and gold for many of the larger transactions.  Both were made legalized forms of money (and standards of deferred payments) in units of specified weights and fineness, the weights bearing a certain ratio to each other.  Thus it was possible for a debtor to discharge his obligations with that one of the two metals that at the moment was the cheaper at the legal ratio.  Fluctuations in the prices of gold in terms of silver were at times such as to cause a large part of the full-weight coins of one or the other metal to leave circulation (in accordance with Gresham’s law).  So from time to time the ratio was slightly changed by law in the various countries to permit the circulation or to bring back the kind of money that had been undervalued in terms of the other.  But it is a very remarkable fact that from the time of Xenophon until the discovery of America (a period of nearly 2000 years), the market ratio of silver to gold bullion in Europe remained pretty close to 10 to 1, being only temporarily altered by sudden and unusual occurrences.  From 1492 to 1660 the ratio changed to 15 to 1, where it remained with remarkable stability until about the year 1800.  At the establishment of the mint of the United States in 1792 that ratio was found to exist.  Men had come to look upon the ratio of 15 to 1 as the natural order, determined (it was sometimes said) providentially by the deposit of the two metals in due proportion in the earth’s surface.  But as we now see it, this in part was mere chance and in part was due to the equalizing effect of the wide use of both metals so that the one could be easily substituted for the other in case of a divergence of the market ratio from the legal ratio as money.  From the year 1500 until 1800 the Western hemisphere was the main source of the precious metals, the alluvial deposits were widely scattered, were gradually discovered, were usually found in small quantities, and were extracted in primitive ways.  The existing stock of precious metals, gold and silver, more than other products of mine and field, is at any time the accumulation of many years’ production, and is changed very little, proportionally, by a large change of output in any year or short period.  It changes in volume as does a glacier fed by the snows of many years, not as does a river, filled by a single rainfall.  For a short time after the discovery of America (from 1493 to about 1544) the average coining value[1] of the world’s production of gold, nearly all found in America, was about 1-1/2 times as great as that of silver; but thereafter for three centuries from about 1545, the annual value of silver produced was between 1-1/2 to 4 times as great as that of gold, averaging about twice as great.  Silver was the money chiefly in use in the ordinary transactions in all of the principal countries of the world.