the chief source of the wealth of Athens.  They ceased to be worked in the second century of the Christian Era.  At the period B.C. 500, the relative value of silver to gold was eighteen to one.  The Romans obtained most of their silver from the very rich mines of Spain, which had previously been worked by the Phoenicians and Carthaginians, and which, though abandoned for those of Mexico, are still not exhausted.  The most important use for silver, among the Greeks, was for money.  At Rome, on the contrary, silver was not coined until B.C. 260.

Silver, as regards its mines, is represented in every portion of our planet.  The richest silver mine in the world is Potosi; it is situated on an elevation thirteen thousand feet above the level of the sea, in a region of perpetual snow; it has always been worked in a very rude manner, yet it has already produced $250,000,000, and shows no signs of exhaustion.  The annual product of the silver mines of South America, at the present time, is estimated to be $22,000,000.  Their total product, to the present time, has amounted to $2,430,000,000.  The silver mines of Mexico were wrought long before Cortez revealed them to the eyes of Europe, in 1513.  Their annual product, at the present time, is estimated to be $30,000,000.  The total product, to the present time, has amounted to $3,834,000,000.  In 1850 Nevada was not reckoned among the silver-producing countries of the world.  In 1867 she could proudly point to an annual product of $13,000,000; but it has declined to $6,000,000 at the present time.  The total product of silver in Nevada has amounted to $340,000,000.  The largest nugget of silver yet obtained was dug up in Arizona, and weighed 43,200 ounces, valued at the same number of dollars.  The highest silver deposit in the world is on King Solomon’s mountain, in Colorado, fourteen thousand feet above the Pacific Ocean.  The annual product of the silver mines of North America is estimated to be $76,480,000.  Their total product has amounted to $4,783,000,000, more than one-third of the entire product of the world from the earliest times to the present day.  The annual product of the silver mines of America at the present time is estimated to be $98,480,000, and their total product has amounted to $7,170,000,000, more than three-fifths of the entire product of the world, from the earliest times to the present day.  The export of silver from the United States, since 1848, has amounted to $413,292,757.  The annual product of the mines of Europe at the present time is estimated to be $15,000,000; and their total product has amounted to $2,600,000,000.  The annual product of the silver mines of Asia (including Australia, New Zealand, and Oceanica), at the present time is estimated to be $480,000; and their total product has amounted to $1,685,000,000.  India has often been represented as destitute of silver, but we have statements from Sir Roderic Murchison that the Kulu valley is so rich in silver ore that it could yield