Chapter 7

Galvani and the beginning of modern electricity--The construction of the voltaic pile--Nicholson's and Carlisle's discovery that the galvanic current decomposes water--Decomposition of various substances by Sir Humphry Davy--His construction of an arc-light--The deflection of the magnetic needle by electricity demonstrated by Oersted--Effect of this important discovery--Ampere creates the science of electro-dynamics--Joseph Henry's studies of electromagnets--Michael Faraday begins his studies of electromagnetic induction--His famous paper before the Royal Society, in 1831, in which he demonstrates electro-magnetic induction--His explanation of Arago's rotating disk--The search for a satisfactory method of storing electricity--Roentgen rays, or X-rays.