The effect relies on simple gimmick and tricks can be performed with it that are self-working, requiring almost no skill.
The effect is usually performed as follows: The magician displays two coins of almost equal size, one copper and one silver.
The copper coin can then be made to appear wherever the magician desires, such as in the spectator's pocket or under an object across the room.
[1][2] A number of books exclusively on the subject describe different effects that can be achieved with the Scotch and Soda gimmick.
In the early 1900s, America's oldest magic company, Martinka made a version that utilized a Barber half dollar and a large cent.