S6S Dr. J. W. Nicholson on a Structural 



It has been shown by G. A. Schott that a system of rotating 

 electrons would rapidly lose energy unless arranged in rings. 

 From the point of view of the present paper, the actual 

 arrangement does not require consideration ; but it is to be 

 noted that the atoms with which we deal can be made to 

 have the necessary permanence by this simple hypothesis. 

 This can be seen intuitively, in fact ; for if n electrons are 

 rotating at equal distances round the same circle, they each 

 have an acceleration of the same amount towards the centre, 

 and the vector sum of these accelerations is zero. This is 

 Larmor's condition for the absonce of radiation. 



This condition cannot be fulfilled for a single electron ; so 

 that the first primary substance must have two ; as we have 

 supposed, if an electrically neutral atom of the simplest kind 

 is to be formed. 



The second primary substance has three electrons, and a 

 corresponding nucleus of a size, and with a charge therefore, 

 sufficient to make the atom electrically neutral. This has 

 been taken as hydrogen in the paper. 



It is important at this point to preclude a misunderstanding ; 

 for it is not intended to state that a hydrogen atom contains 

 three electrons. It certainly contains a very small number, 

 whatever its constitution. In order to find a basis for the 

 reckoning of atomic weights, we have subsequently taken 

 such a unit of weight that the protyle with three electrons 

 has a weight 1*008, the atomic weight of hydrogen, and the 

 weights of the other elements are referred to this scale. 

 Compounds are constructed with the weights usually given 

 as atomic ; so that the elements, except perhaps hydrogen, 

 all have the correct atomic weights relatively to one another. 

 It remains to secure that they shall be correct relatively to 

 that of hydrogen. If hydrogen is the substance with three 

 electrons, this is secured automatically ; but if it is more 

 complex, say equivalent to two atoms of this substance, 

 all the grouping's in the subsequent formulae merely require 

 multiplication by two. We definitely assume that hydrogen 

 is either this substance or a polymer (not quite in the chemical 

 sense), but nothing more definite until further examination 

 has been made. .But in order to work out a theory, it is 

 convenient to suppose this substance to be hydrogen, with 

 this reservation. 



The third primary substance contains four electrons, with 

 the corresponding positive charge in the nucleus. It is 

 identified, with mathematical justification, as nebulium — the 

 source of the principal lines in the spectra of nebulae. 



The fourth substance similarly contains five electrons, and 



