EFFECTS OF LIGHTNING. 



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Classification of the Effects of Lightning. — The sulphureous Odor developed by Lightning.— Cases 

 collected by M. Arago. — Nature of the Odor. — Chemical Changes operated by Lightning. — Nitric 

 Acid formed by the Electric Spark ; also Ammonia and Nitric Acid produced during Thunder 

 Storms. — Fusion and Contraction of Metals. — Observations of the Ancients. — Franklin's cold 

 Fusion. — Evidence against cold Fusion. — Masses of Metal melted by Lightning. — Vitrefactions 

 and Fulgurites. — Heights at which Vitrefactions have been found. — Facta collected by M. Arago. — 

 Fulminary Tubes, or Fulgurites. — Characters of Fulgurites.— Variations dependant on the Na- 

 ture of the Soil where they are found.— Four Hypotheses to explain their Origin. — Their Forma- 

 tions in some Cases are recent — Sand fused by artificial Heat into the State of the Fulgurites. — 

 Artificial Fulgurites formed by the Electrical Battery. — The further Condition essential to explain 

 the Origin of Fulgurites. — Recent Formation of Fulgurites observed. — Mechanical Effects. — In- 

 stances of the Mechanical Action of Lightning. — The Action is exerted in all Directions. — Induc- 

 tive Action of Lightning. — M. Arago's Explanation of the Effect as due to Vaporization. — Objec- 

 tions to the Explanation. — Decompositions of the natural Electricities of Bodies. — Induction be- 

 tween the Clouds and the Earth. — Upward Flashes and Mechanical Effects. — Arago's Explana- 

 tion. — Magnetic Effects. — To be explained in Electro Magnetism. — Effects of conducting 

 Bodies on Lightning. — Conducting Properties of Metallic Bodies. — Lightning passing along Con- 

 ductors in Preference to Non-Conductors. — Protection afforded by conducting Bodies. — Lightning 

 selects conducting Bodies from among others. — Lightning Conductors should descend to a humid 

 Soil. — Necessity of Continuity in a Conductor. — Effects proceeding from the Surface of the Earth. — 

 Ascent or Ebulition of Water. — Inundations from subterranean Sources. — Mosaic Account of the 

 Deluge ; Analogous natural Phenomena. — Electrical State of the Atmosphere Favorable to the 

 Process of barking Trees. — Effect of Thunder on fermented Liquors, &c. — Return Stroke report- 

 ed by Brydone.— Theory of such Effects. — Flame appearing on the Ground. — Not extinguisha- 

 ble by Water. — Superposed Clouds not necessary to its Appearance. — Stationary luminous Ap- 

 pearance. — Lightning rising from the Earth like a Rocket. — Flames observed on exposed Points. — 

 Luminous Rain. — Cases collected by M. Arago. — Luminous Dust 



