There was one circumstance which rendered the direct taxes peculiarly oppressive in the declining periods of the Roman empire, and that was the _solid_ obligation, as the lawyers term it, which attached to the municipalities, into which the whole empire was divided, of making good the amount of their fixed assessment to the public treasury. Of course, if the municipality was declining, and the same quota required to be made up from its assessable inhabitants by the magistracy, who were responsible for its amount, it augmented the burden on those who remained within its limits; and if they dwindled, by public calamities or emigration, to a small number, it might, and often did become of a crushing weight. This system is general over the East; and its oppressive effect in the declining stage of states, is the chief cause of the rapid decay of Oriental empires. There is a remarkable authentic instrument, which attests the ruinous influence of this system in the later stages of the Roman dominion. This is a rescript of the Emperior Majorian, which sets forth:--"The municipal corporations, the lesser senates, as antiquity has justly styled them, deserve to be considered as the heart of the cities, and the sinews of the Republic. And yet so low are they now reduced, by the injustice of magistrates and the venality of collectors, that many of their numbers, renouncing their dignity and their country, have taken refuge in distant and obscure exile." He strongly urges, and even ordains their return to their respective cities; but he removes the grievances which had forced them to desert the exercises of their municipal functions, by directing that they shall be responsible, not for the _whole sum_ assessed on the district, but only for the payments they have actually received, and for the defaulters who are still indebted to the public.[38] But this humane and wise interposition was as shortlived as it was equitable. Succeeding emperors returned to the convenient system of making the municipal corporations responsible for the sum assessed on their respective districts, and it continued to be the general law of the empire down to its very latest day. Sismondi, in his _Décadence de l'Empire Romaine_, and Michelet, in his _Gaule sous les Romains_, concur in ascribing to this system the rapid decline and depopulation of the empire in its later stages.