When the medium picked up the envelope in which to place my paper, there was within it a duplicate piece of paper folded the same, and of the same size (one inch and a quarter by two inches) as the one I had folded.  He kept the face of this envelope opposite me so I could not see that side of it.  On the face of it was a horizontal slit cut with a knife.  This slit was about two inches long and was situated about halfway down the face of the envelope.  The duplicate folded paper was placed vertically in the envelope at its center, so that its center was located against the slit.  This piece of paper was held in position by a touch of paste at a point opposite the slit, which caused it to adhere to the inside of the back of the envelope.

When he picked up this prepared envelope with his left hand, he did so with the slit side or face in his palm next to the fingers of his left hand.  This envelope lay slit side down before he picked it up; so that I did not see the face of the envelope at all, and he kept that side of the envelope from me during the entire trick.  The paper within the envelope had been placed far enough down so that its top part was not exposed to my view.  The envelope thus appeared perfectly natural, as an ordinary one with nothing in it.

He thus held the envelope in his left hand, flap open wide, with the back side of the envelope later to be sealed, facing me.  Now he really inserted my paper in this envelope with his right hand as he took it from me; but in fact, he pushed it down just behind the hidden slip of paper within the envelope.  I mean that he inserted it between the concealed slip and the face or slit side of the envelope; and as he did this he caused the lower end of my slip of paper to pass through the slit in the center of the front of the envelope.  The lower portion of my slip was thus out of the envelope on its rear side, between the front of the envelope and the fingers of his left hand; although I could see nothing of this.  He pushed it down so that the top still remained in view with the bent corner exposed, and then sealed the flap over it.

Holding the envelope toward the window, he called to my notice the fact that my paper was within, and that I could see it plainly.  I could see the shadow of the two papers, which appeared as one, and thus his statement seemed correct.  Of course he did not show me the rear side or face of the envelope, with my paper protruding, which was immediately behind the duplicate, so that the shadow of it was also the shadow of the duplicate.

This shadow also hid from my view the shadow of the slit.  The envelope was sealed fairly.