Gradually the goldsmiths began to lend the money out on behalf of the depositor, which led to the development of modern banking practices; promissory notes (which evolved into banknotes) were issued for money deposited as a loan to the goldsmith.In most common law jurisdictions there is a Bills of Exchange Act that codifies the law in relation to negotiable instruments, including cheques, and this Act contains a statutory definition of the term banker: banker includes a body of persons, whether incorporated or not, who carry on the business of banking’ (Section 2, Interpretation). Although this definition seems circular, it is actually functional, because it ensures that the legal basis for bank transactions such as cheques does not depend on how the bank is structured or regulated. The goldsmith paid interest on these deposits. Since the promissory notes were payable on demand, and the advances (loans) to the goldsmith’s customers were repayable over a longer time period, this was an early form of fractional reserve banking. The promissory notes developed into an assignable instrument which could circulate as a safe and convenient form of money backed by the goldsmith’s promise to pay, allowing goldsmiths to advance loans with little risk of default. Thus, the goldsmiths of London became the forerunners of banking by creating new money based on credit.