The problem with private banks issuing notes is that there would periodically be banking crises when the banks failed to pay on their notes and they couldn't pay out the gold that was demanded--that was required.

私有银行发行纸币的问题在于,当它们没法用要求的金子-规定的金子数量,支付它们发行的纸币时,它们将周期性的,陷入银行业危机。

耶鲁公开课 - 金融市场课程节选

We call them consols because, in the early 1700s, the British Government issued what they called consols or consolidated debt of the British Crown that paid a certain amount of pound sterling every six months forever.

我们称之为公债是因为早在十八世纪初,英国政府规定他们称之为英国皇家,统合公债或者联合公债,要求永久性地,每六个月支付一定数量的英镑

耶鲁公开课 - 金融市场课程节选

They trust to the fact that the depositors won't all come on the same day, just like a goldsmith banker -he leaves only enough gold in the safe to cover the kind of withdrawals that are normally accepted.

他们是基于这样一种考量,即储户们不会在同一天上门来取钱,正如金匠银行家那样,他留存在保险箱中的黄金数量,刚好可以应付一般的提款要求

耶鲁公开课 - 金融市场课程节选