(e) See Wallis v. Littell, 31 L. J. (C. P.) 100.

(f) See Free v. Hawkins, 8 Taunt. (4 E. C. L. E.) 92. For other examples of the application of the same principle in the case of Bills of Exchange and Promissory Notes, see also Hoare v. Graham, 3 Camp. 57; Hogg v. Snaith, 1 Taunt. 347; Moseley v. Hanford, 10 B. & C. (21 E. C. L. R.) 729; Foster v. Jolly, 1 C. M. & R. 703; Adams v. Wordley, 1 M. & W. 374; Brown v. Lang-ley, 4 M. & G. (43 E. C. L. R.) 466; Besant v. Cross, 20 L. J. (C. P.) 173; 10 C. B. (70 E. C. L. R.) 895; Abrey v. Crux, L. R. 5 C. P. 37; 39 L. J. (C. P.) 9

(g) Greaves v. Ashlin, 3 Camp. 426.

1 These rules of course apply exclusively to written and not parol contracts. An illustration of this occurred in the case of an auctioneer, who, at the time of a sale, verbally declared a variation from the printed catalogue; namely, that goods stated therein to be silver were only plated, and so sold them; the actual contract being a parol one, evidence of the parol statement was held admissible to explain it: Eden v. Blake, 13 M. & W. 614; but if the auctioneer had signed an agreement which referred to or formed part of the unaltered catalogue, then his parol declaration of the alteration could not be given in evidence, as it would vary a written contract: Shelton v. Livius, 2 C. & J. 411.-s.

(h) Ford v. Yates, 2 M. & G. 549. See per Parke, B., 2 Ex. 99. (i) Harnor v. Groves, 24 L. J. (C. P.) 53; 15 C. B. (80 E. C. L. E.) 667; Hotson v. Browne, 30 L. J. (C. P.) 106.

(j) Giraud v. Richmond, 15 L. J. (C. P.) 180; 2 C. B. (52 E. C. L. E.) 835, s. c

1 A vast number of authorities upon this much discussed rule of evidence

But though you cannot be allowed to show that the meaning of a written contract was varied at the time of will be found in the digests and elementary treatises, among which may be particularly noticed the notes of Messrs. Cowen and Hill, to the American edition of Phillips on Evidence, and the fifteenth chapter of Professor Green-leafs treatise on that subject. A few only of the instances of the application or non-application of the rule can be noticed here. It has been enforced in the exclusion of evidence to show that a signature in one's own name was intended to be merely as agent: Stackpole v. Arnold, 11 Mass. 27; Hancock v. Fairfield, 30 Me. 299; that a written agreement to deliver wheat to A. was modified by a parol direction to deliver it to B.: Wolfe v. Myers, 3 Sand. 7; Babcock v. May, 4 Hamm. 334; that a written agreement for the purchase of land, whereby the purchaser was not to cut timber, was varied by a parol license to cut it: Pierrepont v. Barnard, 5 Barb. 364; that a check purporting to be for so much money was designed to be payable in the notes of a certain bank: Pack v. Thomas, 13 Sm. & M. 11; or on a contingency: Moseley v. Hanford, 10 B. & C. (21 E. C. L. E.) 729; Cunningham v. Wardell, 3 Fair. 466; Erwin v. Saunders, 1 Cow. 249; that a particular ship was verbally excepted from a policy of insurance on the fleet to which she belonged: Weston ». Ernes, 1 Taunt. 115; that goods to be stowed under deck were verbally allowed to bestowed on deck : Creery v. Holly, 14 Wend. 26 (it would have been different had the evidence been to prove a custom of storage in that manner: Baxter v. Leland, 1 Blatch. 526; see infra, note to page *56). The rule, however, does not exclude the testimony of experts to aid in the reading of the instrument, or to explain a local or technical meaning: Wig-ram on Wills, 48; Sheldon v. Benham, 4 Hill, 129; Smith v. Wilson, 3 B. & Ad. (23 E. C L. R.) 728; Clayton v. Gregson, 5 Ad. & El. (31 E. C. L. R.) 302; The King v Mashiter, 6 lb. (33 E. C. L.R.) 153; Peisch v. Dickson, 1 Mason, 11; unless, indeed, the words have a known legal meaning: Frith v. Barker, 2 Johns. 335. Nor does it exclude the admission of the contemporaneous writings relating to the subject-matter: Bowerbank v. Monteiro, 4 Taunt. 846; Hunt v. Livermore, 5 Pick. 395; Bell v. Bruen, 1 How. 169; Thomas v. Austin, 4 Barb. 265; nor evidence to show the circumstances surrounding the parties at the time : Haigh v. Brooks, 10 Ad. & Ell. (37 E. C. L. R.) 309; Goldshede v. Swan, 1 Exch. 154; Bainbridge v. Wade, 16 Q. B. (71 E. C. L. R.) 98; Smith v. Bell, 6 Pet. 75; Wooster v. Butler, 13 Conn. 309; Knight v. New England Worsted Co., 2 Cush. 271-283; Lowry v. Adams, 22 Vt. 160; for all this, it is said, tends to explain, and not to contradict the writing. And it is obvious that evidence is admissible to show that the writing never was of any validity, as by reason of fraud, illegality, duress, incapacity of parties, etc, for those grounds, as has been shown in the preceding chapter, vitiate the contract ab initio, and to exclude evidence of this, would be to promote and not to repress injustice.

