=The word “battery”=--action of cell--chemical changes; polarization--effects of polarization--methods of depolarization-- depolarizers--depolarizer bag--Volta’s contact law--contact series of metals--=laws of chemical action in cell=-- requirements of a good cell--=single and two fluid cells=-- the Leclanche cell--Fuller bichromate cell--the Edison cell--Grenet bichromate cell--Daniell cell--directions for making a Daniell cell--gravity cells--Daniell gravity cell--so-called “dry” cells--=points relating to dry cells=-- care of cells--cleanliness--separating the elements--creeping-- amalgamated zinc--battery connections. =CONDUCTORS AND INSULATORS= =68 to 74= The so-called “non-conductors”--=table of conductors and insulators=--mode of transmission--effect of heat--heating effect of the current--=insulators=--impregnating compounds-- water as a conductor. =RESISTANCE AND CONDUCTIVITY= =75 to 82= =Standard of resistance=--conductivity of metals and liquids--effect of heat--=laws of electrical resistance=-- conductivity--specific conductivity--=divided circuits=. =ELECTRICAL AND MECHANICAL ENERGY= =83 to 92= =Definitions:= energy, matter, molecule, work, foot-pound, volt-coulomb, ampere-hour, power, horse power, =watt=, kilowatt, watt-hour--mechanical equivalent of heat--=British thermal unit=--=electrical horse power=--the farad. =EFFECTS OF THE CURRENT= =93 to 104= =Thermal effect=--use of heat from the current--magnetic effect--chemical effect--=electrolysis=--electro-chemical series--electric osmose--electric distillation--muscular contractions--=electroplating=--electrotyping. =MAGNETISM= =105 to 124= Two kinds of magnetism--nature of each--=poles=--magnetic field--magnetic force--=magnetic circuit=--magnetic flux--the Maxwell--the Gauss--=magnetic effect of the current=--corkscrew rule--solenoids--permeability--magnetic saturation--magnetomotive force--=reluctance=--analogy between electric and magnetic circuits--=hystereses=--residual magnetism. =ELECTROMAGNETIC INDUCTION= =125 to 136= =Faraday’s discovery=--Faraday’s machine--Faraday’s principle-- line of force--induction of current--laws of electromagnetic induction--rules for direction of induced current--Fleming’s rule--Ampere’s rule--the palm rule--=self-induction=. =INDUCTION COILS= =137 to 154=