[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].