KINETIC OR MECHANICAL VIEW UF NATL'KE, 65 



the history of thought. As tlie study of stiible motion 

 or dynamical equilibrium, it has joined hands with the 

 kinetic theory of gases — i.e., the study of the motion of 

 a swarm of bodies in rectihnear motion, and with the 

 mechanical theory of lieat — i.e., of irregular intinitesimal 

 motion of any kind ; and it has certainly, through the 

 remarkable results gained by Professor J. .1. Thomson, 

 afforded a clue to tlie explanation of chemical linkage, 

 showing how it conies about that stability of chemical 

 compounds is dependent on, and limited to, a small 

 number of combinations or linkages.^ The mathematiciil 

 difficulties in the way of progress are enormous, sufKcient 

 to tax the brains of many generations to come, l)Ut as it 



ideal material system, atomically 

 constitatcd, which could go on 

 automatically without extraneous 

 support. The value of such a 

 picture may be held to lie, not in 

 any supposition that this is the 

 mechanism of the actual world laid 

 bare, but in the vivid illustration it 

 affords of the fundamental postulate 

 of physical science, that mechanical 

 phenomena are not parts of a 

 sclienie too involved for us to 

 explore, but rather present them- 

 selves in definite and consistent 

 correlations, which we are able to 

 disentangle and apprehend with 

 continually increasing precision." 



^ See his essay on the " Motion of 

 Vortex Rings": "Let us suppose 

 that the atoms of the different 

 chemical elements are m.ade up of 

 vortex rings all of the same strength, 

 but that some of these elements 

 consist of only one of these rings, 

 others of two of the rings linked 

 together, or else of a continuous 

 curve with two loops, others of 

 three, and so on. Our investigation 

 shows that no element can consist 



VOL. If. 



of more than six of these rings if 

 they are arranged in the .sym- 

 metrical way there described " (p. 

 119). "Each vortex ring in the 

 atom would correspond to a unit of 

 affinity in the chemical theoiy of 

 quanlivalence. If we regard the 

 vortex rings in those atoms con- 

 sisting of more vortex rings than 

 one as linked together in the most 

 symmetrical way, then no element 

 could have an atom consisting of 

 more than six vortex rings at the 

 most, so that no single atom would 

 be capable of uniting with more 

 than six atoms of another element 

 so as to form a stable conijiound. 

 This agrees witli chemical facts, 

 as Lothar Meyer in his ' Moderne 

 Theorien der Chemie,' 4th ed., p. 

 196, states that no compound con- 

 sisting of more than six atoms of 

 one element combined with only 

 one of another is known to exist in 

 the gaseous state, and that a 

 gaseous comjjound of tungsten, 

 consisting of si.x atoms of chlorine 

 united to one of tungsten, does 

 exist" (p. 120). 



E 



