In the course of Florentine history we often see political revolutions break out suddenly and apparently without warning; but on closer examination we perceive them to be the result of deep social changes which have been maturing for a long time, and although imperceptible at first, afterwards assuming such proportions as to become suddenly visible to all eyes and productive of political reforms. Thus it happens that private law, which always accompanies social movements and changes with them, not unfrequently enables us to trace the sources and unfold the true tendency and inexorable necessity of revolutions, even before they come to pass. Accordingly, the habitual neglect of this particular study in connection with the history of Italy has proved a serious defect. No one at the present day would venture to write the political history of Rome without giving attention to the Roman jurisprudence. Nevertheless, we have written the history of our republics over and over again, without bestowing a thought on their civil and penal legislation. It is true that the investigation required presents very great difficulties, inasmuch as our history was subject, during the Middle Ages, to a series of changes, always rapid and always different. The number of our republics is infinite. Every province of Italy, every fragment of Italian territory is divided and subdivided into communes, every one of which has a distinct history, and political institutions which are constantly changing. This perpetual mutation is faithfully reflected in the statutes of the Commune. On the margins of these statutes we find alterations and corrections registered from year to year, and formulated, not unfrequently, after the streets of the city had begun to run with blood. When annotations and corrections reach a certain number, the statutes are drafted anew, and of these re-drafts also many copies are still extant. It was the duty of the officials in charge of the statutes (_statutari_) to enter from time to time such farther modifications as were afterwards approved of in the Councils of the People. Hence it sometimes happens that on referring to the statutes of a given year, we may find the duties of some chief magistrate of the Republic set forth in their text with the most minute detail, whereas if we look to the notes it will appear that these duties have already been changed. If we next consult the remodelled statute it will be found that the magistracy itself no longer exists. How is it possible, therefore, to give any idea of the political form of a municipality fashioned in such wise? This can only be done by gleaning from the mass of the statutes the history of the constitution through all its successive changes of form. In a word, we must recognise that, instead of being confronted by a system crystallised, fixed and immutable, we are watching a living organism develop under our eyes in obedience to a settled law. This law alone is uniform, and