The principal silver coin is the dollar, which contains 412% grains of standard silver .900 fine. The amount of fine silver in the dollar is 371 1/4 grains, and there are 41% grains of copper alloy. The standard silver dollar was first authorized by the act of April 2, 1792. Its weight was 416 grains .8924 fine. It contained the same quantity of fine silver as the present dollar, whose weight and fineness were established by the act of January 18, 1837. The coinage of the standard silver dollar was discontinued by the act of February 12, 1873, and it was restored by the act of February 28, 1878. The total amount coined from 1792 to 1873 was $8,031,238, and the amount coined from 1878 to December 31, 1904, when the coinage was discontinued, was $570,272,610. The coinage ratio between gold and silver under the act of 1792 was 15 to 1, but by the acts of 1834 and 1837 it was changed first to 16.002 to 1 and finally to 15.988 to 1 (commonly called 16 to 1). This is the present ratio.

Of the 570,272,610 standard silver dollars coined since February 1878, 2,495,000 are reported to have been shipped to Cuba, Porto Rico, and the Philippines, of which 612,730 have been returned; there were held in the Treasury June 30, 1908, $491,895,049, and the amount outside the Treasury in the United States was $76,354,933. Of the amount held in the Treasury $474,-350,000 were held for the redemption of an equal amount of silver certificates outstanding; $4,982,000 were held on account of Treasury notes of 1890, and $12,563,049 were held in the general cash as assets of the Government. The commercial value of an ounce of fine silver June 30, 1908, was $0.54282, and the commercial value of the silver in the silver dollar on that date was 41.983 cents.