Varser, J.

There was much evidence tending to show tbe contentions of tbe respective parties. Tbe plaintiffs introduced direct testimony tending to show that tbe defendant bad admitted that be was a member of'the firm of James Osborne & Co., with bis son, James Osborne. Tbe evidence for plaintiffs further shows that notice that James Osborne bad reported to mercantile agencies that Eielden Osborne was a member of tbis firm bad been brought to tbe knowledge of Eielden Osborne, and that be failed to make timely denial.

Tbe defendant contended that be bad answered all letters and requests that bad come to him, except in one instance. In tbis instance be claims that be was advised by a friend to seek tbe advice of counsel, and that be b'ad done so, and bad followed such advice, and that tbis amounted to due care and ordinary prudence to prevent tbe extending of credit upon bis responsibility.

Tbe trial court permitted tbe plaintiffs to introduce, over defendant’s objection, parol evidence of tbe contents of letters which tbe witness, Tucker, testified be wrote to tbe defendant, Eielden Osborne, and received no reply from him. Over tbe defendant’s objection, tbis witness was allowed to state that be wrote to Eielden Osborne, at Apple Grove, bis postoffice, and never received any reply to any of these letters, and that tbe letters written by tbe witness to Eielden Osborne were to tbe effect that tbe account due by James Osborne & Oo. to tbe West Jefferson Hardware and Supply Company, of which tbe witness was secretary and treasurer, was past due, and that payment was demanded; and that be also wrote Eielden Osborne in these letters that James Osborne said that be, Eielden, was one of tbe partners (in tbe firm of James Osborne & Oo.), and that “We were looking to him to pay tbe bill.”

Tbe record does not disclose that any notice was given to tbe defendant, Eielden Osborne, to produce tbe letter, or letters, or, in default thereof, that secondary evidence would be introduced; nor does tbe record show that tbe witness did not retain or have any duplicate original of tbis letter or copy thereof, nor that any effort, by notice or otherwise, bad been made to procure tbe letter, or letters, from James *447 Osborne, or any preliminary finding that the letters were lost. James, Osborne was not present at the trial, and his wife testified that he was now living in the State of Washington.

There is no evidence tending to show any effort in search for either a duplicate original, or any copy, carbon or press, of these letters. The court found no facts as a basis upon which to introduce this secondary evidence.

The plaintiffs contend that this evidence is competent, for that the letter is collateral to the issue, and therefore the “best-evidence” rule does not apply. Holloman v. R. R., 172 N. C., 372. This case announces that the familiar doctrine contained in Ledford v. Emerson, 138 N. C., 502, that “the rule excluding parol evidence as to the contents of a written instrument applies only in actions between parties to the writing and when its enforcement is the substantial cause of action.”

We are of the opinion that defendant’s exception in the instant case presents the very test, as to the collateral character of the letters to Eielden Osborne, required in Ledford v. Emerson, supra. The action is between the parties to the writing, and the cause of action in the instant case is for. the purpose of enforcing obligations which the plaintiffs seek to establish against Eielden Osborne by virtue of such letters, and his failure to reply thereto. The contents of the letters related directly to the only question at issue. If the situation had presented the converse view, by offering the contents of a letter from Eielden Osborne to the plaintiffs, admitting that he was a partner, or agreeing to pay these debts, it would have been admittedly not collateral to the issue. The same effect is contended for by showing a letter from the plaintiffs to him, and an implied admission resulting from his failure to answer, and the very same direct proof is produced.

When a letter, properly addressed, with the requisite postage thereon, . is placed in the mail, a presumption arises that it was received by the . person to whom it is addressed. Beard v. R. R., 143 N. C., 137.

This, however, does not abrogate the best-evidence rule as to the proof of the contents of such letters. If this letter was received by the addressee, then the value of the contents as evidence arises out of his failure to reply, denying the partnership. Therefore, the very reason for the competency and materiality of the offered evidence is based on the receipt of such a letter, or letters, by this defendant; hence it was necessary to give him timely notice to produce such letters, to lay the foundation for secondary evidence of the contents of these letters.

It is well settled that “where the writing is in the possession of the adverse party, who refuses to produce it, secondary evidence of its contents may be given, even when the contents are directly in issue.” S. v. Wilkerson, 98 N. C., 696; Pollock v. Wilcox, 68 N. C., 47.

*448 If the writing is in the adversary’s possession, notice to produce it must be given to authorize the introduction of secondary evidence. Nicholson v. Hilliard, 6 N. C., 270; Overman v. Clemmons, 19 N. C., 185; Robards v. McLean, 30 N. C., 521; S. v. Wilkerson, supra; S. v. Kimbrough, 13 N. C., 431.

