[D] We would not define cold as "absence of heat." Cold is rather the opposite electrical condition to heat.
CHAPTER XV.
WHY WAS NOT THIS DISCOVERY SOONER MADE?
It may be asked, why should the discovery of this great source of all the forces, vital and physical, have been delayed to the present time? Master minds have been engaged for ages in efforts to solve the wonderful problem.
Herschel, Newton, Humboldt, Faraday, Mossotti, and many others have held the key almost within their control, and the consummation has only failed of being realized at an earlier day by reason of the tenacity with which the minds of men are held by preconceived and pre-existing opinions.
Sir William Herschel regarded solar and stellar light as the effects of an electro-magnetic process.
Newton recognized all movements of the cosmical bodies to be the result of one and the same force; "of some higher and still unknown power," but luminiferous ether shaded his mental vision, and he failed to discern that power. In his investigations of those great subjects he is led to ask, "Are not the sun, and fixed stars, great earths, vehemently hot?"