This rise in the value of silver, in proportion to that of corn, may either have been owing altogether to the increase of the demand for that metal, in consequence of increasing improvement and cultivation, the supply, in the mean time, continuing the same as before; or, the demand continuing the same as before, it may have been owing altogether to the gradual diminution of the supply: the greater part of the mines which were then known in the world being much exhausted, and, consequently, the expense of working them much increased; or it may have been owing partly to the one, and partly to the other of those two circumstances. In the end of the fifteenth and beginning of the sixteenth centuries, the greater part of Europe was approaching towards a more settled form of government than it had enjoyed for several ages before. The increase of security would naturally increase industry and improvement; and the demand for the precious metals, as well as for every other luxury and ornament, would naturally increase with the increase of riches. A greater annual produce would require a greater quantity of coin to circulate it; and a greater number of rich people would require a greater quantity of plate and other ornaments of silver. It is natural to suppose, too, that the greater part of the mines which then supplied the European market with silver might be a good deal exhausted, and have become more expensive in the working. They had been wrought, many of them, from the time of the Romans. It has been the opinion, however, of the greater part of those who have written upon the prices of commodities in ancient times, that, from the Conquest, perhaps from the invasion of Julius Cæsar, till the discovery of the mines of America, the value of silver was continually diminishing. This opinion they seem to have been led into, partly by the observations which they had occasion to make upon the prices both of corn and of some other parts of the rude produce of land, and partly by the popular notion, that as the quantity of silver naturally increases in every country with the increase of wealth, so its value diminishes as its quantity increases. In their observations upon the prices of corn, three different circumstances seem frequently to have misled them.