PHYSICAL FORCES. 47 



tioii will without doubt find another solution for 

 the problem. 



Franklin supposed the ultimate atoms of bodies to be 

 surrounded by a subtile fluid or ether, which they have 

 the power of condensing upon their surfaces with 

 great force and we have experiments showing that 

 this is probable* whilst he regarded the atoms of the 

 ether itself as mutually repellent, thus establishing an 

 equilibrium of forces. jEpinus reduced the hypothesis 

 of Franklin to a mathematical theory; and Coulomb 

 proved that the force with which the repulsion of the 

 ethereal atoms and the attraction of the material mole- 

 cules are produced, is, like universal attraction, to 

 whatever power that maybe due, regulated by the law 

 of the inverse ratio of the square of the distance. These 

 views are found, upon minute examination, to hold true 

 to the phenomena with which inductive science has 

 made us acquainted ; and the striking manner in which, 

 when submitted to the rigorous investigations of geome- 

 ters, they agree with known conditions of electricity, 

 appears certainly to favour the opinion that this power 

 may be materially connected with these molecular 

 arrangements. 



Many of the phenomena which are connected with 

 the magnetic influences also bear in a remarkable 

 manner upon this inquiry. But, without the necessary 

 proof of direct experimental evidence, it were as un- 

 philosophical to refer the binding together of the 

 molecules of matter to the agency of electricity, as it 

 would be to adopt the theory of the hooked atoms of 



-: : New Experiments and Observations on Electricity made at 

 Philadelphia, in America. Addressed to Mr. Collinson, from 1747 

 to 1754. By Benjamin Franklin. Of these Priestley remarks : 

 " It is not easy to say whether we are most pleased with the 

 simplicity and perspicuity with which the author proposes every 

 hypothesis of his own, or the noble frankness with which he 

 relates his mistakes, when they were corrected by subsequent 

 experiments." 



