TIIE WEALTH OF NATIONS.

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before. The increase of security would naturally increase in-dustry and improvement; and the demand for the preciousmetals, as well as for every other luxury and ornament, wouldnaturally increase with the increase of riches. A greater an-nual produce would require a greater quantity of coin to cir-culate it; and greater number of rich people would require agreater quantity of plate and other ornaments of silver. Itis natural to suppose too, that the greater part of the mineswhich then supplied the European market with silver mightbe a good deal exhausted, and have become more expensivein the working. They had been wrought many of themfrom the time of the Romans.

It has been the opinion, however, of the greater part ofthose who have written upon the prices of commodities inancient times, that, from the Conquest, perhaps from the in-vasion of Julius Csesar till the discovery of the mines ofAmerica, the value of silver was continually diminishing.This opinion they seem to have been led into, partly by theobservations which they had occasion to make upon the pricesboth of corn and of some other parts of the rude produce ofland; and partly by the popular notion, that as the quantityof silver naturally increases in every country with the in-crease of wealth, so its value diminishes as its quantity in-creases.

In their observations upon the prices of corn, three diffe-rent circumstances seem frequently to have misled them.

First, in ancient times, almost all rents were paid in kind ;in a certain quantity of corn, cattle, poultry, &c. It sometimeshappened, however, that the landlord would stipulate, that heshould be at liberty to demand of the tenant, either the annualpayment in kind, or a certain sum of money instead of it.The price at which the payment in kind was in this mannerexchanged for a certain sum of money, is in Scotland calledthe conversion price. As the option is always in the landlordto take either the substance or the price, it is necessary forthe safety of the tenant, that the conversion price shouldrather be below than above the average market price. Inmany places, accordingly, it is not much above one half ofthis price. Through the greater part of Scotland this customstill continues with regard to poultry, and in some placeswith regard to cattle. It might probably have continued totake place too with regard to corn, had not the institution ofthe public fiars put an end to it. These are annual valuations,