A SLAVE CATCHER CAUGHT Hf HIS OWX TRAP. GEORGE F. Ai^KBTI PEBfiONATED BY A MEMBER OP THE VIGILANCE COMMITTEE— A LADY TRIGHTENED BY A PLACARD. One afternoon, the quiet of the Anti-Slavery Office was suddenly agitated by the contents of a letter, privately placed in the hands of J. Miller McKirn by one of the clerks of the Philadelphia Ledger office. Said letter it -would seem, had been dropped into the box of the Ledger office, instead of the U. S. box (one of which, was also in the Ledger office), through a mistake, and seeing that it bore the name of a well-known slave-catcher, Albert!, the clerk had a great desire to know its import. Whether it was or was not sealed, the writer cannot say, it certainly was not scaled when it reached the Anti-Slavery office. It stated that-a laxly from Maryland was then in Philadelphia, stopping at a boarding-house on Arch Street, and that she was very desirous of seeing the above-mentioned Albert!, with a view of obtaining his services to help catch an Underground Kail Road so-journer, whom she claimed as her property. That she •wrote the letter could not be proved, but that it was sent by her consent, there was DO doubt. In order to save the poor fellow from bis impending doom, it seemed that nothing would avail but a bold strategical movement. Mr. McKira proposed to find some one who would be willing to answer for Albert!. Cyrus Whitson, a member of the Committee, in Mr. McKim's judgment, could manage the matter successfully. At that time, C. Whitson was engaged in the Free Labor store, at the corner of Fifth and Cherry streets, nenr the Anti-Slavery office. On being eent for, lie immediately answered the summons, and Mr. McKim at once made known to him his plan, which was to save a fellow-man from being dragged back to bondage, by visiting the lady, and ascertaining from her in conversation the whereabouts of the fugitives, the names of the witnesses, and all the particulars. Nothing could have delighted the shrewd Whitson better; he saw just how lie could effect the matter, without the slightest probable failure. So off he started for the boarding-house. Arriving, he rang the hell, and when the servant appeared, he asked if Miss Wilson, from Maryland, was stopping there. " She ie," was tbe answer. " I wish to see her." " Walk in the parlor, sir." In went Mr. W., with his big whiskers. Soon Miss Wilson entered the parlor, a tall, and rather fine-looking well dressed lady. Mr. Whitaon bowing, politely addressed her, substantially thus : " I have oome to see you instead of Mr. Geo. F. Alberti, to whom you addressed a note, this morning. Circumstances, over which Mr. A. bad no control, prevented his coming, BO I have come, madam, to look after your |