Is the electricity generated by these animals the same as that occasioned by the ordinary electrical machine?
It is the same, and produces the same effects.
Do vital action and muscular movements in man and animals give rise to electricity?
They do; and it can be shown by direct experiment that a person cannot even contract the muscles of the arm without exciting an electrical action.
Does change of form or state in bodies generally produce electrical excitation?
Change of form or state is one of the most powerful methods of exciting electricity.
Water, in passing into steam by artificial heat, or in evaporating by the action of the sun or wind, generates large quantities of electricity. The crystallization of solids from liquids, all changes of temperature, the growth and decay of vegetables, are also instrumental in producing electrical phenomena.
What is lightning?
Lightning is accumulated electricity, generally discharged from the clouds to the earth, but sometimes from the earth to the clouds.
What causes the discharge of an electric cloud?