The County Court erred in «arresting the judgment; the sum claimed by the writ and declaration was sufficiently large, and it was reduced by proving a debt due the defendant, which was set off. This is a different case from one where a payment is made in discharge of the debt itself, and that known to both. Jackson could have sued for his demand or set it off, as he pleased. The plaintiff could not sue for $400 before a justice, as he might not know the amount precisely of Jackson’s demand against him, so as to strike the balance and sue for it; his contract entitled him to sue in court. It was not reduced by payments made upon it, but by some independent contract, which might or * might not be set off. The defendant, electing to set it off, ought not to turn Ross round to recover the sum really due before a justice. Where a debt or demand exists, and the debtor makes payment upon that account, so as to reduce the sum really due to less than fifty dollars, the creditor ought then to bring his suit before a single justice of the peace.

We consider the mistake in the finding of the jury mere matter of form.