Coulomb’s balance. Distribution of magnetism on a magnetized bar; distribution of electricity at the surface of isolated conductors. Comparative discussion of the conditions of the two problems and the methods of experiment. Laws of the magnetic attractions and repulsions. Law of electric attractions and repulsions. Comparative discussion of the conditions of the two problems, and the methods of experiment. Determination of the law of magnetic attractions and repulsions by the method of oscillations. Comparison of the magnetic intensity at different points of the earth’s surface. LESSONS 33-34. _Revision._ Considerations on the totality of the subjects of the course. _SECOND YEAR._ DYNAMICAL ELECTRICITY.--GALVANISM. LESSONS 1-2. Chemical sources of electricity. Experimental proofs. Arrangement devised by Volta to accumulate, at least in part, at the extremities of a heterogeneous conductor the electricity developed by chemical actions. Pile. Tension at the two isolated extremities; at one single isolated extremity; at the two extremities reunited by a conductor. Continuous current of electricity. Poles. Direction of the current, &c. Various modifications of the pile of Volta. Woollaston’s pile, Münch’s pile, &c. Dry piles; their application to the electroscope. Principal effects of electricity in motion, and means of making the currents perceptible. Experiment of Oersted. Galvanoscopes. Currents produced by heat in heterogeneous circuits. Thermo-electric piles. Thermometric graduation of thermo-electric piles. Currents produced by the sources of statical electricity. PROPERTIES OF CURRENTS. LESSON 3.   1. _Chemical Actions._ Definitions. Phenomena of decomposition and transference. Reaction of the elements transferred upon electrodes of different kinds. Principles of electrotyping. Causes of the variation of the current in ordinary piles; means of remedying this; Daniell’s pile. Bunsen’s pile. LESSONS 4-8.   2. _Mechanical Properties._ Reciprocal actions of rectilinear or sinuous currents parallel or inclined. Reaction of a current on itself. Reciprocal actions of helices or solenoids. Continuous rotation of currents by their mutual action; by reaction. Analogy of magnets and solenoids. Electro-dynamical theory of magnetism. Action of magnets upon currents and solenoids. Action of currents upon magnets. Experiments of Biot and Savart. Continual rotation of a current by a magnet; of a magnet by a magnet. Action of the earth upon currents; it acts as a rectilinear current directed from east to west, perpendicularly to the magnetic meridian. Continual rotation of a current by the action of the earth. Astatic conductors. LESSONS 9-10.   3. _Magnetic Properties._ Action of an interposed conductor upon iron filings. Electro-magnets. Magnetization temporary or permanent. Principles of the electric telegraph. Electrometers. Reference to diamagnetic phenomena. 4. _Electro-motive Properties._