CHAP. XXIII. 



WEAR OF COIN. 187 



If, then, the rate of loss by wear on gold money 

 was at the rate of one part in six hundred, and 

 that money was one sixth of the circulating me- 

 dium, and if the rate of loss on the silver money 

 was at the rate of one. part in one hundred and 

 fifty, the mean rate of depreciation would be as 

 near to one part in three hundred and sixty as 

 can be calculated. The silver is estimated at one 

 fourth greater degree of friction than our standard 

 silver, because it was at no time equal in fineness 

 to our standards, and in most periods, and some- 

 times for generations, vastly inferior. 



Although the amount of silver in circulation as 

 money at all times must have been greater than 

 that of gold, yet, as the gold has six times the 

 durability of silver, the relative value of the two 

 metals to each other could not be maintained 

 unless the mines produced the two metals in pro- 

 portion to the loss on them by wear respectively. 

 It seems probable that the due proportion was 

 kept up during the existence of the Roman power, 

 and through the dark ages which succeeded, till 

 the discovery of America, and till the dispersion 

 over the world of the excessive surplus produce of 

 silver above that of gold. The value of gold to 

 silver had varied but little before the mines of 

 Potosi were discovered. Among the Romans 

 gold to silver seldom varied more than from nine 

 to eleven for one, that is, a pound of gold was 

 rarely worth either more than eleven or less than 



