The causes which produced the extraordinary, and at first sight unaccountable, depopulation of the country districts, not only in Italy, but in Gaul, Spain, and all the European provinces of the Roman empire, are explained by Guizot in his _Essays on the History of France_, and have been fully demonstrated by Sismondi, Thierry, and Michelet. They were a natural consequence of the municipal system, then universally established as the very basis of civilization in the whole Roman empire, and may be seen urging, from a similar cause, the Turkish empire to dissolution at this day. This was the imposition of a certain fixed duty, as a burden on each municipality, to be raised, indeed, by its own members, but admitting of no diminution, save under the most special circumstances, and on an express exemption by the emperor. Had the great bulk of the people been free, and the empire prosperous, this fixity of impost would have been the greatest of all blessings. It is the precise boon so frequently and earnestly implored by our ryots in India, and indeed by the cultivators all over the East. But when the empire was beset on all sides with enemies--only the more rapacious and pressing, that the might of the legions had so long confined them within the comparatively narrow limits of their own sterile territories--and disasters, frequent and serious, were laying waste the frontier provinces, it became the most dreadful of all scourges; because, as the assessment on each district was fixed, and scarcely ever suffered any abatement, every disaster experienced increased the burden on the survivors who had escaped it; until they became bent down under such a weight of taxation, as, coupled with the small number of freemen on whom it exclusively fell, crushed every attempt at productive industry. It was the same thing as if all the farmers on each estate were to be bound to make up, annually, the same amount of rent to their landlord, no matter how many of them had become insolvent. We know how long the agriculture of Britain, in a period of declining prices and frequent disaster, would exist under such a system.