While keeping strictly to the historical order of things, we shall try first to form a picture of what happens when we connect two electrically charged bodies by a conductor. We know that we rightly describe the change of the dynamic properties of the part of space, in which the two bodies are present, by saying that a certain electric field prevails in it. This field possesses different 'potentials' at its various points and so there exists a certain potential difference between the two electric charges. What then happens when a so-called 'conductor' is brought into such a field?