First Sort
The first sort of rude produce of which the price rises in the progress of improvement, is that which it is scarce in the power of human industry to multiply at all. It consists in those things which nature produces only in certain quantities, and which being of a very perishable nature, it is impossible to accumulate together the produce of many different seasons. Such are the greater part of rare and singular birds and fishes, many different sorts of game, almost all wildfowl, all birds of passage in particular, as well as many other things. When wealth and the luxury which accompanies it increase, the demand for these is likely to increase with them, and no effort of human industry may be able to increase the supply much beyond what it was before this increase of the demand. The quantity of such commodities, therefore, remaining the same, or nearly the same, while the competition to purchase them is continually increasing, their price may rise to any degree of extravagance, and seems not to be limited by any certain boundary. If woodcocks should become so fashionable as to sell for twenty guineas apiece, no effort of human industry could increase the number of those brought to market, much beyond what it is at present. The high price paid by the Romans, in the time of their greatest grandeur, for rare birds and fishes, may in this manner easily be accounted for. These prices were not the effects of the low value of silver in those times, but of the high value of such rarities and curiosities as human industry could not multiply at pleasure. The real value of silver was higher at Rome, for some time before and after the fall of the republic, than it is through the greater part of Europe at present. Three sestertii, equal to about sixpence sterling, was the price which the republic paid for the modius or peck of the tithe wheat of Sicily. This price, however, was probably below the average market price, the obligation to deliver their wheat at this rate being considered as a tax upon the Sicilian farmers. When the Romans, therefore, had occasion to order more corn than the tithe of wheat amounted to, they were bound by capitulation to pay for the surplus at the rate of four sestertii, or eightpence sterling, the peck;616 and this had probably been reckoned the moderate and reasonable, that is, the ordinary or average contract price of those times; it is equal to about one-and-twenty shillings the quarter. Eight-and-twenty shillings the quarter was, before the late years of scarcity, the ordinary contract price of English wheat, which in quality is inferior to the Sicilian, and generally sells for a lower price in the European market. The value of silver, therefore, in those ancient times, must have been to its value in the present, as three to four inversely; that is, three ounces of silver would then have purchased the same quantity of labour and commodities which four ounces will do at present. When we read in Pliny, therefore, that Seius617 bought a white nightingale, as a present for the empress Agrippina, at the price of six thousand sestertii, equal to about fifty pounds of our present money; and that Asinius Celer618 purchased a surmullet at the price of eight thousand sestertii, equal to about sixty-six pounds thirteen shillings and fourpence of our present money; the extravagance of those prices, how much soever it may surprise us, is apt, notwithstanding, to appear to us about one-third less than it really was. Their real price, the quantity of labour and subsistence which was given away for them, was about one-third more than their nominal price is apt to express to us in the present times. Seius gave for the nightingale the command of a quantity of labour and subsistence equal to what £66 13s. 4d. would purchase in the present times; and Asinius Celer gave for the surmullet the command of a quantity equal to what £88 17s. 9d. ⅓, would purchase. What occasioned the extravagance of those high prices was, not so much the abundance of silver, as the abundance of labour and subsistence, of which those Romans had the disposal, beyond what was necessary for their own use. The quantity of silver, of which they had the disposal, was a good deal less than what the command of the same quantity of labour and subsistence would have procured to them in the present times.
Second Sort
The second sort of rude produce of which the price rises in the progress of improvement, is that which human industry can multiply in proportion to the demand. It consists in those useful plants and animals, which, in uncultivated countries, nature produces with such profuse abundance, that they are of little or no value, and which, as cultivation advances, are therefore forced to give place to some more profitable produce. During a long period in the progress of improvement, the quantity of these is continually diminishing, while at the same time the demand for them is continually increasing. Their real value, therefore, the real quantity of labour which they will purchase or command, gradually rises, till at last it gets so high as to render them as profitable a produce as anything else which human industry can raise upon the most fertile and best cultivated land. When it has got so high it cannot well go higher. If it did, more land and more industry would soon be employed to increase their quantity.
When the price of cattle, for example, rises so high that it is as profitable to