Chapter XI: The Banishment of Night

(p. 221). Davy and the electric light. The quotation here given is reproduced from vol. III., pp. 234, 235. The very great importance and general interest of the subject seem to justify the repetition, descriptive of this first electric light. Davy's original paper was given at the Royal Institution in 1810.

(p. 237). "Peter Cooper Hewitt--Inventor," by Ray Stannard Baker, in _McClure's Magazine_, June, 1903, p. 172.

In connection with the problem of color of the light emitted by Mr. Hewitt's mercury-vapor tube, the chapter on "Newton and the Composition of Light" (vol. II., p. 225 _seq._) may be consulted. Also "Modern Theories of Heat and Light," vol. III., p. 206 _seq._