FORT WARREN, April 23, 1862.

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

SIR: I avail myself of the earliest opportunity to communicate to the Government of the United States the circumstances of my arrest at Tangier, Morocco, by the U. S. consul, my removal o the United States and final commitment to Fort Warrne. On reh 19th day of Febraury last on my way from Gibraltar to Cadiz (where I reside and have made it my permanent home, removed from the unfortunate state of affairs that distract and distress my country) the French sttemaer in which I was a passenger touched at Tangier. There I visited the shore in company with other Americans (fellow-passengers) to while away the interal of the steamer's stay. Upon the approach of the hour of departure I proceeded to the beach, where to my surprise I was seized by armed ruffians (the police of Morocco I presume) and dragged through the streets of the city a distance of some 300 yards to the U. S. consulate there searched in the presence of and by order of the consul and dispossessed of my property. Mr. Myers, a fellow-passenger, was seized with me and treated in a similar manner.

On the way from the beach to the consulate I could not conjecture the cause nor conceive who was the author of my apprehension nor did I perceive who it was until I had been dragged some fifty yards, when some one (till then unseen) exclaimed, "Of, you have been burning ships, God damn you! I'll put a stop to that. " I turned in the direction of this exclanation and beholding an individual very much excited inquired if he were the American consul and received in reply, "I'll let you know who I am," adding (addressing the public), "Bring 'em along, bring'em along. " After having been serached as above stated we were conducted by the guard into what I recognized as the stable of his predecessor, to remain in dungeon darkness until a blacksmith (accompanied by the guard and a rabble) entered and riveted upon us (around the ankles) irons weighing seven or eight pounds. We were then removed to a room in the consular building and confined to it under the vigilance of four (and sometimes six) armed Arabs.

In a few minutes after being thus secured the consul, Mr. De Long, presented himself and asked who was Mr. Tunstall. I stated at once who I was and expressed my indignation at the outrage he had committed, and claimed the protection due an american citizen traveling with his passport (as I was), which had been granted to me by the State Department on my departure for Europe in 1856 as U. S. consul for Cadiz. He replied that he did not recognize any passport that had not been granted by the present administration. I then entreated him to remove the irons from me, offering my parole of honor not to leave the room in whicih I then was. This he refused. I demanded to know the cause of my arrest, to which he confessed there was none particularly but that he suspected I was (looking at Mr. Myers) in bad company and that if I had been alone he would not have arrested me. I demanded then the right to communicate with the authoritiet the circumstances of my detention might be made known to them and investigated, feeling assured that a fraud had been practiced upon them in order to avail himself of their acquiescence and services in the accomplishment of his purpose. He denied me this right, affirming that he was the government of Morocco in my case. I then proposed to take the oath of allegiance to the United States, thus asserting my loyalty to the Government but my proposition was declined.

I remained in his possession thus ironed and confined, cut off from all intercourse with my friends or the civilized world, refused permission, to write to my friend and the U. S. consul at Gibraltar, Horatio J.