The defendant was offered as a witness to testify under the provisions of the act of June 25, 1858, in amendment of the act of June 27, 1857, entitled “An act relating to the competency of witnesses.” The original act provides that no person shall be excused or excluded as a witness, in any civil suit, by reason of his interest as a party, but expressly excepts from its operation the cases of attestation of wills, &c., suits pending at the passage of the act, and suits in which one of the parties is executor or administrator, and he does not consent that his adversary shall testify. The amendatory act provides, section one, for taking the deposition of a party, with a proviso that he shall not be required to answer any question or produce any document, the answering or producing of which may tend to criminate himself; and section two *329declares that the provisions of the original act shall extend and be applied to all actions, suits, and proceedings at law or in equity, with the same proviso, however, as to the cases of attestation of wills, &c., and substantially the same as to suits in which one of the parties is executor or administrator, as in the original act, but omitting the exception as to suits pending at the passage of the original act. The question is whether, by the broad and comprehensive terms of section two of the amendatory act, that the provisions of the former act shall extend and be applied to all suits and proceedings at law and in equity, the legislature intended to include indictments and other criminal proceedings. We think it clear that it was not so intended, but that the object of this provision of section two is merely to declare the intention of the legislature to extend the operation of the original act to all civil suits, whether they were pending at the passage of that act or not.
The mere omission of the exception as to pending suits might not of itself be sufficient to give to the statute this intended application, under the well settled rule of construction, that a new enactment is not to be construed as applying to pending causes, unless it is so declared, or it is clearly to be inferred horn the nature of its provisions that it was intended so to be applied. All the other provisions of both acts have reference to civil causes, and not to criminal proceedings; and as the terms in which this is expressed are fully satisfied by the construction that this also refers to such causes, it is no sufficient ground for construing it as including indictments and other criminal proceedings merely because they are broad and comprehensive enough to include them, and might, therefore, he so construed, if, from the context, it appeared that such was the intention. Looking to the other provisions of the act, there is nothing to indicate that this was the intention. The provision in section one, that in taking the deposition of a party he shall not be required to answer *330any question tending to criminate himself, is not to be reconciled with an intention to enact in the next section a provision subjecting him to examination as a witness for the government; or, if voluntarily testifying in the defence, to cross-examination upon the question of his criminality in a proceeding instituted for the purpose of testing his guilt or innocence. If the legislature had intended to enact so great a change of the law, it must be supposed they would have declared it by an explicit and,direct enactment, that the provisions of the original act should extend and be applied to all criminal as well as civil proceedings. Instead of this, the enactment is expressed in terms which, though sufficiently broad and comprehensive to include indictments, if, from its other provisions, the object appeared to be such as to render that construction necessary, are nevertheless made significant and operative by giving them the more limited application to civil causes pending, and so construed more in accordance with the spirit and policy of the acts, as gathered from their other provisions.
If, however, it had been explicitly declared that the enactment was to include criminal as well as civil proceedings, it admits of question whether, by any judicial interpretation, it could be made to have any practical operation without infringing the 15th article in the Bill of Rights, which declares that no person held to answer for any crime or offence shall be compelled to furnish evidence against himself. The provisions x>f the original act, which upon the construction ^contended for by the respondent are by the amendatory act extended and made applicable to indictments, are that “ no person shall be excused as a witness,” &c., that is, exonerated or relieved from obligation to testify when called by the adverse party, or “ excluded as a witness,” &c., that is, rejected when he offers himself to testify in his own favor. Upon that construction, the legislature have enacted not only that the respondent in *331an indictment may voluntarily testify in support of Ms defence, but that he may be compelled to testify at the instance of the government in support of the indictment against himself. So far as the enactment may be construed as undertaHng thus to compel him to testify, it would seem very clearly to be in direct contravention of the Bill of Eights. If the view should be taken that, though inoperative in that provision, it might have effect and operation in the other, which permits him to testify voluntarily, the same objection would arise upon subjecting him to cross-examination. To obviate this it would be necessary to hold, either that the enactment could have no further operation and effect than to permit him to testify, so far as he might choose to make himself a witness — thus leaving it optional with-him whether to submit to cross-examination or not — or that, by volunteering to testify, he had waived the benefit of the constitutional provision, and might therefore be compelled to make full disclosure. In either view the effect must necessarily be to drive him if guilty, to testify to the full confession of his guilt, or to make the confession in another form, by refraining from testifying or declining to submit to cross-examination, when, according to every principle of reason, and to all experience of human conduct, this could be accounted for upon no other hypothesis than that of his guilt. An enactment which should introduce this as the state of the law in reference to criminal trials, would seem to place the accused in every instance in a position where he must necessarily furnish evidence against himself, unless it be assumed at the threshold that he is innocent, and may therefore safely submit to the test of a cross-examination. But every sound principle recognized in the administration of criminal law, no less than this express prohibition in the Bill of Eights, secures to him who may be assumed to be guilty, the same advantages from the course of the trial and from the rules of evidence, as are to be enjoyed *332by him who may be supposed to be innocent. The very necessity which arises for making the distinction at the outset, as to the guilt or innocence of the party accused, in order to relieve such an enactment from the condemnation of the article in the Bill of Bights, demonstrates the proposition that it would fall within its prohibition.
