In the 1990s, during the controversy over alleged animal electricity, Volta was able to discover and measure the contact voltage between two metals (the so-called Volta effect) using a capacitor consisting of two metal discs, whose adjacent faces were both insulated with a thin layer of paint.
In his memoir ‘Observations on the capacity and commotion of electrical conductors …’, alongside the concepts of “capacity” and “quantity”, he uses the concept of electrical voltage for the first time to account for the intensive properties of electricity.
In electrochemistry, the ‘Volta potential’ is defined as the difference in electrical potential between two points, one located near the surface of the first metal and the other near the surface of the second metal, where the two electrically uncharged metals are placed in contact.
The discovery of the contact potential between metals is a very important contribution. In fact, the unit of measurement for electrical potential difference (the volt) is named after Alessandro Volta.
