From some cause or other the atmosphere of Philadelphia is not favorable to this mode of Spiritual manifestation. With the exception of the Medium just alluded to, not a single Professional Independent Slate Writing Medium was known to us at that time in this city, nor is there one resident here even at this present writing, as far as we know. We were, therefore, obliged to send for one to New York. With this Medium, Dr. Henry Slade, we had a number of sittings, and, however wonderful may have been the manifestations of his Mediumship in the past, or elsewhere, we were forced to the conclusion that the character of those which passed under our observation was fraudulent throughout. There was really no need of any elaborate method of investigation; close observation was all that was required. At the risk of appearing inconsequent by mentioning that first which in point of time came last, we must premise that in our investigations with this Medium we early discovered the character of the writing to be twofold, and the difference between the two styles to be striking. In one case the communication written on the slate by the Spirits was general in its tone, legible in its chirography, and usually covered much of the surface of the slate, punctuation being attended to, the _i's_ dotted, and the _t's_ crossed. In the second, when the communication was in answer to a question addressed to a Spirit the writing was clumsy, rude, scarcely legible, abrupt in terms, and sometimes very vague in substance. In short, one bore the marks of deliberation and the other of haste. This difference we found to be due to the different conditions under which the communications were written. The long messages are prepared by the Medium before the séance. The short ones, answers to questions asked during the séance, are written under the table with what skill practice can confer. With this knowledge, it is clear that the investigator has to deal with a simple question of legerdemain. The slate, with its message already written, must in some way be substituted for one which the sitter knows to be clean. The short answers must be written under trying circumstances, out of sight, under the table, with all motions of the arm or hand concealed. It is useless to attempt to limit the methods whereby these two objects may be attained. All that we can do is to describe the processes which we distinctly saw this Medium adopt.