In an action by a creditor against his debtor for the non-payment of the debt, the ordinary measure of damages for non-performance of the contract is the sum of money itself with interest at the legal rate from the time it was due. Tradition has it that the relation between bank and depositor is that of debtor and creditor. Clearly, it is a contractual relationship. The contract, however, is not merely to pay the creditor but also to pay, on his behalf, such third persons as he may designate. It is not an adequate description to say, merely, that the relationship is that of debtor and creditor. What are the consequences of a breach of this extraordinary contract? What is the nature and extent of the liability of the bank to the depositor for the wrongful dishonor of the checks of the depositor?