The plaintiff does not contend that Swan was expressly authorized by Pomroy to put his signature to the note in suit. As a general rule, a special agent, or one who is employed to make purchases for his principal, has no authority, unless it is directly conferred, to bind him by a negotiable note or bill of exchange. But such a power is a necessary implication from his employment, whenever its exercise is indispensable to the discharge of the duties to be performed. Paige v. Stone, 10 Met. 168. Taber v. Cannon, 8 Met. 458, 459. To the general instructions, therefore, of the presiding judge, that if the giving of notes in the name of his principal was necessarily incident to the management of the business which he was to conduct for Pomroy, his agency would imply an authority for that purpose, there appears to be no valid ground of objection. But in reference to particular questions which arose in the progress of the trial, and to which the attention of the court was requested by the defendant, the rulings and instructions given to the jury are not equally satisfactory.

1. Evidence was adduced by the plaintiff, tending to show, and which may now be considered as sufficient to prove, that on some other occasion a note similar to the one in suit, and signed in the same manner, had been made by Swan, in the course of his dealing in the business of Pomroy, payable to a person of the name of Hall, which was afterwards paid by Pomroy, though under protest, and not until he had received from Swan what he considered satisfactory security to indemnify him for doing so. His counsel contended, in substance, that the payment to Hall, under such circumstances, implied no authority in Swan to make other notes, or the note in suit, in his name ; and that, in short, it proved nothing more than that he might in this instance have misunderstood or was willing to waive his rights. But the court declined to rule to this effect, as matter of law, and instructed the jury that they were to determine how far this evidence tended to prove the authority of Swan, as the agent of • Pomroy, to put his signature to the note in suit. This instruc*131tian cannot be sustained. It imported that it was competent for the jury to infer from this evidence the lawful authority of the agent to bind his principal, in another instance and upon another occasion, by a promissory note. This was erroneous, because such an authority is never to be assumed or inferred, unless it results as a necessary implication from the facts established. And surely the transactions concerning the note to Hall afford no ground for such an implication. It does not appear that Pomroy had any knowledge of its existence until the time of its maturity. He paid it then under protest; that is, as we understand it, denying the authority of Swan to make it, and his own liability to be bound by it. And he fortified this denial by persisting in his refusal to pay until he received from Swan security for the reimbursement of the money he should advance for that purpose. All this evidence concerning the note to Hall may have been inadvertently admitted upon the trial, but since it was received, the jury should have been guarded, as the defendants’ counsel desired that they should be, from giving it an effect to which it was not legally entitled.

2. The counsel for Pomroy further requested the court to instruct the jury that no implication of authority to sign the note in suit arose from the fact that Swan was an agent to carry on the business, as shown by the evidence, and that such authority could not be implied from the nature of the business. ' The evidence referred to in this request is so imperfectly detailed and exhibited in the bill of exceptions that it is very difficult, and perhaps impossible, to appreciate exactly the question proposed to the court, or the ruling which was made upon it. Nor is this necessary, since it is apparent that the instructions given to the jury in relation to it were not accompanied by the necessary qualifications and restrictions. It was left to them, in indefinite terms, to find, upon all the evidence in the case, whether Swan was authorized to sign his name to the note in suit without naming his agency. The question of fact, which was in issue in relation to that authority, it was undoubtedly their duty to determine; and so far they were rightly advised by the court. But under the special requests submitted by the counsel for the *132defendant, they should also have been advised that, though an agent employed to make purchases for his principal -may undoubtedly bind him by a contract of sale, he cannot ordinarily, without express authority, bind him by a negotiable promissory note; and that the single exception to this positive rule is in relation to agencies, the objects and purposes of which cannai be accomplished without the exercise of such a power. If the instructions which were given in reply to this request of the defendant had been connected with or limited by those which were given apparently at a later stage in the" trial or charge, though the occasion which induced the later explanation, or the precise evidence to which it was applied, is not developed in the bill of exceptions, they might have been held to be sufficient. But without such limitations they cannot be considered as having been sufficiently guarded to secure to each of the parties the legal rights to which they were respectively entitled.

Exceptions sustained.