344 



INDEX 



Maxwell, eleafcro-magnetic theory of light, 



120 



on electric stresses, 138 

 on residual charge, 114 

 Measurement of charge, 30 

 of permeability, 266 

 of permeability, Ballistic method, 271 

 of permeability, magnetometer 



method, 266 



of susceptibility and permeability 

 of para- and diamagnetic 

 substances, 282 

 Mechanical model to illustrate hysteresis, 



279 

 model to illustrate residual charge, 



118 

 Medium surrounding magnetic body, 



stresses in, 261 



Molecular hypothesis of electric strain, 58 

 hypothesis of magnetism, 192 

 theory and permeability, 241 

 Moment of a magnet, 215 



NATURAL magnets, 165 



Needle, time of vibration of, with small 



susceptibility, 260 

 Negative electrification, 2 

 Nickel and cobalt, magnetisation and 



permeability, 276 

 as a magnet, 203 

 magnets, 176 



PARAMAGNBTICS, 203 



Curie's law for, 291 



tend to move to stronger field, 205 

 Pascal's experiments on magnetic quali- 

 ties of solutions, liquids and gases, 296 

 Permanent magnets, 186 

 Permeability, 180, 184, 234 



and molecular theory, 241 



and temperature, 187 



measurement of, 266 

 Piezoelectric electrometer, 156 

 Piezoelectricity, 148 



discovery by Curie, 153 

 Pole, strength of magnetic, 210 



unit magnetic, 210 

 Positive electrification, '2 

 Potential, 42, 72 



and capacity in certain systems, 80 



at any point in a magnetic field, 21 7 



difference of, 103 



Equations expressing continuity of, 

 236 



Instruments used to measure, 87 



measurement of, practical methods, 

 94 



of a small magnet at any point in its 

 field, 219 



variation of, and intensity, 43 

 Proof plane, 6 



Pyroelectric crystal, change of tempera- 

 ture on change of potential, 161 

 Pyroelectricity/JL-iS 



QUADRANT electrometer, 87 



electrometer, calibration of, 89 

 < lectrometer, theoi 



Quantity of electrinY 



Quincke's experiments on stressi 

 dielectrics, 138 



RECORDING instruments for magnetic 



observations, 

 Refraction, laws of, 106 

 iual chargt . 



charge and discharge, 113 

 charge, Maxwell on, 111 

 charge, mechanical model, 118 

 Resinous or negative electrification, 2 



ntivity in magnets, 169 

 Riecke's researr 

 Rowland's experiments on susceptil 



and permeaV.i 

 Rubbers for electrification, 1 



SOLIDS, specific inductive capacity, 



Solutions, magnetic properties of 



(Pascal), 

 Sparking, 11 



Speciii ; city, 100, 120 



inductive capacity and refr 



x. 120 

 inductive capacity, Boltr.mann's ex- 



periment- 

 inductive capaci<\, Hopkinson's ex- 



" 



inductive capacity of alcohol, 129 

 inductive capacity of gaaes, 

 inductive capacity of solids, 122 ft 



inductive capacity of water, 129 

 Sphere, capacity of, 81 



potential due to charge-' 

 Spheres, con : and 



capacity of, 82 

 Spherical shell, intensity inside, 40 



shell, it , 39 



Storage of Jl 



Strain in < ry. 



in dielectric, pressure transverse to 



lines of. 

 in dielectric, tension along lines of, 



134 



lines or tubes of, 55 

 Stresses in medium surrounding magnetic 



body, 261 



Surface density, definition of, 52 

 Susceptibility, magnetic, 184, 239 



TEMPERATURE, effect of, on magnetism, 



186, 200 



effect of, on permeability 

 effect of rise of, on Verdet's constant, 



323 



Tension along lines of strain, 134 

 Terrestrial magnetism, 300 



magnetism, Gauss's theory, 316 



