When we seek to examine minutely the various monetary changes which have occurred, and to lay hold upon some principle to guide our inquiry, we quickly recognize the fact, that the difference in value between gold and silver increases in proportion to the development of civilization and industry. It is not without some show of reason, that mythology, transporting the analogy of the physical into the moral world, made the age of silver succeed that of gold. Historically, in fact, the discovery of and the working of gold preceded that of silver. Gold is almost always found either pure or mixed with silver. In searching the beds of rivers and streams, it has been obtained by the mere process of washing. This work is within the reach of the rudest state of society. It appears like a treasure spread over the surface of the earth, under the very feet of the first occupier of the soil. Silver, on the contrary, is embedded in rocks of primitive formation, and is seldom found near the surface of the earth; its extraction requires a combination of science, machinery, and capital. It is the work of a state of civilization already far advanced and firmly established. In almost every age, whatever its social position, the use and the value of gold has been known. From India to Iberia, and from Ethiopia to the Poles, there is not a race which has not attempted to discover this source of wealth on its surface. What country has not had its Pactolus! What Prince or Satrap has not been a gold collector, like Midas or Crœsus! The luxuries of ancient monarchs appear to prove an abundance of metallic treasure, which has been subsequently unequalled, but the sources of the supply have faded away in their turn. Dureau de la Malle observes, that from the death of Alexander, the golden sands of Asia and Greece appear to have been exhausted; those of Gaul and Spain seem to have been abandoned after the fall of the Roman Empire. Gold has long since disappeared from the surface of the older inhabited countries; there is only now to come, in quantities of appreciable amount, or capable of affecting the circulation, the produce of those countries which have been unknown to European commerce, or which have been discovered in modern times.