[Sub-inclosure Numbers 8.]

LEGATION OF THE UNITED STATES,

Madrid, January 8, 1862.

Honorable WILLIAM H. SEWARD,

Secretary of State, Washington.

SIR: I had the honor to inform you hastily on the 4th instant (same day on which the last mail for America left Madrid) of the arrival of the privateer steamer Sumter in the bay of Cadiz with a copy of my first telegraphic instructions to the consul at that port; also that I had an interview with Her Majesty's minister of state who had promised to take care that the provisions of the royal decree of June 17 were strictly adhered to by the Spanish authorities at Cadiz.

I have now the honor to lay before you the correspondence telegraphic and written, which has passed through this legation on the subject. My instructions to the consuls at Cadiz have been prmoptly and intelligently carried out so far as I can judge at this moment. You will perceive that my first object has been to secure the release of the prisoners the Sumter brought with her and at all hazards to prevent her leaving port again with them on board. I am still ignorant of the details of what has happened at cadiz, but to day's telegram informs me that the men are safe in the hands of our consul in pursuance of the orders transmitted by this Government at my instance to the authorities at that port. As to my notes to Mr. Calderon I ought to say that it is not my custom to address this Government on any important matter in other than the English language but the time lost in translating and the urgency of this occasion have induced me to write in Spanish and put the original notes immediately into the hands of the minister. Another motive on the 7th instant was the advantage of commenting upon the sense of the royal decree of June 17 in the same language in which it is written. Thus the phrase "armar un buque," employed in the first article of the decree, signifies not merely to arm a vessel but also all that we understand by the phrases to fit out or prepare a vessel for sea. Mr. Calderon not havhat communication I learned that though the authorities at Cadiz had in fact ordered the Sumter to go to sea the captain of the vessel had refused to go, alleging the necessity of repairs before he could sail. Fearing that the Spanish authorities might yield to his request immediately upon the receipt of the telegram of to-day from Mr. Eggleston I returned him the telegraphic instructions to enter formal protest against any kind of repairs being done to the Sumter as contrary to the provisions of the royal decree of June 17 and offensive to the Government of the United States.

I sought also an interview with Mr. Calderon but he has not been at his department to-day nor yesterday, so I immediately communicated this telegraphic correspondence to him in writing with the note of to-day.

MADRID, January 11.

Your attention is called to the telegram received yesterday from Cadiz.

Last evening, 10th instant, Mr. Calderon sent me a request to meet him at the Department of State, which I did at 10 o'clock, when a conference of nearly two hours took place in which Mr. Calderon beganby an effort to convince me that the Spanish Government was perfectly justified in allowing the Sumter to be repaired at Cadiz according to the provisions of the royal decree of June 17, 1861.