The first theory of electrolysis was written in Rome (1805) and was published as a pamphlet-a study that was quickly translated from French into English and German. According to Theodor Grotthuss, author of theory, the electrolyte in between Volta's pile electrodes aligns chains of polarized water particles (molecules). Electric current and matter transfer occurs when these particles instantly switch their polarized water particle fragments. These jumps in the chain of polarized electrolyte held between different electrodes results in oxygen build up next to one electrode and hydrogen build up next to the other electrode. This theory offered several insights for further development. One was the model leap transfers. The other, more fruitful insight was the self-action chain or the force field of force model. That was picked up by Michael Faraday who transformed and developed it further into the concept of electric and magnetic fields and lines of force. In Grotthuss' theory he finds the idea of the concept of ion as an individual charged fragment of molecule. This article is based on the earlier studies of author [J.A. Krikstopaitis, In the wake of Volta's challenge: the electrolysis theory of Theodor Grotthuss, 1805. in: Volta and the history of electricity, Collana di Storia della Scienza, Universita degli studi di Pavia, Hoepli, Milano, 2003, p. 61-68; J.A. Krikstopaitis, Pralenkes laika: Theodor Grotthuss (Theodor Grotthuss: A Step Ahead of His Time), Pradai, Vilnius, 2001]. (c) 2006 Elsevier Ltd. All rights reserved.