721. Effect of rests after satisfaction of mortgage debt.

After the mortgage debt is satisfied, the effect of the rests is to make interest payable by the mortgagee. For each period in which there is an excess of receipts over expenses, there is a balance owing from the mortgagee to the mortgagor; and these balances carry compound interest1, that is, the interest due for any period is added to the balance due at the end of the period, and the interest for the ensuing period is reckoned on the aggregate sum. As long as there is principal due, the rests may be made either from time to time,