Be it enacted by the Senate and House of Representatives of the United States of America in Congress assembled, That the dollar consisting of twenty-five and eight-tenths grains of gold nine-tenths fine, as established by section thirty-five hundred and eleven of the Revised Statutes of the United States, shall be the standard unit of value, and all forms of money issued or coined by the United States shall be maintained at a parity of value with this standard, and it shall be the duty of the secretary of the Treasury to maintain such parity.