delivered the opinion of this court.
This is an action of trover, to recover the value of certain goods alleged to be illegally held by the defendants.
The plaintiffs’ whole case rests upon the testimony of the two Messrs. Mason, who are the legal plaintiffs upon the record. These witnesses were objected to, and if their testimony is deemed inadmissible, the plaintiffs have no case in court.
As a general rule, the legal plaintiff on the record, is not a competent witness to prove any issue in the pending controversy. The legal plaintiff in all cases is, prima facie, liable for costs equally with the equitable plaintiff, which circumstance of itself is sufficient to beget such an interest in the controversy, as to disqualify him from giving evidence against the defendant. It is not to be denied, however, that a party under such circumstances may be so far divested of that interest, as to be made a competent witness, and the point in this case is, does the record disclose that the Masons have been so far discharged from their liability for costs, as to-qualify them to give evidence? We think not.
In the case of William Mason the elder, who was called-' on behalf of the plaintiffs, he was sworn, as the record says, (upon his evidente being objected to by the defendants,) upon his voir dire, at the instance of the party offering him as a witness. To the propriety of which the other party, the defendants, objected.
It has been insisted, that the first exception in its present form, does not properly present the question as to the correct*48ness of allowing this witness to be sworn-on his vóir diré, at the instance of the party calling him,. As the case will go' back upon procedendo, without deciding whether the exception raises the question or not, we will take the occasion to' say, that the right to swear a witness upon his voir dire, clearly belongs to the party objecting to his testimony, and’ hence it was error in this instance to permit the plaintiffs, who offered the witness, to do so.
The objection to William Mason, Jr., as a competent witness, was well taken and ought to have been sustained. In his case there was no effort to divest him of his interest in the suit, by reason of his being the legal plaintiff on the record, nor no attempt, (except the offering of the discharge undef the insolvent laws,} to show such an absence of interest as to authorise the witness to testify. We have no difficulty in reversing the court below upon this exception.
As it is possible that the plaintiffs may, upon another trial, qualify these' witnesses to give evidence, or may prove the same' facts by other competent witnessés, we will proceed to express our view's upon the case as presented by the record, as if the same had been disclosed by legal and competent proof.-
The case thus made, is this:- The defendants below purchased from the Messrs. Mason, a quantity of cotton duck, for cash, which was delivered without any demand for payment at the time, and without any express conditions. A few days afterwards, the defendants upon having payment demanded by the Masons, offered to pay them in part with their own notes, over-due, and the balance in money. This offer was several times' repeated', before the suit was brought, and' as often declined by the' Masons upon the ground of its not being a compliance'with the terms of the sale, which was a sale for cash. In addition, the witness stated, “that when’ he sells for cash, he delivers the article without the cash, if he considers the purchaser good for the money and honorable, that this is the custom, the usage; and that the right to’ the cash was’not waived by the delivery.”
*49We will proceed to express our views upon the case as íhus made in general terms, without referring in detail to the several prayers or exceptions in the order in which they are presented by the record.
Although the sale was for cash, yet if the delivery of the goods was made unconditionally and without fraud or mistake, the title to the goods thereby became vested in the vendees, notwithstanding the cash was not in fact paid, and of a consequence this action could not be maintained if the case rested here.
