FRANKLIN'S RESEARCHES IN ELECTRICITY 

 By Professor Edward L. Nichols 



[Address delivered in Witherspoon Hall, Wednesday, April i8.] 



TO estimate justly the achievements of Benjamin 

 Franklin in electricity it is necessary to consider 

 briefly the state of that science at the time when he 

 began his experiments. It was known at a very early 

 day that certain substances such as amber when rubbed 

 acquire the power of attracting light bodies, but no con- 

 siderable advance beyond the observations recorded by 

 Thales 600 B. C. and Theophrastus 300 B. C. appears 

 to have been made up to the time when Gilbert began 

 his work upon this subject about 1600. Gilbert greatly 

 extended the list of bodies electrified by friction. He 

 found various precious stones and many other substances 

 such as sulphur, resin, and glass to possess this property. 

 Towards the end of the seventeenth century Boyle 

 added something to Gilbert's observations. He discov- 

 ered that the attraction between electrical bodies oc- 

 curred in vacuo as well as through air at ordinary pres- 

 sures, and that an electrified body was attracted by as 

 well as being capable of attracting other bodies. He 

 also studied what we now call the tribo-luminescence of 



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