KINETIC OR MECHANICAL VIEW OF NATURE. 79 



netic, and galvanic phenomena, such as Coulomb's electro- 

 static and magnetic laws, Ampere's electro-dynamic and 

 electro-magnetic formulae, and Ohm's and Faraday's laws- 

 referring to galvanic currents, and many others. It 

 had also to give an intelligible representation of the 

 elementary actions of which these complicated phenom- 

 ena are made up. In order to arrive at the latter, the 

 method usually employed is to look for analogies in 

 other provinces of science where the desired unification 

 has already been brought about. The great natural 

 philosophers of the French school who had so success- 

 fully accomplished the most extensive unification yet 

 attempted in any large branch of knowledge the uni- 

 fication of physical astronomy under Newton's gravita- 

 tion formula had tried to follow up this analogy in 

 other realms of research, and had developed what I 

 called in a former chapter the astronomical view of 

 natural phenomena. Ampere, and notably Weber, had 

 extended this analogy so as to embrace electric and 

 magnetic phenomena. There was, however, another 

 analogy which was more familiar to the great experi- 

 mentalists in this country, notably to Faraday namely,, 

 the analogy of those various phenomena which depend 

 on processes of emanation, of a gradual spreading out, 

 of a flow or conduction : those phenomena where the 

 factor of time comes in, and where an apparently sta- 

 tionary condition is brought about by a mode of motion, 

 or what has been termed a " dynamic equilibrium." 

 Thomson, starting from Fourier's mathematical analysis 

 of such processes, had been led to see how far-reaching 

 this analogy is, and had latterly (1852) extended it to- 



