Up for bid on eBay is this circa 1860s souvenir card from the Magician M. Hartz (a.k.a., Professor M. Hartz).
The seller says, "The back side is written one of his tricks he performed. Measures 3" x 4". Below is information I found online about the magician.
From The Magic Couldren No.29: "In the third floor toy room of the Museum of the City of New York is a gem of a magic set: M. Hartz's Repository, 50 Broadway. The box is about 10" x 14" x 3", is divided into 12 compartments filled with nice boxwood apparatus, and has a printed sheet of instructions for each trick. In the basement of the same museum is a collection of Punch figures and marionettes, including two figures stated to have been made by Houdini... He also performed in New York 1866 for two weeks."
To own this souvenir card, click the link provided to bid.