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.

CHAPTER VIII. THE CONSERVATION OF ENERGY

Faraday narrowly misses the discovery of the doctrine of
conservation--Carnot's belief that a definite quantity of work
can be transformed into a definite quantity of heat--The work
of James Prescott Joule--Investigations begun by Dr.
Mayer--Mayer's paper of 1842--His statement of the law of the
conservation of energy--Mayer and Helmholtz--Joule's paper of
1843--Joule or Mayer--Lord Kelvin and the dissipation of
energy-The final unification.


CHAPTER IX. THE ETHER AND PONDERABLE MATTER

James Clerk-Maxwell's conception of ether--Thomas Young