I should perhaps apologise for again intruding a subject upon which you have so ably commented, and which may be supposed by this time to have been almost exhausted; but as I have been greatly interested in the articles upon “cryptography,” which have appeared in your Magazine, I think that you will excuse the present intrusion of a few remarks. With secret writing I have been practically conversant for several years, and I have found, both in correspondence and in the preservation of private memoranda, the frequent benefit of its peculiar virtues. I have thus a record of thoughts, feelings and occurrences,—a history of my _mental_ existence, to which I may turn, and in imagination, retrace former pleasures, and again live through by-gone scenes,—secure in the conviction that the magic scroll has a tale for _my_ eye alone. Who has not longed for such a confidante? Cryptography is, indeed, not only a topic of mere curiosity, but is of general interest, as furnishing an excellent exercise for mental discipline, and of high _practical_ importance on various occasions;—to the statesman and the general—to the scholar and the traveller,—and, may I not add “last though not least,” to the _lover_? What can be so delightful amid the trials of absent lovers, as a secret intercourse between them of their hopes and fears,—safe from the prying eyes of some old aunt, or it may be, of a perverse and _cruel_ guardian?—a _billet doux_ that will not betray its mission, even if intercepted, and that can “tell no tales” if lost, or, (which _sometimes_ occurs,) if _stolen_ from its violated depository.