It is not necessary, however, to place the decision upon this ground. The views which have been presented in discussing it furnish additional considerations in support of the conclusion that the legislature did not intend to include criminal proceedings, and on that ground the decision is to be understood as placed.
" Another question in the case is, whether the testimony of Aiken, as to his impression, was properly received. He testified that he read the bond hastily when he signed it, and could not say whether it had then been altered or not, hut that he had an impression in regard to it. The government then asked what the impression was^to which the respondent objected. The objection has several aspects. An impression as to a past fact may mean personal knowledge of the fact as it rests in the memory, though the remembrance is so faint that it cannot be characterized as an undoubting recollection, and is therefore spoken of as an impression. This, perhaps, is the sense in which the word is most commonly used by witnesses, in giving their testimony. In this sense the impression of a witness is evidence, however indistinct and unreliable the recollection may be. No line can be drawn for the exclusion of any record left upon the memory, as the impress of personal knowledge, because of the dimness of the inscription. If, therefore, the objection is to be considered as one taken to the general competency of such testimony, it is clear that’ it was properly overruled. An impression, however, may mean an understanding or belief of the fact, derived from some other source than personal observation, as the information of others; or it *333may mean an inference or conclusion of the mind as to the existence of the fact, drawn from a knowledge of other facts. "When used in these senses, it is not evidence; and the objection may be understood to be that enough appears in the other statements of the witness, when considered in connection with the subject of his testimony, to show that he intended to use the word in one of these senses as his understanding and belief, or his inference and conclusion, and not as his recollection. It has been urged in the argument, that when the witness stated that he read the bond hastily, and could not say whether it had then been altered or not, he was fairly to be understood as meaning that he had no such recollection, founded on his personal observation, as would enable him to testify from memory; and that, consequently, by the word impression, he must have meant an understanding or inference, resulting from the information of others, or the operations of his own mind, instead of his personal knowledge of the fact. If it was apparent to the court that the word was thus used, the objection is well taken. We think, however, that, taking the whole testimony together, it may be. understood to mean that, although, from the slight atten- ! tion which he gave to the bond in his hasty reading, he cannot say positively whether the alteration had been made or not, he nevertheless had an impression upon his memory, derived from reading it, that it had not. At least, it may be said that the jury might so understand him, without doing violence to any fact or statement contained in his testimony. If it was susceptible of that construction, it could not be excluded by the court merely because a different interpretation might be put upon it, which would render it incompetent. If the parties choose to leave the testimony of a witness doubtful, by refraining to draw from him an explicit declaration of his meaning, when it is susceptible of two interpretations, one of which renders it competent and the other incompetent, it must *334be submitted to tbe jury, with proper instructions, of course, as to how they are to regard it, when they have ascertained what his meaning really was.
In another view, the objection might have been sustained, if it had appeared in the ease that the objection was placed on that ground at the trial. When the witness stated that he could not say whether the bond had been altered or not, it might well be doubted how he intended to be understood in the subsequent statement that he had an impression in regard to it. If the respondent had objected that the witness should not be asked the question what his impression was, until it had first been ascertained-whether he meant by the word impression, a recollection or not, the objection would have been sustained. It cannot be understood to have been made on that ground. It is stated as a general objection, and, as such, must be understood as taken to the competency of the evidence, and not to the form of the question or other incidental matter, which, if stated at the trial, would have given the counsel for the government an opportunity to obviate it.
