218 ADAM SMITH. 



as making their price vary, and with it the rent of the 

 mines. As society improves the demand of the 

 market may increase, while the produce of the mines 

 remains the same ; or the produce may increase more 

 than the demand increases; or the produce and demand 

 may increase together and equably. In the first case, the 

 money price of goods will fall, and the mine become 

 more valuable ; in the second, the money price will 

 rise, and the mine fall in value ; in the third case, the 

 money price of goods will remain stationary, and with 

 it the value of the mine. By the value of the mine, 

 we, of course, mean the value of the same amount of 

 its produce in the several cases. 



This leads Dr. Smith to enter at great length into 

 the important question, how far the value of silver, the 

 general medium of exchange in the market of the 

 world, has varied at different periods during the four 

 last centuries. 



(1.) The first period is from 1350 to 1570, and he 

 shows that the increased supply from the discovery of 

 America could not have sensibly affected the value of 

 silver during these two centuries. The progress of 

 commerce of all kinds, internal and external, must 

 have been the retarding cause, which prevented the 

 influx of the additional quantity of metal from sensibly 

 raising the money price of commodities. 



(2.) From 1570 to 1640 the newly discovered mines 

 produced their full effect in raising all the prices, and 

 lowering the exchangeable value of silver. That effect 

 was completed between the years 1630 and 1640. 

 Prices had then risen to between three and four times 

 their former rate, although the increase of commerce 

 had increased also the demand for the metallic cur- 

 rency. 



(3.) From 1640 to 1776 Dr. Smith does not consider 

 that any material change has taken place in the relative 

 value of silver and other commodities; and he examines 

 with much particularity, and in great detail, the facts 



