III. The value of any object that supplies the wants or pleasures of mankind is compounded of its substance and its form, of the materials and the manufacture. Its price must depend on the number of persons by whom it may be acquired and used; on the extent of the market; and consequently on the ease or difficulty of remote exportation according to the nature of the commodity, its local situation, and the temporary circumstances of the world. The Barbarian conquerors of Rome usurped in a moment the toil and treasure of successive ages; but except the luxuries of immediate consumption, they must view without desire all that could not be removed from the city in the Gothic wagons or the fleet of the Vandals. Gold and silver were the first objects of their avarice; as in every country, and in the smallest compass, they represent the most ample command of the industry and possessions of mankind. A vase or a statue of those precious metals might tempt the vanity of some Barbarian chief; but the grosser multitude, regardless of the form, was tenacious only of the substance, and the melted ingots might be readily divided and stamped into the current coin of the empire. The less active or less fortunate robbers were reduced to the baser plunder of brass, lead, iron, and copper: whatever had escaped the Goths and Vandals was pillaged by the Greek tyrants; and the Emperor Constans in his rapacious visit stript the bronze tiles from the roof of the Pantheon. The edifices of Rome might be considered as a vast and various mine: the first labor of extracting the materials was already performed; the metals were purified and cast; the marbles were hewn and polished; and after foreign and domestic rapine had been satiated, the remains of the city, could a purchaser have been found, were still venal. The monuments of antiquity had been left naked of their precious ornaments; but the Romans would demolish with their own hands the arches and walls, if the hope of profit could surpass the cost of the labor and exportation. If Charlemagne had fixt in Italy the seat of the Western Empire, his genius would have aspired to restore, rather than to violate, the works of the Caesars: but policy confined the French monarch to the forests of Germany; his taste could be gratified only by destruction; and the new palace of Aix-la-Chapelle was decorated with the marbles of Ravenna and Rome. Five hundred years after Charlemagne, a king of Sicily, Robert--the wisest and most liberal sovereign of the age--was supplied with the same materials by the easy navigation of the Tiber and the sea; and Petrarch sighs an indignant complaint that the ancient capital of the world should adorn from her own bowels the slothful luxury of Naples.