Where there are several documents not physically attached to each other, it may be supposed either that all the documents which it is desired to use are signed by the party to be charged or that some are unsigned by him. In the former case the rule seems to be that all the papers which show by their contents a connection with the bargain sought to be enforced may be taken together though the writings do not refer to each other.24 Parol evidence is not admissible, however, to show that even signed writings relate to the same transaction.25 Where some of the papers which it is sought to include are unsigned, it is sometimes said that one paper must refer to the other, or that there must be mutual reference,26 but this is inaccurate. What is essential is that the signature of the party to be charged shall authenticate the whole of the writing. It is, therefore, necessary to incorporate all the documents into a writing signed by him. It will not be enough to incorporate all into an unsigned writing, or into a writing signed by the plaintiff and, consequently, it is insufficient and immaterial that such a writing refers to a writing signed by the defendant. What is necessary, then, is that a writing so signed refer to all writings not so signed that are sought to be made a part of the memorandum.27 It is not important in what language, reference is principle and authority.30 It has been decided 31 that a reference to a paper hereafter to be made was sufficient to incorporate the paper when thereafter made before the bringing of the action. It may be doubted, however, whether the court so deciding did not place its decision upon too broad a ground. Certainly a memorandum signed by the party to be charged to thiseffect: "I, A, will sell B the goods we may write on a paper to-morrow, at the prices we shall thereto affix," should not be good. Assuming the subsequent paper to be made, it is not authenticated by the signature of A, and this is a requirement of the statute.32 It should be further noticed that even if a
24 Studda v. Watson, 28 Ch. D. 305 (land); Olivor v. Hunting, 44 Ch. D. 206 (land); Brewer v. Horet-Lach-muiid Co., 127 Cal. 643, 60 Pac. 418, 60 L. R. A. 240 (goods); Biest v. Versteeg Shoe Co., 97 Mo. App. 137, 156, 70 S. W. 1081 (contract not to be performed within a year); Boeck-ekr v. McQowan, 12 Mo. App. 507 (land); Marks v.Cowdin, 226 N.Y. 138, 123 N. E. 130; Levin v. Diets, 48 N. Y. Misc. 593, 96 N. Y. S. 468; iThayer v. Luce, 22 Ohio St. 62 (land); Browne, Statute of Frauds, Sec. 348.
25Jacob v, Kirk, 2 M. & R. 221 (goods); Potter v. Peters, 64 L. J. Ch. (N. S.) 357 (land); Rahm v. Kleraer, 99 Va. 10, 37 S. E. 292 (contract not to be performed within a year).
26 Thomas J. Baird Inv. Co. v. Harris, 209 Fed. 291, 295, 126 C. C. A. 217 (land); Devine v. Warner, 76 Conn. 229, 56 Atl. 562.
27 Dewar v Mintoft, 11912] 2 K. B. 373; Thomas J. Baird Inv. Co. v. Harm, 209 Fed. 291, 295, 186 C. C. A. 217; Weymouth v. Goodwin, 105 Me. 510, 75 Atl. 61; Wilkinson v. Taylor Mfg. Co., 67 Miss. 231, 7 So. 366; Donovan v. Schoenhofen Brewing Co., 92 Mo. App. 341, 348; Johnson v. Buck, 35 N. J. L. 338, 10 Am. Rep. 243; Coe v.. Tough, 116 N. Y. 273, 277, 22 N. E. 550; Thayer v. Luce, 22 Ohio St. 62. The case last cited was a suit for specific performance of a contract to sell land. The original memorandum contained no description of the property, and the plaintiff relied also made; it is certainly enough if a plain reference is made by a document signed by the party to be charged, whatever its nature, to any other writing.28 What certainty of reference is necessary, and how far parol evidence may be used to identify a document referred to in a signed writing, present questions entirely analogous to those discussed previously 29 in regard to the necessary certainty of description of the parties, subject-matter, and terms of the contract. While ocasionally expressions may be found that parol evidence is not admissible to identify a document so referred to, this is erroneous both on on a dead which was signed but not delivered. McIlvaine, J., in delivering the opinion of the court, said: "That several writings, though executed at different times, may be construed together, for the purpose of ascertaining the terms of a contract and for the purpose of taking an action founded thereon out of the operation of the Statute of Frauds, is fully settled. 3 Taunt. 169; 1 Ring. 8; 3 Myl. A K. 353; 14 How. (U. S.) 447; 14 N. Y. 684. In such cases, however, the mutual relation of the several writings to the same transaction must appear in the writings themselves, parol evidence being inadmissible for the purpose of showing their connection. If one only of such papers be signed by the party to be charged in the action, the rule seems to be that special reference must be made therein to those papers that are not so signed; but if the several papers relied on be signed by such party, it is sufficient if their connection and relation to the same transaction can be ascertained and determined by inspection and comparison. In this case, upon inspection and comparison of the memorandum and the deed, although no reference is made in either to the other, we find with reasonable certainty that they do relate to the same transaction, and contain fully the terms of a contract of bargain and sale between the parties. The coincidences of names, dates, amount of purchase money, and reference to and description of fractional lota, are quite sufficient. But when these coincidences are considered in connection with the averments and admissions in the pleadings, and the res gestae, we arrive at a degree of certainty far beyond that which is required in determining; civil issues."
