Sir Oliver J. Lodge [Feb. 28, 



likely ; for there is every probability that periodically, as you ascend 

 the series, the outer ring is not occupied by a single electron but by a 

 closed compact sort of structare of many electrons, with very little 

 outside affinity, so that we reach periodically an atom which is 

 chemically inactive, helium, neon, argon, krypton, etc., up to 

 emanation, or what Ramsay called niton. So little cohesion holds 

 between such atoms that they are able to exist as permanent gases in 

 spite of the high density of some of them. This at least appears to 

 be the view of Rutherford and Soddy. Helium only condenses to a 

 liquid when cooled down to near the absolute zero of temperature, 

 [ts cohesion or intermolecular attraction is nearly nil. 



A Fanciful Analogy. 



If I attempt to compare the supposed alternative orbits in an 

 atom with the known orbits of the solar system, it is mainly to 

 emphasise, provisionally and tentatively, and perhaps semi-humorously, 

 the astronomical view of the atom ; and to bring out still more 

 strongly the resemblances, whatever thorough differences there may 

 be as well. 



I write down the squares of the natural numbers, therefore, and 

 underneath put the names of planets, with its real distance written 

 under each in the same units. 



Radii of Bohr'sj^ ^ 9 16 25 36 49 64 81 100 121 144 169 196 

 atomic orbits J .__^__ 



m EM Asteroids J S U 



V 



Planetary 1 3-9 7'2 10 15-2 20-35 52 95-4 192 



distances/ 



The obvious suggestion is that asteroids should be looked for 

 between Jupiter and Saturn, and between Saturn and Uranus ; but I 

 would not venture to predict the existence of any such bodies on the 

 strength of this analogy, because you will doubtless have noticed that 

 no analogue of the planet Venus appears in the list of atomic orbits ; 

 the scheme provides no place for her — a lamentable omission which 

 must discredit and I expect condemn even the analogy. Nevertheless 

 I make no apology for introducing it, in order to emphasise astro- 

 nomical similarities in the possible structure of an atom. 



Quantitative Interpolation. 



0)1 Atomic Radiation. 



Permitting ourselves this view of the atom as a working hypo- 

 thesis, we have to picture each atom as an attracting centre or 

 nucleus, with a number of alternative orbits in regular succession 

 round it, but not all necessarily occupied by revolving electrons. 



