Ueber die Bestimmung der Richtung der durch elektrodynamische Vertheilung erregten galvanischen Ströme in Annalen der Physik und Chemie, s. 2, Bd. 31, 1834

Leipzig: Johann Ambrosius Barth, 1834. 1st Edition. BOUND FIRST EDITION OF THE FIRST APPEARANCE & FORMULATION OF LENZ'S 1833 LAW, stating that "The direction of current induced in a conductor by a changing magnetic field due to Faraday's law of induction will be such that it will create a field that opposes the change that produced it" (Lenz). Obeying both Newton's third law of motion and the conservation of energy, Lenz's law explains the physical meaning of the negative sign in Faraday's law. It was "the first explanation of the choice of sign in Faraday's law of induction and served as the basis for Helmholtz's proof of the law of conservation of energy for electromagnetic phenomena" (History of Physics: The Wenner Collection).

At the beginning of the nineteenth century scientists were beginning to understand electricity and magnetism, but did not understand the relationships between the two. In this paper, Russian physicist Heinrich Friedrich Emil Lenz (1804-1865) took one of the first steps in filling in that gap by formulating Lenz's Law. Lenz was puzzled by the effects of magnets when they were pushed into coils of wire as they produced an electric current. Repeating the work of James Faraday, he observed that when a electrical current is generated by a changing magnetic field, the magnetic field generated by that electrical current opposes the magnetic field that generated the current.

Lenz's study "explains why the direction of the induced electromotive force (EMF) and induced current resulting from electromagnetic induction is the opposite direction to the change in flux (i.e., opposes the change in flux)" (ibid). His law is a manifestation of the conservation of energy. The induced EMF produces a current that opposes the change in flux, because a change in flux means a change in energy. Energy can enter or leave, but not instantaneously. Lenz' law is a consequence. This result is due to the law of conservation of energy. Lenz's results were copiously documented so that they could be easily repeated and his quantitative results were more thorough than the qualitative work that had been done previous to him. CONDITION & DETAILS: Leipzig: Johann Ambrosius Barth. Complete bound volume. 8vo.[x], 678 pages, [2]. Four fold-out plates. Blind perforated library stamp on the title page; no spine or other markings. Tightly and solidly bound in brown cloth, slightly scuffed at the edges. Clean and bright throughout. Very good condition.