In the Kimbrough case the Court, speaking through Henderson, C. J., announces that the basis of secondary evidence of the contents of writing in possession of the adverse party is that the notice to produce must be given to the adverse party for his protection, in order that he may protect himself against the falsity of secondary evidence “which the law presumes may be false as its very name imports.” Notice, therefore, must be given to the adverse party, who either has the possession of such writings, or, according to the prima facie showing of the party offering such evidence, ought to have the possession. This affords an opportunity of correcting the falsity of such evidence, if it should exist. Therefore, the practice has long been to include, in the notice to produce, a statement that if the writings are not produced, secondary evidence will be offered of their contents.

As applied to the instant case, the gist of the reason for requiring the production of the writing is “that the law will not trust to a frail memory of any man upon that point when the higher grade of evidence, constituted by the instrument itself, is kept back.” Threadgill v. White, 33 N. C., 592.

A learned discussion of the notice to produce appears in paragraph 1202, Wigmore on Evidence (2 ed.). Thi.s author'says the true reason upon which this rule is based is that he who offers secondary evidence of the contents of a written instrument must produce the document, if he can, and that when he says that he cannot, and shows that he cannot, because his adversary has it and will not bring it in, he has met this requirement. The courts have not been too strict in the requirement of proof that the proponent cannot bring it in when the opponent is supposed to have possession of the written instrument, and therefore they treat a simple notice, or demand, as a sufficient compliance with this requirement. The other reasons for the rule, to wit, preventing a false copy and preventing surprise on the opponent’s part, have been accepted by the courts in many instances.

Smallwood v. Mitchell, 3 N. C., 144. This case holds unequivocally “that you cannot read the copy unless you have given notice to the plaintiff to produce the original.” In this case a copy is treated as secondary evidence. Bryan v. Parsons, 5 N. C., 153; Nicholson v. Hilliard, 6 N. C., 270; Whitley v. Daniels, 28 N. C., 481; Murchison v. McLeod, 47 N. C., 240; Ivey v. Cotton Mills, 143 N. C., 189.

The policy of the law in this State has moved a long way from the rigid common-law rule when it denied the right to require the adversary *449 to produce writings for the benefit of a party to the suit. From this hard and fast rule, the courts of equity offered relief by way of a bill of discovery, and then the rules relaxed themselves in order to produce less delay and t'o bring about a trial upon the merits. C. S., 1823, 1824, and 1825, make ample provision to allow a party to obtain an inspection, or copy, of documents in his adversary’s control, and also to produce, on motion and notice, books or writings containing evidence pertinent to the issue. C. S., 1825, provides the useful method of obtaining an admission of the genuineness of any paper-writing material to the action, and if the party declines to admit the genuineness, and it is finally proved or admitted on the trial, the court may tax the costs against the party who refuses the admission, unless he has good reasons for refusing. All the hardships that might otherwise result from a rigorous enforcement of the rules in this regard have been obviated under our decisions and these statutes.

If, however, the court below proceeded upon the idea that the letter in controversy was probably in the possession of James Osborne, and that he was out of the State, this reason would not be sufficient. Davidson v. Norment, 27 N. C., 556; Threadgill v. White, supra.

In McCracken v. McCrary, 50 N. C., 400, the Court says: “The fact that the bond was delivered to Brown, and that he had left the State, tended to show that he had it in his possession; if so, the fact of its being out of the State did not make parol evidence of its contents admissible.” This case also holds that, when there is no evidence that the document is in the possession or within the control of the defendant, the notice to him to produce it amounts to nothing. It would be necessary, in the instant case, in order for notice to Fielden Osbofne to support the admission of secondary evidence as to the contents of the letter, or letters, for the court to find that he had either the possession of such letter, or letters, or that they were within his control. If they were lost after receipt, another rule prevails.

If the trial court should find that the letters in controversy were never received by Fielden Osborne, and that he never knew that in such letters he was charged with being a member of the partnership, then, of course, the letters could not be competent for the purpose of showing an implied admission of the partnership. u

It may be that the court may^ hereafter find as a preliminary question of fact that he received such letters, but was now unable to produce them in response to notice, because they were either lost or destroyed. Then it is necessary that such finding be made by the trial court as a prerequisite to the admission of secondary evidence of their contents.

In Gillis v. R. R., 108 N. C., 441, the rule appears in the following statement, taken from 1 Greenleaf Ev., sec. 558: “The question whether *450 tbe loss of tbe instrument is sufficiently proved to admit secondary evidence of its contents is to be determined by tbe court and not by tbe jury.”

