GENTLEMEN:--I have just received your communication of the 28th ult. respecting the “Library of Christian Knowledge,” now in the course of publication by you. I had supposed that the work had already established for itself such a character, as to need no recommendation from any quarter. But, as you are pleased to suppose that my opinion of it, may be of some use in aiding its circulation, I cannot refuse to give it to you. And I can truly say, that, judging from the character of the works already published in the series, I think it a most valuable publication; and one well calculated to introduce and cherish a taste for literature of a high order, and for religious sentiments, the most evangelical and pure. As to the Rev. Mr. Hooker, your editor, I regard him as one of our most accomplished and intellectual men. Any thing that he adjudges fit for the press, and any thing that comes from his pen, has for me sufficient recommendation in that very fact. His name ought to be, for any work, a full passport to the confidence of the public. His work on “Popular Infidelity,” alone, which makes up your fifth volume, is of itself sufficient to secure him a high and lasting reputation, as a man of profound thinking, of very great logical power, and of very enviable literary attainments. I think that volume alone will be worth the price of the whole set. Wishing you success in your laudable enterprise, I am, gentlemen, very respectfully, your obedient servant, HENRY W. DUCACHET, M. D. _Rector of St. Stephens, Philadelphia._ _Philadelphia, March 17, 1837._ MESSRS. WM. MARSHALL & CO. GENTLEMEN:--I have read several of the volumes of the “Library of Christian Knowledge,” edited by the Rev. H. Hooker, and desire to express my strong sense of the importance of the project, and of the worth of the books, which have been published. It is a very important design which proposes to turn the reading of the religious community, from the lighter works of imagination which have been rather gaining in popularity among such readers, to a grave and instructive class of books. I consider Mr. Hooker’s selection, to have been eminently judicious, as far as regards the real improvement of his readers; though I should not be surprised, if some less useful works, should outstrip these, in the market. The worth of a book is too much determined, by the way it sells. If the actual value is the standard of estimation, the Library of Christian Knowledge, will stand very high. Respectfully yours, STEPHEN H. TYNG, D. D. _From the Rev. Charles Henry Alden, A. M. Principal of the Philadelphia High School for Young Ladies, No. 6 Portico Square._