COUNT ALESSANDRO VOLTA ( – ) Count Alessandro Volta ( – ) Italian physicist, professor at Pavia. Volta established that the animal electri- city observed by Luigi Galvani, – , in experiments with frog muscle tissue placed in contact with dissimilar metals, was not due to any exceptional property of animal tissues but was also generated whenever any wet body was sandwiched between dissimilar metals. This led him to develop the first voltaic pile , or battery, consisting of a large stack of moist disks of cardboard (electro- lyte) sandwiched between disks of metal (electrodes). In other words, the electrostatic potential ( V ) at any point in a region with electrostatic field is the work done in bringing a unit positive charge (without acceleration) from infinity to that point.
The qualifying remarks made earlier regarding potential energy also apply to the definition of potential. To obtain the work done per unit test charge, we should take an infinitesimal test charge δ q , obtain the work done δ W in bringing it from infinity to the point and determine the ratio δ W/ δ q . Also, the external force at every point of the path is to be equal and opposite to the electrostatic force on the test charge at that point.