Scarcely had the Emperor established his headquarters at Potsdam than the whole administration of the kingdom was begun to be placed under French rule. Prefects were appointed to different departments of the kingdom; a heavy contribution was imposed upon the nation; and all the offices of the state were subjected to the control of persons named by the Emperor. Among these, the first in importance was the post-office; for, while every precaution was taken that no interruption should occur in the transmission of the mails as usual, a _cabinet noir_ was established here, as at Paris, whose function it was to open the letters of suspected persons, and make copies of them; the latter, indeed, were often so skilfully executed as to be forwarded to the address, while the originals were preserved as “proofs” against parties, if it were found necessary to accuse them afterwards. (And here I might mention that the art of depositing metals in a mould by galvanic process was known and used in imitating and fabricating the seals of various writers, many years before the discovery became generally known in Europe.) The invasion of private right involved in this breach of trust gave, as might be supposed, the greatest offence throughout the kingdom. But the severity with which every case of suspicious meaning was followed up and punished converted the feelings of indignation and anger into those of fear and trepidation. For this was ever part of Napoleon's policy: the penalty of any offence was made to exclude the sense of ridicule its own littleness might have created, and men felt indisposed to jest where their mirth might end in melancholy. The most remarkable case, and that which more than any other impressed the public mind of the period, was that of the Prince de Hatzfeld, whose letter to the King of Prussia was opened at the post-office, and made the subject of a capital charge against him. Its contents were, as might be imagined from the channel of transmission, not such as could substantiate any treasonable intention on his part. A respectful homage to his dethroned sovereign; a detail of the mournful feeling experienced throughout his capital; and some few particulars of the localities occupied by the French troops, was the entire. And for this he was tried and condemned to death,--a sentence which the Emperor commanded to be executed before sunset that same day. Happily for the fate of the noble prince, as for the fair fame of Napoleon, both Duroc and Rapp were ardently attached to him, and at their earnest entreaties his life was spared. But the impression which the circumstances made upon the minds of the inhabitants was deep and lasting; and there was a day to come when all these insults were to be remembered and avenged. If I advert to the occurrence here, it is because I have but too good reason to bear memory of it, influencing, as it did, my own future fortunes.