¶1— To entitle the plaintiff to recover by the instructions given, the jury would be obliged to find, that an account due from plaintiff to defendant had been paid before the plaintiff gave to the defendant a negotiable note on account of it. If they so found, the plaintiff would, by the instructions, be entitled to recover, although he had discov*422ered tbe error and tbe means of proving it, before he paid the note, then over due and in possession of the defendant.
¶2The law is regarded as settled in this State, if one with a full knowledge of all the facts, or with the means of knowledge, voluntarily pays money under a claim of right, that he cannot recover it back. By the law, as administered in England and in many of the United States, the money paid by the plaintiff could not, under any aspect, under which the case could be viewed, be recovered back. But by the law, as administered in this and some other of the States, the negotiable note operated as payment of the account in full or in part; and if that account was thereby paid a second ■ time, under a mistake and without a knowledge, that it had been previously paid, a right of action immediately accrued to the plaintiff, to recover back the amount so paid a second time. This right of action would not be destroyed by a voluntary payment of the note, after a knowledge of the double payment had been obtained. This is, what distinguishes the cases of Dole v. Hayden, 1 Greenl. 152, and of Whitcomb v. Williams, 4 Pick. 228, from the cases cited by defendant’s counsel.
¶3When the note was paid, it appears to have been paid with a full knowledge of all the facts, and the money paid for that purpose cannot be recovered back. The defendant’s promise to deliver it up, if the receipt was found, only constituted an additional ground of defence. It is only by adhering strictly to the distinction between a payment made on the account, by giving the note, and a payment made months afterward, to pay the note, that the action can be maintained. The plaintiff cannot be permitted for one purpose to allege those two payments to be in substance the same, and for another purpose to allege them to be substantially different. The amount to be recovered back might be substantially different by the interest, that might have accrued upon the note.
¶4The first requested instruction should therefore have been given. More especially when it appears, that the declara*423tion contained the money counts dnly; and tjiat a bill of particulars was filed, claiming only to recover back the money paid to pay the note.
¶5Such specification is not required to be exact in form. It must truly state the ground of claim, the gist of the action. It limits the proof, and restricts the right of recovery to that claim. Parker v. Emery, 28 Maine, 492; Babcock v. Thompson, 3 Pick. 446; Smith v. Kirby, 10 Met. 150; Brown v. Williams, 4 Wend. 360; Starkweather v. Kittle, 17 Wend. 20.
¶6According to the terms of the report, the verdict must be set aside. Verdict set aside and new trial granted.