Be it enacted . . . That in order to remove any doubt as to the purpose of the government to discharge all just obligations to the public creditors, and to settle conflicting questions and interpretations of the laws by virtue of which such obligations have been contracted, it is hereby provided and declared that the faith of the United States is solemnly pledged to the payment in coin or its equivalent of all the obligations of the United States not bearing interest, known as United States notes, and of all the interest-bearing obligations of the United States, except in cases where the law authorizing the issue of any such obligation has expressly provided that the same may be paid in lawful money or other currency than gold and silver. But none of said interest bearing obligations not already due shall be redeemed or paid before maturity unless at such time United States notes shall be convertible into coin at the option of the holder, or unless at such time bonds of the United States bearing a lower rate of interest than the bonds to be redeemed can be sold at par in coin. And the United States also solemnly pledges its faith to make provision at the earliest practicable period for the redemption of the United States notes in coin.