RELATIONS TO OTHER SCIENCES 75 



When such an atom impacts against another, the corpuscles in 

 each will be disturbed by the jar in their orbital motion, and there 

 will be superposed oscillations which will cause radiation of energy. 



If a corpuscle escapes from such an atom, the latter will be left 

 with a positive charge, while if an additional free corpuscle is en- 

 trapped, the atom will have a negative charge. The conditions of 

 stability of motion of the corpuscles in the atom would thus deter- 

 mine whether in case of electrolysis the substance would appear 

 electro-positive or electro-negative. 



J. J. Thomson, Drude, and others have discussed the electric 

 conduction of metals from the standpoint of this theory. Drude 

 states that in non-conductors only bound electrons are present, that 

 is, positive and negative in combination; and that it is these that 

 determine the dielectric constant of the medium and consequently 

 its index of refraction and optical dispersion; while Langevin ex- 

 plains magnetism and diamagnetism. 



Thus we have a theory already surprisingly developed which 

 appears to be applicable to explain many of the properties of matter, 

 though it is not clear that it can give an explanation of cohesion and 

 gravitation. A theory of matter, to be accepted as final, must offer 

 some explanation of the relation between the various elements. Many 

 thinkers have been led to look for some primordial element from 

 which the others are derived, influenced on the one hand by the 

 present evolutionary ideas of biology, and on the other by com- 

 parison of spectra and by the remarkable tendency towards whole 

 numbers observed in the atomic weights of the elements which 

 Strutt has discussed from the standpoint of the theory of probabili- 

 ties. Professor Thomson has accordingly shown how atoms of matter 

 containing great numbers of corpuscles may have been evolved from 

 a simpler primordial form containing fewer corpuscles. But though 

 he has made clear how the hydrogen atom with its thousand cor- 

 puscles might be the surviving atom having the least number of 

 corpuscles, it is not so clear why there might not be atoms having 

 any number of corpuscles greater than that of hydrogen, within 

 certain limits; why none should be found between hydrogen and 

 helium for example. Some kind of natural selection seems to be 

 needed to explain why some atoms having special numbers of cor- 

 puscles survive while intermediate ones are eliminated, though prob- 

 ably the answer is to be sought in the conditions of stability of the 

 motions of the corpuscles. 



It is an interesting question what would be the effect of change of 

 temperature of the substance on the motions of the corpuscles in this 

 theory. If the corpuscles in the atom were very numerous, all moving 

 in the same orbit at equal distances apart, they would produce 

 almost the effect of a circular current of electricity, a steady 



