Two years later Kratzenstein wrote the more theoretical work Theoria electricitatis mores geometrica explicata on the nature of electricity.C.G. Kratzenstein, Theoria electricitatis mores geometrica explicata, Halle (1746). Google Books. Around this time he made measurements to find out how the electric force between two charged objects varied with their separation. J.L. Heilbron, Electricity in the 17th and 18th Centuries: A Study of Early Modern Physics, University of California Press, Berkeley (1979). . On the theoretical side he argued that the electrical current was due to the motion of two fluids which today would correspond to the flow of positive and negative electric charges. The charges themselves should be due to vortices in these fluids. Around the same time Benjamin Franklin explained the same phenomena based on a one-fluid picture where negative charge was due to a lack of positive charge. It was this explanation that prevailed.
