As the tax is made payable in money, so the valuation of the land is expressed in money. Since the establishment of this valuation, the value of silver has been pretty uniform, and there has been no alteration in the standard of the coin, either as to weight or fineness. Had silver risen considerably in its value, as it seems to have done in the course of the two centuries which preceded the discovery of the mines of America, the constancy of the valuation might have proved very oppressive to the landlord. Had silver fallen considerably in its value, as it certainly did for about a century at least after the discovery of those mines, the same constancy of valuation would have reduced very much this branch of the revenue of the sovereign. Had any considerable alteration been made in the standard of the money, either by sinking the same quantity of silver to a lower denomination, or by raising it to a higher; had an ounce of silver, for example, instead of being coined into five shillings and two pence, been coined either into pieces which bore so low a denomination as two shillings and seven pence, or into pieces which bore so high a one as ten shillings and four pence, it would, in the one case, have hurt the revenue of the proprietor, in the other that of the sovereign.
In circumstances, therefore, somewhat different from those which have actually taken place, this constancy of valuation might have been a very great inconveniency, either to the contributors or to the commonwealth. In the course of ages, such circumstances, however, must at some time or other happen. But though empires, like all the other works of men, have all hitherto proved mortal, yet every empire aims at immortality. Every constitution, therefore, which it is meant should be as permanent as the empire itself, ought to be convenient, not in certain circumstances only, but in all circumstances; or ought to be suited, not to those circumstances which are transitory, occasional, or accidental, but to those which are necessary, and therefore always the same.
A tax upon the rent of land, which varies with every variation of the rent, or which rises and falls according to the improvement or neglect of