The foregoing remarks apply to all forms and grades of physical phenomena, of which there are many. Some of them possess the most intense interest, not only on account of the wonderful psycho-physical power displayed, but because of their intellectual phases. Slate-writing, for instance, when performed by a first-class medium, gifted with a high order of telepathic power, accompanied by other necessary intellectual qualifications, is one of the most interesting of all phases of psychic power. An instance which occurred within the writer's own experience will be here related, for the reason that it fully illustrates the essential qualifications and characteristics of a first-class medium, shows both the physical and mental powers with which he is endowed, and clearly defines the limitations which hedge him about, and which point, with unerring exactitude, to the source of the phenomena. A few years ago, a conversation which the writer had with a celebrated Union general led to an agreement to visit a prominent slate-writing medium, then sojourning in the city of Washington. Among other things, it was agreed that the general should be the sitter, and that he should be guided entirely by my suggestions relative to the course which he should pursue before and during the séance. My object, which he fully understood and appreciated, was, first, to convince him of the genuineness of the physical phenomena,--that is, that the slate-writing was performed without corporeal contact of the medium with the pencil, and without the shadow of a possibility of the employment of legerdemain; and, secondly, to demonstrate the utter impossibility of the phenomena being attributable to disembodied spirits. It must be premised that the medium was in the habit of causing his sitters to write six short letters to as many different spirits. These epistles are written on separate pieces of paper about three inches square, and are addressed to the spirits by name and signed by the writer, precisely as an ordinary letter would be addressed and signed. Each letter is then rolled into a wad as small as possible, and retained in the hand of the sitter until he is requested to deposit them in a pile on the table. When this is done, the medium reaches his hand across the table and touches the wads with the tips of his fingers, the sitter meanwhile watching the proceeding closely, to prevent the possibility of fraud. After the medium has touched each bit of paper the sitter resumes possession of them and retains them for future reference. It may be here remarked that a sitter has the privilege of bringing his own slates with him, and retaining possession of them until the writing is finished. They need not leave his custody for an instant. He may place the bit of pencil between them himself, and then securely lock or tie them together, and hold them as tightly as he chooses on the top of the table, in the broad light of day, while the writing is going on.