The Boy's Playbook of Science / Including the Various Manipulations and Arrangements of Chemical and Philosophical Apparatus Required for the Successful Performance of Scientific Experiments in Illustration of the Elementary Branches of Chemistry and Natural Philosophy

by John Henry Pepper

MAGNETO-ELECTRICITY.

The correlation of the physical forces, heat, light, electricity, magnetism, and motion, is one of the most interesting subjects for study that can be suggested to the lover of science. The examination of the precise meaning of the term correlation, so ably considered by Professor Grove, indicates a necessary mutual or reciprocal dependence of one force on the other. Thus, electricity will produce heat, and vice versâ; motion, such as friction, produces electricity, and the latter, by its attraction and repulsion, establishes itself as a source of motion. Electricity produces light, also magnetism, and contrariwise light is said to possess the power of magnetizing steel, whilst magnetism again produces light and electricity. Such are the intimate connexions that exist between these imponderable agents, and we may trace cause and effect and its reversal amongst these forces, until the mind is lost in the examination of the bewildering mazes, and is content to return to the beaten track and work out experimentally the practical truths. We have had occasion to notice in another part of this playbook the fact that a current of electricity causes the evolution of magnetism in its passage through various conducting media, and the truth has been specially illustrated by the various experiments in the chapter devoted to electro-magnetism. In commencing this portion of electrical science, we have no new terms to coin for the title of the discourse, as we merely reverse the other when we examine the nature and peculiarities of