Irving, J.,
delivered the opinion of the Court.
This suit is an action of assumpsit, in which commissions for selling the house of the appellant are sought to be recovered by the appellees. There are three exceptions in the record, the first and second haviqg respect to the testimony offered, and acted on by the Court, and the third being to prayers granted and refused. By the recitals in the first bill of exceptions, it appears, that *166the plaintiffs are real estate brokers in Baltimore City, and that the appellant owned a house in the city which he sold to Mrs. Julia O. Fowler for $15,000, subject to a ground rent of $1020, redeemable at any time after one year at six per cent., which sale was made by the appellant in person to Mr. Fowler, who was acting for his wife. Mr. G*. W. Stump, one of the appellees, testified that Mr. Fowler told him he wanted to purchase a house, and asked him who paid commissions. He told Fowler that the seller did, and thereupon Mr. Fowler said “if that is the case see what you can get Blake’s house for.” Stump says, “I called at Blake’s office; told him I was a real estate man; asked him if I could sell his house; he said I could sell it, and his price was $40,000. ” After offering in evidence the letters to Blake containing the offers for the property, Mr. P. O. Dugan was produced as a witness, and testified that he was and had been for 23 years a real estate agent in the City of Baltimore, and was familiar with the customs and usages prevailing amongst real estate brokers in Baltimore City. The following question was then propounded: “If a broker is employed by* the vendor of real estate to find a purchaser for his property, and he does introduce to the vendor as a probable purchaser, a man who buys within a reasonable time, the broker is entitled to his commissions; the only qualification to this rule being the rule that where two or more brokers are employed to negotiate the same transaction, the broker who first succeeds is entitled to full commissions, and the others are not entitled to any.” To this question objection was interposed, which was overruled, and the witness answered, “that is correct sir, that is the rule!” The objection which was to the form of the question as stating a matter of law having been overruled, the first exception was taken. The question as first put was leading, and on objection to it as stating *167a proposition of law, it was recast as quoted, and was more obnoxious to objection than at first, and the objection was renewed. As at last propounded it was no question at all. It is a bare statement of the law as established by usage in the estimation of the questioning counsel, without any interrogation or mark of it, except the statement of counsel that he “wanted to propound this question.” Calling it a question he only states what he understands the usage to be, and the witness replies “that is correct sir, that is the rule.” It needs no argument to demonstrate that such a method of examination is not permissible. As it was claimed that usage made the law of this case, the objection was properly stated that the question stated a proposition of law. It was not the right way of eliciting from the witness whether any usage existed, and if so, what it was, and cannot be approved.
The second exception was to the refusal of the Court to allow a question put to witness Eowler on re-direct examination on the part of the appellant, “whether he was at any time during these transactions in a position to pay $82,000.” It was objected to on the ground that it was new matter, and not brought out on examination in chief, and of course not cross-examined about. The rule is undoubtedly a good one that a party producing a witness must exhaust him on examination in chief, and must on re-examination be confined to the matter brought out on cross-examination as to what was proven in chief. It is, of course, in the discretion of the Court to allow the introduction of something forgotten or omitted in the examination in chief, if to the Court the purposes of justice seem to demand it. There seems to have been no appeal to the Court for permission to ask it, and if there had been, and it had been granted or refused, there would have been no appeal from the exercise of the discretion. Strictly, the question was at that time inadmissible, and the Court ruled rightly.
*168The plaintiffs’ first prayer was specially excepted to on the part of the appellant. This fact does not appear in the hill of exception; but the objection is embodied in the record as having been duly filed; and by agreement filed in this Court, it is provided, that the Court may consider that objection as if embodied regularly in the exception. The special exception is to the effect that there is no evidence of a custom such as is set out in the prayer; and that there was no evidence that thea appellee was employed to sell generally, the contention being that the evidence established that he was to sell at a fixed price, viz., $40,000. The special language of the prayer excepted to is this, “if they shall find that according to the custom of brokers in said Baltimore City, the service undertaken by a broker so employed is simply to introduce to the seller a party who afterwards, within a reasonable time, actually purchases the property at a price acceptable to the seller,” &c. The use of the word “simply” in the connection indicated in this quotation from the prayer, it is claimed is misleading by omitting another essential element to entitle to compensation, viz., that such introduction must have been the procuring cause of the sale. It is the undoubted law, that the introduction must be the foundation of the negotiations and procuring cause of the sale. If it is such foundation and procuring cause, then the broker is entitled to commissions, notwithstanding the sale may have been finally effected by direct treaty of the parties without the broker’s intervention. Jones vs. Adler, 34 Md., 440; Schwartze vs. Yearly, 31 Md., 270; Keener vs. Harrod and Brooke, 2 Md., 71; Attrill vs. Patterson, 58 Md., 251. Eollowed up as it was by the second prayer of the plaintiffs, and the first, sixth and seventh of the defendant, all of which told the jury they must find the introduction was the procuring cause of the sale, we cannot see how the jury could have been misled by the putting of *169the first prayer of the plaintiffs. The word “simply” was unnecessary, but qualified and explained as it was by those other instructions we have mentioned, we do not think that was sufficient entirely to condemn the instruction. It was objected specially that there was no evidence to sustain this prayer as to the usage set up, but that cannot be sustained, for several witnesses testified to it. It is true they did not use the word “simply” which is used in the prayer, but in such language as would justify the jury if they found a usage at all, to find one such