HYPOTHESIS OF TWO FLUIDS. 421 



It was subsequently ascertained, that when- 

 ever two different bodies are rubbed against 

 each other, they are in different states of elec- 

 tricity that when a glass tube is rubbed with a 

 dry silk handkerchief, the former is rendered 

 positive and the latter negative ; but if an insu- 

 lated metal be brought near to the glass, the 

 latter becomes negative and the metal positive. 

 Hence it was concluded by Franklin, that during 

 the action of a common machine, electricity is 

 evolved from the rubber, and attracted by the 

 cylinder of glass, from which it is attracted by 

 the prime conductor, and thence to other con- 

 ducting bodies. When amber and the tourma- 

 line are rubbed together, the latter becomes 

 plus or positive in relation to the amber ; but 

 when the tourmaline is rubbed against the dia- 

 mond, it is minus or negative, and the diamond 

 positive and so of many hundred other bodies. 



The above facts are exceedingly important, 

 and are alone sufficient to prove that positive 

 and negative are only different degrees of one 

 and the same fluid, which accumulates in va- 

 rious proportions on different bodies, according 

 to the relative degrees of their attraction for it. 

 There are no two bodies in nature which have 

 the same degrees of attraction for electricity; 

 nor are there any two bodies which exhibit the 

 same electrical state when rubbed against each 

 other. It has even been found that the same 



