The individuality of crime is remarkable. Each burglar has a distinct method of conducting his operations, and the experienced Detective can recognize these marks or characteristics as he would the features of the offender. Thanks to this experience, which comes only with long and patient study, he is rarely at a loss to name the perpetrator of a crime if that person be a "professional." Appearances which have no significance for the mere outsider are pregnant with meaning to him. He can determine with absolute certainty whether the mischief has been done by skilled or unskilled hands, and he can gather up and link together evidences which entirely escape the unpractised eye. He rejects nothing as unimportant until he has tested it, and is able to conduct his search in a systematic manner, which in the majority of cases is crowned with success. A few years ago a man came into one of the police stations of the city, and complained that his house had been robbed. He had pursued the thief without success, but the latter had dropped a chisel, and had torn up and thrown away a piece of paper in his flight. The captain commanding the station and an experienced Detective were present when the complaint was made. They carefully examined the owner of the house as to the mode by which the entrance had been effected, the marks left by the tools, the kind of property taken, and the action and bearing of the thief while running away. When these facts were laid before them, the two officers, without a moment's hesitation, concluded that the robbery had been committed by a certain gang of thieves well known to them. This settled, it became necessary to identify the individual or individuals belonging to this gang, by whom the robbery had been committed. The chisel was examined, but it could give no clue. The house-owner had fortunately secured the bits of paper which the thief had thrown away. The officers spread a layer of mucilage over a sheet of paper, and on this fitted the scraps which were given them. This at once disclosed the name of the robber, who was well known to the police as a member of the gang to whom the officers attributed the robbery. Their suspicions were at once confirmed, and the next step was to make the arrest. The Detective said that the thief would certainly be at one of three places, which he named. Three policemen were accordingly sent after him, one to each of the places named, and in an hour or two the culprit was safely lodged in the station-house.