 This is called bimetallism and the attempt to create a bimetallic standard where both gold and silver backed currency remained in circulation occupied the efforts of inflationists.Governments at this point could use currency as an instrument of policy, printing paper currency such as the United States greenback, to pay for military expenditures.They could also set the terms at which they would redeem notes for specie, by limiting the amount of purchase, or the minimum amount that could be redeemed.