The judgment of the court below is affirmed on the following grounds: (1) A creditor who receives from his debtor a certificate in writing, not negotiable, of the amount of his debt, and sells the certificate to a third person for value less than its nominal amount, thereby authorizes the purchaser to receive the amount from the debtor, and cannot, after the debtor has paid it to the purchaser, maintain any action against the debtor. (2) A creditor who receives from his debtor a negotiable instrument of the debtor for the amount of his debt, and sells it for its market value to a third person, cannot sue the debtor on the original debt.