as is mentioned in the prayer. It was also contended that there was no evidence of employment such as recited in the prayer, the appellant insisting that if there was any employment it was not general, but special to sell at a specified price. We do not think this objection well taken. The appellant denies in his testimony that he employed the plaintiffs at all; but one of the plaintiffs states what took place between him and the appellant in respect to the matter. It was for the jury to say. whether the plaintiffs were employed and how employed. The statement of what took place as made by Gr. W. Stump is perhaps a little ambiguous, and under such circumstances it was right that the jury should say from the colloquium what the parties intended. As the jury might find that the price named was only a statement of what was desired for the property if it could be obtained, and not a statement that no less would be taken, and therefore not a restricted employment, it was entirely competent for the plaintiffs to put it to the jury to find according to their theory; and if the defendant desired the jury to pass on that question, he ought to have put his theory in the form of an instruction, which he did not do. The jury might find and properly so that there was a general employment; whereas it might be that they would think that the agent was restricted as to price. If the latter, then, of course, according to *170the authorities the agent would not get commissions unless he obtained the specified price, or that was waived. Jones vs. Adler, 34 Md., 440; Mechem on Agency, secs. 965 and 966, and note. This prayer, however, is based on the theory of a usage, which usage, to be available as against the appellant, must be so notorious as to affect appellant with knowledge of it, and raise the presumption that he- dealt with reference to it. Murray, et al. vs. Spencer, 24 Md., 520; Patterson vs. Crowther and Boone, 70 Md., 128. If it was not thus notorious, actual knowledge must be proven to bind a party. There seems to have been no proof of general notoriety, and the only ground set out in the prayer for the assumption it makes, that he knew of it, is that the appellant “was a builder largely engaged in buying and selling real estate, and at times through the agency of real estate brokers. ’ ’ Because of this fact knowledge is imputed without calling on the jury to find that he did have knowledge of the custom, and dealt with plaintiffs with such knowledge. “At times ” the prayer recites he had dealt with and through real estate brokers. “At times"’ is indefinite. It may have been many or few times. Non constat that those times he may not have had a special contract respecting commissions. One of the witnesses for the plaintiffs, Mr. Rogers, said he always bargains about commissions. We think this prayer ought not to have assumed knowledge of the custom from the recited facts, but o .1 ght to have put that to the jury to find on the proofs if they could. No objection was taken to this prayer for such assumption, and as a granted prayer a reversal would not be ordered for that defect, but, as the case must go back for other error, we thought it right to point out this defect.
The rejection of the fifth prayer of the appellant was, in our view, erroneous. The rule of the Real Estate Exchange, according to the tenth section of Article *171seven of its Constitution, is proven to be that “commission shall be chargeable on tbe entire principal or value of the property,” if any “part of the purchase money remains on mortgage or redeemable ground rent;” and some witnesses testified that it was the custom to calculate commissions on the basis of a fee value if mortgage rested on the property, or a lease was taken. It is very certain that the rules of the Brokers' Exchange cannot be allowed to control. Taliaferro vs. First National Bank of Baltimore, 71 Md., 218. It is a question of public and notorious usage, and whether such usage was reasonable and proper. If there was evidence that the appellant contracted to pay according to that rule, he would be bound by that contract. But there is no pretence there was. an express contract on the subject. To bind the defendant to any such rule it must appear to have been of such public notoriety that he must be presumed to have knowledge of it, and therefore dealt expecting to be bound by it. A usage cannot be sustained which violates any well-known rule of law, Raisin vs. Clark, 41 Md., 168; neither can it be sustained if it is unreasonable in its character. Mechem on Agency, page 182. In Livezy vs. Miller, 61 Md., 338, commissions on the actual money value exclusive of the mortgage, were allowed by this Court, and no more. In respect to the rate of compensation for such service, it is said in Mechem on Agency, section 963, that in the absence of agreement, a prevailing usage will control; but in note 1 to same section, on page 792, “to establish such custom, it must be reasonable, certain, uniform, continued, and, moreover, generally understood and acquiesced in by persons engaged in buying and selling. * * * A usage which is to govern a question of right should be so certain, uniform and notorious as probably to be known to, - and understood by, the parties as entering into their contract.” This is cited as the language of Judge Paxon *172in United States vs. Duval, Gilpin, 356; Potts vs. Aechternacht, 93 Penn. St., 138. This statement of the law is certainly just and right. The appellant did not sell his whole property. He only effected a sale of the leasehold. He got only fifteen thousand dollars for the house resting on the ground which he leased, instead of sold. To get the means he wanted, he would have to get some other agent to sell the ground rent, and it is not reasonable to allow the agent pay for more than the fifteen thousand dollars worth actually sold, unless it clearly appeared that the seller contracted so to pay either expressly or by implication. What the agent undertook to do was not accomplished. He did not, therefore; earn his commissions on the value of the whole property. We have already adverted to the only evidence respecting appellant’s dealings, of which evidence was given in commenting on the first prayer of the plaintiffs. The principle asserted by the eighth prayer of the defendant is that a broker cannot act for both seller and purchaser without the full knowledge and consent of each, because their interests are in conflict. That is undeniably the law, and has been maintained by this Court most positively in Schwartze vs. Yearly, 31 Md., 271, and Raisin vs. Clark, 41 Md., 159. But objection is made to its application in this case, first, because it is contended there is no evidence to support the prayer, and secondly, because the prayer is composed of three propositions, distinct in themselves, and which are put to the jury disjunctively, and it is, therefore, calculated to mislead the jury.
