[27] We may remark, in passing, a delusion which is childish enough but very natural, and very common among collectors: they all tend to exaggerate the intrinsic value of the documents they possess, simply because they themselves are the possessors. Documents have been published with a sumptuous array of commentaries by persons who had accidentally acquired them, and who would, quite rightly, have attached no importance to them if they had met with them in public collections. This is, we may add, merely a manifestation, in a somewhat crude form, of a general tendency against which it is always necessary to guard: a man readily exaggerates the importance of the documents he possesses, the documents he has discovered, the texts he has edited, the persons and the questions he has studied. [28] See L. Delisle, _Le Cabinet des manuscrits de la Bibliothèque nationale_, Paris, 1868-81, 3 vols. 4to. The histories of ancient depositories of documents, which have been recently published in considerable number, have been modelled on this admirable work. [29] Many of the ancient documents still in circulation are the proceeds of ancient thefts from state institutions. The precautions now taken against a recurrence of such depredations are stringent, and, in nearly every instance, as effective as could be desired. As to modern (printed) documents, the rule of legal deposit [compulsory presentation of copies to specified libraries], which has now been adopted by nearly all civilised countries, guarantees their preservation in public institutions. [30] It is known that Napoleon I. entertained the chimerical design of concentrating at Paris the archives of the whole of Europe, and that, for a beginning, he conveyed to that city the archives of the Vatican, the Holy Roman Empire, the crown of Castile, and others, which later on the French were compelled to restore. Confiscation is now out of the question. But the ancient archives of the notaries might be centralised everywhere, as in some countries they are already, in public institutions. It is not easy to explain why at Paris the departments of Foreign Affairs, of War, and of Marine preserve ancient papers whose natural place would be at the Archives Nationales. A great many more anomalies of this kind might be mentioned, which in certain cases impede, where they do not altogether preclude, research; for the small collections, whose existence is not required, are precisely those whose regulations are the most oppressive.