, they should be properly authenticated, and papers should be proved by the subscribing witnesses, when there are any; and when there are none, the hand writing of the parties should be proved. They should all be read, or it should be agreed that they be considered in evidence.

After all the evidence of the plaintiff has been given, the plaintiff closes his

case.

3224. At this time is to be considered whether the plaintiff has made out a case or not; if, in the opinion of the court, the plaintiff should not have proved a sufficient case to entitle him to a verdict, if the case were then submitted to the jury, and all his evidence admitted to be true, then it would be useless to proceed further in the case, as in point of law he cannot by any possibility recover, and therefore the plaintiff is non-suited. If, on the other hand, the plaintiff has made a prima facie case, then the court hears the testimony on the other side, which, in the case which has been supposed, would be for the defendant.

3225. In order to let the court and jury understand his case, the counsel for the defendant now opens his defence. The general course which he pursues is much like that adopted by the plaintiff in opening his case. He points out

67 Combs v. Winchester, 39 N. H. 1.

65 See Wright v. Littler, Burr. 1244; 1 W. Blackst. 346.

69 Alexander v. Gibson, 2 Campb. 556; Ewer v. Ambrose, 3 Barnew. & C. 746; Hall v. Houghton, 37 Me. 411; Seavy v. Dearborn, 19 N. H. 351; Brown v. Wood, 19 Miss. 475; Brolley v. Lapham, 13 Gray, Mass. 294; Champ v. Commonwealth, 2 Metc. Ky. 17.

in what the case of the plaintiff is defective, if, in fact, it is not well founded; but, if well founded, he shows how the defendant has been discharged, either by the acts of the plaintiff, by acts of law, or on any other account, briefly stating all the facts and circumstances which have this effect, and the manner in which they will be proved.

3226. The witnesses for the defendant are to be examined by him as those of the plaintiff were for him, and they are subject to the general rules of examination. The party calling a witness, when he examines him, is bound to examine him in chief, and is not allowed to pursue the examination in any other way. The witness is turned over to the plaintiff for cross-examination, and, after such cross-examination, the defendant may again examine him as to the cross-examination, or as to any fact which it may have elicited.

The defendant gives in all his evidence, oral and documentary, as the plaintiff did to support his case, and having done so, he closes.

3227. If the defendant has given testimony in his defence respecting any new matter, the plaintiff has a right to give new evidence, which is called rebutting evidence. This kind of evidence is allowed to explain, repel, counteract, or disprove facts given in evidence on the other side; 70 it may be by proving facts directly opposite to those sworn to, or by circumstances which are sufficient to rebut the most positive testimony."

If the defendant has impeached the character of the plaintiff's witnesses, evidence in support of their character may be introduced in rebutter.

3228. Every witness is liable to be impeached by the adverse party as to his character for truth. By impeachment of a witness is meant an allegation, supported by proof, that a witness who has been examined is unworthy of credit. Till impeached, every man's character is presumed to be good, and he who alleges it is not good must, of course, be able to support his allegation by evidence. A witness testimony may be impeached in three ways: by disproving by other witnesses facts stated by him, by general evidence of his want of character for truth and veracity, and by showing his self-contradiction.

3229. A witness' testimony may be impeached by disproving the facts stated by him, by the testimony of other witnesses; as, for example, if Titus, the witness, were to prove that the defendant had a conversation with the plaintiff, in the presence of Peter and Paul, and that both Peter and Paul made remarks to him at the time as to what then passed; and Peter and Paul should testify that they were not present at such conversation, and that they never remarked any thing to him upon the subject; it is clear, if they were worthy of credit, that Titus could not be believed.

3230. Evidence may be given, generally, affecting a witness' credit as a man of veracity. It is his character which is attacked, not particular instances of his conduct. The examination of a witness whose testimony attacks the general character of another must be confined to his general reputation, and not be permitted to go into any particular facts. Every man of good reputa

70 Scott v. Woodward, 2 M'Cord, So. C. 161. In Massachusetts the order of proof is entirely within the discretion of the court, and the plaintiff may, if allowed, after the close of the defence introduce evidence which does not tend to rebut any new matter shown in defence, and its admission cannot be excepted to. Ray v. Smith, 9 Gray, Mass. 141. And in general the court have discretion to allow evidence after the case is closed. Wheeler v. Smith, 13 Iowa, 564; Baze v. Arper, 6 Minn. 220; Hopkinton v. Waite, 6 R. I. 374; Montag v. Linn, 23 Ill. 551; Dozier v. Jerman, 30 Mo. 216. If new matter is introduced in rebutter, not properly rebutting evidence, the defendant must be allowed to answer it. Kent v. Lincoln, 32 Vt. 591.

71 Nelson v. United States, Pet. C. C. 235.