An Alcohol Rub
By Howard Savage

A calling card is handed to the sitter, who writes a question on it. The medium opens a small envelope, address side down, for the reception of the face down card. The envelope is immediately sealed.

When the medium places an identification mark on it, he not only tells the sitter his question, but also answers it.

The mystery's solution lies in the solution, alcohol, that is in the hollow metal pencil of the medium. He pretends to make a mistake and erase it, but really moistens the envelope with the sponge-rubber false eraser, thereby rendering it transparent.

The chemical dries rapidly and the question is handed back after a lengthy answer.