860 Transactions of the American Institute. 



varying only in velocity. It is not impossible that both magnetism 

 and electricity may be manifested tlirongh the same medinm ; yet, 

 on the supposition we could not accept the idea of Matteucci, that 

 the latter force is the result of vibratory action, although it appears 

 most probable that dynamic electricity is propagated by pulsations, 

 which vary with the elements of resistance. For the present we mar 

 regard Franklin's theory of static electricity quite as plausible as 

 any other, bearing in mind only that he applied the term " electricity" 

 to a subtle fluid, while we now use that word to define the force mani- 

 fested. We can only find room for the following extract from Mr. 

 Quimby's interesting paper : 



" The central idea of the Franklinean theory is, that a mutual 

 attraction exists between electricity and all other matter ; when mat- 

 ter is uniformly saturated with electricity, or, in other words, when 

 the fluid is equally diflfused, this attraction is balanced in all direc- 

 tions, and hence electricity is quiescent, producing no apparent 

 effects. When this state, the equilibrium, as it is called, is disturbed, 

 the balance of attraction is destroyed, and light bodies are set in 

 motion in the direction of the greatest attraction. If they are defi- 

 cient in electricity they move toward the nearest supply ; if they con- 

 tain an excess they are attracted in the directien of the greatest 

 deficiency. Two contiguous negative bodies, while exerting no 

 attraction for each other, are attracted by the electricity in sur- 

 rounding matter, and, therefore, if they are sufficiently light, they 

 recede from each other in obedience to the sum of the attracting 

 forces to which they are respectively subjected. They may be made 

 to move in the same direction by approaching the hand or some 

 other substance, which, being a better conductor than the air sur- 

 rounding them, and, being connected with the earth, will more 

 readily furnish the supply of electricity which they seek. Each of 

 the two negative bodies constitutes or establishes, as it were, with 

 respect to the other, an electrical vacuum, and, as they both require 

 a supply of electricity, they, of course, separate in opposite direc- 

 tions, unless we modify their situation by presenting a superior 

 source of supply at some one point, when, as before remarked, they 

 move toward that in obedience to what is obviously the greater 

 attraction in that direction. Two light positive bodies separate 

 because, being equally oversaturated, the excess of electricity, which 

 they severally contain, carries them with it in its effort to impart 

 itself to >:urroundino: matter. The force which, operating in this 



