Easy Magic Tricks for Beginners - Magic Pens

Take a small quantity of “Aniline Violet,” obtainable at any chemist’s, two pennyworth making about two dozen pens, and make it into a thick paste with water, taking care not to leave any lumps; then add a few drops of mucilage or good gum.
Do not add too much, or the paste will not set well. Apply a small quantity of the paste thus made to the hollow part of a clean pen, within a quarter of an inch of the point, and leave it for a few hours to dry. When dry, tell your friends that you will write anything they like to tell you with the pen, but instead of using ink, you will use water.
Then dip the pen into the water, taking care not to show the side with the paste on, and write whatever they ask you to, the writing appearing the same as if you were using an ordinary pen.

Excerpt from the book: Three Hundred Things A Bright Boy Can Do
BY MANY HANDS - FULLY ILLUSTRATED
LONDON - SAMPSON LOW, MARSTON & CO., LTD. 1914