THE ELECTRIC LIGHT. 665 
by Faraday, being always accompanied, in a closed con- 
ductor, by the production of an "induced" electric cur- 
rent which, as long as the ends of the coil remained 
separate, had no circuit through which it could pass. The 
current here evoked subsides immediately as heat; this 
heat being the exact equivalent of the excess of effort just 
referred to as over and above that necessary to overcome 
the simple weight of the coil. When the coil is liberated 
it falls back to the table, and when its ends are united it 
encounters a resistance over and above that of the air. It 
generates an electric current opposed in direction to the 
first, and reaches the table with a diminished shock. The 
amount of the diminution is accurately represented by the 
warmth which the momentary current develops in the 
coil. Various devices were employed toexalt these induced 
currents, among which the instruments of Pixii, Clarke, 
and Saxton were long conspicuous. Faraday, indeed, fore- 
saw that such attempts were sure to be made; but he 
chose to leave them in the hands of the mechanician, 
while he himself pursued the deeper study of facts and 
principles. "I have rather," he writes in 1831, "been 
desirous of discovering new facts and new relations 
dependent on magneto-electric induction, than of exalting 
the force of those already obtained; being assured that the 
latter would find their full development hereafter." 
For more than twenty years magneto-electricity had 
subserved its first and noblest purpose of augmenting our 
knowledge of the powers of nature. It had been dis- 
covered and applied to intellectual ends, its application to 
practical ends being still unrealized. The Drummond 
light had raised thoughts and hopes of vast improvements 
in public illumination. Many inventors tried to obtain it 
cheaply; and in 1853 an attempt was made to organize a 
company in Paris for the purpose of procuring, through 
the decomposition of water by a powerful magneto-electric 
machine constructed by M. Nollet, the oxygen and 
hydrogen necessary for the lime light. The experiment 
failed, but the apparatus by which it was attempted 
suggested to Mr. Holmes other and more hopeful applica- 
tions. Abandoning the attempt to produce the lime 
light, with persevering skill Holmes continued to improve 
the apparatus and to augment its power, until it wasfinally 
able to yield a magneto-electric light comparable to that of 
