After a commercial crisis, 1866 for example, two things happen: first, we call in the debts which are owing to us in foreign countries; and we require these debts to be paid to us, not in commodities, but in money.

From this cause principally, and omitting minor causes, the bullion in the Bank of England, which was 13,156,000 L.in May 1866, rose to 19,413,000 L.
in January 1867, being an increase of over 6,000,000 L.And then there comes also a second cause, tending in the same direction.
During a depressed period the savings of the country increase considerably faster than the outlet for them.

A person who has made savings does not know what to do with them.

And this new unemployed saving means additional money.

Till a saving is invested or employed it exists only in the form of money: a farmer who has sold his wheat and has 100 L.'to the good,' holds that 100 L.in money, or some equivalent for money, till he sees some advantageous use to be made of it.