"What is that electricity they speak of, whose changes make us well or ill, whose lack or excess blasts, whose even balance revives? What are all those influences that are about us in the atmosphere, that keep playing over our nerves like fingers on stringed instruments, and call forth now a sweet note, and now a wail--now an exultant swell, and anon the saddest cadence?

"What are those influences in the atmosphere, that play over our nerves like fingers on stringed instruments, and call forth now a sweet, exultant note, and now the saddest wail?
