INDEX "OF SUBJECTS. 653 



Damping of Compass Needles 573 



Induction of any Given Conductor 573 



CHAPTER VIIL OPTICAL PHENOMENA. 



Faraday's Discovery 574 



Positive and Negative Bodies 574 



Verdet's Laws. Verdet's Constant 575 



Magnetic Rotatory Dispersion 576 



Mr. Kerr's Experiment 576 



Explanation of Rotatory Polarization 577 



Observations of Sir W. Thomson 582 



Electrical Double Refraction 583 



CHAPTER IX. ELECTRICAL UNITS. 



Fundamental Units. Derived Units 584 



Dimensions of a Derived Unit 585 



Derived Mechanical Units 586 



Electrical and Magnetic Derived Units 587 



Electrostatic System 588 



Electromagnetic System 590 



Dimensions of the Principal Units 592 



Relations between the Two Systems of Units 594 



Choice of Fundamental Units 595 



Absolute C.G.S. System 595 



Practical System 595 



Comparative Values of the Principal Units . , 597 



Physical Conception of the Velocity a 598 



CHAPTER X. GENERAL THEORIES. 



Ampere's Hypotheses 601 



Formulae of Gauss and Weber 601 



Phenomena of Induction 606 



Various Attempts at a Theory 608 



Electromagnetic Theory of Light 609 



General Equations 610 



Propagation of Undulations in a Dielectric 612 



Plane Waves 612 



Distribution of the Energies 614 



Velocity of the Propagation of Light 615 



Specific Inductive Capacity 616 