But upon the ground that parol evidence is admissible to explain in cases of fraud, the courts of Pennsylvania have gone very far, and have in effect taken the position that when the written contract has been entered into with the understanding that it is to be used in a particular way, or with a particulai making it, by words merely spoken, there are some cases in which you may show that it was subsequently so qualification, it is a fraud to violate this understanding. And hence many cases have sanctioned the admission of evidence to show what was the understanding at the time the contract was made. "If the rule is," it was said, in Bollinger v. Eckert, 16 S. & R. 424, "that parol evidence is admissible to correct mistake or fraud, and if the real contract of the parties is not expressed in the writing, this must arise from mistake or fraud. We seem now to have settled down in this; whatever material to the contract was expressed and agreed to when the bargain was concluded and the article drawing, may, if not expressed in the article, be proved by parol." " Ever since the case of Hurst v. Kirkbride, cited in 1 Binn. 616," it was said in Oliver v. Oliver, 4 Rawle, 141, "it has been the practice to receive parol evidence of what passed at the time of the execution of deeds, or at and before the execution. When the fairness of the transaction is impeached, it is immaterial whether the party intended a fraud at the time of the contract, or whether the fraud consists in the fraudulent use of the instrument: Hultz v. Wright, 16 S. & R. 345; Lyon v. Huntington Bank, 14 lb. 283; Thompson v. White, 1 Dall. 424, are of this description;" and many other cases have, while regretting the extent of the innovation, followed it: Partridge v. Clarke, 4 Pa. St. 166; Renshaw v. Gans, 7 lb. 119; Rearick v. Swinehart, 11 lb. 238. But in a somewhat later case on the subject, Rearick's Executors v. Rearick, 15 lb. 66, the Court evinced the strongest disposition to sanction the admission only of contemporaneous evidence, and to apply the strict rule in the exclusion of parol statements occurring previously to the transaction. " In the somewhat unsteady course of decision upon this vexed point of evidence," said Bell, J., who delivered the opinion of the Court, " if any principle has been adhered to with tenacity, it is, that oral proof to vary or affect a written instrument must be confined to what occurred at the execution of it: Bollinger v. Eckert, 16 S. & R. 424; Stine v. Sherk, 1 W. & S. 195. Even thus restricted, it is acknowledged to be full of danger. Were the door opened still wider for the admission of all the loose dicta of the parties, running, it might be, as in this instance, through a long course of years, the flood of evil would become so great as to sweep before it every barrier of confidence and safety, which human forethought, springing from experience, is so sedulous to raise against the treachery of memory and the falsehood of men. To avoid, therefore, what would really be a social calamity, it is recognized as a settled maxim, that oral evidence of an agreement or understanding between parties to a deed or other written instrument, entertained before its execution, shall not be heard to vary or materially affect it: Cozens v. Stevenson, 5 S. & R. 421; Gilpins v. Consequa, 1 Pet. C. C. 85; s. c. 3 Wash. C. C. 184; M'Kennan v. Henderson, 1 P. & W. 417. Accordingly, the settled rule is, that when a contract has been reduced to writing, it is understood as expressing the final conclusions of the contracting parties, and fully accepted as merging all prior negotiations and understandings, whether agreeing or inconsistent with it: Lighty v. Shorb, 3 P. & W. 450; Monongahela Nav. Co. v. Fen Ion, 4 W. & S. 207, 209. If any dicta or even decisions in hostility to this axiom are to be found, they must be ascribed to varied. These are cases in which the contract, although written, is of a description which is not required by law the strong desire we are all apt to be swayed by, to defeat some strongly suspected fraud in the particular case. But these occasional aberrations but lead to the more emphatic reannunciation of a principle found to be essential to the maintenance of that certainty in human dealings, without which commerce must degenerate into chicanery, and trade become but another name for trick."