Electrical Plicenomena. Ill 



When any body contains a superfluous quan- 

 tity of the electric fluid, it is (according to the 

 Franklinean theory) said to electrify positively or 

 plus ; when it contains less than its proper share, 

 it is said to be negative or electrified minus, 

 that is, some of its electricity is taken from it. 

 That electricity, therefore, which was before 

 called the vitreous, Dr. Franklin calls positive 

 electricity; and that which was termed the re- 

 sinous, he considers as negative electricity. If, 

 therefore, a rough and smooth body are rubbed 

 together, the smooth body in general will have 

 the positive electricity, and the rough the nega- 

 tive. Thus, in the ordinary operation of the 

 electrical machine, the cylinder is positively 

 electrified or plus, and the rubber negative or 

 minus ; and the redundancy of the positive elec- 

 tricity is sent from the cylinder to the prime con- 

 ductor. This, however, is supposing the chain, 

 which communicates with the earth, to be at 

 the same time in contact with the rubber; for 

 as the earth is the great repository of electrical 

 matter, if the chain is removed, and put over 

 the prime conductor, these effects will be re- 

 versed, and the prime conductor will then be 

 negatively electrified or minus, and the rubber 

 will be plus or positive *. 



* Whether the theory of Franklin be adopted, or 

 whether the hypothesis of two distinct fluids be retained, 

 signifies nothing as to the fads, it simply regards the 

 manner of explication. On either hypothesis, the fact 