We are clearly of opinion that there was some evidence in support of the contention that Stump was acting for both Blake and Fowler, without the knowledge of Blake. Stump testifies himself to having been requested by Fowler to see what he could buy Blake’s house for; and that in pursuance of that request he approached Blake, told him he was a real estate man, and asked if *173he could sell his house for him; that he was told that he might, and that his price was $40,000. Instead of seeking to get from Fowler Blake's price, he told Fowler that he thought thirty thousand dollars would buy the house, and which offer was made in writing to Blake. This he says in his letter to Fowler of 26th January, 1889. He also said on cross-examination, in his testimony, that he “ did his best to get the house, including lot in rear on Biddle street, for Mr. Fowler at $30,000.” This lot in the rear he says was not part of the lot which Blake authorized him to sell, and asked $40,000 for. It is also in evidence that Fowler so far regarded Stump as acting in his interest, that after he had purchased from Blake he offered Stump o-ne hundred and fifty dollars compensation, which it is true was not received. It is very clear all this was some evidence tending to support the hypothesis of the prayer.
In Schwartze vs. Yearly, 31 Md., 271, a prayer almost exactly like this one was under consideration. Indeed, that prayer seems to have been copied, with the addition of but one phrase. In that case there was a question about the revocation of the agency, and the appointment of another agent, and this Court thought the prayer too broad because it did not restrict the bad faith, supposed to exist, to the period within which the plaintiff was in the employment of the defendant. In the present case there is no contention that any one else was appointed agent of appellant in the place of the Messrs. Stump, the plaintiffs, and the objection which was taken by the Court to the prayer in Schwartze’s Case is sought to be corrected in this prayer by the introduction of a phrase restricting the bad faith to the period whilst the appellees were acting as agents for the appellant. This prayer reads as follows : “ That although the jury shall believe from the evidence that the plaintiffs were employed by the defendant to effect the sale *174in question, if the jury shall also believe that prior to the commencement of negotiations, the purchaser introduced hy the plaintiffs, and who bought the property, had himself employed the plaintiffs to procure the property described in the evidence, and that the plaintiffs, in pursuance of this employment, commenced to treat with the defendant for the purchase of the property; or if the jury shall believe that at any time whilst the plaintiffs were in the employ of the defendant the said plaintiffs were in respect to this purchase and sale in any way in the employ or acting as agent of the purchaser (beyond the power or authority to hind them to a sale hy a memorandum), or that the plaintiffs were acting in the interest of the said purchaser, then the plaintiffs are not entitled to recover.” An objection has been urged to this prayer that it presented three distinct propositions disjunctively coupled, and was thus made misleading. We do not think the prayer, when carefully examined, is liable to the criticism suggested, or was calculated to mislead the jury. What seems to he three propositions is hut a presentation of the same idea in different phraseology. The first paragraph of the prayer or “proposition,” as it is denominated hy appellees, only asserts that if the plaintiffs' were employed in and about the sale of the property hy both buyer and seller, and before he was employed hy the seller, he was employed hy the purchaser, -and that in pursuance of the employment hy the latter he conducted the negotiations with Blake, then they cannot recover. The second branch of the prayer only asserts the same thing in substance, without indicating any particular facts hearing on the subject, hy saying if they found he was, at the time while he was acting for the appellant, also acting for the appellees; and then hy the third so-called proposition adds in further explanation of the language just used “or was acting in the interest” of the ap*175pellees, then they cannot recover. The latter clause is to he read as following the words c (whilst the plaintiffs were acting in the employ of the defendant,” taking the place of all that do follow it in regular sequence up to the word “or.” The last phrase is merely explanatory of what kind of action the appellees were taking under the employment of Mr. Fowler. The prayer in the three forms of expression asserts nothing more than that if the plaintiffs were not in good faith acting wholly in th'e interest of Blake, then they are not entitled to recover from Blake, and we do not see how it was possible for the jury to be misled in any way by it. It asserts sound doctrine, well recognized in this State and everywhere, we think, and ought to have been granted.
(Decided 14th November, 1890.)
The judgment must he reversed, and a new trial will he ordered.
Judgment reversed, and new trial ordered.