But it is said by the appellees, that the delivery cannot be regarded as unconditional, inasmuch as there was evidence that there existed among the merchants of the city of Baltimore an usage, “to deliver merchandise sold for cash, without receiving the cash simultaneously with the delivery, and without the vendors thereby waiving the right to the cash,” and that this usage must be regarded as having entered into, and formed part of this contract. For this principle the case of Powell & others, vs. Bradlee 9 Gill & Johns., 220, is relied on. in many particulars the two cases are strikingly alike, but in others they are wholly dissimilar, as we shall presently attempt to show. The theory of the law of usage rests upon the presumption, that in certain transactions the parties did not intend to expressly stipulate the whole of the contract by which they designed to be bound, but that they intended to contract with reference to the known u'sages upon the subject, and that those usages were to be regarded as part of the contract. And although evidence of usage is sometimes admissible to add to, or to explain the terms of an agreement, yet it will never be permitted to vary or contradict the clear and manifest signification of the terms which the contracting parties may think proper to employ to express their meaning'. Nor is evidence of usage admissible to oppose or alter a general principle or rule of law, and upon a fixed state of facts, to make the legal rights or liabilities of the parties other than they are by the common law. 2 Burr., 1216. 2 Johns., 327. 2 Wash. C. C. Rep., 24. 3 Watts, *50178. And in any case, a usage to be admissible, must be proved to be known to the parties, or be so general and well established that knowledge and adoption of it may be presumed; and it must be certain and uniform. Indeed it may be added that usages, in general, have fallen, in later years, much into disfavor with the courts, as they have been disliked and discountenanced in all times by the ablest of judges. In the case of Stoever vs. Whitman, 6 Binney, 416, C. J. Tilghman says, “Misc.able will be our condition if property is to depend, not on the contract of the parties, expounded by established principles of law, but on what is called the custom of particular places, so that we may have different laws in every town and village.” And also Judge Story remarks, in the case of Donnell vs. Insurance Co., 2 Sumner, 367, “I am among those judges who think usages among merchants should be very sparingly adopted as rules of law, by courts of justice, as they are often founded in mere mistake, and still more often in the want of enlarged and comprehensive views of the full bearing of principles.”
The evidence of usage in this case, was manifestly too vague and unmeaning, to warrant, upon any principles, the court to submit any proposition to the jury based upon it. It is difficult to conceive of a commercial transaction between any parties and relating to any subject matter, and wherever negotiated, that might not be as readily controlled by such a usage as the one now before us. In this particular, this case is wholly unlike the case of Powell vs. Bradlee, 9 G. & J., 220. There, one witness proved “that it was then, and now is, the general usage among flour dealers in the city of Baltimore,” &c.; and by another witness, “that in sales of flour for cash in thecity of Baltimore, it is the general and constant usage,” &c. Thus it will be seen, that this evidence confined the usage, first, to the article of flour, and to flour dealers ; secondly, it showed it to be general; thirdly, that it related to the city of Baltimore; and fourthly, that it was in existence at the time the contract and delivery were made. Upon this evidence the court said, very properly, that the question of usage was rightly left to the jury.
*51Another prayer of the plaintiffs presents the question of fraud, on the part of the defendants, in the purchase of the goods. This fraud is to be gathered, not from any direct proof upon that point, but is to be inferred from the circumstance alone of the defendants having tendered, after obtaining possession of the goods, payment for the same in the plaintiffs’ own over-due notes. Such an inference from such a fact, is wholly unwarrantable. On the contrary, we regard such a transaction, in the absence of direct and independent proof of fraud and circumvention, as legitimate and usual among merchants. Conceding that both the sale and delivery in this case were conditional upon payment in cash, that the alleged usage was clearly established, and that this transaction took place in reference to that usage, still we regard the offer of the defendants to pay for the goods in the plaintiffs’ own over-due paper, to be a virtual compliance with the condition, and for all practicable purposes was equivalent to a tender of payment in cash. A cash payment, in ordinary parlance is understood in contradistinction to a credit payment., and there is no more reason for supposing that the first is to be made in money, than that a deferred or credit payment is, when due. Each payment must be made in the same way. The only difference, as before remarked, is, that one must be made at the time of sale or delivery, the other when the credit has expired. What discharges the one will also discharge the other. Since the case of Clarke vs. Magruder, 2 Harr. & Johns., 77, was determined, it has been regarded as the settled law of this State, that a note drawn by the creditor may be set off, or pleaded in discount, by his debtor, although the latter may have obtained possession of the note, at a discount, and with the view of the set-off, after he became indebted to his creditor. Upon the same principle, we cannot see why, in this case, the possession of the plaintiffs’ notes by the defendants, should not, of itself, have constituted a just and legitimate ground for the purchase of the goods, with the view, in that way, of the liquidation of the notes, and without incurring the imputation of a fraudulent design *52in so doing. Indeed, if fraud is inferable at all from this transaction, as presented by the proof in the record, it should rather be imputed to the vendors, who while they were over anxious to make the defendants pay their debts, were yet unwilling to pay, or even recognise their own.
Judgment reversed and procedendo awarded.