The directors of the London and Westminster Bank had, in the panic of 1857, discounted millions of such bills, and they justly said that if those bills were paid they would have an amount of cash far more than sufficient for any demand.

But how were those bills to be paid?
Some one else must lend the money to pay them.

The mercantile community could not on a sudden bear to lose so large a sum of borrowed money; they have been used to rely on it, and they could not carry on their business without it.

Least of all could they bear it at the beginning of a panic, when everybody wants more money than usual.
Speaking broadly, those bills can only be paid by the discount of other bills.

When the bills (suppose) of a Manchester warehouseman which he gave to the manufacturer become due, he cannot, as a rule, pay for them at once in cash; he has bought on credit, and he has sold on credit.