AMBER. 



483 



together. We are almost incapable even of bodily labour. The 

 reason is, that the portion of the earth on which we live has 

 parted with some of its electricity, and has drawn it out of our 

 bodies. 



Then comes the welcome thunder-storm ; clouds overcharged 

 with electricity come to restore the balance. The lightning 

 flashes from the clouds to the earth as soon as they are near 

 enough; the rain falls, carrying with it stores of silent electricity ; 

 and in an hour or two all seems changed. 



The air, which hitherto seemed to afford no nourishment 

 to the lungs, is bracing and invigorating. The nervous sys- 

 tem recovers its tension, and the brain can act without a pain- 

 ful effect. All Nature seems to put on a different aspect, 

 and brightness and vigour take the place of dulness and lan- 

 guor. 



By a strange coincidence, there is just such a lack of 



GALVANISING A FROG'S LEO. 



VOLTAIC PILE. 



electricity as I am writing, and the barometer has rapidly sunk 

 to such a degree that a storm seems inevitable. 



One of the chief difficulties in dealing with such a subject 

 as this is to know where to begin. We will, however, do our 

 best to take a general view of it, without going into details. 



Many centuries ago it was well known that amber, if rubbed 

 with a dry cloth, would first attract, and then repel, various 

 small and light substances. Indeed, the Greek word for amber, 

 namely, Elektron, has given its name to the modern science of 



ii 9 



