Calendar: 1867-1868 Page 282

2 EVENING CLASSES of Electricity Separation of them by Friction Hypothesis of Electric Fluids II Laws of Electrical Action Effect of Air and Moisture in causing Loss of Electricity In- fluence of the Form of the Body Distribution of Electricity on the Surface of Bodies III Electrical Induction Faraday's Theory of Indue- tion Electroscopes The Electrophorus Elec- trical Machines IV Condensation of Electricity The Leyden Jar Batteries Electrical Discharges Electrometers Atmospheric Electricity Electric Clouds Light- ning Physiological and other Effects of Statical Electricity Wheatstone's Discovery of the Velocity of Electricity VI The Natural Magnet or Loadstone Artificial Magnets Polarity Action of Opposite Poles on one another Magnetic Induction VII Terrestrial Magnetism Magnetic Declination and Dip and their Variations Magnetic Intensity VIII Law of Magnetic Attractions and Repulsions Dis- tribution of Magnetism in Magnets Methods of making Artificial Magnets EfFect of Heat on Magnet Armatures IX Currents of Electricity Intensity of Currents Measurement of the Quantity of Electricity in Current Effect of Current on the Magnetic Needle The Galvanometer Electromotive Force Experiments of Galvani and Volta The Voltaic Pile Dry Piles Electro- motive Force produced by Heat Thermo-Electric Piles XI Voltaic Batteries The Crown of Cups Chemical Action necessary to the Production of Voltaic Action Wollaston's Battery Circuits with one Metal and two Liquids Weakening of the Current Secondary Currents