"You've no need to thank me," he said, as I murmured words of gratitude. "Probably it is I who will be in your debt. I told you that at Lautenburg you will have a magnificent library at your disposal. The librarian, Professor Cyrus Beck--whom I have met occasionally at various conferences--is a jealous guardian, but he is also a man of learning. I have no doubt that you will be allowed the use of the books and manuscripts which do not bear directly on the great work--the history of the theories of the transmutation of metals--on which he is engaged. You may know, perhaps, that I am myself writing a book on manners and customs at the Court of Hanover at the end of the seventeenth century. I noticed at the Nationale in the catalogue of the Ducal library at Lautenburg, that it contains material of the very highest importance. When you left me this morning I went there to make a list of the principal works I should like you to consult for me if you would be so kind. I am sure that you would find the task very absorbing. Here is my list. I attach particular importance to this work, _Stattmutter der Köninglichen Häuser Hannover und Preussen_, by the Grand Duchess of Ahlden, published at Leipzig in 1852. In Paris we have only an incomplete reprint. I also recommend the works of Cramer and Palmblad as well as the _Roman Octavia_ (_Die Römische Octavia_) of Duke Ulrich von Wolfenbüttel. "Unfortunately," he continued, as I carefully folded his list, "I have only been able to note the printed books. The manuscripts at Lautenburg are not catalogued, but it is by examining them, dear boy, that you can render me the greatest service. There is not the slightest doubt that you will discover there the most precious material on German society of the seventeenth century, that society superficially so refined to the outward eye, but in reality more vicious and cruel than has ever been imagined." He held out his hands. His emotion told me that there was something still to come. "I would not for anything hark back to our conversation of this morning," he murmured at length; "but you know, my boy, the interest I take in you. I am more conscious of it than ever now you are going. I beg of you never to yield to the desire, even to the invitations you will doubtless get, to be drawn from your academic functions. Lautenburg is a rich mine of material for those like ourselves whose mission it is to write history. Let us write it and avoid the temptation to make it." There was nothing but sincerity in my promise to keep this parting advice ever present in my mind. "Just one other thing. I know nothing of the Lautenburg household except Prince Joachim, the Grand Duke, the Grand Duchess and Count Marçais. At one time there was a certain Baron von Boose there. If he is still there don't see more of him than you can help. Be on your guard against him; _always_ be on your guard against him."