[Extent and character of their influence][Old channels obliterated, and new ones developed][Sentiments changed][Nebular hypothesis][The sun cool, luminous, and habitable][Celestial spectroscopy][Undulatory theories ignored][Light instantaneously transmitted][Telephone][No light nor heat wasted][Extent of the atmosphere of the spheres][The sun's power overestimated].

[CHAPTER XIII.]

[Influence of the Forces as Causation of Disease] [84]

[Meteorological influence][Higher appreciation of the source of disease, and increased efficiency in its treatment].

[CHAPTER XIV.]

[The Artificial Production of Light, Heat, and Power, and their Utilization] [87]

[CHAPTER XV.]

[Why was not this Discovery sooner made]? [90]

[Its consummation nearly perfected by many others][Its successful accomplishment plainly foretold by Faraday].