Another material question arises upon the instructions to the jury, relative to the assent given by Andrews to the alteration of the bond after it had been executed by him. It must be understood that the jury'may have found, upon the evidence, that, down to the time of the assent, the offence .charged- had not been committed. The case states, it is true, that before this, Andrews had signed the bond, and afterwards, and before the assent, the respondent made the alteration, and that the evidence was positive and uncontradicted that he, subsequently and before the assent, delivered the bond to Webber as genuine, without the knowledge of Andrews that it had been altered. But the court cannot, therefore, hold that the verdict must have been rendered upon the ground that the bond was passed or offered to Webber before the assent; or, if so, that the criminal intent was found by *335the jury upon that evidence. They may have believed that the respondent did not pass or. offer the bond to Webber unconditionally, as binding the obligors to him from that time in every event. They may have believed that the respondent, intending to procure the assent of Andrews, placed it in Webber’s hands, to be kept by him till then, and then to become his, and take effect as their bond. Notwithstanding the positive and uncontradicted character of the testimony as to the delivery, they may have discredited it entirely, or so far as to entertain reasonable doubts of the fact of delivery, or of the understanding and intention of the respondent .in making it. The jury, therefore, may have acquitted the respondent upon any state of facts shown to exist prior to the assent, and convicted him upon the case as presented by the evidence and the instructions of the court upon it in reference to the assent.
Were the instructions correct ? They are in effect that, if Andrews qualified his assent by making it to depend upon the truth of the respondent’s representations, and the representations turned out to be false and fraudulent, this would be sufficient, without other proof of criminal intent, to render the unauthorized alteration of the bond a forgery. The jury were told, in substance, that, if the respondent induced Andrews to consent to the delivery of the bond as his, after it had been so altered, by means of false and fraudulent representations, this of itself would be sufficient to warrant a conviction. This is not said in terms in the instructions, as reported in the case, but such, ’is their obvious meaning, and so they must have been understood by the jury.
Forgery consists in falsely making or altering a writing, with intent to defraud. The essence of the crime is contained in the union of the two elements — that the instrument is a fiction, and that it is a fiction prepared for a fraudulent purpose. The false character of the instru*336ment, independent of the fraudulent purpose for which it is prepared, may consist in the application of a false signature — that is, one which is not that of the party whose signature it purports to be — to any instrument, whether genuine or false ; or, as is claimed in this case, in the application of a genuine signature to an instrument which is false — that is, which is not in fact the instrument to which the party applied his signature. In both cases the falsity in the character of the paper disappears when it is shown that the application of the genuine signature in the one case, and the false one in the other, was made by the consent and authority of the party at the time of making it, or was assented to and ratified by him afterwards ; and it can make no difference in the latter case more than in the former, that his assent was procured by means of false and fraudulent representations. If a party is induced by such representations to authorize another to sign his name to a specified paper, there is no more falsity in the signature, or the application of it to that paper, than if, induced by such representations, he had signed it himself; and it is equally so in the case of a subsequent assent, procured by such means to an unauthorized signature, or to the application of a genuine signature to an instrument to which it was not originally aifixed. In every such case the assent of the party, voluntarily given, though procured through falsehood and fraud, removes the false character which without it might be imputed to the instrument. The fraud may exonerate the party from liability upon it as a contract, and under some circumstances may, in itself, constitute an offence subjecting the party to indictment; but, because false means are employed to procure the consent to the instrument, the instrument itself cannot for that reason be deemed false. I have found no authorities upon the point except the cases of Rex v. Chadwick, 2 Mood. & Rob. 545, and Rex v. Collins, id. 461. Although they are merely nisi prius rulings, they are cited by *337Noscoe, in his treatise on criminal evidence, as establishing the law in accordance with the views here suggested. The rulings were, that it is not forgery to induce a party to execute an instrument by a fraudulent misrepresentation of its contents, or to procure, the signature by fraud to a document which had been altered without the party’s knowledge.
The jury should have been instructed that, upon the facts admitted in reference to the signature of Andrews before the alteration of the bond, and the making of it by the respondent without his authority at the time, if the respondent subsequently procured his assent to the alteration before delivering the bond to Webber, the respondent should be acquitted, unless, upon other evidence in the case, they found the existence of the fraudulent intent prior to the time of procuring the assent. For this cause a new trial must be granted. The other questions presented by the case may not be material on tbe new trial, and have not, therefore, been considered.
Verdict set aside, and new trial granted.