(After Stating the Facts as Above.)— The particular question presented for- decision upon this appeal is whether the trial court departed from the well-settled rule that recovery must be had in accordance with the claim made in the complaint, in rendering judgment in behalf of the company for $40,577.69, lawful money of the United States.
It is a primary and fundamental rule in the Code system of pleading* as well as at common law, that the judgment shall be “secundum, allegata et probata.” 9 Cyc. 748. “Any . . . departure from this rule is sure to produce surprise, confusion, and injustice. ” Day v. Town of New Lots, 107 N. Y. 148, 13 N. E. 915. A litigant cannot proceed upon one cause of action in his complaint and recover upon another distinct cause of action. This would be to ensnare his adversary. Southwick v. Bank, 84 N. Y. 420. The complaint in the case sets up a claim for $150,287.75, Mexican -silver dollars, with interest, or its equivalent in lawful money of the United States. It is clearly *83and distinctly alleged that the company hy virtue of a contract evidenced hy certain telegrams and letters, purchased from the bank $150,287.75, in Mexican silver dollars, for the price of $40,577.69, lawful money of the United States, and that the bank on demand had refused to deliver the Mexican silver dollars.
The answer of the bank concedes that it entered into a contract with the company for the sale of Mexican money, but claims that the bank by the contract sold to .the company Mexican bank bills. At the time the parties entered into the alleged contract Mexican bank bills were quoted around 27 cents gold for each paper dollar, and Mexican silver dollars were quoted around 44 cents gold.
Here a distinct and narrow issue was made up by the pleadings, to wit, a claim based upon a contract of purchase and sale of $150,287.75, Mexican silver dollars, a denial that the contract was for the purchase of Mexican silver dollars, coupled with an averment that the contract was for the purchase and sale of Mexican. bank bills. The bank had the right to expect that upon the trial such issue, and that only, would be tried. The bank was under no obligation to prepare to meet the other and distinct issue that the company had on deposit with it the sum of $40,577.69, lawful money of the United States, which upon demand the bank had refused to pay to the company, and yet upon this distinct and separate issue the court gave judgment in favor of the company and against the bank for said sum of $40,577.69, upon the theory that the minds of the parties never met, and that there was no contract of sale and purchase between the parties. The company, having based its claim and tried the case upon an alleged express contract, was bound thereby, and it was not entitled to recover upon any other theory. Sanders v. Hartge, 17 Ind. App. 243, 46 N. E. 604; Union St. Ry. Co. v. First Nat. Bank of Union, 42 Or. 606, 72 Pac. 586, *8473 Pac. 341; Ingram-Dekle Lumber Co. v. Geiger, 71 Fla. 390, Ann. Cas. 1918A, 971, 71 South. 552. The respective rights of the parties depended upon the terms of the contract, if one existed, and if no contract existed the company was not entitled to any relief in the particular suit. The judgment, therefore, was a clear departure from the pleadings.
Obviously, the trial court placed the wrong construction upon the complaint when it concluded that the action was one to recover $40,577.69,- which the company had on deposit with the bank. True, it is alleged in the complaint that the company had that amount on deposit with the bank prior to the making of the contract; but clearly that is an allegation of matter of inducement only, and in no manner changes or alters the well-defined issue made up by the pleadings. This allegation, and other secondary or subsidiary allegations appearing in the complaint, cannot be treated as stating a cause of action by a depositor against a bank for the recovery of a deposit, when the complaint, as a whole, proceeds upon the definite, clear, and certain theory that the action is one based upon a contract of purchase and sale. “In construing a declaration to determine upon what theory it is drawn, all the averments will be considered, and neither the formal parts, nor isolated averments of fact, will be deemed controlling as against the case substantially made by the general character of the facts alleged.” 31 C'yc. 84. We are not disposed to charge the complaint with the vice of having a double aspect; but, if we did, still we would be required to construe the complaint as stating the cause of action principally intended. ‘‘Where a complaint contains words which, if properly arranged, might state two causes of action, it will be construed as stating only the one principally intended.” Santa Fe etc. Ry. Co. v. Hurley, 4 Ariz. 258, 36 Pac. 216. The issue joined between the parties was on an alleged express eon-*85tract. The complaint presents squarely an action at law. No equitable rights are claimed, and no equitable remedy is invoked. No demand was made by either party for a reformation of the contract sued on, nor was the contract disaffirmed by either party. We do not see how the court could disregard the alleged contract and enter a judgment against the bank on the theory that the relation of banker and depositor existed, without departing widely from the pleadings. 31 Cyc. 673.
In the cross-appeal taken by the company, complaint is made of several rulings of the trial court adverse to the company’s contentions. The final disposition of the case renders it unnecessary really to discuss these contentions, but since that upon a new trial one of these questions will probably arise again, we have concluded to dispose of the assignment upon that question. The assignment referred to is that the court erred in admitting parol evidence of custom and usage to explain the meaning of the language used in the telegrams and letters that passed between the parties. Spanish was the language used in the original telegrams and letters. The translations of these letters and telegrams as they appear in the record were admitted by the parties to be correct. In these telegrams and letters such words and phrases as “moneda Mexicana,” “plata,” “Mex.,” “peso,” “pesos plata,” and “billettes de banco” appear. We understand the objection to the evidence explaining the meanings of these words and phráses is based upon the contention that the language used in the communications was clear and plain, and hence that resort could not be had to parol testimony to place a construction upon the terms; that the words and phrases had plain, ordinary, and popular meaning, and should have been construed by the court without the aid of parol testimony.
*86The general rule unquestionably is that parol evidence is inadmissible to explain, vary, alter, or add to the terms of a written contract in an action at law. This rule, however, is very flexible, and has many exceptions, and in the multitude of exceptions much confusion has arisen. The authorities upon the subject are in hopeless conflict. We are, however, of the opinion that the facts of the instant case present one of the well-defined exceptions 'to the general rule.
Parol testimony of a custom or usage, tending to establish the sense in which certain words or mercantile terms are used in a contract, and elucidating the terms used, is admissible for the purpose of ascertaining the intention of the parties. This is on the theory that parties who contract on a subject, concerning which known usages prevail, by implication, incorporate them into their agreements, if nothing is said to the contrary. Robinson v. United States, 13 Wall. 363, 20 L. Ed. 653 (see also, Rose’s U. S. Notes). See also, Collender v. Dinsmore, 55 N. Y. 200, 14 Am. Rep. 224; Walls v. Bailey, 49 N. Y. 470, 10 Am. Rep. 407.
A reference to the record will disclose that the evidence offered by the bank and admitted by the trial court, as to custom and usage, consisted, of the testimony of men who were and had been for many years in the banking business and money brokerage circles on the border and in Mexico. As we have intimated, we think the evidence was properly received. It did not tend to contradict of vary the contract, but to define and elucidate technical mercantile terms employed therein. The proofs tended to show that the terms “Mex.,” “moneda Mexicana,” “peso,” “plata,” “pesos plata,” and “billettes de banco,” as used in the alleged contract, are not to be understood in the strict sense as meaning Mexican coin silver dollars, but that such terms, by custom and usage *87along the border and in Mexico, should be construed to mean Mexican bank bills.
The judgment rendered was ” outside the issues joined, and therefore a new trial must be had. It follows that the judgment must be, and it is, hereby reversed, and the cause remanded to the trial court, with directions to grant a new trial to the bank, and take such further proceedings as may be proper and not- inconsistent with this opinion.
CUNNINGHAM, C. J., and ROSS, J., concur.