Where a person indebted on account, to two partners, executes a mortgage to one of them, to be transferred to the other partner at a usurious rate of interest, to raise money to pay the debt, and it is -so transferred, and the *119proceeds, to an amount exceeding the amount of the debt, received by the firm" and credited to the debtor in his account, the debt due the firm is thereby cancelled. No recovery can be had on the account, although the mortgagor successfully defended a suit in equity to foreclose the mortgage by setting up and maintaining the defence of usury.