INDEX. 



435 



Coercive force, 897 -#0 



Colour of spark, 289 



Columbtis, Cristofero, on magnetic 



variation, 136 

 Combustion a source of electrification, 



62 



Commutator, 375, 399, 407 ^ 

 Compass (magnetic), Mariner's, 79, 



*34 



Compound circuit, 181 

 Condensation, 48 

 Condensers, 48, 267 



standard, 276 



use of, 275 



Condensing electroscope, 71, 149 

 Conduction, 27, 158 



by liquids, 205 



of gases, 158 



Conductivity, 158, 346, 348 

 Conductors and Non-conductors, 8, 27 

 Consequent Poles, 104, 109 

 Contact Electricity, 71, 149 



Series of metals, 72 

 Continuous electrophorus, 23, 45 

 Convection of Electricity, 45, 337 

 Convection-currents, properties of, 337 

 Convection-induction machines, 45 

 Convection-streams at points, 35 (a), 



43. 249 

 Cooling and heating of junction by 



current, 380 

 Cost of power derived from electricity, 



378 



Coulomb, C. A., Torsion Balance, 15, 

 119 



Law of Inverse Squares, 16, 

 117, 119, 235, 245 



on distribution of charge, 35, 248 

 Couple, magnetic, 123 

 Crookes, William, on shadows in 

 electric discharge, 293 



on repulsion from negative 



electrode, 300 

 Crown of cups, 151 

 Cruickshank 's Trough Battery, 169 

 Crystals, electricity of, 66 



dielectric properties of, 270 



magnetism of, 343 

 Crystallisation, 61 

 Gumming s phenomenon, 382 

 Cuneus' discovery of Leyden Jar, 52 

 Current, effects due to, 153 

 Current Electricity, 147 



strength of, 158, 179 



,, unit of, 196 



Current -re verser (see Commutator) 

 Current sheets, 340 

 Curvature affects surface-density, 35, 

 249 



Curves, magnetic (see Magnetic 



Figures') 

 Cutkbertson's Electric machine, 38, ' 



289 

 Cylinder Electrical machine, 39 



D 



DAILY variations of magnet, 142 

 Dalibard's lightning-rod, 302 

 DanielVs Battery, 170 

 Davy's (Marie] Battery, 175 

 Davy, Sir Humphrey, magnetisation 



by current, 326 

 discovers electric light, 371 

 electrolyses caustic alkalies, 



De Haldat, magnetic writing, in 

 De la Rive's Floating Battery, 194 

 DelaRue, Chloride of Silver Battery, 



174, 291 



on electrotyping, 420 

 on length of spark, 291 

 Declination, Magnetic, 136 

 variations of, 136, 141 

 Decomposition of water, 206, 413 



of alkalies > 417 



Deflections, method of, 118, 123, 32$a 

 Dellmann's electrometer, 260 

 Density (surface) of charge, 35, 248 



magnetic, 127, 311 

 Dewar, James, on currents generated 



by light in the eye, 231 

 his capillary electrometer, 225 

 Diagram, thermo-electric, 383 

 Diamagnetic polarity, 342 

 Diamagnetism, 87, 339 

 of flames, 344 " 

 of gases, 340 



! Diaphragm currents, 224 

 j Dielectric capacity (see Specific In- 

 ductive Capacity) 

 strain, 56, 272 

 strength, 284 

 I Dielectrics, 8, 49, 270 

 i Differential Galvanometer, 203 

 \ Dimensions of Units (see Units) 

 \ Dip, or Inclination, 137 



variation of, 141 

 Diplex signalling, 428 

 Dipping Needle, 137 

 Discharge affected by magnet, 294 

 brush, 43 



by evaporation, 223 

 by flame, 7, 291 

 conductive, 282 

 convective, 43, 283 

 disruptive, 281 