Of course, tbe burden of proof to sbow affirmatively tbe existence of all facts necessary to make secondary evidence competent in sucb instances is upon tbe party offering sucb evidence.

Smith v. Moore, 149 N. C., 185, puts tbe exceptions to tbe best-evidence rule, and to tbe hearsay-evidence rule, in tbe same class, basing both upon tbe doctrine of necessity.

Inasmuch as the plaintiffs relied upon an exception to the best-evidence rule, it was necessary in the instant case for them to sbow either the possession or control of the letters by the defendant, Fielden Osborne, or that the same bad been lost after be bad received them. In the latter instance, proof that a diligent search has been made for the writing, in the proper place, or places, is sufficient to establish the loss of the instrument. Sucb secondary evidence will not be received on the ground that the instrument itself is lost, until it is shown that a diligent search has been made for the writing. Avery v. Stewart, 134 N. C., 287.

The character of the search necessary, and the quantum of proof, and the duty of the trial court with reference to these questions, are fully discussed in Avery v. Stewart, supra. It is therein stated: “In order to dispense with the production of it (written instrument), it was incumbent on the plaintiff to give all the evidence reasonably in bis power to prove the loss of it”; and “it is the duty of the judge to decide the facts upon which depends the admissibility of testimony”; and “it is the duty of the judge to state the facts found by him from the evidence, if requested to do so by the party excepting to bis ruling,” and bis findings of fact cannot be reviewed in this Court; but if be does state the facts, either of bis own motion or at the request of a party, this Court can review a conclusion which is based upon the finding, for this presents necessarily the question of law.

These doctrines, asset forth in Avery v. Stewart, supra, have been reaffirmed in the following: Mitchell v. Garrett, 140 N. C., 397; Green v. Grocery Co., 159 N. C., 121. In Green v. Grocery Co., supra, it appeared that tbe proper custody of tbe writing desired was without tbe jurisdiction of tbe court and in Richmond, Virginia, but that no sufficient search bad been made in Richmond, at tbe proper place, for it, and tbe evidence was held incompetent, citing Blair v. Brown, 116 N. C., 631; Avery v. Stewart, supra; Justice v. Luther, 94 N. C., 793. In Byrd v. Collins, 159 N. C., 641, tbe same doctrine is set forth in a quotation from 3 Redfield on Wills, page 15: “But it must in all cases be shown that an exhaustive search has been made for sucb missing will in all places where there is tbe remotest possibility that it could be *451 found, before any secondary evidence can be received of its contents.” Of course, this doctrine must be interpreted in- the light of the character of the written instrument in each particular csise, and the exhaustiveness of the search must be interpreted in practice in reference to the character of the papers sought; hence it is not easy to define the degree of diligence in the search that is necessary, for each case depends much on its particular circumstances; but, in general, as stated in this latter case, a party is expected to show that he has, in good faith, exhausted in a reasonable degree all sources of information and means of discovery which the nature of the case would naturally suggest and which were accessible to him. This doctrine is taken from 1 Greenleaf Ev., sec. 558. The same rule is announced in Thompson v. Lumber Co., 168 N. C., 226.

In Sermons v. Allen, 184 N. C., 127, the Court announces the same rule, and, upon authority of Beard v. R. R., supra, holds, with reference to the notice to produce, and its timeliness, that, “generally, if the party dwells in another town than that in which the trial is had, a service on him (to produce papers) at the place where the trial is had, or after he has left home to attend the court, is not sufficient.”

This rule also shows that the reasonableness of all the requirements is a necessary test.

The defendant also excepted to the introduction of letters received in reply to letters written to the defendant, Eielden Osborne, properly addressed and put' in the mail, with the requisite amount of postage thereon, and the replies received in due course of mail, purporting to be in reply to the letters so written; and, in fact, the replies were written on the backs of the letters themselves.

This evidence has been held competent in Echerd v. Viele, 164 N. C., 122, wherein the Court says: “A letter received in due course of mail, purporting to be written by a person in answer to another letter, proved to have been sent him, is prima facie genuine, and is admissible in evidence without proof of the handwriting or other proof of its authenticity.”

It therefore appears that the plaintiffs did not bring themselves within any of the provisions whereby secondary evidence of the contents of the letters to Fielden Osborne, about which the witness, Tucker, testified, may be given, and inasmuch as this evidence appeared to be relevant and material to the contested issue, we are constrained to hold that the admission of parol evidence as to the contents of such letters was prejudicial error. The matters in the other exceptions may not present themselves at another trial, and it is therefore unnecessary to discuss them.

For the reasons herein set forth, let there be a

New trial.