But how is the writing done on the slate in the second test? asks the curious reader. Nothing easier! The servant who raps at the door brings with him, concealed under his coat, a second slate, upon which the long message is written. Over the writing is a pad cut from a book-slate, exactly fitting the frame of the prepared slate. It is impossible to detect the fraud when the light in the room is a trifle obscure. The medium makes an exchange of slates, returns to the table, washes both sides of the trick slate, and carelessly exhibits it to the sitter, the writing being protected of course by the pad. Before placing the slate under the chafing-dish cover, he lets the pad drop into his lap. Now comes a crucial point in the imposture: the writing heard beneath the slate, supposed to be the work of a disembodied spirit. The medium under cover of his handkerchief removes from his pocket an instrument known as a "pencil-clamp." This clamp consists of a small block of wood with two sharp steel points protruding from the upper edge and a piece of slate pencil fixed in the lower. The medium presses the steel points into the under surface of the table with sufficient force to attach the block securely to the table, and then rubs a pencil, previously attached to his right knee by silk sutures, against the side of the pencil fastened to the apparatus. The noise produced thereby exactly simulates that of writing upon a slate. In my case the illusion was perfect. During the examination of the message, the medium has ample opportunity to secrete the false pad and the clamp in his pocket. Instead of having a servant bring the slate to him and making the exchange described above, he may have the trick slate concealed about him before the séance begins, with the message written on it, and adroitly make the substitution while the sitter is engaged in lowering the light. Dr. Slade almost invariably adopted the first-mentioned exchange, because it enabled his confederate to write a lucid message to the sitter. An examination of the sitter's overcoat in the hall frequently yielded valuable information in the way of names and initials extracted from letters, sealed or unsealed. Sealed letters? Yes; it is an easy matter to steam a gummed envelope, open it, and seal it again. Another method is to wet the sealed envelope with a sponge dipped in alcohol. The writing will show up tolerably well if written upon a card. In a very short time the envelope will dry and exhibit no evidence of having been tampered with.