The telegraph this morning announces the arrest of Dr. Tumblety at St. Louis on some charge connected with the assassination of Lincoln. The following from the New York Tribune of Friday gives all that is known of Tumblety's connection with the crime:-

A boy about 15 years of age was arrested in Brooklyn on Tuesday by a United States detective on suspicion of having in some way been connected with the assassination plot. The boy was taken to the Forty-first Precinct Station-house, where he was held in custody until Wednesday, and was then taken to Washington. The only explanation which the officer gave in relation to the matter was that the prisoner was one of the persons implicated in the plot for the assassination of Mr. Lincoln, Mr. Johnson and Mr. Seward. During the time that the prisoner was in the station-house, he conversed with some of the police officers, and from his conversation it was discovered that he had been employed by the assassin Booth for some months prior to the assassination of President Lincoln, in the capacity of errand boy, and he was supposed, with his connection with Booth, to be cognizant with the entire plot, and the parties who were connected with it. He refused to give his name, as did also the officer who arrested him. It appears from his conversations with the officers during his stay at the station-house, that Harrold, the companion of Booth, is well known to the citizens of Brooklyn as the agent and companion of a man known as the "Indian Herb Doctor", who came to Brooklyn some eighteen months since and opened an office in Fulton Street, where he made himself notorious by the peculiarity of his dress. Harrold was a kind of confidential valet of this doctor, and was generally attired in the cast-off clothing of the latter, and from the fact that both were continually to be seen promenading the principal streets of the city, their appearance created considerable remark. The doctor got into difficulties with some of his patients, and left the city, and is said to be in New Orleans at the present time, and Harrold returned to Washington. The truth of the boy's story is corroborated by the fact that the published descriptions of the personal appearance of Harrold agree in every particular with the appearance of the companion of the doctor; and there is every probability of its correctness, from the fact that he was always noticed to have the same apparent degree of attachment to the doctor, who was a man of dashing appearance and infinite impudence, that he is said to have manifested toward the assassin Booth. The prisoner also stated that the doctor had been acquainted with Booth in Washington, nd that it was through him that he became acquainted with Harrold.