The imported materials and the manufactures exported with which the external commerce of this country is mainly concerned eventually pay for one another, but settlement is brought about gradually and mediately. The varying price of foreign bills forms the subject-matter of the foreign exchanges; their current price is described as indicating ‘the state of the foreign exchanges.’ Bills on foreign countries are claims for the money of those countries. The American exchange is affected in one direction by every fresh issue of greenbacks, and in the opposite by every withdrawal of the excessive issues. The premium on foreign bills may be so high as to render means other than purchasing them preferable for discharging debt. Cost of transmission limits the difference in the value of money composed of the precious metals that can permanently exist between countries. Rising and falling in value like wheat, cotton, and other commodities, these metals flow to the market where they are in greatest request.