NEW YORK, December 24, 1861.

Honorable W. H. SEWARD, Secretary of State, &c., Washington.

SIR: I had the honor to address you on the 11th instant. I have to-day seen Superintendent Kennedy who wished me to promise to deliver to him all letters we may receive from Europe for parties in the South. He kept me so long while he was preparing the letter to you which he read to me that I would not ask him to write it over again for the purpose of giving more fully the reasons why I preferred returning the letters to Europe to delivering them to him. The first reason is that we have not forwarded any such letters since communication was interdisted; the second, that having informed several of our friends and requested my brother in England so to inform them that we should not forward any such letters until it was legal to do so they may send letters to us to be forwarded at the first moment when it is legal, and you must be aware that it may be a matter of much commercial importance to have their letters conveyed to the South immediately it becomes legal to do so without their waiting to hear that it is so.

I have received a number of our letters since my last which have been opened in Washington, but there are avidently several still wanting which I trust you will send to us, including an account sales of cotton and anything that Edward Heath & Co. may have written us as to a shipment of gunny-bags to this port. I wish also the letters for the South to be returned to us as I named on the 11th instant. Among the letters we have received was an enveloe which has been marked unimportant at your office and none of the contents of which have come to hand, although it appears to have been prepaid double in England. We do not recognize the writing. Upon speaking to Kennedy he thinks we had better send it to you for explanation.

In conclusion we have done everything that we can think of by way of explanation to satisfy you that we are entitled to be regarded as loyal citizens. We hope therefore that you will give orders that for the future our letters shall pass into our hands without obstruction.

With much respect, I have the honor to be, your most obedient servant,

M. MAURY.

P. S. - I have to-day written to my brother that I wish our friends to abstain from sending any letters for the South to us on any pretense whatever.

M. M.

DEPARTMENT OF STATE, Washington, January 2, 1861.

JOHN A. KENNEDY, Esq., Superintendent of Police, New York.

SIR: I am directed by the Secretary of State to say that you may return to Mr. M. Maury, of Maury Bros., the inclosed letters. You may also discontinue the surveillance over their correspondence on their engagement (as proposed by Mr. M.) to return to the future writers all such letters as shall come to them for transmission to the insurrestionary States during the continuance of the insurrection.

I am, sir, very respectfully, your obedient servant,

F. W. SEWARD,

Assistant Secretary.