28Griffiths Cycle Co. v. Humber,  2Q.B. 414; Drovers Bank v. Albany Bank, 44 Fed. Rep. 183 (guarantee); Woodruff v. Butler, 75 Conn. 679, 55 Atl. 167 (land); Tippins v. Phillips, 123 Ga. 415, 51 S. E. 410 (land); Turner v. Lorillard Co., 100 Ga. 645, 28 8. E. 383, 62 Am. St. Rep. 345 (goods); North v. Mendel, 73 Ga. 400, 54 Am. Rep. 879 (goods); Wills v. Ross, 77 Ind. 1, 40 Am. Rep. 279 (guarantee); Savage v. Robinson, 93 Me. 262, 44 Atl. 926 (guarantee); Obon v. Sharplees, 53 Minn. 91, 55 N. W. 125 (goods); Swallow v. Strong, 83 Minn. 87, 85 N. W. 942 (land); Waul v. Kirkman, 27 Miss. 283 (land); Fisher v. Kuhn, 54 Miss. 480, 483; Meek v. Hurst, (Mo .1916), 191 8. W. 68; Fowler Elevator Co. v. Cottrell, 38 Neb. 512, 57 N. W. 19 (goods); Hickey v. Dole, 66 N. H. 336, 31 Atl, 900, 49 Am. St. Rep. 614 (land); Laiorme v. Bradley, 77 N. H. 128, 88 Atl. 1000 (land); Beury v. Fay, 73 W. Va, 460, 80 S. E. 777.
30Bauman v. James, L. R. 3 Ch. 508; Long v. Millar (C. A.), 4 C. P. D. 450; Oliver p. Hunting, 44 Ch. D. 206; Dewar v. Mintoft,  2 K. B. 373; Beckwith ,v. Talbot, 95 U. S. 289, 24 L. Ed. 496; Turner v. Lorillard Co., 100 Ga. 645, 28 8. E. 383, 62 Am. St. Rep. 345; Ansley v. Green, 82 Ga. 181, 7 S. E. 921; Wilkinson v. Taylor Mfg. Co., 67 Miss. 231, 7 So. 356; Gough v. Williamson, 62 N. J. Eq. 526, 50 Atl. 323. In Beckwith v. Talbot, Mr. Justice Bradley said: "It is undoubtedly a general rule that collateral papers adduced to supply the defect of signature of a written agreement under the Statute of Frauds should on their face sufficiently demonstrate their reference to such agreement without the aid of parol proof. But the rule is not absolute. Johnson v. Dodgson, 2 M. & W. 653; Salmon Falls Mfg. Co. v. Goddard, 14 How. 446, 14 L. Ed. 493. There may be cases in which it would be a violation of reason and common sense to ignore a reference which derives its significance from such proof. If there is ground for any doubt in the matter, the general rule should be enforced. But where there is no ground for doubt, Its enforcement would aid, instead of discouraging fraud. Suppose an agreement be made out and signed by one of the parties, the other being absent.
On the following day, the latter writes to the party who signed it as follows: 'My son informs me that you yesterday executed our proposed agreement, as prepared by J. S. I write this to let you know that I recogniie and adopt it." Would not this be a sufficient recognition, especially if the parties should act under the agreement? And yet parol proof would be required to show what agreement was meant."
31 Freeland v. Kits, 154 Mass. 267, 28 N. E. 226, 12 L. R. A. 561, 26 Am. St. Rep. 244 (land). See also Nicker-son v. Weld, 204 Mass. 346, 90 N. E. 589; Cole v. New York, etc., R. Co., 37 Hun, 394.
32 See Fletcher v. Underwood, 240 HI. 554,88 N. E. 1030; Lusky v. Keiser, 128 Tenn. 706, 164 S. W. 777, L. R. A. 1015 C. 400. In Freeland v. Rita, cited in the preceding note, the defendant agreed to take a lease of a portion of a building from the plaintiff who was to receive, but had not yet received, a lease of the whole building from its owner, a third person. The defendant agreed to take a lease of the portion of the building for which he was bargaining, subject to the terms and conditions of the lease thereafter to be made to the plaintiff. It is submitted that this memorandum of the defendant would have been good if it had signed paper does refer to an unsigned paper it may do so in such a way as will not incorporate the contents of the latter under the signature of the former. Thus A's letter may refer to B 's which contains an accurate statement of the contract, but if A's letter repudiates B's statement of the contract A has certainly not signed a memorandum which will bind him. To have this effect, A's letter must not only refer to B's, but by implication at least indicate assent to the accuracy of B's statement.33 It may be supposed, however, that the statement in B's letter is inaccurate, and a correction of it in A's reply is in accordance with the facts. Here A's letter is a sufficient memorandum to charge him and such statements in B's letter as A did not contradict in his reply will be incorporated in the reply.34