HERMANN VON HELMHOLTZ 



gravity should be innate, inherent, and essential to 

 matter, so that one body may act upon another at a 

 distance, through a vacuum, without the mediation 

 of anything else, by and through which their action 

 and force may be conveyed from one to another, is to 

 me so great an absurdity, that I believe no man, who 

 has in philosophical matters a competent faculty of 

 thinking, can ever fall into it.' 



The notion of action at a distance was the first 

 conception of electrical action, and it found expression 

 especially in the well-known law of Wilhelm Weber. 

 He endeavoured to explain electrical attractions by 

 the assumption of a force acting in straight lines, and 

 following the same laws as the laws of gravitation. 

 This was supported by Coulomb. Suppose two 

 electrified bodies near each other, then the intensity 

 of the force is inversely proportional to the square of 

 the distance between the two quantities of electricity 

 on their respective surfaces and directly proportional 

 to the product of the two quantities. There is also 

 repulsion between like, and attraction between unlike, 

 electrical states. Further, it was supposed that this 

 force was instantaneously propagated through space. 

 Weber differed from Coulomb, in holding that both 

 the velocity at which the electric quantities approached 

 or separated, and also the acceleration of the velocity, 

 had an influence on the amount of force exercised 

 between the two bodies. Other similar hypotheses 

 were in vogue, such as those of F. E. Neumann, 

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