CURRENCY AND COINAGE 203 



fittest. And among the metals, what we call the bullion 

 metals, i. e. gold and silver, have come to be generally 

 used for money, and currency has come to be expressed 

 in terms of gold and silver money, only for the reason 

 that civilized man has long found out by experience that 

 these two metals are the most convenient materials to be 

 found on the earth as media of exchange. The insta- 

 bility of a metal as a medium of exchange and money is 

 shown by the general supersession of copper by nickel 

 for low values in our own time, and firmly established 

 as gold and silver may seem to us nowadays to be, they 

 will be most certainly discarded the moment anything 

 more convenient turns up for general use as money. In 

 fact gold is showing a tendency to supersede silver and 

 to become the only currency metal, just as silver super- 

 seded gold in many places for many centuries and still 

 supersedes it, and is and was the only currency metal 

 for those places. 



Modern commercial and financial men among the 

 highly civilized recognize this fact by another name and 

 talk about the 'gold or silver basis': but the meaning is 

 the same, and as surely as gold or silver, or both toge- 

 ther, in a constant or a not too varying ratio to each 

 other, form the most convenient medium of exchange, so 

 surely will one or the other or both be money. In 

 modern parlance, so surely will monometallism in gold 

 or silver or bimetallism in both obtain. It all happens 

 in unconscious obedience to the natural law, already 

 insisted on so often, of the constancy of human reasoning 

 and the action based thereon. 



Having arrived at the crucial point of measuring the 

 relative value of possessions by means of the media of 

 exchange, the next natural mental process is to express 

 that measurement in terms of the media. That is, when 



