RECAPITULATION. 463 



18. It is immaterial whether the glass be flat, or 

 in any other form ; on account of convenience, 

 cylindrical jars are used for this purpose. 



19. A vessel of this kind is called a Ley den 

 phial, from the place where this property was first 

 discovered. 



20. When many of these phials, or jars, are 

 connected together, it is called an electrical battery. 



21. Electricity is capable of producing the most 

 powerful effects, oxidating gold and silver, and 

 firing inflammable substances. 



22. Metallic points attract the electricity from 

 bodies, and discharge them silently. This property 

 has rendered them useful in defending buildings 

 from lightning. 



23. When electricity enters a point, it appears 

 in the form of a star ; when it issues from a point, 

 it puts on the appearance of a brush, or pencil. 



24. Models may be put in motion by the electric 

 fluid which issues from a point. 



25. Lightning appears to be the rapid motion of 

 vast masses of electric matter. 



26. Thunder is the noise produced by the mo- 

 tion of lightning. When electricity passes through 

 highly rarefied air, it constitutes the aurora bo- 

 realis. 



27. Many of the great convulsions of Nature, 

 such as earthquakes, hurricanes, whirlwinds, are 

 generally accompanied by electrical phenomena. 



ABSTRACT OF GALVANISM. 



1. Galvanism is so called from Galvani, an Ita- 

 lian, who first discovered it. 



2. It appears to be only another mode of excit- 

 ing electricity. 



